Nuclear waste solidification

DOEpatents

Bjorklund, William J.

1977-01-01

High level liquid waste solidification is achieved on a continuous basis by atomizing the liquid waste and introducing the atomized liquid waste into a reaction chamber including a fluidized, heated inert bed to effect calcination of the atomized waste and removal of the calcined waste by overflow removal and by attrition and elutriation from the reaction chamber, and feeding additional inert bed particles to the fluidized bed to maintain the inert bed composition.

Technology Demonstration Summary: International Waste Technologies In Situ Stabilization/Solidification, Hialeah, Florida

EPA Science Inventory

An evaluation was performed of the International Waste Technologies (IWT) HWT-20 additive and the Geo-Con, Inc. deep-soil-mixing equipment for an in situ stabilization/solidification process and its applicability as an on-site treatment method for waste site cleanup. The analysis...

A Remote Absorption Process for Disposal of Evaporate and Reverse Osmosis Concentrates

DOE Office of Scientific and Technical Information (OSTI.GOV)

Brunsell, D.A.

2008-07-01

Many commercial nuclear plants and DOE facilities generate secondary waste streams consisting of evaporator bottoms and reverse osmosis (RO) concentrate. Since liquids are not permitted in disposal facilities, these waste streams must be converted to dry solids, either by evaporation to dried solids or by solidification to liquid-free solids. Evaporation of the liquid wastes reduces their volume, but requires costly energy and capital equipment. In some cases, concentration of the contaminants during drying can cause the waste to exceed Class A waste for nuclear utilities or exceed DOE transuranic limits. This means that disposal costs will be increased, or that,more » when the Barnwell, SC disposal site closes to waste outside of the Atlantic Compact in July 2008, the waste will be precluded from disposal for the foreseeable future). Solidification with cement agents requires less energy and equipment than drying, but results in a volume increase of 50-100%. The doubling or tripling of waste weight, along with the increased volume, sharply increases shipping and disposal costs. Confronted with these unattractive alternatives, Diversified Technologies Services (DTS), in conjunction with selected nuclear utilities and D and D operations at Rocky Flats, undertook an exploratory effort to convert this liquid wastewater to a solid without using cement. This would avoid the bulking effect of cement, and permit the waste to be disposed of the Energy Solutions facility in Utah as well as some DOE facilities. To address the need for an attractive alternative to drying and cement solidification, a test program was developed using a polymer absorbent media to convert the concentrate streams to a liquid-free waste form that meets the waste acceptance criteria of the pertinent burial sites. Two approaches for mixing the polymer with the liquid were tested: mechanical mixing and in-situ incorporation. As part of this test program, a process control program (PCP) was developed that is 100% scalable from a concentrate test sample as small as 50 grams to full-scale processing of 100 cubic foot containers or larger. In summary: The absorption process offers utilities a viable and less costly alternative to on-site drying or solidification of concentrates. The absorption process can be completed by site personnel or by a vendor as a turnkey service. The process is suitable for multiple types of waste, including RO and evaporator concentrates, sludges, and other difficult to process waters and wet solids. (author)« less

APPLICATIONS ANALYSIS REPORT: SITE PROGRAM DEMONSTRATION TEST SOLIDITECH, INC. SOLIDIFICATION/ STABILIZATION PROCESS

EPA Science Inventory

This Applications Analysis Report evaluates the Soliditech, Inc., solidification/ stabilization process for the on-site treatment of waste materials. The Soliditech process mixes and chemically treats waste material with Urrichem (a proprietary reagent), additives, pozzolanic mat...

DEMONSTRATION BULLETIN: SOLIDIFICATION/STABILIZATION PROCESS, Hazcon, Inc.

EPA Science Inventory

The solidification/stabilization technology mixes hazardous wastes, cement, water and an additive called Chloranan. Chloranan, a nontoxic chemical, encapsulates organic molecules, rendering them ineffective in retarding or inhibiting solidification. This treatment technol...

TECHNOLOGY EVALUATION REPORT: CHEMFIX TECHNOLOGIES, INC. - SOLIDIFICATION/STABILIZATION PROCESS - CLACKAMAS, OREGON - VOLUME I

EPA Science Inventory

The CHEMFIX solidification/stabilization process was evaluated in the U.S. Environment Protection Agency's SITE program. Waste from an uncontrolled hazardous waste site was treated by the CHEMFIX process and subjected to a variety of physical and chemical test methods. Physical t...

TECHNOLOGY EVALUATION REPORT: CHEMFIX TECHNOLOGIES, INC. - SOLIDIFICATION/STABILIZATION PROCESS - CLACKAMAS, OREGON - VOLUME II

EPA Science Inventory

The CHEMFIX solidification/stabilization process was evaluated in the U.S. Environmental Protection Agency's SITE program. Waste from an uncontrolled hazardous waste site was treated by the CHEMFIX process and subjected to a variety of physical and chemical test methods. Physical...

Method for treating materials for solidification

DOEpatents

Jantzen, Carol M.; Pickett, John B.; Martin, Hollis L.

1995-01-01

A method for treating materials such as wastes for solidification to form a solid, substantially nonleachable product. Addition of reactive silica rather than ordinary silica to the material when bringing the initial molar ratio of its silica constituent to a desired ratio within a preselected range increases the solubility and retention of the materials in the solidified matrix. Materials include hazardous, radioactive, mixed, and heavy metal species. Amounts of other constituents of the material, in addition to its silica content are also added so that the molar ratio of each of these constituents is within the preselected ranges for the final solidified product. The mixture is then solidified by cement solidification or vitrification. The method can be used to treat a variety of wastes, including but not limited to spent filter aids from waste water treatment, waste sludges, combinations of spent filter aids and waste sludges, combinations of supernate and waste sludges, incinerator ash, incinerator offgas blowdown, combinations of incinerator ash and offgas blowdown, cementitious wastes and contaminated soils.

Solidification Technologies for Radioactive and Chemical Liquid Waste Treatment - Final CRADA Report

DOE Office of Scientific and Technical Information (OSTI.GOV)

Castiglioni, Andrew J.; Gelis, Artem V.

This project, organized under DOE/NNSA's Global Initiatives for Proliferation Prevention program, joined Russian and DOE scientists in developing more effective solidification and storage technologies for liquid radioactive waste. Several patent applications were filed by the Russian scientists (Russia only) and in 2012, the technology developed was approved by Russia's Federal State Unitary Enterprise RADON for application throughout Russia in cleaning up and disposing of radioactive waste.

Enviromental impact of a hospital waste incineration plant in Krakow (Poland).

PubMed

Gielar, Agnieszka; Helios-Rybicka, Edeltrauda

2013-07-01

The environmental impact of a hospital waste incineration plant in Krakow was investigated. The objective of this study was to assess the degree of environmental effect of the secondary solid waste generated during the incineration process of medical waste. The analysis of pollution of the air emissions and leaching test of ashes and slag were carried out. The obtained results allowed us to conclude that (i) the hospital waste incineration plant significantly solves the problems of medical waste treatment in Krakow; (ii) the detected contaminant concentrations were generally lower than the permissible values; (iii) the generated ashes and slag contained considerable concentrations of heavy metals, mainly zinc, and chloride and sulfate anions. Ashes and slag constituted 10-15% of the mass of incinerated wastes; they are more harmful for the environment when compared with untreated waste, and after solidification they can be deposited in the hazardous waste disposal.

Review of Literature on Waste Solidification/Stabilization with Emphasis on Metal-Bearing Wastes

DTIC Science & Technology

1989-08-01

applicability to treating a wide variety of waste types, and the ease with 4 which they are implemented in the field (Wiles and Apel , undated). Asphaltic...Wiles, C.C., 1987. A Review of Solidification/Stabilization Technology. Journal of Hazardous Materials, 14:5-21. Wiles, C.C., and Apel , M.L., undated...Personal correspondence and attachments from William McLaughlin, 1-714-693-1818, 1988. Trident Engineering Associates, 48 Maryland Ave., Annapolis, Maryland

Calcination process for radioactive wastes

DOEpatents

Kilian, Douglas C.

1976-05-04

The present invention provides a method for minimizing the volatilization of chlorides during solidification in a fluidized-bed calciner of liquids containing sodium, nitrate and chloride ions. Zirconium and fluoride are introduced into the liquid, and one-half mole of calcium nitrate is added per mole of fluoride present in the liquid mixture. The mixture is calcined in the fluidized-bed calciner at about 500.degree.C., producing a high bulk density calcine product containing the chloride, thus tying up the chloride in the solid product and minimizing chloride volatilization.

Application of stabilization/solidification technology on oil refinery sludge contaminated by heavy metals.

PubMed

Karamalidis, Athanasios K; Voudrias, Evangelos A

2004-01-01

The oily sludge produced by petroleum refineries is classified as a solid hazardous waste, according to European regulations. The objective of this work was to investigate whether stabilization/solidification can be used as a management method for the oily sludge. The sludge samples used originated from a petroleum-storing tank and a centrifuge unit of two Greek refineries. The experiments were designed to study the leachability of the heavy metals Pb, Cr, Cd, Ni, and Cu, which are contained in the sludge, using the Toxicity Characteristic Leaching Procedure (TCLP). Despite the fact that the metals were immobilized in a cement-based environment in the presence of organic load, leaching tests have shown a low metal leachability, less than 5%. Acid Neutralizing Capacity (ANC) tests were employed in order to estimate the acid resistance of the stabilized/solidified waste. In addition to ANC, a sequential TCLP test was employed in order to understand how the pH affects the leachability of Ni from the stabilized/solidified specimen.

Green remediation and recycling of contaminated sediment by waste-incorporated stabilization/solidification.

PubMed

Wang, Lei; Tsang, Daniel C W; Poon, Chi-Sun

2015-03-01

Navigational/environmental dredging of contaminated sediment conventionally requires contained marine disposal and continuous monitoring. This study proposed a green remediation approach to treat and recycle the contaminated sediment by means of stabilization/solidification enhanced by the addition of selected solid wastes. With an increasing amount of contaminated sediment (20-70%), the 28-d compressive strength of sediment blocks decreased from greater than 10MPa to slightly above 1MPa. For augmenting the cement hydration, coal fly ash was more effective than lime and ground seashells, especially at low sediment content. The microscopic and spectroscopic analyses showed varying amounts of hydration products (primarily calcium hydroxide and calcium silicate hydrate) in the presence of coal fly ash, signifying the influence of pozzolanic reaction. To facilitate the waste utilization, cullet from beverage glass bottles and bottom ashes from coal combustion and waste incineration were found suitable to substitute coarse aggregate at 33% replacement ratio, beyond which the compressive strength decreased accordingly. The mercury intrusion porosimetry analysis indicated that the increase in the total pore area and average pore diameter were linearly correlated with the decrease of compressive strength due to waste replacement. All the sediment blocks complied with the acceptance criteria for reuse in terms of metal leachability. These results suggest that, with an appropriate mixture design, contaminated sediment and waste materials are useful resources for producing non-load-bearing masonry units or fill materials for construction uses. Copyright © 2014 Elsevier Ltd. All rights reserved.

Importance of microscopy in durability studies of solidified and stabilized contaminated soils

USGS Publications Warehouse

Klich, I.; Wilding, L.P.; Drees, L.R.; Landa, E.R.

1999-01-01

Solidification/stabilization (S/S) is recognized by the U.S. EPA as a best demonstrated available technology for the containment of contaminated soils and other hazardous wastes that cannot be destroyed by chemical, thermal, or biological means. Despite the increased use of S/S technologies, little research has been conducted on the weathering and degradation of solidified and stabilized wastes once the treated materials have been buried. Published data to verify the performance and durability of landfilled treated wastes over time are rare. In this preliminary study, optical and electron microscopy (scanning electron microscopy [SEM], transmission electron microscopy [TEM] and electron probe microanalyses [EPMA]) were used to evaluate weathering features associated with metal-bearing contaminated soil that had been solidified and stabilized with Portland cement and subsequently buried on site, stored outdoors aboveground, or achieved in a laboratory warehouse for up to 6 yr. Physical and chemical alteration processes identified include: freeze-thaw cracking, cracking caused by the formation of expansive minerals such as ettringite, carbonation, and the movement of metals from waste aggregates into the cement micromass. Although the extent of degradation after 6 yr is considered slight to moderate, results of this study show that the same environmental concerns that affect the durability of concrete must be considered when evaluating the durability and permanence of the solidification and stabilization of contaminated soils with cement. In addition, such evaluations cannot be based on leaching and chemical analyses alone. The use of all levels of microscopic analyses must be incorporated into studies of the long-term performance of S/S technologies.Solidification/stabilization (S/S) is recognized by the U.S. EPA as a best demonstrated available technology for the containment of contaminated soils and other hazardous wastes that cannot be destroyed by chemical, thermal, or biological means. Despite the increased use of S/S technologies, little research has been conducted on the weathering and degradation of solidified and stabilized wastes once the treated materials have been buried. Published data to verify the performance and durability of landfilled treated wastes over time are rare. In this preliminary study, optical and electron microscopy (scanning electron microscopy [SEM], transmission electron microscopy [TEM] and electron probe microanalyses [EPMA]) were used to evaluate weathering features associated with metal-bearing contaminated soil that had been solidified and stabilized with Portland cement and subsequently buried on site, stored outdoors aboveground, or archived in a laboratory, warehouse for up to 6 yr. Physical and chemical alteration processes identified include: freeze-thaw cracking, cracking caused by the formation of expansive minerals such as ettringite, carbonation, and the movement of metals from waste aggregates into the cement micromass. Although the extent of degradation after 6 yr is considered slight to moderate, results of this study show that the same environmental concerns that affect the durability of concrete must be considered when evaluating the durability and permanence of the solidification and stabilization of contaminated soils with cement. In addition, such evaluations cannot be based on leaching and chemical analyses alone. The use of all levels of microscopic analyses must be incorporated into studies of the long-term performance of S/S technologies.

Solidification of radioactive waste resins using cement mixed with organic material

DOE Office of Scientific and Technical Information (OSTI.GOV)

Laili, Zalina, E-mail: liena@nm.gov.my; Waste and Environmental Technology Division, Malaysian Nuclear Agency; Yasir, Muhamad Samudi

2015-04-29

Solidification of radioactive waste resins using cement mixed with organic material i.e. biochar is described in this paper. Different percentage of biochar (0%, 5%, 8%, 11%, 14% and 18%) was investigated in this study. The characteristics such as compressive strength and leaching behavior were examined in order to evaluate the performance of solidified radioactive waste resins. The results showed that the amount of biochar affect the compressive strength of the solidified resins. Based on the data obtained for the leaching experiments performed, only one formulation showed the leached of Cs-134 from the solidified radioactive waste resins.

Long-Term High-Level Defense-Waste technology

NASA Astrophysics Data System (ADS)

1982-07-01

In the residual liquid solidification effort, the primary alternative studied is the wiped film evaporator approach to solidifying salt well pumped liquids and returning the molten material to single shell tanks for microwave final stabilization to a hard dry product. Both systems analysis and experimental work are proceeding to evaluate this approach. The primary alternative for in situ stabilization of in-tank wastes is microwave drying of wet salt cake and unpumped sludges. Experimental work was successfully conducted on a 1/12 scale tank containing wet synthetic salt cake. Related systems analysis of a full scale system was initiated.

A Citizen's Guide to Solidification and Stabilization

EPA Pesticide Factsheets

This guide describes how solidification and stabilization refer to a group of cleanup methods that prevent or slow the release of harmful chemicals from wastes, such as contaminated soil, sediment, and sludge.

System analyses on advanced nuclear fuel cycle and waste management

NASA Astrophysics Data System (ADS)

Cheon, Myeongguk

To evaluate the impacts of accelerator-driven transmutation of waste (ATW) fuel cycle on a geological repository, two mathematical models are developed: a reactor system analysis model and a high-level waste (HLW) conditioning model. With the former, fission products and residual trans-uranium (TRU) contained in HLW generated from a reference ATW plant operations are quantified and the reduction of TRU inventory included in commercial spent-nuclear fuel (CSNF) is evaluated. With the latter, an optimized waste loading and composition in solidification of HLW are determined and the volume reduction of waste packages associated with CSNF is evaluated. WACOM, a reactor system analysis code developed in this study for burnup calculation, is validated by ORIGEN2.1 and MCNP. WACOM is used to perform multicycle analysis for the reference lead-bismuth eutectic (LBE) cooled transmuter. By applying the results of this analysis to the reference ATW deployment scenario considered in the ATW roadmap, the HLW generated from the ATW fuel cycle is quantified and the reduction of TRU inventory contained in CSNF is evaluated. A linear programming (LP) model has been developed for determination of an optimized waste loading and composition in solidification of HLW. The model has been applied to a US-defense HLW. The optimum waste loading evaluated by the LP model was compared with that estimated by the Defense Waste Processing Facility (DWPF) in the US and a good agreement was observed. The LP model was then applied to the volume reduction of waste packages associated with CSNF. Based on the obtained reduction factors, the expansion of Yucca Mountain Repository (YMR) capacity is evaluated. It is found that with the reference ATW system, the TRU contained in CSNF could be reduced by a factor of ˜170 in terms of inventory and by a factor of ˜40 in terms of toxicity under the assumed scenario. The number of waste packages related to CSNF could be reduced by a factor of ˜8 in terms of volume and by factor of ˜10 on the basis of electricity generation when a sufficient cooling time for discharged spent fuel and zero process chemicals in HLW are assumed. The expansion factor of Yucca Mountain Repository capacity is estimated to be a factor of 2.4, much smaller than the reduction factor of CSNF waste packages, due to the existence of DOE-owned spent fuel and HLW. The YMR, however, could support 10 times greater electricity generation as long as the statutory capacity of DOE-owned SNF and HLW remains unchanged. This study also showed that the reduction of the number of waste packages could strongly be subject to the heat generation rate of HLW and the amount of process chemicals contained in HLW. For a greater reduction of the number of waste packages, a sufficient cooling time for discharged fuel and efforts to minimize the amount of process chemicals contained in HLW are crucial.

Waste management technology development and demonstration programs at Brookhaven National Laboratory

NASA Technical Reports Server (NTRS)

Kalb, Paul D.; Colombo, Peter

1991-01-01

Two thermoplastic processes for improved treatment of radioactive, hazardous, and mixed wastes were developed from bench scale through technology demonstration: polyethylene encapsulation and modified sulfur cement encapsulation. The steps required to bring technologies from the research and development stage through full scale implementation are described. Both systems result in durable waste forms that meet current Nuclear Regulatory Commission and Environmental Protection Agency regulatory criteria and provide significant improvements over conventional solidification systems such as hydraulic cement. For example, the polyethylene process can encapsulate up to 70 wt pct. nitrate salt, compared with a maximum of about 20 wt pct. for the best hydraulic cement formulation. Modified sulfur cement waste forms containing as much as 43 wt pct. incinerator fly ash were formulated, whereas the maximum quantity of this waste in hydraulic cement is 16 wt pct.

Factors affecting hazardous waste solidification/stabilization: a review.

PubMed

Malviya, Rachana; Chaudhary, Rubina

2006-09-01

Solidification/stabilization is accepted as a well-established disposal technique for hazardous waste. As a result many different types of hazardous wastes are treated with different binders. The S/S products have different property from waste and binders individually. The effectiveness of S/S process is studied by physical, chemical and microstructural methods. This paper summarizes the effect of different waste stream such as heavy metals bearing sludge, filter cake, fly ash, and slag on the properties of cement and other binders. The factors affecting strength development is studied using mix designs, including metal bearing waste alters the hydration and setting time of binders. Pore structure depends on relative quantity of the constituents, cement hydration products and their reaction products with admixtures. Carbonation and additives can lead to strength improvement in waste-binder matrix.

Waste Management Facilities Cost Information report for Greater-Than-Class C and DOE equivalent special case waste

DOE Office of Scientific and Technical Information (OSTI.GOV)

Feizollahi, F.; Shropshire, D.

This Waste Management Facility Cost Information (WMFCI) report for Greater-Than-Class C low-level waste (GTCC LLW) and DOE equivalent special case waste contains preconceptual designs and planning level life-cycle cost (PLCC) estimates for treatment, storage, and disposal facilities needed for management of GTCC LLW and DOE equivalent waste. The report contains information on 16 facilities (referred to as cost modules). These facilities are treatment facility front-end and back-end support functions (administration support, and receiving, preparation, and shipping cost modules); seven treatment concepts (incineration, metal melting, shredding/compaction, solidification, vitrification, metal sizing and decontamination, and wet/air oxidation cost modules); two storage concepts (enclosedmore » vault and silo); disposal facility front-end functions (disposal receiving and inspection cost module); and four disposal concepts (shallow-land, engineered shallow-land, intermediate depth, and deep geological cost modules). Data in this report allow the user to develop PLCC estimates for various waste management options. A procedure to guide the U.S. Department of Energy (DOE) and its contractor personnel in the use of estimating data is also included in this report.« less

Ordinary portland cement based solidification of toxic wastes: The role of OPC reviewed

DOE Office of Scientific and Technical Information (OSTI.GOV)

Hills, C.D.; Sollars, C.J.; Perry, R.

1993-01-01

A mixed waste stream, which is commercially solidified, has been solidified in the laboratory using OPC and PFA (pulverized fly ash) in a variety of mix proportions. The solidified products have been subjected to calorimetric, physical and microstructural analysis. The heat of hydration for OPC/waste mixes showed that a progressive poisoning of normal hydration reactions occurred with increasing waste addition. Once poisoned OPC failed to act as a cement and was substituted by PFA and other products in this role. Strength development was found to be related to the heat of hydration; this suggests that conduction calorimetry could be usedmore » to determine the suitability of a particular waste for OPC based solidification.« less

APPLICATIONS ANALYSIS REPORT: CHEMFIX TECHNOLOGIES, INC. - SOLIDIFICATION/STABILIZATION PROCESS

EPA Science Inventory

In support of the U.S. Environmental Protection Agency's (EPA) Superfund Innovative Technology Evaluation (SITE) Program, this report evaluates the Chemfix Technologies, Inc. (Chemfix), solidification/stabilization technology for on-site treatment of hazardous waste. The Chemfix ...

DEMONSTRATION BULLETIN - SOLIDIFICATION/ STABILIZATION PROCESS, SOLIDTECH, INC.

EPA Science Inventory

The Soliditech solidification/stabilization technology mixes hazardous waste materials in soils or sludges with pozzolanic material (cement, fly ash, or kiln dust), a proprietary additive called Urrichem, other proprietary additives, and water. The process is designed to aid ...

An alternative method for the treatment of waste produced at a dye and a metal-plating industry using natural and/or waste materials.

PubMed

Fatta, Despo; Papadopoulos, Achilleas; Stefanakis, Nikos; Loizidou, Maria; Savvides, Chrysanthos

2004-08-01

The aim of this study was to develop cost-effective, appropriate solidification technologies for treating hazardous industrial wastes that are currently disposed of in ways that may threaten the quality of local groundwater. One major objective was to use materials other than cement, and preferably materials that are themselves wastes, as the solidification additives, namely using wastes to treat wastes or locally available natural material. This research examines the cement-based and lime-based stabilization/solidification (S/S) techniques applied for waste generated at a metal-plating industry and a dye industry. For the lime-based S/S process the following binder mixtures were used: cement kiln dust/ lime, bentonite/lime and gypsum/lime. For the cement-based S/S process three binder mixtures were used: cement kiln dust/cement, bentonite/cement and gypsum/cement. The leachability of the wastes was evaluated using the toxicity characteristic leaching procedure. The applicability and optimum weight ratio of the binder mixtures were estimated using the unconfined compressive strength test. The optimum ratio mixtures were mixed with waste samples in different ratios and cured for 28 days in order to find the S/S products with the highest strength and lowest leachability at the same time. The results of this work showed that the cement-and lime-based S/S process, using cement kiln dust and bentonite as additives can be effectively used in order to treat industrial waste.

Use of cement-fly ash-based stabilization techniques for the treatment of waste containing aromatic contaminants

NASA Astrophysics Data System (ADS)

Banaszkiewicz, Kamil; Marcinkowski, Tadeusz

2017-11-01

Research on evaluation of evaporation rate of volatile organic compounds from soil beds during processing is presented. For the experiment, soil samples were prepared with the same amounts of benzene and stabilized using a mixture of CEMI 42.5R cement and fly ash from pit-coal combustion. Solidification of soils contaminated with BTEX hydrocarbons using hydraulic binders involves a risk of releasing vapours of these compounds during homogenization of waste with stabilizing mixture introduced and its dilution with water. The primary purposes of the research were: analysis of benzene volume emitted from soil during stabilization/solidification process and characterization of factors that may negatively affect the quality of measurements/the course of stabilization process. Analysis of benzene emission intensity during the process was based on concentration (C6H6) values, recorded with flame-ionization detector above the surface of reacting mixture. At the same time, gaseous contaminants emitted during waste stabilization were passed through pipes filled with activated carbon (SCK, Anasorb CSC). Benzene vapours adsorbed on activated carbon were subjected to analysis using gas chromatograph Varian 450-GC. Evaporation characteristics of benzene during processing contaminated soils revealed the stages creating the highest danger to workers' health, as well as a need for actions connected with modification of technological line.

Technology Demonstration Summary Site Program Demonstration Test Soliditech Inc Solidification-stabilization Process

EPA Science Inventory

The major objective of the Soliditech, Inc., SITE demonstration was to develop reliable performance and cost information about the Soliditech solidification, stabilization technology. The Soliditech process mixes hazardous waste materials with Portland cement or pozzolanic m...

STABILIZATION/SOLIDIFICATION OF CERCLA AND RCRA WASTES

EPA Science Inventory

This Handbook provides U.S. EPA regional staff responsible for reviewing CERCLA remedial action plans and RCRA permit applications with a tool for interpreting information on stabilization/solidification treatment. As a practical day-to-day reference guide, it will also provide t...

SOLIDIFICATION/STABILIZATION: IS IT ALWAYS APPROPRIATE?

EPA Science Inventory

The findings of recent research and evaluation efforts are assessed to determine whether solidification/stabilization (S/S) has been properly and appropriately applied for different types of hazardous wastes. Results from these studies are mixed and, as a result, the need for pro...

SUMMARY OF SOLIDIFICATION/STABILIZATION SITE DEMONSTRATIONS AT UNCONTROLLED HAZARDOUS WASTE SITES

EPA Science Inventory

Four large-scale solidification/stabilization demonstrations have occurred under EPA's SITE program. In general, physical testing results have been acceptable. Reduction in metal leachability, as determined by the TCLP test, has been observed. Reduction in organic leachability ha...

Characteristics of solidified products containing radioactive molten salt waste.

PubMed

Park, Hwan-Seo; Kim, In-Tae; Cho, Yong-Zun; Eun, Hee-Chul; Kim, Joon-Hyung

2007-11-01

The molten salt waste from a pyroprocess to recover uranium and transuranic elements is one of the problematic radioactive wastes to be solidified into a durable wasteform for its final disposal. By using a novel method, named as the GRSS (gel-route stabilization/solidification) method, a molten salt waste was treated to produce a unique wasteform. A borosilicate glass as a chemical binder dissolves the silicate compounds in the gel products to produce one amorphous phase while most of the phosphates are encapsulated by the vitrified phase. Also, Cs in the gel product is preferentially situated in the silicate phase, and it is vitrified into a glassy phase after a heat treatment. The Sr-containing phase is mainly phosphate compounds and encapsulated by the glassy phase. These phenomena could be identified by the static and dynamic leaching test that revealed a high leach resistance of radionuclides. The leach rates were about 10(-3) - 10(-2) g/m2 x day for Cs and 10(-4) - 10(-3) g/m2 x day for Sr, and the leached fractions of them were predicted to be 0.89% and 0.39% at 900 days, respectively. This paper describes the characteristics of a unique wasteform containing a molten salt waste and provides important information on a newly developed immobilization technology for salt wastes, the GRSS method.

SILICATE TECHNOLOGY CORPORATION'S SOLIDIFICATION/ STABILIZATION TECHNOLOGY FOR ORGANIC AND INORGANIC CONTAMINANTS IN SOILS - APPLICATIONS ANALYSIS REPORT

EPA Science Inventory

This Applications Analysis Report evaluates the solidification/stabilization treatment process of Silicate Technology Corporation (STC) for the on-site treatment of hazardous waste. The STC immobilization technology utilizes a proprietary product (FMS Silicate) to chemically stab...

Hazcon Solidification Process, Douglassville, Pa.: Applications Analysis Report

EPA Science Inventory

This document is an evaluation of the HAZCON solidification technology and its applicability as an on-site treatment method for waste site cleanup. A Demonstration was held at the Douglassville, Pennsylvania Superfund site in the fall of 1987. Operational data and sampling and an...

Novel synthesis and applications of Thiomer solidification for heavy metals immobilization in hazardous ASR/ISW thermal residue.

PubMed

Baek, Jin Woong; Mallampati, Srinivasa Reddy; Park, Hung Suck

2016-03-01

The present paper reports the novel synthesis and application of Thiomer solidification for heavy metal immobilization in hazardous automobile shredder residues and industrial solid waste (ASR/ISW) thermal residues. The word Thiomer is a combination of the prefix of a sulfur-containing compound "Thio" and the suffix of "Polymer" meaning a large molecule compound of many repeated subunits. To immobilize heavy metals, either ASR/ISW thermal residues (including bottom and fly ash) was mixed well with Thiomer and heated at 140°C. After Thiomer solidification, approximately 91-100% heavy metal immobilization was achieved. The morphology and mineral phases of the Thiomer-solidified ASR/ISW thermal residue were characterized by field emission-scanning electron microscopy, energy dispersive X-ray spectroscopy and X-ray diffraction (XRD), which indicated that the amounts of heavy metals detectable on the ASR/ISW thermal residue surface decreased and the sulfur mass percent increased. XRD indicated that the main fraction of the enclosed/bound materials on the ASR/ISW residue contained sulfur associated crystalline complexes. The Thiomer solidified process could convert the heavy metal compounds into highly insoluble metal sulfides and simultaneously encapsulate the ASR/ISW thermal residue. These results show that the proposed method can be applied to the immobilization of ASR/ISW hazardous ash involving heavy metals. Copyright © 2015 Elsevier Ltd. All rights reserved.

Dielectric Properties of Low-Level Liquid Waste

DOE Office of Scientific and Technical Information (OSTI.GOV)

L. E. Lagos; M. A. Ebadian

1998-10-20

The purpose of this study was to develop a data collection containing values for the dielectric properties of various low-level liquid waste (LLLW) simulants measured as a function of frequency, temperature, and composition. The investigation was motivated by current interest in the use of microwave processing for the treatment of radioactive waste. A large volume of transuranic liquid and sludge produced by the U.S. Department of Defense (DOD) during the production of nuclear fiel bars is stored at several U.S. Department of Energy (DOE) sites around the United States. Waste storage and disposal space is scarce, expensive, and must bemore » minimized. Thus, several DOE sites are pursuing the use of microwave heating as a means of achieving volume reduction and solidification of low-level liquid wastes. It is important to know which microwave frequencies should be employed tc achieve the most efficient processing at a range of different temperatures. The dielectric properties of the LLLW simulants can be utilized to determine the optimum frequencies for use with a particular LLLW or with other LLLWS of similar composition. Furthermore, nonlinear thermal processes, such as thermal runaway, which occur in the material being treated cannot be modeled without a knowledge of the temperature dependence of the dielectric properties. Often, this data does not exist; however, when it does, only very limited data near room temperature are available. The data collection generated in this study can be used to predict the behavior of a variety of microwave thermal treatment technologies, which have the potential of substantially reducing the volume of the LLLWS that are currently stored at many DOE sites. This information should help the users of the microwave reduction and solidification technology to optimize microwave processes used in the treatment of LLLW. The microwave reduction and solidification technology has clear advantages over other methods of reducing LLLWS. These include the incineration of combustibles, the evaporation of combustibles, the evaporation of liquids, and the compaction of noncombustibles. The handling of radioactive liquid waste is generally carried out within closed systems consisting of highly corrosion-resistant, welded, leak-tight pipes, tanks, and other apparatus. High power microwave processing is a promising technology for reducing risks to the environment and human health, thereby supporting the DOE's decontamination and decommissioning (D&D) objectives.« less

EPA SITE DEMONSTRATION OF THE INTERNATIONAL WASTE TECHNOLOGIES/GEO-CON IN SITU STABILIZATION/ SOLIDIFICATION PROCESS

EPA Science Inventory

This paper presents an EPA evaluation of the first field demonstration of an in situ stabilization/solidification process for contaminated soil under the EPA Superfund Innovative Technology Evaluation (SITE) program. Demonstration of this process was a joint effort of two vendors...

Updated Liquid Secondary Waste Grout Formulation and Preliminary Waste Form Qualification

DOE Office of Scientific and Technical Information (OSTI.GOV)

Saslow, Sarah A.; Um, Wooyong; Russell, Renee L.

This report describes the results from liquid secondary waste grout (LSWG) formulation and cementitious waste form qualification tests performed by Pacific Northwest National Laboratory (PNNL) for Washington River Protection Solutions, LLC (WRPS). New formulations for preparing a cementitious waste form from a high-sulfate liquid secondary waste stream simulant, developed for Effluent Management Facility (EMF) process condensates merged with low activity waste (LAW) caustic scrubber, and the release of key constituents (e.g. 99Tc and 129I) from these monoliths were evaluated. This work supports a technology development program to address the technology needs for Hanford Site Effluent Treatment Facility (ETF) liquid secondarymore » waste (LSW) solidification and supports future Direct Feed Low-Activity Waste (DFLAW) operations. High-priority activities included simulant development, LSWG formulation, and waste form qualification. The work contained within this report relates to waste form development and testing and does not directly support the 2017 integrated disposal facility (IDF) performance assessment (PA). However, this work contains valuable information for use in PA maintenance past FY17, and for future waste form development efforts. The provided data should be used by (i) cementitious waste form scientists to further understanding of cementitious dissolution behavior, (ii) IDF PA modelers who use quantified constituent leachability, effective diffusivity, and partitioning coefficients to advance PA modeling efforts, and (iii) the U.S. Department of Energy (DOE) contractors and decision makers as they assess the IDF PA program. The results obtained help fill existing data gaps, support final selection of a LSWG waste form, and improve the technical defensibility of long-term waste form performance estimates.« less

Overview of waste stabilization with cement.

PubMed

Batchelor, B

2006-01-01

Cement can treat a variety of wastes by improving physical characteristics (solidification) and reducing the toxicity and mobility of contaminants (stabilization). Potentially adverse waste-binder interactions are an important consideration because they can limit solidification. Stabilization occurs when a contaminant is converted from the dissolved (mobile) phase to a solid (immobile) phase by reactions, such as precipitation, sorption, or substitution. These reactions are often strongly affected by pH, so the presence of components of the waste that control pH are critical to stabilization reactions. Evaluating environmental impacts can be accomplished in a tiered strategy in which simplest approach would be to measure the maximum amount of contaminant that could be released. Alternatively, the sequence of release can be determined, either by microcosm tests that attempt to simulate conditions in the disposal zone or by mechanistic models that attempt to predict behavior using fundamental characteristics of the treated waste.

A calorimetric and microstructural study of solidified toxic wastes. Part 2: A model for poisoning of OPC hydration

DOE Office of Scientific and Technical Information (OSTI.GOV)

Hills, C.D.; Sollars, C.J.; Perry, R.

1994-01-01

During cement-based processing of certain hazardous wastes the hydration reactions thought to be responsible for solidification can be poisoned and appear to be retarded indefinitely. A number of wastes known to be capable of poisoning hydration were added to ordinary Portland cement (OPC) and classified on the basis of interference effects observed. This paper reports the results from a characterization of these wastes and the subsequent addition to OPC of waste components identified as significant in single and combined additions. The effects of these additions were examined by conduction calorimetry and microstructural techniques. A comparison of results showed that itmore » was possible to reproduce the poisoning effects observed previously with real wastes by an addition of combined metal hydroxides only. These results suggest that poisoning results from the synergistic effects of compounds contained in the waste. A model, representing the early hydration of OPC, has been modified and is presented and its application in explaining poisoning of hydration is discussed.« less

Secondary Waste Simulant Development for Cast Stone Formulation Testing

DOE Office of Scientific and Technical Information (OSTI.GOV)

Russell, Renee L.; Westsik, Joseph H.; Rinehart, Donald E.

Washington River Protection Solutions, LLC (WRPS) funded Pacific Northwest National Laboratory (PNNL) to conduct a waste form testing program to implement aspects of the Secondary Liquid Waste Treatment Cast Stone Technology Development Plan (Ashley 2012) and the Hanford Site Secondary Waste Roadmap (PNNL 2009) related to the development and qualification of Cast Stone as a potential waste form for the solidification of aqueous wastes from the Hanford Site after the aqueous wastes are treated at the Effluent Treatment Facility (ETF). The current baseline is that the resultant Cast Stone (or grout) solid waste forms would be disposed at the Integratedmore » Disposal Facility (IDF). Data and results of this testing program will be used in the upcoming performance assessment of the IDF and in the design and operation of a solidification treatment unit planned to be added to the ETF. The purpose of the work described in this report is to 1) develop simulants for the waste streams that are currently being fed and future WTP secondary waste streams also to be fed into the ETF and 2) prepare simulants to use for preparation of grout or Cast Stone solid waste forms for testing.« less

Leaching behaviour and mechanical properties of copper flotation waste in stabilized/solidified products.

PubMed

Mesci, Başak; Coruh, Semra; Ergun, Osman Nuri

2009-02-01

This research describes the investigation of a cement-based solidification/stabilization process for the safe disposal of copper flotation waste and the effect on cement properties of the addition of copper flotation waste (CW) and clinoptilolite (C). In addition to the reference mixture, 17 different mixtures were prepared using different proportions of CW and C. Physical properties such as setting time, specific surface area and compressive strength were determined and compared to a reference mixture and Turkish standards (TS). Different mixtures with the copper flotation waste portion ranging from 2.5 to 12.5% by weight of the mixture were tested for copper leachability. The results show that as cement replacement materials especially clinoptilolite had clear effects on the mechanical properties. Substitution of 5% copper flotation waste for Portland cement gave a similar strength performance to the reference mixture. Higher copper flotation waste addition such as 12.5% replacement yielded lower strength values. As a result, copper flotation waste and clinoptilolite can be used as cementitious materials, and copper flotation waste also can be safely stabilized/solidified in a cement-based solidification/stabilization system.

The cement solidification systems at LANL

DOE Office of Scientific and Technical Information (OSTI.GOV)

Veazey, G.W.

1990-01-01

There are two major cement solidification systems at Los Alamos National Laboratory. Both are focused primarily around treating waste from the evaporator at TA-55, the Plutonium Processing Facility. The evaporator receives the liquid waste stream from TA-55's nitric acid-based, aqueous-processing operations and concentrates the majority of the radionuclides in the evaporator bottoms solution. This is sent to the TA-55 cementation system. The evaporator distillate is sent to the TA-50 facility, where the radionuclides are precipitated and then cemented. Both systems treat TRU-level waste, and so are operated according to the criteria for WIPP-destined waste, but they differ in both cementmore » type and mixing method. The TA-55 systems uses Envirostone, a gypsum-based cement and in-drum prop mixing; the TA-50 systems uses Portland cement and drum tumbling for mixing.« less

Reduction of 68Ge activity containing liquid waste from 68Ga PET chemistry in nuclear medicine and radiopharmacy by solidification.

PubMed

de Blois, Erik; Chan, Ho Sze; Roy, Kamalika; Krenning, Eric P; Breeman, Wouter A P

PET with 68 Ga from the TiO 2 - or SnO 2 - based 68 Ge/ 68 Ga generators is of increasing interest for PET imaging in nuclear medicine. In general, radionuclidic purity ( 68 Ge vs. 68 Ga activity) of the eluate of these generators varies between 0.01 and 0.001%. Liquid waste containing low amounts of 68 Ge activity is produced by eluting the 68 Ge/ 68 Ga generators and residues from PET chemistry. Since clearance level of 68 Ge activity in waste may not exceed 10 Bq/g, as stated by European Directive 96/29/EURATOM, our purpose was to reduce 68 Ge activity in solution from >10 kBq/g to <10 Bq/g; which implies the solution can be discarded as regular waste. Most efficient method to reduce the 68 Ge activity is by sorption of TiO 2 or Fe 2 O 3 and subsequent centrifugation. The required 10 Bq per mL level of 68 Ge activity in waste was reached by Fe 2 O 3 logarithmically, whereas with TiO 2 asymptotically. The procedure with Fe 2 O 3 eliminates ≥90% of the 68 Ge activity per treatment. Eventually, to simplify the processing a recirculation system was used to investigate 68 Ge activity sorption on TiO 2 , Fe 2 O 3 or Zeolite. Zeolite was introduced for its high sorption at low pH, therefore 68 Ge activity containing waste could directly be used without further interventions. 68 Ge activity containing liquid waste at different HCl concentrations (0.05-1.0 M HCl), was recirculated at 1 mL/min. With Zeolite in the recirculation system, 68 Ge activity showed highest sorption.

The management of arsenic wastes: problems and prospects.

PubMed

Leist, M; Casey, R J; Caridi, D

2000-08-28

Arsenic has found widespread use in agriculture and industry to control a variety of insect and fungicidal pests. Most of these uses have been discontinued, but residues from such activities, together with the ongoing generation of arsenic wastes from the smelting of various ores, have left a legacy of a large number of arsenic-contaminated sites. The treatment and/or removal of arsenic is hindered by the fact that arsenic has a variety of valence states. Arsenic is most effectively removed or stabilized when it is present in the pentavalent arsenate form. For the removal of arsenic from wastewater, coagulation, normally using iron, is the preferred option. The solidification/stabilization of arsenic is not such a clear-cut process. Factors such as the waste's interaction with the additives (e.g. iron or lime), as well as any effect on the cement matrix, all impact on the efficacy of the fixation. Currently, differentiation between available solidification/stabilization processes is speculative, partly due to the large number of differing leaching tests that have been utilized. Differences in the leaching fluid, liquid-to-solid ratio, and agitation time and method all impact significantly on the arsenic leachate concentrations. This paper reviews options available for dealing with arsenic wastes, both solid and aqueous through an investigation of the methods available for the removal of arsenic from wastewater as well as possible solidification/stabilization options for a variety of waste streams.

[Recent advance in solidification/stabilization technology for the remediation of heavy metals-contaminated soil].

PubMed

Hao, Han-zhou; Chen, Tong-bin; Jin, Meng-gui; Lei, Mei; Liu, Cheng-wu; Zu, Wen-pu; Huang, Li-mi

2011-03-01

Remediation of heavy metals-contaminated soil is still a difficulty and a hotspot of international research projects. At present, the technologies commonly adopted for the remediation of contaminated sites mainly include excavation, solidification/stabilization (S/S), soil washing, soil vapor extraction (SVE), thermal treatment, and bioremediation. Based on the S/S technical guidelines of Unite State Environmental Protection Agency (EPA) and United Kingdom Environment Agency (EA) and the domestic and foreign patents, this paper introduced the concepts of S/S and its development status at home and abroad, and discussed its future development directions. Solidification refers to a process that binds contaminated media with a reagent, changing the media's physical properties via increasing its compressive strength, decreasing its permeability, and encapsulating the contaminants to form a solid material. Stabilization refers to the process that involves a chemical reaction which reduces the leachability of a waste, chemically immobilizes the waste and reduces its solubility, making the waste become less harmful or less mobile. S/S technology includes cement solidification, lime pozzolanic solidification, plastic materials stabilization, vitrification, and regent-based stabilization. Stabilization (or immobilization) treatment processes convert contaminants to less mobile forms through chemical or thermal interactions. In stabilization technology, the aim of adding agents is to change the soil physical and chemical properties through pH control technology, redox potential technology, precipitation techniques, adsorption technology, and ion-exchange technology that change the existing forms of heavy metals in soil, and thus, reduce the heavy metals bioavailability and mobility. This review also discussed the S/S evaluation methods, highlighted the need to enhance S/S technology in the molecular bonding, soil polymers, and formulation of China's S/S technical guidelines.

Method for solidification of radioactive and other hazardous waste

DOEpatents

Anshits, Alexander G.; Vereshchagina, Tatiana A.; Voskresenskaya, Elena N.; Kostin, Eduard M.; Pavlov, Vyacheslav F.; Revenko, Yurii A.; Tretyakov, Alexander A.; Sharonova, Olga M.; Aloy, Albert S.; Sapozhnikova, Natalia V.; Knecht, Dieter A.; Tranter, Troy J.; Macheret, Yevgeny

2002-01-01

Solidification of liquid radioactive waste, and other hazardous wastes, is accomplished by the method of the invention by incorporating the waste into a porous glass crystalline molded block. The porous block is first loaded with the liquid waste and then dehydrated and exposed to thermal treatment at 50-1,000.degree. C. The porous glass crystalline molded block consists of glass crystalline hollow microspheres separated from fly ash (cenospheres), resulting from incineration of fossil plant coals. In a preferred embodiment, the porous glass crystalline blocks are formed from perforated cenospheres of grain size -400+50, wherein the selected cenospheres are consolidated into the porous molded block with a binder, such as liquid silicate glass. The porous blocks are then subjected to repeated cycles of saturating with liquid waste, and drying, and after the last cycle the blocks are subjected to calcination to transform the dried salts to more stable oxides. Radioactive liquid waste can be further stabilized in the porous blocks by coating the internal surface of the block with metal oxides prior to adding the liquid waste, and by coating the outside of the block with a low-melting glass or a ceramic after the waste is loaded into the block.

DOE Office of Scientific and Technical Information (OSTI.GOV)

Majid, Z.A.; Mahmud, H.; Shaaban, M.G.

Stabilization/solidification of hazardous wastes is used to convert hazardous metal hydroxide waste sludge into a solid mass with better handling properties. This study investigated the pore size development of ordinary portland cement pastes containing metal hydroxide waste sludge and rice husk ash using mercury intrusion porosimetry. The effects of acre and the addition of rice husk ash on pore size development and strength were studied. It was found that the pore structures of mixes changed significantly with curing acre. The pore size shifted from 1,204 to 324 {angstrom} for 3-day old cement paste, and from 956 to 263 {angstrom} formore » a 7-day old sample. A reduction in pore size distribution for different curing ages was also observed in the other mixtures. From this limited study, no conclusion could be made as to any correlation between strength development and porosity. 10 refs., 6 figs., 3 tabs.« less

LEACHING BOUNDARY IN CEMENT-BASED WASTE FORMS

EPA Science Inventory

Cement-based fixation systems are among the most commonly employed stabilization/solidification techniques. These cement haste mixtures, however, are vulnerable to ardic leaching solutions. Leaching of cement-based waste forms in acetic acid solutions with different acidic streng...

Air pollution control residues from waste incineration: current UK situation and assessment of alternative technologies.

PubMed

Rani, D Amutha; Boccaccini, A R; Deegan, D; Cheeseman, C R

2008-11-01

Current disposal options for APC residues in the UK and alternative treatment technologies developed world-wide have been reviewed. APC residues are currently landfilled in the UK where they undergo in situ solidification, although the future acceptability of this option is uncertain because the EU waste acceptance criteria (WAC) introduce strict limits on leaching that are difficult to achieve. Other APC residue treatment processes have been developed which are reported to reduce leaching to below relevant regulatory limits. The Ferrox process, the VKI process, the WES-PHix process, stabilisation/solidification using cementitious binders and a range of thermal treatment processes are reviewed. Thermal treatment technologies convert APC residues combined with other wastes into inert glass or glass-ceramics that encapsulate heavy metals. The waste management industry will inevitably use the cheapest available option for treating APC residues and strict interpretation and enforcement of waste legislation is required if new, potentially more sustainable technologies are to become commercially viable.

Solidification of arsenic and heavy metal containing tailings using cement and blast furnace slag.

PubMed

Kim, Jung-Wook; Jung, Myung Chae

2011-01-01

The objective of this study is to examine the solidification of toxic elements in tailings by the use of cement and blast furnace slag. Tailings samples were taken at an Au-Ag mine in Korea. To examine the best mixing ratio of tailings and the mixture of ordinary Portland cement (OPC) and blast furnace slag (SG) of 5:5, 6:6, 7:3, and 8:2, the 7:3 ratio of tailings and OPC+SG was adapted. In addition, the mixing ratios of water and OPC + SG were applied to 10, 20, and 30 wt%. After 7, 14, and 28 days' curing, the UCS test was undertaken. A relatively high strength of solidified material (137.2 kg cm⁻² in average of 3 samples) at 28 days' curing was found in 20 wt% of water content (WC). This study also examined the leachability of arsenic and heavy metals (Cd, Cu, Pb, and Zn) under the Korean Standard Leaching Test, and it showed that the reductions in leachabilities of As and heavy metals of solidified samples were ranged from 76 to 99%. Thus, all the solidified samples were within the guidelines for special and hazardous waste materials by the Waste Management Act in Korea. In addition, the result of freeze-thaw cycle test of the materials indicated that the durability of the materials was sufficient. In conclusion, solidification using a 7:3 mixing ratio of tailings and a 1:1 mixture of OPC + SG with 20% of WC is one of the best methods for the remediation of arsenic and heavy metals in tailings and other contaminated materials.

75 FR 15423 - U.S. Nuclear Regulatory Commission Technical Evaluation Report for the Phase 1 Decommissioning...

Federal Register 2010, 2011, 2012, 2013, 2014

2010-03-29

... DOE to carry out a high-level radioactive waste management demonstration project at the Western New... solidification of high-level radioactive waste for disposal in a Federal repository for permanent disposal. The... and other facilities where the solidified high-level radioactive waste was stored, the facilities used...

Investigation into the artificial ageing effects on the microstructure of an industrial solid waste treated with cement.

PubMed

Choura, M; Keskes, M; Tayibi, H; Rouis, J

2011-04-01

Metal hydroxide sludges are classified as hazardous wastes in the European Hazardous Waste Catalogue (EHWC) because of their high heavy metal contents (Zn, Cr, Fe, Cu, etc.) and the release of these pollutants to the environment. Thereby, the disposal of this waste without any treatment is a substantial environmental problem. Stabilization/solidification technologies are widely used for the treatment of wastes and residues in order to obtain inert materials. This work aims to assess the effectiveness of the chemical fixation and solidification of a metal hydroxide sludge generated by the electrotyping surface treatment industry, using Portland Artificial Cement. In order to predict the medium- and long-term behaviour of the solidified waste, an artificial ageing by means of thermal shocks and humidity variation cycles was applied. Scanning Electron Microscopy (SEM) and X-ray Diffraction studies revealed a considerable increase in calcite within the solid matrix after the artificial ageing, which can be attributed to the phenomenon of carbonation. It was also found that the mechanical properties of the solidified material, after ageing, were improved by up to 30%.

Design and characterization of microporous zeolitic hydroceramic waste forms for the solidification and stabilization of sodium bearing wastes

NASA Astrophysics Data System (ADS)

Bao, Yun

During the production of nuclear weapon by the DOE, large amounts of liquid waste were generated and stored in millions of gallons of tanks at Savannah River, Hanford and INEEL sites. Typically, the waste contains large amounts of soluble NaOH, NaNO2 and NaNO3 and small amounts of soluble fission products, cladding materials and cleaning solution. Due to its high sodium content it has been called sodium bearing waste (SBW). We have formulated, tested and evaluated a new type of hydroceramic waste form specifically designed to solidify SBW. Hydroceramics can be made from an alumosilicate source such as metakaolin and NaOH solutions or the SBW itself. Under mild hydrothermal conditions, the mixture is transformed into a solid consisting of zeolites. This process leads to the incorporation of radionuclides into lattice sites and the cage structures of the zeolites. Hydroceramics have high strength and inherent stability in realistic geologic settings. The process of making hydroceramics from a series of SBWs was optimized. The results are reported in this thesis. Some SBWs containing relatively small amounts of NaNO3 and NaNO2 (SigmaNOx/Sigma Na<25 mol%) can be directly solidified with metakaolin. The remaining SBW having high concentrations of nitrate and nitrite (SigmaNOx/Sigma Na>25 mol%) require pretreatment since a zeolitic matrix such as cancrinite is unable to host more than 25 mol% nitrate/nitrite. Two procedures to denitrate/denitrite followed by solidification were developed. One is based on calcination in which a reducing agent such as sucrose and metakaolin have been chosen as a way of reducing nitrate and nitrite to an acceptable level. The resulting calcine can be solidified using additional metakaolin and NaOH to form a hydroceramic. As an alternate, a chemical denitration/denitrition process using Si and Al powders as the reducing agents, followed by adding metakaolin to the solution prepare a hydroceramic was also investigated. Si and Al not only are the reducing agents, but they also provide Si and Al species to make zeolites during the reducing process. Performance of the hydroceramics was documented using SEM microstructure and X-ray diffraction phase analysis, mechanical property and leaching tests (Product Consistency Test and ANSI/ANS-16.1 leaching test).

Stabilization/solidification of hot dip galvanizing ash using different binders.

PubMed

Vinter, S; Montanes, M T; Bednarik, V; Hrivnova, P

2016-12-15

This study focuses on solidification of hot dip-galvanizing ash with a high content of zinc and soluble substances. The main purpose of this paper is to immobilize these pollutants into a matrix and allow a safer way for landfill disposal of that waste. Three different binders (Portland cement, fly ash and coal fluidized-bed combustion ash) were used for the waste solidification. Effectiveness of the process was evaluated using leaching test according to EN 12457-4 and by using the variance analysis and the categorical multifactorial test. In the leaching test, four parameters were observed: pH, zinc concentration in leachate, and concentration of chlorides and dissolved substances in leachate. The acquired data was then processed using statistical software to find an optimal solidifying ratio of the addition of binder, water, and waste to the mixture, with the aim to fulfil the requirement for landfill disposal set by the Council Decision 2003/33/EC. The influence on the main observed parameters (relative amount of water and a binder) on the effectiveness of the used method and their influence of measured parameters was also studied. Copyright © 2016 Elsevier B.V. All rights reserved.

DEMONSTRATION BULLETIN: SOLIDIFICATION/STABILIZATION OF ORGANIC/INORGANIC CONTAMINANTS - SILICATE TECHNOLOGY CORPORATION

EPA Science Inventory

Silicate Technology Corporation's (STC's) technology for treating hazardous waste utilizes silicate compounds to stabilize organic and inorganic constituents in contaminated soils and sludges. STC has developed two groups of reagents: SOILSORB HM for treating wastes with inorgan...

Alkali-activated complex binders from class C fly ash and Ca-containing admixtures.

PubMed

Guo, Xiaolu; Shi, Huisheng; Chen, Liming; Dick, Warren A

2010-01-15

Processes that maximize utilization of industrial solid wastes are greatly needed. Sodium hydroxide and sodium silicate solution were used to create alkali-activated complex binders (AACBs) from class C fly ash (CFA) and other Ca-containing admixtures including Portland cement (PC), flue gas desulfurization gypsum (FGDG), and water treatment residual (WTR). Specimens made only from CFA (CFA100), or the same fly ash mixed with 40 wt% PC (CFA60-PC40), with 10 wt% FGDG (CFA90-FGDG10), or with 10 wt% WTR (CFA90-WTR10) had better mechanical performance compared to binders using other mix ratios. The maximum compressive strength of specimens reached 80.0 MPa. Geopolymeric gel, sodium polysilicate zeolite, and hydrated products coexist when AACB reactions occur. Ca from CFA, PC, and WTR precipitated as Ca(OH)(2), bonded in geopolymers to obtain charge balance, or reacted with dissolved silicate and aluminate species to form calcium silicate hydrate (C-S-H) gel. However, Ca from FGDG probably reacted with dissolved silicate and aluminate species to form ettringite. Utilization of CFA and Ca-containing admixtures in AACB is feasible. These binders may be widely utilized in various applications such as in building materials and for solidification/stabilization of other wastes, thus making the wastes more environmentally benign.

Effect of heavy metals and water content on the strength of magnesium phosphate cements.

PubMed

Buj, Irene; Torras, Josep; Casellas, Daniel; Rovira, Miquel; de Pablo, Joan

2009-10-15

In this paper the mechanical properties of magnesium potassium phosphate cements used for the Stabilization/Solidification (S/S) of galvanic wastes were investigated. Surrogate wastes (metal nitrate dissolutions) were employed containing Cd, Cr(III), Cu, Ni, Pb or Zn at a concentration of 25 g dm(-3) and different water-to-solid (W/S) ratios (0.3, 0.4, 0.5 and 0.6 dm(3)kg(-1)) have been employed. Cements were prepared by mixing hard burned magnesia of about 70% purity with potassium dihydrogen phosphate. Compressive strength and tensile strength of specimens were determined. In addition the volume of permeable voids was measured. It was found that when comparing pastes that the volume of permeable voids increases and mechanical strength decreases with the increase of water-to-solid ratio (W/S). Nevertheless pastes with the same material proportions containing different metals show different mechanical strength values. The hydration products were analyzed by XRD. With the increase of water content not previously reported hydration compound was detected: bobierrite.

EFFECTS OF LEACHING ON PORE SIZE DISTRIBUTION OF SOLIDIFIED/STABILIZED WASTES

EPA Science Inventory

Chemical solidification/stabilization processes are commonly used to immobilize metals in fly ash and flue gas desulfurization (FGD) sludges and to convert these wastes into monolithic or granular materials with better handling properties and reduced permeabilities. his study eva...

Solidification of Dredged Sludge by Hydraulic Ash-Slag Cementitious Materials

NASA Astrophysics Data System (ADS)

Zhu, Shu-Jing; Qin, Ying; Hwang, Jiann-Yang

Solidification treatment is used to treat hazardous wastes for disposal and to remediate the contaminated land. It is an increasingly popular technology for redevelopment of brown fields since treated wastes can often be left on-site, which can improve the site's soil for subsequent construction. In order to find home for the dredged sludge from the Pearl River Estuary Channel in China, the potential uses of treated dredged sludge by solidification treatment as valuable structural fill was investigated. Structure fills were prepared under various formula and curing conditions. Modulus of elasticity was detemined at 7 days, 14 days and 28 days with different types of load application. Atterberg limit, compactibility and CBR values are reported. The relationship between the microstructure and engineering properties of treated sludge are examined. The results clearly show the technical benefits by stabilizing soft soils with Hydraulic ash-slag cementitious materials. XRD and DTA-TG tests were carried out on certain samples to characterize the hydraulic compounds formed.

Treatment of Petroleum Sludge By Using Solidification/Stabilization (S/S) Method : Effect of Hydration Days to Heavy Metals Leaching and Strength

NASA Astrophysics Data System (ADS)

Murshid, N.; Kamil, N. A. F. M.; Kadir, A. A.

2018-04-01

Petroleum sludge is one of the major solid wastes generated in the petroleum industry. Generally, there are numbers of heavy metals in petroleum sludge and one treatment that is gaining prominence to treat a variety of mixed organic and inorganic waste is solidification/stabilization (S/S) method. The treatment protects human health and the environment by immobilizing contaminants within the treated material and prevents migration of the contaminants. In this study, solidification/stabilization (S/S) method has been used to treat the petroleum sludge. The comparison of hydration days, namely, 7th and 28th days in these cement-based waste materials were studied by using Synthetic Precipitate Leaching Procedure (SPLP). The results were compared to the United States Environmental Protection Agency (USEPA) standards. The results for leaching test concluded that less percentage OPC gave maximum concentration of heavy metals leaching due to deficient in Calcium Oxide (CaO), which is can caused weak solidification in the mixture. Physical and mechanical properties conducted such as compressive strength and density test. From the results, it shows addition up to of 30percentage PS give results which comply with minimum landfill dispose limit. The results shows correlation between strength and density are strong regression coefficient of 82.7%. In conclusion, S/S method can be alternative disposal method for PS in the same time complies with standard for minimum landfill disposal limit. The results for leaching test concluded the less OPC percentage gave maximum concentration of heavy metals leaching.

ICPP tank farm closure study. Volume 2: Engineering design files

DOE Office of Scientific and Technical Information (OSTI.GOV)

NONE

1998-02-01

Volume 2 contains the following topical sections: Tank farm heel flushing/pH adjustment; Grouting experiments for immobilization of tank farm heel; Savannah River high level waste tank 20 closure; Tank farm closure information; Clean closure of tank farm; Remediation issues; Remote demolition techniques; Decision concerning EIS for debris treatment facility; CERCLA/RCRA issues; Area of contamination determination; Containment building of debris treatment facility; Double containment issues; Characterization costs; Packaging and disposal options for the waste resulting from the total removal of the tank farm; Take-off calculations for the total removal of soils and structures at the tank farm; Vessel off-gas systems; Jet-groutedmore » polymer and subsurface walls; Exposure calculations for total removal of tank farm; Recommended instrumentation during retrieval operations; High level waste tank concrete encasement evaluation; Recommended heavy equipment and sizing equipment for total removal activities; Tank buoyancy constraints; Grout and concrete formulas for tank heel solidification; Tank heel pH requirements; Tank cooling water; Evaluation of conservatism of vehicle loading on vaults; Typical vault dimensions and approximately tank and vault void volumes; Radiological concerns for temporary vessel off-gas system; Flushing calculations for tank heels; Grout lift depth analysis; Decontamination solution for waste transfer piping; Grout lift determination for filling tank and vault voids; sprung structure vendor data; Grout flow properties through a 2--4 inch pipe; Tank farm load limitations; NRC low level waste grout; Project data sheet calculations; Dose rates for tank farm closure tasks; Exposure and shielding calculations for grout lines; TFF radionuclide release rates; Documentation of the clean closure of a system with listed waste discharge; and Documentation of the ORNL method of radionuclide concentrations in tanks.« less

Implementation of the Leaching Environmental Assessment Framework (LEAF) in the United States

EPA Science Inventory

LEAF provides a uniform and integrated approach for evaluating leaching from solid materials (e.g., waste, treated wastes such as by solidification/stabilization, secondary materials such as blast furnace slags, energy residuals such as coal fly ash, soil, sediments, mining and m...

Westinghouse Cementation Facility of Solid Waste Treatment System - 13503

DOE Office of Scientific and Technical Information (OSTI.GOV)

Jacobs, Torsten; Aign, Joerg

2013-07-01

During NPP operation, several waste streams are generated, caused by different technical and physical processes. Besides others, liquid waste represents one of the major types of waste. Depending on national regulation for storage and disposal of radioactive waste, solidification can be one specific requirement. To accommodate the global request for waste treatment systems Westinghouse developed several specific treatment processes for the different types of waste. In the period of 2006 to 2008 Westinghouse awarded several contracts for the design and delivery of waste treatment systems related to the latest CPR-1000 nuclear power plants. One of these contracts contains the deliverymore » of four Cementation Facilities for waste treatment, s.c. 'Follow on Cementations' dedicated to three locations, HongYanHe, NingDe and YangJiang, of new CPR-1000 nuclear power stations in the People's Republic of China. Previously, Westinghouse delivered a similar cementation facility to the CPR-1000 plant LingAo II, in Daya Bay, PR China. This plant already passed the hot functioning tests successfully in June 2012 and is now ready and released for regular operation. The 'Follow on plants' are designed to package three 'typical' kind of radioactive waste: evaporator concentrates, spent resins and filter cartridges. The purpose of this paper is to provide an overview on the Westinghouse experience to design and execution of cementation facilities. (authors)« less

Influence of commercial and residual sorbents and silicates as additives on the stabilisation/solidification of organic and inorganic industrial waste.

PubMed

Coz, A; Andrés, A; Soriano, S; Viguri, J R; Ruiz, M C; Irabien, J A

2009-05-30

An environmental problem of the foundry activities is the management of industrial waste generated in different processes. The foundry sludge from gas wet cleaning treatment that contains organic and inorganic compounds and a high content of water is an interesting example. Due to their characteristics, they can be managed using different stabilisation/solidification (S/S) technologies prior to land disposal. The purpose of this work is to study S/S formulations in order to improve the control of the mobility of the pollutants and the ecotoxicity of the samples. Different mixtures of cement or lime as binders and additives (foundry sand, silica fume, sodium silicate, silicic acid, activated carbon and black carbon) have been used in order to reduce the mobility of the chemical and ecotoxicological regulated parameters and to compare the results for commercial and residual additives. The best results have been obtained with sorbents (activated carbon and black carbon) or sodium silicate. The results of the foundry sand ash as additive can conclude that it can be used as replacement in the cement products. However, silica fume in the samples with lime and siliceous resin sand as additives gives products that do not fulfil the regulated limits. Finally, some linear expressions between the chemical parameters and the quantity of material used in the samples have been obtained.

Alkali activated solidification/stabilisation of air pollution control residues and co-fired pulverised fuel ash.

PubMed

Shirley, Robin; Black, Leon

2011-10-30

This paper examines the potential treatment by solidification/stabilisation (S/S) of air pollution control (APC) residues using only waste materials otherwise bound for disposal, namely a pulverised fuel ash (PFA) from a co-fired power station and a waste caustic solution. The use of waste materials to stabilise hazardous wastes in order to meet waste acceptance criteria (WAC) would offer an economical and efficient method for reducing the environmental impact of the hazardous waste. The potential is examined against leach limits for chlorides, sulphates and total dissolved solids, and compressive strength performance described in the WAC for stable non-reactive (SNR) hazardous waste landfill cells in England and Wales. The work demonstrates some potential for the treatment, including suitable compressive strengths to meet regulatory limits. Monolithic leach results showed good encapsulation compared to previous work using a more traditional cement binder. However, consistent with previous work, SNR WAC for chlorides was not met, suggesting the need for a washing stage. The potential problems of using a non-EN450 PFA for S/S applications were also highlighted, as well as experimental results which demonstrate the effect of ionic interactions on the mobility of phases during regulatory leach testing. Copyright © 2011 Elsevier B.V. All rights reserved.

MANAGING ARSENIC CONTAMINATED SOIL, SEDIMENT, AND INDUSTRIAL WASTE WITH SOLIDIFICATION/STABILIZATION TREATMENT

EPA Science Inventory

Arsenic contamination of soil, sediment and groundwater is a widespread problem in certain areas and has caused great public concern due to increased awareness of the health risks. Often the contamination is naturally occurring, but it can also be a result of waste generated from...

Mitigating Impacts Of Arsenic Contaminated Materials Via Two (2) Stabilization Methods Based On Polymeric And Cement Binders

EPA Science Inventory

The primary objective of this study was to evaluate the performance of two selected chemical stabilization and solidification (S/S) techniques to treat three types of arsenic-contaminated wastes 1) chromated copper arsenate (CCA) wood treater waste, 2) La Trinidad Mine tailings, ...

Multi-discipline Waste Acceptance Process at the Nevada National Security Site - 13573

DOE Office of Scientific and Technical Information (OSTI.GOV)

Carilli, Jhon T.; Krenzien, Susan K.

2013-07-01

The Nevada National Security Site low-level radioactive waste disposal facility acceptance process requires multiple disciplines to ensure the protection of workers, the public, and the environment. These disciplines, which include waste acceptance, nuclear criticality, safety, permitting, operations, and performance assessment, combine into the overall waste acceptance process to assess low-level radioactive waste streams for disposal at the Area 5 Radioactive Waste Management Site. Four waste streams recently highlighted the integration of these disciplines: the Oak Ridge Radioisotope Thermoelectric Generators and Consolidated Edison Uranium Solidification Project material, West Valley Melter, and classified waste. (authors)

Dynamic leaching behavior of geogenic As in soils after cement-based stabilization/solidification.

PubMed

Li, Jiang-Shan; Wang, Lei; Tsang, Daniel C W; Beiyuan, Jingzi; Poon, Chi Sun

2017-12-01

Cement-based stabilization/solidification (S/S) is a practical treatment approach for hazardous waste with anthropogenic As sources; however, its applicability for geogenic As-containing soil and the long-term leaching potential remain uncertain. In this study, semi-dynamic leaching test was performed to investigate the influence of S/S binders (cement blended with fuel ash (FA), furnace bottom ash (FBA), or ground granulated blast furnace slag (GGBS)) on the long-term leaching characteristics of geogenic As. The results showed that mineral admixtures with higher Ca content and pozzolanic activity were more effective in reducing the leached As concentrations. Thus, cement blended with FBA was inferior to other binders in suppressing the As leaching, while 20% replacement of ordinary Portland cement by GGBS was considered most feasible for the S/S treatment of As-containing soils. The leachability of geogenic As was suppressed by the encapsulation effect of solidified matrix and interlocking network of hydration products that were supported by scanning electron microscopy (SEM), X-ray diffraction (XRD), and X-ray photoelectron spectroscopy (XPS) results. The long-term leaching of geogenic As from the monolithic samples was diffusion-controlled. Increasing the Ca content in the samples led to a decrease in diffusion coefficient and an increase in feasibility for "controlled utilization" of the S/S-treated soils.

Measurements of Mercury Released from Solidified/Stabilized Waste Forms

DOE Office of Scientific and Technical Information (OSTI.GOV)

Mattus, C.H.

2001-04-19

This report covers work performed during FY 1999-2000 in support of treatment demonstrations conducted for the Mercury Working Group of the U.S. Department of Energy (DOE) Mixed Waste Focus Area. In order to comply with the requirements of the Resource Conservation and Recovery Act, as implemented by the U.S. Environmental Protection Agency (EPA), DOE must use one of these procedures for wastes containing mercury at levels above 260 ppm: a retorting/roasting treatment or an incineration treatment (if the wastes also contain organics). The recovered radioactively contaminated mercury must then be treated by an amalgamation process prior to disposal. The DOEmore » Mixed Waste Focus Area and Mercury Working Group are working with the EPA to determine if some alternative processes could treat these types of waste directly, thereby avoiding for DOE the costly recovery step. They sponsored a demonstration in which commercial vendors applied their technologies for the treatment of two contaminated waste soils from Brookhaven National Laboratory. Each soil was contaminated with {approx}4500 ppm mercury; however, one soil had as a major radioelement americium-241, while the other contained mostly europium-152. The project described in this report addressed the need for data on the mercury vapor released by the solidified/stabilized mixed low-level mercury wastes generated during these demonstrations as well as the comparison between the untreated and treated soils. A related work began in FY 1998, with the measurement of the mercury released by amalgamated mercury, and the results were reported in ORNL/TM-13728. Four treatments were performed on these soils. The baseline was obtained by thermal treatment performed by SepraDyne Corp., and three forms of solidification/stabilization were employed: one using sulfur polymer cement (Brookhaven National Laboratory), one using portland cement [Allied Technology Group (ATG)], and a third using proprietary additives (Nuclear Fuel Services).« less

A study on polypropylene encapsulation and solidification of textile sludge.

PubMed

Kumari, V Krishna; Kanmani, S

2011-10-01

The textile sludge is an inevitable solid waste from the textile wastewater process and is categorised under toxic substances by statutory authorities. In this study, an attempt has been made to encapsulate and solidify heavy metals and dyes present in textile sludge using polypropylene and Portland cement. Sludge samples (2 Nos.) were characterized for pH (8.5, 9.5), moisture content (1.5%, 1.96%) and chlorides (245mg/L, 425.4mg/L). Sludge samples were encapsulated into polypropylene with calcium carbonate (additive) and solidified with cement at four different proportions (20, 30, 40, 50%) of sludge. Encapsulated and solidified cubes were made and then tested for compressive strength. Maximum compressive strength of cubes (size, 7.06cm) containing sludge (50%) for encapsulation (16.72 N/mm2) and solidification (18.84 N/mm2) was more than that of standard M15 mortar cubes. The leachability of copper, nickel and chromium has been effectively reduced from 0.58 mg/L, 0.53 mg/L and 0.07 mg/L to 0.28mg/L, 0.26mg/L and BDL respectively in encapsulated products and to 0.24mg/L, BDL and BDL respectively in solidified products. This study has shown that the solidification process is slightly more effective than encapsulation process. Both the products were recommended for use in the construction of non-load bearing walls.

Comparison of solidification/stabilization effects of calcite between Australian and South Korean cements

DOE Office of Scientific and Technical Information (OSTI.GOV)

Lee, Dongjin; Waite, T. David; Swarbrick, Gareth

2005-11-15

The differences in the effect of calcite on the strength and stability of Pb-rich wastes solidified and stabilized using Australian and South Korean ordinary Portland cements are examined in this study. Pb-rich waste stabilized using Australian OPC has been shown to possess both substantially higher unconfined compressive strength and lead immobilization ability than South Korean OPC as a result of its higher C{sub 3}S content and the associated enhanced degree of precipitation of lead on the surfaces of silicate phases present. Calcite addition is observed to have an accelerating effect on the OPC-induced solidification/stabilization of Pb-rich wastes as gauged bymore » the unconfined compressive strength and leachability of the solids formed. This effect is observed to be far more dramatic for South Korean OPC than for Australian OPC. Using scanning electron microscopy, waste stabilized with cement and calcite was observed to develop significantly greater proportions of hydrated crystals than wastes stabilized with cement alone. The results of X-ray diffraction studies have shown that the presence of calcite in South Korean OPC results in greater acceleration in the formation of portlandite than is the case for Australian OPC.« less

SOLIDIFICATION/STABILIZATION CASE STUDIES AT USEPA SUPERFUND SITES

EPA Science Inventory

Oral presentation dicumenting several completed Superfund remediations using solidification/stabilization, both in situ and ex-situ, to treat soils containing metals and organics.
65 slide presentation.

Data Package for Secondary Waste Form Down-Selection—Cast Stone

DOE Office of Scientific and Technical Information (OSTI.GOV)

Serne, R. Jeffrey; Westsik, Joseph H.

2011-09-05

Available literature on Cast Stone and Saltstone was reviewed with an emphasis on determining how Cast Stone and related grout waste forms performed in relationship to various criteria that will be used to decide whether a specific type of waste form meets acceptance criteria for disposal in the Integrated Disposal Facility (IDF) at Hanford. After the critical review of the Cast Stone/Saltstone literature, we conclude that Cast Stone is a good candidate waste form for further consideration. Cast stone meets the target IDF acceptance criteria for compressive strength, no free liquids, TCLP leachate are below the UTS permissible concentrations andmore » leach rates for Na and Tc-99 are suiteably low. The cost of starting ingredients and equipment necessary to generate Cast Stone waste forms with secondary waste streams are low and the Cast Stone dry blend formulation can be tailored to accommodate variations in liquid waste stream compositions. The database for Cast Stone short-term performance is quite extensive compared to the other three candidate waste solidification processes. The solidification of liquid wastes in Cast Stone is a mature process in comparison to the other three candidates. Successful production of Cast Stone or Saltstone has been demonstrated from lab-scale monoliths with volumes of cm3 through m3 sized blocks to 210-liter sized drums all the way to the large pours into vaults at Savannah River. To date over 9 million gallons of low activity liquid waste has been solidified and disposed in concrete vaults at Savannah River.« less

Solidification characteristics and segregation behavior of a P-containing Ni-Fe-Cr-based alloy

NASA Astrophysics Data System (ADS)

Wang, Changshuai; Su, Haijun; Guo, YongAn; Guo, Jianting; Zhou, Lanzhang

2017-09-01

Solidification characteristics and segregation behavior of a P-containing Ni-Fe-Cr-based alloy, considered as boiler and turbine materials in 700 °C advanced ultra-supercritical coal-fired power plants, have been investigated by differential thermal analysis and directional solidification quenching technique. Results reveal that P decreases the solidus temperature, but only has negligible influence on liquidus temperature. After P was added, the solidification sequence has no apparent change, but the width of the mushy zone increases and dendritic structures become coarser. Moreover, P increases the amount and changes the morphology of MC carbide. Energy-dispersive spectroscopy analysis reveals that P has obvious influence on the segregation behavior of the constitute elements with equilibrium partition coefficients (ki) far away from unity, whereas has negligible effect on the constituent elements with ki close to unity and has more influence on the final stage of solidification than at early stage. The distribution profiles reveal that P atoms pile up ahead of the solid/liquid (S/L) interface and strongly segregate to the interdendritic liquid region. The influence of P on solidification characteristics and segregation behavior of Ni-Fe-Cr-based alloy could be attributed to the accumulation of P ahead of the S/L interface during solidification.

Mercury stabilization in chemically bonded phosphate ceramics

DOE Office of Scientific and Technical Information (OSTI.GOV)

Wagh, A. S.; Singh, D.; Jeong, S. Y.

2000-04-04

Mercury stabilization and solidification is a significant challenge for conventional stabilization technologies. This is because of the stringent regulatory limits on leaching of its stabilized products. In a conventional cement stabilization process, Hg is converted at high pH to its hydroxide, which is not a very insoluble compound; hence the preferred route for Hg sulfidation to convert it into insoluble cinnabar (HgS). Unfortunately, efficient formation of this compound is pH-dependent. At a high pH, one obtains a more soluble Hg sulfate, in a very low pH range, insufficient immobilization occurs because of the escape of hydrogen sulfide, while efficient formationmore » of HgS occurs only in a moderately acidic region. Thus, the pH range of 4 to 8 is where stabilization with Chemically Bonded Phosphate Ceramics (CBPC) is carried out. This paper discusses the authors experience on bench-scale stabilization of various US Department of Energy (DOE) waste streams containing Hg in the CBPC process. This process was developed to treat DOE's mixed waste streams. It is a room-temperature-setting process based on an acid-base reaction between magnesium oxide and monopotassium phosphate solution that forms a dense ceramic within hours. For Hg stabilization, addition of a small amount (< 1 wt.%) of Na{sub 2}S or K{sub 2}S is sufficient in the binder composition. Here the Toxicity Characteristic Leaching Procedure (TCLP) results on CBPC waste forms of surrogate waste streams representing secondary Hg containing wastes such as combustion residues and Delphi DETOX{trademark} residues are presented. The results show that although the current limit on leaching of Hg is 0.2 mg/L, the results from the CBPC waste forms are at least one order lower than this stringent limit. Encouraged by these results on surrogate wastes, they treated actual low-level Hg-containing mixed waste from their facility at Idaho. TCLP results on this waste are presented here. The efficient stabilization in all these cases is attributed to chemical immobilization as both a sulfide (cinnabar) and a phosphate, followed by its physical encapsulation in a dense matrix of the ceramic.« less

Stable solidification of silica-based ammonium molybdophosphate by allophane: Application to treatment of radioactive cesium in secondary solid wastes generated from fukushima.

PubMed

Wu, Yan; Lee, Chuan-Pin; Mimura, Hitoshi; Zhang, Xiaoxia; Wei, Yuezhou

2018-01-05

Silica-based ammonium molybdophosphate (AMP/SiO 2 ) is an absorbent material that can effectively remove Cs from radioactive-contaminated wastewater (RCW) generated by Fukushima nuclide accident. Pressing/sintering method was used for final disposal of secondary waste (spent absorbent) to achieve the volume reduction of AMP-Cs/SiO 2 (AMP/SiO 2 saturation adsorption of Cs) and stable solidification of Cs by adding natural allophane. The structure of AMP-Cs completely collapsed at approximately 700°C, and most Mo and P species in AMP sublimed. The optimal sintering temperature was estimated as 900°C. The stable crystalline phase of Cs 4 Al 4 Si 20 O 48 was recrystallized by the reaction of Cs 2 O, Al 2 O 3 , and SiO 2 , and the immobilization ratio of Cs was approximately 100%. The leachability of Cs from the sintered product in distilled water was approximately 0.41%. The high immobilization and low leachability of Cs were attributed to the excellent solidification properties of the sintered products of AMP-Cs/SiO 2 -allophane. Copyright © 2017 Elsevier B.V. All rights reserved.

Secondary Waste Form Development and Optimization—Cast Stone

DOE Office of Scientific and Technical Information (OSTI.GOV)

Sundaram, S. K.; Parker, Kent E.; Valenta, Michelle M.

2011-07-14

Washington River Protection Services is considering the design and construction of a Solidification Treatment Unit (STU) for the Effluent Treatment Facility (ETF) at Hanford. The ETF is a Resource Conservation and Recovery Act-permitted, multi-waste, treatment and storage unit and can accept dangerous, low-level, and mixed wastewaters for treatment. The STU needs to be operational by 2018 to receive secondary liquid wastes generated during operation of the Hanford Tank Waste Treatment and Immobilization Plant (WTP). The STU to ETF will provide the additional capacity needed for ETF to process the increased volume of secondary wastes expected to be produced by WTP.

Decide, design, and dewater de waste: A blueprint from Fitzpatrick

DOE Office of Scientific and Technical Information (OSTI.GOV)

Robert, D.E.

1994-04-01

Using a different process to clean concentrated waste tanks at the James A. FitzPatrick nuclear power plant in New York saved nearly half million dollars. The plan essentially allowed processing concentrator bottoms as waste sludge (solidification versus dewatering) that could still meet burial ground requirements. The process reduced the volume from 802.2 to 55 cubic feet. This resin throwaway system eliminated chemicals in the radwaste systems and was designed to ease pressure on the pradwaste processing system, reduce waste and improve plant chemistry. This article discusses general aspects of the process.

75 FR 20582 - Record of Decision: Final Environmental Impact Statement for Decommissioning and/or Long-Term...

Federal Register 2010, 2011, 2012, 2013, 2014

2010-04-20

... storage tanks and facilities used in the solidification of high-level radioactive waste, and any material... Act (Pub. L. 96-368, 42 U.S.C. 2021a). The WVDP Act requires DOE to demonstrate that the liquid high... take the following actions: 1. Solidify high-level radioactive waste by vitrification or such other...

Melting and solidification characteristics of a mixture of two types of latent heat storage material in a vessel

NASA Astrophysics Data System (ADS)

Yu, JikSu; Horibe, Akihiko; Haruki, Naoto; Machida, Akito; Kato, Masashi

2016-11-01

In this study, we investigated the fundamental melting and solidification characteristics of mannitol, erythritol, and their mixture (70 % by mass mannitol: 30 % by mass erythritol) as potential phase-change materials (PCMs) for latent heat thermal energy storage systems, specifically those pertaining to industrial waste heat, having temperatures in the range of 100-250 °C. The melting point of erythritol and mannitol, the melting peak temperature of their mixture, and latent heat were measured using differential scanning calorimetry. The thermal performance of the mannitol mixture was determined during melting and solidification processes, using a heat storage vessel with a pipe heat exchanger. Our results indicated phase-change (fusion) temperatures of 160 °C for mannitol and 113 and 150 °C for the mannitol mixture. Nondimensional correlation equations of the average heat transfer during the solidification process, as well as the temperature and velocity efficiencies of flowing silicon oil in the pipe and the phase-change material (PCM), were derived using several nondimensional parameters.

Supplemental Immobilization of Hanford Low-Activity Waste: Cast Stone Screening Tests

DOE Office of Scientific and Technical Information (OSTI.GOV)

Westsik, Joseph H.; Piepel, Gregory F.; Lindberg, Michael J.

2013-09-30

More than 56 million gallons of radioactive and hazardous waste are stored in 177 underground storage tanks at the U.S. Department of Energy’s (DOE’s) Hanford Site in southeastern Washington State. The Hanford Tank Waste Treatment and Immobilization Plant (WTP) is being constructed to treat the wastes and immobilize them in a glass waste form. The WTP includes a pretreatment facility to separate the wastes into a small volume of high-level waste (HLW) containing most of the radioactivity and a larger volume of low-activity waste (LAW) containing most of the nonradioactive chemicals. The HLW will be converted to glass in themore » HLW vitrification facility for ultimate disposal at an offsite federal repository. At least a portion (~35%) of the LAW will be converted to glass in the LAW vitrification facility and will be disposed of onsite at the Integrated Disposal Facility (IDF). The pretreatment and HLW vitrification facilities will have the capacity to treat and immobilize the wastes destined for each facility. However, a second LAW immobilization facility will be needed for the expected volume of LAW requiring immobilization. A cementitious waste form known as Cast Stone is being considered to provide the required additional LAW immobilization capacity. The Cast Stone waste form must be acceptable for disposal in the IDF. The Cast Stone waste form and immobilization process must be tested to demonstrate that the final Cast Stone waste form can comply with the waste acceptance criteria for the disposal facility and that the immobilization processes can be controlled to consistently provide an acceptable waste form product. Further, the waste form must be tested to provide the technical basis for understanding the long-term performance of the waste form in the disposal environment. These waste form performance data are needed to support risk assessment and performance assessment (PA) analyses of the long-term environmental impact of the waste disposal in the IDF. The PA is needed to satisfy both Washington State IDF Permit and DOE Order requirements. Cast Stone has been selected for solidification of radioactive wastes including WTP aqueous secondary wastes treated at the Effluent Treatment Facility (ETF) at Hanford. A similar waste form called Saltstone is used at the Savannah River Site (SRS) to solidify its LAW tank wastes.« less

Optimisation of industrial wastes reuse as construction materials.

PubMed

Collivignarelli, C; Sorlini, S

2001-12-01

This study concerns the reuse of two inorganic wastes, foundry residues and fly ashes from municipal solid waste incineration, as "recycled aggregate" in concrete production. This kind of reuse was optimised by waste treatment with the following steps: waste washing with water; waste stabilisation-solidification treatment with inorganic reagents; final grinding of the stabilised waste after curing for about 10-20 days. Both the treated wastes were reused in concrete production with different mix-designs. Concrete specimens were characterised by means of conventional physical-mechanical tests (compression, elasticity modulus, shrinkage) and different leaching tests. Experimental results showed that a good structural and environmental quality of "recycled concrete" is due both to a correct waste treatment and to a correct mix-design for concrete mixture.

Innovative Solidification Techniques for Hazardous Wastes at Army Installations.

DTIC Science & Technology

1985-11-01

Fixed Hazardous Industrial Wastes and Flue Gas Desulfurization Sludges," Interim Report, EPA-600/2-76-182, US Environmental Protection Agency... flue gas . Flyash from coal-fired power plants is an almost entirely inorganic product having a glassy nature. Consequently, flyash by itself has little...effective- ness of alternative control strategies for reducing environmental impacts. 4. % 46 -"- °° ~~~~~...-.-..o

A comparative study on the heavy metal solidification/stabilization performance of four chemical solidifying agents in municipal solid waste incineration fly ash.

PubMed

Wang, Feng-He; Zhang, Fan; Chen, Ya-Jun; Gao, Jay; Zhao, Bin

2015-12-30

Investigated in this paper were the content, specification distribution, and risk assessment code (RAC) determination of six targeted heavy metals and potentially toxic metals in fly ashes from a municipal solid waste incinerator in China. Contained in it is a comparison of the solidification/stabilization performance of two novel solidifying agents of sixthio guanidine acid (SGA) and tetrathio bicarbamic acid (TBA) with sodium dimethyldithiocarbamate (SDD) and Na2S, and analysis of their leachability in accordance with TCLP 1311 of the US EPA and the extraction procedures of China (HJ/T 299-2007 and HJ/T300-2007). The total concentration of Zn, Cu, Ni, Pb, Cr, Cd is 37383.47, 3080.77, 1583.92, 1356.43, 566.15, and 77.83 mg/kg, respectively. Cr (3.7%) and Pb (7.50%) pose low risk; and Ni (12.93%) and Zn (15.45%) have a medium risk; while Cu (69.84%) and Cd (82.5%) have a very high risk according to their RAC score. Compared with SDD and Na2S, SGA and TBA show an excellent overall solidifying performance due to their multiply hydrosulfide groups that bind with heavy metals very efficiently. The obtained results indicate that the leaching content of Cd, Ni, Pb and Zn is higher than the thresholds prescribed in GB5085.3-2007, and the excessive acetic acid makes its binding capacity stronger in HJ/T 300-2007 than in TCLP 1311. Copyright © 2015 Elsevier B.V. All rights reserved.

Welding Behavior of Free Machining Stainless Steel

DOE Office of Scientific and Technical Information (OSTI.GOV)

BROOKS,JOHN A.; ROBINO,CHARLES V.; HEADLEY,THOMAS J.

2000-07-24

The weld solidification and cracking behavior of sulfur bearing free machining austenitic stainless steel was investigated for both gas-tungsten arc (GTA) and pulsed laser beam weld processes. The GTA weld solidification was consistent with those predicted with existing solidification diagrams and the cracking response was controlled primarily by solidification mode. The solidification behavior of the pulsed laser welds was complex, and often contained regions of primary ferrite and primary austenite solidification, although in all cases the welds were found to be completely austenite at room temperature. Electron backscattered diffraction (EBSD) pattern analysis indicated that the nature of the base metalmore » at the time of solidification plays a primary role in initial solidification. The solid state transformation of austenite to ferrite at the fusion zone boundary, and ferrite to austenite on cooling may both be massive in nature. A range of alloy compositions that exhibited good resistance to solidification cracking and was compatible with both welding processes was identified. The compositional range is bounded by laser weldability at lower Cr{sub eq}/Ni{sub eq} ratios and by the GTA weldability at higher ratios. It was found with both processes that the limiting ratios were somewhat dependent upon sulfur content.« less

Nanoparticle-induced unusual melting and solidification behaviours of metals

PubMed Central

Ma, Chao; Chen, Lianyi; Cao, Chezheng; Li, Xiaochun

2017-01-01

Effective control of melting and solidification behaviours of materials is significant for numerous applications. It has been a long-standing challenge to increase the melted zone (MZ) depth while shrinking the heat-affected zone (HAZ) size during local melting and solidification of materials. In this paper, nanoparticle-induced unusual melting and solidification behaviours of metals are reported that effectively solve this long-time dilemma. By introduction of Al2O3 nanoparticles, the MZ depth of Ni is increased by 68%, while the corresponding HAZ size is decreased by 67% in laser melting at a pulse energy of 0.18 mJ. The addition of SiC nanoparticles shows similar results. The discovery of the unusual melting and solidification of materials that contain nanoparticles will not only have impacts on existing melting and solidification manufacturing processes, such as laser welding and additive manufacturing, but also on other applications such as pharmaceutical processing and energy storage. PMID:28098147

Cytogenotoxicity of sewage sludge leachate before and after calcium oxide-based solidification in human lymphocytes.

PubMed

Gajski, Goran; Oreščanin, Višnja; Garaj-Vrhovac, Vera

2011-07-01

Present study aimed to establish the chemical composition of sewage sludge leachate before/after calcium oxide-based solidification using energy dispersive X-ray fluorescence (EDXRF). The other aim was to determine leachate effects on human lymphocyte and DNA integrity in vitro using a battery of bioassays (DNA diffusion assay, micronucleus test and comet assay) to determine effects of those complex mixtures of elements on cell and DNA integrity. EDXRF showed that nickel concentration in the leachate of untreated sludge was 18.5 times higher than the upper permissible limit for inert waste landfills. Other elements were kept below the permissible values. After sludge solidification, leachate concentrations of Cr, Mn, Fe, Ni, Cu, Zn, and Pb dropped 1.6, 2.7, 37, 5.9, 3.2, 7.8, and 2.6 times, respectively. Untreated sludge leachate was cytogenotoxic to lymphocytes, and may lead to adverse effects on the exposed human populations, but calcium oxide-based solidification reduced these effects in significant manner. Copyright © 2011 Elsevier Inc. All rights reserved.

Liquid secondary waste. Waste form formulation and qualification

DOE Office of Scientific and Technical Information (OSTI.GOV)

Cozzi, A. D.; Dixon, K. L.; Hill, K. A.

The Hanford Site Effluent Treatment Facility (ETF) currently treats aqueous waste streams generated during Site cleanup activities. When the Hanford Tank Waste Treatment and Immobilization Plant (WTP) begins operations, a liquid secondary waste (LSW) stream from the WTP will need to be treated. The volume of effluent for treatment at the ETF will increase significantly. Washington River Protection Solutions is implementing a Secondary Liquid Waste Immobilization Technology Development Plan to address the technology needs for a waste form and solidification process to treat the increased volume of waste planned for disposal at the Integrated Disposal Facility IDF). Waste form testingmore » to support this plan is composed of work in the near term to demonstrate the waste form will provide data as input to a performance assessment (PA) for Hanford’s IDF.« less

Solidification Technologies for Restoration of Sites Contaminated with Hazardous Wastes

DTIC Science & Technology

1998-01-01

OR1 -5- 10-0 1 to DOE, Office of Technology Development. Kalb, P., J. Heiser, and P. Colombo, 1991. “ Modified Sulfur Cement Encapsulation of Mixed...Incinerator Ash Waste Encapsulated in Modified Sulfur Cement,” Brookhaven National Laboratory for US DOE Contract No DE-AC02-76CD000 16. Lin, S...wastes, 2 modified sulfur cement, 22,72 47,49,5 I , 53,55,57,59,61,63,65 obsidian, 35,36,38,39,40,32,43 organic binders, 7,25 organic polymer binders

Microgravity

NASA Image and Video Library

1992-03-12

The Advanced Automated Directional Solidification Furnace (AADSF) with the Experimental Apparatus Container (EAC) removed flew during the USMP-2 mission. During USMP-2, the AADSF was used to study the growth of mercury cadmium telluride crystals in microgravity by directional solidification, a process commonly used on earth to process metals and grow crystals. The furnace is tubular and has three independently controlled temperature zones . The sample travels from the hot zone of the furnace (1600 degrees F) where the material solidifies as it cools. The solidification region, known as the solid/liquid interface, moves from one end of the sample to the other at a controlled rate, thus the term directional solidification.

Solidification and Microstructure of Ni-Containing Al-Si-Cu Alloy

NASA Astrophysics Data System (ADS)

Fang, Li; Ren, Luyang; Geng, Xinyu; Hu, Henry; Nie, Xueyuan; Tjong, Jimi

2018-01-01

2 wt. % nickel (Ni) addition was introduced into a conventional cast aluminum alloy A380. The influence of transition alloying element nickel on the solidification behavior of cast aluminum alloy A380 was investigated via thermal analyses based on temperature measurements recorded on cooling curves. The corresponding first and second derivatives of the cooling curves were derived to reveal the details of phase changes during solidification. The nucleation of the primary α-Al phase and eutectic phases were analyzed. The microstructure analyses by scanning electron microscopy (SEM) with energy dispersive X-ray spectroscopy (EDS) indicate that different types and amount of eutectic phases are present in the tested two alloys. The introduction of Ni forms the complex Ni-containing intermetallic phases with Cu and Al.

The bulk composition and leaching properties of electroplating sludge prior/following the solidification/stabilization by calcium oxide.

PubMed

Orescanin, Visnja; Mikulic, Nenad; Mikelic, Ivanka Lovrencic; Posedi, Mario; Kampic, Stefica; Medunic, Gordana

2009-10-01

Eighteen samples of electroplating sludge were taken from three vertical profiles of waste storage pond of the zinc plating facility. Dry matter and organic matter content, pH value, bulk concentrations and leachate composition were determined. A sludge sample with the highest zinc value in the leachate was treated with calcium oxide (10% to 70%) and the obtained solidificate was repeatedly tested. There were found significant variations of all measured parameters among the profiles of untreated waste. Dry matter content varied from 125 to 455 mgg(-1), organic matter varied from 94.3 to 293.9 mgg(-1), and pH value varied from 3.42 to 5.90 (mean 4.34). Iron content ranged from 38.4 to 191.4 mgg(-1) (mean 136 mgg(-1); RSD 0.25), while zinc ranged from 10.9 to 58.2 mgg(-1) (mean 33.4 mgg(-1); RSD 0.38). According to its DIN38414-S4 leachate composition, this material was not suitable for landfilling of inert waste since zinc and nickel mean values were 10 and 1.5 times higher, respectively, and maximum values 27 and 2.5 times higher, respectively, compared to the upper permissible limit. Maximum values of Cr(VI), Fe, Ni, Cu, and Zn in the DIN38414-S4 leachate were 0.183 mgL(-1), 34.085 mgL(-1), 1.052 mgL(-1), 0.829 mgL(-1) and 107.475 mgL(-1)L, respectively. Following the solidification/stabilization procedure with CaO (sample/CaO = 90/10), concentrations of Cr(VI), Fe, Cu and Zn were reduced 92, 44, 66 and 57 times, respectively, compared to the untreated sample. The addition of 50% of CaO into the sludge reduced zinc and nickel concentrations 79 and 45 times, respectively, in the DIN38414-S4 leachate of the solidified waste compared to the original sludge, thereby converting an hazardous waste into the inert material suitable for landfilling or reuse in the construction processes.

SOLIDIFICATION/STABILIZATION OF SLUDGE AND ASH FROM WASTEWATER TREATMENT PLANTS

EPA Science Inventory

Tests were performed to determine the physical properties and chemical leaching characteristics of the residuals and the stabilized/solidified products from two publicly-owned wastewater treatment works (POTW). The two POTW waste products included in this study were an anaerobic ...

ONSITE ENGINEERING REPORT FOR SOLIDIFICATION/ STABILIZATION TREATMENT TESTING OF CONTAMINATED SOILS

EPA Science Inventory

The EPA's Office of Solid Waste and Emergency Response (OSWER) is currently developing land disposal restrictions (LDRs) for contaminated soil and debris (CS&D). The Office of Research and Development, through its Risk Reduction Engineering Laboratory (RREL), is providing support...

Technology Demonstration Summary Technology Evaluation Report, Site Demonstration Test, Hazcon Solidification, Douglassville, Pennsylvania

EPA Science Inventory

The major objective of the HAZCON Solidification SITE Program Demonstration Test was to develop reliable performance and cost information. The demonstration occurred at a 50-acre site of a former oil reprocessing plant at Douglassville, PA containing a wide range of organic...

Characterizations of mortar-degraded spinney waste composite nominated as solidifying agent for radwastes due to immersion processes

NASA Astrophysics Data System (ADS)

Saleh, H. M.; Eskander, S. B.

2012-11-01

Immobilization process of radioactive wastes is a compromise between economic and reliability factors. It involves the use of inert and cheap matrices to fix the wastes in homogenous monolithic solid forms. The characteristics of the resulting waste form were studied in various disposal options before coming to the final conclusion concerning the solidification process. A proposed mortar composite is formed from a mixture of Portland cement and sand in the weight ratio of 0.33 which by slurry of degraded spinney waste fibers at the ratio of 0.7 relative to the Portland cement. The composite was prepared at the laboratory ambient conditions (25 ± 5 °C). The temperature changes accompanying the hydration process were followed up to 96 h. At the end of 28 days, curing period, the performance of the obtained composite was evaluated under immersion circumstances imitating a flooding scenario that could happen at a disposal site. Compressive strength, porosity and mass changes were investigated under complete static immersion conditions in three different leachants, namely acetic acid, groundwater and seawater for 48 weeks. X-ray and scanning electron microscopy were used to follow and evaluate the changes that may occur for the proposed composite under flooding conditions. Based on the experimental data reached, it could be concluded that the prepared mortar composite can be nominated as a matrix for solidification/stabilization of some radwaste categories, even under the aggressive attacks of various immersion media.

The effect of solidification rate on the formability of nickel aluminide containing iron and boron

NASA Technical Reports Server (NTRS)

Carro, G.; Flanagan, W. F.

1987-01-01

Following reports that rapid solidification improves the ductility of some nickel aluminides, an investigation has been conducted of the possibility of additional improvement in a nickel aluminide containing both Fe and B. Free fall-solidified and free fall/splat-quenched samples similar to those producible under microgravity conditions in space were prepared, and their microstructure was characterized. Attention is given to the preliminary results of tests quantitatively measuring mechanical properties.

Analysis of the factors that impact the reliability of high level waste canister materials

DOE Office of Scientific and Technical Information (OSTI.GOV)

Boyd, W.K.; Hall, A.M.

1977-09-19

The analysis encompassed identification and analysis of potential threats to canister integrity arising in the course of waste solidification, interim storage at the fuels reprocessing plant, wet and dry shipment, and geologic storage. Fabrication techniques and quality assurance requirements necessary to insure optimum canister reliability were considered taking into account such factors as welding procedure, surface preparation, stress relief, remote weld closure, and inspection methods. Alternative canister materials and canister systems were also considered in terms of optimum reliability in the face of threats to the canister's integrity, ease of fabrication, inspection, handling and cost. If interim storage in airmore » is admissible, the sequence suggested comprises producing a glass-type waste product in a continuous ceramic melter, pouring into a carbon steel or low-alloy steel canister of moderately heavy wall thickness, storing in air upright on a pad and surrounded by a concrete radiation shield, and thereafter placing in geologic storage without overpacking. Should the decision be to store in water during the interim period, then use of either a 304 L stainless steel canister overpacked with a solution-annealed and fast-cooled 304 L container, or a single high-alloy canister, is suggested. The high alloy may be Inconel 600, Incoloy Alloy 800, or Incoloy Alloy 825. In either case, it is suggested that the container be overpacked with a moderately heavy wall carbon steel or low-alloy steel cask for geologic storage to ensure ready retrievability. 19 figs., 5 tables.« less

Recovery of soluble chloride salts from the wastewater generated during the washing process of municipal solid wastes incineration fly ash.

PubMed

Tang, Hailong; Erzat, Aris; Liu, Yangsheng

2014-01-01

Water washing is widely used as the pretreatment method to treat municipal solid waste incineration fly ash, which facilitates the further solidification/stabilization treatment or resource recovery of the fly ash. The wastewater generated during the washing process is a kind of hydrosaline solution, usually containing high concentrations of alkali chlorides and sulphates, which cause serious pollution to environment. However, these salts can be recycled as resources instead of discharge. This paper explored an effective and practical recovery method to separate sodium chloride, potassium chloride, and calcium chloride salts individually from the hydrosaline water. In laboratory experiments, a simulating hydrosaline solution was prepared according to composition of the waste washing water. First, in the three-step evaporation-crystallization process, pure sodium chloride and solid mixture of sodium and potassium chlorides were obtained separately, and the remaining solution contained potassium and calcium chlorides (solution A). And then, the solid mixture was fully dissolved into water (solution B obtained). Finally, ethanol was added into solutions A and B to change the solubility of sodium, potassium, and calcium chlorides within the mixed solvent of water and ethanol. During the ethanol-adding precipitation process, each salt was separated individually, and the purity of the raw production in laboratory experiments reached about 90%. The ethanol can be recycled by distillation and reused as the solvent. Therefore, this technology may bring both environmental and economic benefits.

Displacement-dispersive liquid-liquid microextraction based on solidification of floating organic drop of trace amounts of palladium in water and road dust samples prior to graphite furnace atomic absorption spectrometry determination.

PubMed

Ghanbarian, Maryam; Afzali, Daryoush; Mostafavi, Ali; Fathirad, Fariba

2013-01-01

A new displacement-dispersive liquid-liquid microextraction method based on the solidification of floating organic drop was developed for separation and preconcentration of Pd(ll) in road dust and aqueous samples. This method involves two steps of dispersive liquid-liquid microextraction based on solidification. In Step 1, Cu ions react with diethyldithiocarbamate (DDTC) to form Cu-DDTC complex, which is extracted by dispersive liquid-liquid microextraction based on a solidification procedure using 1-undecanol (extraction solvent) and ethanol (dispersive solvent). In Step 2, the extracted complex is first dispersed using ethanol in a sample solution containing Pd ions, then a dispersive liquid-liquid microextraction based on a solidification procedure is performed creating an organic drop. In this step, Pd(ll) replaces Cu(ll) from the pre-extracted Cu-DDTC complex and goes into the extraction solvent phase. Finally, the Pd(ll)-containing drop is introduced into a graphite furnace using a microsyringe, and Pd(ll) is determined using atomic absorption spectrometry. Several factors that influence the extraction efficiency of Pd and its subsequent determination, such as extraction and dispersive solvent type and volume, pH of sample solution, centrifugation time, and concentration of DDTC, are optimized.

Radionuclide Migration through Sediment and Concrete: 16 Years of Investigations

DOE Office of Scientific and Technical Information (OSTI.GOV)

Golovich, Elizabeth C.; Mattigod, Shas V.; Snyder, Michelle MV

The Waste Management Project provides safe, compliant, and cost-effective waste management services for the Hanford Site and the U.S. Department of Energy (DOE) complex. Part of these services includes safe disposal of low-level waste and mixed low-level waste at the Hanford Low-Level Waste Burial Grounds in accordance with the requirements of DOE Order 435.1, Radioactive Waste Management. To partially satisfy these requirements, performance assessment analyses were completed and approved. DOE Order 435.1 also requires continuing data collection to increase confidence in the critical assumptions used in these analyses to characterize the operational features of the disposal facility that are reliedmore » on to satisfy the performance objectives identified in the order. Cement-based solidification and stabilization is considered for hazardous waste disposal because it is easily done and cost-efficient. One critical assumption is that concrete will be used as a waste form or container material at the Hanford Site to control and minimize the release of radionuclide constituents in waste into the surrounding environment. Concrete encasement would contain and isolate the waste packages from the hydrologic environment and act as an intrusion barrier. Any failure of concrete encasement may result in water intrusion and consequent mobilization of radionuclides from the waste packages. The radionuclides iodine-129, selenium-75, technetium-99, and uranium-238 have been identified as long-term dose contributors (Mann et al. 2001; Wood et al. 1995). Because of their anionic nature in aqueous solutions, these constituents of potential concern may be released from the encased concrete by mass flow and/or diffusion and migrate into the surrounding subsurface environment (Serne et al. 1989; 1992; 1993a, b; 1995). Therefore, it is necessary to assess the performance of the concrete encasement structure and the ability of the surrounding soil to retard radionuclide migration. Each of the test methods performed throughout the lifetime of the project has focused on different aspects of the concrete waste form weathering process. Diffusion of different analytes [technetium-99 (Tc-99), iodine-125 (I-125), stable iodine (I), uranium (U), and rhenium (Re)] has been quantified from experiments under both saturated and unsaturated conditions. The water-saturated conditions provide a conservative estimate of the concrete’s performance in situ, and the unsaturated conditions provide a more accurate estimate of the diffusion of contaminants from the concrete.« less

U.S. Department of Energy's initiatives for proliferation prevention program: solidification technologies for radioactive waste treatment in Russia

DOE Office of Scientific and Technical Information (OSTI.GOV)

Pokhitonov, Y.; Kelley, D.

Large amounts of liquid radioactive waste have existed in the U.S. and Russia since the 1950's as a result of the Cold War. Comprehensive action to treat and dispose of waste products has been lacking due to insufficient funding, ineffective technologies or no proven technologies, low priority by governments among others. Today the U.S. and Russian governments seek new, more reliable methods to treat liquid waste, in particular the legacy waste streams. A primary objective of waste generators and regulators is to find economical and proven technologies that can provide long-term stability for repository storage. In 2001, the V.G. Khlopinmore » Radium Institute (Khlopin), St. Petersburg, Russia, and Pacific Nuclear Solutions (PNS), Indianapolis, Indiana, began extensive research and test programs to determine the validity of polymer technology for the absorption and immobilization of standard and complex waste streams. Over 60 liquid compositions have been tested including extensive irradiation tests to verify polymer stability and possible degradation. With conclusive scientific evidence of the polymer's effectiveness in treating liquid waste, both parties have decided to enter the Russian market and offer the solidification technology to nuclear sites for waste treatment and disposal. In conjunction with these efforts, the U.S. Department of Energy (DOE) will join Khlopin and PNS to explore opportunities for direct application of the polymers at predetermined sites and to conduct research for new product development. Under DOE's 'Initiatives for Proliferation Prevention'(IPP) program, funding will be provided to the Russian participants over a three year period to implement the program plan. This paper will present details of U.S. DOE's IPP program, the project structure and its objectives both short and long-term, training programs for scientists, polymer tests and applications for LLW, ILW and HLW, and new product development initiatives. (authors)« less

Removal of radioactive contaminants by polymeric microspheres.

PubMed

Osmanlioglu, Ahmet Erdal

2016-11-01

Radionuclide removal from radioactive liquid waste by adsorption on polymeric microspheres is the latest application of polymers in waste management. Polymeric microspheres have significant immobilization capacity for ionic substances. A laboratory study was carried out by using poly(N-isopropylacrylamide) for encapsulation of radionuclide in the liquid radioactive waste. There are numbers of advantages to use an encapsulation technology in radioactive waste management. Results show that polymerization step of radionuclide increases integrity of solidified waste form. Test results showed that adding the appropriate polymer into the liquid waste at an appropriate pH and temperature level, radionuclide was encapsulated into polymer. This technology may provide barriers between hazardous radioactive ions and the environment. By this method, solidification techniques became easier and safer in nuclear waste management. By using polymer microspheres as dust form, contamination risks were decreased in the nuclear industry and radioactive waste operations.

Equipment evaluation for low density polyethylene encapsulated nitrate salt waste at the Rocky Flats Plant

DOE Office of Scientific and Technical Information (OSTI.GOV)

Yamada, W.I.; Faucette, A.M.; Jantzen, R.C.

1993-08-30

Mixed wastes at the Rocky Flats Plant (RFP) are subject to regulation by the Resource Conservation and Recovery Act (RCRA). Polymer solidification is being developed as a final treatment technology for several of these mixed wastes, including nitrate salts. Encapsulation nitrate salts with low density polyethylene (LDPE) has been the preliminary focus of the RFP polymer solidification effort. Literature reviews, industry surveys, and lab-scale and pilot-scale tests have been conducted to evaluate several options for encapsulating nitrate salts with LDPE. Most of the effort has focused on identifying compatible drying and extrusion technologies. Other processing options, specifically meltration and non-heatedmore » compounding machines, were also investigated. The best approach appears to be pretreatment of the nitrate salt waste brine in either a vertical or horizontal thin film evaporator followed by compounding of the dried waste with LDPE in an intermeshing, co-rotating, twin-screw extruder. Additional pilot-scale tests planned for the fall of 1993 should further support this recommendation. Preliminary evaluation work indicates that meltration is not possible at atmospheric pressure with the LDPE (Chevron PE-1409) provided by RFP. However, meltration should be possible at atmospheric pressure using another LDPE formulation with altered physical and rheological properties: Lower molecular weight and lower viscosity (Epoline C-15). Contract modifications are now in process to allow a follow-on pilot scale demonstration. Questions regarding changed safety and physical properties of the resultant LDPE waste form due to use of the Epoline C-15 will be addressed. No additional work with non-heated mixer compounder machines is planned at this time.« less

Liquid secondary waste: Waste form formulation and qualification

DOE Office of Scientific and Technical Information (OSTI.GOV)

Cozzi, A. D.; Dixon, K. L.; Hill, K. A.

The Hanford Site Effluent Treatment Facility (ETF) currently treats aqueous waste streams generated during site cleanup activities. When the Hanford Tank Waste Treatment and Immobilization Plant (WTP) begins operations, including Direct Feed Low Activity Waste (DFLAW) vitrification, a liquid secondary waste (LSW) stream from the WTP will need to be treated. The volume of effluent for treatment at the ETF will increase significantly. The powdered salt waste form produced by the ETF will be replaced by a stabilized solidified waste form for disposal in Hanford’s Integrated Disposal Facility (IDF). Washington River Protection Solutions is implementing a Secondary Liquid Waste Immobilizationmore » Technology Development Plan to address the technology needs for a waste form and solidification process to treat the increased volume of waste planned for disposal at the IDF. Waste form testing to support this plan is composed of work in the near term to provide data as input to a performance assessment (PA) for Hanford’s IDF. In 2015, three Hanford Liquid Secondary Waste simulants were developed based on existing and projected waste streams. Using these waste simulants, fourteen mixes of Hanford Liquid Secondary Waste were prepared and tested varying the waste simulant, the water-to-dry materials ratio, and the dry materials blend composition.1 In FY16, testing was performed using a simulant of the EMF process condensate blended with the caustic scrubber—from the Low Activity Waste (LAW) melter—, processed through the ETF. The initial EMF-16 simulant will be based on modeling efforts performed to determine the mass balance of the ETF for the DFLAW.2 The compressive strength of all of the mixes exceeded the target of 3.4 MPa (500 psi) to meet the requirements identified as potential IDF Waste Acceptance Criteria in Table 1 of the Secondary Liquid Waste Immobilization Technology Development Plan.3 The hydraulic properties of the waste forms tested (hydraulic conductivity and water characteristic curves) were comparable to the properties measured on the Savannah River Site (SRS) Saltstone waste form. Future testing should include efforts to first; 1) determine the rate and amount of ammonia released during each unit operation of the treatment process to determine if additional ammonia management is required, then; 2) reduce the ammonia content of the ETF concentrated brine prior to solidification, making the waste more amenable to grouting, or 3) manage the release of ammonia during production and ongoing release during storage of the waste form, or 4) develop a lower pH process/waste form thereby precluding ammonia release.« less

Treatment Of Arsenic-Contaminated Materials Using Selected Stabilization And Solidification Technologies

EPA Science Inventory

Arsenic contamination of soil, sediment and groundwater is a widespread problem in certain areas and has caused great public concern due to increased awareness of the health risks. Often the contamination is naturally occurring, but it can also be a result of waste generated fro...

Cement-based stabilization/solidification of oil refinery sludge: Leaching behavior of alkanes and PAHs.

PubMed

Karamalidis, Athanasios K; Voudrias, Evangelos A

2007-09-05

Stabilization/solidification is a process widely applied for the immobilization of inorganic constituents of hazardous wastes, especially for metals. Cement is usually one of the most common binders for that purpose. However, limited results have been presented on immobilization of hydrocarbons in cement-based stabilized/solidified petroleum solid waste. In this study, real oil refinery sludge samples were stabilized and solidified with various additions of I42.5 and II42.5 cement (Portland and blended cement, respectively) and subject to leaching. The target analytes were total petroleum hydrocarbons, alkanes and 16 polycyclic aromatic hydrocarbons of the EPA priority pollutant list. The experiments showed that the waste was confined in the cement matrix by macroencapsulation. The rapture of the cement structure led to the increase of leachability for most of the hydrocarbons. Leaching of n-alkanes from II42.5 cement-solidified samples was lower than that from I42.5 solidified samples. Leaching of alkanes in the range of n-C(10) to n-C(27) was lower than that of long chain alkanes (>n-C(27)), regardless the amount of cement addition. Generally, increasing the cement content in the solidified waste samples, increased individual alkane leachability. This indicated that cement addition resulted in destabilization of the waste. Addition of I42.5 cement favored immobilization of anthracene, benzo[a]anthracene, benzo[b]fluoroanthene, benzo[k]fluoroanthene, benzo[a]pyrene and dibenzo[a,h]anthracene. However, addition of II42.5 favored 5 out of 16, i.e., naphthalene, anthracene, benzo[b]fluoroanthene, benzo[k]fluoroanthene and dibenzo[a,h]anthracene.

Validation of an in situ solidification/stabilization technique for hazardous barium and cyanide waste for safe disposal into a secured landfill.

PubMed

Vaidya, Rucha; Kodam, Kisan; Ghole, Vikram; Surya Mohan Rao, K

2010-09-01

The aim of the present study was to devise and validate an appropriate treatment process for disposal of hazardous barium and cyanide waste into a landfill at a Common Hazardous Waste Treatment Storage Disposal Facility (CHWTSDF). The waste was generated during the process of hardening of steel components and contains cyanide (reactive) and barium (toxic) as major contaminants. In the present study chemical fixation of the contaminants was carried out. The cyanide was treated by alkali chlorination with calcium hypochlorite and barium by precipitation with sodium sulfate as barium sulfate. The pretreated mixture was then solidified and stabilized by binding with a combination of slag cement, ordinary Portland cement and fly ash, molded into blocks (5 x 5 x 5 cm) and cured for a period of 3, 7 and 28 days. The final experiments were conducted with 18 recipe mixtures of waste + additive:binder (W:B) ratios. The W:B ratios were taken as 80:20, 70:30 and 50:50. The optimum proportions of additives and binders were finalized on the basis of the criteria of unconfined compressive strength and leachability. The leachability studies were conducted using the Toxicity Characteristic Leaching Procedure. The blocks were analyzed for various physical and leachable chemical parameters at the end of each curing period. Based on the results of the analysis, two recipe mixtures, with compositions - 50% of [waste + (120 g Ca(OCl)(2) + 290 g Na(2)SO(4)) kg(-1) of waste] + 50% of binders, were validated for in situ stabilization into a secured landfill of CHWTSDF. 2010 Elsevier Ltd. All rights reserved.

Design and development of a space station hazardous material system for assessing chemical compatibility

NASA Technical Reports Server (NTRS)

Congo, Richard T.

1990-01-01

As the Space Station nears reality in funding support from Congress, NASA plans to perform over a hundred different missions in the coming decade. Incrementally deployed, the Space Station will evolve into modules linked to an integral structure. Each module will have characteristic functions, such as logistics, habitation, and materials processing. Because the Space Station is to be user friendly for experimenters, NASA is anticipating that a variety of different chemicals will be taken on-board. Accidental release of these potentially toxic chemicals and their chemical compatibility is the focus of this discourse. The Microgravity Manufacturing Processing Facility (MMPF) will contain the various facilities within the U.S. Laboratory (USL). Each facility will have a characteristic purpose, such as alloy solidification or vapor crystal growth. By examining the proposed experiments for each facility, identifying the chemical constituents, their physical state and/or changes, byproducts and effluents, those payloads can be identified which may contain toxic, explosive, or reactive compounds that require processing or containment in mission peculiar waste management systems. Synergistic reactions from mixed effluent streams is of major concern. Each experiment will have it own data file, complete with schematic, chemical listing, physical data, etc. Chemical compatibility information from various databases will provide assistance in the analysis of alternate disposal techniques (pretreatment, separate storage, etc.). Along with data from the Risk Analysis of the Proposed USL Waste Management System, accidental release of potentially toxic and catastrophic chemicals would be eliminated or reduced.

Proposal of a sequential treatment methodology for the safe reuse of oil sludge-contaminated soil.

PubMed

Mater, L; Sperb, R M; Madureira, L A S; Rosin, A P; Correa, A X R; Radetski, C M

2006-08-25

In this study sequential steps were used to treat and immobilize oil constituents of an oil sludge-contaminated soil. Initially, the contaminated soil was oxidized by a Fenton type reaction (13 wt% for H(2)O(2); 10mM for Fe(2+)). The oxidative treatment period of 80 h was carried out under three different pH conditions: 20 h at pH 6.5, 20 h at pH 4.5, and 40 h at pH 3.0. The oxidized contaminated sample (3 kg) was stabilized and solidified for 2h with clay (1 kg) and lime (2 kg). Finally, this mixture was solidified by sand (2 kg) and Portland cement (4 kg). In order to evaluate the efficiency of different processes to treat and immobilize oil contaminants of the oil sludge-contaminated soil, leachability and solubility tests were performed and extracts were analyzed according to the current Brazilian waste regulations. Results showed that the Fenton oxidative process was partially efficient in degrading the oil contaminants in the soil, since residual concentrations were found for the PAH and BTEX compounds. Leachability tests showed that clay-lime stabilization/solidification followed by Portland cement stabilization/solidification was efficient in immobilizing the recalcitrant and hazardous constituents of the contaminated soil. These two steps stabilization/solidification processes are necessary to enhance environmental protection (minimal leachability) and to render final product economically profitable. The treated waste is safe enough to be used on environmental applications, like roadbeds blocks.

The growth of metastable peritectic compounds

NASA Technical Reports Server (NTRS)

Larson, D. J., Jr.; Pirich, R. G.

1981-01-01

The influence of gravitationally driven thermosolutal convection on the directional solidification of peritectic alloys is considered as well as the relationships between the solidification processing conditions, and the microstructure, chemistry, and magnetic properties of such alloys. Analysis of directionally solidified Pb-Bi peritectic samples indicates that appreciable macrosegregation occurs due to thermosolutal convection and/or Soret diffusion. A peritectic solidification model which accounts for partial mixing in the liquid ahead of the planar solidification interface and describes macrosegregation has been developed. Two-phase dendritic and banded microstructures were grown in the Pb-Bi peritectic system, refined two-phase microstructures have were observed, and candidate formation mechanisms proposed. Material handling, containment, casting, microstructural and magnetic characterization techniques were developed for the Sm-Co system. Alloys produced with these procedures are homogeneous.

An Overview of the MSFC Electrostatic Levitation Facility

NASA Technical Reports Server (NTRS)

Rogers, J. R.; Robinson, M. B.; Hyers, R. W.; Savage, L.; Rathz, T.

2000-01-01

Electrostatic levitation (ESL) provides a means to study molten materials in a contamination-free environment, including no contact with a container. Many phenomena important to materials science can be studied in the ESL. Solidification of metals, alloys and undercooled materials represent an important topic for research in the ESL. Recent studies of metals and alloys during solidification in the ESL are reported. Measurements include time, temperature and transformation of metallic glass-forming alloys, solidification velocities, and microstructure. This multimedia report includes a video clip showing processing in the ESL, with descriptions of the different segments in the text.

Westinghouse Modular Grinding Process - Enhancement of Volume Reduction for Hot Resin Supercompaction - 13491

DOE Office of Scientific and Technical Information (OSTI.GOV)

Fehrmann, Henning; Aign, Joerg

2013-07-01

In nuclear power plants (NPP) ion exchange (IX) resins are used in several systems for water treatment. Spent resins can contain a significant amount of contaminates which makes treatment for disposal of spent resins mandatory. Several treatment processes are available such as direct immobilization with technologies like cementation, bitumisation, polymer solidification or usage of a high integrity container (HIC). These technologies usually come with a significant increase in final waste volume. The Hot Resin Supercompaction (HRSC) is a thermal treatment process which reduces the resin waste volume significantly. For a mixture of powdered and bead resins the HRSC process hasmore » demonstrated a volume reduction of up to 75 % [1]. For bead resins only the HRSC process is challenging because the bead resins compaction properties are unfavorable. The bead resin material does not form a solid block after compaction and shows a high spring back effect. The volume reduction of bead resins is not as good as for the mixture described in [1]. The compaction properties of bead resin waste can be significantly improved by grinding the beads to powder. The grinding also eliminates the need for a powder additive.Westinghouse has developed a modular grinding process to grind the bead resin to powder. The developed process requires no circulation of resins and enables a selective adjustment of particle size and distribution to achieve optimal results in the HRSC or in any other following process. A special grinding tool setup is use to minimize maintenance and radiation exposure to personnel. (authors)« less

EVALUATION OF CONTAMINANT LEACHABILITY FACTORS BY COMPARISON OF TREATABILITY STUDY DATA FOR MULTIPLE SOLIDIFIED/STABILIZED MATERIALS

EPA Science Inventory

Solidification/stabilization (S/S) technology is widely used in the treatment of hazardous waste and contaminated soil in the US. In a project sponsored by the US Navy and the USEPA, treatability test data were compiled into a data base listing contaminant concentration and matri...

Solidification of Savannah River plant high level waste

NASA Astrophysics Data System (ADS)

Maher, R.; Shafranek, L. F.; Kelley, J. A.; Zeyfang, R. W.

1981-11-01

Authorization for construction of the Defense Waste Processing Facility (DWPF) is expected in FY-83. The optimum time for stage 2 authorization is about three years later. Detailed design and construction will require approximately five years for stage 1, with stage 2 construction completed about two to three years later. Production of canisters of waste glass would begin in 1988, and the existing backlog of high level waste sludge stored at SRP would be worked off by about the year 2000. Stage 2 operation could begin in 1990. The technology and engineering are ready for construction and eventual operation of the DWPF for immobilizing high level radioactive waste at Savannah River Plant (SRP). Proceeding with this project will provide the public, and the leadership of this country, with a crucial demonstration that a major quanitity of existing high level nuclear wastes can be safely and permanently immobilized.

Experiments with the Kema cyclone incinerator for radioactive waste

NASA Astrophysics Data System (ADS)

Matteman, J. L.; Tigchelaar, P.

A cyclone incinerator for the treatment of solid waste at a nuclear power station was developed to reduce volume and weight of the final waste; reductions by factors of 7 and 80 respectively are possible (after solidification). For burnable waste the throughput is 23 kg/hr for 6 hr runs. About 7000 kg of nonradioactive waste were treated in total. The behavior of potentially dangerous radionuclides (Co, Cs, Mn and Sr) was studied by tracers. It appears that Co, Mn and Sr are concentrated in the resulting ashes, where 55% of the Cs is also found; the remaining Cs is unaccounted for. The ashes were solidified by mixing them with concrete in a 1:1 ratio. Due to the flexibility of the facility, start-up and turn-down periods are short. Since the process can be controlled automatically, the operation can be run by one employee, to load the waste and handle the ashes.

Chemical stabilization of air pollution control residues from municipal solid waste incineration.

PubMed

Quina, Margarida J; Bordado, João C M; Quinta-Ferreira, Rosa M

2010-07-15

The by-products of the municipal solid waste incineration (MSWI) generally contain hazardous pollutants, with particular relevance to air pollution control (APC) residues. This waste may be harmful to health and detrimental to the environmental condition, mainly due to soluble salts, toxic heavy metals and trace organic compounds. Solidification/stabilization (S/S) with binders is a common industrial technology for treating such residues, involving however, a significant increase in the final mass that is landfilled. In our work, the chemical stabilization of APC residues by using NaHS x xH(2)O, H(3)PO(4), Na(2)CO(3), C(5)H(10)NNaS(2) x 3 H(2)O, Na(2)O x SiO(2) was investigated, and it was possible to conclude that all these additives lead to an improvement of the stabilization process of the most problematic heavy metals. Indeed, compliance leaching tests showed that after the stabilization treatment the waste becomes non-hazardous with respect to heavy metals. Chromium revealed to be a problematic metal, mainly when H(3)PO(4), Na(2)CO(3) and Na(2)O x SiO(2) were used for stabilization. Nevertheless, soluble phosphates are the most efficient additives for stabilizing the overall metals. The effect of the additives tested on the elements associated with soluble salts (K, Na, Cl(-)) is almost negligible, and therefore, the soluble fraction is hardly reduced without further treatment, such as pre-washing. 2010 Elsevier B.V. All rights reserved.

Special Analysis for the Disposal of the Consolidated Edison Uranium Solidification Project Waste Stream at the Area 5 Radioactive Waste Management Site, Nevada National Security Site, Nye County, Nevada

DOE Office of Scientific and Technical Information (OSTI.GOV)

NSTec Environmental Management

2013-01-31

The purpose of this Special Analysis (SA) is to determine if the Oak Ridge (OR) Consolidated Edison Uranium Solidification Project (CEUSP) uranium-233 (233U) waste stream (DRTK000000050, Revision 0) is acceptable for shallow land burial (SLB) at the Area 5 Radioactive Waste Management Site (RWMS) on the Nevada National Security Site (NNSS). The CEUSP 233U waste stream requires a special analysis because the concentrations of thorium-229 (229Th), 230Th, 232U, 233U, and 234U exceeded their NNSS Waste Acceptance Criteria action levels. The acceptability of the waste stream is evaluated by determining if performance assessment (PA) modeling provides a reasonable expectation that SLBmore » disposal is protective of human health and the environment. The CEUSP 233U waste stream is a long-lived waste with unique radiological hazards. The SA evaluates the long-term acceptability of the CEUSP 233U waste stream for near-surface disposal as a two tier process. The first tier, which is the usual SA process, uses the approved probabilistic PA model to determine if there is a reasonable expectation that disposal of the CEUSP 233U waste stream can meet the performance objectives of U.S. Department of Energy Manual DOE M 435.1-1, “Radioactive Waste Management,” for a period of 1,000 years (y) after closure. The second tier addresses the acceptability of the OR CEUSP 233U waste stream for near-surface disposal by evaluating long-term site stability and security, by performing extended (i.e., 10,000 and 60,000 y) modeling analyses, and by evaluating the effect of containers and the depth of burial on performance. Tier I results indicate that there is a reasonable expectation of compliance with all performance objectives if the OR CEUSP 233U waste stream is disposed in the Area 5 RWMS SLB disposal units. The maximum mean and 95th percentile PA results are all less than the performance objective for 1,000 y. Monte Carlo uncertainty analysis indicates that there is a high likelihood of compliance with all performance objectives. Tier II results indicate that the long-term performance of the OR CEUSP 233U waste stream is protective of human health and the environment. The Area 5 RWMS is located in one of the least populated and most arid regions of the U.S. Site characterization data indicate that infiltration of precipitation below the plant root zone at 2.5 meters (8.2 feet) ceased 10,000 to 15,000 y ago. The site is not expected to have a groundwater pathway as long as the current arid climate persists. The national security mission of the NNSS and the location of the Area 5 RWMS within the Frenchman Flat Corrective Action Unit require that access controls and land use restrictions be maintained indefinitely. PA modeling results for 10,000 to 60,000 y also indicate that the OR CEUSP 233U waste stream is acceptable for near-surface disposal. The mean resident air pathway annual total effective dose (TED), the resident all-pathways annual TED, and the acute drilling TED are less than their performance objectives for 10,000 y after closure. The mean radon-222 (222Rn) flux density exceeds the performance objective at 4,200 y, but this is due to waste already disposed at the Area 5 RWMS and is only slightly affected by disposal of the CEUSP 233U. The peak resident all-pathways annual TED from CEUSP key radionuclides occurs at 48,000 y and is less than the 0.25 millisievert performance objective. Disposal of the OR CEUSP 233U waste stream in a typical SLB trench slightly increases PA results. Increasing the depth was found to eliminate any impacts of the OR CEUSP 233U waste stream. Containers could not be shown to have any significant impact on performance due to the long half-life of the waste stream and a lack of data for pitting corrosion rates of stainless steel in soil. The results of the SA indicate that all performance objectives can be met with disposal of the OR CEUSP 233U waste stream in the SLB units at the Area 5 RWMS. The long-term performance of the OR CEUSP 233U waste stream disposed in the near surface is protective of human health and the environment. The waste stream is recommended for disposal without conditions.« less

Space Processing Applications Rocket project, SPAR 1

NASA Technical Reports Server (NTRS)

Reeves, F. (Compiler); Chassay, R. (Compiler)

1976-01-01

The experiment objectives, design/operational concepts, and final results of each of nine scientific experiments conducted during the first Space Processing Applications Rocket (SPAR) flight are summarized. The nine individual SPAR experiments, covering a wide and varied range of scientific materials processing objectives, were entitled: solidification of Pb-Sb eutectic, feasibility of producing closed-cell metal foams, characterization of rocket vibration environment by measurement of mixing of two liquids, uniform dispersions of crystallization processing, direct observation of solidification as a function of gravity levels, casting thoria dispersion-strengthened interfaces, contained polycrystalline solidification, and preparation of a special alloy for manufacturing of magnetic hard superconductor under zero-g environment.

Secondary Waste Form Down Selection Data Package – Ceramicrete

DOE Office of Scientific and Technical Information (OSTI.GOV)

Cantrell, Kirk J.; Westsik, Joseph H.

2011-08-31

As part of high-level waste pretreatment and immobilized low activity waste processing, liquid secondary wastes will be generated that will be transferred to the Effluent Treatment Facility on the Hanford Site for further treatment. These liquid secondary wastes will be converted to stable solid waste forms that will be disposed in the Integrated Disposal Facility. Currently, four waste forms are being considered for stabilization and solidification of the liquid secondary wastes. These waste forms are Cast Stone, Ceramicrete, DuraLith, and Fluidized Bed Steam Reformer. The preferred alternative will be down selected from these four waste forms. Pacific Northwest National Laboratorymore » is developing data packages to support the down selection process. The objective of the data packages is to identify, evaluate, and summarize the existing information on the four waste forms being considered for stabilization and solidification of the liquid secondary wastes. The information included will be based on information available in the open literature and from data obtained from testing currently underway. This data package is for the Ceramicrete waste form. Ceramicrete is a relatively new engineering material developed at Argonne National Laboratory to treat radioactive and hazardous waste streams (e.g., Wagh 2004; Wagh et al. 1999a, 2003; Singh et al. 2000). This cement-like waste form can be used to treat solids, liquids, and sludges by chemical immobilization, microencapsulation, and/or macroencapsulation. The Ceramicrete technology is based on chemical reaction between phosphate anions and metal cations to form a strong, dense, durable, low porosity matrix that immobilizes hazardous and radioactive contaminants as insoluble phosphates and microencapsulates insoluble radioactive components and other constituents that do not form phosphates. Ceramicrete is a type of phosphate-bonded ceramic, which are also known as chemically bonded phosphate ceramics. The Ceramicrete binder is formed through an acid-base reaction between calcined magnesium oxide (MgO; a base) and potassium hydrogen phosphate (KH{sub 2}PO{sub 4}; an acid) in aqueous solution. The reaction product sets at room temperature to form a highly crystalline material. During the reaction, the hazardous and radioactive contaminants also react with KH{sub 2}PO{sub 4} to form highly insoluble phosphates. In this data package, physical property and waste acceptance data for Ceramicrete waste forms fabricated with wastes having compositions that were similar to those expected for secondary waste effluents, as well as secondary waste effluent simulants from the Hanford Tank Waste Treatment and Immobilization Plant were reviewed. With the exception of one secondary waste form formulation (25FA+25 W+1B.A. fabricated with the mixed simulant did not meet the compressive strength requirement), all the Ceramicrete waste forms that were reviewed met or exceeded Integrated Disposal Facility waste acceptance criteria.« less

Thermo-Electric-Magnetic Hydrodynamics in Solidification: In Situ Observations and Theory

NASA Astrophysics Data System (ADS)

Fautrelle, Y.; Wang, J.; Salloum-Abou-Jaoude, G.; Abou-Khalil, L.; Reinhart, G.; Li, X.; Ren, Z. M.; Nguyen-Thi, H.

2018-02-01

Solidification of liquid metals contains all the ingredients for the development of the thermo-electric (TE) effect, namely liquid-solid interface and temperature gradients. The combination of TE currents with a superimposed magnetic field gives rise to thermo-electromagnetic (TEM) volume forces acting on both liquid and solid. This results in the generation of fluid flows, which considerably modifies the morphology of the solidification front as well as that of the mushy zone. TEM forces also act on the solid and cause both fragmentation of dendrite branches and a movement of equiaxed grains in suspension. These phenomena have already been unveiled by post-mortem analysis of samples, but they can be analyzed in more detail by using x-ray in situ and real-time observations. Here, we present conclusive evidence of all the aforementioned effects thanks to in situ observations of Al-Cu alloy solidification under static magnetic field.

A calorimetric and microstructural study of solidified toxic wastes. Part 1: A classification of OPC/waste interference effects

DOE Office of Scientific and Technical Information (OSTI.GOV)

Hills, C.D.; Sollars, C.J.; Perry, R.

1994-01-01

Ordinary Portland cement (OPC) has been used to solidify hazardous waste for about 25 years. The effects of waste components on the hydraulic activity of his binder have been subject to increasing research. Under certain circumstances, as yet to be defined, the hydration reactions thought responsible for solidification can be poisoned and appear to be retarded indefinitely. In this study, a number of wastes known to be capable of poisoning hydration were added to OPC and the effects were examined by conduction calorimetry and microstructural analysis techniques. A comparison of results showed that it was possible to classify waste/OPC interactionsmore » by phase development and the heat of hydration evolved. During the second part of this work, which is reported separately, the individual wastes were characterized, and the individual components identified as significant were added to OPC in single and combined additions. A comparison of results showed that it was possible to reproduce the poisoning effects observed.« less

MSW fly ash stabilized with coal ash for geotechnical application.

PubMed

Kamon, M; Katsumi, T; Sano, Y

2000-09-15

The solidification and stabilization of municipal solid waste (MSW) fly ash for the purpose of minimizing the geo-environmental impact caused by toxic heavy metals as well as ensuring engineering safety (strength and soaking durability) are experimentally evaluated. The mixtures of MSW fly ash stabilized with cement and fluidized bed combustion coal fly ash (FCA) were used for unconfined compressive strength tests, leachate tests, and soaking tests. The behavior of soluble salts contained in the MSW fly ash significantly affects strength development, soaking durability, and the hardening reaction of the stabilized MSW fly ash mixtures. The cement stabilization of the MSW fly ash does not have enough effect on strength development and soaking durability. The addition of cement only contributes to the containment of heavy metals due to the high level of alkalinity. When using FCA as a stabilizing agent for MSW fly ash, the mixture exhibits high strength and durability. However, the Cd leachate cannot be prevented in the early stages of curing. Using a combination of cement and FCA as a MSW fly ash stabilizer can attain high strength, high soaking durability, and the containment of heavy metals. The stabilized MSW fly ash with cement and FCA can be practically applied to embankments.

Evaluation of sulfidic mine tailings solidified/stabilized with cement kiln dust and fly ash to control acid mine drainage

DOE Office of Scientific and Technical Information (OSTI.GOV)

Nehdi, M.; Tariq, A.

2008-11-15

In the present research, industrial byproducts, namely, cement kiln dust (CKD) and Class C fly ash (FAC) have been used as candidate materials along with the partial addition of sulfate-resistant cement (SRC) in the Stabilization/solidification of polymetallic sulfidic mine tailings (MT). The effectiveness of S/S was assessed by comparing laboratory experimental values obtained from unconfined compressive strength, hydraulic conductivity and leaching propensity tests of S/S samples with regulatory standards for safe surface disposal of such wastes. Despite general regulatory compliance of compressive strength and hydraulic conductivity, some solidified/stabilized-cured matrices were found unable to provide the required immobilization of pollutants. Solidified/stabilizedmore » and 90-day cured mine tailings specimens made with composite binders containing (10% CKD + 10% FAC), (5% SRC + 15% FAC) and (5% SRC + 5% CKD + 10% FAC) significantly impaired the solubility of all contaminants investigated and proved successful in fixing metals within the matrix, in addition to achieving adequate unconfined compressive strength and hydraulic conductivity values, thus satisfying USEPA regulations. Laboratory investigations revealed that, for polymetallic mining waste, leachate concentrations are the most critical factor in assessing the effectiveness of S/S technology.« less

Effect of Chemical Composition on Susceptibility to Weld Solidification Cracking in Austenitic Weld Metal

NASA Astrophysics Data System (ADS)

Kadoi, Kota; Shinozaki, Kenji

2017-12-01

The influence of the chemical composition, especially the niobium content, chromium equivalent Creq, and nickel equivalent Nieq, on the weld solidification cracking susceptibility in the austenite single-phase region in the Schaeffler diagram was investigated. Specimens were fabricated using the hot-wire laser welding process with widely different compositions of Creq, Nieq, and niobium in the region. The distributions of the susceptibility, such as the crack length and brittle temperature range (BTR), in the Schaeffler diagram revealed a region with high susceptibility to solidification cracking. Addition of niobium enhanced the susceptibility and changed the distribution of the susceptibility in the diagram. The BTR distribution was in good agreement with the distribution of the temperature range of solidification (Δ T) calculated by solidification simulation based on Scheil model. Δ T increased with increasing content of alloying elements such as niobium. The distribution of Δ T was dependent on the type of alloying element owing to the change of the partitioning behavior. Thus, the solidification cracking susceptibility in the austenite single-phase region depends on whether the alloy contains elements. The distribution of the susceptibility in the region is controlled by the change in Δ T and the segregation behavior of niobium with the chemical composition.

Strength characteristics of lightly solidified dredged marine clay admixed with bentonite

NASA Astrophysics Data System (ADS)

Ariffin, Syazwana Tajul; Chan, Chee-Ming

2017-11-01

Strength characteristic is a significant parameter in measuring the effect of soil improvement and effective composition of solidification. In this study, the dredged marine sediment (DMS) collected from Kuala Perlis (Malaysia) was examined to determine its strength characteristics under light cement solidification with bentonite. Dredged marine clay generally has the low shear strength and high void ratio, and consists mainly of soil particles of the fine-grained type. As a discarded geo-waste, it can be potentially treated to for reuse as a backfill material instead of being disposed of, hence reducing the negative impact on the environment. Physico-chemical parameters of the dredged sample were first determined, then solidification was carried out to improve the engineering properties by admixing ordinary Portland cement (OPC) as the binder and bentonite as a volume enhancer to the soil. The DMS was treated with the addition of 3 % and 6 % cement and bentonite within the range of 0-30 %. The specimens were cured at room temperature for 3, 7 and 14 days. The strength gain was measured by unconfined compression test and vane shear test. The laboratory test results were analyzed to establish the relationship between strength properties and solidification specifications. In summary, the strength of specimens increased with the increase of the quantity of bentonite and cement to get the effective composition of the specimen.

Directional solidification of eutectic composites in space environment

NASA Technical Reports Server (NTRS)

Yue, A. S.

1972-01-01

The Ni-Ni3Ta eutectic and a nickel-base alloy containing 30 wt pct Ta were solidified unidirectionally in an electron beam floating zone melting apparatus. It was found that the volume fraction of the Ni3Ta phase in the Ni-Ni3Ta eutectic mixture was increased from 7.6 to 36 volume pct in agreement with the theory as predicted. Tensile properties of the randomly solidified and unidirectionally solidified Ni-Ni3Ta eutectic were determined as function of solidification rate and temperature. It was found that the ultimate tensile strength decreased as both the test temperature and solidification rate increased. An elongation of 40 pct was obtained for a nickelbase alloy containing 30 wt at room temperature. This unusually large elongation was attributed to the superplastic behavior of the alloy. The critical currents versus the external fields at 2.5, 3.0, 3.5 and 4.2 deg for the unidirectionally solidified Pb-Sn eutectic were measured. The values of critical fields at zero critical currents were obtained by extrapolation.

Ternary blends containing demercurated lighting phosphor and MSWI fly ash as high-performance binders for stabilizing and recycling electroplating sludge.

PubMed

Huang, Wu-Jang; Wu, Chia-Teng; Wu, Chang-En; Hsieh, Lin-Huey; Li, Chang-Chien; Lain, Chi-Yuan; Chu, Wei

2008-08-15

This paper describes the solidification and stabilization of electroplating sludge treated with a high-performance binder made from portland type-I cement, municipal solid waste incineration fly ash, and lighting phosphor powder (called as cement-fly ash-phosphor binder, CFP). The highest 28-day unconfined compressive strength of the CFP-treated paste was 816 kg/cm(2) at a ratio of cement to fly ash to lighting phosphor powder of 90:5:5; the strength of this composition also fulfilled the requirement of a high-strength concrete (>460 kg/cm(2) at 28 days). The CFP-stabilized sludge paste samples passed the Taiwanese EPA toxicity characteristic leaching procedure test and, therefore, could be used either as a building material or as a controlled low-strength material, depending on the sludge-to-CFP binder ratio.

Electromagnetic containerless undercooling facility and experiments for the Shuttle

NASA Technical Reports Server (NTRS)

Frost, R. T.; Flemings, M. C.; Szekely, J.; El-Kaddah, N.; Shiohara, Y.

1984-01-01

An electromagnetic furnace is being prepared for flights aboard the Space Shuttle. This apparatus is capable of melting metals and alloys up to 1400 C melting point by induction heating with subsequent solidification of the freely levitated melt without contact with any container. The solidification can be carried out with greatly reduced fields resulting in minimal heating and stirring of the free melt. Sequential specimens can be processed during flight. Several experiments are planned for a series of flights, beginning in 1985 with an undercooling experiment of NiSn alloys. These will be interspersed with detailed studies of fluid flow caused by low and high field levels in order to quantify the corresponding effect upon the solidification process.

Solidification and solidification cracking in nitrogen-strengthened austenitic stainless steels

NASA Astrophysics Data System (ADS)

Ritter, Ann M.; Savage, Warren F.

1986-04-01

The solidification behavior of three heats of nitrogen-strengthened austenitic stainless steel was examined and was correlated with solidification mode predictions and with hot cracking resistance. The heat of NITRONIC* 50 solidified by the austenitic-ferrite mode, and the NITRONIC 50W and NITRONIC 50W - Nb heats solidified by the ferritic-austenitic mode. This behavior was in good agreement with predictions based on Espy’s formulas for Cr and Ni equivalents. Both the NITRONIC 50W and NITRONIC 50W + Nb welds contained primary delta-ferrite, with the latter weld and the NITRONIC 50 weld also containing some eutectic ferrite. Solute profiles in austenite near the eutectic ferrite showed decreasing Fe and increasing Cr, Ni, Mn, and Mo relative to austenite in the dendrite cores. Numerous Nb-rich precipitates were found on the eutectic ferrite/austenite interfaces and within the eutectic ferrite. The precipitates were mainly Nb(C, N), with some Z-phase, a Nb-rich nitride, also detected. One instance of the transformation of eutectic ferrite to sigma-phase was observed to have occurred during cooling of the NITRONIC 50 weld. Hot cracking was seen in the NITRONIC 50 and NITRONIC 50W + Nb welds and resulted from the formation of a niobium carbonitride eutectic in the interdendritic regions. In the absence of Nb, the NITRONIC 50W heat formed no observable eutectic constituents and did not hot crack. The presence of hot cracks in the NITRONIC 50W + Nb weld indicates that solidification by the ferritic-austenitic mode did not counteract the effects of small Nb additions.

Design of model experiments for melt flow and solidification in a square container under time-dependent magnetic fields

NASA Astrophysics Data System (ADS)

Meier, D.; Lukin, G.; Thieme, N.; Bönisch, P.; Dadzis, K.; Büttner, L.; Pätzold, O.; Czarske, J.; Stelter, M.

2017-03-01

This paper describes novel equipment for model experiments designed for detailed studies on electromagnetically driven flows as well as solidification and melting processes with low-melting metals in a square-based container. Such model experiments are relevant for a validation of numerical flow simulation, in particular in the field of directional solidification of multi-crystalline photovoltaic silicon ingots. The equipment includes two square-shaped electromagnetic coils and a melt container with a base of 220×220 mm2 and thermostat-controlled heat exchangers at top and bottom. A system for dual-plane, spatial- and time-resolved flow measurements as well as for in-situ tracking of the solid-liquid interface is developed on the basis of the ultrasound Doppler velocimetry. The parameters of the model experiment are chosen to meet the scaling laws for a transfer of experimental results to real silicon growth processes. The eutectic GaInSn alloy and elemental gallium with melting points of 10.5 °C and 29.8 °C, respectively, are used as model substances. Results of experiments for testing the equipment are presented and discussed.

Stabilization/solidification of an alkyd paint waste by carbonation of waste-lime based formulations.

PubMed

Arce, R; Galán, B; Coz, A; Andrés, A; Viguri, J R

2010-05-15

The application of solvent-based paints by spraying in paint booths is extensively used in a wide range of industrial activities for the surface treatment of a vast array of products. The wastes generated as overspray represent an important environmental and managerial problem mainly due to the hazardous characteristics of the organic solvent, rendering it necessary to appropriately manage this waste. In this paper a solidification/stabilization (S/S) process based on accelerated carbonation was investigated as an immobilization pre-treatment prior to the disposal, via landfill, of an alkyd solvent-based paint waste coming from the automotive industry; the purpose of this S/S process was to immobilize the contaminants and reduce their release into the environment. Different formulations of paint waste with lime, lime-coal fly-ash and lime-Portland cement were carbonated to study the effect of the water/solid ratio and carbonation time on the characteristics of the final product. To assess the efficiency of the studied S/S process, metals, anions and dissolved organic carbon (DOC) were analyzed in the leachates obtained from a battery of compliance and characterization leaching tests. Regarding the carbonation of paint waste-lime formulations, a mathematical expression has been proposed to predict the results of the leachability of DOC from carbonated mixtures working at water/solid ratios from 0.2 to 0.6. However, lower DOC concentrations in leachates (400mg/kg DOC in L/S=10 batch leaching test) were obtained when carbonation of paint waste-lime-fly-ash mixtures was used at 10h carbonation and water to solid ratio of 0.2. The flammability characteristics, the total contents of contaminants and the contaminant release rate in compliance leaching tests provide evidence for a final product suitable for deposition in non-hazardous landfills. The characterization of this carbonated sample using a dynamic column leaching test shows a high stabilization of metals, partial immobilization of Cl(-), SO(4)(2-), F(-) and limited retention of DOC. However, the obtained results improve the previous findings obtained after the paint waste S/S using uncarbonated formulations and would be a useful pre-treatment technique of the alkyd paint waste prior to its disposal in a landfill. Copyright (c) 2009 Elsevier B.V. All rights reserved.

Preliminary assessment of the aquatic impacts of a proposed defense waste processing facility at the Savannah River Plant

DOE Office of Scientific and Technical Information (OSTI.GOV)

Mackey, H.E. Jr.

1979-01-01

A review of the literature indicates that a significant body of descriptive information exists concerning the aquatic ecology of Upper Three Runs Creek and Four Mile Creek of the Savannah River Plant south of Aiken, South Carolina. This information is adequate for preparation of an environmental document evaluating these streams. These streams will be impacted by construction and operation of a proposed Defense Waste Processing Facility for solidification of high level defense waste. Potential impacts include (1) construction runoff, erosion, and siltation, (2) effluents from a chemical and industrial waste treatment facility, and (3) radionuclide releases. In order to bettermore » evaluate potential impacts, recommend mitigation methods, and comply with NEPA requirements, additional quantitative biological information should be obtained through implementation of an aquatic baseline program.« less

Development Of A Magnetic Directional-Solidification Furnace

NASA Technical Reports Server (NTRS)

Aldrich, Bill R.; Lehoczky, Sandor L.

1996-01-01

Report describes development of directional-solidification furnace in which axial magnetic field is imposed by surrounding ring permanent magnets and/or electromagnets and pole pieces. Furnace provides controlled axial temperature gradients in multiple zones, through which ampoule containing sample of material to be solidified is translated at controlled speed by low-vibration, lead-screw, stepping-motor-driven mechanism. Intended for use in low-gravity (spaceflight) experiments on melt growth of high-purity semiconductor crystals.

Nasreya: a treatment and disposal facility for industrial hazardous waste in Alexandria, Egypt: phase I.

PubMed

Ramadan, Adham R; Kock, Per; Nadim, Amani

2005-04-01

A facility for the treatment and disposal of industrial hazardous waste has been established in Alexandria, Egypt. Phase I of the facility encompassing a secure landfill and solar evaporation ponds is ready to receive waste, and Phase II encompassing physico-chemical treatment, solidification, and interim storage is underway. The facility, the Nasreya Centre, is the first of its kind in Egypt, and represents the nucleus for the integration, improvement and further expansion of different hazardous waste management practices and services in Alexandria. It has been developed within the overall legal framework of the Egyptian Law for the Environment, and is expected to improve prospects for enforcement of the regulatory requirements specified in this law. It has been developed with the overall aim of promoting the establishment of an integrated industrial hazardous waste management system in Alexandria, serving as a demonstration to be replicated elsewhere in Egypt. For Phase I, the Centre only accepts inorganic industrial wastes. In this respect, a waste acceptance policy has been developed, which is expected to be reviewed during Phase II, with an expansion of the waste types accepted.

Application of the Evacuated Canister System for Removing Residual Molten Glass From the West Valley Demonstration Project High-Level Waste Melter

DOE Office of Scientific and Technical Information (OSTI.GOV)

May, Joseph J.; Dombrowski, David J.; Valenti, Paul J.

The principal mission of the West Valley Demonstration Project (WVDP) is to meet a series of objectives defined in the West Valley Demonstration Project Act (Public Law 96-368). Chief among these is the objective to solidify liquid high-level waste (HLW) at the WVDP site into a form suitable for disposal in a federal geologic repository. In 1982, the Secretary of Energy formally selected vitrification as the technology to be used to solidify HLW at the WVDP. One of the first steps in meeting the HLW solidification objective involved designing, constructing and operating the Vitrification (Vit) Facility, the WVDP facility thatmore » houses the systems and subsystems used to process HLW into stainless steel canisters of borosilicate waste-glass that satisfy waste acceptance criteria (WAC) for disposal in a federal geologic repository. HLW processing and canister production began in 1996. The final step in meeting the HLW solidification objective involved ending Vit system operations and shut ting down the Vit Facility. This was accomplished by conducting a discrete series of activities to remove as much residual material as practical from the primary process vessels, components, and associated piping used in HLW canister production before declaring a formal end to Vit system operations. Flushing was the primary method used to remove residual radioactive material from the vitrification system. The inventory of radioactivity contained within the entire primary processing system diminished by conducting the flushing activities. At the completion of flushing activities, the composition of residual molten material remaining in the melter (the primary system component used in glass production) consisted of a small quantity of radioactive material and large quantities of glass former materials needed to produce borosilicate waste-glass. A special system developed during the pre-operational and testing phase of Vit Facility operation, the Evacuated Canister System (ECS), was deployed at the West Valley Demonstration Project to remove this radioactively dilute, residual molten material from the melter before Vit system operations were brought to a formal end. The ECS consists of a stainless steel canister of the same size and dimensions as a standard HLW canister that is equipped with a special L-shaped snorkel assembly made of 304L stainless steel. Both the canister and snorkel assembly fit into a stainless steel cage that allows the entire canister assembly to be positioned over the melter as molten glass is drawn out by a vacuum applied to the canister. This paper describes the process used to prepare and apply the ECS to complete molten glass removal before declaring a formal end to Vit system operations and placing the Vit Facility into a safe standby mode awaiting potential deactivation.« less

West Valley feasibility study

DOE Office of Scientific and Technical Information (OSTI.GOV)

Pirro, J.

This report presents the results of a technical assessment of decontamination alternative prepared for the Western New York Nuclear Service Center (WNYNSC). The purpose of the assessment is to determine the recommended method for decontamination of cell surfaces and decontamination and removal of fuel reprocessing cell equipment to permit manual entry into the cells for the installation of waste solidification equipment. The primary cells of interest are the PMC, GPC, and CPC because they offer the largest usable volume for the solidification program. The secondary cells include XC-1, XC-2, XC-3 and the PPC which may be needed to support themore » solidification program. Five decontamination assessments were evaluated (A-E). The assessments included the estimated cost, occupational exposure, duration, manpower, waste volume generated, and final cell radiation levels achieved with the alternative decontamination methods. The methods varied from thorough destructive decontamination to equipment removal without decontamination followed by cell wall and floor decontamination. The recommended method for the primary cells is to utilize the remote manipulators and cranes to the maximum extent possible to decontaminate equipment and cell surfaces remotely, and to remove the equipment for temporary on-site storage. The recommended method for secondary cell decontamination is to remotely decontaminate the cells to the maximum extent possible prior to manned entry for contact-removal of the fuel reprocessing equipment (Assessment D). Assessment A is expected to cost $8,713,500 in 1980 dollars (including a 25% contingency) and will result in an occupational exposure of 180.3 manRem. Assessment D is expected to cost $11,039,800 and will result in an occupational exposure of 259 manRems.« less

Formation of the Fe-Containing Intermetallic Compounds during Solidification of Al-5Mg-2Si-0.7Mn-1.1Fe Alloy

NASA Astrophysics Data System (ADS)

Que, Zhongping; Wang, Yun; Fan, Zhongyun

2018-06-01

Iron (Fe) is the most common and the most detrimental impurity element in Al alloys due to the formation of Fe-containing intermetallic compounds (IMCs), which are harmful to mechanical performance of the Al-alloy components. In this paper we investigate the formation of Fe-containing IMCs during solidification of an Al-5Mg-2Si-0.7Mn-1.1Fe alloy under varied solidification conditions. We found that the primary Fe-containing intermetallic compound (P-IMC) in the alloy is the BCC α-Al15(Fe,Mn)3Si2 phase and has a polyhedral morphology with {1 1 0} surface termination. The formation of the P-IMCs can be easily suppressed by increasing the melt superheat and/or cooling rate, suggesting that the nucleation of the α-Al15(Fe,Mn)3Si2 phase is difficult. In addition, we found that the IMCs with a Chinese script morphology is initiated on the {1 0 0} surfaces of the P-IMCs during the binary eutectic reaction with the α-Al phase. Both the binary and ternary eutectic IMCs are also identified as the BCC α-Al15(Fe,Mn)3Si2 phase. Furthermore, we found that the Fe content increases and the Mn content decreases in the Fe-containing intermetallic compounds with the decrease of the formation temperature, although the sum of the Fe and Mn contents in all of the IMCs is constant.

Examination of Multiphase (Zr,Ti)(V,Cr,Mn,Ni)2 Ni-MH Electrode Alloys: Part I. Dendritic Solidification Structure

NASA Astrophysics Data System (ADS)

Boettinger, W. J.; Newbury, D. E.; Wang, K.; Bendersky, L. A.; Chiu, C.; Kattner, U. R.; Young, K.; Chao, B.

2010-08-01

The solidification microstructures of three nine-element Zr-Ni-based AB2 type C14/C15 Laves hydrogen storage alloys are determined. The selected compositions represent a class of alloys being examined for usage as an MH electrode in nickel metal-hydride batteries that often have their best properties in the cast state. Solidification is accomplished by dendritic growth of hexagonal C14 Laves phase, peritectic solidification of cubic C15 Laves phase, and formation of cubic B2 phase in the interdendritic regions. The B2 phase decomposes in the solid state into a complex multivariate platelike structure containing Zr-Ni-rich intermetallics. The observed sequence C14/C15 upon solidification agrees with predictions using effective compositions and thermodynamic assessments of the ternary systems, Ni-Cr-Zr and Cr-Ti-Zr. Experimentally, the closeness of the compositions of the C14 and C15 phases required the use of compositional mapping with an energy dispersive detector capable of processing a very high X-ray flux to locate regions in the microstructure for quantitative composition measurement and transmission electron microscope examination.

Gravitational Acceleration Effects on Macrosegregation: Experiment and Computational Modeling

NASA Technical Reports Server (NTRS)

Leon-Torres, J.; Curreri, P. A.; Stefanescu, D. M.; Sen, S.

1999-01-01

Experiments were performed under terrestrial gravity (1g) and during parabolic flights (10-2 g) to study the solidification and macrosegregation patterns of Al-Cu alloys. Alloys having 2% and 5% Cu were solidified against a chill at two different cooling rates. Microscopic and Electron Microprobe characterization was used to produce microstructural and macrosegregation maps. In all cases positive segregation occurred next to the chill because shrinkage flow, as expected. This positive segregation was higher in the low-g samples, apparently because of the higher heat transfer coefficient. A 2-D computational model was used to explain the experimental results. The continuum formulation was employed to describe the macroscopic transports of mass, energy, and momentum, associated with the solidification phenomena, for a two-phase system. The model considers that liquid flow is driven by thermal and solutal buoyancy, and by solidification shrinkage. The solidification event was divided into two stages. In the first one, the liquid containing freely moving equiaxed grains was described through the relative viscosity concept. In the second stage, when a fixed dendritic network was formed after dendritic coherency, the mushy zone was treated as a porous medium. The macrosegregation maps and the cooling curves obtained during experiments were used for validation of the solidification and segregation model. The model can explain the solidification and macrosegregation patterns and the differences between low- and high-gravity results.

Combination Of Investment And Centrifugal Casting

NASA Technical Reports Server (NTRS)

Creeger, Gordon A.

1994-01-01

Modifications, including incorporation of centrifugal casting, made in investment-casting process reducing scrap rate. Used to make first- and second-stage high-pressure-fuel-turbopump nozzles, containing vanes with thin trailing edges and other thin sections. Investment mold spun for short time while being filled, and stopped before solidification occurs. Centrifugal force drives molten metal into thin trailing edges, ensuring they are filled. With improved filling, preheat and pour temperatures reduced and solidification hastened so less hot tearing.

Utilization of air pollution control residues for the stabilization/solidification of trace element contaminated soil.

PubMed

Travar, I; Kihl, A; Kumpiene, J

2015-12-01

The aim of this study was to evaluate the stabilization/solidification (S/S) of trace element-contaminated soil using air pollution control residues (APCRs) prior to disposal in landfill sites. Two soil samples (with low and moderate concentrations of organic matter) were stabilized using three APCRs that originated from the incineration of municipal solid waste, bio-fuels and a mixture of coal and crushed olive kernels. Two APCR/soil mixtures were tested: 30% APCR/70% soil and 50% APCR/50% soil. A batch leaching test was used to study immobilization of As and co-occurring metals Cr, Cu, Pb and Zn. Solidification was evaluated by measuring the unconfined compression strength (UCS). Leaching of As was reduced by 39-93% in APCR/soil mixtures and decreased with increased amounts of added APCR. Immobilization of As positively correlated with the amount of Ca in the APCR and negatively with the amount of soil organic matter. According to geochemical modelling, the precipitation of calcium arsenate (Ca3(AsO4)2/4H2O) and incorporation of As in ettringite (Ca6Al2(SO4)3(OH)12 · 26H2O) in soil/APCR mixtures might explain the reduced leaching of As. A negative effect of the treatment was an increased leaching of Cu, Cr and dissolved organic carbon. Solidification of APCR/soil was considerably weakened by soil organic matter.

Performance evaluation of rotating pump jet mixing of radioactive wastes in Hanford Tanks 241-AP-102 and -104

DOE Office of Scientific and Technical Information (OSTI.GOV)

Onishi, Y.; Recknagle, K.P.

The purpose of this study was to confirm the adequacy of a single mixer pump to fully mix the wastes that will be stored in Tanks 241-AP-102 and -104. These Hanford double-shell tanks (DSTs) will be used as staging tanks to receive low-activity wastes from other Hanford storage tanks and, in turn, will supply the wastes to private waste vitrification facilities for eventual solidification. The TEMPEST computer code was applied to Tanks AP-102 and -104 to simulate waste mixing generated by the 60-ft/s rotating jets and to determine the effectiveness of the single rotating pump to mix the waste. TEMPESTmore » simulates flow and mass/heat transport and chemical reactions (equilibrium and kinetic reactions) coupled together. Section 2 describes the pump jet mixing conditions the authors evaluated, the modeling cases, and their parameters. Section 3 reports model applications and assessment results. The summary and conclusions are presented in Section 4, and cited references are listed in Section 5.« less

Natural convection in the Hale-Shaw cell of horizontal Bridgman solidification

DOE Office of Scientific and Technical Information (OSTI.GOV)

Lu, Y.; Liu, J.; Zhou, Y.

1995-08-01

The numerical simulation of natural convection in the Hale-Shaw cell during horizontal Bridgman solidification reveals that the convection is present even for the very thin cell. The effects of the horizontal temperature gradient, G, thickness of the cell, H, temperature difference between the top and bottom of the cell, and other parameters have been studied. These findings have been confirmed by experiments through direct observation and measurement of convection in the cell containing succinonitrile transparent model alloy.

Heat of Hydration of Low Activity Cementitious Waste Forms

DOE Office of Scientific and Technical Information (OSTI.GOV)

Nasol, D.

2015-07-23

During the curing of secondary waste grout, the hydraulic materials in the dry mix react exothermally with the water in the secondary low-activity waste (LAW). The heat released, called the heat of hydration, can be measured using a TAM Air Isothermal Calorimeter. By holding temperature constant in the instrument, the heat of hydration during the curing process can be determined. This will provide information that can be used in the design of a waste solidification facility. At the Savannah River National Laboratory (SRNL), the heat of hydration and other physical properties are being collected on grout prepared using three simulantsmore » of liquid secondary waste generated at the Hanford Site. From this study it was found that both the simulant and dry mix each had an effect on the heat of hydration. It was also concluded that the higher the cement content in the dry materials mix, the greater the heat of hydration during the curing of grout.« less

Treatability studies performed in support of an engineering evaluation/cost analysis

DOE Office of Scientific and Technical Information (OSTI.GOV)

Myers, J.M.; Mueller, J.P.; Sundquist, J.A.

1995-12-31

The Southern Shipbuilding Corporation (SSC) site is located on 54 acres of wooded land adjacent to Bayou Bonfouca, approximately 1.8 miles downstream of the Bayou Bonfouca National Priorities List (NPL) Superfund site in Slidell, St. Tammany Parish, Louisiana. Two one-acre, impoundments on the SSC site were used to store wastes generated from vessel cleaning. Wastes stored in the impoundments are migrating into Bayou Bonfouca, which empties into Lake Pontchartrain. In addition, the impoundments are frequently invaded by flood waters. The US EPA Emergency Response Branch (EPA-ERB) performed a site investigation which indicated that the majority of the contamination is petroleum-relatedmore » and that the compounds of concern are polycyclic aromatic hydrocarbons (PARs). The wastes are generally contained with the two impoundments and surrounding soils. As part of an Engineering Evaluation/Cost Basis (EE/CA) of potential response action alternatives, four treatability studies were performed. A thermal treatment (incineration) study was performed at the EPA`s Incineration Research Facility (IRF). Biodegradation remedy selection feasibility assessment was conducted on-site. A remedy screening soil washing study was also performed by TAT. A solidification/stabilization (S/S) study was conducted through EPA`s Risk Reduction Engineering Laboratory (RREL) to ascertain if the PAHs could be immobilized within a solid matrix. Experimental objectives, dead methodology and conclusions for these studies are presented as they relate to potential response actions being evaluated at the SSC site.« less

Furfural-based polymers for the sealing of reactor vessels dumped in the Arctic Kara Sea

DOE Office of Scientific and Technical Information (OSTI.GOV)

HEISER,J.H.; COWGILL,M.G.; SIVINTSEV,Y.V.

1996-10-07

Between 1965 and 1988, 16 naval reactor vessels were dumped in the Arctic Kara Sea. Six of the vessels contained spent nuclear fuel that had been damaged during accidents. In addition, a container holding {approximately} 60% of the damaged fuel from the No. 2 reactor of the atomic icebreaker Lenin was dumped in 1967. Before dumping, the vessels were filled with a solidification agent, Conservant F, in order to prevent direct contact between the seawater and the fuel and other activated components, thereby reducing the potential for release of radionuclides into the environment. The key ingredient in Conservant F ismore » furfural (furfuraldehyde). Other constituents vary, depending on specific property requirements, but include epoxy resin, mineral fillers, and hardening agents. In the liquid state (prior to polymerization) Conservant F is a low viscosity, homogeneous resin blend that provides long work times (6--9 hours). In the cured state, Conservant F provides resistance to water and radiation, has high adhesion properties, and results in minimal gas evolution. This paper discusses the properties of Conservant F in both its cured and uncured states and the potential performance of the waste packages containing spent nuclear fuel in the Arctic Kara Sea.« less

Development of a High Chromium Ni-Base Filler Metal Resistant to Ductility Dip Cracking and Solidification Cracking

NASA Astrophysics Data System (ADS)

Hope, Adam T.

Many nuclear reactor components previously constructed with Ni-based alloys containing 20 wt% Cr have been found to be susceptible to stress corrosion cracking. The nuclear power industry now uses high chromium (˜30wt%) Ni-based filler metals to mitigate stress corrosion cracking. Current alloys are plagued with weldability issues, either solidification cracking or ductility dip cracking (DDC). Solidification cracking is related to solidification temperature range and the DDC is related to the fraction eutectic present in the microstructure. It was determined that an optimal alloy should have a solidification temperature range less than 150°C and at least 2% volume fraction eutectic. Due to the nature of the Nb rich eutectic that forms, it is difficult to avoid both cracking types simultaneously. Through computational modeling, alternative eutectic forming elements, Hf and Ta, have been identified as replacements for Nb in such alloys. Compositions have been optimized through a combination of computational and experimental techniques combined with a design of experiment methodology. Small buttons were melted using commercially pure materials in a copper hearth to obtain the desired compositions. These buttons were then subjected to a gas tungsten arc spot weld. A type C thermocouple was used to acquire the cooling history during the solidification process. The cooling curves were processed using Single Sensor Differential Thermal Analysis to determine the solidification temperature range, and indicator of solidification cracking susceptibility. Metallography was performed to determine the fraction eutectic present, an indicator of DDC resistance. The optimal level of Hf to resist cracking was found to be 0.25 wt%. The optimal level of Ta was found to be 4 wt%. gamma/MC type eutectics were found to form first in all Nb, Ta, and Hf-bearing compositions. Depending on Fe and Cr content, gamma/Laves eutectic was sometimes found in Nb and Ta-bearing compositions, while Hf-bearing compositions had gamma/Ni7Hf2 as the final eutectic to solidify. This study found that the extra Cr in the current generation alloys promotes the gamma/Laves phase eutectic, which expands the solidification temperature range and promotes solidification cracking. Both Ta-bearing and Hf-bearing eutectics were found to solidify at higher temperatures than Nb-bearing eutectics, leading to narrower solidification temperature ranges. Weldability testing on the optimized Ta-bearing compositions revealed good resistance to both DDC and solidification cracking. Unexpectedly, the optimized Hf-bearing compositions were quite susceptible to solidification cracking. This led to an investigation on the possible wetting effect of eutectics on solidification cracking susceptibly, and a theory on how wetting affects the solidification crack susceptibility and the volume fraction of eutectic needed for crack healing has been proposed. Alloys with eutectics that easily wet the grain boundaries have increased solidification crack susceptibility at low volume fraction eutectics, but as the fraction eutectic is increased, experience crack healing at relatively lower fraction eutectics than alloys with eutectics that don't wet as easily. Hf rich eutectics were found to wet grain boundaries significantly more than Nb rich eutectics. Additions of Mo were also found to increase the wetting of eutectics in Nb-bearing alloys.

Hydrothermal solidification of municipal solid waste incineration bottom ash with slag addition.

PubMed

Jing, Zhenzi; Ran, Xianqiang; Jin, Fangming; Ishida, Emile H

2010-01-01

Hydrothermal solidification of municipal solid waste incineration (MSWI) bottom ash has been carried out under saturated steam pressure (1.56 MPa) at 200 degrees C for up to 24 h by mixing quartz, slaked lime and water-cooled blast furnace slag (WBFS). The strength enhancement for the WBFS addition was best. The strength development was shown to be due mainly to tobermorite formation, and the tobermorite formation densified matrix, thus promoting the strength development. WBFS seemed to have a higher reactivity than the quartz during the initial hydrothermal process, which provided more silica available to harden the solidified specimens. However, a longer curing time (24 h) was favorable to the quartz dissolution for tobermorite formation, which in turn, enhanced the strength for quartz addition. Curing time affected the crystal morphology evolution, and the stubby plate of tobermorite seemed to result in a high strength enhancement in this study. Laboratory leaching tests were conducted to determine the amount of heavy metals dissolved from the final solidified specimens, and the leaching results showed that after hydrothermal processing the heavy metals dissolved from the solidified specimens were reduced effectively. As such, the hydrothermal processing may have a high potential for recycling/reusing MSWI ash on a large scale. 2010 Elsevier Ltd. All rights reserved.

WEST VALLEY DEMONSTRATION PROJECT ANNUAL SITE ENVIRONMENTAL REPORT CALENDAR YEAR 2002

DOE Office of Scientific and Technical Information (OSTI.GOV)

NONE

2003-09-12

This annual environmental monitoring report for the West Valley Demonstration Project (WVDP or Project) is published to inform those with interest about environmental conditions at the WVDP. In accordance with U.S. Department of Energy (DOE) Order 231.1, Environment, Safety, and Health Reporting, the report summarizes calendar year (CY) 2002 environmental monitoring data so as to describe the performance of the WVDP's environmental management system, confirm compliance with standards and regulations, and highlight important programs. In 2002, the West Valley Demonstration Project, the site of a DOE environmental cleanup activity operated by West Valley Nuclear Services Co. (WVNSCO), was in themore » final stages of stabilizing high-level radioactive waste (HLW) that remained at the site after commercial nuclear fuel reprocessing had been discontinued in the early 1970s. The Project is located in western New York State, about 30 miles south of Buffalo, within the New York State-owned Western New York Nuclear Service Center (WNYNSC). The WVDP is being conducted in cooperation with the New York State Energy Research and Development Authority (NYSERDA). Ongoing work activities at the WVDP during 2002 included: (1) completing HLW solidification and melter shutdown; (2) shipping low-level radioactive waste off-site for disposal; (3) constructing a facility where large high-activity components can be safely packaged for disposal; (4) packaging and removing spent materials from the vitrification facility; (5) preparing environmental impact statements for future activities; (6) removing as much of the waste left behind in waste tanks 8D-1 and 8D-2 as was reasonably possible; (7) removing storage racks, canisters, and debris from the fuel receiving and storage pool, decontaminating pool walls, and beginning shipment of debris for disposal; (8) ongoing decontamination in the general purpose cell and the process mechanical cell (also referred to as the head end cells); (9) planning for cleanup of waste in the plutonium purification cell (south) and extraction cell number 2 in the main plant; (10) ongoing characterization of facilities such as the waste tank farm and process cells; (11) monitoring the environment and managing contaminated areas within the Project facility premises; and (12) flushing and rinsing HLW solidification facilities.« less

TREATMENT OF METAL-LADEN HAZARDOUS WASTES WITH ADVANCED CLEAN COAL TECHNOLOGY BY-PRODUCTS

DOE Office of Scientific and Technical Information (OSTI.GOV)

James T. Cobb, Jr.

2003-09-12

Metal-laden wastes can be stabilized and solidified using advanced clean coal technology by-products (CCTBs)--fluid bed combustor ash and spray drier solids. These utility-generated treatment chemicals are available for purchase through brokers, and commercial applications of this process are being practiced by treaters of metal-laden hazardous waste. A complex of regulations governs this industry, and sensitivities to this complex has discouraged public documentation of treatment of metal-laden hazardous wastes with CCTBs. This report provides a comprehensive public documentation of laboratory studies that show the efficacy of the stabilization and solidification of metal-laden hazardous wastes--such as lead-contaminated soils and sandblast residues--through treatmentmore » with CCTBs. It then describes the extensive efforts that were made to obtain the permits allowing a commercial hazardous waste treater to utilize CCTBs as treatment chemicals and to install the equipment required to do so. It concludes with the effect of this lengthy process on the ability of the treatment company to realize the practical, physical outcome of this effort, leading to premature termination of the project.« less

Solidification and stabilization of the incinerated wastewater sludge from textile industry

NASA Astrophysics Data System (ADS)

Aziz, Hamidi Abdul; Ghazali, Miskiah Fadzilah; Omran, Abdelnaser; Umar, Muhammad

2017-10-01

This paper describes the investigation of solidification and stabilization (S/S) process for the safe disposal of incinerated wastewater sludge produced from a textile industry in Penang, Malaysia. Physical and chemical properties of the samples were first characterized. Various ratios of ordinary Portland cement (OPC) as a binder were used to immobilize the metals. The leachability of metals in these cement-based waste materials was studied by standard toxicity characteristic leaching procedure (TCLP) and the mechanical strength was tested by a compressive strength test. TCLP results showed the ability of OPC to immobilize various metals such as Zn, Cu, Fe, Al, Ti, and K within the limits set by USEPA and Malaysia Environment Quality Act, 1974. However, the strength of the solidified matrixes was generally lower than the control specimens, ranging from 1-23 Mpa, which was well above the specified limit of 414 kPa for such matrices for their disposal in landfills.

A Study on Generation Ice Containing Ozone

NASA Astrophysics Data System (ADS)

Yoshimura, Kenji; Koyama, Shigeru; Yamamoto, Hiromi

Ozone has the capability of sterilization and deodorization due to high oxidation power. It is also effective for the conservation of perishable foods and purification of water. However, ozone has a disadvantage, that is, conservation of ozone is difficult because it changes back into oxygen. Recently, ice containing ozone is taken attention for the purpose of its conservation. The use of ice containing ozone seems to keep food fresher when we conserve and transport perishable foods due to effects of cooling and sterilization of ice containing ozone. In the present study, we investigated the influence of temperatures of water dissolving ozone on the timewise attenuations of ozone concentration in water. We also investigated the influence of cooling temperature, ice diameter, initial temperatures of water dissolving ozone and container internal pressure of the water dissolving ozone on ozone concentration in the ice. In addition, we investigated the influence of the ice diameter on the timewise attenuations of ozone concentration in the ice. It was confirmed that the solidification experimental data can be adjusted by a correlation between ozone concentration in the ice and solidification time.

Chemical characteristics and leachability of organically contaminated heavy metal sludge solidified by silica fume and cement.

PubMed

Jun, K S; Hwang, B G; Shin, H S; Won, Y S

2001-01-01

This paper discusses the development of mixtures with silica fume as a stabilization/solidification agent and binder for industrial wastewater residue containing organic and heavy metal contaminants. The UCS (Unconfined Compressive Strength) gradually increased to 66.7% as the silica fume content increased to 15%. The leaching of TOC and chromium decreased as more OPC was substituted with silica fume. When the mix had 5% silica fume, it retained about 85% TOC, and chromium leached out 0.76 mg-Cr/g-Cr in acidic solution. Also, microstructural studies on the solidified wastes through the scanning electron microscopy/energy dispersive spectroscopy (SEM/EDS) and X-ray diffraction analysis showed that the silica fume caused an inhibition to the ettringite formation which did not contribute to setting, but coated the cement particles and retarded the setting reactions. The results indicated that the incorporation of silica fume into the cement matrix minimized the detrimental effects of organic materials on the cement hydration reaction and contaminant leachability.

Solidification studies of monotectic systems

NASA Technical Reports Server (NTRS)

Chang, K.

1982-01-01

Described is an attempt to determine critical wetting temperatures in monotectic systems and to investigate the wetting phase on container walls and the phase preferential wetting of a monotectic solid.

Immobilization of iodine in concrete

DOEpatents

Clark, Walter E.; Thompson, Clarence T.

1977-04-12

A method for immobilizing fission product radioactive iodine recovered from irradiated nuclear fuel comprises combining material comprising water, Portland cement and about 3-20 wt. % iodine as Ba(IO.sub.3).sub.2 to provide a fluid mixture and allowing the fluid mixture to harden, said Ba(IO.sub.3).sub.2 comprising said radioactive iodine. An article for solid waste disposal comprises concrete prepared by this method. BACKGROUND OF THE INVENTION This invention was made in the course of, or under a contract with the Energy Research and Development Administration. It relates in general to reactor waste solidification and more specifically to the immobilization of fission product radioactive iodine recovered from irradiated nuclear fuel for underground storage.

Remediation by in-situ solidification/stabilisation of Ardeer landfill, Scotland

DOE Office of Scientific and Technical Information (OSTI.GOV)

Wyllie, M.; Esnault, A.; Barker, P.

1997-12-31

The Ardeer Landfill site at ICI Explosives factory on the west coast of Scotland had been a repository for waste from the site for 40 years. In order to safeguard the local environment ICI Explosives, with approval of Local Authorities and the Clyde River Purification Board put into action a programme of investigation and planning which culminated in the in-situ treatment of 10,000 m3 of waste within the landfill by a deep mixing method using the {open_quotes}Colmix{close_quotes} system. The paper describes in varying degrees of detail the remediation from investigation to the execution of the in-situ stabilisation and presents themore » post construction monitoring results.« less

Performance Test on Polymer Waste Form - 12137

DOE Office of Scientific and Technical Information (OSTI.GOV)

Lee, Se Yup

Polymer solidification was attempted to produce stable waste form for the boric acid concentrates and the dewatered spent resins. The polymer mixture was directly injected into the mold or drum which was packed with the boric acid concentrates and the dewatered spent resins, respectively. The waste form was produced by entirely curing the polymer mixture. A series of performance tests was conducted including compressive strength test, water immersion test, leach test, thermal stability test, irradiation stability test and biodegradation stability test for the polymer waste forms. From the results of the performance tests for the polymer waste forms, it ismore » believed that the polymer waste form is very stable and can satisfy the acceptance criteria for permanent disposal. At present, performance tests with full scale polymer waste forms are being carried out in order to obtain qualification certificate by the regulatory institute in Korea. Polymer waste forms were prepared with the surrogate of boric acid concentrates and the surrogate of spent ion exchange resins respectively. Waste forms were also made in lab scale and in full scale. Lab. scale waste forms were directly subjected to a series of the performance tests. In the case of full scale waste form, the test specimens for the performance test were taken from a part of waste form by coring. A series of performance tests was conducted including compressive strength test, thermal stability test, irradiation stability test and biodegradation stability test, water immersion test, leach test, and free standing water for the polymer waste forms. In addition, a fire resistance test was performed on the waste forms by the requirement of the regulatory institute in Korea. Every polymer waste forms containing the boric acid concentrates and the spent ion exchange resins had exhibited excellent structural integrity of more than 27.58 MPa (4,000 psi) of compressive strength. On thermal stability testing, biodegradation testing and water immersion testing, no degradation was observed in the waste forms. Also, by measuring the compressive strength after these tests, it was confirmed that the structural integrity was still retained. A leach test was performed by using non radioactive cobalt, cesium and strontium. The leaching of cobalt, cesium and strontium from the polymer waste forms was very low. Also, the polymer waste forms were found to possess adequate fire resistance. From the results of the performance tests, it is believed that the polymer waste form is very stable and can satisfy the acceptance criteria for permanent disposal. At present, Performance tests with full scale polymer waste forms are on-going in order to obtain qualification certificate by the regulatory institute in Korea. (authors)« less

Influence of solidification accelerators on structure formation of anhydrite-containing binders

NASA Astrophysics Data System (ADS)

Anikanova, L.; Volkova, O.; Kudyakov, A.; Sarkisov, Y.; Tolstov, D.

2016-01-01

The article presents results of scientific analysis of chemical additives influence on acid fluoride binder. It was found that the influence of sulfate nature additives on the process of hydration and solidification of the binder is similar to influence of additives on indissoluble anhydrite. Additives with SO42- anion NO- are more efficient. The mentioned additives according to accelerating effect belong to the following succession: K2SO4 > Na2SO4 > FeSO4 > MgSO4. Facilitation of the process of hydration and solidification of the binder, increase in density and durability of the binder (32 MPa) is to the greatest extent achieved with the introduction of 2% sodium sulfate additive of the binder's mass into the composition of the binder along with the ultrasonic treatment of water solution. Directed crystal formation process with healing of porous structure by new growths presented as calcium sulfate dehydrate and hydroglauberite provides positive effect.

Secondary Waste Cast Stone Waste Form Qualification Testing Plan

DOE Office of Scientific and Technical Information (OSTI.GOV)

Westsik, Joseph H.; Serne, R. Jeffrey

2012-09-26

The Hanford Tank Waste Treatment and Immobilization Plant (WTP) is being constructed to treat the 56 million gallons of radioactive waste stored in 177 underground tanks at the Hanford Site. The WTP includes a pretreatment facility to separate the wastes into high-level waste (HLW) and low-activity waste (LAW) fractions for vitrification and disposal. The LAW will be converted to glass for final disposal at the Integrated Disposal Facility (IDF). Cast Stone – a cementitious waste form, has been selected for solidification of this secondary waste stream after treatment in the ETF. The secondary-waste Cast Stone waste form must be acceptablemore » for disposal in the IDF. This secondary waste Cast Stone waste form qualification testing plan outlines the testing of the waste form and immobilization process to demonstrate that the Cast Stone waste form can comply with the disposal requirements. Specifications for the secondary-waste Cast Stone waste form have not been established. For this testing plan, Cast Stone specifications are derived from specifications for the immobilized LAW glass in the WTP contract, the waste acceptance criteria for the IDF, and the waste acceptance criteria in the IDF Permit issued by the State of Washington. This testing plan outlines the testing needed to demonstrate that the waste form can comply with these waste form specifications and acceptance criteria. The testing program must also demonstrate that the immobilization process can be controlled to consistently provide an acceptable waste form product. This testing plan also outlines the testing needed to provide the technical basis for understanding the long-term performance of the waste form in the disposal environment. These waste form performance data are needed to support performance assessment analyses of the long-term environmental impact of the secondary-waste Cast Stone waste form in the IDF« less

SECONDARY WASTE/ETF (EFFLUENT TREATMENT FACILITY) PRELIMINARY PRE-CONCEPTUAL ENGINEERING STUDY

DOE Office of Scientific and Technical Information (OSTI.GOV)

MAY TH; GEHNER PD; STEGEN GARY

2009-12-28

This pre-conceptual engineering study is intended to assist in supporting the critical decision (CD) 0 milestone by providing a basis for the justification of mission need (JMN) for the handling and disposal of liquid effluents. The ETF baseline strategy, to accommodate (WTP) requirements, calls for a solidification treatment unit (STU) to be added to the ETF to provide the needed additional processing capability. This STU is to process the ETF evaporator concentrate into a cement-based waste form. The cementitious waste will be cast into blocks for curing, storage, and disposal. Tis pre-conceptual engineering study explores this baseline strategy, in additionmore » to other potential alternatives, for meeting the ETF future mission needs. Within each reviewed case study, a technical and facility description is outlined, along with a preliminary cost analysis and the associated risks and benefits.« less

Critical Review of Cement-Based Stabilisation/Solidification Techniques for the Disposal of Hazardous Wastes.

DTIC Science & Technology

1986-12-01

composed of crystalline par- ticles for one or more types accepted and studies of clay organic intaractions gained momentum (7), with some of the...ammonium cations) lessens this effect as the water of hydratior is less strongly held creating a more hydrophobic environment between the layers and...soil (35) and the wate- solubility of the compounds influences the extent of adsorption (19,20), presumably by increasing the extent of hydrophobic

A comparison of the technical sustainability of in situ stabilisation/solidification with disposal to landfill.

PubMed

Harbottle, M J; Al-Tabbaa, A; Evans, C W

2007-03-15

Sustainability is becoming a very important issue in contaminated land remediation and should form one of the factors used in future selection of treatment technologies. In situ stabilisation/solidification (S/S) is a remediation technique that is increasingly being applied to the treatment of contaminated sites because of numerous advantages over other remediation techniques. This paper assesses and compares aspects of the technical sustainability of in situ S/S with landfilling. Criteria previously established for the assessment of the technical sustainability of the remediation of contaminated land are employed. The comparison is presented in the form of a case study based on a real remediation project in the UK. The analysis indicated that landfilling had a larger impact than S/S in the majority of areas investigated, such as waste production (1000 kg waste/t soil remediated for landfilling compared to none for S/S), transportation (12.9 km/t for landfilling, 0.4 km/t for S/S) and use of raw materials (1005.5 kg/t for landfilling, 88.9 kg/t for S/S), although S/S had high greenhouse gas emissions (12.6 kg/t for landfilling, 40.9 kg/t for S/S). In addition, a multi-criteria/cost-effectiveness analysis gave cost effectiveness scores of -34.2 to S/S and -138.1 to landfill (where more positive is better).

Containerless drop tube solidification and grain refinement of NiAl3

NASA Technical Reports Server (NTRS)

Ethridge, E. C.; Curreri, P. A.; Kelly, M.; Workman, G.; Smith, A. M.; Bond, R.

1984-01-01

The possibility of undercooling Ni-Al alloys below the liquidus in order to produce a single phase peritectic structure by containerless drop tube solidification was studied. Containerless process is a technique for both high purity contamination free studies as well as for investigating the undercooling and rapid solidification of alloys by suppression of heterogeneous nucleation on container walls. In order to achieve large undercoolings one must avoid heterogeneous nucleation of crystallization. It was shown that the Marshall Space Flight Center drop tubes ae unique facilities for containerless solidification experiments and large undercoolings are possible with some alloys. The original goal of undercooling the liquid metal well below the liquidus to the peritectic temperature during containerless free to form primarily NiAl3 was achieved. The microstructures were interesting from another point of view. The microstructure from small diameter samples is greatly refined. Small dendrite arm spacings such as these could greatly facilitate the annealing and solid state transformation of the alloy to nearly 10% NiAl3 by reducing the distance over which diffusion needs to occur. This could minimize annealing time and might make it economically feasible to produce NiAl3 alloy.

Influence of Melt Superheating Treatment on Solidification Characteristics and Rupture Life of a Third-Generation Ni-Based Single-Crystal Superalloy

NASA Astrophysics Data System (ADS)

Su, Haijun; Wang, Haifeng; Zhang, Jun; Guo, Min; Liu, Lin; Fu, Hengzhi

2018-05-01

The influence of melt superheating treatment on the melt properties, solidification characteristics, and rupture life of a third-generation Ni-based single-crystal superalloy was investigated to reveal the critical temperature range of melt structure evolution and its effect on rupture life. The results showed that the viscosity of superalloy decreased but the surface tension increased with increasing superheating temperature. Two characteristic temperature points where the melt viscosity and undercooling degree suddenly change were determined to be 1600 °C and 1700 °C, respectively. Similarly, the stability of the solidification interface firstly improved and then weakened with increasing superheating temperature. The dendrite arms were well refined and the segregation was reduced at 1700 °C. In addition, the rupture life obtained at 1100 °C and 137 MPa increased by approximately 30 pct, approaching the rupture life of the corresponding superalloy containing 2 pct Ru, with increasing superheating temperature from 1500 °C to 1700 °C. When the melt was further heated to 1800 °C, the rupture life decreased. The evolutions of solidification characteristics and rupture life with increasing melt superheating temperature were attributed to changes in the melt structure.

DOE Office of Scientific and Technical Information (OSTI.GOV)

Wu, Zeen; Hu, Rui; Zhang, Tiebang, E-mail: tiebang

The microstructure and solidification behavior of high Nb containing TiAl alloys with the composition of Ti-46Al-8Nb-xC (x = 0.1, 0.7, 1.4, 2.5 at.%) prepared by arc-melting method have been investigated in this work. The results give evidence that the addition of carbon changes the solidification behavior from solidification via the β phase to the peritectic solidification. And carbon in solid solution enriches in the α{sub 2} phase and increases the microhardness. As the carbon content increases to 1.4 at.%, plate-shape morphology carbides Ti{sub 2}AlC (H phase) precipitate from the TiAl matrix which leads to the refinement microstructure. By aging atmore » 1173 K for 24 h after quenching treatment, fine needle-like and granular shape Ti{sub 3}AlC (P phase) carbides are observed in the matrix of Ti-46Al-8Nb-2.5C alloy, which distribute along the lamellar structure or around the plate-shape Ti{sub 2}AlC. Transmission electron microscope observation shows that the Ti{sub 3}AlC carbides precipitate at dislocations. The phase transformation in-situ observations indicate that the Ti{sub 2}AlC carbides partly precipitate during the solid state phase transformation process. - Highlights: •Carbon changes the solidification behavior from β phase to peritectic solidification. •Dislocations in solution treated γ phase act as nucleation sites of Ti{sub 3}AlC precipitations. •Ti{sub 3}AlC precipitates as fine needle-like or granular shape in the solution treated matrix. •Ti{sub 2}AlC carbides precipitate during the solid state phase transformation process.« less

DOE Office of Scientific and Technical Information (OSTI.GOV)

Tumurugoti, P.; Clark, B.M.; Edwards, D.J.

Hollandite-rich multiphase waste form compositions processed by melt-solidification and spark plasma sintering (SPS) were characterized, compared, and validated for nuclear waste incorporation. Phase identification by x-ray diffraction (XRD) and electron back-scattered diffraction (EBSD) confirmed hollandite as the major phase present in these samples along with perovskite, pyrochlore and zirconolite. Distribution of selected elements observed by wavelength dispersive spectroscopy (WDS) maps indicated that Cs formed a secondary phase during SPS processing, which was considered undesirable. On the other hand, Cs partitioned into the hollandite phase in melt-processed samples. Further analysis of hollandite structure in melt-processed composition by selected area electron diffractionmore » (SAED) revealed ordered arrangement of tunnel ions (Ba/Cs) and vacancies, suggesting efficient Cs incorporation into the lattice.« less

Evidence for an early wet Moon from experimental crystallization of the lunar magma ocean

NASA Astrophysics Data System (ADS)

Lin, Yanhao; Tronche, Elodie J.; Steenstra, Edgar S.; van Westrenen, Wim

2017-01-01

The Moon is thought to have been covered initially by a deep magma ocean, its gradual solidification leading to the formation of the plagioclase-rich highland crust. We performed a high-pressure, high-temperature experimental study of lunar mineralogical and geochemical evolution during magma ocean solidification that yields constraints on the presence of water in the earliest lunar interior. In the experiments, a deep layer containing both olivine and pyroxene is formed in the first ~50% of crystallization, β-quartz forms towards the end of crystallization, and the last per cent of magma remaining is extremely iron rich. In dry experiments, plagioclase appears after 68 vol.% solidification and yields a floatation crust with a thickness of ~68 km, far above the observed average of 34-43 km based on lunar gravity. The volume of plagioclase formed during crystallization is significantly less in water-bearing experiments. Using the relationship between magma water content and the resulting crustal thickness in the experiments, and considering uncertainties in initial lunar magma ocean depth, we estimate that the Moon may have contained at least 270 to 1,650 ppm water at the time of magma ocean crystallization, suggesting the Earth-Moon system was water-rich from the start.

Stabilisation/solidification of synthetic petroleum drill cuttings.

PubMed

Al-Ansary, Marwa S; Al-Tabbaa, Abir

2007-03-15

This paper presents the results of an experimental investigation into the use of stabilisation/solidification (S/S) to treat synthetic drill cuttings as a pre-treatment to landfilling or for potential re-use as construction products. Two synthetic mixes were used based on average concentrations of specific contaminates present in typical drill cuttings from the North Sea and the Red Sea areas. The two synthetic drill cuttings contained similar chloride content of 2.03% and 2.13% by weight but different hydrocarbon content of 4.20% and 10.95% by weight, respectively; hence the mixes were denoted as low and high oil content mixes, respectively. A number of conventional S/S binders were tested including Portland cement (PC), lime and blast-furnace slag (BFS), in addition to novel binders such as microsilica and magnesium oxide cement. Physical, chemical and microstructural analyses were used to compare the relative performance of the different binder mixes. The unconfined compressive strength (UCS) values were observed to cover a wide range depending on the binder used. Despite the significant difference in the hydrocarbon content in the two synthetic cuttings, the measured UCS values of the mixes with the same binder type and content were similar. The leachability results showed the reduction of the synthetic drill cuttings to a stable non-reactive hazardous waste, compliant with the UK acceptance criteria for non-hazardous landfills: (a) by most of the binders for chloride concentrations, and (b) by the 20% BFS-PC and 30% PC binders for the low oil content mix. The 30% BFS-PC binder successfully reduced the leached oil concentration of the low oil content mix to inert levels. Finally, the microstructural analysis offered valuable information on the morphology and general behaviour of the mixes that were not depicted by the other tests.

Letter Report: LAW Simulant Development for Cast Stone Screening Test

DOE Office of Scientific and Technical Information (OSTI.GOV)

Russell, Renee L.; Westsik, Joseph H.; Swanberg, David J.

2013-03-27

More than 56 million gallons of radioactive and hazardous waste are stored in 177 underground storage tanks at the U.S. Department of Energy’s (DOE’s) Hanford Site in southeastern Washington State. The Hanford Tank Waste Treatment and Immobilization Plant (WTP) is being constructed to treat the wastes and immobilize them in a glass waste form. The WTP includes a pretreatment facility to separate the wastes into a small volume of high-level waste (HLW) containing most of the radioactivity and a larger volume of low-activity waste (LAW) containing most of the nonradioactive chemicals. The HLW will be converted to glass in themore » HLW vitrification facility for ultimate disposal at an offsite federal repository. At least a portion (~35%) of the LAW will be converted to glass in the LAW vitrification facility and will be disposed of onsite at the Integrated Disposal Facility (IDF). The pretreatment and HLW vitrification facilities will have the capacity to treat and immobilize the wastes destined for each facility. However, a second facility will be needed for the expected volume of additional LAW requiring immobilization. A cementitious waste form known as Cast Stone is being considered to provide the required additional LAW immobilization capacity. The Cast Stone waste form must be acceptable for disposal in the IDF. The Cast Stone waste form and immobilization process must be tested to demonstrate that the final Cast Stone waste form can comply with waste acceptance criteria for the IDF disposal facility and that the immobilization processes can be controlled to consistently provide an acceptable waste form product. Further, the waste form must be tested to provide the technical basis for understanding the long term performance of the waste form in the IDF disposal environment. These waste form performance data are needed to support risk assessment and performance assessment (PA) analyses of the long-term environmental impact of the waste disposal in the IDF. A testing program was developed in fiscal year (FY) 2012 describing in some detail the work needed to develop and qualify Cast Stone as a waste form for the solidification of Hanford LAW (Westsik et al. 2012). Included within Westsik et al. (2012) is a section on the near-term needs to address Tri-Party Agreement Milestone M-062-40ZZ. The objectives of the testing program to be conducted in FY 2013 and FY 2014 are to: • Determine an acceptable formulation for the LAW Cast Stone waste form. • Evaluate sources of dry materials for preparing the LAW Cast Stone. • Demonstrate the robustness of the Cast Stone waste form for a range of LAW compositions. • Demonstrate the robustness of the formulation for variability in the Cast Stone process. • Provide Cast Stone contaminant release data for PA and risk assessment evaluations. The first step in determining an acceptable formulation for the LAW Cast Stone waste form is to conduct screening tests to examine expected ranges in pretreated LAW composition, waste stream concentrations, dry-materials sources, and mix ratios of waste feed to dry blend. A statistically designed test matrix will be used to evaluate the effects of these key parameters on the properties of the Cast Stone as it is initially prepared and after curing. The second phase of testing will focus on selection of a baseline Cast Stone formulation for LAW and demonstrating that Cast Stone can meet expected waste form requirements for disposal in the IDF. It is expected that this testing will use the results of the screening tests to define a smaller suite of tests to refine the composition of the baseline Cast Stone formulation (e.g. waste concentration, water to dry mix ratio, waste loading).« less

Engineering and Development Support of General Decon Technology for the DARCOM Installation Restoration Program. Task 4. General Technology Literature Searches (II) Solidification Techniques for Lagoon Waters

DTIC Science & Technology

1980-12-01

40.8 Sodium 70.1 Zinc 0.01 37 The process includes the following steps (Pichat et al., 1979): - neutralization precipitation (silicates, borates...Compressive Strength of Polyester - Encapsulated Sodium Sulfate Waste Composite ....... .............. 64 9. Deep Chemical Mixer Mounted on a Barge...zinc, copper, lead, manganese and tin; sodium salts of arsenate, borate, phosphate, iodate, and sulfide; and sulfate salts. Sulfate salts form calcium

Performance of a cylindrical phase-change thermal energy storage unit

NASA Astrophysics Data System (ADS)

Jacobson, D. L.; Ponnappan, R.

1983-05-01

The high-temperature performance of a eutectic salt Phase Change Material (PCM) in a cylindrical Thermal Energy Storage Container (TESC) sample is evaluated by means of an experimental apparatus with a water-circulated calorimeter. The phase change characteristics of the salt during melting and solidification were observed by monitoring the external axial temperature profile of the container, and the analysis of the phase change heat transfer in the cylindrical geometry was based on the modified heat balance integral method of Tien (1980), which provides the solidification rate and time. Melting point (983 K), freezing point (944 K), latent heat of fusion (782.26 J/gm) and thermal diffusivity (0.00799 sq cm/sec) results are in agreement with those found in the literature. The experimental and analytical results of the nondimensionalized heat transfer resistance as a function of the solidified or melted weight fraction are compared.

Iron in solution with aluminum matrix after non-equilibrium processing: an atom probe tomography study

NASA Astrophysics Data System (ADS)

Saller, Brandon D.; Sha, Gang; Yang, Li Mei; Liu, Fan; Ringer, Simon P.; Schoenung, Julie M.

2017-03-01

In this paper, we report on the influence of rapid solidification and severe plastic deformation on the solid solubility of Fe in Al. Atom probe tomography, for the first time, was performed on fine (3-4 μm diameter) and coarse ( 100 μm) as-atomised Al-5 at.% Fe powder and cryomilled Al-5 at.% Fe powder. The atomised powders exhibited negligible Fe in solution with Al, whereas the cryomilled powder contained 2 at.% Fe in solution. Moreover, our results suggest that severe plastic deformation is preferable to atomisation/rapid solidification for increasing the non-equilibrium solid solubility of Fe in Al.

Iron-phosphate ceramics for solidification of mixed low-level waste

DOEpatents

Aloy, Albert S.; Kovarskaya, Elena N.; Koltsova, Tatiana I.; Macheret, Yevgeny; Medvedev, Pavel G.; Todd, Terry

2000-01-01

A method of immobilizing mixed low-level waste is provided which uses low cost materials and has a relatively long hardening period. The method includes: forming a mixture of iron oxide powders having ratios, in mass %, of FeO:Fe.sub.2 O.sub.3 :Fe.sub.3 O.sub.4 equal to 25-40:40-10:35-50, or weighing a definite amount of magnetite powder. Metallurgical cinder can also be used as the source of iron oxides. A solution of the orthophosphoric acid, or a solution of the orthophosphoric acid and ferric oxide, is formed and a powder phase of low-level waste and the mixture of iron oxide powders or cinder (or magnetite powder) is also formed. The acid solution is mixed with the powder phase to form a slurry with the ratio of components (mass %) of waste:iron oxide powders or magnetite:acid solution=30-60:15-10:55-30. The slurry is blended to form a homogeneous mixture which is cured at room temperature to form the final product.

Directionally solidified article with weld repair

NASA Technical Reports Server (NTRS)

Smashey, Russell W. (Inventor); Snyder, John H. (Inventor); Borne, Bruce L. (Inventor)

2003-01-01

A directionally solidified nickel-base superalloy article has a defect therein extending parallel to the solidification direction. The article is repaired by removing any foreign matter present in the defect, and then heating the article to a repair temperature of from about 60 to about 98 percent of the solidus temperature of the base material in a chamber containing a protective gas that inhibits oxidation of the base material. The defect is filled with a filler metal while maintaining the article at the repair temperature. The filling is accomplished by providing a source of the filler metal of substantially the same composition as the base material of the directionally solidified article, and melting the filler metal into the defect progressively while moving the source of the filler metal relative to the article in a direction parallel to the solidification direction. Optionally, additional artificial heat extraction is accomplished in a heat-flow direction that is within about 45 degrees of the solidification direction, as the filler metal solidifies within the defect. The article may thereafter be heat treated.

Weld repair of directionally solidified articles

NASA Technical Reports Server (NTRS)

Smashey, Russell W. (Inventor); Snyder, John H. (Inventor); Borne, Bruce L. (Inventor)

2002-01-01

A directionally solidified nickel-base superalloy article has a defect therein extending parallel to the solidification direction. The article is repaired by removing any foreign matter present in the defect, and then heating the article to a repair temperature of from about 60 to about 98 percent of the solidus temperature of the base material in a chamber containing a protective gas that inhibits oxidation of the base material. The defect is filled with a filler metal while maintaining the article at the repair temperature. The filling is accomplished by providing a source of the filler metal of substantially the same composition as the base material of the directionally solidified article, and melting the filler metal into the defect progressively while moving the source of the filler metal relative to the article in a direction parallel to the solidification direction. Optionally, additional artificial heat extraction is accomplished in a heat-flow direction that is within about 45 degrees of the solidification direction, as the filler metal solidifies within the defect. The article may thereafter be heat treated.

Thermosolutal convection during dendritic solidification

NASA Technical Reports Server (NTRS)

Heinrich, J. C.; Nandapurkar, P.; Poirier, D. R.; Felicelli, S.

1989-01-01

This paper presents a mathematical model for directional solidification of a binary alloy including a dendritic region underlying an all-liquid region. It is assumed initially that there exists a nonconvecting state with planar isotherms and isoconcentrates solidifying at a constant velocity. The stability of this system has been analyzed and nonlinear calculations are performed that show the effect of convection in the solidification process when the system is unstable. Results of calculations for various cases defined by the initial temperature gradient at the dendrite tips and varying strength of the gravitational field are presented for systems involving lead-tin alloys. The results show that the systems are stable for a gravitational constant of 0.0001 g(0) and that convection can be suppressed by appropriate choice of the container's size for higher values of the gravitational constant. It is also concluded that for the lead-tin systems considered, convection in the mushy zone is not significant below the upper 20 percent of the dendritic zone, if al all.

On oscillatory microstructure during cellular growth of directionally solidified Sn–36at.%Ni peritectic alloy

PubMed Central

Peng, Peng; Li, Xinzhong; Li, Jiangong; Su, Yanqing; Guo, Jingjie

2016-01-01

An oscillatory microstructure has been observed during deep-cellular growth of directionally solidified Sn–36at.%Ni hyperperitectic alloy containing intermetallic compounds with narrow solubility range. This oscillatory microstructure with a dimension of tens of micrometers has been observed for the first time. The morphology of this wave-like oscillatory structure is similar to secondary dendrite arms, and can be observed only in some local positions of the sample. Through analysis such as successive sectioning of the sample, it can be concluded that this oscillatory microstructure is caused by oscillatory convection of the mushy zone during solidification. And the influence of convection on this oscillatory microstructure was characterized through comparison between experimental and calculations results on the wavelength. Besides, the change in morphology of this oscillatory microstructure has been proved to be caused by peritectic transformation during solidification. Furthermore, the melt concentration increases continuously during solidification of intermetallic compounds with narrow solubility range, which helps formation of this oscillatory microstructure. PMID:27066761

On oscillatory microstructure during cellular growth of directionally solidified Sn-36at.%Ni peritectic alloy.

PubMed

Peng, Peng; Li, Xinzhong; Li, Jiangong; Su, Yanqing; Guo, Jingjie

2016-04-12

An oscillatory microstructure has been observed during deep-cellular growth of directionally solidified Sn-36at.%Ni hyperperitectic alloy containing intermetallic compounds with narrow solubility range. This oscillatory microstructure with a dimension of tens of micrometers has been observed for the first time. The morphology of this wave-like oscillatory structure is similar to secondary dendrite arms, and can be observed only in some local positions of the sample. Through analysis such as successive sectioning of the sample, it can be concluded that this oscillatory microstructure is caused by oscillatory convection of the mushy zone during solidification. And the influence of convection on this oscillatory microstructure was characterized through comparison between experimental and calculations results on the wavelength. Besides, the change in morphology of this oscillatory microstructure has been proved to be caused by peritectic transformation during solidification. Furthermore, the melt concentration increases continuously during solidification of intermetallic compounds with narrow solubility range, which helps formation of this oscillatory microstructure.

Arsenic removal by iron oxide coated sponge: treatment and waste management.

PubMed

Nguyen, Tien Vinh; Rahman, Abdur; Vigneswaran, Saravanamuthu; Ngo, Huu Hao; Kandasamy, Jaya; Nguyen, Duc Tho; Do, Tuan Anh; Nguyen, Trung Kien

2009-01-01

One of the problems in drinking water that raises concern over the world is that millions of people still have to use arsenic-contaminated water. There is a worldwide need to develop appropriate technologies to remove arsenic from water for household and community water supply systems. In this study, a new material namely iron oxide coated sponge (IOCSp) was developed and used to remove arsenic (As) from contaminated groundwater in Vietnam. The results indicated that IOCSp has a high capacity in removing both As (V) and As (III). The adsorption capacity of IOCSp was up to 4.6 mg As/g IOCSp, showing better than many other materials. It was observed from a pilot study that a small quantity of IOCSp (180 g) could reduce As concentration of 480 microg/L in 1.5 m3 of contaminated natural water to below 40 microg/L. In addition, an exhausted IOCSp, containing a large amount of arsenic (up to 0.42 wt %) could safely be disposed through the solidification/stabilization with cement. Addition of fly ash also reduced the amount of arsenic in the leachate.

The Characteristics and Generating Mechanism of Large Precipitates in Ti-Containing H13 Tool Steel

NASA Astrophysics Data System (ADS)

Xie, You; Cheng, Guoguang; Chen, Lie; Zhang, Yandong; Yan, Qingzhong

2017-02-01

The characteristics of large precipitates in H13 tool steel with 0.015wt% Ti were studied. The result shows that three types of phases larger than 1 μm exist in the as-cast ingot, that is, (Ti, V) (C, N) type phase, (V, Mo, Cr)C type phase and sulfide. (Ti, V) (C, N) type phase could be further classified as the homogeneous Ti-rich one and the Ti-V-rich one in which Ti/V ratio gradually changes. (V, Mo, Cr)C type phase contains the V-rich one and the Mo-Cr-rich one. The compositional characteristics in all of them have little relation with the cutting position or cooling rate. The precipitating process could be well described through calculation by Thermo-Calc software. During solidification, the primary phase (Ti, V)(C, N) first starts to precipitate in the form of Ti-rich carbonitride. With the development of solidification, the ratio of Ti decreases and that of V increases. Then the primary phase Ti-V-rich (Ti, V)(C, N) and V-rich (V, Mo, Cr)C appears successively. Mo-Cr-rich (V, Mo, Cr)C phase does not precipitate until the solidification process reaches to the end. Sulfide precipitates before (V, Mo, Cr)C type phase and it could act as the nucleus of (V, Mo, Cr)C.

A safer disposal of hazardous phosphate coating sludge by formation of an amorphous calcium phosphate matrix.

PubMed

Navarro-Blasco, I; Duran, A; Pérez-Nicolás, M; Fernández, J M; Sirera, R; Alvarez, J I

2015-08-15

Phosphate coating hazardous wastes originated from the automotive industry were efficiently encapsulated by an acid-base reaction between phosphates present in the sludge and calcium aluminate cement, yielding very inert and stable monolithic blocks of amorphous calcium phosphate (ACP). Two different compositions of industrial sludge were characterized and loaded in ratios ranging from 10 to 50 wt.%. Setting times and compressive strengths were recorded to establish the feasibility of this method to achieve a good handling and a safe landfilling of these samples. Short solidification periods were found and leaching tests showed an excellent retention for toxic metals (Zn, Ni, Cu, Cr and Mn) and for organic matter. Retentions over 99.9% for Zn and Mn were observed even for loadings as high as 50 wt.% of the wastes. The formation of ACP phase of low porosity and high stability accounted for the effective immobilization of the hazardous components of the wastes. Copyright © 2015 Elsevier Ltd. All rights reserved.

Secondary Waste Form Down-Selection Data Package—Fluidized Bed Steam Reforming Waste Form

DOE Office of Scientific and Technical Information (OSTI.GOV)

Qafoku, Nikolla; Westsik, Joseph H.; Strachan, Denis M.

2011-09-12

The Hanford Site in southeast Washington State has 56 million gallons of radioactive and chemically hazardous wastes stored in 177 underground tanks (ORP 2010). The U.S. Department of Energy (DOE), Office of River Protection (ORP), through its contractors, is constructing the Hanford Tank Waste Treatment and Immobilization Plant (WTP) to convert the radioactive and hazardous wastes into stable glass waste forms for disposal. Within the WTP, the pretreatment facility will receive the retrieved waste from the tank farms and separate it into two treated process streams. These waste streams will be vitrified, and the resulting waste canisters will be sentmore » to offsite (high-level waste [HLW]) and onsite (immobilized low-activity waste [ILAW]) repositories. As part of the pretreatment and ILAW processing, liquid secondary wastes will be generated that will be transferred to the Effluent Treatment Facility (ETF) on the Hanford Site for further treatment. These liquid secondary wastes will be converted to stable solid waste forms that will be disposed of in the Integrated Disposal Facility (IDF). To support the selection of a waste form for the liquid secondary wastes from WTP, Washington River Protection Solutions (WRPS) has initiated secondary waste form testing work at Pacific Northwest National Laboratory (PNNL). In anticipation of a down-selection process for a waste form for the Solidification Treatment Unit to be added to the ETF, PNNL is developing data packages to support that down-selection. The objective of the data packages is to identify, evaluate, and summarize the existing information on the four waste forms being considered for stabilizing and solidifying the liquid secondary wastes. At the Hanford Site, the FBSR process is being evaluated as a supplemental technology for treating and immobilizing Hanford LAW radioactive tank waste and for treating secondary wastes from the WTP pretreatment and LAW vitrification processes.« less

WASTE TREATMENT BUILDING SYSTEM DESCRIPTION DOCUMENT

DOE Office of Scientific and Technical Information (OSTI.GOV)

F. Habashi

2000-06-22

The Waste Treatment Building System provides the space, layout, structures, and embedded subsystems that support the processing of low-level liquid and solid radioactive waste generated within the Monitored Geologic Repository (MGR). The activities conducted in the Waste Treatment Building include sorting, volume reduction, and packaging of dry waste, and collecting, processing, solidification, and packaging of liquid waste. The Waste Treatment Building System is located on the surface within the protected area of the MGR. The Waste Treatment Building System helps maintain a suitable environment for the waste processing and protects the systems within the Waste Treatment Building (WTB) from mostmore » of the natural and induced environments. The WTB also confines contaminants and provides radiological protection to personnel. In addition to the waste processing operations, the Waste Treatment Building System provides space and layout for staging of packaged waste for shipment, industrial and radiological safety systems, control and monitoring of operations, safeguards and security systems, and fire protection, ventilation and utilities systems. The Waste Treatment Building System also provides the required space and layout for maintenance activities, tool storage, and administrative facilities. The Waste Treatment Building System integrates waste processing systems within its protective structure to support the throughput rates established for the MGR. The Waste Treatment Building System also provides shielding, layout, and other design features to help limit personnel radiation exposures to levels which are as low as is reasonably achievable (ALARA). The Waste Treatment Building System interfaces with the Site Generated Radiological Waste Handling System, and with other MGR systems that support the waste processing operations. The Waste Treatment Building System interfaces with the General Site Transportation System, Site Communications System, Site Water System, MGR Site Layout, Safeguards and Security System, Site Radiological Monitoring System, Site Electrical Power System, Site Compressed Air System, and Waste Treatment Building Ventilation System.« less

STS-26 MS Nelson adjusts ADSF power cable on Discovery's middeck

NASA Technical Reports Server (NTRS)

1988-01-01

STS-26 Mission Specialist (MS) George D. Nelson adjusts power cable on automated directional solidification furnace (ADSF) support electronics package. ADSF is located in forward (starboard side) lockers on Discovery's, Orbiter Vehicle (OV) 103's, middeck. ADSF consists of the furnace container (left) and the control electronics container (right). An Air National Guard, Houston, Texas, decal appears on middeck locker above ADSF.

Biochar-attenuated desorption of heavy metals in small arms range soils

USDA-ARS?s Scientific Manuscript database

Stabilization (capping/solidification) and dilution (e.g., washing, chelate-assisted phytoremediation) represent non-removal and removal remediation technologies for heavy metal contaminated soils. Biochar is stable in soil, and contains carboxyl and other surface ligands; these properties are usef...

Radionuclide Retention Mechanisms in Secondary Waste-Form Testing: Phase II

DOE Office of Scientific and Technical Information (OSTI.GOV)

Um, Wooyong; Valenta, Michelle M.; Chung, Chul-Woo

2011-09-26

This report describes the results from laboratory tests performed at Pacific Northwest National Laboratory (PNNL) for Washington River Protection Solutions (WRPS) to evaluate candidate stabilization technologies that have the potential to successfully treat liquid secondary waste stream effluents produced by the Hanford Tank Waste Treatment and Immobilization Plant (WTP). WRPS is considering the design and construction of a Solidification Treatment Unit (STU) for the Effluent Treatment Facility (ETF) at Hanford. The ETF, a multi-waste, treatment-and-storage unit that has been permitted under the Resource Conservation and Recovery Act (RCRA), can accept dangerous, low-level, and mixed wastewaters for treatment. The STU needsmore » to be operational by 2018 to receive secondary liquid waste generated during operation of the WTP. The STU will provide the additional capacity needed for ETF to process the increased volume of secondary waste expected to be produced by WTP. This report on radionuclide retention mechanisms describes the testing and characterization results that improve understanding of radionuclide retention mechanisms, especially for pertechnetate, {sup 99}TcO{sub 4}{sup -} in four different waste forms: Cast Stone, DuraLith alkali aluminosilicate geopolymer, encapsulated fluidized bed steam reforming (FBSR) product, and Ceramicrete phosphate bonded ceramic. These data and results will be used to fill existing data gaps on the candidate technologies to support a decision-making process that will identify a subset of the candidate waste forms that are most promising and should undergo further performance testing.« less

Understanding the solidification and microstructure evolution during CSC-MIG welding of Fe–Cr–B-based alloy

DOE Office of Scientific and Technical Information (OSTI.GOV)

Sorour, A.A., E-mail: ahmad.sorour@mail.mcgill.ca; Chromik, R.R., E-mail: richard.chromik@mcgill.ca; Gauvin, R., E-mail: raynald.gauvin@mcgill.ca

2013-12-15

The present is a study of the solidification and microstructure of Fe–28.2%Cr–3.8%B–1.5%Si–1.5%Mn (wt.%) alloy deposited onto a 1020 plain carbon steel substrate using the controlled short-circuit metal inert gas welding process. The as-solidified alloy was a metal matrix composite with a hypereutectic microstructure. Thermodynamic calculation based on the Scheil–Gulliver model showed that a primary (Cr,Fe){sub 2}B phase formed first during solidification, followed by an eutectic formation of the (Cr,Fe){sub 2}B phase and a body-centered cubic Fe-based solid solution matrix, which contained Cr, Mn and Si. Microstructure analysis confirmed the formation of these phases and showed that the shape of themore » (Cr,Fe){sub 2}B phase was irregular plate. As the welding heat input increased, the weld dilution increased and thus the volume fraction of the (Cr,Fe){sub 2}B plates decreased while other microstructural characteristics were similar. - Highlights: • We deposit Fe–Cr–B-based alloy onto plain carbon steel using the CSC-MIG process. • We model the solidification behavior using thermodynamic calculation. • As deposited alloy consists of (Cr,Fe){sub 2}B plates embedded in Fe-based matrix. • We study the effect of the welding heat input on the microstructure.« less

Strength, leachability and microstructure characteristics of cement-based solidified plating sludge

DOE Office of Scientific and Technical Information (OSTI.GOV)

Asavapisit, Suwimol; Naksrichum, Siripat; Harnwajanawong, Naraporn

2005-06-01

The solidification of the stabilized zinc-cyanide plating sludge was carried out using ordinary Portland cement (OPC) and pulverized fuel ash (PFA) as solidification binders. The plating sludge were used at the level of 0%, 10%, 20% and 30% dry weight, and PFA was used to replace OPC at 0%, 10%, 20% and 30% dry weight, respectively. Experimental results showed that a significant reduction in strength was observed when the plating sludge was added to both the OPC and OPC/PFA binders, but the negative effect was minimized when PFA was used as part substitute for OPC. SEM observation reveals that themore » deposition of the plating sludge on the surface of the clinkers and PFA could be the cause for hydration retardation. In addition, calcium zinc hydroxide hydrate complex and the unreacted di- and tricalcium silicates were the major phases in X-ray diffraction (XRD) patterns of the solidified plating waste hydrated for 28 days, although the retardation effect on hydration reactions but Cr concentration in toxicity characteristic leaching procedure (TCLP) leachates was lower than the U.S. EPA regulatory limit.« less

An investigation of the elevated temperature cracking susceptibility of alloy C-22 weld-metal

NASA Astrophysics Data System (ADS)

Gallagher, Morgan Leo

Alloy C-22 is one of the most corrosion resistant Ni-Cr-Mo alloys available today, and is particularly versatile. As a result, Alloy C-22 is being considered for use in the construction of storage canisters for permanent disposal of radioactive waste in the Yucca Mountain Project. However, in such a critical application, weld related defects (such as these two forms of cracking) are simply unacceptable. Solidification cracking occurs when weld shrinkage strains are applied to liquid films that result from microsegregation during solidification. Many nickel-base alloys are susceptible to solidification cracking since they solidify as austenite and many of their alloying additions partition during solidification and form low melting eutectic constituents. The transvarestraint test was used to quantify the susceptibility of Alloy C-22 to solidification cracking. The solidification cracking temperature range (SCTR) was found to be approximately 50°C (90°F); this SCTR predicts that Alloy-C-22 will have only slightly higher susceptibility than known crack-resistant alloys, such as duplex stainless-steel 2205 and austenitic stainless-steel Type 304 (FN6). Ductility-dip cracking (DDC) is a solid-state cracking phenomenon that occurs below the effective solidus temperature in highly restrained austenitic alloys. Although this type of cracking is relatively uncommon, it can be costly in critical applications where there is a low tolerance for defects. This investigation used two separate tests to quantify the susceptibility of the alloy to DDC: the hot-ductility test and the strain-to-fracture (STF) test. The hot-ductility test revealed that Alloy C-22 weld-metal exhibits an intermediate temperature ductility-dip, with ductility recovery at the upper end of the testing temperature range. The ductility minimum in the hot-ductility tests occurred around 950°C (1742°F) in both the on-heating and on-cooling tests. The strain-to-fracture test also revealed Alloy C-22 to be susceptible to ductility-dip cracking. Alloy C-22 displayed a low threshold strain necessary to initiate cracking, a wide temperature range over which cracking occurred, and no recovery of ductility at the upper end of the testing temperature range. The recovery of ductility at the upper end of the testing temperature range in the hotductility test, and the absence of this recovery in the STF test, is explained by the recrystallization behavior of the metal. Alloy C-22 has a low stacking-fault-energy, as compared to other DDC susceptible nickel-base alloys, and accordingly requires higher levels of deformation before recrystallization begins. With the relatively low strains experienced by the samples in the STF test (less than ten-percent), cracking will occur before enough strain is accumulated to cause recrystallization. In the hot-ductility test, where the sample is pulled to failure, sufficient strain (forty-percent or greater) is applied such that recrystallization occurs. This recrystallization is responsible for the recovery of ductility at the high end of the testing temperature range in the hot-ductility test. The low threshold strain that is observed in the STF test is in part explained by the behavior of the metal during the thermal cycle of the test. Experimental observations indicate that tortuous (wavy) solidification grain boundaries (SGB) migrate, or straighten, during the temperature upslope and hold period of the STF test. This migration of the grain boundaries reduces the mechanical locking effect that tortuous grain boundaries provide, allowing cracking to occur at lower applied strains. Button-melting experiments were conducted to examine the effect of compositional variation on both solidification cracking and ductility-dip cracking susceptibility of the alloy. Molybdenum, tungsten, and iron were selected for variation, as previous research has shown these three elements to be significantly enriched or depleted in the terminal solidification products of Alloy C-22 weld-metal. The solidification temperature range and volume fraction of secondary phases were used as indicators of the susceptibility of the experimental alloys to solidification cracking and ductility-dip cracking, respectively. Previous research on nickel-base alloys has demonstrated that the solidification temperature range of an alloy is directly proportional to the susceptibility of the alloy to solidification cracking. Experiments conducted within this investigation indicate that increasing the volume fraction of secondary phases in Alloy C-22 acts to increase the elevated temperature cracking-resistance and ductility of the alloy. The solidification temperature ranges of the Alloy C-22 variants examined within the button-melting experiments did not significantly widen or narrow with increases in composition. These same compositional variations demonstrated that increasing amounts of molybdenum, tungsten, and iron increased the volume fraction of secondary phases, with each element having relatively the same potency. Based on the button melting experiments and thermodynamic simulations, it is expected that Alloy C-22 will have good resistance to weld solidification cracking over its entire composition range. (Abstract shortened by UMI.)

Method of preparing a high heating value fuel product

DOE Office of Scientific and Technical Information (OSTI.GOV)

Somerville, R.; Fan, L.T.

1989-10-24

This patent describes a method of preparing a high heating value fuel product. The method comprising the steps of: blending a high heating value waste material with a cellulosic material; mixing an organic reagent to the blended mixture of the waste material and the cellulosic material, the organic reagent being a mixture having a 4-15 weight percent of a chemical selected from the group consisting of: triethylene, glycol, diethylene glycol, and glycerin propylene glycol; introducing a pozzolanic agent to the blended mixture for controlling the rate of solidification; and forming the blended mixture into a form suitable for handling. Alsomore » described is the same method with the mixture of the organic reagent further comprising: a 20-32 weight percent calcium chloride solution. Another method of preparing a fuel product is also described.« less

SOLIDIFICATION/STABILIZATION: A LOW COST TREATMENT FOR WOOD PRESERVING SITES

EPA Science Inventory

Over 600 curent and former wood preserving sites have been identified across the U.S. Many of these have been placed on the EPA Superfund NPL (National Priorities List). Most of these sites contain soils contaminated with pentachlorophenol, dioxins, and/or creosote. Treatability...

Convective and interfacial instabilities during solidification of succinonitrile containing ethanol

NASA Technical Reports Server (NTRS)

Schaefer, R. J.; Coriell, S. R.

1982-01-01

Even though slow convective flow is difficult to detect in solidifying metals, it can readily be observed in transparent materials by observing the motion of small neutrally buoyant particles. Succinonitrile, which solidifies with an unfaceted solid/liquid interface and has well characterized physical properties, is considered an excellent material for such studies. For studies of solute-induced convection, ethanol is a useful addition to succinonitrile since it has a lower density and a somewhat similar molecular structure. Samples of high purity and ethanol-doped succinonitrile are unidirectionally solidified in a vertical temperature gradient. Latex mimcrospheres 2 microns in diameter are suspended in the liquid to reveal the convective flow. Convective and morphological stability is observed as a function of solute concentration and growth velocity. These measurements are compared with theoretical calculations that predict the transition from stability to instability as a function of solidification conditions. The predicted transitions occur at low concentrations and solidification velocities; for this reason, extreme care must be taken in order to eliminate the effects of impurities or thermally induced convection.

Influence of solidification accelerators on structure formation of anhydrite-containing binders

DOE Office of Scientific and Technical Information (OSTI.GOV)

Anikanova, L., E-mail: alasmit@mail.ru; Volkova, O., E-mail: v.olga.nikitina@gmail.com; Kudyakov, A.

2016-01-15

The article presents results of scientific analysis of chemical additives influence on acid fluoride binder. It was found that the influence of sulfate nature additives on the process of hydration and solidification of the binder is similar to influence of additives on indissoluble anhydrite. Additives with SO{sub 4}{sup 2−} anion NO{sup −} are more efficient. The mentioned additives according to accelerating effect belong to the following succession: K{sub 2}SO{sub 4} > Na{sub 2}SO{sub 4} > FeSO{sub 4} > MgSO{sub 4}. Facilitation of the process of hydration and solidification of the binder, increase in density and durability of the binder (32 MPa)more » is to the greatest extent achieved with the introduction of 2% sodium sulfate additive of the binder’s mass into the composition of the binder along with the ultrasonic treatment of water solution. Directed crystal formation process with healing of porous structure by new growths presented as calcium sulfate dehydrate and hydroglauberite provides positive effect.« less

Effects of Non-equilibrium Solidification on the Material Properties of Brick Silicon for Photovoltaics

NASA Technical Reports Server (NTRS)

Regnault, W. F.; Yoo, K. C.; Soltani, P. K.; Johnson, S. M.

1984-01-01

Silicon ingot growth technologies like the Ubiquitous Crystallization Process (UCP) are solidified within a shaping crucible. The rate at which heat can be lost from this crucible minus the rate at which heat is input from an external source determines the rate at which crystallization will occur. Occasionally, when the process parameters for solidification are exceeded, the normally large multi-centimeter grain size material assocated with the UCP will break down into regions containing extremely small, millimeter or less, grain size material. Accompanying this breakdown in grain growth is the development of so called sinuous grain boundaries. The breakdown in grain growth which results in this type of small grain structure with sinuous boundaries is usually associated with the rapid crystallization that would accompany a system failure. This suggests that there are limits to the growth velocity that one can obtain and still expect to produce material that would possess good photovoltaic properties. It is the purpose to determine the causes behind the breakdown of this material and what parameters will determine the best rates of solidification.

Grain Refinement and Texture Mitigation in Low Boron Containing TiAl-Alloys

NASA Astrophysics Data System (ADS)

Hecht, Ulrike; Witusiewicz, Victor T.

2017-12-01

Controlling the grain size and texture of lamellar TiAl-alloys is essential for well-balanced creep and fatigue properties. Excellent refinement and texture mitigation are achieved in aluminum lean alloys by low boron additions of 0.2 at.%. This amount is sufficient to promote in situ formation of ultrafine borides during the last stages of body centered cubic (BCC) solidification. The borides subsequently serve as nucleation sites for hexagonal close packed (HCP) during the BCC-HCP phase transformation. Bridgman solidification experiments with alloy Ti-43Al-8Nb-0.2C-0.2B were performed under a different growth velocity, i.e., cooling rate, to evaluate the HCP grain size distribution and texture. For slow-to-moderate cooling rates, about 65% of HCP grains are randomly oriented, despite the pronounced texture of the parent BCC phase resulting from directional solidification. For high cooling rates, obtained by quenching, texture mitigation is less pronounced. Only 28% of the HCP grains are randomly oriented, the majority being crystallographic variants of the Burgers orientation relationship.

Eutectic Experiment Development for Space Processing

NASA Technical Reports Server (NTRS)

Hopkins, R. H.

1972-01-01

A ground base test plan and a specimen evaluation scheme have been developed for the aluminum-copper eutectic solidification experiment to be run in the M518 multipurpose electric furnace during the Skylab mission. Besides thermal and solidification studies a detailed description is given of the quantitative metallographic technique which is appropriate for characterizing eutectic structures. This method should prove a key tool for evaluating specimen microstructure which is the most sensitive indicator of changes produced during solidification. It has been recommended that single grain pre-frozen eutectic specimens be used to simplify microstructural evaluation and to eliminate any porosity in the as-cast eutectic specimens. High purity (99.999%) materials from one supplier should be employed for all experiments. Laboratory studies indicate that porosity occurs in the MRC as-cast eutectic ingots but that this porosity can be eliminated by directional freezing. Chemical analysis shows that the MRC ingots are slightly Al rich and contain about .03% impurity. Because of the impurity content the lower cooldown rate (1.2 C/min) should be used for eutectic freezing if MRC material is used in the M518 furnace.

Microstructural indicators of convection in sills and dykes

NASA Astrophysics Data System (ADS)

Holness, Marian; Neufeld, Jerome; Gilbert, Andrew

2016-04-01

The question of whether or not magma convects is a vexed one, with some advocating vigorous convection in crustal magma chambers while others suggest that convection is weak and short-lived. From a detailed microstructural study of a range of tabular mafic intrusions, we argue that it is possible to determine whether crystallization took place predominantly in solidification fronts (i.e. the magma was essentially crystal-free) or whether crystals grew suspended in a convecting magma. The 168m thick Shiant Isles Main Sill is a composite body, dominated by a 140m thick unit with a 45m thick base rich in olivine phenocrysts (picrodolerite). The remainder of the unit contains only interstitial olivine. The average olivine grain size in the picrodolerite decreases upwards in the lowermost 10m, but then increases upwards. The coarsening-upwards sequence is marked by the onset of clustering of olivine grains. The extent to which these clusters are sintered, and the average cluster size, increase upwards. The coarsening-upwards sequence and the clustering are mirrored in a thinner (<10m) sequence at the roof. The fining-upwards sequence of non-clustered olivine formed by the rapid settling of incoming cargo crystals, while the coarsening-upwards sequence of clustered olivine represents post-emplacement growth of grains suspended in a convecting magma. The clusters grew by synneusis, with the extensive sintering pointing to the retention of the clusters in the convecting magma for a considerable time. The presence of large clusters at the intrusion roof can be reconciled with their high Stokes settling velocity if they were brought up in rapidly moving convective currents and entangled in the downwards-propagating solidification front. A further indication of convection is provided by plagioclase grain shape. During interface-controlled growth, plagioclase grows as well-facetted compact grains: these grains are platy in rapidly-cooled rocks and blocky in slowly-cooled rocks. In mafic sills, the average apparent aspect ratio (AR), as measured in thin-section, varies smoothly with model crystallization times (calculated assuming diffusive heat loss), consistent with in situ growth in solidification fronts. However, AR is invariant across individual mafic dykes, with decreasing values (i.e. more blocky grains) as the dyke width increases. This difference can be accounted for by the plagioclase in dykes growing as individual grains and clusters suspended in a convecting magma. Cooling at a vertical wall, as is the case for dykes, will always result in a gravitational convective instability, and therefore crystal-poor magma in dykes will always convect. As solidification proceeds, the increasing volume fraction of suspended crystals will eventually damp convection: the final stages of solidification occur in static crystal-rich magma, containing a well-mixed grain population. That the Shiant Isles Main Sill exhibits evidence for prolonged convection of sufficient vigour to suspend 5 mm olivine clusters, while other sills of comparable thickness contain plagioclase with grain shapes indicative of growth predominantly in solidification fronts, is most likely due to the composite nature of the Shiant. The 140m unit is underlain by 23m of picrite which intruded shortly before - this heat source would have acted as a strong driver for convection.

A comprehensive review on removal of arsenic using activated carbon prepared from easily available waste materials.

PubMed

Mondal, Monoj Kumar; Garg, Ravi

2017-05-01

Arsenic contamination in water bodies is a serious problem and causes various health problems due to which US Environment Protection Agency (USEPA) set its maximum permissible limit of 10 ppb. The present review article starts with the removal of toxic arsenic using adsorbents prepared from easily available waste materials. Adsorbent either commercial or low-cost adsorbent can be used for arsenic removal but recent research was focused on the low-cost adsorbent. Preparation and activation of various adsorbents were discussed. Adsorption capacities, surface area, thermodynamic, and kinetics data of various adsorbents for As(III) and As(V) removal were compiled. Desorption followed by regeneration and reuse of adsorbents is an important step in adsorption and leads to economical process. Various desorbing and regenerating agents were discussed for arsenic decontamination from the adsorbent surface. Strong acids, bases, and salts are the main desorbing agents. Disposal of arsenic-contaminated adsorbent and arsenic waste was also a big problem because of the toxic and leaching effect of arsenic. So, arsenic waste was disposed of by proper stabilization/solidification (S/S) technique by mixing it in Portland cement, iron, ash, etc. to reduce the leaching effect.

Process envelopes for stabilisation/solidification of contaminated soil using lime-slag blend.

PubMed

Kogbara, Reginald B; Yi, Yaolin; Al-Tabbaa, Abir

2011-09-01

Stabilisation/solidification (S/S) has emerged as an efficient and cost-effective technology for the treatment of contaminated soils. However, the performance of S/S-treated soils is governed by several intercorrelated variables, which complicates the optimisation of the treatment process design. Therefore, it is desirable to develop process envelopes, which define the range of operating variables that result in acceptable performance. In this work, process envelopes were developed for S/S treatment of contaminated soil with a blend of hydrated lime (hlime) and ground granulated blast furnace slag (GGBS) as the binder (hlime/GGBS = 1:4). A sand contaminated with a mixture of heavy metals and petroleum hydrocarbons was treated with 5%, 10% and 20% binder dosages, at different water contents. The effectiveness of the treatment was assessed using unconfined compressive strength (UCS), permeability, acid neutralisation capacity and contaminant leachability with pH, at set periods. The UCS values obtained after 28 days of treatment were up to ∼800 kPa, which is quite low, and permeability was ∼10(-8) m/s, which is higher than might be required. However, these values might be acceptable in some scenarios. The binder significantly reduced the leachability of cadmium and nickel. With the 20% dosage, both metals met the waste acceptance criteria for inert waste landfill and relevant environmental quality standards. The results show that greater than 20% dosage would be required to achieve a balance of acceptable mechanical and leaching properties. Overall, the process envelopes for different performance criteria depend on the end-use of the treated material.

Characterization of oily sludge from a Tehran oil refinery.

PubMed

Heidarzadeh, Nima; Gitipour, Saeid; Abdoli, Mohammad Ali

2010-10-01

In this study, oily sludge samples generated from a Tehran oil refinery (Pond I) were evaluated for their contamination levels and to propose an adequate remediation technique for the wastes. A simple, random, sampling method was used to collect the samples. The samples were analyzed to measure Total petroleum hydrocarbon (TPH), polyaromatic hydrocarbon (PAH) and heavy metal concentrations in the sludge. Statistical analysis showed that seven samples were adequate to assess the sludge with respect to TPH analyses. The mean concentration of TPHs in the samples was 265,600 mg kg⁻¹. A composite sample prepared from a mix of the seven samples was used to determine the sludge's additional characteristics. Composite sample analysis showed that there were no detectable amounts of PAHs in the sludge. In addition, mean concentrations of the selected heavy metals Ni, Pb, Cd and Zn were 2700, 850, 100, 6100 mg kg⁻¹, respectively. To assess the sludge contamination level, the results from the analysis above were compared with soil clean-up levels. Due to a lack of national standards for soil clean-up levels in Iran, sludge pollutant concentrations were compared with standards set in developed countries. According to these standards, the sludge was highly polluted with petroleum hydrocarbons. The results indicated that incineration, biological treatment and solidification/stabilization treatments would be the most appropriate methods for treatment of the sludges. In the case of solidification/stabilization, due to the high organic content of the sludge, it is recommended to use organophilic clays prior to treatment of the wastes.

Solidification of spent ion exchange resins into the SIAL matrix at the Dukovany NPP, Czech Republic

DOE Office of Scientific and Technical Information (OSTI.GOV)

Tatransky, Peter; Prazska, Milena; Harvan, David

2013-07-01

Based on the decision of the State Office for Nuclear Safety, the Dukovany NPP has been obliged to secure the efficient capacities for the disposal of spent ion exchange resins. Therefore, in September 2010, based on the contract with supplier company AMEC Nuclear Slovakia s.r.o. has begun with pumping and treatment of ion exchange resins from the storage tank 0TW30B02, situated in the auxiliary building. The SIAL{sup R} technology, developed in AMEC Nuclear Slovakia, has been used for the solidification purposes. This technology allows an on-site treatment of various special radioactive waste streams (resins, sludge, sludge/resins and borates) at themore » room temperature. The SIAL{sup R} matrix and technology were licensed by the Czech State Office for Nuclear Safety in 2007. On-site treatment and solidification of spent ion exchange resins at Dukovany NPP involves process of resin removal from tank using remotely operated manipulator, resin transportation, resin separation from free water, resin filling into 200 dm{sup 3} drums and solidification into SIAL{sup R} matrix in 200 dm{sup 3} drums using the FIZA S 200 facility. The final product is observed for compressive strength, leachability, radionuclide composition, dose rate, solids and total weight. After meeting the requirements for final disposal and consolidation, the drums are being transported for the final disposal to the Repository at Dukovany site. During the 3 month's trial operation in 2010, and the normal operation in 2011 and 2012, 189 tons of dewatered resins have been treated into 1960 drums, with total activity higher than 920 GBq. At the end of trial run (2010), 22 tons of dewatered resins were treated into 235 drums. During standard operation approximately 91 tons in 960 drums (2011) and 76 tons in 765 drums (2012) were treated. The weights of resins in the drum ware in the range from 89 - 106 kg and compressive strength limit (10 MPa) has already been achieved 24 hours after fixation. The final measured strength values ranged from 19.0 - 34.7 MPa and real leachability values ranged from 0.03 - 0.65%, far below the 4% limit value. Collective effective dose of all workers in 2012 was 7.7 mSv (12.6 mSv in 2011, 6.2 mSv in 2010). Average individual effective dose in 2012 was 0.55 mSv (14 workers), and maximal individual effective dose was 2.25 mSv. This approach allows fast, safe and cost effective immobilization and transformation of dangerous radioactive waste such as sludge and resins into the solid form, which is suitable for long term storage or disposal. (authors)« less

Application of Solidification Theory to Rapid Solidification Processing

DTIC Science & Technology

1984-07-01

solubility; _NiAl -Cr quasibinary alloys ; Rapid solidification ; Solidification theory I’.ASRACT ICfene an roerso aid it 000e..yV SON identify0 by Week...110100a) ~j ~apid solidification allows the production of alloys with new compositions and * uphases and also allows production of improved alloys by...control of microstructure;L and homogeneity. The effect of rapid solidification velocity on the micro- structure of Ag-Cu alloys is comprehensively

Laser weldability of 21Cr-6Ni-9Mn stainless steel: Part I - Impurity effects and solidifcation mode

DOE Office of Scientific and Technical Information (OSTI.GOV)

Tate, Stephen B.; Javernick, Daniel Anthony; Lienert, Thomas J.

For laser welded type 21Cr-6Ni-9Mn (21-6-9) stainless steels, the relationship between solidification cracking susceptibility and chemical composition was examined, and primary solidification mode (PSM) diagrams were developed to predict solidification mode. Sigmajig testing was used with experimental heats of type 21-6-9 to determine the effect of P and S on solidification cracking w hen primary austenite solidification occurred. Phosphorus showed a larger influence on solidification cracking relative to S, and a relationship of (P+0.2S ) was found for total impurity content. PSM diagrams to predict solidification mode were developed by analyzing welds made at three travel speeds for a widemore » range of 21-6-9 alloys and some other similar alloys. The minimum Cr eq/Ni eq required for primary ferrite solidification increased as travel speed increased, with more alloys showing primary austenite solidification at higher travel rates. Furthermore, as travel speed increased from 21 to 85 mm/s, the average solidification rate increased from 6 to 25 mm/s.« less

Laser weldability of 21Cr-6Ni-9Mn stainless steel: Part I - Impurity effects and solidifcation mode

DOE PAGES

Tate, Stephen B.; Javernick, Daniel Anthony; Lienert, Thomas J.; ...

2016-11-02

For laser welded type 21Cr-6Ni-9Mn (21-6-9) stainless steels, the relationship between solidification cracking susceptibility and chemical composition was examined, and primary solidification mode (PSM) diagrams were developed to predict solidification mode. Sigmajig testing was used with experimental heats of type 21-6-9 to determine the effect of P and S on solidification cracking w hen primary austenite solidification occurred. Phosphorus showed a larger influence on solidification cracking relative to S, and a relationship of (P+0.2S ) was found for total impurity content. PSM diagrams to predict solidification mode were developed by analyzing welds made at three travel speeds for a widemore » range of 21-6-9 alloys and some other similar alloys. The minimum Cr eq/Ni eq required for primary ferrite solidification increased as travel speed increased, with more alloys showing primary austenite solidification at higher travel rates. Furthermore, as travel speed increased from 21 to 85 mm/s, the average solidification rate increased from 6 to 25 mm/s.« less

40 CFR Appendix D to Part 300 - Appropriate Actions and Methods of Remedying Releases

Code of Federal Regulations, 2013 CFR

2013-07-01

...) Neutralization. (D) Equalization. (E) Chemical oxidation. (iii) Physical methods, including the following: (A... treatment. (F) Wet air oxidation. (G) Solidification. (H) Encapsulation. (I) Soil washing or flushing. (J... containment. (iv) Leachate control, including the following: (A) Subsurface drains. (B) Drainage ditches. (C...

40 CFR Appendix D to Part 300 - Appropriate Actions and Methods of Remedying Releases

Code of Federal Regulations, 2014 CFR

2014-07-01

...) Neutralization. (D) Equalization. (E) Chemical oxidation. (iii) Physical methods, including the following: (A... treatment. (F) Wet air oxidation. (G) Solidification. (H) Encapsulation. (I) Soil washing or flushing. (J... containment. (iv) Leachate control, including the following: (A) Subsurface drains. (B) Drainage ditches. (C...

40 CFR Appendix D to Part 300 - Appropriate Actions and Methods of Remedying Releases

Code of Federal Regulations, 2012 CFR

2012-07-01

...) Neutralization. (D) Equalization. (E) Chemical oxidation. (iii) Physical methods, including the following: (A... treatment. (F) Wet air oxidation. (G) Solidification. (H) Encapsulation. (I) Soil washing or flushing. (J... containment. (iv) Leachate control, including the following: (A) Subsurface drains. (B) Drainage ditches. (C...

Novel method of realizing metal freezing points by induced solidification

NASA Astrophysics Data System (ADS)

Ma, C. K.

1997-07-01

The freezing point of a pure metal, tf, is the temperature at which the solid and liquid phases are in equilibrium. The purest metal available is actually a dilute alloy. Normally, the liquidus point of a sample, tl, at which the amount of the solid phase in equilibrium with the liquid phase is minute, provides the closest approximation to tf. Thus the experimental realization of tf is a matter of realizing tl. The common method is to cool a molten sample continuously so that it supercools and recalesces. The highest temperature after recalescence is normally the best experimental value of tl. In the realization, supercooling of the sample at the sample container and the thermometer well is desirable for the formation of dual solid-liquid interfaces to thermally isolate the sample and the thermometer. However, the subsequent recalescence of the supercooled sample requires the formation of a certain amount of solid, which is not minute. Obviously, the plateau temperature is not the liquidus point. In this article we describe a method that minimizes supercooling. The condition that provides tl is closely approached so that the latter may be measured. As the temperature of the molten sample approaches the anticipated value of tl, a small solid of the same alloy is introduced into the sample to induce solidification. In general, solidification does not occur as long as the temperature is above or at tl, and occurs as soon as the sample supercools minutely. Thus tl can be obtained, in principle, by observing the temperature at which induced solidification begins. In case the solid is introduced after the sample has supercooled slightly, a slight recalescence results and the subsequent maximum temperature is a close approximation to tl. We demonstrate that the principle of induced solidification is indeed applicable to freezing point measurements by applying it to the design of a copper-freezing-point cell for industrial applications, in which a supercooled sample is reheated and then induced to solidify by the solidification of an auxiliary sample. Further experimental studies are necessary to assess the practical advantages and disadvantages of the induction method.

Secondary Waste Form Screening Test Results—Cast Stone and Alkali Alumino-Silicate Geopolymer

DOE Office of Scientific and Technical Information (OSTI.GOV)

Pierce, Eric M.; Cantrell, Kirk J.; Westsik, Joseph H.

2010-06-28

PNNL is conducting screening tests on the candidate waste forms to provide a basis for comparison and to resolve the formulation and data needs identified in the literature review. This report documents the screening test results on the Cast Stone cementitious waste form and the Geopolymer waste form. Test results suggest that both the Cast Stone and Geopolymer appear to be viable waste forms for the solidification of the secondary liquid wastes to be treated in the ETF. The diffusivity for technetium from the Cast Stone monoliths was in the range of 1.2 × 10-11 to 2.3 × 10-13 cm2/smore » during the 63 days of testing. The diffusivity for technetium from the Geopolymer was in the range of 1.7 × 10-10 to 3.8 × 10-12 cm2/s through the 63 days of the test. These values compare with a target of 1 × 10-9 cm2/s or less. The Geopolymer continues to show some fabrication issues with the diffusivities ranging from 1.7 × 10-10 to 3.8 × 10-12 cm2/s for the better-performing batch to from 1.2 × 10-9 to 1.8 × 10-11 cm2/s for the poorer-performing batch. In the future more comprehensive and longer term performance testing will be conducted, to further evaluate whether or not these waste forms will meet the regulation and performance criteria needed to cost-effectively dispose of secondary wastes.« less

Final waste forms project: Performance criteria for phase I treatability studies

DOE Office of Scientific and Technical Information (OSTI.GOV)

Gilliam, T.M.; Hutchins, D.A.; Chodak, P. III

1994-06-01

This document defines the product performance criteria to be used in Phase I of the Final Waste Forms Project. In Phase I, treatability studies will be performed to provide {open_quotes}proof-of-principle{close_quotes} data to establish the viability of stabilization/solidification (S/S) technologies. This information is required by March 1995. In Phase II, further treatability studies, some at the pilot scale, will be performed to provide sufficient data to allow treatment alternatives identified in Phase I to be more fully developed and evaluated, as well as to reduce performance uncertainties for those methods chosen to treat a specific waste. Three main factors influence themore » development and selection of an optimum waste form formulation and hence affect selection of performance criteria. These factors are regulatory, process-specific, and site-specific waste form standards or requirements. Clearly, the optimum waste form formulation will require consideration of performance criteria constraints from each of the three categories. Phase I will focus only on the regulatory criteria. These criteria may be considered the minimum criteria for an acceptable waste form. In other words, a S/S technology is considered viable only if it meet applicable regulatory criteria. The criteria to be utilized in the Phase I treatability studies were primarily taken from Environmental Protection Agency regulations addressed in 40 CFR 260 through 265 and 268; and Nuclear Regulatory Commission regulations addressed in 10 CFR 61. Thus the majority of the identified criteria are independent of waste form matrix composition (i.e., applicable to cement, glass, organic binders etc.).« less

Phase-field simulation of weld solidification microstructure in an Al Cu alloy

NASA Astrophysics Data System (ADS)

Farzadi, A.; Do-Quang, M.; Serajzadeh, S.; Kokabi, A. H.; Amberg, G.

2008-09-01

Since the mechanical properties and the integrity of the weld metal depend on the solidification behaviour and the resulting microstructural characteristics, understanding weld pool solidification is of importance to engineers and scientists. Thermal and fluid flow conditions affect the weld pool geometry and solidification parameters. During solidification of the weld pool, a columnar grain structure develops in the weld metal. Prediction of the formation of the microstructure during welding may be an important and supporting factor for technology optimization. Nowadays, increasing computing power allows direct simulations of the dendritic and cell morphology of columnar grains in the molten zone for specific temperature conditions. In this study, the solidification microstructures of the weld pool at different locations along the fusion boundary are simulated during gas tungsten arc welding of Al-3wt%Cu alloy using the phase-field model for the directional solidification of dilute binary alloys. A macroscopic heat transfer and fluid flow model was developed to assess the solidification parameters, notably the temperature gradient and solidification growth rate. The effect of the welding speed is investigated. Computer simulations of the solidification conditions and the formation of a cellular morphology during the directional solidification in gas tungsten arc welding are described. Moreover, the simulation results are compared with existing theoretical models and experimental findings.

Preinvestigation evaluation of corrective measure technologies for the Badger Army Ammunition Plant

DOE Office of Scientific and Technical Information (OSTI.GOV)

Benioff, P.A.; Tsai, S.Y.

1989-02-01

This report briefly describes and evaluates the suitability of corrective measure technologies for possible use at the solid waste management units (SWMUs) at the Badger Army Ammunition Plant (BAAP), near Baraboo, Wisconsin. Corrective measure technologies considered for contaminated soils include excavation plus on- or off-site disposal in landfills or by incineration, use of solidification or stabilization methods, and in-situ methods such as bioreclamation and chemical or physical methods. Technologies considered for treatment of contaminated groundwater include groundwater pumping followed by discharge or treatment by air stripping and use of subsurface barriers. 5 refs., 1 tab.

Applications analysis report: Silicate Technology Corporation's solidification/stabilization technology for organic and inorganic contaminants in soils

NASA Astrophysics Data System (ADS)

Bates, E.

1992-12-01

The STC demonstration was conducted under EPA's Superfund Innovative Technology Evaluation (SITE) Program in November, 1990, at the Selma Pressure Treating (SPT) wood preserving site in Selma, California. The SPT site was contaminated with both organics, predominantly pentachlorophenol (PCP), inorganics, mainly arsenic, chromium, and copper. Extensive sampling and analyses were performed on the waste both before and after treatment to compare physical, chemical, and leaching characteristics of raw and treated wastes. STC's contaminated soil treatment process was evaluated based on contaminant mobility measured by numerous leaching tests, structural integrity of the solidified material, measured by physical and engineering tests and morphological examinations; and economic analysis, using cost information supplied by STC and the results of the SITE demonstration, the vendor's design and test data, and other laboratory and field applications of the technology. It discusses the advantages, disadvantages, and limitations, as well as estimated costs of the technology.

Implementation of the Leaching Environmental Assessment ...

EPA Pesticide Factsheets

LEAF provides a uniform and integrated approach for evaluating leaching from solid materials (e.g., waste, treated wastes such as by solidification/stabilization, secondary materials such as blast furnace slags, energy residuals such as coal fly ash, soil, sediments, mining and mineral processing wastes). Assessment using LEAF applies a stepwise approach that considers the leaching behavior of COPCs in response to chemical and physical factors that control and material properties across a range of plausible field conditions (US EPA, 2010). The framework provides the flexibility to tailor testing to site conditions and select the extent of testing based on assessment objectives and the level of detailed information needed to support decision-making. The main focus will be to discuss the implementation of LEAF in the US and the How to Guide that has recently been completed. To present the How To Guide for the implementation of the leaching environmental assessment framework to an international audience already familiar with comparable leaching tests in use in Europe. Will be meeting with European colleagues on their interest in expanding methods to include organics.

The solidification velocity of nickel and titanium alloys

NASA Astrophysics Data System (ADS)

Altgilbers, Alex Sho

2002-09-01

The solidification velocity of several Ni-Ti, Ni-Sn, Ni-Si, Ti-Al and Ti-Ni alloys were measured as a function of undercooling. From these results, a model for alloy solidification was developed that can be used to predict the solidification velocity as a function of undercooling more accurately. During this investigation a phenomenon was observed in the solidification velocity that is a direct result of the addition of the various alloying elements to nickel and titanium. The additions of the alloying elements resulted in an additional solidification velocity plateau at intermediate undercoolings. Past work has shown a solidification velocity plateau at high undercoolings can be attributed to residual oxygen. It is shown that a logistic growth model is a more accurate model for predicting the solidification of alloys. Additionally, a numerical model is developed from simple description of the effect of solute on the solidification velocity, which utilizes a Boltzmann logistic function to predict the plateaus that occur at intermediate undercoolings.

Visualization of solidification front phenomena

NASA Technical Reports Server (NTRS)

Workman, Gary L.; Smith, Guy A.

1993-01-01

Directional solidification experiments have been utilized throughout the Materials Processing in Space Program to provide an experimental platform which minimizes variables in solidification experiments. Because of the wide-spread use of this experimental technique in space-based research, it has become apparent that a better understanding of all the phenomena occurring during solidification can be better understood if direct visualization of the solidification interface were possible.

Microscopic calculations of liquid and solid neutron star matter

DOE Office of Scientific and Technical Information (OSTI.GOV)

Chakravarty, Sudip; Miller, Michael D.; Chia-Wei, Woo

1974-02-01

As the first step to a microscopic determination of the solidification density of neutron star matter, variational calculations are performed for both liquid and solid phases using a very simple model potential. The potential, containing only the repulsive part of the Reid /sup 1/S/sub o/ interaction, together with Boltzmann statistics defines a homework problem'' which several groups involved in solidification calculations have agreed to solve. The results were to be compared for the purpose of checking calculational techniques. For the solid energy good agreement with Canuto and Chitre was found. Both the liquid and solid energies are much lower thanmore » those of Pandharipande. It is shown that for this oversimplified model, neutron star matter will remain solid down to ordinary nuclear matter density.« less

Distribution of molecular weight in glyceride polymerizates or aggregates of them after contact with lunar grains

NASA Technical Reports Server (NTRS)

Asunmaa, S. K.; Haack, R.

1977-01-01

An attempt is made to report on experiments in which a molecular-weight increase was determined in thin layers of triglyceride-containing glycerides after thin-layer contact for two years with lunar topsoil grains at 25 C without any thermal activation. It is noted that solidification was observed on both dielectric grains and metal-rich areas and that changes in viscosity and molecular weights were first detected by solidification of surface layers. Gel permeation chromatography is described which detected a general shift of the Gaussian distribution of the molecular-weight data toward generally higher molecular weights as well as an increase in mean molecular weight. Reaction mechanisms are considered, and results of spectrographic analysis are cited which support the interpretations of the molecular-weight data.

The preparation and characterization of monomethoxypoly(ethylene glycol)-b-poly-DL-lactide microcapsules containing bovine hemoglobin.

PubMed

Meng, Fan-Tao; Zhang, Wan-Zhong; Ma, Guang-Hui; Su, Zhi-Guo

2003-08-01

Methoxypoly(ethylene glycol)-b-poly-DL-lactide (PELA) microcapsules containing bovine hemoglobin (bHb) were prepared by a W/O/W double emulsion-solvent diffusion process. bHb solution was used as the internal aqueous phase, PELA/organic solvent as the oil phase, and polyvinyl alcohol (PVA) solution as the external aqueous phase. This W/O/W double emulsion was added into a large volume of water (solidification solution) to allow organic solvent to diffuse into water. The optimum preparative condition for PELA microcapsules loaded with bovine hemoglobin was investigated. It was found that homogenization rate, type of organic solvent, and volume of the solidification solution influenced the activity of bovine hemoglobin encapsulated. When the homogenization rate was lower than 9000 rpm and ethyl acetate was used as the organic solvent, there was no significant influence on the activity of hemoglobin. High homogenization rate as 12 000 rpm decreased the P50 and Hill coefficient. Increasing the volume of solidification solution had an effect of improving the activity of microencapsulated hemoglobin. The composition of the PELA had the most important influence on the success of encapsulation. Microcapsules fabricated by PELA with MPEG2k block (molecular weight of MPEG block: 2000) achieved a high entrapment efficiency of 90%, better than PL A homopolymer and PELA with MPEG5k blocks. Hemoglobin microcapsules with native loading oxygen activity (P50 = 26.0 mmHg, Hill coefficient = 2.4), mean size of about 10 microm, and high entrapment efficiency (ca. 93%) were obtained at the optimum condition.

High temperature phase chemistries and solidification mode prediction in nitrogen-strengthened austenitic stainless steels

NASA Astrophysics Data System (ADS)

Ritter, Ann M.; Henry, Michael F.; Savage, Warren F.

1984-07-01

Nitronic 50 and Nitronic 50W, two nitrogen-strengthened stainless steels, were heat treated over a wide range of temperatures, and the compositions of the ferrite and austenite at each temperature were measured with analytical electron microscopy techniques. The compositional data were used to generate the (γ + δ phase field on a 58 pct Fe vertical section. Volume fractions of ferrite and austenite were calculated from phase chemistries and compared with volume fractions determined from optical micrographs. Weld solidification modes were predicted by reference to the Cr and Ni contents of each alloy, and the results were compared with predictions based on the ratios of calculated Cr and Ni equivalents for the alloys. Nitronic 50, which contained ferrite and austenite at the solidus temperature of 1370 °C, solidified through the eutectic triangle, and the weld microstructure was similar to that of austenitic-ferritic solidification. Nitronic 50W was totally ferritic at 1340 °C and solidified as primary delta ferrite. During heat treatments, Nitronic 50 and Nitronic 50W precipitated secondary phases, notably Z-phase (NbCrN), sigma phase, and stringered phases rich in Mn and Cr.

Structural evolutions and hereditary characteristics of icosahedral nano-clusters formed in Mg70Zn30 alloys during rapid solidification processes

NASA Astrophysics Data System (ADS)

Liang, Yong-Chao; Liu, Rang-Su; Xie, Quan; Tian, Ze-An; Mo, Yun-Fei; Zhang, Hai-Tao; Liu, Hai-Rong; Hou, Zhao-Yang; Zhou, Li-Li; Peng, Ping

2017-02-01

To investigate the structural evolution and hereditary mechanism of icosahedral nano-clusters formed during rapid solidification, a molecular dynamics (MD) simulation study has been performed for a system consisting of 107 atoms of liquid Mg70Zn30 alloy. Adopting Honeycutt-Anderson (HA) bond-type index method and cluster type index method (CTIM-3) to analyse the microstructures in the system it is found that for all the nano-clusters including 2~8 icosahedral clusters in the system, there are 62 kinds of geometrical structures, and those can be classified, by the configurations of the central atoms of basic clusters they contained, into four types: chain-like, triangle-tailed, quadrilateral-tailed and pyramidal-tailed. The evolution of icosahedral nano-clusters can be conducted by perfect heredity and replacement heredity, and the perfect heredity emerges when temperature is slightly less than Tm then increase rapidly and far exceeds the replacement heredity at Tg; while for the replacement heredity, there are three major modes: replaced by triangle (3-atoms), quadrangle (4-atoms) and pentagonal pyramid (6-atoms), rather than by single atom step by step during rapid solidification processes.

Characterization of the solid low level mixed waste inventory for the solid waste thermal treatment activity - III

DOE Office of Scientific and Technical Information (OSTI.GOV)

Place, B.G., Westinghouse Hanford

1996-09-24

The existing thermally treatable, radioactive mixed waste inventory is characterized to support implementation of the commercial, 1214 thermal treatment contract. The existing thermally treatable waste inventory has been identified using a decision matrix developed by Josephson et al. (1996). Similar to earlier waste characterization reports (Place 1993 and 1994), hazardous materials, radionuclides, physical properties, and waste container data are statistically analyzed. In addition, the waste inventory data is analyzed to correlate waste constituent data that are important to the implementation of the commercial thermal treatment contract for obtaining permits and for process design. The specific waste parameters, which were analyzed,more » include the following: ``dose equivalent`` curie content, polychlorinated biphenyl (PCB) content, identification of containers with PA-related mobile radionuclides (14C, 12 79Se, 99Tc, and U isotopes), tritium content, debris and non-debris content, container free liquid content, fissile isotope content, identification of dangerous waste codes, asbestos containers, high mercury containers, beryllium dust containers, lead containers, overall waste quantities, analysis of container types, and an estimate of the waste compositional split based on the thermal treatment contractor`s proposed process. A qualitative description of the thermally treatable mixed waste inventory is also provided.« less

Ageless Aluminum-Cerium-Based Alloys in High-Volume Die Casting for Improved Energy Efficiency

DOE PAGES

Stromme, Eric T.; Henderson, Hunter B.; Sims, Zachary C.; ...

2018-04-25

Strong chemical reactions between Al and Ce lead to the formation of intermetallics with exceptional thermal stability. The rapid formation of intermetallics directly from the liquid phase during solidification of Al-Ce alloys leads to an ultrafine microconstituent structure that effectively strengthens as-cast alloys without further microstructural optimization via thermal processing. Die casting is a high-volume manufacturing technology that accounts for greater than 40% of all cast Al products, whereas Ce is highly overproduced as a waste product of other rare earth element (REE) mining. Reducing heat treatments would stimulate significant improvements in manufacturing energy efficiency, exceeding (megatonnes/year) per large-scale heat-treatmentmore » line. In this study, multiple compositions were evaluated with wedge mold castings to test the sensitivity of alloys to the variable solidification rate inherent in high-pressure die casting. Once a suitable composition was determined, it was successfully demonstrated at 800 lbs/h in a 600-ton die caster, after which the as-die cast parts performed similarly to ubiquitous A380 in the same geometry without requiring heat treatment. Furthermore, this work demonstrates the compatibility of Al REE alloys with high-volume die-casting applications with minimal heat treatments.« less

Ageless Aluminum-Cerium-Based Alloys in High-Volume Die Casting for Improved Energy Efficiency

NASA Astrophysics Data System (ADS)

Stromme, Eric T.; Henderson, Hunter B.; Sims, Zachary C.; Kesler, Michael S.; Weiss, David; Ott, Ryan T.; Meng, Fanqiang; Kassoumeh, Sam; Evangelista, James; Begley, Gerald; Rios, Orlando

2018-06-01

Strong chemical reactions between Al and Ce lead to the formation of intermetallics with exceptional thermal stability. The rapid formation of intermetallics directly from the liquid phase during solidification of Al-Ce alloys leads to an ultrafine microconstituent structure that effectively strengthens as-cast alloys without further microstructural optimization via thermal processing. Die casting is a high-volume manufacturing technology that accounts for greater than 40% of all cast Al products, whereas Ce is highly overproduced as a waste product of other rare earth element (REE) mining. Reducing heat treatments would stimulate significant improvements in manufacturing energy efficiency, exceeding (megatonnes/year) per large-scale heat-treatment line. In this study, multiple compositions were evaluated with wedge mold castings to test the sensitivity of alloys to the variable solidification rate inherent in high-pressure die casting. Once a suitable composition was determined, it was successfully demonstrated at 800 lbs/h in a 600-ton die caster, after which the as-die cast parts performed similarly to ubiquitous A380 in the same geometry without requiring heat treatment. This work demonstrates the compatibility of Al REE alloys with high-volume die-casting applications with minimal heat treatments.

Ageless Aluminum-Cerium-Based Alloys in High-Volume Die Casting for Improved Energy Efficiency

NASA Astrophysics Data System (ADS)

Stromme, Eric T.; Henderson, Hunter B.; Sims, Zachary C.; Kesler, Michael S.; Weiss, David; Ott, Ryan T.; Meng, Fanqiang; Kassoumeh, Sam; Evangelista, James; Begley, Gerald; Rios, Orlando

2018-04-01

Strong chemical reactions between Al and Ce lead to the formation of intermetallics with exceptional thermal stability. The rapid formation of intermetallics directly from the liquid phase during solidification of Al-Ce alloys leads to an ultrafine microconstituent structure that effectively strengthens as-cast alloys without further microstructural optimization via thermal processing. Die casting is a high-volume manufacturing technology that accounts for greater than 40% of all cast Al products, whereas Ce is highly overproduced as a waste product of other rare earth element (REE) mining. Reducing heat treatments would stimulate significant improvements in manufacturing energy efficiency, exceeding (megatonnes/year) per large-scale heat-treatment line. In this study, multiple compositions were evaluated with wedge mold castings to test the sensitivity of alloys to the variable solidification rate inherent in high-pressure die casting. Once a suitable composition was determined, it was successfully demonstrated at 800 lbs/h in a 600-ton die caster, after which the as-die cast parts performed similarly to ubiquitous A380 in the same geometry without requiring heat treatment. This work demonstrates the compatibility of Al REE alloys with high-volume die-casting applications with minimal heat treatments.

Ageless Aluminum-Cerium-Based Alloys in High-Volume Die Casting for Improved Energy Efficiency

DOE Office of Scientific and Technical Information (OSTI.GOV)

Stromme, Eric T.; Henderson, Hunter B.; Sims, Zachary C.

Strong chemical reactions between Al and Ce lead to the formation of intermetallics with exceptional thermal stability. The rapid formation of intermetallics directly from the liquid phase during solidification of Al-Ce alloys leads to an ultrafine microconstituent structure that effectively strengthens as-cast alloys without further microstructural optimization via thermal processing. Die casting is a high-volume manufacturing technology that accounts for greater than 40% of all cast Al products, whereas Ce is highly overproduced as a waste product of other rare earth element (REE) mining. Reducing heat treatments would stimulate significant improvements in manufacturing energy efficiency, exceeding (megatonnes/year) per large-scale heat-treatmentmore » line. In this study, multiple compositions were evaluated with wedge mold castings to test the sensitivity of alloys to the variable solidification rate inherent in high-pressure die casting. Once a suitable composition was determined, it was successfully demonstrated at 800 lbs/h in a 600-ton die caster, after which the as-die cast parts performed similarly to ubiquitous A380 in the same geometry without requiring heat treatment. Furthermore, this work demonstrates the compatibility of Al REE alloys with high-volume die-casting applications with minimal heat treatments.« less

Microstructure Evolution in the Presence of Constraints and Implications on the Properties of Mg - Li and Nb - Al Composites

DTIC Science & Technology

1991-05-30

alloys and composites Solidification experiments with Succinonitrile-acetone system Experimerts with Salol I Directional Solidification of Mg-Li alloys ...Directional Solidification of Mg-Li Composites Microstructural Analysis and Modeling Combustion Synthesis Principles ( theory ) Nb-AI alloys made by...Combustion Synthesis Nb-AI - NbB composites made by Combustion Synthesis Directional Solidification of Nb-AI Alloys Directional Solidification of Nb- Al

The influence of gravity level during directional solidification of immiscible alloys

NASA Technical Reports Server (NTRS)

Andrews, J. B.; Schmale, A. L.; Sandlin, A. C.

1992-01-01

During directional solidification of immiscible (hypermonotectic) alloys it is theoretically possible to establish a stable macroscopically-planar solidification front, and thus avoid sedimentation. Unfortunately, convective instabilities often occur which interfere with the directional solidification process. In this paper, stability conditions are discussed and results presented from directional solidification studies carried out aboard NASA's KC-135 zero-g aircraft. Samples were directionally solidified while the effective gravity level was varied from approximately 0.01 g for 25 s to 1.8 g for 45 s. Dramatic variations in microstructure were observed with gravity level during solidification.

Tranpsort phenomena in solidification processing of functionally graded materials

NASA Astrophysics Data System (ADS)

Gao, Juwen

A combined numerical and experimental study of the transport phenomena during solidification processing of metal matrix composite functionally graded materials (FGMs) is conducted in this work. A multiphase transport model for the solidification of metal-matrix composite FGMs has been developed that accounts for macroscopic particle segregation due to liquid-particle flow and particle-solid interactions. An experimental study has also been conducted to gain physical insight as well as to validate the model. A novel method to in-situ measure the particle volume fraction using fiber optic probes is developed for transparent analogue solidification systems. The model is first applied to one-dimensional pure matrix FGM solidification under gravity or centrifugal field and is extensively validated against the experimental results. The mechanisms for the formation of particle concentration gradient are identified. Two-dimensional solidification of pure matrix FGM with convection is then studied using the model as well as experiments. The interaction among convection flow, solidification process and the particle transport is demonstrated. The results show the importance of convection in the particle concentration gradient formation. Then, simulations for alloy FGM solidification are carried out for unidirectional solidification as well as two-dimensional solidification with convection. The interplay among heat and species transport, convection and particle motion is investigated. Finally, future theoretical and experimental work is outlined.

Solidification/stabilization of spent abrasives and use as nonstructural concrete

DOE Office of Scientific and Technical Information (OSTI.GOV)

Brabrand, D.J.; Loehr, R.C.

1993-01-01

Tons of spent abrasives result each year from the removal of old paint from bridges. Because the spent abrasives contain metals from the paint, some spent abrasives may be considered hazardous by the Toxicity Characteristic (TC) criteria. Incorporation of the spent blasting abrasives in nonstructural concrete (rip-rap, dolphins) offers an opportunity to recycle the spent abrasives while immobilizing potentially leachable metals. This study focused on the Portland Cement Solidification/Stabilization (S/S) of spent blasting abrasives taken from a bridge located in Southeast Texas. The study examined (a) the cadmium, chromium, and lead concentrations in extracts obtained by using the Toxicity Characteristicmore » Leaching Procedure (TCLP) and (b) the compressive strengths of Portland Cement mixes that contained different amounts of the spent abrasives. Performance was measured by meeting the TC criteria as well as the requirements for compressive strength. Study results indicated that considerable quantities of these spent abrasives can be solidified/stabilized while reducing the leachability of cadmium, chromium, and lead and producing compressive strengths over 6,895 kN/m[sup 2] (1,000 psi).« less

40 CFR 761.207 - The manifest-general requirements.

Code of Federal Regulations, 2014 CFR

2014-07-01

...) (2) For each PCB Article Container or PCB Container, the unique identifying number, type of PCB waste... PCB Article not in a PCB Container or PCB Article Container, the serial number if available, or other... only containing PCB waste. However, some States track PCB wastes as State-regulated hazardous wastes...

40 CFR 761.207 - The manifest-general requirements.

Code of Federal Regulations, 2013 CFR

2013-07-01

...) (2) For each PCB Article Container or PCB Container, the unique identifying number, type of PCB waste... PCB Article not in a PCB Container or PCB Article Container, the serial number if available, or other... only containing PCB waste. However, some States track PCB wastes as State-regulated hazardous wastes...

On the Role of Mantle Overturn during Magma Ocean Solidification

NASA Astrophysics Data System (ADS)

Boukaré, C. E.; Parmentier, E.; Parman, S. W.

2017-12-01

Solidification of potential global magma ocean(s) (MO) early in the history of terrestrial planets may play a key role in the evolution of planetary interiors by setting initial conditions for their long-term evolution. Constraining this initial structure of solid mantles is thus crucial but remains poorly understood. MO fractional crystallization has been proposed to generate gravitationally unstable Fe-Mg chemical stratification capable of driving solid-state mantle overturn. Fractional solidification and overturn hypothesis, while only an ideal limiting case, can explain important geochemical features of both the Moon and Mars. Current overturn models consider generally post-MO overturn where the cumulate pile remains immobile until the end of MO solidification. However, if the cumulate pile overturns during MO solidification, the general picture of early planet evolution might differ significantly from the static crystallization models. We show that the timing of mantle overturn can be characterized with a dimensionless number measuring the ratio of the MO solidification time and the purely compositional overturn timescale. Syn-solidification overturn occurs if this dimensionless parameter, Rc, exceeds a critical value. Rc is mostly affected by the competition between the MO solidification time and mantle viscosity. Overturn that occurs during solidification can result in smaller scales of mantle chemical heterogeneity that could persist for long times thus influencing the whole evolution of a planetary body. We will discuss the effects of compaction/percolation on mantle viscosity. If partially molten cumulate do not have time to compact during MO solidification, viscosity of cumulates would be significantly lower as the interstitcial melt fraction would be large. Both solid mantle remelting during syn-solidification overturn and porous convection of melt retained with the cumulates are expected to reduce the degree of fractional crystallization. Syn-solidification overturn of a sluggish mantle can thus be an alternative to solid-state post-MO solidification overturn.

Modelling directional solidification

NASA Technical Reports Server (NTRS)

Wilcox, William R.

1991-01-01

The long range goal of this program is to develop an improved understanding of phenomena of importance to directional solidification and to enable explanation and prediction of differences in behavior between solidification on Earth and in space. Current emphasis is on determining the influence of perturbations on directional solidification.

Improved Crystal Quality By Detached Solidification in Microgravity

NASA Technical Reports Server (NTRS)

Regel, Liya L.; Wilcox, William R.; Wang, Yaz-Hen; Wang, Jian-Bin

2003-01-01

Many microgravity directional solidification experiments yielded ingots with portions that grew without contacting the ampoule wall, leading to greatly improved crystallographic perfection. Our long term goals have been: (1) To develop a complete understanding of all of the phenomena of detached solidification.; (2) To make it possible to achieve detached solidification reproducibly; (3) To increase crystallographic perfection through detached solidification. We have three major achievements to report here: (1) We obtained a new material balance solution for the Moving Meniscus Model of detached solidification. This solution greatly clarifies the physics as well as the roles of the parameters in the system; (2) We achieved detached solidification of InSb growing on earth in BN-coated ampoules; (3) We performed an extensive series of experiments on freezing water that showed how to form multiple gas bubbles or tubes on the ampoule wall. However, these did not propagate around the wall and lead to fully detached solidification unless the ampoule wall was extremely rough and non-wetted.

Relationships Between Solidification Parameters in A319 Aluminum Alloy

NASA Astrophysics Data System (ADS)

Vandersluis, E.; Ravindran, C.

2018-03-01

The design of high-performance materials depends on a comprehensive understanding of the alloy-specific relationships between solidification and properties. However, the inconsistent use of a particular solidification parameter for presenting materials characterization in the literature impedes inter-study comparability and the interpretation of findings. Therefore, there is a need for accurate expressions relating the solidification parameters for each alloy. In this study, A319 aluminum alloy castings were produced in a permanent mold with various preheating temperatures in order to control metal cooling. Analysis of the cooling curve for each casting enabled the identification of its liquidus, Al-Si eutectic, and solidus temperatures and times. These values led to the calculation of the primary solidification rate, total solidification rate, primary solidification time, and local solidification time for each casting, which were related to each other as well as to the average casting SDAS and material hardness. Expressions for each of their correlations have been presented with high coefficients of determination, which will aid in microstructural prediction and casting design.

Modeling of Detached Solidification

NASA Technical Reports Server (NTRS)

Regel, Liya L.; Wilcox, William R.; Popov, Dmitri

1997-01-01

Our long term goal is to develop techniques to achieve detached solidification reliably and reproducibly, in order to produce crystals with fewer defects. To achieve this goal it is necessary to understand thoroughly the physics of detached solidification. It was the primary objective of the current project to make progress toward this complete understanding. 'Me products of this grant are attached. These include 4 papers and a preliminary survey of the observations of detached solidification in space. We have successfully modeled steady state detached solidification, examined the stability of detachment, and determined the influence of buoyancy-driven convection under different conditions. Directional solidification in microgravity has often led to ingots that grew with little or no contact with the ampoule wall. When this occurred, crystallographic perfection was usually greatly improved -- often by several orders of magnitude. Indeed, under the Soviet microgravity program the major objective was to achieve detached solidification with its resulting improvement in perfection and properties. Unfortunately, until recently the true mechanisms underlying detached solidification were unknown. As a consequence, flight experiments yielded erratic results. Within the past three years, we have developed a new theoretical model that explains many of the flight results. This model gives rise to predictions of the conditions required to yield detached solidification.

Modelling Directional Solidification

NASA Technical Reports Server (NTRS)

Wilcox, William R.; Regel, Liya L.; Zhou, Jian; Yuan, Weijun

1992-01-01

The long range goal of this program has been to develop an improved understanding of phenomena of importance to directional solidification, in order to enable explanation and prediction of differences in behavior between solidification on Earth and in space. Current emphasis is on determining the influence of perturbations on directional solidification.

Laser weldability of 21Cr-6Ni-9Mn stainless steel: Part II - Weldability diagrams

DOE Office of Scientific and Technical Information (OSTI.GOV)

Tate, Stephen B.; Javernick, Daniel Anthony; Lienert, Thomas J.

In this second part of the study, weldability diagrams developed to relate solidification crack susceptibility and chemical composition for laser welded type 21Cr-6Ni-9Mn (21-6-9) stainless steel are presented. Sigmajig testing on 14 commercial 21-6-9 alloys, 20 experimental 21-6-9 alloys, and 7 other high-N, high-Mn austenitic stainless steels was used to develop weldability diagrams for solidification crack susceptibility for laser welding of type 21-6-9. Three travel speeds were used to show the changes in minimum Cr eq/Ni eq for primary ferrite solidification as solidification rate increase d with travel speed . Primary austenite solidification was observed below 1.55 Cr eq/Ni eqmore » (Espy equivalents) at 21 mm/s travel speed. At 42 mm/s travel speed , a mix of solidification modes were displayed for alloys from 1.55-1.75 Cr eq/Ni eq. Primary ferrite solidification was observed above 1.75 Cr eq/Ni eq at both 42 and 85 mm/s travel speeds. No solidification cracking was observed for alloys with primary ferrite solidification. Lastly, variable cracking behavior was found in alloys with primary austenite solidification, but in general cracking was observed in alloys with greater than 0.02 wt-% combined impurity content according to (P+0.2S).« less

Laser weldability of 21Cr-6Ni-9Mn stainless steel: Part II - Weldability diagrams

DOE PAGES

Tate, Stephen B.; Javernick, Daniel Anthony; Lienert, Thomas J.; ...

2016-11-02

In this second part of the study, weldability diagrams developed to relate solidification crack susceptibility and chemical composition for laser welded type 21Cr-6Ni-9Mn (21-6-9) stainless steel are presented. Sigmajig testing on 14 commercial 21-6-9 alloys, 20 experimental 21-6-9 alloys, and 7 other high-N, high-Mn austenitic stainless steels was used to develop weldability diagrams for solidification crack susceptibility for laser welding of type 21-6-9. Three travel speeds were used to show the changes in minimum Cr eq/Ni eq for primary ferrite solidification as solidification rate increase d with travel speed . Primary austenite solidification was observed below 1.55 Cr eq/Ni eqmore » (Espy equivalents) at 21 mm/s travel speed. At 42 mm/s travel speed , a mix of solidification modes were displayed for alloys from 1.55-1.75 Cr eq/Ni eq. Primary ferrite solidification was observed above 1.75 Cr eq/Ni eq at both 42 and 85 mm/s travel speeds. No solidification cracking was observed for alloys with primary ferrite solidification. Lastly, variable cracking behavior was found in alloys with primary austenite solidification, but in general cracking was observed in alloys with greater than 0.02 wt-% combined impurity content according to (P+0.2S).« less

Solidification Sequence of Spray-Formed Steels

NASA Astrophysics Data System (ADS)

Zepon, Guilherme; Ellendt, Nils; Uhlenwinkel, Volker; Bolfarini, Claudemiro

2016-02-01

Solidification in spray-forming is still an open discussion in the atomization and deposition area. This paper proposes a solidification model based on the equilibrium solidification path of alloys. The main assumptions of the model are that the deposition zone temperature must be above the alloy's solidus temperature and that the equilibrium liquid fraction at this temperature is reached, which involves partial remelting and/or redissolution of completely solidified droplets. When the deposition zone is cooled, solidification of the remaining liquid takes place under near equilibrium conditions. Scanning electron microscopy (SEM) and optical microscopy (OM) were used to analyze the microstructures of two different spray-formed steel grades: (1) boron modified supermartensitic stainless steel (SMSS) and (2) D2 tool steel. The microstructures were analyzed to determine the sequence of phase formation during solidification. In both cases, the solidification model proposed was validated.

Waste Acceptance Testing of Secondary Waste Forms: Cast Stone, Ceramicrete and DuraLith

DOE Office of Scientific and Technical Information (OSTI.GOV)

Mattigod, Shas V.; Westsik, Joseph H.; Chung, Chul-Woo

2011-08-12

To support the selection of a waste form for the liquid secondary wastes from WTP, Washington River Protection Solutions has initiated secondary-waste-form testing work at Pacific Northwest National Laboratory (PNNL). In anticipation of a down-selection process for a waste form for the Solidification Treatment Unit to be added to the ETF, PNNL is conducting tests on four candidate waste forms to evaluate their ability to meet potential waste acceptance criteria for immobilized secondary wastes that would be placed in the IDF. All three waste forms demonstrated compressive strengths above the minimum 3.45 MPa (500 psi) set as a target formore » cement-based waste forms. Further, none of the waste forms showed any significant degradation in compressive strength after undergoing thermal cycling (30 cycles in a 10 day period) between -40 C and 60 C or water immersion for 90 days. The three leach test methods are intended to measure the diffusion rates of contaminants from the waste forms. Results are reported in terms of diffusion coefficients and a leachability index (LI) calculated based on the diffusion coefficients. A smaller diffusion coefficient and a larger LI are desired. The NRC, in its Waste Form Technical Position (NRC 1991), provides recommendations and guidance regarding methods to demonstrate waste stability for land disposal of radioactive waste. Included is a recommendation to conduct leach tests using the ANS 16.1 method. The resulting leachability index (LI) should be greater than 6.0. For Hanford secondary wastes, the LI > 6.0 criterion applies to sodium leached from the waste form. For technetium and iodine, higher targets of LI > 9 for Tc and LI > 11 for iodine have been set based on early waste-disposal risk and performance assessment analyses. The results of these three leach tests conducted for a total time between 11days (ASTM C1308) to 90 days (ANS 16.1) showed: (1) Technetium diffusivity: ANSI/ANS 16.1, ASTM C1308, and EPA 1315 tests indicated that all the waste forms had leachability indices better than the target LI > 9 for technetium; (2) Rhenium diffusivity: Cast Stone 2M specimens, when tested using EPA 1315 protocol, had leachability indices better than the target LI > 9 for technetium based on rhenium as a surrogate for technetium. All other waste forms tested by ANSI/ANS 16.1, ASTM C1308, and EPA 1315 test methods had leachability indices that were below the target LI > 9 for Tc based on rhenium release. These studies indicated that use of Re(VII) as a surrogate for 99Tc(VII) in low temperature secondary waste forms containing reductants will provide overestimated diffusivity values for 99Tc. Therefore, it is not appropriate to use Re as a surrogate 99Tc in future low temperature waste form studies. (3) Iodine diffusivity: ANSI/ANS 16.1, ASTM C1308, and EPA 1315 tests indicated that the three waste forms had leachability indices that were below the target LI > 11 for iodine. Therefore, it may be necessary to use a more effective sequestering material than silver zeolite used in two of the waste forms (Ceramicrete and DuraLith); (4) Sodium diffusivity: All the waste form specimens tested by the three leach methods (ANSI/ANS 16.1, ASTM C1308, and EPA 1315) exceeded the target LI value of 6; (5) All three leach methods (ANS 16.1, ASTM C1308 and EPA 1315) provided similar 99Tc diffusivity values for both short-time transient diffusivity effects as well as long-term ({approx}90 days) steady diffusivity from each of the three tested waste forms (Cast Stone 2M, Ceramicrete and DuraLith). Therefore, any one of the three methods can be used to determine the contaminant diffusivities from a selected waste form.« less

DESIGN ANALYSIS FOR THE DEFENSE HIGH-LEVEL WASTE DISPOSAL CONTAINER

DOE Office of Scientific and Technical Information (OSTI.GOV)

G. Radulesscu; J.S. Tang

The purpose of ''Design Analysis for the Defense High-Level Waste Disposal Container'' analysis is to technically define the defense high-level waste (DHLW) disposal container/waste package using the Waste Package Department's (WPD) design methods, as documented in ''Waste Package Design Methodology Report'' (CRWMS M&O [Civilian Radioactive Waste Management System Management and Operating Contractor] 2000a). The DHLW disposal container is intended for disposal of commercial high-level waste (HLW) and DHLW (including immobilized plutonium waste forms), placed within disposable canisters. The U.S. Department of Energy (DOE)-managed spent nuclear fuel (SNF) in disposable canisters may also be placed in a DHLW disposal container alongmore » with HLW forms. The objective of this analysis is to demonstrate that the DHLW disposal container/waste package satisfies the project requirements, as embodied in Defense High Level Waste Disposal Container System Description Document (SDD) (CRWMS M&O 1999a), and additional criteria, as identified in Waste Package Design Sensitivity Report (CRWMS M&Q 2000b, Table 4). The analysis briefly describes the analytical methods appropriate for the design of the DHLW disposal contained waste package, and summarizes the results of the calculations that illustrate the analytical methods. However, the analysis is limited to the calculations selected for the DHLW disposal container in support of the Site Recommendation (SR) (CRWMS M&O 2000b, Section 7). The scope of this analysis is restricted to the design of the codisposal waste package of the Savannah River Site (SRS) DHLW glass canisters and the Training, Research, Isotopes General Atomics (TRIGA) SNF loaded in a short 18-in.-outer diameter (OD) DOE standardized SNF canister. This waste package is representative of the waste packages that consist of the DHLW disposal container, the DHLW/HLW glass canisters, and the DOE-managed SNF in disposable canisters. The intended use of this analysis is to support Site Recommendation reports and to assist in the development of WPD drawings. Activities described in this analysis were conducted in accordance with the Development Plan ''Design Analysis for the Defense High-Level Waste Disposal Container'' (CRWMS M&O 2000c) with no deviations from the plan.« less

RCRA, superfund and EPCRA hotline training module. Introduction to: Containers (40 cfr parts 264/265, subpart i; section 261.7) updated July 1996

DOE Office of Scientific and Technical Information (OSTI.GOV)

NONE

1996-07-01

The module reviews two sets of regulatory requirements for containers: requirements that pertain to the management of hazardous waste containers and regulations governing residues of hazardous waste in empty containers. It defines `container` and `empty container` and provides examples and citations for each. It provides an overview of the requirements for the design and operation of hazardous waste containers. It explains the difference between the container standards set out in part 264 and part 265. It states the requirements for rendering a hazardous waste container `RCRA empty`. It explains when container rinsate must be managed as a hazardous waste.

Leaching behaviour of hazardous demolition waste.

PubMed

Roussat, Nicolas; Méhu, Jacques; Abdelghafour, Mohamed; Brula, Pascal

2008-11-01

Demolition wastes are generally disposed of in unlined landfills for inert waste. However, demolition wastes are not just inert wastes. Indeed, a small fraction of demolition waste contains components that are hazardous to human health and the environment, e.g., lead-based paint, mercury-contained in fluorescent lamps, treated wood, and asbestos. The objective of this study is to evaluate the release potential of pollutants contained in these hazardous components when they are mixed with inert wastes in unlined landfills. After identification of the different building products which can contain hazardous elements and which can be potentially pollutant in landfill scenario, we performed leaching tests using three different lysimeters: one lysimeter containing only inert wastes and two lysimeters containing inert wastes mixed with hazardous demolition wastes. The leachates from these lysimeters were analysed (heavy metals, chlorides, sulphates fluoride, DOC (Dissolved Organic Carbon), phenol index, and PAH). Finally, we compared concentrations and cumulative releases of elements in leachates with the limits values of European regulation for the acceptance of inert wastes at landfill. Results indicate that limit values are exceeded for some elements. We also performed a percolation column test with only demolition hazardous wastes to evaluate the specific contribution of these wastes in the observed releases.

Nuclear waste storage container with metal matrix

DOEpatents

Sump, Kenneth R.

1978-01-01

The invention relates to a storage container for high-level waste having a metal matrix for the high-level waste, thereby providing greater impact strength for the waste container and increasing heat transfer properties.

Hanford Site annual dangerous waste report: Volume 3, Part 1, Waste Management Facility report, dangerous waste

DOE Office of Scientific and Technical Information (OSTI.GOV)

NONE

This report contains information on hazardous wastes at the Hanford Site. Information consists of shipment date, physical state, chemical nature, waste description, handling method and containment vessel, waste number, waste designation, and amount of waste.

Hanford Site annual dangerous waste report: Volume 4, Waste Management Facility report, Radioactive mixed waste

DOE Office of Scientific and Technical Information (OSTI.GOV)

NONE

1994-12-31

This report contains information on radioactive mixed wastes at the Hanford Site. Information consists of shipment date, physical state, chemical nature, waste description, handling method and containment vessel, waste number, waste designation and amount of waste.

Treatability Variance for Containerised Liquids in Mixed Debris Waste - 12101

DOE Office of Scientific and Technical Information (OSTI.GOV)

Alstatt, Catherine M.

2012-07-01

The TRU Waste Processing Center (TWPC) is a Department of Energy facility whose mission is to receive and process for appropriate disposal legacy Contact Handled (CH) and Remote Handled (RH) waste, including debris waste stored at various DOE Oak Ridge facilities. Acceptable Knowledge (AK) prepared for the waste characterizes the waste as mixed waste, meaning it is both radioactive and regulated under the Resource Conservation and Recovery Act (RCRA). The AK also indicates that a number of the debris waste packages contain small amounts of containerised liquids. The documentation indicates liquid wastes generated in routine lab operations were typically collectedmore » for potential recovery of valuable isotopes. However, during activities associated with decontamination and decommissioning (D and D), some containers with small amounts of liquids were placed into the waste containers with debris waste. Many of these containers now hold from 2.5 milliliters (ml) to 237 ml of liquid; a few contain larger volumes. At least some of these containers were likely empty at the time of generation, but documentation of this condition is lacking. Since WIPP compliant AK is developed on a waste stream basis, rather than an individual container basis, and includes every potential RCRA hazardous constituent within the waste stream, it is insufficient for the purpose of characterizing individual containers of liquid. Debris waste is defined in 40 CFR 268.2(g) as 'solid material exceeding a 60 mm particle size that is intended for disposal and that is: a manufactured object; or plant or animal matter; or natural geologic material'. The definition further states that intact containers of hazardous waste that are not ruptured and that retain at least 75% of their original volume are not debris. The prescribed treatment is removal of intact containers from the debris waste, and treatment of their contents to meet specific Land Disposal Restrictions (LDR) standards. This is true for containers with incidental amounts of liquids, even if the liquid is less than 50% of the total waste volume. Under the proposed variance, all free or containerised liquids (up to 3.8 liters(L)) found in the debris would be treated and returned in solid form to the debris waste stream from which they originated. The waste would then be macro-encapsulated. (author)« less

Casting And Solidification Technology (CAST): Directional solidification phenomena in a metal model at reduced gravity

NASA Technical Reports Server (NTRS)

Mccay, M. H.

1988-01-01

The Casting and Solidification Technology (CAST) experiment will study the phenomena that occur during directional solidification of an alloy, e.g., constitutional supercooling, freckling, and dendrite coarsening. The reduced gravity environment of space will permit the individual phenomena to be examined with minimum complication from buoyancy driven flows.

Simulation Computation of 430 Ferritic Stainless Steel Solidification

NASA Astrophysics Data System (ADS)

Pang, Ruipeng; Li, Changrong; Wang, Fuming; Hu, Lifu

The solidification structure of 430 ferritic stainless steel has been calculated in the solidification process by using 3D-CAFE model under the condition of water cooling. The calculated results consistent with those obtained from experiment. Under watercooling condition, the solidification structure consists of chilled layer, columnar grain zone, transition zone and equiaxed grain zone.

Treatment of halogen-containing waste and other waste materials

DOEpatents

Forsberg, Charles W.; Beahm, Edward C.; Parker, George W.

1997-01-01

A process for treating a halogen-containing waste material. The process provides a bath of molten glass containing a sacrificial metal oxide capable of reacting with a halogen in the waste material. The sacrificial metal oxide is present in the molten glass in at least a stoichiometric amount with respect to the halogen in the waste material. The waste material is introduced into the bath of molten glass to cause a reaction between the halogen in the waste material and the sacrificial metal oxide to yield a metal halide. The metal halide is a gas at the temperature of the molten glass. The gaseous metal halide is separated from the molten glass and contacted with an aqueous scrubber solution of an alkali metal hydroxide to yield a metal hydroxide or metal oxide-containing precipitate and a soluble alkali metal halide. The precipitate is then separated from the aqueous scrubber solution. The molten glass containing the treated waste material is removed from the bath as a waste glass. The process of the invention can be used to treat all types of waste material including radioactive wastes. The process is particularly suited for separating halogens from halogen-containing wastes.

Treatment of halogen-containing waste and other waste materials

DOEpatents

Forsberg, C.W.; Beahm, E.C.; Parker, G.W.

1997-03-18

A process is described for treating a halogen-containing waste material. The process provides a bath of molten glass containing a sacrificial metal oxide capable of reacting with a halogen in the waste material. The sacrificial metal oxide is present in the molten glass in at least a stoichiometric amount with respect to the halogen in the waste material. The waste material is introduced into the bath of molten glass to cause a reaction between the halogen in the waste material and the sacrificial metal oxide to yield a metal halide. The metal halide is a gas at the temperature of the molten glass. The gaseous metal halide is separated from the molten glass and contacted with an aqueous scrubber solution of an alkali metal hydroxide to yield a metal hydroxide or metal oxide-containing precipitate and a soluble alkali metal halide. The precipitate is then separated from the aqueous scrubber solution. The molten glass containing the treated waste material is removed from the bath as a waste glass. The process of the invention can be used to treat all types of waste material including radioactive wastes. The process is particularly suited for separating halogens from halogen-containing wastes. 3 figs.

Microstructural Indicators Of Convection In Sills And Dykes

NASA Astrophysics Data System (ADS)

Holness, M. B.; Neufeld, J. A.; Gilbert, A. J.; Macdonald, R.

2016-12-01

The question of whether or not convection occurs in crustal magma chambers is a vexed one, with some advocating vigorous convection while others argue that convection is weak and short-lived. We argue that microstructural analysis is key to determining whether crystallization took place in solidification fronts or whether crystals grew suspended in a convecting magma before settling. The 168m, composite, Shiant Isles Main Sill is dominated by a 140m unit, of which the lower 45m contains olivine phenocrysts. The phenocrysts first fine upwards, then coarsen upwards. The coarsening-upwards sequence contains clustered olivines. Both the extent of sintering and average cluster size increase upwards. The coarsening-upwards sequence is mirrored at the roof. The fining-upwards sequence formed by rapid settling of incoming cargo crystals, while the coarsening-upwards sequence represents post-emplacement growth and clustering of grains suspended in a convecting magma. Convection is also recorded by plagioclase grain shape. Well-facetted and compact plagioclase grains are platy in rapidly-cooled rocks and blocky in slowly-cooled rocks. Plagioclase grain shape varies smoothly across mafic sills, consistent with growth in solidification fronts. In contrast, grain shape is invariant across mafic dykes, consistent with growth as individual grains and clusters suspended in a convecting magma. Convection in sills occurs when the critical Rayleigh number is exceeded, but cooling at vertical walls always results in convective instabilities. That the Shiant Isles Main Sill records prolonged and vigorous convection, while other sills of comparable thickness record grain growth predominantly in solidification fronts, is most likely due to the composite nature of the Shiant. The 140m unit is underlain by 23m of picrite which intruded shortly before - the strongly asymmetric cooling and absence of a cold, stagnant basal thermal boundary layer make convection throughout the sill more likely.

40 CFR 265.316 - Disposal of small containers of hazardous waste in overpacked drums (lab packs).

Code of Federal Regulations, 2010 CFR

2010-07-01

... OPERATORS OF HAZARDOUS WASTE TREATMENT, STORAGE, AND DISPOSAL FACILITIES Landfills § 265.316 Disposal of small containers of hazardous waste in overpacked drums (lab packs). Small containers of hazardous waste... hazardous waste in overpacked drums (lab packs). 265.316 Section 265.316 Protection of Environment...

40 CFR 264.316 - Disposal of small containers of hazardous waste in overpacked drums (lab packs).

Code of Federal Regulations, 2010 CFR

2010-07-01

... HAZARDOUS WASTE TREATMENT, STORAGE, AND DISPOSAL FACILITIES Landfills § 264.316 Disposal of small containers of hazardous waste in overpacked drums (lab packs). Small containers of hazardous waste in overpacked... hazardous waste in overpacked drums (lab packs). 264.316 Section 264.316 Protection of Environment...

Remote vacuum compaction of compressible hazardous waste

DOEpatents

Coyne, M.J.; Fiscus, G.M.; Sammel, A.G.

1998-10-06

A system is described for remote vacuum compaction and containment of low-level radioactive or hazardous waste comprising a vacuum source, a sealable first flexible container, and a sealable outer flexible container for receiving one or more first flexible containers. A method for compacting low level radioactive or hazardous waste materials at the point of generation comprising the steps of sealing the waste in a first flexible container, sealing one or more first containers within an outer flexible container, breaching the integrity of the first containers, evacuating the air from the inner and outer containers, and sealing the outer container shut. 8 figs.

Remote vacuum compaction of compressible hazardous waste

DOEpatents

Coyne, Martin J.; Fiscus, Gregory M.; Sammel, Alfred G.

1998-01-01

A system for remote vacuum compaction and containment of low-level radioactive or hazardous waste comprising a vacuum source, a sealable first flexible container, and a sealable outer flexible container for receiving one or more first flexible containers. A method for compacting low level radioactive or hazardous waste materials at the point of generation comprising the steps of sealing the waste in a first flexible container, sealing one or more first containers within an outer flexible container, breaching the integrity of the first containers, evacuating the air from the inner and outer containers, and sealing the outer container shut.

Remote vacuum compaction of compressible hazardous waste

DOE Office of Scientific and Technical Information (OSTI.GOV)

Coyne, M.J.; Fiscus, G.M.; Sammel, A.G.

1996-12-31

A system is described for remote vacuum compaction and containment of low-level radioactive or hazardous waste comprising a vacuum source, a sealable first flexible container, and a sealable outer flexible container for receiving one or more first flexible containers. A method for compacting low level radioactive or hazardous waste materials at the point of generation comprising the steps of sealing the waste in a first flexible container, sealing one or more first containers within an outer flexible container, breaching the integrity of the first containers, evacuating the air from the inner and outer containers, and sealing the outer container shut.

In-situ vitrification of waste materials

DOEpatents

Powell, J.R.; Reich, M.; Barletta, R.

1997-10-14

A method for the in-situ vitrification of waste materials in a disposable can that includes an inner container and an outer container is disclosed. The method includes the steps of adding frit and waste materials to the inner container, removing any excess water, heating the inner container such that the frit and waste materials melt and vitrify after cooling, while maintaining the outer container at a significantly lower temperature than the inner container. The disposable can is then cooled to ambient temperatures and stored. A device for the in-situ vitrification of waste material in a disposable can is also disclosed. 7 figs.

In-situ vitrification of waste materials

DOEpatents

Powell, James R.; Reich, Morris; Barletta, Robert

1997-11-14

A method for the in-situ vitrification of waste materials in a disposable can that includes an inner container and an outer container is disclosed. The method includes the steps of adding frit and waste materials to the inner container, removing any excess water, heating the inner container such that the frit and waste materials melt and vitrify after cooling, while maintaining the outer container at a significantly lower temperature than the inner container. The disposable can is then cooled to ambient temperatures and stored. A device for the in-situ vitrification of waste material in a disposable can is also disclosed.

Stabilization/solidification of radioactive salt waste by using xSiO2-yAl2O3-zP2O5 (SAP) material at molten salt state.

PubMed

Park, Hwan-Seo; Kim, In-Tae; Cho, Yong-Zun; Eun, Hee-Chul; Lee, Han-Soo

2008-12-15

The molten salt waste from the pyroprocess is one of the problematic wastes to directly apply a conventional process such as vitrification or ceramization. This study suggested a novel method using a reactive material for metal chlorides at a molten temperature of salt waste, and then converting them into manageable product at a high temperature. The inorganic composite, SAP (SiO2-Al2O3-P2O5), synthesized by a conventional sol-gel process has three or four distinctive domains that are bonded sequentially, Si-O-Si-O-A-O-P-O-P. The P-rich phase in the SAP composite is unstable for producing a series of reactive sites when in contact with a molten LiCl salt. After the reaction, metal aluminosilicate, metal aluminophosphate, metal phosphates and gaseous chlorines are generated. From this process, the volatile salt waste is stabilized and it is possible to apply a high temperature process. The reaction products were fabricated successfully by using a borosilicate glass with an arbitrary composition as a chemical binder. There was a low possibility for the valorization of radionuclides up to 1200 degrees C, based on the result of the thermo gravimetric analysis. The Cs and Sr leach rates by the PCT-A method were about 1 x 10(-3) g/(m2 day). For the final disposal of the problematic salt waste, this approach suggested the design concept of an effective stabilizer for metal chlorides and revealed the chemical route to the fabrication of monolithic wasteform by using a composite as an example. Using this method, we could obtain a higher disposal efficiency and lower waste volume, compared with the present immobilization methods.

Numerical simulation of the interaction of biological cells with an ice front during freezing

NASA Astrophysics Data System (ADS)

Carin, M.; Jaeger, M.

2001-12-01

The goal of this study is a better understanding of the interaction between cells and a solidification front during a cryopreservation process. This technique of freezing is commonly used to conserve biological material for long periods at low temperatures. However the biophysical mechanisms of cell injuries during freezing are difficult to understand because a cell is a very sophisticated microstructure interacting with its environment. We have developed a finite element model to simulate the response of cells to an advancing solidification front. A special front-tracking technique is used to compute the motion of the cell membrane and the ice front during freezing. The model solves the conductive heat transfer equation and the diffusion equation of a solute on a domain containing three phases: one or more cells, the extra-cellular solution and the growing ice. This solid phase growing from a binary salt solution rejects the solute in the liquid phase and increases the solute gradient around the cell. This induces the shrinkage of the cell. The model is used to simulate the engulfment of one cell modelling a red blood cell by an advancing solidification front initially planar or not is computed. We compare the incorporation of a cell with that of a solid particle.

An evaluation of the benefits of utilizing rapid solidification for development of 2XXX (Al-Cu-Mg) alloys

NASA Technical Reports Server (NTRS)

Paris, H. G.; Chellman, D. J.

1986-01-01

The advantages of rapid solidification processing over ingot metallurgy processing in the development of 2XXX aluminum alloy compositions were evaluated using a similarly processed ingot metallurgy (IM) control alloy. The powder metallurgy (PM) alloy extrusions showed a reduced age-hardening response in comparison with similar IM compositions, with higher tensile properties for naturally aged extrusions but lower properties for artificially aged ones. However, the tensile properties of naturally and artificially aged PM alloy extrusions based on a version of IM 2034 alloy, but containing 0.6 weight percent zirconium, were comparable to those of the IM control extrusions and had significantly superior combinations of strength and toughness. The tensile properties of this PM alloy showed even greater advantage in 6.4-mm (0.25-in.) and 1.8-mm (0.070-in.) plate and sheet, the yield strength being about 68 MPa (10 ksi) greater than reported values for the IM 2034 alloy sheet. An artificially aged PM alloy based on 2219 alloy also showed a strength and strength-toughness combination comparable to those of the PM Al-Cu-Mg-Zr alloy, substantially outperforming the IM 2219 alloy. These results show that rapid solidification offers the flexibility needed to modify conventional IM compositions to produce new alloy compositions with superior mechanical properties.

Solidification/Stabilization Resource Guide

EPA Pesticide Factsheets

This Solidification/Stabilization Resource Guide is intended to inform site cleanup managers of recently-published materials such as field reports and guidance documents that address issues relevant to solidification/stabilization technologies.

The Solidification of Multicomponent Alloys

PubMed Central

Boettinger, William J.

2017-01-01

Various topics taken from the author’s research portfolio that involve multicomponent alloy solidification are reviewed. Topics include: ternary eutectic solidification and Scheil-Gulliver paths in ternary systems. A case study of the solidification of commercial 2219 aluminum alloy is described. Also described are modifications of the Scheil-Gulliver analysis to treat dendrite tip kinetics and solid diffusion for multicomponent alloys. PMID:28819348

X-ray imaging and controlled solidification of Al-Cu alloys toward microstructures by design

DOE PAGES

Clarke, Amy J.; Tourret, Damien; Imhoff, Seth D.; ...

2015-01-30

X-ray imaging, which permits the microscopic visualization of metal alloy solidification dynamics, can be coupled with controlled solidification to create microstructures by design. In this study, this x-ray image shows a process-derived composite microstructure being made from a eutectic Al-17.1 at.%Cu alloy by successive solidification and remelting steps.

Parabolic aircraft solidification experiments

NASA Technical Reports Server (NTRS)

Workman, Gary L. (Principal Investigator); Smith, Guy A.; OBrien, Susan

1996-01-01

A number of solidification experiments have been utilized throughout the Materials Processing in Space Program to provide an experimental environment which minimizes variables in solidification experiments. Two techniques of interest are directional solidification and isothermal casting. Because of the wide-spread use of these experimental techniques in space-based research, several MSAD experiments have been manifested for space flight. In addition to the microstructural analysis for interpretation of the experimental results from previous work with parabolic flights, it has become apparent that a better understanding of the phenomena occurring during solidification can be better understood if direct visualization of the solidification interface were possible. Our university has performed in several experimental studies such as this in recent years. The most recent was in visualizing the effect of convective flow phenomena on the KC-135 and prior to that were several successive contracts to perform directional solidification and isothermal casting experiments on the KC-135. Included in this work was the modification and utilization of the Convective Flow Analyzer (CFA), the Aircraft Isothermal Casting Furnace (ICF), and the Three-Zone Directional Solidification Furnace. These studies have contributed heavily to the mission of the Microgravity Science and Applications' Materials Science Program.

Solidification kinetics of a Cu-Zr alloy: ground-based and microgravity experiments

NASA Astrophysics Data System (ADS)

Galenko, P. K.; Hanke, R.; Paul, P.; Koch, S.; Rettenmayr, M.; Gegner, J.; Herlach, D. M.; Dreier, W.; Kharanzhevski, E. V.

2017-04-01

Experimental and theoretical results obtained in the MULTIPHAS-project (ESA-European Space Agency and DLR-German Aerospace Center) are critically discussed regarding solidification kinetics of congruently melting and glass forming Cu50Zr50 alloy samples. The samples are investigated during solidification using a containerless technique in the Electromagnetic Levitation Facility [1]. Applying elaborated methodologies for ground-based and microgravity experimental investigations [2], the kinetics of primary dendritic solidification is quantitatively evaluated. Electromagnetic Levitator in microgravity (parabolic flights and on board of the International Space Station) and Electrostatic Levitator on Ground are employed. The solidification kinetics is determined using a high-speed camera and applying two evaluation methods: “Frame by Frame” (FFM) and “First Frame - Last Frame” (FLM). In the theoretical interpretation of the solidification experiments, special attention is given to the behavior of the cluster structure in Cu50Zr50 samples with the increase of undercooling. Experimental results on solidification kinetics are interpreted using a theoretical model of diffusion controlled dendrite growth.

Thermophysical and heat transfer properties of phase change material candidate for waste heat transportation system

NASA Astrophysics Data System (ADS)

Kaizawa, Akihide; Maruoka, Nobuhiro; Kawai, Atsushi; Kamano, Hiroomi; Jozuka, Tetsuji; Senda, Takeshi; Akiyama, Tomohiro

2008-05-01

A waste heat transportation system trans-heat (TH) system is quite attractive that uses the latent heat of a phase change material (PCM). The purpose of this paper is to study the thermophysical properties of various sugars and sodium acetate trihydrate (SAT) as PCMs for a practical TH system and the heat transfer property between PCM selected and heat transfer oil, by using differential scanning calorimetry (DSC), thermogravimetry-differential thermal analysis (TG-DTA) and a heat storage tube. As a result, erythritol, with a large latent heat of 344 kJ/kg at melting point of 117°C, high decomposition point of 160°C and excellent chemical stability under repeated phase change cycles was found to be the best PCM among them for the practical TH system. In the heat release experiments between liquid erythritol and flowing cold oil, we observed foaming phenomena of encapsulated oil, in which oil droplet was coated by solidification of PCM.

Physical barrier effect of geopolymeric waste form on diffusivity of cesium and strontium.

PubMed

Jang, J G; Park, S M; Lee, H K

2016-11-15

The present study investigates the physical barrier effect of geopolymeric waste form on leaching behavior of cesium and strontium. Fly ash-based geopolymers and slag-blended geopolymers were used as solidification agents. The leaching behavior of cesium and strontium from geopolymers was evaluated in accordance with ANSI/ANS-16.1. The diffusivity of cesium and strontium in a fly ash-based geopolymer was lower than that in Portland cement by a factor of 10(3) and 10(4), respectively, showing significantly improved immobilization performance. The leaching resistance of fly ash-based geopolymer was relatively constant regardless of the type of fly ash. The diffusivity of water-soluble cesium and strontium ions were highly correlated with the critical pore diameter of the binder. The critical pore diameter of the fly ash-based geopolymer was remarkably smaller than those of Portland cement and slag-blended geopolymer; consequently, its ability physically to retard the diffusion of nuclides (physical barrier effect) was superior. Copyright © 2016 Elsevier B.V. All rights reserved.

The Use of In Situ X-ray Imaging Methods in the Research and Development of Magnesium-Based Grain-Refined and Nanocomposite Materials

NASA Astrophysics Data System (ADS)

Sillekens, W. H.; Casari, D.; Mirihanage, W. U.; Terzi, S.; Mathiesen, R. H.; Salvo, L.; Daudin, R.; Lhuissier, P.; Guo, E.; Lee, P. D.

2016-12-01

Metallurgists have an ever-increasing suite of analytical techniques at their disposition. Among these techniques are the in situ methods, being those approaches that are designed to actually study events that occur in the material during for instance solidification, (thermo)-mechanical working or heat treatment. As such they are a powerful tool in unraveling the mechanisms behind these processes, supplementary to ex situ methods that instead analyze the materials before and after their processing. In this paper, case studies are presented of how in situ imaging methods—and more specifically micro-focus x-ray radiography and synchrotron x-ray tomography—are used in the research and development of magnesium-based grain-refined and nanocomposite materials. These results are drawn from the EC collaborative research project ExoMet (www.exomet-project.eu). The first example concerns the solidification of a Mg-Nd-Gd alloy with Zr addition to assess the role of zirconium content and cooling rate in crystal nucleation and growth. The second example concerns the solidification of a Mg-Zn-Al alloy and its SiC-containing nanocomposite material to reveal the influence of particle addition on microstructural development. The third example concerns the (partial) melting-solidification of Elektron21/AlN and Elektron21/Y2O3 nanocomposite materials to study such effects as particle pushing/engulfment and agglomeration during repeated processing. Such studies firstly visualize and by that confirm what is known or assumed. Secondly, they advance science by monitoring and quantifying phenomena as they evolve during processing and by that contribute toward a better understanding of the physics at play.

Federal Register Notice: Final Rule Listing as Hazardous Wastes Certain Dioxin Containing Wastes

EPA Pesticide Factsheets

EPA is amending the regulations for hazardous waste management under the RCRA by listing as hazardous wastes certain wastes containing particular chlorinated dioxins, -dibenzofurans, and -phenols, and by specifying a engagement standards for these wastes.

Study of Solidification Cracking in a Transformation-Induced Plasticity-Aided Steel

NASA Astrophysics Data System (ADS)

Agarwal, G.; Kumar, A.; Gao, H.; Amirthalingam, M.; Moon, S. C.; Dippenaar, R. J.; Richardson, I. M.; Hermans, M. J. M.

2018-04-01

In situ high-temperature laser scanning confocal microscopy is applied to study solidification cracking in a TRIP steel. Solidification cracking was observed in the interdendritic region during the last stage of solidification. Atom probe tomography revealed notable enrichment of phosphorus in the last remaining liquid. Phase field simulations also confirm phosphorus enrichment leading to severe undercooling of more than 160 K in the interdendritic region. In the presence of tensile stress, an opening at the interdendritic region is difficult to fill with the remaining liquid due to low permeability and high viscosity, resulting in solidification cracking.

NASA MSFC Electrostatic Levitator (ESL) Rapid Quench System

NASA Technical Reports Server (NTRS)

SanSoucie, Michael P.; Craven, Paul D.

2014-01-01

Electrostatic levitation, a form of containerless processing, is an important tool in materials research. Levitated specimens are free from contact with a container; therefore, heterogeneous nucleation on container walls is not possible. This allows studies of deeply undercooled melts. Furthermore, studies of high-temperature, highly reactive materials are also possible. Studies of the solidification and crystallization of undercooled melts is vital to the understanding of microstructure development, particularly the formation of alloys with unique properties by rapid solidification. The NASA Marshall Space Flight Center (MSFC) Electrostatic Levitator (ESL) lab has recently been upgraded to allow for rapid quenching of levitated materials. The ESL Rapid Quench System uses a small crucible-like vessel that can be partially filled with a low melting point material, such as a Gallium alloy, as a quench medium. An undercooled sample can be dropped into the vessel to rapidly quench the sample. A carousel with nine vessels sits below the bottom electrode assembly. This system allows up to nine rapid quenches before having to break vacuum and remove the vessels. This new Rapid Quench System will allow materials science studies of undercooled materials and new materials development. In this presentation, the system is described and initial results are presented.

Microstructural development during solidification of stainless steel alloys

NASA Astrophysics Data System (ADS)

Elmer, J. W.; Allen, S. M.; Eagar, T. W.

1989-10-01

The microstructures that develop during the solidification of stainless steel alloys are related to the solidification conditions and the specific alloy composition. The solidification conditions are determined by the processing method, i.e., casting, welding, or rapid solidification, and by parametric variations within each of these techniques. One variable that has been used to characterize the effects of different processing conditions is the cooling rate. This factor and the chemical composition of the alloy both influence (1) the primary mode of solidification, (2) solute redistribution and second-phase formation during solidification, and (3) the nucleation and growth behavior of the ferrite-to-austenite phase transformation during cooling. Consequently, the residual ferrite content and the microstructural morphology depend on the cooling rate and are governed by the solidification process. This paper investigates the influence of cooling rate on the microstructure of stainless steel alloys and describes the conditions that lead to the many microstructural morphologies that develop during solidification. Experiments were performed on a series of seven high-purity Fe-Ni-Cr alloys that spanned the line of twofold saturation along the 59 wt pct Fe isopleth of the ternary alloy system. High-speed electron-beam surface-glazing was used to melt and resolidify these alloys at scan speeds up to 5 m/s. The resulting cooling rates were shown to vary from 7°C/s to 7.5×106°C/s, and the resolidified melts were analyzed by optical metallographic methods. Five primary modes of solidification and 12 microstructural morphologies were characterized in the resolidified alloys, and these features appear to be a complete “set” of the possible microstructures for 300-series stainless steel alloys. The results of this study were used to create electron-beam scan speed vs composition diagrams, which can be used to predict the primary mode of solidification and the microstructural morphology for different processing conditions. Furthermore, changes in the primary solidification mode were observed in alloys that lie on the chromium-rich side of the line of twofold saturation when they are cooled at high rates. These changes were explained by the presence of metastable austenite, which grows epitaxially and can dominate the solidification microstructure throughout the resolidified zone at high cooling rates.

Analysis and calculation of macrosegregation in a casting ingot. MPS solidification model. Volume 3: Operating manual

NASA Technical Reports Server (NTRS)

Maples, A. L.

1980-01-01

The operation of solidification model 1 is described. Model 1 calculates the macrosegregation in a rectangular ingot of a binary alloy as a result of horizontal axisymmetric bidirectional solidification. The calculation is restricted to steady-state solidification; there is no variation in final local average composition in the direction of isotherm movement. The physics of the model are given.

Advanced powder metallurgy aluminum alloys via rapid solidification technology

NASA Technical Reports Server (NTRS)

Ray, R.

1984-01-01

Aluminum alloys containing 10 to 11.5 wt. pct. of iron and 1.5 to 3 wt. pct. of chromium using the technique of rapid solidification powder metallurgy were studied. Alloys were prepared as thin ribbons (.002 inch thick) rapidly solidified at uniform rate of 10(6) C/second by the melt spinning process. The melt spun ribbons were pulverized into powders (-60 to 400 mesh) by a rotating hammer mill. The powders were consolidated by hot extrusion at a high reduction ratio of 50:1. The powder extrusion temperature was varied to determine the range of desirable processing conditions necessary to yield useful properties. Powders and consolidated alloys were characterized by SEM and optical metallography. The consolidated alloys were evaluated for (1) thermal stability, (2) tensile properties in the range, room temperature to 450 F, and (3) notch toughness in the range, room temperature to 450 F.

The microstructure and properties of rapidly solidified, dispersion-strengthened NiAl

NASA Technical Reports Server (NTRS)

Jha, S. C.; Ray, R.

1990-01-01

An advanced rapid solidification technology for processing reactive and refractory alloys, utilized to produce large quantities of melt-spun filaments of NiAl, is presented. The melt-spun filaments are pulverized to fine particle sizes, and subsequently consolidated by hot extrusion or hot isostatic pressing. Rapid solidification process gives rise to very fine-grained microstructures. However, exposure to elevated temperature during hot consolidation leads to grain growth. Alloying agents such as borides, carbides, and tungsten can pin the grain boundaries and retard the grain growth. Various alloy compositions are investigated. The eventual goal is to utilize the hot-extruded and forged stock to grow single-crystal NiAl blades for advanced gas-turbine engine applications. Single-crystal NiAl, containing a uniform dispersion of carbide strengthening precipitates, is expected to lead to highly creep-resistant turbine blades, and is of considerable interest to the aerospace propulsion industry.

Liquidus Temperatures and Solidification Behavior in the Copper-Niobium System

NASA Technical Reports Server (NTRS)

Li, D.; Robinson, M. B.; Rathz, T. J.; Williams, G.

1998-01-01

The copper-niobium phase diagram has been under active debate; thus, a corroboratory experimental study is needed. In this investigation, the melts of Cu-Nb alloys at compositions ranging from 5 lo 86 wt% Nb were processed in different environments and solidified at relatively low rates of 50-75 C/s to determine liquidus temperatures and to study solidification behavior. For all samples processed under very clean conditions, only Nb dendrites in a Cu matrix were observed; while in the presents of oxygen impurities, the alloys containing 5-35 wt% Nb exhibited microstructure of Nb-rich spheroids and Nb dendrites in the Cu matrix. The results obtained from clean conditions are in fair agreement with the Cu-Nb phase diagram having an S-shaped, near-horizontal appearances of the liquidus. The formation of Nb-rich droplets at slow cooling rates is discussed in terms of a stable liquid miscibility gap induced by oxygen.

Containerless processing of Nb-Ge alloys in a long drop tube

NASA Technical Reports Server (NTRS)

Bayuzick, R. J.

1982-01-01

The thirty-two meter drop tube at the Marshall Space Flight Center was used to study the effect of zero gravity containerless processing on the structure and properties of materials. The concept involves the suppression of heterogeneous nucleation of solid in liquid and, therefore, solidification accompanied by large degrees of undercooling. Under these conditions metastable phases can be formed or, at the very least, unique nonequilibrium microstructures (containing equilibrium phases) with unique properties can be produced. The drop tube solidification was applied to niobium base alloys with emphasis on the Nb-Ge binary system in an effort to produce metastable phases with high superconducting transition temperatures in bulk specimens. In the past, only lower Ge alloys (Nb-13 a/o, Nb-18 a/o, and Nb-22 a/o) could be undercooled. Higher Ge alloys (e.g., Nb-25 a/o Ge and Nb-27 a/o Ge) can now be undercooled on a routine basis.

Indium antimonide crystal growth experiment M562. [Skylab weightless conditions

NASA Technical Reports Server (NTRS)

Gatos, H. C.; Witt, A. F.

1974-01-01

It was established that ideal diffusion controlled steady state conditions, never accomplished on earth, were achieved during the growth of Te-doped InSb crystals in Skylab. Surface tension effects led to nonwetting conditions under which free surface solidification took place in confined geometry. It was further found that, under forced contact conditions, surface tension effects led to the formation of surface ridges (not previously observed on earth) which isolated the growth system from its container. In addition, it was possible, for the first time, to identify unambiguously: the origin of segregation discontinuities associated with facet growth, the mode of nucleation and propagation of rotational twin boundaries, and the specific effect of mechanical-shock perturbations on segregation. The results obtained prove the advantageous conditions provided by outer space. Thus, fundamental data on solidification thought to be unattainable because of gravity-induced interference on earth are now within reach.

Investigating gas-phase defect formation in late-stage solidification using a novel phase-field crystal alloy model

NASA Astrophysics Data System (ADS)

Wang, Nan; Smith, Nathan; Provatas, Nikolas

2017-09-01

We study late-stage solidification and the associated formation of defects in alloy materials using a novel model based on the phase-field-crystal technique. It is shown that our model successfully captures several important physical phenomena that occur in the late stages of solidification, including solidification shrinkage, liquid cavitation and microsegregation, all in a single framework. By examining the interplay of solidification shrinkage and solute segregation, this model reveals that the formation of gas pore defects at the late stage of solidification can lead to nucleation of second phase solid particles due to solute enrichment in the eutectic liquid driven by gas-phase nucleation and growth. We also predict a modification of the Gulliver-Scheil equation in the presence of gas pockets in confined liquid pools.

Core solidification and dynamo evolution in a mantle-stripped planetesimal

NASA Astrophysics Data System (ADS)

Scheinberg, A.; Elkins-Tanton, L. T.; Schubert, G.; Bercovici, D.

2016-01-01

The physical processes active during the crystallization of a low-pressure, low-gravity planetesimal core are poorly understood but have implications for asteroidal magnetic fields and large-scale asteroidal structure. We consider a core with only a thin silicate shell, which could be analogous to some M-type asteroids including Psyche, and use a parameterized thermal model to predict a solidification timeline and the resulting chemical profile upon complete solidification. We then explore the potential strength and longevity of a dynamo in the planetesimal's early history. We find that cumulate inner core solidification would be capable of sustaining a dynamo during solidification, but less power would be available for a dynamo in an inward dendritic solidification scenario. We also model and suggest limits on crystal settling and compaction of a possible cumulate inner core.

Size-dependent microstructures in rapidly solidified uranium-niobium powder particles

DOE PAGES

McKeown, Joseph T.; Hsiung, Luke L.; Park, Jong M.; ...

2016-06-14

The microstructures of rapidly solidified U-6wt%Nb powder particles synthesized by centrifugal atomization were characterized using scanning electron microscopy and transmission electron microscopy. Observed variations in microstructure are related to particle sizes. All of the powder particles exhibited a two-zone microstructure. The formation of this two-zone microstructure is described by a transition from solidification controlled by internal heat flow and high solidification rate during recalescence (micro-segregation-free or partitionless growth) to solidification controlled by external heat flow with slower solidification rates (dendritic growth with solute redistribution). The extent of partitionless solidification increased with decreasing particle size due to larger undercoolings in smallermore » particles prior to solidification. The metastable phases that formed are related to variations in Nb concentration across the particles. Lastly, the microstructures of the powders were heavily twinned.« less

Airborne microorganisms from waste containers.

PubMed

Jedlicka, Sabrina S; Stravitz, David M; Lyman, Charles E

2012-01-01

In physician's offices and biomedical labs, biological waste is handled every day. This waste is disposed of in waste containers designed for holding red autoclave bags. The containers used in these environments are closed hands-free containers, often with a step pedal. While these containers protect the user from surface-borne microorganisms, the containers may allow airborne microorganisms to escape via the open/close mechanism because of the air current produced upon open/close cycles. In this study, the air current was shown to be sufficient to allow airborne escape of microorganisms held in the container, including Aspergillus niger. However, bacterial cultures, such as Escherichia coli and Lactococcus lactis did not escape. This may be due to the choice of bacterial cultures and the absence of solid waste, such as dust or other particulate matter in the waste containers, that such strains of bacteria could travel on during aerosolization. We compared these results to those obtained using a re-designed receptacle, which mimimizes air currents, and detected no escaping microorganisms. This study highlights one potential source of airborne contamination in labs, hospitals, and other environments that dispose of biological waste.

Directional Solidification and Liquidus Projection of the Sn-Co-Cu System

NASA Astrophysics Data System (ADS)

Chen, Sinn-Wen; Chang, Jui-Shen; Pan, Kevin; Hsu, Chia-Ming; Hsu, Che-Wei

2013-04-01

This study investigates the Sn-Co-Cu ternary system, which is of interest to the electronics industry. Ternary Sn-Co-Cu alloys were prepared, their as-solidified microstructures were examined, and their primary solidification phases were determined. The primary solidification phases observed were Cu, Co, Co3Sn2, CoSn, CoSn2, Cu6Sn5, Co3Sn2, γ, and β phases. Although there are ternary compounds reported in this ternary system, no ternary compound was found as the primary solidification phase. The directional solidification technique was applied when difficulties were encountered using the conventional quenching method to distinguish the primary solidification phases, such as Cu6Sn5, Cu3Sn, and γ phases. Of all the primary solidification phases, the Co3Sn2 and Co phases have the largest compositional regimes in which alloys display them as the primary solidification phases. There are four class II reactions and four class III reactions. The reactions with the highest and lowest reaction temperatures are both class III reactions, and are L + CoSn2 + Cu6Sn5 = CoSn3 at 621.5 K (348.3 °C) and L + Co3Sn2 + CoSn = Cu6Sn5 at 1157.8 K (884.6 °C), respectively.

WIPP

Science.gov Websites

waste Semi Truck with trailer hauling two TRUPACT-II containers Safely disposed of more than 170,000 waste containers WIPP has been disposing of legacy transuranic (TRU) waste since 1999, cleaning up 22 once waste... [January 17, 2018] read more... Semi Truck hauling three TRUPACT-II containers THE WIPP

40 CFR 268.31 - Waste specific prohibitions-Dioxin-containing wastes.

Code of Federal Regulations, 2010 CFR

2010-07-01

... 40 Protection of Environment 26 2010-07-01 2010-07-01 false Waste specific prohibitions-Dioxin-containing wastes. 268.31 Section 268.31 Protection of Environment ENVIRONMENTAL PROTECTION AGENCY (CONTINUED) SOLID WASTES (CONTINUED) LAND DISPOSAL RESTRICTIONS Prohibitions on Land Disposal § 268.31 Waste...

40 CFR 268.31 - Waste specific prohibitions-Dioxin-containing wastes.

Code of Federal Regulations, 2014 CFR

2014-07-01

... 40 Protection of Environment 27 2014-07-01 2014-07-01 false Waste specific prohibitions-Dioxin-containing wastes. 268.31 Section 268.31 Protection of Environment ENVIRONMENTAL PROTECTION AGENCY (CONTINUED) SOLID WASTES (CONTINUED) LAND DISPOSAL RESTRICTIONS Prohibitions on Land Disposal § 268.31 Waste...

40 CFR 268.31 - Waste specific prohibitions-Dioxin-containing wastes.

Code of Federal Regulations, 2013 CFR

2013-07-01

... 40 Protection of Environment 28 2013-07-01 2013-07-01 false Waste specific prohibitions-Dioxin-containing wastes. 268.31 Section 268.31 Protection of Environment ENVIRONMENTAL PROTECTION AGENCY (CONTINUED) SOLID WASTES (CONTINUED) LAND DISPOSAL RESTRICTIONS Prohibitions on Land Disposal § 268.31 Waste...

40 CFR 268.31 - Waste specific prohibitions-Dioxin-containing wastes.

Code of Federal Regulations, 2011 CFR

2011-07-01

... 40 Protection of Environment 27 2011-07-01 2011-07-01 false Waste specific prohibitions-Dioxin-containing wastes. 268.31 Section 268.31 Protection of Environment ENVIRONMENTAL PROTECTION AGENCY (CONTINUED) SOLID WASTES (CONTINUED) LAND DISPOSAL RESTRICTIONS Prohibitions on Land Disposal § 268.31 Waste...

40 CFR 268.31 - Waste specific prohibitions-Dioxin-containing wastes.

Code of Federal Regulations, 2012 CFR

2012-07-01

... 40 Protection of Environment 28 2012-07-01 2012-07-01 false Waste specific prohibitions-Dioxin-containing wastes. 268.31 Section 268.31 Protection of Environment ENVIRONMENTAL PROTECTION AGENCY (CONTINUED) SOLID WASTES (CONTINUED) LAND DISPOSAL RESTRICTIONS Prohibitions on Land Disposal § 268.31 Waste...

Rapid Solidification in Bulk Ti-Nb Alloys by Single-Track Laser Melting

NASA Astrophysics Data System (ADS)

Roehling, John D.; Perron, Aurélien; Fattebert, Jean-Luc; Haxhimali, Tomorr; Guss, Gabe; Li, Tian T.; Bober, David; Stokes, Adam W.; Clarke, Amy J.; Turchi, Patrice E. A.; Matthews, Manyalibo J.; McKeown, Joseph T.

2018-05-01

Single-track laser melting experiments were performed on bulk Ti-Nb alloys to explore process parameters and the resultant macroscopic structure and microstructure. The microstructures in Ti-20Nb and Ti-50Nb (at.%) alloys exhibited cellular growth during rapid solidification, with average cell size of approximately 0.5 µm. Solidification velocities during cellular growth were calculated from images of melt tracks. Measurements of the composition in the cellular and intercellular regions revealed nonequilibrium partitioning and its dependence on velocity during rapid solidification. Experimental results were used to benchmark a phase-field model to describe rapid solidification under conditions relevant to additive manufacturing.

Evolutions of lamellar structure during melting and solidification of Fe9577 nanoparticle from molecular dynamics simulations

NASA Astrophysics Data System (ADS)

Wu, Yongquan; Shen, Tong; Lu, Xionggang

2013-03-01

A structural evolution during solidification and melting processes of nanoparticle Fe9577 was investigated from MD simulations. A perfect lamellar structure, consisting alternately of fcc and hcp layers, was obtained from solidification process. A structural heredity of early embryo is proposed to explain the structural preference of solidification. Defects were found inside the solid core and play the same role as surface premelting on melting. hcp was found more stable than fcc in high temperature. The difference between melting and solidification points can be deduced coming fully from the overcoming of thermodynamic energy barrier, instead of kinetic delay of structural relaxation.

The Solidification Velocity of Undercooled Nickel and Titanium Alloys with Dilute Solute

NASA Technical Reports Server (NTRS)

Algoso, Paul R.; Altgilbers, A. S.; Hofmeister, William H.; Bayuzick, Robert J.

2003-01-01

The study of solidification velocity is important for two reasons. First, understanding the manner in which the degree of undercooling of the liquid and solidification velocity affect the microstructure of the solid is fundamental. Second, there is disagreement between theoretical predictions of the relationship between undercooling and solidification velocity and experimental results. Thus, the objective of this research is to accurately and systematically quantify the solidification velocity as a function of undercooling for dilute nickel-and titanium-based alloys. The alloys chosen for study cover a wide range of equilibrium partition coefficients, and the results are compared to current theory.

Configuration management at an environmental restoration DOE facility (Fernald)

DOE Office of Scientific and Technical Information (OSTI.GOV)

Beckett, C.; Pasko, W.; Kupinski, T.

This report contains information about a meeting held to discuss the decontamination and decommissioning of the Fernald site in Ohio. This site contains two major types of waste. First is the legacy waste. This waste consists of the wastes which were left over from production which is stored in various drums and containers across the site. Second is the waste generated from the remedial activities.

Separation of heavy metals: Removal from industrial wastewaters and contaminated soil

DOE Office of Scientific and Technical Information (OSTI.GOV)

Peters, R.W.; Shem, L.

1993-01-01

This paper reviews the applicable separation technologies relating to removal of heavy metals from solution and from soils in order to present the state-of-the-art in the field. Each technology is briefly described and typical operating conditions and technology performance are presented. Technologies described include chemical precipitation (including hydroxide, carbonate, or sulfide reagents), coagulation/flocculation, ion exchange, solvent extraction, extraction with chelating agents, complexation, electrochemical operation, cementation, membrane operations, evaporation, adsorption, solidification/stabilization, and vitrification. Several case histories are described, with a focus on waste reduction techniques and remediation of lead-contaminated soils. The paper concludes with a short discussion of important research needsmore » in the field.« less

Separation of heavy metals: Removal from industrial wastewaters and contaminated soil

DOE Office of Scientific and Technical Information (OSTI.GOV)

Peters, R.W.; Shem, L.

1993-03-01

This paper reviews the applicable separation technologies relating to removal of heavy metals from solution and from soils in order to present the state-of-the-art in the field. Each technology is briefly described and typical operating conditions and technology performance are presented. Technologies described include chemical precipitation (including hydroxide, carbonate, or sulfide reagents), coagulation/flocculation, ion exchange, solvent extraction, extraction with chelating agents, complexation, electrochemical operation, cementation, membrane operations, evaporation, adsorption, solidification/stabilization, and vitrification. Several case histories are described, with a focus on waste reduction techniques and remediation of lead-contaminated soils. The paper concludes with a short discussion of important research needsmore » in the field.« less

Space Processing Applications Rocket (SPAR) project, SPAR 9

NASA Technical Reports Server (NTRS)

Poorman, R. (Compiler)

1984-01-01

SPAR 9 (R-17) payload configuration, rocket performance, payload support, science payload instrumentation, and payload recovery are discussed. Directional solidification of magnetic composites, directional solidification of immiscible aluminum-indium alloys, and comparative alloy solidification experiments are reported.

Modelling direction solidification

NASA Technical Reports Server (NTRS)

Wilcox, W. R.

1986-01-01

The overall objective of this program is to develop an improved understanding of some phenomena of importance to directional solidification. The aim of this research is also to help predict differences in behavior between solidification on Earth and solidification in space. In this report, the validity of the Burton-Primslichter equation is explored. The influence of operating variables on grain and twin generation and propagation in single crystals of In sub (x) Ga sub (1-x) Sb is also investigated.

Optimization of Superaustenitic Stainless Steel Filler Metals for Welding Advanced Double Hull Combatant Ships

DTIC Science & Technology

2005-02-16

alloy is also given. The solidification mode of martensitic samples has been omitted and replaced with ’M’. Mo Ni +Cr Cr Ni ... alloys composed predominately of austenite. The four solidification modes present in the remaining 64 alloys , in order of increasing Cr/ Ni content, were...result in Fe- Ni -Cr-Mo alloys from the arc-melt condition. Solidification Solidification Primar- Secondar- Final microstrncture Mode

Application of Solidification Theory to Rapid Solidification Processing

DTIC Science & Technology

1983-08-01

1879 (1982). E 7] W. J. Boettinger, R. J. Schaefer, F. Biancaniello, and D. Shechtman, Met. Trans. A ., to be published. E 8] W. J. Bettinger , S. R...solidification velocity which produce a special "banded" microstructure in Ag-Cu alloys. Related lower bound to theoretical limits on solidification...partitionless rapid solidifi- cation of NiAl-Cr quasibinary eutectic alloy rather than a disordered structure incorporating Ni and Al into Cr randomly

Melt Flow Control in the Directional Solidification of Binary Alloys

NASA Technical Reports Server (NTRS)

Zabaras, Nicholas

2003-01-01

Our main project objectives are to develop computational techniques based on inverse problem theory that can be used to design directional solidification processes that lead to desired temperature gradient and growth conditions at the freezing front at various levels of gravity. It is known that control of these conditions plays a significant role in the selection of the form and scale of the obtained solidification microstructures. Emphasis is given on the control of the effects of various melt flow mechanisms on the local to the solidification front conditions. The thermal boundary conditions (furnace design) as well as the magnitude and direction of an externally applied magnetic field are the main design variables. We will highlight computational design models for sharp front solidification models and briefly discuss work in progress toward the development of design techniques for multi-phase volume-averaging based solidification models.

Experimental Study on the Anisotropic Stress-Strain Behavior of Polycrystalline Ni-Mn-Ga in Directional Solidification

NASA Astrophysics Data System (ADS)

Teng, Yao; Shi, Tao; Zhu, Yuping; Li, Zongbin; Deng, Tao; Bai, Guonan

2016-03-01

A polycrystalline Ni-Mn-Ga ferromagnetic shape memory alloy produced by directional solidification is the subject of this research paper. The compressive stress-strain curves of the material for different cutting angles to the solidification direction are tested. The martensite Young's modulus, macroscopic reorientation strain, and phase transition critical stress are analyzed experimentally. The results show that mechanical behaviors in the loading-unloading cycle of the material present nonlinear and anisotropic characteristics, which are all closely related to the material's orientation to the solidification direction. The martensite Young's modulus, macroscopic reorientation strain, and phase transition critical stress achieve maximum values in the solidification direction. A 50° orientation to the solidification direction is the cut-off direction of the mechanical properties, where the martensite Young's modulus and reorientation start critical stress reach minimum values. The present study is expected to provide sound guidance for practical applications.

Experimental study of void formation during aluminum solidification in reduced gravity. Ph.D. Thesis - Toledo Univ.

NASA Technical Reports Server (NTRS)

Chiaramonte, Francis Paul, III

1993-01-01

Void formation due to volumetric shrinkage and liquid/vapor reorientation during aluminum solidification was observed in real time by using a radiographic viewing system in normal and reduced gravity. An end-chill directional solidification furnace with water quench was designed and constructed to solidify aluminum samples during the approximately 16 sec of reduced gravity (+/-0.02g) achieved by flying an aircraft through a parabolic trajectory. In the first series of tests the aluminum was contained in a vacuum sealed, pyrolytic boron nitride crucible. An ullage space was present during each test. Void formation was recorded for two cases: a nonwetting system, and a wetting system where wetting occurred between the aluminum and the crucible lid. The void formation in the nonwetting case was similar in normal and reduced gravity, with a single vapor cavity forming at the top of the crucible. In the wetting case during reduced gravity surface tension caused two voids to form in the top corners of the crucible, but during normal gravity only one large void formed across the top. In the second series of tests the aluminum was contained in a pyrolytic boron nitride crucible that was placed in a stainless steel container and sealed in an environment of argon plus 4 percent hydrogen. An ullage space was present during each test. Void formation was recorded for two cases: a nonwetting system, and a wetting system where wetting occurred between the aluminum and one side wall and the lid. The void for nation in the nonwetting case was similar in normal and reduced gravity, with a single vapor cavity forming at the top of the crucible, although the meniscus became more convex in reduced gravity. In the wetting case the aluminum did not climb up the corners in 1g, and one large symmetric void resulted at the top when the aluminum had solidified. In the wetting case during reduced gravity the molten aluminum was drawn up the wetted wall and partially across the lid by a capillary underpressure; however, on the nonwetting wall the aluminum moved down. One void resulted along the nonwetting side of the container continuing to the top on the same side.

Treatment for hydrazine-containing waste water solution

NASA Technical Reports Server (NTRS)

Yade, N.

1986-01-01

The treatment for waste solutions containing hydrazine is presented. The invention attempts oxidation and decomposition of hydrazine in waste water in a simple and effective processing. The method adds activated charcoal to waste solutions containing hydrazine while maintaining a pH value higher than 8, and adding iron salts if necessary. Then, the solution is aerated.

Applications of fiber reinforced concrete containers in France and in Slovakia

DOE Office of Scientific and Technical Information (OSTI.GOV)

Verdier, A.; Delgrande, J.; Remias, V.

Radioactive waste immobilization is an integral part of operations in nuclear facilities. The goal of immobilization is to contain radioactive materials in a waste form which can maintain its integrity over very long periods of time, thus effectively isolating the materials from the environment and hence from the public. This is true regardless of the activity of the waste, including low-, and medium-level waste (LLW, MLW). A multiple-year research effort by COGEMA culminated in the development of a new process to immobilize nuclear waste in concrete containers reinforced with metal fibers. The fiber reinforced concrete containers satisfy all French safetymore » requirements relating to waste immobilization and disposal, and have been certified by ANDRA, the national radioactive waste management agency. The fiber reinforced concrete containers have been fabricated on a production scale since July 1990 by Sogefibre, a jointly-owned subsidiary of SGN and Campaign Generale des Eaux. This technology is being transferred to Slovenske Elektrarne (Slovak Power Plant) to intern the waste produced by Bohunice and Mochovce power plants in cubical fiber reinforced concrete containers.« less

Premature melt solidification during mold filling and its influence on the as-cast structure

NASA Astrophysics Data System (ADS)

Wu, M.; Ahmadein, M.; Ludwig, A.

2018-03-01

Premature melt solidification is the solidification of a melt during mold filling. In this study, a numerical model is used to analyze the influence of the pouring process on the premature solidification. The numerical model considers three phases, namely, air, melt, and equiaxed crystals. The crystals are assumed to have originated from the heterogeneous nucleation in the undercooled melt resulting from the first contact of the melt with the cold mold during pouring. The transport of the crystals by the melt flow, in accordance with the socalled "big bang" theory, is considered. The crystals are assumed globular in morphology and capable of growing according to the local constitutional undercooling. These crystals can also be remelted by mixing with the superheated melt. As the modeling results, the evolutionary trends of the number density of the crystals and the volume fraction of the solid crystals in the melt during pouring are presented. The calculated number density of the crystals and the volume fraction of the solid crystals in the melt at the end of pouring are used as the initial conditions for the subsequent solidification simulation of the evolution of the as-cast structure. A five-phase volume-average model for mixed columnar-equiaxed solidification is used for the solidification simulation. An improved agreement between the simulation and experimental results is achieved by considering the effect of premature melt solidification during mold filling. Finally, the influences of pouring parameters, namely, pouring temperature, initial mold temperature, and pouring rate, on the premature melt solidification are discussed.

Mold with improved core for metal casting operation

DOEpatents

Gritzner, Verne B.; Hackett, Donald W.

1977-01-01

The present invention is directed to a mold containing an improved core for use in casting hollow, metallic articles. The core is formed of, or covered with, a layer of cellular material which possesses sufficient strength to maintain its structural integrity during casting, but will crush to alleviate the internal stresses that build up if the normal contraction during solidification and cooling is restricted.

Convection and Solidification with Applications to Crystal Growth

NASA Technical Reports Server (NTRS)

DeVahl Davis, Graham

1994-01-01

An outline is given of research on the directional solidification of a liquid, and of the effects of natural convection thereon. Three problems which have been studied are described. Finally, current work on solidification in microgravity conditions is discussed.

Investigation of the Relationship between Undercooling and Solidification Velocity

NASA Technical Reports Server (NTRS)

Bayuzick, Robert J.; Hofmeister, William H.

2004-01-01

This work was aimed at reconciling the differences between experimental measurements of the theoretical predictions of the solidification velocity as a function of undercooling. The theory proposed by Boettinger, Coriell and Trivedi (the BCT theory) has been one of the most widely used models for describing the nature of the solidification of undercooled metals and alloys. However, for undercoolings greater than about 5% of the absolute melting temperature, there is considerable discrepancy between theory and experiment. At these large undercoolings, experimental results exhibit a much lessened dependency of solidification velocity on undercooling than is predicted by theory. Furthermore, unpredicted plateaus in the solidification velocity as a function of undercooling are observed.

MPS Solidification Model. Volume 2: Operating guide and software documentation for the unsteady model

NASA Technical Reports Server (NTRS)

Maples, A. L.

1981-01-01

The operation of solidification Model 2 is described and documentation of the software associated with the model is provided. Model 2 calculates the macrosegregation in a rectangular ingot of a binary alloy as a result of unsteady horizontal axisymmetric bidirectional solidification. The solidification program allows interactive modification of calculation parameters as well as selection of graphical and tabular output. In batch mode, parameter values are input in card image form and output consists of printed tables of solidification functions. The operational aspects of Model 2 that differ substantially from Model 1 are described. The global flow diagrams and data structures of Model 2 are included. The primary program documentation is the code itself.

Modeling of Microstructure Evolution During Alloy Solidification

NASA Astrophysics Data System (ADS)

Zhu, Mingfang; Pan, Shiyan; Sun, Dongke

In recent years, considerable advances have been achieved in the numerical modeling of microstructure evolution during solidification. This paper presents the models based on the cellular automaton (CA) technique and lattice Boltzmann method (LBM), which can reproduce a wide variety of solidification microstructure features observed experimentally with an acceptable computational efficiency. The capabilities of the models are addressed by presenting representative examples encompassing a broad variety of issues, such as the evolution of dendritic structure and microsegregation in two and three dimensions, dendritic growth in the presence of convection, divorced eutectic solidification of spheroidal graphite irons, and gas porosity formation. The simulations offer insights into the underlying physics of microstructure formation during alloy solidification.

45 CFR 671.11 - Waste storage.

Code of Federal Regulations, 2011 CFR

2011-10-01

... containers or tanks labeled to indicate their contents and the beginning date of accumulation of such waste... McMurdo Station or other disposition, for a period not to exceed 28 months; (4) Containers holding... ability of the containers to contain such waste is not impaired; (iii) Stored in a manner that allows...

45 CFR 671.11 - Waste storage.

Code of Federal Regulations, 2012 CFR

2012-10-01

... containers or tanks labeled to indicate their contents and the beginning date of accumulation of such waste... McMurdo Station or other disposition, for a period not to exceed 28 months; (4) Containers holding... ability of the containers to contain such waste is not impaired; (iii) Stored in a manner that allows...

45 CFR 671.11 - Waste storage.

Code of Federal Regulations, 2014 CFR

2014-10-01

... containers or tanks labeled to indicate their contents and the beginning date of accumulation of such waste... McMurdo Station or other disposition, for a period not to exceed 28 months; (4) Containers holding... ability of the containers to contain such waste is not impaired; (iii) Stored in a manner that allows...

45 CFR 671.11 - Waste storage.

Code of Federal Regulations, 2013 CFR

2013-10-01

... containers or tanks labeled to indicate their contents and the beginning date of accumulation of such waste... McMurdo Station or other disposition, for a period not to exceed 28 months; (4) Containers holding... ability of the containers to contain such waste is not impaired; (iii) Stored in a manner that allows...

40 CFR 148.11 - Waste specific prohibitions-dioxin-containing wastes.

Code of Federal Regulations, 2010 CFR

2010-07-01

... 40 Protection of Environment 22 2010-07-01 2010-07-01 false Waste specific prohibitions-dioxin-containing wastes. 148.11 Section 148.11 Protection of Environment ENVIRONMENTAL PROTECTION AGENCY (CONTINUED) WATER PROGRAMS (CONTINUED) HAZARDOUS WASTE INJECTION RESTRICTIONS Prohibitions on Injection § 148.11...

Method for acid oxidation of radioactive, hazardous, and mixed organic waste materials

DOEpatents

Pierce, Robert A.; Smith, James R.; Ramsey, William G.; Cicero-Herman, Connie A.; Bickford, Dennis F.

1999-01-01

The present invention is directed to a process for reducing the volume of low level radioactive and mixed waste to enable the waste to be more economically stored in a suitable repository, and for placing the waste into a form suitable for permanent disposal. The invention involves a process for preparing radioactive, hazardous, or mixed waste for storage by contacting the waste starting material containing at least one organic carbon-containing compound and at least one radioactive or hazardous waste component with nitric acid and phosphoric acid simultaneously at a contacting temperature in the range of about 140.degree. C. to about 210 .degree. C. for a period of time sufficient to oxidize at least a portion of the organic carbon-containing compound to gaseous products, thereby producing a residual concentrated waste product containing substantially all of said radioactive or inorganic hazardous waste component; and immobilizing the residual concentrated waste product in a solid phosphate-based ceramic or glass form.

40 CFR 270.300 - What container information must I keep at my facility?

Code of Federal Regulations, 2010 CFR

2010-07-01

... (CONTINUED) SOLID WASTES (CONTINUED) EPA ADMINISTERED PERMIT PROGRAMS: THE HAZARDOUS WASTE PERMIT PROGRAM... containers holding ignitable or reactive wastes) and 40 CFR 267.175(c) (location of incompatible wastes in...

CONTAINMENT TECHNOLOGIES

EPA Science Inventory

Hazardous waste containment's primary objective is to isolate wastes deemed as hazardous from man and environmental systems of air, soil, and water. Hazardous wastes differ from other waste classifications due to their increased potential to cause human health effects or environ...

Greater-than-Class C low-level radioactive waste shipping package/container identification and requirements study. National Low-Level Waste Management Program

DOE Office of Scientific and Technical Information (OSTI.GOV)

Tyacke, M.

1993-08-01

This report identifies a variety of shipping packages (also referred to as casks) and waste containers currently available or being developed that could be used for greater-than-Class C (GTCC) low-level waste (LLW). Since GTCC LLW varies greatly in size, shape, and activity levels, the casks and waste containers that could be used range in size from small, to accommodate a single sealed radiation source, to very large-capacity casks/canisters used to transport or dry-store highly radioactive spent fuel. In some cases, the waste containers may serve directly as shipping packages, while in other cases, the containers would need to be placedmore » in a transport cask. For the purpose of this report, it is assumed that the generator is responsible for transporting the waste to a Department of Energy (DOE) storage, treatment, or disposal facility. Unless DOE establishes specific acceptance criteria, the receiving facility would need the capability to accept any of the casks and waste containers identified in this report. In identifying potential casks and waste containers, no consideration was given to their adequacy relative to handling, storage, treatment, and disposal. Those considerations must be addressed separately as the capabilities of the receiving facility and the handling requirements and operations are better understood.« less

40 CFR 148.10 - Waste specific prohibitions-solvent wastes.

Code of Federal Regulations, 2010 CFR

2010-07-01

... 40 Protection of Environment 22 2010-07-01 2010-07-01 false Waste specific prohibitions-solvent wastes. 148.10 Section 148.10 Protection of Environment ENVIRONMENTAL PROTECTION AGENCY (CONTINUED) WATER... injection unless the solvent waste is a solvent-water mixture or solvent-containing sludge containing less...

INNOVATIVE PRACTICES FOR TREATING WASTE STREAMS CONTAINING HEAVY METALS: A WASTE MINIMIZATION APPROACH

EPA Science Inventory

Innovative practices for treating waste streams containing heavy metals often involve technologies or systems that either reduce the amount of waste generated or recover reusable resources. With the land disposal of metal treatment residuals becoming less of an accepted waste man...

Water Balance Covers For Waste Containment: Principles and Practice

EPA Science Inventory

Water Balance Covers for Waste Containment: Principles and Practices introduces water balance covers and compares them with conventional approaches to waste containment. The authors provided detailed analysis of the fundamentals of soil physics and design issues, introduce appl...

Underground waste barrier structure

DOEpatents

Saha, Anuj J.; Grant, David C.

1988-01-01

Disclosed is an underground waste barrier structure that consists of waste material, a first container formed of activated carbonaceous material enclosing the waste material, a second container formed of zeolite enclosing the first container, and clay covering the second container. The underground waste barrier structure is constructed by forming a recessed area within the earth, lining the recessed area with a layer of clay, lining the clay with a layer of zeolite, lining the zeolite with a layer of activated carbonaceous material, placing the waste material within the lined recessed area, forming a ceiling over the waste material of a layer of activated carbonaceous material, a layer of zeolite, and a layer of clay, the layers in the ceiling cojoining with the respective layers forming the walls of the structure, and finally, covering the ceiling with earth.

Effect of solidification rate on microstructure evolution in dual phase microalloyed steel

PubMed Central

Kostryzhev, A. G.; Slater, C. D.; Marenych, O. O.; Davis, C. L.

2016-01-01

In steels the dependence of ambient temperature microstructure and mechanical properties on solidification rate is not well reported. In this work we investigate the microstructure and hardness evolution for a low C low Mn NbTi-microalloyed steel solidified in the cooling rate range of 1–50 Cs−1. The maximum strength was obtained at the intermediate solidification rate of 30 Cs−1. This result has been correlated to the microstructure variation with solidification rate. PMID:27759109

Al and Mg Alloys for Aerospace Applications Using Rapid Solidification and Power Metallurgy Processing.

DTIC Science & Technology

1981-10-07

primary solidification phase in the alloy in this condition was identified by CBED as Mg 2 Si , which formed dendrites within the matrix. Each... solidification below the extended c-liquidus. Evolution of Microstructure in Melt-spun Mg- Si Alloys -, The microstructurcs observed in the alloys can...solidificaion pr(es .. in the cellular (dendritic) regime. Solidification of the 5.0 wt.% Si alloy occurs in the coupled eutectic region, and the 8.0 wt.% Si

Rapid solidification of levitation melted Ni-Sn alloy droplets with high undercooling

NASA Technical Reports Server (NTRS)

Shiohara, Yuh; Flemings, Merton C.; Wu, Yanzhong; Piccone, Thomas J.

1985-01-01

Experimental results obtained by high-speed optical temperature sensing for the rapid solidification of highly undercooled, levitation-melted Ni-Sn alloy droplets are presented. These data suggest a solidification model proceeding according to overlapping steps: (1) dendritic growth within the bulk undercooled melt, (2) continued recalescence as supersaturation of the interdendritic liquid dissipates, (3) fine-scale remelting within the dendrites, (4) ripening of the fine structure, and (5) solidification of remaining liquid at the end of recalescence.

Fundamentals of rapid solidification processing

NASA Technical Reports Server (NTRS)

Flemings, Merton C.; Shiohara, Yuh

1985-01-01

An attempt is made to illustrate the continuous change that occurs in the solidification behavior of undercooled melts, as cooling rates increase from 0.0001 K/sec to about 1000 K/sec. At the higher cooling rates, more significant changes occur as the dendrite tip temperature begins to drop from the equilibrium liquidus. Discontinuous solidification behavior changes will occur if absolute stability is reached, or a metastable phase forms, or solidification proceeds to a glass rather than to a crystalline solid, or if there is significant undercooling prior to nucleation.

78 FR 46447 - Conditional Exclusions From Solid Waste and Hazardous Waste for Solvent-Contaminated Wipes

Federal Register 2010, 2011, 2012, 2013, 2014

2013-07-31

... Waste Landfill NODA Notice of Data Availability NPDES National Pollutant Discharge Elimination System...-contaminated wipe or from the container holding the wipes. In addition, the exclusions are not applicable to... containers. The containers must be able to contain free liquids, should free liquids occur, and the...

40 CFR 273.4 - Applicability-Mercury-containing equipment.

Code of Federal Regulations, 2010 CFR

2010-07-01

... equipment. 273.4 Section 273.4 Protection of Environment ENVIRONMENTAL PROTECTION AGENCY (CONTINUED) SOLID WASTES (CONTINUED) STANDARDS FOR UNIVERSAL WASTE MANAGEMENT General § 273.4 Applicability—Mercury...-containing components have been removed. (c) Generation of waste mercury-containing equipment. (1) Used...

RCRA Part A Permit Application for Waste Management Activities at the Nevada Test Site, Part B Permit Application Hazardous Waste Storage Unit, Nevada Test Site, and Part B Permit Application - Explosives Ordnance Disposal Unit (EODU)

DOE Office of Scientific and Technical Information (OSTI.GOV)

NSTec Environmental Programs

2010-06-17

The Area 5 Hazardous Waste Storage Unit (HWSU) was established to support testing, research, and remediation activities at the Nevada Test Site (NTS), a large-quantity generator of hazardous waste. The HWSU, located adjacent to the Area 5 Radioactive Waste Management Site (RWMS), is a prefabricated, rigid steel-framed, roofed shelter used to store hazardous nonradioactive waste generated on the NTS. No offsite generated wastes are managed at the HWSU. Waste managed at the HWSU includes the following categories: Flammables/Combustibles; Acid Corrosives; Alkali Corrosives; Oxidizers/Reactives; Toxics/Poisons; and Other Regulated Materials (ORMs). A list of the regulated waste codes accepted for storage atmore » the HWSU is provided in Section B.2. Hazardous wastes stored at the HWSU are stored in U.S. Department of Transportation (DOT) compliant containers, compatible with the stored waste. Waste transfer (between containers) is not allowed at the HWSU and containers remain closed at all times. Containers are stored on secondary containment pallets and the unit is inspected monthly. Table 1 provides the metric conversion factors used in this application. Table 2 provides a list of existing permits. Table 3 lists operational Resource Conservation and Recovery Act (RCRA) units at the NTS and their respective regulatory status.« less

Materials Science Laboratory - Columnar-to-Equiaxed Transition in Solidification Processing and Microstructure Formation in Casting of Technical Alloys under Diffusive and Magnetically Controlled Convective Conditions

NASA Technical Reports Server (NTRS)

Gandin, Charles-Andre; Ratke, Lorenz

2008-01-01

The Materials Science Laboratory - Columnar-to-Equiaxed Transition in Solidification Processing and Microstructure Formation in Casting of Technical Alloys under Diffusive and Magnetically Controlled Convective Conditions (MSL-CETSOL and MICAST) are two investigations which supports research into metallurgical solidification, semiconductor crystal growth (Bridgman and zone melting), and measurement of thermo-physical properties of materials. This is a cooperative investigation with the European Space Agency (ESA) and National Aeronautics and Space Administration (NASA) for accommodation and operation aboard the International Space Station (ISS). Research Summary: Materials Science Laboratory - Columnar-to-Equiaxed Transition in Solidification Processing (CETSOL) and Microstructure Formation in Casting of Technical Alloys under Diffusive and Magnetically Controlled Convective Conditions (MICAST) are two complementary investigations which will examine different growth patterns and evolution of microstructures during crystallization of metallic alloys in microgravity. The aim of these experiments is to deepen the quantitative understanding of the physical principles that govern solidification processes in cast alloys by directional solidification.

WASTE CONTAINMENT OVERVIEW

EPA Science Inventory

BSE waste is derived from diseased animals such as BSE (bovine spongiform encepilopothy, also known as Mad Cow) in cattle and CWD (chronic wasting disease) in deer and elk. Landfilling is examined as a disposal option and this presentation introduces waste containment technology...

Technology Performance Review: Selecting And Using Solidification/Stabilization Treatment For Site Remediation

EPA Science Inventory

Solidification/Stabilization (S/S) is a widely used treatment technology to prevent migration and exposure of contaminants from a contaminated media (i.e., soil, sludge and sediment). Solidification refers to a process that binds a contaminated media with a reagent changing its ...

Method for immobilizing mixed waste chloride salts containing radionuclides and other hazardous wastes

DOEpatents

Lewis, Michele A.; Johnson, Terry R.

1993-01-01

The invention is a method for the encapsulation of soluble radioactive waste chloride salts containing radionuclides such as strontium, cesium and hazardous wastes such as barium so that they may be permanently stored without future threat to the environment. The process consists of contacting the salts containing the radionuclides and hazardous wastes with certain zeolites which have been found to ion exchange with the radionuclides and to occlude the chloride salts so that the resulting product is leach resistant.

Method for immobilizing mixed waste chloride salts containing radionuclides and other hazardous wastes

DOEpatents

Lewis, Michele A.; Johnson, Terry R.

1993-09-07

The invention is a method for the encapsulation of soluble radioactive waste chloride salts containing radionuclides such as strontium, cesium and hazardous wastes such as barium so that they may be permanently stored without future threat to the environment. The process consists of contacting the salts containing the radionuclides and hazardous wastes with certain zeolites which have been found to ion exchange with the radionuclides and to occlude the chloride salts so that the resulting product is leach resistant.

Toxicity mitigation and solidification of municipal solid waste incinerator fly ash using alkaline activated coal ash.

PubMed

Diaz-Loya, E Ivan; Allouche, Erez N; Eklund, Sven; Joshi, Anupam R; Kupwade-Patil, Kunal

2012-08-01

Municipal solid waste (MSW) incineration is a common and effective practice to reduce the volume of solid waste in urban areas. However, the byproduct of this process is a fly ash (IFA), which contains large quantities of toxic contaminants. The purpose of this research study was to analyze the chemical, physical and mechanical behaviors resulting from the gradual introduction of IFA to an alkaline activated coal fly ash (CFA) matrix, as a mean of stabilizing the incinerator ash for use in industrial construction applications, where human exposure potential is limited. IFA and CFA were analyzed via X-ray fluorescence (XRF), X-ray diffraction (XRD) and Inductive coupled plasma (ICP) to obtain a full chemical analysis of the samples, its crystallographic characteristics and a detailed count of the eight heavy metals contemplated in US Title 40 of the Code of Federal Regulations (40 CFR). The particle size distribution of IFA and CFA was also recorded. EPA's Toxicity Characteristic Leaching Procedure (TCLP) was followed to monitor the leachability of the contaminants before and after the activation. Also images obtained via Scanning Electron Microscopy (SEM), before and after the activation, are presented. Concrete made from IFA, CFA and IFA-CFA mixes was subjected to a full mechanical characterization; tests include compressive strength, flexural strength, elastic modulus, Poisson's ratio and setting time. The leachable heavy metal contents (except for Se) were below the maximum allowable limits and in many cases even below the reporting limit. The leachable Chromium was reduced from 0.153 down to 0.0045 mg/L, Arsenic from 0.256 down to 0.132 mg/L, Selenium from 1.05 down to 0.29 mg/L, Silver from 0.011 down to .001 mg/L, Barium from 2.06 down to 0.314 mg/L and Mercury from 0.007 down to 0.001 mg/L. Although the leachable Cd exhibited an increase from 0.49 up to 0.805 mg/L and Pd from 0.002 up to 0.029 mg/L, these were well below the maximum limits of 1.00 and 5.00 mg/L, respectively. Copyright © 2012 Elsevier Ltd. All rights reserved.

Rapid solidification and dynamic compaction of Ni-base superalloy powders

NASA Technical Reports Server (NTRS)

Field, R. D.; Hales, S. J.; Powers, W. O.; Fraser, H. L.

1984-01-01

A Ni-base superalloy containing 13Al-9Mo-2Ta (in at. percent) has been characterized in both the rapidly solidified condition and after dynamic compaction. Dynamically compacted specimens were examined in the as-compacted condition and observations related to current theories of interparticle bonding. In addition, the recrystallization behavior of the compacted material at relatively low temperature (about 0.5-0.75 Tm) was investigated.

Effect of boron on intergranular hot cracking in Ni-Cr-Fe superalloys containing niobium

NASA Technical Reports Server (NTRS)

Thompson, R. G.

1990-01-01

Solidification mechanisms had a dominant influence on microfissuring behavior of the test group. Carbon modified the Laves formation significantly and showed that one approach to alloy design would be balancing carbide formers against Laves formers. Boron's strong effect on microfissuring can be traced to its potency as a Laves former. Boron's segregation to grain boundaries plays at best a secondary role in microfissuring.

Plasma methods for metals recovery from metal-containing waste.

PubMed

Changming, Du; Chao, Shang; Gong, Xiangjie; Ting, Wang; Xiange, Wei

2018-04-27

Metal-containing waste, a kind of new wastes, has a great potential for recycling and is also difficult to deal with. Many countries pay more and more attention to develop the metal recovery process and equipment of this kind of waste as raw material, so as to solve the environmental pollution and comprehensively utilize the discarded metal resources. Plasma processing is an efficient and environmentally friendly way for metal-containing waste. This review mainly discuss various metal-containing waste types, such as printed circuit boards (PCBs), red mud, galvanic sludge, Zircon, aluminium dross and incinerated ash, and the corresponding plasma methods, which include DC extended transferred arc plasma reactor, DC non-transferred arc plasma torch, RF thermal plasma reactor and argon and argon-hydrogen plasma jets. In addition, the plasma arc melting technology has a better purification effect on the extraction of useful metals from metal-containing wastes, a great capacity of volume reduction of waste materials, and a low leaching toxicity of solid slag, which can also be used to deal with all kinds of metal waste materials, having a wide range of applications. Copyright © 2018 Elsevier Ltd. All rights reserved.

Method for recovering metals from waste

DOEpatents

Wicks, George G.; Clark, David E.; Schulz, Rebecca L.

2000-01-01

A method for recovering metals from metals-containing wastes, and vitrifying the remainder of the wastes for disposal. Metals-containing wastes such as circuit boards, cathode ray tubes, vacuum tubes, transistors and so forth, are broken up and placed in a suitable container. The container is heated by microwaves to a first temperature in the range of approximately 300-800.degree. C. to combust organic materials in the waste, then heated further to a second temperature in the range of approximately 1,000-1,550.degree. C. at which temperature glass formers present in the waste will cause it to melt and vitrify. Low-melting-point metals such as tin and aluminum can be recovered after organics combustion is substantially complete. Metals with higher melting points, such as gold, silver and copper, can be recovered from the solidified product or separated from the waste at their respective melting points. Network former-containing materials can be added at the start of the process to assist vitrification.

Method for recovering materials from waste

DOEpatents

Wicks, G.G.; Clark, D.E.; Schulz, R.L.

1994-01-01

A method for recovering metals from metals-containing wastes, a vitrifying the remainder of the wastes for disposal. Metals-containing wastes such as circuit boards, cathode ray tubes, vacuum tubes, transistors and so forth, are broken up and placed in a suitable container. The container is heated by microwaves to a first temperature in the range of approximately 300--800{degrees}C to combust organic materials in the waste, then heated further to a second temperature in the range of approximately 1000--1550{degrees}C at which temperature glass formers present in the waste will cause it to melt and vitrify. Low-melting-point metals such as tin and aluminum can be recovered after organics combustion is substantially complete. Metals with higher melting points, such as gold, silver and copper, can be recovered from the solidified product or separated from the waste at their respective melting points. Network former-containing materials can be added at the start of the process to assist vitrification.

Method for recovering metals from waste

DOEpatents

Wicks, George G.; Clark, David E.; Schulz, Rebecca L.

1998-01-01

A method for recovering metals from metals-containing wastes, and vitrifying the remainder of the wastes for disposal. Metals-containing wastes such as circuit boards, cathode ray tubes, vacuum tubes, transistors and so forth, are broken up and placed in a suitable container. The container is heated by microwaves to a first temperature in the range of approximately 300.degree.-800.degree. C. to combust organic materials in the waste, then heated further to a second temperature in the range of approximately 1,000.degree.-1,550.degree. C. at which temperature glass formers present in the waste will cause it to melt and vitrify. Low-melting-point metals such as tin and aluminum can be recovered after organics combustion is substantially complete. Metals with higher melting points, such as gold, silver and copper, can be recovered from the solidified product or separated from the waste at their respective melting points. Network former-containing materials can be added at the start of the process to assist vitrification.

Method for recovering metals from waste

DOEpatents

Wicks, G.G.; Clark, D.E.; Schulz, R.L.

1998-12-01

A method is described for recovering metals from metals-containing wastes, and vitrifying the remainder of the wastes for disposal. Metals-containing wastes such as circuit boards, cathode ray tubes, vacuum tubes, transistors and so forth, are broken up and placed in a suitable container. The container is heated by microwaves to a first temperature in the range of approximately 300--800 C to combust organic materials in the waste, then heated further to a second temperature in the range of approximately 1,000--1,550 C at which temperature glass formers present in the waste will cause it to melt and vitrify. Low-melting-point metals such as tin and aluminum can be recovered after organics combustion is substantially complete. Metals with higher melting points, such as gold, silver and copper, can be recovered from the solidified product or separated from the waste at their respective melting points. Network former-containing materials can be added at the start of the process to assist vitrification. 2 figs.

Hazardous Waste and Wastewater Characterization Survey, Columbus AFB, Mississippi

DTIC Science & Technology

1988-06-01

behind bldg 322 (Liquid Fuels Maintenance Branch). These wastes are then picked up by a waste oil contractor. All other drummed wastes are disposed of...is responsible for custody of the waste until a contractor (currently, Chemical Waste Management) comes to pick up the waste. Prior to disposal...chemicals are used up in the process. Any leftover chemicals are drained and stored in containers for use at a later time. All empty containers are

Effect of the temperature-rate parameters of directional solidification on the structure formation in high-temperature materials

NASA Astrophysics Data System (ADS)

Svetlov, I. L.; Neiman, A. V.

2017-03-01

The effect of the temperature gradient and the crystal growth rate on the structure formation in nickel and niobium superalloys is studied under the conditions of the flat, cellular, dendritic, or dendritic-cellular configuration of a solidification front during directional solidification.

Analysis and calculation of macrosegregation in a casting ingot. MPS solidification model. Volume 2: Software documentation

NASA Technical Reports Server (NTRS)

Maples, A. L.

1980-01-01

The software developed for the solidification model is presented. A link between the calculations and the FORTRAN code is provided, primarily in the form of global flow diagrams and data structures. A complete listing of the solidification code is given.

SOLIDIFICATION/STABILIZATION FOR REMEDIATON OF WOOD PRESERVING SITES: TREATMENT FOR DIOXINS, PCP, CREOSOTE, AND METALS

EPA Science Inventory

This article discusses the use of solidification/stabilization (S/S) to treat soils contaminated with organic and inorganic chemicals at wood preserving sites. Solidification is defined for this article as making a material into a free standing solid. Stabilization is defined as ...

Numerical simulation of freckle formation in directional solidification of binary alloys

NASA Technical Reports Server (NTRS)

Felicelli, Sergio D.; Heinrich, Juan C.; Poirier, David R.

1992-01-01

A mathematical model of solidification is presented which simulates the formation of segregation models known as 'freckles' during directional solidification of binary alloys. The growth of the two-phase or dendritic zone is calculated by solving the coupled equations of momentum, energy, and solute transport, as well as maintaining the thermodynamic constraints dictated by the phase diagram of the alloy. Calculations for lead-tin alloys show that the thermosolutal convection in the dendritic zone during solidification can produce heavily localized inhomogeneities in the composition of the final alloy.

Microsegregation during directional solidification

NASA Technical Reports Server (NTRS)

Coriell, S. R.; Mcfadden, G. B.

1984-01-01

During the directional solidification of alloys, solute inhomogeneities transverse to the growth direction arise due to morphological instabilities (leading to cellular or dendritic growth) and/or due to convection in the melt. In the absence of convection, the conditions for the onset of morphological instability are given by the linear stability analysis of Mullins and Sekerka. For ordinary solidification rates, the predictions of linear stability analysis are similar to the constitutional supercooling criterion. However, at very rapid solidification rates, linear stability analysis predicts a vast increase in stabilization in comparison to constitutional supercooling.

Evolution of solidification texture during additive manufacturing.

PubMed

Wei, H L; Mazumder, J; DebRoy, T

2015-11-10

Striking differences in the solidification textures of a nickel based alloy owing to changes in laser scanning pattern during additive manufacturing are examined based on theory and experimental data. Understanding and controlling texture are important because it affects mechanical and chemical properties. Solidification texture depends on the local heat flow directions and competitive grain growth in one of the six <100> preferred growth directions in face centered cubic alloys. Therefore, the heat flow directions are examined for various laser beam scanning patterns based on numerical modeling of heat transfer and fluid flow in three dimensions. Here we show that numerical modeling can not only provide a deeper understanding of the solidification growth patterns during the additive manufacturing, it also serves as a basis for customizing solidification textures which are important for properties and performance of components.

In Situ X-Ray Observations of Dendritic Fragmentation During Directional Solidification of a Sn-Bi Alloy

DOE Office of Scientific and Technical Information (OSTI.GOV)

Gibbs, John W.; Tourret, Damien; Gibbs, Paul J.

2015-09-25

Dendrite fragmentation is an important phenomenon in microstructural development during solidification. For instance, it plays a key role in initiating the columnar-to-equiaxed transition (CET). Here, we use x-ray radiography to study dendrite fragmentation rate in a Sn-39.5 wt.% Bi alloy during directional solidification. Experiments were performed in which solidification was parallel and anti-parallel to gravity, leading to significantly different fragmentation rates. We quantify the distribution of fragmentation rate as a function of distance from the solidification front, time in the mushy zone, and volume fraction of solid. While the observed fragmentation rate can be high, there is no evidence ofmore » a CET, illustrating that it requires more than just fragmentation to occur.« less

Scaling Analysis of Alloy Solidification and Fluid Flow in a Rectangular Cavity

NASA Astrophysics Data System (ADS)

Plotkowski, A.; Fezi, K.; Krane, M. J. M.

A scaling analysis was performed to predict trends in alloy solidification in a side-cooled rectangular cavity. The governing equations for energy and momentum were scaled in order to determine the dependence of various aspects of solidification on the process parameters for a uniform initial temperature and an isothermal boundary condition. This work improved on previous analyses by adding considerations for the cooling bulk fluid flow. The analysis predicted the time required to extinguish the superheat, the maximum local solidification time, and the total solidification time. The results were compared to a numerical simulation for a Al-4.5 wt.% Cu alloy with various initial and boundary conditions. Good agreement was found between the simulation results and the trends predicted by the scaling analysis.

Efficient estimation of diffusion during dendritic solidification

NASA Technical Reports Server (NTRS)

Yeum, K. S.; Poirier, D. R.; Laxmanan, V.

1989-01-01

A very efficient finite difference method has been developed to estimate the solute redistribution during solidification with diffusion in the solid. This method is validated by comparing the computed results with the results of an analytical solution derived by Kobayashi (1988) for the assumptions of a constant diffusion coefficient, a constant equilibrium partition ratio, and a parabolic rate of the advancement of the solid/liquid interface. The flexibility of the method is demonstrated by applying it to the dendritic solidification of a Pb-15 wt pct Sn alloy, for which the equilibrium partition ratio and diffusion coefficient vary substantially during solidification. The fraction eutectic at the end of solidification is also obtained by estimating the fraction solid, in greater resolution, where the concentration of solute in the interdendritic liquid reaches the eutectic composition of the alloy.

The growth of metastable peritectic compounds

NASA Technical Reports Server (NTRS)

Larson, D. J., Jr.

1984-01-01

The influence of gravitationally driven convection on the directional solidification of peritectic alloys was evaluated. The Pb-Bi peritectic was studied as a model solidification system. Analyses of directionally solidified Pb-Bi peritectic samples indicate that appreciable macrosegregation occurs due to thermosolutal convection and/or Soret diffusion. The macrosegregation results in sequantial change of phase and morphology as solidification progresses down the length of the sample. Banding was eliminated when furnace conditions were selected which resulted in a planar solidification interface. The directional solidification that occurs in the vicinity of the Pb-Bi peritectic isothermal was found to be isocompositional and to consist solely of the equilibrium terminal solid solution and peritectic phases on an extremely fine scale. Evidence was found to support the peritectic supercooling mechanism, but not the proposed peritectic superheat mechanism.

In Situ X-Ray Observations of Dendritic Fragmentation During Directional Solidification of a Sn-Bi Alloy

DOE PAGES

Gibbs, John W.; Tourret, Damien; Gibbs, Paul J.; ...

2015-09-25

Dendrite fragmentation is an important phenomenon in microstructural development during solidification. For instance, it plays a key role in initiating the columnar-to-equiaxed transition (CET). In this paper, we use x-ray radiography to study dendrite fragmentation rate in a Sn-39.5 wt.% Bi alloy during directional solidification. Experiments were performed in which solidification was parallel and anti-parallel to gravity, leading to significantly different fragmentation rates. We quantify the distribution of fragmentation rate as a function of distance from the solidification front, time in the mushy zone, and volume fraction of solid. Finally, while the observed fragmentation rate can be high, there ismore » no evidence of a CET, illustrating that it requires more than just fragmentation to occur.« less

Multiscale X-ray and Proton Imaging of Bismuth-Tin Solidification

NASA Astrophysics Data System (ADS)

Gibbs, P. J.; Imhoff, S. D.; Morris, C. L.; Merrill, F. E.; Wilde, C. H.; Nedrow, P.; Mariam, F. G.; Fezzaa, K.; Lee, W.-K.; Clarke, A. J.

2014-08-01

The formation of structural patterns during metallic solidification is complex and multiscale in nature, ranging from the nanometer scale, where solid-liquid interface properties are important, to the macroscale, where casting mold filling and intended heat transfer are crucial. X-ray and proton imaging can directly interrogate structure, solute, and fluid flow development in metals from the microscale to the macroscale. X-rays permit high spatio-temporal resolution imaging of microscopic solidification dynamics in thin metal sections. Similarly, high-energy protons permit imaging of mesoscopic and macroscopic solidification dynamics in large sample volumes. In this article, we highlight multiscale x-ray and proton imaging of bismuth-tin alloy solidification to illustrate dynamic measurement of crystal growth rates and solute segregation profiles that can be that can be acquired using these techniques.

Modeling of Rapid Solidification with Undercooling Effect During Droplet Flattening on a Substrate in Coating Formation

NASA Astrophysics Data System (ADS)

Shukla, Rajesh Kumar; Patel, Virendra; Kumar, Arvind

2018-02-01

The coating deposit on the substrate in thermal spray coating process develops by solidification of individual molten particle which impacts, flattens and solidifies on the surface of the substrate. Droplet flattening and solidification typically involves rapid cooling. In this paper, a model for non-equilibrium rapid solidification of a molten droplet spreading onto a substrate is presented. Transient flow during droplet impact and its subsequent spreading is considered using the volume of fluid surface tracking method which was fully coupled with the rapid solidification model. The rapid solidification model includes undercooling, nucleation, interface tracking, non-equilibrium solidification kinetics and combined heat transfer and fluid flow as required to treat a non-stagnant splat formed from droplet flattening. The model is validated with the literature results on stagnant splats. Subsequently, using the model the characteristics of the rapidly solidifying interface for non-stagnant splat, such as interface velocity and interface temperature, are described and the effect of undercooling and interfacial heat transfer coefficient are highlighted. In contrast to the stagnant splat, the non-stagnant splat considered in this study displays interesting features in the rapidly solidifying interface. These are attributed to droplet thinning and droplet recoiling that occur during the droplet spreading process.

Timing of mantle overturn during magma ocean solidification

NASA Astrophysics Data System (ADS)

Boukaré, C.-E.; Parmentier, E. M.; Parman, S. W.

2018-06-01

Solidification of magma oceans (MOs) formed early in the evolution of planetary bodies sets the initial condition for their evolution on much longer time scales. Ideal fractional crystallization would generate an unstable chemical stratification that subsequently overturns to form a stably stratified mantle. The simplest model of overturn assumes that cumulates remain immobile until the end of MO solidification. However, overturning of cumulates and thermal convection during solidification may act to reduce this stratification and introduce chemical heterogeneity on scales smaller than the MO thickness. We explore overturning of cumulates before the end of MO crystallization and the possible consequences for mantle structure and composition. In this model, increasingly dense iron-rich layers, crystallized from the overlying residual liquid MO, are deposited on a thickening cumulate layer. Overturn during solidification occurs if the dimensionless parameter, Rc, measuring the ratio of the MO time of crystallization τMO to the timescale associated with compositional overturn τov = μ / ΔρgH exceeds a threshold value. If overturn did not occur until after solidification, this implies that the viscosity of the solidified mantle must have been sufficiently high (possibly requiring efficient melt extraction from the cumulate) for a given rate of solidification. For the lunar MO, possible implications for the generation of the Mg-suites and mare basalt are suggested.

The effects of solidification on sill propagation dynamics and morphology

NASA Astrophysics Data System (ADS)

Chanceaux, L.; Menand, T.

2016-05-01

Sills are an integral part of the formation and development of larger plutons and magma reservoirs. Thus sills are essential for both the transport and the storage of magma in the Earth's crust. However, although cooling and solidification are central to magmatism, their effects on sills have been so far poorly studied. Here, the effects of solidification on sill propagation dynamics and morphology are studied by means of analogue laboratory experiments. Hot fluid vegetable oil (magma analogue), that solidifies during its propagation, is injected as a sill in a colder layered gelatine solid (elastic host rock analogue). The injection flux and temperature are maintained constant during an experiment and systematically varied between each experiment, in order to vary and quantify the amount of solidification between each experiments. The oil is injected directly at the interface between the two gelatine layers. When solidification effects are small (high injection temperatures and fluxes), the propagation is continuous and the sill has a regular and smooth surface. Inversely, when solidification effects are important (low injection temperatures and fluxes), sill propagation is discontinuous and occurs by steps of surface-area creation interspersed with periods of momentary arrest. The morphology of these sills displays folds, ropy structures on their surface, and lobes with imprints of the leading fronts that correspond to each step of area creation. These experiments show that for a given, constant injected volume, as solidification effects increase, the area of the sills decreases, their thickness increases, and the number of propagation steps increases. These results have various geological and geophysical implications. The morphology of sills, such as lobate structures (interpretation of 3D seismic studies in sedimentary basin) and ropy flow structures (field observations) can be related to solidification during emplacement. Moreover, a non-continuous morphology as observed in the field does not necessarily involve multiple injections, but could instead reflect a continuous, yet complex morphology induced by solidification effects during emplacement. Also, a discontinuous sill propagation induced by solidification effects should be associated with bursts of seismic activity. Finally, our study shows that once a sill has initiated, the dimensionless flux influences the sill thermal state, and in turn its propagation, and final extent and thickness. In restricting the lateral extent of sills, magma cooling and solidification are likely to impact directly the size of plutons constructed by amalgamated sills.

Process for removing sulfate anions from waste water

DOEpatents

Nilsen, David N.; Galvan, Gloria J.; Hundley, Gary L.; Wright, John B.

1997-01-01

A liquid emulsion membrane process for removing sulfate anions from waste water is disclosed. The liquid emulsion membrane process includes the steps of: (a) providing a liquid emulsion formed from an aqueous strip solution and an organic phase that contains an extractant capable of removing sulfate anions from waste water; (b) dispersing the liquid emulsion in globule form into a quantity of waste water containing sulfate anions to allow the organic phase in each globule of the emulsion to extract and absorb sulfate anions from the waste water and (c) separating the emulsion including its organic phase and absorbed sulfate anions from the waste water to provide waste water containing substantially no sulfate anions.

Injectable barriers for waste isolation

DOE Office of Scientific and Technical Information (OSTI.GOV)

Persoff, P.; Finsterle, S.; Moridis, G.J.

In this paper the authors report laboratory work and numerical simulation done in support of development and demonstration of injectable barriers formed from either of two fluids: colloidal silica or polysiloxane. Two principal problems addressed here are control of gel time and control of plume emplacement in the vadose zone. Gel time must be controlled so that the viscosity of the barrier fluid remains low long enough to inject the barrier, but increases soon enough to gel the barrier in place. During injection, the viscosity must be low enough to avoid high injection pressures which could uplift or fracture themore » formation. To test the grout gel time in the soil, the injection pressure was monitored as grouts were injected into sandpacks. When grout is injected into the vadose zone, it slumps under the influence of gravity, and redistributes due to capillary forces as it gels. The authors have developed a new module for the reservoir simulator TOUGH2 to model grout injection into the vadose zone, taking into account the increase of liquid viscosity as a function of gel concentration and time. They have also developed a model to calculate soil properties after complete solidification of the grout. The numerical model has been used to design and analyze laboratory experiments and field pilot tests. The authors present the results of computer simulations of grout injection, redistribution, and solidification.« less

Influence of pH, curing time and environmental stress on the immobilization of hazardous waste using activated fly ash.

PubMed

Srivastava, Shefali; Chaudhary, Rubina; Khale, Divya

2008-05-30

The current work is related to inorganic species in sludge generated from Common Effluent Treatment Plant contaminated with hazardous wastes at relatively high concentration. The environmental sensitive metals studied in the sludge are Pb, Fe, Ni, Zn and Mn. The solidification/stabilization (S/S) of heavy metals within fly ash-cement-based matrix was conducted for low cost treatment and reuse of sludge. The study examines the strength of the S/S product by predicting the effect of supplementary cementing material from efficiency factor (k) at 60 degrees C curing temperature. The leaching test was performed at two different pH 7 and 4 to determine the efficiency of heavy metal immobilization. It was observed that replacing 76% OPC by 56% fly ash and 20% sludge for 28 days curing period shows increase in strength as well as rate of stabilization for zinc, iron and manganese at pH 7, lead and nickel were stabilized by 79 and 82%, respectively. Environmental stress test was performed to evaluate the tolerance of extreme adverse environmental condition.

Macrosegregation Resulting from Directional Solidification Through an Abrupt Change in Cross-Sections

NASA Technical Reports Server (NTRS)

Lauer, M.; Poirier, D. R.; Ghods, M.; Tewari, S. N.; Grugel, R. N.

2017-01-01

Simulations of the directional solidification of two hypoeutectic alloys (Al-7Si alloy and Al-19Cu) and resulting macrosegregation patterns are presented. The casting geometries include abrupt changes in cross-section from a larger width of 9.5 mm to a narrower 3.2 mm width then through an expansion back to a width of 9.5 mm. The alloys were chosen as model alloys because they have similar solidification shrinkages, but the effect of Cu on changing the density of the liquid alloy is about an order of magnitude greater than that of Si. The simulations compare well with experimental castings that were directionally solidified in a graphite mold in a Bridgman furnace. In addition to the simulations of the directional solidification in graphite molds, some simulations were effected for solidification in an alumina mold. This study showed that the mold must be included in numerical simulations of directional solidification because of its effect on the temperature field and solidification. For the model alloys used for the study, the simulations clearly show the interaction of the convection field with the solidifying alloys to produce a macrosegregation pattern known as "steepling" in sections with a uniform width. Details of the complex convection- and segregation-patterns at both the contraction and expansion of the cross-sectional area are revealed by the computer simulations. The convection and solidification through the expansions suggest a possible mechanism for the formation of stray grains. The computer simulations and the experimental castings have been part of on-going ground-based research with the goal of providing necessary background for eventual experiments aboard the ISS. For casting practitioners, the results of the simulations demonstrate that computer simulations should be applied to reveal interactions between alloy solidification properties, solidification conditions, and mold geometries on macrosegregation. The simulations also presents the possibility of engineering the mold-material to avoid, or mitigate, the effects of thermosolutal convection and macrosegregation by selecting a mold material with suitable thermal properties, especially its thermal conductivity.

10 CFR 71.97 - Advance notification of shipment of irradiated reactor fuel and nuclear waste.

Code of Federal Regulations, 2013 CFR

2013-01-01

... notification of shipment of irradiated reactor fuel and nuclear waste. (a)(1) As specified in paragraphs (b... shipment of irradiated reactor fuel or nuclear waste must contain the following information: (1) The name... nuclear waste shipment; (2) A description of the irradiated reactor fuel or nuclear waste contained in the...

10 CFR 71.97 - Advance notification of shipment of irradiated reactor fuel and nuclear waste.

Code of Federal Regulations, 2014 CFR

2014-01-01

... notification of shipment of irradiated reactor fuel and nuclear waste. (a)(1) As specified in paragraphs (b... shipment of irradiated reactor fuel or nuclear waste must contain the following information: (1) The name... nuclear waste shipment; (2) A description of the irradiated reactor fuel or nuclear waste contained in the...

Fiber reinforced concrete: An advanced technology for LL/ML radwaste conditioning and disposal

DOE Office of Scientific and Technical Information (OSTI.GOV)

Tchemitcheff, E.; Verdier, A.

Radioactive waste immobilization is an integral part of operations in nuclear facilities. The goal of immobilization is to contain radioactive materials in a waste form which can maintain its integrity over very long periods of time, thus effectively isolating the materials from the environment and hence from the public. This is true regardless of the activity of the waste, including low-, and medium-level waste (LLW, MLW). A multiple-year research effort by Cogema culminated in the development of a new process to immobilize nuclear waste in concrete containers reinforced with metal fibers. The fiber concrete containers satisfy all French safety requirementsmore » relating to waste immobilization and disposal, and have been certified by ANDRA, the national radioactive waste management agency. The fiber concrete containers have been fabricated on a production scale since July 1990 by Sogefibre, a jointly-owned subsidiary of SGN and Compagnie Generale des Eaux.« less

On the hot cracking susceptibility of a semisolid aluminium 6061 weld: Application of a coupled solidification- thermomechanical model

NASA Astrophysics Data System (ADS)

Zareie Rajani, H. R.; Phillion, A. B.

2015-06-01

A coupled solidification-thermomechanical model is presented that investigates the hot tearing susceptibility of an aluminium 6061 semisolid weld. Two key phenomena are considered: excessive deformation of the semisolid weld, initiating a hot tear, and the ability of the semisolid weld to heal the hot tear by circulation of the molten metal. The model consists of two major modules: weld solidification and thermomechanical analysis. 1) By means of a multi-scale model of solidification, the microstructural evolution of the semisolid weld is simulated in 3D. The semisolid structure, which varies as a function of welding parameters, is composed of solidifying grains and a network of micro liquid channels. The weld solidification module is utilized to obtain the solidification shrinkage. The size of the micro liquid channels is used as an indicator to assess the healing ability of the semisolid weld. 2) Using the finite element method, the mechanical interaction between the weld pool and the base metal is simulated to capture the transient force field deforming the semisolid weld. Thermomechanical stresses and shrinkage stresses are both considered in the analysis; the solidification contractions are extracted from the weld solidification module and applied to the deformation simulation as boundary conditions. Such an analysis enables characterization of the potential for excessive deformation of the weld. The outputs of the model are used to study the effect of welding parameters including welding current and speed, and also welding constraint on the hot cracking susceptibility of an aluminium alloy 6061 semisolid weld.

Interaction of Multiple Particles with a Solidification Front: From Compacted Particle Layer to Particle Trapping.

PubMed

Saint-Michel, Brice; Georgelin, Marc; Deville, Sylvain; Pocheau, Alain

2017-06-13

The interaction of solidification fronts with objects such as particles, droplets, cells, or bubbles is a phenomenon with many natural and technological occurrences. For an object facing the front, it may yield various fates, from trapping to rejection, with large implications regarding the solidification pattern. However, whereas most situations involve multiple particles interacting with each other and the front, attention has focused almost exclusively on the interaction of a single, isolated object with the front. Here we address experimentally the interaction of multiple particles with a solidification front by performing solidification experiments of a monodisperse particle suspension in a Hele-Shaw cell with precise control of growth conditions and real-time visualization. We evidence the growth of a particle layer ahead of the front at a close-packing volume fraction, and we document its steady-state value at various solidification velocities. We then extend single-particle models to the situation of multiple particles by taking into account the additional force induced on an entering particle by viscous friction in the compacted particle layer. By a force balance model this provides an indirect measure of the repelling mean thermomolecular pressure over a particle entering the front. The presence of multiple particles is found to increase it following a reduction of the thickness of the thin liquid film that separates particles and front. We anticipate the findings reported here to provide a relevant basis to understand many complex solidification situations in geophysics, engineering, biology, or food engineering, where multiple objects interact with the front and control the resulting solidification patterns.

Household disposables as breeding habitats of dengue vectors: Linking wastes and public health

DOE Office of Scientific and Technical Information (OSTI.GOV)

Banerjee, Soumyajit, E-mail: soumyajitb@gmail.com; Aditya, Gautam, E-mail: gautamaditya2001@gmail.com; Department of Zoology, The University of Burdwan, Golapbag, Burdwan 713 104

Highlights: Black-Right-Pointing-Pointer An assessment of different household wastes as larval habitats of dengue vectors Aedes aegypti and Aedes albopictus was made using Kolkata, India as a model geographical area. Black-Right-Pointing-Pointer Household wastes of four major categories namely earthen, porcelain, plastic and coconut shells varied significantly for Aedes immature depending on species, month and location. Black-Right-Pointing-Pointer Based on the relative density of Aedes immature, cluster analyses allowed segregation and classification of the waste containers and relative importance as mosquito larval habitats. Black-Right-Pointing-Pointer Conversion of disposed wastes into larval habitats cautions for continuance of Aedes population in Kolkata and similar cities ofmore » tropics lacking suitable waste management practices. - Abstract: An assessment of the household wastes as larval habitats of the dengue vectors was made considering Kolkata, India, as geographical area. Wastes of four major categories, namely, earthen, porcelain, plastic and coconut shells were monitored for positive with immature of either Aedes aegypti or Aedes albopictus. Twenty six types of wastes with varying size and shape, resembling containers, were identified that hosted mosquito immature. The number of waste containers positive for Aedes immature varied significantly (P < 0.05) with respect to location, type and month. The relative density of Aedes immature in the waste containers varied significantly (P < 0.05) with the types and months. The significant interaction between the month, waste container types and density of Aedes immature suggest that the household wastes are important contributors to the maintenance of the population of Aedes mosquito in the city. Based on the relative density of mosquito immature in the wastes, cluster analysis allowed segregation and classification of the wastes and their importance as mosquito larval habitats. Apparently, the containers that are most frequently disposed off contributed largely to the sustenance of Aedes mosquito population in the city. This calls for a strict legislation towards disposal as well as enhanced management of the household wastes. A link between the wastes disposed and subsequent conversion to the mosquito larval habitats cautions for continuance of Aedes population and possibility of dengue epidemics if the existing management practices are not improved.« less

Technetium Getters to Improve Cast Stone Performance

DOE Office of Scientific and Technical Information (OSTI.GOV)

Neeway, James J.; Lawter, Amanda R.; Serne, R. Jeffrey

2015-10-15

The cementitious material known as Cast Stone has been selected as the preferred waste form for solidification of aqueous secondary liquid effluents from the Hanford Tank Waste Treatment and Immobilization Plant (WTP) process condensates and low-activity waste (LAW) melter off-gas caustic scrubber effluents. Cast Stone is also being evaluated as a supplemental immobilization technology to provide the necessary LAW treatment capacity to complete the Hanford tank waste cleanup mission in a timely and cost effective manner. Two radionuclides of particular concern in these waste streams are technetium-99 (99Tc) and iodine-129 (129I). These radioactive tank waste components contribute the most tomore » the environmental impacts associated with the cleanup of the Hanford site. A recent environmental assessment of Cast Stone performance, which assumes a diffusion controlled release of contaminants from the waste form, calculates groundwater in excess of the allowable maximum permissible concentrations for both contaminants. There is, therefore, a need and an opportunity to improve the retention of both 99Tc and 129I in Cast Stone. One method to improve the performance of Cast Stone is through the addition of “getters” that selectively sequester Tc and I, therefore reducing their diffusion out of Cast Stone. In this paper, we present results of Tc and I removal from solution with various getters with batch sorption experiments conducted in deionized water (DIW) and a highly caustic 7.8 M Na Ave LAW simulant. In general, the data show that the selected getters are effective in DIW but their performance is comprised when experiments are performed with the 7.8 M Na Ave LAW simulant. Reasons for the mitigated performance in the LAW simulant may be due to competition with Cr present in the 7.8 M Na Ave LAW simulant and to a pH effect.« less

Treatment of radioactive waste salt by using synthetic silica-based phosphate composite for de-chlorination and solidification

NASA Astrophysics Data System (ADS)

Cho, In-Hak; Park, Hwan-Seo; Lee, Ki-Rak; Choi, Jung-Hun; Kim, In-Tae; Hur, Jin Mok; Lee, Young-Seak

2017-09-01

In the radioactive waste management, waste salts as metal chloride generated from a pyrochemical process to recover uranium and transuranic elements are one of problematic wastes due to their intrinsic properties such as high volatility and low compatibility with conventional glasses. This study reports a method to stabilize and solidify LiCl waste via de-chlorination using a synthetic composite, U-SAP (SiO2-Al2O3-B2O3-Fe2O3-P2O5) prepared by a sol-gel process. The composite was reacted with alkali metal elements to produce some metal aluminosilicates, aluminophosphates or orthophosphate as a crystalline or amorphous compound. Different from the original SAP (SiO2-Al2O3-P2O5), the reaction product of U-SAP could be successfully fabricated as a monolithic wasteform without a glassy binder at a proper reaction/consolidation condition. From the results of the FE-SEM, FT-IR and MAS-NMR analysis, it could be inferred that the Si-rich phase and P-rich phase as a glassy grains would be distributed in tens of nm scale, where alkali metal elements would be chemically interacted with Si-rich or P-rich region in the virgin U-SAP composite and its products was vitrified into a silicate or phosphate glass after a heat-treatment at 1150 °C. The PCT-A (Product Consistency Test, ASTM-1208) revealed that the mass loss of Cs and Sr in the U-SAP wasteform had a range of 10-3∼10-1 g/m2 and the leach-resistance of the U-SAP wasteform was comparable to other conventional wasteforms. From the U-SAP method, LiCl waste salt was effectively stabilized and solidified with high waste loading and good leach-resistance.

Surface Structure Formation in Direct Chill (DC) Casting of Al Alloys

NASA Astrophysics Data System (ADS)

Bayat, Nazlin; Carlberg, Torbjörn

2014-05-01

The aim of this study is to increase the understanding of the surface zone formation during direct chill (DC) casting of aluminum billets produced by the air slip technology. The depth of the shell zone, with compositions deviating from the bulk, is of large importance for the subsequent extrusion productivity and quality of final products. The surface microstructures of 6060 and 6005 aluminum alloys in three different surface appearances—defect free, wavy surface, and spot defects—were studied. The surface microstructures and outer appearance, segregation depth, and phase formation were investigated for the mentioned cases. The results were discussed and explained based on the exudation of liquid metal through the mushy zone and the fact that the exudated liquid is contained within a surface oxide skin. Outward solidification in the surface layer was quantitatively analyzed, and the oxide skin movements explained meniscus line formation. Phases forming at different positions in the segregation zone were analyzed and coupled to a cellular solidification in the exudated layer.

Eutectic superalloys strengthened by sigma, Ni3CB lamellae and gamma prime, Ni3Al precipitates

NASA Technical Reports Server (NTRS)

Lemkey, F. D.

1973-01-01

By means of a screening and solidification optimization study of certain alloys located on the gamma-sigma liquidus surface within the Ni-Cb-Cr-Al system, alloys with high temperature properties superior to those of all known superalloys were defined. One alloy, Ni - 19.7w/o Cb - 6.0w/o Cr - 2.5w/o Al, directionally solidified at 3 cm/hr met or exceeded each program goal. A second alloy, Ni-21.75 w/o Cb-2.55 w/o Al, although deficient in its inherent oxidation resistance, met the other program goals and combined a remarkable insensitivity of composite microstructure to solidification parameters with excellent low temperature toughness. This investigation demonstrated that useful properties for gas turbine airfoil application have been achieved by reinforcing a strong and tough gamma solid solution matrix containing precipitated gamma prime by a lamellar intermetallic compound Ni3 Cb having greater strength at elevated temperature.

Thrust chamber material technology program

NASA Technical Reports Server (NTRS)

Andrus, J. S.; Bordeau, R. G.

1989-01-01

This report covers work performed at Pratt & Whitney on development of copper-based materials for long-life, reusable, regeneratively cooled rocket engine thrust chambers. The program approached the goal of enhanced cyclic life through the application of rapid solidification to alloy development, to introduce fine dispersions to strengthen and stabilize the alloys at elevated temperatures. After screening of alloy systems, copper-based alloys containing Cr, Co, Hf, Ag, Ti, and Zr were processed by rapid-solidification atomization in bulk quantities. Those bulk alloys showing the most promise were characterized by tensile testing, thermal conductivity testing, and elevated-temperature, low-cycle fatigue (LFC) testing. Characterization indicated that Cu- 1.1 percent Hf exhibited the greatest potential as an improved-life thrust chamber material, exhibiting LCF life about four times that of NASA-Z. Other alloys (Cu- 0.6 percent Zr, and Cu- 0.6 percent Zr- 1.0 percent Cr) exhibited promise for use in this application, but needed more development work to balance properties.

Liquidus Temperatures and Solidification Behavior in the Copper-Niobium System

NASA Technical Reports Server (NTRS)

Li, D.; Robinson, M. B.; Rathz, T. J.; Williams, G.

1998-01-01

The copper-niobium phase diagram has been under active debate; thus, a corroboratory experimental study is needed. In this investigation, the melts of Cu-Nb alloys at compositions ranging from 5 to 86 wt pct Nb were processed in different environments and solidified at relatively low cooling rates of 50 to 75 C/s to determine liquidus temperatures and to study solidification behavior. For all samples processed under very clean conditions, only Nb dendrites in a Cu matrix were observed; while in the presence of oxygen impurities the alloys containing 5 to 35 wt pct Nb exhibited microstructure of Nb-rich spheroids and Nb dendrites in the Cu matrix. The results obtained from clean conditions are in fair agreement with the Cu-Nb phase diagram having an S-shaped, near-horizontal appearance of the liquidus. The formation of Nb- rich droplets at slow cooling rates is discussed in terms of a stable liquid miscibility gap induced by oxygen.

40 CFR 61.155 - Standard for operations that convert asbestos-containing waste material into nonasbestos...

Code of Federal Regulations, 2012 CFR

2012-07-01

... asbestos-containing waste material into nonasbestos (asbestos-free) material. 61.155 Section 61.155... EMISSION STANDARDS FOR HAZARDOUS AIR POLLUTANTS National Emission Standard for Asbestos § 61.155 Standard for operations that convert asbestos-containing waste material into nonasbestos (asbestos-free...

40 CFR 61.155 - Standard for operations that convert asbestos-containing waste material into nonasbestos...

Code of Federal Regulations, 2011 CFR

2011-07-01

... asbestos-containing waste material into nonasbestos (asbestos-free) material. 61.155 Section 61.155... EMISSION STANDARDS FOR HAZARDOUS AIR POLLUTANTS National Emission Standard for Asbestos § 61.155 Standard for operations that convert asbestos-containing waste material into nonasbestos (asbestos-free...

40 CFR 61.155 - Standard for operations that convert asbestos-containing waste material into nonasbestos...

Code of Federal Regulations, 2010 CFR

2010-07-01

... asbestos-containing waste material into nonasbestos (asbestos-free) material. 61.155 Section 61.155... EMISSION STANDARDS FOR HAZARDOUS AIR POLLUTANTS National Emission Standard for Asbestos § 61.155 Standard for operations that convert asbestos-containing waste material into nonasbestos (asbestos-free...

40 CFR 61.155 - Standard for operations that convert asbestos-containing waste material into nonasbestos...

Code of Federal Regulations, 2013 CFR

2013-07-01

... asbestos-containing waste material into nonasbestos (asbestos-free) material. 61.155 Section 61.155... EMISSION STANDARDS FOR HAZARDOUS AIR POLLUTANTS National Emission Standard for Asbestos § 61.155 Standard for operations that convert asbestos-containing waste material into nonasbestos (asbestos-free...

40 CFR 61.155 - Standard for operations that convert asbestos-containing waste material into nonasbestos...

Code of Federal Regulations, 2014 CFR

2014-07-01

... asbestos-containing waste material into nonasbestos (asbestos-free) material. 61.155 Section 61.155... EMISSION STANDARDS FOR HAZARDOUS AIR POLLUTANTS National Emission Standard for Asbestos § 61.155 Standard for operations that convert asbestos-containing waste material into nonasbestos (asbestos-free...

Experimental and Computational Studies of the Control of Convection of Non-Conducting Liquids During solidification by Means of a Magnetic Field Gradient

NASA Technical Reports Server (NTRS)

Seybert, C. D.; Evans, J. W.; Leslie, F.; Jones, W. K., Jr.

2001-01-01

The elimination of convection is essential in experimental investigations of diffusive transport (of heat and matter) during solidification. One classical approach to damping convection in a conducting liquid is the application of a magnetic field. The damping phenomenon is the induction, by the motion of a conductor in a magnetic field, of currents which interact with the field to produce Lorentz forces that oppose the flow. However, there are many liquids which are not sufficiently conducting to exploit this phenomenon; examples include the transparent liquids (such as succinonitrile-acetone) that are used as "model alloys" in fundamental solidification studies. There have been several investigations of the solidification of these liquids that have been carried out in orbiting laboratories to eliminate natural convection. The paper describes an investigation of an alternative approach whereby a magnetic field gradient is applied to the liquid. A magnetic body force then arises which is dependent on the susceptibility of the liquid and thereby on the temperature and or concentration. With the field gradient aligned vertically and of correct magnitude, the variation of gravitational body force due to temperature/concentration dependent density can be counterbalanced by a variation in magnetic body force. Experiments have been carried out in a super-conducting magnet at Marshall Space Flight Center to measure velocities in an aqueous manganese chloride solution. The solution was contained in a chamber with temperature controlled end walls and glass side walls. Velocities were measured by particle image velocimetry. Starting from zero current in the magnet (zero field gradient) flow driven by the temperature difference between the end walls was measured. At a critical current the flow was halted. At higher currents the normal convection was reversed. The experiments included ones where the solution was solidified and were accompanied by solution of the flow/transport equations using the software package FLUENT.

Powder-Metallurgy Process And Product

NASA Technical Reports Server (NTRS)

Paris, Henry G.

1988-01-01

Rapid-solidification processing yields alloys with improved properties. Study undertaken to extend favorable property combinations of I/M 2XXX alloys through recently developed technique of rapid-solidification processing using powder metallurgy(P/M). Rapid-solidification processing involves impingement of molten metal stream onto rapidly-spinning chill block or through gas medium using gas atomization technique.

Flight Planning for the International Space Station-Levitation Observation of Dendrite Evolution in Steel Ternary Alloy Rapid Solidification

NASA Technical Reports Server (NTRS)

Flemings, M. C.; Matson, D. M.; Loser, W.; Hyers, R. W.; Rogers, J. R.; Curreri, Peter A. (Technical Monitor)

2002-01-01

The paper is an overview of the status and science for the LODESTARS (Levitation Observation of Dendrite Evolution in Steel Ternary Alloy Rapid Solidification) research project. The program is aimed at understanding how melt convection influences phase selection and the evolution of rapid solidification microstructures.

Effects of Traveling Magnetic Field on Dynamics of Solidification

NASA Technical Reports Server (NTRS)

2003-01-01

The Lorentz body force induced in electrically conducting fluids can be utilized for a number of materials processing technologies. An application of strong static magnetic fields can be beneficial for damping convection present during solidification. On the other hand, alternating magnetic fields can be used to reduce as well as to enhance convection. However, only special types of time dependent magnetic fields can induce a non-zero time averaged Lorentz force needed for convection control. One example is the rotating magnetic field. This field configuration induces a swirling flow in circular containers. Another example of a magnetic field configuration is the traveling magnetic field (TMF). It utilizes axisymmetric magnetostatic waves. This type of field induces an axial recirculating flow that can be advantageous for controlling axial mass transport, such as during solidification in long cylindrical tubes. Incidentally, this is the common geometry for crystal growth research. The Lorentz force induced by TMF can potentially counter-balance the buoyancy force, diminishing natural convection, or even setting up the flow in reverse direction. Crystal growth process in presence of TMF can be then significantly modified. Such properties as the growth rate, interface shape and macro segregation can be affected and optimized. Melt homogenization is the other potential application of TMF. It is a necessary step prior to solidification. TMF can be attractive for this purpose, as it induces a basic flow along the axis of the ampoule. TMF can be a practical alloy mixing method especially suited for solidification research in space. In the theoretical part of this work, calculations of the induced Lorentz force in the whole frequency range have been completed. The basic flow characteristics for the finite cylinder geometry are completed and first results on stability analysis for higher Reynolds numbers are obtained. A theoretical model for TMF mixing is also developed. In the experimental part, measurements of flow induced by TMF in a column of mercury (Hg) are presented. Also, an alloy mixing of Bi-Sn of the eutectic composition is demonstrated. A traveling magnetic field of 4mT at 3kHz applied for 120 minutes is found to be sufficient to homogenize an alloy enclosed in a 1cm diameter and 12 cm long tube.

Evolution of solidification texture during additive manufacturing

PubMed Central

Wei, H. L.; Mazumder, J.; DebRoy, T.

2015-01-01

Striking differences in the solidification textures of a nickel based alloy owing to changes in laser scanning pattern during additive manufacturing are examined based on theory and experimental data. Understanding and controlling texture are important because it affects mechanical and chemical properties. Solidification texture depends on the local heat flow directions and competitive grain growth in one of the six <100> preferred growth directions in face centered cubic alloys. Therefore, the heat flow directions are examined for various laser beam scanning patterns based on numerical modeling of heat transfer and fluid flow in three dimensions. Here we show that numerical modeling can not only provide a deeper understanding of the solidification growth patterns during the additive manufacturing, it also serves as a basis for customizing solidification textures which are important for properties and performance of components. PMID:26553246

Evolution of solidification texture during additive manufacturing

DOE PAGES

Wei, H. L.; Mazumder, J.; DebRoy, T.

2015-11-10

Striking differences in the solidification textures of a nickel based alloy owing to changes in laser scanning pattern during additive manufacturing are examined based on theory and experimental data. Understanding and controlling texture are important because it affects mechanical and chemical properties. Solidification texture depends on the local heat flow directions and competitive grain growth in one of the six <100> preferred growth directions in face centered cubic alloys. Furthermore, the heat flow directions are examined for various laser beam scanning patterns based on numerical modeling of heat transfer and fluid flow in three dimensions. Here we show that numericalmore » modeling can not only provide a deeper understanding of the solidification growth patterns during the additive manufacturing, it also serves as a basis for customizing solidification textures which are important for properties and performance of components.« less

Influences on Distribution of Solute Atoms in Cu-8Fe Alloy Solidification Process Under Rotating Magnetic Field

NASA Astrophysics Data System (ADS)

Zou, Jin; Zhai, Qi-Jie; Liu, Fang-Yu; Liu, Ke-Ming; Lu, De-Ping

2018-05-01

A rotating magnetic field (RMF) was applied in the solidification process of Cu-8Fe alloy. Focus on the mechanism of RMF on the solid solution Fe(Cu) atoms in Cu-8Fe alloy, the influences of RMF on solidification structure, solute distribution, and material properties were discussed. Results show that the solidification behavior of Cu-Fe alloy have influenced through the change of temperature and solute fields in the presence of an applied RMF. The Fe dendrites were refined and transformed to rosettes or spherical grains under forced convection. The solute distribution in Cu-rich phase and Fe-rich phase were changed because of the variation of the supercooling degree and the solidification rate. Further, the variation in solute distribution was impacted the strengthening mechanism and conductive mechanism of the material.

Evolution of Secondary Phases Formed upon Solidification of a Ni-Based Alloy

NASA Astrophysics Data System (ADS)

Zuo, Qiang; Liu, Feng; Wang, Lei; Chen, Changfeng

2013-07-01

The solidification of UNS N08028 alloy subjected to different cooling rates was studied, where primary austenite dendrites occur predominantly and different amounts of sigma phase form in the interdendritic regions. The solidification path and elemental segregation upon solidification were simulated using the CALPHAD method, where THERMO-CALC software packages and two classical segregation models were employed to predict the real process. It is thus revealed that the interdendritic sigma phase is formed via eutectic reaction at the last stage of solidification. On this basis, an analytical model was developed to predict the evolution of nonequilibrium eutectic phase, while the isolated morphology of sigma phase can be described using divorced eutectic theory. Size, fraction, and morphology of the sigma phase were quantitatively studied by a series of experiments; the results are in good agreement with the model prediction.

TECHNICAL RESOURCE DOCUMENT: TREATMENT TECHNOLOGIES FOR CORROSIVE-CONTAINING WASTES. VOLUME 2

EPA Science Inventory

The Technical Resource Document (TRD) for wastes containing corrosives is one in a series of five documents which evaluate waste management alternatives to land disposal. In addition to this TRD for corrosive wastes, the other four TRDs in the series address land disposal alterna...

SOLIDIFICATION OF THE HANFORD LAW WASTE STREAM PRODUCED AS A RESULT OF NEAR-TANK CONTINUOUS SLUDGE LEACHING AND SODIUM HYDROXIDE RECOVERY

DOE Office of Scientific and Technical Information (OSTI.GOV)

Reigel, M.; Johnson, F.; Crawford, C.

2011-09-20

The U.S. Department of Energy (DOE), Office of River Protection (ORP), is responsible for the remediation and stabilization of the Hanford Site tank farms, including 53 million gallons of highly radioactive mixed wasted waste contained in 177 underground tanks. The plan calls for all waste retrieved from the tanks to be transferred to the Waste Treatment Plant (WTP). The WTP will consist of three primary facilities including pretreatment facilities for Low Activity Waste (LAW) to remove aluminum, chromium and other solids and radioisotopes that are undesirable in the High Level Waste (HLW) stream. Removal of aluminum from HLW sludge canmore » be accomplished through continuous sludge leaching of the aluminum from the HLW sludge as sodium aluminate; however, this process will introduce a significant amount of sodium hydroxide into the waste stream and consequently will increase the volume of waste to be dispositioned. A sodium recovery process is needed to remove the sodium hydroxide and recycle it back to the aluminum dissolution process. The resulting LAW waste stream has a high concentration of aluminum and sodium and will require alternative immobilization methods. Five waste forms were evaluated for immobilization of LAW at Hanford after the sodium recovery process. The waste forms considered for these two waste streams include low temperature processes (Saltstone/Cast stone and geopolymers), intermediate temperature processes (steam reforming and phosphate glasses) and high temperature processes (vitrification). These immobilization methods and the waste forms produced were evaluated for (1) compliance with the Performance Assessment (PA) requirements for disposal at the IDF, (2) waste form volume (waste loading), and (3) compatibility with the tank farms and systems. The iron phosphate glasses tested using the product consistency test had normalized release rates lower than the waste form requirements although the CCC glasses had higher release rates than the quenched glasses. However, the waste form failed to meet the vapor hydration test criteria listed in the WTP contract. In addition, the waste loading in the phosphate glasses were not as high as other candidate waste forms. Vitrification of HLW waste as borosilicate glass is a proven process; however the HLW and LAW streams at Hanford can vary significantly from waste currently being immobilized. The ccc glasses show lower release rates for B and Na than the quenched glasses and all glasses meet the acceptance criterion of < 4 g/L. Glass samples spiked with Re{sub 2}O{sub 7} also passed the PCT test. However, further vapor hydration testing must be performed since all the samples cracked and the test could not be performed. The waste loading of the iron phosphate and borosilicate glasses are approximately 20 and 25% respectively. The steam reforming process produced the predicted waste form for both the high and low aluminate waste streams. The predicted waste loadings for the monolithic samples is approximately 39%, which is higher than the glass waste forms; however, at the time of this report, no monolithic samples were made and therefore compliance with the PA cannot be determined. The waste loading in the geopolymer is approximately 40% but can vary with the sodium hydroxide content in the waste stream. Initial geopolymer mixes revealed compressive strengths that are greater than 500 psi for the low aluminate mixes and less than 500 psi for the high aluminate mixes. Further work testing needs to be performed to formulate a geopolymer waste form made using a high aluminate salt solution. A cementitious waste form has the advantage that the process is performed at ambient conditions and is a proven process currently in use for LAW disposal. The Saltstone/Cast Stone formulated using low and high aluminate salt solutions retained at least 97% of the Re that was added to the mix as a dopant. While this data is promising, additional leaching testing must be performed to show compliance with the PA. Compressive strength tests must also be performed on the Cast Stone monoliths to verify PA compliance. Based on testing performed for this report, the borosilicate glass and Cast Stone are the recommended waste forms for further testing. Both are proven technologies for radioactive waste disposal and the initial testing using simulated Hanford LAW waste shows compliance with the PA. Both are resistant to leaching and have greater than 25% waste loading.« less

Microgravity

NASA Image and Video Library

1991-09-01

The Advanced Automated Directional Solidification Furnace (AADSF) flew during the USMP-2 mission. During USMP-2, the AADSF was used to study the growth of mercury cadmium telluride crystals in microgravity by directional solidification, a process commonly used on earth to process metals and grow crystals. The furnace is tubular and has three independently controlled temperature zones. The sample travels from the hot zone of the furnace (1600 degrees F) where the material solidifies as it cools. The solidification region, known as the solid/liquid interface, moves from one end of the sample to the other at a controlled rate, thus the term directional solidification.

Solidification rate influence on orientation and mechanical properties of MAR-M-246+Hf

NASA Technical Reports Server (NTRS)

Hamilton, D.

1983-01-01

The influence of solidification rates on the orientation and mechanical properties of MAR-M-246+Hf was studied. The preferred orientation was found to be (001) for single crystals, with all samples with 45 degrees of (001). Tensile tests were performed at room temperature. The anisotropy of directionally solidified MAR-M-246+Hf was demonstrated by gage section deformation. Dendrite arm spacing and crystal growth were found to depend on solidification rates and source material conditions. The greatest strength occurred at lower solidification rates. Some single crystals were grown by control of growth rates without seeding.

Modelling directional solidification

NASA Technical Reports Server (NTRS)

Wilcox, William R.; Regel, Liya L.

1994-01-01

This grant, NAG8-831, was a continuation of a previous grant, NAG8-541. The long range goal of this program has been to develop an improved understanding of phenomena of importance to directional solidification, in order to enable explanation and prediction of differences in behavior between solidification on Earth and in space. Emphasis in the recently completed grant was on determining the influence of perturbations on directional solidification of InSb and InSb-GaSb alloys. In particular, the objective was to determine the influence of spin-up/spin-down (ACRT), electric current pulses and vibrations on compositional homogeneity and grain size.

A novel way to upgrade the coarse part of a high calcium fly ash for reuse into cement systems.

PubMed

Antiohos, S K; Tsimas, S

2007-01-01

Reject fly ash (rFA) represents a significant portion of the fly ashes produced from coal-fired power plants. Due to the high carbon content and large particle mean diameter, rFA is not utilized in the construction sector (for example, as supplementary cementing material) and is currently dumped into landfills, thus representing an additional environmental burden. Recently, the feasibility of using rFA in a relatively small number of applications, like solidification/stabilization of other wastes, has been investigated by different researchers. However, as the overall amount of fly ash utilized in such applications is still limited, there is a need to investigate other possibilities for rFA utilization starting from a deeper understanding of its properties. In the work presented herein, mechanical and hydration properties of cementitious materials prepared by blending the coarse fraction of a lignite high-calcium fly ash with ordinary cement were monitored and compared with the respective ones of a good quality fly ash-cement mixture. The results of this work reveal that a relatively cheap, bilateral classification-grinding method is able to promote the pozzolanic behavior of the rFAs, so that the overall performances of rFA containing cements are drastically improved. The evaluation of these results supports the belief that appropriate utilization of non-standardized materials may lead to new environmental-friendly products of superior quality.

Co-treatment of gypsum sludge and Pb/Zn smelting slag for the solidification of sludge containing arsenic and heavy metals.

PubMed

Li, Yuan-Cheng; Min, Xiao-Bo; Chai, Li-Yuan; Shi, Mei-Qing; Tang, Chong-Jian; Wang, Qing-Wei; Liang, Yan-Jie; Lei, Jie; Liyang, Wen-Jun

2016-10-01

Wastewater treatment sludge from a primary lead-zinc smelter is characterized as hazardous waste and requires treatment prior to disposal due to its significant arsenic and heavy metals contents. This study presents a method for the stabilization of arsenic sludge that uses a slag based curing agent composed of smelting slag, cement clinker and limestone. The Unconfined Compressive Strength (UCS) test, the China Standard Leaching Test (CSLT), and the Toxicity Characteristic Leaching Procedures (TCLP) were used to physically and chemically characterize the solidified sludge. The binder ratio was determined according to the UCS and optimal experiments, and the optimal mass ratio of m (smelting slag): m (cement clinker): m (gypsum sludge): m (limestone) was 70:13:12:5. When the binder was mixed with arsenic sludge using a mass ratio of 1:1 and then maintained at 25 °C for 28 d, the UCS reached 9.30 MPa. The results indicated that the leached arsenic content was always less than 5 mg/L, which is a safe level, and does not contribute to recontamination of the environment. The arsenic sludge from the Zn/Pb metallurgy plant can be blended with cement clinker and smelting slag materials for manufacturing bricks and can be recycled as construction materials. Copyright © 2016 Elsevier Ltd. All rights reserved.

Microgravity research at the University of Mexico: Experiments in payload G-006

NASA Technical Reports Server (NTRS)

Peralta-Fabi, Ricardo; Mendieta-Jimenez, Javier

1988-01-01

The experiments contained in the G-006 payload related to thin film vapor deposition, vacuum variations in a chamber vented to space, solidification of a Zn-Al-Cu alloy, and multiple location temperature monitoring for thermal model validation are described in detail. A discussion of the expected results is presented, together with the methods selected to conduct the postflight analysis, and finally, a overview of the future activities in this field.

40 CFR 261.7 - Residues of hazardous waste in empty containers.

Code of Federal Regulations, 2010 CFR

2010-07-01

... 40 Protection of Environment 25 2010-07-01 2010-07-01 false Residues of hazardous waste in empty containers. 261.7 Section 261.7 Protection of Environment ENVIRONMENTAL PROTECTION AGENCY (CONTINUED) SOLID WASTES (CONTINUED) IDENTIFICATION AND LISTING OF HAZARDOUS WASTE General § 261.7 Residues of hazardous...

Transporting Radioactive Waste: An Engineering Activity. Grades 5-12.

ERIC Educational Resources Information Center

HAZWRAP, The Hazardous Waste Remedial Actions Program.

This brochure contains an engineering activity for upper elementary, middle school, and high school students that examines the transportation of radioactive waste. The activity is designed to inform students about the existence of radioactive waste and its transportation to disposal sites. Students experiment with methods to contain the waste and…

Associate Directorate Environmental Management Infrastructure Plan for Area G and Area L Domes

DOE Office of Scientific and Technical Information (OSTI.GOV)

Stevens, Patrice Ann; Baumer, Andrew Ronald

Technical Area 54, at Los Alamos National Laboratory (LANL) is situated in the east-central portion of the Laboratory on the Mesita del Buey between Pajarito Canyon to the south and Cañada del Buey to the north. TA-54 includes four MDAs designated as G, H, J, and L; a waste characterization, container storage, and transfer facility; active TRU waste and MLLW waste storage and low-level waste (LLW) disposal operations at Area G; active hazardous and mixed low-level (MLLW) waste storage operations at Area L; and administrative and support areas. MDA J has previously under-gone closure. Area G is a waste managementmore » and disposal area, used for the disposal and storage of radioactive wastes since 1957. Since August 2015, Area G has been in warm standby and provides minimal operations to support safety, compliance, and nitrate salt remediation. Located within Area G, MDA G covers 63-acres. MDA G contains 334 active and inactive waste management units, which include 36 pits, 294 shafts, and 4 trenches. In 1971, Area G began use for the retrievable storage of TRU waste. There are two pits, four trenches and 60 shafts that contain retrievable TRU waste. Thirty-three of the shafts contain TRU waste that may present unique problems for retrieval. In 1986, segregation of MLLW was initiated at Area G for treatment and temporary storage or for off-site disposal. Area G is the only active LLW disposal facility at the Laboratory. Current operations at Area G include storage and characterization of TRU and mixed TRU waste destined for off-site disposal at the Waste Isolation Pilot Plant (WIPP) in southeastern New Mexico and the storage of MLLW destined for off-site treatment and/or disposal. Several above-ground container storage units (CSUs) are currently used for storage of containerized MLLW and/or mixed TRU wastes. These consist of asphalt pads and associated fabric domes or other structures. As defined by the Consent Order, MDA G contains 229 of the 334 subsurface waste management units at Area G. These MDA G disposal units include 32 pits, 193 shafts, and 4 trenches and contain LLW, MLLW and TRU waste. The remaining 105 solid waste management units (SWMUs) include RCRA-regulated landfill and storage units and DOE-regulated LLW disposal units. The TA-54 closure project must ensure that continuing waste operations at Area G and their transition to an interim or enduring facility are coordinated with closure activities.« less

Particle Engulfment and Pushing Micro-Gravity Experiments and Mathematical Modeling

NASA Technical Reports Server (NTRS)

Stefanescu, Doru M.; Catalina, A. V.; Juretzko, F.; Mukherjee, S.; Sen, S.

2000-01-01

The phenomenon of interaction of particles with solid-liquid interfaces that results in particle engulfment or pushing (PEP) has been Studied since mid 1960's. While the original interest stemmed from geology applications (frost heaving in soil), it was recognized early that understanding particle behavior at solidifying interfaces mi ht yield 9 practical benefits in other fields. In metallurgical applications the issue is the location of particles with respect to grain boundaries at the end of solidification. Considerable amount of experimental and theoretical research was lately focused on applications to metal matrix composites produced by casting; or spray forming techniques. Another application of PEP is in the growing of Y1Ba2CU3O7-delta(123) superconductor crystals from an undercooled liquid. The oxide melt contains Y2Ba1CU1O5 (211) precipitates, which act as flux pinning sites. The paper presents results of PEP micro-gravity research performed by the authors on two shuttle missions using metallic and polymeric materials. In addition. a discussion on the theoretical aspects of the physics of PEP is offered. Analytical and numerical models for planar solidification interfaces developed by the authors are used to explain the experimental results. Shortcomings of steady-state models are emphasized. A numerical model that includes the effect of the solutal field and of natural convection is introduced. A discussion of phenomena associated with dendritic solidification based on experimental observations is also offered. A mechanism of engulfment is proposed.

Dispersive solid-phase extraction followed by vortex-assisted dispersive liquid-liquid microextraction based on the solidification of a floating organic droplet for the determination of benzoylurea insecticides in soil and sewage sludge.

PubMed

Peng, Guilong; He, Qiang; Mmereki, Daniel; Lu, Ying; Zhong, Zhihui; Liu, Hanyang; Pan, Weiliang; Zhou, Guangming; Chen, Junhua

2016-04-01

A novel dispersive solid-phase extraction combined with vortex-assisted dispersive liquid-liquid microextraction based on solidification of floating organic droplet was developed for the determination of eight benzoylurea insecticides in soil and sewage sludge samples before high-performance liquid chromatography with ultraviolet detection. The analytes were first extracted from the soil and sludge samples into acetone under optimized pretreatment conditions. Clean-up of the extract was conducted by dispersive solid-phase extraction using activated carbon as the sorbent. The vortex-assisted dispersive liquid-liquid microextraction based on solidification of floating organic droplet procedure was performed by using 1-undecanol with lower density than water as the extraction solvent, and the acetone contained in the solution also acted as dispersive solvent. Under the optimum conditions, the linearity of the method was in the range 2-500 ng/g with correlation coefficients (r) of 0.9993-0.9999. The limits of detection were in the range of 0.08-0.56 ng/g. The relative standard deviations varied from 2.16 to 6.26% (n = 5). The enrichment factors ranged from 104 to 118. The extraction recoveries ranged from 81.05 to 97.82% for all of the analytes. The good performance has demonstrated that the proposed methodology has a strong potential for application in the multiresidue analysis of complex matrices. © 2016 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

Closed solutions to a differential-difference equation and an associated plate solidification problem.

PubMed

Layeni, Olawanle P; Akinola, Adegbola P; Johnson, Jesse V

2016-01-01

Two distinct and novel formalisms for deriving exact closed solutions of a class of variable-coefficient differential-difference equations arising from a plate solidification problem are introduced. Thereupon, exact closed traveling wave and similarity solutions to the plate solidification problem are obtained for some special cases of time-varying plate surface temperature.

Nature of solidification of nanoconfined organic liquid layers.

PubMed

Lang, X Y; Zhu, Y F; Jiang, Q

2007-01-30

A simple model is established for solidification of a nanoconfined liquid under nonequilibrium conditions. In terms of this model, the nature of solidification is the conjunct finite size and interface effects, which is directly related to the cooling rate or the relaxation time of the undercooled liquid. The model predictions are consistent with available experimental results.

Hanford Waste Physical and Rheological Properties: Data and Gaps

DOE Office of Scientific and Technical Information (OSTI.GOV)

Wells, Beric E.; Kurath, Dean E.; Mahoney, Lenna A.

2011-08-01

The Hanford Site in Washington State manages 177 underground storage tanks containing approximately 250,000 m3 of waste generated during past defense reprocessing and waste management operations. These tanks contain a mixture of sludge, saltcake and supernatant liquids. The insoluble sludge fraction of the waste consists of metal oxides and hydroxides and contains the bulk of many radionuclides such as the transuranic components and 90Sr. The saltcake, generated by extensive evaporation of aqueous solutions, consists primarily of dried sodium salts. The supernates consist of concentrated (5-15 M) aqueous solutions of sodium and potassium salts. The 177 storage tanks include 149 single-shellmore » tanks (SSTs) and 28 double -hell tanks (DSTs). Ultimately the wastes need to be retrieved from the tanks for treatment and disposal. The SSTs contain minimal amounts of liquid wastes, and the Tank Operations Contractor is continuing a program of moving solid wastes from SSTs to interim storage in the DSTs. The Hanford DST system provides the staging location for waste feed delivery to the Department of Energy (DOE) Office of River Protection’s (ORP) Hanford Tank Waste Treatment and Immobilization Plant (WTP). The WTP is being designed and constructed to pretreat and then vitrify a large portion of the wastes in Hanford’s 177 underground waste storage tanks.« less

Minimizing Segregation during the Controlled Directional Solidification of Dendric Alloys

NASA Technical Reports Server (NTRS)

Grugel, Richard N.; Fedoseyev, Alex; Kim, Shin-Woo

2003-01-01

Gravity-driven convection induced in the liquid by density gradients of temperature or composition disrupts uniform dendritic growth during controlled directional solidification and promotes severe macrosegregation. The solute-rich region about the dendrite tip appears to play a pivotal role in channel initiation. Allen and Hunt referred to this region as an "initial transient" or dynamic region constituting steep concentration gradients. Experimental investigation also point to the role the tip region plays in developing microstructure. Hellawell and co-workers showed that flow-through dendritic channels could be effectively disrupted, and segregation minimized, during the gradient freezing of bulk castings by rotating the melt through a slight angle with respect to Earth's gravity vector. Adapting this principle to controlled directional solidification, it has been shown" that segregation in dendritic alloys can be minimized, and properties improved, by processing the sample near horizontal in conjunction with a slow axial rotation of the crucible. It is postulated that the observed microstructural uniformity arises by maintaining the developing solute field about the dendrite tip. Solute rejected during vertical directional solidification will rise or sink parallel to the primary dendrite arms during axial rotation setting the stage for accumulation, instabilities, and segregation. In contrast, during horizontal growth, the rejected solute will sink or rise perpendicular to the primary dendrite. Now, in the presence of a slight axial rotation, solute that was initially sinking (or rising) will find itself above (or below) its parent dendrite, i.e., still about the tip region. The following is intended to experimentally demonstrate the viability of this concept in coordination with a model that gives predictive insight regarding solute distribution about growing dendrites. Alloys based on the lead-tin eutectic system were used in this study. The system is well characterized, the constituent metals are available in a very pure form, and the thermophysical properties are well known. During solidification of hypoeutectic alloys, e.g., 55 wt pct Pb, the primary dendrites reject the less dense tin, and for the hypereutectic alloys, e.g., 75 wt pct Sn, the primary dendrites reject denser lead. Alloys were prepared by melting appropriate amounts of lead and tin in a glass crucible after which the homogeneous liquid was sucked directly into 5-mm i.d. glass tubes. The sample tube, containing approximately 30 cm of alloy, was then mechanically driven into the directional solidification furnace assembly and positioned such that approx. 20 cm of the sample was remelted. Subsequently, directional solidification was initiated by withdrawing the sample through a water-cooled jacket at a constant growth velocity of 2 ,microns/s. After 5 to 6 cm of growth, the sample was quickly removed from the furnace and quenched in a water bath to preserve the solid-liquid interface. Samples were directionally solidified vertically upward, nearly horizontally, and some in conjunction with an applied axial rotation of the crucible. Temperature gradients at the solid-liquid interface were measured with an in-siru K-type thermocouple. Solidified samples were cut perpendicular and parallel to the growth direction and conventionally prepared for microscopic examination.

Simultaneous treatment of SO2 containing stack gases and waste water

NASA Technical Reports Server (NTRS)

Poradek, J. C.; Collins, D. D. (Inventor)

1978-01-01

A process for simultaneously removing sulfur dioxide from stack gases and the like and purifying waste water such as derived from domestic sewage is described. A portion of the gas stream and a portion of the waste water, the latter containing dissolved iron and having an acidic pH, are contacted in a closed loop gas-liquid scrubbing zone to effect absorption of the sulfur dioxide into the waste water. A second portion of the gas stream and a second portion of the waste water are controlled in an open loop gas-liquid scrubbing zone. The second portion of the waste water contains a lesser amount of iron than the first portion of the waste water. Contacting in the openloop scrubbing zone is sufficient to acidify the waste water which is then treated to remove solids originally present.

Quantifying capital goods for collection and transport of waste.

PubMed

Brogaard, Line K; Christensen, Thomas H

2012-12-01

The capital goods for collection and transport of waste were quantified for different types of containers (plastic containers, cubes and steel containers) and an 18-tonnes compacting collection truck. The data were collected from producers and vendors of the bins and the truck. The service lifetime and the capacity of the goods were also assessed. Environmental impact assessment of the production of the capital goods revealed that, per tonne of waste handled, the truck had the largest contribution followed by the steel container. Large high density polyethylene (HDPE) containers had the lowest impact per tonne of waste handled. The impact of producing the capital goods for waste collection and transport cannot be neglected as the capital goods dominate (>85%) the categories human-toxicity (non-cancer and cancer), ecotoxicity, resource depletion and aquatic eutrophication, but also play a role (>13%) within the other impact categories when compared with the impacts from combustion of fuels for the collection and transport of the waste, when a transport distance of 25 km was assumed.

Solidification effects on sill formation: An experimental approach

NASA Astrophysics Data System (ADS)

Chanceaux, L.; Menand, T.

2014-10-01

Sills represent a major mechanism for constructing continental Earth's crust because these intrusions can amalgamate and form magma reservoirs and plutons. As a result, numerous field, laboratory and numerical studies have investigated the conditions that lead to sill emplacement. However, all previous studies have neglected the potential effect magma solidification could have on sill formation. The effects of solidification on the formation of sills are studied and quantified with scaled analogue laboratory experiments. The experiments presented here involved the injection of hot vegetable oil (a magma analogue) which solidified during its propagation as a dyke in a colder and layered solid of gelatine (a host rock analogue). The gelatine solid had two layers of different stiffness, to create a priori favourable conditions to form sills. Several behaviours were observed depending on the injection temperature and the injection rate: no intrusions (extreme solidification effects), dykes stopping at the interface (high solidification effects), sills (moderate solidification effects), and dykes passing through the interface (low solidification effects). All these results can be explained quantitatively as a function of a dimensionless temperature θ, which describes the experimental thermal conditions, and a dimensionless flux ϕ, which describes their dynamical conditions. The experiments reveal that sills can only form within a restricted domain of the (θ , ϕ) parameter space. These experiments demonstrate that contrary to isothermal experiments where cooling could not affect sill formation, the presence of an interface that would be a priori mechanically favourable is not a sufficient condition for sill formation; solidification effects restrict sill formation. The results are consistent with field observations and provide a means to explain why some dykes form sills when others do not under seemingly similar geological conditions.

Coupled Growth in Hypermonotectics

NASA Technical Reports Server (NTRS)

Andrews, J. Barry; Coriell, Sam R.

2001-01-01

The overall objective of this project is to obtain a fundamental understanding of the physics controlling solidification processes in immiscible alloy systems. The investigation involves both experimentation and the development of a model describing solidification in monotectic systems. The experimental segment was designed to first demonstrate that it is possible to obtain interface stability and steady state coupled growth in hypermonotectic alloys through microgravity processing. Microgravity results obtained to date have verified this possibility. Future flights will permit experimental determination of the limits of interface stability and the influence of alloy composition and growth rate on microstructure. The objectives of the modeling segment of the investigation include prediction of the limits of interface stability, modeling of convective flow due to residual acceleration, and the influence of surface tension driven flows at the solidification interface. The study of solidification processes in immiscible alloy systems is hindered by the inherent convective flow that occurs on Earth and by the possibility of sedimentation of the higher density immiscible liquid phase. It has been shown that processing using a high thermal gradient and a low growth rate can lead to a stable macroscopically planar growth front even in hypermonotectic alloys. Processing under these growth conditions can avoid constitutional supercooling and prevent the formation of the minor immiscible liquid phase in advance of the solidification front. However, the solute depleted boundary layer that forms in advance of the solidification front is almost always less dense than the liquid away from the solidification front. As a result, convective instability is expected. Ground based testing has indicated that convection is a major problem in these alloy systems and leads to gross compositional variations along the sample and difficulties maintaining interface stability. Sustained low gravity processing conditions are necessary in order to minimize these problems and obtain solidification conditions which approach steady state.

Passive Neutron Non-Destructive Assay for Remediation of Radiological Waste at Hanford Burial Grounds- 13189

DOE Office of Scientific and Technical Information (OSTI.GOV)

Simpson, A.; Pitts, M.; Ludowise, J.D.

The Hanford burial grounds contains a broad spectrum of low activity radioactive wastes, transuranic (TRU) wastes, and hazardous wastes including fission products, byproduct material (thorium and uranium), plutonium and laboratory chemicals. A passive neutron non-destructive assay technique has been developed for characterization of shielded concreted drums exhumed from the burial grounds. This method facilitates the separation of low activity radiological waste containers from TRU waste containers exhumed from the burial grounds. Two identical total neutron counting systems have been deployed, each consisting of He-3 detectors surrounded by a polyethylene moderator. The counts are processed through a statistical filter that removesmore » outliers in order to suppress cosmic spallation events and electronic noise. Upon completion of processing, a 'GO / NO GO' signal is provided to the operator based on a threshold level equivalent to 0.5 grams of weapons grade plutonium in the container being evaluated. This approach allows instantaneous decisions to be made on how to proceed with the waste. The counting systems have been set up using initial on-site measurements (neutron emitting standards loaded into surrogate waste containers) combined with Monte Carlo modeling techniques. The benefit of this approach is to allow the systems to extend their measurement ranges, in terms of applicable matrix types and container sizes, with minimal interruption to the operations at the burial grounds. (authors)« less

The Effect of Bi Contamination on the Solidification Behavior of Sn-Pb Solders

NASA Astrophysics Data System (ADS)

Moon, Kil-Won; Kattner, Ursula R.; Handwerker, Carol A.

2007-06-01

This paper presents experimental results and theoretical calculations that evaluate the effects of Bi contamination on the solidification behavior of Sn-Pb alloys. The pasty (mushy) range, the type of solidification path, and the microstructure of the solidified alloys are described. The experimental results are obtained from thermal analysis and metallography, and the solidification calculations are performed using the lever rule and Scheil assumptions. The experimental results show that the solidification behavior of the contaminated solder at cooling rates of 5°C/min and 23°C/min is closer to the predictions of the lever rule calculations than those of the Scheil calculations. Although the freezing range of Bi-contaminated Sn-Pb solders is increased, formation of a ternary eutectic reaction at 95°C is not observed for contamination levels below the Bi mass fraction of 6%.

Kinetic Phase Diagrams of Ternary Al-Cu-Li System during Rapid Solidification: A Phase-Field Study

PubMed Central

Yang, Xiong; Zhang, Lijun; Sobolev, Sergey; Du, Yong

2018-01-01

Kinetic phase diagrams in technical alloys at different solidification velocities during rapid solidification are of great importance for guiding the novel alloy preparation, but are usually absent due to extreme difficulty in performing experimental measurements. In this paper, a phase-field model with finite interface dissipation was employed to construct kinetic phase diagrams in the ternary Al-Cu-Li system for the first time. The time-elimination relaxation scheme was utilized. The solute trapping phenomenon during rapid solidification could be nicely described by the phase-field simulation, and the results obtained from the experiment measurement and/or the theoretical model were also well reproduced. Based on the predicted kinetic phase diagrams, it was found that with the increase of interface moving velocity and/or temperature, the gap between the liquidus and solidus gradually reduces, which illustrates the effect of solute trapping and tendency of diffusionless solidification. PMID:29419753

Five-dimensional imaging of freezing emulsions with solute effects.

PubMed

Dedovets, Dmytro; Monteux, Cécile; Deville, Sylvain

2018-04-20

The interaction of objects with a moving solidification front is a common feature of many industrial and natural processes such as metal processing, the growth of single crystals, the cryopreservation of cells, or the formation of sea ice. Interaction of solidification fronts with objects leads to different outcomes, from total rejection of the objects to their complete engulfment. We imaged the freezing of emulsions in five dimensions (space, time, and solute concentration) with confocal microscopy. We showed that the solute induces long-range interactions that determine the solidification microstructure. The local increase of solute concentration enhances premelting, which controls the engulfment of droplets by the front and the evolution of grain boundaries. Freezing emulsions may be a good analog of many solidification systems where objects interact with a solidification interface. Copyright © 2018 The Authors, some rights reserved; exclusive licensee American Association for the Advancement of Science. No claim to original U.S. Government Works.

U.S. Department of Energy Implementation of Chemical Evaluation Requirements for Transuranic Waste Disposal at the Waste Isolation Pilot Plant

DOE Office of Scientific and Technical Information (OSTI.GOV)

Moon, Alison; Barkley, Michelle; Poppiti, James

This report summarizes new controls designed to ensure that transuranic waste disposed at the Waste Isolation Pilot Plant (WIPP) does not contain incompatible chemicals. These new controls include a Chemical Compatibility Evaluation, an evaluation of oxidizing chemicals, and a waste container assessment to ensure that waste is safe for disposal. These controls are included in the Chapter 18 of the Documented Safety Analysis for WIPP (1).

40 CFR 265.173 - Management of containers.

Code of Federal Regulations, 2010 CFR

2010-07-01

... 40 Protection of Environment 25 2010-07-01 2010-07-01 false Management of containers. 265.173... DISPOSAL FACILITIES Use and Management of Containers § 265.173 Management of containers. (a) A container... waste. (b) A container holding hazardous waste must not be opened, handled, or stored in a manner which...

STS-26 crewmembers experiment with microgravity and eat on middeck

NASA Technical Reports Server (NTRS)

1988-01-01

STS-26 Mission Specialist John M. Lounge, using a beverage container, experiments with microgravity as Commander Frederick H. Hauck (left) and MS David C. Hilmers (right) look on. Lounge freefloats as he closes in on a sphere of the red liquid drifting in front of his mouth. Hauck holds a spoon while sipping from a beverage container as he balances a meal tray assembly on his thighs. Hilmers, partially blocked by the open airlock hatch and holding a spoon and a can of food, pauses to watch the experiment. Automated Directional Solidification Furnace (ADSF) and forward middeck lockers appear on Lounge's right.

Mercury methylation in mine wastes collected from abandoned mercury mines in the USA

USGS Publications Warehouse

Gray, J.E.; Hines, M.E.; Biester, H.; Lasorsa, B.K.; ,

2003-01-01

Speciation and transformation of Hg was studied in mine wastes collected from abandoned Hg mines at McDermitt, Nevada, and Terlingua, Texas, to evaluate formation of methyl-Hg, which is highly toxic. In these mine wastes, we measured total Hg and methyl-Hg contents, identified various Hg compounds using a pyrolysis technique, and determined rates of Hg methylation and methyl-Hg demethylation using isotopic-tracer methods. Mine wastes contain total Hg contents as high as 14000 ??g/g and methyl-Hg concentrations as high as 88 ng/g. Mine wastes were found to contain variable amounts of cinnabar, metacinnabar, Hg salts, Hg0, and Hg0 and Hg2+ sorbed onto matrix particulates. Samples with Hg0 and matrix-sorbed Hg generally contained significant methyl-Hg contents. Similarly, samples containing Hg0 compounds generally produced significant Hg methylation rates, as much as 26%/day. Samples containing mostly cinnabar showed little or no Hg methylation. Mine wastes with high methyl-Hg contents generally showed low methyl-Hg demethylation, suggesting that Hg methylation was dominant. Methyl-Hg demethylation was by both oxidative and microbial pathways. The correspondence of mine wastes containing Hg0 compounds and measured Hg methylation suggests that Hg0 oxidizes to Hg2+, which is subsequently bioavailable for microbial Hg methylation.

Direct chill casting of aluminium alloys under electromagnetic interaction by permanent magnet assembly

NASA Astrophysics Data System (ADS)

Bojarevičs, Andris; Kaldre, Imants; Milgrāvis, Mikus; Beinerts, Toms

2018-05-01

Direct chill casting is one of the methods used in industry to obtain good microstructure and properties of aluminium alloys. Nevertheless, for some alloys grain structure is not optimal. In this study, we offer the use of electromagnetic interaction to modify melt convection near the solidification interface. Solidification under various electromagnetic interactions has been widely studied, but usually at low solidification velocity and high thermal gradient. This type of interaction may succeed fragmentation of dendrite arms and transport of solidification nuclei thus leading to improved material structure and properties. Realization of experimental small-scale crystallizer and electromagnetic system has been described in this article.

Enthalpies of a binary alloy during solidification

NASA Technical Reports Server (NTRS)

Poirier, D. R.; Nandapurkar, P.

1988-01-01

The purpose of the paper is to present a method of calculating the enthalpy of a dendritic alloy during solidification. The enthalpies of the dendritic solid and interdendritic liquid of alloys of the Pb-Sn system are evaluated, but the method could be applied to other binaries, as well. The enthalpies are consistent with a recent evaluation of the thermodynamics of Pb-Sn alloys and with the redistribution of solute in the same during dendritic solidification. Because of the heat of mixing in Pb-Sn alloys, the interdendritic liquid of hypoeutectic alloys (Pb-rich) of less than 50 wt pct Sn has enthalpies that increase as temperature decreases during solidification.

MPS solidification model. Analysis and calculation of macrosegregation in a casting ingot

NASA Technical Reports Server (NTRS)

Poirier, D. R.; Maples, A. L.

1985-01-01

Work performed on several existing solidification models for which computer codes and documentation were developed is presented. The models describe the solidification of alloys in which there is a time varying zone of coexisting solid and liquid phases; i.e., the S/L zone. The primary purpose of the models is to calculate macrosegregation in a casting or ingot which results from flow of interdendritic liquid in this S/L zone during solidification. The flow, driven by solidification contractions and by gravity acting on density gradients in the interdendritic liquid, is modeled as flow through a porous medium. In Model 1, the steady state model, the heat flow characteristics are those of steady state solidification; i.e., the S/L zone is of constant width and it moves at a constant velocity relative to the mold. In Model 2, the unsteady state model, the width and rate of movement of the S/L zone are allowed to vary with time as it moves through the ingot. Each of these models exists in two versions. Models 1 and 2 are applicable to binary alloys; models 1M and 2M are applicable to multicomponent alloys.

Effects of N/C Ratio on Solidification Behaviors of Novel Nb-Bearing Austenitic Heat-Resistant Cast Steels for Exhaust Components of Gasoline Engines

NASA Astrophysics Data System (ADS)

Zhang, Yinhui; Li, Mei; Godlewski, Larry A.; Zindel, Jacob W.; Feng, Qiang

2017-03-01

In order to comply with more stringent environmental and fuel consumption regulations, novel Nb-bearing austenitic heat-resistant cast steels that withstand exhaust temperatures as high as 1,323 K (1,050 °C) is urgently demanded from automotive industries. In the current research, the solidification behavior of these alloys with variations of N/C ratio is investigated. Directional solidification methods were carried out to examine the microstructural development in mushy zones. Computational thermodynamic calculations under partial equilibrium conditions were performed to predict the solidification sequence of different phases. Microstructural characterization of the mushy zones indicates that N/C ratio significantly influenced the stability of γ-austenite and the precipitation temperature of NbC/Nb(C,N), thereby altering the solidification path, as well as the morphology and distribution of NbC/Nb(C,N) and γ-ferrite. The solidification sequence of different phases predicted by thermodynamic software agreed well with the experimental results, except the specific precipitation temperatures. The generated data and fundamental understanding will be helpful for the application of computational thermodynamic methods to predict the as-cast microstructure of Nb-bearing austenitic heat-resistant steels.

Analysis and calculation of macrosegregation in a casting ingot. MPS solidification model. Volume 1: Formulation and analysis

NASA Technical Reports Server (NTRS)

Maples, A. L.; Poirier, D. R.

1980-01-01

The physical and numerical formulation of a model for the horizontal solidification of a binary alloy is described. It can be applied in an ingot. The major purpose of the model is to calculate macrosegregation in a casting ingot which results from flow of interdendritic liquid during solidification. The flow, driven by solidification contractions and by gravity acting on density gradients in the interdendritic liquid, was modeled as flow through a porous medium. The symbols used are defined. The physical formulation of the problem leading to a set of equations which can be used to obtain: (1) the pressure field; (2) the velocity field: (3) mass flow and (4) solute flow in the solid plus liquid zone during solidification is presented. With these established, the model calculates macrosegregation after solidification is complete. The numerical techniques used to obtain solution on a computational grid are presented. Results, evaluation of the results, and recommendations for future development of the model are given. The macrosegregation and flow field predictions for tin-lead, aluminum-copper, and tin-bismuth alloys are included as well as comparisons of some of the predictions with published predictions or with empirical data.

Hanford Site Waste Management Units Report

DOE Office of Scientific and Technical Information (OSTI.GOV)

Shearer, Jeffrey P.

2012-02-29

The Hanford Site Waste Management Units Report (HSWMUR) has been created to meet the requirements of the Tri-Party Agreement (TPA) Action Plan, Section 3.5, which states: “The Hanford Site Waste Management Units Report shall be generated, in a format agreed upon by the Parties, as a calendar year report and issued annually by the DOE by the end of February of each year, and posted electronically for regulator and public access. This report shall reflect all changes made in waste management unit status during the previous year.” This February 2012 version of the HSWMUR contains a comprehensive inventory of themore » 3389 sites and 540 subsites in the Waste Information Data System (WIDS). The information for each site contains a description of each unit and the waste it contains, where applicable. The WIDS database provides additional information concerning the sites contained in this report and is maintained with daily changes to these sites.« less

Hanford Site Waste Management Units Report

DOE Office of Scientific and Technical Information (OSTI.GOV)

Shearer, Jeffrey P.

2014-02-19

The Hanford Site Waste Management Units Report (HSWMUR) has been created to meet the requirements of the Tri-Party Agreement (TPA) Action Plan, Section 3.5, which states: “The Hanford Site Waste Management Units Report shall be generated, in a format agreed upon by the Parties, as a calendar year report and issued annually by the DOE by the end of February of each year, and posted electronically for regulator and public access. This report shall reflect all changes made in waste management unit status during the previous year.” This February 2013 version of the HSWMUR contains a comprehensive inventory of themore » 3438 sites and 569 subsites in the Waste Information Data System (WIDS). The information for each site contains a description of each unit and the waste it contains, where applicable. The WIDS database provides additional information concerning the sites contained in this report and is maintained with daily changes to these sites.« less

Hanford Site Waste Management Units Report

DOE Office of Scientific and Technical Information (OSTI.GOV)

Shearer, Jeffrey P.

2013-02-13

The Hanford Site Waste Management Units Report (HSWMUR) has been created to meet the requirements of the Tri-Party Agreement (TPA) Action Plan, Section 3.5, which states: “The Hanford Site Waste Management Units Report shall be generated, in a format agreed upon by the Parties, as a calendar year report and issued annually by the DOE by the end of February of each year, and posted electronically for regulator and public access. This report shall reflect all changes made in waste management unit status during the previous year.” This February 2013 version of the HSWMUR contains a comprehensive inventory of themore » 3427 sites and 564 subsites in the Waste Information Data System (WIDS). The information for each site contains a description of each unit and the waste it contains, where applicable. The WIDS database provides additional information concerning the sites contained in this report and is maintained with daily changes to these sites.« less

Method for stabilizing low-level mixed wastes at room temperature

DOEpatents

Wagh, A.S.; Singh, D.

1997-07-08

A method to stabilize solid and liquid waste at room temperature is provided comprising combining solid waste with a starter oxide to obtain a powder, contacting the powder with an acid solution to create a slurry, said acid solution containing the liquid waste, shaping the now-mixed slurry into a predetermined form, and allowing the now-formed slurry to set. The invention also provides for a method to encapsulate and stabilize waste containing cesium comprising combining the waste with Zr(OH){sub 4} to create a solid-phase mixture, mixing phosphoric acid with the solid-phase mixture to create a slurry, subjecting the slurry to pressure; and allowing the now pressurized slurry to set. Lastly, the invention provides for a method to stabilize liquid waste, comprising supplying a powder containing magnesium, sodium and phosphate in predetermined proportions, mixing said powder with the liquid waste, such as tritium, and allowing the resulting slurry to set. 4 figs.

Method for stabilizing low-level mixed wastes at room temperature

DOEpatents

Wagh, Arun S.; Singh, Dileep

1997-01-01

A method to stabilize solid and liquid waste at room temperature is provided comprising combining solid waste with a starter oxide to obtain a powder, contacting the powder with an acid solution to create a slurry, said acid solution containing the liquid waste, shaping the now-mixed slurry into a predetermined form, and allowing the now-formed slurry to set. The invention also provides for a method to encapsulate and stabilize waste containing cesium comprising combining the waste with Zr(OH).sub.4 to create a solid-phase mixture, mixing phosphoric acid with the solid-phase mixture to create a slurry, subjecting the slurry to pressure; and allowing the now pressurized slurry to set. Lastly, the invention provides for a method to stabilize liquid waste, comprising supplying a powder containing magnesium, sodium and phosphate in predetermined proportions, mixing said powder with the liquid waste, such as tritium, and allowing the resulting slurry to set.

Biotechnology in the management and resource recovery from metal bearing solid wastes: Recent advances.

PubMed

Sethurajan, Manivannan; van Hullebusch, Eric D; Nancharaiah, Yarlagadda V

2018-04-01

Solid metalliferous wastes (sludges, dusts, residues, slags, red mud and tailing wastes) originating from ferrous and non-ferrous metallurgical industries are a serious environmental threat, when waste management practices are not properly followed. Metalliferous wastes generated by metallurgical industries are promising resources for biotechnological extraction of metals. These wastes still contain significant amounts of valuable non-ferrous metals, sometimes precious metals and also rare earth elements. Elemental composition and mineralogy of the metallurgical wastes is dependent on the nature of mining site and composition of primary ores mined. Most of the metalliferous wastes are oxidized in nature and contain less/no reduced sulfidic minerals (which can be quite well processed by biohydrometallurgy). However, application of biohydrometallurgy is more challenging while extracting metals from metallurgical wastes that contain oxide minerals. In this review, origin, elemental composition and mineralogy of the metallurgical solid wastes are presented. Various bio-hydrometallurgical processes that can be considered for the extraction of non-ferrous metals from metal bearing solid wastes are reviewed. Copyright © 2018 Elsevier Ltd. All rights reserved.

Recycling of air pollution control residues from municipal solid waste incineration into lightweight aggregates.

PubMed

Quina, Margarida J; Bordado, João M; Quinta-Ferreira, Rosa M

2014-02-01

This work focuses on the assessment of technological properties and on the leaching behavior of lightweight aggregates (LWA) produced by incorporating different quantities of air pollution control (APC) residues from municipal solid waste (MSW) incineration. Currently this hazardous waste has been mostly landfilled after stabilization/solidification. The LWA were produced by pelletizing natural clay, APC residues as-received from incineration plant, or after a washing treatment, a small amount of oil and water. The pellets were fired in a laboratory chamber furnace over calcium carbonate. The main technological properties of the LWA were evaluated, mainly concerning morphology, bulk and particle densities, compressive strength, bloating index, water adsorption and porosity. Given that APC residues do not own expansive (bloating) properties, the incorporation into LWA is only possible in moderate quantities, such as 3% as received or 5% after pre-washing treatment. The leaching behavior of heavy metals from sintered LWA using water or acid solutions was investigated, and despite the low acid neutralization capacity of the synthetic aggregates, the released quantities were low over a wide pH range. In conclusion, after a washing pre-treatment and if the percentage of incorporation is low, these residues may be incorporated into LWA. However, the recycling of APC residues from MSW incineration into LWA does not revealed any technical advantage. Copyright © 2013 Elsevier Ltd. All rights reserved.

Analytical and Experimental Investigations of Sodium Heat Pipes and Thermal Energy Storage Systems.

DTIC Science & Technology

1982-01-01

continued) Figure Page 5.1 Cylindrical container for eutectic salt (LiF-NgF -KF) . . . . . . 91 5.2 TESC sample . . . . . . ... . . 0...of fluorides of Mg, Li and K. Experimental results have been used to verify the melting point, and latent heat of fusion of the eutectic salt , in...a melting or solidification curve will provide experimental verification for the latent heat value and melting point of a given eutectic salt . In the

Space Processing Application Rocket project, SPAR 5

NASA Technical Reports Server (NTRS)

Reeves, F. (Compiler); Schaefer, D. (Compiler)

1980-01-01

Post flight results and analysis are presented on the following experiments: 'Agglomeration in Immiscible Liquids', 'Contained Polycrystalline Solidification in Low G', 'The Direct Observation of Dendrite Remelting and Macrosegregation in Casting', and 'Uniform Dispersion by Crystallization'. An engineering report on the performance of the SPAR Black Brant rocket is also included. Much useful data and information were accumulated for directing and developing experimental techniques and investigations toward an expanding commercially beneficial program of materials processing in the coming shuttle era.

Leaching of radionuclides from furfural-based polymers used to solidify reactor compartments and components disposed of in the Arctic Kara Sea

DOE Office of Scientific and Technical Information (OSTI.GOV)

HEISER,J.H.; SIVINTSEV,Y.; ALEXANDROV,V.P.

1999-09-01

Within the course of operating its nuclear navy, the former Soviet Union (FSU) disposed of reactor vessels and spent nuclear fuel (SNF) in three fjords on the east coast of Novaya Zemlya and in the open Kara Sea within the Novaya Zemlya Trough during the period 1965 to 1988. The dumping consisted of 16 reactors, six of which contained SNF and one special container that held ca. 60% of the damaged SNF and the screening assembly from the No. 2 reactor of the atomic icebreaker Lenin. At the time, the FSU considered dumping of decommissioned nuclear submarines with damaged coresmore » in the bays of and near by the Novaya Zemlya archipelago in the Arctic Kara Sea to be acceptable. To provide an additional level of safety, a group of Russian scientists embarked upon a course of research to develop a solidification agent that would provide an ecologically safe barrier. The barrier material would prevent direct contact of seawater with the SNF and the resultant leaching and release of radionuclides. The solidification agent was to be introduced by flooding the reactors vessels and inner cavities. Once introduced the agent would harden and form an impermeable barrier. This report describes the sample preparation of several ``Furfurol'' compositions and their leach testing using cesium 137 as tracer.« less

49 CFR 228.325 - Food service in a camp car or separate kitchen or dining facility in a camp.

Code of Federal Regulations, 2012 CFR

2012-10-01

... be stored to prevent vermin and insect infestation. (4) All food waste disposal containers shall be constructed to prevent vermin and insect infestation. (i) All food waste disposal containers used within a...) All food waste disposal containers used outside a camp car shall be located to prevent offensive odors...

Application of Solidification Theory to Rapid Solidification Processing

DTIC Science & Technology

1982-09-01

period were achieved in the following areas : Extended Solid Solubilities -- for Produetion of Alloys with New Compositions and Phases o At high growth... Areas where significant improvements In alloy properties can be produced by rapid solidification will be emphasized. Technical Problem and General...focussed on the science underlying areas where Improved materials can be obtained in order to provide such prediction and control. This work is both

Solidification of basaltic magma during flow in a dike.

USGS Publications Warehouse

Delaney, P.T.; Pollard, D.D.

1982-01-01

A model for time-dependent unsteady heat transfer from magma flowing in a dyke is developed. The ratio of solidification T to magma T is the most important parameter. Observations of volcanic fissure eruptions and study of dykes near Ship Rock, New Mexico, show that the low T at dyke margins and the rapidly advancing solidification front predicted by the model are qualitatively correct.-M.S.

Chernobyl NPP: Completion of LRW Treatment Plant and LRW Management on Site - 12568

DOE Office of Scientific and Technical Information (OSTI.GOV)

Fedorov, Denis; Adamovich, Dmitry; Klimenko, I.

2012-07-01

Since a beginning of ChNPP operation, and after a tragedy in 1986, a few thousands m3 of LRW have been collected in a storage tanks. In 2004 ChNPP started the new project on creation of LRW treatment plant (LRWTP) financed from EBRD fund. But it was stopped in 2008 because of financial and contract problems. In 2010 SIA RADON jointly with Ukrainian partners has won a tender on completion of LRWTP, in particular I and C system. The purpose of LRTP is to process liquid rad-wastes from SSE 'Chernobyl NPP' site and those liquids stored in the LRWS and SLRWSmore » tanks as well as the would-be wastes after ChNPP Power Units 1, 2 and 3 decommissioning. The LRTP design lifetime - 20 years. Currently, the LRTP is getting ready to perform the following activities: 1. retrieval of waste from tanks stored at ChNPP LWS using waste retrieval system with existing equipment involved; 2. transfer of retrieved waste into LRTP reception tanks with partial use of existing transfer pipelines; 3. laboratory chemical and radiochemical analysis of reception tanks contest to define the full spectrum of characteristics before processing, to acknowledge the necessity of preliminary processing and to select end product recipe; 4. preliminary processing of the waste to meet the requirements for further stages of the process; 5. shrinkage (concentrating) of preliminary processed waste; 6. solidification of preliminary processed waste with concrete to make a solid-state (end product) and load of concrete compound into 200-l drums; 7. curing of end product drums in LRTP curing hall; 8. radiologic monitoring of end product drums and their loading into special overpacks; 9. overpack radiological monitoring; 10. send for disposal (ICSRM Lot 3); The current technical decisions allow to control and return to ChNPP of process media and supporting systems outputs until they satisfy the following quality norms: salt content: < 100 g/l; pH: 1 - 11; anionic surface-active agent: < 25 mg/l; oil dissipated in the liquid: < 2 mg/l; overall gamma-activity: < 3,7 x10{sup 5} Bq/l. (authors)« less

Direct observation of spatially isothermal equiaxed solidification of an Al-Cu alloy in microgravity on board the MASER 13 sounding rocket

NASA Astrophysics Data System (ADS)

Murphy, A. G.; Mathiesen, R. H.; Houltz, Y.; Li, J.; Lockowandt, C.; Henriksson, K.; Melville, N.; Browne, D. J.

2016-11-01

For the first time, isothermal equiaxed solidification of a metallic alloy has been observed in situ in space, providing unique benchmark experimental data. The experiment was completed on board the MASER 13 sounding rocket, launched in December 2015, using a newly developed isothermal solidification furnace. A grain-refined Al-20 wt%Cu sample was fully melted and solidified during 360 s of microgravity and the solidification sequence was recorded using time-resolved X-radiography. Equiaxed nucleation, dendritic growth, solutal impingement, and eutectic transformation were thus observed in a gravity-free environment. Equiaxed nucleation was promoted through application of a controlled cooling rate of -0.05 K/s producing a 1D grain density of 6.5 mm-1, uniformly distributed throughout the field of view (FOV). Primary growth slowed to a visually imperceptible level at an estimated undercooling of 7 K, after which the cooling rate was increased to -1.0 K/s for the remainder of solidification and eutectic transformation, ensuring the sample was fully solidified inside the microgravity time window. The eutectic transformation commenced at the centre of the FOV proceeding radially outwards covering the entire FOV in 3 s Microgravity-based solidification is compared to an identical pre-flight ground-based experiment using the same sample and experiment timeline. The ground experiment was designed to minimise gravity effects, by choice of a horizontal orientation for the sample, so that any differences would be subtle. The first equiaxed nucleation occurred at an apparent undercooling of 0.6 K less than the equivalent event during microgravity. During primary equiaxed solidification, as expected, no buoyant grain motion was observed during microgravity, compared to modest grain rotation and reorientation observed during terrestrial-based solidification. However, when the cooling rate was increased from -0.05 K/s to -1.0 K/s during the latter stages of solidification, in both 1g and micro-g environments, some grain movement was apparent due to liquid feeding and mechanical impingement of neighbouring grains.

Waste from grocery stores

DOE Office of Scientific and Technical Information (OSTI.GOV)

Lieb, K.

1993-11-01

The Community Recycling Center, Inc., (CRC, Champaign, Ill.), last year conducted a two-week audit of waste generated at two area grocery stores. The stores surveyed are part of a 10-store chain. For two of the Kirby Foods Stores, old corrugated containers (OCC) accounted for 39-45% of all waste. The summary drew correlations between the amount of OCC and the sum of food and garbage waste. The study suggested that one can reasonably estimate volumes of waste based on the amount of OCC because most things come in a box. Auditors set up a series of containers to make the collectionmore » process straightforward. Every day the containers were taken to local recycling centers and weighed. Approximate waste breakdowns for the two stores were as follows: 45% OCC; 35% food waste; 20% nonrecyclable or noncompostable items; and 10% other.« less

Hanford Site annual dangerous waste report: Volume 2, Generator dangerous waste report, radioactive mixed waste

DOE Office of Scientific and Technical Information (OSTI.GOV)

NONE

1994-12-31

This report contains information on radioactive mixed wastes at the Hanford Site. Information consists of shipment date, physical state, chemical nature, waste description, waste number, waste designation, weight, and waste designation.

Consolidation process for producing ceramic waste forms

DOEpatents

Hash, Harry C.; Hash, Mark C.

2000-01-01

A process for the consolidation and containment of solid or semisolid hazardous waste, which process comprises closing an end of a circular hollow cylinder, filling the cylinder with the hazardous waste, and then cold working the cylinder to reduce its diameter while simultaneously compacting the waste. The open end of the cylinder can be sealed prior to or after the cold working process. The preferred method of cold working is to draw the sealed cylinder containing the hazardous waste through a plurality of dies to simultaneously reduce the diameter of the tube while compacting the waste. This process provides a quick continuous process for consolidating hazardous waste, including radioactive waste.

Improved Crystal Quality by Detached Solidification in Microgravity

NASA Technical Reports Server (NTRS)

Regel, Liya L.; Wilcox, William R.

1999-01-01

Directional solidification in microgravity has often led to ingots that grew with little or no contact with the ampoule wall. When this occurred, crystallographic perfection was usually greatly improved -- often by several orders of magnitude. Unfortunately, until recently the true mechanisms underlying detached solidification were unknown. As a consequence, flight experiments yielded erratic results. Within the past four years, we have developed a new theoretical model that explains many of the flight results. This model gives rise to predictions of the conditions required to yield detached solidification, both in microgravity and on earth. A discussion of models of detachment, the meniscus models and results of theoretical modeling, and future plans are presented.

Modelling directional solidification

NASA Technical Reports Server (NTRS)

Wilcox, William R.

1987-01-01

An improved understanding of the phenomena of importance to directional solidification is attempted to enable explanation and prediction of differences in behavior between solidification on Earth and in space. Emphasis is now on experimentally determining the influence of convection and freezing rate fluctuations on compositional homogeneity and crystalline perfection. A correlation is sought between heater temperature profiles, buoyancy-driven convection, and doping inhomogeneities using naphthalene doped with anthracene. The influence of spin-up/spin-down is determined on compositional homogeneity and microstructure of indium gallium antimonide. The effect is determined of imposed melting - freezing cycles on indium gallium antimonide. The mechanism behind the increase of grain size caused by using spin-up/spin-down in directional solidification of mercury cadimum telluride is sought.

Cooling and solidification of liquid-metal drops in a gaseous atmosphere

NASA Technical Reports Server (NTRS)

Mccoy, J. K.; Markworth, A. J.; Collings, E. W.; Brodkey, R. S.

1992-01-01

The free fall of a liquid-metal drop, heat transfer from the drop to its environment, and solidification of the drop are described for both gaseous and vacuum atmospheres. A simple model, in which the drop is assumed to fall rectilinearly, with behavior like that of a rigid particle, is developed to describe cooling behavior. Recalescence of supercooled drops is assumed to occur instantaneously when a specified temperature is passed. The effects of solidification and experimental parameters on drop cooling are calculated and discussed. Major results include temperature as a function of time, and of drag, time to complete solidification, and drag as a function of the fraction of the drop solidified.

Inverse Thermal Analysis of Alloy 690 Laser and Hybrid Laser-GMA Welds Using Solidification-Boundary Constraints

NASA Astrophysics Data System (ADS)

Lambrakos, S. G.

2017-08-01

An inverse thermal analysis of Alloy 690 laser and hybrid laser-GMA welds is presented that uses numerical-analytical basis functions and boundary constraints based on measured solidification cross sections. In particular, the inverse analysis procedure uses three-dimensional constraint conditions such that two-dimensional projections of calculated solidification boundaries are constrained to map within experimentally measured solidification cross sections. Temperature histories calculated by this analysis are input data for computational procedures that predict solid-state phase transformations and mechanical response. These temperature histories can be used for inverse thermal analysis of welds corresponding to other welding processes whose process conditions are within similar regimes.

Anomalous eutectic formation in the solidification of undercooled Co-Sn alloys

NASA Astrophysics Data System (ADS)

Liu, L.; Wei, X. X.; Huang, Q. S.; Li, J. F.; Cheng, X. H.; Zhou, Y. H.

2012-11-01

Three Co-Sn alloys with compositions around the eutectic point were undercooled to different degrees below the equilibrium liquidus temperature and the solidification behaviors were investigated by monitoring the temperature recalescence and examing the solidification structure. It is revealed that the primary phase during rapid solidification changes complexly with the increasing undercooling in the off-eutectic alloys, while coupled eutectic growth takes place at all undercoolings in the eutectic alloy. Two types of anomalous eutectics form in the alloys: one evolving from coupled eutectics and the other from single phase dendrites or seaweeds. The crystallographic orientation of eutectic phases in the anomalous eutectic is dependent on which type their precursors belong to.

40 CFR 273.4 - Applicability-Mercury-containing equipment.

Code of Federal Regulations, 2011 CFR

2011-07-01

... 40 Protection of Environment 27 2011-07-01 2011-07-01 false Applicability-Mercury-containing... WASTES (CONTINUED) STANDARDS FOR UNIVERSAL WASTE MANAGEMENT General § 273.4 Applicability—Mercury-containing equipment. (a) Mercury-containing equipment covered under this part 273. The requirements of this...

40 CFR 273.4 - Applicability-Mercury-containing equipment.

Code of Federal Regulations, 2013 CFR

2013-07-01

... 40 Protection of Environment 28 2013-07-01 2013-07-01 false Applicability-Mercury-containing... WASTES (CONTINUED) STANDARDS FOR UNIVERSAL WASTE MANAGEMENT General § 273.4 Applicability—Mercury-containing equipment. (a) Mercury-containing equipment covered under this part 273. The requirements of this...

40 CFR 273.4 - Applicability-Mercury-containing equipment.

Code of Federal Regulations, 2012 CFR

2012-07-01

... 40 Protection of Environment 28 2012-07-01 2012-07-01 false Applicability-Mercury-containing... WASTES (CONTINUED) STANDARDS FOR UNIVERSAL WASTE MANAGEMENT General § 273.4 Applicability—Mercury-containing equipment. (a) Mercury-containing equipment covered under this part 273. The requirements of this...

40 CFR 273.4 - Applicability-Mercury-containing equipment.

Code of Federal Regulations, 2014 CFR

2014-07-01

... 40 Protection of Environment 27 2014-07-01 2014-07-01 false Applicability-Mercury-containing... WASTES (CONTINUED) STANDARDS FOR UNIVERSAL WASTE MANAGEMENT General § 273.4 Applicability—Mercury-containing equipment. (a) Mercury-containing equipment covered under this part 273. The requirements of this...

Radioactive waste processing apparatus

DOEpatents

Nelson, Robert E.; Ziegler, Anton A.; Serino, David F.; Basnar, Paul J.

1987-01-01

Apparatus for use in processing radioactive waste materials for shipment and storage in solid form in a container is disclosed. The container includes a top, and an opening in the top which is smaller than the outer circumference of the container. The apparatus includes an enclosure into which the container is placed, solution feed apparatus for adding a solution containing radioactive waste materials into the container through the container opening, and at least one rotatable blade for blending the solution with a fixing agent such as cement or the like as the solution is added into the container. The blade is constructed so that it can pass through the opening in the top of the container. The rotational axis of the blade is displaced from the center of the blade so that after the blade passes through the opening, the blade and container can be adjusted so that one edge of the blade is adjacent the cylindrical wall of the container, to insure thorough mixing. When the blade is inside the container, a substantially sealed chamber is formed to contain vapors created by the chemical action of the waste solution and fixant, and vapors emanating through the opening in the container.

Progress in modeling solidification in molten salt coolants

NASA Astrophysics Data System (ADS)

Tano, Mauricio; Rubiolo, Pablo; Doche, Olivier

2017-10-01

Molten salts have been proposed as heat carrier media in the nuclear and concentrating solar power plants. Due to their high melting temperature, solidification of the salts is expected to occur during routine and accidental scenarios. Furthermore, passive safety systems based on the solidification of these salts are being studied. The following article presents new developments in the modeling of eutectic molten salts by means of a multiphase, multicomponent, phase-field model. Besides, an application of this methodology for the eutectic solidification process of the ternary system LiF-KF-NaF is presented. The model predictions are compared with a newly developed semi-analytical solution for directional eutectic solidification at stable growth rate. A good qualitative agreement is obtained between the two approaches. The results obtained with the phase-field model are then used for calculating the homogenized properties of the solid phase distribution. These properties can then be included in a mixture macroscale model, more suitable for industrial applications.

X-Ray Radiographic Observation of Directional Solidification Under Microgravity: XRMON-GF Experiments on MASER12 Sounding Rocket Mission

NASA Technical Reports Server (NTRS)

Reinhart, G.; NguyenThi, H.; Bogno, A.; Billia, B.; Houltz, Y.; Loth, K.; Voss, D.; Verga, A.; dePascale, F.; Mathiesen, R. H.;

Effect of process parameters on hardness, temperature profile and solidification of different layers processed by direct metal laser sintering (DMLS)

NASA Astrophysics Data System (ADS)

Ahmed, Sazzad Hossain; Mian, Ahsan; Srinivasan, Raghavan

2016-07-01

In DMLS process objects are fabricated layer by layer from powdered material by melting induced by a controlled laser beam. Metallic powder melts and solidifies to form a single layer. Solidification map during layer formation is an important route to characterize micro-structure and grain morphology of sintered layer. Generally, solidification leads to columnar, equiaxed or mixture of these two types grain morphology depending on solidification rate and thermal gradient. Eutectic or dendritic structure can be formed in fully equiaxed zone. This dendritic growth has a large effect on material properties. Smaller dendrites generally increase ductility of the layer. Thus, materials can be designed by creating desired grain morphology in certain regions using DMLS process. To accomplish this, hardness, temperature distribution, thermal gradient and solidification cooling rate in processed layers will be studied under change of process variables by using finite element analysis, with specific application to Ti-6Al-4V.

Time-Resolved In Situ Measurements During Rapid Alloy Solidification: Experimental Insight for Additive Manufacturing

NASA Astrophysics Data System (ADS)

McKeown, Joseph T.; Zweiacker, Kai; Liu, Can; Coughlin, Daniel R.; Clarke, Amy J.; Baldwin, J. Kevin; Gibbs, John W.; Roehling, John D.; Imhoff, Seth D.; Gibbs, Paul J.; Tourret, Damien; Wiezorek, Jörg M. K.; Campbell, Geoffrey H.

2016-03-01

Additive manufacturing (AM) of metals and alloys is becoming a pervasive technology in both research and industrial environments, though significant challenges remain before widespread implementation of AM can be realized. In situ investigations of rapid alloy solidification with high spatial and temporal resolutions can provide unique experimental insight into microstructure evolution and kinetics that are relevant for AM processing. Hypoeutectic thin-film Al-Cu and Al-Si alloys were investigated using dynamic transmission electron microscopy to monitor pulsed-laser-induced rapid solidification across microsecond timescales. Solid-liquid interface velocities measured from time-resolved images revealed accelerating solidification fronts in both alloys. The observed microstructure evolution, solidification product, and presence of a morphological instability at the solid-liquid interface in the Al-4 at.%Cu alloy are related to the measured interface velocities and small differences in composition that affect the thermophysical properties of the alloys. These time-resolved in situ measurements can inform and validate predictive modeling efforts for AM.

Time-Resolved In Situ Measurements During Rapid Alloy Solidification: Experimental Insight for Additive Manufacturing

DOE PAGES

McKeown, Joseph T.; Zweiacker, Kai; Liu, Can; ...

2016-01-27

In research and industrial environments, additive manufacturing (AM) of metals and alloys is becoming a pervasive technology, though significant challenges remain before widespread implementation of AM can be realized. In situ investigations of rapid alloy solidification with high spatial and temporal resolutions can provide unique experimental insight into microstructure evolution and kinetics that are relevant for AM processing. Hypoeutectic thin-film Al–Cu and Al–Si alloys were investigated using dynamic transmission electron microscopy to monitor pulsed-laser-induced rapid solidification across microsecond timescales. Solid–liquid interface velocities measured from time-resolved images revealed accelerating solidification fronts in both alloys. We observed microstructure evolution, solidification product, andmore » presence of a morphological instability at the solid–liquid interface in the Al–4 at.%Cu alloy are related to the measured interface velocities and small differences in composition that affect the thermophysical properties of the alloys. These time-resolved in situ measurements can inform and validate predictive modeling efforts for AM.« less

The study of flow pattern and phase-change problem in die casting process

NASA Technical Reports Server (NTRS)

Wang, T. S.; Wei, H.; Chen, Y. S.; Shang, H. M.

1996-01-01

The flow pattern and solidification phenomena in die casting process have been investigated in the first phase study. The flow pattern in filling process is predicted by using a VOF (volume of fluid) method. A good agreement with experimental observation is obtained for filling the water into a die cavity with different gate geometry and with an obstacle in the cavity. An enthalpy method has been applied to solve the solidification problem. By treating the latent heat implicitly into the enthalpy instead of explicitly into the source term, the CPU time can be reduced at least 20 times. The effect of material properties on solidification fronts is tested. It concludes that the dependence of properties on temperature is significant. The influence of the natural convection over the diffusion has also been studied. The result shows that the liquid metal solidification phenomena is diffusion dominant, and the natural convection can affect the shape of the interface. In the second phase study, the filling and solidification processes will be considered simultaneously.

Macrosegregation and Grain Formation Caused by Convection Associated with Directional Solidification Through Cross-Section Increase

NASA Technical Reports Server (NTRS)

Ghods, Masoud; Lauer, Mark; Tewari, Surendra; Poirier, David; Grugel, Richard

2016-01-01

Cylindrical Al-7 wt% Silicon, Al-19 wt% Copper and Lead-6 wt% Antimony alloy samples were directionally solidified (DS) with liquid above, solid below, and gravity pointing down, in graphite crucibles having an abrupt cross-sectional increase. These alloys have similar solidification shrinkage but are expected to have different degrees of thermosolutal convection during solidification. Microstructures in the DS samples in the vicinity of the section change have been studied in order to examine the effect of convection associated with the combined influence of thermosolutal effects and solidification shrinkage. Extensive radial and axial macrosegregation associated with cross-section change is observed. It also appears that steepling and local primary alpha-phase remelting resulting from convection are responsible for stray grain formation at the reentrant corners. Preliminary results from a numerical model, which includes solidification shrinkage and thermosolutal convection in the mushy zone, indicate that these regions are prone to solutal remelting of dendrites.

SolTrack: an automatic video processing software for in situ interface tracking.

PubMed

Griesser, S; Pierer, R; Reid, M; Dippenaar, R

2012-10-01

High-Resolution in situ observation of solidification experiments has become a powerful technique to improve the fundamental understanding of solidification processes of metals and alloys. In the present study, high-temperature laser-scanning confocal microscopy (HTLSCM) was utilized to observe and capture in situ solidification and phase transformations of alloys for subsequent post processing and analysis. Until now, this analysis has been very time consuming as frame-by-frame manual evaluation of propagating interfaces was used to determine the interface velocities. SolTrack has been developed using the commercial software package MATLAB and is designed to automatically detect, locate and track propagating interfaces during solidification and phase transformations as well as to calculate interfacial velocities. Different solidification phenomena have been recorded to demonstrate a wider spectrum of applications of this software. A validation, through comparison with manual evaluation, is included where the accuracy is shown to be very high. © 2012 The Authors Journal of Microscopy © 2012 Royal Microscopical Society.

Solid-liquid and liquid-solid transitions in metal nanoparticles.

PubMed

Hou, M

2017-02-22

The melting and solidification temperatures of nanosystems may differ by several hundred Kelvin. To understand the origin of this difference, transitions in small metallic nanoparticles on the atomic scale were analyzed using molecular dynamics (MD). Palladium was used as a case study, which was then extended to a range of other elemental metals. It was argued that in realistic environments, such as gases at low pressure (of the order of 1 mbar), heat transfers allow the microcanonical thermal equilibrium evolution of the nanoparticles between successive collisions with gas atoms. This is shown to have no significant influence on the mechanism of melting, whereas in an isolated nanoparticle, solidification triggers a huge and rapid increase in temperature. A simple relationship between the melting and solidification temperatures was found, indicating that the magnitude of the latent heat of melting governs undercooling. Whereas melting occurs via heterogeneous nucleation, solidification displays characteristics of spinodal decomposition. Consistently, the melting temperature scales with the surface-to-volume ratio, whereas the solidification temperature displays no significant dependence on the particle size.

Preliminary in situ and real-time study of directional solidification of metallic alloys by x-ray imaging techniques

NASA Astrophysics Data System (ADS)

Nguyen Thi, H.; Jamgotchian, H.; Gastaldi, J.; Härtwig, J.; Schenk, T.; Klein, H.; Billia, B.; Baruchel, J.; Dabo, Y.

2003-05-01

During directional solidification of a binary alloy, the solid-liquid interface exhibits a variety of patterns that are due to the Mullins-Sekerka instability and governed by the growth conditions. It is well known that properties of the grown material are largely controlled by the microstructures left in the solid during processing. Thus, a precise mastering of the solidification is essential to tailor products in a reproducible fashion to a specified quality. One major difficulty for this study is the real-time and in situ observation of the interface, especially for metallic alloys. A possibility is to use an intense and coherent third generation x-ray beam. By combining different x-ray imaging techniques (absorption/phase contrast radiography and diffraction topography), we have studied the directional melting and solidification of aluminium-based alloys. The preliminary results show the great potential of these techniques for the study of the coupling between stress effects and microstructure formation in solidification processing.

Hanford Site annual dangerous waste report: Volume 1, Part 1, Generator dangerous waste report, dangerous waste

DOE Office of Scientific and Technical Information (OSTI.GOV)

NONE

This report contains information on hazardous wastes at the Hanford Site. Information consists of shipment date, physical state, chemical nature, waste description, waste number, weight, and waste designation.

Frequent Questions About Universal Waste

EPA Pesticide Factsheets

Frequent questions such as Who is affected by the universal waste regulations? What is “mercury-containing equipment”? How are waste batteries managed under universal waste? How are waste pesticides managed under universal waste?

ASSESSMENT AND RECOMMENDATIONS FOR IMPROVING THE PERFORMANCE OF WASTE CONTAINMENT SYSTEMS

EPA Science Inventory

This broad-based study addressed three categories of issues related to the design,
construction, and performance of waste containment systems used at landfills, surface
impoundments, and waste piles, and in the remediation of contaminated sites. Geosynthetic materials have...

Segregation effects during solidification in weightless melts

NASA Technical Reports Server (NTRS)

Li, C.; Gershinsky, M.

1974-01-01

The generalized problem of determining the temperature and solute concentration profiles during directional solidification of binary alloys with surface evaporation was mathematically formulated. Realistic initial and boundary conditions were defined, and a computer program was developed and checked out. The programs computes the positions of two moving boundaries, evaporation and solidification, and their velocities. Temperature and solute concentration profiles in the semiinfinite material body at selected instances of time are also computed.

Functional Nanoclay Suspension for Printing-Then-Solidification of Liquid Materials.

PubMed

Jin, Yifei; Compaan, Ashley; Chai, Wenxuan; Huang, Yong

2017-06-14

Additive manufacturing (AM) enables the freeform fabrication of complex structures from various build materials. The objective of this study is to develop a novel Laponite nanoclay-enabled "printing-then-solidification" additive manufacturing approach to extrude complex three-dimensional (3D) structures made of various liquid build materials. Laponite, a member of the smectite mineral family, is investigated to serve as a yield-stress support bath material for the extrusion printing of liquid build materials. Using the printing-then-solidification approach, the printed structure remains liquid and retains its shape with the help of the Laponite support bath. Then the completed liquid structures are solidified in situ by applying suitable cross-linking mechanisms. Finally, the solidified structures are harvested from the Laponite nanoclay support bath for any further processing as needed. Due to its chemical and physical stability, liquid build materials with different solidification/curing/gelation mechanisms can be fabricated in the Laponite bath using the printing-then-solidification approach. The feasibility of the proposed Laponite-enabled printing-then-solidification approach is demonstrated by fabricating several complicated structures made of various liquid build materials, including alginate with ionic cross-linking, gelatin with thermal cross-linking, and SU-8 with photo-cross-linking. During gelatin structure printing, living cells are included and the postfabrication cell viability is above 90%.

Matching time and spatial scales of rapid solidification: dynamic TEM experiments coupled to CALPHAD-informed phase-field simulations

NASA Astrophysics Data System (ADS)

Perron, Aurelien; Roehling, John D.; Turchi, Patrice E. A.; Fattebert, Jean-Luc; McKeown, Joseph T.

2018-01-01

A combination of dynamic transmission electron microscopy (DTEM) experiments and CALPHAD-informed phase-field simulations was used to study rapid solidification in Cu-Ni thin-film alloys. Experiments—conducted in the DTEM—consisted of in situ laser melting and determination of the solidification kinetics by monitoring the solid-liquid interface and the overall microstructure evolution (time-resolved measurements) during the solidification process. Modelling of the Cu-Ni alloy microstructure evolution was based on a phase-field model that included realistic Gibbs energies and diffusion coefficients from the CALPHAD framework (thermodynamic and mobility databases). DTEM and post mortem experiments highlighted the formation of microsegregation-free columnar grains with interface velocities varying from ˜0.1 to ˜0.6 m s-1. After an ‘incubation’ time, the velocity of the planar solid-liquid interface accelerated until solidification was complete. In addition, a decrease of the temperature gradient induced a decrease in the interface velocity. The modelling strategy permitted the simulation (in 1D and 2D) of the solidification process from the initially diffusion-controlled to the nearly partitionless regimes. Finally, results of DTEM experiments and phase-field simulations (grain morphology, solute distribution, and solid-liquid interface velocity) were consistent at similar time (μs) and spatial scales (μm).

Matching time and spatial scales of rapid solidification: Dynamic TEM experiments coupled to CALPHAD-informed phase-field simulations

DOE Office of Scientific and Technical Information (OSTI.GOV)

Perron, Aurelien; Roehling, John D.; Turchi, Patrice E. A.

A combination of dynamic transmission electron microscopy (DTEM) experiments and CALPHAD-informed phase-field simulations was used to study rapid solidification in Cu–Ni thin-film alloys. Experiments—conducted in the DTEM—consisted of in situ laser melting and determination of the solidification kinetics by monitoring the solid–liquid interface and the overall microstructure evolution (time-resolved measurements) during the solidification process. Modelling of the Cu–Ni alloy microstructure evolution was based on a phase-field model that included realistic Gibbs energies and diffusion coefficients from the CALPHAD framework (thermodynamic and mobility databases). DTEM and post mortem experiments highlighted the formation of microsegregation-free columnar grains with interface velocities varying frommore » ~0.1 to ~0.6 m s –1. After an 'incubation' time, the velocity of the planar solid–liquid interface accelerated until solidification was complete. In addition, a decrease of the temperature gradient induced a decrease in the interface velocity. The modelling strategy permitted the simulation (in 1D and 2D) of the solidification process from the initially diffusion-controlled to the nearly partitionless regimes. Lastly, results of DTEM experiments and phase-field simulations (grain morphology, solute distribution, and solid–liquid interface velocity) were consistent at similar time (μs) and spatial scales (μm).« less

Matching time and spatial scales of rapid solidification: Dynamic TEM experiments coupled to CALPHAD-informed phase-field simulations

DOE PAGES

Perron, Aurelien; Roehling, John D.; Turchi, Patrice E. A.; ...

2017-12-05

A combination of dynamic transmission electron microscopy (DTEM) experiments and CALPHAD-informed phase-field simulations was used to study rapid solidification in Cu–Ni thin-film alloys. Experiments—conducted in the DTEM—consisted of in situ laser melting and determination of the solidification kinetics by monitoring the solid–liquid interface and the overall microstructure evolution (time-resolved measurements) during the solidification process. Modelling of the Cu–Ni alloy microstructure evolution was based on a phase-field model that included realistic Gibbs energies and diffusion coefficients from the CALPHAD framework (thermodynamic and mobility databases). DTEM and post mortem experiments highlighted the formation of microsegregation-free columnar grains with interface velocities varying frommore » ~0.1 to ~0.6 m s –1. After an 'incubation' time, the velocity of the planar solid–liquid interface accelerated until solidification was complete. In addition, a decrease of the temperature gradient induced a decrease in the interface velocity. The modelling strategy permitted the simulation (in 1D and 2D) of the solidification process from the initially diffusion-controlled to the nearly partitionless regimes. Lastly, results of DTEM experiments and phase-field simulations (grain morphology, solute distribution, and solid–liquid interface velocity) were consistent at similar time (μs) and spatial scales (μm).« less

Liquid-liquid phase separation and solidification behavior of Al55Bi36Cu9 monotectic alloy with different cooling rates

NASA Astrophysics Data System (ADS)

Bo, Lin; Li, Shanshan; Wang, Lin; Wu, Di; Zuo, Min; Zhao, Degang

2018-03-01

The cooling rate has a significant effect on the solidification behavior and microstructure of monotectic alloy. In this study, different cooling rate was designed through casting in the copper mold with different bore diameters. The effects of different cooling rate on the solidification behavior of Al55Bi36Cu9 (at.%) immiscible alloy have been investigated. The liquid-liquid phase separation of Al55Bi36Cu9 immiscible alloy melt was investigated by resistivity test. The solidification microstructure and phase analysis of Al55Bi36Cu9 immiscible alloy were performed by the SEM and XRD, respectively. The results showed that the liquid-liquid phase separation occurred in the solidification of Al55Bi36Cu9 monotectic melt from 917 °C to 653 °C. The monotectic temperature, liquid phase separation temperature and immiscibility zone of Al55Bi36Cu9 monotectic alloy was lower than those of Al-Bi binary monotectic alloy. The solidification morphology of Al55Bi36Cu9 monotectic alloy was very sensitive to the cooling rate. The Al/Bi core-shell structure formed when Al55Bi36Cu9 melt was cast in the copper mold with a 8 mm bore diameter.

Containerless solidification of BiFeO3 oxide under microgravity

NASA Astrophysics Data System (ADS)

Yu, Jianding; Arai, Yasutomo; Koshikawa, Naokiyo; Ishikawa, Takehito; Yoda, Shinichi

1999-07-01

Containerless solidification of BiFeO3 oxide has been carried out under microgravity with Electrostatic Levitation Furnace (ELF) aboard on the sounding rocket (TR-IA). It is a first containerless experiment using ELF under microgravity for studying the solidification of oxide insulator material. Spherical BiFeO3 sample with diameter of 5mm was heated by two lasers in oxygen and nitrogen mixing atmosphere, and the sample position by electrostatic force under pinpoint model and free drift model. In order to compare the solidification behavior in microgravity with on ground, solidification experiments of BiFeO3 in crucible and drop tube were carried out. In crucible experiment, it was very difficult to get single BiFeO3 phase, because segregation of Fe2O3 occured very fast and easily. In drop tube experiment, fine homogeneous BiFeO3 microstructure was obtained in a droplet about 300 μm. It implies that containerless processing can promote the phase selection in solidification. In microgravity experiment, because the heating temperature was lower than that of estimated, the sample was heated into Fe2O3+liquid phase region. Fe2O3 single crystal grew on the surface of the spherical sample, whose sample was clearly different from that observed in ground experiments.

Integrated System of Thermal/Dimensional Analysis for Quality Control of Metallic Melt and Ductile Iron Casting Solidification

NASA Astrophysics Data System (ADS)

Stan, Stelian; Chisamera, Mihai; Riposan, Iulian; Neacsu, Loredana; Cojocaru, Ana Maria; Stan, Iuliana

2018-03-01

The main objective of the present work is to introduce a specific experimental instrument and technique for simultaneously evaluating cooling curves and expansion or contraction of cast metals during solidification. Contraction/expansion analysis illustrates the solidification parameters progression, according to the molten cast iron characteristics, which are dependent on the melting procedure and applied metallurgical treatments, mold media rigidity and thermal behavior [heat transfer parameters]. The first part of the paper summarizes the performance of this two-mold device. Its function is illustrated by representative shrinkage tendency results in ductile cast iron as affected by mold rigidity (green sand and furan resin sand molds) and inoculant type (FeSi-based alloys), published in part previously. The second part of the paper illustrates an application of this equipment adapted for commercial foundry use. It conducts thermal analysis and volume change measurements in a single ceramic cup so that mold media as well as solidification conditions are constants, with cast iron quality as the variable. Experiments compared gray and ductile cast iron solidification patterns. Gray iron castings are characterized by higher undercooling at the beginning and at the end of solidification and lower graphitic expansion. Typically, ductile cast iron exhibits higher graphitic, initial expansion, conducive for shrinkage formation in soft molds.

Toxic-Waste Disposal by Combustion in Containers

NASA Technical Reports Server (NTRS)

Houseman, J.; Stephens, J. B.; Moynihan, P. I.; Compton, L. E.; Kalvinskas, J. J.

1986-01-01

Chemical wastes burned with minimal handling in storage containers. Technique for disposing of chemical munitions by burning them inside shells applies to disposal of toxic materials stored in drums. Fast, economical procedure overcomes heat-transfer limitations of conventional furnace designs by providing direct contact of oxygenrich combustion gases with toxic agent. No need to handle waste material, and container also decontaminated in process. Oxygen-rich torch flame cuts burster well and causes vaporization and combustion of toxic agent contained in shell.

Pit 9 Category of Transuranic Waste Stored Below Ground within Area G

DOE Office of Scientific and Technical Information (OSTI.GOV)

Hargis, Kenneth M.

2014-01-08

A large wildfire called the Las Conchas Fire burned large areas near Los Alamos National Laboratory (LANL) in 2011 and heightened public concern and news media attention over transuranic (TRU) waste stored at LANL’s Technical Area 54 (TA-54) Area G waste management facility. The removal of TRU waste from Area G had been placed at a lower priority in budget decisions for environmental cleanup at LANL because TRU waste removal is not included in the March 2005 Compliance Order on Consent (Reference 1) that is the primary regulatory driver for environmental cleanup at LANL. The Consent Order is an agreementmore » between LANL and the New Mexico Environment Department (NMED) that contains specific requirements and schedules for cleaning up historical contamination at the LANL site. After the Las Conchas Fire, discussions were held by the U.S. Department of Energy (DOE) with the NMED on accelerating TRU waste removal from LANL and disposing it at the Waste Isolation Pilot Plant (WIPP).This report summarizes available information on the origin, configuration, and composition of the waste containers within Pit 9, their physical and radiological characteristics, and issues that may be encountered in their retrieval and processing. Review of the available information indicates that Pit 9 should present no major issues in retrieval and processing, and most drums contain TRU waste that can be shipped to WIPP. The primary concern in retrieval is the integrity of containers that have been stored below-ground for 35 to 40 years. The most likely issue that will be encountered in processing containers retrieved from Pit 9 is the potential for items that are prohibited at WIPP such as sealed containers greater than four liters in size and free liquids that exceed limits for WIPP.« less