Science.gov

Sample records for advanced column flotation

  1. The flotation column as a froth separator

    SciTech Connect

    Schultz, C.W.; Mehta, R.K.; Bates, J.B. )

    1991-12-01

    The Mineral Resources Institute, The University of Alabama, has for the past three years been engaged in a program to develop a beneficiation system for eastern (Devonian) oil shales. One objective of that program was to evaluate advanced technologies for effecting a kerogen-mineral matter separation. Column flotation was among the advanced technologies selected for evaluation. One observation made in the course of optimization testing was that introducing the feed into the froth (above the pulp- froth interface) resulted in an improved combination of concentrate grade and kerogen recovery. This observation was reported in a previous paper. Because the practice of maintaining the pulp froth interface below the feed point is contrary to conventional practice, it was decided to subject the observation to a systematic series of tests. This paper describes a recent series of tests and the results that were obtained.

  2. Cross flow cyclonic flotation column for coal and minerals beneficiation

    DOEpatents

    Lai, Ralph W.; Patton, Robert A.

    2000-01-01

    An apparatus and process for the separation of coal from pyritic impurities using a modified froth flotation system. The froth flotation column incorporates a helical track about the inner wall of the column in a region intermediate between the top and base of the column. A standard impeller located about the central axis of the column is used to generate a centrifugal force thereby increasing the separation efficiency of coal from the pyritic particles and hydrophillic tailings.

  3. Coal desulfurization by bacterial treatment and column flotation. Final report

    SciTech Connect

    Kawatra, S.K.

    1994-06-01

    A review of the literature showed that bacterial leaching, using the microorganism Thiobacillus ferrooxidans, was a very effective technique for removing pyrite from coal, as it could dissolve even the finest pyrite particles without the need for expensive reagents or extreme processing conditions. Unfortunately, bacterial leaching is also rather slow, and so the initial goal of this research was to decrease the leaching time as much as possible. However, this still left the bacteria needing approximately a week to remove half of the pyritic sulfur, and so a faster technique was sought. Since it had been reported in the literature that T. ferrooxidans could be used to depress the flotation of pyrite during froth flotation of coal, this was investigated further. By studying the recovery mechanisms of coal-pyrite in froth flotation, it was found that pyrite was being recovered by entrainment and by locking to coal particles, not by true flotation of hydrophobic pyrite. Therefore, no pyrite depressant could be of any significant benefit for keeping pyrite out of the coal froth product, and it was much more important to prevent entrainment from occurring. Countercurrent flotation columns were invented to essentially eliminate entrainment effects, by washing the froth and reducing mixing of the froth and tailings products. Existing flotation columns tend to be quite simple, and in order to give reasonable product quality they must be very tall (typically 30--45 feet). As a result, they have difficulty in handling the high froth volumes which occur in coal flotation, and are awkward to install in existing plants. The bulk of this project therefore concentrated on developing an improved coal flotation column, and testing it under actual plant conditions.

  4. In-plant testing of microbubble column flotation

    SciTech Connect

    Yoon, R.H.; Luttrell, G.H.; Adel, G.T.; Mankosa, M.J.

    1991-07-31

    Microbubble column flotation (MCF) was developed at the Virginia Center for Coal and Minerals Processing (VCCMP) for the selective recovery of fine particles. Bench-scale test work conducted at VCCMP, largely under the sponsorship of the U.S. Department of Energy (DOE), showed that the technology worked well for both coal and mineral applications. For the technology to be commercially successful, however, a full-scale demonstration of the MCF technology was deemed necessary. This report summarizes the results of work performed under the DOE project entitled In-plant Testing of Microbubble Column Flotation.'' The objectives of this research and development effort were to duplicate the bench-scale performance of the MCF process in a full-scale unit, to verify the scale-up procedure developed in an earlier project, and to demonstrate the applicability of the MCF technology to the coal industry.

  5. In-plant testing of microbubble column flotation. Final report

    SciTech Connect

    Yoon, R.H.; Luttrell, G.H.; Adel, G.T.; Mankosa, M.J.

    1991-07-31

    Microbubble column flotation (MCF) was developed at the Virginia Center for Coal and Minerals Processing (VCCMP) for the selective recovery of fine particles. Bench-scale test work conducted at VCCMP, largely under the sponsorship of the U.S. Department of Energy (DOE), showed that the technology worked well for both coal and mineral applications. For the technology to be commercially successful, however, a full-scale demonstration of the MCF technology was deemed necessary. This report summarizes the results of work performed under the DOE project entitled ``In-plant Testing of Microbubble Column Flotation.`` The objectives of this research and development effort were to duplicate the bench-scale performance of the MCF process in a full-scale unit, to verify the scale-up procedure developed in an earlier project, and to demonstrate the applicability of the MCF technology to the coal industry.

  6. Initial testing of a dynamic column for fine coal flotation

    SciTech Connect

    Lai, R.W.; Patton, R.A.; He, D.X.; Joyce, T.; Chiang, S.H.

    1995-12-31

    This paper describes the design and initial performance of a dynamic column for fine coal column flotation. A dynamic column is a modified conventional column with the insertion of a series of draft tubes that provide individual mixing stages. The mixing is beneficial in generating small and uniform bubbles over a wide range of frother dosages. It is also beneficial in the control of flotation where the fluctuation of froth volume should be minimized. In the modified design, a vortex-inducing plate is attached to the top of each draft tube to create an artificial vortex. In theory the vortex action is desirable for collecting the light clean coal froth within the inner mixing zone, and for passing it upward to the next draft tube stage. The mineral laden slurry, particularly the pyrite, is accelerated outside the vortex zone by centrifugal force to reach the wall where it is carried downward to the bottom of the column. The draft tubes are arranged in a series to accomplish multistage cleaning. The experimental results showed that this dynamic column has the potential advantage of higher throughput and better product recovery as well as improved product quality.

  7. Improving the performance of conventional and column froth flotation cells

    SciTech Connect

    Arnold, B.J.

    1995-11-01

    Many existing mining operations hover on the brink of producing competitively priced fuel with marginally acceptable sulfur levels. To remain competitive, these operations need to improve the yield of their coal processing facilities, lower the sulfur content of their clean coal, or lower the ash content of their clean coal. Fine coal cleaning processes offer the best opportunity for coal producers to increase their yield of high quality product. Over 200 coal processing plants in the U.S. already employ some type of conventional or column flotation device to clean fines. an increase in efficiency in these existing circuits could be the margin required to make these coal producers competitive.

  8. Method for enhancing selectivity and recovery in the fractional flotation of particles in a flotation column

    DOEpatents

    Klunder, Edgar B.

    2011-08-09

    The method relates to particle separation from a feed stream. The feed stream is injected directly into the froth zone of a vertical flotation column in the presence of a counter-current reflux stream. A froth breaker generates a reflux stream and a concentrate stream, and the reflux stream is injected into the froth zone to mix with the interstitial liquid between bubbles in the froth zone. Counter-current flow between the plurality of bubbles and the interstitial liquid facilitates the attachment of higher hydrophobicity particles to bubble surfaces as lower hydrophobicity particles detach. The height of the feed stream injection and the reflux ratio may be varied in order to optimize the concentrate or tailing stream recoveries desired based on existing operating conditions.

  9. Hydrocarbon-oil encapsulated bubble flotation of fine coal using 3-in. ID flotation column. Technical progress report for the eleventh quarter, April 1--June 30, 1993

    SciTech Connect

    Peng, F.F.

    1996-05-01

    There are four modes of the collector dispersion techniques. They are (1) direct liquid additions and stirring, (2) ultrasonic energy collector dispersion, (3) atomized collector dispersion, and (4) gasified collector transported in air stream. Among those collector dispersion techniques, the technique using the gasified collector transported in air phase can be used to enhance the flotation performance with substantial reduction in collector usage and selectivity, compared to the flotation using direct liquid addition (and mechanical agitation) technique. In this phase of study, two modes of collector addition techniques including gasified collector transported in gas phase and direct collector addition techniques were applied in the column flotation to demonstrate the selectivity of utilizing the hydrocarbon-oil encapsulated air bubbles in the fine coal flotation process. The 1-in. ID flotation column was used to scale-up to 3-in. ID flotation column. The initial starting point to operate the 3-in ID flotation column were determined using both 1-in. and 3-in. flotation columns based on the three phases of work plans and experiment design. A 3-in. flotation column was used to evaluate two modes of collector dispersion and addition techniques on the recovery and grade of fine coals using various ranks of coal.

  10. Separation of algal cells from water by column flotation

    SciTech Connect

    Liu, J.C.; Chen, Y.M.; Ju, Y.H.

    1999-08-01

    The dispersed air flotation (DiAF) process was utilized to separate algal cells (Chlorella sp.) from water. Two types of collector, cationic N-cetyl-N,N,N-trimethylammonium bromide (CTAB) and anionic sodium dodecylsulfate (SDS), were used. It was observed that 20% of cell removal was achieved in the presence of 40 mg/L of SDS, and ca. 86% of the cells were removed at 40 mg/L of CTAB. Upon the addition of 10 mg/L of chitosan, over 90% of the cells were removed when SDS (20 mg/L) was used as the collector. Air flow rate affected cell flotation slightly. Optimum pH values for cell flotation were from 4.0 to 5.0. Flotation efficiency decreased at high ionic strength. The electrostatic interaction between collector and cell surface plays a critical role in the separation processes.

  11. Use of hydrocyclone and flotation column for reducing the volume of contaminated dredged material.

    PubMed

    Park, K H; Lee, J H; Bae, B H; Kim, Y H; Choung, Y K

    2006-01-01

    As sediment contamination problems have recently been raised in Korea, the need for technologies to clean contaminants in sediments has increased. Although the recalcitrant organic matters and heavy metals in the contaminated sediments are of primary concern, large amounts of sediment makes the removal of the contaminants in them more difficult. In this study, the performance of hydrocyclone and flotation column was tested to reduce the volume of contaminated dredged materials (CDMs) prior to treating recalcitrant matters, such as various organic chemicals and heavy metals, in an integrated treatment system. When hydrocyclone was operated with 10% (w/v) solids concentration of the feed slurry, the total solids of upflow products were 4 to 7% (w/v) when the inlet pressure was changed from 1.0 to 2.0 kg/cm2. The volume reduction ratio of CDMs by hydrocyclone was approximately 90% (v/v). When the upflow products in hydrocyclone was then spiked with automobile transmission oil and fed to the flotation colum to see the performance of the column flotation on the volume reduction and the TPH removal, 44% of the TPHs in feed were removed at the tails and the volume reduction ratio of CDMs by column flotation was 18% at 200 L/min of wash water. The flotation column could be proposed as a potential preliminary treatment process of CDMs prior to subsequent biological treatments.

  12. An experimental study on desulfurization of high-sulfur coal slime with free jet flotation column

    SciTech Connect

    Xie Hua; Huang Bo; Xia Qing

    1998-12-31

    A free jet flotation column gives good selectivity and high separation efficiency in treating fine and ultra-fine coal. This paper reports test results of coal desulfurization with a free jet flotation column. Test results showed that when the coal sample from Zhong Liang Shan was processed its pyritic sulfur content was reduced from 3.08% to 0.84%, with 72.22% recovery of combustible matter in clean coal. The concept of Desulfurization Efficiency Index E(ds) for a comprehensive evaluation of desulfurization process is proposed, which is defined as the product of the ratio of sulfur content reduction and the recovery of combustible matters in clean coal.

  13. Engineering development of advanced froth flotation. Volume 2, Final report

    SciTech Connect

    Ferris, D.D.; Bencho, J.R.; Torak, E.R.

    1995-03-01

    This report is an account of findings related to the Engineering and Development of Advanced Froth Flotation project. The results from benchscale and proof-of-concept (POC) level testing are presented and the important results from this testing are used to refine a conceptual design and cost estimate for a 20 TPH Semi-Works Facility incorporating the final proposed technology.

  14. Experimental and modeling evaluation of upward and downward velocities in the coaxial flotation column.

    PubMed

    Park, K; Cho, J M; Oh, J; Chung, K

    2001-01-01

    This study was conducted to show the influence of upward velocity in the inner column and downward velocity in the outer column of the coaxial cylinder-type flotation column on the solids removal efficiency, solids concentration in the treated water, and so on. The SIMPLE (Semi-Implicit Method for Pressure Linked Equation) solution was applied to the coaxial flotation column to simulate the velocity vectors of the elements of water flowing in the column. The effects of solids loading and residence time in the agglomerate separation zone on the solids removal efficiency were also tested. In the pilot scale coaxial DAF column experiments with solids concentration of 1,000-2,000 mg of SS per liter and solids loading less than 350 kg/m2/day, approximately 90% of the solids removal efficiencies were obtained using the upward velocity of up to 110 cm/min in the contact zone of the inner column and the downward velocity of up to 30 cm/min in the outer column. In the simulation, similar results were observed as in the experiments. The solids loading in the excess of 350 kg/m2/day caused the instability of the sludge float layer and aggravated the quality of the treated water. PMID:11394274

  15. Gas holdup in cyclone-static micro-bubble flotation column.

    PubMed

    Li, Xiaobing; Zhu, Wei; Liu, Jiongtian; Zhang, Jian; Xu, Hongxiang; Deng, Xiaowei

    2016-01-01

    The present work has been carried out to investigate the effect of process variables on gas holdup and develop an empirical equation and a neural network model for online process control of the gas holdup based on the operating variables. In this study, the effect of process variables (nozzle diameter, circulation pressure, aeration rate, and frother dosage) on gas holdup in a cyclone-static micro-bubble flotation column of an air/oily wastewater system was investigated. Gas holdup was estimated using a pressure difference method and an empirical equation was proposed to predict gas holdup. A general regression neural network (GRNN) model was also introduced to predict gas holdup for the cyclone-static micro-bubble flotation column. The predictions from the empirical equation and the GRNN are in good agreement with the experiment data for gas holdup, while the GRNN provides higher accuracy and stability compared with that of the empirical equation.

  16. Combined column and cell flotation process for the treatment of PAH contaminated hazardous wastes produced by an aluminium production plant.

    PubMed

    Dhenain, Aurélie; Mercier, Guy; Blais, Jean-François; Chartier, Myriam

    2009-06-15

    The aluminium electrolytic plants generate PAH and fluoride contaminated wastes which are usually classified as hazardous material. These residues are generally disposed in secure landfill sites. A flotation cell process was previously developed to remove PAH from these aluminium industry wastes. The tests were done on composite samples made of particle size fractions under 50mm. The efficiency of the flotation cell process was demonstrated but the high quantity of concentrate produced (14.0%) during the air injection period, because of the solid entrainment, raised the treatment cost. The aim of this study was to reduce the entrainment of fine particles in order to obtain an efficient and economic technology. The process initially developed was modified: the smallest particle size fraction (<0.5mm) of the composite sample was treated in a flotation column, whereas the other particle size fractions (0.5-50mm) were treated in a flotation cell. The separated treatment allowed to reduce the entrainment during the air injection period of the flotation cell step from 14.0% to 10.1%. The optimum total solids of the pulp and cocamidopropylhydroxysultaine (CAS) concentration were 3.33% and 0.50% (ww(-1)) for the flotation column, and 15% and 0.25% (ww(-1)) for the flotation cell. This combined flotation process minimized the total entrainment which allowed a 23.6% abatement of the concentrate quantity initially produced, and reduced the PAH concentrations of the wastes under the authorized limit of 1000 mg kg(-1).

  17. Coal surface control for advanced fine coal flotation

    SciTech Connect

    Fuerstenau, D.W.; Hanson, J.S.; Diao, J.; Harris, G.H.; De, A.; Sotillo, F. ); Somasundaran, P.; Harris, C.C.; Vasudevan, T.; Liu, D.; Li, C. ); Hu, W.; Zou, Y.; Chen, W. ); Choudhry, V.; Shea, S.; Ghosh, A.; Sehgal, R. )

    1992-03-01

    The initial goal of the research project was to develop methods of coal surface control in advanced froth flotation to achieve 90% pyritic sulfur rejection, while operating at Btu recoveries above 90% based on run-of-mine quality coal. Moreover, the technology is to concomitantly reduce the ash content significantly (to six percent or less) to provide a high-quality fuel to the boiler (ash removal also increases Btu content, which in turn decreases a coal's emission potential in terms of lbs SO{sub 2}/million Btu). (VC)

  18. Coal pond fines cleaning with classifying cyclones, spirals, and column flotation

    SciTech Connect

    Carson, W.R.; Arnold, B.J.; Raleigh, C.E. Jr.; Parekh, B.K.

    1997-07-01

    Large reserves of coal pond fines arc found in the Illinois Basin--over 40 million tons in Western Kentucky, over 65 million tons in Southern Illinois, and over 35 million tons in Southern Indiana. If these fines are used to produce coal-water slurry (CWS), fuel costs, NO{sub x} emissions, and pond closure costs can be reduced. Coal fines from this region that are used to produce CWS for co-fire or re-burn may require processing, however, to attain proper particle size distribution and fuel quality. To evaluate the effectiveness of using coal cleaning technologies to control these CWS quality parameters, a simple flowsheet for recovering and processing coal pond fines was designed and tested. Coal fines processing consisted of using classifying cyclones to size at nominal minus 200 mesh, cleaning the classifying cyclone underflow using spirals, and cleaning the overflow using column froth flotation. Ash content of the dean coal from the spiral was reduced to about 10 percent, winch is satisfactory to use for CWS co-firing in a cyclone-fired boiler. The clean coal from column flotation may be used for re-burn in a cydone-fired boiler or as co-fire fuel in a wall-fired or tangentially-fired boiler Heating value recovery during laboratory scale, pilot-scale, and commercial-scale coal cleaning testing was about 80 percent.

  19. Apparatus and process for the separation of hydrophobic and hydrophilic particles using microbubble column flotation together with a process and apparatus for generation of microbubbles

    DOEpatents

    Yoon, R.H.; Adel, G.T.; Luttrell, G.H.

    1998-09-29

    A method and apparatus are disclosed for the microbubble flotation separation of very fine and coarse particles, especially coal and minerals, so as to produce high purity and high recovery efficiency. This is accomplished through the use of a flotation column, microbubbles, recycling of the flotation pulp, and countercurrent wash water to gently wash the froth. Also disclosed are unique processes and apparatus for generating microbubbles for flotation in a highly efficient and inexpensive manner using either a porous tube or in-line static generators. 14 figs.

  20. Apparatus and process for the separation of hydrophobic and hydrophilic particles using microbubble column flotation together with a process and apparatus for generation of microbubbles

    DOEpatents

    Yoon, Roe-Hoan; Adel, Gregory T.; Luttrell, Gerald H.

    1992-01-01

    A method and apparatus are disclosed for the microbubble flotation separation of very fine and coarse particles, especially coal and minerals, so as to produce high purity and high recovery efficiency. This is accomplished through the use of a flotation column, microbubbles, recycling of the flotation pulp, and countercurrent wash water to gently wash the froth. Also disclosed are unique processes and apparatus for generating microbubbles for flotation in a highly efficient and inexpensive manner using either a porous tube or in-line static generators.

  1. Apparatus and process for the separation of hydrophobic and hydrophilic particles using microbubble column flotation together with a process and apparatus for generation of microbubbles

    DOEpatents

    Yoon, Roe-Hoan; Adel, Gregory T.; Luttrell, Gerald H.

    1998-01-01

    A method and apparatus are disclosed for the microbubble flotation separation of very fine and coarse particles, especially coal and minerals, so as to produce high purity and high recovery efficiency. This is accomplished through the use of a flotation column, microbubbles, recycling of the flotation pulp, and countercurrent wash water to gently wash the froth. Also disclosed are unique processes and apparatus for generating microbubbles for flotation in a highly efficient and inexpensive manner using either a porous tube or in-line static generators.

  2. Apparatus for the separation of hydrophobic and hydrophilic particles using microbubble column flotation together with a process and apparatus for generation of microbubbles

    DOEpatents

    Yoon, Roe-Hoan; Adel, Gregory T.; Luttrell, Gerald H.

    1995-01-01

    An apparatus is disclosed for the microbubble flotation separation of very fine and coarse particles, especially coal, and minerals so as to produce high purity and high recovery efficiency. This is accomplished through the use of a flotation column, microbubbles, recycling of the flotation pulp, and countercurrent wash water to gently wash the froth. Also disclosed are unique processes and apparatus for generating microbubbles for flotation in a highly efficient and inexpensive manner using either a porous tube or in-line static generators.

  3. Apparatus for the separation of hydrophobic and hydrophilic particles using microbubble column flotation together with a process and apparatus for generation of microbubbles

    DOEpatents

    Yoon, R.H.; Adel, G.T.; Luttrell, G.H.

    1995-03-14

    An apparatus is disclosed for the microbubble flotation separation of very fine and coarse particles, especially coal, and minerals so as to produce high purity and high recovery efficiency. This is accomplished through the use of a flotation column, microbubbles, recycling of the flotation pulp, and countercurrent wash water to gently wash the froth. Also disclosed are unique processes and apparatus for generating microbubbles for flotation in a highly efficient and inexpensive manner using either a porous tube or in-line static generators. 14 figs.

  4. Apparatus and process for the separation of hydrophobic and hydrophilic particles using microbubble column flotation together with a process and apparatus for generation of microbubbles

    DOEpatents

    Yoon, R.H.; Adel, G.T.; Luttrell, G.H.

    1992-12-01

    A method and apparatus are disclosed for the microbubble flotation separation of very fine and coarse particles, especially coal and minerals, so as to produce high purity and high recovery efficiency. This is accomplished through the use of a flotation column, microbubbles, recycling of the flotation pulp, and countercurrent wash water to gently wash the froth. Also disclosed are unique processes and apparatus for generating microbubbles for flotation in a highly efficient and inexpensive manner using either a porous tube or in-line static generators. 14 figs.

  5. An Advanced Control System For Fine Coal Flotation

    SciTech Connect

    G. H. Luttrell; G. T. Adel

    1998-08-25

    A model-based flotation control scheme is being implemented to achieve optimal performance in the handling and treatment of fine coal. The control scheme monitors flotation performance through on-line analysis of ash content. Then, based on the economic and metallurgical performance of the circuit, variables such as collector dosage, frother dosage, and pulp level are adjusted using model-based control algorithms to compensate for feed variations and other process disturbances. Recent developments in sensor technology are being applied for on-line determination of slurry ash content. During the ninth quarter of this project, Task 3 (Model Building and Computer Simulation) and Task 4 (Sensor Testing) were nearly completed, and Task 6 (Equipment Procurement and Installation) was initiated. Previously, data collected from the plant sampling campaign (Task 2) were used to construct a population balance model to describe the steady-state and dynamic behavior of the flotation circuit. The details of this model were presented in the Eighth Quarterly Technical Progress Report. During the past quarter, a flotation circuit simulator was designed and used to evaluate control strategies. As a result of this work, a model-based control strategy has been conceived which will allow manipulated variables to be adjusted in response to disturbances to achieve a target incremental ash value in the last cell of the bank. This will, in effect, maximize yield at an acceptable product quality. During this same period, a video-based ash analyzer was installed on the flotation tailings stream at the Moss No. 3 preparation plant. A preliminary calibration curve was established, and data are continuing to be collected in order to improve the calibration of the analyzer.

  6. Bench-scale testing of on-line control of column flotation using a novel analyzer

    SciTech Connect

    Not Available

    1992-01-22

    This document contains the first quarterly technical progress report for PTI's Bench-Scale Testing Project of a circuit integrating PTI's KEN-FLOTETM Column Flotation Technology and PTI's On-Line Quality Monitor Control System. The twelve-month project will involve installation of a 300 lb/hr. bench-scale testing circuit at PETC's Coal Preparation Process Research Facility (CPPRF) and testing of two bituminous coals (Upper Freeport and Pittsburgh No. 8 Seam Raw Coals). Figure 1 contains the project plan as well as the approach to completing the major tasks within the twelvemonth project. The project is broken down into three phases, which include: Phase I - Preparation: The preparation phase was performed principally at PTI's Calumet offices from October through December, 1992. It involved building of the equipment and circuitry, as well as some preliminary design and equipment testing. Phase II - ET Circuit Installation and Testing: This installation and testing phase of the project will be performed at PETC's CPPRF from January through May, 1993, and will be the major focus of the project. It will involve testing of the continuous 300 lb/hr. circuit. Phase II - Project Finalization: The project finalization phase will occur from June through September, 1993, at PTI's Calumet offices and will involve finalizing analytical work and data evaluation, as well as final project reporting. This quarterly progress report principally summarizes the results from the Phase I preparation work and the plan for the early portions of the Phase 11 installation and commissioning, which will occur in January and the first week of February, 1993.

  7. AN ADVANCED CONTROL SYSTEM FOR FINE COAL FLOTATION

    SciTech Connect

    G.H. Luttrell; G.T. Adel

    1999-01-11

    A model-based flotation control scheme is being implemented to achieve optimal performance in the handling and treatment of fine coal. The control scheme monitors flotation performance through on-line analysis of tailings ash content. Then, based on an on-line estimate of incremental ash, the pulp level is adjusted using a model-based control algorithm to compensate for feed variations and other process disturbances. Recent developments in sensor technology are being applied for on-line determination of slurry ash content. During the eleventh quarter of this project, Task 7 (Operation and Testing) was nearly completed through the efforts of J.A. Herbst and Associates, Virginia Tech, and Pittston Coal Company. As a result of this work, a model-based control system has now been installed which can predict incremental ash based on tailings ash content and general plant data, and adjust pulp level accordingly to maintain a target incremental ash. The system has gone through a shake-down period, training has been carried out for plant operators, and the bulk of the control logic testing has been completed with the results of these tests awaiting analysis under Task 8 (System Evaluation). The flotation model has been shown to predict incremental ash quite successfully, implying that this approach may provide the basis for a useful ''soft sensor'' for on-line incremental ash analysis.

  8. AN ADVANCED CONTROL SYSTEM FOR FINE COAL FLOTATION

    SciTech Connect

    1998-10-25

    A model-based flotation control scheme is being implemented to achieve optimal performance in the handling and treatment of fine coal. The control scheme monitors flotation performance through on-line analysis of tailings ash content. Then, based on an on-line estimate of incremental ash, the pulp level is adjusted using a model-based control algorithm to compensate for feed variations and other process disturbances. Recent developments in sensor technology are being applied for on-line determination of slurry ash content. During the tenth quarter of this project, Task 6 (Equipment Procurement and Installation) was completed through the efforts of J.A. Herbst and Associates, Virginia Tech, Pittston Coal Company, and FGR Automation. As a result of this work, a model-based control system is now in place which can predict incremental ash based on tailings ash content and general plant data, and adjust pulp level accordingly to maintain a target incremental ash. Testing of this control system is expected to be carried out during the next quarter, and the results of this testing will be reported in the Eleventh Quarterly report. In addition, calibration of the video-based ash analyzer was continued and an extensive set of calibration data were obtained showing that the plant is running remarkably well under manual control. This may be a result of increased attention being paid to froth flotation as a result of this project.

  9. Engineering development of advanced physical fine coal cleaning technologies: Froth flotation

    SciTech Connect

    Not Available

    1991-01-01

    The design criteria for each unit operation have been developed based upon a number of variables. These variables, at this time, are based upon the best engineering design information available to industry. A number of assumptions utilized in the design criteria are uncertain. The uncertainties of inert atmospheres for grinding and flotation as well as pyrite depressants were answered by the Surface Control Project. It was determined that inerting was not required and no new'' reagents were presented that improved the flotation results. In addition, Tasks 5 and 6 results indicated the required reagent dosage for conventional flotation and advanced flotation. Task 5 results also indicated the need for a clean coal,thickener, the flocculent dosages for both the clean coal and refuse thickeners, and final dewatering requirements. The results from Tasks 5 and 6 and summarized in Task 7 indicate several uncertainties that require continuous long duration testing. The first is the possibility of producing a grab product for both the Pittsburgh and Illinois No. 6 coals in conventional flotation. Second what does long-term recirculation of clarified water do to the product quality The verification process and real data obtained from Tasks 5 and 6 greatly reduced the capital and operating costs for the process. This was anticipated and the test work indeed provided confirming data.

  10. Engineering development of advanced physical fine coal cleaning technologies: Froth flotation. Quarterly technical progress report No. 19, April 1, 1993--June 30, 1993

    SciTech Connect

    Not Available

    1993-11-01

    The first system to test in the advanced DOE POC was the grinding circuit. The grinding circuit consists of the mill classifying cyclones in reverse closed circuit with the ball mill. Reverse closed circuit means the incoming feed and ball mill product are sized in the mill classifying cyclones ahead of the ball mill. This permits removal of natural-sized material and ground-sized material before recirculation through the ball mill. Numerous tests were conducted to establish the correct combination of orifice sizes, pressures and grinding media to meet the design criteria of 95% passing 200 mesh in the column flotation feed. The results from this test work are shown on Table 13.1, Grinding Circuit Test Results and graphically on Figure 13.2 and 13.3. These graphs show the relationship to Column Feed Rate Versus Size of Column Feed and Column Feed Rate Versus Column Feed Mean Particle Size. Our examination of the data indicates that the ball mill must have the smaller grinding media, and the mill classifying cyclone must be arranged as shown in test 93041901. The next step in the test plan was the 16-test resolution IV fractional factorial experiment of a 2{sup 6-2} experiment to determine major interaction of operating parameters. The column flotation independent variables are shown on Table 13.2, and the proposed test matrix is shown on Table 13.3.

  11. Engineering development of advanced physical fine coal cleaning technologies: Froth flotation

    SciTech Connect

    Not Available

    1992-01-01

    In order to develop additional confidence in the conceptual design of the advanced froth flotation circuit, a 2-3 TPH Proof-of-Concept (POC) facility was necessary. During operation of this facility, the ICF KE team will demonstrate the ability of the conceptual flowsheets to meet the program goals of maximum pyritic sulfur reduction coupled with maximum energy recovery on three DOE specified coals. The POC circuit was designed to be integrated into the Ohio Coal Development's facility near Beverly, Ohio. OCDO's facility will provide the precleaning unit operations and ICF KE will add the advanced froth flotation circuitry. The work in this task will include the POC conceptual design, flowsheet development, equipment list, fabrication and construction drawings, procurement specifications and bid packages and a facilities.

  12. Enhanced phosphorus removal in the DAF process by flotation scum recycling for advanced treatment of municipal wastewater.

    PubMed

    Kwak, Dong-Heui; Lee, Ki-Cheol

    2015-01-01

    To remove phosphorus (P) from municipal wastewater, various types of advanced treatment processes are being actively applied. However, there is commonly a space limit in municipal wastewater treatment plants (MWTPs). For that reason, the dissolved air flotation (DAF), which is well known for small space and flexible application process, is preferred as an additive process to enhance the removal of P. A series of experiments were conducted to investigate the feasibility of flotation scum recycling for effective P removal from a MWTP using a DAF pilot plant over 1 year. The average increases in the removal efficiencies due to flotation scum recycling were 22.6% for total phosphorus (T-P) and 18.3% for PO4-P. A higher removal efficiency of T-P was induced by recycling the flotation scum because a significant amount of Al components remained in the flotation scum. The increase in T-P removal efficiency, due to the recycling of flotation scum, shifted from the boundary of the stoichiometric precipitate to the equilibrium control region. Flotation scum recycling may contribute to improving the quality of treated water and reducing treatment costs by minimizing the coagulant dosage required.

  13. Coal surface control for advanced fine coal flotation. Final report, October 1, 1988--March 31, 1992

    SciTech Connect

    Fuerstenau, D.W.; Hanson, J.S.; Diao, J.; Harris, G.H.; De, A.; Sotillo, F.; Somasundaran, P.; Harris, C.C.; Vasudevan, T.; Liu, D.; Li, C.; Hu, W.; Zou, Y.; Chen, W.; Choudhry, V.; Shea, S.; Ghosh, A.; Sehgal, R.

    1992-03-01

    The initial goal of the research project was to develop methods of coal surface control in advanced froth flotation to achieve 90% pyritic sulfur rejection, while operating at Btu recoveries above 90% based on run-of-mine quality coal. Moreover, the technology is to concomitantly reduce the ash content significantly (to six percent or less) to provide a high-quality fuel to the boiler (ash removal also increases Btu content, which in turn decreases a coal`s emission potential in terms of lbs SO{sub 2}/million Btu). (VC)

  14. Engineering development of advanced physical fine coal cleaning technologies: Froth flotation

    SciTech Connect

    Not Available

    1990-01-01

    An engineering development project was prepared to build upon the basic research effort conducted under a solicitation for research into Fine Coal Surface Control. The engineering development project is intended to use general plant design knowledge and conceptualize a plant to utilize advanced froth flotation technology to process coal and produce a product having maximum practical pyritic sulfur reduction consistent with maximum practical BTU recovery. This is being accomplished by utilization the basic research data on the surface properties of coal, mineral matter and pyrite obtained from the Coal Surface Control for Advanced Fine Coal Flotation Project, to develop this conceptual flowsheet. The conceptual flowsheet must be examined to identify critical areas that need additional design data. This data will then be developed using batch and semi-continuous bench scale testing. In addition to actual bench scale testing other unit operations from other industries processing fine material will be reviewed for potential application and incorporated into the design if appropriate. 31 figs., 22 tabs.

  15. Engineering development of advanced physical fine coal cleaning technologies: Froth flotation

    SciTech Connect

    Not Available

    1992-01-01

    A study conducted by Pittsburgh Energy Technology Center of sulfur emissions from about 1,300 United States coal-fired utility boilers indicated that half of the emissions were the result of burning coals having greater than 1.2 pounds of SO[sub 2] per million BTU. This was mainly attributed to the high pyritic sulfur content of the boiler fuel. A significant reduction in SO[sub 2] emissions could be accomplished by removing the pyrite from the coals by advanced physical fine coal cleaning. An engineering development project was prepared to build upon the basic research effort conducted under a solicitation for research into Fine Coal Surface Control. The engineering development project is intended to use general plant design knowledge and conceptualize a plant to utilize advanced froth flotation technology to process coal and produce a product having maximum practical pyritic sulfur reduction consistent with maximum practical BTU recovery.

  16. Engineering development of advanced physical fine coal cleaning technologies - froth flotation

    SciTech Connect

    Ferris, D.D.; Bencho, J.R.

    1995-11-01

    In 1988, ICF Kaiser Engineers was awarded DOE Contract No. DE-AC22-88PC88881 to research, develop, engineer and design a commercially acceptable advanced froth flotation coal cleaning technology. The DOE initiative is in support of the continued utilization of our most abundant energy resource. Besides the goal of commercialability, coal cleaning performance and product quality goals were established by the DOE for this and similar projects. primary among these were the goals of 85 percent energy recovery and 85 percent pyrite rejection. Three nationally important coal resources were used for this project: the Pittsburgh No. 8 coal, the Upper Freeport coal, and the Illinois No. 6 coal. Following is a summary of the key findings of this project.

  17. Engineering development of advanced physical fine coal cleaning technologies: Froth flotation

    SciTech Connect

    Not Available

    1993-02-12

    The Department of Energy (DOE) awarded a contract entitled Engineering Development of Advanced Physical Fine Coal Cleaning Technology - Froth Flotation'', to ICF Kaiser Engineers with the following team members, Ohio Coal Development Office, Babcock and Wilcox, Consolidation Coal Company, Eimco Process Equipment Company, Illinois State Geological Survey, Virginia Polytechnic Institute and State University, Process Technology, Inc. This document a quarterly report prepared in accordance with the project reporting requirements covering the period from July 1, 1992 to September 30, 1992. This report provides a summary of the technical work undertaken during this period, highlighting the major results. A brief description of the work done prior to this quarter is provided in this report under the task headings.

  18. Engineering development of advanced physical fine coal cleaning technologies: Froth flotation

    SciTech Connect

    Not Available

    1990-01-01

    a study conducted by Pittsburgh Energy Technology Center of sulfur emissions from about 1300 United States coal-fired utility boilers indicated that half of the emissions were the result of burning coals having greater than 1.2 pounds of SO{sub 2} per million BTU. This was mainly attributed to the high pyritic sulfur content of the boiler fuel. A significant reduction in SO{sub 2} emissions could be accomplished by removing the pyrite from the coals by advanced physical fine coal cleaning. An engineering development project was prepared to build upon the basic research effort conducted under a solicitation for research into Fine Coal Surface Control. The engineering development project is intended to use general plant design knowledge and conceptualize a plant to utilize advanced froth flotation technology to process coal and produce a product having maximum practical pyritic sulfur reduction consistent with maximum practical BTU recovery. This document is the eighth quarterly report prepared in accordance with the project reporting requirements covering the period from July 1,1990 to September 30, 1990. The overall project scope of the engineering development project is to conceptually develop a commercial flowsheet to maximize pyritic sulfur reduction at practical energy recovery values. The data from the basic research on coal surfaces, bench scale testing and proof-of-concept scale testing will be utilized to design a final conceptual flowsheet. The economics of the flowsheet will be determined to enable industry to assess the feasibility of incorporating the advanced fine coal cleaning technology into the production of clean coal for generating electricity. 22 figs., 11 tabs.

  19. Engineering development of advanced physical fine coal cleaning technologies: Froth flotation

    SciTech Connect

    Not Available

    1991-01-01

    This document a quarterly report prepared in accordance with the project reporting requirements covering the period from July 1, 1992 to September 30, 1992. This report provides a summary of the technical work undertaken during this period, highlighting the major results. A brief description of the work done prior to this quarter is provided in this report under the task headings. The overall project scope of the engineering development project is to conceptually develop a commercial flowsheet to maximize pyritic sulfur reduction at practical energy recovery values. This is being accomplished by utilizing the basic research data on the surface properties of coal, mineral matter and pyrite obtained from the Coal Surface Control for Advanced Fine Coal Flotation Project, to develop this conceptual flowsheet. The conceptual flowsheet must be examined to identify critical areas that need additional design data. This data will then be developed using batch and semi-continuous bench scale testing. In addition to actual bench scale testing, other unit operations from other industries processing fine material will be reviewed for potential application and incorporated into the design if appropriate. The conceptual flowsheet will be revised based on the results of the bench scale testing and areas will be identified that need further larger scale design data verification, to prove out the design.

  20. Bench-scale testing of on-line control of column flotation using a novel analyzer. Revised final report, [October 1992--October 1993]: Volume 1

    SciTech Connect

    Not Available

    1993-10-27

    The main advantage of the project is that it allowed PTI to gain knowledge and experience about the proper approach, methods and hardware required to properly optimize and control column flotation performance. Many operational problems were incurred during the project, some of that PTI was able to solve during the project and other that must be overcome as the technology is further developed and commercialized. The key operating problems experienced with the KEN-FLOTE{sup TM} Column that must be further researched and overcome include: (1)The low concentrate solids content which limited the throughput capacity of the column, due to high froth washing requirements. The low concentrate solids content also lead to difficulty obtaining accurate On-Line Monitor measurements, due to the poor measurement sensitivity obtained with low solids content samples (particularly less than 5.0 wt %). (2) The higher-than-anticipated reagent dosages that undoubtedly contributed to the low solids content listed above, and also caused foaming problems within PTI`s On-Line Monitor. A defoaming reagent addition (Nalco 7810) was required to provide consistent sample size and reproducible On-Line Monitor counts for the concentrate samples collected within the circuit. PTI and UK`s CAER staff will continue to research alternative column design, particularly alternative air bubble generation and air distribution systems, to try to maximize column concentrate solids content while reducing reagent dosage requirements. In addition to the KEN-FLOTE{sup TM} Column operation there were also a number of hardware problems with PTI`s On-Line Quality Monitor that must be remedied for future commercial installations.

  1. Bench-scale testing of on-line control of column flotation using a novel analyzer. Second quarterly technical progress report, January 1, 1993--March 31, 1993

    SciTech Connect

    Not Available

    1993-04-16

    This document contains the second quarterly technical progress report for PTI`s Bench-Scale Testing Project of a circuit integrating PTI`s KEN-FLOTE{trademark} Column Flotation Technology and PTI`s On-Line Quality Monitor and Control System. The twelve-month project involves installation and testing of a 200--300 lb/hr. bench-scale testing circuit at PETC`s Coal Preparation Process Research Facility (CPPRF) for two bituminous coals (Upper Freeport and Pittsburgh No. 8 Seam Raw Coals). The project schedule timeline by task series for the twelve month project, as it was laid out in the initial Project Work Plan. At the present time, all tasks are progressing according to schedule with the exception of the Task 800 Circuit Testing and Sample Prep and Task 1000 Circuit Decommissioning, which have slipped approximately five weeks due to delays incurred within in the project.

  2. An Advanced Control System for Fine Coal Flotation. Sixth quarter, technical progress report, July 1-September 30, 1997

    SciTech Connect

    Adel, G.T.; Luttrell, G.H.

    1997-10-27

    Over the past thirty years, process control has spread from the chemical industry into the fields of mineral and coal processing. Today, process control computers, combined with improved instrumentation, are capable of effective control in many modem flotation circuits. Unfortunately, the classical methods used in most control strategies have severe limitations when used in froth flotation. For example, the nonlinear nature of the flotation process can cause single-input, single-output lines to battle each other in attempts to achieve a given objective. Other problems experienced in classical control schemes include noisy signals from sensors and the inability to measure certain process variables. For example, factors related to ore type or water chemistry, such as liberation, froth stability, and floatability, cannot be measured by conventional means. The purpose of this project is to demonstrate an advanced control system for fine coal flotation. The demonstration is being carried out at an existing coal preparation plant by a team consisting of Virginia Polytechnic Institute and State University (VPI&SU) as the prime contractor and J.A. Herbst and Associates as a subcontractor. The objectives of this work are: (1) to identify through sampling, analysis, and simulation those variables which can be manipulated to maintain grades, recoveries, and throughput rates at levels set by management; (2) to develop and implement a model-based computer control strategy that continuously adjusts those variables to maximize revenue subject to various metallurgical, economic, and environmental constraints; and (3) to employ a video-based optical analyzer for on-line analysis of ash content in fine coal slurries.

  3. Bench-scale testing of on-line control of column flotation using a novel analyzer. Third quarterly technical progress report, April 1, 1993--June 30, 1993

    SciTech Connect

    Not Available

    1993-08-24

    This document contains the third quarterly technical progress report for PTI`s Bench-Scale Testing Project of a circuit integrating PTI`s KEN-FLOTETM Column Flotation Technology and PTI`s On-Line Quality Monitor and Control System. The twelve-month project involves installation and testing of a 200--300 lb/hr. bench-scale flotation circuit at PETC`s Coal Preparation Process Research Facility (CPPRF) for two bituminous coals (Upper Freeport and Pittsburgh No. 8 Seam Raw Coals). Figure 1 contains the project plan, as well as the approach to completing the major tasks within the twelve-month project schedule. The project is broken down into three phases, which include: Phase I -- Preparation: The preparation phase was performed principally at PTI`s Calumet offices from October through December, 1992. It involved building of the equipment and circuitry, as well as some preliminary design and equipment testing; Phase II -- ET Circuit Installation and Testing: This installation and testing phase of the project was performed at PETC`s CPPRF from January through June, 1993, and was the major focus of the project. It involved testing of the continuous 200--300 lb/hr. circuit; and Phase III -- Project Finalization: The project finalization phase is occurring from July through September, 1993, at PTI`s Calumet offices and involves finalizing analytical work and data evaluation, as well as final project reporting. This Third Quarterly Technical Progress Report principally summarizes the results from the benchscale testing with the second coal (Pittsburgh No. 8 Seam Coal), which occurred in April through June, 1993. It also contains preliminary economic evaluations that will go into the Final Report, as well as the plan for the final reporting task.

  4. Engineering development of advanced physical fine coal cleaning technologies: Froth flotation. Quarterly technical progress report No. 12, July 1, 1991--September 30, 1991

    SciTech Connect

    Not Available

    1991-12-31

    The design criteria for each unit operation have been developed based upon a number of variables. These variables, at this time, are based upon the best engineering design information available to industry. A number of assumptions utilized in the design criteria are uncertain. The uncertainties of inert atmospheres for grinding and flotation as well as pyrite depressants were answered by the Surface Control Project. It was determined that inerting was not required and no ``new`` reagents were presented that improved the flotation results. In addition, Tasks 5 and 6 results indicated the required reagent dosage for conventional flotation and advanced flotation. Task 5 results also indicated the need for a clean coal,thickener, the flocculent dosages for both the clean coal and refuse thickeners, and final dewatering requirements. The results from Tasks 5 and 6 and summarized in Task 7 indicate several uncertainties that require continuous long duration testing. The first is the possibility of producing a grab product for both the Pittsburgh and Illinois No. 6 coals in conventional flotation. Second what does long-term recirculation of clarified water do to the product quality? The verification process and real data obtained from Tasks 5 and 6 greatly reduced the capital and operating costs for the process. This was anticipated and the test work indeed provided confirming data.

  5. Bench-scale testing of on-line control of column flotation using a novel analyzer. Quarterly technical progress report, September 21, 1992--December 31, 1992

    SciTech Connect

    Not Available

    1992-01-22

    This document contains the first quarterly technical progress report for PTI`s Bench-Scale Testing Project of a circuit integrating PTI`s KEN-FLOTETM Column Flotation Technology and PTI`s On-Line Quality Monitor Control System. The twelve-month project will involve installation of a 300 lb/hr. bench-scale testing circuit at PETC`s Coal Preparation Process Research Facility (CPPRF) and testing of two bituminous coals (Upper Freeport and Pittsburgh No. 8 Seam Raw Coals). Figure 1 contains the project plan as well as the approach to completing the major tasks within the twelvemonth project. The project is broken down into three phases, which include: Phase I - Preparation: The preparation phase was performed principally at PTI`s Calumet offices from October through December, 1992. It involved building of the equipment and circuitry, as well as some preliminary design and equipment testing. Phase II - ET Circuit Installation and Testing: This installation and testing phase of the project will be performed at PETC`s CPPRF from January through May, 1993, and will be the major focus of the project. It will involve testing of the continuous 300 lb/hr. circuit. Phase II - Project Finalization: The project finalization phase will occur from June through September, 1993, at PTI`s Calumet offices and will involve finalizing analytical work and data evaluation, as well as final project reporting. This quarterly progress report principally summarizes the results from the Phase I preparation work and the plan for the early portions of the Phase 11 installation and commissioning, which will occur in January and the first week of February, 1993.

  6. Engineering development of advanced physical fine coal cleaning technologies: Froth flotation. Quarterly technical progress report No. 14, January 1, 1992--March 31, 1992

    SciTech Connect

    Not Available

    1992-12-31

    In order to develop additional confidence in the conceptual design of the advanced froth flotation circuit, a 2-3 TPH Proof-of-Concept (POC) facility was necessary. During operation of this facility, the ICF KE team will demonstrate the ability of the conceptual flowsheets to meet the program goals of maximum pyritic sulfur reduction coupled with maximum energy recovery on three DOE specified coals. The POC circuit was designed to be integrated into the Ohio Coal Development`s facility near Beverly, Ohio. OCDO`s facility will provide the precleaning unit operations and ICF KE will add the advanced froth flotation circuitry. The work in this task will include the POC conceptual design, flowsheet development, equipment list, fabrication and construction drawings, procurement specifications and bid packages and a facilities.

  7. Controlled comparison of advanced froth flotation process technology and economic evaluations for maximizing BTU recovery and pyritic sulfur rejection

    SciTech Connect

    Harrison, K.E.; Ferris, D.D. ); Kosky, R.M. ); Warchol, J.J.; Musiol, W.F.; Shiao, S.Y. ); Luttrell, G.H.; Adel, G.T.; Yoon, R.H. )

    1990-01-01

    The overall objective of this round robin project was to select the most efficient, as determined by the efficiency index, cost effective, as determined by the annual cost per ton of SO{sub 2} removed, advanced flotation device available. This machine was to process ultra fine coal, maximize Btu recovery and maximize pyritic sulfur rejection. The device will first be installed as a one hundred pound per hour capacity unit and, subject to the outcome of Task 6 of the Engineering Development Contract, increased to a 3 ton per hour capacity unit for installation into a proof-of-concept preparation plant. All of the technical and economic results were submitted to the TST for consideration. The TST members evaluated the data and determined to rank each of the participants 50% on technical merit and 50% on economic merit. The technical merit was to be the efficiency index. The economical merit was to be the annual dollars per ton of clean coal corrected for carrying capacity and frother concentration and the results of Test No. 4. This factor does not penalize a particular technology for not meeting a 90% pyritic sulfur rejection and therefore leaves something to be desired as the only economic basis for decision. A second economic evaluation criteria was required that considered the $/ton of sulfur dioxide removed. The technical and economic factors were calculated and added together for the final evaluation ranking. The technical factor was calculated by multiplying the efficiency index for each participant by 0.5. The two economic factors were calculated by dividing 1000 by the $/ton of clean coal and multiplying by 0.5 and by dividing 10,000 by the $/ton of sulfur dioxide removed and multiply by 0.5. The 1000 and 10,000 are numbers selected such that when divided by their economic factors, respective numbers resulted in a two digit number. The results of these calculations are discussed. 4 refs., 18 figs., 27 tabs.

  8. Comparative study of flotation techniques for the treatment of liquid effluents.

    PubMed

    Puget, F P; Melo, M V; Massarani, G

    2004-01-01

    This work aimed to study the performance of three different induced air flotation units (flotation column, flotation tank and centrifugal flotation in hydrocyclone) for the treatment of a synthetic dairy effluent. Under continuous operation, it was possible to achieve removal efficiencies of milky material in suspension up to 90%, both for the flotation column and the flotation tank units. Using the centrifugal flotation unit in hydrocyclone, it was possible to decrease up to 45% of all suspended material in the effluent, with a clarified flow rate approximately three times greater than those found for the previous flotation units. In the centrifugal flotation unit, better results were obtained for air flow rate-feed flow rate ratios (Q(air)/Q(L)) greater than 0.15, and for underflow-overflow ratios (Qu/Qo) lower than 1.0.

  9. Engineering development of advanced physical fine coal cleaning technologies: Froth flotation. Quarterly technical progress report No. 26, January 1, 1995--March 31, 1995

    SciTech Connect

    1995-07-01

    A study conducted by Pittsburgh Energy Technology Center of sulfur emissions from about 1,300 United States coal-fired utility boilers indicated that half of the emissions were the result of burning coals having greater than 1.2 pounds of SO{sub 2} per million BTU. This was mainly attributed to the high pyritic sulfur content of the boiler fuel. A significant reduction in SO{sub 2} emissions could be accomplished by removing the pyrite from the coals by advanced physical fine coal cleaning. An engineering development project was prepared to build upon the basic research effort conducted under a solicitation for research into Fine Coal Surface Control. The engineering development project is intended to use general plant design knowledge and conceptualize a plant to utilize advanced froth flotation technology to process coal and produce a product having maximum practical pyritic sulfur reduction consistent with maximum practical BTU recovery. The overall project scope of the engineering development project is to conceptually develop a commercial flowsheet to maximize pyritic sulfur reduction at practical energy recovery values. This is being accomplished by utilizing the basic research data on the surface properties of coal, mineral matter and pyrite obtained from the Coal Surface Control for Advanced Fine Coal Flotation Project, to develop this conceptual flowsheet. This progress report provides a summary of the technical work undertaken during this period, highlighting the major results. A brief description of the work done prior to this quarter is provided in this report under the task headings.

  10. Engineering development of advanced physical fine coal cleaning technologies - froth flotation. Quarterly technical progress report No. 23, April 1, 1994--June 30, 1994

    SciTech Connect

    1995-04-01

    A study conducted by Pittsburgh Energy Technology Center of sulfur emissions from about 1,300 United States coal-fired utility boilers indicated that half of the emissions were the result of burning coals having greater than 1.2 pounds of SO{sub 2} per million BTU. This was mainly attributed to the high pyritic sulfur content of the boiler fuel. A significant reduction in SO{sub 2} emissions could be accomplished by removing the pyrite from the coals by advanced physical fine coal cleaning. An engineering development project was prepared to build upon the basic research effort conducted under a solicitation for research into Fine Coal Surface Control. The engineering development project is intended to use general plant design knowledge and conceptualize a plant to utilize advanced froth flotation technology to process coal and produce a product having maximum practical pyritic sulfur reduction consistent with maximum practical BTU recovery.

  11. Engineering development of advanced physical fine coal cleaning technologies: Froth flotation. Quarterly technical progress report No. 16, July 1, 1992--September 30, 1992

    SciTech Connect

    Not Available

    1992-12-31

    A study conducted by Pittsburgh Energy Technology Center of sulfur emissions from about 1,300 United States coal-fired utility boilers indicated that half of the emissions were the result of burning coals having greater than 1.2 pounds of SO{sub 2} per million BTU. This was mainly attributed to the high pyritic sulfur content of the boiler fuel. A significant reduction in SO{sub 2} emissions could be accomplished by removing the pyrite from the coals by advanced physical fine coal cleaning. An engineering development project was prepared to build upon the basic research effort conducted under a solicitation for research into Fine Coal Surface Control. The engineering development project is intended to use general plant design knowledge and conceptualize a plant to utilize advanced froth flotation technology to process coal and produce a product having maximum practical pyritic sulfur reduction consistent with maximum practical BTU recovery.

  12. Engineering development of advanced physical fine coal cleaning technologies: Froth flotation. Quarterly technical progress report No. 15, April 1, 1992--June 30, 1992

    SciTech Connect

    Not Available

    1993-02-12

    The Department of Energy (DOE) awarded a contract entitled ``Engineering Development of Advanced Physical Fine Coal Cleaning Technology - Froth Flotation``, to ICF Kaiser Engineers with the following team members, Ohio Coal Development Office, Babcock and Wilcox, Consolidation Coal Company, Eimco Process Equipment Company, Illinois State Geological Survey, Virginia Polytechnic Institute and State University, Process Technology, Inc. This document a quarterly report prepared in accordance with the project reporting requirements covering the period from July 1, 1992 to September 30, 1992. This report provides a summary of the technical work undertaken during this period, highlighting the major results. A brief description of the work done prior to this quarter is provided in this report under the task headings.

  13. Engineering development of advanced physical fine coal cleaning technologies: Froth flotation. Quarterly technical progress report No. 25, October 1, 1994--December 31, 1994

    SciTech Connect

    1994-12-31

    A study conducted by Pittsburgh Energy Technology Center of sulfur emissions from about 1300 United States coal-fired utility boilers indicated that half of the emissions were the result of burning coals having greater than 1.2 pounds of SO{sub 2} per million BTU. This was mainly attributed to the high pyritic sulfur content of the boiler fuel. A significant reduction in SO{sub 2} emissions could be accomplished by removing the pyrite from the coals by advanced physical fine coal cleaning. An engineering development project was prepared to build upon the basic research effort conducted under a solicitation for research into Fine Coal Surface Control. The engineering development project is intended to use general plant design knowledge and conceptualize a plant to utilize advanced froth flotation technology to process coal and produce a product having maximum practical pyritic sulfur reduction consistent with maximum practical BTU recovery. This progress report provides a summary of the technical work undertaken during this period, highlighting the major results. A brief description of the work done prior to this quarter is provided in this report under the task headings.

  14. Engineering Development of Advanced Physical Fine Coal Cleaning Technologies: Froth flotation. Quarterly technical progress report No. 21, October 1, 1993--December 31, 1993

    SciTech Connect

    Not Available

    1993-12-31

    A study conducted by Pittsburgh Energy Technology Center of sulfur emissions from about 1,300 United States coal-fired utility boilers indicated that half of the emissions were the result of burning coals having greater than 1.2 pounds of SO{sub 2} per million BTU. This was mainly attributed to the high pyritic sulfur content of the boiler fuel. A significant reduction in SO{sub 2} emissions could be accomplished by removing the pyrite from the coals by advanced physical fine coal cleaning. The overall project scope of the engineering development project is to conceptually develop a commercial flowsheet to maximize pyritic sulfur reduction at practical energy recovery values. This is being accomplished by utilizing the basic research data on the surface properties of coal, mineral matter and pyrite obtained from the Coal Surface Control for Advanced Fine Coal Flotation Project, to develop this conceptual flowsheet. The conceptual flowsheet must be examined to identify critical areas that need additional design data. This data will then be developed using batch and semi-continuous bench scale testing. In addition to actual bench scale testing, other unit operations from other industries processing fine material will be reviewed for potential application and incorporated into the design if appropriate.

  15. Engineering development of advanced physical fine coal cleaning technologies: Froth flotation. Quarterly technical progress report No. 18, January 1, 1993--March 31, 1993

    SciTech Connect

    Not Available

    1993-07-01

    This task is the actual demonstration of the advanced froth flotation technology. All previous work has led to this task. ICF KE technicians and process engineers from the team will operate the plant over a 10 month period to demonstrate the capability of the technology to remove 85% of the pyritic sulfur from three different test coals while recovering at least 85% of the as-mined coal`s energy content. Six major subtasks have been included to better define the overall work scope for this task. The ICF KE team will test the Pittsburgh No. 8 seam, the Illinois No. 6 seam and the Upper Freeport seam; the team will operate the circuit in a continuous run; the team will analyze all samples generated in those runs and will develop a plan to store and dispose of the coal and refuse products. All laboratory data generated will be accessible to all team members and the DOE. The test program for the Pittsburgh No. 8 coal began during March 1, 1993. An arrangement has been made between ICF Kaiser Engineers (ICF KE) and American Electric Power (AEP), who is the host for the DOE POC facility. The arrangement calls for AEP to purchase the raw coal and use the clean coal generated by the DOE POC facility. This arrangement permits the processing of raw coal at a very minimal cost of purchasing the raw coal.

  16. Engineering development of advanced physical fine coal cleaning technologies: Froth flotation. Quarterly technical progress report No. 11, April 1, 1991--June 30, 1991

    SciTech Connect

    Not Available

    1991-12-31

    This document a quarterly report prepared in accordance with the project reporting requirements covering the period from July 1, 1992 to September 30, 1992. This report provides a summary of the technical work undertaken during this period, highlighting the major results. A brief description of the work done prior to this quarter is provided in this report under the task headings. The overall project scope of the engineering development project is to conceptually develop a commercial flowsheet to maximize pyritic sulfur reduction at practical energy recovery values. This is being accomplished by utilizing the basic research data on the surface properties of coal, mineral matter and pyrite obtained from the Coal Surface Control for Advanced Fine Coal Flotation Project, to develop this conceptual flowsheet. The conceptual flowsheet must be examined to identify critical areas that need additional design data. This data will then be developed using batch and semi-continuous bench scale testing. In addition to actual bench scale testing, other unit operations from other industries processing fine material will be reviewed for potential application and incorporated into the design if appropriate. The conceptual flowsheet will be revised based on the results of the bench scale testing and areas will be identified that need further larger scale design data verification, to prove out the design.

  17. Oil removal from produced water by conjugation of flotation and photo-Fenton processes.

    PubMed

    da Silva, Syllos Santos; Chiavone-Filho, Osvaldo; de Barros Neto, Eduardo Lins; Foletto, Edson Luiz

    2015-01-01

    The present work investigates the conjugation of flotation and photo-Fenton techniques on oil removal performance from oilfield produced water. The experiments were conducted in a column flotation and annular lamp reactor for induced air flotation and photodegradation steps, respectively. A nonionic surfactant was used as a flotation agent. The flotation experimental data were analyzed in terms of a first-order kinetic rate model. Two experimental designs were employed to evaluate the oil removal efficiency: fractional experimental design and central composite rotational design (CCRD). Overall oil removal of 99% was reached in the optimum experimental condition after 10 min of flotation followed by 45 min of photo-Fenton. The results of the conjugation of induced air flotation and photo-Fenton processes allowed meeting the wastewater limits established by the legislations for disposal. PMID:25239685

  18. Flotation techniques for oily water treatment.

    PubMed

    Melo, M V; Sant'anna, G L; Massarani, G

    2003-07-01

    The aim of this work is to develop alternative techniques for the treatment of waters heavily contaminated by oil. Furthermore, the treatment system should achieve high removal efficiencies even under unfavorable conditions, when oil is finely dispersed in the water phase and oil droplet sizes range from 5-30 mm and concentrations are between 100 and 300 mg l(-1). The first experiments were carried out in an induced air flotation system where a flotation column performance was evaluated in batch and continuous operation. The second system investigated in this work focused on the association of centrifugal separation in a hydrocyclone and the flotation operation. The considered system is characterized by the association of these two processes, resulting the set-up in a compact unit (centrifugal flotation system). The bubbles generation and the droplet-bubble contact are performed through a gas-liquid ejector, while the separation of the phase rich in oil (froth phase) is promoted by a hydrocyclone. In both systems, it was possible to reduce the chemical demand of oxygen by more than 85% and the oil concentration of an emulsion containing droplets with sizes between 10 and 20 mm, using Polyacrilamide as destabilizing agent.

  19. SURFACTANT SPRAY: A NOVEL TECHNOLOGY TO IMPROVE FLOTATION DEINKING PERFORMANCE

    SciTech Connect

    Yulin Deng; Junyong Zhu

    2004-01-31

    Based on the fundamental understanding of ink removal and fiber loss mechanism in flotation deinking process, we developed this innovative technology using surfactant spray to improve the ink removal efficiency, reduce the water and fiber loss, reduce the chemical consumption and carry over in the flotation deinking. The innovative flotation deinking process uses a spray to deliver the frothing agent during flotation deinking to control several key process variables. The spray can control the foam stability and structure and modify the fluid dynamics to reduce the fibers entrapped in the froth layer. The froth formed at the top part of the flotation column will act as a physical filter to prevent the penetration of frothing agent into the pulp suspension to eliminate fiber contamination and unfavorable deinking surface chemistry modification due to surfactant adsorption on the fiber surface. Because of the filter effect, frothing agents will be better utilized. Under the sponsorships of the US Dept. of Energy (DOE) and the member companies of the Institute of Paper Science and Technology, we studied the chem-mechanical mechanism of surfactant spray for flotation deinking using different furnishes, chemicals, and flotation devices in the past four years. In the final year of the project, we successfully conducted mill trials at Abitibi-Consolidated, Inc., Snowflake paper recycling operation of 100% mixture of ONP/OMG. Results from laboratory, pilot-plant and mill trials indicated that surfactant spray technology can significantly reduce fiber loss in flotation deinking. It can be concluded that paper industry can profit greatly when this technology is commercialized in flotation deinking mills.

  20. Froth flotation of xenotime

    NASA Astrophysics Data System (ADS)

    Zhang, Yicheng

    Froth flotation as a fundamental method for processing complex minerals is commonly applied to the surface chemistry and beneficiation of rare-earth-bearing minerals. This is due to the fact that it is possible to process a wide range of fine particle sizes and the process can be tailored to the unique mineralogy of a given deposit. Flotation effectiveness is primarily controlled by the surface-chemical properties of the minerals and related adsorption phenomena at the liquid--solid interface. This research program was designed to investigate the principles of surface chemistry and froth flotation of xenotime and selected gangue minerals. This led to a better understanding of the factors affecting flotation performance and separation of xenotime from associated gangue minerals in an efficient way. This investigation includes MLA analysis, surface area measurement, zeta potential tests, and adsorption tests of xenotime, ilmenite, zircon, schorl, and staurolite under conditions of various reagent additions and different temperatures. Octano-hydroxamic acid, sodium oleate, sodium silicates, and ammonium lignosulfonate were used in microflotation behavior evaluation. Efforts were made to evaluate the effects of temperature, pH, concentration, addition order, and depressants in the microflotation of minerals with anionic collectors such as octano-hydroxamic acid and sodium oleate. Other factors, such as bubble surface tension and bubble particle size, are also discussed based on the literature review and lab observations.

  1. Engineering development of advanced physical fine coal cleaning for premium fuel applications. Quarterly report, April 1--June 30, 1997

    SciTech Connect

    Moro, N.; Shields, G.L.; Smit, F.J.; Jha, M.C.

    1997-12-31

    The primary goal of this project is the engineering development of two advanced physical fine coal cleaning processes, column flotation and selective agglomeration, for premium fuel applications. The project scope includes laboratory research and bench-scale testing on six coals to optimize these processes, followed by the design, construction, and operation of a 2 t/hr process development unit (PDU). Accomplishments during the quarter are described on the following tasks and subtasks: Development of near-term applications (engineering development and dewatering studies); Engineering development of selective agglomeration (bench-scale testing and process scale-up); PDU and advanced column flotation module (coal selection and procurement and advanced flotation topical report); Selective agglomeration module (module operation and clean coal production with Hiawatha, Taggart, and Indiana 7 coals); Disposition of the PDU; and Project final report. Plans for next quarter are discussed and agglomeration results of the three tested coals are presented.

  2. Controlling air toxics through advanced coal preparation

    SciTech Connect

    Straszheim, W.E.; Buttermore, W.H.; Pollard, J.L.

    1995-11-01

    This project involves the assessment of advanced coal preparation methods for removing trace elements from coal to reduce the potential for air toxic emissions upon combustion. Scanning electron microscopy-based automated image analysis (SEM-AIA) and advanced washability analyses are being applied with state-of-the-art analytical procedures to predict the removal of elements of concern by advanced column flotation and to confirm the effectiveness of preparation on the quality of quantity of clean coal produced. Specific objectives are to maintain an acceptable recovery of combustible product, while improving the rejection of mineral-associated trace elements. Current work has focused on determining conditions for controlling column flotation system across its operating range and on selection and analysis of samples for determining trace element cleanability.

  3. Advanced intensity-modulation continuous-wave lidar techniques for ASCENDS CO2 column measurements

    NASA Astrophysics Data System (ADS)

    Campbell, Joel F.; Lin, Bing; Nehrir, Amin R.; Harrison, F. W.; Obland, Michael D.; Meadows, Byron

    2015-10-01

    Global atmospheric carbon dioxide (CO2) measurements for the NASA Active Sensing of CO2 Emissions over Nights, Days, and Seasons (ASCENDS) space mission are critical for improving our understanding of global CO2 sources and sinks. Advanced Intensity- Modulated Continuous-Wave (IM-CW) lidar techniques are investigated as a means of facilitating CO2 measurements from space to meet the ASCENDS measurement requirements. In recent numerical, laboratory and flight experiments we have successfully used the Binary Phase Shift Keying (BPSK) modulation technique to uniquely discriminate surface lidar returns from intermediate aerosol and cloud contamination. We demonstrate the utility of BPSK to eliminate sidelobes in the range profile as a means of making Integrated Path Differential Absorption (IPDA) column CO2 measurements in the presence of optically thin clouds, thereby eliminating the need to correct for sidelobe bias errors caused by the clouds. Furthermore, high accuracy and precision ranging to the surface as well as to the top of intermediate cloud layers, which is a requirement for the inversion of column CO2 number density measurements to column CO2 mixing ratios, has been demonstrated using new hyperfine interpolation techniques that takes advantage of the periodicity of the modulation waveforms. This approach works well for both BPSK and linear swept-frequency modulation techniques. The BPSK technique under investigation has excellent auto-correlation properties while possessing a finite bandwidth. A comparison of BPSK and linear swept-frequency is also discussed in this paper. These results are extended to include Richardson-Lucy deconvolution techniques to extend the resolution of the lidar beyond that implied by limit of the bandwidth of the modulation, where it is shown useful for making tree canopy measurements.

  4. Advanced Intensity-Modulation Continuous-Wave Lidar Techniques for Column CO2 Measurements

    NASA Astrophysics Data System (ADS)

    Campbell, J. F.; Lin, B.; Nehrir, A. R.; Obland, M. D.; Liu, Z.; Browell, E. V.; Chen, S.; Kooi, S. A.; Fan, T. F.

    2015-12-01

    Global and regional atmospheric carbon dioxide (CO2) measurements for the NASA Active Sensing of CO2 Emissions over Nights, Days, and Seasons (ASCENDS) space mission and Atmospheric Carbon and Transport (ACT) - America airborne investigation are critical for improving our understanding of global CO2 sources and sinks. Advanced Intensity-Modulated Continuous-Wave (IM-CW) lidar techniques are being investigated as a means of facilitating CO2 measurements from space and airborne platforms to meet the mission science measurement requirements. In recent numerical, laboratory and flight experiments we have successfully used the Binary Phase Shift Keying (BPSK) modulation technique to uniquely discriminate surface lidar returns from intermediate aerosol and cloud returns. We demonstrate the utility of BPSK to eliminate sidelobes in the range profile as a means of making Integrated Path Differential Absorption (IPDA) column CO2 measurements in the presence of intervening optically thin clouds, thereby minimizing bias errors caused by the clouds. Furthermore, high accuracy and precision ranging to the Earth's surface as well as to the top of intermediate cloud layers, which is a requirement for the inversion of column CO2 number density measurements to column CO2 mixing ratios, has been demonstrated using new hyperfine interpolation techniques that takes advantage of the periodicity of the modulation waveforms. This approach works well for both BPSK and linear swept-frequency modulation techniques and provides very high (at sub-meter level) range resolution. The BPSK technique under investigation has excellent auto-correlation properties while possessing a finite bandwidth. A comparison of BPSK and linear swept-frequency is also discussed in this paper. These techniques are used in a new data processing architecture to support the ASCENDS CarbonHawk Experiment Simulator (ACES) and ACT-America programs.

  5. Advanced Intensity-Modulation Continuous-Wave Lidar Techniques for ASCENDS O2 Column Measurements

    NASA Technical Reports Server (NTRS)

    Campbell, Joel F.; Lin, Bing; Nehrir, Amin R.; Harrison, F. Wallace; Obland, Michael D.; Meadows, Byron

    2015-01-01

    Global atmospheric carbon dioxide (CO2) measurements for the NASA Active Sensing of CO2 Emissions over Nights, Days, and Seasons (ASCENDS) space mission are critical for improving our understanding of global CO2 sources and sinks. Advanced Intensity- Modulated Continuous-Wave (IM-CW) lidar techniques are investigated as a means of facilitating CO2 measurements from space to meet the ASCENDS measurement requirements. In recent numerical, laboratory and flight experiments we have successfully used the Binary Phase Shift Keying (BPSK) modulation technique to uniquely discriminate surface lidar returns from intermediate aerosol and cloud contamination. We demonstrate the utility of BPSK to eliminate sidelobes in the range profile as a means of making Integrated Path Differential Absorption (IPDA) column CO2 measurements in the presence of optically thin clouds, thereby eliminating the need to correct for sidelobe bias errors caused by the clouds. Furthermore, high accuracy and precision ranging to the surface as well as to the top of intermediate cloud layers, which is a requirement for the inversion of column CO2 number density measurements to column CO2 mixing ratios, has been demonstrated using new hyperfine interpolation techniques that takes advantage of the periodicity of the modulation waveforms. This approach works well for both BPSK and linear swept-frequency modulation techniques. The BPSK technique under investigation has excellent auto-correlation properties while possessing a finite bandwidth. A comparison of BPSK and linear swept-frequency is also discussed in this paper. These results are extended to include Richardson-Lucy deconvolution techniques to extend the resolution of the lidar beyond that implied by limit of the bandwidth of the modulation, where it is shown useful for making tree canopy measurements.

  6. An overview of oil-water separation using gas flotation systems.

    PubMed

    Saththasivam, Jayaprakash; Loganathan, Kavithaa; Sarp, Sarper

    2016-02-01

    Oil concentration levels in municipal waste water effluent streams are stringently regulated in most parts of the world. Apart from municipal waste, stricter oil/grease discharge limits are also enforced in oil and gas sectors as large volumes of produced water is being discharged to open ocean. One of the feasible, practical and established methods to remove oil substances from waste water sources is by gas flotation. In this overview, gas flotation technologies, namely dissolved and induced flotation systems, are discussed. Physico-chemical interaction between oil-water-gas during flotation is also summarized. In addition to a brief review on design advancements in flotation systems, enhancement of flotation efficiency by using pre-treatment methods, particularly coagulation-flocculation, is also presented.

  7. An overview of oil-water separation using gas flotation systems.

    PubMed

    Saththasivam, Jayaprakash; Loganathan, Kavithaa; Sarp, Sarper

    2016-02-01

    Oil concentration levels in municipal waste water effluent streams are stringently regulated in most parts of the world. Apart from municipal waste, stricter oil/grease discharge limits are also enforced in oil and gas sectors as large volumes of produced water is being discharged to open ocean. One of the feasible, practical and established methods to remove oil substances from waste water sources is by gas flotation. In this overview, gas flotation technologies, namely dissolved and induced flotation systems, are discussed. Physico-chemical interaction between oil-water-gas during flotation is also summarized. In addition to a brief review on design advancements in flotation systems, enhancement of flotation efficiency by using pre-treatment methods, particularly coagulation-flocculation, is also presented. PMID:26408973

  8. Engineering development of advanced physical fine coal cleaning for premium fuel applications. Quarterly technical progress report 15, April--June 1996

    SciTech Connect

    Moro, N.; Shields, G.L.; Smit, F.J.; Jha, M.C.

    1996-07-25

    Goal is engineering development of two advanced physical fine coal cleaning processes, column flotation and selective agglomeration, for premium fuel applications. Scope includes laboratory research and bench-scale testing on 6 coals to optimize these processes, followed by design/construction/operation of a 2-t/hr PDU. During this quarter, parametric testing of the 30-in. Microcel{trademark} flotation column at the Lady Dunn plant was completed and clean coal samples submitted for briquetting. A study of a novel hydrophobic dewatering process continued at Virginia Tech. Benefits of slurry PSD (particle size distribution) modification and pH adjustment were evaluated for the Taggart and Hiawatha coals; they were found to be small. Agglomeration bench-scale test results were positive, meeting product ash specifications. PDU Flotation Module operations continued; work was performed with Taggart coal to determine scaleup similitude between the 12-in. and 6-ft Microcel{trademark} columns. Construction of the PDU selective agglomeration module continued.

  9. Engineering development of advanced physical fine coal cleaning for premium fuel applications

    SciTech Connect

    Shields, G.L.; Smit, F.J.; Jha, M.C.

    1997-08-28

    The primary goal of this project is the engineering development of two advanced physical fine coal cleaning processes, column flotation and selective agglomeration, for premium fuel applications. The project scope included laboratory research and bench-scale testing on six coals to optimize these processes, followed by the design, construction and operation of 2 t/hr process development unit (PDU). This report represents the findings of the PDU Advanced Column Flotation Testing and Evaluation phase of the program and includes a discussion of the design and construction of the PDU. Three compliance steam coals, Taggart, Indiana VII and Hiawatha, were processed in the PDU to determine performance and design parameters for commercial production of premium fuel by advanced flotation. Consistent, reliable performance of the PDU was demonstrated by 72-hr production runs on each of the test coals. Its capacity generally was limited by the dewatering capacity of the clean coal filters during the production runs rather than by the flotation capacity of the Microcel column. The residual concentrations of As, Pb, and Cl were reduced by at least 25% on a heating value basis from their concentrations in the test coals. The reduction in the concentrations of Be, Cd, Cr, Co, Mn, Hg, Ni and Se varied from coal to coal but the concentrations of most were greatly reduced from the concentrations in the ROM parent coals. The ash fusion temperatures of the Taggart and Indiana VII coals, and to a much lesser extent the Hiawatha coal, were decreased by the cleaning.

  10. Dolomite flotation of high magnesium phosphate ores using fatty acid soap collectors

    NASA Astrophysics Data System (ADS)

    Gu, Zhengxing

    The separation of dolomite from apatite has been recognized as one of the most difficult subjects in mineral processing due to the similarities in their physiochemical properties. In this study, selective surfactants were used with a fatty acid soap collector to improve the flotation performance of separating dolomite from high magnesium phosphate ores. Three surfactants, diethyl phthalate (DP), Tween-80 (TW) and derivative of sulfonate salt (DSS1) were used. Hallimond cell flotation was conducted using pure dolomite sample to determine the effects of various factors including dosages, particle size, Ca2+ ions and slimes on the dolomite flotation recovery. The results showed that the surfactants can significantly improve dolomite flotation performance by increasing collecting ability and tolerating the effect of calcium ions and slime contents. The stirrer-tank cell batch flotation tests were carried out using two natural high magnesium phosphate ore samples containing 3.3% and 1.5% MgO. The test results showed that the surfactant DP could improve dolomite flotation at low dosages, and DSS1 could enhance the separation of dolomite from phosphate by improving both collecting ability and flotation selectivity. When 10% of DSS1 was used with the fatty acid soap as collector, at least 10% more dolomite can be removed with less P2O5 loss. The effectiveness of the surfactant DSS1 in enhancing dolomite flotation was further demonstrated in modified packed column flotation with natural dolomitic phosphate ore sample. The addition of the surfactant DSS1 into fatty acid soap collector could improve its frothability and froth stability, and reduce the bubble size. It has been found that the dolomite flotation performance has a close relationship with the frothability and froth stability of the collector.

  11. Selective flotation of fossil resin from Western coal. Final report, July 1, 1990--May 25, 1992

    SciTech Connect

    Jensen, G.F.; Miller, J.D.

    1992-05-25

    The proof-of-concept test program was designed to clarify a number of concerns that have been raised by coal companies who own the valuable resin resource. First, from laboratory bench-scale flotation experiments, a froth product from cleaner flotation containing more than 80% hexane-extractable resin at higher than 80% recovery can be produced. Pilot-plant testing was initiated to demonstrate the selective flotation of fossil resin and to establish a better confidence level in the new technology. Second, pilot-plant testing was designed to evaluate the effect and impact of random variation in slurry solids concentration and feed grade on this new selective fossil resin flotation technology. The flotation performance obtained under these industrial conditions is more realistic for process evaluation. Third, more accurate operating cost data was to be obtained for economic analysis. Fourth, sufficient quantities of the fossil resin concentrate were to be produced from the test program for evaluation by potential industrial users. Fifth, and finally, optimum levels for the operating variables were to be established. Such information was required for eventual scale-up and design of a fossil resin flotation plant. The pilot-plant proof-of-concept testing of selective resinate flotation has demonstrated that: (1) technically, the new flotation technologies discovered at the University of Utah and then improved upon by Advanced Processing Technologies, Inc. provide a highly efficient means to selectively recover fossil resin from coal. The proof-of-concept continuous flotation circuit (about 0.1 tph) resulted in fossil resin recovery with the same separation efficiency as was obtained from laboratory bench-scale testing (more than 80% recovery at about 80% concentrate grade); and (2) economically, the selective flotation process has been shown to be sufficiently profitable to justify the development of a fossil resin industry based on this new flotation process.

  12. Engineering development of advanced physical fine coal cleaning for premium fuel applications. Quarterly progress report No. 10, January--March 1995

    SciTech Connect

    Moro, N.; Shields, G.L.; Smit, F.J.; Jha, M.C.

    1995-04-27

    The primary goal of this project is the engineering development of two advanced physical fine coal cleaning processes, column flotation and selective agglomeration, for premium fuel applications. The project scope includes laboratory research and benchscale testing on six coals to optimize these processes, followed by design, and construction of a 2-t/hr process development unit (PDU). The PDU will then be operated to generate 200 ton lots of each of three project coals, by each process. The project began in October, 1992 and is scheduled for completion by June, 1997. During Quarter 10 (January--March, 1995), preliminary work continued for the Subtask 3.2 in-plant testing of the Microcel{trademark} flotation column at the Lady Dunn Preparation Plant. Towards this end, laboratory flotation testing and refurbishing of the column have been started. The final version of the Subtask 4.2 Advanced Flotation Process Optimization Research topical report was issued, as was a draft version of the Subtask 4.3 report discussing the formulation of coal-water slurry fuels (CWF) from advanced flotation products. A number of product samples from Subtask 4.4 testing were sent to both Combustion Engineering and Penn State for combustion testing. The evaluation of toxic trace element analyses of column flotation products also continued. The detailed design of the 2 t/hr PDU was essentially completed with the approval of various process flow, plant layout, electrical, and vendor equipment drawings. The final version of the Subtask 6.5 -- Selective Agglomeration Bench-Scale Design and Test Plan Report was issued during this reporting quarter. Design and construction of this 25 lb/hr selective agglomeration test unit was completed and preliminary testing started. Construction of the 2 t/hr PDU began following the selection of TIC. The Industrial Company as the construction subcontractor.

  13. Recent advances in the preparation and application of monolithic capillary columns in separation science.

    PubMed

    Hong, Tingting; Yang, Xi; Xu, Yujing; Ji, Yibing

    2016-08-10

    Novel column technologies involving various materials and efficient reactions have been investigated for the fabrication of monolithic capillary columns in the field of analytical chemistry. In addition to the development of these miniaturized systems, a variety of microscale separation applications have achieved noteworthy results, providing a stepping stone for new types of chromatographic columns with improved efficiency and selectivity. Three novel strategies for the preparation of capillary monoliths, including ionic liquid-based approaches, nanoparticle-based approaches and "click chemistry", are highlighted in this review. Furthermore, we present the employment of state-of-the-art capillary monolithic stationary phases for enantioseparation, solid-phase microextraction, mixed-mode separation and immobilized enzyme reactors. The review concludes with recommendations for future studies and improvements in this field of research. PMID:27282747

  14. Recent advances in the preparation and application of monolithic capillary columns in separation science.

    PubMed

    Hong, Tingting; Yang, Xi; Xu, Yujing; Ji, Yibing

    2016-08-10

    Novel column technologies involving various materials and efficient reactions have been investigated for the fabrication of monolithic capillary columns in the field of analytical chemistry. In addition to the development of these miniaturized systems, a variety of microscale separation applications have achieved noteworthy results, providing a stepping stone for new types of chromatographic columns with improved efficiency and selectivity. Three novel strategies for the preparation of capillary monoliths, including ionic liquid-based approaches, nanoparticle-based approaches and "click chemistry", are highlighted in this review. Furthermore, we present the employment of state-of-the-art capillary monolithic stationary phases for enantioseparation, solid-phase microextraction, mixed-mode separation and immobilized enzyme reactors. The review concludes with recommendations for future studies and improvements in this field of research.

  15. High-efficiency flotation of coarse and fine coal

    SciTech Connect

    Atkinson, B.W.; Conway, C.J.; Jameson, G.J.

    1995-10-01

    The flotation of coal in the fine and coarse particle size ranges presents particular problems. Fine or ultra-fine coal less than 100 microns presents a challenge to conventional flotation machines because the rate of capture of the coal particles can be very low, so longer residence times are needed. Also, conventional mechanical cells are not normally designed with froth properties in mind. Froth drainage may be inadequate, leading to excessive entrainment of ash. The upper limit of flotation of coal is normally put at about 500 {micro}m (30 mesh). It appears that, in mechanical cells, coarser particles tend to be torn away from bubbles in the turbulent environment created by the impeller. In this paper, results are presented from plant trials of a high-intensity flotation column of novel design, namely the Jameson cell. Extensive trials have been conducted on coal slurries with a top size of around 1 mm. Size-by size analysis shows that it is possible to achieve high yields of low ash product over the whole particle size range.

  16. ADVANCED DIAGNOSTIC TECHNIQUES FOR THREE-PHASE SLURRY BUBBLE COLUMN REACTORS(SBCR)

    SciTech Connect

    M.H. Al-Dahhan; L.S. Fan; M.P. Dudukovic

    2002-07-25

    This report summarizes the accomplishment made during the third year of this cooperative research effort between Washington University, Ohio State University and Air Products and Chemicals. Data processing of the performed Computer Automated Radioactive Particle Tracking (CARPT) experiments in 6 inch column using air-water-glass beads (150 {micro}m) system has been completed. Experimental investigation of time averaged three phases distribution in air-Therminol LT-glass beads (150 {micro}m) system in 6 inch column has been executed. Data processing and analysis of all the performed Computed Tomography (CT) experiments have been completed, using the newly proposed CT/Overall gas holdup methodology. The hydrodynamics of air-Norpar 15-glass beads (150 {micro}m) have been investigated in 2 inch slurry bubble column using Dynamic Gas Disengagement (DGD), Pressure Drop fluctuations, and Fiber Optic Probe. To improve the design and scale-up of bubble column reactors, a correlation for overall gas holdup has been proposed based on Artificial Neural Network and Dimensional Analysis.

  17. ADVANCED DIAGNOSTIC TECHNIQUES FOR THREE-PHASE SLURRY BUBBLE COLUMN REACTORS (SBCR)

    SciTech Connect

    M.H. Al-Dahhan; M.P. Dudukovic; L.S. Fan

    2001-07-25

    This report summarizes the accomplishment made during the second year of this cooperative research effort between Washington University, Ohio State University and Air Products and Chemicals. The technical difficulties that were encountered in implementing Computer Automated Radioactive Particle Tracking (CARPT) in high pressure SBCR have been successfully resolved. New strategies for data acquisition and calibration procedure have been implemented. These have been performed as a part of other projects supported by Industrial Consortium and DOE via contract DE-2295PC95051 which are executed in parallel with this grant. CARPT and Computed Tomography (CT) experiments have been performed using air-water-glass beads in 6 inch high pressure stainless steel slurry bubble column reactor at selected conditions. Data processing of this work is in progress. The overall gas holdup and the hydrodynamic parameters are measured by Laser Doppler Anemometry (LDA) in 2 inch slurry bubble column using Norpar 15 that mimic at room temperature the Fischer Tropsch wax at FT reaction conditions of high pressure and temperature. To improve the design and scale-up of bubble column, new correlations have been developed to predict the radial gas holdup and the time averaged axial liquid recirculation velocity profiles in bubble columns.

  18. Selective flotation of inorganic sulfides from coal

    DOEpatents

    Miller, K.J.; Wen, Wu-Wey

    1988-05-31

    Pyritic sulfur is removed from coal or other carbonaceous material through the use of humic acid as a coal flotation depressant. Following the removal of coarse pyrite, the carbonaceous material is blended with humic acid, a pyrite flotation collector and a frothing agent within a flotation cell to selectively float pyritic sulfur leaving clean coal as an underflow. 1 fig., 2 tabs.

  19. 77 FR 19937 - Inflatable Personal Flotation Devices

    Federal Register 2010, 2011, 2012, 2013, 2014

    2012-04-03

    ... Personal Flotation Devices'' in the Federal Register. 76 FR 17561. We received three submissions in... Personal Flotation Devices); 60 FR 32836 (June 23, 1995). Subpart 160.076 incorporates by reference three... SECURITY Coast Guard 46 CFR Part 160 RIN 1625-AB60 Inflatable Personal Flotation Devices AGENCY:...

  20. 76 FR 60405 - Inflatable Personal Flotation Devices

    Federal Register 2010, 2011, 2012, 2013, 2014

    2011-09-29

    ... Flotation Devices'' in the Federal Register (76 FR 17561). The Coast Guard received three submissions in... SECURITY Coast Guard 46 CFR Part 160 RIN 1625-AB60 Inflatable Personal Flotation Devices AGENCY: Coast... performance standards for inflatable recreational personal flotation devices (PFDs) with current...

  1. 76 FR 17561 - Inflatable Personal Flotation Devices

    Federal Register 2010, 2011, 2012, 2013, 2014

    2011-03-30

    ... Final Agency Policy'' (67 FR 48244, July 23, 2002). This rule involves personal flotation device... SECURITY Coast Guard 46 CFR Part 160 RIN 1625-AB60 Inflatable Personal Flotation Devices AGENCY: Coast... flotation devices (PFDs) with current voluntary industry consensus standards. This direct final rule...

  2. Selective flotation of inorganic sulfides from coal

    DOEpatents

    Miller, Kenneth J.; Wen, Wu-Wey

    1989-01-01

    Pyritic sulfur is removed from coal or other carbonaceous material through the use of humic acid as a coal flotation depressant. Following the removal of coarse pyrite, the carbonaceous material is blended with humic acid, a pyrite flotation collector and a frothing agent within a flotation cell to selectively float pyritic sulfur leaving clean coal as an underflow.

  3. 33 CFR 183.322 - Flotation materials.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... 33 Navigation and Navigable Waters 2 2010-07-01 2010-07-01 false Flotation materials. 183.322 Section 183.322 Navigation and Navigable Waters COAST GUARD, DEPARTMENT OF HOMELAND SECURITY (CONTINUED... of 2 Horsepower or Less General § 183.322 Flotation materials. (a) Flotation materials must meet...

  4. 33 CFR 183.322 - Flotation materials.

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ... 33 Navigation and Navigable Waters 2 2012-07-01 2012-07-01 false Flotation materials. 183.322 Section 183.322 Navigation and Navigable Waters COAST GUARD, DEPARTMENT OF HOMELAND SECURITY (CONTINUED... of 2 Horsepower or Less General § 183.322 Flotation materials. (a) Flotation materials must meet...

  5. 33 CFR 183.322 - Flotation materials.

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... 33 Navigation and Navigable Waters 2 2014-07-01 2014-07-01 false Flotation materials. 183.322 Section 183.322 Navigation and Navigable Waters COAST GUARD, DEPARTMENT OF HOMELAND SECURITY (CONTINUED... of 2 Horsepower or Less General § 183.322 Flotation materials. (a) Flotation materials must meet...

  6. Process and apparatus for separating fine particles by microbubble flotation together with a process and apparatus for generation of microbubbles

    DOEpatents

    Yoon, Roe-Hoan; Adel, Gregory T.; Luttrell, Gerald H.

    1991-01-01

    A method and apparatus are disclosed for the microbubble flotation separation of very fine particles, especially coal, so as to produce a high purity and large recovery efficiently. This is accomplished through the use of a high aspect ratio flotation column, microbubbles, and a countercurrent use of wash water to gently wash the froth. Also, disclosed are unique processes and apparatus for generating microbubbles for flotation in a high efficient and inexpensive manner using either a porous tube or an in-line static generator.

  7. Process and apparatus for separating fine particles by microbubble flotation together with a process and apparatus for generation of microbubbles

    DOEpatents

    Yoon, R.H.; Adel, G.T.; Luttrell, G.H.

    1991-01-01

    A method and apparatus are disclosed for the microbubble flotation separation of very fine particles, especially coal, so as to produce a high purity and large recovery efficiently. This is accomplished through the use of a high aspect ratio flotation column, microbubbles, and a countercurrent use of wash water to gently wash the froth. Also, disclosed are unique processes and apparatus for generating microbubbles for flotation in a high efficient and inexpensive manner using either a porous tube or an in-line static generator. 23 figures.

  8. Final Report - Advanced Hydraulic and Mass Transfer Models for Distillation Column Optimization and Design

    SciTech Connect

    Eldridge, Robert, B.

    2005-10-13

    The project successfully developed a computational fluid dynamics (CFD) based simulation of the hydrodynamics of flow in a commercial structured packing element. This result fulfilled the prime objective of the research program. The simulation utilized commercial CFD code marketed by Fluent Inc. in combination with a novel graphical interface developed by Oak Ridge National Lab. The end product will allow the design of next generation column internals without the need for extensive experimental validation and will expand the fundamental understanding of the vapor-liquid contacting process.

  9. Semi-industrial experimental study on bauxite separation using a cell-column integration process

    NASA Astrophysics Data System (ADS)

    Zhang, Ning-ning; Zhou, Chang-chun; Cong, Long-fei; Cao, Wen-long; Zhou, You

    2016-01-01

    The cyclonic-static micro-bubble flotation column (FCSMC) is a highly efficient mineral processing equipment. In this study, a cell-column (FCSMC) integration process was investigated for the separation of bauxite and its feasibility was analyzed on a theoretical basis. The properties of low-grade bauxite ore from Henan Province, China were analyzed. Parameters such as reagent dosage, scraping bubble time, and pressure of the circulating pump during the sorting process were investigated and optimized to improve the flotation efficiency. On the basis of these parameters, continuous separation experiments were conducted. Bauxite concentrate with an aluminum-to-silicon (A/S) mass ratio of 6.37 and a 77.63wt% recovery rate were achieved via a flow sheet consisting of "fast flotation using a flotation cell, one roughing flotation and one cleaning flotation using flotation columns". Compared with the full-flotation-cells process, the cell-column integration process resulted in an increase of the A/S ratio by 0.41 and the recovery rate by 17.58wt%. Cell-column integration separation technology represents a new approach for the separation of middle-to-low-grade bauxite ore.

  10. Selective flotation of fossil resin from western coal

    SciTech Connect

    Jensen, G.F.; Miller, J.D.

    1992-03-20

    The test program has demonstrated that: (1) technically, the new flotation technologies discovered at the University of Utah and then improved upon by Advanced Processing Technologies, Inc. provide a highly efficient means to selectively recover fossil resin from coal. The proof-of-concept continuous flotation circuit resulted in fossil resin recovery with the same separation efficiency as was obtained from laboratory bench-scale testing (more than 80% recovery at about 80% concentrate grade); and (2) economically, the selective flotation process has been shown to be sufficiently profitable to justify the development of a fossil resin industry based on this new flotation process. The proof-of-concept testing has resulted in significant interest from several coal mining companies and has sparked the desire of local and state government to establish a fossil resin industry in the Wasatch Plateau coal field. In this view, the results from the current proof-of-concept testing program have been successful. This special report provides theoretical and analytical data on some surface chemistry work pertinent to fossil resin characterization, and other efforts carried out during the past months.

  11. Advances in the development of organic polymer monolithic columns and their applications in food analysis--a review.

    PubMed

    Jandera, Pavel

    2013-10-25

    Monolithic continuous separation media are gradually finding their way to sample pre-treatment, isolation, enrichment and final analytical separations of a plethora of compounds, occurring as food components, additives or contaminants, including pharmaceuticals, pesticides and toxins, which have traditionally been the domain of particulate chromatographic materials. In the present review, recent advances in the technology of monolithic columns and the applications in food analysis are addressed. Silica-based monoliths are excellent substitutes to conventional particle-packed columns, improving the speed of analysis for low-molecular weight compounds, due to their excellent efficiency and high permeability. These properties have been recently appreciated in two-dimensional HPLC, where the performance in the second dimension is of crucial importance. Organic-polymer monoliths in various formats provide excellent separations of biopolymers. Thin monolithic disks or rod columns are widely employed in isolation, purification and pre-treatment of sample containing proteins, peptides or nucleic acid fragments. Monolithic capillaries were originally intended for use in electrochromatography, but are becoming more frequently used for capillary and micro-HPLC. Monoliths are ideal highly porous support media for immobilization or imprinting template molecules, to provide sorbents for shape-selective isolation of target molecules from various matrices occurring in food analysis. The separation efficiency of organic polymer monoliths for small molecules can be significantly improved by optimization of polymerization approach, or by post-polymerization modification. This will enable full utilization of a large variety of available monomers to prepare monoliths with chemistry matching the needs of selectivity of separations of various food samples containing even very polar or ionized compounds.

  12. Advanced landfill leachate treatment using iron-carbon microelectrolysis- Fenton process: Process optimization and column experiments.

    PubMed

    Wang, Liqun; Yang, Qi; Wang, Dongbo; Li, Xiaoming; Zeng, Guangming; Li, Zhijun; Deng, Yongchao; Liu, Jun; Yi, Kaixin

    2016-11-15

    A novel hydrogen peroxide-enhanced iron-carbon (Fe-C) microelectrolysis reactor was proposed for the pretreatment of mature landfill leachate. This reactor, combining microelectrolysis with Fenton process, revealed high treatment efficiency. The operating variables, including Fe-C dosage, H2O2 concentration and initial pH, were optimized by the response surface methodology (RSM), regarding the chemical oxygen demand (COD) removal efficiency and biochemical oxygen demand: chemical oxygen demand (BOD5/COD) as the responses. The highest COD removal (74.59%) and BOD5/COD (0.50) was obtained at optimal conditions of Fe-C dosage 55.72g/L, H2O2 concentration 12.32mL/L and initial pH 3.12. Three-dimensional excitation and emission matrix (3D-EEM) fluorescence spectroscopy and molecular weight (MW) distribution demonstrated that high molecular weight fractions such as refractory fulvic-like substances in leachate were effectively destroyed during the combined processes, which should be attributed to the combination oxidative effect of microelectrolysis and Fenton. The fixed-bed column experiments were performed and the breakthrough curves at different flow rates were evaluated to determine the practical applicability of the combined process. All these results show that the hydrogen peroxide-enhanced iron-carbon (Fe-C) microelectrolysis reactor is a promising and efficient technology for the treatment of mature landfill leachate. PMID:27450338

  13. Hydrocarbon-oil encapsulate bubble flotation of fine coal. Technical progress report for the twelfth quarter, July 1--September 30, 1993

    SciTech Connect

    Peng, F.F.

    1993-12-31

    Two modes of collector addition techniques including gasified collector transported in gas phase and direct collector addition techniques were applied in the column flotation to demonstrate the selectivity of utilizing the hydrocarbon-oil encapsulated air bubbles in the fine coal flotation process. A 3-in. flotation column was used to evaluate two modes of collector dispersion and addition techniques on the recovery and grade of fine coals using various ranks of coal. Five different coal samples were used in the column flotation test program. They are Mammoth, Lower Kittanning, Upper Freeport, Pittsburgh No. 8, and Illinois No. 6 seam coals, which correspond to anthracite-, low volatile-, medium volatile-, and high volatile-seam coals, respectively. In this quarterly report, the test results for the Upper Freeport seam coal and Pittsburgh No. 8 seam coal are reported.

  14. Hydrocarbon-oil encapsulated air bubble flotation of fine coal. Technical progress report for the third quarter, April 1, 1991--June 30, 1991

    SciTech Connect

    Peng, F.F.

    1995-01-01

    This report is concerned with the progress made during the third period of the two year project. A significant portion of this reporting period has been consumed in measurement of induction time of oil-free and oil-coated bubbles, modification of collector gasifier, hydrocarbon oil encapsulated flotation tests and float and sink analyses of various rank of coal samples, building a 1-inch column cell, as well as building the ultrasound collector emulsification apparatus. Induction time has been measured using an Electronic Induction Timer. The results indicate that alteration of chemical properties of air bubble by applying hydrocarbon oil or reagent can drastically improve the rate of flotation process. Various techniques have been employed in hydrocarbon oil encapsulated flotation processes to further enhance the selectivity of the process, which include: (1) gasified collector flotation with addition of gasified collector into the air stream in the initial stage; (2) two-stage (rougher-cleaner) gasified collector flotation; and (3) starvation gasified collector flotation by addition of gasified collector at various flotation times. Among these, three techniques used in hydrocarbon oil encapsulated flotation process, the starvation flotation technique provides the best selectivity.

  15. 33 CFR 183.114 - Test of flotation materials.

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ... (CONTINUED) BOATING SAFETY BOATS AND ASSOCIATED EQUIPMENT Flotation Requirements for Inboard Boats, Inboard/Outdrive Boats, and Airboats § 183.114 Test of flotation materials. (a) Vapor test. The flotation...

  16. 33 CFR 183.114 - Test of flotation materials.

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... (CONTINUED) BOATING SAFETY BOATS AND ASSOCIATED EQUIPMENT Flotation Requirements for Inboard Boats, Inboard/Outdrive Boats, and Airboats § 183.114 Test of flotation materials. (a) Vapor test. The flotation...

  17. Distillation Column Modeling Tools

    SciTech Connect

    2001-09-01

    Advanced Computational and Experimental Techniques will Optimize Distillation Column Operation. Distillation is a low thermal efficiency unit operation that currently consumes 4.8 quadrillion BTUs of energy...

  18. Sewage treatment-flotation apparatus

    SciTech Connect

    Hines, D.A.; Jones, R.T.; Roesler, F.C.

    1981-03-03

    Solids-liquid separation, wherein a solids-liquid mixture containing dissolved oxygen-containing gas is circulated around a circulatory system comprising a downcomer and a riser, part of the mixture in the riser being introduced into a flotation chamber in which the hydrostatic pressure gradually decreases as the mixture flows upwards, with consequent release from solution of gas bubbles which carry solid particles to the top of the mixture.

  19. 21 CFR 890.3175 - Flotation cushion.

    Code of Federal Regulations, 2012 CFR

    2012-04-01

    ... 21 Food and Drugs 8 2012-04-01 2012-04-01 false Flotation cushion. 890.3175 Section 890.3175 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED) MEDICAL DEVICES PHYSICAL MEDICINE DEVICES Physical Medicine Prosthetic Devices § 890.3175 Flotation cushion....

  20. 21 CFR 890.3175 - Flotation cushion.

    Code of Federal Regulations, 2013 CFR

    2013-04-01

    ... 21 Food and Drugs 8 2013-04-01 2013-04-01 false Flotation cushion. 890.3175 Section 890.3175 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED) MEDICAL DEVICES PHYSICAL MEDICINE DEVICES Physical Medicine Prosthetic Devices § 890.3175 Flotation cushion....

  1. 21 CFR 890.3175 - Flotation cushion.

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ... 21 Food and Drugs 8 2010-04-01 2010-04-01 false Flotation cushion. 890.3175 Section 890.3175 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED) MEDICAL DEVICES PHYSICAL MEDICINE DEVICES Physical Medicine Prosthetic Devices § 890.3175 Flotation cushion....

  2. 21 CFR 890.3175 - Flotation cushion.

    Code of Federal Regulations, 2014 CFR

    2014-04-01

    ... 21 Food and Drugs 8 2014-04-01 2014-04-01 false Flotation cushion. 890.3175 Section 890.3175 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED) MEDICAL DEVICES PHYSICAL MEDICINE DEVICES Physical Medicine Prosthetic Devices § 890.3175 Flotation cushion....

  3. 21 CFR 890.3175 - Flotation cushion.

    Code of Federal Regulations, 2011 CFR

    2011-04-01

    ... 21 Food and Drugs 8 2011-04-01 2011-04-01 false Flotation cushion. 890.3175 Section 890.3175 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED) MEDICAL DEVICES PHYSICAL MEDICINE DEVICES Physical Medicine Prosthetic Devices § 890.3175 Flotation cushion....

  4. Automation and optimization of froth flotation

    NASA Astrophysics Data System (ADS)

    Karr, C. L.; Stanley, D. A.; Scheiner, B. J.

    The U.S. Bureau of Mines is developing techniques to optimize the design of mineral processing equipment and to control the mineral processing sequence. Emphasis at the present time is on the optimization of froth flotation. The optimization of flotation devices, such as the air-injected hydrocyclone, has been accomplished using genetic algorithms. An expert system for the flotation of phosphate has been developed. Control of various operations in flotation is being studied using a combination of fuzzy logic and genetic algorithms. The combining of the control capabilities of fuzzy logic with the search capabilities of genetic algorithms make the production of an expert system that develops rules on-line a distinct possibility. Also, the use of computer vision for on-line analysis of processing streams in phosphate flotation is being investigated. This paper describes the progress to date on these processing problems.

  5. Dissolved air-flotation processes. Technical report

    SciTech Connect

    Krofta, M.; Wang, L.K.

    1986-11-05

    The theories and applications of various dissolved-air-flotation clarifiers (Supracell, Sandfloat, Floatpress, and Sedifloat) are presented. Supracell is a high-rate dissolved-air-flotation clarifier with only 3 to 5 minutes of detention time. Major application of Supracell is industrial-effluent treatment. Sandfloat is a package plant consisting of flocculation, dissolved-air floatation and automatic backwash filtration, and designed for either potable water treatment or tertiary wastewater-treatment. Sedifloat is a wastewater-treatment package plant consisting of both sedimentation and dissolved-air flotation. Floatpress consists of both dissolved air flotation and filter press and is specifically designed for sludge thickening. A Krofta Bargefloat is a floating lake-water clarification plant designed for acid-rain neutralization, phosphorus removal, algae removal and lake-water purification. Bargefloat has built-in chemical feeders, flocculator, dissolved-air-flotation clarifier and sand filter on a barge.

  6. Engineering development of advanced physical fine coal cleaning for premium fuel applications. Quarterly technical progress report 16, July--September, 1996

    SciTech Connect

    Shields, G.L.; Moro, N.; Smit, F.J.; Jha, M.C.

    1996-10-30

    The primary goal of this project is the engineering development of two advanced physical fine coal cleaning processes, column flotation and selective agglomeration, for premium fuel applications. The project scope includes laboratory research and bench-scale testing on six coals to optimize these processes, followed by the design, construction, and operation of a 2-t/hr process development unit (PDU). The project began in October, 1992, and is scheduled for completion by September 1997. 28 refs., 13 figs., 19 tabs.

  7. Engineering development of advanced physical fine coal cleaning for premium fuel applications. Quarterly technical progress report 11, April--June, 1995

    SciTech Connect

    Moro, N.; Shields, G.L.; Smit, F.J.; Jha, M.C.

    1995-07-31

    The primary goal of this project is the engineering development of two advanced physical fine coal cleaning processes, column flotation and selective agglomeration, for premium fuel applications. The project scope includes laboratory research and bench-scale testing on six coals to optimize these processes, followed by design, and construction of a 2-t/hr process development unit (PDU). The PDU will then be operated to generate 200 tons of each of three project coals, by each process. During Quarter 11 (April--June, 1995), work continued on the Subtask 3.2 in-plant testing of the Microcel{trademark} flotation column at the Lady Dunn Preparation Plant with the installation and calibration of a refurbished 30-inch diameter column. The evaluation of toxic trace element data for column flotation samples continued, with preliminary analysis indicating that reasonably good mass balances were achieved for most elements, and that significant reductions in the concentration of many elements were observed from raw coal, to flotation feed, to flotation product samples. Significant progress was made on Subtask 6.5 selective agglomeration bench-scale testing. Data from this work indicates that project ash specifications can be met for all coals evaluated, and that the bulk of the bridging liquid (heptane) can be removed from the product for recycle to the process. The detailed design of the 2 t/hr selective agglomeration module progressed this quarter with the completion of several revisions of both the process flow, and the process piping and instrument diagrams. Procurement of coal for PDU operation began with the purchase of 800 tons of Taggart coal. Construction of the 2 t/hr PDU continued through this reporting quarter and is currently approximately 60% complete.

  8. Isolation and characterization of lost copper and molybdenum particles in the flotation tailings of Kennecott copper porphyry ores

    NASA Astrophysics Data System (ADS)

    Tserendavga, Tsend-Ayush

    The importance of flotation separation has long been, and continues to be, an important technology for the mining industry, especially to metallurgical engineers. However, the flotation process is quite complex and expensive, in addition to being influenced by many variables. Understanding the variables affecting flotation efficiency and how valuable minerals are lost to the tailings gives metallurgists an advantage in their attempts to increase efficiency by designing operations to target the areas of greatest potential value. A successful, accurate evaluation of lost minerals in the tailings and appropriate solutions to improve flotation efficiency can save millions of dollars in the effective utilization of our mineral resources. In this dissertation research, an attempt has been made to understand the reasons for the loss of valuable mineral particles in the tailings from Kennecott Utah Copper ores. Possibilities include liberation, particle aggregation (slime coating) and surface chemistry issues associated with the flotation separation. This research generally consisted of three main aspects. The first part involved laboratory flotation experiments and factors, which affect the flotation efficiency. Results of flotation testing are reported that several factors such as mineral exposure/liberation and slime coating and surface oxidation strongly affect the flotation efficiency. The second part of this dissertation research was to develop a rapid scan dual energy (DE) methodology using 2D radiography to identify, isolate, and prepare lost sulfide mineral particles with the advantages of simple sample preparation, short analysis time, statistically reliable accuracy and confident identification. The third part of this dissertation research was concerned with detailed characterization of lost particles including such factors as liberation, slime coating, and surface chemistry characteristics using advanced analytical techniques and instruments. Based on the

  9. Engineering Development of Advanced Physical Fine Coal Cleaning for Premium Fuel Applications

    SciTech Connect

    Smit, Frank J; Schields, Gene L; Jha, Mehesh C; Moro, Nick

    1997-09-26

    The ash in six common bituminous coals, Taggart, Winifrede, Elkhorn No. 3, Indiana VII, Sunnyside and Hiawatha, could be liberated by fine grinding to allow preparation of clean coal meeting premium fuel specifications (< 1- 2 lb/ MBtu ash and <0.6 lb/ MBtu sulfur) by laboratory and bench- scale column flotation or selective agglomeration. Over 2,100 tons of coal were cleaned in the PDU at feed rates between 2,500 and 6,000 lb/ h by Microcel™ column flotation and by selective agglomeration using recycled heptane as the bridging liquid. Parametric testing of each process and 72- hr productions runs were completed on each of the three test coals. The following results were achieved after optimization of the operating parameters: The primary objective was to develop the design base for commercial fine coal cleaning facilities for producing ultra- clean coals which can be converted into coal-water slurry premium fuel. The coal cleaning technologies to be developed were advanced column flotation and selective agglomeration, and the goal was to produce fuel meeting the following specifications.

  10. Foam flotation as a separation process

    NASA Technical Reports Server (NTRS)

    Currin, B. L.

    1986-01-01

    The basic principles of foam separation techniques are discussed. A review of the research concerning bubble-particle interaction and its role in the kinetics of the flotation process is given. Most of the research in this area deals with the use of theoretical models to predict the effects of bubble and particle sizes, of liquid flow, and of various forces on the aperture and retention of particles by bubbles. A discussion of fluid mechanical aspects of particle flotation is given.

  11. Flotation separation of waste plastics for recycling-A review.

    PubMed

    Wang, Chong-qing; Wang, Hui; Fu, Jian-gang; Liu, You-nian

    2015-07-01

    The sharp increase of plastic wastes results in great social and environmental pressures, and recycling, as an effective way currently available to reduce the negative impacts of plastic wastes, represents one of the most dynamic areas in the plastics industry today. Froth flotation is a promising method to solve the key problem of recycling process, namely separation of plastic mixtures. This review surveys recent literature on plastics flotation, focusing on specific features compared to ores flotation, strategies, methods and principles, flotation equipments, and current challenges. In terms of separation methods, plastics flotation is divided into gamma flotation, adsorption of reagents, surface modification and physical regulation. PMID:25869841

  12. Flotation separation of waste plastics for recycling-A review.

    PubMed

    Wang, Chong-qing; Wang, Hui; Fu, Jian-gang; Liu, You-nian

    2015-07-01

    The sharp increase of plastic wastes results in great social and environmental pressures, and recycling, as an effective way currently available to reduce the negative impacts of plastic wastes, represents one of the most dynamic areas in the plastics industry today. Froth flotation is a promising method to solve the key problem of recycling process, namely separation of plastic mixtures. This review surveys recent literature on plastics flotation, focusing on specific features compared to ores flotation, strategies, methods and principles, flotation equipments, and current challenges. In terms of separation methods, plastics flotation is divided into gamma flotation, adsorption of reagents, surface modification and physical regulation.

  13. Distillation Column Flooding Predictor

    SciTech Connect

    2002-02-01

    This factsheet describes a research project whose goal is to develop the flooding predictor, an advanced process control strategy, into a universally useable tool that will maximize the separation yield of a distillation column.

  14. Advanced dress-up chiral columns: New removable chiral stationary phases for enantioseparation of chiral carboxylic acids.

    PubMed

    Todoroki, Kenichiro; Ishii, Yasuhiro; Ide, Takafumi; Min, Jun Zhe; Inoue, Koichi; Huang, Xin; Zhang, Wei; Hamashima, Yoshitaka; Toyo'oka, Toshimasa

    2015-07-01

    This paper describes the preparation of new dress-up columns featuring reproducibly removable and replaceable chiral stationary phases. After synthesizing perfluroalkylated quinine and quinidine derivatives as chiral stationary phase compounds (F-CSPs), we adsorbed them reversibly onto a fluorous LC column through pumping of their solutions. Using this dress-up chiral column and fluorophobic elution of aqueous ammonium formate/MeOH mixtures, we could enantioseparate four racemic N-acetyl amino acids, dichlorprop, and sixteen fluorescent 6-aminoquinolyl-N-hydroxysuccinimidyl carbamate (AQC)-derivatized amino acids. Dressing and undressing of the coated F-CSPs could be controlled by varying the fluorophilicity and fluorophobicity of the eluent. The relative standard deviations of the retention times, the retention factors, the number of theoretical plates, the enantioseparation factors, and the resolutions of each of four preparations of such dress-up columns were all less than or equal to 5.26% (from 20 repeated analyses); the reproducibilities from four different preparations were all less than or equal to 10.6%. These columns also facilitated highly sensitive and selective analyses of AQC-amino acids when detected using LC-MS/MS.

  15. Engineering development of advanced physical fine coal cleaning for premium fuel applications

    SciTech Connect

    Smit, F.J.; Jha, M.C.; Phillips, D.I.; Yoon, R.H.

    1997-04-25

    The goal of this project is engineering development of two advanced physical fine coal cleaning processes, column flotation and selective agglomeration, for premium fuel applications. Its scope includes laboratory research and bench-scale testing on six coals to optimize these processes, followed by design and construction of a 2 t/h process development unit (PDU). Large lots of clean coal are to be produced in the PDU from three project coals. Investigation of the near-term applicability of the two advanced fine coal cleaning processes in an existing coal preparation plant is another goal of the project and is the subject of this report.

  16. 33 CFR 183.112 - Flotation material and air chambers.

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... SECURITY (CONTINUED) BOATING SAFETY BOATS AND ASSOCIATED EQUIPMENT Flotation Requirements for Inboard Boats, Inboard/Outdrive Boats, and Airboats § 183.112 Flotation material and air chambers. (a)...

  17. 33 CFR 183.112 - Flotation material and air chambers.

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... SECURITY (CONTINUED) BOATING SAFETY BOATS AND ASSOCIATED EQUIPMENT Flotation Requirements for Inboard Boats, Inboard/Outdrive Boats, and Airboats § 183.112 Flotation material and air chambers. (a)...

  18. 33 CFR 183.112 - Flotation material and air chambers.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... SECURITY (CONTINUED) BOATING SAFETY BOATS AND ASSOCIATED EQUIPMENT Flotation Requirements for Inboard Boats, Inboard/Outdrive Boats, and Airboats § 183.112 Flotation material and air chambers. (a)...

  19. 33 CFR 183.112 - Flotation material and air chambers.

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ... SECURITY (CONTINUED) BOATING SAFETY BOATS AND ASSOCIATED EQUIPMENT Flotation Requirements for Inboard Boats, Inboard/Outdrive Boats, and Airboats § 183.112 Flotation material and air chambers. (a)...

  20. Dissolved air flotation and me.

    PubMed

    Edzwald, James K

    2010-04-01

    This paper is mainly a critical review of the literature and an assessment of what we know about dissolved air flotation (DAF). A few remarks are made at the outset about the author's personal journey in DAF research, his start and its progression. DAF has been used for several decades in drinking water treatment as an alternative clarification method to sedimentation. DAF is particularly effective in treating reservoir water supplies; those supplies containing algae, natural color or natural organic matter; and those with low mineral turbidity. It is more efficient than sedimentation in removing turbidity and particles for these type supplies. Furthermore, it is more efficient in removing Giardia cysts and Cryptosporidium oocysts. In the last 20 years, fundamental models were developed that provide a basis for understanding the process, optimizing it, and integrating it into water treatment plants. The theories were tested through laboratory and pilot-plant studies. Consequently, there have been trends in which DAF pretreatment has been optimized resulting in better coagulation and a decrease in the size of flocculation tanks. In addition, the hydraulic loading rates have increased reducing the size of DAF processes. While DAF has been used mainly in conventional type water plants, there is now interest in the technology as a pretreatment step in ultrafiltration membrane plants and in desalination reverse osmosis plants.

  1. Advanced spatio-temporal modelling in long-term radiological assessment models--radionuclides in the soil column.

    PubMed

    Kłos, R A; Limer, L; Shaw, G; Pérez-Sánchez, D; Xu, S

    2014-03-01

    Recent developments in the modelling of key radionuclides in long-timescale assessments of the safety of geological disposal of spent fuel and other radioactive wastes emphasise the influence of the redox conditions of the soil column. Models with higher spatial resolution than typically employed in standard modelling approaches have been shown to capture important features of experimental observations that are not otherwise manifested. Furthermore, models with monthly, rather than annually, averaged parameters and with dynamic transfers between soil and plant have been shown to lead to key differences compared with standard models employing soil-plant concentration ratios. This paper looks at the potential for the inclusion of a higher spatio-temporal resolution in models for long-timescale dose assessments and includes representations of measured plant-root distributions as well as the effects of bioturbation. Focusing here on the distribution and dynamics of radionuclides in the soil column, the effects of different spatial and temporal resolution are compared, together with an investigation of the way in which the hydrology of the soil column is represented. The approach has been successfully incorporated into a practical assessment-level model. Results indicate the potential importance of higher spatio-temporal resolution in modelling soil column dynamics, particularly of weakly sorbing radionuclides in long-timescale assessments featuring sudden transitions between ecosystem types. PMID:24270190

  2. 21 CFR 880.5550 - Alternating pressure air flotation mattress.

    Code of Federal Regulations, 2014 CFR

    2014-04-01

    ... 21 Food and Drugs 8 2014-04-01 2014-04-01 false Alternating pressure air flotation mattress. 880... Personal Use Therapeutic Devices § 880.5550 Alternating pressure air flotation mattress. (a) Identification. An alternating pressure air flotation mattress is a device intended for medical purposes...

  3. 46 CFR 25.25-13 - Personal flotation device lights.

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    ... 46 Shipping 1 2010-10-01 2010-10-01 false Personal flotation device lights. 25.25-13 Section 25.25... Preservers and Other Lifesaving Equipment § 25.25-13 Personal flotation device lights. (a) This section... device intended to be worn, and each buoyant vest must have a personal flotation device light that...

  4. 46 CFR 25.25-13 - Personal flotation device lights.

    Code of Federal Regulations, 2011 CFR

    2011-10-01

    ... 46 Shipping 1 2011-10-01 2011-10-01 false Personal flotation device lights. 25.25-13 Section 25.25... Preservers and Other Lifesaving Equipment § 25.25-13 Personal flotation device lights. (a) This section... device intended to be worn, and each buoyant vest must have a personal flotation device light that...

  5. 33 CFR 183.105 - Quantity of flotation required.

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ... (CONTINUED) BOATING SAFETY BOATS AND ASSOCIATED EQUIPMENT Flotation Requirements for Inboard Boats, Inboard/Outdrive Boats, and Airboats § 183.105 Quantity of flotation required. (a) Each boat must have enough flotation to keep any portion of the boat above the surface of the water when the boat has been submerged...

  6. 33 CFR 183.105 - Quantity of flotation required.

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... (CONTINUED) BOATING SAFETY BOATS AND ASSOCIATED EQUIPMENT Flotation Requirements for Inboard Boats, Inboard/Outdrive Boats, and Airboats § 183.105 Quantity of flotation required. (a) Each boat must have enough flotation to keep any portion of the boat above the surface of the water when the boat has been submerged...

  7. 33 CFR 183.105 - Quantity of flotation required.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... (CONTINUED) BOATING SAFETY BOATS AND ASSOCIATED EQUIPMENT Flotation Requirements for Inboard Boats, Inboard/Outdrive Boats, and Airboats § 183.105 Quantity of flotation required. (a) Each boat must have enough flotation to keep any portion of the boat above the surface of the water when the boat has been submerged...

  8. 33 CFR 183.105 - Quantity of flotation required.

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... (CONTINUED) BOATING SAFETY BOATS AND ASSOCIATED EQUIPMENT Flotation Requirements for Inboard Boats, Inboard/Outdrive Boats, and Airboats § 183.105 Quantity of flotation required. (a) Each boat must have enough flotation to keep any portion of the boat above the surface of the water when the boat has been submerged...

  9. 33 CFR 175.15 - Personal flotation devices required.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... 33 Navigation and Navigable Waters 2 2010-07-01 2010-07-01 false Personal flotation devices... SECURITY (CONTINUED) BOATING SAFETY EQUIPMENT REQUIREMENTS Personal Flotation Devices § 175.15 Personal flotation devices required. Except as provided in § 175.17 and 175.25: (a) No person may use a...

  10. 46 CFR 25.25-13 - Personal flotation device lights.

    Code of Federal Regulations, 2012 CFR

    2012-10-01

    ... 46 Shipping 1 2012-10-01 2012-10-01 false Personal flotation device lights. 25.25-13 Section 25.25... Preservers and Other Lifesaving Equipment § 25.25-13 Personal flotation device lights. (a) This section... device intended to be worn, and each buoyant vest must have a personal flotation device light that...

  11. 46 CFR 25.25-13 - Personal flotation device lights.

    Code of Federal Regulations, 2013 CFR

    2013-10-01

    ... 46 Shipping 1 2013-10-01 2013-10-01 false Personal flotation device lights. 25.25-13 Section 25.25... Preservers and Other Lifesaving Equipment § 25.25-13 Personal flotation device lights. (a) This section... device intended to be worn, and each buoyant vest must have a personal flotation device light that...

  12. 46 CFR 25.25-13 - Personal flotation device lights.

    Code of Federal Regulations, 2014 CFR

    2014-10-01

    ... 46 Shipping 1 2014-10-01 2014-10-01 false Personal flotation device lights. 25.25-13 Section 25.25... Preservers and Other Lifesaving Equipment § 25.25-13 Personal flotation device lights. (a) This section... device intended to be worn, and each buoyant vest must have a personal flotation device light that...

  13. 21 CFR 880.5550 - Alternating pressure air flotation mattress.

    Code of Federal Regulations, 2012 CFR

    2012-04-01

    ... 21 Food and Drugs 8 2012-04-01 2012-04-01 false Alternating pressure air flotation mattress. 880... Personal Use Therapeutic Devices § 880.5550 Alternating pressure air flotation mattress. (a) Identification. An alternating pressure air flotation mattress is a device intended for medical purposes...

  14. 21 CFR 880.5550 - Alternating pressure air flotation mattress.

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ... 21 Food and Drugs 8 2010-04-01 2010-04-01 false Alternating pressure air flotation mattress. 880... Personal Use Therapeutic Devices § 880.5550 Alternating pressure air flotation mattress. (a) Identification. An alternating pressure air flotation mattress is a device intended for medical purposes...

  15. 21 CFR 880.5550 - Alternating pressure air flotation mattress.

    Code of Federal Regulations, 2013 CFR

    2013-04-01

    ... 21 Food and Drugs 8 2013-04-01 2013-04-01 false Alternating pressure air flotation mattress. 880... Personal Use Therapeutic Devices § 880.5550 Alternating pressure air flotation mattress. (a) Identification. An alternating pressure air flotation mattress is a device intended for medical purposes...

  16. 21 CFR 880.5550 - Alternating pressure air flotation mattress.

    Code of Federal Regulations, 2011 CFR

    2011-04-01

    ... 21 Food and Drugs 8 2011-04-01 2011-04-01 false Alternating pressure air flotation mattress. 880... Personal Use Therapeutic Devices § 880.5550 Alternating pressure air flotation mattress. (a) Identification. An alternating pressure air flotation mattress is a device intended for medical purposes...

  17. 14 CFR 121.340 - Emergency flotation means.

    Code of Federal Regulations, 2010 CFR

    2010-01-01

    ... 14 Aeronautics and Space 3 2010-01-01 2010-01-01 false Emergency flotation means. 121.340 Section... Emergency flotation means. (a) Except as provided in paragraph (b) of this section, no person may operate an...(a)(1) or with an approved flotation means for each occupant. This means must be within easy reach...

  18. Physically absorbable reagents-collectors in elementary flotation

    SciTech Connect

    S.A. Kondrat'ev; I.G. Bochkarev

    2007-09-15

    Based on the reviewed researches held at the Institute of Mining, Siberian Branch, Russian Academy of Sciences, the effect of physically absorbable reagents-collectors on formation of a flotation complex and its stability in turbulent pulp flows in flotation machines of basic types is considered. The basic requirements for physically absorbable reagents-collectors at different flotation stages are established.

  19. Effect of microwave radiation on coal flotation

    SciTech Connect

    Ozbayoglu, G.; Depci, T.; Ataman, N.

    2009-07-01

    Most low-rank coals are high in moisture and acid functional groups, therefore showing poor floatability. Drying, which removes the water molecules trapped in the pores and adsorbed at the surface of coal, decreases the hydrophilic character and improves the floatability. Microwave heating, whose simplest application is drying, was applied at 0.9 kW power level for 60 sec exposure time in the experiments to decrease the moisture content of coal in order to enhance the hydrophobicity. The flotation tests of microwave-treated coal by using heptanol and octanol lead to a higher flotation yield and ash removal than original coal.

  20. 76 FR 56294 - Inflatable Personal Flotation Devices

    Federal Register 2010, 2011, 2012, 2013, 2014

    2011-09-13

    ... issues in a notice of proposed rulemaking. DATES: The direct final rule published March 30, 2011, (76 FR... rule entitled ``Inflatable Personal Flotation Devices'' in the Federal Register (76 FR 17561). That..., or why it would be ineffective or unacceptable without a change (76 FR 17563). This...

  1. Plagioclase flotation and lunar crust formation

    NASA Technical Reports Server (NTRS)

    Walker, D.; Hays, J. F.

    1977-01-01

    Anorthitic plagioclase floats in liquids parental to the lunar highlands crust. The plagioclase enrichment that is characteristic of lunar highlands rocks can be the result of plagioclase flotation. Such rocks would form a gravitationally stable upper crust on their parental magma.

  2. Distillation Column Flooding Predictor

    SciTech Connect

    George E. Dzyacky

    2010-11-23

    The Flooding Predictor™ is a patented advanced control technology proven in research at the Separations Research Program, University of Texas at Austin, to increase distillation column throughput by over 6%, while also increasing energy efficiency by 10%. The research was conducted under a U. S. Department of Energy Cooperative Agreement awarded to George Dzyacky of 2ndpoint, LLC. The Flooding Predictor™ works by detecting the incipient flood point and controlling the column closer to its actual hydraulic limit than historical practices have allowed. Further, the technology uses existing column instrumentation, meaning no additional refining infrastructure is required. Refiners often push distillation columns to maximize throughput, improve separation, or simply to achieve day-to-day optimization. Attempting to achieve such operating objectives is a tricky undertaking that can result in flooding. Operators and advanced control strategies alike rely on the conventional use of delta-pressure instrumentation to approximate the column’s approach to flood. But column delta-pressure is more an inference of the column’s approach to flood than it is an actual measurement of it. As a consequence, delta pressure limits are established conservatively in order to operate in a regime where the column is never expected to flood. As a result, there is much “left on the table” when operating in such a regime, i.e. the capacity difference between controlling the column to an upper delta-pressure limit and controlling it to the actual hydraulic limit. The Flooding Predictor™, an innovative pattern recognition technology, controls columns at their actual hydraulic limit, which research shows leads to a throughput increase of over 6%. Controlling closer to the hydraulic limit also permits operation in a sweet spot of increased energy-efficiency. In this region of increased column loading, the Flooding Predictor is able to exploit the benefits of higher liquid

  3. Engineering development of advanced physical fine coal cleaning for premium fuel applications

    SciTech Connect

    Smit, F.J.; Jha, M.C.

    1993-01-18

    This project is a step in the Department of Energy's program to show that ultra-clean fuel can be produced from selected coals and that the fuel will be a cost-effective replacement for oil and natural gas now fueling boilers in this country. The replacement of premium fossil fuels with coal can only be realized if retrofit costs are kept to a minimum and retrofit boiler emissions meet national goals for clean air. These concerns establish the specifications for maximum ash and sulfur levels and combustion properties of the ultra-clean coal. The primary objective is to develop the design base for prototype commercial advanced fine coal cleaning facilities capable of producing ultra-clean coals suitable for conversion to coal-water slurry fuel. The fine coal cleaning technologies are advanced column flotation and selective agglomeration. A secondary objective is to develop the design base for near-term commercial integration of advanced fine coal cleaning technologies in new or existing coal preparation plants for economically and efficiently processing minus 28-mesh coal fines. A third objective is to determine the distribution of toxic trace elements between clean coal and refuse when applying the advance column flotation and selective agglomeration technologies. The project team consists of Amax Research Development Center (Amax R D), Amax Coal industries, Bechtel Corporation, Center for Applied Energy Research (CAER) at the University of Kentucky, and Arcanum Corporation.

  4. A Multi-Objective Advanced Design Methodology of Composite Beam-to-Column Joints Subjected to Seismic and Fire Loads

    SciTech Connect

    Pucinotti, Raffaele; Ferrario, Fabio; Bursi, Oreste S.

    2008-07-08

    A multi-objective advanced design methodology dealing with seismic actions followed by fire on steel-concrete composite full strength joints with concrete filled tubes is proposed in this paper. The specimens were designed in detail in order to exhibit a suitable fire behaviour after a severe earthquake. The major aspects of the cyclic behaviour of composite joints are presented and commented upon. The data obtained from monotonic and cyclic experimental tests have been used to calibrate a model of the joint in order to perform seismic simulations on several moment resisting frames. A hysteretic law was used to take into account the seismic degradation of the joints. Finally, fire tests were conducted with the objective to evaluate fire resistance of the connection already damaged by an earthquake. The experimental activity together with FE simulation demonstrated the adequacy of the advanced design methodology.

  5. Visualized study on the interaction between single bubbles and curved solid surface in flotation separation process.

    PubMed

    Yang, Liwei; Zhao, Yue; Yang, Jingjing; Li, Yanpeng; Meng, Qinglong

    2014-01-01

    The present study has been devoted to bubble-curved solid surface interaction in water, which is critical to the separation of suspended particles by air flotation. For this purpose, two particular stages of the interaction (collision and attachment) have been examined visually using high-speed photography in a laboratory-scale flotation column. The effects of the surface material and surfactant concentration on these two stages have been also studied quantitatively. The considered solid materials are the cleaned glass as hydrophilic surface and Teflon as hydrophobic surface. The experimental results show that the presence of surfactant significantly affects the collision and rebound process of a gas bubble, while there is no obvious effect of the surface material on the rebound process. An increase in surfactant concentration has been observed to suppress the rebound number and maximal distance of the bubble from the surface. Moreover, the three-phase contact time of the bubble is a strong function of the surfactant concentration and surface hydrophobicity as well as of the bubble diameter. Another important finding is that the bubble attachment is only observed at the hydrophobic Teflon surface below the surfactant CMC (critical micelle concentration). Results of this study are relevant for deep understanding of the attachment mechanism and to determine the proper conditions for a selective flotation process.

  6. Improved algal harvesting using suspended air flotation.

    PubMed

    Wiley, Patrick E; Brenneman, Kristine J; Jacobson, Arne E

    2009-07-01

    Current methods to remove algae from a liquid medium are energy intensive and expensive. This study characterized algae contained within a wastewater oxidation pond and sought to identify a more efficient harvesting technique. Analysis of oxidation pond wastewater revealed that algae, consisting primarily of Chlorella and Scenedesmus, composed approximately 80% of the solids inventory during the study period. Results demonstrated that suspended air flotation (SAF) could harvest algae with a lower air:solids (A/S) ratio, lower energy requirements, and higher loading rates compared to dissolved air flotation (DAF) (P < 0.001). Identification of a more efficient algal harvesting system may benefit wastewater treatment plants by enabling cost effective means to reduce solids content of the final effluent. Furthermore, use of SAF to harvest commercially grown Chlorella and Scenedesmus may reduce manufacturing costs of algal-based products such as fuel, fertilizer, and fish food.

  7. Elk Valley coal implements smartcell flotation technology

    SciTech Connect

    Stirling, J.C.

    2008-06-15

    In anticipation of future raw coal containing higher fines content, Elk Valley Coal Corp.'s Greenhills Operations upgraded their fines circuit to include Wemco SmartCells in March 2007. Positive results were immediately achieved increasing the average flotation tailings ash by 16%. With this increase in yield the SmartCells project paid for itself in less than eight months. 2 figs., 1 tab., 1 photo.

  8. Flotation machine and process for removing impurities from coals

    DOEpatents

    Szymocha, K.; Ignasiak, B.; Pawlak, W.; Kulik, C.; Lebowitz, H.E.

    1995-12-05

    The present invention is directed to a type of flotation machine that combines three separate operations in a single unit. The flotation machine is a hydraulic separator that is capable of reducing the pyrite and other mineral matter content of a coal. When the hydraulic separator is used with a flotation system, the pyrite and certain other mineral particles that may have been entrained by hydrodynamic forces associated with conventional flotation machines and/or by the attachment forces associated with the formation of microagglomerates are washed and separated from the coal. 4 figs.

  9. Flotation machine and process for removing impurities from coals

    DOEpatents

    Szymocha, K.; Ignasiak, B.; Pawlak, W.; Kulik, C.; Lebowitz, H.E.

    1997-02-11

    The present invention is directed to a type of flotation machine that combines three separate operations in a single unit. The flotation machine is a hydraulic separator that is capable of reducing the pyrite and other mineral matter content of a coal. When the hydraulic separator is used with a flotation system, the pyrite and certain other minerals particles that may have been entrained by hydrodynamic forces associated with conventional flotation machines and/or by the attachment forces associated with the formation of microagglomerates are washed and separated from the coal. 4 figs.

  10. Flotation machine and process for removing impurities from coals

    DOEpatents

    Szymocha, Kazimierz; Ignasiak, Boleslaw; Pawlak, Wanda; Kulik, Conrad; Lebowitz, Howard E.

    1997-01-01

    The present invention is directed to a type of flotation machine that combines three separate operations in a single unit. The flotation machine is a hydraulic separator that is capable of reducing the pyrite and other mineral matter content of a coal. When the hydraulic separator is used with a flotation system, the pyrite and certain other minerals particles that may have been entrained by hydrodynamic forces associated with conventional flotation machines and/or by the attachment forces associated with the formation of microagglomerates are washed and separated from the coal.

  11. Flotation machine and process for removing impurities from coals

    DOEpatents

    Szymocha, Kazimierz; Ignasiak, Boleslaw; Pawlak, Wanda; Kulik, Conrad; Lebowitz, Howard E.

    1995-01-01

    The present invention is directed to a type of flotation machine that combines three separate operations in a single unit. The flotation machine is a hydraulic separator that is capable of reducing the pyrite and other mineral matter content of a coal. When the hydraulic separator is used with a flotation system, the pyrite and certain other minerals particles that may have been entrained by hydrodynamic forces associated with conventional flotation machines and/or by the attachment forces associated with the formation of microagglomerates are washed and separated from the coal.

  12. 33 CFR 183.325 - Flotation test for persons capacity.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... 33 Navigation and Navigable Waters 2 2010-07-01 2010-07-01 false Flotation test for persons capacity. 183.325 Section 183.325 Navigation and Navigable Waters COAST GUARD, DEPARTMENT OF HOMELAND SECURITY (CONTINUED) BOATING SAFETY BOATS AND ASSOCIATED EQUIPMENT Flotation Requirements for Outboard Boats Rated for Engines of 2 Horsepower or...

  13. 33 CFR 183.225 - Flotation test for persons capacity.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... 33 Navigation and Navigable Waters 2 2010-07-01 2010-07-01 false Flotation test for persons capacity. 183.225 Section 183.225 Navigation and Navigable Waters COAST GUARD, DEPARTMENT OF HOMELAND SECURITY (CONTINUED) BOATING SAFETY BOATS AND ASSOCIATED EQUIPMENT Flotation Requirements for Outboard Boats Rated for Engines of More Than 2...

  14. 33 CFR 183.202 - Flotation and certification requirements.

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... SECURITY (CONTINUED) BOATING SAFETY BOATS AND ASSOCIATED EQUIPMENT Flotation Requirements for Outboard Boats Rated for Engines of More Than 2 Horsepower General § 183.202 Flotation and certification requirements. Each boat to which this subpart applies must be manufactured, constructed, or assembled to...

  15. 33 CFR 183.202 - Flotation and certification requirements.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... SECURITY (CONTINUED) BOATING SAFETY BOATS AND ASSOCIATED EQUIPMENT Flotation Requirements for Outboard Boats Rated for Engines of More Than 2 Horsepower General § 183.202 Flotation and certification requirements. Each boat to which this subpart applies must be manufactured, constructed, or assembled to...

  16. 46 CFR 170.245 - Foam flotation material.

    Code of Federal Regulations, 2012 CFR

    2012-10-01

    ... by reference; see 46 CFR 170.015), including the requirements for fire resistance. (3) A submergence... 46 Shipping 7 2012-10-01 2012-10-01 false Foam flotation material. 170.245 Section 170.245... REQUIREMENTS FOR ALL INSPECTED VESSELS Special Installations § 170.245 Foam flotation material....

  17. 46 CFR 170.245 - Foam flotation material.

    Code of Federal Regulations, 2011 CFR

    2011-10-01

    ... by reference; see 46 CFR 170.015), including the requirements for fire resistance. (3) A submergence... 46 Shipping 7 2011-10-01 2011-10-01 false Foam flotation material. 170.245 Section 170.245... REQUIREMENTS FOR ALL INSPECTED VESSELS Special Installations § 170.245 Foam flotation material....

  18. 46 CFR 170.245 - Foam flotation material.

    Code of Federal Regulations, 2014 CFR

    2014-10-01

    ... 46 Shipping 7 2014-10-01 2014-10-01 false Foam flotation material. 170.245 Section 170.245 Shipping COAST GUARD, DEPARTMENT OF HOMELAND SECURITY (CONTINUED) SUBDIVISION AND STABILITY STABILITY REQUIREMENTS FOR ALL INSPECTED VESSELS Special Installations § 170.245 Foam flotation material....

  19. Beneficiation of borax by reverse flotation in boron saturated brine.

    PubMed

    Cafer Cilek, Emin; Uresin, Hasan

    2005-10-15

    Flotation is one of the plausible methods for recovering borax fines discharged as fine waste to the tailings dam in the Kirka borax processing plant. A literature review dealing with the flotation behavior of boron minerals reveals that clay minerals in the boron ores coat boron minerals and thus deteriorate the quality of boron concentrates produced by direct flotation. The main objective of this study is therefore to recover borax fines from the tailings of the concentrator by reverse flotation. A three-level-factor experimental design was used to determine the main and interaction effects of variables selected on the metallurgical performance of reverse flotation. An analysis of variance for experimental results indicates that interaction effects of the variables for concentrate quality and recovery of B2O3 is nonsignificant and the most important variable for grade of concentrate and recovery is the collector dosage. It is shown that a concentrate assaying 11.25% B2O3 with 89.90% B2O3 recovery could be produced by means of single-stage (rougher) reverse flotation. Additionally, in order to produce a sufficient-quality concentrate, a multistage reverse flotation scheme involving rougher, scavenger, and two cleaners was devised. A final concentrate containing 23.47% B2O3 with 81.78% B2O3 recovery was obtained from these tests. The reverse flotation method can be thus considered as an important option for the beneficiation of borax fines.

  20. ENGINEERING DEVELOPMENT OF ADVANCED PHYSICAL FINE COAL CLEANING FOR PREMIUM FUEL APPLICATIONS

    SciTech Connect

    none,

    1997-06-01

    Bechtel, together with Amax Research and Development Center (Amax R&D), has prepared this study which provides conceptual cost estimates for the production of premium quality coal-water slurry fuel (CWF) in a commercial plant. Two scenarios are presented, one using column flotation technology and the other the selective agglomeration to clean the coal to the required quality specifications. This study forms part of US Department of Energy program "Engineering Development of Advanced Physical Fine Coal Cleaning for Premium Fuel Applications," (Contract No. DE-AC22- 92PC92208), under Task 11, Project Final Report. The primary objective of the Department of Energy program is to develop the design base for prototype commercial advanced fine coal cleaning facilities capable of producing ultra-clean coals suitable for conversion to stable and highly loaded CWF. The fuels should contain less than 2 lb ash/MBtu (860 grams ash/GJ) of HHV and preferably less than 1 lb ash/MBtu (430 grams ash/GJ). The advanced fine coal cleaning technologies to be employed are advanced column froth flotation and selective agglomeration. It is further stipulated that operating conditions during the advanced cleaning process should recover not less than 80 percent of the carbon content (heating value) in the run-of-mine source coal. These goals for ultra-clean coal quality are to be met under the constraint that annualized coal production costs does not exceed $2.5 /MBtu ($ 2.37/GJ), including the mine mouth cost of the raw coal. A further objective of the program is to determine the distribution of a selected suite of eleven toxic trace elements between product CWF and the refuse stream of the cleaning processes. Laboratory, bench-scale and Process Development Unit (PDU) tests to evaluate advanced column flotation and selective agglomeration were completed earlier under this program with selected coal samples. A PDU with a capacity of 2 st/h was designed by Bechtel and installed at Amax R

  1. Additive-free harvesting of oleaginous phagotrophic microalga by oil and air flotation.

    PubMed

    Hosseini, Majid; Starvaggi, Haley A; Ju, Lu-Kwang

    2016-07-01

    A unique oleaginous phagotrophic microalga Ochromonas danica is poised for effective lipid production from waste. Cell harvesting and dewatering are major costs in making algae-based products. In this work an effective additive-free harvesting method was developed, taking advantage of O. danica's comparatively more hydrophobic surface and larger size. The algal cells' partitioning to oil/water interface was evaluated. Recovery by flotation with waste cooking oil was optimized using an L-9 Taguchi orthogonal-array design. Further, additive-free cell collection and concentrating by air flotation was studied for the effects of both physical factors (column dimension, air-stone pore size, sample-to-column volume ratio) and culture properties (pH, culture growth stage, cell concentration, and pure versus impure cultures). The optimized process consistently achieved >90 % recovery in a single stage. 98+ % recovery could be achieved when starting concentrations were >10(8) cells/ml, or potentially using a two- or multi-stage process for diluter cultures. PMID:27025209

  2. PULSE COLUMN

    DOEpatents

    Grimmett, E.S.

    1964-01-01

    This patent covers a continuous countercurrent liquidsolids contactor column having a number of contactor states each comprising a perforated plate, a layer of balls, and a downcomer tube; a liquid-pulsing piston; and a solids discharger formed of a conical section at the bottom of the column, and a tubular extension on the lowest downcomer terminating in the conical section. Between the conical section and the downcomer extension is formed a small annular opening, through which solids fall coming through the perforated plate of the lowest contactor stage. This annular opening is small enough that the pressure drop thereacross is greater than the pressure drop upward through the lowest contactor stage. (AEC)

  3. The sensitivity of direct faecal examination, direct faecal flotation, modified centrifugal faecal flotation and centrifugal sedimentation/flotation in the diagnosis of canine spirocercosis.

    PubMed

    Christie, J; Schwan, E V; Bodenstein, L L; Sommerville, J E M; van der Merwe, L L

    2011-06-01

    Several faecal examination techniques have shown variable sensitivity in demonstrating Spirocerca lupi (S. lupi) eggs. The objective of this study was to determine which faecal examination technique, including a novel modified centrifugal flotation technique, was most sensitive to diagnose spirocercosis. Ten coproscopic examinations were performed on faeces collected from 33 dogs confirmed endoscopically to have spirocercosis. The tests included a direct faecal examination, a faecal sedimentation/flotation test, 4 direct faecal flotations and 4 modified faecal centrifugal flotations. These latter 2 flotation tests utilised 4 different faecal flotation solutions: NaNO3 (SG 1.22), MgSO4 (SG 1.29), ZnSO4 (SG 1.30) and sugar (SG 1.27). The sensitivity of the tests ranged between 42% and 67%, with the NaNO3 solution showing the highest sensitivity in both the direct and modified-centrifugal flotations. The modified NaNO3 centrifugal method ranked 1st with the highest mean egg count (45.24 +/- 83), and was superior (i.e. higher egg count) and significantly different (P < 0.05) compared with the routine saturated sugar, ZnSO4 and MgSO4 flotation methods. The routine NaNO3 flotation method was also superior and significantly different (P < 0.05) compared with the routine ZnSO4 and MgSO4 flotation methods. Fifteen per cent (n = 5) of dogs had neoplastic oesophageal nodules and a further 18% (n = 6) had both neoplastic and non-neoplastic nodules. S. lupi eggs were demonstrated in 40% of dogs with neoplastic nodules only and 72.9% of the dogs with non-neoplastic nodules. The mean egg count in the non-neoplastic group (61) was statistically greater (P = 0.02) than that of the neoplastic group (1). The results show that faecal examination using a NaNO3 solution is the most sensitive in the diagnosis of spirocercosis. The modified centrifugal flotation faecal method using this solution has the highest egg count. The study also found that dogs with neoplastic nodules shed

  4. Engineereing development of advanced physical fine coal cleaning for premium fuel applications. Quarterly technical progress report No. 5, October--December 1993

    SciTech Connect

    Smit, F.J.; Jha, M.C.

    1994-02-18

    This project is a major step in the Department of Energy`s program to show that ultra-clean coal-water slurry fuel (CWF) can be produced from selected coals and that this premium fuel will be a cost-effective replacement for oil and natural gas now fueling some of the industrial and utility boilers in the United States. The replacement of oil and gas with CWF can only be realized if retrofit costs are kept to a minimum and retrofit boiler emissions meet national goals for clean air. These concerns establish the specifications for maximum ash and sulfur levels and combustion properties of the CWF. The project has three major objectives: The primary objective is to develop the design base for prototype commercial advanced fine coal cleaning facilities capable of producing ultra-clean coals suitable for conversion to coal-water slurry fuel for premium fuel applications. The fine coal cleaning technologies are advanced column flotation and selective agglomeration. A secondary objective is to develop the design base for near-term application of these advanced fine coal cleaning technologies in new or existing coal preparation plants for efficiently processing minus 28-mesh coal fines and converting this to marketable products in current market economics. A third objective is to determine the removal of toxic trace elements from coal by advance column flotation and selective agglomeration technologies.

  5. Engineering development of advanced physical fine coal cleaning for premium fuel applications. Quarterly technical progress report No. 1, October--December 1992

    SciTech Connect

    Smit, F.J.; Jha, M.C.

    1993-01-18

    This project is a step in the Department of Energy`s program to show that ultra-clean fuel can be produced from selected coals and that the fuel will be a cost-effective replacement for oil and natural gas now fueling boilers in this country. The replacement of premium fossil fuels with coal can only be realized if retrofit costs are kept to a minimum and retrofit boiler emissions meet national goals for clean air. These concerns establish the specifications for maximum ash and sulfur levels and combustion properties of the ultra-clean coal. The primary objective is to develop the design base for prototype commercial advanced fine coal cleaning facilities capable of producing ultra-clean coals suitable for conversion to coal-water slurry fuel. The fine coal cleaning technologies are advanced column flotation and selective agglomeration. A secondary objective is to develop the design base for near-term commercial integration of advanced fine coal cleaning technologies in new or existing coal preparation plants for economically and efficiently processing minus 28-mesh coal fines. A third objective is to determine the distribution of toxic trace elements between clean coal and refuse when applying the advance column flotation and selective agglomeration technologies. The project team consists of Amax Research & Development Center (Amax R&D), Amax Coal industries, Bechtel Corporation, Center for Applied Energy Research (CAER) at the University of Kentucky, and Arcanum Corporation.

  6. Eruption column physics

    SciTech Connect

    Valentine, G.A.

    1997-03-01

    In this paper the author focuses on the fluid dynamics of large-scale eruption columns. The dynamics of these columns are rooted in multiphase flow phenomena, so a major part of the paper sets up a foundation on that topic that allows one to quickly assess the inherent assumptions made in various theoretical and experimental approaches. The first part is centered on a set of complex differential equations that describe eruption columns, but the focus is on a general understanding of important physical processes rather than on the mathematics. The author discusses briefly the relative merits and weaknesses of different approaches, emphasizing that the largest advances in understanding are made by combining them. He then focuses on dynamics of steady eruption columns and then on transient phenomena. Finally he briefly reviews the effects of varying behavior of the ambient medium through which an eruption column moves. These final sections will emphasize concepts and a qualitative understanding of eruption dynamics. This paper relies on principles of continuum mechanics and transport processes but does not go into detail on the development of those principles. 36 refs., 36 figs., 3 tabs.

  7. Column internals

    SciTech Connect

    Bravo, J.L.

    1998-02-01

    In the fields of distillation, absorption, stripping and extraction, theory and technology go hand in hand. The thermodynamic principles of phase equilibrium and the concepts of mass transfer and fluid flow are of primary importance in all of these operations. The engineer must understand these phenomena to select equipment effectively. This article discusses the latest in commercial technology in column internals for gas-liquid and liquid-liquid contacting. The principles of operation are explained vis-a-vis the characteristics of the applications in which they are used. The focus is on moderate-to-large columns for refining and chemical applications. Guidelines for selecting the most appropriate type of device are presented, and examples of typical applications are described.

  8. Swimming kinematic and flotation analysis of conscious and sedated dogs using 3 canine flotation devices.

    PubMed

    Corum, China Prentice; Wichtowski, Maja; Hetts, Suzanne; Estep, Dan; Bertone, Joseph J

    2014-12-01

    Canine flotation devices (CFDs) are very popular; however, their efficacy is still under debate. There is no oversight to standardize device testing, certification, or qualification for use. We set out to assess the biomechanical and behavioral effects of 3 CFDs on swim and flotation characteristics of dogs. High-speed video recordings were used to measure behavior, range of motion (ROM), maximum flexion angle, and cycles of motion per minute while swimming and roll, yaw, and fear or panic scoring while floating. Predictably, swimming with no CFD yielded the largest ROM and flexion angles. CFDINF was associated with the least ROM. During flotation, CFDAB and CFDRW caused significant rolling and fear, whereas CFDINF was the most stable. CFDAB was associated with cranial downpitch in 2 dogs. Interpretation of the kinematics for CFDAB and CFDRW suggests that decreased stability in the water leads to a greater forced ROM when the position of the dog was conducive to swimming. When positioning forced the dog into a downward pitch, ROM was decreased because of the increased effort for the dogs to keep their head above water. CFDINF was most stable overall owing to a decreased swim effort, with most dogs showing the lowest fear scores and absolute relaxation. CFDAB and CFDRW caused the dogs significant rolling, fear, and distress, with obvious fighting of sedation. We hope to disseminate these results to dog owners in the hopes of providing a valid assessment of these devices.

  9. Particle-bubble aggregate stability on static bubble generated by single nozzle on flotation process

    NASA Astrophysics Data System (ADS)

    Warjito, Harinaldi, Setyantono, Manus; Siregar, Sahala D.

    2016-06-01

    There are three sub-processes on flotation. These processes are intervening liquid film into critical thickness, rupture of liquid film forming three phase contact line, and expansion three phase contact line forming aggregate stability. Aggregate stability factor contribute to determine flotation efficiency. Aggregate stability has some important factors such as reagent and particle geometry. This research focussed on to understand effect of particle geometry to aggregate stability. Experimental setup consists of 9 x 9 x26 cm flotation column made of glass, bubble generator, particle feeding system, and high speed video camera. Bubble generator made from single nozzle with 0.3 mm diameter attached to programmable syringe pump. Particle feeding system made of pipette. Particle used in this research is taken from open pit Grasberg in Timika, Papua. Particle has sub-angular geometry and its size varies from 38 to 300 µm. Bubble-particle interaction are recorded using high speed video camera. Recordings from high speed video camera analyzed using image processing software. Experiment result shows that aggregate particle-bubble and induction time depends on particle size. Small particle (38-106 µm) has long induction time and able to rupture liquid film and also forming three phase contact line. Big particle (150-300 µm) has short induction time, so it unable to attach with bubble easily. This phenomenon is caused by apparent gravity work on particle-bubble interaction. Apparent gravity worked during particle sliding on bubble surface experience increase and reached its maximum magnitude at bubble equator. After particle passed bubble equator, apparent gravity force experience decrease. In conclusion particle size from 38-300 µm can form stable aggregate if particle attached with bubble in certain condition.

  10. Zircon-rutile-ilmenite froth flotation process

    SciTech Connect

    Schmidt, R.; Denham, D.L. Jr.

    1992-04-21

    This patent describes a method for separating a mixture of minerals comprising at least zircon, ilmenite and rutile. It comprises adding an acid solution to the mixture to acidify to a pH of between about 2.0 and 6.0; adding starch to the mixture to depress the ilmenite and the rutile; adding a source of fluoride ions to the mixture to provide a negative surface charge on the zircon surface to activate the zircon; adding an amine cationic collector to the mixture to float the activated zircon; subjecting the mixture containing the added acid solution, the fluoride ions, the starch and the cationic collector, to froth flotation; and withdrawing a float product comprising the zircon and a sink product comprising the ilmenite and rutile.

  11. Effect and mechanism of siderite on reverse flotation of hematite

    NASA Astrophysics Data System (ADS)

    Yin, Wan-zhong; Li, Dong; Luo, Xi-mei; Yao, Jin; Sun, Qian-yu

    2016-04-01

    The effects of siderite on reverse flotation of hematite were investigated using micro flotation, adsorption tests, and Fourier transform infrared spectroscopy. The flotation results show that interactions between siderite and quartz are the main reasons that siderite significantly influences the floatability. The interactions are attributed to dissolved siderite species and fine siderite particles. The interaction due to the dissolved species is, however, dominant. Derjaguin-Landau-Verwey-Overbeek (DLVO) theoretical calculations reveal that adhesion on quartz increases when the siderite particle size decreases and that fine particles partly influence quartz floatability. Chemical solution calculations indicate that the dissolved species of siderite might convert the surface of active quartz to CaCO3 precipitates that can be depressed by starch. The theoretical calculations are in good agreement with the results of adsorption tests and FTIR spectroscopy and explain the reasons why siderite significantly influences reverse flotation of hematite.

  12. Application of Hydrodynamics in Design of Flotation Deinking Cell

    NASA Astrophysics Data System (ADS)

    Li, R. G.; Xie, X. F.; Wang, A. L.; Chen, K. F.

    Recovery and recycling of waste paper has become increasingly important with demand for paper products sharply growing. The flotation process is the predominant technology for the removal of inks from waste paper because of its advantages. Flotation cells may be very different in size and shape, but the key elements ensuring aeration, ink collection and bubble separation are always present. Different aeration systems have been developed by the equipment suppliers. The hydrodynamic method, based on the self suction and mixing of air according to the Venturi principle has become the most common aeration technique. Injectors of various sizes and designs have been investigated and constantly improved and adapted to different designs of flotation units. Step diffuser is a common and predominant injector used in the flotation deinking cell.

  13. 33 CFR 183.114 - Test of flotation materials.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... vapor atmosphere for 30 days at a minimum temperature of 38 °C. (b) 24-hour gasoline test. The flotation... water. (h) The buoyant force reduction in paragraphs (a) through (g) of this section is measured...

  14. Harvesting of Scenedesmus obliquus FSP-3 using dispersed ozone flotation.

    PubMed

    Cheng, Ya-Ling; Juang, Yu-Chuan; Liao, Guan-Yu; Tsai, Pei-Wen; Ho, Shih-Hsin; Yeh, Kuei-Ling; Chen, Chun-Yen; Chang, Jo-Shu; Liu, Jhy-Chern; Chen, Wen-Ming; Lee, Duu-Jong

    2011-01-01

    The Scenedesmus obliquus FSP-3, a species with excellent potential for CO(2) capture and lipid production, was harvested using dispersed ozone flotation. While air aeration does not, ozone produces effective solid-liquid separation through flotation. Ozone dose applied for sufficient algal flotation is similar to those used in practical drinking waterworks. The algae removal rate, surface charge, and hydrophobicity of algal cells, and fluorescence characteristics and proteins and polysaccharides contents of algogenic organic matter (AOM) were determined during ozonation. Proteins released from tightly bound AOM are essential to modifying the hydrophobicity of bubble surfaces for easy cell attachment and to forming a top froth layer for collecting floating cells. Humic substances in the suspension scavenge dosed ozone that adversely affects ozone flotation efficiency of algal cells.

  15. FLOTATION ROOM, LOOKING SOUTHWEST, WITH LEAD ROUGHER CELLS AT RIGHT ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    FLOTATION ROOM, LOOKING SOUTHWEST, WITH LEAD ROUGHER CELLS AT RIGHT AND LEAD CLEANER CELLS AT LEFT. NOTE SUNNYSIDE GOLD CORP. "SG" LOGO ON ROUGHER CELL LAUNDER. - Shenandoah-Dives Mill, 135 County Road 2, Silverton, San Juan County, CO

  16. Interfacial interactions between plastic particles in plastics flotation.

    PubMed

    Wang, Chong-qing; Wang, Hui; Gu, Guo-hua; Fu, Jian-gang; Lin, Qing-quan; Liu, You-nian

    2015-12-01

    Plastics flotation used for recycling of plastic wastes receives increasing attention for its industrial application. In order to study the mechanism of plastics flotation, the interfacial interactions between plastic particles in flotation system were investigated through calculation of Lifshitz-van der Waals (LW) function, Lewis acid-base (AB) Gibbs function, and the extended Derjaguin-Landau-Verwey-Overbeek potential energy profiles. The results showed that van der Waals force between plastic particles is attraction force in flotation system. The large hydrophobic attraction, caused by the AB Gibbs function, is the dominant interparticle force. Wetting agents present significant effects on the interfacial interactions between plastic particles. It is found that adsorption of wetting agents promotes dispersion of plastic particles and decreases the floatability. Pneumatic flotation may improve the recovery and purity of separated plastics through selective adsorption of wetting agents on plastic surface. The relationships between hydrophobic attraction and surface properties were also examined. It is revealed that there exists a three-order polynomial relationship between the AB Gibbs function and Lewis base component. Our finding provides some insights into mechanism of plastics flotation.

  17. Modelling Of Flotation Processes By Classical Mathematical Methods - A Review

    NASA Astrophysics Data System (ADS)

    Jovanović, Ivana; Miljanović, Igor

    2015-12-01

    Flotation process modelling is not a simple task, mostly because of the process complexity, i.e. the presence of a large number of variables that (to a lesser or a greater extent) affect the final outcome of the mineral particles separation based on the differences in their surface properties. The attempts toward the development of the quantitative predictive model that would fully describe the operation of an industrial flotation plant started in the middle of past century and it lasts to this day. This paper gives a review of published research activities directed toward the development of flotation models based on the classical mathematical rules. The description and systematization of classical flotation models were performed according to the available references, with emphasize exclusively given to the flotation process modelling, regardless of the model application in a certain control system. In accordance with the contemporary considerations, models were classified as the empirical, probabilistic, kinetic and population balance types. Each model type is presented through the aspects of flotation modelling at the macro and micro process levels.

  18. Boiling treatment of ABS and PS plastics for flotation separation.

    PubMed

    Wang, Chong-qing; Wang, Hui; Wu, Bao-xin; Liu, Qun

    2014-07-01

    A new physical method, namely boiling treatment, was developed to aid flotation separation of acrylonitrile-butadiene-styrene (ABS) and polystyrene (PS) plastics. Boiling treatment was shown to be effective in producing a hydrophilic surface on ABS plastic. Fourier Transform Infrared analysis was conducted to investigate the mechanism of boiling treatment of ABS. Surface rearrangement of polymer may be responsible for surface change of boiling treated ABS, and the selective influence of boiling treatment on the floatability of boiling treated plastics may be attributed to the difference in the molecular mobility of polymer chains. The effects of flotation time, frother concentration and particle size on flotation behavior of simple plastic were investigated. Based on flotation behavior of simple plastic, flotation separation of boiling treatment ABS and PS with different particle sizes was achieved efficiently. The purity of ABS and PS was up to 99.78% and 95.80%, respectively; the recovery of ABS and PS was up to 95.81% and 99.82%, respectively. Boiling treatment promotes the industrial application of plastics flotation and facilitates plastic recycling.

  19. Interfacial interactions between plastic particles in plastics flotation.

    PubMed

    Wang, Chong-qing; Wang, Hui; Gu, Guo-hua; Fu, Jian-gang; Lin, Qing-quan; Liu, You-nian

    2015-12-01

    Plastics flotation used for recycling of plastic wastes receives increasing attention for its industrial application. In order to study the mechanism of plastics flotation, the interfacial interactions between plastic particles in flotation system were investigated through calculation of Lifshitz-van der Waals (LW) function, Lewis acid-base (AB) Gibbs function, and the extended Derjaguin-Landau-Verwey-Overbeek potential energy profiles. The results showed that van der Waals force between plastic particles is attraction force in flotation system. The large hydrophobic attraction, caused by the AB Gibbs function, is the dominant interparticle force. Wetting agents present significant effects on the interfacial interactions between plastic particles. It is found that adsorption of wetting agents promotes dispersion of plastic particles and decreases the floatability. Pneumatic flotation may improve the recovery and purity of separated plastics through selective adsorption of wetting agents on plastic surface. The relationships between hydrophobic attraction and surface properties were also examined. It is revealed that there exists a three-order polynomial relationship between the AB Gibbs function and Lewis base component. Our finding provides some insights into mechanism of plastics flotation. PMID:26337962

  20. Removal of Wax and Stickies from OCC by Flotation

    SciTech Connect

    M. R. Doshi; J. Dyer

    2000-01-31

    Laboratory research indicates that wax is amenable to removal by froth flotation provided it is free or detached from the fiber. The only effective means, at this time, of maximizing detachment of wax is through the use of low consistency pulping at temperatures above the melting point of wax. Wax removal from WCC through washing, flotation, or a combination of both was approximately 90% in these laboratory studies, indicating that not all of the wax is detached from fibers. These results were summarized in Annual Report 1, December 1, 1997 to November 30, 1998. Pilot trials were conducted in which the authors simulated a conventional OCC repulping process with and without flotation. Additional aggressive washing and water clarification were also examined during the study. The inclusion of flotation in the OCC stock preparation system significantly improved the removal of wax spots and extractable material from the furnish. Based on this study, the authors predict that a compact flotation system with 2 lb surfactant/ton of fiber would improve the OCC pulp quality with regard to wax spots by 60% and would not negatively affect strength properties. Flotation losses would be in the 2-5% range. Two mill trials were conducted during the last quarter of the project. One trial was carried out at Green Bay Packaging, Green Bay, WI, and a second trial was conducted at Menasha Corporation, Otsego, MI. A 250-liter Voith Sulzer Ecocell was used to evaluate the removal of wax and stickies from the OCC processing systems at these two mills. The inclusion of flotation in the OCC stock preparation system significantly improved the removal of wax spots from the furnish. The data indicate that flotation was more effective in removing wax and stickies than reverse cleaners. The mill trials have demonstrated that flotation can be substituted for or replace existing reverse cleaning systems and, in some cases, can replace dispersion systems. In this manner, the use of flotation can

  1. Some physicochemical aspects of water-soluble mineral flotation.

    PubMed

    Wu, Zhijian; Wang, Xuming; Liu, Haining; Zhang, Huifang; Miller, Jan D

    2016-09-01

    Some physicochemical aspects of water-soluble mineral flotation including hydration phenomena, associations and interactions between collectors, air bubbles, and water-soluble mineral particles are presented. Flotation carried out in saturated salt solutions, and a wide range of collector concentrations for effective flotation of different salts are two basic aspects of water-soluble mineral flotation. Hydration of salt ions, mineral particle surfaces, collector molecules or ions, and collector aggregates play an important role in water-soluble mineral flotation. The adsorption of collectors onto bubble surfaces is suggested to be the precondition for the association of mineral particles with bubbles. The association of collectors with water-soluble minerals is a complicated process, which may include the adsorption of collector molecules or ions onto such surfaces, and/or the attachment of collector precipitates or crystals onto the mineral surfaces. The interactions between the collectors and the minerals include electrostatic and hydrophobic interactions, hydrogen bonding, and specific interactions, with electrostatic and hydrophobic interactions being the common mechanisms. For the association of ionic collectors with minerals with an opposite charge, electrostatic and hydrophobic interactions could have a synergistic effect, with the hydrophobic interactions between the hydrophobic groups of the previously associated collectors and the hydrophobic groups of oncoming collectors being an important attractive force. Association between solid particles and air bubbles is the key to froth flotation, which is affected by hydrophobicity of the mineral particle surfaces, surface charges of mineral particles and bubbles, mineral particle size and shape, temperature, bubble size, etc. The use of a collector together with a frother and the use of mixed surfactants as collectors are suggested to improve flotation. PMID:27346329

  2. Some physicochemical aspects of water-soluble mineral flotation.

    PubMed

    Wu, Zhijian; Wang, Xuming; Liu, Haining; Zhang, Huifang; Miller, Jan D

    2016-09-01

    Some physicochemical aspects of water-soluble mineral flotation including hydration phenomena, associations and interactions between collectors, air bubbles, and water-soluble mineral particles are presented. Flotation carried out in saturated salt solutions, and a wide range of collector concentrations for effective flotation of different salts are two basic aspects of water-soluble mineral flotation. Hydration of salt ions, mineral particle surfaces, collector molecules or ions, and collector aggregates play an important role in water-soluble mineral flotation. The adsorption of collectors onto bubble surfaces is suggested to be the precondition for the association of mineral particles with bubbles. The association of collectors with water-soluble minerals is a complicated process, which may include the adsorption of collector molecules or ions onto such surfaces, and/or the attachment of collector precipitates or crystals onto the mineral surfaces. The interactions between the collectors and the minerals include electrostatic and hydrophobic interactions, hydrogen bonding, and specific interactions, with electrostatic and hydrophobic interactions being the common mechanisms. For the association of ionic collectors with minerals with an opposite charge, electrostatic and hydrophobic interactions could have a synergistic effect, with the hydrophobic interactions between the hydrophobic groups of the previously associated collectors and the hydrophobic groups of oncoming collectors being an important attractive force. Association between solid particles and air bubbles is the key to froth flotation, which is affected by hydrophobicity of the mineral particle surfaces, surface charges of mineral particles and bubbles, mineral particle size and shape, temperature, bubble size, etc. The use of a collector together with a frother and the use of mixed surfactants as collectors are suggested to improve flotation.

  3. Role of the collecting agent sorption forms in the elementary act of flotation

    SciTech Connect

    Abramov, A.A.

    2005-02-01

    A new hypothesis of flotation is substantiated based on the well-known hypotheses, theoretical analysis of the elementary act, and experimental results. The hypothesis presented allows the processes of flotation activation, depression, and intensification to be explained and optimized.

  4. Relationships in flotation recovery of thorium-containing anions

    SciTech Connect

    Skrylev, L.D.; Menchuk, V.V.; Seifullina, I.I.

    1981-11-20

    The possibility of flotation recovery of thorium from solutions was first pointed out by Sebba. He also proposed a flotation method for the separation of thorium and uranium, based on the formation of anionic complexes by uranium at levels of solution pH at which thorium is still in the form of simple cations. Later, Shakir carried out a detailed investigation of the flotation recovery of thorium from dilute aqueous solutions by means of cetyltrimethylammonium bromide and lauryl sulfate, and Jacobelli-Turi in media.Sekine applied flotation in the concentration of thorium in the form of a complex with arsenazo III, for analytical purposes. In our previous studies, we had shown that it was possible in principle to recover thorium from dilute sulfuric acid solutions by flotation with aliphatic amines. Here we are reporting on further studies of this process. The materials we chose as thorium collectors in our studies were AAK and primary aliphatic amines (typical cationic surfactants); this type of surfactant was chosen because thorium in sulfuric acid solutions exists in the form of complex anions.

  5. Intensification of flotation treatment by exposure to vibration.

    PubMed

    Ivanov, M V; Ksenofontov, B S

    2014-01-01

    In this paper, an intensification of wastewater flotation treatment by exposure to vibration is studied. Exposure to vibration results in the decrease of air bubble size, increase of air flow through the aerator and more even dispersion of air bubbles in water. This intensifies the aeration process, thus significantly improving the treatment efficiency. A multistage model of flotation kinetics has been applied in order to take into consideration the effects of vibration. The model gives a thorough explanation of the flotation process with consideration of 'air bubble - contaminant particle' aggregate formation. A large series of experiments was conducted with paint and varnish industry wastewaters. It is shown that vibroflotation results in an increase of treatment efficiency by up to three times. A comparison of the experimental data with the results of mathematical modeling is presented, showing a good correlation of theoretical and experimental results.

  6. Preparation and utilization of slurry fuel with flotation tailing

    SciTech Connect

    Jiang Shixin; Jiang Qiyun; Lui Qing; Shao Peozao; Wang Zuna; Guo Baoxin

    1993-12-31

    Most coal preparation plants treating metallurgical coal employ flotation process for recovering concentrate from -0.5mm fraction. For full utilization of combustibles, the common practice of flotation operation is to give a relatively low ash concentrate while leaving a medium ash tailing as an inferior fuel. In this case, the dilute flotation tailing is thickened and dewatered, giving a filtering cake containing about 20-30% moisture as the final product. Difficulties are confronted in handling of this sticky mass. Besides, combustion of such high-moisture inferior fuel would be less efficient and more pollutant. Ways have been sought to solve these problems. Conversion of such dewatered flotation tailing into slurry fuel is one of possible options in view of its good handleability and high efficiency of carbon burnout in combustion even in small outfits. In Chinese situation, a coal mine area always includes population points and associate utilities and consumes about 5% of coal produced, some of which should be of good quality. Clean and efficient usage of such coal sludge in-situ will be of benefit to the mine in that locally consumed coal could be substituted, which can be in turns loaded out as regular commodity or joining with the main stream to coal preparation plant for production of more premium coal. Datun Coal Preparation Plant employs jig-flotation process and produces concentrate for coking plants. It has a designed annual capacity of treating 1.8 Mt feed coal and the highest record of operation was 2.1 Mt. Average yield of flotation tailing in recent years is 3.5%. Economy would be the prime importance to be considered for converting this sludge into slurry fuel, as preparation of coal slurry is usually considered to be expensive.

  7. The effect of asphaltene particle size and distribution on the temporal advancement of the asphaltene deposition profile in the well column

    NASA Astrophysics Data System (ADS)

    Zeinali Hasanvand, Mahdi; Mosayebi Behbahani, Reza; Feyzi, Farzaneh; Ali Mousavi Dehghani, Seyed

    2016-05-01

    Asphaltene deposition in oil wells is an inconvenient production problem. Generating a precise deposition model for the well column is essential for optimal well design and prevention/reduction of deposition-associated difficulties. The goal of this study is to determine the effects of various parameters on the deposition process. These parameters include oil viscosity, temperature, flow velocity, well diameter and asphaltene particle size and particle size distribution. The first five parameters are analyzed using Escobedo and Mansoori (2010), Cleaver and Yates (1975) and Friedlander and Johnstone (1957) asphaltene deposition models. The last parameter (asphaltene particle size distribution) is not directly included in the asphaltene deposition models. Therefore, a dynamic well column model is generated by combining transport phenomena (mass, heat and momentum transfer) equations with thermodynamic models. The model is fine-tuned and verified based on field data from an Iranian producing oil well with frequent asphaltene deposition problem and subsequently used for predicting the time-dependent development of the asphaltene deposition profile in the well column for a series of asphaltene particle size distributions. The results show the effect of the said parameters depends on how the buffer layer and Brownian motion are defined. The Escobedo and Mansoori (2010) model is found to make better predictions of deposited asphaltene in the studied well.

  8. Relative flotation response of zinc sulfide: Mineral and precipitate

    SciTech Connect

    Rao, S.R.; Finch, J.A.; Zhou, Z.; Xu, Z.

    1998-04-01

    Flotation continues to extend to nonmineral applications, including recycling of materials, soil remediation, and effluent treatment. A study has been conducted to compare the floatability of fine zinc sulfide (ZnS) precipitates and sphalerite particles. The floatability of the precipitates was significantly poorer compared to sphalerite particles when xanthate was used as the collector. The floatability was improved by using dodecylamine as the collector, and the difference in floatability between the precipitates was further improved significantly by incorporating a hydrodynamic cavitation tube in a conventional (mechanical) flotation cell. The improved kinetics was attributed to in-situ gas nucleation on the precipitates.

  9. Chemical and colloidal aspects of collectorless flotation behavior of sulfide and non-sulfide minerals.

    PubMed

    Aghazadeh, Sajjad; Mousavinezhad, Seyed Kamal; Gharabaghi, Mahdi

    2015-11-01

    Flotation has been widely used for separation of valuable minerals from gangues based on their surface characterizations and differences in hydrophobicity on mineral surfaces. As hydrophobicity of minerals widely differs from each other, their separation by flotation will become easier. Collectors are chemical materials which are supposed to make selectively valuable minerals hydrophobic. In addition, there are some minerals which based on their surface and structural features are intrinsically hydrophobic. However, their hydrophobicities are not strong enough to be floatable in the flotation cell without collectors such as sulfide minerals, coal, stibnite, and so forth. To float these minerals in a flotation cell, their hydrophobicity should be increased in specific conditions. Various parameters including pH, Eh, size distribution, mill types, mineral types, ore characterization, and type of reaction in flotation cells affect the hydrophobicity of minerals. Surface analysis results show that when sulfide minerals experience specific flotation conditions, the reactions on the surface of these minerals increase the amount of sulfur on the surface. These phenomenons improve the hydrophobicity of these minerals due to strong hydrophobic feature of sulfurs. Collectorless flotation reduces chemical material consumption amount, increases flotation selectivity (grade increases), and affects the equipment quantities; however, it can also have negative effects. Some minerals with poor surface floatability can be increased by adding some ions to the flotation system. Depressing undesirable minerals in flotation is another application of collectorless flotation.

  10. Phenol biodegradation using a repeated batch culture of Candida tropicalis in a multistage bubble column.

    PubMed

    Ruiz-Ordaz, N; Ruiz-Lagunez, J C; Castañon-González, J H; Hernández-Manzano, E; Cristiani-Urbina, E; Galíndez-Mayer, J

    2001-01-01

    As in many other microorganisms, the growth rate of C. tropicalis is affected by phenol. Besides, when the yeast is aerobically cultivated in a medium containing phenol, using a bubble column, the yeast cell flotation phenomenon occurs, which makes the continuous operation of this type of reactor difficult. Therefore, a system of phenol degradation, which recycles the biomass separated by flotation, was devised in this work. In order to reduce the substrate toxicity observed at high phenol concentrations, the bubble column used in the biodegradation studies was fed in a semibatch mode. So, a semicontinuous system was implemented to treat effluents with relatively high concentrations (> 9,000 ppm) of phenol, by replacing periodically about 22% of the bioreactor operational volume. The phenol removal efficiencies obtained with this system were higher than 98.7%.

  11. 14 CFR 121.340 - Emergency flotation means.

    Code of Federal Regulations, 2014 CFR

    2014-01-01

    ... 14 Aeronautics and Space 3 2014-01-01 2014-01-01 false Emergency flotation means. 121.340 Section 121.340 Aeronautics and Space FEDERAL AVIATION ADMINISTRATION, DEPARTMENT OF TRANSPORTATION (CONTINUED... airplane in any overwater operation unless it is equipped with life preservers in accordance with §...

  12. Measuring turbulence in a flotation cell using electrical resistance tomography

    NASA Astrophysics Data System (ADS)

    Meng, Jun; Xie, Weiguo; Runge, Kym; Bradshaw, Dee

    2015-11-01

    Measuring turbulence in an industrial flotation environment has long been problematic due to the opaque, aggressive, and abrasive three-phase environment in a flotation cell. One of the promising measurement techniques is electrical resistance tomography (ERT). By measuring the conductivity distribution across a measurement area, ERT has been adopted by many researchers to monitor and investigate many processes involving multiphase flows. In the research outlined in this paper, a compact ERT probe was built and then used to measure the conductivity distribution within a 60 l flotation cell operated with water and air. Two approaches were then developed to process the ERT data and estimate turbulence-related parameters. One is a conductivity variance method and the other is based on the Green-Kubo relations. Both rely on and use the fluctuation in the ERT measurement caused by bubbles moving through the measurement area changing the density of the fluid. The results from both approaches were validated by comparing the results produced by the ERT probe in a 60l flotation cell operated at different air rates and impeller speeds to that measured using an alternative turbulence measurement device. The second approach is considered superior to the first as the first requires the development of auxiliary information which would not usually be known for a new system.

  13. Beneficiation of U. S. oil shales by froth flotation

    SciTech Connect

    Krishnan, G.N.; Farley, E.P.; Murray, R.G.

    1983-04-01

    A bench-scale study of the beneficiation of western and eastern oil shales was conducted using ball mill grinding and froth flotation techniques. The liberation of organic and inorganic particles required reducing the particles to about 10-20 ..mu..m. Ball mill grinding energies were estimated to be about 50 kwh/ton for the western ''Anvil Points'' shale (13.5 wt% organics, 24 GPT) and 30 kwh/ton for the eastern ''Antrim'' shale (8 wt% organics, 7 GPT) for reduction to 20 ..mu..m. Froth flotation can increase the organic content of Anvil Points shale to about 27 wt% (50 GPT) at about 80% recovery. Froth flotation of finely ground Antrim shale produced concentrates containing 21 wt% organics (23 GPT) with 90% recovery. Higher grades of concentrates at lower recoveries can be obtained with additional stages of grinding and froth flotation. The separation efficiencies for the Anvil Points and Antrim shales were found to be 52% and 60% at the optimum conditions.

  14. 33 CFR 142.45 - Personal flotation devices.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... fall, they would likely fall into water, shall wear a work vest that meets the requirements of 33 CFR 146.20 or a life preserver that meets the requirements of 46 CFR 160.002, 160.005, or 160.055, except... 33 Navigation and Navigable Waters 2 2010-07-01 2010-07-01 false Personal flotation devices....

  15. 46 CFR 179.240 - Foam flotation material.

    Code of Federal Regulations, 2012 CFR

    2012-10-01

    ..., see 46 CFR 175.600). The fire resistance test is not required. (2) Foam may be installed only in void spaces that are free of ignition sources, unless the foam complies with the requirements of 33 CFR 183... 46 Shipping 7 2012-10-01 2012-10-01 false Foam flotation material. 179.240 Section...

  16. 46 CFR 179.240 - Foam flotation material.

    Code of Federal Regulations, 2011 CFR

    2011-10-01

    ..., see 46 CFR 175.600). The fire resistance test is not required. (2) Foam may be installed only in void spaces that are free of ignition sources, unless the foam complies with the requirements of 33 CFR 183... 46 Shipping 7 2011-10-01 2011-10-01 false Foam flotation material. 179.240 Section...

  17. 46 CFR 179.240 - Foam flotation material.

    Code of Federal Regulations, 2014 CFR

    2014-10-01

    ... spaces that are free of ignition sources, unless the foam complies with the requirements of 33 CFR 183... 46 Shipping 7 2014-10-01 2014-10-01 false Foam flotation material. 179.240 Section 179.240 Shipping COAST GUARD, DEPARTMENT OF HOMELAND SECURITY (CONTINUED) SMALL PASSENGER VESSELS (UNDER 100...

  18. 33 CFR 183.225 - Flotation test for persons capacity.

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    .... Flotation standard. When the conditions prescribed in § 183.220 are met, the boat must float in fresh, calm water as follows: (a) The angle of heel does not exceed 10 degrees from the horizontal. (b) Any point on either the forward or aft reference area is above the surface of the water. (c) The reference depth...

  19. 33 CFR 183.325 - Flotation test for persons capacity.

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    .... Flotation standard. When the conditions prescribed in § 183.320 are met, the boat must float in fresh, calm water as follows: (a) The angle of heel does not exceed 10 degrees from the horizontal. (b) Any point on either the forward or aft reference area is above the surface of the water. (c) The reference depth...

  20. 33 CFR 183.325 - Flotation test for persons capacity.

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    .... Flotation standard. When the conditions prescribed in § 183.320 are met, the boat must float in fresh, calm water as follows: (a) The angle of heel does not exceed 10 degrees from the horizontal. (b) Any point on either the forward or aft reference area is above the surface of the water. (c) The reference depth...

  1. 33 CFR 183.225 - Flotation test for persons capacity.

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    .... Flotation standard. When the conditions prescribed in § 183.220 are met, the boat must float in fresh, calm water as follows: (a) The angle of heel does not exceed 10 degrees from the horizontal. (b) Any point on either the forward or aft reference area is above the surface of the water. (c) The reference depth...

  2. 33 CFR 183.325 - Flotation test for persons capacity.

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    .... Flotation standard. When the conditions prescribed in § 183.320 are met, the boat must float in fresh, calm water as follows: (a) The angle of heel does not exceed 10 degrees from the horizontal. (b) Any point on either the forward or aft reference area is above the surface of the water. (c) The reference depth...

  3. 33 CFR 183.225 - Flotation test for persons capacity.

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    .... Flotation standard. When the conditions prescribed in § 183.220 are met, the boat must float in fresh, calm water as follows: (a) The angle of heel does not exceed 10 degrees from the horizontal. (b) Any point on either the forward or aft reference area is above the surface of the water. (c) The reference depth...

  4. 21 CFR 890.5170 - Powered flotation therapy bed.

    Code of Federal Regulations, 2014 CFR

    2014-04-01

    ... 21 Food and Drugs 8 2014-04-01 2014-04-01 false Powered flotation therapy bed. 890.5170 Section 890.5170 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED) MEDICAL DEVICES PHYSICAL MEDICINE DEVICES Physical Medicine Therapeutic Devices §...

  5. 21 CFR 890.5170 - Powered flotation therapy bed.

    Code of Federal Regulations, 2013 CFR

    2013-04-01

    ... 21 Food and Drugs 8 2013-04-01 2013-04-01 false Powered flotation therapy bed. 890.5170 Section 890.5170 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED) MEDICAL DEVICES PHYSICAL MEDICINE DEVICES Physical Medicine Therapeutic Devices §...

  6. 21 CFR 890.5170 - Powered flotation therapy bed.

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ... 21 Food and Drugs 8 2010-04-01 2010-04-01 false Powered flotation therapy bed. 890.5170 Section 890.5170 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED) MEDICAL DEVICES PHYSICAL MEDICINE DEVICES Physical Medicine Therapeutic Devices §...

  7. 21 CFR 890.5170 - Powered flotation therapy bed.

    Code of Federal Regulations, 2012 CFR

    2012-04-01

    ... 21 Food and Drugs 8 2012-04-01 2012-04-01 false Powered flotation therapy bed. 890.5170 Section 890.5170 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED) MEDICAL DEVICES PHYSICAL MEDICINE DEVICES Physical Medicine Therapeutic Devices §...

  8. 21 CFR 890.5170 - Powered flotation therapy bed.

    Code of Federal Regulations, 2011 CFR

    2011-04-01

    ... 21 Food and Drugs 8 2011-04-01 2011-04-01 false Powered flotation therapy bed. 890.5170 Section 890.5170 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED) MEDICAL DEVICES PHYSICAL MEDICINE DEVICES Physical Medicine Therapeutic Devices §...

  9. Surface chemistry control for selective fossil resin flotation

    DOEpatents

    Miller, J.D.; Yi, Y.; Yu, Q.

    1994-06-07

    A froth flotation method is disclosed for separating fine particles of fossil resin by use of frothing reagents which include an aliphatic organic compound having a polar group and containing not more than four carbon atoms. Butanol is an effective frothing reagent in this method. 12 figs.

  10. Surface chemistry control for selective fossil resin flotation

    DOEpatents

    Miller, Jan D.; Yi, Ye; Yu, Qiang

    1994-01-01

    A froth flotation method is disclosed for separating fine particles of fossil resin from by use of frothing reagents which include an aliphatic organic compound having a polar group and containing not more than four carbon atoms. Butanol is an effective frothing reagent in this method.

  11. 33 CFR 142.45 - Personal flotation devices.

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... § 142.45 Personal flotation devices. Personnel, when working in a location such that, in the event of a fall, they would likely fall into water, shall wear a work vest that meets the requirements of 33 CFR 146.20 or a life preserver that meets the requirements of 46 CFR 160.002, 160.005, or 160.055,...

  12. FRACTIONATING COLUMN PRODUCT COLLECTOR CONTROL

    DOEpatents

    Paxson, G.D. Jr.

    1964-03-10

    Means for detecting minute fluid products from a chemical separation column and for advancing a collector tube rack in order to automatically separate and collect successive fractionated products are described. A charge is imposed on the forming drops at the column orifice to create an electric field as the drop falls in the vicinity of a sensing plate. The field is detected by an electrometer tube coupled to the plate causing an output signal to actuate rotation of a collector turntable rack, thereby positioning new collectors under the orifice. The invention provides reliable automatic collection independent of drop size, rate of fall, or chemical composition. (AEC)

  13. Removal of arsenopyrite from complex sulfide minerals by froth flotation

    NASA Astrophysics Data System (ADS)

    Choi, Jin-young; Kim, Yang-soo; Kim, Dong-gyu; Han, Oh-hyung; Park, Chul-hyun

    2016-04-01

    Arsenic (As) is one of hazardous materials and a penalty element in metal concentrates and so metal concentrates containing arsenic of over 0.5% has been currently restricted in import and export trade. It also corrodes a smelting furnace as well as shortens its life cycle. In korea, Janggun mine that produces galena (PbS) /sphalerite (ZnS) concentrate containing arsenic of 1.78% charges a penalty of US 2/ton to LS-Nikko smelter. Hence in this work, flotation tests for removal of arsenopyrite (FeAsS) from sulfide mineral concentrates were carried out using lab scale flotation cell, which maintain grade and recovery of PbS and ZnS in comparison to flotation plant. Particularly, this study was focused on investigating the combination of several chemical reagents (depressant, collector, activator and etc.) that affect flotation performance. In the straight differential flotation for PbS, a PbS grade of 75.80% and a recovery of 90.12% could be obtained with FeAsS removal of 84.1% (0.2% As) under the conditions of 20% feed solids concentration, pH 8.5, 50g/t frother (AF65), 40g/t collector (AP242) and 800g/t As depressant (NaHSO3) and 600g/t Zn depressant (ZnSO4). In the ZnS flotation, the maximum separation achievable for ZnS using froth flotation has been shown to be a grade of 72.57% and a recovery of 95.43%. At this time, FeAsS removal of 87.8% (0.16% As) could be successfully accomplished under pH 11, and 800g/t Zn activator (CuSO4), 75g/t frother (AF65), 60g/t collector (AP211) and 600g/t As depressant (NaHSO3). Acknowledgments This work was supported by the Energy and Resources Engineering Program Grant funded by the Ministry of Trade, Industry and Energy, Korea

  14. Advancements in Algorithms for the Retrieval of CO2 Column Amount and Path Length Using an Intensity-Modulated Continuous-Wave Lidar

    NASA Astrophysics Data System (ADS)

    Harrison, F. W.; Lin, B.; Ismail, S.; Nehrir, A. R.; Dobler, J. T.; Browell, E. V.; Kooi, S. A.; Campbell, J. F.; Obland, M. D.; Yang, M. M.; Meadows, B.

    2014-12-01

    This paper presents an overview of the methods for the retrieval of carbon dioxide (CO2) and oxygen (O2) column amounts and their associated path lengths measured by the Multi-Functional Fiber Laser Lidar (MFLL) and the ASCENDS CarbonHawk Experiment Simulator (ACES). MFLL and ACES are multi-frequency, Intensity-Modulated, Continuous-Wave (IM-CW) Lidar systems developed as proof-of-concept demonstrators for NASA's Active Sensing of CO2 Emissions over Nights, Days, and Seasons (ASCENDS) mission. The National Research Council identified ASCENDS in 2007 as an important mid-term decadal survey mission to provide measurements critical to improved projections of the Earth's future climate. The ASCENDS measurement requirements have evolved significantly since first proposed by the NRC as has our understanding of the IM-CW measurement technique we propose for use by ASCENDS. To meet these requirements, both MFLL and ACES transmit wavelengths near 1.57 and 1.26 μm modulated with range-encoded signals to minimize bias from thin clouds in the CO2 and O2 column measurements while simultaneously measuring the path length to the surface and to intervening cloud layers. In preparation for the ASCENDS mission, the MFLL has been deployed on 13 airborne field campaigns since 2005, including the latest series of flights in August 2014. NASA also flew the ACES instrument as a technology demonstrator in 2014. In this paper we describe the current ASCENDS retrieval technique and present the accuracy and precision of the measurements obtained using this technique. We also present a reanalysis of the 2011 MFLL measurements and compare the results previously reported to the reanalysis. Reanalysis yields range precisions of less that one meter from an altitude of 12 kilometers from the CO2 offline channel with 1.6 watts of transmitted power.

  15. Engineering development of advanced physical fine coal cleaning for premium fuel applications. Quarterly technical progress report No. 6, January--March 1994

    SciTech Connect

    Smit, F.J.; Rowe, R.M.; Anast, K.R.; Jha, M.C.

    1994-05-06

    This project is a major step in the Department of Energy`s program to show that ultra-clean coal-water slurry fuel (CWF) can be produced from selected coals and that this premium fuel will be a cost-effectve replacement for oil and natural gas now fueling some of the industrial and utility boilers in the United States as well as for advanced combustars currently under development. The replacement of oil and gas with CWF can only be realized if retrofit costs are kept to a minimum and retrofit boiler emissions meet national goals fbr clean air. These concerns establish the specifications for maximum ash and sulfur levels and combustion properties of the CWF. This cost-share contract is a 51-month program which started on September 30, 1992. This report discusses the technical progress, made during the 6th quarter of the project from January 1 to March 31, 1994. The project has three major objectives: (1) The primary objective is to develop the design base for prototype commercial advanced fine coal cleaning facilities capable of producing ultra-clean coals suitable for conversion to coal-water slurry fuel for premium fuel applications. The fine coal cleaning technologies are advanced column flotation and selective agglomeration. (2) A secondary objective is to develop the design base for near-term application of these advanced fine coal cleaning technologies in new or existing coal preparation plants for efficiently processing minus 28-mesh coal fines and converting this to marketable products in current market economics. (3) A third objective is to determine the removal of toxic trace elements from coal by advance column flotation and selective agglomeration technologies.

  16. Flotation rate and residence time distribution in continuous coal froth flotation circuits and an evaluation of reagents and circuit variations for pyritic sulfur removal

    SciTech Connect

    Arnold, B.J.

    1989-01-01

    This thesis gives the results of research conducted on several aspects of coal froth flotation. The effect of operating variables on the residence time distribution in coal froth flotation cells is discussed, and a model of the residence time distribution is presented for use with flotation rate models in scaling up from laboratory to plant scale. Flotation rate models are also investigated in detail for continuous coal froth flotation circuits. Changes in operating variables were found to affect the mean residence time in cells, but they did not have much effect on the mixing behavior. The use of a time lag was found to be an important part of rate models for continuous froth flotation cells. An important aspect of the use of such rate and residence time equations is their application to the flotation of gangue constituents, which often enter the froth by water carry-over in addition to natural flotation or flotation as slime coatings. As such, water carry-over is also investigated in this thesis for the laboratory and the plant and for both ash-forming minerals and pyrite. Maintaining a constant froth factor, the percentage of froth above the weir, in both laboratory and plant tests is believed to be a critical factor in predicting plant results using a kinetic factor ratio documented in the literature. Removing the pyrite and ash-forming minerals from coal that may be recovered by the water carry-over or other mechanisms is an important goal in coal froth flotation. This thesis also contains the results of tests with pyrite depressants and circuit variations for removal of pyritic sulfur.

  17. Improved flotation performance of hematite fines using citric acid as a dispersant

    NASA Astrophysics Data System (ADS)

    Luo, Xi-mei; Yin, Wan-zhong; Sun, Chuan-yao; Wang, Nai-ling; Ma, Ying-qiang; Wang, Yun-fan

    2016-10-01

    In this study, citric acid was used as a dispersant to improve the flotation performance of hematite fines. The effect and mechanism of citric acid on the reverse flotation of hematite fines were investigated by flotation tests, sedimentation experiments, scanning electron microscopy (SEM), zeta-potential measurements, and X-ray photoelectron spectroscopy (XPS). The results of SEM analysis and flotation tests reveal that a strong heterocoagulation in the form of slime coating or coagulation in hematite fine slurry affects the beneficiation of hematite ores by froth flotation. The addition of a small amount of citric acid (less than 300 g/t) favorably affects the reverse flotation of hematite fines by improving particle dispersion. The results of sedimentation experiments, zeta-potential measurements, and XPS measurements demonstrate that citric acid adsorbs onto hematite and quartz surfaces via hydrogen bonding, thereby reducing the zeta potentials of mineral surfaces, strengthening the electrical double-layer repulsion between mineral particles, and dispersing the pulp particles.

  18. Microalgae harvesting by flotation using natural saponin and chitosan.

    PubMed

    Kurniawati, H Agnes; Ismadji, Suryadi; Liu, J C

    2014-08-01

    This study aims to investigate the harvesting of microalgae by dispersed air flotation (DiAF) using natural biosurfactant saponin as the collector and chitosan as the flocculant. Two types of microalgae, Chlorella vulgaris and Scenedesmus obliquus, were used in this study. It was observed that saponin was a good frother, but not an effective collector when used alone for flotation separation of algae. However, with the pre-flocculation of 5 mg/L of chitosan, separation efficiency of >93% microalgae cells was found at 20 mg/L of saponin. Removal efficiency of >54.4% and >73.0% was found for polysaccharide and protein, respectively at 20 mg/L of saponin and chitosan each. Experimental results show that DiAF using saponin and chitosan is effective for separation of microalgae, and algogenic organic matter (AOM). It can potentially be applied in the integrated microalgae-based biorefinery.

  19. On the Methodology of Nematode Extraction from Field Samples: Density Flotation Techniques

    PubMed Central

    Viglierchio, David R.; Yamashita, Tom T.

    1983-01-01

    Density flotation has been frequently used for the extraction of nematodes from field samples. Density flotation curves for four nematode species and five solutes have been prepared. The curves confirm that flotation was governed by several factors: solute density, solute osmotic activity, and physiological properties of the nematode species. Nematode viability and function can be adversely affected by improper selection of solute for density extraction of nematodes; nevertheless, some nematode species can be enriched from mixtures by density and solute selection. PMID:19295831

  20. Starch columns: Analog model for basalt columns

    NASA Astrophysics Data System (ADS)

    Müller, Gerhard

    1998-07-01

    Desiccation of starch-water mixtures produces tensile-crack patterns which appear to be interesting, but largely unknown study objects for fracture mechanics, structural geology, and volcanology. This paper concentrates on columnar jointing and on columns in starch. Starch columns have polygonal cross sections and are very similar to basalt columns. They are produced by lamp drying starch specimens with dimensions of several centimeters and have diameters in the millimeter range. The columns develop behind a crack front which propagates from the surface into the interior. The experiments, supported by X ray tomograms, show that polygonal regularity of the crack pattern is not present at the surface but develops during penetration. This transition is steered by a minimum-fracture-energy principle. The analogy between basalt cooling and starch desiccation is far reaching: water concentration in starch is analogous to temperature in basalt, both quantities obey diffusion equations, water loss is equivalent to heat loss, the resulting contraction stresses have similar dependences on depth and time, and in both cases the material strength is exceeded. The starch experiments show that column diameters are controlled by the depth gradient of water concentration at the crack front. High (low) gradients are connected with thin (thick) columns. By analogy, a similar relation with the temperature gradient exists for basalt columns. The (normalized) starch gradients are about 3 orders of magnitude larger than the (normalized) gradients in basalt. This explains why starch columns are much thinner than basalt columns. The gradients are so different, because the crack front speeds differ by a factor of about 10: after 3 days the speed is about 10 mm/d in starch but about 100 mm/d in basalt [Peck, 1978]. The speed difference, in turn, results from the difference of the diffusion constants: the hydraulic diffusivity of starch is 2 orders of magnitude lower than the thermal

  1. Flotation: A promising microalgae harvesting and dewatering technology for biofuels production.

    PubMed

    Ndikubwimana, Theoneste; Chang, Jingyu; Xiao, Zongyuan; Shao, Wenyao; Zeng, Xianhai; Ng, I-Son; Lu, Yinghua

    2016-03-01

    Microalgal biomass as renewable energy source is believed to be of great potential for reliable and sustainable biofuels production. However, microalgal biomass production is pinned by harvesting and dewatering stage thus hindering the developing and growing microalgae biotechnology industries. Flotation technology applied in mineral industry could be potentially applied in microalgae harvesting and dewatering, however substantial knowledge on different flotation units is essential. This paper presents an overview on different flotation units as promising cost-effective technologies for microalgae harvesting thus bestowing for further research in development and commercialization of microalgae based biofuels. Dispersed air flotation was found to be less energy consuming. Moreover, Jameson cell flotation and dispersed ozone flotation are believed to be energy efficient microalgae flotation approaches. Microalgae harvesting and dewatering by flotation is still at embryonic stage, therefore extended studies with the focus on life cycle assessment, sustainability of the flotation unit, optimization of the operating parameters using different algal species is imperative. Though there are a number of challenges in microalgae harvesting and dewatering, with well designed and developed cultivation, harvesting/dewatering, extraction and conversion technologies, progressively, microalgae technology will be of great potential for biological carbon sequestration, biofuels and biochemicals production.

  2. Flotation: A promising microalgae harvesting and dewatering technology for biofuels production.

    PubMed

    Ndikubwimana, Theoneste; Chang, Jingyu; Xiao, Zongyuan; Shao, Wenyao; Zeng, Xianhai; Ng, I-Son; Lu, Yinghua

    2016-03-01

    Microalgal biomass as renewable energy source is believed to be of great potential for reliable and sustainable biofuels production. However, microalgal biomass production is pinned by harvesting and dewatering stage thus hindering the developing and growing microalgae biotechnology industries. Flotation technology applied in mineral industry could be potentially applied in microalgae harvesting and dewatering, however substantial knowledge on different flotation units is essential. This paper presents an overview on different flotation units as promising cost-effective technologies for microalgae harvesting thus bestowing for further research in development and commercialization of microalgae based biofuels. Dispersed air flotation was found to be less energy consuming. Moreover, Jameson cell flotation and dispersed ozone flotation are believed to be energy efficient microalgae flotation approaches. Microalgae harvesting and dewatering by flotation is still at embryonic stage, therefore extended studies with the focus on life cycle assessment, sustainability of the flotation unit, optimization of the operating parameters using different algal species is imperative. Though there are a number of challenges in microalgae harvesting and dewatering, with well designed and developed cultivation, harvesting/dewatering, extraction and conversion technologies, progressively, microalgae technology will be of great potential for biological carbon sequestration, biofuels and biochemicals production. PMID:26928758

  3. Beneficiation of flotation tailing from Polish copper sulfide ores

    SciTech Connect

    Luszczkiewicz, A.; Sztaba, K.S.

    1995-12-31

    Flotation tailing of Polish copper sulfide ores represents more than 90% of the mass of run-of-mine ore. The tailing contains mainly quartz, dolomite, clay minerals, traces of sulfides, and some accessory minerals. Almost all minerals of the tailing are well liberated and, therefore, any further beneficiation process applied to the tailing is expected to be inexpensive. In this work, results of investigations on utilization of flotation tailing using classification and gravity concentration are presented. It is shown that due to classification of flotation tailing in hydrocyclones, the coarse fraction becomes suitable material for gravity separation providing backfill material for underground mines as well as heavy minerals, a source of valuable rare elements. It was also found that heavy minerals separated by gravity methods contain a significant amount of rare elements such as zirconium, titanium, silver, rare earth metals, and uranium. The light fraction of the gravity separation contains well deslimed quartz particles and meets strict requirements for hydraulic filling material used for structural support in underground mines. Evaluation of the cost of the proposed technology indicated that investment to implement the method would provide a return within 2--4 years.

  4. Flotation and flocculation chemistry of coal and oxidized coals

    SciTech Connect

    Somasundaran, P.

    1990-01-01

    The objective of this research project is to understand the fundamentals involved in the flotation and flocculation of coal and oxidized coals and elucidate mechanisms by which surface interactions between coal and various reagents enhance coal beneficiation. An understanding of the nature of the heterogeneity of coal surfaces arising from the intrinsic distribution of chemical moieties is fundamental to the elucidation of mechanism of coal surface modification and its role in interfacial processes such as flotation, flocculation and agglomeration. A new approach for determining the distribution in surface properties of coal particles was developed in this study and various techniques capable of providing such information were identified. Distributions in surface energy, contact angle and wettability were obtained using novel techniques such as centrifugal immersion and film flotation. Changes in these distributions upon oxidation and surface modifications were monitored and discussed. An approach to the modelling of coal surface site distributions based on thermodynamic information obtained from gas adsorption and immersion calorimetry is proposed. Polyacrylamide and dodecane was used to alter the coal surface. Methanol adsorption was also studied. 62 figs.

  5. Laboratory study of electro-coagulation-flotation for water treatment.

    PubMed

    Jiang, Jia-Qian; Graham, Nigel; André, Cecile; Kelsall, Geoff H; Brandon, Nigel

    2002-09-01

    An electro-coagulation-flotation process has been developed for water treatment. This involved an electrolytic reactor with aluminium electrodes and a separation/flotation tank. The water to be treated passed through the reactor and was subjected to coagulation/flotation, by Al(III) ions dissolved from the electrodes, the resulting flocs floating after being captured by hydrogen gas bubbles generated at cathode surfaces. Apparent current efficiencies for Al dissolution as aqueous Al(III) species at pH 6.5 and 7.8 were greater than unity. This was due to additional reactions occurring in parallel with Al dissolution: oxygen reduction at anodes and cathodes, and hydrogen evolution at cathodes, resulting in net (i.e. oxidation + reduction) currents at both anodes and cathodes. The specific electrical energy consumption of the reactor for drinking water treatment was as low as 20 kWh (kg Al)(-1) for current densities of 10-20A m(-2). The water treatment performance of the electrocoagulation process was found to be superior to that of conventional coagulation with aluminium sulphate for treating a model-coloured water, with 20% more dissolved organic carbon (DOC) being removed for the same Al(III) dose. However, for a lowland surface water sample, the two processes achieved a similar performance for DOC and UV-absorbance removal. In addition, an up-flow electrocoagulator configuration performed better than a horizontal flow configuration, with both bipolar and monopolar electrodes. PMID:12405415

  6. Estimated water requirements for the conventional flotation of copper ores

    USGS Publications Warehouse

    Bleiwas, Donald I.

    2012-01-01

    This report provides a perspective on the amount of water used by a conventional copper flotation plant. Water is required for many activities at a mine-mill site, including ore production and beneficiation, dust and fire suppression, drinking and sanitation, and minesite reclamation. The water required to operate a flotation plant may outweigh all of the other uses of water at a mine site, [however,] and the need to maintain a water balance is critical for the plant to operate efficiently. Process water may be irretrievably lost or not immediately available for reuse in the beneficiation plant because it has been used in the production of backfill slurry from tailings to provide underground mine support; because it has been entrapped in the tailings stored in the TSF, evaporated from the TSF, or leaked from pipes and (or) the TSF; and because it has been retained as moisture in the concentrate. Water retained in the interstices of the tailings and the evaporation of water from the surface of the TSF are the two most significant contributors to water loss at a conventional flotation circuit facility.

  7. Laboratory study of electro-coagulation-flotation for water treatment.

    PubMed

    Jiang, Jia-Qian; Graham, Nigel; André, Cecile; Kelsall, Geoff H; Brandon, Nigel

    2002-09-01

    An electro-coagulation-flotation process has been developed for water treatment. This involved an electrolytic reactor with aluminium electrodes and a separation/flotation tank. The water to be treated passed through the reactor and was subjected to coagulation/flotation, by Al(III) ions dissolved from the electrodes, the resulting flocs floating after being captured by hydrogen gas bubbles generated at cathode surfaces. Apparent current efficiencies for Al dissolution as aqueous Al(III) species at pH 6.5 and 7.8 were greater than unity. This was due to additional reactions occurring in parallel with Al dissolution: oxygen reduction at anodes and cathodes, and hydrogen evolution at cathodes, resulting in net (i.e. oxidation + reduction) currents at both anodes and cathodes. The specific electrical energy consumption of the reactor for drinking water treatment was as low as 20 kWh (kg Al)(-1) for current densities of 10-20A m(-2). The water treatment performance of the electrocoagulation process was found to be superior to that of conventional coagulation with aluminium sulphate for treating a model-coloured water, with 20% more dissolved organic carbon (DOC) being removed for the same Al(III) dose. However, for a lowland surface water sample, the two processes achieved a similar performance for DOC and UV-absorbance removal. In addition, an up-flow electrocoagulator configuration performed better than a horizontal flow configuration, with both bipolar and monopolar electrodes.

  8. Column Liquid Chromatography.

    ERIC Educational Resources Information Center

    Majors, Ronald E.; And Others

    1984-01-01

    Reviews literature covering developments of column liquid chromatography during 1982-83. Areas considered include: books and reviews; general theory; columns; instrumentation; detectors; automation and data handling; multidimensional chromatographic and column switching techniques; liquid-solid chromatography; normal bonded-phase, reversed-phase,…

  9. Engineering development of advanced physical fine coal cleaning for premium fuel applications. Quarterly technical progress report No. 3, April--June 1993

    SciTech Connect

    Smit, F.J.; Hogsett, R.F.; Jha, M.C.

    1993-07-28

    This project is a major step in the Department of Energy`s program to show that ultra-clean coal-water slurry fuel (CWF) can be produced from selected coals and that this premium fuel will be a cost-effective replacement for oil and natural gas now fueling some of the industrial and utility boilers in the United States. The replacement of oil and gas with CWF can only be realized if retrofit costs are kept to a minimum and retrofit boiler emissions meet national goals for clean air. These concerns establish the specifications for maximum ash and sulfur levels and combustion properties of the CWF. This cost-share contract is a 48-month program which started on September 30, 1992. This report discusses the technical progress made during the quarter from April 1 to June 30, 1993. The project has three major objectives: (1) the primary objective is to develop the design base for prototype commercial advanced fine coal cleaning facilities capable of producing ultra-clean coals suitable for conversion to coal-water slurry fuel for premium fuel applications. The fine coal cleaning technologies are advanced column flotation and selective agglomeration. (2) a secondary objective is to develop the design base for near-term application of these advanced fine coal cleaning technologies in new or existing coal preparation plants for efficiently processing minus 28-mesh coal fines and converting this to marketable products in current market economics; and (3) a third objective is to determine the removal of toxic trace elements from coal by advance column flotation and selective agglomeration technologies.

  10. Development of an Advanced Fine Coal Suspension Dewatering Process

    SciTech Connect

    B. K. Parekh; D. P. Patil

    2008-04-30

    With the advancement in fine coal cleaning technology, recovery of fine coal (minus 28 mesh) has become an attractive route for the U.S. coal industry. The clean coal recovered using the advanced flotation technology i.e. column flotation, contains on average 20% solids and 80% water, with an average particle size of 35 microns. Fine coal slurry is usually dewatered using a vacuum dewatering technique, providing a material with about 25 to 30 percent moisture. The process developed in this project will improve dewatering of fine (0.6mm) coal slurry to less than 20 percent moisture. Thus, thermal drying of dewatered wet coal will be eliminated. This will provide significant energy savings for the coal industry along with some environmental benefits. A 1% increase in recovery of coal and producing a filter cake material of less than 20 % moisture will amount to energy savings of 1900 trillion Btu/yr/unit. In terms of the amount of coal it will be about 0.8% of the total coal being used in the USA for electric power generation. It is difficult to dewater the fine clean coal slurry to about 20% moisture level using the conventional dewatering techniques. The finer the particle, the larger the surface area and thus, it retains large amounts of moisture on the surface. The coal industry has shown some reluctance in using the advanced coal recovery techniques, because of unavailability of an economical dewatering technique which can provide a product containing less than 20% moisture. The U.S.DOE and Industry has identified the dewatering of coal fines as a high priority problem. The goal of the proposed program is to develop and evaluate a novel two stage dewatering process developed at the University of Kentucky, which involves utilization of two forces, namely, vacuum and pressure for dewatering of fine coal slurries. It has been observed that a fine coal filter cake formed under vacuum has a porous structure with water trapped in the capillaries. When this porous cake

  11. Advanced physical coal cleaning to comply with potential air toxic regulations. Quarterly report, 1 March 1995--31 May 1995

    SciTech Connect

    Honaker, R.Q.; Paul, B.C.; Mohanty, M.K.; Wang, D.

    1995-12-31

    Studies have indicated that the potentially hazardous trace elements found in coal have a strong affinity for coal pyrite. Thus, by maximizing the rejection of pyrite, one can minimize the trace element content of a given coal while also reducing sulfur emissions. The pyrite in most Illinois Basin coals, however, is finely disseminated within the coal matrix. Therefore, to remove the pyrite using physical coal cleaning techniques, the pyrite must be liberated by grinding the coal to ultrafine particle sizes. Fortunately, the coals being fed to pulverized coal boilers (PCB) are already ground to a very fine size, i.e., 70% passing 200 mesh. Therefore, this research project will investigate the use of advanced fine coal cleaning technologies for cleaning PCB feed as a compliance strategy. Work in this quarter has focused on the processing of a run-of-mine coal sample collected from Amax Coal Company`s Delta Coal mine using column flotation and an enhanced gravity separator as separate units and in circuitry arrangements. The {minus}60 mesh run-of-mine sample having an ash content of about 22% was cleaned to 6% while achieving a very high energy recovery of about 87% and a sulfur rejection value of 53% in a single stage column flotation operation. Enhanced gravity treatment is believed to be providing excellent total sulfur rejection values, although with inferior ash rejection for the {minus}400 mesh size fraction. The circuitry arrangement with the Falcon concentrator as the primary cleaner followed by the Packed-Column resulted in an excellent ash rejection performance, which out performed the release analysis. Trace element analyses of the samples collected from these tests will be conducted during the next report period.

  12. Advanced physical coal cleaning to comply with potential air toxic regulations. Quarterly report, 1 December 1994--28 February 1995

    SciTech Connect

    Honaker, R.Q.; Paul, B.C.; Wang, D.

    1995-12-31

    Studies have indicated that the potentially hazardous trace elements found in coal have a strong affinity for coal pyrite. Thus, by maximizing the rejection of pyrite, one can minimize the trace element content of a given coal while also reducing sulfur emissions. The pyrite in most Illinois Basin coals, however, is finely disseminated within the coal matrix. Therefore, to remove the pyrite using physical coal cleaning techniques, the pyrite must be liberated by grinding the coal to ultrafine particle sizes. Fortunately, the coals being fed to pulverized coal boilers (PCB) are already ground to a very fine size, i.e., 70% passing 200 mesh. Therefore, this research project will investigate the use of advanced fine coal cleaning technologies for cleaning PCB feed as a compliance strategy. Work in this quarter has focused on the processing of a PCB feed sample collected from Central Illinois Power`s Newton Power Station using column flotation and an enhanced gravity separator as separate units and in a circuitry arrangement. The PCB feed sample having a low ash content of about 12% was further cleaned to 6% while achieving a very high energy recovery of about 90% in a single stage column flotation operation. Enhanced gravity treatment is believed to be providing excellent total sulfur rejection values, although with inferior ash rejection for the {minus}400 mesh size fraction. The circuitry arrangement with the Falcon concentrator as the primary cleaner followed by the Microcel column resulted in an excellent ash rejection performance, which out performed the release analysis. Trace element analyses of the samples collected from these tests will be conducted during the next report period.

  13. Dorsal column stimulator applications

    PubMed Central

    Yampolsky, Claudio; Hem, Santiago; Bendersky, Damián

    2012-01-01

    Background: Spinal cord stimulation (SCS) has been used to treat neuropathic pain since 1967. Following that, technological progress, among other advances, helped SCS become an effective tool to reduce pain. Methods: This article is a non-systematic review of the mechanism of action, indications, results, programming parameters, complications, and cost-effectiveness of SCS. Results: In spite of the existence of several studies that try to prove the mechanism of action of SCS, it still remains unknown. The mechanism of action of SCS would be based on the antidromic activation of the dorsal column fibers, which activate the inhibitory interneurons within the dorsal horn. At present, the indications of SCS are being revised constantly, while new applications are being proposed and researched worldwide. Failed back surgery syndrome (FBSS) is the most common indication for SCS, whereas, the complex regional pain syndrome (CRPS) is the second one. Also, this technique is useful in patients with refractory angina and critical limb ischemia, in whom surgical or endovascular treatment cannot be performed. Further indications may be phantom limb pain, chronic intractable pain located in the head, face, neck, or upper extremities, spinal lumbar stenosis in patients who are not surgical candidates, and others. Conclusion: Spinal cord stimulation is a useful tool for neuromodulation, if an accurate patient selection is carried out prior, which should include a trial period. Undoubtedly, this proper selection and a better knowledge of its underlying mechanisms of action, will allow this cutting edge technique to be more acceptable among pain physicians. PMID:23230533

  14. 46 CFR 169.741 - Personal flotation devices and ring life buoys.

    Code of Federal Regulations, 2014 CFR

    2014-10-01

    ... 46 Shipping 7 2014-10-01 2014-10-01 false Personal flotation devices and ring life buoys. 169.741 Section 169.741 Shipping COAST GUARD, DEPARTMENT OF HOMELAND SECURITY (CONTINUED) NAUTICAL SCHOOLS SAILING... devices and ring life buoys. Each personal flotation device and ring life buoy must be marked with...

  15. 46 CFR 169.741 - Personal flotation devices and ring life buoys.

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    ... 46 Shipping 7 2010-10-01 2010-10-01 false Personal flotation devices and ring life buoys. 169.741 Section 169.741 Shipping COAST GUARD, DEPARTMENT OF HOMELAND SECURITY (CONTINUED) NAUTICAL SCHOOLS SAILING... devices and ring life buoys. Each personal flotation device and ring life buoy must be marked with...

  16. 46 CFR 169.741 - Personal flotation devices and ring life buoys.

    Code of Federal Regulations, 2012 CFR

    2012-10-01

    ... 46 Shipping 7 2012-10-01 2012-10-01 false Personal flotation devices and ring life buoys. 169.741 Section 169.741 Shipping COAST GUARD, DEPARTMENT OF HOMELAND SECURITY (CONTINUED) NAUTICAL SCHOOLS SAILING... devices and ring life buoys. Each personal flotation device and ring life buoy must be marked with...

  17. 46 CFR 169.741 - Personal flotation devices and ring life buoys.

    Code of Federal Regulations, 2013 CFR

    2013-10-01

    ... 46 Shipping 7 2013-10-01 2013-10-01 false Personal flotation devices and ring life buoys. 169.741 Section 169.741 Shipping COAST GUARD, DEPARTMENT OF HOMELAND SECURITY (CONTINUED) NAUTICAL SCHOOLS SAILING... devices and ring life buoys. Each personal flotation device and ring life buoy must be marked with...

  18. 46 CFR 169.741 - Personal flotation devices and ring life buoys.

    Code of Federal Regulations, 2011 CFR

    2011-10-01

    ... 46 Shipping 7 2011-10-01 2011-10-01 false Personal flotation devices and ring life buoys. 169.741 Section 169.741 Shipping COAST GUARD, DEPARTMENT OF HOMELAND SECURITY (CONTINUED) NAUTICAL SCHOOLS SAILING... devices and ring life buoys. Each personal flotation device and ring life buoy must be marked with...

  19. 46 CFR 28.110 - Life preservers or other personal flotation devices.

    Code of Federal Regulations, 2014 CFR

    2014-10-01

    ... 46 Shipping 1 2014-10-01 2014-10-01 false Life preservers or other personal flotation devices. 28.110 Section 28.110 Shipping COAST GUARD, DEPARTMENT OF HOMELAND SECURITY UNINSPECTED VESSELS REQUIREMENTS FOR COMMERCIAL FISHING INDUSTRY VESSELS Requirements for All Vessels § 28.110 Life preservers or other personal flotation devices. (a) Except...

  20. 46 CFR 28.110 - Life preservers or other personal flotation devices.

    Code of Federal Regulations, 2013 CFR

    2013-10-01

    ... 46 Shipping 1 2013-10-01 2013-10-01 false Life preservers or other personal flotation devices. 28.110 Section 28.110 Shipping COAST GUARD, DEPARTMENT OF HOMELAND SECURITY UNINSPECTED VESSELS REQUIREMENTS FOR COMMERCIAL FISHING INDUSTRY VESSELS Requirements for All Vessels § 28.110 Life preservers or other personal flotation devices. (a) Except...

  1. 33 CFR 183.235 - Level flotation test without weights for persons capacity.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... 33 Navigation and Navigable Waters 2 2010-07-01 2010-07-01 false Level flotation test without weights for persons capacity. 183.235 Section 183.235 Navigation and Navigable Waters COAST GUARD, DEPARTMENT OF HOMELAND SECURITY (CONTINUED) BOATING SAFETY BOATS AND ASSOCIATED EQUIPMENT Flotation Requirements for Outboard Boats Rated for Engines...

  2. 33 CFR 183.235 - Level flotation test without weights for persons capacity.

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... 33 Navigation and Navigable Waters 2 2011-07-01 2011-07-01 false Level flotation test without weights for persons capacity. 183.235 Section 183.235 Navigation and Navigable Waters COAST GUARD, DEPARTMENT OF HOMELAND SECURITY (CONTINUED) BOATING SAFETY BOATS AND ASSOCIATED EQUIPMENT Flotation Requirements for Outboard Boats Rated for Engines...

  3. 33 CFR 149.331 - What are the requirements for hybrid personal flotation devices?

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... for them in 46 CFR 160.077-29, and all limitations, if any, marked on them. (b) All commercial hybrid... hybrid personal flotation devices? 149.331 Section 149.331 Navigation and Navigable Waters COAST GUARD... hybrid personal flotation devices? (a) The operator must ensure that the use and stowage of...

  4. 33 CFR 149.331 - What are the requirements for hybrid personal flotation devices?

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... for them in 46 CFR 160.077-29, and all limitations, if any, marked on them. (b) All commercial hybrid... hybrid personal flotation devices? 149.331 Section 149.331 Navigation and Navigable Waters COAST GUARD... hybrid personal flotation devices? (a) The operator must ensure that the use and stowage of...

  5. 33 CFR 149.331 - What are the requirements for hybrid personal flotation devices?

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... for them in 46 CFR 160.077-29, and all limitations, if any, marked on them. (b) All commercial hybrid... hybrid personal flotation devices? 149.331 Section 149.331 Navigation and Navigable Waters COAST GUARD... hybrid personal flotation devices? (a) The operator must ensure that the use and stowage of...

  6. 33 CFR 149.331 - What are the requirements for hybrid personal flotation devices?

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... for them in 46 CFR 160.077-29, and all limitations, if any, marked on them. (b) All commercial hybrid... hybrid personal flotation devices? 149.331 Section 149.331 Navigation and Navigable Waters COAST GUARD... hybrid personal flotation devices? (a) The operator must ensure that the use and stowage of...

  7. 33 CFR 149.331 - What are the requirements for hybrid personal flotation devices?

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ... for them in 46 CFR 160.077-29, and all limitations, if any, marked on them. (b) All commercial hybrid... hybrid personal flotation devices? 149.331 Section 149.331 Navigation and Navigable Waters COAST GUARD... hybrid personal flotation devices? (a) The operator must ensure that the use and stowage of...

  8. Inelastic column behavior

    NASA Technical Reports Server (NTRS)

    Duberg, John E; Wilder, Thomas W , III

    1952-01-01

    The significant findings of a theoretical study of column behavior in the plastic stress range are presented. When the behavior of a straight column is regarded as the limiting behavior of an imperfect column as the initial imperfection (lack of straightness) approaches zero, the departure from the straight configuration occurs at the tangent-modulus load. Without such a concept of the behavior of a straight column, one is led to the unrealistic conclusion that lateral deflection of the column can begin at any load between the tangent-modulus value and the Euler load, based on the original elastic modulus. A family of curves showing load against lateral deflection is presented for idealized h-section columns of various lengths and of various materials that have a systematic variation of their stress-strain curves.

  9. The kinetics of fossil resin extraction from a flotation concentrate

    SciTech Connect

    Li, L.; Yu, Q.; Miller, J.D.

    1995-11-01

    The kinetics of fossil resin extraction from a flotation concentrate by heptane were investigated as a function of process variables using monosize particles. Experimental results provide for a better understanding of the refining process and the basis for subsequent design and construction of a continuous resin refining circuit. Based on the effect of process variables (particle size, stirring speed, and temperature) the resin extraction rate appears to be controlled by surface solvation phenomena. The initial extraction rate was found to be inversely proportional to the initial particle size and a kinetic model is being developed to describe the experimental results.

  10. Inflatable Column Structure

    NASA Technical Reports Server (NTRS)

    Hedgepeth, J. M.

    1985-01-01

    Lightweight structural member easy to store. Billowing between circumferential loops of fiber inflated column becomes series of cells. Each fiber subjected to same tension along entire length (though tension is different in different fibers). Member is called "isotensoid" column. Serves as jack for automobiles or structures during repairs. Also used as support for temporary bleachers or swimming pools.

  11. Glass-silicon column

    DOEpatents

    Yu, Conrad M.

    2003-12-30

    A glass-silicon column that can operate in temperature variations between room temperature and about 450.degree. C. The glass-silicon column includes large area glass, such as a thin Corning 7740 boron-silicate glass bonded to a silicon wafer, with an electrode embedded in or mounted on glass of the column, and with a self alignment silicon post/glass hole structure. The glass/silicon components are bonded, for example be anodic bonding. In one embodiment, the column includes two outer layers of silicon each bonded to an inner layer of glass, with an electrode imbedded between the layers of glass, and with at least one self alignment hole and post arrangement. The electrode functions as a column heater, and one glass/silicon component is provided with a number of flow channels adjacent the bonded surfaces.

  12. Winter operation of nation's largest potable flotation plant. Technical report

    SciTech Connect

    Krofta, M.; Wang, L.K.

    1987-09-20

    The heart of the Pittsfield (Massachusetts) water-supply system is two potable flotation plants: Ashley Plant (2 Sandfloats) and Cleveland Plant (4 Sandfloats). Each sandfloat unit has a capacity of 6.25 MGD (million gallons per day). Sandfloat is a package clarifier consisting of flocculation, flotation, and filtration. Complete chronological testing of Pittsfield's two plants in the winter period, December 1986 through March 1987, is documented. The technical and economical feasibilities of Sandfloat are presented. Cleveland raw water having sufficient alkalinity and low temperature in winter was treated satisfactorily by Sandfloat at 6.25 MGD per unit using the chemical combination of sodium aluminate, polymer, and alum at a cost of $0.02458/1000 gal. At Ashley Plant, the mixture of 28% Ashley raw water and 72% Farnham raw water, having moderate alkalinity and low winter temperature was treated adequately by Sandfloat at 5.5-5.8 MGD per unit using the same chemicals. When 100% Farnham raw water with extremely low alkalinity and low pH was treated at Ashley Plant, PAC, sodium aluminate and polymer 1849A was found to be the best chemical combination for clarification.

  13. Nanoparticle flotation collectors--the influence of particle softness.

    PubMed

    Yang, Songtao; Razavizadeh, Bi Bi Marzieh; Pelton, Robert; Bruin, Gerard

    2013-06-12

    The ability of polymeric nanoparticles to promote glass bead and pentlandite (Pn, nickel sulfide mineral) attachment to air bubbles in flotation was measured as a function of the nanoparticle glass transition temperature using six types of nanoparticles based on styrene/N-butylacrylate copolymers. Nanoparticle size, surface charge density, and hydrophobicity were approximately constant over the series. The ability of the nanoparticles to promote air bubble attachment and perform as flotation collectors was significantly greater for softer nanoparticles. We propose that softer nanoparticles were more firmly attached to the glass beads or mineral surface because the softer particles had a greater glass/polymer contact areas and thus stronger overall adhesion. The diameters of the contact areas between polymeric nanoparticles and glass surfaces were estimated with the Young-Laplace equation for soft, liquidlike particles, whereas JKR adhesion theory was applied to the harder polystyrene particles. The diameters of the contact areas were estimated to be more than an order of magnitude greater for the soft particles compared to harder polystyrene particles.

  14. Nanoparticle flotation collectors--the influence of particle softness.

    PubMed

    Yang, Songtao; Razavizadeh, Bi Bi Marzieh; Pelton, Robert; Bruin, Gerard

    2013-06-12

    The ability of polymeric nanoparticles to promote glass bead and pentlandite (Pn, nickel sulfide mineral) attachment to air bubbles in flotation was measured as a function of the nanoparticle glass transition temperature using six types of nanoparticles based on styrene/N-butylacrylate copolymers. Nanoparticle size, surface charge density, and hydrophobicity were approximately constant over the series. The ability of the nanoparticles to promote air bubble attachment and perform as flotation collectors was significantly greater for softer nanoparticles. We propose that softer nanoparticles were more firmly attached to the glass beads or mineral surface because the softer particles had a greater glass/polymer contact areas and thus stronger overall adhesion. The diameters of the contact areas between polymeric nanoparticles and glass surfaces were estimated with the Young-Laplace equation for soft, liquidlike particles, whereas JKR adhesion theory was applied to the harder polystyrene particles. The diameters of the contact areas were estimated to be more than an order of magnitude greater for the soft particles compared to harder polystyrene particles. PMID:23692163

  15. Inclusion flotation-driven channel segregation in solidifying steels

    PubMed Central

    Li, Dianzhong; Chen, Xing-Qiu; Fu, Paixian; Ma, Xiaoping; Liu, Hongwei; Chen, Yun; Cao, Yanfei; Luan, Yikun; Li, Yiyi

    2014-01-01

    Channel segregation, which is featured by the strip-like shape with compositional variation in cast materials due to density contrast-induced flow during solidification, frequently causes the severe destruction of homogeneity and some fatal damage. An investigation of its mechanism sheds light on the understanding and control of the channel segregation formation in solidifying metals, such as steels. Until now, it still remains controversial what composes the density contrasts and, to what extent, how it affects channel segregation. Here we discover a new force of inclusion flotation that drives the occurrence of channel segregation. It originates from oxide-based inclusions (Al2O3/MnS) and their sufficient volume fraction-driven flotation becomes stronger than the traditionally recognized inter-dendritic thermosolutal buoyancy, inducing the destabilization of the mushy zone and dominating the formation of channels. This study uncovers the mystery of oxygen in steels, extends the classical macro-segregation theory and highlights a significant technological breakthrough to control macrosegregation. PMID:25422943

  16. Adsorption mechanism of mixed cationic/anionic collectors in feldspar-quartz flotation system.

    PubMed

    Vidyadhar, A; Hanumantha Rao, K

    2007-02-15

    The adsorption mechanism of mixed cationic alkyl diamine and anionic sulfonate/oleate collectors at acidic pH values was investigated on microcline and quartz minerals through Hallimond flotation, electrokinetic and diffuse reflectance FTIR studies. In the presence of anionic collectors, neither of the minerals responded to flotation but the diamine flotation of the minerals was observed to be pH and concentration dependent. The presence of sulfonate enhanced the diamine flotation of the minerals by its co-adsorption. The difference in surface charge between the minerals at pH 2 was found to be the basis for preferential feldspar flotation from quartz in mixed diamine/sulfonate collectors. The infrared spectra revealed no adsorption of sulfonate collector when used alone but displayed its co-adsorption as diamine-sulfonate complex when used with diamine. The presence of sulfonate increased the diamine adsorption due to a decrease in the electrostatic head-head repulsion between the adjacent surface ammonium ions and thereby increasing the lateral tail-tail hydrophobic bonds. The mole ratio of diamine/sulfonate was found to be an important factor in the orientation of alkyl chains and thus the flotation response of minerals. The increase in sulfonate concentration beyond diamine concentration leads to the formation of soluble 1:2 diamine-sulfonate complex or precipitate and the adsorption of these species decreased the flotation since the alkyl chains are in chaotical orientation with a conceivable number of head groups directing towards the solution phase.

  17. POC-scale testing of an advanced fine coal dewatering equipment/technique. Quarterly technical progress report No. 5, October--December, 1995

    SciTech Connect

    Groppo, J.G.; Parekh, B.K.

    1996-02-01

    Froth flotation technique is an effective and efficient process for recovering of ultra-fine (minus 74{mu}m) clean coal. Economical dewatering of an ultrafine clean coal product to a 20% level moisture will be an important step in successful implementation of the advanced cleaning processes. The main objective of the proposed program is to evaluate a novel surface modification technique, which utilizes the synergistic effect of metal ions-surfactant combination, for dewatering of ultra-fine clean coal on a proof-of-concept scale of 1 to 2 tph. The novel surface modification technique developed at the the University of Kentucky Center for Applied Energy Research will be evaluated using vacuum, centrifuge, and hyperbaric filtration equipment. Dewatering tests will be conducted using the fine clean coal froth produced by the column flotation units at the Powell Mountain Coal Company, Mayflower Preparation Plant in St. Charles, Virginia. The POC-scale studies will be conducted on two different types of clean coal, namely, high sulfur and low sulfur clean coal. Accomplishments for the past quarter are described.

  18. Gas Chromatograph Method Optimization Trade Study for RESOLVE: 20-meter Column v. 8-meter Column

    NASA Technical Reports Server (NTRS)

    Huz, Kateryna

    2014-01-01

    detection via good peak separation with a longer run time is a better asset than moderate peak separation with a shorter run time. Even given that RESOLVE is highly interested in water and that mission timeline is of significant importance given the short seven-to-ten-day mission timeline, worse detection with an 8m column may lead to overlooking other substances existing on the moon that could advance planetary science. Thus, I recommend the 20m column. However, if mission timeline and water separation are deemed the highest priority, the 8m column should be selected due to its ability to separate water within a shorter run time than the 20m column.

  19. Nuclear reactor control column

    DOEpatents

    Bachovchin, Dennis M.

    1982-01-01

    The nuclear reactor control column comprises a column disposed within the nuclear reactor core having a variable cross-section hollow channel and containing balls whose vertical location is determined by the flow of the reactor coolant through the column. The control column is divided into three basic sections wherein each of the sections has a different cross-sectional area. The uppermost section of the control column has the greatest cross-sectional area, the intermediate section of the control column has the smallest cross-sectional area, and the lowermost section of the control column has the intermediate cross-sectional area. In this manner, the area of the uppermost section can be established such that when the reactor coolant is flowing under normal conditions therethrough, the absorber balls will be lifted and suspended in a fluidized bed manner in the upper section. However, when the reactor coolant flow falls below a predetermined value, the absorber balls will fall through the intermediate section and into the lowermost section, thereby reducing the reactivity of the reactor core and shutting down the reactor.

  20. Selective flotation of fossil resin from western coal. A special report comprising: Monthly report for December 1991--April 1992 and Quarterly reports for December 1, 1991--February 29, 1992

    SciTech Connect

    Jensen, G.F.; Miller, J.D.

    1992-03-20

    The test program has demonstrated that: (1) technically, the new flotation technologies discovered at the University of Utah and then improved upon by Advanced Processing Technologies, Inc. provide a highly efficient means to selectively recover fossil resin from coal. The proof-of-concept continuous flotation circuit resulted in fossil resin recovery with the same separation efficiency as was obtained from laboratory bench-scale testing (more than 80% recovery at about 80% concentrate grade); and (2) economically, the selective flotation process has been shown to be sufficiently profitable to justify the development of a fossil resin industry based on this new flotation process. The proof-of-concept testing has resulted in significant interest from several coal mining companies and has sparked the desire of local and state government to establish a fossil resin industry in the Wasatch Plateau coal field. In this view, the results from the current proof-of-concept testing program have been successful. This special report provides theoretical and analytical data on some surface chemistry work pertinent to fossil resin characterization, and other efforts carried out during the past months.

  1. Modelling and calculation of flotation process in one-dimensional formulation

    NASA Astrophysics Data System (ADS)

    Amanbaev, Tulegen; Tilleuov, Gamidulla; Tulegenova, Bibigul

    2016-08-01

    In the framework of the assumptions of the mechanics of the multiphase media is constructed a mathematical model of the flotation process in the dispersed mixture of liquid, solid and gas phases, taking into account the degree of mineralization of the surface of the bubbles. Application of the constructed model is demonstrated on the example of one-dimensional stationary flotation and it is shown that the equations describing the process of ascent of the bubbles are singularly perturbed ("rigid"). The effect of size and concentration of bubbles and the volumetric content of dispersed particles on the flotation process are analyzed.

  2. Engineering development of advanced physical fine coal cleaning for premium fuel applications. Quarterly technical progress report 13, October--December, 1995

    SciTech Connect

    Moro, N.; Shields, G.L.; Smit, F.J.; Jha, M.C.

    1996-01-31

    The primary goal of this project is the engineering development of two advanced physical fine coal cleaning processes, column flotation and selective agglomeration, for premium fuel applications. The project scope includes laboratory research and bench-scale testing on six coals to optimize these processes, followed by the design, construction, and operation of a 2-t/hr process development unit. During Quarter 13 (October--December 1995), testing of the GranuFlow dewatering process indicated a 3--4% reduction in cake moisture for screen-bowl and solid-bowl centrifuge products. The Orimulsion additions were also found to reduce the potential dustiness of the fine coal, as well as improve solids recovery in the screen-bowl centrifuge. Based on these results, Lady Dunn management now plans to use a screen bowl centrifuge to dewater their Microcel{trademark} column froth product. Subtask 3.3 testing, investigating a novel Hydrophobic Dewatering process (HD), continued this quarter. Continuing Subtask 6.4 work, investigating coal-water-slurry formulation, indicated that selective agglomeration products can be formulated into slurries with lower viscosities than advanced flotation products. Subtask 6.5 agglomeration bench-scale testing results indicate that a very fine grind is required to meet the 2 lb ash/MBtu product specification for the Winifrede coal, while the Hiawatha coal requires a grind in the 100- to 150-mesh topsize range. Detailed design work remaining involves the preparation and issuing of the final task report. Utilizing this detailed design, a construction bid package was prepared and submitted to three Colorado based contractors for quotes as part of Task 9.

  3. Microminiature gas chromatographic column

    NASA Technical Reports Server (NTRS)

    Donaldson, R. W., Jr.

    1972-01-01

    Techniques commonly used for fabrication of integrated circuits are utilized to produce long capillary tubes for microminiature chromatographs. Method involves bonding of flat silicon plate to top of spirally grooved silicon chip to close groove and form capillary column.

  4. Towards Atomic Column-by-Column Spectroscopy

    SciTech Connect

    Pennycook, S.J.; Rafferty, B.

    1998-09-06

    The optical arrangement of the scanning transmission electron microscope (STEM) is ideally suited for performing analysis of individual atomic columns in materials. Using the incoherent Z-contrast image as a reference, and arranging incoherent conditions also for the spectroscopy, a precise correspondence is ensured between features in the inelastic image and elastic signals. In this way the exact probe position needed to maximise the inelastic signal from a selected column can be located and monitored during the analysis using the much higher intensity elastic signal. Although object functions for EELS are typically less than 1 {Angstrom} full width at half maximum, this is still an order of magnitude larger than the corresponding object functions for elastic (or diffuse) scattering used to form the Z-contrast image. Therefore the analysis is performed with an effective probe that is significantly broader than that used for the reference Z-contrast image. For a 2.2 {Angstrom} probe the effective probe is of the order of 2.5 {Angstrom}, while for a 1.3 {Angstrom} probe the effective probe is 1.6 {Angstrom}. Such increases in effective probe size can significantly reduce or even eliminate contrast between atomic columns that are visible in the image. However, this is only true if we consider circular collector apertures. Calculations based upon the theory of Maslen and Rossouw (Maslen and Rossouw 1984; Rossouw and Maslen 1984) show that employing an annular aperture can reduce the FWHM of the inelastic object function down to values close 0.1 {Angstrom}. With practical aperture sizes it should be possible to achieve this increased spatial resolution without loosing too much signal.

  5. Froth flotation of oil-bearing metal sulfide wastes

    SciTech Connect

    Miller, R.L. ); Atwood, R.L.; Ye, Yi )

    1991-01-01

    An industrial wastewater, including plating wastes, is treated with sodium sulfide and ferrous sulfate to form a sulfide-oxide precipitate containing chromium and other toxic metals. Hydrocarbons, in the water, coat the sulfide-oxide particles, impeding metal recovery. Froth flotation, without reagent addition, was found to recover 93.9% of the solids from the sludge with simultaneous rejection of 89% of the water. Methyl isobutyl carbinol (MIBC) improved recovery and potassium amyl xanthate improved both recovery and grade. The process design has wastewater feed (without MIBC) to the rougher circuit. The rougher concentrate is conditioned with MIBC and fed to a cleaner circuit to achieve a high grade concentrate. About 95% of the water is recirculated to the waste treatment plant. 3 refs., 3 figs., 4 tabs.

  6. Froth flotation of oil-bearing metal sulfide wastes

    SciTech Connect

    Miller, R.L.; Atwood, R.L.; Ye, Yi

    1991-12-01

    An industrial wastewater, including plating wastes, is treated with sodium sulfide and ferrous sulfate to form a sulfide-oxide precipitate containing chromium and other toxic metals. Hydrocarbons, in the water, coat the sulfide-oxide particles, impeding metal recovery. Froth flotation, without reagent addition, was found to recover 93.9% of the solids from the sludge with simultaneous rejection of 89% of the water. Methyl isobutyl carbinol (MIBC) improved recovery and potassium amyl xanthate improved both recovery and grade. The process design has wastewater feed (without MIBC) to the rougher circuit. The rougher concentrate is conditioned with MIBC and fed to a cleaner circuit to achieve a high grade concentrate. About 95% of the water is recirculated to the waste treatment plant. 3 refs., 3 figs., 4 tabs.

  7. An investigation of variables in a fecal flotation technique.

    PubMed

    O'Grady, M R; Slocombe, J O

    1980-04-01

    Several variables in a standard vial fecal gravitational flotation technique were investigated. These were the specific gravity of the sodium nitrate flotation solution, duration of flotation and mesh sizes of strainers. The number of eggs which floated and adhered to a coverslip were counted and estimates of the number of eggs remaining in the strained fecal suspension and in the feces trapped on the strainer were made. Eggs from hookworms, Trichuris vulpis and Toxocara canis in feces from dogs, Nematodirus spp. from sheep and Parascaris equorum from horses floated equally well in solutions with specific gravities (SpGr) ranging from 1.22-1.38. Taenia spp. from dogs had a slightly narrower range (SpGr 1.27-1.38) for best recovery. Eggs from Haemonchus contortus from sheep appeared to float best between SpGr 1.22- 1.32. Strongyles from one horse floated best with SpGr 1.27-1.32 and from another with SpGr 1.11-1.38. Coccidial oocysts from sheep floated best in a narrow range of SpGr from 1.22-1.27. However, as the SpGr of the solution was increased the recognition of eggs under the coverslip was increasingly difficult and especially so at SpGr 1.38 with sheep feces. This was due to the increasing amount of debris and the more rapid formation of crystals with evaporation with solutions of higher SpGr. It appeared, therefore, that solutions with SpGr of 1.22-1.35 would be best for routine laboratory use. At specific gravity 1.27, there appeared to be no difference in the number of eggs recovered for a four, eight and 12 min flotation period. Only 3-7% of the eggs in 4 g of feces were counted under the coverslip. This poor efficacy resulted first because approximately 50% of the eggs were trapped in the feces and retained on the strainer. Secondly, only one half of the strained fecal suspension, containing approximately 25% of the eggs, was placed in the vial for examination. Thirdly, of those eggs in the vial only 16-29% were counted under the coverslip. When the

  8. Selective flotation of phosphate minerals with hydroxamate collectors

    DOEpatents

    Miller, Jan D.; Wang, Xuming; Li, Minhua

    2002-01-01

    A method is disclosed for separating phosphate minerals from a mineral mixture, particularly from high-dolomite containing phosphate ores. The method involves conditioning the mineral mixture by contacting in an aqueous in environment with a collector in an amount sufficient for promoting flotation of phosphate minerals. The collector is a hydroxamate compound of the formula; ##STR1## wherein R is generally hydrophobic and chosen such that the collector has solubility or dispersion properties it can be distributed in the mineral mixture, typically an alkyl, aryl, or alkylaryl group having 6 to 18 carbon atoms. M is a cation, typically hydrogen, an alkali metal or an alkaline earth metal. Preferably, the collector also comprises an alcohol of the formula, R'--OH wherein R' is generally hydrophobic and chosen such that the collector has solubility or dispersion properties so that it can be distributed in the mineral mixture, typically an alkyl, aryl, or alkylaryl group having 6 to 18 carbon atoms.

  9. Flotation purification of industrial wastewater by removing cyanide ions

    SciTech Connect

    Evtyugina, N.M.; Derbysheva, E.K.; Kopktova, L.A.

    1984-01-01

    One of the oldest and most common methods of purifying sewage by removing cyanide ions is binding them to nontoxic compounds of ferrous salts, principally divalent ferrous salts. Research in this direction has also been realized for the sewage of coking plants. One of the reasons why the method has not been introduced is tied to the difficulty of separating the finely-dispersed slime of the divalent ferrous cyanide K/sub 4/(Fe(CN)/sub 6/). This study investigates methods of producing complex compounds of cyanide ions with ferrous salts which have low solubility and, as far as possible, are easily extracted from water. To achieve this, it is suggested that one of the promising methods of water purification - flotation - be used and that the sludge extracted be utilized in accordance with wellknown plans.

  10. Nickel Ore Dispersion Evaluation and Consequences in Flotation Process

    NASA Astrophysics Data System (ADS)

    de São José, Fábio; Imbelloni, Alaine Moreira; Nogueira, Francielle Câmara; Pereira, Carlos Alberto

    2016-04-01

    Nickel ore dispersion before flotation using different reagents was investigated on a bench scale to improve metallurgical recovery and selectivity. The nickel ore had a content of 0.8 pct nickel and 14.5 pct MgO. A positive linear correlation between MgO and Ni was found. Carboxy methyl cellulose, both pure and combined with Na2CO3, was the best dispersant used. The most efficient collector was potassium amyl xanthate combined with mercaptobenzothiazole, and the addition of xanthate was decisive for this good result because it is normally more stable in the pH range used in the tests. A pH change from 7 to 9 resulted in a metal recovery increase of 49.3 pct, together with an increase of 6.25 pct of MgO in the concentrate.

  11. An investigation of variables in a fecal flotation technique.

    PubMed

    O'Grady, M R; Slocombe, J O

    1980-04-01

    Several variables in a standard vial fecal gravitational flotation technique were investigated. These were the specific gravity of the sodium nitrate flotation solution, duration of flotation and mesh sizes of strainers. The number of eggs which floated and adhered to a coverslip were counted and estimates of the number of eggs remaining in the strained fecal suspension and in the feces trapped on the strainer were made. Eggs from hookworms, Trichuris vulpis and Toxocara canis in feces from dogs, Nematodirus spp. from sheep and Parascaris equorum from horses floated equally well in solutions with specific gravities (SpGr) ranging from 1.22-1.38. Taenia spp. from dogs had a slightly narrower range (SpGr 1.27-1.38) for best recovery. Eggs from Haemonchus contortus from sheep appeared to float best between SpGr 1.22- 1.32. Strongyles from one horse floated best with SpGr 1.27-1.32 and from another with SpGr 1.11-1.38. Coccidial oocysts from sheep floated best in a narrow range of SpGr from 1.22-1.27. However, as the SpGr of the solution was increased the recognition of eggs under the coverslip was increasingly difficult and especially so at SpGr 1.38 with sheep feces. This was due to the increasing amount of debris and the more rapid formation of crystals with evaporation with solutions of higher SpGr. It appeared, therefore, that solutions with SpGr of 1.22-1.35 would be best for routine laboratory use. At specific gravity 1.27, there appeared to be no difference in the number of eggs recovered for a four, eight and 12 min flotation period. Only 3-7% of the eggs in 4 g of feces were counted under the coverslip. This poor efficacy resulted first because approximately 50% of the eggs were trapped in the feces and retained on the strainer. Secondly, only one half of the strained fecal suspension, containing approximately 25% of the eggs, was placed in the vial for examination. Thirdly, of those eggs in the vial only 16-29% were counted under the coverslip. When the

  12. Foaming and cell flotation in suspended plant cell cultures and the effect of chemical antifoams.

    PubMed

    Wongsamuth, R; Doran, P M

    1994-08-01

    Foam development and stability in Atropa belladonna suspensions were investigated as a function of culture conditions. Foaming was due mainly to properties of the cell-free broth and was correlated with protein content; effects due to presence of cells increased towards the end of batch culture. Highest foam levels were measured 11 days after inoculation. Air flow rate was of major importance in determining foam volume; foam volume and stability were also strongly dependent on pH. Foam flotation of plant cells was very effective. After 30 min foaming, ca. 55% of cells were found in the foam; this increased to ca. 75% after 90 min. Polypropylene glycol 1025 and 2025, Pluronic PE 6100, and Antifoam-C emulsion were tested as chemical antifoams. Polypropylene glycol 1025 and Antifoam C at concentrations up to 600 ppm had no adverse effect on growth in shake flasks; Pluronic PE 6100 has an inhibitory effect at all levels tested. Concentrations of polypropylene glycol 2025 and Pluronic PE 6100 as low as 20 ppm reduced foam volumes by a factor of ca. 10. Addition of antifoam reduced k(L)a values in bubble-column and stirred-tank bioreactors. After operation of a stirred reactor for 2 days using Antifoam C for foam control, cell production was limited by oxygen due to the effect of antifoam on mass transfer. Theoretical analysis showed that maximum cell concentrations and biomass levels decline with increasing reactors working volume due to greater consumption of antifoam to prevent foam overflow. The results indicate that when chemical foam control is used in plant cell cultures, head-space volume and tolerable foam levels must be considered to optimize biomass production. (c) 1994 John Wiley & Sons, Inc.

  13. Achieved slime flotation in centrifugal force field by float-hydrocyclone

    SciTech Connect

    Guode Xuzhanxian; Gaozhenshen Songzhiwei

    1997-12-31

    Based on the theory of intensifying flotation in a centrifugal force field, float-hydrocyclone (FH) is developed, which is a new type of equipment for slime flotation and consists of an air bubble generator and the cylindrical section of a hydrocyclone. The combination of pulp and air bubbles is fed into the FH tangentially at a high speed to effect the separation of slime in the centrifugal force field. It offers many advantages over mechanically agitated flotation cells. Commercial test results show that slime, especially fine slime, can be perfectly floated in the FH with rapid flotation and fine froth size. The quality and quantity of concentrate and tailings can be adjusted conveniently within a certain range according to different requirements.

  14. Commercial tests of cationic flocculant in flotation treatment of waste water

    SciTech Connect

    Sokolov, V.P.; Chikunova, L.A.; Kudrina, L.A.; Gustov, V.A.

    1987-07-01

    This work has been aimed at testing the efficiency of a polyacrylamide with cationic properties in the flotation separation of oil matter from waste water under industrial conditions. The N-dimethylaminated polyacrylamide that they synthesized manifests the properties of a high-molecular-weight cationic polyelectrolyte. This particular flocculant was selected because of its relatively high flocculating power, the sharp reduction that it gives in the volume of slime (foam) in reagent flotation treatment of waste water, and the lower content of mineral salts in the treated water. Commercial tests of the cationic flocculant were performed at the Gor'kii petroleum oil plant. The treating facilities in this plant include the following: reagent section, pumping station, flotation unit, and section for gravitational compaction of oil slime rejected from the flotation cell.

  15. Statistical Evaluation and Optimization of Factors Affecting the Leaching Performance of Copper Flotation Waste

    PubMed Central

    Çoruh, Semra; Elevli, Sermin; Geyikçi, Feza

    2012-01-01

    Copper flotation waste is an industrial by-product material produced from the process of manufacturing copper. The main concern with respect to landfilling of copper flotation waste is the release of elements (e.g., salts and heavy metals) when in contact with water, that is, leaching. Copper flotation waste generally contains a significant amount of Cu together with trace elements of other toxic metals, such as Zn, Co, and Pb. The release of heavy metals into the environment has resulted in a number of environmental problems. The aim of this study is to investigate the leaching characteristics of copper flotation waste by use of the Box-Behnken experimental design approach. In order to obtain the optimized condition of leachability, a second-order model was examined. The best leaching conditions achieved were as follows: pH = 9, stirring time = 5 min, and temperature = 41.5°C. PMID:22629194

  16. 46 CFR 28.110 - Life preservers or other personal flotation devices.

    Code of Federal Regulations, 2011 CFR

    2011-10-01

    ... be equipped with at least one immersion suit, exposure suit, or wearable personal flotation device of... commercial fishing activities must meet the requirements of this paragraph. (b) Each wearable...

  17. 46 CFR 28.110 - Life preservers or other personal flotation devices.

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    ... be equipped with at least one immersion suit, exposure suit, or wearable personal flotation device of... commercial fishing activities must meet the requirements of this paragraph. (b) Each wearable...

  18. Effects of particle size and chain length on flotation of quaternary ammonium salts onto kaolinite

    NASA Astrophysics Data System (ADS)

    Longhua, Xu; Yuehua, Hu; Faqin, Dong; Hao, Jiang; Houqin, Wu; Zhen, Wang; Ruohua, Liu

    2015-06-01

    Effects of particle size and chain length on flotation of quaternary ammonium salts (QAS) onto kaolinite have been investigated by flotation tests. Dodecyltrimethylammonium chloride (DTAC) and cetyltrimethylammonium chloride (CTAC) were used as collectors for kaolinite in different particle size fractions (0.075 ~ 0.01 mm, 0.045 ~ 0.075 mm, 0 ~ 0.045 mm). The anomalous flotation behavior of kaolinite have been further explained based on crystal structure considerations by adsorption tests and molecular dynamics (MD) simulation. The results show that the flotation recovery of kaolinite in all different particle size fractions decreases with an increase in pH. As the concentration of collectors increases, the flotation recovery increases. The longer the carbon chain of QAS is, the higher the recoveries of coarse kaolinite (0.075 ~ 0.01 mm and 0.045 ~ 0.075 mm) are. But the flotation recovery of the finest kaolinite (0 ~ 0.045 mm) decreases with chain lengths of QAS collectors increasing, which is consistent with the flotation results of unscreened kaolinite (0 ~ 0.075 mm). It is explained by the froth stability related to the residual concentration of QAS collector in mineral pulp. In lower residual concentration, the froth stability becomes worse. Within the range of flotation collector concentration, it's easy of CTAC to be completely adsorbed by kaolinite in the particle size fraction (0-0.045 mm), which led to lower flotation recovery. Moreover, it is interesting that the coarser particle size of kaolinite is, the higher flotation recovery is. The anomalous flotation behavior of kaolinite is rationalized based on crystal structure considerations. The results of MD simulations show that the (001) kaolinite surface has the strongest interaction with DTAC, compared with the (00 1) face, (010) and (110) edges. On the other hand, when particle size of kaolinite is altered, the number of basal planes and edge planes is changed. It is observed that the finer kaolinite

  19. Heavy metals in the products of deinking flotation of digital offset prints.

    PubMed

    Barbaric-Mikocevic, Zeljka; Orescanin, Visnja; Bolanca, Zdenka; Lulic, Stipe; Rozic, Mirela

    2004-01-01

    This study was undertaken to investigate the suitability of applying the conventional method of chemical deinking flotation of digital offset prints and ecological implications of the disposal of digital offset prints, with special emphasis on the content of heavy metal cations. The EDXRF method was used to determine the concentrations of Pb, Zr, Sr, As, Co, Zn, Cu, Ni, Fe, Mn, Cr, V, Ti, Ca, and K cations in handsheet ashes after flotation as well as in ashes of foams separated from cellulose suspension in the flotation phase. The same method was applied to determine the concentrations of Pb, Cr, Mn, Fe, Ni, Cu, Zn, and Co in process water filtrates obtained from the cellulose suspension after flotation and in foam filtrates. Centrifuging and coagulation previously treated flotation process water, while foam filtrates were centrifuged. Concentrations of Pb, As, Sr, Zr, K, Ca, Ti, V, Cr, Mn, Fe, Cu, and Zn were determined in the sediments obtained by centrifuging process water. The trials were done with unprinted substrates without deinking chemicals, with unprinted substrates in the presence of deinking chemicals and with printed substrates in the presence of deinking chemicals. Cation analysis revealed that deinking chemicals facilitate release of cations from the substrate and their transition into process water. Concentrations of most cations in the flotation process water, in foam water as well as in the sediment of the process water of printed substrate flotation deinking were lower than those obtained by flotation of unprinted substrate suspension. Polymer particles of ElectroInk incompletely separated from cellulose fibers prevent release of cations from cellulose fibers into process water. Deinking chemicals do not affect release of cations from ElectroInk particles, so the substrate is the main source of increased concentration of cations in the water of digital offset print deinking. The major part of cations in process water is bound to the colloid

  20. Flotation separation of polyvinyl chloride and polyethylene terephthalate plastics combined with surface modification for recycling.

    PubMed

    Wang, Chongqing; Wang, Hui; Fu, Jiangang; Zhang, Lingling; Luo, Chengcheng; Liu, Younian

    2015-11-01

    Surface modification with potassium permanganate (KMnO4) solution was developed for separation of polyvinyl chloride (PVC) and polyethylene terephthalate (PET) waste plastics. The floatability of PVC decreases with increasing of KMnO4 concentration, treatment time, temperature and stirring rate, while that of PET is unaffected. Fourier transform infrared (FT-IR) analysis confirms that mechanism of surface modification may be due to oxidization reactions occurred on PVC surface. The optimum conditions are KMnO4 concentration 1.25 mM/L, treatment time 50 min, temperature 60°C, stirring rate 300 r/min, frother concentration 17.5 g/L and flotation time 1 min. PVC and PET with different particle sizes were separated efficiently through two-stage flotation. Additionally, after ultrasonic assisted surface modification, separation of PVC and PET with different mass ratios was obtained efficiently through one-stage flotation. The purity and the recovery of the obtained products after flotation separation are up to 99.30% and 99.73%, respectively. A flotation process was designed for flotation separation of PVC and PET plastics combined with surface modification. This study provides technical insights into physical separation of plastic wastes for recycling industry.

  1. Ammonia modification for flotation separation of polycarbonate and polystyrene waste plastics.

    PubMed

    Wang, Chong-qing; Wang, Hui; Gu, Guo-hua; Lin, Qing-quan; Zhang, Ling-ling; Huang, Luo-luo; Zhao, Jun-yao

    2016-05-01

    A promising method, ammonia modification, was developed for flotation separation of polycarbonate (PC) and polystyrene (PS) waste plastics. Ammonia modification has little effect on flotation behavior of PS, while it changes significantly that of PC. The PC recovery in the floated product drops from 100% to 3.17% when modification time is 13min and then rises to 100% after longer modification. The mechanism of ammonia modification was studied by contact angle, and Fourier transform infrared (FT-IR) and X-ray photoelectron spectroscopy (XPS) measurements. Contact angle of PC indicates the decline of PC recovery in the floated product is ascribed to an increase in surface wettability. FT-IR and XPS spectra suggest that ammonia modification causes chemical reactions occurred on PC surface. Flotation behavior of ammonia-modified PC and PS was investigated with respect to flotation time, frother concentration and particle sizes. Flotation separation of PC and PS waste plastics was conducted based on the flotation behavior of single plastic. PC and PS mixtures with different particle sizes are separated efficiently, implying that the technology possesses superior applicability to particle sizes of plastics. The purity of PS and PC is up to 99.53% and 98.21%, respectively, and the recovery of PS and PC is larger than 92.06%. A reliable, cheap and effective process is proposed for separation of PC and PS waste plastics.

  2. Characteristic of flotation deinking using bio and synthetic surfactant at different air flow rate

    NASA Astrophysics Data System (ADS)

    Trismawati, Wardana, I. N. G.; Hamidi, Nurkholis; Sasongko, Mega Nur

    2016-03-01

    Flotation deinking has industrially applied but several problems keep unsolved because limitations have to compete with several variables present. Flotation deinking is multi variables process, so studying flotation deinking is still interesting. In this research, the amount of variables was reduced and focused to the performance comparison between flotation deinking of old newspaper (ONP) using biodegradable fatty acid of morinda citrifolia as the raw bio surfactant (RBS) and biodegradable fatty acid of palm oil that had been converted to be commercial surfactant (CS). The flotation was done at laboratory flotation cell equipped with orifice at different diameter (orifice number 20, 40 and 60) with adjustable airflow rate. Brightness and Effective Residual Ink Concentration (ERIC) of the deinked pulp were measured. The best results were achieved on orifice number 40 with the highest brightness of 41.96 °ISO and 40.96 °ISO when using CS and RBS respectively, and lowest ERIC of 896.82 ppm and 1001.72 ppm when using CS and RBS respectively. The percentage delta of deinking power characteristic between CS and RBS was 2.36% and 11.70% for brightness and ERIC, respectively.

  3. Kinetic approach to the study of froth flotation applied to a lepidolite ore

    NASA Astrophysics Data System (ADS)

    Vieceli, Nathália; Durão, Fernando O.; Guimarães, Carlos; Nogueira, Carlos A.; Pereira, Manuel F. C.; Margarido, Fernanda

    2016-07-01

    The number of published studies related to the optimization of lithium extraction from low-grade ores has increased as the demand for lithium has grown. However, no study related to the kinetics of the concentration stage of lithium-containing minerals by froth flotation has yet been reported. To establish a factorial design of batch flotation experiments, we conducted a set of kinetic tests to determine the most selective alternative collector, define a range of pulp pH values, and estimate a near-optimum flotation time. Both collectors (Aeromine 3000C and Armeen 12D) provided the required flotation selectivity, although this selectivity was lost in the case of pulp pH values outside the range between 2 and 4. Cumulative mineral recovery curves were used to adjust a classical kinetic model that was modified with a non-negative parameter representing a delay time. The computation of the near-optimum flotation time as the maximizer of a separation efficiency (SE) function must be performed with caution. We instead propose to define the near-optimum flotation time as the time interval required to achieve 95%-99% of the maximum value of the SE function.

  4. Separation of polyethylene terephthalate from municipal waste plastics by froth flotation for recycling industry

    SciTech Connect

    Wang, Chong-Qing; Wang, Hui Liu, You-Nian

    2015-01-15

    Highlights: • Factors of NaOH treatment were studied by orthogonal and single factor experiments. • Mechanism of alkaline treatment for facilitating flotation was manifested. • Flotation separation of PET was achieved with high purity and efficiency. • A flow sheet of purification PET from MWP was designed. - Abstract: Recycling is an effective way to manage plastic wastes and receives considerable attention. Since plastic mixtures are difficult to recycle because of their intrinsic characteristics, separation of mixed plastics is the key problem for recycling. Separation of polyethylene terephthalate (PET) from municipal waste plastics (MWP) by froth flotation combined with alkaline pretreatment was investigated for recycling industry. The effect of process variables was estimated by L{sub 9} (3{sup 4}) orthogonal array of experiments and single factor experiments. The optimum conditions of alkaline pretreatment are 10 wt% sodium hydroxide, 20 min and 70 °C. After alkaline pretreatment under optimum conditions, flotation separation PET from acrylonitrile–butadiene–styrene, polystyrene, polycarbonate or polyvinyl chloride was achieved with high purity and efficiency. The purity of PET is up to 98.46% and the recovery is above 92.47%. A flow sheet of separation PET from MWP by a combination of froth flotation and sink float separation was designed. This study facilitates industrial application of plastics flotation and provides technical insights into recycling of waste plastics.

  5. Ammonia modification for flotation separation of polycarbonate and polystyrene waste plastics.

    PubMed

    Wang, Chong-qing; Wang, Hui; Gu, Guo-hua; Lin, Qing-quan; Zhang, Ling-ling; Huang, Luo-luo; Zhao, Jun-yao

    2016-05-01

    A promising method, ammonia modification, was developed for flotation separation of polycarbonate (PC) and polystyrene (PS) waste plastics. Ammonia modification has little effect on flotation behavior of PS, while it changes significantly that of PC. The PC recovery in the floated product drops from 100% to 3.17% when modification time is 13min and then rises to 100% after longer modification. The mechanism of ammonia modification was studied by contact angle, and Fourier transform infrared (FT-IR) and X-ray photoelectron spectroscopy (XPS) measurements. Contact angle of PC indicates the decline of PC recovery in the floated product is ascribed to an increase in surface wettability. FT-IR and XPS spectra suggest that ammonia modification causes chemical reactions occurred on PC surface. Flotation behavior of ammonia-modified PC and PS was investigated with respect to flotation time, frother concentration and particle sizes. Flotation separation of PC and PS waste plastics was conducted based on the flotation behavior of single plastic. PC and PS mixtures with different particle sizes are separated efficiently, implying that the technology possesses superior applicability to particle sizes of plastics. The purity of PS and PC is up to 99.53% and 98.21%, respectively, and the recovery of PS and PC is larger than 92.06%. A reliable, cheap and effective process is proposed for separation of PC and PS waste plastics. PMID:26965210

  6. Separation of plastics: The importance of kinetics knowledge in the evaluation of froth flotation.

    PubMed

    Censori, Matteo; La Marca, Floriana; Carvalho, M Teresa

    2016-08-01

    Froth flotation is a promising technique to separate polymers of similar density. The present paper shows the need for performing kinetic tests to evaluate and optimize the process. In the experimental study, batch flotation tests were performed on samples of ABS and PS. The floated product was collected at increasing flotation time. Two variables were selected for modification: the concentration of the depressor (tannic acid) and airflow rate. The former is associated with the chemistry of the process and the latter with the transport of particles. It was shown that, like mineral flotation, plastics flotation can be adequately assumed as a first order rate process. The results of the kinetic tests showed that the kinetic parameters change with the operating conditions. When the depressing action is weak and the airflow rate is low, the kinetic is fast. Otherwise, the kinetic is slow and a variable percentage of the plastics never floats. Concomitantly, the time at which the maximum difference in the recovery of the plastics in the floated product is attained changes with the operating conditions. The prediction of flotation results, process evaluation and comparisons should be done considering the process kinetics. PMID:27256781

  7. Flotation separation of polyvinyl chloride and polyethylene terephthalate plastics combined with surface modification for recycling.

    PubMed

    Wang, Chongqing; Wang, Hui; Fu, Jiangang; Zhang, Lingling; Luo, Chengcheng; Liu, Younian

    2015-11-01

    Surface modification with potassium permanganate (KMnO4) solution was developed for separation of polyvinyl chloride (PVC) and polyethylene terephthalate (PET) waste plastics. The floatability of PVC decreases with increasing of KMnO4 concentration, treatment time, temperature and stirring rate, while that of PET is unaffected. Fourier transform infrared (FT-IR) analysis confirms that mechanism of surface modification may be due to oxidization reactions occurred on PVC surface. The optimum conditions are KMnO4 concentration 1.25 mM/L, treatment time 50 min, temperature 60°C, stirring rate 300 r/min, frother concentration 17.5 g/L and flotation time 1 min. PVC and PET with different particle sizes were separated efficiently through two-stage flotation. Additionally, after ultrasonic assisted surface modification, separation of PVC and PET with different mass ratios was obtained efficiently through one-stage flotation. The purity and the recovery of the obtained products after flotation separation are up to 99.30% and 99.73%, respectively. A flotation process was designed for flotation separation of PVC and PET plastics combined with surface modification. This study provides technical insights into physical separation of plastic wastes for recycling industry. PMID:26253330

  8. Micro-agglomerate flotation for deep cleaning of coal. Quarterly progress report, October 1--December 30, 1995

    SciTech Connect

    Chandler, S.; Hogg, R.

    1996-04-01

    Goals are to demonstrate the technical and economic feasibility of a micro-agglomerate flotation process (combination of oil-agglomeration and froth flotation) and to establish the essential criteria for reagent selection and system design and operation. The research program was organized into the following tasks: interfacial studies, emulsification, agglomerate growth and structure, and agglomerate flotation. Work on the first two tasks has been completed.

  9. Nonambulatory cows: Duration of recumbency and quality of nursing care affect outcome of flotation therapy.

    PubMed

    Stojkov, J; Weary, D M; von Keyserlingk, M A G

    2016-03-01

    Cows that are unable or unwilling to stand and remain recumbent for ≥ 12 h are defined as nonambulatory. Care and management of nonambulatory cattle is considered a major animal welfare concern facing the livestock industry, particularly the dairy sector. Flotation therapy has gained interest as a means to promote recovery in nonambulatory cows and is based on the concept that by floating the cow in warm water, secondary pressure damage to muscles and nerves will be reduced. The objective of this study was to assess the physiological responses to stress related to the flotation therapy and to evaluate the effect of recumbency duration and nursing care on the outcome of the flotation therapy. The outcomes of 34 nonambulatory Holstein dairy cows were analyzed after they were subjected to flotation therapy. The duration of recumbency and quality of nursing care provided before initiation of the flotation treatment were assessed based on producer responses to survey questions, and from on-site observations by the researchers. A veterinarian examined all cows before flotation therapy began. The treatment was divided into 5 phases: baseline (before filling), manipulation (placing the cow into the tank), filling (the tank was filled with water), flotation (the cow was confined in the filled tank), and draining (water was removed from the tank). Stress responses to the procedure, excluding the manipulation portion, were assessed using heart rate variability. The high-frequency component (HF normalized units) decreased during the filling and draining phases (2.8 ± 0.2 and 3.1 ± 0.4, respectively) compared with the baseline and floating phase (5.1 ± 0.6 and 4.9 ± 0.3, [corrected] respectively). These results indicate that the stress related to the flotation therapy is greatest during the filling and draining phases of the treatment, when cows likely have to exert increased effort to transition to a standing position. The flotation therapy was less likely to be

  10. Columns in Clay

    ERIC Educational Resources Information Center

    Leenhouts, Robin

    2010-01-01

    This article describes a clay project for students studying Greece and Rome. It provides a wonderful way to learn slab construction techniques by making small clay column capitols. With this lesson, students learn architectural vocabulary and history, understand the importance of classical architectural forms and their influence on today's…

  11. A Column Dispersion Experiment.

    ERIC Educational Resources Information Center

    Corapcioglu, M. Y.; Koroglu, F.

    1982-01-01

    Crushed glass and a Rhodamine B solution are used in a one-dimensional optically scanned column experiment to study the dispersion phenomenon in porous media. Results indicate that the described model gave satisfactory results and that the dispersion process in this experiment is basically convective. (DC)

  12. Accuracy of egg flotation throughout incubation to determine embryo age and incubation day in waterbird nests

    USGS Publications Warehouse

    Ackerman, Joshua T.; Eagles-Smith, Collin A.

    2010-01-01

    Floating bird eggs to estimate their age is a widely used technique, but few studies have examined its accuracy throughout incubation. We assessed egg flotation for estimating hatch date, day of incubation, and the embryo's developmental age in eggs of the American Avocet (Recurvirostra americana), Black-necked Stilt (Himantopus mexicanus), and Forster's Tern (Sterna forsteri). Predicted hatch dates based on egg flotation during our first visit to a nest were highly correlated with actual hatch dates (r = 0.99) and accurate within 2.3 ± 1.7 (SD) days. Age estimates based on flotation were correlated with both day of incubation (r = 0.96) and the embryo's developmental age (r = 0.86) and accurate within 1.3 ± 1.6 days and 1.9 ± 1.6 days, respectively. However, the technique's accuracy varied substantially throughout incubation. Flotation overestimated the embryo's developmental age between 3 and 9 days, underestimated age between 12 and 21 days, and was most accurate between 0 and 3 days and 9 and 12 days. Age estimates based on egg flotation were generally accurate within 3 days until day 15 but later in incubation were biased progressively lower. Egg flotation was inaccurate and overestimated embryo age in abandoned nests (mean error: 7.5 ± 6.0 days). The embryo's developmental age and day of incubation were highly correlated (r = 0.94), differed by 2.1 ± 1.6 days, and resulted in similar assessments of the egg-flotation technique. Floating every egg in the clutch and refloating eggs at subsequent visits to a nest can refine age estimates.

  13. Comparison of passive fecal flotation run by veterinary students to zinc-sulfate centrifugation flotation run in a diagnostic parasitology laboratory.

    PubMed

    Gates, Maureen C; Nolan, Thomas J

    2009-10-01

    The sensitivity of fecal examination methods can be influenced by both technician error and methodology. In this analysis, we compared the results of 335 passive fecal flotation examinations performed on the feces of stray dogs by 3rd-yr veterinary students at the University of Pennsylvania, School of Veterinary Medicine, to the results obtained through zinc-sulfate centrifugation performed by the diagnostic parasitology laboratory on the same fecal samples. The students' passive flotation results agreed with the laboratory zinc-sulfate centrifugation for only 62.4% of samples. Students were able to diagnose 75.0% of Ancylostoma caninum cases, 71.4% of Toxocara canis cases, 54.2% of Trichuris vulpis cases, 26.7% of Cystoisospora spp. (C. ohioensis-like and C. canis) cases, and 14.7% of Giardia lamblia cases. There were also 70 instances where students reported the presence of parasites in the sample that were not diagnosed by zinc-sulfate centrifugation. Based on the overall study findings, passive fecal flotation examinations run in private practice could be missing up to 50.5% of infected dogs, due to either technician error or inherent limitations to the passive fecal flotation technique.

  14. Electro-coagulation-flotation process for algae removal.

    PubMed

    Gao, Shanshan; Yang, Jixian; Tian, Jiayu; Ma, Fang; Tu, Gang; Du, Maoan

    2010-05-15

    Algae in surface water have been a long-term issue all over the world, due to their adverse influence on drinking water treatment process as well as drinking water quality. The algae removal by electro-coagulation-flotation (ECF) technology was investigated in this paper. The results indicated that aluminum was an excellent electrode material for algae removal as compared with iron. The optimal parameters determined were: current density=1 mA/cm(2), pH=4-7, water temperature=18-36 degrees C, algae density=0.55 x 10(9)-1.55 x 10(9) cells/L. Under the optimal conditions, 100% of algae removal was achieved with the energy consumption as low as 0.4 kWh/m(3). The ECF performed well in acid and neutral conditions. At low initial pH of 4-7, the cell density of algae was effectively removed in the ECF, mainly through the charge neutralization mechanism; while the algae removal worsened when the pH increased (7-10), and the main mechanism shifted to sweeping flocculation and enmeshment. The mechanisms for algae removal at different pH were also confirmed by atomic force microscopy (AFM) analysis. Furthermore, initial cell density and water temperature could also influence the algae removal. Overall, the results indicated that the ECF technology was effective for algae removal, from both the technical and economical points of view. PMID:20042280

  15. Hydrophobic flocculation flotation for beneficiating fine coal and minerals

    SciTech Connect

    Song, S.; Valdivieso, A.L.

    1998-06-01

    It is shown that hydrophobic flocculation flotation (HFF) is an effective process to treat finely ground ores and slimes so as to concentrate coal and mineral values at a fine size range. The process is based on first dispersing the fine particles suspension, followed by flocculation of fine mineral values or coal in the form of hydrophobic surfaces either induced by specifically adsorbed surfactants or from nature at the conditioning of the slurry with the shear field of sufficient magnitude. The flocculation is intensified by the addition of a small amount of nonpolar oil. finely ground coals, ilmenite slimes, and gold finely disseminated in a slag have been treated by this process. Results are presented indicating that cleaned coal with low ash and sulfur remaining and high Btu recovery can be obtained, and the refractory ores of ilmenite slimes and fine gold-bearing slag can be reasonably concentrated, leading to better beneficiation results than other separation techniques. In addition, the main operating parameters affecting the HFF process are discussed.

  16. Electro-coagulation-flotation process for algae removal.

    PubMed

    Gao, Shanshan; Yang, Jixian; Tian, Jiayu; Ma, Fang; Tu, Gang; Du, Maoan

    2010-05-15

    Algae in surface water have been a long-term issue all over the world, due to their adverse influence on drinking water treatment process as well as drinking water quality. The algae removal by electro-coagulation-flotation (ECF) technology was investigated in this paper. The results indicated that aluminum was an excellent electrode material for algae removal as compared with iron. The optimal parameters determined were: current density=1 mA/cm(2), pH=4-7, water temperature=18-36 degrees C, algae density=0.55 x 10(9)-1.55 x 10(9) cells/L. Under the optimal conditions, 100% of algae removal was achieved with the energy consumption as low as 0.4 kWh/m(3). The ECF performed well in acid and neutral conditions. At low initial pH of 4-7, the cell density of algae was effectively removed in the ECF, mainly through the charge neutralization mechanism; while the algae removal worsened when the pH increased (7-10), and the main mechanism shifted to sweeping flocculation and enmeshment. The mechanisms for algae removal at different pH were also confirmed by atomic force microscopy (AFM) analysis. Furthermore, initial cell density and water temperature could also influence the algae removal. Overall, the results indicated that the ECF technology was effective for algae removal, from both the technical and economical points of view.

  17. 11. TIMBER COLUMN AND CAST IRON COLUMN CAP IN FIFTH ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    11. TIMBER COLUMN AND CAST IRON COLUMN CAP IN FIFTH FLOOR WAREHOUSE SPACE. VIEW TO SOUTHWEST. - Commercial & Industrial Buildings, Becker-Hazelton Company Warehouse, 280 Iowa Street, Dubuque, Dubuque County, IA

  18. Successfully downsize trayed columns

    SciTech Connect

    Sloley, A.W.; Fleming, B. )

    1994-03-01

    Techniques for the design and sizing of new trayed distillation columns are abundant in the literature. So, too, are the guidelines for modifying towers for operation beyond their original design range. Reducing capacity of distillation trays merits at least as much consideration. Indeed, lack of knowledge and experience in this area causes many tower failures and misdesigned columns. In this article, the authors present some practical design considerations, based on field experience, for tower trays operating at loadings dramatically lower than normal for a particular design. General considerations cover liquid and vapor hydraulics and flow behavior. Case studies are included for there typical units: a refinery vacuum crude still, a petrochemical superfractionator, and a steam stripper.

  19. Anglesite and silver recovery from jarosite residues through roasting and sulfidization-flotation in zinc hydrometallurgy.

    PubMed

    Han, Haisheng; Sun, Wei; Hu, Yuehua; Jia, Baoliang; Tang, Honghu

    2014-08-15

    Hazardous jarosite residues contain abundant valuable minerals that are difficult to be recovered by traditional flotation process. This study presents a new route, roasting combined with sulfidization-flotation, for the recovery of anglesite and silver from jarosite residues of zinc hydrometallurgy. Surface appearance and elemental distribution of jarosite residues was examined by scanning electron microscopy and energy dispersive X-ray spectrometry analysis, respectively. Decomposition and transformation mechanisms of jarosite residues were illustrated by differential thermal analysis. Results showed that after roasting combined with flotation, the grade and recovery of lead were 43.89% and 66.86%, respectively, and those of silver were 1.3 kg/t and 81.60%, respectively. At 600-700 °C, jarosite was decomposed to release encapsulated valuable minerals such as anglesite (PbSO4) and silver mineral; silver jarosite decomposed into silver sulfate (Ag2SO4); and zinc ferrite (ZnO · Fe2O3) decomposed into zinc sulfate (ZnSO4) and hematite (Fe2O3). Bared anglesite and silver minerals were modified by sodium sulfide and easily collected by flotation collectors. This study demonstrates that the combination of roasting and sulfidization-flotation provides a promising process for the recovery of zinc, lead, and silver from jarosite residues of zinc hydrometallurgy.

  20. Results of fibre and toner flotation depending on oleic acid dosage.

    PubMed

    Trumic, Maja S; Trumic, Milan Z; Vujic, Bogdana; Andric, Ljubisa; Bogdanovic, Grozdanka

    2016-09-01

    The literature was reviewed with respect to deinking flotation methods with toner samples, specifically emphasizing the speciation of copy machine and laser printing, which produce an increasing quantity of paper that is difficult to recycle. Speciation here refers to the physical-chemical characteristics of the toner, which change because of the polymerization (fusion) and oxidation process, due to exposure to heat, light and oxygen (air) during the printing process. To simulate the deinking flotation, after the ideal disintegration process, samples of toner were prepared in order to provide free toner particles. Synthetic toner has iron content and the same physical-chemical features as free disintegrated printed toner particles.We report the toner (I) and fibre (Y) recovery and the brightness (B) of laboratory filter pads formed of deinked product as deinking efficiencies. The application of oleic acid as the collector in the flotation stage gives a better flotation recovery in alkaline than in acidic conditions. The highest brightness (BF = 93.66%) and flotation recoveries (I = 90, Y = 92.82%) were achieved during testing at an oleic acid concentration of 3.38·10(-6) mol l(-1), which is the lowest dose used. This makes the use of oleic acid economical and environmentally friendly. PMID:27354017

  1. A study of the interfacial chemistry of pyrite and coal in fine coal cleaning using flotation

    SciTech Connect

    Jiang, C.

    1993-12-31

    Surface oxidation, surface charge, and flotation properties have been systematically studied for coal, coal-pyrite and ore-pyrite. Electrochemical studies show that coal-pyrite exhibits much higher and more complex surface oxidation than ore-pyrite and its oxidation rate depends strongly on the carbon/coal content. Flotation studies indicate that pyrites have no self-induced floatability. Fuel oil significantly improves the floatability of coal and induces considerable flotation for coal-pyrite due to the hydrophobic interaction of fuel oil with the carbon/coal inclusions on the pyrite surface. Xanthate is a good collector for ore-pyrite but a poor collector for coal and coal-pyrite. The results from thermodynamic calculations, flotation and zeta potential measurements show that iron ions greatly affect the flotation of pyrite with xanthate and fuel oil. Various organic and inorganic chemicals have been examined for depressing coal-pyrite. It was found, for the first time, that sodium pyrophosphate is an effective depressant for coal-pyrite. Solution chemistry shows that pyrophosphate reacts with iron ions to form stable iron pyrophosphate complexes. Using pyrophosphate, the complete separation of pyrite from coal can be realized over a wide pH range at relatively low dosage.

  2. Production of brown and black pigments by using flotation waste from copper slag.

    PubMed

    Ozel, Emel; Turan, Servet; Coruh, Semra; Ergun, Osman Nuri

    2006-04-01

    One of the major problems in copper-producing countries is the treatment of the large amount of copper slag or copper flotation waste generated from copper slag which contains significant amounts of heavy metals such as Cu, Zn, Pb and Co. Dumping or disposal of such large quantities of flotation waste from copper slag causes environmental and space problems. In this study, the treatment of flotation waste from copper slag by a thermal method and its use as an iron source in the production of inorganic brown and black pigments that are used in the ceramic industry were investigated. The pigments were produced by calcining different amounts of flotation waste and chromite, Cr2O3, ZnO and CoO mixtures. The pigments obtained were added to transparent ceramic glazes and porcelainized tile bodies. Their colours were defined by L*a*b* measurements with a spectrophotometer. The results showed that flotation waste from copper slag could be used as an iron source to produce brown and black pigments in both ceramic body and glazes.

  3. Preparation of nuclear fuel spheres by flotation-internal gelation

    DOEpatents

    Haas, Paul A.; Fowler, Victor L.; Lloyd, Milton H.

    1987-01-01

    A simplified internal gelation process for the preparation of gel spheres of nuclear fuels. The process utilizes perchloroethylene as a gelation medium. Gelation is accomplished by directing droplets of a nuclear fuel broth into a moving volume of hot perchloroethylene (about 85.degree. C.) in a trough. Gelation takes place as the droplets float on the surface of the perchloroethylene and the resultant gel spheres are carried directly into an ager column which is attached to the trough. The aged spheres are disengaged from the perchloroethylene on a moving screen and are deposited in an aqueous wash column.

  4. Column test-rig facility for column scanning studies

    NASA Astrophysics Data System (ADS)

    Zain, Rasif M.; Roslan, Y.

    2010-03-01

    Distillation columns are considered as one of the most critical components in oil and gas plants. The plant performance depends on the ability of these columns to function as intended. Defective columns may lead to serious consequences to the plant operation, and hence the quality of product. In order to perform any inspection techniques to distillation column for NDT practitioner, the best facility was designed when the adjustable defeats of distillation column test rig has been developed. The paper discussed the development and the function of this facility.

  5. Column test-rig facility for column scanning studies

    NASA Astrophysics Data System (ADS)

    Zain, Rasif M.; Roslan, Y.

    2009-12-01

    Distillation columns are considered as one of the most critical components in oil and gas plants. The plant performance depends on the ability of these columns to function as intended. Defective columns may lead to serious consequences to the plant operation, and hence the quality of product. In order to perform any inspection techniques to distillation column for NDT practitioner, the best facility was designed when the adjustable defeats of distillation column test rig has been developed. The paper discussed the development and the function of this facility.

  6. Separation of packaging plastics by froth flotation in a continuous pilot plant

    SciTech Connect

    Carvalho, Teresa; Durao, Fernando; Ferreira, Celia

    2010-11-15

    The objective of the research was to apply froth flotation to separate post-consumer PET (Polyethylene Terephthalate) from other packaging plastics with similar density, in a continuously operated pilot plant. A representative sample composed of 85% PET, 2.5% PVC (Polyvinyl Chloride) and 11.9% PS (Polystyrene) was subjected to a combination of alkaline treatment and surfactant adsorption followed by froth flotation. A mineral processing pilot plant, owned by a Portuguese mining company, was adapted for this purpose. The experimentation showed that it is possible to produce an almost pure concentrate of PET, containing 83% of the PET in feed, in a single bank of mechanical flotation cells. The concentrate grade attained was 97.2% PET, 1.1% PVC and 1.1% PS. By simulation it was shown that the Portuguese recycling industry specifications can be attained if one cleaning and one scavenger stages are added to the circuit.

  7. Utilization of starch graft copolymers as selective depressants for lizardite in the flotation of pentlandite

    NASA Astrophysics Data System (ADS)

    Cao, Jian; Luo, Yong-Chun; Xu, Guo-Qiang; Qi, Li; Hu, Xiu-Qin; Xu, Peng-Fei; Zhang, Liu-Yi; Cheng, Shao-Yi

    2015-05-01

    This paper investigates the detrimental effect of lizardite surface characteristics on pentlandite flotation. To reduce the effect, two different starch graft copolymers, starch-graft-polyacrylamide (S-g-PAM) and starch-graft-polyacrylic acid (S-g-PAA) were synthesized as depressants for lizardite. The flotation results show that at pH value of 8, where the flotation of lizardite and pentlandite are routinely performed, S-g-PAM and S-g-PAA improve pentlandite recovery efficiently, compared with the traditional depressant carboxymethyl cellulose (CMC). Experimental results demonstrate that S-g-PAM and S-g-PAA disperse the hydrophilic lizardite particles from the pentlandite surface and also flocculate lizardite particles.

  8. Flotation performances and adsorption mechanism of α-hydroxyoctyl phosphinic acid to cassiterite

    NASA Astrophysics Data System (ADS)

    Li, Fangxu; Zhong, Hong; Zhao, Gang; Wang, Shuai; Liu, Guangyi

    2015-10-01

    In this paper, the flotation performances and adsorption mechanism of α-hydroxyoctyl phosphinic acid (HPA) to cassiterite were investigated by adsorption experiments, micro-flotation tests, zeta potential measurements, Fourier transform infrared spectroscopy (FTIR) and X-ray photoelectron spectroscopy (XPS) analyses. The micro-flotation results indicated that compared with styrene phosphonic acid (SPA), diphosphonic acid (DPA), benzohydroxamic acid (BHA) and salicylhydroxamic acid (SHA), HPA exhibited excellent collecting power to cassiterite and superior selectivity against magnetite or hematite over a wide pH range. The results of adsorption experiments and zeta potential deduced that HPA chemisorb on cassiterite surfaces. The results of FTIR inferred HPA chemisorb onto cassiterite surfaces through its P and O atoms with the P-H and O-H bonds broken. XPS analysis further demonstrated HPA react with Sn species by formation of Sn-O-P and Sn-P bond.

  9. Final Report, Distillation Column Flooding Predictor

    SciTech Connect

    George E. Dzyacky

    2003-05-31

    The Flooding Predictor is an advanced process control strategy comprising a patented pattern-recognition methodology that identifies pre-flood patterns discovered to precede flooding events in distillation columns. The grantee holds a U.S. patent on the modeling system. The technology was validated at the Separations Research Program, The University of Texas at Austin under a grant from the U. S. Department of Energy, Inventions & Innovation Program. Distillation tower flooding occurs at abnormally high vapor and/or liquid rates. The loss in tray efficiencies is attributed to unusual behavior of liquid inventories inside the column leading to conditions of flooding of the space in between trays with liquid. Depending on the severity of the flood condition, consequences range from off spec products to equipment damage and tower shutdown. This non-intrusive pattern recognition methodology, processes signal data obtained from existing column instrumentation. Once the pattern is identified empirically, it is modeled and coded into the plant's distributed control system. The control system is programmed to briefly "unload" the tower each time the pattern appears. The unloading takes the form of a momentary reduction in column severity, e.g., decrease bottom temperature, reflux or tower throughput. Unloading the tower briefly at the pre-flood state causes long-term column operation to become significantly more stable - allowing an increase in throughput and/or product purity. The technology provides a wide range of value between optimization and flooding. When a distillation column is not running at capacity, it should be run in such a way ("pushed") that optimal product purity is achieved. Additional benefits include low implementation and maintenance costs, and a high level of console operator acceptance. The previous commercial applications experienced 98% uptime over a four-year period. Further, the technology is unique in its ability to distinguish between different

  10. Coal froth flotation: effects of reagent adsorption on the froth structure

    SciTech Connect

    Meryem Ozmak; Zeki Aktas

    2006-05-15

    The amount and quality of concentrate obtained from froth flotation of a coal are very important to determine the efficiency of the separation process. The shape and size of the bubbles in the froth directly affect the amount and purity of the concentrate overflowed during the froth flotation of the coal. The froth structure is significantly dependent on parameters such as the size of the solid particles, the surface properties of the particles, the chemical structure of surface active agents, the reagents adsorbed onto solid particles, and the reagents remaining in water. This work was performed to determine the relationship between the reagents adsorbed on the solid particles, froth structure, and froth flotation performance. The -53 {mu}m size fraction of a bituminous coal was used to perform froth flotation experiments. The froth flotation of the coal used was performed in the presence of two nonionic surfactants, Triton x-100 (poly(ethylene glycol) tert-octylphenyl ether) and MIBC (methyl isobutyl carbinol), and an anionic surfactant, SDS (sodium dodecyl sulfate). The results showed that the adsorption of a high amount of reagent on the particles decreased the ability of separation, thus a substantial amount of mineral particles overflowed along with the hydrophobic coal particles. The use of MIBC with Triton x-100 or SDS as mixture increased solid recovery, and it was concluded that MIBC selectively adsorbed on solids acting as collector as well as a frother. Reagent adsorption has a crucial effect on the froth structure, which is strongly related to flotation performance. 33 refs., 18 figs.

  11. Refining of fossil resin flotation concentrate from western coal. Final report

    SciTech Connect

    Jensen, G.F.; Miller, J.D.

    1995-02-16

    During the past several years, significant research efforts have been made to develop process technology for the selective flotation of fossil resin from western coals. As a result of these efforts, several new flotation technologies have been developed. Operation of a proof-of-concept continuous flotation circuit showed the selective flotation process to be sufficiently profitable to justify the development of a fossil resin industry. However, little attention has been given to the refining of the fossil resin flotation concentrate although solvent refining is a critical step for the fossil resin to become a marketable product. In view of this situation, DOE funded this two-year project to evaluate the following aspects of the fossil resin refining technology: 1) Characterization of the fossil resin flotation concentrate and its refined products; 2) Kinetics of fossil resin extraction; 3) Effects of operating variables on solvent extraction; 4) Extraction solvents; 5) Proof-of-concept continuous refining tests; and 6) Technical and economic analysis. The results from this research effort have led to the following conclusions: Hexane- or heptane-refined fossil resin has a light-yellow color, a melting point of 140 - 142{degrees}C, a density of 1.034 gram/cm, and good solubility in nonpolar solvents. Among the four solvents evaluated (hexane, heptane, toluene and ethyl acetate), hexane is the most appropriate solvent based on overall technical and economic considerations. Batch extraction tests and kinetic studies suggest that the main interaction between the resin and the solvent is expected to be the forces associated with solvation phenomena. Temperature has the most significant effect on extraction rate. With hexane as the solvent, a recovery of 90% cam be achieved at 50{degrees}C and 10% solids concentration with moderate agitation for 1 hour.

  12. Microhydrodynamics of flotation processes in the sea surface layer

    NASA Astrophysics Data System (ADS)

    Grammatika, Marianne; Zimmerman, William B.

    2001-10-01

    The uppermost surface of the ocean forms a peculiarly important ecosystem, the sea surface microlayer (SML). Comprising the top 1-1000 μm of the ocean surface, the SML concentrates many chemical substances, particularly those that are surface active. Important economically as a nursery for fish eggs and larvae, the SML unfortunately is also especially vulnerable to pollution. Contaminants that settle out from the air, have low solubility, or attach to floatable matter tend to accumulate in the SML. Bubbles contribute prominently to the dynamics of air-sea exchanges, playing an important role in geochemical cycling of material in the upper ocean and SML. In addition to the movement of bubbles, the development of a bubble cloud interrelates with the single particle dynamics of all other bubbles and particles. In the early sixties, several in situ oceanographic techniques revealed an "unbelievably immense" number of coastal bubbles of radius 15-300 μm. The spatial and temporal variation of bubble numbers were studied; acoustical oceanographers now use bubbles as tracers to determine ocean processes near the ocean surface. Sea state and rain noises have both been definitively ascribed to the radiation from huge numbers of infant micro bubbles [The Acoustic Bubble. Academic Press, San Diego]. Our research programme aims at constructing a hydrodynamic model for particle transport processes occurring at the microscale, in multi-phase flotation suspensions. Current research addresses bubble and floc microhydrodynamics as building blocks for a microscale transport model. This paper reviews sea surface transport processes in the microlayer and the lower atmosphere, and identifies those amenable to microhydrodynamic modelling and simulation. It presents preliminary simulation results including the multi-body hydrodynamic mobility functions for the modelling of "dynamic bubble filters" and floc suspensions. Hydrodynamic interactions versus spatial anisotropy and size of

  13. A saltwater flotation technique to identify unincubated eggs

    USGS Publications Warehouse

    Devney, C.A.; Kondrad, S.L.; Stebbins, K.R.; Brittingham, K.D.; Hoffman, D.J.; Heinz, G.H.

    2009-01-01

    Field studies on nesting birds sometimes involve questions related to nest initiation dates, length of the incubation period, or changes in parental incubation behavior during various stages of incubation. Some of this information can be best assessed when a nest is discovered before the eggs have undergone any incubation, and this has traditionally been assessed by floating eggs in freshwater. However, because the freshwater method is not particularly accurate in identifying unincubated eggs, we developed a more reliable saltwater flotation method. The saltwater method involves diluting a saturated saltwater solution with freshwater until a salt concentration is reached where unincubated eggs sink to the bottom and incubated eggs float to the surface. For Laughing Gulls (Leucophaeus atricilla), floating eggs in freshwater failed to identify 39.0% (N = 251) of eggs that were subsequently found by candling to have undergone incubation prior to collection. By contrast, in a separate collection of gull eggs, no eggs that passed the saltwater test (N = 225) were found by a later candling to have been incubated prior to collection. For Double-crested Cormorants (Phalacrocorax auritus), floating eggs in freshwater failed to identify 15.6% (N = 250) of eggs that had undergone incubation prior to collection, whereas in a separate collection, none of the eggs that passed the saltwater test (N = 85) were found by a later candling to have been incubated prior to collection. Immersion of eggs in saltwater did not affect embryo survival. Although use of the saltwater method is likely limited to colonial species and requires calibrating a saltwater solution, it is a faster and more accurate method of identifying unincubated eggs than the traditional method of floating eggs in freshwater.

  14. Laboratory and in situ flotation rates of lecithotrophic eggs from the bathyal echinoid Phormosoma placenta

    NASA Astrophysics Data System (ADS)

    Young, Craig M.; Cameron, J. Lane

    1987-09-01

    The large, lecithotrophic eggs of the bathyal echinothuriid echinoid Phormosoma placenta are positively buoyant both in vitro and in situ to depths of at least 608 m. Eggs attain terminal velocity in less than 5 cm. At constant salinity, flotation rate is related linearly to temperature; eggs move more slowly at lower temperatures. This effect is attributed to increased water viscosity at lower temperatures, not differential changes in egg and water density. Based on an average flotation velocity of 0.42 cm s -1, it is predicted that eggs produced at bathyal depths will reach the surface in approximately 2 days.

  15. SPIRAL CONTACTOR FOR SOLVENT EXTRACTION COLUMN

    DOEpatents

    Cooley, C.R.

    1961-06-13

    The patented extraction apparatus includes a column, perforated plates extending across the column, liquid pulse means connected to the column, and an imperforate spiral ribbon along the length of the column.

  16. Why Hexagonal Basalt Columns?

    PubMed

    Hofmann, Martin; Anderssohn, Robert; Bahr, Hans-Achim; Weiß, Hans-Jürgen; Nellesen, Jens

    2015-10-01

    Basalt columns with their preferably hexagonal cross sections are a fascinating example of pattern formation by crack propagation. Junctions of three propagating crack faces rearrange such that the initial right angles between them tend to approach 120°, which enables the cracks to form a pattern of regular hexagons. To promote understanding of the path on which the ideal configuration can be reached, two periodically repeatable models are presented here involving linear elastic fracture mechanics and applying the principle of maximum energy release rate. They describe the evolution of the crack pattern as a transition from rectangular start configuration to the hexagonal pattern. This is done analytically and by means of three-dimensional finite element simulation. The latter technique reproduces the curved crack path involved in this transition.

  17. Why Hexagonal Basalt Columns?

    PubMed

    Hofmann, Martin; Anderssohn, Robert; Bahr, Hans-Achim; Weiß, Hans-Jürgen; Nellesen, Jens

    2015-10-01

    Basalt columns with their preferably hexagonal cross sections are a fascinating example of pattern formation by crack propagation. Junctions of three propagating crack faces rearrange such that the initial right angles between them tend to approach 120°, which enables the cracks to form a pattern of regular hexagons. To promote understanding of the path on which the ideal configuration can be reached, two periodically repeatable models are presented here involving linear elastic fracture mechanics and applying the principle of maximum energy release rate. They describe the evolution of the crack pattern as a transition from rectangular start configuration to the hexagonal pattern. This is done analytically and by means of three-dimensional finite element simulation. The latter technique reproduces the curved crack path involved in this transition. PMID:26550724

  18. Seed flotation and germination of salt marsh plants: The effects of stratification, salinity, and/or inundation regime

    USGS Publications Warehouse

    Elsey-Quirk, T.; Middleton, B.A.; Proffitt, C.E.

    2009-01-01

    We examined the effects of cold stratification and salinity on seed flotation of eight salt marsh species. Four of the eight species were tested for germination success under different stratification, salinity, and flooding conditions. Species were separated into two groups, four species received wet stratification and four dry stratification and fresh seeds of all species were tested for flotation and germination. Fresh seeds of seven out of eight species had flotation times independent of salinity, six of which had average flotation times of at least 50 d. Seeds of Spartina alterniflora and Spartina patens had the shortest flotation times, averaging 24 and 26 d, respectively. Following wet stratification, the flotation time of S. alterniflora seeds in higher salinity water (15 and 36 ppt) was reduced by over 75% and germination declined by more than 90%. Wet stratification reduced the flotation time of Distichlis spicata seeds in fresh water but increased seed germination from 2 to 16% in a fluctuating inundation regime. Fresh seeds of Iva frutescens and S. alternflora were capable of germination and therefore are non-dormant during dispersal. Fresh seeds of I. frutescens had similar germination to dry stratified seeds ranging 25-30%. Salinity reduced seed germination for all species except for S. alterniflora. A fluctuating inundation regime was important for seed germination of the low marsh species and for germination following cold stratification. The conditions that resulted in seeds sinking faster were similar to the conditions that resulted in higher germination for two of four species. ?? 2009 Elsevier B.V.

  19. A novel collector 2-ethyl-2-hexenoic hydroxamic acid: Flotation performance and adsorption mechanism to ilmenite

    NASA Astrophysics Data System (ADS)

    Xu, Haifeng; Zhong, Hong; Tang, Qing; Wang, Shuai; Zhao, Gang; Liu, Guangyi

    2015-10-01

    In this paper, a novel collector, 2-ethyl-2-hexenoic hydroxamic acid (EHHA) was prepared and characterized by elemental analysis, infrared, 1H NMR, 13C NMR and mass spectra. The flotation performance and adsorption mechanism of EHHA to ilmenite were investigated by micro-flotation tests, density functional theory (DFT) calculations, FTIR spectra, zeta potential and solution chemistry analyses. The micro-flotation results indicated that EHHA exhibited superior flotation performance compared to isooctyl hydroximic acid (IOHA) and octyl hydroxamic acid (OHA), and floated out 84.03% ilmenite at pH 8.0 with 250 mg/L dosage. The analyses of FTIR spectra and zeta potential demonstrated that EHHA might chemisorb onto ilmenite surfaces by form of five-membered chelates. The solution chemistry analyses further inferred that at pH 6.3-10.5, both Fe and Ti species on ilmenite surfaces could chelate EHHA. DFT calculation results implied EHHA owned the strongest affinity to ilmenite among the three C8 hydroximic acids. To discern the sharply improving floatability of ilmenite at pH 8-10, a schematic co-adsorption molecule-ion model of EHHA on ilmenite surfaces was suggested.

  20. 46 CFR 28.110 - Life preservers or other personal flotation devices.

    Code of Federal Regulations, 2012 CFR

    2012-10-01

    ... 46 Shipping 1 2012-10-01 2012-10-01 false Life preservers or other personal flotation devices. 28.110 Section 28.110 Shipping COAST GUARD, DEPARTMENT OF HOMELAND SECURITY UNINSPECTED VESSELS REQUIREMENTS FOR COMMERCIAL FISHING INDUSTRY VESSELS Requirements for All Vessels § 28.110 Life preservers...

  1. Separation of polyethylene terephthalate from municipal waste plastics by froth flotation for recycling industry.

    PubMed

    Wang, Chong-Qing; Wang, Hui; Liu, You-Nian

    2015-01-01

    Recycling is an effective way to manage plastic wastes and receives considerable attention. Since plastic mixtures are difficult to recycle because of their intrinsic characteristics, separation of mixed plastics is the key problem for recycling. Separation of polyethylene terephthalate (PET) from municipal waste plastics (MWP) by froth flotation combined with alkaline pretreatment was investigated for recycling industry. The effect of process variables was estimated by L9 (3(4)) orthogonal array of experiments and single factor experiments. The optimum conditions of alkaline pretreatment are 10 wt% sodium hydroxide, 20 min and 70°C. After alkaline pretreatment under optimum conditions, flotation separation PET from acrylonitrile-butadiene-styrene, polystyrene, polycarbonate or polyvinyl chloride was achieved with high purity and efficiency. The purity of PET is up to 98.46% and the recovery is above 92.47%. A flow sheet of separation PET from MWP by a combination of froth flotation and sink float separation was designed. This study facilitates industrial application of plastics flotation and provides technical insights into recycling of waste plastics.

  2. 46 CFR 180.72 - Personal flotation devices carried in addition to life jackets.

    Code of Federal Regulations, 2013 CFR

    2013-10-01

    ... 46 Shipping 7 2013-10-01 2013-10-01 false Personal flotation devices carried in addition to life jackets. 180.72 Section 180.72 Shipping COAST GUARD, DEPARTMENT OF HOMELAND SECURITY (CONTINUED) SMALL PASSENGER VESSELS (UNDER 100 GROSS TONS) LIFESAVING EQUIPMENT AND ARRANGEMENTS Ring Life Buoys and...

  3. 46 CFR 180.72 - Personal flotation devices carried in addition to life jackets.

    Code of Federal Regulations, 2012 CFR

    2012-10-01

    ... 46 Shipping 7 2012-10-01 2012-10-01 false Personal flotation devices carried in addition to life jackets. 180.72 Section 180.72 Shipping COAST GUARD, DEPARTMENT OF HOMELAND SECURITY (CONTINUED) SMALL PASSENGER VESSELS (UNDER 100 GROSS TONS) LIFESAVING EQUIPMENT AND ARRANGEMENTS Ring Life Buoys and...

  4. 46 CFR 180.72 - Personal flotation devices carried in addition to life jackets.

    Code of Federal Regulations, 2011 CFR

    2011-10-01

    ... 46 Shipping 7 2011-10-01 2011-10-01 false Personal flotation devices carried in addition to life jackets. 180.72 Section 180.72 Shipping COAST GUARD, DEPARTMENT OF HOMELAND SECURITY (CONTINUED) SMALL PASSENGER VESSELS (UNDER 100 GROSS TONS) LIFESAVING EQUIPMENT AND ARRANGEMENTS Ring Life Buoys and...

  5. 46 CFR 180.72 - Personal flotation devices carried in addition to life jackets.

    Code of Federal Regulations, 2014 CFR

    2014-10-01

    ... 46 Shipping 7 2014-10-01 2014-10-01 false Personal flotation devices carried in addition to life jackets. 180.72 Section 180.72 Shipping COAST GUARD, DEPARTMENT OF HOMELAND SECURITY (CONTINUED) SMALL PASSENGER VESSELS (UNDER 100 GROSS TONS) LIFESAVING EQUIPMENT AND ARRANGEMENTS Ring Life Buoys and...

  6. Flotation Thickening. Sludge Treatment and Disposal Course #166. Instructor's Guide [and] Student Workbook.

    ERIC Educational Resources Information Center

    Klopping, Paul H.

    This lesson describes the process of dissolved air flotation thickening. The material is intended to acquaint students with the fundamental principles of operation, components found on a typical thickener, factors that affect operation, a comparison with other thickening processes, and the calculations and laboratory tests required in establishing…

  7. Parachute/flotation bag recovery system for a large RV nose cone

    SciTech Connect

    Pepper, W.M.

    1980-03-01

    This report describes the design and development of a single-stage recovery system consisting of a 6-ft dia guide surface parachute with a 3.5 ft/sup 3/ ram-air-filled flotation bag for ocean recovery of a 120-lb nose cone. Recovery procedures start with jettisoning a portion of the initial reentry mass before deploying the parachute.

  8. Sensory Isolation in Flotation Tanks: Altered States of Consciousness and Effects on Well-Being

    ERIC Educational Resources Information Center

    Kjellgren, Anette; Lyden, Francisca; Norlander, Torsten

    2008-01-01

    A qualitative analysis (The Empirical Phenomenological Psychological method) of interviews involving eight patients (depression, burn-out syndrome, and chronic pain) was carried out in order to obtain knowledge regarding the effects of flotation tank therapy. This knowledge might be helpful for both professionals and potential floaters. The…

  9. 46 CFR 117.72 - Personal flotation devices carried in addition to life jackets.

    Code of Federal Regulations, 2014 CFR

    2014-10-01

    ... approved life jackets required to be worn during drills and emergencies. (b) Wearable marine buoyant... 46 Shipping 4 2014-10-01 2014-10-01 false Personal flotation devices carried in addition to life... PASSENGERS LIFESAVING EQUIPMENT AND ARRANGEMENTS Ring Life Buoys and Life Jackets § 117.72 Personal...

  10. 46 CFR 117.72 - Personal flotation devices carried in addition to life jackets.

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    ... approved life jackets required to be worn during drills and emergencies. (b) Wearable marine buoyant... 46 Shipping 4 2010-10-01 2010-10-01 false Personal flotation devices carried in addition to life... PASSENGERS LIFESAVING EQUIPMENT AND ARRANGEMENTS Ring Life Buoys and Life Jackets § 117.72 Personal...

  11. 46 CFR 117.72 - Personal flotation devices carried in addition to life jackets.

    Code of Federal Regulations, 2013 CFR

    2013-10-01

    ... approved life jackets required to be worn during drills and emergencies. (b) Wearable marine buoyant... 46 Shipping 4 2013-10-01 2013-10-01 false Personal flotation devices carried in addition to life... PASSENGERS LIFESAVING EQUIPMENT AND ARRANGEMENTS Ring Life Buoys and Life Jackets § 117.72 Personal...

  12. 46 CFR 117.72 - Personal flotation devices carried in addition to life jackets.

    Code of Federal Regulations, 2012 CFR

    2012-10-01

    ... approved life jackets required to be worn during drills and emergencies. (b) Wearable marine buoyant... 46 Shipping 4 2012-10-01 2012-10-01 false Personal flotation devices carried in addition to life... PASSENGERS LIFESAVING EQUIPMENT AND ARRANGEMENTS Ring Life Buoys and Life Jackets § 117.72 Personal...

  13. 46 CFR 117.72 - Personal flotation devices carried in addition to life jackets.

    Code of Federal Regulations, 2011 CFR

    2011-10-01

    ... 46 Shipping 4 2011-10-01 2011-10-01 false Personal flotation devices carried in addition to life jackets. 117.72 Section 117.72 Shipping COAST GUARD, DEPARTMENT OF HOMELAND SECURITY (CONTINUED) SMALL PASSENGER VESSELS CARRYING MORE THAN 150 PASSENGERS OR WITH OVERNIGHT ACCOMMODATIONS FOR MORE THAN 49 PASSENGERS LIFESAVING EQUIPMENT...

  14. Flotation of Mineral and Dyes: A Laboratory Experiment for Separation Method Molecular Hitchhikers

    ERIC Educational Resources Information Center

    Rappon, Tim; Sylvestre, Jarrett A.; Rappon, Manit

    2016-01-01

    Flotation as a method of separation is widely researched and is applied in many industries. It has been used to address a wide range of environmental issues including treatment of wastewater, recovery of heavy metals for recycling, extraction of minerals in mining, and so forth. This laboratory attempts to show how such a simple method can be used…

  15. Use of alkyl sulfates in the dewaterng of a coal flotation concentrate

    SciTech Connect

    Zubkova, Yu.N.; Basenkova, V.L.; Kucher, R.V.

    1981-01-01

    The possibility has been shown of using anionic SAAs in the dewatering of a coal flotation concentrate. It has been established that the adsorption of alkyl sulfates (ASs) obeys the general laws of the adsorption of organic substances from solutions on coals. The addition of electrolytes intensifies the adsorption of ASs, leading to the hydrophobization of the coal particles. 10 refs.

  16. Effects of ozone and peroxone on algal separation via dispersed air flotation.

    PubMed

    Nguyen, Truc Linh; Lee, D J; Chang, J S; Liu, J C

    2013-05-01

    Effects of pre-oxidation on algal separation by dispersed air flotation were examined. Ozone (O3) and peroxone (O3 and H2O2) could induce cell lysis, release of intracellular organic matter (IOM), and mineralization of organic substances. Separation efficiency of algal cells improved when pre-oxidized. Total of 76.4% algal cells was separated at 40 mg/L of N-cetyl-N-N-N-trimethylammonium bromide (CTAB), while 95% were separated after 30-min ozonation. Pre-oxidation by ozone and peroxone also enhanced flotation separation efficiency of dissolved organic carbon (DOC), polysaccharide, and protein, in which peroxone process exerted more significantly than O3. Two main mechanisms were involved in flotation separation of unoxidized algal suspension, namely hydrophobic cell surface and cell flocculation resulting from CTAB adsorption. However, flocculation by CTAB was hindered for pre-oxidized algal suspensions. It implied that the compositional changes in extracellular organic matter (EOM) by pre-oxidation were more determined for flotation separation of pre-oxidized cells.

  17. Flotation properties of some oxygen-containing compounds of the acyclic series

    SciTech Connect

    Shreider, E.M.; Para, S.F.; Galanov, M.E.; Trachik, T.L.; Lagutina, L.V.

    1981-01-01

    In the monatomic alcohols series, maximum flotation activity is reached at 6 to 8 carbon atoms in the radical. It was decided to investigate the reagent properties of some other substances containing hydroxyl radicals which have not previously been considered. Oxygen-containing compounds in the acyclic series were examined, including alcohols: I - ethanol, ethylene-glycol, glycerol, pentaerythrytol, D-mannitol; II - dulcitol, D-sorbitol, D-mannitol, xylitol; glycols - monoethyleneglycol, diethyleneglycol, triethyleneglycol, polyethyleneglycol; and ethanolamines - ethanolamine, triethanolamine. The flotation properties of the reagents were determined in a Mekhanobr laboratory flotation machine with a chamber volume of 1.5 liter and an impeller speed of 1800 rpm. The materials tested were the <1 mm size fractions from run-of-plant charge and slurry from the radial thickeners. The samples were first dried and averaged. The pulp density was 200 g/l. The reagent conditions were kept constant throughout (50% of the total added at the start of a test, 25% after 2 min and 25% after 4 min from the start). The reagent additions were 1.0 to 1.4 kg/ton. All of these compounds had a very weak flotation activity.

  18. 18 CFR 1304.400 - Flotation devices and material, all floating structures.

    Code of Federal Regulations, 2014 CFR

    2014-04-01

    ... 18 Conservation of Power and Water Resources 2 2014-04-01 2014-04-01 false Flotation devices and material, all floating structures. 1304.400 Section 1304.400 Conservation of Power and Water Resources... withstanding prolonged exposure to wave wash and weather conditions....

  19. 18 CFR 1304.400 - Flotation devices and material, all floating structures.

    Code of Federal Regulations, 2013 CFR

    2013-04-01

    ... 18 Conservation of Power and Water Resources 2 2013-04-01 2012-04-01 true Flotation devices and material, all floating structures. 1304.400 Section 1304.400 Conservation of Power and Water Resources... withstanding prolonged exposure to wave wash and weather conditions....

  20. 18 CFR 1304.400 - Flotation devices and material, all floating structures.

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ... 18 Conservation of Power and Water Resources 2 2010-04-01 2010-04-01 false Flotation devices and material, all floating structures. 1304.400 Section 1304.400 Conservation of Power and Water Resources... withstanding prolonged exposure to wave wash and weather conditions....

  1. 18 CFR 1304.400 - Flotation devices and material, all floating structures.

    Code of Federal Regulations, 2011 CFR

    2011-04-01

    ... 18 Conservation of Power and Water Resources 2 2011-04-01 2011-04-01 false Flotation devices and material, all floating structures. 1304.400 Section 1304.400 Conservation of Power and Water Resources... withstanding prolonged exposure to wave wash and weather conditions....

  2. 18 CFR 1304.400 - Flotation devices and material, all floating structures.

    Code of Federal Regulations, 2012 CFR

    2012-04-01

    ... 18 Conservation of Power and Water Resources 2 2012-04-01 2012-04-01 false Flotation devices and material, all floating structures. 1304.400 Section 1304.400 Conservation of Power and Water Resources... withstanding prolonged exposure to wave wash and weather conditions....

  3. A Simple Flotation De-Linking Experiment for the Recycling of Paper

    ERIC Educational Resources Information Center

    Venditti, Richard A.

    2004-01-01

    A laboratory exercise for the flotation de-linking of wastepaper is described, which consists of disintegrating printed wastepaper in a blender and then removing the ink or toner contaminants by pumping air bubbles through suspension using an aquarium pump or other source of air bubbles. The exercise has proven extremely reliable and consistent in…

  4. Silicone glycol collectors in the beneficiation of fine coal by froth flotation

    SciTech Connect

    Owen, M.J.

    1985-07-02

    A froth flotation process for the beneficiation of fine coal is disclosed which employs as a collector a water-dispersible polyorganosiloxane or a mixture of water-dispersible polyorganosiloxanes which contain organic radicals selected from the group consisting of polyethylene oxide and polypropylene oxide radicals. The process of this invention is especially useful for the beneficiation of difficult-to-float fine coals.

  5. Psychotherapeutic Treatment in Combination with Relaxation in a Flotation Tank: Effects on "Burn-Out Syndrome"

    ERIC Educational Resources Information Center

    Kjellgren, Anette; Buhrkall, Hanne; Norlander, Torsten

    2010-01-01

    The focus of this study was to investigate experiences gained from treatment combining relaxation in flotation tank with psychotherapy for sufferers from "burn-out syndrome". Six people participated in a ten week program. They were all interviewed; the data were analyzed using the Empirical Phenomenological Psychological method. Five themes…

  6. Buckling of a holey column.

    PubMed

    Pihler-Puzović, D; Hazel, A L; Mullin, T

    2016-09-14

    We report the results from a combined experimental and numerical investigation of buckling in a novel variant of an elastic column under axial load. We find that including a regular line of centred holes in the column can prevent conventional, global, lateral buckling. Instead, the local microstructure introduced by the holes allows the column to buckle in an entirely different, internal, mode in which the holes are compressed in alternate directions, but the column maintains the lateral reflection symmetry about its centreline. The internal buckling mode can be accommodated within a smaller external space than the global one; and it is the preferred buckling mode over an intermediate range of column lengths for sufficiently large holes. For very short or sufficiently long columns a modification of the classical, global, lateral buckling is dominant. PMID:27501288

  7. Compact electron beam focusing column

    SciTech Connect

    Persaud, Arun; Leung, Ka-Ngo; Reijonen, Jani

    2001-07-13

    A novel design for an electron beam focusing column has been developed at LBNL. The design is based on a low-energy spread multicusp plasma source which is used as a cathode for electron beam production. The focusing column is 10 mm in length. The electron beam is focused by means of electrostatic fields. The column is designed for a maximum voltage of 50 kV. Simulations of the electron trajectories have been performed by using the 2-D simulation code IGUN and EGUN. The electron temperature has also been incorporated into the simulations. The electron beam simulations, column design and fabrication will be discussed in this presentation.

  8. Sensitivity of double centrifugation sugar fecal flotation for detecting intestinal helminths in coyotes (Canis latrans).

    PubMed

    Liccioli, Stefano; Catalano, Stefano; Kutz, Susan J; Lejeune, Manigandan; Verocai, Guilherme G; Duignan, Padraig J; Fuentealba, Carmen; Ruckstuhl, Kathreen E; Massolo, Alessandro

    2012-07-01

    Fecal analysis is commonly used to estimate prevalence and intensity of intestinal helminths in wild carnivores, but few studies have assessed the reliability of fecal flotation compared to analysis of intestinal tracts. We investigated sensitivity of the double centrifugation sugar fecal flotation and kappa agreement between fecal flotation and postmortem examination of intestines for helminths of coyotes (Canis latrans). We analyzed 57 coyote carcasses that were collected between October 2010 and March 2011 in the metropolitan area of Calgary and Edmonton, Alberta, Canada. Before analyses, intestines and feces were frozen at -80 C for 72 hr to inactivate Echinococcus eggs, protecting operators from potential exposure. Five species of helminths were found by postmortem examination, including Toxascaris leonina, Uncinaria stenocephala, Ancylostoma caninum, Taenia sp., and Echinococcus multilocularis. Sensitivity of fecal flotation was high (0.84) for detection of T. leonina but low for Taenia sp. (0.27), E. multilocularis (0.46), and U. stenocephala (0.00). Good kappa agreement between techniques was observed only for T. leonina (0.64), for which we detected also a significant correlation between adult female parasite intensity and fecal egg counts (R(s)=0.53, P=0.01). Differences in sensitivity may be related to parasite characteristics that affect recovery of eggs on flotation. Fecal parasitologic analyses are highly applicable to study the disease ecology of urban carnivores, and they often provide important information on environmental contamination and potential of zoonotic risks. However, fecal-based parasitologic surveys should first assess the sensitivity of the techniques to understand their biases and limitations.

  9. The acute effects of flotation restricted environmental stimulation technique on recovery from maximal eccentric exercise.

    PubMed

    Morgan, Paul M; Salacinski, Amanda J; Stults-Kolehmainen, Matthew A

    2013-12-01

    Flotation restricted environmental stimulation technique (REST) involves compromising senses of sound, sight, and touch by creating a quiet dark environment. The individual lies supine in a tank of Epsom salt and water heated to roughly skin temperature (34-35° C). This study was performed to determine if a 1-hour flotation REST session would aid in the recovery process after maximal eccentric knee extensions and flexions. Twenty-four untrained male students (23.29 ± 2.1 years, 184.17 ± 6.85 cm, 85.16 ± 11.54 kg) participated in a randomized, repeated measures crossover study. The participants completed 2 exercise and recovery protocols: a 1-hour flotation REST session and a 1-hour seated control (passive recovery). After isometric muscle strength testing, participants were fatigued with eccentric isokinetic muscle contractions (50 repetitions at 60°·s) of the nondominant knee extensors and flexors. Blood lactate, blood glucose, heart rate, OMNI-rating of perceived exertion for resistance exercise (OMNI-RPE), perceived pain, muscle soreness, and isometric strength were collected before exercise, after treatment, and 24 and 48 hours later. A multivariate analysis of covariance found that treatment had a significant main effect on blood lactate, whereas subsequent univariate analyses of variance found statistical significance with the immediate posttreatment blood lactate measures. The results indicate that flotation REST appears to have a significant impact on blood lactate and perceived pain compared with a 1-hour passive recovery session in untrained healthy men. No difference was found between conditions for muscle strength, blood glucose, muscle soreness, heart rate, or OMNI-RPE. Flotation REST may be used for recreational and professional athletes to help reduce blood lactate levels after eccentric exercise. PMID:23478477

  10. Separation of polyvinyl chloride (PVC) from automobile shredder residue (ASR) by froth flotation with ozonation.

    PubMed

    Reddy, Mallampati Srinivasa; Kurose, Keisuke; Okuda, Tetsuji; Nishijima, Wataru; Okada, Mitsumasa

    2007-08-25

    The purpose of this study is to develop froth flotation to separate polyvinyl chloride (PVC) from automobile shredder residue (ASR) plastic mixtures of variable composition. Some polymers in ASR polymer mixtures have similar density and hydrophobicity with PVC and thus selective flotation of PVC from ASR polymer mixtures cannot be achieved. The present study focused on the surface modification of PVC with ozonation, and then the modified PVC can be separated from other polymers by the following froth flotation. The results of this study indicate that the selective recovery of PVC from real ASR polyethylene tetra pethelate (PET), polymethyl methacrylate (PMMA), polybutyl methacralate (PBMA), ethyl acrylate (EA), polycarbonate (PC) and rubber mixtures can be accomplished in a three-step process involving a gravity separation, ozonation and froth flotation. The rubber was removed from other heavy ASR (PVC, PET, PMMA, PBMA, EA and PC) polymers by froth flotation without mixing. It was found that ozonation process produced the desired difference in contact angle required (from 89.5 to 73.0 degrees ) for separation of PVC from other heavy ASR polymers, whereas the contact angles of other polymers was slightly decreased. The most of the load ASR, i.e. about 72.4% is floated away and 27.6% was settled down. The highest component 96.7% of PVC was recovered in the settled fraction. As a result of this research effort, the surface modification of PVC with ozonation can be efficiently useful to separate the PVC from other similar density ASR mixed polymers. PMID:17360113

  11. 45. MAIN MEETING ROOM COLUMNS. Ends of gallery columns identified ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    45. MAIN MEETING ROOM COLUMNS. Ends of gallery columns identified at the time of removal for transfer to the George School for re-erection. The stamp reads, 'REMOVED FROM 12th ST. MTG HSE PHILA 1972'. - Twelfth Street Meeting House, 20 South Twelfth Street, Philadelphia, Philadelphia County, PA

  12. Water leaching of titanium from ore flotation residue

    SciTech Connect

    Jaworska, Malgorzata M.; Guibal, Eric

    2003-07-01

    Copper ore tailings were tested for the stability of titanium submitted to water leaching in three different reactor systems (agitated vessel, bioreactor and percolated fixed-bed column). For each of these systems, titanium extraction did not exceed 1% of the available metal. Biomass removed from ore residue adsorbed a small part of the titanium with sorption capacities below 20-30 mg g{sup -1}, but most of this biomass was sequestered in the ore residue. Oxygen and carbon dioxide concentrations were monitored and changes in concentration correlated with bacteria development at the initial stage of the process and to fungal development in the latter stages.

  13. Wiring dendrites in layers and columns.

    PubMed

    Luo, Jiangnan; McQueen, Philip G; Shi, Bo; Lee, Chi-Hon; Ting, Chun-Yuan

    2016-06-01

    The most striking structure in the nervous system is the complex yet stereotyped morphology of the neuronal dendritic tree. Dendritic morphologies and the connections they make govern information flow and integration in the brain. The fundamental mechanisms that regulate dendritic outgrowth and branching are subjects of extensive study. In this review, we summarize recent advances in the molecular and cellular mechanisms for routing dendrites in layers and columns, prevalent organizational structures in the brain. We highlight how dendritic patterning influences the formation of synaptic circuits. PMID:27315108

  14. Advanced systems for producing superclean coal

    SciTech Connect

    Yoon, R.H.; Luttrell, G.H.; Adel, G.T.

    1990-08-01

    The purpose of this project was to develop several advanced separation processes for producing superclean coal containing 0.4--2.0% ash and very little pyritic sulfur. Three physical and physico-chemical processes were studied: microbubble flotation, selective hydrophobic coagulation, and electrochemical coal cleaning. Information has been collected from bench-scale experiments in order to determine the basic mechanisms of all three processes. Additionally, because microbubble flotation has already been proven on a bench scale, preliminary scale-up models have been developed for this process. A fundamental study of the electrochemistry of coal pyrite has also been conducted in conjunction with this scale-up effort in order to provide information useful for improving sulfur rejection. The effects of additives (NaCl and kerosene) were also investigated. 94 refs., 167 figs., 25 tabs.

  15. An Undergraduate Column Chromatography Experiment.

    ERIC Educational Resources Information Center

    Danot, M.; And Others

    1984-01-01

    Background information, list of materials needed, and procedures used are provided for an experiment designed to introduce undergraduate students to the theoretical and technical aspects of column chromatography. The experiment can also be shortened to serve as a demonstration of the column chromatography technique. (JN)

  16. Analyze distillation columns with thermodynamics

    SciTech Connect

    Ognisty, T.P. )

    1995-02-01

    In a distillation column, heat supplies the work for separating the components of a feed stream into products. Distillation columns consume some 95% of the total energy used in separations. This amounts to roughly 3% of the energy consumed in the US. Since distillation is so energy intensive and requires significant capital outlays, an endless quest to improve the economics has continued since the beginning of the industry. By analyzing the thermodynamics of a distillation column, an engineer can quantify the thermodynamic efficiency of the process, identify the regions where energy can be better utilized, and define the minimum targets for energy consumption. This article reviews the principles of distillation column thermodynamics and outlines the analysis of lost work profiles and column heat profiles. It then illustrates these concepts through three examples.

  17. An investigation of the efficacy of biological additives for the suppression of pyritic sulphur during simulated froth flotation of coal.

    PubMed

    Stainthorpe, A C

    1989-02-01

    The biological molecule responsible for the suppression of pyritic sulfur in fine coal simulated froth flotation treated with bacteria was identified. Protein was found to be the most effective agent in pyrite suppression of the three cell components (protein, lipid, and carbohydrate) assayed. Coal recovery and ash removal of the flotation process were only slightly reduced by this treatment. Other protein-containing materials were evaluated for their ability to suppress pyrite flotation. Whey was found to be the most cost-effective flotation additive of those assayed. The sulfur content of the whey-treated float was reduced by 84.0% in a synthetically prepared fractionated coal (10.7% sulfur), by a raw whey dosage of 20 microL/g coal. The inorganic sulfur component of a natural high sulfur coal fraction (10.9%) was completely depressed by this whey addition. The effect of particle size and pulp density upon the process were investigated.

  18. Engineering development of advanced physical fine coal cleaning technologies: Froth flotation

    SciTech Connect

    Not Available

    1992-01-01

    The construction of the DOE POC at the OCDO facility continued through this entire quarter. By the end of the quarter approximately 90% of all of the construction had been completed. All equipment has beeninstalled, checked for mechanical and installation and operated from a local pushbutton. During this quarter a review of items to be completed for start-up was compiled. This information was then presented to the construction subcontractors and agreement was concluded that all items will be completed and operational for processing coal by February 1, 1993. There are still several items that were not on site for installation during this quarter. These items are the flocculant controls supplied by Westec Engineering, Inc., and the discharge valve for the hyperbaric filter supplied by KHD. Neither of these items will prevent start-up. The flocculants can be manually controlled and provisions are all ready provided to bypass the hyperbaric filter to the Sharpels high-G centrifuge. Both of these items are scheduled for delivery in mid-January.

  19. Engineering development of advanced physical fine coal cleaning technologies: Froth flotation

    SciTech Connect

    Not Available

    1993-02-12

    Work completed produced the criteria for additional engineering analysis, computation and detailed experimental benchscale testing for areas of uncertainty. The engineering analysis, computation, bench-scale testing and component development was formulated to produce necessary design information to define a commercially operating system. In order to produce the required information by means of bench-scale testing and component development, a uniform coal sample was procured. After agreement with DOE, a selected sample of coal from those previously listed was secured. The test plan was developed in two parts. The first part listed procedures for engineering and computational analyses of those deficiencies previously identified that could be solved without bench scale testing. Likewise, the second part prepared procedures for bench-scale testing and component development for those deficiencies previously identified in Task 3.

  20. Installation of the Pulse-Plate Column Pilot Plant

    SciTech Connect

    Nick R. Mann

    2009-07-01

    There are three primary types of solvent extraction equipment utilized in the nuclear industry for reprocessing of used nuclear fuel; pulse columns, mixer-settlers, and centrifugal contactors. Considerable research and development has been performed at the INL and throughout the DOE complex on the application of centrifugal contactors for used fuel reprocessing and these contactors offer many significant advantages. However, pulse columns have been used extensively in the past in throughout the world for aqueous separations processes and remain the preferred equipment by many commercial entities. Therefore, a pulse-plate column pilot plant has been assembled as part of the Advanced Fuel Cycle Initiative to support experimentation and demonstration of pulse column operation. This will allow the training of personnel in the operation of pulse columns. Also, this capability will provide the equipment to allow for research to be conducted in the operation of pulse columns with advanced solvents and processes developed as part of the fuel cycle research and development being performed in the AFCI program.

  1. Engineering development of advance physical fine coal cleaning for premium fuel applications

    SciTech Connect

    Jha, M.C.; Smit, F.J.; Shields, G.L.

    1995-11-01

    The objective of this project is to develop the engineering design base for prototype fine coal cleaning plants based on Advanced Column Flotation and Selective Agglomeration processes for premium fuel and near-term applications. Removal of toxic trace elements is also being investigated. The scope of the project includes laboratory research and bench-scale testing of each process on six coals followed by design, construction, and operation of a 2 tons/hour process development unit (PDU). Three coals will be cleaned in tonnage quantity and provided to DOE and its contractors for combustion evaluation. Amax R&D (now a subsidiary of Cyprus Amax Mineral Company) is the prime contractor. Entech Global is managing the project and performing most of the research and development work as an on-site subcontractor. Other participants in the project are Cyprus Amax Coal Company, Arcanum, Bechtel, TIC, University of Kentucky and Virginia Tech. Drs. Keller of Syracuse and Dooher of Adelphi University are consultants.

  2. Mush Column Magma Chambers

    NASA Astrophysics Data System (ADS)

    Marsh, B. D.

    2002-12-01

    Magma chambers are a necessary concept in understanding the chemical and physical evolution of magma. The concept may well be similar to a transfer function in circuit or time series analysis. It does what needs to be done to transform source magma into eruptible magma. In gravity and geodetic interpretations the causative body is (usually of necessity) geometrically simple and of limited vertical extent; it is clearly difficult to `see' through the uppermost manifestation of the concentrated magma. The presence of plutons in the upper crust has reinforced the view that magma chambers are large pots of magma, but as in the physical representation of a transfer function, actual magma chambers are clearly distinct from virtual magma chambers. Two key features to understanding magmatic systems are that they are vertically integrated over large distances (e.g., 30-100 km), and that all local magmatic processes are controlled by solidification fronts. Heat transfer considerations show that any viable volcanic system must be supported by a vertically extensive plumbing system. Field and geophysical studies point to a common theme of an interconnected stack of sill-like structures extending to great depth. This is a magmatic Mush Column. The large-scale (10s of km) structure resembles the vertical structure inferred at large volcanic centers like Hawaii (e.g., Ryan et al.), and the fine scale (10s to 100s of m) structure is exemplified by ophiolites and deeply eroded sill complexes like the Ferrar dolerites of the McMurdo Dry Valleys, Antarctica. The local length scales of the sill reservoirs and interconnecting conduits produce a rich spectrum of crystallization environments with distinct solidification time scales. Extensive horizontal and vertical mushy walls provide conditions conducive to specific processes of differentiation from solidification front instability to sidewall porous flow and wall rock slumping. The size, strength, and time series of eruptive behavior

  3. Comparison of the egg flotation and egg candling techniques for estimating incubation day of Canada Goose nests

    USGS Publications Warehouse

    Reiter, M.E.; Andersen, D.E.

    2008-01-01

    Both egg flotation and egg candling have been used to estimate incubation day (often termed nest age) in nesting birds, but little is known about the relative accuracy of these two techniques. We used both egg flotation and egg candling to estimate incubation day for Canada Geese (Branta canadensis interior) nesting near Cape Churchill, Manitoba, from 2000 to 2007. We modeled variation in the difference between estimates of incubation day using each technique as a function of true incubation day, as well as, variation in error rates with each technique as a function of the true incubation day. We also evaluated the effect of error in the estimated incubation day on estimates of daily survival rate (DSR) and nest success using simulations. The mean difference between concurrent estimates of incubation day based on egg flotation minus egg candling at the same nest was 0.85 ?? 0.06 (SE) days. The positive difference in favor of egg flotation and the magnitude of the difference in estimates of incubation day did not vary as a function of true incubation day. Overall, both egg flotation and egg candling overestimated incubation day early in incubation and underestimated incubation day later in incubation. The average difference between true hatch date and estimated hatch date did not differ from zero (days) for egg flotation, but egg candling overestimated true hatch date by about 1 d (true - estimated; days). Our simulations suggested that error associated with estimating the incubation day of nests and subsequently exposure days using either egg candling or egg flotation would have minimal effects on estimates of DSR and nest success. Although egg flotation was slightly less biased, both methods provided comparable and accurate estimates of incubation day and subsequent estimates of hatch date and nest success throughout the entire incubation period. ?? 2008 Association of Field Ornithologists.

  4. METHOD TO TEST ISOTOPIC SEPARATION EFFICIENCY OF PALLADIUM PACKED COLUMNS

    SciTech Connect

    Heung, L; Gregory Staack, G; James Klein, J; William Jacobs, W

    2007-06-27

    The isotopic effect of palladium has been applied in different ways to separate hydrogen isotopes for many years. At Savannah River Site palladium deposited on kieselguhr (Pd/k) is used in a thermal cycling absorption process (TCAP) to purify tritium for over ten years. The need to design columns for different throughputs and the desire to advance the performance of TCAP created the need to evaluate different column designs and packing materials for their separation efficiency. In this work, columns with variations in length, diameter and metal foam use, were tested using an isotope displacement method. A simple computer model was also developed to calculate the number of theoretical separation stages using the test results. The effects of column diameter, metal foam and gas flow rate were identified.

  5. Headgroup interactions and ion flotation efficiency in mixtures of a chelating surfactant, different foaming agents, and divalent metal ions.

    PubMed

    Svanedal, Ida; Boija, Susanne; Norgren, Magnus; Edlund, Håkan

    2014-06-10

    The correlation between interaction parameters and ion flotation efficiency in mixtures of chelating surfactant metal complexes and different foaming agents was investigated. We have recently shown that chelating surfactant 2-dodecyldiethylenetriaminepentaacetic acid (4-C12-DTPA) forms strong coordination complexes with divalent metal ions, and this can be utilized in ion flotation. Interaction parameters for mixed micelles and mixed monolayer formation for Mg(2+) and Ni(2+) complexes with the chelating surfactant 4-C12-DTPA and different foaming agents were calculated by Rubingh's regular solution theory. Parameters for the calculations were extracted from surface tension measurements and NMR diffusometry. The effects of metal ion coordination on the interactions between 4-C12-DTPA and the foaming agents could be linked to a previously established difference in coordination chemistry between the examined metal ions. As can be expected from mixtures of amphoteric surfactants, the interactions were strongly pH-dependent. Strong correlation was found between interaction parameter β(σ) for mixed monolayer formation and the phase-transfer efficiency of Ni(2+) complexes with 4-C12-DTPA during flotation in a customized flotation cell. In a mixture of Cu(2+) and Zn(2+), the significant difference in conditional stability constants (log K) between the metal complexes was utilized to selectively recover the metal complex with the highest log K (Cu(2+)) by ion flotation. Flotation experiments in an excess concentration of metal ions confirmed the coordination of more than one metal ion to the headgroup of 4-C12-DTPA.

  6. Use of centrifugal-gravity concentration for rejection of talc and recovery improvement in base-metal flotation

    NASA Astrophysics Data System (ADS)

    Klein, Bern; Altun, Naci Emre; Ghaffari, Hassan

    2016-08-01

    The possibility of using a centrifugal-gravity concentrator to reject Mg-bearing minerals and minimize metal losses in the flotation of base metals was evaluated. Sample characterization, batch scoping tests, pilot-scale tests, and regrind-flotation tests were conducted on a Ni flotation tailings stream. Batch tests revealed that the Mg grade decreased dramatically in the concentrate products. Pilot-scale testing of a continuous centrifugal concentrator (Knelson CVD6) on the flotation tailings revealed that a concentrate with a low mass yield, low Mg content, and high Ni upgrade ratio could be achieved. Under optimum conditions, a concentrate at 6.7% mass yield was obtained with 0.85% Ni grade at 12.9% Ni recovery and with a low Mg distribution (1.7%). Size partition curves demonstrated that the CVD also operated as a size classifier, enhancing the rejection of talc fines. Overall, the CVD was capable of rejecting Mg-bearing minerals. Moreover, an opportunity exists for the novel use of centrifugal-gravity concentration for scavenging flotation tailings and/or after comminution to minimize amount of Mg-bearing minerals reporting to flotation.

  7. Headgroup interactions and ion flotation efficiency in mixtures of a chelating surfactant, different foaming agents, and divalent metal ions.

    PubMed

    Svanedal, Ida; Boija, Susanne; Norgren, Magnus; Edlund, Håkan

    2014-06-10

    The correlation between interaction parameters and ion flotation efficiency in mixtures of chelating surfactant metal complexes and different foaming agents was investigated. We have recently shown that chelating surfactant 2-dodecyldiethylenetriaminepentaacetic acid (4-C12-DTPA) forms strong coordination complexes with divalent metal ions, and this can be utilized in ion flotation. Interaction parameters for mixed micelles and mixed monolayer formation for Mg(2+) and Ni(2+) complexes with the chelating surfactant 4-C12-DTPA and different foaming agents were calculated by Rubingh's regular solution theory. Parameters for the calculations were extracted from surface tension measurements and NMR diffusometry. The effects of metal ion coordination on the interactions between 4-C12-DTPA and the foaming agents could be linked to a previously established difference in coordination chemistry between the examined metal ions. As can be expected from mixtures of amphoteric surfactants, the interactions were strongly pH-dependent. Strong correlation was found between interaction parameter β(σ) for mixed monolayer formation and the phase-transfer efficiency of Ni(2+) complexes with 4-C12-DTPA during flotation in a customized flotation cell. In a mixture of Cu(2+) and Zn(2+), the significant difference in conditional stability constants (log K) between the metal complexes was utilized to selectively recover the metal complex with the highest log K (Cu(2+)) by ion flotation. Flotation experiments in an excess concentration of metal ions confirmed the coordination of more than one metal ion to the headgroup of 4-C12-DTPA. PMID:24824327

  8. Microbial activity in weathering columns.

    PubMed

    García, C; Ballester, A; González, F; Blázquez, M L

    2007-03-22

    The aim of the present work was to evaluate the metabolic activity of the microbial population associated with a pyritic tailing after a column-weathering test. For this purpose, a column 150cm high and 15cm diameter was used. The solid was a tailing with 63.4% pyrite and with minor amounts of Cu, Pb and Zn sulfides (1.4, 0.5 and 0.8%, respectively). The column model was the habitual one for weathering tests: distilled water was added at the top of the column; the water flowed down through tailings and finally was collected at the bottom for chemical and microbiological analysis. Weathering was maintained for 36 weeks. The results showed a significant presence of microbial life that was distributed selectively over the column: sulfur- and iron-oxidizing aerobic bacteria were in the more oxygenated zone; anaerobic sulfur-reducing bacteria were isolated from the samples taken from the anoxic part of the column. Activity testing showed that (oxidizing and reducing) bacteria populations were active at the end of the weathering test. The quality of the water draining from the column was thus the final product of biological oxidation and reduction promoted by the bacteria consortia.

  9. Post column derivatisation analyses review. Is post-column derivatisation incompatible with modern HPLC columns?

    PubMed

    Jones, Andrew; Pravadali-Cekic, Sercan; Dennis, Gary R; Shalliker, R Andrew

    2015-08-19

    Post Column derivatisation (PCD) coupled with high performance liquid chromatography or ultra-high performance liquid chromatography is a powerful tool in the modern analytical laboratory, or at least it should be. One drawback with PCD techniques is the extra post-column dead volume due to reaction coils used to enable adequate reaction time and the mixing of reagents which causes peak broadening, hence a loss of separation power. This loss of efficiency is counter-productive to modern HPLC technologies, -such as UHPLC. We reviewed 87 PCD methods published from 2009 to 2014. We restricted our review to methods published between 2009 and 2014, because we were interested in the uptake of PCD methods in UHPLC environments. Our review focused on a range of system parameters including: column dimensions, stationary phase and particle size, as well as the geometry of the reaction loop. The most commonly used column in the methods investigated was not in fact a modern UHPLC version with sub-2-micron, (or even sub-3-micron) particles, but rather, work-house columns, such as, 250 × 4.6 mm i.d. columns packed with 5 μm C18 particles. Reaction loops were varied, even within the same type of analysis, but the majority of methods employed loop systems with volumes greater than 500 μL. A second part of this review illustrated briefly the effect of dead volume on column performance. The experiment evaluated the change in resolution and separation efficiency of some weak to moderately retained solutes on a 250 × 4.6 mm i.d. column packed with 5 μm particles. The data showed that reaction loops beyond 100 μL resulted in a very serious loss of performance. Our study concluded that practitioners of PCD methods largely avoid the use of UHPLC-type column formats, so yes, very much, PCD is incompatible with the modern HPLC column. PMID:26343427

  10. Optimal design of thermally coupled distillation columns

    SciTech Connect

    Duennebier, G.; Pantelides, C.C.

    1999-01-01

    This paper considers the optimal design of thermally coupled distillation columns and dividing wall columns using detailed column models and mathematical optimization. The column model used is capable of describing both conventional and thermally coupled columns, which allows comparisons of different structural alternatives to be made. Possible savings in both operating and capital costs of up to 30% are illustrated using two case studies.

  11. Treating chemical mechanical polishing (CMP) wastewater by electro-coagulation-flotation process with surfactant.

    PubMed

    Hu, C Y; Lo, S L; Li, C M; Kuan, W H

    2005-04-11

    The effect of surfactants on the treatment of chemical mechanical polishing (CMP) wastewater by electro-coagulation-flotation (ECF) process was studied. Two surfactants, cetyltrimethylammonium bromide (CTAB) and sodium dodecylsulfate (SDS) were employed in this study to compare the effect of cationic (CTAB) and anodic (SDS) surfactants on ECF. The cationic surfactant can enhance the removal of the turbidity, but anodic surfactant cannot. It can be explained by the hetero-coagulation theory. Moreover, the addition of CTAB in CMP wastewater can reduce the sludge volume and the flotation/sedimentation time in ECF process. The residual turbidity and dissolved silicon dropped with the increase of charge loading. No CTAB pollution problem exists after the ECF process. PMID:15811659

  12. A study on the effects of ozone dosage on dissolved-ozone flotation (DOF) process performance.

    PubMed

    Jin, Xin; Jin, Pengkang; Wang, Xiaochang

    2015-01-01

    Dissolved-ozone flotation (DOF) is a tertiary wastewater treatment process, which combines ozonation and flotation. In this paper, a pilot-scale DOF system fed by secondary effluent from a wastewater treatment plant (WWTP) in China was used to study the effect of ozone dosage on the DOF process performance. The results show that an ozone dosage could affect the DOF performance to a large extent in terms of color and organic matter removal as well as disinfection performance. The optimal color and organic matter removal was achieved at an ozone dosage of 0.8 mg/l. For disinfection, significant improvement in performance could be achieved only when the organic matter removal was optimal. The optimal ozone dosage of at least 1.6 mg/l was put forward, in this case, in order to achieve the optimal color, turbidity, organic matter and disinfection performance.

  13. Method for simultaneous use of a single additive for coal flotation, dewatering and reconstitution

    SciTech Connect

    Wen, Wu-Wey; Gray, M.L.; Champagne, K.J.

    1993-11-09

    A single dose of additive contributes to three consecutive fine coal unit operations, i.e., flotation, dewatering and reconstitution, whereby the fine coal is first combined with water in a predetermined proportion so as to formulate a slurry. The slurry is then mixed with a heavy hydrocarbon-based emulsion in a second predetermined proportion and at a first predetermined mixing speed and for a predetermined period of time. The conditioned slurry is then cleaned by a froth flotation method to form a clean coal froth and then the froth is dewatered by vacuum filtration or a centrifugation process to form reconstituted products that are dried to dust-less clumps prior to combustion.

  14. Investigation of thermal treatment on selective separation of post consumer plastics prior to froth flotation.

    PubMed

    Guney, Ali; Poyraz, M Ibrahim; Kangal, Olgac; Burat, Firat

    2013-09-01

    Plastics have become the widely used materials because of their advantages, such as cheapness, endurance, lightness, and hygiene. However, they cause waste and soil pollution and they do not easily decompose. Many promising technologies are being investigated for separating mixed thermoplastics, but they are still uneconomical and unreliable. Depending on their surface characteristics, these plastics can be separated from each other by flotation method which is useful mineral processing technique with its low cost and simplicity. The main objective of this study is to investigate the flotation characteristics of PET and PVC and determine the effect of plasticizer reagents on efficient plastic separation. For that purpose, various parameters such as pH, plasticizer concentration, plasticizer type, conditioning temperature and thermal conditioning were investigated. As a result, PET particles were floated with 95.1% purity and 65.3% efficiency while PVC particles were obtained with 98.1% purity and 65.3% efficiency.

  15. Method for simultaneous use of a single additive for coal flotation, dewatering, and reconstitution

    DOEpatents

    Wen, Wu-Wey; Gray, McMahan L.; Champagne, Kenneth J.

    1995-01-01

    A single dose of additive contributes to three consecutive fine coal unit operations, i.e., flotation, dewatering and reconstitution, whereby the fine coal is first combined with water in a predetermined proportion so as to formulate a slurry. The slurry is then mixed with a heavy hydrocarbon-based emulsion in a second predetermined proportion and at a first predetermined mixing speed and for a predetermined period of time. The conditioned slurry is then cleaned by a froth flotation method to form a clean coal froth and then the froth is dewatered by vacuum filtration or a centrifugation process to form reconstituted products that are dried to dust-less clumps prior to combustion.

  16. High-pH-induced flocculation-flotation of the hypersaline microalga Dunaliella salina.

    PubMed

    Besson, Alexandre; Guiraud, Pascal

    2013-11-01

    Natural autoflocculation was not observed in a Dunaliella salina hypersaline culture and the microalgae did not float without destabilization of the algal suspension. High-pH-induced flocculation by sodium hydroxide addition was chosen to induce flotation. Recovery efficiencies greater than 90% and concentration factors of around 20 were reached. An autoflocculation mechanism, with precipitation of magnesium hydroxide, is proposed to explain a sweeping flotation of D. salina cells. The influence of the flow rate of sodium hydroxide addition was also studied to anticipate the constraints related to the industrialization of this process. The flow rate of sodium hydroxide addition had no effect on the recovery efficiency and reduced the concentration factor only for abrupt injections. Natural increase of culture pH by photosynthetic activity could reduce the amount of base consumed. Non-harvested cells remained viable during pH increase and could be used as inoculum for a new culture.

  17. Treating chemical mechanical polishing (CMP) wastewater by electro-coagulation-flotation process with surfactant.

    PubMed

    Hu, C Y; Lo, S L; Li, C M; Kuan, W H

    2005-04-11

    The effect of surfactants on the treatment of chemical mechanical polishing (CMP) wastewater by electro-coagulation-flotation (ECF) process was studied. Two surfactants, cetyltrimethylammonium bromide (CTAB) and sodium dodecylsulfate (SDS) were employed in this study to compare the effect of cationic (CTAB) and anodic (SDS) surfactants on ECF. The cationic surfactant can enhance the removal of the turbidity, but anodic surfactant cannot. It can be explained by the hetero-coagulation theory. Moreover, the addition of CTAB in CMP wastewater can reduce the sludge volume and the flotation/sedimentation time in ECF process. The residual turbidity and dissolved silicon dropped with the increase of charge loading. No CTAB pollution problem exists after the ECF process.

  18. Possibility of using strain F9 ( Serratia marcescens) as a bio-collector for hematite flotation

    NASA Astrophysics Data System (ADS)

    Yang, Hui-fen; Li, Tian; Chang, Yan-hong; Luo, Hui; Tang, Qiong-yao

    2014-03-01

    In this study, we characterized strain F9 and evaluated the interaction between strain F9 and hematite by scanning electron microscopy (SEM), Fourier transform infrared spectrophotometry (FTIR), zeta potential, flotation, and other methods. The results showed that strain F9 belongs to Serratia marcescens. This brevibacterium had CH2, CH3, and hydroxyl groups on its cell wall, which imparted a strong hydrophobic and negative charge. Adsorption of strain F9 reduced the zeta potential of the hematite surface and increased the hydrophobicity of the hematite surface, thereby generating hydrophobic hematite agglomerates. At least four groups on strain F9 interacted with the hematite surface, which contributed to chemical interactions of carboxylic groups and hydrophobic association among hydrophobic hematite particles. The possible use of strain F9 as a bio-collector for hematite flotation was proved.

  19. The first case of Demodex gatoi in Austria, detected with fecal flotation.

    PubMed

    Silbermayr, Katja; Joachim, Anja; Litschauer, Barbara; Panakova, Lucia; Sastre, Natalia; Ferrer, Lluis; Horvath-Ungerboeck, Christa

    2013-08-01

    Feline demodicosis is a rare parasitic condition caused by three different species of mites (Demodex cati, Demodex gatoi, and an unnamed species). D. gatoi inhabits the superficial skin layer (stratum corneum) and is easily transmitted between individual cats. A 2-year-old female spayed Cornish Rex was presented with alopecia and pruritus. The dermatological examination revealed bilateral alopecia and excoriations on trunk, limbs, and belly. The second cat in the household, a 3-year-old female spayed Thai, showed no clinical signs. Superficial and deep skin scrapings were performed and cellophane tapes applied, and living D. gatoi mites could be detected in both cats. Oral ivermectin (0.25 mg/kg every other day) was subscribed. Feces were collected from both cats and fecal flotation with sugar and zinc solutions performed. When compared to skin scrapings and cellophane tapes, D. gatoi was detected more frequently and in higher numbers in fecal samples. Our findings suggest that D. gatoi can be efficiently diagnosed with coproscopy, particularly in asymptomatic carrier animals. DNA was extracted from the flotation liquid, and a PCR protocol for the species verification was designed. A fragment targeting a 325-bp DNA fragment of the D. gatoi mitochondrial 16S rDNA gene was amplified with a 100% similarity to the D. gatoi entry in GenBank® (GI 421920216). We report the first finding of D. gatoi in Austria and propose fecal flotation as a valuable tool for mite detection. Fecal flotation liquid is suitable for DNA extraction and PCR-based species verification of D. gatoi.

  20. Some aspects of using ultrasounds to improve sulfurous mineral flotation technology

    NASA Technical Reports Server (NTRS)

    Mihu, V. P.; Pop, I.

    1974-01-01

    The results are discussed which were obtained with a new method of desorption of collector reagents connected with improving the selectivity of the flotation of copper and lead concentrate through the action of ultrasounds. Analysis of the results obtained by treating copper and lead concentrate in an ultraacoustic field indicates an increase in the copper content of the copper concentrate, of the lead content in the lead concentrate and, at the same time, a reduction in the lead of the copper concentrate.

  1. Wastewater treatment using flocculation, coagulation, and flotation. (Latest citations from the NTIS bibliographic database). Published Search

    SciTech Connect

    1995-12-01

    The bibliography contains citations concerning the design, development, and evaluation of flocculation coagulation and flotation processes for the treatment of sewage and industrial wastes. Citations examine technology requirements and limitations, activated sludge and anaerobic processes, chlorination, runoff pollution control, wastewater recycling and reuse, and materials recovery.(Contains 50-250 citations and includes a subject term index and title list.) (Copyright NERAC, Inc. 1995)

  2. Wastewater treatment using flocculation, coagulation, and flotation. (Latest citations from the NTIS bibliographic database). Published Search

    SciTech Connect

    1996-11-01

    The bibliography contains citations concerning the design, development, and evaluation of flocculation coagulation and flotation processes for the treatment of sewage and industrial wastes. Citations examine technology requirements and limitations, activated sludge and anaerobic processes, chlorination, runoff pollution control, wastewater recycling and reuse, and materials recovery.(Contains 50-250 citations and includes a subject term index and title list.) (Copyright NERAC, Inc. 1995)

  3. The removal of heavy metals from contaminated soil by a combination of sulfidisation and flotation.

    PubMed

    Vanthuyne, Mathias; Maes, André

    2002-05-01

    The possibility of removing cadmium, copper, lead and zinc from Belgian loamy soil by a combination of sulfidisation pre-treatment and Denver flotation was investigated. The potentially available--sulfide convertible--metal content of the metal polluted soil was estimated by EDTA (0.1 M, pH 4.65) extraction and BCR sequential extraction. EDTA extraction is better at approximating the metal percentage that is expected to be convertible into a metal sulfide phase, in contrast to the sequential extraction procedure of 'Int. J. Environ. Anal. Chem. 51 (1993) pp. 135-151' in which transition metals present as iron oxide co-precipitates are dissolved by hydroxylammoniumchloride in the second extraction step. To compare the surface characteristics of metal sulfides formed by sulfidisation with those of crystalline metal sulfides, two types of synthetic sediments were prepared and extracted with 0.1 M EDTA (pH 4.65) in anoxic conditions. Separate metal sulfides or co-precipitates with iron sulfide were formed by sulfide conditioning. The Denver flotation of both types of synthetic sediments (kerosene as collector at high background electrolyte concentrations) resulted in similar concentrating factors for freshly formed metal sulfides as for fine-grained crystalline metal sulfides. The selective flotation of metal sulfides after sulfide conditioning of a polluted soil, using kerosene or potassium ethyl xanthate as collectors and MIBC as frother, was studied at high background electrolyte concentrations. The sulfidisations were made in ambient air and inside an anoxic glove box. The concentrating factors corrected by the potentially available metal percentage, determined by 0.1 M EDTA extraction, lie between 2 and 3. The selective flotation of these finely dispersed, amorphous, metal sulfides can possibly be improved by optimising the bubble-particle interaction. PMID:12083717

  4. Method for the flotation oil extraction of light filth from ground capsicums.

    PubMed

    Thrasher, J J; Colliflower, E J

    1977-05-01

    The present official first action method for ground capsicums, 44.123, was adopted in 1945 and there have been great changes in processing and examination of spices since that time. The proposed method involves isopropanol pretreatment, followed by wet sieving and extraction of the light filth from 60% ethanol with flotation oil. The filter papers were clean and recoveries were good (95%) for 5 different lots of capsicums and annato spiked with insect fragments and rodent hairs. PMID:870482

  5. Fossil resin flotation from coal by selective coagulation and depression of coal

    SciTech Connect

    Miller, J.D.; Yi, Y.

    1990-02-27

    This patent describes a method for separating minute resin particles from a slurry mixture of minute resin particles and minute coal particles. It comprises: adjusting the pH of the slurry mixture of minute resin particles and minute coal particles to above about 12 and subjecting the pH adjusted slurry mixture of particles to froth flotation in the presence of a frothing agent, to produce a froth fraction enriched with respect to the minute resin particles.

  6. Use of coagulants in treatment of olive oil wastewater model solutions by induced air flotation.

    PubMed

    Meyssami, B; Kasaeian, A B

    2005-02-01

    Natural polyelectrolytes are suitable coagulants for the treatment of industrial and minicipal wastewaters because they are safe and have environmental benefits. Chitosan, a natural cationic polyelectrolyte, and other similar coagulants were used in the treatment of an olive oil water suspension as a model for the processing wastewater. The effect of chitosan, starch, alum and ferric chloride on the coagulation of oil droplets were determined by the jar test apparatus and turbidometric measurements. Olive oil emulsion samples were prepared by the use of surface active agents and other agents that could form stable oil water emulsions. The effect of parameters such as pH, ionic strength and optimum dosage of the coagulants were determined in the jar test experiments. Following the jar experiments, with the optimum concentration of the suitable coagulant, the emulsions were placed in an induced air flotation (IAF) cell to separate the coagulated oil droplets from solution. In the air flotation experiments, the effect of temperature, surfactant concentration and air flowrate were determined on the decrease of turbidity and COD of the emulsion samples. In the jar experiments, chitosan and alum used together at concentrations of 15 and 25 ppm, respectively, at pH 6 produced the lowest turbidity values. In the air flotation experiments, a concentration of 100 ppm of chitosan, an air flowrate of 3 l/min, aeration time of 45 s, temperature of 20 degrees C and pH 6 produced optimum levels. At optimum conditions of coagulation and flotation stages, the COD of the olive oil emulsion could be reduced by 95%.

  7. Self-regenerating column chromatography

    DOEpatents

    Park, Woo K.

    1995-05-30

    The present invention provides a process for treating both cations and anions by using a self-regenerating, multi-ionic exchange resin column system which requires no separate regeneration steps. The process involves alternating ion-exchange chromatography for cations and anions in a multi-ionic exchange column packed with a mixture of cation and anion exchange resins. The multi-ionic mixed-charge resin column works as a multi-function column, capable of independently processing either cationic or anionic exchange, or simultaneously processing both cationic and anionic exchanges. The major advantage offered by the alternating multi-function ion exchange process is the self-regeneration of the resins.

  8. Flotability and flotation separation of polymer materials modulated by wetting agents.

    PubMed

    Wang, Hui; Wang, Chong-qing; Fu, Jian-gang; Gu, Guo-hua

    2014-02-01

    The surface free energy, surface tension and contact angles were performed to investigate the properties of wetting agents. Adsorption of wetting agents changes wetting behavior of polymer resins. Flotability of polymer materials modulated by wetting agents was studied, and wetting agents change significantly flotability of polymer materials. The flotability decreases with increasing the concentration of wetting agents, and the wetting ability is lignin sulfonate (LS)>tannic acid (TA)>methylcellulose (MC)>triton X-100 (TX-100) (from strong to weak). There is significant difference in the flotability between polymer resins and plastics due to the presence of additives in the plastics. Flotation separation of two-component and multicomponent plastics was conducted based on the flotability modulated by wetting agents. The two-component mixtures can be efficiently separated using proper wetting agent through simple flotation flowsheet. The multicomponent plastic mixtures can be separated efficiently through multi-stage flotation using TA and LS as wetting agents, and the purity of separated component was above 94%, and the recovery was more than 93%.

  9. A novel surfactant S-benzoyl-N,N-diethyldithiocarbamate synthesis and its flotation performance to galena

    NASA Astrophysics Data System (ADS)

    Ma, Xin; Hu, Yuan; Zhong, Hong; Wang, Shuai; Liu, Guangyi; Zhao, Gang

    2016-03-01

    In this paper, a novel dithiocarbamate compound, S-benzoyl-N,N-diethyldithiocarbamate (BEDTC), was synthesized via one-pot reaction of diethylamine, carbon disulfide, sodium hydroxide and benzoyl chloride using abundant carbon disulfide as a solvent. Its flotation performance and adsorption mechanism on the galena was first investigated by flotation tests, adsorption quantity measurements, FTIR spectra, X-ray photoelectron spectra (XPS) and density functional theory (DFT) calculation. The flotation results illustrated that BEDTC exhibited stronger collecting power than the conventional sulphide collectors such as sodium diethyl dithiocarbamate (SEDTC) and sodium isobutyl xanthate (SIBX) and superior selectivity for galena against sphalerite. The adsorption data demonstrated that the adsorption affinity of BEDTC to galena was stronger than that of SEDTC and SIBX, and the preferable pH range for BEDTC adsorption on galena surfaces was 6-10. The results of FTIR spectra and XPS indicated that the interaction of BEDTC with galena may be dominated by the chemical adsorption, which was further confirmed by DFT calculation. BEDTC probably acted as a bidentate ligand, bonding with lead through the thiol sulfur and carbonyl oxygen atoms to form two distinct adsorption geometries, one with the same Pb atom to form a six-membered ring complex, and the other with two different Pb atoms to form a "bullet" shape complex.

  10. Guidance Regarding Sample Collection and Refinement of Fecal Flotation Exam for the Isolation of Aspiculuris tetraptera.

    PubMed

    Goodroe, Anna E; Baxter, Victoria K; Watson, Julie

    2016-01-01

    Aspiculuris tetraptera continues to be a problem in rodent vivaria, in part due to difficulties in parasite detection. Although PCR testing is highly sensitive, it is expensive and does not always provide immediate results. Consequently, many institutions rely on passive fecal flotation as a quick inhouse exam for diagnosing A. tetraptera infections. To increase the sensitivity of this test, we examined multiple parameters to determine the optimal test protocol. A 30-min soaking period prior to fecal flotation for 15 min allowed fecal pellets to soften and facilitated efficient egg isolation. We also evaluated the effect of time of day, sample size, age, sex, and housing status on egg isolation. No evidence of cyclical egg shedding was found, and although larger fecal sample sizes did not result in more eggs isolated, their use reduced the incidence of false-negative exams. The most eggs were isolated from 8- and 12-wk-old mice, and as mice aged, the number of eggs isolated declined. Overall, neither sex nor housing status influenced the number of eggs isolated. Finally, examination of multiple diagnostic tests (fecal flotation exam, direct examination of cecal and colonic contents, and fecal PCR) revealed that no single test was definitive, thus indicating that multiple tests might be required to successfully screen mice with low pinworm burdens. These findings provide guidance regarding sample selection, collection, and processing to efficiently detect A. tetraptera. PMID:27657708

  11. Micro-agglomerate flotation for deep cleaning of coal. Final report

    SciTech Connect

    Chander, S.; Hogg, R.

    1997-01-15

    The development of practical technologies for the deep cleaning of coal has been seriously hampered by the problems of carrying out efficient coal/mineral separations at the very fine sizes (often finer than 10 {micro}m) needed to achieve adequate liberation of the mineral matter from the coal matrix. In this investigation a hybrid process--Micro-agglomerate flotation--which is a combination of oil-agglomeration and froth flotation was studied. The basic concept is to use small quantities of oil to promote the formation of dense micro-agglomerates with minimal entrapment of water and mineral particles and to use froth flotation to separate these micro-agglomerates from the water/dispersed-mineral phase. Since the floating units will be relatively large agglomerates (30--50 {micro}m in size) rather than fine coal particles (1--10 {micro}m) the problems of froth overload and water/mineral carryover should be significantly alleviated. There are, however, complications. The process involves at least five phases: two or more solids (coal and mineral), two liquids (oil and water) and one gas (air). It is demonstrated in this study that the process is very sensitive to fluctuations in operating parameters. It is necessary to maintain precise control over the chemistry of the liquid phases as well as the agitation conditions in order to promote selectivity. Both kinetics as well as thermodynamic factors play a critical role in determining overall system response.

  12. Immersion calorimetry of fine coal particles and its relation to flotation

    SciTech Connect

    Melkus, T.G.; Chiang, S.H.; Wen, W.W.

    1987-01-01

    A Setaram C-80 heat flux microcalorimeter was used to study the surface and interfacial properties of fine coal particles in water containing flotation agents via heat of immersion measurements. Heat of immersion (..delta..H/sub imm/) is usually a small exothermic quantity and can be used to characterize a solid in terms of its relative hydrophobicity or hydrophilicity. The effects of coal type, surface oxidation, mineral matter content, kerosene concentration, and pH on the wetting characteristics were investigated. Although coal is a heterogeneous mixture of organic and inorganic materials, immersional calorimetry has proven to be quite helpful in measuring surface properties of coal, and the following conclusions can be drawn: The heat of immersion decreased with increasing kerosene concentration, which corresponds to the coal particles increasing hydrophobicity; in varying the pH, the ..delta..H/sub imm/ went through a minimum at a pH value of 6.5 to 7.0, which coincides with the reported optimum pH range for flotation; both oxidation and clay slime coating (addition of kaolin), which are known to make the coal less hydrophobic, increased the ..delta..H/sub imm/; and the trends that were shown to exist in the heat of immersion measurements (for varying kerosene concentration, pH oxidation, and clay slime coating) correlated well with independent flotation experiments. 16 refs., 6 figs., 2 tabs.

  13. CFD simulation and optimization of the capillary throttling of air-flotation unit

    NASA Astrophysics Data System (ADS)

    Bin, Huang; Yi, Jiajing; Tao, Jiayue; Lu, Rongsheng

    2016-01-01

    With respect to orifice throttling or compensating, capillary throttling has following advantages: smaller mass flow rate and stronger anti-interference ability. This paper firstly gives the required average pressure of air-film when shipping a piece of LCD glass. Then, dimensional flow model of the capillary throttling of air-flotation unit is established. Based on the model, we firstly analyze the flowing process of the lubricated air through the capillary. Secondly, the pressure distribution equation of air-film is derived from the Navier-Stokes Equation. Furthermore, the approximate functional relations between model parameters and static characteristics of the air-film, such as mass flow rate, static bearing capacity, are obtained and then influence of the former on the latter is analyzed . Finally, according to the continuity of air flow, the function relation between model parameters and pressure of core nodes in the air-film is also derived. On foundation of theoretical analysis, the impacts of each model parameter on static characteristics of the air-film flow field, are respectively simulated and analyzed by CFD software Fluent. Based on these simulations and analysis, radius and length of the capillary, density of the gas supply orifices and other model parameters are optimized. Finally, the best unit model is acquired, which greatly improves the static working performance of air-film in air-flotation unit. Research results of this paper can provide guidance and basis for the design and optimization of air-flotation transporting system.

  14. Hybrid flotation--membrane filtration process for the removal of heavy metal ions from wastewater.

    PubMed

    Blöcher, C; Dorda, J; Mavrov, V; Chmiel, H; Lazaridis, N K; Matis, K A

    2003-09-01

    A promising process for the removal of heavy metal ions from aqueous solutions involves bonding the metals firstly to a special bonding agent and then separating the loaded bonding agents from the wastewater stream by separation processes. For the separation stage, a new hybrid process of flotation and membrane separation has been developed in this work by integrating specially designed submerged microfiltration modules directly into a flotation reactor. This made it possible to combine the advantages of both flotation and membrane separation while overcoming the limitations. The feasibility of this hybrid process was proven using powdered synthetic zeolites as bonding agents. Stable fluxes of up to 80l m(-2)h(-1) were achieved with the ceramic flat-sheet multi-channel membranes applied at low transmembrane pressure (<100 mbar). The process was applied in lab-scale to treat wastewater from the electronics industry. All toxic metals in question, namely copper, nickel and zinc, were reduced from initial concentrations of 474, 3.3 and 167mg x l(-1), respectively, to below 0.05 mg x l(-1), consistently meeting the discharge limits.

  15. Determination of iron in drinking water after its flotation concentration by two new dithiocarbamate collectors.

    PubMed

    Pavlovska, Gorica; Stafilov, Trajče; Čundeva, Katarina

    2015-01-01

    Two new methods for the determination of iron by atomic absorption spectrometry (AAS) are proposed for drinking water. The determination was made after flotation concentration of Fe by using of two new flotation collectors: lead(II) heptyldithiocarbamate, Pb(HpDTC)2 and cobalt(III) heptyldithiocarbamate Co(HpDTC)3. All important parameters for the two proposed procedures were optimised (pH, mass of Pb, mass of Co, amount of HpDTC(-), type of surfactant, induction time, etc.). Flotation recovery (R) of Fe was very high (from 94.4 to 104.4%) for the two proposed procedures. The detection limit of the methods was 2.17 μg L(-1) for Pb(HpDTC)2 and 2.39 μg L(-1) for Co(HpDTC)3, respectively. The proposed methods have been applied for the analysis of five samples of drinking water. The acquired AAS results for Fe by both new methods were compared with those obtained by inductively coupled plasma-atomic emission spectrometry (AES-ICP). It is shown that they are in good agreement. The results are also confirmed by the method of standard additions.

  16. LIQUID-LIQUID EXTRACTION COLUMNS

    DOEpatents

    Thornton, J.D.

    1957-12-31

    This patent relates to liquid-liquid extraction columns having a means for pulsing the liquid in the column to give it an oscillatory up and down movement, and consists of a packed column, an inlet pipe for the dispersed liquid phase and an outlet pipe for the continuous liquid phase located in the direct communication with the liquid in the lower part of said column, an inlet pipe for the continuous liquid phase and an outlet pipe for the dispersed liquid phase located in direct communication with the liquid in the upper part of said column, a tube having one end communicating with liquid in the lower part of said column and having its upper end located above the level of said outlet pipe for the dispersed phase, and a piston and cylinder connected to the upper end of said tube for applying a pulsating pneumatic pressure to the surface of the liquid in said tube so that said surface rises and falls in said tube.

  17. Accuracy of egg flotation throughout incubation to determine embryo age and incubation day in water bird nests

    USGS Publications Warehouse

    Ackerman, J.T.; Eagles-Smith, C. A.

    2010-01-01

    Floating bird eggs to estimate their age is a widely used technique, but few studies have examined its accuracy throughout incubation. We assessed egg flotation for estimating hatch date, day of incubation, and the embryo's developmental age in eggs of the American Avocet (Recurvirostra americana), Black-necked Stilt (Himantopus mexicanus), and Forster's Tern (Sterna forsteri). Predicted hatch dates based on egg flotation during our first visit to a nest were highly correlated with actual hatch dates (r = 0.99) and accurate within 2.3 ?? 1.7 (SD) days. Age estimates based on flotation were correlated with both day of incubation (r = 0.96) and the embryo's developmental age (r = 0.86) and accurate within 1.3 ?? 1.6 days and 1.9 ?? 1.6 days, respectively. However, the technique's accuracy varied substantially throughout incubation. Flotation overestimated the embryo's developmental age between 3 and 9 days, underestimated age between 12 and 21 days, and was most accurate between 0 and 3 days and 9 and 12 days. Age estimates based on egg flotation were generally accurate within 3 days until day 15 but later in incubation were biased progressively lower. Egg flotation was inaccurate and overestimated embryo age in abandoned nests (mean error: 7.5 ?? 6.0 days). The embryo's developmental age and day of incubation were highly correlated (r = 0.94), differed by 2.1 ?? 1.6 days, and resulted in similar assessments of the egg-flotation technique. Floating every egg in the clutch and refloating eggs at subsequent visits to a nest can refine age estimates. ?? The Cooper Ornithological Society 2010.

  18. Pyrite surface characterization and control for advanced fine coal desulfurization technologies

    SciTech Connect

    Wang, X.H.; Leonard, J.W.; Parekh, B.K.; Raichur, A.M.; Jiang, C.L.

    1992-01-01

    The objective of the project is to conduct extensive fundamental studies on the surface reactivity and surface hydrophobicity of coal-pyrites using various surface characterization techniques and to understand how the alteration of the coal-pyrite surface affects the efficiency of pyrite rejection in coal flotation. During this reporting period, the influence of the impurity content, particularly coal/carbon content, on the electrochemical oxidation of pyrite surfaces was investigated. The studies demonstrate that the coal/carbon content in coal-pyrite has a determining effect on the surface reactivity of pyrite. The oxidation behavior of high carbon-content coal-pyrite is completely different from that of purer coal-pyrite and ore-pyrite. The effects of flotation gases on the flotation behavior of coal and the surface hydrophobicity of various coal-pyrite were investigated. It was found from the lab-scale column flotation studies that among the various gases studied (air, oxygen, argon, nitrogen and carbon dioxide), carbon dioxide produced the best results with a combustible recovery of 90% and ash-content of less than 9 percent. Finally, the surface energetic studies revealed that the surfaces of pyrites and coals produced by wet grinding is more heterogenous than that prepared by dry grinding.

  19. Replacing synthetic with microbial surfactants as collectors in the treatment of aqueous effluent produced by acid mine drainage, using the dissolved air flotation technique.

    PubMed

    Menezes, Carlyle T B; Barros, Erilson C; Rufino, Raquel D; Luna, Juliana M; Sarubbo, Leonie A

    2011-02-01

    Dissolved air flotation (DAF) is a well-established separation process employing micro bubbles as a carrier phase. The application of this technique in the treatment of acid mine drainage, using three yeast biosurfactants as alternative collectors, is hereby analyzed. Batch studies were carried out in a 50-cm high acrylic column with an external diameter of 2.5 cm. High percentages (above 94%) of heavy metals Fe(III) and Mn(II) were removed by the biosurfactants isolated from Candida lipolytica and Candida sphaerica and the values were found to be similar to those obtained with the use of the synthetic sodium oleate surfactant. The DAF operation with both surfactant and biosurfactants, achieved acceptable turbidity values, in accordance with Brazilian standard limits. The best ones were obtained by the biosurfactant from C. lipolytica, which reached 4.8 NTU. The results obtained with a laboratory synthetic effluent were also satisfactory. The biosurfactants removed almost the same percentages of iron, while the removal percentages of manganese were slightly higher compared with those obtained in the acid mine drainage effluent. They showed that the use of low-cost biosurfactants as collectors in the DAF process is a promising technology for the mining industries.

  20. Evaluation of faecal flotation methods followed by species-specific PCR for detection of Echinococcus multilocularis in the definitive hosts.

    PubMed

    Széll, Zoltán; Sréter-Lancz, Zsuzsanna; Sréter, Tamás

    2014-06-01

    Echinococcus multilocularis is one of the most pathogenic zoonotic parasites in the temperate and arctic region of the Northern Hemisphere. For estimating the potential risk of human infection in endemic areas, reliable antemortem methods are needed to detect the parasite in carnivore definitive hosts. The sensitivity of routine flotation techniques for detection of E. multilocularis eggs was found to be low (3-33%) depending on the flotation solution used (specific gravities = 1.3-1.4). An improved faecal flotation followed by a species-specific PCR is described with a sensitivity of 74% (95% CI = 62-84%) and a specificity of 100% (95% CI = 94-100%). These parameters are similar to those of the intestinal scraping technique (sensitivity = 78%, specificity = 100%). The sensitivity of the improved flotation was significantly higher (P < 0.0001) than that of routine flotation techniques. The costs of the method are similar or lower than those of other antemortem diagnostic methods. Based on these data, the method is suitable for surveys of domesticated and wild carnivores.

  1. Integrating flotation to improve the performance of an HMC circuit treating a low-rank fine coal

    SciTech Connect

    Celik, H.; Polat, M.

    2005-11-01

    One reason that heavy media cyclone (HMC) circuits suffer from the inadvertent loss of magnetite and fine coal is the presence of nonmagnetic material in the magnetic separator feed. In this study, flotation was applied to the undersize fractions of the HMC drain-and-rinse screens to minimize these problems. These fractions, which contain 17.9% nonmagnetic material, are currently sent to magnetic separators and the nonmagnetic portion from the separators contains 39.1% ash. Applying flotation resulted in a clean coal product with an ash content of 8.7% and a calorific value of 6,300 kcal/kg. The refuse from flotation, which will be sent to the magnetic separators, contains 7.7% nonmagnetics.

  2. Removal of Gangue Minerals Containing Major Elements from Karlıova-Derinçay (Bingöl) Lignite Using a Reverse Flotation Method

    NASA Astrophysics Data System (ADS)

    Temel, Halime Abakay

    2015-12-01

    The removal of gangue minerals containing major elements was investigated using a reverse flotation method. Experiments were conducted on lignite samples, with high-ash and low-sulphur contents taken from a lignite field in Karlıova-Derinçay (Bingöl), Turkey. Predominant gangue minerals in the samples were found to be quartz, gypsum, feldspar minerals, mica minerals, and clays (smectite group). Preliminary flotation studies showed that gangue materials are more buoyant than the lignite sample. Some parameters that markedly influence the effectiveness of reverse flotation, such as grinding time, pH, collector type and volume, frother type and volume, and salt, were investigated. Quartz was found to cause a major problem in terms of reverse flotation. Flotation measurements showed that anionic collectors in an acidic medium result in the following element reduction order: sulphur trioxide > ferric oxide > magnesium oxide > calcium oxide > silicon dioxide > aluminium oxide.

  3. Utilization of flotation wastes of copper slag as raw material in cement production.

    PubMed

    Alp, I; Deveci, H; Süngün, H

    2008-11-30

    Copper slag wastes, even if treated via processes such as flotation for metal recovery, still contain heavy metals with hazardous properties posing environmental risks for disposal. This study reports the potential use of flotation waste of a copper slag (FWCS) as iron source in the production of Portland cement clinker. The FWCS appears a suitable raw material as iron source containing >59% Fe(2)O(3) mainly in the form of fayalite (Fe(2)SiO(4)) and magnetite (Fe(3)O(4)). The clinker products obtained using the FWCS from the industrial scale trial operations over a 4-month period were characterised for the conformity of its chemical composition and the physico-mechanical performance of the resultant cement products was evaluated. The data collected for the clinker products produced using an iron ore, which is currently used as the cement raw material were also included for comparison. The results have shown that the chemical compositions of all the clinker products including those of FWCS are typical of a Portland cement clinker. The mechanical performance of the standard mortars prepared from the FWCS clinkers were found to be similar to those from the iron ore clinkers with the desired specifications for the industrial cements e.g. CEM I type cements. Furthermore, the leachability tests (TCLP and SPLP) have revealed that the mortar samples obtained from the FWCS clinkers present no environmental problems while the FWCS could act as the potential source of heavy metal contamination. These findings suggest that flotation wastes of copper slag (FWCS) can be readily utilised as cement raw material due to its availability in large quantities at low cost with the further significant benefits for waste management/environmental practices of the FWCS and the reduced production and processing costs for cement raw materials.

  4. Closed-water circuitry of a coal preparation plant with jig-flotation process

    SciTech Connect

    Shao Peizao; Guo Baoxin

    1993-12-31

    Typical flowsheet of coal preparation Plants for metallurgical coal in China is shown in Figure 1: (a) Crushed raw coal, 50{times}0 mm in size, treated in jig circuit, giving reject, middling and overflow; (b) The jig overflow directed to a spitzkasten, in which the granular concentrate settles and is dug up by a dewatering bucket elevator and discharged onto a sizing-dewatering screen; the +13 mm fraction from the screen, together with that of -13+0.5 mm after going through the dewatering centrifuge, contributing the main portion of the plant concentrate; (c) The screen underflow directed back to the spitzkasten, the overflow from which is the main stream of slime water to be treated by a thickener; the clearified overflow is the circulating wash water and its thickened underflow directed to flotation circuit; (d) In the flotation circuit, the froth concentrate is dewatered by vacuum filter and the tailing, after thickened, by press filter; vacuum filtrate directed back to the preceding spitzkaten and the clear filtrate joining with the circulating water. The specific features of such a coal preparation process is its simplicity, both in circuitry and equipment layout, and full treatment of coal down to 0 mm. On the other hand, much problems arise with slime water treatment in that: (a) Large quantity of slime water to be processed, large volume of holding vessels required and consequently large quantity of coal fines kept circulated; (b) Long contact time of fine particles with water, leading to their poorer floatability; (c) Time lag between jig circuit and flotation circuit unavoidable for their normal operation; (d) Closed-water circuit difficult to be maintained, leading to high solid content in circulating water and blackwater discharge.

  5. Evaluation of rhamnolipid (RL) as a biosurfactant for the removal of chromium from aqueous solutions by precipitate flotation.

    PubMed

    Salmani Abyaneh, Ali; Fazaelipoor, Mohammad Hassan

    2016-01-01

    Rhamnolipid (RL) is a biosurfactant which is produced by the bacterial species Pseudomonas aeruginosa. Although applications of this material have been examined in various fields, its applications in the flotation of heavy metals remain to be explored. In this research, rhamnolipid was applied as a collector in the flotation of Cr(III) from aqueous solutions. FeSO4 was used for the precipitation of Cr(VI) to Cr(III) which was subsequently removed by flotation. A two level full factorial design (with center points) was used to evaluate the effects of pH, air flow rate, RL/Cr and Fe/Cr molar ratios on the performance of the flotation system. The results showed that the biosurfactant was highly effective in the removal of chromium, and all of the factors had significant effects on the flotation performance. The chromium removal efficiencies of greater than 95% were obtained with the initial chromium concentration of 40 ppm within 5 min. Kinetic studies showed that a first order kinetic model was appropriate to describe the precipitate flotation of Cr(III) using rhamnolipid as a collector. The interference of NaCl, CaCl2, CaSO4, and CaCO3 on the Cr removal was also investigated, and it was demonstrated that CaSO4 and CaCO3 as sparingly water soluble salts, and CaCl2 as a contributor to water hardness had significant negative impacts on Cr removal efficiency of rhamnolipid.

  6. Sensitivity and efficiency of selected coproscopical methods-sedimentation, combined zinc sulfate sedimentation-flotation, and McMaster method.

    PubMed

    Becker, Ann-Christin; Kraemer, Amelie; Epe, Christian; Strube, Christina

    2016-07-01

    Coproscopical methods used in veterinary-parasitological diagnostics were validated according to their sensitivity (Se) and egg recovery rate [efficiency (Ef)]. Validation of the combined sedimentation-flotation method and the modified McMaster method was performed by using feces spiked with eggs of Ancylostoma caninum, Uncinaria stenocephala, Cooperia oncophora, cyathostomins, Ascaris suum, Toxascaris leonina, Toxocara canis, Trichuris vulpis, Moniezia expansa, and Anoplocephala perfoliata. For validation of the sedimentation method, Fasciola hepatica eggs were used. With the combined sedimentation-flotation method using ZnSO4 as flotation medium [specific gravity (SG) 1.30], 5 g fecal samples of all tested parasite species (concentration levels 1, 5, 10, 20, 40, 60, and 80 epg) were reproducibly detected "positive" (100 % Se) as of 80 epg. The Ef of the combined sedimentation-flotation method, defined as percentage of rediscovered eggs, revealed clear differences between parasites and showed the highest value for cyathostomins and the lowest for U. stenocephala and T. leonina eggs. The average Ef for all parasite species at 80 epg was 1.50 %. With the McMaster method (concentration levels 1, 30, 50, 80, 100, 500, and 1000 epg), all tested parasite species were detected reliably positive as of 500 epg with a mean Ef of 46.4 %. When evaluating the sedimentation method (concentration levels 1, 5, 10, 15, 20, 25, and 30 epg), F. hepatica eggs were reproducibly found in 5 g fecal samples as of 20 epg with 20.0 % Ef. The result that the combined zinc sulfate sedimentation-flotation method (SG 1.30) as flotation medium provides diagnostic certainty only as of 80 epg has to be considered at preventing zoonoses. If pet owners wish to prevent any zoonotic infection ("zero tolerance"), a monthly anthelminthic treatment should be advised instead of monthly fecal examinations. PMID:26997342

  7. Determination of trace elements in dolomite and gypsum by atomic absorption spectrometry: overcoming the matrix interference by flotation separation

    NASA Astrophysics Data System (ADS)

    Stafilov, Trajče; Zendelovska, Dragica; Pavlovska, Gorica; Čundeva, Katarina

    2002-05-01

    The interferences of Ca and Mg as matrix elements in dolomite and gypsum on Ag, Cd, Cr, Mn, Tl and Zn absorbances during their electrothermal atomic absorption spectrometric (ETAAS) determination are investigated. The results reveal that Ca and Mg do not interfere on Zn and Mn, tend to decrease absorbances of Ag, Cd and Cr, while Tl suffers the most significant influence. A flotation separation method is proposed to eliminate matrix interferences. Hydrated iron(III) oxide, Fe 2O 3· xH 2O, and iron(III) hexamethylenedithiocarbamate, Fe(HMDTC) 3, are applied as flotation collectors. The influence of hydrophobic dithiocarbamate anion, HMDTC, on flotation recoveries of each analyte is studied. The most suitable concentrations of dolomite and gypsum solutions for flotation are determined. To avoid flotation suppression due to the reaction of Ca 2+ and Mg 2+ with surfactant ions, a fit foaming agent was selected. The elements present in dolomite and gypsum as traces have been analyzed by ETAAS. Their ETAAS limits of detection following flotation are found to be 0.021 μg·g -1 for Ag, 0.019 μg·g -1 for Cd, 0.014 μg·g -1 for Cr and 0.11 μg·g -1 for Tl. The determination of Mn and Zn can be performed by flame AAS (FAAS). The limit of detection for Mn is 1.5 μg·g -1, while for Zn 0.8 μg·g -1.

  8. Sensitivity and efficiency of selected coproscopical methods-sedimentation, combined zinc sulfate sedimentation-flotation, and McMaster method.

    PubMed

    Becker, Ann-Christin; Kraemer, Amelie; Epe, Christian; Strube, Christina

    2016-07-01

    Coproscopical methods used in veterinary-parasitological diagnostics were validated according to their sensitivity (Se) and egg recovery rate [efficiency (Ef)]. Validation of the combined sedimentation-flotation method and the modified McMaster method was performed by using feces spiked with eggs of Ancylostoma caninum, Uncinaria stenocephala, Cooperia oncophora, cyathostomins, Ascaris suum, Toxascaris leonina, Toxocara canis, Trichuris vulpis, Moniezia expansa, and Anoplocephala perfoliata. For validation of the sedimentation method, Fasciola hepatica eggs were used. With the combined sedimentation-flotation method using ZnSO4 as flotation medium [specific gravity (SG) 1.30], 5 g fecal samples of all tested parasite species (concentration levels 1, 5, 10, 20, 40, 60, and 80 epg) were reproducibly detected "positive" (100 % Se) as of 80 epg. The Ef of the combined sedimentation-flotation method, defined as percentage of rediscovered eggs, revealed clear differences between parasites and showed the highest value for cyathostomins and the lowest for U. stenocephala and T. leonina eggs. The average Ef for all parasite species at 80 epg was 1.50 %. With the McMaster method (concentration levels 1, 30, 50, 80, 100, 500, and 1000 epg), all tested parasite species were detected reliably positive as of 500 epg with a mean Ef of 46.4 %. When evaluating the sedimentation method (concentration levels 1, 5, 10, 15, 20, 25, and 30 epg), F. hepatica eggs were reproducibly found in 5 g fecal samples as of 20 epg with 20.0 % Ef. The result that the combined zinc sulfate sedimentation-flotation method (SG 1.30) as flotation medium provides diagnostic certainty only as of 80 epg has to be considered at preventing zoonoses. If pet owners wish to prevent any zoonotic infection ("zero tolerance"), a monthly anthelminthic treatment should be advised instead of monthly fecal examinations.

  9. Characterization of multiphase fluid flow during air-sparged hydrocyclone flotation by x-ray CT. Final report, 14 August 1990--13 August 1994

    SciTech Connect

    Miller, J.D.

    1994-10-18

    Air sparged hydrocyclone (ASH) flotation is a new particle separation technology that has been developed at the University of Utah. This technology combines froth flotation principles with the flow characteristics of a hydrocyclone such that the ASH system can perform flotation separations in less than a second. This feature provides the ASH with a high specific capacity, 100 to 600 times greater than the specific capacity of conventional flotation machines. In an effort to develop a more detailed understanding of ASH flotation, multiphase flow characteristics of the air sparged hydrocyclone were studied and the relationship of these characteristics with flotation performance was investigated. This investigation was divided into four phases. In the first phase, the time-averaged multiphase flow characteristics of the ASH during its steady state operation were studied using x-ray computed tomography (x-ray CT). In this regard, a model system, mono-sized quartz flotation with dodecyl amine as collector, using a 2 in. diameter ASH unit (ASH-2C), was selected for study. Various flow regimes, namely, the air core, the froth phase, and the swirl layer, were identified and their spatial extent established for different experimental conditions by x-ray CT analysis. In the second phase, a detailed parametric study of flotation response of the ASH for the same system was carried out in order to establish the effect of various operating variables on flotation response. The findings of this phase of investigation were then correlated with the multiphase flow characteristics as revealed by x-ray CT in the first phase. Thus, the impact of various operating variables on the flow regimes, and hence, on flotation response was established.

  10. Recovering mercury from a flotation concentrate by continuous leaching-electrolysis. Report of investigations

    SciTech Connect

    Atkinson, G.B.; Murphy, J.E.; Eisele, J.A.

    1983-05-01

    The Bureau of Mines, in cooperation with McDermitt Mine, investigated a method for recovering mercury metal from mercury sulfide flotation concentrate by a hydrometallurgical technique. This preliminary report shows the feasibility of leaching mercury with a cupric chloride solution and electrowinning mercury from the solution. Results from a preliminary economic evaluation indicated that a plant producing 31,500 flasks of mercury per year would have a capital cost of $3.7 million and an operating cost of $62 per flask of mercury.

  11. Treatment of a dilute waste oil emulsion by chemical addition (CA)-dissolved air flotation (DAF)

    SciTech Connect

    Reed, B.E.; Carriere, P.; Zhu, X.; Lorkowski, T.

    1995-12-31

    Treatment of wastewater from aluminum rolling mill operations is an inherent problem in the aluminum fabrication industry. In this study, wastewater from the manufacturer`s processes was transferred to two holding ponds having a total capacity of about 5 million gallons and a detention time of about 10 days. In the holding ponds, free oil was allowed to rise to the surface where it was periodically removed. Wastewater from the holding ponds was withdrawn from about a depth of 9 ft. and used as influent to a variety of technologies. In this paper, results from the chemical addition (CA)-dissolved air flotation (DAF) portion of the treatability study are presented.

  12. High pressure humidification columns: Design equations, algorithm, and computer code

    SciTech Connect

    Enick, R.M.; Klara, S.M.; Marano, J.J.

    1994-07-01

    This report describes the detailed development of a computer model to simulate the humidification of an air stream in contact with a water stream in a countercurrent, packed tower, humidification column. The computer model has been developed as a user model for the Advanced System for Process Engineering (ASPEN) simulator. This was done to utilize the powerful ASPEN flash algorithms as well as to provide ease of use when using ASPEN to model systems containing humidification columns. The model can easily be modified for stand-alone use by incorporating any standard algorithm for performing flash calculations. The model was primarily developed to analyze Humid Air Turbine (HAT) power cycles; however, it can be used for any application that involves a humidifier or saturator. The solution is based on a multiple stage model of a packed column which incorporates mass and energy, balances, mass transfer and heat transfer rate expressions, the Lewis relation and a thermodynamic equilibrium model for the air-water system. The inlet air properties, inlet water properties and a measure of the mass transfer and heat transfer which occur in the column are the only required input parameters to the model. Several example problems are provided to illustrate the algorithm`s ability to generate the temperature of the water, flow rate of the water, temperature of the air, flow rate of the air and humidity of the air as a function of height in the column. The algorithm can be used to model any high-pressure air humidification column operating at pressures up to 50 atm. This discussion includes descriptions of various humidification processes, detailed derivations of the relevant expressions, and methods of incorporating these equations into a computer model for a humidification column.

  13. Mass transfer kinetics, band broadening and column efficiency.

    PubMed

    Gritti, Fabrice; Guiochon, Georges

    2012-01-20

    Important progress was recently made in our understanding of the physico-chemical aspects of mass transfer kinetics in chromatographic columns, in methods used for accurate determination of the different contributions to the height equivalent to a theoretical plate (HETP), and in the application of these advances to the elucidation of mass transfer mechanisms in columns packed with recent chromatographic supports (sub-2 μm fully porous particles, sub-3 μm core-shell particles, and monoliths). The independent contributions to the HETP are longitudinal diffusion, eddy dispersion, liquid-solid mass transfer (including trans-particle or trans-skeleton mass transfer and external film mass transfer), and the contributions caused by the thermal heterogeneity of the column. The origin and importance of these contributions are investigated in depth. This work underlines the areas in which improvements are needed, an understanding of the contribution of the external film mass transfer term, a better design of HPLC instruments providing a decrease of the extra-column band broadening contributions to the apparent HETP, the development of better packing procedures giving more radially homogeneous column beds, and new packing materials having a higher thermal conductivity to eliminate the nefarious impact of heat effects in very high pressure liquid chromatography (vHPLC) and supercritical fluid chromatography (SFC).

  14. Beam Studies with Electron Columns

    SciTech Connect

    Shiltsev, V.; Valishev, A.; Kuznetsov, G.; Kamerdzhiev, V.; Romanov, A.; /Novosibirsk, IYF

    2009-04-01

    We report preliminary results of experimental studies of 'electron columns' in the Tevatron and in a specialized test setup. In the Tevatron, a beam of 150 GeV protons ionizes residual gas and ionization electrons are stored in an electrostatic trap immersed into strong longitudinal magnetic field. Shifts of proton betatron frequencies are observed. In the test setup, we observe effects pointing to accumulation and escape of ionization electrons.

  15. The behavior of thiourea and flotation reagents in zinc electrowinning circuits

    NASA Astrophysics Data System (ADS)

    MacKinnon, D. J.; Dutrizac, J. E.; Brannen, J. M.; Hardy, D. J.

    1988-04-01

    The effect of thiourea and flotation reagents on the electrowinning of zinc from industrial electrolytes was studied, and all the compounds were found to reduce the zinc deposition current efficiency and to change the properties of the zinc deposits. The effectiveness of activated carbon, two-stage cementation, and hot acid leaching on the destruction/removal of the organic compounds also was addressed. Activated carbon pretreatment of thiourea-containing electrolytes restored the current efficiency for 1-hour zinc deposits to values comparable to those obtained for thiourea-free electrolytes. The activated carbon pretreatment, however, altered the deposit morphology and orientation, but produced a cyclic voltammogram similar to that of the thiourea-free solution. Two-stage cementation did not counteract the harmful effects of thiourea. Hot acid leaching destroyed the thiourea but generated large concentrations of ferrous ion that reduced the current efficiency. The ferrous concentrations, however, were readily controlled by KMnO4 or MnO2 oxidation. None of the treatment options (activated carbon, two-stage cementation, or hot acid leaching) was effective in controlling the flotation reagents, and their moderately harmful effect on zinc electrowinning persisted. Even low concentrations of these reagents polarized zinc deposition, and this resulted in a “glue-type” zinc deposit.

  16. Effects of chloride ions on electro-coagulation-flotation process with aluminum electrodes for algae removal.

    PubMed

    Gao, Shanshan; Du, Maoan; Tian, Jiayu; Yang, Jianyu; Yang, Jixian; Ma, Fang; Nan, Jun

    2010-10-15

    Electro-coagulation-flotation (ECF) is one of the most promising technologies that offers an attractive alternative to conventional coagulation and flotation. In this study, the effectiveness and mechanisms of algae removal by ECF process using aluminum electrodes was investigated in the presence of Cl(-) ions. The results showed that the addition of Cl(-) ions (1.0, 3.0, 5.0 and 8.0 mM) had a promoting effect on the algae removal in terms of both the cell density and chlorophyll-a, which could be attributed to the following two reasons. Firstly, active chlorine could be generated in the ECF when Cl(-) ions were present. The electrochemically generated active chlorine was demonstrated to be effective for the inactivation of algae cells with the aid of the electric field in the ECF. Secondly, the Cl(-) ions in the algae solution could enhance the release of Al(3+) from the aluminum electrodes in the ECF. Through SEM-EDX analysis, pitting corrosion and alleviated formation of oxide film by Cl(-) ions were observed on the anode surface. When considering that Cl(-) ions are universally present in natural waters, the effects of Cl(-) on ECF process for algae removal are of great significance. PMID:20667652

  17. Survey of dissolved air flotation system efficiency for reduce of pollution of vegetable oil industry wastewater.

    PubMed

    Keramati, H; Alidadi, H; Parvaresh, A R; Movahedian, H; Mahvi, A H

    2008-10-01

    The aim of this research was to sudy the reduction of pollution of vegetable oil manufacturing wastewater with DAF system. At first phase of this examination, the optimum dosage of the coagulants was determined. The coagulants that used in this study were Alum and Ferric Chloride. The second phase was flotation in this series of examinations, oil, COD, total solid, volatile solid, fixed solid and suspended solid measured in raw wastewater and the effluent of the DAF pilot. Optimum value of pH for alum and ferric chloride obtained 7.5 and 5.5, respectively. Optimum dosage for these obtained 30 and 32 mg L(-1) in this research. Mean removal for the parameters ofoil, COD, total solid, volatile solid, fixed solid and suspended solid obtained 75.85, 78.27, 77.32, 82.47, 73.52 and 85.53%, respectively. With pressure rising from 3 to 4 and 5 atm removing rate of COD, total solid, volatile solid, fixed solid parameters reduced, but oil and suspended solid have increase. In addition, following increase of flotation time up to 120 sec all of the measured parameters have increase in removing rate. Optimum A/S for removal of COD, total solid, volatile solid, fixed solid parameters obtained 0.001 and for oil and suspended solid obtained 0.0015.

  18. The role of selected tree species in industrial sewage sludge/flotation tailing management.

    PubMed

    Mleczek, Mirosław; Rutkowski, Paweł; Niedzielski, Przemysław; Goliński, Piotr; Gąsecka, Monika; Kozubik, Tomisław; Dąbrowski, Jędrzej; Budzyńska, Sylwia; Pakuła, Jarosław

    2016-11-01

    The aim of the study was to estimate the ability of ten tree and bush species to tolerate and accumulate Cd, Cu, Pb, Zn, and As species [As(III), As(V), and total organic arsenic] in industrial sewage sludge extremely contaminated with arsenic (almost 27.5 g kg(-1)) in a pot experiment. The premise being that it will then be possible to select the most promising tree/bush species, able to grow in the vicinity of dams where sewage sludge/flotation tailings are used as landfill. Six of the ten tested tree species were able to grow on the sludge. The highest content of total As was observed in Betula pendula roots (30.0 ± 1.3 mg kg(-1) DW), where the dominant As species was the toxic As(V). The highest biomass of Quercus Q1 robur (77.3 § 2.6 g) and Acer platanoides (76.0 § 4.9 g) was observed. A proper planting of selected tree species that are able to thrive on sewage sludge/flotation tailings could be an interesting and promising way to protect dams. By utilizing differences in their root systems and water needs, we will be able to reduce the risk of fatal environmental disasters. PMID:27348264

  19. FTIR and XPS studies of surface chemistry of pyrite in flotation

    SciTech Connect

    Leppinen, J.; Laajalehto, K.; Kartio, I.; Suoninen, E.

    1995-12-31

    Efficient separation of pyrite is of great importance for the metallurgical performance of flotation processes. Presently, separation of pyrite by flotation is becoming more and more important for reduction of sulfur in coal. In this work Fourier Transform Infrared Spectroscopy (FTIR) and X-ray Photoelectron Spectroscopy (XPS) were used to study the surface chemistry of pyrite in depression, activation and xanthate adsorption under conditions of controlled potential. Modifications of pyrite surfaces after treatment with depressants (lime, sulfur dioxide, sodium cyanide) and after activation with metal ions (Cu, Pb) were studied. The principal adsorption product identified on pyrite was dixanthogen whose formation started at about +0.15 V and +0.25 V (vs, SHE) in ethyl and amyl xanthate solutions, respectively. Copper xanthate was formed on copper(II) activated pyrite. Activation mechanism of pyrite by copper(II) salts is likely to be electrochemical where copper occurs as copper(I) on the surface of pyrite. Effective depression is achieved by sulfur dioxide and sodium cyanide. Depression at high pH is due to formation of iron(III) hydroxides. Calcium ions do not affect the electrochemistry but adsorb on pyrite and reduce the surface sites for dixanthogen adsorption.

  20. Investigation of thermal treatment on selective separation of post consumer plastics prior to froth flotation

    SciTech Connect

    Guney, Ali; Poyraz, M. Ibrahim; Kangal, Olgac Burat, Firat

    2013-09-15

    Highlights: • Both PET and PVC have nearly the same densities. • The best pH value will be 4 for optimizing pH values. • Malic acid gave the best results for selective separation of PET and PVC. - Abstract: Plastics have become the widely used materials because of their advantages, such as cheapness, endurance, lightness, and hygiene. However, they cause waste and soil pollution and they do not easily decompose. Many promising technologies are being investigated for separating mixed thermoplastics, but they are still uneconomical and unreliable. Depending on their surface characteristics, these plastics can be separated from each other by flotation method which is useful mineral processing technique with its low cost and simplicity. The main objective of this study is to investigate the flotation characteristics of PET and PVC and determine the effect of plasticizer reagents on efficient plastic separation. For that purpose, various parameters such as pH, plasticizer concentration, plasticizer type, conditioning temperature and thermal conditioning were investigated. As a result, PET particles were floated with 95.1% purity and 65.3% efficiency while PVC particles were obtained with 98.1% purity and 65.3% efficiency.

  1. Selective Sulfidation of Lead Smelter Slag with Pyrite and Flotation Behavior of Synthetic ZnS

    NASA Astrophysics Data System (ADS)

    Han, Junwei; Liu, Wei; Wang, Dawei; Jiao, Fen; Zhang, Tianfu; Qin, Wenqing

    2016-08-01

    The selective sulfidation of lead smelter slag with pyrite in the presence of carbon and Na salts, and the flotation behavior of synthetic ZnS were studied. The effects of temperature, time, pyrite dosage, Na salts, and carbon additions were investigated based on thermodynamic calculation, and correspondingly, the growth mechanism of ZnS particles was studied at high temperatures. The results indicated that the zinc in lead smelter slag was selectively converted into zinc sulfides by sulfidation roasting. The sulfidation degree of zinc was increased until the temperature, time, pyrite, and carbon dosages reached their optimum values, under which it was more than 95 pct. The growth of ZnS particles largely depended upon roasting temperature, and the ZnS grains were significantly increased above 1373 K (1100 °C) due to the formation of a liquid phase. After the roasting, the zinc sulfides generated had a good floatability, and 88.34 pct of zinc was recovered by conventional flotation.

  2. Selective separation of virgin and post-consumer polymers (PET and PVC) by flotation method.

    PubMed

    Burat, Firat; Güney, Ali; Olgaç Kangal, M

    2009-06-01

    More and more polymer wastes are generated by industry and householders today. Recycling is an important process to reduce the amount of waste resulting from human activities. Currently, recycling technologies use relatively homogeneous polymers because hand-sorting waste is costly. Many promising technologies are being investigated for separating mixed thermoplastics, but they are still uneconomical and unreliable. At present, most waste polymers cause serious environmental problems. Burning polymers for recycling is not practiced since poisonous gases are released during the burning process. Particularly, polyvinyl chloride (PVC) materials among waste polymers generate hazardous HCl gas, dioxins containing Cl, etc., which lead to air pollution and shorten the life of the incinerator. In addition, they make other polymers difficult to recycle. Both polyethylene terephthalate (PET) and PVC have densities of 1.30-1.35g /cm(3) and cannot be separated using conventional gravity separation techniques. For this reason, polymer recycling needs new techniques. Among these techniques, froth flotation, which is also used in mineral processing, can be useful because of its low cost and simplicity. The main objective of this research is to recycle PET and PVC selectively from post-consumer polymer wastes and virgin polymers by using froth flotation. According to the results, all PVC particles were floated with 98.8% efficiency in virgin polymer separation while PET particles were obtained with 99.7% purity and 57.0% efficiency in post-consumer polymer separation.

  3. Effects of chloride ions on electro-coagulation-flotation process with aluminum electrodes for algae removal.

    PubMed

    Gao, Shanshan; Du, Maoan; Tian, Jiayu; Yang, Jianyu; Yang, Jixian; Ma, Fang; Nan, Jun

    2010-10-15

    Electro-coagulation-flotation (ECF) is one of the most promising technologies that offers an attractive alternative to conventional coagulation and flotation. In this study, the effectiveness and mechanisms of algae removal by ECF process using aluminum electrodes was investigated in the presence of Cl(-) ions. The results showed that the addition of Cl(-) ions (1.0, 3.0, 5.0 and 8.0 mM) had a promoting effect on the algae removal in terms of both the cell density and chlorophyll-a, which could be attributed to the following two reasons. Firstly, active chlorine could be generated in the ECF when Cl(-) ions were present. The electrochemically generated active chlorine was demonstrated to be effective for the inactivation of algae cells with the aid of the electric field in the ECF. Secondly, the Cl(-) ions in the algae solution could enhance the release of Al(3+) from the aluminum electrodes in the ECF. Through SEM-EDX analysis, pitting corrosion and alleviated formation of oxide film by Cl(-) ions were observed on the anode surface. When considering that Cl(-) ions are universally present in natural waters, the effects of Cl(-) on ECF process for algae removal are of great significance.

  4. Selective separation of virgin and post-consumer polymers (PET and PVC) by flotation method

    SciTech Connect

    Burat, Firat; Gueney, Ali; Olgac Kangal, M.

    2009-06-15

    More and more polymer wastes are generated by industry and householders today. Recycling is an important process to reduce the amount of waste resulting from human activities. Currently, recycling technologies use relatively homogeneous polymers because hand-sorting waste is costly. Many promising technologies are being investigated for separating mixed thermoplastics, but they are still uneconomical and unreliable. At present, most waste polymers cause serious environmental problems. Burning polymers for recycling is not practiced since poisonous gases are released during the burning process. Particularly, polyvinyl chloride (PVC) materials among waste polymers generate hazardous HCl gas, dioxins containing Cl, etc., which lead to air pollution and shorten the life of the incinerator. In addition, they make other polymers difficult to recycle. Both polyethylene terephthalate (PET) and PVC have densities of 1.30-1.35 g/cm{sup 3} and cannot be separated using conventional gravity separation techniques. For this reason, polymer recycling needs new techniques. Among these techniques, froth flotation, which is also used in mineral processing, can be useful because of its low cost and simplicity. The main objective of this research is to recycle PET and PVC selectively from post-consumer polymer wastes and virgin polymers by using froth flotation. According to the results, all PVC particles were floated with 98.8% efficiency in virgin polymer separation while PET particles were obtained with 99.7% purity and 57.0% efficiency in post-consumer polymer separation.

  5. Engineering development of advanced physical fine coal cleaning for premium fuel applications. Quarterly technical progress report No. 2, January--March 1993

    SciTech Connect

    Smit, F.J.; Jha, M.C.

    1993-04-26

    The main purpose of this project is engineering development of advanced column flotation and selective agglomeration technologies for cleaning coal. Development of these technologies is an important step in the Department of Energy program to show that ultra-clean fuel can be produced from selected United States coals and that this fuel will be a cost-effective replacement for a portion of the premium fuels (oil and natural gas) burned by electric utility and industrial boilers in this country. Capturing a relatively small fraction of the total utility and industrial oil-fired boiler fuel market would have a significant impact on domestic coal production and reduce national dependence on petroleum fuels. Significant potential export markets also exist in Europe and the Pacific Rim for cost-effective premium fuels prepared from ultra-clean coal. The replacement of premium fossil fuels with coal can only be realized if retrofit costs, and boiler derating are kept to a minimum. Also, retrofit boiler emissions must be compatible with national goals for clean air. These concerns establish the specifications for the ash and sulfur levels and combustion properties of ultra-clean coal discussed below. The cost-shared contract effort is for 48 months beginning September 30, 1992, and ending September 30, 1996. This report discusses the technical progress made during the second 3 months of the project, January 1 to March 31, 1993.

  6. Tests on the centrifugal flotation technique and its use in estimating the prevalence of Toxocara in soil samples from urban and suburban areas of Malaysia.

    PubMed

    Loh, A G; Israf, D A

    1998-03-01

    The influence of soil texture (silt, sand and laterite) and flotation solutions (saturated NaCl, sucrose, NaNO3, and ZnSO4) upon the recovery of Toxocara ova from seeded soil samples with the centrifugal flotation technique was investigated. Soil samples of different texture were artificially seeded with Toxocara spp. ova and subjected to a centrifugal flotation technique which used various flotation solutions. The results showed significant (P < 0.001) interactions between the soil types and the flotation solutions. The highest percentage of ova recovery was obtained with silty soil (34.9-100.8%) with saturated NaCl as the flotation solution (45.3-100.8%). A combination of washing of soil samples with 0.1% Tween 80, and flotation using saturated NaCl and a 30 min coverslip recovery period was used to study the prevalence of contamination of soil samples. Forty-six soil samples were collected from up to 24 public parks/playgrounds in urban areas of Petaling Jaya and suburban areas of Serdang. The prevalence of Toxocara species in the urban and suburban areas was 54.5% and 45.8% respectively. PMID:9639899

  7. Tests on the centrifugal flotation technique and its use in estimating the prevalence of Toxocara in soil samples from urban and suburban areas of Malaysia.

    PubMed

    Loh, A G; Israf, D A

    1998-03-01

    The influence of soil texture (silt, sand and laterite) and flotation solutions (saturated NaCl, sucrose, NaNO3, and ZnSO4) upon the recovery of Toxocara ova from seeded soil samples with the centrifugal flotation technique was investigated. Soil samples of different texture were artificially seeded with Toxocara spp. ova and subjected to a centrifugal flotation technique which used various flotation solutions. The results showed significant (P < 0.001) interactions between the soil types and the flotation solutions. The highest percentage of ova recovery was obtained with silty soil (34.9-100.8%) with saturated NaCl as the flotation solution (45.3-100.8%). A combination of washing of soil samples with 0.1% Tween 80, and flotation using saturated NaCl and a 30 min coverslip recovery period was used to study the prevalence of contamination of soil samples. Forty-six soil samples were collected from up to 24 public parks/playgrounds in urban areas of Petaling Jaya and suburban areas of Serdang. The prevalence of Toxocara species in the urban and suburban areas was 54.5% and 45.8% respectively.

  8. Separation of polycarbonate and acrylonitrile-butadiene-styrene waste plastics by froth flotation combined with ammonia pretreatment.

    PubMed

    Wang, Chong-Qing; Wang, Hui; Liu, Qun; Fu, Jian-Gang; Liu, You-Nian

    2014-12-01

    The objective of this research is flotation separation of polycarbonate (PC) and acrylonitrile-butadiene-styrene (ABS) waste plastics combined with ammonia pretreatment. The PC and ABS plastics show similar hydrophobicity, and ammonia treatment changes selectively floatability of PC plastic while ABS is insensitive to ammonia treatment. The contact angle measurement indicates the dropping of flotation recovery of PC is ascribed to a decline of contact angle. X-ray photoelectron spectroscopy demonstrates reactions occur on PC surface, which makes PC surface more hydrophilic. Separation of PC and ABS waste plastics was conducted based on the flotation behavior of single plastic. At different temperatures, PC and ABS mixtures were separated efficiently through froth flotation with ammonia pretreatment for different time (13 min at 23 °C, 18 min at 18 °C and 30 min at 23 °C). For both PC and ABS, the purity and recovery is more than 95.31% and 95.35%, respectively; the purity of PC and ABS is up to 99.72% and 99.23%, respectively. PC and ABS mixtures with different particle sizes were separated effectively, implying that ammonia treatment possesses superior applicability.

  9. Separation of polycarbonate and acrylonitrile–butadiene–styrene waste plastics by froth flotation combined with ammonia pretreatment

    SciTech Connect

    Wang, Chong-qing; Wang, Hui Liu, Qun; Fu, Jian-gang; Liu, You-nian

    2014-12-15

    Highlights: • Ammonia treatment changes selectively floatability of PC. • The effects of ammonia on PC were investigated through contact angle and XPS. • Reactions between ammonia and PC surface make PC more hydrophilic. • PC and ABS mixtures with different particle sizes were separated effectively. - Abstract: The objective of this research is flotation separation of polycarbonate (PC) and acrylonitrile–butadiene–styrene (ABS) waste plastics combined with ammonia pretreatment. The PC and ABS plastics show similar hydrophobicity, and ammonia treatment changes selectively floatability of PC plastic while ABS is insensitive to ammonia treatment. The contact angle measurement indicates the dropping of flotation recovery of PC is ascribed to a decline of contact angle. X-ray photoelectron spectroscopy demonstrates reactions occur on PC surface, which makes PC surface more hydrophilic. Separation of PC and ABS waste plastics was conducted based on the flotation behavior of single plastic. At different temperatures, PC and ABS mixtures were separated efficiently through froth flotation with ammonia pretreatment for different time (13 min at 23 °C, 18 min at 18 °C and 30 min at 23 °C). For both PC and ABS, the purity and recovery is more than 95.31% and 95.35%, respectively; the purity of PC and ABS is up to 99.72% and 99.23%, respectively. PC and ABS mixtures with different particle sizes were separated effectively, implying that ammonia treatment possesses superior applicability.

  10. Removal of wax and stickies from OCC by flotation. Progress report No. 3, July 1--September 30, 1998

    SciTech Connect

    Dosh, M.R.; Dyer, J.; Heise, O.; Cao, B.

    1998-11-01

    In this quarter we completed low consistency laboratory pulping trials. Pulping results were analyzed in terms of defibering index or yield and the concentration of free wax. The objective of these trials is to identify pulping conditions that will give higher yield and higher concentration of free wax. The yields from low consistency pulping trials ranged from 90 to 99% based on 6-cut laboratory screen rejects. In general, high temperatures (140-150{degrees}F) and high pH (9.5-10) conditions resulted in higher yield and the generation of free wax. Factors such as rotor speed and the gap (between the rotor and grate) were not significant in affecting defibering. Generally, the turbidities of filtrates from wax-contaminated pulps increased with increase in temperature and/or pH. The filtrate turbidity indicated the relative concentration of finely dispersed wax that could be removed from pulp dewatered on a 30 {micro}m filter paper. Preliminary experiments were conducted to study flotation conditions necessary for effective removal of wax from pulp. Factors which are important for effective flotation include flotation time, volume of air, surfactant concentration and type, and low temperature. Future plans include additional flotation trials to better optimize conditions. Other contaminant types include pressure sensitive adhesives and hot melts will also be examined. This will be followed by pilot plant and mill trials.

  11. Wastewater treatment using flocculation, coagulation, and flotation. (Latest citations from the NTIS bibliographic database). NewSearch

    SciTech Connect

    Not Available

    1994-10-01

    The bibliography contains citations concerning the design, development, and evaluation of flocculation coagulation and flotation processes for the treatment of sewage and industrial wastes. Citations examine technology requirements and limitations, activated sludge and anaerobic processes, chlorination, runoff pollution control, wastewater recycling and reuse, and materials recovery. (Contains 250 citations and includes a subject term index and title list.)

  12. Micro-agglomerate flotation for deep cleaning of coal. Quarterly progress report, 1 April--30 June 1994

    SciTech Connect

    Chander, S.; Hogg, R.

    1994-07-01

    The authors are investigating the use of a hybrid process--Micro-agglomerate flotation--which is a combination of oil-agglomeration and froth flotation. The basic concepts is to use small quantities of oil to promote the formation of dense micro-agglomerates with minimal entrapment of water and mineral particles, and to use froth flotation to extract these micro-agglomerates from the water/dispersed-mineral phase. Since the floating units are agglomerates (about 30--50 {mu}m in size) rather than individual coal particles (1--10 {mu}m) the problems of froth overload water/mineral carryover should be significantly alleviated. The process involves at least five phases: two or more solids (coal and mineral), two liquids (oil and water) and one gas (air). It is necessary to maintain precise control over the chemistry of the liquid phases in order to promote the interfacial reactions and interactions between phases necessary to ensure selectivity. Kinetics as well as thermodynamic factors may be critical in determining overall system response. The research program has been organized into several specific tasks: Task 1, interfacial studies; Task 2, emulsification; Task 3, agglomerate growth and structure; and Task 4, agglomerate flotation. This report summarizes the status of Tasks 2, 3, and 4.

  13. Investigation of the effects of various water mediums on desulfurization and deashing of a coal sample by flotation

    SciTech Connect

    Ayhan, F.D.

    2009-08-15

    The aim of this study was to investigate the effects of various water mediums on desulfurization and deashing of a coal sample using flotation. For this purpose, experimental studies were conducted on a coal sample containing high ash and sulfur contents. The effects of pH, solid concentration, collector amount and frother amount on the flotation were investigated separately in Mediterranean Sea water, Cermik thermal spring water, snow water and tap water. Flotation, results indicated that, when comparing the various water mediums, the following order for the ash content was obtained: snow water < Cermik thermal spring water < tap water < the Mediterranean Sea water. For the reduction of total sulfur, the following order was obtained: snow water > Cermik thermal spring water > Mediterranean Sea water > tap water. When snow water was used as a flotation medium, it was found that a concentrate containing 3.01% total sulfur and 27.64% ash with a total sulfur reduction of 57.06% was obtained from a feed containing 7.01% total sulfur and 4.1.17% ash.

  14. Removal of wax and stickies from OCC by flotation. Progress report No. 3, July 1--September 30, 1998

    SciTech Connect

    Doshi, M.R.; Dyer, J.; Heise, O.; Cao, B.

    1998-11-01

    In this quarter we completed low consistency laboratory pulping trials. Pulping results were analyzed in terms of defibering index or yield and the concentration of free wax. The objective of these trials is to identify pulping conditions that will give higher yield and higher concentration of free wax. The yields from low consistency pulping trials ranged from 90 to 99% based on 6-cut laboratory screen rejects. In general, high temperatures (140-150{degree}F) and high pH (9.5-10) conditions resulted in higher yield and the generation of free wax. Factors such as rotor speed and the gap (between the rotor and grate) were not significant in affecting defibering. Generally, the turbidities of filtrates from wax-contaminated pulps increased with increase in temperature and/or pH. The filtrate turbidity indicated the relative concentration of finely dispersed wax that could be removed from pulp dewatered on a 30 {micro}m filter paper. Preliminary experiments were conducted to study flotation conditions necessary for effective removal of wax from pulp. Factors which are important for effective flotation include flotation time, volume of air, surfactant concentration and type, and low temperature. Future plans include additional flotation trials to better optimize conditions. Other contaminant types include pressure sensitive adhesives and hot melts will also be examined. This will be followed by pilot plant and mill trials.

  15. Removal of cadmium, lead, mercury, tin, antimony, and arsenic from drinking and seawaters by colloid precipitate flotation

    SciTech Connect

    Ghazy, S.E.

    1995-04-01

    The removal of Cd(II), Pb(II), Hg(II), Sn(II), Sn(IV), Sb(III), Sb(V), As(III), and As(V) from aqueous solutions by colloid precipitate flotation using sodium sulfide as the coagulent and oleic acid (HOL) as the surfactant has been investigated. The complete flotation (about 100%) of these elements was attained at pH values of 5.5-6.5, 3-6.5, {le}1, 1-4, 0.5-3, and {le}2, respectively. The effects of some other factors, such as surfactant and coagulent concentrations, sequence of adding reagents, some selected foreign ions, ionic strength, and temperature, on the floatability of these elements have been studied. It was found that both temperature and ionic strength have no appreciable effect on the flotation efficiency of the metal ions investigated. The method was successfully applied to remove completely these metal ions added to 1 L samples of drinking and seawaters at the optimum conditions for each element. Moreover, the mechanism of flotation is proposed.

  16. Temperature programmable microfabricated gas chromatography column

    DOEpatents

    Manginell, Ronald P.; Frye-Mason, Gregory C.

    2003-12-23

    A temperature programmable microfabricated gas chromatography column enables more efficient chemical separation of chemical analytes in a gas mixture by the integration of a resistive heating element and temperature sensing on the microfabricated column. Additionally, means are provided to thermally isolate the heated column from their surroundings. The small heat capacity and thermal isolation of the microfabricated column improves the thermal time response and power consumption, both important factors for portable microanalytical systems.

  17. 29 CFR 1926.755 - Column anchorage.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ...) General requirements for erection stability. (1) All columns shall be anchored by a minimum of 4 anchor rods (anchor bolts). (2) Each column anchor rod (anchor bolt) assembly, including the column-to-base... of anchor rods (anchor bolts). (1) Anchor rods (anchor bolts) shall not be repaired, replaced...

  18. 29 CFR 1926.755 - Column anchorage.

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... 29 Labor 8 2011-07-01 2011-07-01 false Column anchorage. 1926.755 Section 1926.755 Labor... (CONTINUED) SAFETY AND HEALTH REGULATIONS FOR CONSTRUCTION Steel Erection § 1926.755 Column anchorage. (a) General requirements for erection stability. (1) All columns shall be anchored by a minimum of 4...

  19. Data book for 12.5-inch diameter SRB thermal model water flotation test; 1.29 psia, series P022

    NASA Technical Reports Server (NTRS)

    Allums, S. L.

    1974-01-01

    Data acquired from tests conducted to determine how thermal conditions affect SRB (Space Shuttle Solid Rocket Booster) flotation at a scaled pressure of 1.29 psia are presented. Included are acceleration, pressure, and temperature data recorded from initial water impact to final flotation position using a 12.5-inch diameter thermal model of the SRB. Nineteen valid tests were conducted. These thermal tests indicated the following basic differences relative to the ambient temperature and pressure model tests: (1) more water was taken on board during penetration and (2) model flotation/sinking was temperature sensitive.

  20. Data book for 12.5-inch diameter SRB thermal model water flotation test - 14.7 psia, series P024

    NASA Technical Reports Server (NTRS)

    Allums, S. L.

    1974-01-01

    Tests were conducted to determine how thermal conditions affect space shuttle solid rocket booster (SRB) flotation. Acceleration, pressure, and temperature data were recorded from initial water impact to final flotation position using a 12.5-inch diameter thermal model of the SRB at ambient pressure. The model was 136.9 inches long and weighed 117.3 lbm. The tests indicated the following differences from ambient temperature tests: (1) significant negative static pressures can occur during penetration; (2) maximum penetration is increased; and (3) final flotation is in the spar buoy mode.

  1. Data book for 12.5-inch diameter SRB thermal model water flotation test: 14.7 psia, series P020

    NASA Technical Reports Server (NTRS)

    Allums, S. L.

    1974-01-01

    Data acquired from the initial series of tests conducted to determine how thermal conditions affect SRB (Space Shuttle Solid Rocket Booster) flotation are presented. Acceleration, pressure, and temperature data recorded from initial water impact to final flotation position using a 12.5-inch diameter thermal model of the SRB at ambient pressure are included. The model was 136.9 inches long and weighed 117.3 lbm. The tests indicated the following differences from ambient temperature tests: (1) significant negative static pressures can occur during penetration; (2) maximum penetration is increased; and (3) final flotation is in the spar buoy mode.

  2. POC-scale testing of an advanced fine coal dewatering equipment/technique. Quarterly progress report, July - September 1996

    SciTech Connect

    Tao, D.; Groppo, J.G.; Parekh, B.K.

    1996-10-01

    The advanced fine-coal cleaning techniques such as column flotation, recovers a low-ash ultra-fine size clean-coal product. However, economical dewatering of the clean coal product to less than 20 percent moisture using conventional technology is difficult. This research program objective is to evaluate a novel coal surface modification technique developed at the University of Kentucky Center for Applied Energy Research in conjunction with conventional and advanced dewatering technique at a pilot scale. The study which is in progress is being conducted at the Powell Mountain Coal Company`s Mayflower preparation plant located in St. Charles, VA. During this quarter laboratory dewatering studies were conducted using a 4-in diameter laboratory chemical centrifuge. The baseline data provided a filter cake with about 32% moisture. Addition of 0.3 kg/t of a cationic surfactant lowered the moisture to 29%. Addition of anionic and non-ionic surfactant was not effective in reducing the filter cake moisture content. In the pilot scale studies, a comparison was conducted between the high pressure and vacuum dewatering techniques. The base line data with high pressure and vacuum filtration provided filter cakes with 23.6% and 27.8% moisture, respectively. Addition of 20 g/t of cationic flocculent provided 21% filter cake moisture using the high pressure filter. A 15% moisture filter cake was obtained using 1.5 kg/t of non-ionic surfactant. Vacuum filter provided about 23% to 25% moisture product with additional reagents. The high pressure filter processed about 3 to 4 times more solids compared to vacuum filter.

  3. Water column correction for coral reef studies by remote sensing.

    PubMed

    Zoffoli, Maria Laura; Frouin, Robert; Kampel, Milton

    2014-09-11

    Human activity and natural climate trends constitute a major threat to coral reefs worldwide. Models predict a significant reduction in reef spatial extension together with a decline in biodiversity in the relatively near future. In this context, monitoring programs to detect changes in reef ecosystems are essential. In recent years, coral reef mapping using remote sensing data has benefited from instruments with better resolution and computational advances in storage and processing capabilities. However, the water column represents an additional complexity when extracting information from submerged substrates by remote sensing that demands a correction of its effect. In this article, the basic concepts of bottom substrate remote sensing and water column interference are presented. A compendium of methodologies developed to reduce water column effects in coral ecosystems studied by remote sensing that include their salient features, advantages and drawbacks is provided. Finally, algorithms to retrieve the bottom reflectance are applied to simulated data and actual remote sensing imagery and their performance is compared. The available methods are not able to completely eliminate the water column effect, but they can minimize its influence. Choosing the best method depends on the marine environment, available input data and desired outcome or scientific application.

  4. Water Column Correction for Coral Reef Studies by Remote Sensing

    PubMed Central

    Zoffoli, Maria Laura; Frouin, Robert; Kampel, Milton

    2014-01-01

    Human activity and natural climate trends constitute a major threat to coral reefs worldwide. Models predict a significant reduction in reef spatial extension together with a decline in biodiversity in the relatively near future. In this context, monitoring programs to detect changes in reef ecosystems are essential. In recent years, coral reef mapping using remote sensing data has benefited from instruments with better resolution and computational advances in storage and processing capabilities. However, the water column represents an additional complexity when extracting information from submerged substrates by remote sensing that demands a correction of its effect. In this article, the basic concepts of bottom substrate remote sensing and water column interference are presented. A compendium of methodologies developed to reduce water column effects in coral ecosystems studied by remote sensing that include their salient features, advantages and drawbacks is provided. Finally, algorithms to retrieve the bottom reflectance are applied to simulated data and actual remote sensing imagery and their performance is compared. The available methods are not able to completely eliminate the water column effect, but they can minimize its influence. Choosing the best method depends on the marine environment, available input data and desired outcome or scientific application. PMID:25215941

  5. Water column correction for coral reef studies by remote sensing.

    PubMed

    Zoffoli, Maria Laura; Frouin, Robert; Kampel, Milton

    2014-01-01

    Human activity and natural climate trends constitute a major threat to coral reefs worldwide. Models predict a significant reduction in reef spatial extension together with a decline in biodiversity in the relatively near future. In this context, monitoring programs to detect changes in reef ecosystems are essential. In recent years, coral reef mapping using remote sensing data has benefited from instruments with better resolution and computational advances in storage and processing capabilities. However, the water column represents an additional complexity when extracting information from submerged substrates by remote sensing that demands a correction of its effect. In this article, the basic concepts of bottom substrate remote sensing and water column interference are presented. A compendium of methodologies developed to reduce water column effects in coral ecosystems studied by remote sensing that include their salient features, advantages and drawbacks is provided. Finally, algorithms to retrieve the bottom reflectance are applied to simulated data and actual remote sensing imagery and their performance is compared. The available methods are not able to completely eliminate the water column effect, but they can minimize its influence. Choosing the best method depends on the marine environment, available input data and desired outcome or scientific application. PMID:25215941

  6. Effects of dissolved air flotation hydraulic loading rate on water treatment performance

    SciTech Connect

    Tobiason, J.E.; Edzwald, J.K.; Amato, T.; Maggi, L.J.

    1999-07-01

    The performance of dissolved air flotation (DAF) followed by granular media filtration for water treatment was evaluated via pilot-scale studies for two water sources. The study focused on short flocculation times (5--8 minutes), high DAF hydraulic loading rates (17--44 m/hr (7--18 gpm/ft{sup 2})) and rapid rate filtration (10--20 m/hr (4--8 gpm/ft{sup 2})). Excellent treatment performance was achieved in terms of DAF clarified water turbidity, filtered water turbidity, organic matter removal and filtered water production. Bubble carryover from the DAF tank was mitigated by employing either internal or external air removal strategies. Overall, the results demonstrate the effectiveness of an integrated, high rate flocculation/DAF/filtration water treatment strategy.

  7. Influence of growth phase on harvesting of Chlorella zofingiensis by dissolved air flotation.

    PubMed

    Zhang, Xuezhi; Amendola, Pasquale; Hewson, John C; Sommerfeld, Milton; Hu, Qiang

    2012-07-01

    The effects of changes in cellular characteristics and dissolved organic matter (DOM) on dissolved air flotation (DAF) harvesting of Chlorella zofingiensis at the different growth phases were studied. Harvesting efficiency increased with Al(3+) dosage and reached more than 90%, regardless of growth phases. In the absence of DOM, the ratio of Al(3+) dosage to surface functional group concentration determined the harvesting efficiency. DOM in the culture medium competed with algal cell surface functional groups for Al(3+), and more Al(3+) was required for cultures with DOM than for DOM-free cultures to achieve the same harvesting efficiency. As the culture aged, the increase of Al(3+) dosage due to increased DOM was less than the decrease of Al(3+) dosage associated with reduced cell surface functional groups, resulting in overall reduced demand for Al(3+). The interdependency of Al(3+) dosage and harvesting efficiency on concentrations of cell surface functional groups and DOM was successfully modeled. PMID:22541950

  8. Flotation Immunoassay: Masking the Signal from Free Reporters in Sandwich Immunoassays.

    PubMed

    Chen, Hui; Hagström, Anna E V; Kim, Jinsu; Garvey, Gavin; Paterson, Andrew; Ruiz-Ruiz, Federico; Raja, Balakrishnan; Strych, Ulrich; Rito-Palomares, Marco; Kourentzi, Katerina; Conrad, Jacinta C; Atmar, Robert L; Willson, Richard C

    2016-04-14

    In this work, we demonstrate that signal-masking reagents together with appropriate capture antibody carriers can eliminate the washing steps in sandwich immunoassays. A flotation immunoassay (FI) platform was developed with horseradish peroxidase chemiluminescence as the reporter system, the dye Brilliant Blue FCF as the signal-masking reagent, and buoyant silica micro-bubbles as the capture antibody carriers. Only reporters captured on micro-bubbles float above the dye and become visible in an analyte-dependent manner. These FIs are capable of detecting proteins down to attomole levels and as few as 10(6) virus particles. This signal-masking strategy represents a novel approach to simple, sensitive and quantitative immunoassays in both laboratory and point-of-care settings.

  9. Effects of Dry Flotation Restricted Environmental Stimulation on Hypnotizability and Pain Control.

    PubMed

    Darakjy, Jennifer; Barabasz, Marianne; Barabasz, Arreed

    2015-10-01

    The effects of dry flotation restricted environmental stimulation (REST) on hypnotizability and pain control were tested in lighted and unlighted conditions. Participants (N = 30, ages 18-30) were exposed to hypnosis maximizing (plateauing) experiences prior to the experiment. Participants were exposed to 6 hours of lighted REST (N = 10), 6 hours of unlighted REST (N = 10), or 6 hours of normal stimulation (N = 10). The Stanford Hypnotic Susceptibility Scale: Form C (SHSS: C) (Weitzenhoffer & Hilgard, 1962) and standardized ischemic pain tests were administered before and after the conditions and at a 2-week follow-up. Both REST groups shared significantly higher SHSS: C scores and significantly lower pain scores from pre-test to post-test and follow-up. The lighted REST group showed significantly higher SHSS: C scores and significantly lower pain scores than the unlighted REST group at post-test and follow-up. The findings supported Barabasz's (1982) theory of REST responding. PMID:26264543

  10. Leaching of a copper flotation concentrate with ammonium persulfate in an autoclave system

    NASA Astrophysics Data System (ADS)

    Deniz Turan, M.; Soner Altundoğan, H.

    2014-09-01

    The leaching behavior of a copper flotation concentrate was investigated using ammonium persulfate (APS) in an autoclave system. The decomposition products of APS, active oxygen, and acidic medium were used to extract metals from the concentrate. Leaching experiments were performed to compare the availability of APS as an oxidizing agent for leaching of the concentrate under atmospheric conditions and in an autoclave system. Leaching temperature and APS concentration were found to be important parameters in both leaching systems. Atmospheric leaching studies showed that the metal extractions increased with the increase in APS concentration and temperature (up to 333 K). A similar tendency was determined in the autoclave studies up to 423 K. It was also determined that the metal extractions decreased at temperatures above 423 K due to the passivation of the particle surface by molten elemental sulfur. The results showed that higher copper extractions could be achieved using an autoclave system.

  11. Effects of Dry Flotation Restricted Environmental Stimulation on Hypnotizability and Pain Control.

    PubMed

    Darakjy, Jennifer; Barabasz, Marianne; Barabasz, Arreed

    2015-10-01

    The effects of dry flotation restricted environmental stimulation (REST) on hypnotizability and pain control were tested in lighted and unlighted conditions. Participants (N = 30, ages 18-30) were exposed to hypnosis maximizing (plateauing) experiences prior to the experiment. Participants were exposed to 6 hours of lighted REST (N = 10), 6 hours of unlighted REST (N = 10), or 6 hours of normal stimulation (N = 10). The Stanford Hypnotic Susceptibility Scale: Form C (SHSS: C) (Weitzenhoffer & Hilgard, 1962) and standardized ischemic pain tests were administered before and after the conditions and at a 2-week follow-up. Both REST groups shared significantly higher SHSS: C scores and significantly lower pain scores from pre-test to post-test and follow-up. The lighted REST group showed significantly higher SHSS: C scores and significantly lower pain scores than the unlighted REST group at post-test and follow-up. The findings supported Barabasz's (1982) theory of REST responding.

  12. Flotation Immunoassay: Masking the Signal from Free Reporters in Sandwich Immunoassays.

    PubMed

    Chen, Hui; Hagström, Anna E V; Kim, Jinsu; Garvey, Gavin; Paterson, Andrew; Ruiz-Ruiz, Federico; Raja, Balakrishnan; Strych, Ulrich; Rito-Palomares, Marco; Kourentzi, Katerina; Conrad, Jacinta C; Atmar, Robert L; Willson, Richard C

    2016-01-01

    In this work, we demonstrate that signal-masking reagents together with appropriate capture antibody carriers can eliminate the washing steps in sandwich immunoassays. A flotation immunoassay (FI) platform was developed with horseradish peroxidase chemiluminescence as the reporter system, the dye Brilliant Blue FCF as the signal-masking reagent, and buoyant silica micro-bubbles as the capture antibody carriers. Only reporters captured on micro-bubbles float above the dye and become visible in an analyte-dependent manner. These FIs are capable of detecting proteins down to attomole levels and as few as 10(6) virus particles. This signal-masking strategy represents a novel approach to simple, sensitive and quantitative immunoassays in both laboratory and point-of-care settings. PMID:27075635

  13. Flotation Immunoassay: Masking the Signal from Free Reporters in Sandwich Immunoassays

    PubMed Central

    Chen, Hui; Hagström, Anna E. V.; Kim, Jinsu; Garvey, Gavin; Paterson, Andrew; Ruiz-Ruiz, Federico; Raja, Balakrishnan; Strych, Ulrich; Rito-Palomares, Marco; Kourentzi, Katerina; Conrad, Jacinta C.; Atmar, Robert L.; Willson, Richard C.

    2016-01-01

    In this work, we demonstrate that signal-masking reagents together with appropriate capture antibody carriers can eliminate the washing steps in sandwich immunoassays. A flotation immunoassay (FI) platform was developed with horseradish peroxidase chemiluminescence as the reporter system, the dye Brilliant Blue FCF as the signal-masking reagent, and buoyant silica micro-bubbles as the capture antibody carriers. Only reporters captured on micro-bubbles float above the dye and become visible in an analyte-dependent manner. These FIs are capable of detecting proteins down to attomole levels and as few as 106 virus particles. This signal-masking strategy represents a novel approach to simple, sensitive and quantitative immunoassays in both laboratory and point-of-care settings. PMID:27075635

  14. Determination of polynuclear aromatic hydrocarbons in water by flotation enrichment and HPLC.

    PubMed

    Bo-Xing, X; Yu-Zhi, F

    1988-11-01

    A method of concentration and determination of several polynuclear aromatic hydrocarbons (PAHs) in water by flotation enrichment and HPLC is described. Triton X-100 was used as the foaming agent to extract the PAHs from water by passage of nitrogen. Reversed-phase liquid chromatography with coupled fluorescence detection was applied to separate and determine these PAHs. Various factors which may affect the recovery of PAHs from water, including pH, temperature and the concentration of Triton X-100 added, are discussed. This simplified method of concentrating PAHs from water has been applied to determine PAHs in water from Lake Erie. The method has practical value for the determination of PAHs in large volumes of water.

  15. Optimization of Cu-Zn Massive Sulphide Flotation by Selective Reagents

    NASA Astrophysics Data System (ADS)

    Soltani, F.; Koleini, S. M. J.; Abdollahy, M.

    2014-10-01

    Selective floatation of base metal sulphide minerals can be achieved by using selective reagents. Sequential floatation of chalcopyrite-sphalerite from Taknar (Iran) massive sulphide ore with 3.5 % Zn and 1.26 % Cu was studied. D-optimal design of response surface methodology was used. Four mixed collector types (Aer238 + SIPX, Aero3477 + SIPX, TC1000 + SIPX and X231 + SIPX), two depressant systems (CuCN-ZnSO4 and dextrin-ZnSO4), pH and ZnSO4 dosage were considered as operational factors in the first stage of flotation. Different conditions of pH, CuSO4 dosage and SIPX dosage were studied for sphalerite flotation from first stage tailings. Aero238 + SIPX induced better selectivity for chalcopyrite against pyrite and sphalerite. Dextrin-ZnSO4 was as effective as CuCN-ZnSO4 in sphalerite-pyrite depression. Under optimum conditions, Cu recovery, Zn recovery and pyrite content in Cu concentrate were 88.99, 33.49 and 1.34 % by using Aero238 + SIPX as mixed collector, CuCN-ZnSO4 as depressant system, at ZnSO4 dosage of 200 g/t and pH 10.54. When CuCN was used at the first stage, CuSO4 consumption increased and Zn recovery decreased during the second stage. Maximum Zn recovery was 72.19 % by using 343.66 g/t of CuSO4, 22.22 g/t of SIPX and pH 9.99 at the second stage.

  16. Abnormal gel flotation caused by contrast media during adrenal vein sampling

    PubMed Central

    Lima-Oliveira, Gabriel; Lippi, Giuseppe; Salvagno, Gian Luca; Gelati, Matteo; Bassi, Antonella; Contro, Alberto; Pizzolo, Francesca; Guidi, Gian Cesare

    2016-01-01

    Introduction During adrenal venous sampling (AVS) procedure, radiologists administer a contrast agent via the catheter to visualize the proper catheter position. Materials and methods A patient with primary aldosteronism diagnostic-hypothesis was admitted for AVS. A venogram was performed to
confirm the catheter’s position with 2mL of Iopamidol 300 mg/mL. Samples were collected with syringe connected to a hydrophilic coated catheter by low-pressure aspiration from each of the four collection sites: inferior vena cava in the suprarenal portion, inferior vena cava in the infrarenal portion, left adrenal vein, and right adrenal vein; then immediately transferred from syringe to tubes with gel separator. All tubes were centrifuged at 1200 x g for 10 minutes. Results At the end of centrifugation process, primary blood tubes containing blood from inferior vena cava and left adrenal vein exhibited the standard gel separator barrier, while tubes from right adrenal vein showed abnormal flotation of gel separator. The radiologist confirmed the usage of 2.6 mL instead of 2.0 mL of Iopamidol 300 mg/mL. This iodinated contrast media, with 1.33 g/cm3 of density, was used close to the right adrenal vein due to some difficulty to access it. Conclusion The abnormal flotation of gel separator in samples taken from right adrenal vein can be explained by the usage of the iodinated
contrast media. We suggest using plain-tubes (without gel separator) for AVS in order to avoid preanalytical nonconformities. Moreover, a blood volume equivalent to twice the catheter extension should be discarded to eliminate residual contrast media before collection of samples for laboratory assays. PMID:27812311

  17. In-plant testing of a novel coal cleaning circuit using advanced technologies. Final technical report, September 1, 1995--August 31, 1996

    SciTech Connect

    Honaker, R.Q.; Reed, S.; Mohanty, M.K.

    1997-05-01

    A circuit comprised of advanced fine coal cleaning technologies was evaluated in an operating preparation plant to determine circuit performance and to compare the performance with current technologies used to treat -16 mesh fine coal. The circuit integrated a Floatex hydrosizer, a Falcon enhanced gravity concentrator and a Jameson flotation cell. A Packed-Column was used to provide additional reductions in the pyritic sulfur and ash contents by treatment of the Floatex-Falcon-Jameson circuit product. For a low sulfur Illinois No. 5 coal, the pyritic sulfur content was reduced from 0.67% to 0.34% at a combustible recovery of 93.2%. The ash content was decreased from 27.6% to 5.84%, which equates to an organic efficiency of 95% according to gravity-based washability data. The separation performance achieved on a high sulfur Illinois No. 5 coal resulted in the rejection of 72.7% of the pyritic sulfur and 82.3% of the ash-forming material at a recovery of 8 1 %. Subsequent pulverization of the cleaned product and retreatment in a Falcon concentrator and Packed-Column resulted in overall circuit ash and pyritic sulfur rejections of 89% and 93%, respectively, which yielded a pyritic sulfur content reduction from 2.43% to 0.30%. This separation reduced the sulfur dioxide emission rating of an Illinois No. 5 coal from 6.21 to 1.75 lbs SO{sub 2}/MBTU, which is Phase I compliance coal. A comparison of the results obtained from the Floatex-Falcon-Jameson circuit with those of the existing circuit revealed that the novel fine coal circuit provides 10% to 20% improvement in mass yield to the concentrate while rejecting greater amounts of ash and pyritic sulfur.

  18. Pyrite surface characterization and control for advanced fine coal desulfurization technologies. Eighth quarterly technical progress report, June 1, 1992--August 31, 1992

    SciTech Connect

    Wang, X.H.; Leonard, J.W.; Parekh, B.K.; Raichur, A.M.; Jiang, C.L.

    1992-12-01

    The objective of the project is to conduct extensive fundamental studies on the surface reactivity and surface hydrophobicity of coal-pyrites using various surface characterization techniques and to understand how the alteration of the coal-pyrite surface affects the efficiency of pyrite rejection in coal flotation. During this reporting period, the influence of the impurity content, particularly coal/carbon content, on the electrochemical oxidation of pyrite surfaces was investigated. The studies demonstrate that the coal/carbon content in coal-pyrite has a determining effect on the surface reactivity of pyrite. The oxidation behavior of high carbon-content coal-pyrite is completely different from that of purer coal-pyrite and ore-pyrite. The effects of flotation gases on the flotation behavior of coal and the surface hydrophobicity of various coal-pyrite were investigated. It was found from the lab-scale column flotation studies that among the various gases studied (air, oxygen, argon, nitrogen and carbon dioxide), carbon dioxide produced the best results with a combustible recovery of 90% and ash-content of less than 9 percent. Finally, the surface energetic studies revealed that the surfaces of pyrites and coals produced by wet grinding is more heterogenous than that prepared by dry grinding.

  19. Oscillating water column structural model

    SciTech Connect

    Copeland, Guild; Bull, Diana L; Jepsen, Richard Alan; Gordon, Margaret Ellen

    2014-09-01

    An oscillating water column (OWC) wave energy converter is a structure with an opening to the ocean below the free surface, i.e. a structure with a moonpool. Two structural models for a non-axisymmetric terminator design OWC, the Backward Bent Duct Buoy (BBDB) are discussed in this report. The results of this structural model design study are intended to inform experiments and modeling underway in support of the U.S. Department of Energy (DOE) initiated Reference Model Project (RMP). A detailed design developed by Re Vision Consulting used stiffeners and girders to stabilize the structure against the hydrostatic loads experienced by a BBDB device. Additional support plates were added to this structure to account for loads arising from the mooring line attachment points. A simplified structure was designed in a modular fashion. This simplified design allows easy alterations to the buoyancy chambers and uncomplicated analysis of resulting changes in buoyancy.

  20. Advanced offshore oil platforms

    SciTech Connect

    Ellers, F.S.

    1982-04-01

    Four innovative offshore platforms that are designed to withstand 100-foot waves in waters 600-feet deep are described. These platforms are: (1) Stratfjord B Concrete Gravity-Base Platform; (2) Magnus Steel-Template-Jacket Platform; (3) Hutton Tension-Leg Platform; and (4) Block 280 Guyed Tower. The Statfjord B platform, designed in Norway, rests on four massive concrete columns with storage tanks at the base. It depends solely on its own mass for stability. The Magnus platform, designed by the British, is the heaviest offshore platform yet fabricated, weighing 41,000 tons. Two of the platform's four legs will incorporate flotation chambers so that the structure can be floated to its site in the North Sea. The Hutton structure, also designed in England, will consist of a buoyant hull tethered to the sea floor by slender steel tubes at its four corners. The first platform of its type, the Hutton structure is also destined for the North Sea. The US designed Block 280 guyed tower is designed for service in the Gulf of Mexico in water 1000 feet deep. It will be pinned to the sea floor by a spokelike array of 20 steel cables, each one more than 3000 feet long. The tower and its guys will weigh 43,000 tons, slightly more than the Magnus steel-template jacket and more than four time as much as the Eiffel Tower. At a cost of approximately $2.6 billion, the Magnus is the most expensive offshore platform to date. The Statfjord B was put into production in 1982. The Magnus is scheduled for oil production in 1983. The Hutton and the Block 280 will both be producing in 1984. (JMT)

  1. Characterization of polyacrylamide based monolithic columns.

    PubMed

    Plieva, Fatima M; Andersson, Jonatan; Galaev, Igor Yu; Mattiasson, Bo

    2004-07-01

    Supermacroporous monolithic polyacrylamide (pAAm)-based columns have been prepared by radical cryo-copolymerization (copolymerization in the moderately frozen system) of acrylamide with functional co-monomer, allyl glycidyl ether (AGE), and cross-linker N,N'-methylene-bis-acrylamide (MBAAm) directly in glass columns (ID 10 mm). The monolithic columns have uniform supermacroporous sponge-like structure with interconnected supermacropores of pore size 5-100 microm. The monoliths can be dried and stored in the dry state. High mechanical stability of the monoliths allowed sterilization by autoclaving. Column-to-column reproducibility of pAAm-monoliths was demonstrated on 5 monolithic columns from different batches prepared under the same cryostructuration conditions.

  2. Characterization of polyacrylamide based monolithic columns.

    PubMed

    Plieva, Fatima M; Andersson, Jonatan; Galaev, Igor Yu; Mattiasson, Bo

    2004-07-01

    Supermacroporous monolithic polyacrylamide (pAAm)-based columns have been prepared by radical cryo-copolymerization (copolymerization in the moderately frozen system) of acrylamide with functional co-monomer, allyl glycidyl ether (AGE), and cross-linker N,N'-methylene-bis-acrylamide (MBAAm) directly in glass columns (ID 10 mm). The monolithic columns have uniform supermacroporous sponge-like structure with interconnected supermacropores of pore size 5-100 microm. The monoliths can be dried and stored in the dry state. High mechanical stability of the monoliths allowed sterilization by autoclaving. Column-to-column reproducibility of pAAm-monoliths was demonstrated on 5 monolithic columns from different batches prepared under the same cryostructuration conditions. PMID:15354560

  3. REDISTRIBUTOR FOR LIQUID-LIQUID EXTRACTION COLUMNS

    DOEpatents

    Bradley, J.G.

    1957-10-29

    An improved baffle plate construction to intimately mix immiscible liquid solvents for solvent extraction processes in a liquid-liquid pulse column is described. To prevent the light and heavy liquids from forming separate continuous homogeneous vertical channels through sections of the column, a baffle having radially placed rectangular louvers with deflection plates opening upon alternate sides of the baffle is placed in the column, normal to the axis. This improvement substantially completely reduces strippiig losses due to poor mixing.

  4. Distillation of light hydrocarbons in packed columns

    SciTech Connect

    Strigle, R.F.

    1985-04-01

    Newly developed design procedures have led to a wider acceptance of packed columns for distillation operations, especially those operating at atmospheric or higher pressures. Based on these new design methods, modern IMTP packing has been used in a wide variety of services to revamp over 300 distillation columns previously equipped with trays. A few of these columns are listed. These revamps were justified by capacity increase and by greater product recovery. In addition, energy savings were realized from reduction of reflux ratio.

  5. Interstitial gas effect on vibrated granular columns

    NASA Astrophysics Data System (ADS)

    Pastenes, Javier C.; Géminard, Jean-Christophe; Melo, Francisco

    2014-06-01

    Vibrated granular materials have been intensively used to investigate particle segregation, convection, and heaping. We report on the behavior of a column of heavy grains bouncing on an oscillating solid surface. Measurements indicate that, for weak effects of the interstitial gas, the temporal variations of the pressure at the base of the column are satisfactorily described by considering that the column, despite the observed dilation, behaves like a porous solid. In addition, direct observation of the column dynamics shows that the grains of the upper and lower surfaces are in free fall in the gravitational field and that the dilation is due to a small delay between their takeoff times.

  6. Soil column leaching of pesticides.

    PubMed

    Katagi, Toshiyuki

    2013-01-01

    In this review, I address the practical and theoretical aspects of pesticide soil mobility.I also address the methods used to measure mobility, and the factors that influence it, and I summarize the data that have been published on the column leaching of pesticides.Pesticides that enter the unsaturated soil profile are transported downwards by the water flux, and are adsorbed, desorbed, and/or degraded as they pass through the soil. The rate of passage of a pesticide through the soil depends on the properties of the pesticide, the properties of the soil and the prevailing environmental conditions.Because large amounts of many different pesticides are used around the world, they and their degradates may sometimes contaminate groundwater at unacceptable levels.It is for this reason that assessing the transport behavior and soil mobility of pesticides before they are sold into commerce is important and is one indispensable element that regulators use to assess probable pesticide safety. Both elementary soil column leaching and sophisticated outdoor lysimeter studies are performed to measure the leaching potential for pesticides; the latter approach more reliably reflects probable field behavior, but the former is useful to initially profile a pesticide for soil mobility potential.Soil is physically heterogeneous. The structure of soil varies both vertically and laterally, and this variability affects the complex flow of water through the soil profile, making it difficult to predict with accuracy. In addition, macropores exist in soils and further add to the complexity of how water flow occurs. The degree to which soil is tilled, the density of vegetation on the surface, and the type and amounts of organic soil amendments that are added to soil further affect the movement rate of water through soil, the character of soil adsorption sites and the microbial populations that exist in the soil. Parameters that most influence the rate of pesticide mobility in soil are

  7. Effect of column dimension on observed column efficiency in very high pressure liquid chromatography.

    PubMed

    Wu, Naijun; Bradley, Ashley C

    2012-10-26

    The effect of extra-column volume on observed linear velocity was investigated for columns of various internal diameters in very high pressure liquid chromatography. The results showed that the observed linear velocities were approximately 4.5, 9.5, 16.8, and 39.5% lower than the linear velocities corrected for the extra-column volume contribution for 4.6, 3.0, 2.1, and 1.0mm internal diameter columns, respectively. An empirical relationship between extra-column band broadening and extra-column volume was obtained using 50 cm long tubings of various internal diameters. The peak variance from the extra-column volume is near linearly proportional to the square of the extra-column volume for tubings with 0.0635-0.178 mm (0.025-0.07 in.) i.d. using a 50/50 acetonitrile/water mobile phase at flow rates greater than 0.3 mL/min. The effect of column internal diameter and column length on observed efficiency was studied using 50mm columns with four different column internal diameters and 2.1mm i.d columns with three different lengths. The results showed that the observed column efficiencies for 3.0, 2.1, and 1.0mm internal diameter columns were 18, 33, and 73% lower than that for a 4.6mm internal diameter column for benzophenone (k=5.5), respectively. An approximate 20% decrease in theoretical plate number was observed for propiophenone (k=3.3) using a 50 mm × 2.1 mm column packed with 1.7 μm particles compared to a 150 mm × 2.1 mm column packed with 5.0 μm particles, while the former column provided 9 fold faster separation. It is the column to extra column volume ratio instead of absolute extra-column volume that determines the degree of extra-column band-broadening in VHPLC.

  8. Flotation and flocculation chemistry of coal and oxidized coals: Technical progress report, June 15, 1988--September 15, 1988

    SciTech Connect

    Somasundaran, P.

    1988-01-01

    This project is designed to develop an understanding of the fundamentals involved in flotation and flocculation chemistry of coal, and of coal in various states of oxidation. The main objective of this study is to elucidate mechanisms by which surface interactions between coal and various reagents enhance the benefication of coal. The effect of oxidation on the modification of surface characteristics of coal will also be studied. 1 ref., 7 figs.

  9. Optimal operation of multivessel batch distillation columns

    SciTech Connect

    Furlonge, H.I.; Pantelides, C.C.; Soerensen, E.

    1999-04-01

    Increased interest in unconventional batch distillation column configurations offers new opportunities for increasing the flexibility and energy efficiency of batch distillation. One configuration of particular interest is the multivessel column, which can be viewed as a generalization of all previously studied batch column configurations. A detailed dynamic model was used for comparing various optimal operating policies for a batch distillation column with two intermediate vessels. A wide variety of degrees of freedom including reflux ratios, product withdrawal rates, heat input to the reboiler, and initial feed distribution were considered. A mixture consisting of methanol, ethanol, n-propanol and n-butanol was studied using an objective function relating to the economics of the column operation. Optimizing the initial distribution of the feed among the vessels improved column performance significantly. For some separations, withdrawing product from the vessels into accumulators was better than total reflux operation in terms of energy consumption. Open-loop optimal operation was also compared to a recently proposed feedback control strategy where the controller parameters are optimized. The energy consumption of a regular column was about twice that of a multivessel column having the same number of stages.

  10. Circulation in gas-slurry column reactors

    SciTech Connect

    Clark, N.; Kuhlman, J.; Celik, I.; Gross, R.; Nebiolo, E.; Wang, Yi-Zun.

    1990-08-15

    Circulation in bubble columns, such as those used in fischer-tropsch synthesis, detracts from their performance in that gas is carried on average more rapidly through the column, and the residence time distribution of the gas in the column is widened. Both of these factors influence mass-transfer operations in bubble columns. Circulation prediction and measurement has been undertaken using probes, one-dimensional models, laser Doppler velocimetry, and numerical modeling. Local void fraction was measured using resistance probes and a newly developed approach to determining air/water threshold voltage for the probe. A tall column of eight inch diameter was constructed of Plexiglas and the distributor plate was manufactured to distribute air evenly through the base of the column. Data were gathered throughout the volume at three different gas throughputs. Bubble velocities proved difficult to measure using twin probes with cross-correlation because of radial bubble movement. A series of three-dimensional mean and RMS bubble and liquid velocity measurements were also obtained for a turbulent flow in a laboratory model of a bubble column. These measurements have been made using a three-component laser Doppler velocimeter (LDV), to determine velocity distributions non-intrusively. Finally, the gas-liquid flow inside a vertically situated circular isothermal column reactor was simulated numerically. 74 refs., 170 figs., 5 tabs.

  11. Modeling of column apparatuses: A review

    SciTech Connect

    Doichinova, M. E-mail: petyabs@yahoo.com; Popova-Krumova, P. E-mail: petyabs@yahoo.com

    2013-12-18

    This paper presents a review of the modeling method on the base of the physical approximations of the mechanics of continua, which have been developed for processes in column apparatuses. This method includes diffusion type of model for modeling of mass transfer with chemical reaction in column apparatuses with and without circulation zones. The diffusion type of model is used for modeling of scale effect in column apparatuses too. The study concluded that the proposal method is possibility for investigation the influence of radial non uniformity of the velocity distribution on the process efficiency, influence of zones breadths on the mass transfer efficiency in the column. The method of the column apparatuses modeling can be used for modeling of physical and chemical absorption, chemical adsorption, homogeneous and heterogeneous (catalytic) chemical reactions, airlift reactors for chemical and photochemical reactions.

  12. POC-scale testing of an advanced fine coal dewatering equipment/technique: Quarterly technical progress report No. 9, October 1996--December 1996

    SciTech Connect

    Tao, D.; Groppo, J.G.; Parekh, B.K.

    1997-01-21

    The advanced fine-coal cleaning techniques such as column flotation, recovers a low-ash ultra-fine size clean-coal product. However, economical dewatering of the clean coal product to less than 20 percent moisture using conventional technology is difficult. This research program objective is to evaluate a novel coal surface modification technique developed at the University of Kentucky Center for Applied Energy Research in conjunction with conventional and advanced dewatering technique at a pilot scale at the Powell Mountain Coal Company`s Mayflower preparation plant located in St. Charles, VA. During this quarter in the laboratory dewatering studies were conducted using copper and aluminum ions showed that for the low sulfur clean coal slurry addition of 0.1 Kg/t of copper ions was effective in lowering the filter cake moisture from 29 percent to 26.3 percent. Addition of 0.3 Kg/t of aluminum ions provided filter cake with 28 percent moisture. For the high sulfur clean coal slurry 0.5 Kg/t of copper and 0.1 Kg/t of aluminum ions reduced cake moisture from 30.5 percent to 28 percent respectively. Combined addition of anionic (10 g/t) and cationic (10 g/t) flocculants was effective in providing a filter cake with 29.8 percent moisture. Addition of flocculants was not effective in centrifuge dewatering. In pilot scale screen bowl centrifuge dewatering studies it was found that the clean coal slurry feed rate of 30 gpm was optimum to the centrifuge, which provided 65 percent solids capture. Addition of anionic or cationic flocculants was not effective in lowering of filter cake moisture, which remained close to 30 percent for both clean coal slurries.

  13. Methodology for optimally sized centrifugal partition chromatography columns.

    PubMed

    Chollet, Sébastien; Marchal, Luc; Jérémy Meucci; Renault, Jean-Hugues; Legrand, Jack; Foucault, Alain

    2015-04-01

    Centrifugal Partition Chromatography (CPC) is a separation process based on the partitioning of solutes between two partially miscible liquid phases. There is no solid support for the stationary phase. The centrifugal acceleration is responsible for both stationary phase retention and mobile phase dispersion. CPC is thus a process based on liquid-liquid mass transfer. The separation efficiency is mainly influenced by the hydrodynamics of the phases in each cell of the column. Thanks to a visualization system, called "Visual CPC", it was observed that the mobile phase can flow through the stationary phase as a sheet, or a spray. Hydrodynamics, which directly governs the instrument efficiency, is directly affected during scale changes, and non-linear phenomena prevent the successful achievement of mastered geometrical scale changes. In this work, a methodology for CPC column sizing is proposed, based on the characterization of the efficiency of advanced cell shapes, taking into account the hydrodynamics. Knowledge about relationship between stationary phase volume, cell efficiency and separation resolution in CPC allowed calculating the optimum cell number for laboratory and industrial scale CPC application. The methodology is highlighted with results on five different geometries from 25 to 5000 mL, for two applications: the separation of alkylbenzene by partitioning with heptane/methanol/water biphasic system; and the separation of peptides by partitioning with n-butanol/acetic acid/water (4/1/5) biphasic system. With this approach, it is possible to predict the optimal CPC column length leading to highest productivity.

  14. Highly efficient capillary columns packed with superficially porous particles via sequential column packing.

    PubMed

    Treadway, James W; Wyndham, Kevin D; Jorgenson, James W

    2015-11-27

    Highly efficient capillary columns packed with superficially porous particles were created for use in ultrahigh pressure liquid chromatography. Superficially porous particles around 1.5μm in diameter were packed into fused silica capillary columns with 30, 50, and 75μm internal diameters. To create the columns, several capillary columns were serially packed from the same slurry, with packing progress plots being generated to follow the packing of each column. Characterization of these columns using hydroquinone yielded calculated minimum reduced plate heights as low as 1.24 for the most efficient 30μm internal diameter column, corresponding to over 500,000plates/m. At least one highly efficient column (minimum reduced plate height less than 2) was created for all three of the investigated column inner diameters, with the smallest diameter columns having the highest efficiency. This study proves that highly efficient capillary columns can be created using superficially porous particles and shows the efficiency potential of these particles.

  15. Comparative evaluation of flotation techniques for the detection of soil borne parasites.

    PubMed

    V Gnani Charitha; V C Rayulu; P M Kondaiah; Ch Srilatha

    2013-10-01

    Efficacy of the three conventional flotation techniques in recovering the parasitic forms from soil samples was compared after screening both naturally contaminated and experimentally seeded soil samples. Out of 200 soil samples screened from different locations of Rayalaseema region of Andhra Pradesh, parasitic stages were isolated in 62 (31.0 %), 32 (16.0 %) and 16 (8.0 %) samples by O'Lorcain (J Helminthol, 68:237-241,1994), Kazakos (Am J Vet Res 44:896-900, 1983) and Santarém et al. (Rev Inst Med trop Sao Paulo 51(3):163-167, 2009) methods, respectively. One hundred and forty-four soil samples were seeded with two different concentrations (100/200) of the eggs of Toxocara spp., Ascaris spp. and Ancylostoma spp. and oocysts of Eimeria spp. and were processed by these techniques. Irrespective of parasitic species or concentration, the mean recovery rate of parasitic stages obtained was above 50 ± 4.32, above 33.67 ± 5.084 and below 22.33 ± 2.37 percent by O'Lorcain (1994), Kazakos (1983) and Santarém et al. (2009) methods, respectively. O'Lorcain (1994) method was found better than the other methods for the isolation of soil borne parasitic stages but none of these methods were found to be cent per cent sensitive. PMID:24431580

  16. Electrochemical pretreatment of recycled water in flotation of non-sulfide and diamond-containing ores

    SciTech Connect

    Chanturiya, V.A.; Trofimova, E.A.; Dvoichenkova, G.P.; Zaskevich, M.V.

    1995-12-31

    The paper presents theoretical and practical aspects of directed adjustment of the physicochemical properties (pH,Eh) and ion composition of recycle and mine water by an electrochemical treatment. Treatment is run in diaphragm-type conditioners with production of alkaline catholyte of pH value up to 12 and acidic anolyte of pH up to 2. In the process of water electrolysis the directed motion of Mg{sup 2+} and Ca{sup 2+} ions is observed from anode volume to cathode one, where they precipitate as hydroxides and carbonates; it leads to a decrease of salt content in anolyte and catholyte. The results of experimental and industrial testing of the electrochemical technique for mine and recycle water in flotation of diamond-containing and sulfide-scheelite, hematite, phosphorite, apatite-nephelite, bauxite ores indicated the increase of recovery up to 2--15% and grade up to 0.5--2%, concurrent with a decrease of reagent consumption from 15 to 50%. Modules of industrial conditioners of different type capacity have been developed.

  17. Factors affecting degradation of polyethylene terephthalate (PET) during pre-flotation conditioning

    SciTech Connect

    Caparanga, Alvin R. Basilia, Blessie A.; Dagbay, Kevin B.; Salvacion, Jonathan W.L.

    2009-09-15

    In general, plastics are exposed to different degrading agents in every procedure involved in their recovery from waste mixture and from subsequent recycling. In this study, two methods of pre-flotation conditioning were used to determine how these methods affect the general properties of the pre-conditioned PET particles to be recovered from the PET-PVC mixture. The first method comprised the conditioning of PET samples using an alkaline solution of nonionic surfactant (Triton X-100) based on the patent by the Goodyear Tire and Rubber Company. The second method, developed in this study, was a conditioning process which used an alkali-less solution of the same nonionic surfactant (Triton X-100) used in the first method. The following analytical methods were used to characterize properties of the pre-conditioned PET samples that were correlated to relative degradation of the samples: differential scanning calorimetry (DSC), for thermal behavior of the samples; FT-IR spectroscopy, for functional groups present in the samples; and, Pohl's method, for carboxyl end-group concentration count. Results show that in addition to water the presence of NaOH in the conditioning solution contributes to the further degradation of the polymer.

  18. Critical evaluation and modeling of algal harvesting using dissolved air flotation. DAF Algal Harvesting Modeling

    SciTech Connect

    Zhang, Xuezhi; Hewson, John C.; Amendola, Pasquale; Reynoso, Monica; Sommerfeld, Milton; Chen, Yongsheng; Hu, Qiang

    2014-07-14

    In our study, Chlorella zofingiensis harvesting by dissolved air flotation (DAF) was critically evaluated with regard to algal concentration, culture conditions, type and dosage of coagulants, and recycle ratio. Harvesting efficiency increased with coagulant dosage and leveled off at 81%, 86%, 91%, and 87% when chitosan, Al3+, Fe3+, and cetyl trimethylammonium bromide (CTAB) were used at dosages of 70, 180, 250, and 500 mg g-1, respectively. The DAF efficiency-coagulant dosage relationship changed with algal culture conditions. In evaluating the influence of the initial algal concentration and recycle ratio revealed that, under conditions typical for algal harvesting, we found that it is possible that the number of bubbles is insufficient. A DAF algal harvesting model was developed to explain this observation by introducing mass-based floc size distributions and a bubble limitation into the white water blanket model. Moreover, the model revealed the importance of coagulation to increase floc-bubble collision and attachment, and the preferential interaction of bubbles with larger flocs, which limited the availability of bubbles to the smaller sized flocs. The harvesting efficiencies predicted by the model agree reasonably with experimental data obtained at different Al3+ dosages, algal concentrations, and recycle ratios. Based on this modeling, critical parameters for efficient algal harvesting were identified.

  19. Compliance with an Ordinance Requiring the Use of Personal Flotation Devices by Children in Public Waterways

    PubMed Central

    Wintemute, Garen J.; Anton, Amy; Andrada, Emily; Ribeira, Ryan

    2013-01-01

    Introduction: For children ages 1–14, 21.6% of drowning cases involve swimming, wading, or playing in natural bodies of water, such as rivers and lakes. Personal flotation devices (PFDs) are believed to be an effective prevention measure. We measure compliance with city and county ordinances, publicized but not actively enforced, requiring that PFDs be worn by children accessing public bodies of water in Sacramento County, California. Methods: During June–August 2010, volunteers conducted 79 observation sessions at three popular local river beaches where PFDs were available for use at no cost. They recorded personal characteristics and PFD use for 1,727 children in or very near the water and believed to be 0–13 years of age (the age covered by the ordinances). We used logistic regression to quantify differences in use by subject characteristics and study site. Results: The prevalence of PFD use was 29.9% overall, with large and significant differences by age: < 1, 55.6%; 1–4, 37.6%; 5–10, 29.4%; 10–13, 14.6%; P < 0.0001. Usage did not vary significantly by sex or race/ethnicity, and was somewhat higher at one study site (33.1%) than at the others (25.9% and 27.3%), P = 0.009. Conclusion: The combination of a statutory requirement and a cost-elimination strategy was associated with moderate rates of PFD use that were highest among young children. PMID:23599870

  20. Flotation process for removal of precipitates from electrochemical chromate reduction unit

    DOEpatents

    DeMonbrun, James R.; Schmitt, Charles R.; Williams, Everett H.

    1976-01-01

    This invention is an improved form of a conventional electrochemical process for removing hexavalent chromium or other metal-ion contaminants from cooling-tower blowdown water. In the conventional process, the contaminant is reduced and precipitated at an iron anode, thus forming a mixed precipitate of iron and chromium hydroxides, while hydrogen being evolved copiously at a cathode is vented from the electrochemical cell. In the conventional process, subsequent separation of the fine precipitate has proved to be difficult and inefficient. In accordance with this invention, the electrochemical operation is conducted in a novel manner permitting a much more efficient and less expensive precipitate-recovery operation. That is, the electrochemical operation is conducted under an evolved-hydrogen partial pressure exceeding atmospheric pressure. As a result, most of the evolved hydrogen is entrained as bubbles in the blowdown in the cell. The resulting hydrogen-rich blowdown is introduced to a vented chamber, where the entrained hydrogen combines with the precipitate to form a froth which can be separated by conventional techniques. In addition to the hydrogen, two materials present in most blowdown act as flotation promoters for the precipitate. These are (1) air, with which the blowdown water becomes saturated in the course of normal cooling-tower operation, and (2) surfactants which commonly are added to cooling-tower recirculating-water systems to inhibit the growth of certain organisms or prevent the deposition of insoluble particulates.

  1. Oxidation of aniline aerofloat in flotation wastewater by sodium hypochlorite solution.

    PubMed

    Lin, Weixiong; Tian, Jing; Ren, Jie; Xu, Pingting; Dai, Yongkang; Sun, Shuiyu; Wu, Chun

    2016-01-01

    Aniline aerofloat (dianilinodithiophosphoric acid (C6H5NH)2PSSH) is a widely used phosphorodithioic organic flotation collector that contains aniline groups and dithiophosphate groups. In the present study, sodium hypochlorite solution was used to oxidize aniline aerofloat. The effect of operational parameters and optimum oxidation conditions on aniline aerofloat was studied, and the oxidation pathway of aniline aerofloat was proposed by analyzing its main oxidation intermediates. The results showed that NaOCl concentration had a significant influence on aniline aerofloat oxidation and at 100 mg/L aniline aerofloat, 84.54% was removed under the following optimal conditions: NaOCl concentration = 1.25 g/L, pH = 4, and reaction time = 60 min. The main reaction of aniline aerofloat by NaOCl included N-P bond cleavage, aniline group oxidation, aniline group chlorination, and dithiophosphate group oxidation. The initial reaction was the N-P bond cleavage and the anilines and dithiophosphate was further oxidized to other intermediates by five parallel reaction pathways.

  2. Effects of waterbed flotation on indicators of energy expenditure in preterm infants.

    PubMed

    Deiriggi, P M

    1990-01-01

    The purpose of this investigation was to study the effects of nonoscillating waterbeds on three indices of energy expenditure: activity level, heart rate, and behavioral state. Subjects were 22 healthy preterm infants in a neonatal intensive care unit who had reached 31-35 weeks postconceptional age, and whose average weight was 1,482 grams at the onset of the study. Infants were placed on a waterbed for 3 consecutive days and on a standard incubator mattress for 3 consecutive days. Infants served as their own controls on and off the waterbed. Treatment order was randomly counterbalanced. One-hour observations of activity and state occurring in conjunction with heartbeat counts were the repeated measures on each day over both treatment and control conditions. Infants experienced longer durations of quiet sleep, less active awake and fuss states, and fewer state changes and awakenings while on the waterbed. Heart rates were higher after infants were taken off the waterbed. The findings suggest that nonoscillating waterbed flotation is a simple, cost-effective intervention that reduces energy expenditure.

  3. Use of balloon flotation pacing catheters for prophylactic temporary pacing during diagnostic and therapeutic catheterization procedures.

    PubMed

    Harvey, J R; Wyman, R M; McKay, R G; Baim, D S

    1988-11-01

    The use of prophylactic temporary pacemakers during diagnostic catheterization, coronary angioplasty and percutaneous balloon valvuloplasty was investigated retrospectively over an 18-month period. Balloon flotation temporary pacemaker leads were placed in 193 (12%) of 1,609 patients undergoing diagnostic catheterization, 641 (65%) of 993 patients undergoing coronary angioplasty and 199 (100%) of 199 patients undergoing aortic or mitral valvuloplasty. There were no perforations or significant arrhythmic complications related to pacemaker placement in these 1,033 cases, and pacing was initiated promptly when required by withdrawal of the catheter tip into the right ventricle. Significant bradycardia or new conduction defects developed in 17 patients (1%) during diagnostic catheterization, 10 patients (1%) during angioplasty and 20 patients (10%) during valvuloplasty, but were severe enough to require initiation of temporary pacing in only 1 (0.06%), 4 (0.4%) and 5 (2.5%) patients, respectively. No patient undergoing diagnostic catheterization or angioplasty (but 5 patients undergoing valvuloplasty) required immediate pacing support to treat a life-threatening bradycardia. The total cost of prophylactic pacemakers was $103,300, with a cost per actual use of $19,300 for diagnostic cases, $16,025 for angioplasty and $3,980 for balloon valvuloplasty. These data suggest that prophylactic temporary pacing is not indicated during either diagnostic catheterization or coronary angioplasty, but should be used routinely during balloon valvuloplasty.

  4. A case study of dissolved air flotation for seasonal high turbidity water in Korea.

    PubMed

    Kwon, S B; Ahn, H W; Ahn, C J; Wang, C K

    2004-01-01

    A DAF (Dissolved-Air-Flotation) process has been designed considering raw water quality characteristics in Korea. Although direct filtration is usually operated, DAF is operated when freshwater algae blooms occur or raw water turbidity becomes high. Pre-sedimentation is operated in case when the raw water turbidity is very high due to rainstorms. A main feature of this plant is that the operation mode can be changed (controlled) based on the characteristics of the raw water to optimize the effluent quality and the operation costs. Treatment capacity (surface loading rate) and efficiency of DAF was found to be better than the conventional sedimentation process. Moreover, low-density particles (algae and alum flocs) are easily separated while the removal of them by sedimentation is more difficult. One of the main concerns for DAF operation is a high raw water turbidity. DAF is not adequate for raw water, which is more turbid than 100 NTU. In order to avoid this problem, pre-sedimentation basins are installed in the DAF plant to decrease the turbidity of the DAF inflow. For simulation of the actual operation, bench and full-scale tests were performed for highly turbid water conditions. Consequently, it is suggested that pre-sedimentation with optimum coagulation prior to DAF is the appropriate treatment scheme.

  5. Introducing economic parameters in industrial flotation dimensionless models used for intra-factory technology transfer

    NASA Astrophysics Data System (ADS)

    Batzias, Dimitris; Ifanti, Konstantina

    2012-12-01

    In this work, intra-factory technology transfer is realized by means of scale-up procedures, including the formation of a representative original set of dimensionless groups, when know-how obtained in the laboratory is transferred progressively (in successive steps) into industrial scale. For saving resources (highly skilled manpower, time, materials, energy) a Knowledge Base (KB) is designed/developed to maintain experience in flotation and select relevant information from other Data/Information/Knowledge Bases. Of significant importance is the introduction of economic parameters referring to investment and operation of the industrial unit, thus taking into account the capital and operating cost of output, respectively. We have proved that this introduction causes several problems since new technological dimensions should be also introduced (so that the economic parameters become meaningful) resulting by dimensional analysis to a new solution set that is incompatible to the original one. We solved this problem by keeping the original set and incorporating into it only the new dimensionless groups (eliminating all additional technological dimensions introduced ad hoc).

  6. The influence of reagent type on the kinetics of ultrafine coal flotation

    USGS Publications Warehouse

    Read, R.B.; Camp, L.R.; Summers, M.S.; Rapp, D.M.

    1989-01-01

    A kinetic study has been conducted to determine the influence of reagent type on flotation rates of ultrafine coal. Two ultrafine coal samples, the Illinois No. 5 (Springfield) and Pittsburgh No. 8, have been evaluated with various reagent types in order to derive the rate constants for coal (kc), ash (ka), and pyrite (kc). The reagents used in the study include anionic surfactants, anionic surfactant-alcohol mixtures, and frothing alcohols. In general, the surfactant-alcohol mixtures tend to float ultrafine coal at a rate three to four times faster than either pure alcohols or pure anionic surfactants. Pine oil, a mixture of terpene alcohols and hydrocarbons, was an exception to this finding; it exhibited higher rate constants than the pure aliphatic alcohols or other pure anionic surfactants studied; this may be explained by the fact that the sample of pine oil used (70% alpha-terpineol) acted as a frother/collector system similar to alcohol/kerosene. The separation efficiencies of ash and pyrite from coal, as evidenced by the ratios of kc/ka or kc/kp, tend to indicate, however, that commercially available surfactant-alcohol mixtures are not as selective as pure alcohols such as 2-ethyl-1-hexanol or methylisobutylcarbinol. Some distinct differences in various rate constants, or their ratios, were noted between the two coals studied, and are possibly attributable to surface chemistry effects. ?? 1989.

  7. Critical evaluation and modeling of algal harvesting using dissolved air flotation. DAF Algal Harvesting Modeling

    DOE PAGES

    Zhang, Xuezhi; Hewson, John C.; Amendola, Pasquale; Reynoso, Monica; Sommerfeld, Milton; Chen, Yongsheng; Hu, Qiang

    2014-07-14

    In our study, Chlorella zofingiensis harvesting by dissolved air flotation (DAF) was critically evaluated with regard to algal concentration, culture conditions, type and dosage of coagulants, and recycle ratio. Harvesting efficiency increased with coagulant dosage and leveled off at 81%, 86%, 91%, and 87% when chitosan, Al3+, Fe3+, and cetyl trimethylammonium bromide (CTAB) were used at dosages of 70, 180, 250, and 500 mg g-1, respectively. The DAF efficiency-coagulant dosage relationship changed with algal culture conditions. In evaluating the influence of the initial algal concentration and recycle ratio revealed that, under conditions typical for algal harvesting, we found that itmore » is possible that the number of bubbles is insufficient. A DAF algal harvesting model was developed to explain this observation by introducing mass-based floc size distributions and a bubble limitation into the white water blanket model. Moreover, the model revealed the importance of coagulation to increase floc-bubble collision and attachment, and the preferential interaction of bubbles with larger flocs, which limited the availability of bubbles to the smaller sized flocs. The harvesting efficiencies predicted by the model agree reasonably with experimental data obtained at different Al3+ dosages, algal concentrations, and recycle ratios. Based on this modeling, critical parameters for efficient algal harvesting were identified.« less

  8. [Treatment of high algae-laden water by step-recycle counter current flotation].

    PubMed

    Wang, Yu-Heng; Wang, Qi-Shan; Wu, Yu-Bao; Yue, Lin; Yang, Jian-Kang

    2008-11-01

    High algae-laden water was treated respectively by single-recycle and step-recycle counter current flotation. The results indicate that step-recycle mode of dissolved air water can strengthen capturing of bubbles and flocs association suspension bed, and extend the collision time of smaller flee and bubble because of reducing the thickness of suspension bed and increasing that of transition bed. Given the condition that other parameters were same, the biggest hydraulic loading of single-recycle could reach 11 m/h, and that of step-recycle could reach 17 m/h which is increased by 50%. Efficiency of treatment was improved by a large margin. The recycle ratio of two releasers and position of the pensile releaser influenced removal effect remarkably. The distance between settled releaser and inlet of raw water is 180 cm, and the range of distance between pensile releaser and inlet of raw water is 60-90 cm. The flow of pensile releaser is 2-3 times as much as settled releaser.

  9. Removal of natural organic matter and arsenic from water by electrocoagulation/flotation continuous flow reactor.

    PubMed

    Mohora, Emilijan; Rončević, Srdjan; Dalmacija, Božo; Agbaba, Jasmina; Watson, Malcolm; Karlović, Elvira; Dalmacija, Milena

    2012-10-15

    The performance of the laboratory scale electrocoagulation/flotation (ECF) reactor in removing high concentrations of natural organic matter (NOM) and arsenic from groundwater was analyzed in this study. An ECF reactor with bipolar plate aluminum electrodes was operated in the horizontal continuous flow mode. Electrochemical and flow variables were optimized to examine ECF reactor contaminants removal efficiency. The optimum conditions for the process were identified as groundwater initial pH 5, flow rate=4.3 l/h, inter electrode distance=2.8 cm, current density=5.78 mA/cm(2), A/V ratio=0.248 cm(-1). The NOM removal according to UV(254) absorbance and dissolved organic matter (DOC) reached highest values of 77% and 71% respectively, relative to the raw groundwater. Arsenic removal was 85% (6.2 μg As/l) relative to raw groundwater, satisfying the drinking water standards. The specific reactor electrical energy consumption was 17.5 kWh/kg Al. The specific aluminum electrode consumption was 66 g Al/m(3). According to the obtained results, ECF in horizontal continuous flow mode is an energy efficient process to remove NOM and arsenic from groundwater. PMID:22902131

  10. The cleavage and surface properties of wet and dry ground spodumene and their flotation behavior

    NASA Astrophysics Data System (ADS)

    Zhu, Guangli; Wang, Yuhua; Liu, Xiaowen; Yu, Fushun; Lu, Dongfang

    2015-12-01

    The flotability of wet and dry ground spodumene was found different when sodium oleate was used as a collector, and the flotation recovery of wet ground spodumene was higher than that of dry ground spodumene. It is well known that the flotability of minerals is closely related with their crystal structures and surface properties, therefore morphology and structure examinations on wet and dry ground spodumene were performed by SEM and XRD. It was confirmed that wet ground spodumene had smoother surface and more exposed {1 1 0} and {1 0 0} planes, while more exposed {0 1 0} planes were found on dry ground spodumene surface. The specific surface areas of wet and dry ground spodumene in size fraction of -105 + 38 μm were determined to be 0.252 m2/g and 0.382 m2/g, respectively. However, the maximum adsorption densities of sodium oleate on wet and dry ground spodumene were 21.5 × 10-6 mol/m2 and 12.5 × 10-6 mol/m2, respectively. The densities of surface Alsbnd O broken bonds were calculated to be 6.376 × 1018, 4.351 × 1018 and 14.057 × 1018/m2 for {1 1 0}, {0 1 0} and {1 0 0}, respectively. The result indicated that {1 0 0} and {1 1 0} planes were more favorable for the adsorption of oleic acid ion than {0 1 0} plane.

  11. Microwaves Scattering by Underdense Inhomogeneous Plasma Column

    NASA Astrophysics Data System (ADS)

    Zhang, Lin; Ouyang, Jiting

    2016-03-01

    The scattering characteristics of microwaves (MWs) by an underdense inhomogeneous plasma column have been investigated. The plasma column is generated by hollow cathode discharge (HCD) in a glass tube filled with low pressure argon. The plasma density in the column can be varied by adjusting the discharge current. The scattering power of X-band MWs by the column is measured at different discharge currents and receiving angles. The results show that the column can affect the properties of scattering wave significantly regardless of its plasma frequency much lower than the incident wave frequency. The power peak of the scattering wave shifts away from 0° to about ±15° direction. The finite-different time-domain (FDTD) method is employed to analyze the wave scattering by plasma column with different electron density distributions. The reflected MW power from a metal plate located behind the column is also measured to investigate the scattering effect on reducing MW reflectivity of a metal target. This study is expected to deepen the understanding of plasma-electromagnetic wave interaction and expand the applications concerning plasma antenna and plasma stealth.

  12. Mechanical interactions of UIS support columns. [LMFBR

    SciTech Connect

    Kennedy, J.M.; Belytschko, T.B.

    1983-01-01

    Code development involving above-core structures (ACS) has recently focused on modeling the complexities of mechanical interactions in the ACS support columns which play a very important role in their behavior. These developments are directed toward two considerations: (1) the prediction of the forces exerted by the column in a hypothetical core-disruptive accident (HCDA) in order that the motion of the ACS can be predicted in a coupled fluid-structure analysis, (2) the calculation of the strains and deformations of the support columns so that situations which lead to complete failure can be identified. Finite element capabilities have been developed to handle various types of plant design for the analysis of coupled hydrodynamics and structural response. Beam elements, which previously represented the support columns were able to account for geometric nonlinearities and material nonlinearities, however, changes in the column cross section were not treated. Therefore, one of the aims of this study was to examine the effect of the change in cross section on the behavior of the support columns. A second effect which has been studied is the behavior of support columns consisting of two concentric cylinders.

  13. Neural network modeling of distillation columns

    SciTech Connect

    Baratti, R.; Vacca, G.; Servida, A.

    1995-06-01

    Neural network modeling (NNM) was implemented for monitoring and control applications on two actual distillation columns: the butane splitter tower and the gasoline stabilizer. The two distillation columns are in operation at the SARAS refinery. Results show that with proper implementation techniques NNM can significantly improve column operation. The common belief that neural networks can be used as black-box process models is not completely true. Effective implementation always requires a minimum degree of process knowledge to identify the relevant inputs to the net. After background and generalities on neural network modeling, the paper describes efforts on the development of neural networks for the two distillation units.

  14. Removal of copper (II) from aqueous solutions by flotation using polyaluminum chloride silicate (PAX-XL60 S) as coagulant and carbonate ion as activator.

    PubMed

    Ghazy, S E; Mahmoud, I A; Ragab, A H

    2006-01-01

    Flotation is a separation technology for removing toxic heavy metal ions from aqueous solutions. Here a simple and rapid flotation procedure is presented for the removal of copper(II) from aqueous solutions. It is based on the use of polyaluminum chloride silicate (PAX-XL60 S) as coagulant and flocculent, carbonate ion as activator and oleic acid (HOL) as surfactant. Both ion and precipitate flotation are included depending on the solution pH. Ion and precipitate flotation in the aqueous HOL-PAX-XL60 S-Cu2+-CO3(2-) system gave powerful preferential removal of Cu2+ (F -100%) over the HOL-PAX-XL60 S-Cu2+ system containing no CO3(2+) ion (F approximately 86%). The role of CO3(2-) ion is also evident from decreasing the dose of PAX-XL60 S from 700 mg l(-1) to 200 mg l(-1). The other parameters, influencing the flotation process, namely: metal ion, surfactant and PAX-XL60 S concentrations, ionic strength, temperature and foreign ions were examined. Moreover, the procedure was successfully applied to recover Cu2+ ions from different volumes up to 11 and from natural water samples. PMID:16457175

  15. Removal of copper (II) from aqueous solutions by flotation using polyaluminum chloride silicate (PAX-XL60 S) as coagulant and carbonate ion as activator.

    PubMed

    Ghazy, S E; Mahmoud, I A; Ragab, A H

    2006-01-01

    Flotation is a separation technology for removing toxic heavy metal ions from aqueous solutions. Here a simple and rapid flotation procedure is presented for the removal of copper(II) from aqueous solutions. It is based on the use of polyaluminum chloride silicate (PAX-XL60 S) as coagulant and flocculent, carbonate ion as activator and oleic acid (HOL) as surfactant. Both ion and precipitate flotation are included depending on the solution pH. Ion and precipitate flotation in the aqueous HOL-PAX-XL60 S-Cu2+-CO3(2-) system gave powerful preferential removal of Cu2+ (F -100%) over the HOL-PAX-XL60 S-Cu2+ system containing no CO3(2+) ion (F approximately 86%). The role of CO3(2-) ion is also evident from decreasing the dose of PAX-XL60 S from 700 mg l(-1) to 200 mg l(-1). The other parameters, influencing the flotation process, namely: metal ion, surfactant and PAX-XL60 S concentrations, ionic strength, temperature and foreign ions were examined. Moreover, the procedure was successfully applied to recover Cu2+ ions from different volumes up to 11 and from natural water samples.

  16. Multi-Column Experimental Test Bed for Xe/Kr Separation

    SciTech Connect

    Greenhalgh, Mitchell Randy; Garn, Troy Gerry; Welty, Amy Keil; Lyon, Kevin Lawrence; Watson, Tony Leroy

    2015-08-31

    Previous research studies have shown that INL-developed engineered form sorbents are capable of capturing both Kr and Xe from various composite gas streams. The previous experimental test bed provided single column testing for capacity evaluations over a broad temperature range. To advance research capabilities, the employment of an additional column to study selective capture of target species to provide a defined final gas composition for waste storage was warranted. The second column addition also allows for compositional analyses of the final gas product to provide for final storage determinations. The INL krypton capture system was modified by adding an additional adsorption column in order to create a multi-column test bed. The purpose of this modification was to investigate the separation of xenon from krypton supplied as a mixed gas feed. The extra column was placed in a Stirling Ultra-low Temperature Cooler, capable of controlling temperatures between 190 and 253K. Additional piping and valves were incorporated into the system to allow for a variety of flow path configurations. The new column was filled with the AgZ-PAN sorbent which was utilized as the capture medium for xenon while allowing the krypton to pass through. The xenon-free gas stream was then routed to the cryostat filled with the HZ-PAN sorbent to capture the krypton at 191K. Selectivities of xenon over krypton were determined using the new column to verify the system performance and to establish the operating conditions required for multi-column testing. Results of these evaluations verified that the system was operating as designed and also demonstrated that AgZ-PAN exhibits excellent selectivity for xenon over krypton in air at or near room temperature. Two separation tests were performed utilizing a feed gas consisting of 1000 ppmv xenon and 150 ppmv krypton with the balance being made up of air. The AgZ-PAN temperature was held at 295 or 253K while the HZ-PAN was held at 191K for both

  17. The accretion column of AE Aqr

    NASA Astrophysics Data System (ADS)

    Rodrigues, Claudia; Costa, D. Joaquim; Luna, Gerardo; Lima, Isabel J.; Silva, Karleyne M. G.; De Araujo, Jose Carlos N.; Coelho, Jaziel

    2016-07-01

    AE Aqr is a magnetic cataclysmic variable, whose white dwarf rotates at the very fast rate of 33 s modulating the flux from high-energies to optical wavelengths. There are many studies of the origin of its emission, which consider emission from a rotating magnetic field or from an accretion column. Recently, MAGIC observations have discarded AE Aqr emission in very high energy gamma-rays discarding non-thermal emission. Furthermore, soft and hard X-ray data from Swift and NuSTAR were fitted using thermal models. Here we present the modelling of AE Aqr X-ray spectra and light curve considering the emission of a magnetic accretion column using the Cyclops code. The model takes into consideration the 3D geometry of the system, allowing to properly represent the white-dwarf auto eclipse, the pre-shock column absorption, and the varying density and temperature of a tall accretion column.

  18. PRTR ion exchange vault column sampling

    SciTech Connect

    Cornwell, B.C.

    1995-03-14

    This report documents ion exchange column sampling and Non Destructive Assay (NDA) results from activities in 1994, for the Plutonium Recycle Test Reactor (PRTR) ion exchange vault. The objective was to obtain sufficient information to prepare disposal documentation for the ion exchange columns found in the PRTR Ion exchange vault. This activity also allowed for the monitoring of the liquid level in the lower vault. The sampling activity contained five separate activities: (1) Sampling an ion exchange column and analyzing the ion exchange media for purpose of waste disposal; (2) Gamma and neutron NDA testing on ion exchange columns located in the upper vault; (3) Lower vault liquid level measurement; (4) Radiological survey of the upper vault; and (5) Secure the vault pending waste disposal.

  19. A Versatile, Automatic Chromatographic Column Packing Device

    ERIC Educational Resources Information Center

    Barry, Eugene F.; And Others

    1977-01-01

    Describes an inexpensive apparatus for packing liquid and gas chromatographic columns of high efficiency. Consists of stainless steel support struts, an Automat Getriebmotor, and an associated three-pulley system capable of 10, 30, and 300 rpm. (MLH)

  20. Fabrication of Graphite/Epoxy Column Elements

    NASA Technical Reports Server (NTRS)

    Bluck, R. M.; Grotbeck, G. H.; Reighard, W. M.

    1983-01-01

    Dimensionally precise columns wound on vertical mandrels. Dry fiber wound on tapered aluminum mandrel and outer sleeve. Winding and injection done at elevated temperature to minimize thermal-expansion problems during curing of resin. Technique used in textile industry.