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Sample records for reef ore flotation

  1. 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.

  2. 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.

  3. 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.

  4. The impact of bacteria of circulating water on apatite-nepheline ore flotation.

    PubMed

    Evdokimova, G A; Gershenkop, A Sh; Fokina, N V

    2012-01-01

    A new phenomenon has been identified and studied-the impact of bacteria on the benefication process of non-sulphide ores using circulating water supply-a case study of apatite-nepheline ore. It is shown that bacteria deteriorate the floatability of apatite due to their interaction with active centres of calcium-containing minerals and intense flocculation, resulting in a decrease of the flotation process selectivity thus deteriorating the quality of concentrate. Based on the comparative analysis of primary sequences of 16S rRNA genes, there have been identified dominating bacteria species, recovered from the circulating water used at apatite-nepheline concentrating mills, and their phylogenetic position has been determined. All the bacteria were related to γ-Proteobacteria, including the Acinetobacter species, Pseudomonas alcaliphila, Ps. plecoglossicida, Stenotrophomonas rhizophila. A method of non-sulphide ores flotation has been developed with consideration of the bacterial factor. It consists in use of small concentrations of sodium hypochlorite, which inhibits the development of bacteria in the flotation of apatite-nepheline ores.

  5. [Thermoacidophilic micirobial community oxidizing the gold-bearing flotation concentrate of a pyrite-arsenopyrite ore].

    PubMed

    Paniushkina, A E; Tsaplina, I A; Grigor'eva, N V; Kondrat'eva, T F

    2014-01-01

    An aboriginal community of thermophilic acidophilic chemolithotrophic microorganisms (ACM) was isolated from a sample of pyrite gold-bearing flotation concentrateat 45-47 degrees C and pH 1.8-2.0. Compared to an experimental thermoacidophilic microbial consortium formed in the course of cultivation in parallel bioreactors, it had lower rates of iron leaching and oxidation, while its rate of sulfur oxidation was higher. A new thermophilic acidophilic microbial community was obtained by mutual enrichment with the micioorganisms from thie experimental and aboriginal communities during oxidation of sulfide ore flotation concentrate at 47 degrees C. The dominant bacteria of this new ACM community were Acidithiobacillus caldus strains (the most active sulfur oxidizers) and Sulfobacillus thermotolerans strains (active oxidizers of both iron and sulfur), while iron-oxidizing archaea of the family Ferroplasmaceae and heterotrophic bacteria Alicyclobacillus tolerans were the minor components. The new ACM community showed promise for leaching/oxidation of sulfides from flotation concentrates at high pulp density (S:L = 1:4).

  6. 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

  7. 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.

  8. Implementation of reverse flotation method to reduce reactive and non-reactive silica in bauxite ore from West Kalimantan

    NASA Astrophysics Data System (ADS)

    Wulandari, Winny; Purwasasmita, Mubiar; Sanwani, Edy; Pixelina, Adinda Asri; Maulidan, Agus

    2017-01-01

    This paper reports a study that implements reverse flotation method to separate silica from West Kalimantan bauxite ores. The study is aimed to find the good process condition to obtain low-silica bauxite as the feed for the Bayer process. The experiments were carried out in a 1 L of flotation cell tank. Dodecylamine was used as the collector, starch as the depressant, and MIBC as the frother. The varied parameters were solid content to solution (15-30% w/w), and pH (6 - 10). The results of XRF of products show that in all reverse flotation experiments, the ratio of alumina to silica (Al/Si) are increased from 7 up to 14. The increase of solid percentage in the flotation gives a good result for Al/Si ratio as well as alumina and silica recovery in concentrate, with 30% w/w solid percentage to solution increases Al/Si ratio to 14.38, with silica recovery of 20%. The good separation with variation of depressants is obtained with depressant concentration of 400 g/ton bauxite, with Al/Si ratio in concentrate 15 and ratio in tailing 7. For the pH variation, the good condition is obtained at pH 8, while for collector concentration, the good condition is obtained at 200 g/ton bauxite. XRD analysis of the feed indicates that bauxite ore consists of gibbsite, diaspore, kaolinite, halloysite, quartz, boehmite, hematite and rutile. It is found that the concentrate has similar minerals, but halloysite became very minor or classified as a trace.

  9. Effect of carboxymethyl cellulose and ionic strength on stability of mineral suspensions in potash ore flotation systems.

    PubMed

    Pawlik, M; Laskowski, J S; Ansari, A

    2003-04-15

    The adsorption of sodium carboxymethyl cellulose from aqueous solutions varying in ionic strength from that of distilled water to 50% NaCl/KCl brine (about 3.5 mol/dm(3)) onto illite and dolomite has been studied. The purpose of this work was to investigate the solvency effects in the phenomena underlying the potash flotation process that is carried out in saturated brine. Based on viscosity measurements, the adsorption results were analyzed in terms of a simple model of polymer macromolecules in solution. Suspension stability measurements carried out concomitantly with adsorption tests showed the ranges of carboxymethyl cellulose concentration over which the tested suspensions either were aggregated or were restabilized.

  10. The theory of flotation

    NASA Technical Reports Server (NTRS)

    Ostwald, Wolfgang

    1988-01-01

    A brief summary of the fundamentals of the Linear theory of flotation is given. The theory by no means contradicts the previous Laminar theory or even the thermodynamics (Wark-Siedler), rather it is a refinement of the known Hardy-Langmuir-Harkin conceptions for the case when there are not two phases and phase boundaries, but rather three phases and corresponding phase boundary edges. The appearance of such three-phase boundaries (ore, water, air) is characteristic for modern flotation methods.

  11. Phytostabilization of Zn-Pb ore flotation tailings with Dianthus carthusianorum and Biscutella laevigata after amending with mineral fertilizers or sewage sludge.

    PubMed

    Ciarkowska, Krystyna; Hanus-Fajerska, Ewa; Gambuś, Florian; Muszyńska, Ewa; Czech, Tomasz

    2017-03-15

    Zinc-lead mining wastes remain largely unvegetated and prone to erosion for many years because of phytotoxic levels of residual heavy metals, low nutrient status and poor physical structure. The optimal solution for these areas is to restore plant cover using species which spontaneously appear on the spoils. These species are adapted to the conditions of tailings, and their establishment will promote further vegetation by increasing soil organic matter and development of a soil system capable of supporting the nutrient and water requirements of plants and microoorganisms. The potential of Dianthus carthusianorum and Biscutella laevigata to stabilize mine spoils was analysed in a three-year pot experiment. Post-flotation wastes accumulated after Zn and Pb recovery from ores, were collected from tailings and used as a substrate for plant growth. Seeds for seedling production were collected from plants growing spontaneously on mine tailings. Prior to the establishment of the three-year pot experiment, the substrate was amended with fertilizer NPK or municipal sewage sludge, supplemented with K2O (SS). Substrate samples were collected for chemical analyses, dehydrogenase and urease activities measurements each year at the end of the growing season. The plants were harvested three years after the amendments. Both tested plant species were equally suitable for revegetation of the tailings. The amendment including both SS and NPK resulted in an increase of Corg, Nt, available P, K, Mg contents, an increase of dehydrogenase (DHA) and urease activities and a decrease in the concentrations of the soluble forms of Zn, Pb and Cd. However, nutrient content, DHA activity and plant biomass were higher with SS than NPK addition. NPK application enhanced the substrate properties after the first growing season, while positive effects of SS use were still observed after three years. A longer-lasting positive effect of SS than NPK application was probably due to the high organic

  12. Foam flotation

    SciTech Connect

    Clarke, A.N.; Wilson, D.J.

    1983-01-01

    This book is a review of precipitate and absorbing colloid flotation and mathemataical analyses of physical models regarding foam flotation phenomena. Over 800 literature references are cited. Contents include some fluid mechanical aspects of particle flotation, theoretical aspects of particulate flotation, column design considerations, solvent sublation, the future and appendices.

  13. Method and apparatus for column flotation of mineral matter

    SciTech Connect

    Trigg, R.D.

    1990-10-30

    This patent describes a method for the separation of the components of a slurry of ore by froth flotation in a vertically aligned, elongated zone having an upper section, an intermediate section and a lower section. Also described is an apparatus for the separation of components of a slurry of ore by froth flotation.

  14. Adsorption of N-tallow 1,3-propanediamine-dioleate collector on albite and quartz minerals, and selective flotation of albite from greek stefania feldspar ore.

    PubMed

    Vidyadhar, A; Hanumantha Rao, K; Forssberg, K S E

    2002-04-01

    The adsorption behavior of tallow 1,3-propanediamine-dioleate (Duomeen TDO) collector on albite and quartz minerals is assessed through Hallimond flotation, zeta potential, and diffuse reflectance FTIR investigations, together with the species distribution of the collector. The collector performance on albite separation from a natural feldspar material is evaluated in bench scale flotation tests. The Hallimond flotation responses of the minerals as a function of pH and collector concentration indicate that albite can be selectively floated from quartz at pH 2 where the doubly positively charged collector species adsorb on albite but not on quartz. However, the zeta potential and infrared spectra reveal that the adsorption behavior of the collector is similar on both minerals. The discrepancy in the flotation and adsorption results is attributed to the coarse and fine particle size fractions, and the shorter and longer equilibration periods employed in these studies respectively. The comparable adsorption on fine particles of albite and quartz at pH 2 is explained by the interaction of ammonium ions on silanol groups by hydrogen bonding as well as electrostatic interactions. The changes in zeta potentials are in good agreement with the formation of ionic species and free molecular forms of the collector. The IR spectra show the coexistence of neutral oleic acid together with charged amine species at low pH values in accordance with the species distribution diagram. Selective flotation of albite is accomplished from a natural feldspar material with tallow diamine-dioleate collector at pH 2 using sulfuric acid, only when the feed is deslimed prior to the bench scale flotation tests. An albite recovery exceeding 85% is achieved from a feed material containing about 50% albite.

  15. 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.

  16. Column flotation: Processes, designs and practices. Process engineering for the chemical, metals and minerals industry, Volume 2

    SciTech Connect

    Rubinstein, J.B. . Flotation Equipment and Process Engineering Dept.)

    1994-01-01

    Practically all mined ores of non-ferrous and rare metals and an increasing share of industrial minerals and coal are processed through flotation. This book presents the analysis of a wide range of problems in the process theory of flotation columns, including the first published analysis of models of flotation froths. The experience of pilot tests and commercial applications of column flotation for mineral processing and in waste water treatment circuits are also considered. This is the first book to consider column flotation design and operation experience and to present data on column parameters. Topics include: design of flotation columns; aerators in flotation columns; experimental methods of column aerohydrodynamics investigation; aerohydrodynamic characteristics of flotation columns; experimental investigation of the flotation process in columns; kinetics aspects of column flotation; scaling-up methods for flotation columns; structure and mass transfer in flotation froths; column flotation practice; and column flotation control.

  17. Platinum-group elements in the Merensky reef. I. PGE in solid solution in base metal sulfides and the down-temperature equilibration history of Merensky ores

    NASA Astrophysics Data System (ADS)

    Ballhaus, C.; Ryan, C. G.

    1995-12-01

    The platinum-group elements (PGE) in base metal sulfides (BMS) of the Merensky reef are mostly close to the detection limit of the proton microprobe. The only phase that accommodates appreciable PGE is pentlandite. Total average PGE plus Au grades of the sulfide fraction of the Merensky reef are about 500 ppm. We estimate the modal proportions of the major BMS to be around 53 percent pyrrhotite, 25 percent pentlandite, and 22 percent chalcopyrite (ignoring minor phases). Using this estimate, we calculate by how much the sulfides are oversaturated with respect to individual PGE. With respect to Pt, the sulfides are many times oversaturated, i.e., nearly all Pt occurs as discrete PGE phases. With regard to Pd the sulfides are oversaturated by about a factor of two. The Ru and Rh levels are at and below saturation levels. Available experiments suggest that the entire PGE content of the sulfide fraction can easily be accommodated in solid solution in BMS at temperatures as low as 500°C. The fact that the BMS are oversaturated with most PGE thus indicates that the sulfides have continued to exsolve PGE below that temperature. Calculated sulfur fugacities indicate that f S2 is controlled by silica activity, as expected in high-temperature ores, suggesting that metal/sulfur ratios of the ore may not have changed much since complete solidification of the intercumulus silicate melt of the Merensky reef. All sulfides investigated have cooled below the maximum temperature of pentlandite-pyrite coexistence, which experiments place at 250±30°C. Final closure temperatures of the sulfide-PGE mineral assemblages, approximated by extrapolating the pentlandite-pyrrhotite solvus beyond its experimentally determined range, are possibly as low as 80 to 90°C.

  18. Magmatic ore deposits in layered intrusions - Descriptive model for reef-type PGE and contact-type Cu-Ni-PGE deposits

    USGS Publications Warehouse

    Zientek, Michael L.

    2012-01-01

    Layered, ultramafic to mafic intrusions are uncommon in the geologic record, but host magmatic ore deposits containing most of the world's economic concentrations of platinum-group elements (PGE) (figs. 1 and 2). These deposits are mined primarily for their platinum, palladium, and rhodium contents (table 1). Magmatic ore deposits are derived from accumulations of crystals of metallic oxides, or immiscible sulfide, or oxide liquids that formed during the cooling and crystallization of magma, typically with mafic to ultramafic compositions. "PGE reefs" are stratabound PGE-enriched lode mineralization in mafic to ultramafic layered intrusions. The term "reef" is derived from Australian and South African literature for this style of mineralization and used to refer to (1) the rock layer that is mineralized and has distinctive texture or mineralogy (Naldrett, 2004), or (2) the PGE-enriched sulfide mineralization that occurs within the rock layer. For example, Viljoen (1999) broadly defined the Merensky Reef as "a mineralized zone within or closely associated with an unconformity surface in the ultramafic cumulate at the base of the Merensky Cyclic Unit." In this report, we will use the term PGE reef to refer to the PGE-enriched mineralization, not the host rock layer. Within a layered igneous intrusion, reef-type mineralization is laterally persistent along strike, extending for the length of the intrusion, typically tens to hundreds of kilometers. However, the mineralized interval is thin, generally centimeters to meters thick, relative to the stratigraphic thickness of layers in an intrusion that vary from hundreds to thousands of meters. PGE-enriched sulfide mineralization is also found near the contacts or margins of layered mafic to ultramafic intrusions (Iljina and Lee, 2005). This contact-type mineralization consists of disseminated to massive concentrations of iron-copper-nickel-PGE-enriched sulfide mineral concentrations in zones that can be tens to hundreds

  19. Flotation machine

    SciTech Connect

    Zlobin, M.N.; Permyakov, G.P.; Nemarov, A.A.; Metsik, V.M.; Medetsky, J.V.; Taraban, N.T.

    1993-08-10

    A flotation machine is described for beneficiating minerals comprising: a vertical cylindrical chamber for circulating a flotation pulp; a downwardly tapered bottom connected to said vertical cylindrical chamber; feed pipe means for feeding the flotation pulp carrying mineral particles of fine fraction, particles of the useful ingredient of the fine fraction being capable of floating up from the volume of said aerated pulp; discharge pipe means connected to the tapered bottom near its lowest point for discharging gangue; an annular trough for collecting froth concentrate at the top of said chamber; a group of frustoconical shells each having bases of different diameters and a tapered surface secured axially in said chamber and spaced equidistantly from one another height wise of said chamber; aerator means for aerating the flotation pulp secured to the walls of said chamber and communicating therewith to provide aerated water into said chamber; means for feeding mineral particles of coarse fraction, particles of the useful ingredient of the coarse fraction being capable of floating in the froth layer of the flotation pulp, in the form of a hydrocyclone having a cylindrical casing positioned axially over said chamber and a downwardly tapering outlet directed downwardly to feed the coarse particles to said chamber; feed pipe means for feeding the flotation pulp carrying mineral particles of coarse fraction positioned tangentially at said cylindrical casing of the hydrocyclone; and evacuation means for evacuating the liquid phase of the flotation pulp positioned tangentially at said casing of the hydrocyclone over said feed pipe means and connected to said feed pipe means for feeding the flotation pulp carrying mineral particles of the fine fraction.

  20. Column flotation '88

    SciTech Connect

    Sastry, K.V.S.

    1988-01-01

    This book contains 34 selections. Some of the titles are: Column flotation of ultrafine coal: experience at BHP-Utah Coal Limited's Riverside mine; Measurement of rate data in flotation columns; Factors influencing the structure of a 3-phase coal flotation froth; and Microbubble flotation of fine coal.

  1. Flotation separation of coal concentrates. 1976-1981 (citations from the Energy Data Base). Report for Jan 76-Dec 81

    SciTech Connect

    Not Available

    1981-12-01

    Reports are cited which discuss flotation separation of mineral particles using the different surface chemical properties to cause the selected particles to float. Coal-washery flotation circuits are emphasized. Sorting and separating using compressed air jets into the mineral concentration, flotation reagent effects on coal concentrate quality, and economy of flotation separation of coal concentrates are included in this bibliography. Froth flotation, foam separation, and foam flotation processes are included with respect to oil and water mixtures, ore concentrates, and minerals, as well as coal concentrates. (Contains 213 citations fully indexed and including a title list.)

  2. The action of macrosounds on graphite ore and derived products

    NASA Technical Reports Server (NTRS)

    Bradeteanu, C.; Dragan, O.

    1974-01-01

    A suspension of graphite ore, floated graphite, and the gangue left over from flotation were subjected to the action of macrosounds under determinant conditions. The following was found: (1) The graphite ore undergoes an efficient settling action. (2) The floated graphite is strongly crushed down to the dimensions of colloidal graphite. (3) The gangue left over from flotation can be further processed to recuperate graphite from its nuclei.

  3. Pressure flotation of nitrocellulose fines: Hydrodynamics and interfacial chemistry

    SciTech Connect

    Grasso, D.; Hu, H.L.; LaFrance, P.; Kim, B.J.

    1996-11-01

    The production of nitrocellulose (NC) creates large quantities of waste NC fines in wash water streams. Current processing techniques attempt to remove these fines by cross-flow microfiltration, pressure flotation, settling, centrifugation, and lime precipitation. Pressure flotation, or dissolved air flotation (DAF), is a solid/liquid separation process first developed in the ore processing industry. DAF has since found many applications in the environmental engineering field including: drinking water clarification, sludge thickening, and the clarification of wastewater from a variety of industrial and municipal processes. The work presented herein is part of a larger effort to explore techniques to recover and reuse nitrocellulose (NC) fines resulting from propellant manufacturing processes. Previous papers investigated NC particle stability and interfacial thermodynamics and developed a flotation trajectory model. This paper builds on that work and presents a sensitivity analysis of the flotation trajectory model. The sensitivity analysis explores both operational and parameter estimation uncertainty.

  4. Desulfurization of coal by microbial column flotation.

    PubMed

    Ohmura, N; Saiki, H

    1994-06-05

    Twenty-three strains capable of oxidizing iron were isolated from coal and ore storage sites as well as coal and ore mines, volcanic areas, and hot spring. Four strains were found to have high iron-oxidizing activity. One strain (T-4) was selected for this experiment since the strain showed the fastest leaching rate of iron and sulfate from pyrite among the four strains. The T-4 strain was assigned for Thiobacillus ferrooxidans from its cultural and morphological characteristics.Bacterial treatment was applied to column flotation. An increase of cell density in the microbial column flotation resulted in the increase of pyrite removal from a coal-pyrite mixture (high sulfur imitated coal) with corresponding decrease of coal recovery. The addition of kerosene into the microbial column flotation increased the recovery of the imitated coal from 55% (without kerosene) to 81% (with 50 microL/L kerosene) with the reduction of pyrite sulfur content from 11% (feed coal) to 3.9% (product coal). The kerosene addition could reduce the pyritic sulfur content by collecting the coal in the recovery. However, the addition could not enhance separation of pyrite from the coal-pyrite mixture, since pyrite rejection was not affected by the increase of the kerosene addition. An excellent separation was obtained by the microbial flotation using a long column which had a length-diameter (L/D) ratio of 12.7. The long column flotation reduced the pyritic sulfur content from 11% (feed coal) to 1.8% (product coal) when 80% of the feed coal was recovered without the kerosene addition. The long column flotation not only attained an excellent separation but also reduced the amount of cells for desulfurization to as little as one-tenth of the reported amount.

  5. Desulfurization of coal by microbial column flotation

    SciTech Connect

    Ohmura, Naoya; Saiki, Hiroshi . Dept. of Biotechnology)

    1994-06-05

    Twenty-three strains capable of oxidizing iron were isolated from coal and ore storage sites as well as coal and ore mines, volcanic areas, and hot spring. Four strains were found to have high iron-oxidizing activity. One strain (T-4) was selected for this experiment since the strain showed the fastest leaching rate of iron and sulfate from pyrite among the four strains. The T-4 strain was assigned for Thiobacillus ferrooxidans from its cultural and morphological characteristics. Bacterial treatment was applied to column flotation. An increase of cell density in the microbial column flotation resulted in the increase of pyrite removal from a coal-pyrite mixture with corresponding decrease of coal recovery. The addition of kerosene into the microbial column flotation increased the recovery of the imitated coal from 55% (without kerosene) to 81% (with 50 [mu]L/L kerosene) with the reduction of pyrite sulfur content from11% (feed coal) to 3.9% (product coal). An excellent separation was obtained by the microbial flotation using a long column which had a length-diameter (L/D) ratio of 12.7.

  6. 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.

  7. 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.

  8. A review of zinc oxide mineral beneficiation using flotation method.

    PubMed

    Ejtemaei, Majid; Gharabaghi, Mahdi; Irannajad, Mehdi

    2014-04-01

    In recent years, extraction of zinc from low-grade mining tailings of oxidized zinc has been a matter of discussion. This is a material which can be processed by flotation and acid-leaching methods. Owing to the similarities in the physicochemical and surface chemistry of the constituent minerals, separation of zinc oxide minerals from their gangues by flotation is an extremely complex process. It appears that selective leaching is a promising method for the beneficiation of this type of ore. However, with the high consumption of leaching acid, the treatment of low-grade oxidized zinc ores by hydrometallurgical methods is expensive and complex. Hence, it is best to pre-concentrate low-grade oxidized zinc by flotation and then to employ hydrometallurgical methods. This paper presents a critical review on the zinc oxide mineral flotation technique. In this paper, the various flotation methods of zinc oxide minerals which have been proposed in the literature have been detailed with the aim of identifying the important factors involved in the flotation process. The various aspects of recovery of zinc from these minerals are also dealt with here. The literature indicates that the collector type, sulfidizing agent, pH regulator, depressants and dispersants types, temperature, solid pulp concentration, and desliming are important parameters in the process. The range and optimum values of these parameters, as also the adsorption mechanism, together with the resultant flotation of the zinc oxide minerals reported in the literature are summarized and highlighted in the paper. This review presents a comprehensive scientific guide to the effectiveness of flotation strategy.

  9. 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.

  10. Advances in flotation technology

    SciTech Connect

    Parekh, B.K.; Miller, J.D.

    1999-07-01

    The ability to selectively separate fine and coarse particles by flotation is the heart of most mineral processing operations. Significant developments in flotation technology are reflected in this proceedings including: equipment design and development, instrumentation and control, sulfides and precious metals, nonsulfide minerals, coal cleaning, and fundamentals.

  11. Modeling of column flotation

    SciTech Connect

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

    1987-01-01

    Many investigators believe that column flotation cells offer significant advantages over standard mechanical machines for the flotation of fine particles. However, because of their unique design and operation, conventional techniques for flotation cell scale-up and design cannot be applied to columns. In an attempt to help alleviate this problem, a population balance model based on first principles has been developed for fine particle flotation in a column. Two different terms have been considered in the model, i.e., transport and rate. Transport terms, incorporating fluid flow and buoyancy, are used to describe the movement of air bubbles, unattached particles and bubble-particle aggregates along the length of the column. Rate terms, which describe the bubble-particle attachment process, have been derived from first principle considerations. Because the model is based on first principles, it can be useful for the design, control, optimization and scale-up of column flotation cells. 9 refs., 12 figs.

  12. The Bateman Flotation Machine

    SciTech Connect

    Bezuidenhout, G.

    1995-12-31

    The newly developed Bateman Flotation Machine has proven its versatility in roughing and cleaning flotation circuits. This mechanical flotation machine has the dual performance capability of suspending solids and dispersing air at relatively low power inputs without compromising these two important fundamentals. This new development has been successfully marketed to a wide cross section of concentrator mineral processes. The mechanical design of the flotation mechanism has been optimized to reduce operational costs and to lower manufacturing costs. Production process environments were utilized for verification of the scale-up of each cell volume size rated mechanism. These thorough investigations produced performance data which could be accurately quoted. This paper is a historical account of the Batement Flotation Machine. Technical details of the development are covered with descriptions of the operational applications.

  13. Host-rock controlled epigenetic, hydrothermal metasomatic origin of the Bayan Obo REEFe-Nb ore deposit, Inner Mongolia, P.R.C.

    USGS Publications Warehouse

    Chao, E.C.T.; Back, J.M.; Minkin, J.A.; Yinchen, R.

    1992-01-01

    Bayan Obo, a complex rare earth element (REE)FeNb ore deposit, located in Inner Mongolia, P.R.C. is the world's largest known REE deposit. The deposit is chiefly in a marble unit (H8), but extends into an overlying unit of black shale, slate and schist unit (H9), both of which are in the upper part of the Middle Proterozoic Bayan Obo Group. Based on sedimentary structures, the presence of detrital quartz and algal fossil remains, and the 16-km long geographic extent, the H8 marble is a sedimentary deposit, and not a carbonatite of magmatic origin, as proposed by some previous investigators. The unit was weakly regionally metamorphosed (most probably the lower part of the green schist facies) into marble and quartzite prior to mineralization. Tectonically, the deposit is located on the northern flank of the Sino-Korean craton. Many hypotheses have been proposed for the origin of the Bayan Obo deposit; the studies reported here support an epigenetic, hydrothermal, metasomatic origin. Such an origin is supported by field and laboratory textural evidence; 232Th/208Pb internal isochron mineral ages of selected monazite and bastnaesite samples; 40Ar/39Ar incremental heating minimum mineral ages of selected alkali amphiboles; chemical compositions of different generations of both REE ore minerals and alkali amphiboles; and evidence of host-rock influence on the various types of Bayan Obo ores. The internal isochron ages of the REE minerals indicate Caledonian ages for various episodes of REE and Fe mineralization. No evidence was found to indicate a genetic relation between the extensive biotite granitic rocks of Hercynian age in the mine region and the Bayan Obo are deposit, as suggested by previous workers. ?? 1992.

  14. Comprehensive recovery of gold and base-metal sulfide minerals from a low-grade refractory ore

    NASA Astrophysics Data System (ADS)

    Li, Wen-juan; Liu, Shuang; Song, Yong-sheng; Wen, Jian-kang; Zhou, Gui-ying; Chen, Yong

    2016-12-01

    The comprehensive recovery of small amounts of valuable minerals such as gold and base-metal sulfide minerals from a low-grade refractory ore was investigated. The following treatment strategy was applied to a sample of this ore: gold flotation-gold concentrate leaching-lead and zinc flotation from the gold concentrate leaching residue. Closed-circuit trials of gold flotation yielded a gold concentrate that assayed at 40.23 g·t-1 Au with a recovery of 86.25%. The gold concentrate leaching rate was 98.76%. Two variants of lead-zinc flotation from the residue—preferential flotation of lead and zinc and bulk flotation of lead and zinc—were tested using the middling processing method. Foam from the reflotation was returned to the lead rougher flotation or lead-zinc bulk flotation, whereas middlings from reflotation were discarded. Sulfur concentrate was a byproduct. The combined strategy of flotation, leaching, and flotation is recommended for the treatment of this kind of ore.

  15. Low energy ballasted flotation.

    PubMed

    Jarvis, P; Buckingham, P; Holden, B; Jefferson, B

    2009-08-01

    A novel process which involves the replacement or supplementation of bubbles in the dissolved air flotation process with low density beads is presented. The work comprised a series of bench-scale flotation trials treating three commonly encountered algal species (Microcystis, Melosira and Chlorella) that were removed in a flotation cell configured as either: conventional dissolved air flotation (DAF); ballasted flotation using low density 70 microm glass beads with a density of 100 kg m(-3); or a hybrid process of ballasted flotation combined with conventional DAF. Results indicated that the bead only system was capable of achieving better residual turbidity than standard DAF at bead concentrations of 500 mg L(-1). Addition of beads in combination with standard DAF reduced turbidity further to even lower residual turbidity levels. Algae removal was improved when glass beads were dosed, but removal was dependent on algal species. Microcystis was removed by 97% for bead only systems and this removal did not change significantly with the addition of air bubbles. Melosira was the next best removed algae with bead only dosed systems giving similar removals to that achieved by standard DAF using a 10% air recycle ratio (81 and 76% removal respectively). Chlorella was the least well removed algae by bead only systems (63% removal). However, removal was rapidly improved to 86% by the addition of air bubbles using only a 2% recycle ratio. Energy estimations suggested that at least a 50% energy reduction could be achieved using the process offering a potential route for future development of low energy separation processes for algae removal.

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

    SciTech Connect

    Jiang, Chengliang

    1993-01-01

    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.

  17. 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.

  18. Development of Technology for Enrichment of Silver Containing Ores

    NASA Astrophysics Data System (ADS)

    Shekiladze, Asmati; Kavtelashvili, Otari; Bagnashvili, Mamuka

    2016-10-01

    The progress of Georgian economics is substantially associated with a development of new deposits of mineral resources. Among them is the David-Gareji deposit where at present the intensive searching geological works are performed. The work goal involves the elaboration of the technology for processing of silver-containing quartz-barite ores. Without its development the mining of more valuable gold-polymetallic ores is impossible. Because of ore complexity silver and barite are considered in a common technological aspect. The investigations were carried out on the representative samples of quartz-barite ores containing 78-88 g/ton of silver and 27-29 % of silver is a nugget in the form of the simple sulphides and chlorides. The ore is characterized by fine coalescence of barite and ore-generating minerals. Non-ferrous metals haven't any industrial value because of their very low content. Therefore, for the processing of the ores under study the direct selective scheme of flotation enrichment was chosen and the formula of optimal reagent regime was elaborated. Potassium xanthogenate is used as a collector for flotation of silver minerals and pine oil- as a foaming agent. The effect of the pulp - pH and medium temperature on silver flotation was studied. It was established that the silver is actively floats in neutral medium. For barite flotation the various collectors were tested: sulfidezid cotton oil-soap stock, soaps of fatty acids and alkyl sulphates of C12 - C16 row, among the “Baritol” is the most efficient one. Depression of the barren rock was carried out by liquid glass in alkaline medium. The effect of pulp pH on barite flotation has been investigated. The best results were obtained at pH=8.5. The increase of the pulp alkalinity has no essential effect on the indexes of the barite enrichment. Conditional concentrate of the barite is obtained by two fold purification of the main flotation concentrate by the addition of the liquid glass to the re

  19. New aspects in the theory and practice of column flotation

    SciTech Connect

    Rubinstein, J.; Badenicov, V.

    1995-12-31

    The high efficiency of column flotation allows a reduction in process time, a decrease in the number of cleaner stages and in the volume of the circulating load in the flotation circuit, and, as a result of this, an increase in consistency and reliability of operations. Unique multisectional column flotation apparatuses were developed. To attain that aim particular hydrodynamics and aeration regime is established in each section of the column, operational variables being adjusted according to the floatability of the material. Therefore in multisectional column machines, the material-apparatus feedback can be established, and process variables optimized depending on the characteristics of the floated materials. Successful operation was reported of the new generation of columns with cell volumes of 10 to 80 m{sup 3} and the height of 4--6 m in copper, molybdenum, antimony, tungsten and nickel ores and coal slurry processing at different plants. Operational experience of these cells showed their considerable design and operational advantages and verified the proposed options and relationships. The new apparatus is provided with a pneumohydraulic aerator allowing to control bubble size distribution, the service life of the aerator is not less than two years. A multilevel flotation model was developed and used to work out a technique of column design and process parameters calculation. A method of the apparatus design parameters calculation based on laboratory test results (scaling up) was worked out.

  20. Hemimorphite Ores: A Review of Processing Technologies for Zinc Extraction

    NASA Astrophysics Data System (ADS)

    Chen, Ailiang; Li, Mengchun; Qian, Zhen; Ma, Yutian; Che, Jianyong; Ma, Yalin

    2016-10-01

    With the gradual depletion of zinc sulfide ores, exploration of zinc oxide ores is becoming more and more important. Hemimorphite is a major zinc oxide ore, attracting much attention in the field of zinc metallurgy although it is not the major zinc mineral. This paper presents a critical review of the treatment for extraction of zinc with emphasis on flotation, pyrometallurgical and hydrometallurgical methods based on the properties of hemimorphite. The three-dimensional framework structure of hemimorphite with complex linkage of its structural units lead to difficult desilicification before extracting zinc in the many metallurgical technologies. It is found that the flotation method is generally effective in enriching zinc minerals from hemimorphite ores into a high-grade concentrate for recovery of zinc. Pure zinc can be produced from hemimorphite or/and willemite with a reducing reagent, like methane or carbon. Leaching reagents, such as acid and alkali, can break the complex structure of hemimorphite to release zinc in the leached solution without generation of silica gel in the hydrometallurgical process. For optimal zinc extraction, combing flotation with pyrometallurgical or hydrometallurgical methods may be required.

  1. Strategy for adaptive process control for a column flotation unit

    SciTech Connect

    Karr, C.L.; Ferguson, C.R.

    1994-12-31

    Researchers at the U.S. Bureau of Mines (USBM) have developed adaptive process control systems in which genetic algorithms (GAs) are used to augment fuzzy logic controllers (FLCs). Together, GAs and FLCs possess the capabilities necessary to produce powerful, efficient, and robust adaptive control systems. To perform efficiently, such control systems require a control element to manipulate the problem environment, an analysis element to recognize changes in the problem environment, and a learning element to adjust to the changes in the problem environment. In this paper, the details of an ongoing research effort to develop and implement an adaptive process control system for a column flotation unit are discussed. Column flotation units are used extensively in the mineral processing industry to recover valuable minerals from their ores.

  2. Picobubble enhanced fine coal flotation

    SciTech Connect

    Tao, Y.J.; Liu, J.T.; Yu, S.; Tao, D.

    2006-07-01

    Froth flotation is widely used in the coal industry to clean -28 mesh fine coal. A successful recovery of particles by flotation depends on efficient particle-bubble collision and attachment with minimal subsequent particle detachment from bubble. Flotation is effective in a narrow size range beyond which the flotation efficiency drops drastically. It is now known that the low flotation recovery of particles in the finest size fractions is mainly due to a low probability of bubble-particle collision while the main reason for poor coarse particle flotation recovery is the high probability of detachment. A fundamental analysis has shown that use of picobubbles can significantly improve the flotation recovery of particles in a wide range of size by increasing the probability of collision and attachment and reducing the probability of detachment. A specially designed column with a picobubble generator has been developed for enhanced recovery of fine coal particles. Picobubbles were produced based on the hydrodynamic cavitation principle. They are characterized by a size distribution that is mostly below 1 {mu}m and adhere preferentially to the hydrophobic surfaces. The presence of picobubbles increases the probability of collision and attachment and decreases the probability of detachment, thus enhancing flotation recovery. Experimental results with the Coalberg seam coal in West Virginia, U.S.A. have shown that the use of picobubbles in a 2 in. column flotation increased fine coal recovery by 10-30%, depending on the feed rate, collector dosage, and other flotation conditions. Picobubbles also acted as a secondary collector and reduced the collector dosage by one third to one half.

  3. 33 CFR 183.322 - Flotation materials.

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... 33 Navigation and Navigable Waters 2 2011-07-01 2011-07-01 false Flotation materials. 183.322...) BOATING SAFETY BOATS AND ASSOCIATED EQUIPMENT Flotation Requirements for Outboard Boats Rated for Engines 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, 2013 CFR

    2013-07-01

    ... 33 Navigation and Navigable Waters 2 2013-07-01 2013-07-01 false Flotation materials. 183.322...) BOATING SAFETY BOATS AND ASSOCIATED EQUIPMENT Flotation Requirements for Outboard Boats Rated for Engines of 2 Horsepower or Less General § 183.322 Flotation materials. (a) Flotation materials must meet...

  5. Research of Geochemical Associations of Nephelin Ores

    NASA Astrophysics Data System (ADS)

    Vulf, M.; Simonov, K.; Sazonov, A.

    of contact of ore body and adjacent wall rocks. Also it is possible to point, that the segments enriched with gold do not coincide with segments of high-alumna rocks but they are phase-opposite. High concentrations of alum earth, earth silicon, alkalis and low contents of ferric oxide, calcium and sulphur determine high-alumina rocks. Thus, one group of members determines high quality of nephelin ore, and the sec- ond U noble metal ore-bearing bound with members aggravating quality of nephelin ore. Therefore, it is possible to draw a conclusion, that the preliminary enrichment of nephelin ore with the help of flotation will allow to receive two kinds of high quality concentrate: aluminous and noblemetal. The research also allows developing ways of a practical solution of a problem of de- terioration quality of nephelin ore with increasing depth and, accordingly, increases its cost price. These problems apparently connected with economical planning of a production activity of the ore mine and the financial state of the alumnus plant. 2

  6. Effect of reverse flotation on magnetic separation concentrates

    NASA Astrophysics Data System (ADS)

    Bada, S. O.; Afolabi, A. S.; Makhula, M. J.

    2012-08-01

    Reverse flotation studies on magnetite samples have revealed that the use of starch as a depressant of Fe-oxides has a hydrophilic effect on the surface of Fe-bearing silicates and significantly decreases Fe in the silica-rich stream when used in combination with an amine (Lilaflot D817M). In this study, the effect of reverse flotation on the optimization of products obtained from magnetic separation was investigated. Two different magnetic samples, zones 1 and 2, were milled to <75 μm and then subjected to low intensity magnetic separation (LIMS). The LIMS test conducted on the <75 μm shown an upgrade of 46.40wt% Fe, 28.40wt% SiO2 and 2.61wt% MnO for zone 1 and 47.60wt% Fe, 29.17wt% SiO2 and 0.50wt% MnO for zone 2. Further milling of the ore to <25 μm resulted in a higher magnetic-rich product after magnetic separation. Reverse flotation tests were conducted on the agitated magnetic concentrate feed, and the result shows a significant upgrade of Fe compared to that obtained from the non-agitated feed. Iron concentrations greater than 69%, and SiO2 concentrations less than 2% with overall magnetite recoveries greater than 67% and 71% were obtained for zones 1 and 2, respectively.

  7. 33 CFR 183.302 - Flotation requirements.

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ... 33 Navigation and Navigable Waters 2 2012-07-01 2012-07-01 false Flotation requirements. 183.302...) BOATING SAFETY BOATS AND ASSOCIATED EQUIPMENT Flotation Requirements for Outboard Boats Rated for Engines of 2 Horsepower or Less General § 183.302 Flotation requirements. Each boat to which this...

  8. 33 CFR 183.302 - Flotation requirements.

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... 33 Navigation and Navigable Waters 2 2013-07-01 2013-07-01 false Flotation requirements. 183.302...) BOATING SAFETY BOATS AND ASSOCIATED EQUIPMENT Flotation Requirements for Outboard Boats Rated for Engines of 2 Horsepower or Less General § 183.302 Flotation requirements. Each boat to which this...

  9. 33 CFR 183.302 - Flotation requirements.

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... 33 Navigation and Navigable Waters 2 2011-07-01 2011-07-01 false Flotation requirements. 183.302...) BOATING SAFETY BOATS AND ASSOCIATED EQUIPMENT Flotation Requirements for Outboard Boats Rated for Engines of 2 Horsepower or Less General § 183.302 Flotation requirements. Each boat to which this...

  10. 33 CFR 183.302 - Flotation requirements.

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... 33 Navigation and Navigable Waters 2 2014-07-01 2014-07-01 false Flotation requirements. 183.302...) BOATING SAFETY BOATS AND ASSOCIATED EQUIPMENT Flotation Requirements for Outboard Boats Rated for Engines of 2 Horsepower or Less General § 183.302 Flotation requirements. Each boat to which this...

  11. 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.

  12. 76 FR 56294 - Inflatable Personal Flotation Devices

    Federal Register 2010, 2011, 2012, 2013, 2014

    2011-09-13

    ... 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, and to slightly modify... rule entitled ``Inflatable Personal Flotation Devices'' in the Federal Register (76 FR 17561)....

  13. 33 CFR 183.302 - Flotation requirements.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... 33 Navigation and Navigable Waters 2 2010-07-01 2010-07-01 false Flotation requirements. 183.302...) BOATING SAFETY BOATS AND ASSOCIATED EQUIPMENT Flotation Requirements for Outboard Boats Rated for Engines of 2 Horsepower or Less General § 183.302 Flotation requirements. Each boat to which this...

  14. 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...

  15. 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...

  16. 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...

  17. 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.

  18. Bubble injected hydrocyclone flotation cell

    SciTech Connect

    Stanley, D.A.; Jordon, C.E.

    1990-11-20

    This patent describes an apparatus for selective separation of a mixture of hydrophobic and hydrophilic mineral particles. It comprises: a bubble-injected hydrocyclone flotation cell and a bubble slurry. The cell comprises an enclosed body section; a mineral pulp feed port; a bubble slurry feed port; and a vortex finder.

  19. 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.

  20. Great Barrier Reef

    Atmospheric Science Data Center

    2013-04-16

    article title:  Australia's Great Barrier Reef     View Larger Image ... reef, but a vast maze of reefs, passages, and coral cays (islands that are part of the reef). This nadir true-color image was acquired by ...

  1. The jet flotation column control system

    SciTech Connect

    Xu Zhiqiang; Ming Shangzhi; Liu Lijian; Huangfu Jinghua; Huo Sen; Zhang Rongzeng; Yang Hongjun

    1998-12-31

    Compared with the conventional mechanical flotation column, the jet flotation column has the advantages of high selectivity of separation, low investment and production cost, low floor space requirement, low dosage of reagent, easy control; it is more suitable to process fine particles. Recently, many new types of flotation columns have been developed with new methods. Mineral Processing Dept., China University of Mining and Technology (Beijing) designed an aerated, double-jet flotation column in the lab and the industrial trial will be put into operation. One of the significant characteristics of the new type of flotation column is high selectivity of separation, fast bubble mineralization speed. As it is sensitive to various factors, a control system for flotation column has been developed to stabilize the working condition, and this set of control system has been operated in the lab experiment.

  2. Column flotation of coal with fluorosurfactants

    SciTech Connect

    Not Available

    1989-10-01

    Laboratory tests were carried out by the US Bureau of Mines, Salt Lake City Research Center to evaluate the potential of column flotation technology, coupled with novel fluorosurfactant collectors, for the selective flotation of fine coal from pyritic sulfur and mineral matter. The results on flotation feeds of both {minus}100 and {minus}400 mesh Middle Kittaning seam coal samples are presented. 4 refs., 23 figs., 9 tabs.

  3. Comparison of column flotation cells

    SciTech Connect

    Honaker, R.Q.; Mohanty, M.K.; Ho, K.

    1995-08-01

    Six commercial column flotation technologies, i.e., Canadian, Flotaire, Jameson, Microcel, Packed-Column, and Turbo-air, were tested for the treatment of Illinois Basin fine coal and the results from each column compared based on separation performance and throughout capacity. The separation performance achieved by each cell approached and, in some cases, exceeded the ultimate performance predicted by release analysis. A comparison of the test results indicates differences in the selectivity obtained by each flotation column on the basis of both ash and sulfur rejection. This finding may be due to variations in cell hydrodynamics and the ability to support a deep froth phase among the different column cells. In addition, throughput capacity of each cell was found to differ, apparently due to the differences in the bubble-particle attachment environment, bubble size, and bubble population. Variations in the operating characteristics, such as reagent additions, aeration rate and wash water rate, were also noted and summarized in this publication.

  4. A dynamics model for fine coal flotation

    SciTech Connect

    Youjun, T.; Maixi, L.

    1999-07-01

    Through a large amount of experiments, this article studied the effect of the entrapment of water flow on the fine coal flotation during the flotation, and also investigated the relation between the constant of water flotation rate and different operation variables, and resulted in its equation. The water-recycling model is determined, and finally, the dynamics model on relation between the recovery of fine particle and the water recovery in concentration is established. The equation about ash of fine clean coal in any flotation time is derived by introduction of de-ashed coefficient.

  5. 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.

  6. N-(6-(hydroxyamino)-6-oxohexyl) decanamide collector: Flotation performance and adsorption mechanism to diaspore

    NASA Astrophysics Data System (ADS)

    Deng, Lanqing; Wang, Shuai; Zhong, Hong; Liu, Guangyi

    2015-08-01

    In this paper, a novel surfactant, N-(6-(hydroxyamino)-6-oxohexyl)decanamide (NHOD) was synthesized and used as a collector for flotation separation of diaspore and aluminosilicate minerals. The adsorption mechanism of NHOD onto diaspore was also investigated by FTIR spectra, zeta potential measurement and XPS. The flotation results demonstrated that NHOD exhibited superior collecting power to diaspore and selectivity against kaolinite and illite and could effectively realize flotation recovery of diaspore from bauxite ores contained aluminosilicate minerals under neutral conditions. The results of XPS, FTIR spectra and zeta potential illustrated that at around pH 7.0, NHOD might chemisorb on diaspore surfaces through Alsbnd O coordination bonds formed by binding its sbnd C(dbnd O)NHOH or sbnd C(dbnd O)NHsbnd chelate groups with aluminum atoms on diaspore surfaces. NHOD's unique properties, such as characteristic bond patterns onto diaspore surfaces, two hydrophobic groups, and intermolecular hydrogen bonds between neighboring NHOD molecules coated on diaspore surfaces, rendered it to be a superior flotation collector for diaspore.

  7. Taguchi optimization: Case study of gold recovery from amalgamation tailing by using froth flotation method

    NASA Astrophysics Data System (ADS)

    Sudibyo, Aji, B. B.; Sumardi, S.; Mufakir, F. R.; Junaidi, A.; Nurjaman, F.; Karna, Aziza, Aulia

    2017-01-01

    Gold amalgamation process was widely used to treat gold ore. This process produces the tailing or amalgamation solid waste, which still contains gold at 8-9 ppm. Froth flotation is one of the promising methods to beneficiate gold from this tailing. However, this process requires optimal conditions which depends on the type of raw material. In this study, Taguchi method was used to optimize the optimum conditions of the froth flotation process. The Taguchi optimization shows that the gold recovery was strongly influenced by the particle size which is the best particle size at 150 mesh followed by the Potassium amyl xanthate concentration, pH and pine oil concentration at 1133.98, 4535.92 and 68.04 gr/ton amalgamation tailing, respectively.

  8. 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.

  9. 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....

  10. 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....

  11. 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....

  12. 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....

  13. 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....

  14. Dispersed ozone flotation of Chlorella vulgaris.

    PubMed

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

    2010-12-01

    Flotation separation of Chlorella vulgaris, a species with excellent potential for CO(2) capture and lipid production, was studied using dispersed ozone gas. Pure oxygen aeration did not yield flotation. Conversely, applying ozone effectively separation algae from broth through flotation. The ozone dose applied for sufficient algal flotation is <0.05 mg/g biomass, much lower than those used in practical drinking waterworks (0.1-0.3 mg/g suspended solids). Main products, lipid C16:0, was effectively collected in the flotage phase. The algae removal rate, surface charge, and hydrophobicity of algal cells, and proteins and polysaccharides contents of algogenic organic matter (AOM) were determined. Certain quantities of proteins were present in the cultivated algal suspension, hence, minimal quantity of ozone was required to release intracellular proteins as surfactants to lead to effective flotation.

  15. 46 CFR 179.240 - 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. 179.240 Section 179.240... Requirements § 179.240 Foam flotation material. (a) Foam may only be installed as flotation material on a vessel when approved by the cognizant OCMI. (b) If foam is installed as flotation material on a...

  16. 33 CFR 183.114 - Test of flotation materials.

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... 33 Navigation and Navigable Waters 2 2013-07-01 2013-07-01 false Test of flotation materials. 183.../Outdrive Boats, and Airboats § 183.114 Test of flotation materials. (a) Vapor test. The flotation material... gasoline test. The flotation material must not reduce in buoyant force more than 5 percent after...

  17. 33 CFR 183.114 - Test of flotation materials.

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... 33 Navigation and Navigable Waters 2 2011-07-01 2011-07-01 false Test of flotation materials. 183.../Outdrive Boats, and Airboats § 183.114 Test of flotation materials. (a) Vapor test. The flotation material... gasoline test. The flotation material must not reduce in buoyant force more than 5 percent after...

  18. 33 CFR 183.114 - Test of flotation materials.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... 33 Navigation and Navigable Waters 2 2010-07-01 2010-07-01 false Test of flotation materials. 183.../Outdrive Boats, and Airboats § 183.114 Test of flotation materials. (a) Vapor test. The flotation material... gasoline test. The flotation material must not reduce in buoyant force more than 5 percent after...

  19. 33 CFR 183.114 - Test of flotation materials.

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ... 33 Navigation and Navigable Waters 2 2012-07-01 2012-07-01 false Test of flotation materials. 183.../Outdrive Boats, and Airboats § 183.114 Test of flotation materials. (a) Vapor test. The flotation material... gasoline test. The flotation material must not reduce in buoyant force more than 5 percent after...

  20. 33 CFR 183.114 - Test of flotation materials.

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... 33 Navigation and Navigable Waters 2 2014-07-01 2014-07-01 false Test of flotation materials. 183.../Outdrive Boats, and Airboats § 183.114 Test of flotation materials. (a) Vapor test. The flotation material... gasoline test. The flotation material must not reduce in buoyant force more than 5 percent after...

  1. Idea of Identification of Copper Ore with the Use of Process Analyser Technology Sensors

    NASA Astrophysics Data System (ADS)

    Jurdziak, Leszek; Kaszuba, Damian; Kawalec, Witold; Król, Robert

    2016-10-01

    The Polish resources of the copper ore exploited by the KGHM S.A. underground mines are considered as one of the most complex in the world and - consequently - the most difficult to be processed. The ore consists of three lithology forms: dolomites, shales and sandstones but in different proportions which has a significant impact on the effectiveness of the grinding and flotation processes. The lithological composition of the ore is generally recognised in-situ but after being mined it is blended on its long way from various mining fields to the processing plant by the complex transportation system consisting of belt conveyors with numerous switching points, ore bunkers and shafts. Identification of the lithological composition of the ore being supplied to the processing plant should improve the adjustments of the ore processing machinery equipment aiming to decrease the specific processing (mainly grinding) energy consumption as well as increase the metal recovery. The novel idea of Process Analyser Technology (PAT) sensors - information carrying pellets, dropped into the transported or processed bulk material which can be read directly when needed - is investigated for various applications within the DISIRE project (a part of the SPIRE initiative, acting under the Horizon2020 framework program) and here is adopted for implementing the annotation the transported copper ore for the needs of ore processing plants control. The identification of the lithological composition of ore blended on its way to the processing plant can be achieved by an information system consisting of pellets that keep the information about the original location of the portions of conveyed ore, the digital, geological database keeping the data of in-situ lithology and the simulation models of the transportation system, necessary to evaluate the composition of the blended ore. The assumptions of the proposed solution and the plan of necessary in-situ tests (with the special respect to harsh

  2. Shale-oil-recovery systems incorporating ore beneficiation. Final report.

    SciTech Connect

    Weiss, M.A.; Klumpar, I.V.; Peterson, C.R.; Ring, T.A.

    1982-10-01

    This study analyzed the recovery of oil from oil shale by use of proposed systems which incorporate beneficiation of the shale ore (that is concentration of the kerogen before the oil-recovery step). The objective was to identify systems which could be more attractive than conventional surface retorting of ore. No experimental work was carried out. The systems analyzed consisted of beneficiation methods which could increase kerogen concentrations by at least four-fold. Potentially attractive low-enrichment methods such as density separation were not examined. The technical alternatives considered were bounded by the secondary crusher as input and raw shale oil as output. A sequence of ball milling, froth flotation, and retorting concentrate is not attractive for Western shales compared to conventional ore retorting; transporting the concentrate to another location for retorting reduces air emissions in the ore region but cost reduction is questionable. The high capital and energy cost s results largely from the ball milling step which is very inefficient. Major improvements in comminution seem achievable through research and such improvements, plus confirmation of other assumptions, could make high-enrichment beneficiation competitive with conventional processing. 27 figures, 23 tables.

  3. Beneficiation of rare earth minerals from Bokan Mountain - Dotson Ridge ore

    NASA Astrophysics Data System (ADS)

    Narantsetseg, Purevbaatar

    The purpose of this research work was to study the beneficiation of rare earth ore of the Bokan Mountain - Dotson Ridge deposit, located near Ketchikan, Alaska. Rare earth element (REE) composite ore samples from the Bokan Mountain - Dotson Ridge deposit were tested using gravity concentration, magnetic separation, flotation, and leaching techniques to separate the REE. The composite ore sample was a product of a preliminary x-ray sorting process. Qualitative electron microprobe analysis of the ore showed that most of the REE minerals in the ore were silicate minerals. Since the electron microprobe analysis samples were coated with carbon during sample preparation, the carbon element was inactivated for analysis. Because of this, carbonate compounds of minerals' particles could not be detected. 95% of the REE mineral particles appear to be smaller than about 10 microm in size (about 100 microm2 in area). For the gravity concentration, light rare earth elements (LREE) and heavy rare earth elements' (HREE) individual elemental recovery values were in the ranges of 49.6-52.8% and 46.3-48.8%, respectively, at 25% of mass yield. In order to separate a larger amount of the REE, a wet high intensity magnetic separation (WHIMS) test was carried out on tailings of the gravity concentration tests. The HREE individual elemental recovery values ranged from 56.3-63.1% at 37% mass yield, while LREE individual elemental recovery values were in the 57.9% - 59.1% range. For the combined gravity and magnetic separation processes, the net individual elemental recovery values of the LREE and the HREE were in the range of 79.6-80.5% and 76.5-80.9%, respectively. The combined mass yield of the gravity and magnetic separation processes was 53%. Direct leaching tests conducted on the composite ground ore feed yielded high individual elemental recovery values of 90-92% of the LREE. The HREE individual elemental recovery values ranged from 56.5-87.3%. In the leaching, 20% HCl was used in

  4. 26. NORTHERN VIEW OF ORE YARD WITH ORE BRIDGES IN ...

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

    26. NORTHERN VIEW OF ORE YARD WITH ORE BRIDGES IN THE BACKGROUND. BLAST FURNACES ALONG THE RIGHT SIDE. (Martin Stupich) - U.S. Steel Duquesne Works, Blast Furnace Plant, Along Monongahela River, Duquesne, Allegheny County, PA

  5. 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.

  6. Flotation selectivity of novel alkyl dicarboxylate reagents for apatite-calcite separation.

    PubMed

    Karlkvist, Tommy; Patra, Anuttam; Rao, Kota Hanumantha; Bordes, Romain; Holmberg, Krister

    2015-05-01

    The investigation aims to demonstrate the conceptual thoughts behind developing mineral specific reagents for use in flotation of calcium containing ores. For this purpose, a series of dicarboxylate-based surfactants with varying distance between the carboxylate groups (one, two or three methylene groups) was synthesized. A surfactant with the same alkyl chain length but with only one carboxylate group was also synthesized and evaluated. The adsorption behavior of these new reagents on pure apatite and pure calcite surfaces was studied using Hallimond tube flotation, FTIR and ζ potential measurements. The relation between the adsorption behavior of a given surfactant at a specific mineral surface and its molecular structure over a range of concentrations and pH values, as well as the region of maximum recovery, was established. It was found that one of the reagents, with a specific distance between the carboxylate groups, was much more selective for a particular mineral surface than the other homologues. For example, out of the four compounds synthesized, only the one where the carboxylate groups were separated by a single methylene group floated apatite but not calcite, whereas calcite was efficiently floated with the monocarboxylic reagent, but not with the other reagents synthesized. This selective adsorption of a given surfactant to a particular mineral surface relative to other mineral surfaces as evidenced in the flotation studies was substantiated by ζ potential and infra-red spectroscopy data.

  7. Introduction to ore geology

    SciTech Connect

    Evans, A.M.

    1987-01-01

    This textbook on ore geology is for second and third year undergraduates and closely parallels the undergraduate course given in this subject at England's University of Leicester. The volume covers three major areas: (1) principles of ore geology, (2) examples of the most important types of ore deposits, and (3) mineralization in space and time. Many chapters have been thoroughly revised for this edition and a chapter on diamonds has been added. Chapters on greisen and pegmatite have also been added, the former in response to the changing situation in tin mining following the recent tin crisis, and the latter in response to suggestions from geologists in a number of overseas countries. Some chapters have been considerably expanded and new sections added, including disseminated gold deposits and unconformity-associated uranium deposits. The author also expands on the importance of viewing mineral deposits from an economic standpoint.

  8. Plant practices in fine coal column flotation

    SciTech Connect

    Davis, V.L. Jr.; Bethell, P.J.; Stanley, F.L.; Luttrell, G.H.

    1995-10-01

    Five 3 m (10 ft) diameter Microcel{trademark} flotation columns were installed at Clinchfield Coal Company`s Middle Fork preparation facility in order to reduce product ash and increase recovery and plant capacity. The Middle Fork facility is utilized for the recovery of fine coal from a feed stream that consists primarily of 1.5 mm x 0 material. The columns replaced conventional flotation cells for the treatment of the minus 150 {micro}m fraction while spirals are used to upgrade the plus 150 {micro}m material in the plant feed. The addition of the column flotation circuit resulted in an increase in plant capacity in excess of 20 percent while reducing the flotation product ash content by approximately 7 percentage points. Flotation circuit combustible recovery wa increased by 17 percentage points. This paper discusses circuit design, commissioning, and sparging system design. Circuit instrumentation, level control, reagent system control, performance comparisons with conventional flotation, and general operating procedures are also discussed.

  9. Pilot-scale testing of microbubble flotation

    SciTech Connect

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

    1991-01-01

    Fundamental investigations into the effect of bubble size on coal flotation have established that the use of microbubbles can improve the recovery of fine coal during flotation while, at the same time, increasing the rejection of ash-forming mineral matter. When used in conjunction with the quiescent conditions provided by a column, the microbubble flotation process has been demonstrated on a laboratory scale to be capable of producing superclean coal containing less than 1 or 2% ash and very little pyritic sulfur. The main objective of this project is to demonstrate the microbubble column flotation process on a pilot-scale. A 500 lb/hr pilot plant is being constructed for the purpose of: 910 demonstrating the feasibility of the microbubble flotation process for producing superclean coal, (2) collecting scale-up data for designing commercial-scale microbubble flotation columns, and (3) collecting cost data for an economic evaluation of the process. In addition to micronized coal, the process is also being tested on coarse coal and refuse pond material. 20 figs.

  10. 14. HULETT ORE UNLOADERS IN MOTION; UNLOADING CANADIAN RED ORE ...

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

    14. HULETT ORE UNLOADERS IN MOTION; UNLOADING CANADIAN RED ORE FROM THE 'GEORGE M. CAR.' VIEW LOOKING EAST. (Also see OH-18-38, OH-18-39, and OH-18-40.) - Pennsylvania Railway Ore Dock, Lake Erie at Whiskey Island, approximately 1.5 miles west of Public Square, Cleveland, Cuyahoga County, OH

  11. 38. HULETT ORE UNLOADERS IN MOTION; UNLOADING CANADIAN RED ORE ...

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

    38. HULETT ORE UNLOADERS IN MOTION; UNLOADING CANADIAN RED ORE FROM THE GEORGE M. CARL.' VIEW LOOKING EAST. (Also see OH-18-14, OH-18-39, and OH-18-40) - Pennsylvania Railway Ore Dock, Lake Erie at Whiskey Island, approximately 1.5 miles west of Public Square, Cleveland, Cuyahoga County, OH

  12. 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.

  13. Evaluation and development of integrated technology of rare metal concentrate production in high-level ore processing at Zashikhinsk deposit

    NASA Astrophysics Data System (ADS)

    Khokhulya, MS; Mukhina, TN; Ivanova, V. A.; Mitrofanova, G. V.; Fomin, A. V.; Sokolov, VD

    2017-02-01

    The authors discuss material constitution of columbite ore sample and recommend optimized pretreatment modes to obtain ball milling products at the maximum dissociation of ore minerals in aggregates. A concentration technology is proposed, with division of material into two flows –0.315 mm and –0.2 mm in sizes, generated in the milling and screening cycles and subjected to gravity–magnetic and magnetic–gravity treatment, respectively. It is shown that the technology ensures production of both tantalum–niobium and zircon concentrates. It has become possible to additionally recover rare metal components Nb2O5 and ZrO2 from tailings through flotation.

  14. 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)...

  15. 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)...

  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. Vitrification of copper flotation waste.

    PubMed

    Karamanov, Alexander; Aloisi, Mirko; Pelino, Mario

    2007-02-09

    The vitrification of an hazardous iron-rich waste (W), arising from slag flotation of copper production, was studied. Two glasses, containing 30wt% W were melted for 30min at 1400 degrees C. The first batch, labeled WSZ, was obtained by mixing W, blast furnace slag (S) and zeolite tuff (Z), whereas the second, labeled WG, was prepared by mixing W, glass cullet (G), sand and limestone. The glass frits showed high chemical durability, measured by the TCLP test. The crystallization of the glasses was evaluated by DTA. The crystal phases formed were identified by XRD resulting to be pyroxene and wollastonite solid solutions, magnetite and hematite. The morphology of the glass-ceramics was observed by optical and scanning electron microscopy. WSZ composition showed a high rate of bulk crystallization and resulted to be suitable for producing glass-ceramics by a short crystallization heat-treatment. WG composition showed a low crystallization rate and good sinterability; glass-ceramics were obtained by sinter-crystallization of the glass frit.

  18. 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...

  19. 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...

  20. 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...

  1. 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...

  2. 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...

  3. 33 CFR 183.222 - Flotation material and air chambers.

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ... 33 Navigation and Navigable Waters 2 2012-07-01 2012-07-01 false Flotation material and air... SECURITY (CONTINUED) BOATING SAFETY BOATS AND ASSOCIATED EQUIPMENT Flotation Requirements for Outboard Boats Rated for Engines of More Than 2 Horsepower General § 183.222 Flotation material and air...

  4. 33 CFR 183.222 - Flotation material and air chambers.

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... 33 Navigation and Navigable Waters 2 2011-07-01 2011-07-01 false Flotation material and air... SECURITY (CONTINUED) BOATING SAFETY BOATS AND ASSOCIATED EQUIPMENT Flotation Requirements for Outboard Boats Rated for Engines of More Than 2 Horsepower General § 183.222 Flotation material and air...

  5. 14 CFR 121.340 - Emergency flotation means.

    Code of Federal Regulations, 2012 CFR

    2012-01-01

    ... 14 Aeronautics and Space 3 2012-01-01 2012-01-01 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...

  6. 33 CFR 183.222 - Flotation material and air chambers.

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... 33 Navigation and Navigable Waters 2 2013-07-01 2013-07-01 false Flotation material and air... SECURITY (CONTINUED) BOATING SAFETY BOATS AND ASSOCIATED EQUIPMENT Flotation Requirements for Outboard Boats Rated for Engines of More Than 2 Horsepower General § 183.222 Flotation material and air...

  7. 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...

  8. 33 CFR 175.15 - Personal flotation devices required.

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ... 33 Navigation and Navigable Waters 2 2012-07-01 2012-07-01 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...

  9. 33 CFR 175.15 - Personal flotation devices required.

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... 33 Navigation and Navigable Waters 2 2013-07-01 2013-07-01 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. 33 CFR 183.202 - Flotation and certification requirements.

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... 33 Navigation and Navigable Waters 2 2014-07-01 2014-07-01 false Flotation and certification... 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...

  11. Frothing in flotation. Volume 2: Recent advances in coal processing

    SciTech Connect

    Laskowski, J.S.; Woodburn, E.T.

    1998-11-01

    This volume summarizes the achievements on various aspects of flotation froth properties and behavior, and relationship between froth appearance and flotation performance. Flotation kinetics involves a number of mass transfer processes with some of them being critically determined by the behavior of froth. Since froth is complex, and controlled experimentation is difficult, the froth phase was, until recently, either ignored or treated entirely empirically. With wide applications of flotation columns, the behavior of the froth is now often recognized as being dominant in determining flotation performance, and the research in this area is one of the most actively pursued. Contents include: Frothers and frothing; Effect of particle and bubble size on flotation kinetics; Water content and distribution in flotation froths; Mechanisms operating in flotation froths; Characterization of flotation froth; Simultaneous determination of collection zone rate constant and froth zone recovery factor; Modelling of froth dynamics with implications for feed-back control; The interrelationship between flotation variables and froth appearance; Froth image analysis in a flotation control system; Kinetic flotation modelling using froth imaging data; and Dependence of froth behavior on galvanic interactions.

  12. 33 CFR 175.15 - Personal flotation devices required.

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... 33 Navigation and Navigable Waters 2 2014-07-01 2014-07-01 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...

  13. Froth flotation for fine-coal cleaning. Final report

    SciTech Connect

    Olson, T.J.

    1985-12-01

    Froth flotation of fine coal was investigated with the objectives of improving flotation at existing coal-cleaning plants and providing design guidance for future plants. Using hydrodynamically scaled-down laboratory and pilot flotation cells, and the Klimpel flotation model, a methodology was developed to relate laboratory-scale flotation results to full-scale flotation circuits. Froth Factor, the percent of froth over the froth lip, was determined to be the key element of this scale-up methodology. Results showed that simple, inexpensive changes in flotation parameters such as air rate and reagent dosages can significantly improve full-scale flotation product recovery and grade, and that more complex flotation circuitry can produce better recovery levels of high-grade coal than more commonly used rougher-only flotation circuits. In particular, cleaning rougher product can effectively reduce pyritic sulfur content. Results also demonstrated interaction between different size fractions of coal. Flotation rates were shown to depend on feed size consist, and it was found that separations based on differences in flotation rates are more advantageously performed on fine topsizes. Ultimate recoveries appear unaffected by size consist. 6 refs.

  14. 14 CFR 121.340 - Emergency flotation means.

    Code of Federal Regulations, 2011 CFR

    2011-01-01

    ... 14 Aeronautics and Space 3 2011-01-01 2011-01-01 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...

  15. 33 CFR 175.15 - Personal flotation devices required.

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... 33 Navigation and Navigable Waters 2 2011-07-01 2011-07-01 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...

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

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... 33 Navigation and Navigable Waters 2 2013-07-01 2013-07-01 false Flotation material and air... 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. 14 CFR 121.340 - Emergency flotation means.

    Code of Federal Regulations, 2013 CFR

    2013-01-01

    ... 14 Aeronautics and Space 3 2013-01-01 2013-01-01 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. 33 CFR 183.105 - Quantity of flotation required.

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... 33 Navigation and Navigable Waters 2 2013-07-01 2013-07-01 false Quantity of flotation required... (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...

  19. 33 CFR 183.202 - Flotation and certification requirements.

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... 33 Navigation and Navigable Waters 2 2013-07-01 2013-07-01 false Flotation and certification... 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...

  20. 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... 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...

  1. 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...

  2. 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.

  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. 33 CFR 183.222 - Flotation material and air chambers.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... 33 Navigation and Navigable Waters 2 2010-07-01 2010-07-01 false Flotation material and air... SECURITY (CONTINUED) BOATING SAFETY BOATS AND ASSOCIATED EQUIPMENT Flotation Requirements for Outboard Boats Rated for Engines of More Than 2 Horsepower General § 183.222 Flotation material and air...

  5. 33 CFR 183.202 - Flotation and certification requirements.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... 33 Navigation and Navigable Waters 2 2010-07-01 2010-07-01 false Flotation and certification... 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...

  6. 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...

  7. 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...

  8. 33 CFR 183.112 - Flotation material and air chambers.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... 33 Navigation and Navigable Waters 2 2010-07-01 2010-07-01 false Flotation material and air... 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)...

  9. 33 CFR 183.105 - Quantity of flotation required.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... 33 Navigation and Navigable Waters 2 2010-07-01 2010-07-01 false Quantity of flotation required... (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...

  10. 21 CFR 880.5150 - Nonpowered flotation therapy mattress.

    Code of Federal Regulations, 2012 CFR

    2012-04-01

    ... 21 Food and Drugs 8 2012-04-01 2012-04-01 false Nonpowered flotation therapy mattress. 880.5150... Therapeutic Devices § 880.5150 Nonpowered flotation therapy mattress. (a) Identification. A nonpowered flotation therapy mattress is a mattress intended for medical purposes which contains air, fluid, or...

  11. 21 CFR 880.5150 - Nonpowered flotation therapy mattress.

    Code of Federal Regulations, 2013 CFR

    2013-04-01

    ... 21 Food and Drugs 8 2013-04-01 2013-04-01 false Nonpowered flotation therapy mattress. 880.5150... Therapeutic Devices § 880.5150 Nonpowered flotation therapy mattress. (a) Identification. A nonpowered flotation therapy mattress is a mattress intended for medical purposes which contains air, fluid, or...

  12. Dissolved mineral species precipitation during coal flotation

    SciTech Connect

    Somasundaran, P.; Liu, D.

    1995-12-31

    Beneficiation by froth flotation, which exploits the difference in surface properties of minerals, has been a promising method for coal cleaning.However, dissolved mineral species present in coal flotation systems can interact with particles and other species leading to drastic effects on flotation. Particularly, precipitation or adsorption of such species on the particles can alter their surface properties and thus influence the efficiency of coal cleaning. In this work, the bulk and surface precipitation of the dissolved mineral species present in Pittsburgh No. 8 coal was investigated under controlled experimental conditions. Changes in the surface properties of coal due to the precipitation were monitored by following zeta potential. Solution potential data were used to elucidate the mechanism of the precipitation. The effect of the precipitation of the dissolved species on the floatability of coal was found to be marked.

  13. Flotation of cadmium-loaded biomass

    SciTech Connect

    Matis, K.A.; Zouboulis, A.I. . Chemical Technology Div.)

    1994-07-01

    Biosorption of heavy metal ions such as Cd[sup 2+] by dead biomass has been recognized as a potential alternative to existing removal technologies applied to wastewater treatment. Two bacterial strains were studied in the laboratory, Streptomyces griseus and S. clavuligerus, an industrial by-product. Both washed and unwashed samples were examined. Foam flotation is proposed in this work as the separation stage following biosorption. Effective biomass separation was conducted in the presence of a frother, ethanol. The pH of the solution was a crucial parameter for flotation and also for metal binding. Other basic parameters of flotation examined were the initial cadmium concentration in the dilute aqueous solution and the quantity of biomass used. A study of [zeta]-potential measurements of the actinomycetes was carried out under the conditions used in the separation; surface tension was also measured. These provided useful information on the process.

  14. Computer finds ore

    NASA Astrophysics Data System (ADS)

    Bell, Peter M.

    Artificial intelligence techniques are being used for the first time to evaluate geophysical, geochemical, and geologic data and theory in order to locate ore deposits. After several years of development, an intelligent computer code has been formulated and applied to the Mount Tolman area in Washington state. In a project funded by the United States Geological Survey and the National Science Foundation a set of computer programs, under the general title Prospector, was used successfully to locate a previously unknown ore-grade porphyry molybdenum deposit in the vicinity of Mount Tolman (Science, Sept. 3, 1982).The general area of the deposit had been known to contain exposures of porphyry mineralization. Between 1964 and 1978, exploration surveys had been run by the Bear Creek Mining Company, and later exploration was done in the area by the Amax Corporation. Some of the geophysical data and geochemical and other prospecting surveys were incorporated into the programs, and mine exploration specialists contributed to a set of rules for Prospector. The rules were encoded as ‘inference networks’ to form the ‘expert system’ on which the artificial intelligence codes were based. The molybdenum ore deposit discovered by the test is large, located subsurface, and has an areal extent of more than 18 km2.

  15. Possible lunar ores

    NASA Technical Reports Server (NTRS)

    Gillett, Stephen L.

    1991-01-01

    Despite the conventional wisdom that there are no lunar ores, geochemical considerations suggest that local concentrations of useful rare elements exist on the Moon in spite of its extreme dryness. The Moon underwent protracted igneous activity in its history, and certain magmatic processes can concentrate incompatible elements even if anhydrous. Such processes include: (1) separation of a magma into immiscible liquid phases (depending on composition, these could be silicate-silicate, silicate-oxide, silicate-sulfide, or silicate-salt); (2) cumulate deposits in layered igneous intrusions; and (3) concentrations of rare, refractory, lithophile elements (e.g., Be, Li, Zr) in highly differentiated, silica-rich magmas, as in the lunar granites. Terrestrial mining experience indicates that the single most important characteristic of a potential ore is its concentration of the desire element. The utility of a planet as a resource base is that the welter of interacting processes over geologic time can concentrate rare element automatically. This advantage is squandered if adequate exploration for ores is not first carried out.

  16. 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.

  17. Removal of molybdate and arsenate from aqueous solutions by flotation

    SciTech Connect

    Zhao, Y.; Zouboulis, A.I.; Matis, K.A.

    1996-03-01

    Ion flotation and adsorbing colloid flotation have been studied in this paper for the effective removal of molybdenum(VI) and arsenic(V) from dilute aqueous solutions. These different flotation methods were also compared. Ion flotation using a cationic surfactant (dodecylamine) as collector, as well as adsorbing colloid flotation using ferric hydroxide as coprecipitant (or sorbent) and an anionic surfactant (sodium dodecyl sulfate) as collector were examined. Laboratory-scale experiments were conducted in order to assess the effects of the following parameters of the efficiency of the process: pH value, dosages of chemical reagents, initial concentrations of arsenic and molybdenum, and the presence of foreign anions, such as Cl{sup -} and SO{sup 2}{sub 4}{sup -}. In practical applications, ion flotation or adsorbing colloid flotation may be selected according to the concentration of arsenic, molybdenum, and also the initial [Mo]/[As] molar ratios in solution.

  18. A novel multistage kinetic modeling of flotation for wastewater treatment.

    PubMed

    Ksenofontov, B S; Ivanov, M V

    2013-01-01

    This study develops a new model for description of flotation kinetics. It defines flotation as a process that consists of several stages: separated air bubbles and particles, air bubbles and particles forming an aggregate, aggregate rising to the froth layer. This description significantly differs from known models, which are much simplified. The multistage model gives a novel in-depth description and considers different aspects of flotation, i.e. aggregate formation, which is critically important for flotation to take place. Experimental approval of the new model resulted in its accuracy. The model is to be used for a description of kinetics of all flotation processes in wastewater treatment. It helps in accurate design of flotation treatment plants and may be used for further research of the flotation process.

  19. Benzene stripping in a flotation unit

    SciTech Connect

    Hillquist, D.; Litchfield, J.; Willet, S.; Whiteford, R.

    1994-12-31

    An induced gas flotation unit is used as a combination stripping/flotation vessel with fuel gas as the stripping/flotation medium. The gas bubbles simultaneously float the oils and solids, and strip out and recover the benzene and other volatile components from wastewater and from the floated oils and solids. The effluent stripping gas is then either used as fuel gas, or recycled to the process for product recovery. The induced gas flotation stripper, IGFS, is self-cleaning and normally experiences no sludge build up or fouling. The unit requires a minimum of operator attention and maintenance. It is sealed to eliminate emissions, has a high stripping efficiency, and has a significantly wider operating range than conventional strippers. The unit does not experience the biological fouling and disposal problems of air strippers, or the fouling and higher capital and operating costs of steam strippers. The IGFS unit was installed at the BF Goodrich ethylene plant in Calvert City in 1991. The unit was designed to treat a combined stream consisting of quench water, neutralized spent caustic, and a number of intermittent smaller oily water streams. The unit is operating effectively in stripping the benzene to levels below the NESHAP requirements. The average benzene removal efficiency is above 97%. Operating data indicate that the benzene removal efficiency can be further enhanced by increasing temperature, increasing stripping flow, reducing oil emulsions in the influent and eliminating dilution from recycled water. This paper presents performance and operating experience of the IGFS unit.

  20. 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.

  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. Journey to the Reef

    ERIC Educational Resources Information Center

    Bryson, Linda

    2010-01-01

    Despite their experiences with a cartoon sponge, most elementary students know little about the diverse inhabitants of coral reefs. Therefore, with vivid photography and video, diverse coral reef inhabitants were brought to life for the author's fifth-grade students. Students shared their knowledge in language arts and even explored coral reefs in…

  3. Reefs happen

    USGS Publications Warehouse

    Kinzie, R. A.; Buddemeier, R.W.

    1996-01-01

    Corals and coral reefs confront us with a variety of paradoxes in terms of their responses to global change. The species appear evolutionarily long-lived and stable, and combinations of organisms recur and persist at levels ranging from endosymbiosis to palaeocommunity structure. The fact that these organisms and communities occupy a seemingly precarious environment near the common interface of land, sea, and air suggests that they possess powerful adaptive and acclimative mechanisms, and the special characteristics associated with their range of reproductive options, their modular (colonial) form, and their symbiotic associations provide multiple pathways for adaptation. At the same time, they are widely considered to be vulnerable to anthropogenic stresses, and to show signs of deterioration on a global scale. Interest in corals is further enhanced by their unique position with regard to the carbon cycle, with inorganic and organic carbon metabolisms that are of comparable magnitudes. The durable limestone structures they create modify the shallow-water environment, and their mineral skeletons preserve in their isotopic, chemical, and structural characteristics records of past environmental conditions. Whether as survivors, recorders, or victims, their relationship to global change is fascinating and instructive. This paper provides a general background and context for the specific papers that make up this topical issue of Global Change Biology. ?? 1996 Blackwell Science Ltd.

  4. Geochemistry of sedimentary ore deposits

    SciTech Connect

    Maynard, J. B.

    1983-01-01

    A text providing a sedimentological treatment of a study on ore deposits, and especially as related to geochemistry. Excellently documented (about 5000 citations). Well indexed with the index of deposits and localities separated. Contents, Iron. Copper and silver. Aluminum and nickel. Manganese. Uranium. Lead and zinc. Volcanic-sedimentary ores. Appendix. Indexes.

  5. Can I Trust ORE Reports?

    ERIC Educational Resources Information Center

    Feedback, 1984

    1984-01-01

    This issue of FEEDBACK, a newsletter produced by the the Austin Independent School District Office of Research and Evaluation (ORE), illustrates the accuracy, validity, and fairness of ORE reports. The independence of the reports is explained. Internal and external quality controls are used to ensure reliability and accuracy of the reports.…

  6. Dispersion characteristics in column flotation of fine coal

    SciTech Connect

    Peng, F.F.; Lili, L.

    1995-10-01

    The dispersion model of nonideal flow was applied to describe the hydrodynamic state within the flotation column. Residence time distribution (RTD) data of a laboratory flotation column were measured to determine the parameters of the model. The effects of operating variables and column geometry on the Peclet number which reflects the extent of axial dispersion were investigated and a semi-empirical expression of Pe was formulated. The dispersion model was validated for the column flotation of ultrafines coal. Under the conditions of sufficient aeration rate and frother addition, a good agreement between the measured recoveries and predicted data was obtained. The dispersion model with first-order flotation rate process of the flotation column developed in this study is useful in predicting the collection zone recovery of fine coal, and for the flotation column scale-up.

  7. Uranium resources in the Silver Reef (Harrisburg) district, Washington County, Utah

    USGS Publications Warehouse

    Stugard, Frederick

    1951-01-01

    The Silver Reef district is near Leeds, about 16 miles north of St. George, Utah. The major structural feature of the district is the Virgin anticline, a fold extending southwestward toward St. George. The anticline has been breached by erosion, and sandstone hogbacks or 'reefs' are carved from the Shinarump conglomerate mud sandstone members of the Chinle formation, both of Triassic age. Thirteen occurrences of uranium-vanadium minerals, all within the Tecumseh sandstone, which is the upper part of the Silver Reef sandstone member of the Chinle formation, have been examined over an area about 1.75 miles wide and 3 miles long. Two shipments of uranium-vanadium ore have been produced from the Chloride Chief and Silver Point claims. Samples from the deposits contain as much as 0.94 percent U3O8. The ore contains several times as much vanadium oxide as uranium, some copper, and traces of silver. It occurs in thinly bedded cross-bedded shales and sandstones within the fluviatile Tecumseh sandstone member of the Chinle formation. The ore beds are lenticular and are localized 2 near the base, center, and top of this sandstone member. The uranium-vanadium ore contains several yellow and green minerals not yet identified; the occurrences are similar to, but not associated with, the cerargyrite ore that made the district famous from 1879 to 1909.

  8. The industrial practice and development of flotation column in China

    SciTech Connect

    Liu Jiongtian; Zhang Shuangquan

    1997-12-31

    This paper reviewed the developing course of the flotation column since the 1960`s in China. Based on the practical data from several coal preparation plants, two types of flotation columns (the pressure aerated column and the jetting-cyclone column) were compared by their operation, performance and the reasons why they succeeded in the coal industry in China. The paper points out that the flotation column has come into commercial use and has good application prospects in China.

  9. Enhanced pyrite rejection in coal flotation

    SciTech Connect

    Tao, D.P.; Lu, M.X.; Richardson, P.E.; Luttrell, G.H.; Adel, G.T.; Yoon, R.H.

    1994-12-31

    Difficulties in rejecting pyrite from coal by flotation primarily result from two mechanisms of particle recovery: attachment and middlings. Attachment of pyrite is the consequence of surface hydrophobicity induced by superficial oxidation; middlings that can float readily are caused by incomplete liberation of pyrite from coal. New flotation schemes have been developed to enhance pyrite rejection. They are referred to as Electrochemically-Enhanced Sulfur Rejection (EESR) and Polymer-Enhanced Sulfur Rejection (PESR) processes. In the EESR process, the formation of hydrophobic products is prevented by electrochemical techniques in which active metals are used as sacrificial anodes to cathodically protect pyrite from oxidation; in the PESR process, hydrophilic polymers is used to mask coal in middlings by specific adsorption on pyrite, and thus depress coal-pyrite middlings.

  10. 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.

  11. 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.

  12. The behavior of each species in coal flotation

    SciTech Connect

    Liu, W.; Lu, M.; Ren, S.; Kou, C.

    1999-07-01

    The work presented in this paper mainly focused on the study into the flotation behavior of each species at different levels of collector dosage, frother dosage, and air volumetric flow rate. Examination of the flotation response of the discrete particle size fraction reveals that the flotation behavior of each size fraction does not follow the first order model. The flotation rate constant decreases with the increase of flotation time. The recovery of minus 74 micron fraction has a good relationship with the amount of floated water. The relationship between water flotation rate, Kw, and frother dosage, collector dosage and air volumetric flow rate is also discussed. By this relationship, the amount of floated water can be predicted according to the addition rate of frother, collector and air volumetric flow rate during the flotation procedure, and further the recovery of minus 74 micron coal can also be predicted. Examination of the flotation behavior of each discrete density fraction shows that it also does not follow the first order model. A further investigation of each density fraction within the same size fraction is also conducted. It is found that the behavior of the narrower species fits the first order model well. By statistical analysis, the models, which represent the relationship between the flotation rate constant of each narrower species and the manipulated variables (frother, collector and air flow rate), have been built. On these models built above, the product quantity and quality can be predicted on-line.

  13. Advanced froth flotation techniques for fine coal cleaning

    SciTech Connect

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

    1994-12-31

    Advanced column flotation cells offer many potential advantages for the treatment of fine coal. The most important of these is the ability to achieve high separation efficiencies using only a single stage of processing. Unfortunately, industrial flotation columns often suffer from poor recovery, low throughput and high maintenance requirements as compared to mechanically-agitated conventional cells. These problems can usually be attributed to poorly-designed air sparging systems. This article examines the problems of air sparging in greater detail and offers useful guidelines for designing bubble generators for industrial flotation columns. The application of these principles in the design of a successful advanced fine coal flotation circuit is also presented.

  14. 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.

  15. 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.

  16. [Assessment of schemes for sewage purification from petroleum products, by using various flotation methods].

    PubMed

    Zabuga, G A; Filippova, T M; Sivkov, A A

    2010-01-01

    Petroleum products are the most common pollutants in petroleum refinery wastewater and are freed from the latter by flotation that is one of the most frequently applied physicochemical methods. The existing petroleum refinery OAO "Angara Petroleum Company" scheme for sewage purification from petroleum products, by using pressure flotation and proposed as a competitive purification scheme by applying electrical and impeller flotations underwent a comparative ecologoeconomic analysis. The use of electrical flotation instead of pressure flotation and that of an impeller flotation-electrical flotation system instead of a mechanical purification-pressure flotation one can considerably lower the concentration of petroleum products at the wastewater outlet into the Angara river.

  17. 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.

  18. A theoretical model of flotation deinking efficiency

    SciTech Connect

    Bloom, F.; Heindel, T.J.

    1997-06-01

    The associated probabilities of each microprocess occurring in flotation deinking are employed in the development of a kinetic or population balance-type model of the overall flotation process. The overall model contains two kinetic constants: The first, k{sub 1}, governs the overall probability of a free ink particle successfully being intercepted by and adhering to an air bubble; the second, k{sub 2}, is a measure of the probability that a particle/bubble aggregate pair will become unstable and split to yield a new free ink particle. The solution to the kinetic model is presented in terms of k{sub 1} and k{sub 2}, which are themselves functions of system parameters such as bubble and particle physical properties (e.g., diameter, density) and fluid properties (e.g., viscosity, surface tension). From this solution, a definition of theoretical flotation efficiency is presented, as well as definitions of other system performance parameters, and selected predictions are displayed.

  19. Ore metals through geologic history.

    PubMed

    Meyer, C

    1985-03-22

    The ores of chromite, nickel, copper, and zinc show a wide distribution over geologic time, but those of iron, titanium, lead, uranium, gold, silver, molybdenum, tungsten, and tin are more restricted. Many of the limitations to specific time intervals are probably imposed by the evolving tectonic history of Earth interacting with the effects of the biomass on the evolution of the earth's s surface chemistry. Photosynthetic generation of free oxygen and "carbon" contributes significantlly to the diversity of redox potentials in both sedimentary and igneous-related processes of ore formation, influencing the selection of metals at the source, during transport, and at the site of ore deposition.

  20. 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.

  1. Microbial reduction of iron ore

    DOEpatents

    Hoffmann, M.R.; Arnold, R.G.; Stephanopoulos, G.

    1989-11-14

    A process is provided for reducing iron ore by treatment with microorganisms which comprises forming an aqueous mixture of iron ore, microorganisms operable for reducing the ferric iron of the iron ore to ferrous iron, and a substrate operable as an energy source for the microbial reduction; and maintaining the aqueous mixture for a period of time and under conditions operable to effect the reduction of the ore. Preferably the microorganism is Pseudomonas sp. 200 and the reduction conducted anaerobically with a domestic wastewater as the substrate. An aqueous solution containing soluble ferrous iron can be separated from the reacted mixture, treated with a base to precipitate ferrous hydroxide which can then be recovered as a concentrated slurry. 11 figs.

  2. Microbial reduction of iron ore

    DOEpatents

    Hoffmann, Michael R.; Arnold, Robert G.; Stephanopoulos, Gregory

    1989-01-01

    A process is provided for reducing iron ore by treatment with microorganisms which comprises forming an aqueous mixture of iron ore, microorganisms operable for reducing the ferric iron of the iron ore to ferrous iron, and a substrate operable as an energy source for the microbial reduction; and maintaining the aqueous mixture for a period of time and under conditions operable to effect the reduction of the ore. Preferably the microorganism is Pseudomonas sp. 200 and the reduction conducted anaerobically with a domestic wastewater as the substrate. An aqueous solution containing soluble ferrous iron can be separated from the reacted mixture, treated with a base to precipitate ferrous hydroxide which can then be recovered as a concentrated slurry.

  3. 21 CFR 880.5550 - Alternating pressure air flotation mattress.

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ... body pressure. The device is used to prevent and treat decubitus ulcers (bed sores). (b) Classification... 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)...

  4. 33 CFR 142.45 - Personal flotation devices.

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... 33 Navigation and Navigable Waters 2 2013-07-01 2013-07-01 false Personal flotation devices. 142.45 Section 142.45 Navigation and Navigable Waters COAST GUARD, DEPARTMENT OF HOMELAND SECURITY... § 142.45 Personal flotation devices. Personnel, when working in a location such that, in the event of...

  5. 33 CFR 142.45 - Personal flotation devices.

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ... 33 Navigation and Navigable Waters 2 2012-07-01 2012-07-01 false Personal flotation devices. 142.45 Section 142.45 Navigation and Navigable Waters COAST GUARD, DEPARTMENT OF HOMELAND SECURITY... § 142.45 Personal flotation devices. Personnel, when working in a location such that, in the event of...

  6. 33 CFR 142.45 - Personal flotation devices.

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... 33 Navigation and Navigable Waters 2 2014-07-01 2014-07-01 false Personal flotation devices. 142.45 Section 142.45 Navigation and Navigable Waters COAST GUARD, DEPARTMENT OF HOMELAND SECURITY... § 142.45 Personal flotation devices. Personnel, when working in a location such that, in the event of...

  7. 33 CFR 142.45 - Personal flotation devices.

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... 33 Navigation and Navigable Waters 2 2011-07-01 2011-07-01 false Personal flotation devices. 142.45 Section 142.45 Navigation and Navigable Waters COAST GUARD, DEPARTMENT OF HOMELAND SECURITY... § 142.45 Personal flotation devices. Personnel, when working in a location such that, in the event of...

  8. 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...

  9. 33 CFR 183.202 - Flotation and certification requirements.

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ... 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...

  10. 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... REQUIREMENTS FOR ALL INSPECTED VESSELS Special Installations § 170.245 Foam flotation material. (a... strength to withstand a hydrostatic head equivalent to that which would be imposed if the vessel...

  11. 33 CFR 183.225 - Flotation test for persons capacity.

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... 33 Navigation and Navigable Waters 2 2013-07-01 2013-07-01 false Flotation test for persons capacity. 183.225 Section 183.225 Navigation and Navigable Waters COAST GUARD, DEPARTMENT OF HOMELAND... Boats Rated for Engines of More Than 2 Horsepower Tests § 183.225 Flotation test for persons...

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

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... 33 Navigation and Navigable Waters 2 2013-07-01 2013-07-01 false Flotation test for persons capacity. 183.325 Section 183.325 Navigation and Navigable Waters COAST GUARD, DEPARTMENT OF HOMELAND... Boats Rated for Engines of 2 Horsepower or Less Tests § 183.325 Flotation test for persons...

  13. 33 CFR 183.222 - Flotation material and air chambers.

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... 33 Navigation and Navigable Waters 2 2014-07-01 2014-07-01 false Flotation material and air chambers. 183.222 Section 183.222 Navigation and Navigable Waters COAST GUARD, DEPARTMENT OF HOMELAND... Boats Rated for Engines of More Than 2 Horsepower General § 183.222 Flotation material and air...

  14. Reef Education Evaluation: Environmental Knowledge and Reef Experience

    ERIC Educational Resources Information Center

    Stepath, Carl M.

    2005-01-01

    Background: The Reef education evaluation: environmental knowledge and reef experience report concerns PhD research about marine education, and the investigation of learning with high school students and the effect of coral reef monitoring marine experiential education interventions. The effectiveness of classroom learning and reef trips were…

  15. Great Barrier Reef

    NASA Technical Reports Server (NTRS)

    2002-01-01

    A better than average view of the Great Barrier Reef was captured by SeaWiFS on a recent overpass. There is sunglint northeast of the reef and there appears to be some sort of filamentous bloom in the Capricorn Channel.

  16. Vessel-to-Reef Projects

    EPA Pesticide Factsheets

    Using vessels as artificial reefs is an option for disposal. Artificial reefs serve to benefit the environment. Vessel-to-reef projects can follow the best management practices guidance. Guidance are provided for how to clean up vessels for use as reefs.

  17. 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

  18. Gold-bearing reefs of the Witwatersrand Basin: A model of synsedimentation hydrothermal formation

    NASA Astrophysics Data System (ADS)

    Safonov, Yu. G.; Prokof'ev, V. Yu.

    2006-12-01

    The current concepts concerning the genesis of the unique ore-bearing reefs of the Witwatersrand Basin and its gold resource potential are considered. The results of microscopic examination of ore from the Black, Ventersdorp Contact, Carbon Leader, and Vaal reefs, as well as of thermobarometric study of quartz, are presented. A model of synsedimentation hydrothermal origin of the reefs in the process of evolution of primary colloidal-disperse systems is substantiated on the basis of these results and the data published by other authors. The formation of these systems is related to the periodic gain of deep ore-bearing gas-saturated fluids. The gold mineralization was formed under conditions of partially closed systems, where various mineral-forming processes developed (metasomatism, crystallization of true solutions and gels, gel metasomatism, dispersion of crystalline phases, segregation of mineral particles, formation of early minerals, etc.). New data on REE specialization of ore-bearing fluids are discussed. The specific features of the gold, carbonic, and uranium mineralization of the intracratonic basin are emphasized.

  19. Column flotation shows higher recovery with less ash

    SciTech Connect

    Groppo, J.

    1986-08-01

    Why column flotation. It can effectively clean fines and yield a saleable low-ash coal from what would otherwise be the waste stream. Not only does the coal recovery improve, but the waste tonnage is reduced, thereby prolonging the life of waste storage facilities. Although regular froth flotation has proven to be an effective method for recovering fine coal (-28 mesh), flotation efficiency often drops for the finest fractions, particularly when an excessive amount of fine clays are present. Because of their small mass and momentum, these fine particles wind up in the froth and get physically entrained with particles that float. Countercurrent column flotation solves this problem by providing a stream of wash water flowing against the bubble/particle aggregates. This action allows the sticky ash to be washed from the bubble as well as from the froth. Column flotation is not new to the mining industry; it has been used to separate fine graphite from clay, and such sulfide mineral separations as molybdenum and copper. The big advantage provided by countercurrent column flotation was it required only a single step to do what cleaner flotation did in several stages.

  20. 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.

  1. Two types of ore-bearing mafic complexes of the Early Proterozoic East-Scandinavian LIP and their ore potential

    NASA Astrophysics Data System (ADS)

    Mitrofanov, Felix; Zhirov, Dmitry; Bayanova, Tamara; Korchagin, Alexey; Chaschin, Victor

    2015-04-01

    Two types of the ore-bearing mafic complexes are allotted in the East-Scandinavian large igneous province (LIP). They differ in geodynamic setting, structure, isotope geochemistry, petrology and mineralogy. The PGE-bearing mafic-ultramafic layered intrusions are associated with the first complex. They have been formed at an initial (pre-rift) stage of LIP. Features of origin of this complex are: 1) large-scale, protracted, and multiple episodes of deep mantle plume or asthenosphere upwelling; 2) the vast non-subduction-type basaltic magma in an intraplate continental setting; 3) low-sulfide Pt-Pd (with Ni, Cu, Au, Co and Rh) mineralization in different geological setting (reef- and contact type etc.); 4) anomalously high concentrations of PGEs in the bulk sulfides, inferred platinum distribution coefficient between silicate and sulfide melts of >100000. Deep mantle magma source is enriched in ore components (fertile source) and lithophile elements. It is reflected in the isotope indicators such as ɛNd(T) from -1 to -3, ISr(87Sr/86Sr) from 0.702 to 0.704, 3Не/4Не = (10 ^-5 ÷ 10 ^-6). Magma and ore sources differ from those of Mid-Ocean Ridge basalts (MORB), subduction-related magma but are similar to EM-I. Ore-bearing mafic complexes formed during a long period of time and by different episodes (2490±10 Ma; 2470±10 Ma; 2450±10 Ma; 2400±10 Ma), and by mixing between the boninitic an anorthositic magmas. It is known about 10 deposits and occurrences in Kola region with total reserves and resources about 2000 tons in palladium equivalent (with an average content ≥2-3 ppm). Intrusions with the rich sulfide Ni-Cu ore (with Co and poor PGE) are associated with the second mafic complex. Ore-controlling mafic-ultramafic intrusions are formed at a final stage of the intracontinental rifting of the Transitional period (2200-1980 Ma). Initial magma is depleted and similar to the MORB in terms of rare earths distribution. Enriched ferropicritic Fe-Ti derivatives of

  2. O-ring gasket test fixture

    NASA Technical Reports Server (NTRS)

    Turner, James Eric (Inventor); Mccluney, Donald Scott (Inventor)

    1991-01-01

    An apparatus is presented for testing O-ring gaskets under a variety of temperature, pressure, and dynamic loading conditions. Specifically, this apparatus has the ability to simulate a dynamic loading condition where the sealing surface in contact with the O-ring moves both away from and axially along the face of the O-ring.

  3. The modes of occurrence of rare-earths ores and the issues on their beneficiation processes

    NASA Astrophysics Data System (ADS)

    Takagi, T.

    2012-04-01

    , which is also a refractory material. 4. Medium- to coarse-grained carbonates: This type ores occur in less weathered carbonatite bodies. Mountain Pass (US), Maoniuping (China) and Dong Pao (Vietnam) are the representative deposits. Bastnasite is a main RE mineral. Though, the ores can readily be beneficiated by conventional flotation and dissolved by acid solution, they are always depleted in heavy RE.

  4. Physical exploration for uranium during 1951 in the Silver Reef district, Washington County, Utah

    USGS Publications Warehouse

    Stugard, Frederick

    1954-01-01

    During 1951 a joint exploration program of the most promising uraniferous areas in the Silver Reef district was made by the U.S. Geological Survey and the U.S. atomic Energy Commission. A U.S. Bureau of Mines drill crew, on contract to the Atomic Energy Commission, did 2,450 feet of diamond drilling under the geological supervision of the U.S. Geological Survey. The purpose of the drilling was to delineate broadly the favorable ground for commercial development of the uranium deposits. Ten drill holes were located around Pumpkin Point, which is the northeastern end of Buckeye Reef, to probe for extensions of small ore sheets mined on the Point in fine-grained sandstones of the Chinle formation. Three additional holes were located around Tecumseh Hill to probe for extensions of the small showings of uranium-bearing rocks of Buckeye Reef. Only one trace of uranium mineral was detected in the 13 drill holes by logging of drill cores, gamma-ray logging of the holes, and analysis of many core splits from favorable lithology. Extensive traversing with Geiger counters throughout the district and detailed geologic mapping of areas on Buckeye Reef and on East Reef indicate that the chances of discovering significant uranium deposits in the Silver Reef district are very poor, because of: highly variable lithology, closely faulted structure, and obliteration of the shallow uranium-bearing lenses by silver mining. Most of the available ore in the district was in the Pumpkin Point area and has been mined during 1950 to 1953. No ore reserves can be computed for the district before further development work. The most favorable remaining area in the district is now being explored by the operators with Atomic Energy Commission supervision.

  5. 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.

  6. Conical O-ring seal

    DOEpatents

    Chalfant, Jr., Gordon G.

    1984-01-01

    A shipping container for radioactive or other hazardous materials which has a conical-shaped closure containing grooves in the conical surface thereof and an O-ring seal incorporated in each of such grooves. The closure and seal provide a much stronger, tighter and compact containment than with a conventional flanged joint.

  7. Conical O-ring seal

    DOEpatents

    Chalfant, G.G. Jr.

    A shipping container for radioactive or other hazardous materials has a conical-shaped closure containing grooves in the conical surface thereof and an O-ring seal incorporated in each of such grooves. The closure and seal provide a much stronger, tighter and compact containment than with a conventional flanged joint.

  8. Australia's Great Barrier Reef

    NASA Technical Reports Server (NTRS)

    2001-01-01

    The Great Barrier Reef extends for 2,000 kilometers along the northeastern coast of Australia. It is not a single reef, but a vast maze of reefs, passages, and coral cays (islands that are part of the reef). This nadir true-color image was acquired by the MISR instrument on August 26, 2000 (Terra orbit 3679), and shows part of the southern portion of the reef adjacent to the central Queensland coast. The width of the MISR swath is approximately 380 kilometers, with the reef clearly visible up to approximately 200 kilometers from the coast. It may be difficult to see the myriad details in the browse image, but if you retrieve the higher resolution version, a zoomed display reveals the spectacular structure of the many reefs.

    The more northerly coastal area in this image shows the vast extent of sugar cane cultivation, this being the largest sugar producing area in Australia, centered on the city of Mackay. Other industries in the area include coal, cattle, dairying, timber, grain, seafood, and fruit. The large island off the most northerly part of the coast visible in this image is Whitsunday Island, with smaller islands and reefs extending southeast, parallel to the coast. These include some of the better known resort islands such as Hayman, Lindeman, Hamilton, and Brampton Islands.

    Further south, just inland of the small semicircular bay near the right of the image, is Rockhampton, the largest city along the central Queensland coast, and the regional center for much of central Queensland. Rockhampton is just north of the Tropic of Capricorn. Its hinterland is a rich pastoral, agricultural, and mining region.

    MISR was built and is managed by NASA's Jet Propulsion Laboratory, Pasadena, CA, for NASA's Office of Earth Science, Washington, DC. The Terra satellite is managed by NASA's Goddard Space Flight Center, Greenbelt, MD. JPL is a division of the California Institute of Technology.

  9. 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.

  10. Coral Reef Ecosystems

    NASA Astrophysics Data System (ADS)

    Yap, Helen T.

    Coral reefs are geological structures of significant dimensions, constructed over millions of years by calcifying organisms. The present day reef-builders are hard corals belonging to the order Scleractinia, phylum Cnidaria. The greatest concentrations of coral reefs are in the tropics, with highest levels of biodiversity situated in reefs of the Indo-West Pacific region. These ecosystems have provided coastal protection and livelihood to human populations over the millennia. Human activities have caused destruction of these habitats, the intensity of which has increased alarmingly since the latter decades of the twentieth century. The severity of this impact is directly related to exponential growth rates of human populations especially in the coastal areas of the developing world. However, a more recently recognized phenomenon concerns disturbances brought about by the changing climate, manifested mainly as rising sea surface temperatures, and increasing acidification of ocean waters due to greater drawdown of higher concentrations of atmospheric carbon dioxide. Management efforts have so far not kept pace with the rates of degradation, so that the spatial extent of damaged reefs and the incidences of localized extinction of reef species are increasing year after year. The major management efforts to date consist of establishing marine protected areas and promoting the active restoration of coral habitats.

  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. 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

  13. 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.

  14. A parametric study of fine coal cleaning using column flotation

    SciTech Connect

    Parekh, B.K.; Groppo, J.G.; Bland, A.E.

    1986-01-01

    Recovery of fine coal is becoming an important and integral part of coal cleaning plants. Conventional froth flotation, which is commonly used in the coal industry, is inefficient at cleaning fine coal which contains large amounts of ultrafine ash or clays. The Kentucky Center for Energy Research Laboratory (KCERL) has been investigating an alternative method, counter-current column flotation, which is widely used in the mineral industry. Through an advanced cell design and counter-current wash of the froth, column flotation can produce a low-ash, clean coal product without sacrificing combustible recovery. An experimental program was conducted using a 2-inch internal diameter Canadian column flotation cell to examine the effect of various operating parameters on clean coal recovery and quality. The study investigated six operational parameters: feed rate, frother concentration, air flow rate, column height, pulp density and wash water rate.

  15. Flotation kinetics: Methods for estimating distribution of rate constants

    SciTech Connect

    Chander, S.; Polat, M.

    1995-12-31

    Many models have been suggested in the past to obtain a satisfactory fit to flotation data. Of these, first-order kinetics models with a distribution of flotation rate constants are most common. A serious limitation of these models is that type of the distribution must be pre-supposed. Methods to overcome this limitation are discussed and a procedure is suggested for estimating the actual distribution of flotation rate constants. It is demonstrated that the classical first-order model fits the data well when applied to coal flotation in narrow size-specific gravity intervals. When applied to material which is fractionated on the basis of size alone, the use of three parameter models, which were modified from their two parameter analogs such as rectangular, sinusoidal, and triangular, gave most reliable results.

  16. Colloidal titanium dioxide separation from water by foam flotation

    SciTech Connect

    Shen, Y.H.

    1998-12-01

    Colloidal titanium dioxide (TiO{sub 2}) was separated from an aqueous suspension (1,000 ppm) by foam flotation using cationic or anionic surfactants. The effects of surfactant dosage, suspension pH value, suspension ionic strength, and gas flow rate on the dispersed-air flotation of colloidal TiO{sub 2} were investigated. TiO{sub 2} separation was almost complete in optimum conditions. It was found that the coulombic interaction between charged TiO{sub 2} particle surfaces and ionic collectors plays a dominant role in this system. Both flotation rate and foamate volume are dependent upon the gas flow rate. Foam flotation may find application in the separation of submicron TiO{sub 2} particles in suspend-photocatalyst systems.

  17. Towards high throughput screening of nanoparticle flotation collectors.

    PubMed

    Abarca, Carla; Yang, Songtao; Pelton, Robert H

    2015-12-15

    To function as flotation collectors for mineral processing, polymeric nanoparticles require a delicate balance of surface properties to give mineral-specific deposition and colloidal stability in high ionic strength alkaline media, while remaining sufficiently hydrophobic to promote flotation. Combinatorial nanoparticle surface modification, in conjunction with high throughput screening, is a promising approach for nanoparticle development. However, efficient automated screening assays are required to reject ineffective particles without having to undergo time consuming flotation testing. Herein we demonstrate that determining critical coagulation concentrations of sodium carbonate in combination with measuring the advancing water contact angle of nanoparticle-saturated glass surfaces can be used to screen ineffective nanoparticles. Finally, none of our first nanoparticle library based on poly(ethylene glycol) methyl ether methacrylate (PEG-methacrylate) were effective flotation collectors because the nanoparticles were too hydrophilic.

  18. 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.

  19. 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.

  20. 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.

  1. A comparison study of commercially-available column flotation technologies

    SciTech Connect

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

    1994-12-31

    A direct comparison of three commercially-available column flotation technologies, i.e., Jameson Cell, Microcel, and Packed-Column, has been conducted using a {minus}100 mesh Illinois No. 5 flotation feed coal sample. The separation performance of each flotation technology was optimized and their performance levels compared on the basis of both ash rejection, sulfur rejection, and throughput capacities. A parametric study using a statistically-designed experimental program was conducted to optimize the critical operating parameter values of each column. The ultimate performance curves for each column were generated by conducting additional tests using the optimized operating parameter values. The throughput capacity of each flotation cell was determined by conducting tests over a range of feed rates at the maximum superficial gas rate while maintaining the other parameters at their optimum values. The separation performance achieved by each of the three flotation cells was found to be comparable to the idealistic flotation performance predicted by release analysis. However, the fraction of wash water reporting to tailings (bias factor) was found to be critical in achieving the near idealistic performance. The bias factor required for the Packed-Column was found to be less than that required by the other two flotation cells. The sulfur rejection achieved by the Microcel and the Packed-Column were found to be greater than that achieved by the Jameson Cell and all three produced sulfur rejections exceeding the values obtained from release analysis. The throughput capacity, on the other hand, differed among the three flotation columns. The Jameson Cell and the Microcel were found to have comparable throughput capacities while the Packed-Column was found to have a lower capacity.

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

    SciTech Connect

    Lai, R.W.; Patton, R.A.

    2000-05-02

    An apparatus and process are disclosed 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 hydrophilic tailings.

  3. Cross flow flotation column for coal and minerals beneficiation

    SciTech Connect

    Lai, Ralph W.; Patton, Robert A.

    1997-12-01

    An apparatus and process are disclosed 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 hydrophilic tailings.

  4. 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.

  5. 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.

  6. Investigation of foam flotation and phase partitioning techniques

    NASA Technical Reports Server (NTRS)

    Currin, B. L.

    1985-01-01

    The present status of foam flotation as a separation process is evaluated and limitations for cells and proteins are determined. Possible applications of foam flotation to separations in microgravity are discussed. Application of the fluid mechanical aspects of foam separation techniques is made to phase partitioning in order to investigate the viscous drag forces that may effect the partitioning of cells in a two phase poly(ethylene glycol) and dextran system.

  7. Remediation of metal-contaminated urban soil using flotation technique.

    PubMed

    Dermont, G; Bergeron, M; Richer-Laflèche, M; Mercier, G

    2010-02-01

    A soil washing process using froth flotation technique was evaluated for the removal of arsenic, cadmium, copper, lead, and zinc from a highly contaminated urban soil (brownfield) after crushing of the particle-size fractions >250microm. The metal contaminants were in particulate forms and distributed in all the particle-size fractions. The particle-by-particle study with SEM-EDS showed that Zn was mainly present as sphalerite (ZnS), whereas Cu and Pb were mainly speciated as various oxide/carbonate compounds. The influence of surfactant collector type (non-ionic and anionic), collector dosage, pulp pH, a chemical activation step (sulfidization), particle size, and process time on metal removal efficiency and flotation selectivity was studied. Satisfactory results in metal recovery (42-52%), flotation selectivity (concentration factor>2.5), and volume reduction (>80%) were obtained with anionic collector (potassium amyl xanthate). The transportation mechanisms involved in the separation process (i.e., the true flotation and the mechanical entrainment) were evaluated by the pulp chemistry, the metal speciation, the metal distribution in the particle-size fractions, and the separation selectivity indices of Zn/Ca and Zn/Fe. The investigations showed that a great proportion of metal-containing particles were recovered in the froth layer by entrainment mechanism rather than by true flotation process. The non-selective entrainment mechanism of the fine particles (<20 microm) caused a flotation selectivity drop, especially with a long flotation time (>5 min) and when a high collector dose is used. The intermediate particle-size fraction (20-125 microm) showed the best flotation selectivity.

  8. An overview of Miocene reefs

    SciTech Connect

    Jordan, C.F. Jr. ); Colgan, M.W. ); Frost, S.H. ); Glenn, E.C. ); Bosence, D. ); Esteban, M. )

    1990-05-01

    Miocene reefs lived approximately within the latitudes of 27{degree}S to 48{degree}N compared with 25{degree}S and 32{degree}N for Holocene reefs. This expansion of reef-growing environments was the result of warm Miocene climates, aided by a eustatic sea level rise and tectonic styles that provided numerous foundations for reef development. The majority of Miocene reefs are found in three main areas: (1) Southeast Asia and the western Pacific, (2) the Mediterranean-Middle East, and (3) Middle America and the Caribbean. These regions, with their distinctive suites of coral and foramineral species, formed three biological provinces; respectively, they are the Indo-Pacific, Tethyan, and Western Atlantic provinces. Miocene reefs in Southeast Asia occur in several foreland basins as patch reef complexes on paleohighs and as barrier reefs in back-arc basins. Those reefs in the Mediterranean occur as fringing reefs, middle-shelf patch reefs, or as barrier reefs on the edges of tectonic blocks associated with Alpine thrust belts. Most reefs in the Caribbean grew on isolated open-ocean highs of volcanic origin. Miocene reefs display a diversity of framework types: (1) coral-encrusting, red algal boundstones with diverse coral faunas, (2) branching coral-encrusting, red algal boundstones with a limited Poritid fauna, (3) encrusting red algal boundstones. Barrier reef systems are especially rich in encrusting red algae and robust corals; grainstones are common as interbedded sediment. Patch reef complexes, however, display muddy carbonate textures, may have less diverse coral faunas, and commonly have larger foraminifera. The global distribution of Miocene reefs is important because (1) it provides insight into a paleoclimatic view of the earth during a major greenhouse stage and (2) Miocene buildups, such as the Arun (EUR of 14 tcf) and Bima fields (EUR of about 100 MMBO), are exploration targets.

  9. Virtual phosphorus ore requirement of Japanese economy.

    PubMed

    Matsubae, Kazuyo; Kajiyama, Jun; Hiraki, Takehito; Nagasaka, Tetsuya

    2011-08-01

    Phosphorus is indispensable for agricultural production. Hence, the consumption of imported food indirectly implies the import of phosphorus resources. The global consumption of agricultural products depends on a small number of ore-producing countries. For sustainable management of phosphorus resources, the global supply and demand network should be clarified. In this study, we propose the virtual phosphorus ore requirement as a new indicator of the direct and indirect phosphorus requirements for our society. The virtual phosphorus ore requirement indicates the direct and indirect demands for phosphorus ore transformed into agricultural products and fertilizer. In this study, the virtual phosphorus ore requirement was evaluated for the Japanese economy in 2005. Importantly, the results show that our society requires twice as much phosphorus ore as the domestic demand for fertilizer production. The phosphorus contained in "eaten" agricultural products was only 12% of virtual phosphorus ore requirement.

  10. Application of electrochemical investigation methods in high sulfur coal flotation

    SciTech Connect

    Zhu Hong; Ou Zeshen; Shi Xiuping; Shen Yanchun

    1997-12-31

    More and more attention has been paid to sulfur dioxide pollution caused by coal burning. It is important that sulfur in coal should be reduced before combustion. Flotation is an important method for the removal of pyrite from high sulfur coal. Many chemicals have been tested as a pyrite depressant. In recent years many tests have been done in the laboratory on the flotation behavior of pyrite, and the results have confirmed that the hydrophobicity of the pyrite surface is dependent on the redox potential of the pulp. The mechanism and the reaction products on the pyrite surface are discussed under various conditions. And pyrite depression in coal flotation by electrochemical control are further studied on the basis of what has been achieved. There are two methods in electrochemical control: chemical reagent and control potential by electrochemical instrument (``control potential`` for short). This paper studies pyrite depression in coal flotation by electrochemical control. The influence of sulfur removal in coal flotation has been probed by chemical reagent and control potential. Experiment shows that at low pulp potential the pyrite flotation is generally suppressed. This is new, efficient and simple method of pyrite depression without environmental pollution. The following main conclusions can be drawn from this study: (1) The control of pulp potential can regulate and lead to electrochemical reaction of the hydrophobicity or hydrophilicity on the pyrite surface; and (2) The characteristics of electrochemical methods are normal atmospheric temperature, simple technological process and strong selection.

  11. 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.

  12. Selective flotation of fossil resins from Northeast China coal

    SciTech Connect

    Hua, X.; Bo, H.; Qing, X.; Lijian, L.; Rong-Zeng, Z.

    1999-07-01

    For a feed which came from Northeast China containing 11.4 per cent fossil resin, by conventional single stage flotation, the fossil resin concentrate gained had a low grade. Adjusting the pH of the feed slurry with HCl or CaO before flotation or treating the feed with H{sub 2}O{sub 2} solution before flotation did not improve the selectivity of flotation. In order to improve the selectivity of flotation for fossil resin, the authors treated the feed slurry of flotation with several surfactants. Although most of them did not work very well, one surfactant was able to increase the grade of concentrate to over 80% as the recovery rate was higher than 82%. The result of mechanism research into the performance of the best surfactant indicated that the selective adsorption of the hydrophobic side of the surfactant onto the surface of coal particle made it more hydrophilic, so that the difference between the hydrophobicity of the coal particle's surface and that of the fossil resin's surface was enlarged.

  13. 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.

  14. 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.

  15. Contradicting Barrier Reef relationships for Darwin's Evolution of reef types

    NASA Astrophysics Data System (ADS)

    Purdy, Edward G.; Winterer, Edward L.

    2006-02-01

    The Darwinian progressive subsidence model for the evolution of fringing reefs, barrier reefs and atolls has been generally accepted following the indisputable proof of subsidence provided by drilling results in the Pacific. Nonetheless, there are data that do not fit the expectations of the model, such as the similar lagoon depths of barrier reefs and atolls as opposed to the subsidence theory’s implicit prediction that atolls should have significantly greater depths. In contrast, a great deal of evidence supports the influence of meteoric solution on barrier reef morphology. For example, the maximum lagoon depth of 56 modern barrier reefs is statistically correlated with the lagoon catchment area for modern annual rainfall. These modern rainfall patterns would seem to be a reasonable proxy for relative geographic differences in glacial lowstand rainfall, even though the absolute amounts of such rainfall are unknown. The correlation therefore suggests the importance of Pleistocene subaerial solution in contributing to barrier reef morphology. Further support for antecedent influence occurs in the form of barrier reef passes in which the depth of the reef pass is correlated with onshore drainage volumes. On a larger scale, the Cook Island of Mangaia provides evidence that solution can produce barrier reef morphology independent of reef development. In contrast, there are no examples of the subsidence-predicted lagoon transition of fringing reefs to barrier reefs to atolls. Moreover, the common occurrence of fringing reefs within barrier reefs negates subsidence as a causal factor in their ‘presumed progressive evolutionary development. Consequently, the evidence to date suggests that a solution morphology template has been accentuated by reef construction to produce the diagnostic barrier reef morphology we see today. The importance of subsidence would seem to be in accounting for the overall thickness of the resulting carbonate caps of oceanic examples and in

  16. 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

  17. FennoFlakes: a project for identifying flake graphite ores in the Fennoscandian shield and utilizing graphite in different applications

    NASA Astrophysics Data System (ADS)

    Palosaari, Jenny; Eklund, O.; Raunio, S.; Lindfors, T.; Latonen, R.-M.; Peltonen, J.; Smått, J.-H.; Kauppila, J.; Lund, S.; Sjöberg-Eerola, P.; Blomqvist, R.; Marmo, J.

    2016-04-01

    Natural graphite is a strategic mineral, since the European Commission stated (Report on critical raw materials for the EU (2014)) that graphite is one of the 20 most critical materials for the European Union. The EU consumed 13% of all flake graphite in the world but produced only 3%, which stresses the demand of the material. Flake graphite, which is a flaky version of graphite, forms under high metamorphic conditions. Flake graphite is important in different applications like batteries, carbon brushes, heat sinks etc. Graphene (a single layer of graphite) can be produced from graphite and is commonly used in many nanotechnological applications, e.g. in electronics and sensors. The steps to obtain pure graphene from graphite ore include fragmentation, flotation and exfoliation, which can be cumbersome and resulting in damaging the graphene layers. We have started a project named FennoFlakes, which is a co-operation between geologists and chemists to fill the whole value chain from graphite to graphene: 1. Exploration of graphite ores (geological and geophysical methods). 2. Petrological and geochemical analyses on the ores. 3. Development of fragmentation methods for graphite ores. 4. Chemical exfoliation of the enriched flake graphite to separate flake graphite into single and multilayer graphene. 5. Test the quality of the produced material in several high-end applications with totally environmental friendly and disposable material combinations. Preliminary results show that flake graphite in high metamorphic areas has better qualities compared to synthetic graphite produced in laboratories.

  18. Coral reef hydrogeology

    SciTech Connect

    Buddemeier, R.W.; Oberdorfer, J.A.

    1985-05-21

    Knowledge of internal flow velocities and pore water residence time is important in understanding pore water geochemistry, nutrient fluxes at the benthic boundary, reef diagenesis, and fresh water resources in reef islands. Hydrogeologic studies of Pacific and Indian Ocean reef and atoll islands indicate a dual aquifer systems; the major Pleistocene aquifer has hydraulic conductivities on the order of 1000 m/d, while the overlying Holocene aquifer of unconsolidated sediments is at least an order of magnitude less permeable. The high permeability in the Pleistocene formation is the result of large voids, both constructional and from subaerial solution during low stands of the sea. Wind, wave and tide induced head differences ranging from a few centimeters to several tens of centimeters provide the driving force for internal flow. Pore water residence times and geochemistry will vary greatly, depending on whether the water is in a major flow channel or in more restricted pores. Studies of both submerged reefs and atoll islands give bulk pore water residence times on the order of months to a few years. Chemical analyses of pore water indicate that both carbonate solution and precipitation are taking place, which will alter porosity and permeability with time. The dual aquifer model also suggests that the Ghyben-Herzberg lens approach to reef island fresh water resources is inaccurate and can lead to a gross overestimation of the potable resource. 18 refs., 5 figs.

  19. Method for beneficiating coal ore

    SciTech Connect

    Irons, S.D.

    1983-03-15

    A new heavy liquid parting medium comprising an emulsion of water and a substantially water immiscible heavy parting liquid for use in beneficiating ores by gravity separations such as sink -float processes. The specific gravity of the emulsion parting medium can be adjusted by proportioning the relative amounts of water and the substantially water immiscible heavy liquid. Asmined coal is beneficiated using a water-trichlorofluoromethane emulsion as the parting medium in a sink-float separation process.

  20. Ordovician reef-hosted Jiaodingshan Mn-Co deposit and Dawashan Mn deposit, Sichuan Province, China

    USGS Publications Warehouse

    Fan, Delian; Hein, James R.; Ye, Jie

    1999-01-01

    The Jiaodingshan Mn-Co and Dawashan Mn deposits are located in the approximately 2-m thick Daduhe unit of the Wufengian strata of Late Ordovician (Ashgill) age. Paleogeographic reconstruction places the deposits at the time of their formation in a gulf between Chengdu submarine rise and the Kangdian continent. The Jiaodingshan and Dawashan deposits occur in algal-reef facies, the former in an atoll-like structure and the latter in a pinnacle reef. Ores are mainly composed of rhodochrosite, kutnahorite, hausmannite, braunite, manganosite, and bementite. Dark red, yellowish-pink, brown, green-gray, and black ores are massive, banded, laminated, spheroidal, and cryptalgal (oncolite, stromatolite, algal filaments) boundstones. Blue, green, and red algal fossils show in situ growth positions. Samples of high-grade Jiaodingshan and Dawashan ores assay as much as 66.7% MnO. Jiaodingshan Mn carbonate ores have mean contents of Ba, Co, and Pb somewhat higher than in Dawashan ores. Cobalt is widely distributed and strongly enriched in all rock types as compared to its crustal mean content. Cobalt is correlated with Cu, Ni, and MgO in both deposits and additionally with Ba and Zn in the Dawashan deposit. The δ13C(PDB) values of Mn carbonate ores (-7.8 to -16.3‰) indicate contributions of carbon from both seawater bicarbonate and the bacterial degradation of organic matter, the latter being 33% to 68%, assuming about -24‰ for the δ13C(PDB) of the organic matter. Host limestones derived carbon predominantly from seawater bicarbonate δ1313C(PDB) of +0.2 to -7‰). NW-trending fault zones controlled development of lithofacies, whereas NE-trending fault zones provided pathways for movement of fluids. The source of Co, Ni, and Cu was mainly from weathering of mafic and ultramafic rocks on the Kangdian continent, whereas contemporaneous volcanic eruptions were of secondary importance. The reefs were likely mineralized during early diagenesis under shallow burial. The reefs

  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.

  2. Postglacial Fringing-Reef to Barrier-Reef conversion on Tahiti links Darwin's reef types

    PubMed Central

    Blanchon, Paul; Granados-Corea, Marian; Abbey, Elizabeth; Braga, Juan C.; Braithwaite, Colin; Kennedy, David M.; Spencer, Tom; Webster, Jody M.; Woodroffe, Colin D.

    2014-01-01

    In 1842 Charles Darwin claimed that vertical growth on a subsiding foundation caused fringing reefs to transform into barrier reefs then atolls. Yet historically no transition between reef types has been discovered and they are widely considered to develop independently from antecedent foundations during glacio-eustatic sea-level rise. Here we reconstruct reef development from cores recovered by IODP Expedition 310 to Tahiti, and show that a fringing reef retreated upslope during postglacial sea-level rise and transformed into a barrier reef when it encountered a Pleistocene reef-flat platform. The reef became stranded on the platform edge, creating a lagoon that isolated it from coastal sediment and facilitated a switch to a faster-growing coral assemblage dominated by acroporids. The switch increased the reef's accretion rate, allowing it to keep pace with rising sea level, and transform into a barrier reef. This retreat mechanism not only links Darwin's reef types, but explains the re-occupation of reefs during Pleistocene glacio-eustacy. PMID:24845540

  3. Postglacial fringing-reef to barrier-reef conversion on Tahiti links Darwin's reef types.

    PubMed

    Blanchon, Paul; Granados-Corea, Marian; Abbey, Elizabeth; Braga, Juan C; Braithwaite, Colin; Kennedy, David M; Spencer, Tom; Webster, Jody M; Woodroffe, Colin D

    2014-05-21

    In 1842 Charles Darwin claimed that vertical growth on a subsiding foundation caused fringing reefs to transform into barrier reefs then atolls. Yet historically no transition between reef types has been discovered and they are widely considered to develop independently from antecedent foundations during glacio-eustatic sea-level rise. Here we reconstruct reef development from cores recovered by IODP Expedition 310 to Tahiti, and show that a fringing reef retreated upslope during postglacial sea-level rise and transformed into a barrier reef when it encountered a Pleistocene reef-flat platform. The reef became stranded on the platform edge, creating a lagoon that isolated it from coastal sediment and facilitated a switch to a faster-growing coral assemblage dominated by acroporids. The switch increased the reef's accretion rate, allowing it to keep pace with rising sea level, and transform into a barrier reef. This retreat mechanism not only links Darwin's reef types, but explains the re-occupation of reefs during Pleistocene glacio-eustacy.

  4. Postglacial Fringing-Reef to Barrier-Reef conversion on Tahiti links Darwin's reef types

    NASA Astrophysics Data System (ADS)

    Blanchon, Paul; Granados-Corea, Marian; Abbey, Elizabeth; Braga, Juan C.; Braithwaite, Colin; Kennedy, David M.; Spencer, Tom; Webster, Jody M.; Woodroffe, Colin D.

    2014-05-01

    In 1842 Charles Darwin claimed that vertical growth on a subsiding foundation caused fringing reefs to transform into barrier reefs then atolls. Yet historically no transition between reef types has been discovered and they are widely considered to develop independently from antecedent foundations during glacio-eustatic sea-level rise. Here we reconstruct reef development from cores recovered by IODP Expedition 310 to Tahiti, and show that a fringing reef retreated upslope during postglacial sea-level rise and transformed into a barrier reef when it encountered a Pleistocene reef-flat platform. The reef became stranded on the platform edge, creating a lagoon that isolated it from coastal sediment and facilitated a switch to a faster-growing coral assemblage dominated by acroporids. The switch increased the reef's accretion rate, allowing it to keep pace with rising sea level, and transform into a barrier reef. This retreat mechanism not only links Darwin's reef types, but explains the re-occupation of reefs during Pleistocene glacio-eustacy.

  5. 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.

  6. Microwave heating characteristics of magnetite ore

    NASA Astrophysics Data System (ADS)

    Rajavaram, Ramaraghavulu; Lee, Jaehong; Oh, Joon Seok; Kim, Han Gyeol; Lee, Joonho

    2016-11-01

    The heating characteristics of magnetite ore under microwave irradiation were investigated as a function of incident microwave power, particle size, and magnetite ore mass. The results showed that the heating rate of magnetite ore is highly dependent on microwave power and magnetite ore mass. The maximum heating rate was obtained at a microwave irradiation power of 1.70 kW with a mass of 25 g and particle size between 53-75 µm. The volumetric heating rate of magnetite ore was investigated by measuring the temperature at different depths during microwave irradiation. Microwave irradiation resulted in modification of the microstructure of the magnetite ore, but new phases such as FeO or Fe2O3 were not formed. In addition, the crystal size decreased from 115 nm to 63 nm after microwave irradiation up to 1573 K.

  7. Application of Odor Sensors to Ore Sorting and Mill Feed Control

    SciTech Connect

    Michael G. Nelson

    2005-08-01

    Control of the feed provided to mineral processing facilities is a continuing challenge. Much effort is currently being devoted to overcoming these problems. These projects are usually described under the general headings of Mine-to-Mill Integration or Mine-Mill Optimization. It should be possible to combine the knowledge of ore type, mineralogy, and other characteristics (located in the mine modeling system), with the advanced capabilities of state-of-the-art mill control systems, to achieve an improved level of control in mineral processing that will allow optimization of the mill processes on an almost real-time basis. This is not happening because mill feed it is often treated as a uniform material, when in reality it varies in composition and characteristics. An investigation was conducted to assess the suitability of odor sensors for maintaining traceability in ore production and processing. Commercially available sensors are now used in food processing, environmental monitoring, and other applications and can detect the presence of very small amounts (0.1-500 ppm) of some molecules. An assortment of such molecules could be used to ''tag'' blocks of ore as they are mined, according to their respective characteristics. Then, as the ore came into the mill, an array of ''electronic noses'' could be used to assess its characteristics in real time. It was found that the Cyranose 320{trademark}, a commercially available odor sensor, can easily distinguish among samples of rock marked with almond, cinnamon, citronella, lemon, and orange oils. Further, the sensor could detect mixtures of rocks marked with various combinations of these oils. Treatment of mixtures of galena and silica with odorant compounds showed no detrimental effects on flotation response in laboratory tests. Additional work is recommended to determine how this concept can be extended to the marking of large volumes of materials.

  8. Evolution of ore deposits on terrestrial planets

    NASA Technical Reports Server (NTRS)

    Burns, R. G.

    1991-01-01

    Ore deposits on terrestrial planets materialized after core formation, mantle evolution, crustal development, interactions of surface rocks with the hydrosphere and atmosphere, and, where life exists on a planet, the involvement of biological activity. Core formation removed most of the siderophilic and chalcophilic elements, leaving mantles depleted in many of the strategic and noble metals relative to their chondritic abundances. Basaltic magma derived from partial melting of the mantle transported to the surface several metals contained in immiscible silicate and sulfide melts. Magmatic ore deposits were formed during cooling, fractional crystallization and density stratification from the basaltic melts. Such ore deposits found in earth's Archean rocks were probably generated during early histories of all terrestrial planets and may be the only types of igneous ores on Mars. Where plate tectonic activity was prevalent on a terrestrial planet, temporal evolution of ore deposits took place. Repetitive episodes of subduction modified the chemical compositions of the crust and upper mantles, leading to porphyry copper and molybdenum ores in calc-alkaline igneous rocks and granite-hosted tin and tungsten deposits. Such plate tectonic-induced mineralization in relatively young igneous rocks on earth may also have produced hydrothermal ore deposits on Venus in addition to the massive sulfide and cumulate chromite ores associated with Venusian mafic igneous rock. Sedimentary ore deposits resulting from mechanical and chemical weathering in reducing atmospheres in Archean earth included placer deposits (e.g., uraninite, gold, pyrite ores). Chromite, ilmenite, and other dense unreactive minerals could also be present on channel floors and in valley networks on Mars, while banded iron formations might underlie the Martian northern plains regions. As oxygen evolved in earth's atmosphere, so too did oxide ores. By analogy, gossans above sulfide ores probably occur on Mars

  9. Coral reef resilience through biodiversity

    USGS Publications Warehouse

    Rogers, Caroline S.

    2013-01-01

    Irrefutable evidence of coral reef degradation worldwide and increasing pressure from rising seawater temperatures and ocean acidification associated with climate change have led to a focus on reef resilience and a call to “manage” coral reefs for resilience. Ideally, global action to reduce emission of carbon dioxide and other greenhouse gases will be accompanied by local action. Effective management requires reduction of local stressors, identification of the characteristics of resilient reefs, and design of marine protected area networks that include potentially resilient reefs. Future research is needed on how stressors interact, on how climate change will affect corals, fish, and other reef organisms as well as overall biodiversity, and on basic ecological processes such as connectivity. Not all reef species and reefs will respond similarly to local and global stressors. Because reef-building corals and other organisms have some potential to adapt to environmental changes, coral reefs will likely persist in spite of the unprecedented combination of stressors currently affecting them. The biodiversity of coral reefs is the basis for their remarkable beauty and for the benefits they provide to society. The extraordinary complexity of these ecosystems makes it both more difficult to predict their future and more likely they will have a future.

  10. The evolution of reef communities

    SciTech Connect

    Fagerstrom, J.A.

    1987-01-01

    This book discusses the composition, structure, occurrence, and changes in reefs during the past 2 billion years. It emphasizes the functional roles of major groups (guilds) of reef-building, reef-destroying, and reed-dwelling organisms in the most complex of all marine communities. A structural model, based on modern reef guilds, is developed. Then the functional roles of each major reef-building higher biologic taxon (algae, sponges, coral, etc.) is determined, and, on this basis, each such taxon is assigned to a reef community guild. Next, the authors traces the geologic history and guild assignment of each major taxon through geologic time. The final chapter establishes a succession of ten major reef community types, and considers their extinction and recovery in the light of modern theories of cosmic and earthly events.

  11. Commercialization of the Microcel{trademark} column flotation technology

    SciTech Connect

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

    1994-12-31

    Hydrodynamic analyses suggest that the recovery of fine particles by flotation can be improved through the use of smaller air bubbles. Unfortunately, many of the commercial methods for generating small air bubbles are difficult to scale-up and maintain. To overcome these problems, a novel flotation system known as Microcel{trademark} column flotation was developed at Virginia Tech. In this process, compressed air is injected into flotation pulp that is circulated through a parallel set of static in-line mixers. This arrangement provides a means of creating high energy dissipation, which is essential for producing small bubbles, without creating serious wear and maintenance problems. This article reviews some of the fundamental principles involved m the development of the Microcel{trademark} technology and provides guidelines for designing an effective fine coal flotation system. An example of a commercial installation of the Microcel{trademark} technology is also presented along with the economic benefits of using this advanced fine coal cleaning technique.

  12. Nanoparticle flotation collectors II: the role of nanoparticle hydrophobicity.

    PubMed

    Yang, Songtao; Pelton, Robert

    2011-09-20

    The ability of polystyrene nanoparticles to facilitate the froth flotation of glass beads was correlated to the hydrophobicity of the nanoparticles. Contact angle measurements were used to probe the hydrophobicity of hydrophilic glass surfaces decorated with hydrophobic nanoparticles. Both sessile water drop advancing angles, θ(a), and attached air bubble receding angle measurements, θ(r), were performed. For glass surfaces saturated with adsorbed nanoparticles, flotation recovery, a measure of flotation efficiency, increased with increasing values of each type of contact angle. As expected, the advancing water contact angle on nanoparticle-decorated, dry glass surfaces increased with surface coverage, the area fraction of glass covered with nanoparticles. However, the nanoparticles were far more effective at raising the contact angle than the Cassie-Baxter prediction, suggesting that with higher nanoparticle coverages the water did not completely wet the glass surfaces between the nanoparticles. A series of polystyrene nanoparticles was prepared to cover a range of surface energies. Water contact angle measurements, θ(np), on smooth polymer films formed from organic solutions of dissolved nanoparticles were used to rank the nanoparticles in terms of hydrophobicity. Glass spheres were saturated with adsorbed nanoparticles and were isolated by flotation. The minimum nanoparticle water contact angle to give high flotation recovery was in the range of 51° < θ(np(min)) ≤ 85°.

  13. Coal surface control for advanced fine coal flotation

    SciTech Connect

    Fuerstenau, D.W.; Sastry, K.V.S.; Hanson, J.S.; Diao, J.; De, A.; Sotillo, F.; Harris, G. ); Somasundaran, P.; Harris, C.C.; Vasudevan, T.; Liu, D.; Li, C. ); Hu, W.; Zou, Y.; Chen, W. ); Choudhry, V.; Sehgal, R.; Ghosh, A. (Praxis Engineers, Inc., Milpitas, CA (United Stat

    1991-05-15

    The primary objective in the scope of this research project is to develop advanced flotation methods for coal cleaning in order to achieve near total pyritic-sulfur removal at 90% Btu recovery, using coal samples procured from three major US coal seams. Concomitantly, the ash content of these coals is to be reduced to 6% or less. Investigation of mechanisms for the control of coal and pyrite surfaces prior to fine coal flotation is the main aspect of the project objectives. Research topics covered during this quarter include the characterization of the base coals, various flotation studies on optimization and pyrite rejection, and a detailed flotation kinetic study. The effect of hexanol, butanol, dodecane, and polyethylene glycol on flotation is described. A second major objective is to investigate factors involved in the progressive weathering and oxidation of coal that had been exposed to varying weathered degrees, namely, open, covered and in an argon-inerted'' atmosphere, over a period of twelve months. After regular intervals if weathering, samples of the three base coals (Illinois No. 6, Pittsburgh No. 8 and Upper Freeport PA) were collected and shipped to both the University of Pittsburgh and the University of California at Berkeley for characterization studies of the weathered material. 35 figs., 17 tabs.

  14. High intensity conditioning to improve flotation of gold fine particles

    SciTech Connect

    Valderrama, L.; Perez, C.; Rubio, J.

    1995-12-31

    This work describes the effect of the degree of energy transferred to the pulp, during the conditioning stage, on gold flotation fines recovery, grade and kinetics, with three types of frother (Dowfroth 250, pine oil and MIBC) and amyl xanthate as collector. Best results show an increase in 24% recovery and 50% in concentrate grade, depending on the intensity of conditioning and type of frother (better with Dowfroth 250). For low or intermediate energies (0.5--1.5 kWh/m3 pulp), the fine particles adhere to larger ones, increasing the recovery due to a mixture of carrier (pyrite, in this case) and autogeneous carrier flotation and at higher shear (2--3 kWh/m3 pulp), gold fine particles aggregate themselves. These phenomena are demonstrated by measurements of flotation rate, true flotation (flotation by actual particle-bubble adhesion), and by the amount of entrained particles. Alternatives for this type of pulp conditioning and mechanisms involved are discussed.

  15. Sintering Characteristics of Indian Chrome Ore Fines

    NASA Astrophysics Data System (ADS)

    Nandy, Bikash; Chaudhury, Manoj Kumar; Paul, Jagannath; Bhattacharjee, D.

    2009-10-01

    Chrome ore concentrate consists of high-temperature melting oxides such as Cr2O3, MgO, and Al2O3. The presence of these refractory constituents makes the ore a very high melting mineral. Hence, it is difficult to produce sinter from chrome ore by a pyrometallurgical route. Currently, chrome ore is ground to below 75 μm, pelletized, heat hardened through carbothermic reaction at 1300 °C to 1400 °C, and then charged into a submerged electric arc furnace (EAF), along with lumpy ore for ferrochrome/charge-chrome production. Electricity is a major cost element in this extraction process. This work explores the sinterability of chrome ore. The objective of this study was to: (1) determine whether chrome ore is sinterable and, if so, (2) ascertain ways of achieving satisfactory properties at a low temperature of sintering. Sintering of the raw material feed could be a way to reduce electricity consumption, because during sintering a partial reduction of minerals is expected along with agglomeration. Studies carried out by the authors show that it is possible to agglomerate chrome ore fines through sintering. The chrome ore sinter thus produced was found to be inferior in strength, comparable to that of an iron ore sinter, but strength requirements may not be the same for both. Because the heat generation during chrome ore sintering is high owing to some exothermic reactions, compared with iron ore, and because chrome ore contains a high amount of fines, shallow-bed-depth sinter cake production was attempted in the laboratory-scale pot-sintering machine. The sintered product was found to be a good conductor of electricity because of the presence of phases such as magnetite and maghemite. This characteristic of the chrome ore sinter will subsequently have a favorable impact in terms of power consumption during the production of ferrochrome in a submerged EAF. The sinter made was melted in the arc furnace and it was found that the specific melting energy is comparable to

  16. Metallization of siderite ore in reducing roasting

    NASA Astrophysics Data System (ADS)

    Vusikhis, A. S.; Leont'ev, L. I.; Kudinov, D. Z.; Gulyakov, V. S.

    2016-05-01

    The behavior of the initial ore and the concentrate of magnetoroasting beneficiation during metallization under the conditions that are close to those for reducing roasting of iron ores in a rotary furnace is studied in terms of works on extending the field of application of Bakal siderites. A difference in the mechanisms of the metallization of crude ore and the roasted concentrate is observed. The metallization of roasted concentrate lumps is more efficient than that of crude siderite ore. In this case, the process ends earlier and can be carried out at higher temperatures (1250-1300°C) without danger of skull formation.

  17. 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 Personal flotation devices carried in addition to life jackets. (a) Equipment carried... flotation devices (PFD) approved in accordance with § 160.077 of this chapter, or other standard...

  18. 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... other personal flotation devices. (a) Except as provided by § 28.305 of this chapter, each vessel must be equipped with at least one immersion suit, exposure suit, or wearable personal flotation device...

  19. 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 Personal flotation devices carried in addition to life jackets. (a) Equipment carried... flotation devices (PFD) approved in accordance with § 160.077 of this chapter, or other standard...

  20. 33 CFR 183.335 - Level flotation test without weights for persons capacity.

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... 33 Navigation and Navigable Waters 2 2013-07-01 2013-07-01 false Level flotation test without..., DEPARTMENT OF HOMELAND SECURITY (CONTINUED) BOATING SAFETY BOATS AND ASSOCIATED EQUIPMENT Flotation Requirements for Outboard Boats Rated for Engines of 2 Horsepower or Less Tests § 183.335 Level flotation...

  1. 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... SCHOOL VESSELS Vessel Control, Miscellaneous Systems, and Equipment Markings § 169.741 Personal flotation devices and ring life buoys. Each personal flotation device and ring life buoy must be marked with...

  2. 33 CFR 175.25 - Enforcement of State requirements for children to wear personal flotation devices.

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ... 33 Navigation and Navigable Waters 2 2012-07-01 2012-07-01 false Enforcement of State requirements for children to wear personal flotation devices. 175.25 Section 175.25 Navigation and Navigable Waters... Flotation Devices § 175.25 Enforcement of State requirements for children to wear personal flotation...

  3. 33 CFR 175.25 - Enforcement of State requirements for children to wear personal flotation devices.

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... 33 Navigation and Navigable Waters 2 2013-07-01 2013-07-01 false Enforcement of State requirements for children to wear personal flotation devices. 175.25 Section 175.25 Navigation and Navigable Waters... Flotation Devices § 175.25 Enforcement of State requirements for children to wear personal flotation...

  4. 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... other personal flotation devices. (a) Except as provided by § 28.305 of this chapter, each vessel must be equipped with at least one immersion suit, exposure suit, or wearable personal flotation device...

  5. 46 CFR 117.72 - Personal flotation devices carried in addition to life jackets.

    Code of Federal Regulations, 2013 CFR

    2013-10-01

    ... 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 flotation... persons working near or over the water. (d) Commercial hybrid personal flotation devices (PFD) approved...

  6. Engineering development of advanced physical fine coal cleaning technolgies: Froth flotation

    SciTech Connect

    Not Available

    1991-01-01

    The Task 6 effort involves three main elements including column cell development, flotation circuit testing and flotation cell modeling. The work outlined is to research column designs and operation parameters in developing an optimized column flotation cell (OCFC) to meet the overall program objectives. Any design parameters that were not evaluated as part of the optimized column development work will be reviewed and tested so as to incorporate all possible scenarios in presenting DOE with the best available flotation process for use in the 2 to 3 ton per hour POC. Following development of the OCFC, various flotation circuit configurations will be evaluated determine the best'' circuit design for the 2 to 3 ton per hour POC. Single and multiple stage flotation, grab and run, rougher/scavenger/cleaner, etc., test circuits will be tested as part of this effort. Upon completion of this test work, the best'' possible flotation cell will have been tested in a number of possible flotation circuit designs to possibly provide the best'' flotation approach in meeting the design criteria. In conjunction with the flotation test effort, model development work will be conducted to provide a tool in evaluating the various flotation circuit configurations and in predicting flotation performance. The model will be useful in selecting operating conditions in the POC and in evaluating the performance of the POC.

  7. 33 CFR 175.25 - Enforcement of State requirements for children to wear personal flotation devices.

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... 33 Navigation and Navigable Waters 2 2011-07-01 2011-07-01 false Enforcement of State requirements for children to wear personal flotation devices. 175.25 Section 175.25 Navigation and Navigable Waters... Flotation Devices § 175.25 Enforcement of State requirements for children to wear personal flotation...

  8. 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 Personal flotation devices carried in addition to life jackets. (a) Equipment carried... flotation devices (PFD) approved in accordance with § 160.077 of this chapter, or other standard...

  9. 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... SCHOOL VESSELS Vessel Control, Miscellaneous Systems, and Equipment Markings § 169.741 Personal flotation devices and ring life buoys. Each personal flotation device and ring life buoy must be marked with...

  10. 33 CFR 175.25 - Enforcement of State requirements for children to wear personal flotation devices.

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... 33 Navigation and Navigable Waters 2 2014-07-01 2014-07-01 false Enforcement of State requirements for children to wear personal flotation devices. 175.25 Section 175.25 Navigation and Navigable Waters... Flotation Devices § 175.25 Enforcement of State requirements for children to wear personal flotation...

  11. Where we are in flotation chemistry after 70 years of research

    SciTech Connect

    Fuerstenau, D.W.

    1995-12-31

    The success of industrial flotation separations has been the design of specific chemical schemes for regulating the bulk and the surface chemistry of the system. Highlights of fundamental research on the nature of flotation reagents and their mode of action in flotation, which has been carried on for about the past 65 years, is briefly reviewed.

  12. 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... SCHOOL VESSELS Vessel Control, Miscellaneous Systems, and Equipment Markings § 169.741 Personal flotation devices and ring life buoys. Each personal flotation device and ring life buoy must be marked with...

  13. 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 Personal flotation devices carried in addition to life jackets. (a) Equipment carried... flotation devices (PFD) approved in accordance with § 160.077 of this chapter, or other standard...

  14. 18 CFR 1304.400 - Flotation devices and material, all floating structures.

    Code of Federal Regulations, 2014 CFR

    2014-04-01

    ..., shall be of materials commercially manufactured for marine use. Flotation materials shall be fabricated... materials shall be resistant to puncture, penetration, damage by animals, and fire. Any flotation within 40... manufactured flotation device or material specifically designed for marine applications (for example,...

  15. 18 CFR 1304.400 - Flotation devices and material, all floating structures.

    Code of Federal Regulations, 2013 CFR

    2013-04-01

    ..., shall be of materials commercially manufactured for marine use. Flotation materials shall be fabricated... materials shall be resistant to puncture, penetration, damage by animals, and fire. Any flotation within 40... manufactured flotation device or material specifically designed for marine applications (for example,...

  16. 33 CFR 149.331 - What are the requirements for hybrid personal flotation devices?

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... 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 all commercial hybrid personal flotation devices (PFDs) used as work vests comply with the procedures...

  17. 33 CFR 149.331 - What are the requirements for hybrid personal flotation devices?

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... 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 all commercial hybrid personal flotation devices (PFDs) used as work vests comply with the procedures...

  18. 33 CFR 149.331 - What are the requirements for hybrid personal flotation devices?

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ... 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 all commercial hybrid personal flotation devices (PFDs) used as work vests comply with the procedures...

  19. 33 CFR 149.331 - What are the requirements for hybrid personal flotation devices?

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... 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 all commercial hybrid personal flotation devices (PFDs) used as work vests comply with the procedures...

  20. 46 CFR 180.72 - Personal flotation devices carried in addition to life jackets.

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    ... 46 Shipping 7 2010-10-01 2010-10-01 false Personal flotation devices carried in addition to life... Jackets § 180.72 Personal flotation devices carried in addition to life jackets. (a) Equipment carried... flotation devices (PFD) approved in accordance with § 160.077 of this chapter, or other standard...

  1. 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... SCHOOL VESSELS Vessel Control, Miscellaneous Systems, and Equipment Markings § 169.741 Personal flotation devices and ring life buoys. Each personal flotation device and ring life buoy must be marked with...

  2. 33 CFR 175.25 - Enforcement of State requirements for children to wear personal flotation devices.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... 33 Navigation and Navigable Waters 2 2010-07-01 2010-07-01 false Enforcement of State requirements for children to wear personal flotation devices. 175.25 Section 175.25 Navigation and Navigable Waters... Flotation Devices § 175.25 Enforcement of State requirements for children to wear personal flotation...

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

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... 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 all commercial hybrid personal flotation devices (PFDs) used as work vests comply with the procedures...

  4. 46 CFR 117.72 - Personal flotation devices carried in addition to life jackets.

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    ... 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 flotation... persons working near or over the water. (d) Commercial hybrid personal flotation devices (PFD) approved...

  5. Physical exploration for uranium during 1951 in the Silver Reef district, Washington County, Utah

    USGS Publications Warehouse

    Stugard, Frederick

    1953-01-01

    During 1951 a joint exploration program of the most promising uraniferous areas in the Silver Reef district was made by the U.S. Geological Survey and the u.S. Atomic Energy Commission.  A U.S. Bureau of Mines drill crew, on contract to the Atomic Energy Commission, did 2,450 feet of diamond drilling under the geological supervision of the U.S. Geological Survey.  The purpose of the drilling was to delineate broadly the favorable ground for commercial development of the uranium depostis.  Ten drill holes were located around Pumpkin Point, which is the northeastern end of Buckeye Reef, to probe for extensions of small ore shootsmined on the Point in fine-grained sandstones of the Chinle formation.  Three additional holes were located around teh Tecumseh Hill to prbe for extensions of the small showings of uranium-bearing rocks of Buckeye Reef.

  6. Coral Reef Biological Criteria

    EPA Science Inventory

    Coral reefs worldwide are experiencing decline from a variety of stressors. Some important stressors are land-based sources of pollution and human activities in the coastal zone. However, few tools are available to offset the impact of these stressors. The Clean Water Act (CWA...

  7. Rivers, runoff, and reefs

    USGS Publications Warehouse

    McLaughlin, C.J.; Smith, C.A.; Buddemeier, R.W.; Bartley, J.D.; Maxwell, B.A.

    2003-01-01

    The role of terrigenous sediment in controlling the occurrence of coral reef ecosystems is qualitatively understood and has been studied at local scales, but has not been systematically evaluated on a global-to-regional scale. Current concerns about degradation of reef environments and alteration of the hydrologic and sediment cycles place the issue at a focal point of multiple environmental concerns. We use a geospatial clustering of a coastal zone database of river and local runoff identified with 0.5?? grid cells to identify areas of high potential runoff effects, and combine this with a database of reported coral reef locations. Coastal cells with high runoff values are much less likely to contain reefs than low runoff cells and GIS buffer analysis demonstrates that this inhibition extends to offshore ocean cells as well. This analysis does not uniquely define the effects of sediment, since salinity, nutrients, and contaminants are potentially confounding variables also associated with runoff. However, sediment effects are likely to be a major factor and a basis is provided for extending the study to higher resolution with more specific variables. ?? 2003 Elsevier B.V. All rights reserved.

  8. CORAL REEF BIOCRITERIA

    EPA Science Inventory

    Coral reefs worldwide are experiencing the greatest decline of their known existence and few tools are available to offset the growing impacts of human coastal and watershed activities. Biocriteria are a potentially effective means to evaluate and restore impaired waters, but are...

  9. Selective flotation of PVC using gelatin and lignin alkali.

    PubMed

    Yenial, Unzile; Kangal, Olgaç; Güney, Ali

    2013-06-01

    Recycling has become one of the most important issues as a result of increasing waste mass in present day. This is especially important for polymer wastes as they are hard to degenerate in nature. Today, most of the practical methods used for the recycling of waste mass, such as hand sorting, gravity separation, etc., cannot be performed successfully owing to close densities of polymers. Froth flotation can be used successfully and economically for this purpose. The main objective of this study was to investigate the effect of plasticizer reagents and the success of froth flotation at plastic recycling. In this study, lignin alkali and gelatin were used as plasticizer reagents. The effect of these reagents was searched with the parameters of pH, concentration, conditioning and flotation time. In the case of post-consumed polyethylene terephthalate and polyvinyl chloride (PVC), 98.9% purity of PVC was obtained at optimum conditions.

  10. Toxicity of nickel ores to marine organisms.

    PubMed

    Florence, T M; Stauber, J L; Ahsanullah, M

    1994-06-06

    Queensland Nickel proposes to import New Caledonian (Ballande) and Indonesian (Gebe) nickel ores, one option being ship-to-barge transfer in Halifax Bay, North Queensland. Because small amounts of ore may be split during the unloading and transfer operations, it was important to investigate the potential impact of the spilt ore on the ecological health of the Bay. Long-term leaching of the ores with seawater showed that only nickel and chromium (VI) were released from the ores in sufficient concentrations to cause toxicity to a range of marine organisms. The soluble fractions of nickel and chromium (VI) were released from the ores within a few days. Nickel, chromium (VI) and the ore leachates showed similar toxicity to the juvenile banana prawn Penaeus merguiensis, the amphipod Allorchestes compressa and both temperature (22 degrees C) and tropical (27 degrees C) strains of the unicellular marine alga Nitzschia closterium. In a series of 30-day sub-chronic microcosm experiments, juvenile leader prawns Penaeus monodon, polychaete worms Galeolaria caespitosa and the tropical gastropod Nerita chamaeleon were all very resistant to the nickel ores, with mortality unaffected by 700 g ore per 50 l seawater. The growth rate of the leader prawns was, however, lower than that of the controls. From these data, a conservative maximum safe concentration of the nickel ores in seawater is 0.1 g l-1. The nickel ore was not highly toxic and if spilt in the quantities predicted, would not have a significant impact on the ecological health of the Bay.

  11. Miocene reefs in western Mediterranean

    SciTech Connect

    Esteban, M.

    1988-01-01

    Coral reefs were particularly abundant and well developed during the late Tortonian and Messinian in southeastern Spain, the Balearic Islands, Italy, Sicily, Algeria, and Morocco. These reefs occurred just before and during the deposition of the thick Messinian evaporite units in the basinal areas and disappeared completely from Mediteranean during the early Pliocene. Most of the coral reefs are fringing terrigenous coastal fan complexes with very small lagoons and show progradation of less than 2 km. Some of the reefs occur on, or are intercalated with, Neogene volcanics or Messinian evaporites. Barrier-reef complexes are less common, have extensive lagoons behind them, and show complex progradational geometries more than 10 km wide. Excellent outcrops allow detailed reconstruction of paleogeography and sea level changes. Progradation predominated during phases of relative sea level drops and stillsands, while significant retrogradation occurred during sea level rises. The coral reef wall framework is commonly less than 20 m thick and is dominated by Porites and, locally, Tarbellastrae. Older Miocene reefs are less well developed, but show greater diversity of corals and reef organisms. Younger Miocene reef complexes occurring in open ocean settings are formed by only one branching coral genus (Porites or, locally, Tarbellastraea) with branching colonies up to 7 m high. Halimeda sands are particularly abundant in the upper reef slopes with occasional intercalations of red algae pavements that most likely coincide with episodes of terrigenous influx.

  12. Iron ore: energy, labor, and capital changes with technology.

    PubMed

    Kakela, P J

    1978-12-15

    Resource gathering is depending on leaner crude ores. Iron ore mining typifies this trend. To make lean taconite iron ores useful required a technologic breakthrough-pelletization. The shift to iron ore pellets has the advantage that they require less energy and labor per ton of molten iron than high-grade naturally concentrated ores. Increased reliance on pellets causes a geographic shift of some jobs and environmental effects from blast furnaces to iron ore mines.

  13. Column flotation results at Powell Mountain Coal Company

    SciTech Connect

    Peters, W.J. Parekh, B.K. )

    1992-01-01

    In 1989 a column flotation process was developed at the CAER, which enabled the economical recovery of coal fines from high-ash fine refuse. The laboratory design was expanded to commercial scale and installed at the Mayflower Coal Preparation Plant of Powell Mountain Coal Company in December, 1989. It has been in continuous operation there since that time. This article is a summary of the past two years' experiences with this applied technology, applicable dewatering tests and flotation tests results from the plant.

  14. Enhanced column flotation of fine and ultrafine coal

    SciTech Connect

    Slomka, B.J.; Buttermore, W.H.; Birlingmair, D.H.; Dawson, M.R.; Pollard, J.L.; Enustun, B.V.

    1992-12-01

    A 2-inch diameter, twenty-foot tall, glass laboratory flotation column was modified to incorporate digital control of critical operating parameters. Different column control strategies were explored including location of the froth interface, and manipulation of volumetric flow ratios. Column flotation tests were performed with both fine (-250{mu}m) and ultrafine (-5{mu}m) Pittsburgh seam coal. Both moisture- and ash-free (MAF) recovery, and ash rejection were improved when the partition of the column`s liquid content into froth and tailings was directly controlled. MAF recovery and ash rejection were also enhanced by brief exposure of the coarser feed to pulsed sonic energy.

  15. Enhanced column flotation of fine and ultrafine coal

    SciTech Connect

    Slomka, B.J.; Buttermore, W.H.; Birlingmair, D.H.; Dawson, M.R.; Pollard, J.L.; Enustun, B.V.

    1992-01-01

    A 2-inch diameter, twenty-foot tall, glass laboratory flotation column was modified to incorporate digital control of critical operating parameters. Different column control strategies were explored including location of the froth interface, and manipulation of volumetric flow ratios. Column flotation tests were performed with both fine (-250[mu]m) and ultrafine (-5[mu]m) Pittsburgh seam coal. Both moisture- and ash-free (MAF) recovery, and ash rejection were improved when the partition of the column's liquid content into froth and tailings was directly controlled. MAF recovery and ash rejection were also enhanced by brief exposure of the coarser feed to pulsed sonic energy.

  16. In-plant testing of microbubble column flotation

    SciTech Connect

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

    1990-01-01

    During the past year, a joint project between the US Department of Energy (DOE), the Virginia Center for Coal and Minerals Processing (VCCMP) and the Shell Mining Corporation (SMC) was initiated to implement the testing of a full-scale microbubble flotation column. The work is being carried out at the Marrowbone Preparation Plant, located near Naugatuck in southwestern West Virginia. The primary objective of this effort was to determine the feasibility of using microbubble column flotation for the recovery of coal fines from a classifying cyclone overflow stream that is presently being discarded as refuse.

  17. Selective flotation of fossil resin from western coal

    SciTech Connect

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

    1992-03-30

    Economic analysis of this fossil resin project mainly focused on the flotation plant which is intended to be designed with data obtained from the current proof-of-concept flotation test program. It is believed that the analysis of this step is fairly accurate. The other two economic aspects of fossil in resin recovery/utilization are refining and marketing. Cost data used for refining were from an estimated base and are believed to have a large variance. Marketing data used were obtained from two independent marketing studies which were made available on confidentiality basis. Nevertheless, the data used are believed to be fairly accurate with respect to the market potential.

  18. Ecological intereactions of reef building corals

    EPA Science Inventory

    Coral reefs are very important marine ecosystems because they support tremendous biodiversity and reefs are critical economic resources many coastal nations. Tropical reef structures are largely built by stony corals. This presentation provides background on basic coral biology t...

  19. Bleaching drives collapse in reef carbonate budgets and reef growth potential on southern Maldives reefs

    PubMed Central

    Perry, C. T.; Morgan, K. M.

    2017-01-01

    Sea-surface temperature (SST) warming events, which are projected to increase in frequency and intensity with climate change, represent major threats to coral reefs. How these events impact reef carbonate budgets, and thus the capacity of reefs to sustain vertical growth under rising sea levels, remains poorly quantified. Here we quantify the magnitude of changes that followed the ENSO-induced SST warming that affected the Indian Ocean region in mid-2016. Resultant coral bleaching caused an average 75% reduction in coral cover (present mean 6.2%). Most critically we report major declines in shallow fore-reef carbonate budgets, these shifting from strongly net positive (mean 5.92 G, where G = kg CaCO3 m−2 yr−1) to strongly net negative (mean −2.96 G). These changes have driven major reductions in reef growth potential, which have declined from an average 4.2 to −0.4 mm yr−1. Thus these shallow fore-reef habitats are now in a phase of net erosion. Based on past bleaching recovery trajectories, and predicted increases in bleaching frequency, we predict a prolonged period of suppressed budget and reef growth states. This will limit reef capacity to track IPCC projections of sea-level rise, thus limiting the natural breakwater capacity of these reefs and threatening reef island stability. PMID:28084450

  20. Bleaching drives collapse in reef carbonate budgets and reef growth potential on southern Maldives reefs.

    PubMed

    Perry, C T; Morgan, K M

    2017-01-13

    Sea-surface temperature (SST) warming events, which are projected to increase in frequency and intensity with climate change, represent major threats to coral reefs. How these events impact reef carbonate budgets, and thus the capacity of reefs to sustain vertical growth under rising sea levels, remains poorly quantified. Here we quantify the magnitude of changes that followed the ENSO-induced SST warming that affected the Indian Ocean region in mid-2016. Resultant coral bleaching caused an average 75% reduction in coral cover (present mean 6.2%). Most critically we report major declines in shallow fore-reef carbonate budgets, these shifting from strongly net positive (mean 5.92 G, where G = kg CaCO3 m(-2) yr(-1)) to strongly net negative (mean -2.96 G). These changes have driven major reductions in reef growth potential, which have declined from an average 4.2 to -0.4 mm yr(-1). Thus these shallow fore-reef habitats are now in a phase of net erosion. Based on past bleaching recovery trajectories, and predicted increases in bleaching frequency, we predict a prolonged period of suppressed budget and reef growth states. This will limit reef capacity to track IPCC projections of sea-level rise, thus limiting the natural breakwater capacity of these reefs and threatening reef island stability.

  1. Bleaching drives collapse in reef carbonate budgets and reef growth potential on southern Maldives reefs

    NASA Astrophysics Data System (ADS)

    Perry, C. T.; Morgan, K. M.

    2017-01-01

    Sea-surface temperature (SST) warming events, which are projected to increase in frequency and intensity with climate change, represent major threats to coral reefs. How these events impact reef carbonate budgets, and thus the capacity of reefs to sustain vertical growth under rising sea levels, remains poorly quantified. Here we quantify the magnitude of changes that followed the ENSO-induced SST warming that affected the Indian Ocean region in mid-2016. Resultant coral bleaching caused an average 75% reduction in coral cover (present mean 6.2%). Most critically we report major declines in shallow fore-reef carbonate budgets, these shifting from strongly net positive (mean 5.92 G, where G = kg CaCO3 m‑2 yr‑1) to strongly net negative (mean ‑2.96 G). These changes have driven major reductions in reef growth potential, which have declined from an average 4.2 to ‑0.4 mm yr‑1. Thus these shallow fore-reef habitats are now in a phase of net erosion. Based on past bleaching recovery trajectories, and predicted increases in bleaching frequency, we predict a prolonged period of suppressed budget and reef growth states. This will limit reef capacity to track IPCC projections of sea-level rise, thus limiting the natural breakwater capacity of these reefs and threatening reef island stability.

  2. An observational heat budget analysis of a coral reef, Heron Reef, Great Barrier Reef, Australia

    NASA Astrophysics Data System (ADS)

    MacKellar, Mellissa C.; McGowan, Hamish A.; Phinn, Stuart R.

    2013-03-01

    Measurements of the surface energy balance, the structure and evolution of the convective atmospheric reef layer (CARL), and local meteorology and hydrodynamics were made during June 2009 and February 2010 at Heron Reef, Australia, to establish the relative partitioning of heating within the water and atmosphere. Horizontal advection was shown to moderate temperature in the CARL and the water, having a cooling influence on the atmosphere, and providing an additional source or sink of energy to the water overlying the reef, depending on tide. The key driver of atmospheric heating was surface sensible heat flux, while heating of the reef water was primarily due to solar radiation, and thermal conduction and convection from the reef substrate. Heating and cooling processes were more defined during winter due to higher sensible and latent heat fluxes and strong diurnal evolution of the CARL. Sudden increases in water temperature were associated with inundation of warmer oceanic water during the flood tide, particularly in winter due to enhanced nocturnal cooling of water overlying the reef. Similarly, cooling of the water over the reef occurred during the ebb tide as heat was transported off the reef to the surrounding ocean. While these results are the first to shed light on the heat budget of a coral reef and overlying CARL, longer-term, systematic measurements of reef thermal budgets are needed under a range of meteorological and hydrodynamic conditions, and across various reef types to elucidate the influence on larger-scale oceanic and atmospheric processes. This is essential for understanding the role of coral reefs in tropical and sub-tropical meteorology; the physical processes that take place during coral bleaching events, and coral and algal community dynamics on coral reefs.

  3. 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.

  4. 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.

  5. 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.

  6. Wave transformation over coral reefs

    NASA Astrophysics Data System (ADS)

    Young, Ian R.

    1989-07-01

    Ocean wave attenuation on coral reefs is discussed using data obtained from a preliminary field experiment and from the Seasat altimeter. Marked attenuation of the waves is observed, the rate being consistent with existing theories of bottom friction and wave breaking decay. In addition, there is a significant broadening of the spectrum during propagation across reefs. Three-dimensional effects, such as refraction and defraction, can also lead to substantial wave height reduction for significant distances adjacent to coral reefs. As a result, a matrix of such reefs provides significantly more wave attenuation than may initially be expected.

  7. Digital Reef Rugosity Estimates Coral Reef Habitat Complexity

    PubMed Central

    Dustan, Phillip; Doherty, Orla; Pardede, Shinta

    2013-01-01

    Ecological habitats with greater structural complexity contain more species due to increased niche diversity. This is especially apparent on coral reefs where individual coral colonies aggregate to give a reef its morphology, species zonation, and three dimensionality. Structural complexity is classically measured with a reef rugosity index, which is the ratio of a straight line transect to the distance a flexible chain of equal length travels when draped over the reef substrate; yet, other techniques from visual categories to remote sensing have been used to characterize structural complexity at scales from microhabitats to reefscapes. Reef-scale methods either lack quantitative precision or are too time consuming to be routinely practical, while remotely sensed indices are mismatched to the finer scale morphology of coral colonies and reef habitats. In this communication a new digital technique, Digital Reef Rugosity (DRR) is described which utilizes a self-contained water level gauge enabling a diver to quickly and accurately characterize rugosity with non-invasive millimeter scale measurements of coral reef surface height at decimeter intervals along meter scale transects. The precise measurements require very little post-processing and are easily imported into a spreadsheet for statistical analyses and modeling. To assess its applicability we investigated the relationship between DRR and fish community structure at four coral reef sites on Menjangan Island off the northwest corner of Bali, Indonesia and one on mainland Bali to the west of Menjangan Island; our findings show a positive relationship between DRR and fish diversity. Since structural complexity drives key ecological processes on coral reefs, we consider that DRR may become a useful quantitative community-level descriptor to characterize reef complexity. PMID:23437380

  8. Digital reef rugosity estimates coral reef habitat complexity.

    PubMed

    Dustan, Phillip; Doherty, Orla; Pardede, Shinta

    2013-01-01

    Ecological habitats with greater structural complexity contain more species due to increased niche diversity. This is especially apparent on coral reefs where individual coral colonies aggregate to give a reef its morphology, species zonation, and three dimensionality. Structural complexity is classically measured with a reef rugosity index, which is the ratio of a straight line transect to the distance a flexible chain of equal length travels when draped over the reef substrate; yet, other techniques from visual categories to remote sensing have been used to characterize structural complexity at scales from microhabitats to reefscapes. Reef-scale methods either lack quantitative precision or are too time consuming to be routinely practical, while remotely sensed indices are mismatched to the finer scale morphology of coral colonies and reef habitats. In this communication a new digital technique, Digital Reef Rugosity (DRR) is described which utilizes a self-contained water level gauge enabling a diver to quickly and accurately characterize rugosity with non-invasive millimeter scale measurements of coral reef surface height at decimeter intervals along meter scale transects. The precise measurements require very little post-processing and are easily imported into a spreadsheet for statistical analyses and modeling. To assess its applicability we investigated the relationship between DRR and fish community structure at four coral reef sites on Menjangan Island off the northwest corner of Bali, Indonesia and one on mainland Bali to the west of Menjangan Island; our findings show a positive relationship between DRR and fish diversity. Since structural complexity drives key ecological processes on coral reefs, we consider that DRR may become a useful quantitative community-level descriptor to characterize reef complexity.

  9. Coal surface control for advanced fine coal flotation

    SciTech Connect

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

    1990-08-15

    The primary objective of this research project is to develop advanced flotation methods for coal cleaning in order to achieve near total pyritic-sulfur removal at 90% Btu recovery, using coal samples procured from six major US coal seams. Concomitantly, the ash content of these coals is to be reduced to 6% or less. Work this quarter concentrated on the following: washability studies, which included particle size distribution of the washability samples, and chemical analysis of washability test samples; characterization studies of induction time measurements, correlation between yield, combustible-material recovery (CMR), and heating-value recovery (HVR), and QA/QC for standard flotation tests and coal analyses; surface modification and control including testing of surface-modifying reagents, restoration of hydrophobicity to lab-oxidized coals, pH effects on coal flotation, and depression of pyritic sulfur in which pyrite depression with calcium cyanide and pyrite depression with xanthated reagents was investigated; flotation optimization and circuitry included staged reagent addition, cleaning and scavenging, and scavenging and middling recycling. Weathering studies are also discussed. 19 figs., 28 tabs.

  10. 21 CFR 880.5150 - Nonpowered flotation therapy mattress.

    Code of Federal Regulations, 2011 CFR

    2011-04-01

    ... 21 Food and Drugs 8 2011-04-01 2011-04-01 false Nonpowered flotation therapy mattress. 880.5150 Section 880.5150 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES... materials that have the functionally equivalent effect of supporting a patient and avoiding excess...

  11. 21 CFR 880.5150 - Nonpowered flotation therapy mattress.

    Code of Federal Regulations, 2014 CFR

    2014-04-01

    ... 21 Food and Drugs 8 2014-04-01 2014-04-01 false Nonpowered flotation therapy mattress. 880.5150 Section 880.5150 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES... materials that have the functionally equivalent effect of supporting a patient and avoiding excess...

  12. Flotation of fine coal with different volatility in China

    SciTech Connect

    Guo, M.X.; Hui, W.D.; An, Z.; Ren, Z.M.; Wang, Q.F.; Dai, Z.; Xiao, Z.Q.; Cui, Y.B.; Zhang, X.J.

    1997-12-31

    This paper contains three parts. The first part interprets the surface hydrophobicity and theoretical floatability of different rank coals from the organic molecular component point of view. The theoretical floatability between bituminous and anthracite is solved by the molecular theory. The second part describes a study of the interactive energy between hydrocarbon oil and coal particle using DLVO theory showing that the controlling factor in determining the repulsive energy barrier preventing oil from wetting and spreading on the coal surface is the same sign charge and Zeta potential. Some surfactants to promote the interaction of hydrocarbon oil and coal surface were investigated. The batch tests show a new flotation promoter having a higher efficiency and performance. A discussion is centered on the relationship between the floatabilities of coals with different volatile matter and the character of the new reagent. A molecular theory for the explanation of the interaction mechanism of the flotation reagent on coal surface was summarized. A survey of four coal preparation plants (Xiqu, Malan, Taiyuan and Tianzhuang) in Shanxi and Henan provinces was introduced. The flotation performance of coal with different volatility using commercial flotation cells in the above mentioned plants was tested.

  13. 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 §...

  14. 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 §...

  15. 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 §...

  16. 33 CFR 183.325 - Flotation test for persons capacity.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... Boats Rated for Engines of 2 Horsepower or Less Tests § 183.325 Flotation test for persons capacity... 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...

  17. 33 CFR 183.225 - Flotation test for persons capacity.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... Boats Rated for Engines of More Than 2 Horsepower Tests § 183.225 Flotation test for persons capacity... 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...

  18. 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 §...

  19. 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 §...

  20. 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.

  1. Micro-agglomerate flotation for deep cleaning of coal

    SciTech Connect

    Chander, S.; Hogg, R.

    1993-04-01

    We are investigating the use of a hybrid process, Micro-agglomerate flotation, which is a combination of oil-agglomeration and froth flotation. 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 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 and water/mineral carryover should be significantly alleviated.Micro-agglomerate flotation has considerable potential for the practical deep cleaning of coal on a commercial scale. In principle, it should be possible to achieve both high selectivity and high yield at reasonable cost. The process requires only conventional, off-the-shelf equipment and reagent usage (oil, surfactants, etc.) should be small. 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 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.

  2. Micro-agglomerate flotation for deep cleaning of coal

    SciTech Connect

    Chander, S.; Hogg, R.

    1993-01-01

    We are investigating the use of a hybrid process - Micro-agglomerate flotation - which is a combination of oil-agglomeration and froth flotation. 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 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 and water/mineral carryover should be significantly alleviated. Micro-agglomerate flotation has considerable potential for the practical deep cleaning of coal on a commercial scale. In principle, it should be possible to achieve both high selectivity and high yield at reasonable cost. The process requires only conventional, off-the-shelf equipment and reagent usage (oil, surfactants, etc.) should be small. 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 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.

  3. 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.

  4. 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.

  5. 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.

  6. 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. 880.5550 Section 880.5550 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED) MEDICAL DEVICES GENERAL HOSPITAL AND PERSONAL USE DEVICES General Hospital...

  7. Zeta potentials in the flotation of oxide and silicate minerals.

    PubMed

    Fuerstenau, D W; Pradip

    2005-06-30

    Adsorption of collectors and modifying reagents in the flotation of oxide and silicate minerals is controlled by the electrical double layer at the mineral-water interface. In systems where the collector is physically adsorbed, flotation with anionic or cationic collectors depends on the mineral surface being charged oppositely. Adjusting the pH of the system can enhance or prevent the flotation of a mineral. Thus, the point of zero charge (PZC) of the mineral is the most important property of a mineral in such systems. The length of the hydrocarbon chain of the collector is important because of chain-chain association enhances the adsorption once the surfactant ions aggregate to form hemimicelles at the surface. Strongly chemisorbing collectors are able to induce flotation even when collector and the mineral surface are charged similarly, but raising the pH sufficiently above the PZC can repel chemisorbing collectors from the mineral surface. Zeta potentials can be used to delineate interfacial phenomena in these various systems.

  8. 33 CFR 142.45 - Personal flotation devices.

    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. 142.45 Section 142.45 Navigation and Navigable Waters COAST GUARD, DEPARTMENT OF HOMELAND SECURITY (CONTINUED) OUTER CONTINENTAL SHELF ACTIVITIES WORKPLACE SAFETY AND HEALTH Personal Protective...

  9. Frogmen on Apollo command module boilerplate flotation collar during recovery

    NASA Technical Reports Server (NTRS)

    1966-01-01

    Apollo command module boilerplate floats in the Atlantic Ocean during a practice recovery exercise. Frogmen in a liferaft and on the flotation collar secure the command module boilerplate for hoisting onto a nearby recovery ship. The exercise was conducted in preparation for the forthcoming Apollo-Saturn 201 (AS-201) mission.

  10. Navy frogmen attach flotation collar to Apollo 7 command module

    NASA Technical Reports Server (NTRS)

    1968-01-01

    U.S. Navy frogmen attach a flotation collar to the Apollo 7 command module during recovery operations in the Atlantic. The Apollo 7 spacecraft splashed down at 7:11 a.m., October 22, 1968, approximately 200 nautical miles south-southwest of Bermuda.

  11. 33 CFR 183.225 - Flotation test for persons capacity.

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ... Boats Rated for Engines of More Than 2 Horsepower Tests § 183.225 Flotation test for persons capacity... 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...

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

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ... Boats Rated for Engines of 2 Horsepower or Less Tests § 183.325 Flotation test for persons capacity... 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...

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

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... Boats Rated for Engines of More Than 2 Horsepower Tests § 183.225 Flotation test for persons capacity... 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...

  14. 33 CFR 183.325 - Flotation test for persons capacity.

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... Boats Rated for Engines of 2 Horsepower or Less Tests § 183.325 Flotation test for persons capacity... 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...

  15. 33 CFR 183.325 - Flotation test for persons capacity.

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... Boats Rated for Engines of 2 Horsepower or Less Tests § 183.325 Flotation test for persons capacity... 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...

  16. 33 CFR 183.225 - Flotation test for persons capacity.

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... Boats Rated for Engines of More Than 2 Horsepower Tests § 183.225 Flotation test for persons capacity... 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...

  17. Mineral and Elemental Composition Features of "Loose" Oolitic Ores in Bakchar Iron Ore Cluster (Tomsk Oblast)

    NASA Astrophysics Data System (ADS)

    Rudmin, M.; Mazurov, A.; Bolsunovskaya, L.

    2014-08-01

    Geo-technological investigation considerations of iron ore deposits within the Bakchar ore cluster are being carried out. The mineral and elemental composition of "loose" ores have been studied, embracing such important aspects as the distribution pattern of valuable and harmful impurities, the determination of element concentrators (such as vanadium, phosphate and sulphur) in basic minerals and the analysis of ore composition varaiation in volume ore cluster. Based on investigation results the mineral and elemental composition characteristic features of "loose" ores were defined. Although hydrogoethite was the basic identified ore mineral, such minerals as goethite, lepidocrocite, leptochlorite, siderite and hisingerite were also found. The deportment of calcium phosphate (anapaite) and phosphates of rare-earth elements (monazite, killarite), which are associated with the harmful impurity- phosphorous, are described. It has been defined that the ore constituent composition contains such persistent impurities as vanadium and manganese, the content of which is 0.35% and 0.03%, respectively. The "loose" ores are continuous in mineral composition, both in area and cross-section throughout the Bakchar ore cluster. Based on the sample element composition analysis the most perspective areas for further mineral processing could be: western with the fraction of 1....0.2mm. and eastern- fraction of 1...0.1mm.

  18. 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

  19. Direct Reduction of Iron Ore

    NASA Astrophysics Data System (ADS)

    Small, M.

    1981-04-01

    In the search for a pure, available iron source, steelmakers are focusing their attention on Directly Reduced Iron (DRI). This material is produced by the reaction of a low gangue iron ore with a hydrocarbonaceous substance. Commercially, DRI is generated in four different reactors: shaft (moving-bed), rotary kiln, fluidized bed, and retort (fixed-bed). Annual worldwide production capacity approaches 33 million metric tons. Detailed assessments have been made of the uses of DRI, especially as a substitute for scrap in electric furnace (EF) steelmaking. DRI is generally of a quality superior to current grades of scrap, with steels produced more efficiently in the EF and containing lower levels of impurities. However, present economics favor EF steel production with scrap. But this situation could change within this decade because of a developing scarcity of good quality scrap.

  20. 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.

  1. On prediction and discovery of lunar ores

    NASA Technical Reports Server (NTRS)

    Haskin, Larry A.; Colson, Russell O.; Vaniman, David

    1991-01-01

    Sampling of lunar material and remote geochemical, mineralogical, and photogeologic sensing of the lunar surface, while meager, provide first-cut information about lunar composition and geochemical separation processes. Knowledge of elemental abundances in known lunar materials indicates which common lunar materials might serve as ores if there is economic demand and if economical extraction processes can be developed, remote sensing can be used to extend the understanding of the Moon's major geochemical separations and to locate potential ore bodies. Observed geochemical processes might lead to ores of less abundant elements under extreme local conditions.

  2. 25. FRONT END LOADERS MOMENTARILY IN REPOSE IN THE ORE ...

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

    25. FRONT END LOADERS MOMENTARILY IN REPOSE IN THE ORE STORAGE YARD. AN ORE BRIDGE THAT FORMERLY TRANSFERRED ORE WITHIN THE STORAGE YARD WAS DESTROYED BY A BLIZZARD IN 1978. - Pennsylvania Railway Ore Dock, Lake Erie at Whiskey Island, approximately 1.5 miles west of Public Square, Cleveland, Cuyahoga County, OH

  3. 36. ORE DOCK, LOOKING WEST. HULETT UNLOADERS AWAIT THE NEXT ...

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

    36. ORE DOCK, LOOKING WEST. HULETT UNLOADERS AWAIT THE NEXT ORE BOAT. BY LATE WINTER, THE ORE STORAGE YARD SEEN AT LEFT WILL BE DEPLETED. - Pennsylvania Railway Ore Dock, Lake Erie at Whiskey Island, approximately 1.5 miles west of Public Square, Cleveland, Cuyahoga County, OH

  4. Black reefs: iron-induced phase shifts on coral reefs.

    PubMed

    Kelly, Linda Wegley; Barott, Katie L; Dinsdale, Elizabeth; Friedlander, Alan M; Nosrat, Bahador; Obura, David; Sala, Enric; Sandin, Stuart A; Smith, Jennifer E; Vermeij, Mark J A; Williams, Gareth J; Willner, Dana; Rohwer, Forest

    2012-03-01

    The Line Islands are calcium carbonate coral reef platforms located in iron-poor regions of the central Pacific. Natural terrestrial run-off of iron is non-existent and aerial deposition is extremely low. However, a number of ship groundings have occurred on these atolls. The reefs surrounding the shipwreck debris are characterized by high benthic cover of turf algae, macroalgae, cyanobacterial mats and corallimorphs, as well as particulate-laden, cloudy water. These sites also have very low coral and crustose coralline algal cover and are call black reefs because of the dark-colored benthic community and reduced clarity of the overlying water column. Here we use a combination of benthic surveys, chemistry, metagenomics and microcosms to investigate if and how shipwrecks initiate and maintain black reefs. Comparative surveys show that the live coral cover was reduced from 40 to 60% to <10% on black reefs on Millennium, Tabuaeran and Kingman. These three sites are relatively large (>0.75 km(2)). The phase shift occurs rapidly; the Kingman black reef formed within 3 years of the ship grounding. Iron concentrations in algae tissue from the Millennium black reef site were six times higher than in algae collected from reference sites. Metagenomic sequencing of the Millennium Atoll black reef-associated microbial community was enriched in iron-associated virulence genes and known pathogens. Microcosm experiments showed that corals were killed by black reef rubble through microbial activity. Together these results demonstrate that shipwrecks and their associated iron pose significant threats to coral reefs in iron-limited regions.

  5. The Geohydrology of MVT-Ore Genesis in the Canning Basin, Western Australia

    NASA Astrophysics Data System (ADS)

    Garven, G.; Wallace, M. M.

    2009-05-01

    In the Lennard Shelf, Western Australia, epigenetic MVT-type Pb-Zn mineralization occurs in Middle Devonian evaporitic dolomites which were part of a barrier reef system (Hurley & Lohmann, 1989). Ore mineralization exhibits a strong structural control at the basin scale and normal faults probably controlled pathways for brine and petroleum migration that affected ore deposition (Wallace et al., 1999). For the Canning basin, finite element simulations show that compaction was the most important process for creating overpressures and driving basinal fluids in this thick extensional basin. Basinal fluids are shown to have been driven across the Fitzroy Trough through permeable and deeply buried Silurian-Ordovician aquifer units. The fluids then migrated upwards at rates of m/yr up during periods of episodic extension (Braun, 1992) where fluid flow was channeled by major normal fault zones like the Cadjebut and Pinnacles Faults. Reactive flow simulations test a petroleum-reservoir model for mineralization whereby metal-bearing brines mix with accumulated hydrocarbons (Anderson & Garven, 1987). The results show that compaction-driven flow, as proposed by Beales & Jackson (1966) and Jackson & Beales (1967), works rather well in this ore district--other mechanisms such as sealevel tidal pumping (Cathles, 1988) or topographic drive (Solomon & Groves, 1994) are more tenuous and really unnecessary from a mass transport or geohydrologic basis.

  6. Oolitic ores in the Bakchar iron-ore cluster (Tomsk Oblast)

    NASA Astrophysics Data System (ADS)

    Rudmin, M. A.; Mazurov, A. K.

    2016-12-01

    Oolitic iron ores are typified, and their morphology and composition are studied. Special attention is focused on the character of distribution of valuable and harmful admixtures and determination of the principal minerals concentrating these elements. As a result of this study, three types of ores are identified, such as "loose" ores, cemented ores with glauconite-chlorite-clay cement, and well-cemented ores with siderite cement. The morphology and composition of the ore oolites are characterized. The forms of occurrence of calcium phosphates (anapaite) and phosphates of rare-earth elements (monazite, cularite) that are related to the harmful phosphorus admixture are described. According to the analysis of the elemental composition, the fractions of (-1…+0.2) and (-1…+0.1) mm in the western and eastern segments, respectively, may be promising for processing.

  7. Coral reefs and carbon dioxide

    SciTech Connect

    Buddemeier, R.W.

    1996-03-01

    This commentary argues the conclusion from a previous article, which investigates diurnal changes in carbon dioxide partial pressure and community metabolism on coral reefs, that coral `reefs might serve as a sink, not a source, for atmospheric carbon dioxide.` Commentaries from two groups are given along with the response by the original authors, Kayanne et al. 27 refs.

  8. Characterisation and Processing of Some Iron Ores of India

    NASA Astrophysics Data System (ADS)

    Krishna, S. J. G.; Patil, M. R.; Rudrappa, C.; Kumar, S. P.; Ravi, B. P.

    2013-10-01

    Lack of process characterization data of the ores based on the granulometry, texture, mineralogy, physical, chemical, properties, merits and limitations of process, market and local conditions may mislead the mineral processing entrepreneur. The proper implementation of process characterization and geotechnical map data will result in optimized sustainable utilization of resource by processing. A few case studies of process characterization of some Indian iron ores are dealt with. The tentative ascending order of process refractoriness of iron ores is massive hematite/magnetite < marine black iron oxide sands < laminated soft friable siliceous ore fines < massive banded magnetite quartzite < laminated soft friable clayey aluminous ore fines < massive banded hematite quartzite/jasper < massive clayey hydrated iron oxide ore < manganese bearing iron ores massive < Ti-V bearing magnetite magmatic ore < ferruginous cherty quartzite. Based on diagnostic process characterization, the ores have been classified and generic process have been adopted for some Indian iron ores.

  9. Confronting the coral reef crisis

    NASA Astrophysics Data System (ADS)

    Bellwood, D. R.; Hughes, T. P.; Folke, C.; Nyström, M.

    2004-06-01

    The worldwide decline of coral reefs calls for an urgent reassessment of current management practices. Confronting large-scale crises requires a major scaling-up of management efforts based on an improved understanding of the ecological processes that underlie reef resilience. Managing for improved resilience, incorporating the role of human activity in shaping ecosystems, provides a basis for coping with uncertainty, future changes and ecological surprises. Here we review the ecological roles of critical functional groups (for both corals and reef fishes) that are fundamental to understanding resilience and avoiding phase shifts from coral dominance to less desirable, degraded ecosystems. We identify striking biogeographic differences in the species richness and composition of functional groups, which highlight the vulnerability of Caribbean reef ecosystems. These findings have profound implications for restoration of degraded reefs, management of fisheries, and the focus on marine protected areas and biodiversity hotspots as priorities for conservation.

  10. 40 CFR 230.44 - Coral reefs.

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... 40 Protection of Environment 25 2011-07-01 2011-07-01 false Coral reefs. 230.44 Section 230.44... Aquatic Sites § 230.44 Coral reefs. (a) Coral reefs consist of the skeletal deposit, usually of calcareous... organisms present in growing portions of the reef. (b) Possible loss of values: The discharge of dredged...

  11. 40 CFR 230.44 - Coral reefs.

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ... 40 Protection of Environment 26 2012-07-01 2011-07-01 true Coral reefs. 230.44 Section 230.44... Aquatic Sites § 230.44 Coral reefs. (a) Coral reefs consist of the skeletal deposit, usually of calcareous... organisms present in growing portions of the reef. (b) Possible loss of values: The discharge of dredged...

  12. 40 CFR 230.44 - Coral reefs.

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... 40 Protection of Environment 25 2014-07-01 2014-07-01 false Coral reefs. 230.44 Section 230.44... Aquatic Sites § 230.44 Coral reefs. (a) Coral reefs consist of the skeletal deposit, usually of calcareous... organisms present in growing portions of the reef. (b) Possible loss of values: The discharge of dredged...

  13. 40 CFR 230.44 - Coral reefs.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... 40 Protection of Environment 24 2010-07-01 2010-07-01 false Coral reefs. 230.44 Section 230.44... Aquatic Sites § 230.44 Coral reefs. (a) Coral reefs consist of the skeletal deposit, usually of calcareous... organisms present in growing portions of the reef. (b) Possible loss of values: The discharge of dredged...

  14. 8. EAST ELEVATION OF SKIDOO MILL AND UPPER ORE BIN, ...

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

    8. EAST ELEVATION OF SKIDOO MILL AND UPPER ORE BIN, LOOKING WEST FROM ACCESS ROAD. THE ROADWAY ON THIS LEVEL (CENTER) WAS USED FOR UNLOADING ORE BROUGHT ON BURROWS INTO THE ORE BIN AT THE TOP LEVEL OF THE MILL. THE ORE BIN IN THE UPPER LEFT WAS ADDED LATER WHEN ORE WAS BROUGHT TO THE MILL BY TRUCKS. - Skidoo Mine, Park Route 38 (Skidoo Road), Death Valley Junction, Inyo County, CA

  15. The sources of our iron ores. II

    USGS Publications Warehouse

    Burchard, E.F.

    1933-01-01

    In this instalment** the iron ore deposits of the Lake Superior States, which normally furnish about 80 per cent, of the annual output of the United States, are described together with historical notes on discovery and transportation of ore. Deposits in the Mississippi Valley and Western States are likewise outlined and the sources of imported ore are given. Reviewing the whole field, it is indicated that the great producing deposits of the Lake Superior and southern Appalachian regions are of hematite in basin areas of sedimentary rocks, that hydrated iron oxides and iron carbonates are generally found in undisturbed comparatively recent sediments, and that magnetite occurs in metamorphic and igneous rocks; also that numerical abundance of deposits is not a criterion as to their real importance as a source of supply. Statistics of production of iron ore and estimates of reserves of present grade conclude the paper.

  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. Biomining: metal recovery from ores with microorganisms.

    PubMed

    Schippers, Axel; Hedrich, Sabrina; Vasters, Jürgen; Drobe, Malte; Sand, Wolfgang; Willscher, Sabine

    2014-01-01

    Biomining is an increasingly applied biotechnological procedure for processing of ores in the mining industry (biohydrometallurgy). Nowadays the production of copper from low-grade ores is the most important industrial application and a significant part of world copper production already originates from heap or dump/stockpile bioleaching. Conceptual differences exist between the industrial processes of bioleaching and biooxidation. Bioleaching is a conversion of an insoluble valuable metal into a soluble form by means of microorganisms. In biooxidation, on the other hand, gold is predominantly unlocked from refractory ores in large-scale stirred-tank biooxidation arrangements for further processing steps. In addition to copper and gold production, biomining is also used to produce cobalt, nickel, zinc, and uranium. Up to now, biomining has merely been used as a procedure in the processing of sulfide ores and uranium ore, but laboratory and pilot procedures already exist for the processing of silicate and oxide ores (e.g., laterites), for leaching of processing residues or mine waste dumps (mine tailings), as well as for the extraction of metals from industrial residues and waste (recycling). This chapter estimates the world production of copper, gold, and other metals by means of biomining and chemical leaching (bio-/hydrometallurgy) compared with metal production by pyrometallurgical procedures, and describes new developments in biomining. In addition, an overview is given about metal sulfide oxidizing microorganisms, fundamentals of biomining including bioleaching mechanisms and interface processes, as well as anaerobic bioleaching and bioleaching with heterotrophic microorganisms.

  18. Separating dolomite from phosphate rock by reactive flotation: Fundamentals and application

    NASA Astrophysics Data System (ADS)

    El-Midany, Ayman A.

    Florida is currently one of the largest phosphate producers in the world. Unfortunately, the phosphate industry in Florida is suffering from depletion of the phosphate-rich ore. Dolomite, however, is a major impurity in the ores. The presence of MgO, in dolomite, can cause several problems during production of phosphoric acid and final fertilizers. Efforts to solve the dolomite problem have been reported by several researchers throughout the world. Yet, only heavy media separation process has been applied commercially. However, the process was discontinued because of its low separation efficiency in terms of grade and recovery. In this study, we tested an innovative idea based on simple fact that dolomite, as a carbonate mineral, generates CO2 when exposed to a slightly acidic solution, capturing CO2 bubbles at dolomite particle surface can selectively float the dolomite and separate it from phosphate. Formation of such bubbles requires a surface-active agent(s) at solution/dolomite interface. Preliminary tests indicated that polyvinyl alcohol (PVA) could serve this function. This process is called the Reactive Flotation, RF. To develop this process and to scale it up for industrial use, we conducted fundamental and applied research studies. Among these studies were optimizing of RF process by investigating the factors affecting the process (including bench and pilot scale tests) using statistical experimental designs. It was found that the acid concentration, PVA concentration, and particle size are the main factors. The optimum conditions were determined and applied to usage in a gravity separation device, (i.e., a sluice). Using such a device, a concentrate contains 0.65% MgO with >94 MgO % removal can be achieved. In addition, fundamental studies revealed that the hydrogen bonding is the adsorption mechanism confirmed by adsorption isotherm of PVA on dolomite and phosphate, adhesion of PVA to dolomite surface (using contact angle and surface tension), Fourier

  19. The influence of reagent dosage on the floatability of pyrite during coal flotation

    SciTech Connect

    Bonner, C.M.; Aplan, F.F.

    1993-01-01

    In general, as the quantity of frother and/or coal collector is increased, so too, does the flotation of the undesired pyrite. The problem is particularly serious with oil reagents. For some coals, however, a collector, such as fuel oil, is required to achieve a high coal recovery. This requires a compromise between the competing desires of a high coal recovery and a high pyrite rejection. This study gives the quantitative effect of reagent dosage on coal and pyrite floatability and details several means of minimizing pyrite floatability during coal flotation. The effect of fuel oil on coal flotation is especially interesting in that the flotation process changes from froth flotation to emulsion or agglomerative flotation as the amount of oil is increased. This phenomenon provides an additional method of rejecting pyritic sulfur.

  20. 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.

  1. Self-generated morphology in lagoon reefs.

    PubMed

    Blakeway, David; Hamblin, Michael G

    2015-01-01

    The three-dimensional form of a coral reef develops through interactions and feedbacks between its constituent organisms and their environment. Reef morphology therefore contains a potential wealth of ecological information, accessible if the relationships between morphology and ecology can be decoded. Traditionally, reef morphology has been attributed to external controls such as substrate topography or hydrodynamic influences. Little is known about inherent reef morphology in the absence of external control. Here we use reef growth simulations, based on observations in the cellular reefs of Western Australia's Houtman Abrolhos Islands, to show that reef morphology is fundamentally determined by the mechanical behaviour of the reef-building organisms themselves-specifically their tendency to either remain in place or to collapse. Reef-building organisms that tend to remain in place, such as massive and encrusting corals or coralline algae, produce nodular reefs, whereas those that tend to collapse, such as branching Acropora, produce cellular reefs. The purest reef growth forms arise in sheltered lagoons dominated by a single type of reef builder, as in the branching Acropora-dominated lagoons of the Abrolhos. In these situations reef morphology can be considered a phenotype of the predominant reef building organism. The capacity to infer coral type from reef morphology can potentially be used to identify and map specific coral habitat in remotely sensed images. More generally, identifying ecological mechanisms underlying other examples of self-generated reef morphology can potentially improve our understanding of present-day reef ecology, because any ecological process capable of shaping a reef will almost invariably be an important process in real time on the living reef.

  2. Self-generated morphology in lagoon reefs

    PubMed Central

    Hamblin, Michael G.

    2015-01-01

    The three-dimensional form of a coral reef develops through interactions and feedbacks between its constituent organisms and their environment. Reef morphology therefore contains a potential wealth of ecological information, accessible if the relationships between morphology and ecology can be decoded. Traditionally, reef morphology has been attributed to external controls such as substrate topography or hydrodynamic influences. Little is known about inherent reef morphology in the absence of external control. Here we use reef growth simulations, based on observations in the cellular reefs of Western Australia’s Houtman Abrolhos Islands, to show that reef morphology is fundamentally determined by the mechanical behaviour of the reef-building organisms themselves—specifically their tendency to either remain in place or to collapse. Reef-building organisms that tend to remain in place, such as massive and encrusting corals or coralline algae, produce nodular reefs, whereas those that tend to collapse, such as branching Acropora, produce cellular reefs. The purest reef growth forms arise in sheltered lagoons dominated by a single type of reef builder, as in the branching Acropora-dominated lagoons of the Abrolhos. In these situations reef morphology can be considered a phenotype of the predominant reef building organism. The capacity to infer coral type from reef morphology can potentially be used to identify and map specific coral habitat in remotely sensed images. More generally, identifying ecological mechanisms underlying other examples of self-generated reef morphology can potentially improve our understanding of present-day reef ecology, because any ecological process capable of shaping a reef will almost invariably be an important process in real time on the living reef. PMID:26175962

  3. Ores and Climate Change - Primary Shareholders

    NASA Astrophysics Data System (ADS)

    Stein, Holly J.; Hannah, Judith L.

    2015-04-01

    Many in the economic geology community concern themselves with details of ore formation at the deposit scale, whether tallying fluid inclusion data to get at changes in ore-forming fluids or defining structures that aid and abet mineralization. These compilations are generally aimed at interpretation of events at the site of ore formation, with the goal being assignment of the deposit to a sanctioned ore deposit model. While providing useful data, this approach is incomplete and does not, by itself, serve present-day requirements for true interdisciplinary science. The ore-forming environment is one of chaos and disequilibrium at nearly all scales (Stein, 2014). Chaos and complexity are documented by variably altered rocks, veins or disseminated mineralization with multi-generational fluid histories, erratic and unusual textures in host rocks, and the bitumen or other hydrocarbon products entwined within many ore deposits. This should give pause to our drive for more data as a means to find "the answer". The answer lies in the kind of data collected and more importantly, in the way we interpret those data. Rather than constructing an ever-increasing catalog of descriptive mutations on sanctioned ore deposit models (e.g., IOGC or Iron-Oxide Copper Gold deposits), the way forward is to link source and transport of metals, sulfur, and organic material with regional and ultimately whole Earth chemical evolution. Important experimental work provides chemical constraints in controlled and behaved environments. To these data, we add imagination and interpretation, always tying back to field observations. In this paper, several key points are made by way of ore deposit examples: (1) many IOCG deposits are outcomes of profound changes in the chemistry of the Earth's surface, in the interplay of the atmosphere, hydrosphere, biosphere, and lithosphere; (2) the redox history of Fe in deep earth may be ultimately expressed in the ore-forming sequence; and (3) the formation of

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

    SciTech Connect

    Not Available

    1992-01-01

    The Task 6 effort involves three main elements including column cell development, flotation circuit testing and flotation cell modeling. The work outlined is to research column designs and operation parameters in developing an optimized column flotation cell (OCFC) to meet the overall program objectives. The test results obtained through this effort will be evaluated against the results obtained from the round-robin test program in Task 5. Any design parameters or operating conditions that are unique with the round-robin test winner that were not evaluated as part of the optimized column developments work will be reviewed and tested so as to incorporate all possible scenarios in presenting DOE with the best available flotation process for use in the 2 to 3 ton per hour POC. Following development of the OCFC, various flotation circuit configurations will be evaluated determine the best'' circuit design for the 2 to 3 ton per hour POC. Single and multiple stage flotation, grab and run,rougher/scavenger/cleaner, etc., test circuits will be tested as part of this effort. Upon completion of this test work, the best'' possible flotation cell will have been tested in a number of possible flotation circuit designs to possibly provide the best'' flotation approach in meeting the design criteria. In conjunction with the flotation test effort, model development work will be conducted to provide a tool in evaluating the various flotation circuit configurations and in predicting flotation performance. The model will be useful in selecting operating conditions in the POC and in evaluating the performance of the POC.

  5. 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

  6. Adaptive Avoidance of Reef Noise

    PubMed Central

    Simpson, Stephen D.; Radford, Andrew N.; Tickle, Edward J.; Meekan, Mark G.; Jeffs, Andrew G.

    2011-01-01

    Auditory information is widely used throughout the animal kingdom in both terrestrial and aquatic environments. Some marine species are dependent on reefs for adult survival and reproduction, and are known to use reef noise to guide orientation towards suitable habitat. Many others that forage in food-rich inshore waters would, however, benefit from avoiding the high density of predators resident on reefs, but nothing is known about whether acoustic cues are used in this context. By analysing a sample of nearly 700,000 crustaceans, caught during experimental playbacks in light traps in the Great Barrier Reef lagoon, we demonstrate an auditory capability in a broad suite of previously neglected taxa, and provide the first evidence in any marine organisms that reef noise can act as a deterrent. In contrast to the larvae of species that require reef habitat for future success, which showed an attraction to broadcasted reef noise, taxa with a pelagic or nocturnally emergent lifestyle actively avoided it. Our results suggest that a far greater range of invertebrate taxa than previously thought can respond to acoustic cues, emphasising yet further the potential negative impact of globally increasing levels of underwater anthropogenic noise. PMID:21326604

  7. Adaptive avoidance of reef noise.

    PubMed

    Simpson, Stephen D; Radford, Andrew N; Tickle, Edward J; Meekan, Mark G; Jeffs, Andrew G

    2011-02-04

    Auditory information is widely used throughout the animal kingdom in both terrestrial and aquatic environments. Some marine species are dependent on reefs for adult survival and reproduction, and are known to use reef noise to guide orientation towards suitable habitat. Many others that forage in food-rich inshore waters would, however, benefit from avoiding the high density of predators resident on reefs, but nothing is known about whether acoustic cues are used in this context. By analysing a sample of nearly 700,000 crustaceans, caught during experimental playbacks in light traps in the Great Barrier Reef lagoon, we demonstrate an auditory capability in a broad suite of previously neglected taxa, and provide the first evidence in any marine organisms that reef noise can act as a deterrent. In contrast to the larvae of species that require reef habitat for future success, which showed an attraction to broadcasted reef noise, taxa with a pelagic or nocturnally emergent lifestyle actively avoided it. Our results suggest that a far greater range of invertebrate taxa than previously thought can respond to acoustic cues, emphasising yet further the potential negative impact of globally increasing levels of underwater anthropogenic noise.

  8. Flotation classification of ultrafine particles -- A novel classification approach

    SciTech Connect

    Qiu Guanzhou; Luo Lin; Hu Yuehua; Xu Jin; Wang Dianzuo

    1995-12-31

    This paper introduces a novel classification approach named the flotation classification approach which works by controlling interactions between particles. It differs considerably from the conventional classification processes operating on mechanical forces. In the present test, the micro-bubble flotation technology is grafted onto hydro-classification. Selective aggregation and dispersion of ultrafine particles are achieved through governing the interactions in the classification process. A series of laboratory classification tests for {minus}44 gm kaolin have been conducted on a classification column. As a result, about 92% recovery for minus 2 {micro}m size fraction Kaolin in the final product is obtained. In addition, two criteria for the classification are set up. Finally, a principle of classifying and controlling the interactions between particles is discussed in terms of surface thermodynamics and hydrodynamics.

  9. Column flotation research at United Coal looks to pay off

    SciTech Connect

    Merritt, P.

    1988-07-01

    Column flotation technology, designed to recover coal fines, has been the focus of research in private, university, and government laboratories for several years. While the potential of this technology continues to be scrutinized by scientists, the first commercial-size units have also been quietly placed on-line in two eastern preparation plants. The recently installed cells at both plants have gone through debugging procedures and are now achieving substantial recoveries of fine coal formerly lost to waste. For Tanoma that added production is 10.4 tph of fine coal; for United Coal, fine coal recovery exceeds 15 tph, an amount expected to rise to perhaps as much as 25 tph. The author describes how column flotation works and the systems at Tanoma Mining and United Coal.

  10. In-plant testing of microbubble column flotation

    SciTech Connect

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

    1990-01-01

    During the past year, a joint project between the US Department of Energy (DOE), the Virginia Center for Coal and Minerals Processing (VCCMP) and the Shell Mining Corporation (SMC) was initiated to implement the testing of a full-scale microbubble flotation column. The work is being carried out at the Marrowbone Preparation Plant, located near Naugatuck in southwestern West Virginia. The primary objective of this effort was to determine the feasibility of using microbubble column flotation for the recovery of coal fines from a classifying cyclone overflow stream that is presently being discarded as refuse. During the past quarter, results obtained using a 30-inch diameter test unit were reviewed, flowsheet layouts and preliminary scale-up projections were generated and design, engineering, fabrication and installation of the full-scale test unit was completed. Preliminary results were also obtained with the full-scale test unit and are presented in this report. 5 figs., 7 tabs.

  11. 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.

  12. 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.

  13. 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.

  14. Miocene reef corals: A review

    SciTech Connect

    Frost, S.H.

    1988-01-01

    Tectonic blockage in the Middle East of westward-flowing Tethys surface circulation during the latest Oligocene led to creation in the earliest Miocene of endemic Mediterranean, Western Atlantic-Caribbean, and Indo-Pacific realms. A great reduction in reef coral diversity from 60-80 Oligocene species to 25-35 early Miocene species occurred in the Western Atlantic-Caribbean and Mediterranean areas accompanied by a decrease in reef growth. A slower and less drastic change apparently occurred in the Indo-Pacific area. Early Miocene reef corals of the Western Atlantic-Caribbean comprise a transition between the cosmopolitan Oligocene fauna and its endemic mid-Miocene to modern counterpart. Although early Miocene reefs were dominated by a Porites-Montastrea assemblage, eastward flow of Pacific circulation brought with it ''exotic'' corals such as Coscinaraea and Pseudocolumnastrea. Also, many cosmopolitan genera persisted from the Oligocene. During the middle to late Miocene, most of the species still living on Holocene reefs evolved. As the Mediterranean basin became more restricted, there was a slow decline in reef corals from 20 - 25 species in the Aquitainian to less than five species in the Messinian. Eustatic lowstand led to the extinction of reef-building corals in the late Messinian. In the Indo-Pacific, Neogene evolution of reef corals was conservative. Excluding the Acroporidae and Seriatoporidae, most Holocene framework species had evolved by the middle Miocene. Interplay between regional tectonics and eustatic sea level changes led to extensive development of middle to late Miocene pinnacle reefs over the southwestern Pacific.

  15. Final report on agglomerate column flotation for cleaning and desulfurization of Ohio coal fines

    SciTech Connect

    Attia, Y.A.; El Zeky, M.; Yu, Mulong . Dept. of Materials Science and Engineering)

    1990-08-30

    The objective of this research program was investigate the feasibility of cleaning and desulfurization of Ohio coal by an agglomerate column flotation process, which integrates selective flocculation with conventional column flotation. It was concluded earlier on in the program that the conventional design of flotation column was not particularly efficient for pyrite rejection. A novel design for flotation column system was conceived and a prototype unit was manufactured and tested in the laboratory. Several design and operational parameters for the column and the agglomerate flotation process were briefly investigated to define proper design and working conditions for a satisfactory performance. The novel design was compared with conventional design of flotation column through laboratory tests and through published results. The role of selective flocculation of coal including selective depression of pyrite has been identified and tested with both novel and conventional design of flotation columns. The results of these brief investigations, which are summarized in this report, suggest that: (1) excellent performance ca n be obtained with agglomerate column flotation using the new design. For example, a raw coal containing 3.16% total sulfur, 2.11% pyritic sulfur, and 17% ash can be cleaned to 1.91 % ash, 0.42% pyritic sulfur, 1.32% total sulfur, while maintaining a projected Btu/coal recovery of 86% (mmmf basis). This is equivalent to 89% ash removal and 81% pyritic sulfur (58% total sulfur) rejection. (2) The novel design of flotation column is superior to conventional design particularly for pyrite rejection.

  16. An investigation of pyrite depression in coal flotation by electrochemical pyrite surface control

    SciTech Connect

    Zhu Hong; Ou Zeshen; Shi Xiuping; Shen Yanchun

    1995-12-31

    This paper introduces a new potential method of pyrite depression in the flotation of high sulfur coal based on the electrochemical pyrite surface control. Experimental date show that the natural hydrophobicity of pyrite depends on the oxidation-reduction potential of the pulp. The mechanism and products of electrochemical reaction on the pyrite surface are also discussed under various conditions. The pyrite flotation is generally suppressed under low pulp potentials. Therefore, the sulfur removal in the flotation of high sulfur coal could be improved by the pulp redox potential control, while the coal flotation is materially not affected.

  17. Using alternative chemicals in the flotation of heavy metals from lead mill tailings

    SciTech Connect

    Benn, F.W.

    1995-04-01

    The U.S. Bureau of Mines (USBM) investigated alternative chemicals for the flotation of heavy metal values from southeast Missouri lead mill tailings. The objectives of the study were to lower the Pb remaining in the reprocessed tailings to <500 ppm, concentrate the metal values, and lower the overall toxicity of the flotation reagent scheme. Due to the high toxicity of classic flotation chemicals, collectorless flotation, as well as nontoxic or less-toxic chemicals, was studied for use in the flotation process. The investigation centered on the National tailings pile in Flat River, MO. Advantages to using alternative chemicals for the flotation process are presented. Novel reagent schemes are discussed for the treatment of the tailings. Various nontoxic or less-toxic oils were tested, and a substitute for sodium sulfide was investigated. Using a food additive oil, soda ash, and a frother as the reagent scheme, froth flotation recovered 89% of the Pb values. Further scavenging lowered the Pb remaining in the reprocessed tailings to <500 ppm. A less-toxic substitute for sodium cyanide was also studied for use in the cleaner flotation stages. Preliminary results indicate that the food additive oil, canola oil, to be as effective as classic sulfide flotation reagents.

  18. 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.

  19. Personal Flotation Devices Research. Volume 2. Research Report.

    DTIC Science & Technology

    1978-01-01

    statistical techniques , inc l uding factor analysis, canonical correlation analysis , and multiple linear regression were used to develop indices of PFD...of inflatable PFDs subjected to this test plan showed that an Accelerated Testing Technique - is feasible for testing inflatable PFDs , that latent...tool, with related techniques and procedures that organize and summarize accident data so that the role of personal flotation devices in saving lives

  20. SYNTHESIS AND EVALUATION OF NEW AND IMPROVED GYRO FLOTATION FLUIDS.

    DTIC Science & Technology

    on a proprietary fluid. The synthesis of heavy metal alkanethiolates was investigated and two compounds were isolated and characterized. Both are...viscous, high boiling liquids. Methods of preparing fluoroalkanethiols were explored as a means of providing starting materials for the synthesis of heavy metal fluoroalkanethiolates. (Author)...The purpose of this research program is to produce liquids which have densities between 2.5 and 3.0 g./cc. for use as gyro flotation fluids. Heavy

  1. Antimony ore in the Fairbanks district, Alaska

    USGS Publications Warehouse

    Killeen, Pemberton Lewis; Mertie, John B.

    1951-01-01

    Antimony-bearing ores in the Fairbanks district, Alaska, are found principally in two areas, the extremities of which are at points 10 miles west and 23 miles northeast of Fairbanks; and one of two minor areas lies along this same trend 30 miles farther to the northeast. These areas are probably only local manifestations of mineralization that affected a much broader area and formed antimony-bearing deposits in neighboring districts, the closest of which is 50 miles away. The ores were exposed largely as a result of lode gold mining, but at two periods in the past, high prices for antimony ore warranted an independent production and about 2500 tons of stibnite ore was shipped. The sulfide deposits occupy the same fractures along which a gold-quartz mineralization of greater economic importance occurred; and both are probably genetically related to igneous rocks which intrude the schistose country rock. The sulfide is in part contemporaneous with some late-stage quartz in which it occurs as disseminated crystals; and in part the latest filling in the mineralized zones where it forms kidney-shaped masses of essentially solid sulfide. One extremely long mass must have contained nearly 100 tons of ore, but the average of the larger kidneys is closer to several tons. Much of the ore is stibnite, with quartz as a minor impurity, and assays show the tenor to vary from 40 to 65 percent antimony. Sulphantimonites are less abundant but likewise occur as disseminated crystals and as kidney-shaped bodies. Antimony oxides appear on the weathered surface and along fractures within the sulfide ore. Deposits containing either stibnite or sulphantimonite are known at more than 50 localities, but only eighteen have produced ore and the bulk of this came from the mines. The geology of the deposit, and the nature, extent, and period of the workings are covered in the detailed descriptions of individual occurrences. Several geologic and economic factors, which greatly affect

  2. NOAA's hydrolab conducts reef studies

    NASA Astrophysics Data System (ADS)

    This summer, scuba-diving scientists operating from Hydrolab, NOAA's undersea laboratory, are carrying out four experiments aimed at producing better management of coral reefs and their fishery resources. Hydrolab is located at a depth of 50 feet, near the mouth of the Salt River, off St. Croix, U.S. Virgin Islands. The lab houses four scientists for up to 2 weeks at a time, permitting them to swim out into the water to conduct research. The projects make use of both the natural coral reef near Hydrolab and the nearby artificial reef constructed for comparison studies.

  3. Characterisation of flotation froth colour and structure by machine vision

    NASA Astrophysics Data System (ADS)

    Bonifazi, Giuseppe; Serranti, Silvia; Volpe, Fabio; Zuco, Riccardo

    2001-11-01

    It is well known and well recognised that flotation is a process that is complex to monitor and study if a classical approach based on the evaluation of the signals resulting from sensors is adopted. Sensors are usually strategically positioned in the bank cells and detect global process variables such as pH, reagent addition, froth level, on-stream chemical analysis, particle size distribution, etc. In the last ten years several studies have been carried out with the main goal to utilise imaging techniques to detect froth bubbles characteristics and to evaluate the flotation process performance. In this paper an approach of this type is described. More specifically, image processing techniques to automatically measure the colour and the structure of the froth bubbles are presented and the results are discussed. All the investigations are carried out on digital sample images collected in an industrial flotation plant operating in steady-state conditions. The colour analysis is performed on the whole surface of the froth images considering different colour reference systems (RGB, HSV, HSI); the morphological measurements are obtained after the application of selected enhancement and segmentation techniques, necessary to consider the bubbles as separate domains. The multiple correlation analysis performed between froth mineral concentrations (Cu, MgO, Zn and Pb content) and the extracted colour and structure parameters are good in most situations.

  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. 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.

  6. 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.

  7. Coal surface control for advanced fine coal flotation

    SciTech Connect

    Fuerstenau, D.W.; Sastry, K.V.S.; Hanson, J.S.; Diao, J.; De, A.; Sotillo, F.; Harris, G. ); Somasundaran, P.; Harris, C.C.; Vasudevan, T.; Liu, D.; Li, C. ); Hu, Weibai; Zou, Y.; Chen, W. ); Choudhry, V.; Sehgal, R.; Ghosh, A. (Praxis Engineers, Inc., Milpitas, CA (United

    1991-07-30

    The primary objective in the scope of this research project is to develop advanced flotation methods for coal cleaning in order to achieve near total pyritic-sulfur removal at 90% Btu recovery, using coal samples procured from three major US coal seams. Concomitantly, the ash content of these coals is to be reduced to 6% or less. Investigation of mechanisms for the control of coal and pyrite surfaces prior to fine coal flotation is the main aspect of the project objectives. The results of this research are to be made available to ICF Kaiser Engineers who are currently working on the Engineering Development of Advanced Flotation under a separate contract with DOE under the Acid Rain Control Initiative program. A second major objective is to investigate factors involved in the progressive weathering and oxidation of coal that had been exposed to varying degrees of weathering, namely, open to the atmosphere, covered and in an argon-inerted'' atmosphere, over a period of twelve months. After regular intervals of weathering, samples of the three base coals (Illinois No. 6, Pittsburgh No. 8 and Upper Freeport PA) were collected and shipped to both the University of Pittsburgh and the University of California at Berkeley for characterization studies of the weathered material. 29 figs., 29 tabs.

  8. Home Reef, South Pacific

    NASA Technical Reports Server (NTRS)

    2006-01-01

    In the South Pacific, south of Late Island along the Tofua volcanic arc in Tonga, a new volcanic island Home Reef is being re-born. The island is thought to have emerged after a volcanic eruption in mid-August that has also spewed large amounts of floating pumice into Tongan waters and sweeping across to Fiji about 350 km (220 miles) to the west of where the new island has formed. In 2004 a similar eruption created an ephemeral island about 0.5 by 1.5 km (0.3 by 0.9 miles) in size; it was no longer visible in an ASTER image acquired November 2005. This simulated natural color image shows the vegetation-covered stratovolcanic island of Late in the upper right. Home Reef is found in the lower left. The two bluish plumes are hot seawater that is laden with volcanic ash and chemicals; the larger one can be traced for more than 14 km (8.4 miles) to the east. The image was acquired October 10, 2006 and covers an area of 24.3 by 30.2 km. It is located at 18.9 degrees South latitude, 174.7 degrees west longitude.

    With its 14 spectral bands from the visible to the thermal infrared wavelength region, and its high spatial resolution of 15 to 90 meters (about 50 to 300 feet), ASTER images Earth to map and monitor the changing surface of our planet.

    ASTER is one of five Earth-observing instruments launched December 18, 1999, on NASA's Terra satellite. The instrument was built by Japan's Ministry of Economy, Trade and Industry. A joint U.S./Japan science team is responsible for validation and calibration of the instrument and the data products.

    The broad spectral coverage and high spectral resolution of ASTER provides scientists in numerous disciplines with critical information for surface mapping, and monitoring of dynamic conditions and temporal change. Example applications are: monitoring glacial advances and retreats; monitoring potentially active volcanoes; identifying crop stress; determining cloud morphology and physical properties; wetlands evaluation

  9. Coral Reefs on the Edge? Carbon Chemistry on Inshore Reefs of the Great Barrier Reef

    PubMed Central

    Uthicke, Sven; Furnas, Miles; Lønborg, Christian

    2014-01-01

    While increasing atmospheric carbon dioxide (CO2) concentration alters global water chemistry (Ocean Acidification; OA), the degree of changes vary on local and regional spatial scales. Inshore fringing coral reefs of the Great Barrier Reef (GBR) are subjected to a variety of local pressures, and some sites may already be marginal habitats for corals. The spatial and temporal variation in directly measured parameters: Total Alkalinity (TA) and dissolved inorganic carbon (DIC) concentration, and derived parameters: partial pressure of CO2 (pCO2); pH and aragonite saturation state (Ωar) were measured at 14 inshore reefs over a two year period in the GBR region. Total Alkalinity varied between 2069 and 2364 µmol kg−1 and DIC concentrations ranged from 1846 to 2099 µmol kg−1. This resulted in pCO2 concentrations from 340 to 554 µatm, with higher values during the wet seasons and pCO2 on inshore reefs distinctly above atmospheric values. However, due to temperature effects, Ωar was not further reduced in the wet season. Aragonite saturation on inshore reefs was consistently lower and pCO2 higher than on GBR reefs further offshore. Thermodynamic effects contribute to this, and anthropogenic runoff may also contribute by altering productivity (P), respiration (R) and P/R ratios. Compared to surveys 18 and 30 years ago, pCO2 on GBR mid- and outer-shelf reefs has risen at the same rate as atmospheric values (∼1.7 µatm yr−1) over 30 years. By contrast, values on inshore reefs have increased at 2.5 to 3 times higher rates. Thus, pCO2 levels on inshore reefs have disproportionately increased compared to atmospheric levels. Our study suggests that inshore GBR reefs are more vulnerable to OA and have less buffering capacity compared to offshore reefs. This may be caused by anthropogenically induced trophic changes in the water column and benthos of inshore reefs subjected to land runoff. PMID:25295864

  10. Coral reefs on the edge? Carbon chemistry on inshore reefs of the great barrier reef.

    PubMed

    Uthicke, Sven; Furnas, Miles; Lønborg, Christian

    2014-01-01

    While increasing atmospheric carbon dioxide (CO2) concentration alters global water chemistry (Ocean Acidification; OA), the degree of changes vary on local and regional spatial scales. Inshore fringing coral reefs of the Great Barrier Reef (GBR) are subjected to a variety of local pressures, and some sites may already be marginal habitats for corals. The spatial and temporal variation in directly measured parameters: Total Alkalinity (TA) and dissolved inorganic carbon (DIC) concentration, and derived parameters: partial pressure of CO2 (pCO2); pH and aragonite saturation state (Ωar) were measured at 14 inshore reefs over a two year period in the GBR region. Total Alkalinity varied between 2069 and 2364 µmol kg-1 and DIC concentrations ranged from 1846 to 2099 µmol kg-1. This resulted in pCO2 concentrations from 340 to 554 µatm, with higher values during the wet seasons and pCO2 on inshore reefs distinctly above atmospheric values. However, due to temperature effects, Ωar was not further reduced in the wet season. Aragonite saturation on inshore reefs was consistently lower and pCO2 higher than on GBR reefs further offshore. Thermodynamic effects contribute to this, and anthropogenic runoff may also contribute by altering productivity (P), respiration (R) and P/R ratios. Compared to surveys 18 and 30 years ago, pCO2 on GBR mid- and outer-shelf reefs has risen at the same rate as atmospheric values (∼1.7 µatm yr-1) over 30 years. By contrast, values on inshore reefs have increased at 2.5 to 3 times higher rates. Thus, pCO2 levels on inshore reefs have disproportionately increased compared to atmospheric levels. Our study suggests that inshore GBR reefs are more vulnerable to OA and have less buffering capacity compared to offshore reefs. This may be caused by anthropogenically induced trophic changes in the water column and benthos of inshore reefs subjected to land runoff.

  11. Artificial Reefs and Ocean Dumping.

    ERIC Educational Resources Information Center

    Glueck, Richard D.

    1983-01-01

    Activities and instructional strategies for two multigrade lessons are provided. Activity objectives include describing an artificial reef (such as a sunken ocean liner) as an ecosystem, knowing animal types in the ecosystem, and describing a food web. (JN)

  12. Commencement on a Coral Reef

    ERIC Educational Resources Information Center

    Webster, Steven K.

    1973-01-01

    Describes an environmental program in which sixteen students and three biology teachers from Northfield Mount Hermon School in Massachusetts spent two weeks examining the ecology of a Caribbean reef.. (JR)

  13. 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.

  14. Benthic community composition on submerged reefs in the central Great Barrier Reef

    NASA Astrophysics Data System (ADS)

    Roberts, T. E.; Moloney, J. M.; Sweatman, H. P. A.; Bridge, T. C. L.

    2015-06-01

    Community dynamics on coral reefs are often examined only in relatively shallow waters, which are most vulnerable to many disturbances. The Great Barrier Reef World Heritage Area (GBRWHA) includes extensive submerged reefs that do not approach sea level and are within depths that support many coral reef taxa that also occur in shallow water. However, the composition of benthic communities on submerged reefs in the GBRWHA is virtually unknown. We examined spatial patterns in benthic community composition on 13 submerged reefs in the central Great Barrier Reef (GBR) at depths of 10-30 m. We show that benthic communities on submerged reefs include similar species groups to those on neighbouring emergent reefs. The spatial distribution of species groups was well explained by depth and cross-shelf gradients that are well-known determinants of community composition on emergent reefs. Many equivalent species groups occurred at greater depths on submerged reefs, likely due to variability in the hydrodynamic environment among reef morphologies. Hard coral cover and species richness were lowest at the shallowest depth (6 m) on emergent reefs and were consistently higher on submerged reefs for any given depth. These results suggest that disturbances are less frequent on submerged reefs, but evidence that a severe tropical cyclone in 2011 caused significant damage to shallow regions of more exposed submerged reefs demonstrates that they are not immune. Our results confirm that submerged reefs in the central GBR support extensive and diverse coral assemblages that deserve greater attention in ecosystem assessments and management decisions.

  15. Coral reef bleaching: ecological perspectives

    NASA Astrophysics Data System (ADS)

    Glynn, P. W.

    1993-03-01

    Coral reef bleaching, the whitening of diverse invertebrate taxa, results from the loss of symbiotic zooxanthellae and/or a reduction in photosynthetic pigment concentrations in zooxanthellae residing within the gastrodermal tissues of host animals. Of particular concern are the consequences of bleaching of large numbers of reef-building scleractinian corals and hydrocorals. Published records of coral reef bleaching events from 1870 to the present suggest that the frequency (60 major events from 1979 to 1990), scale (co-occurrence in many coral reef regions and often over the bathymetric depth range of corals) and severity (>95% mortality in some areas) of recent bleaching disturbances are unprecedented in the scientific literature. The causes of small scale, isolated bleaching events can often be explained by particular stressors (e.g., temperature, salinity, light, sedimentation, aerial exposure and pollutants), but attempts to explain large scale bleaching events in terms of possible global change (e.g., greenhouse warming, increased UV radiation flux, deteriorating ecosystem health, or some combination of the above) have not been convincing. Attempts to relate the severity and extent of large scale coral reef bleaching events to particular causes have been hampered by a lack of (a) standardized methods to assess bleaching and (b) continuous, long-term data bases of environmental conditions over the periods of interest. An effort must be made to understand the impact of bleaching on the remainder of the reef community and the long-term effects on competition, predation, symbioses, bioerosion and substrate condition, all factors that can influence coral recruitment and reef recovery. If projected rates of sea warming are realized by mid to late AD 2000, i.e. a 2°C increase in high latitude coral seas, the upper thermal tolerance limits of many reef-building corals could be exceeded. Present evidence suggests that many corals would be unable to adapt

  16. Nitrification on a coral reef.

    PubMed

    Webb, K L; Wiebe, W J

    1975-09-01

    We report that the algal pavement just behind the reef crest at Enewetak Atoll produces nitrate at measurable rates. In situ and in vitro incubations with N-Serve indicate that the autotrophic pathway involving two separate organisms is effective in this oxidation of ammonia to nitrate. Significant nitrification is indicated throughout the reef environment; Nitrobacter agilis has specifically been identified as at least one of the organisms responsible for the terminal oxidation of nitrite to nitrate.

  17. Fish Assemblages on Estuarine Artificial Reefs: Natural Rocky-Reef Mimics or Discrete Assemblages?

    PubMed Central

    Folpp, Heath; Lowry, Michael; Gregson, Marcus; Suthers, Iain M.

    2013-01-01

    If the primary goal of artificial reef construction is the creation of additional reef habitat that is comparable to adjacent natural rocky-reef, then performance should be evaluated using simultaneous comparisons with adjacent natural habitats. Using baited remote underwater video (BRUV) fish assemblages on purpose-built estuarine artificial reefs and adjacent natural rocky-reef and sand-flat were assessed 18 months post-deployment in three south-east Australian estuaries. Fish abundance, species richness and diversity were found to be greater on the artificial reefs than on either naturally occurring reef or sand-flat in all estuaries. Comparisons within each estuary identified significant differences in the species composition between the artificial and natural rocky-reefs. The artificial reef assemblage was dominated by sparid species including Acanthopagrus australis and Rhabdosargus sarba. The preference for a range of habitats by theses sparid species is evident by their detection on sand-flat, natural rocky reef and artificial reef habitats. The fish assemblage identified on the artificial reefs remained distinct from the adjacent rocky-reef, comprising a range of species drawn from naturally occurring rocky-reef and sand-flat. In addition, some mid-water schooling species including Trachurus novaezelandiae and Pseudocaranx georgianus were only identified on the artificial reef community; presumably as result of the reef's isolated location in open-water. We concluded that estuarine artificial reef assemblages are likely to differ significantly from adjacent rocky-reef, potentially as a result of physical factors such as reef isolation, coupled with species specific behavioural traits such as the ability of some species to traverse large sand flats in order to locate reef structure, and feeding preferences. Artificial reefs should not be viewed as direct surrogates for natural reef. The assemblages are likely to remain distinct from naturally occurring

  18. Fish assemblages on estuarine artificial reefs: natural rocky-reef mimics or discrete assemblages?

    PubMed

    Folpp, Heath; Lowry, Michael; Gregson, Marcus; Suthers, Iain M

    2014-01-01

    If the primary goal of artificial reef construction is the creation of additional reef habitat that is comparable to adjacent natural rocky-reef, then performance should be evaluated using simultaneous comparisons with adjacent natural habitats. Using baited remote underwater video (BRUV) fish assemblages on purpose-built estuarine artificial reefs and adjacent natural rocky-reef and sand-flat were assessed 18 months post-deployment in three south-east Australian estuaries. Fish abundance, species richness and diversity were found to be greater on the artificial reefs than on either naturally occurring reef or sand-flat in all estuaries. Comparisons within each estuary identified significant differences in the species composition between the artificial and natural rocky-reefs. The artificial reef assemblage was dominated by sparid species including Acanthopagrus australis and Rhabdosargus sarba. The preference for a range of habitats by theses sparid species is evident by their detection on sand-flat, natural rocky reef and artificial reef habitats. The fish assemblage identified on the artificial reefs remained distinct from the adjacent rocky-reef, comprising a range of species drawn from naturally occurring rocky-reef and sand-flat. In addition, some mid-water schooling species including Trachurus novaezelandiae and Pseudocaranx georgianus were only identified on the artificial reef community; presumably as result of the reef's isolated location in open-water. We concluded that estuarine artificial reef assemblages are likely to differ significantly from adjacent rocky-reef, potentially as a result of physical factors such as reef isolation, coupled with species specific behavioural traits such as the ability of some species to traverse large sand flats in order to locate reef structure, and feeding preferences. Artificial reefs should not be viewed as direct surrogates for natural reef. The assemblages are likely to remain distinct from naturally occurring

  19. Ecology of the south Florida coral reefs: a community profile

    SciTech Connect

    Jaap, W.C.

    1984-08-01

    An overview of coral reef research in southern Florida is provided as a prelude to a genuine description of the coral reef ecosystem in the Florida Keys and surrounding environments. Coral reef community types, reef benthos, plankton and reef fish are given specific treatment. Coral reef ecology and management are described. 27 figs., 31 tabs.

  20. 40 CFR 440.20 - Applicability; description of the aluminum ore subcategory.

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ... aluminum ore subcategory. 440.20 Section 440.20 Protection of Environment ENVIRONMENTAL PROTECTION AGENCY... Aluminum Ore Subcategory § 440.20 Applicability; description of the aluminum ore subcategory. The... an aluminum ore....

  1. 40 CFR 440.20 - Applicability; description of the aluminum ore subcategory.

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... aluminum ore subcategory. 440.20 Section 440.20 Protection of Environment ENVIRONMENTAL PROTECTION AGENCY... Aluminum Ore Subcategory § 440.20 Applicability; description of the aluminum ore subcategory. The... an aluminum ore....

  2. 40 CFR 440.20 - Applicability; description of the aluminum ore subcategory.

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... aluminum ore subcategory. 440.20 Section 440.20 Protection of Environment ENVIRONMENTAL PROTECTION AGENCY... Aluminum Ore Subcategory § 440.20 Applicability; description of the aluminum ore subcategory. The... an aluminum ore....

  3. The indirect electrochemical refining of lunar ores

    NASA Technical Reports Server (NTRS)

    Semkow, Krystyna W.; Sammells, Anthony F.

    1987-01-01

    Recent work performed on an electrolytic cell is reported which addresses the implicit limitations in various approaches to refining lunar ores. The cell uses an oxygen vacancy conducting stabilized zirconia solid electrolyte to effect separation between a molten salt catholyte compartment where alkali metals are deposited, and an oxygen-evolving anode of composition La(0.89)Sr(0.1)MnO3. The cell configuration is shown and discussed along with a polarization curve and a steady-state current-voltage curve. In a practical cell, cathodically deposited liquid lithium would be continuously removed from the electrolytic cell and used as a valuable reducing agent for ore refining under lunar conditions. Oxygen would be indirectly electrochemically extracted from lunar ores for breathing purposes.

  4. The physical hydrogeology of ore deposits

    USGS Publications Warehouse

    Ingebritsen, Steven E.; Appold, M.S.

    2012-01-01

    Hydrothermal ore deposits represent a convergence of fluid flow, thermal energy, and solute flux that is hydrogeologically unusual. From the hydrogeologic perspective, hydrothermal ore deposition represents a complex coupled-flow problem—sufficiently complex that physically rigorous description of the coupled thermal (T), hydraulic (H), mechanical (M), and chemical (C) processes (THMC modeling) continues to challenge our computational ability. Though research into these coupled behaviors has found only a limited subset to be quantitatively tractable, it has yielded valuable insights into the workings of hydrothermal systems in a wide range of geologic environments including sedimentary, metamorphic, and magmatic. Examples of these insights include the quantification of likely driving mechanisms, rates and paths of fluid flow, ore-mineral precipitation mechanisms, longevity of hydrothermal systems, mechanisms by which hydrothermal fluids acquire their temperature and composition, and the controlling influence of permeability and other rock properties on hydrothermal fluid behavior. In this communication we review some of the fundamental theory needed to characterize the physical hydrogeology of hydrothermal systems and discuss how this theory has been applied in studies of Mississippi Valley-type, tabular uranium, porphyry, epithermal, and mid-ocean ridge ore-forming systems. A key limitation in the computational state-of-the-art is the inability to describe fluid flow and transport fully in the many ore systems that show evidence of repeated shear or tensional failure with associated dynamic variations in permeability. However, we discuss global-scale compilations that suggest some numerical constraints on both mean and dynamically enhanced crustal permeability. Principles of physical hydrogeology can be powerful tools for investigating hydrothermal ore formation and are becoming increasingly accessible with ongoing advances in modeling software.

  5. Ancient reef ecosystem expansion and collapse

    NASA Astrophysics Data System (ADS)

    Copper, P.

    1994-01-01

    Platform carbonate and, particularly, reef ecosystem development (with reefs representing the acme of carbonate platform growth) were highly cyclical in early to mid Paleozoic time, especially in relation to known or postulated times of global warming or cooling. These cycles do not appear to correspond to postulated 26 Ma rhythms seen in diversity patterns, nor were they regular. There were major periods of worldwide reef expansion (e.g. mid-Silurian-Late Devonian), corresponding to global warming well above present day norms, and periods of complete global reef collapse (e.g., mid-Cambrian to mid-Ordovician, Late Devonian) corresponding to global perturbations. At times of major reef expansion in the Paleozoic, areas covered by equatorial reef and inter-reef carbonate platforms are conservatively estimated to have periodically exceeded 5 million sq. km, nearly ten times that in the modern ocean. At times of global reef collapse, e.g. the Famennian (Late Devonian), reef complexes were completely absent or, at best, covered <1000 sq. km. The chief factors relating to periodic collapse and mass extinction of reef biotas appear to be related to climatic change and possibly ocean anoxic events, in turn as a response to large scale, geologically disruptive factors such as plate collisions, plate movement across equatorial belts and volcanism. Stress “signals” in Cambrian through Cretaceous reef ecosystems appear to be comparable to those of today: whether these relate to physical versus biological stress is uncertain. Reef stress is evident in globally reduced areas and thicknesses of reef carbonate production, the absence of large scale barrier reef systems and reduction to smaller patch reef complexes (or, periodically, following mass extinctions, no reefs at all), reduced species and genus diversity, small skeletons or colonies, limited or no biotic zonation along reef transects, and arrested succession and ecologic replacement of complex, more highly evolved

  6. Miocene precursors to Great Barrier Reef

    SciTech Connect

    Davies, P.J.; Symonds, P.A.; Feary, D.A.; Pigram, C.

    1988-01-01

    Huge reefs of Miocene age are present in the Gulf of Papua north of the present-day Great Barrier Reef and to the east on the Marion and Queensland Plateaus. In the Gulf of Papua, Miocene barrier reefs formed the northern forerunner of the Great Barrier Reef, extending for many hundreds of kilometers along the eastern and northern margin of the Australian craton within a developing foreland basin. Barrier reefs, slope pinnacle reefs, and platform reefs are seen in seismic sections and drill holes. Leeside talus deposits testify to the high energy impinging on the eastern margin of these Miocene reefs. The Queensland Plateau is a marginal plateau east of the central Great Barrier Reef and separated from it by a rift trough. Miocene reefs occupied an area of about 50,000 km/sup 2/ and grew on salt-controlled highs on the western margin of the plateau and on a regional basement high extending from the platform interior to its southern margin. Reef growth has continued to the present day, although two major contractions in the area covered by reefs occurred during the Miocene. The Marion Plateau is present directly east of the Great Barrier Reef and during the Micoene formed a 30,000-km/sup 2/ platform with barrier reefs along its northern margin and huge platform reefs and laggons on the platform interior. These reefs grew on a flat peneplained surface, the whole area forming a large shallow epicontinental sea. In all three areas, the middle Miocene formed the acme of reef expansion in the region.

  7. 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... structures. (a) All flotation for docks, boat mooring buoys, and other water-use structures and...

  8. Study on the application of FCMC-1500 cyclonic microbubble flotation column for coal preparation

    SciTech Connect

    Xie Guangyuan; Ou Zeshen; Ge Mi; Wang Yongtian; Liu Jiongtian

    1997-12-31

    In this paper the cyclonic microbubble flotation column is introduced. Its structure and the principle of operation along with some results in a commercial plant are also presented. The test results have demonstrated the cyclonic microbubble flotation column to be highly selective and extremely efficient in ash rejection from fine coals, oil consumption, and energy conservation. It has a great future for commercialization.

  9. 46 CFR 25.25-15 - Retroreflective material for personal flotation devices.

    Code of Federal Regulations, 2012 CFR

    2012-10-01

    ... 46 Shipping 1 2012-10-01 2012-10-01 false Retroreflective material for personal flotation devices. 25.25-15 Section 25.25-15 Shipping COAST GUARD, DEPARTMENT OF HOMELAND SECURITY UNINSPECTED VESSELS... flotation devices. (a) Each life preserver, each marine buoyant device intended to be worn, and each...

  10. 46 CFR 25.25-15 - Retroreflective material for personal flotation devices.

    Code of Federal Regulations, 2014 CFR

    2014-10-01

    ... 46 Shipping 1 2014-10-01 2014-10-01 false Retroreflective material for personal flotation devices. 25.25-15 Section 25.25-15 Shipping COAST GUARD, DEPARTMENT OF HOMELAND SECURITY UNINSPECTED VESSELS... flotation devices. (a) Each life preserver, each marine buoyant device intended to be worn, and each...

  11. 46 CFR 25.25-15 - Retroreflective material for personal flotation devices.

    Code of Federal Regulations, 2013 CFR

    2013-10-01

    ... 46 Shipping 1 2013-10-01 2013-10-01 false Retroreflective material for personal flotation devices. 25.25-15 Section 25.25-15 Shipping COAST GUARD, DEPARTMENT OF HOMELAND SECURITY UNINSPECTED VESSELS... flotation devices. (a) Each life preserver, each marine buoyant device intended to be worn, and each...

  12. 46 CFR 25.25-15 - Retroreflective material for personal flotation devices.

    Code of Federal Regulations, 2011 CFR

    2011-10-01

    ... 46 Shipping 1 2011-10-01 2011-10-01 false Retroreflective material for personal flotation devices. 25.25-15 Section 25.25-15 Shipping COAST GUARD, DEPARTMENT OF HOMELAND SECURITY UNINSPECTED VESSELS... flotation devices. (a) Each life preserver, each marine buoyant device intended to be worn, and each...

  13. 33 CFR 183.235 - Level flotation test without weights for persons capacity.

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... 33 Navigation and Navigable Waters 2 2013-07-01 2013-07-01 false Level flotation test without..., DEPARTMENT OF HOMELAND SECURITY (CONTINUED) BOATING SAFETY BOATS AND ASSOCIATED EQUIPMENT Flotation Requirements for Outboard Boats Rated for Engines of More Than 2 Horsepower Tests § 183.235 Level...

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

    Code of Federal Regulations, 2011 CFR

    2011-04-01

    ... STRUCTURES AND OTHER ALTERATIONS Miscellaneous § 1304.400 Flotation devices and material, all floating... 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...

  16. 18 CFR 1304.400 - Flotation devices and material, all floating structures.

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ... STRUCTURES AND OTHER ALTERATIONS Miscellaneous § 1304.400 Flotation devices and material, all floating... 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...

  17. 46 CFR 25.25-15 - Retroreflective material for personal flotation devices.

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    ... 46 Shipping 1 2010-10-01 2010-10-01 false Retroreflective material for personal flotation devices. 25.25-15 Section 25.25-15 Shipping COAST GUARD, DEPARTMENT OF HOMELAND SECURITY UNINSPECTED VESSELS... flotation devices. (a) Each life preserver, each marine buoyant device intended to be worn, and each...

  18. CONTEXT VIEW ALONG EXISTING PERIMETER TRACKS LOOKING OVER IRON ORE ...

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

    CONTEXT VIEW ALONG EXISTING PERIMETER TRACKS LOOKING OVER IRON ORE CARS TOWARDS CLEVELAND BULK TERMINAL BUILDINGS. LOOKING SOUTH. - Pennsylvania Railway Ore Dock, Lake Erie at Whiskey Island, approximately 1.5 miles west of Public Square, Cleveland, Cuyahoga County, OH

  19. CONTEXT VIEW ACROSS ORE YARD AT MODERN SELFUNLOADING BOOM IN ...

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

    CONTEXT VIEW ACROSS ORE YARD AT MODERN SELF-UNLOADING BOOM IN FRONT OF HULETTS. LOOKING SOUTHWEST. - Pennsylvania Railway Ore Dock, Lake Erie at Whiskey Island, approximately 1.5 miles west of Public Square, Cleveland, Cuyahoga County, OH

  20. CONTEXT VIEW SHOWING MODERN TRACKS PASSING UNDER HULETTS AND ORE ...

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

    CONTEXT VIEW SHOWING MODERN TRACKS PASSING UNDER HULETTS AND ORE YARD. LOOKING NORTHEAST. - Pennsylvania Railway Ore Dock, Lake Erie at Whiskey Island, approximately 1.5 miles west of Public Square, Cleveland, Cuyahoga County, OH

  1. CONTEXT VIEW ACROSS ORE YARD AT MODERN SELFUNLOADING SHIP UNLOADING ...

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

    CONTEXT VIEW ACROSS ORE YARD AT MODERN SELF-UNLOADING SHIP UNLOADING IN FRONT OF HULETTS. LOOKING SOUTHWEST. - Pennsylvania Railway Ore Dock, Lake Erie at Whiskey Island, approximately 1.5 miles west of Public Square, Cleveland, Cuyahoga County, OH

  2. 24. OVERHEAD VIEW OF MARISCAL WORKS ORE BIN FOUNDATION AND ...

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

    24. OVERHEAD VIEW OF MARISCAL WORKS ORE BIN FOUNDATION AND CONDENSERS, TOWARD WHERE ORE DELIVERY TRACK WOULD HAVE RUN, LOOKING NORTHEAST. - Mariscal Quicksilver Mine & Reduction Works, Terlingua, Brewster County, TX

  3. OVERHEAD VIEW OF MARISCAL WORKS ORE BIN FOUNDATION AND CONDENSERS, ...

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

    OVERHEAD VIEW OF MARISCAL WORKS ORE BIN FOUNDATION AND CONDENSERS, TOWARD WHERE ORE DELIVERY TRACK WOULD HAVE RUN, LOOKING NORTHEAST. - Mariscal Quicksilver Mine & Reduction Works, Terlingua, Brewster County, TX

  4. 4. DETAIL OF ORE RECEIVING PLATFORM AND GRIZZLY, VIEW TO ...

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

    4. DETAIL OF ORE RECEIVING PLATFORM AND GRIZZLY, VIEW TO EAST. - Vanadium Corporation of America (VCA) Naturita Mill, Sampling Building & Ore Receiving Platform, 3 miles Northwest of Naturita, between Highway 141 & San Miguel River, Naturita, Montrose County, CO

  5. 3. DETAIL OF ORE RECEIVING PLATFORM AND GRIZZLY, VIEW TO ...

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

    3. DETAIL OF ORE RECEIVING PLATFORM AND GRIZZLY, VIEW TO WEST. - Vanadium Corporation of America (VCA) Naturita Mill, Sampling Building & Ore Receiving Platform, 3 miles Northwest of Naturita, between Highway 141 & San Miguel River, Naturita, Montrose County, CO

  6. 2. VIEW TO NORTHEAST (ORE RECEIVING PLATFORM OUT OF VIEW ...

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

    2. VIEW TO NORTHEAST (ORE RECEIVING PLATFORM OUT OF VIEW TO RIGHT). - Vanadium Corporation of America (VCA) Naturita Mill, Sampling Building & Ore Receiving Platform, 3 miles Northwest of Naturita, between Highway 141 & San Miguel River, Naturita, Montrose County, CO

  7. 1. VIEW TO SOUTH (RETAINING WALL OF ORE RECEIVING PLATFORM ...

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

    1. VIEW TO SOUTH (RETAINING WALL OF ORE RECEIVING PLATFORM TO LEFT). - Vanadium Corporation of America (VCA) Naturita Mill, Sampling Building & Ore Receiving Platform, 3 miles Northwest of Naturita, between Highway 141 & San Miguel River, Naturita, Montrose County, CO

  8. AERIAL OVERVIEW, LOOKING NORTH, WITH FORMER TCIUS STEEL ORE MINE ...

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

    AERIAL OVERVIEW, LOOKING NORTH, WITH FORMER TCI-US STEEL ORE MINE HEADQUARTERS (BOTTOM) AND SUPERINTENDENT'S AND FOREMAN HOUSING ALONG MINNESOTA AVENUE AT CREST OF RED MOUNTAIN (TOP LEFT). - Muscoda Red Ore Mining Community, Bessemer, Jefferson County, AL

  9. 4. From west side of boat slip; ore piles, unloaders, ...

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

    4. From west side of boat slip; ore piles, unloaders, blast furnaces, tube conveyors, ore conveyors, stock house, powerhouse. Looking north/northeast - Rouge Steel Company, 3001 Miller Road, Dearborn, MI

  10. Method for extraction of uranium from ores

    SciTech Connect

    Bings, H.; Fischer, P.; Kampf, F.; Pietsch, H.; Thome, R.; Turke, W.; Wargalla, G.; Winkhaus, G.

    1982-11-30

    A method for continuously extracting uranium from ores comprises the steps of: forming a slurry of ore in a leaching solution; heating the slurry while pumping it through a tube reactor at high turbulences characterized by Reynolds numbers in excess of 50,000; supplying gaseous oxygen at high pressures into the tube reactor such that the uranium is substantially completely oxidized in a soluble form but impurities in the slurry are substantially kept from becoming soluble; recovering the uranium oxide solute which is substantially free of impurities.

  11. Processing of Goethitic Iron Ore Fines

    NASA Astrophysics Data System (ADS)

    Sharma, J.; Sharma, T.; Mandre, N. R.

    2015-10-01

    In the present investigation an attempt has been made to beneficiate goethitic iron ore containing 59.02 % Iron, 6.51 % Alumina, 4.79 % Silica, 0.089 % Phosphorus with 7.11 % loss on ignition. For this purpose, different beneficiation techniques such as gravity and magnetic separation processes have been employed. During the process two conceptual flow sheets were also developed for the beneficiation of goethite iron ore fines. In the prsent work it was possible to enhance grade of iron to 63.35, 63.18, and 65.35 % from Jigging, Multi Gravity Separation (MGS) and Wet High Intensity Magnetic Separator (WHIMS) respectively.

  12. CoBOP Coral Reefs: Optical Closure of a Coral Reef Submarine Light Field

    DTIC Science & Technology

    2001-09-30

    CoBOP Coral Reefs : Optical Closure of a Coral Reef Submarine Light Field Dr. Charles S. Yentsch Bigelow Laboratory McKown Point Road West...2001 to 00-00-2001 4. TITLE AND SUBTITLE CoBOP Coral Reefs : Optical Closure of a Coral Reef Submarine Light Field 5a. CONTRACT NUMBER 5b. GRANT

  13. Effective harvesting of low surface-hydrophobicity microalgae by froth flotation.

    PubMed

    Garg, Sourabh; Wang, Liguang; Schenk, Peer M

    2014-05-01

    Microalgae harvesting by air flotation is a promising technology for large-scale production of biofuel, feed and nutraceuticals from algae. With an adherence-to-hydrocarbon method and two different types of flotation cells (mechanically agitated cell and Jameson cell), microalgal surface hydrophobicity and bubble size were identified to be critical for effective froth flotation of microalgae. Freshwater alga Chlorella sp. BR2 showed naturally a high hydrophobicity and an ideal response to flotation. However, many marine microalgae possess a low surface hydrophobicity and are thus difficult to harvest. This paper shows that a step-wise optimization approach can substantially improve the flotation of a low surface hydrophobicity marine microalga, Tetraselmis sp. M8, to near full recovery with an enrichment ratio of 11.4.

  14. Response of coral reefs to climate change: Expansion and demise of the southernmost Pacific coral reef

    NASA Astrophysics Data System (ADS)

    Woodroffe, Colin D.; Brooke, Brendan P.; Linklater, Michelle; Kennedy, David M.; Jones, Brian G.; Buchanan, Cameron; Mleczko, Richard; Hua, Quan; Zhao, Jian-xin

    2010-08-01

    Coral reefs track sea level and are particularly sensitive to changes in climate. Reefs are threatened by global warming, with many experiencing increased coral bleaching. Warmer sea surface temperatures might enable reef expansion into mid latitudes. Here we report multibeam sonar and coring that reveal an extensive relict coral reef around Lord Howe Island, which is fringed by the southernmost reef in the Pacific Ocean. The relict reef, in water depths of 25-50 m, flourished in early Holocene and covered an area more than 20 times larger than the modern reef. Radiocarbon and uranium-series dating indicates that corals grew between 9000 and 7000 years ago. The reef was subsequently drowned, and backstepped to its modern limited extent. This relict reef, with localised re-establishment of corals in the past three millennia, could become a substrate for reef expansion in response to warmer temperatures, anticipated later this century and beyond, if corals are able to recolonise its surface.

  15. 29. ORE DOCK, LOOKING WEST; AT WORK UNLOADING THE 'GEORGE ...

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

    29. ORE DOCK, LOOKING WEST; AT WORK UNLOADING THE 'GEORGE M. HUMPHREY'S' CARGO OF 25,000. TONS OF ORE. - Pennsylvania Railway Ore Dock, Lake Erie at Whiskey Island, approximately 1.5 miles west of Public Square, Cleveland, Cuyahoga County, OH

  16. 17. ORE DOCK, LOOKING EAST FROM HULETT NO. 1. WHEN ...

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

    17. ORE DOCK, LOOKING EAST FROM HULETT NO. 1. WHEN BUILT IN 1911-1912, THIS WAS THE LARGEST ORE-UNLOADING DOCK ON THE GREAT LAKES. - Pennsylvania Railway Ore Dock, Lake Erie at Whiskey Island, approximately 1.5 miles west of Public Square, Cleveland, Cuyahoga County, OH

  17. CONTEXT VIEW ALONG EXISTING PERIMETER TRACKS LOOKING OVER IRON ORE ...

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

    CONTEXT VIEW ALONG EXISTING PERIMETER TRACKS LOOKING OVER IRON ORE CARS TOWARDS WESTERN SIDE OF CLEVELAND BULK TERMINAL BUILDINGS AND A SELF-UNLOADING IRON ORE SHIP AT DOCK. LOOKING SOUTHWEST. - Pennsylvania Railway Ore Dock, Lake Erie at Whiskey Island, approximately 1.5 miles west of Public Square, Cleveland, Cuyahoga County, OH

  18. 3. EAGLE MILL, DETAIL OF CRUDE ORE BIN FROM NORTH, ...

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

    3. EAGLE MILL, DETAIL OF CRUDE ORE BIN FROM NORTH, c. 1908-10. SHOWS EXPOSED CRUSHER HOUSE IN FRONT OF (SOUTH) CRUDE ORE BIN AND SNOW SHED ADDED OVER TRAM TRACKS. NOTE LACK OF EAST OR WEST CRUDE ORE BINS. CREDIT JW. - Bald Mountain Gold Mill, Nevada Gulch at head of False Bottom Creek, Lead, Lawrence County, SD

  19. 18. VIEW OF CRUDE ORE BINS FROM WEST. WEST CRUDE ...

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

    18. VIEW OF CRUDE ORE BINS FROM WEST. WEST CRUDE ORE BIN AND TRESTLE FROM TWO JOHNS TRAMLINE TO SOUTH, CRUDE ORE BIN IN FOREGROUND. MACHINE SHOP IN BACKGROUND. THE TRAM TO PORTLAND PASSED TO NORTH OF MACHINE SHOP. - Bald Mountain Gold Mill, Nevada Gulch at head of False Bottom Creek, Lead, Lawrence County, SD

  20. An evaluation of fine coal flotation at the Chaili Coal Washery

    SciTech Connect

    Zhang, R.Z.; Jiang, S.X.; Yu, Z.D.; Phillips, D.I.; Gebhardt, J.E.

    1995-12-31

    The potential application of flotation for the treatment and processing of a fine-particle coal stream was investigated for the Chaili Coal Washery of the Zaozhuang Coal Mine Administration, Shandong Province, China. A goal of the test work was to evaluate the application of the Microcel{trademark} flotation column and compare its performance to conventional flotation. Small-scale flotation tests were performed in the laboratory and on-site with fine coal slurry samples from the plant thickener underflow, i.e., the washing plant`s undersized reject material. Flotation tests were conducted on-site with a 7.6-cm diameter Microcel{trademark} column and with small-scale conventional cells. Column flotation tests were performed to determine a recovery-grade relationship for the fine coal feed, which contained about 24% ash, and to obtain sufficient data to enable scale-up to a large-diameter unit. A primary objective was to establish the maximum throughput capacity of a Microcel flotation column while operating to produce a clean coal product with ash content of 7.5--7.8%. Results of the test work indicate that this product quality could be achieved at feed rates of 15--19 tph to a 3-m diameter Microcel flotation column. Lower ash products, i.e. 5--7% ash, were obtained but at lower column throughput capacities. Comparative flotation tests, conducted with conventional flotation cells, indicated that a product ash of only 8% or greater was achieved in a single-stage test.

  1. Quantitative mineralogical characterization of chrome ore beneficiation plant tailing and its beneficiated products

    NASA Astrophysics Data System (ADS)

    Das, S. K.

    2015-04-01

    Mineralogical characterization and liberation of valuable minerals are primary concerns in mineral processing industries. The present investigation focuses on quantitative mineralogy, elemental deportment, and locking-liberation characteristics of the beneficiation of tailings from a chrome ore beneficiation plant in the Sukinda region, Odisha; methods used for the study of the beneficiated tailings are QEMSCAN®, X-ray diffraction (XRD), and mineral chemistry by a scanning electron microscope equipped with an energy-dispersive spectrometer (SEM-EDS). The tailing sample was fine grained (69.48wt% below 45 μm size), containing 20.25wt% Cr2O3 and 39.19wt% Fe2O3, with a Cr:Fe mass ratio of 0.51. Mineralogical investigations using QEMSCAN studies revealed that chromite, goethite, and gibbsite are the dominant mineral phases with minor amounts of hematite, kaolinite, and quartz. The sample contained 34.22wt% chromite, and chromite liberation is more than 80% for grains smaller than 250 μm in size. Based on these results, it was predicted that liberated chromite and high-grade middling chromite particles could be separated from the gangue by various concentration techniques. The tailing sample was beneficiated by hydrocyclone, tabling, wet high-intensity magnetic separation (WHIMS), and flotation in order to recover the chromite. A chromite concentrate with 45.29wt% Cr2O3 and a Cr:Fe mass ratio of 1.85 can be produced from these low-grade chromite ore beneficiation plant rejects.

  2. CoBOP Coral Reefs: Optical Closure of a Coral Reef Submarine Light Field

    DTIC Science & Technology

    2002-09-30

    CoBOP Coral Reefs : Optical Closure of a Coral Reef Submarine Light Field Dr. Charles S. Yentsch Bigelow Laboratory McKown Point Road West...TYPE 3. DATES COVERED 00-00-2002 to 00-00-2002 4. TITLE AND SUBTITLE CoBOP Coral Reefs : Optical Closure of a Coral Reef Submarine Light Field...remote assessment of salinity and ocean color in Florida Bay. In: The Everglades, Florida Bay and Coral Reefs of the Florida Keys: An Ecosystem

  3. CoBOP Coral Reefs: Optical Closure of a Coral Reef Submarine Light Field

    DTIC Science & Technology

    1999-09-30

    CoBOP Coral Reefs : Optical Closure of a Coral Reef Submarine Light Field Charles S. Yentsch Bigelow Laboratory for Ocean Sciences 180 McKown Point W...REPORT TYPE 3. DATES COVERED 00-00-1999 to 00-00-1999 4. TITLE AND SUBTITLE CoBOP Coral Reefs : Optical Closure of a Coral Reef Submarine...affecting the decline of coral reefs is change in water transparency driven by anthropogenic rather than natural processes. Corals are known to

  4. In-plant testing of microbubble column flotation

    SciTech Connect

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

    1990-01-01

    This report describes progress in two areas: advanced instrumentation and column installation. The project is working with both 30-inch and 8-foot columns for coal flotation. The paper describes installation of the instrument package, the control loops, and the data acquisition system. Under the second area of study, a test plan was developed for a parametric study of the 8-foot column operating conditions (feed flow rate, gas flow rate, wash water flow rate, and froth addition) that were determined to influence separation efficiency on the 30-inch column. Results to date are discussed. 7 refs., 4 tabs. (CK)

  5. 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)

  6. 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.

  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. Equity flotation cost adjustments in utilities' cost of service

    SciTech Connect

    Bierman, H. Jr.; Hass, J.E.

    1984-03-01

    Recovery of the unavoidable costs of issuing new shares of stock is generally agreed to be appropriate in determining utility revenue requirements. This article suggests that the methods by which that is usually accomplished are of questionable accuracy. The conventional practice of adjusting the allowed rate of return on common equity is examined, and an improved adjustment formulation is presented. Acknowledging that application of the formula remains subject to considerable error, however, the authors propose yet another solution. Capitalization of flotation costs as intangible assets is suggested as a way of more accurately factoring such expenses into tariff determinations. 6 references.

  9. PROCESS OF RECOVERING URANIUM FROM ITS ORES

    DOEpatents

    Galvanek, P. Jr.

    1959-02-24

    A process is presented for recovering uranium from its ores. The crushed ore is mixed with 5 to 10% of sulfuric acid and added water to about 5 to 30% of the weight of the ore. This pugged material is cured for 2 to 3 hours at 100 to 110 deg C and then cooled. The cooled mass is nitrate-conditioned by mixing with a solution equivalent to 35 pounds of ammunium nitrate and 300 pounds of water per ton of ore. The resulting pulp containing 70% or more solids is treated by upflow percolation with a 5% solution of tributyl phosphate in kerosene at a rate equivalent to a residence time of about one hour to extract the solubilized uranium. The uranium is recovered from the pregnant organic liquid by counter-current washing with water. The organic extractant may be recycled. The uranium is removed from the water solution by treating with ammonia to precipitate ammonium diuranate. The filtrate from the last step may be recycled for the nitrate-conditioning treatment.

  10. Ore Melting and Reduction in Silicomanganese Production

    NASA Astrophysics Data System (ADS)

    Ringdalen, Eli; Gaal, Sean; Tangstad, Merete; Ostrovski, Oleg

    2010-12-01

    The charge for silicomangansese production consists of manganese ore (often mixed with ferromanganese slag) dolomite or calcite, quartz, and in some cases, other additions. These materials have different melting properties, which have a strong effect on reduction and smelting reactions in the production of a silicomanganese alloy. This article discusses properties of Assman, Gabonese, and Companhia Vale do Rio Doce (CVRD) ores, CVRD sinter and high-carbon ferromanganese (HC FeMn) slag, and their change during silicomanganese production. The melting and reduction temperatures of these manganese sources were measured in a carbon monoxide atmosphere, using the sessile drop method and a differential thermal analysis/thermogravimetric analysis. Equilibrium phases were analyzed using FACTSage (CRCT, Montreal, Canada and GTT, Aachen, Germany) software. Experimental investigations and an analysis of equilibrium phases revealed significant differences in the melting behavior and reduction of different manganese sources. The difference in smelting of CVRD ore and CVRD sinter was attributed to a faster reduction of sinter by the graphite substrate and carbon monoxide. The calculation of equilibrium phases in the reduction process of manganese ores using FACTSage correctly reflects the trends in the production of manganese alloys. The temperature at which the manganese oxide concentration in the slag was reduced below 10 wt pct can be assigned to the top of the coke bed in the silicomanganese furnace. This temperature was in the range 1823 K to 1883 K (1550 °C to 1610 °C).

  11. Sources of ores of the ferroalloy metals

    USGS Publications Warehouse

    Burchard, E.F.

    1933-01-01

    Since all steel is made with the addition of alloying elements, the record of the metallic raw materials contributory to the steel industry would be far from complete without reference to the ferroalloy metals. This paper, therefore, supplements two preceding arvicles on the sources of our iron ores. The photographs, with the exception of those relating to molybdenum and vanadium, are by the author.

  12. Nitrogen fixation in a coral reef community.

    PubMed

    Wiebe, W J; Johannes, R E; Webb, K L

    1975-04-18

    Algal reef flats at Enewetak Atoll, Marshall Islands, fix atmospheric nitrogen at rates comparable to those in managed agriculture. The dominant nitrogen fixer appears to be the blue-green alga Calothrix crustacea. Since this nutrient enrichment contributes to the high productivity of adjacent coral reefs and undoubtedly to atoll lagoons, it is recommended that the algal reef flats receive increased conservation priority.

  13. Photography of Coral Reefs from ISS

    NASA Technical Reports Server (NTRS)

    Robinson, Julie A.

    2009-01-01

    This viewgraph presentation reviews the uses of photography from the International Space Station (ISS) in studying Earth's coral reefs. The photographs include reefs in various oceans . The photographs have uses for science in assisting NASA mapping initiatives, distribution worldwide through ReefBase, and by biologist in the field.

  14. REEF: Retainable Evaluator Execution Framework.

    PubMed

    Weimer, Markus; Chen, Yingda; Chun, Byung-Gon; Condie, Tyson; Curino, Carlo; Douglas, Chris; Lee, Yunseong; Majestro, Tony; Malkhi, Dahlia; Matusevych, Sergiy; Myers, Brandon; Narayanamurthy, Shravan; Ramakrishnan, Raghu; Rao, Sriram; Sears, Russell; Sezgin, Beysim; Wang, Julia

    2015-01-01

    Resource Managers like Apache YARN have emerged as a critical layer in the cloud computing system stack, but the developer abstractions for leasing cluster resources and instantiating application logic are very low-level. This flexibility comes at a high cost in terms of developer effort, as each application must repeatedly tackle the same challenges (e.g., fault-tolerance, task scheduling and coordination) and re-implement common mechanisms (e.g., caching, bulk-data transfers). This paper presents REEF, a development framework that provides a control-plane for scheduling and coordinating task-level (data-plane) work on cluster resources obtained from a Resource Manager. REEF provides mechanisms that facilitate resource re-use for data caching, and state management abstractions that greatly ease the development of elastic data processing work-flows on cloud platforms that support a Resource Manager service. REEF is being used to develop several commercial offerings such as the Azure Stream Analytics service. Furthermore, we demonstrate REEF development of a distributed shell application, a machine learning algorithm, and a port of the CORFU [4] system. REEF is also currently an Apache Incubator project that has attracted contributors from several instititutions.

  15. REEF: Retainable Evaluator Execution Framework

    PubMed Central

    Weimer, Markus; Chen, Yingda; Chun, Byung-Gon; Condie, Tyson; Curino, Carlo; Douglas, Chris; Lee, Yunseong; Majestro, Tony; Malkhi, Dahlia; Matusevych, Sergiy; Myers, Brandon; Narayanamurthy, Shravan; Ramakrishnan, Raghu; Rao, Sriram; Sears, Russell; Sezgin, Beysim; Wang, Julia

    2015-01-01

    Resource Managers like Apache YARN have emerged as a critical layer in the cloud computing system stack, but the developer abstractions for leasing cluster resources and instantiating application logic are very low-level. This flexibility comes at a high cost in terms of developer effort, as each application must repeatedly tackle the same challenges (e.g., fault-tolerance, task scheduling and coordination) and re-implement common mechanisms (e.g., caching, bulk-data transfers). This paper presents REEF, a development framework that provides a control-plane for scheduling and coordinating task-level (data-plane) work on cluster resources obtained from a Resource Manager. REEF provides mechanisms that facilitate resource re-use for data caching, and state management abstractions that greatly ease the development of elastic data processing work-flows on cloud platforms that support a Resource Manager service. REEF is being used to develop several commercial offerings such as the Azure Stream Analytics service. Furthermore, we demonstrate REEF development of a distributed shell application, a machine learning algorithm, and a port of the CORFU [4] system. REEF is also currently an Apache Incubator project that has attracted contributors from several instititutions.1 PMID:26819493

  16. Miocene reefs of Dominican Republic

    SciTech Connect

    Evans, C.C.

    1988-01-01

    The reefs are overlain by conglomeratic strata. The stratigraphic setting of these reefs suggests that they have developed along the stalled portions of rapidly prograding fan deltas. Thickets and layers of coral debris are found seaward and stratigraphically above the well-developed reef. The matrix sediments are exclusively fine-grained sand to mud, and the fauna are suggestive of more open shelf conditions. In thickets, branched (porites spp., Pocillopora spp.), small massive (Montastrea spp., Siderastrea spp.), and foliose or plate like (Agaricia spp.) corals are found upright in the muddy sediment. Similarities in coral species and areal proximity suggest that thickets are the source of most layers of coralline debris. The association of coral debris with graded bedding and cross-bedding suggests that coral debris has been reworked by storms. The growth of corals and development of coral reefs in the Miocene-Pliocene Yaque Group is limited only by opportunities created by the slowing of siliciclastic sedimentation. Soft, muddy, terrigenous substrates and a continuing supply of terrigenous mud exert only a limited, indirect effect on reef growth.

  17. Influence of hydrodynamic energy on Holocene reef flat accretion, Great Barrier Reef

    NASA Astrophysics Data System (ADS)

    Dechnik, Belinda; Webster, Jody M.; Nothdurft, Luke; Webb, Gregory E.; Zhao, Jian-xin; Duce, Stephanie; Braga, Juan C.; Harris, Daniel L.; Vila-Concejo, Ana; Puotinen, Marji

    2016-01-01

    The response of platform reefs to sea-level stabilization over the past 6 ka is well established for the Great Barrier Reef (GBR), with reefs typically accreting laterally from windward to leeward. However, these observations are based on few cores spread across reef zones and may not accurately reflect a reef's true accretional response to the Holocene stillstand. We present a new record of reef accretion based on 49 U/Th ages from Heron and One Tree reefs in conjunction with re-analyzed data from 14 reefs across the GBR. We demonstrate that hydrodynamic energy is the main driver of accretional direction; exposed reefs accreted primarily lagoon-ward while protected reefs accreted seawards, contrary to the traditional growth model in the GBR. Lateral accretion rates varied from 86.3 m/ka-42.4 m/ka on the exposed One Tree windward reef and 68.35 m/ka-15.7 m/ka on the protected leeward Heron reef, suggesting that wind/wave energy is not a dominant control on lateral accretion rates. This represents the most comprehensive statement of lateral accretion direction and rates from the mid-outer platform reefs of the GBR, confirming great variability in reef flat growth both within and between reef margins over the last 6 ka, and highlighting the need for closely-spaced transects.

  18. Hydrogen Plasma Processing of Iron Ore

    NASA Astrophysics Data System (ADS)

    Sabat, Kali Charan; Murphy, Anthony B.

    2017-03-01

    Iron is currently produced by carbothermic reduction of oxide ores. This is a multiple-stage process that requires large-scale equipment and high capital investment, and produces large amounts of CO2. An alternative to carbothermic reduction is reduction using a hydrogen plasma, which comprises vibrationally excited molecular, atomic, and ionic states of hydrogen, all of which can reduce iron oxides, even at low temperatures. Besides the thermodynamic and kinetic advantages of a hydrogen plasma, the byproduct of the reaction is water, which does not pose any environmental problems. A review of the theory and practice of iron ore reduction using a hydrogen plasma is presented. The thermodynamic and kinetic aspects are considered, with molecular, atomic and ionic hydrogen considered separately. The importance of vibrationally excited hydrogen molecules in overcoming the activation energy barriers, and in transferring energy to the iron oxide, is emphasized. Both thermal and nonthermal plasmas are considered. The thermophysical properties of hydrogen and argon-hydrogen plasmas are discussed, and their influence on the constriction and flow in the of arc plasmas is considered. The published R&D on hydrogen plasma reduction of iron oxide is reviewed, with both the reduction of molten iron ore and in-flight reduction of iron ore particles being considered. Finally, the technical and economic feasibility of the process are discussed. It is shown that hydrogen plasma processing requires less energy than carbothermic reduction, mainly because pelletization, sintering, and cokemaking are not required. Moreover, the formation of the greenhouse gas CO2 as a byproduct is avoided. In-flight reduction has the potential for a throughput at least equivalent to the blast furnace process. It is concluded that hydrogen plasma reduction of iron ore is a potentially attractive alternative to standard methods.

  19. 13. ORE DOCK, LOOKING EAST FROM HULETT NO. 1. WHEN ...

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

    13. ORE DOCK, LOOKING EAST FROM HULETT NO. 1. WHEN BUILT IN 1911-1912, THIS WAS THE LARGEST ORE-UNLOADING DOCK ON THE GREAT LAKES. THE DOCK FEATURED FOUR HULETT UNLOADERS, EACH WITH A BUCKET CAPACITY OF 17 TONS; A 15-TON CAPACITY ORE STOCKING AND REHANDLING BRIDGE; AND A ONE-MILLION-TON CAPACITY ORE STORAGE YARD. THE WILLIAM-SEAVER-MORGAN COMPANY OF CLEVELAND BUILT THE DOCK EQUIPMENT. - Pennsylvania Railway Ore Dock, Lake Erie at Whiskey Island, approximately 1.5 miles west of Public Square, Cleveland, Cuyahoga County, OH

  20. DETAIL VIEW OF LOWER TRAM TERMINAL, SECONDARY ORE BIN, CRUSHER ...

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

    DETAIL VIEW OF LOWER TRAM TERMINAL, SECONDARY ORE BIN, CRUSHER FOUNDATION, AND BALL MILL FOUNDATIONS, LOOKING NORTH NORTHWEST. ORE FROM THE MINES WAS DUMPED FROM THE TRAM BUCKETS INTO THE PRIMARY ORE BIN UNDER THE TRAM TERMINAL. A SLIDING CONTROL DOOR INTRODUCED THE INTO THE JAW CRUSHER (FOUNDATIONS,CENTER). THE CRUSHED ORE WAS THEN CONVEYED INTO THE SECONDARY ORE BIN AT CENTER LEFT. A HOLE IN THE FLOOR OF THE ORE BIN PASSED ORE ONTO ANOTHER CONVEYOR THAT BROUGHT IT OUT TO THE BALL MILL(FOUNDATIONS,CENTER BOTTOM). THIS SYSTEM IS MOST LIKELY NOT THE ORIGINAL SET UP, PROBABLY INSTALLED IN THE MINE'S LAST OCCUPATION IN THE EARLY 1940s. - Keane Wonder Mine, Park Route 4 (Daylight Pass Cutoff), Death Valley Junction, Inyo County, CA

  1. Enhanced desulfurizing flotation of coal using sonoelectrochemical method.

    PubMed

    Zhang, Hong-Xi; Hou, Xiao-Yang; Xu, Shi-Xun; Li, Zhi-Long; Yu, Hai-Feng; Shen, Xue-Hua

    2013-09-01

    Enhanced desulfurizing flotation of low sulfur coal was investigated using sonoelectrochemical method. The supporting electrolyte used in this process was sodium chloride and the additive was anhydrous ethanol. The effects of treatment conditions on desulfurization were studied by a single-factor method. The conditions include anhydrous ethanol concentration, sodium chloride concentration, sonoelectrolytic voltage, sonoelectrolytic temperature, sonoelectrolytic time and coal sample granulometry. The optimal experimental conditions achieved for anhydrous ethanol concentration, sodium chloride concentration, sonoelectrolytic voltage, sonoelectrolytic temperature and sonoelectrolytic time are 1.7 mol L(-1), 5.1×10(-3) mol L(-1), 10 V, 70 °C, 50 min achieved for a -0.18 mm coal sample. Optimal conditions cause a sulfur reduction of up to 69.4%. The raw and treated coals were analyzed by infrared spectroscopy and a chemical method. Pyritic sulfur, organic sulfur, ash as well as moisture are partially removed. The combination of high sulfur reduction, high yield, as well as high ash reduction was obtained in the newly developed method of enhanced flotation by sonoelectrochemistry. Ultrasound irradiation promotes electron transfer efficiency and increases clean coal yield.

  2. 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.

  3. Column flotation to produce ultra-clean coal

    SciTech Connect

    Parekh, B.K.; Groppo, J.G.; Smit, F.; Jha, M.C.; Feeley, T.

    1994-12-31

    Recovery of ultra-fine (minus 200 mesh) coal can be achieved using surface chemical based techniques such as froth flotation and oil agglomeration. Column flotation technique has shown potential to produce ultra-fine clean coal with low ash at high HHV recovery. The objective of this ongoing US DOE sponsored study is to evaluate various column configuration six different types of coal to produce premium quality coal containing less than 0.6 lb/mm Btu sulfur and less than 1 lb/mm Btu ash. The other goal of the study is to produce this ultra-clean coal at a cost of about $2.50/mm Btu. Amax Research and Development Center, prime contractor on this project, and other team members selected six different coals which are low in organic sulfur and have shown potential of cleaning to low ash level. The Center for Applied Energy Research (CAER) has evaluated two different types of bubble generating systems on six different coals to produce low ash clean coal at high ({approximately}90 percent) HHV recovery.

  4. 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

  5. A Novel Mineral Flotation Process Using Thiobacillus ferrooxidans

    PubMed Central

    Nagaoka, Toru; Ohmura, Naoya; Saiki, Hiroshi

    1999-01-01

    Oxidative leaching of metals by Thiobacillus ferrooxidans has proven useful in mineral processing. Here, we report on a new use for T. ferrooxidans, in which bacterial adhesion is used to remove pyrite from mixtures of sulfide minerals during flotation. Under control conditions, the floatabilities of five sulfide minerals tested (pyrite, chalcocite, molybdenite, millerite, and galena) ranged from 90 to 99%. Upon addition of T. ferrooxidans, the floatability of pyrite was significantly suppressed to less than 20%. In contrast, addition of the bacterium had little effect on the floatabilities of the other minerals, even when they were present in relatively large quantities: their floatabilities remained in the range of 81 to 98%. T. ferrooxidans thus appears to selectively suppress pyrite floatability. As a consequence, 77 to 95% of pyrite was removed from mineral mixtures while 72 to 100% of nonpyrite sulfide minerals was recovered. The suppression of pyrite floatability was caused by bacterial adhesion to pyrite surfaces. When normalized to the mineral surface area, the number of cells adhering to pyrite was significantly larger than the number adhering to other minerals. These results suggest that flotation with T. ferrooxidans may provide a novel approach to mineral processing in which the biological functions involved in cell adhesion play a key role in the separation of minerals. PMID:10427053

  6. Sewage sludge and fly ash mixture as an alternative for decontaminating lead and zinc ore regions.

    PubMed

    Pogrzeba, M; Galimska-Stypa, R; Krzyżak, J; Sas-Nowosielska, A

    2015-01-01

    Many years of heavy industrial processes in the Upper Silesian Industrial Region in Poland (ore flotation, metal smelting and battery scrap processing) have resulted in lead, zinc and cadmium pollution of the air and soil. The most significant issues stem not only from elevated levels of these metals in environmental compartments, but also from the uneven pattern of their distribution. Point sources of local metal concentration are to be found dispersed over areas of contaminated soil. Such distribution is a challenge for remediation technology, as it precludes the introduction of standard procedures. Metals present in the soil pose a constant risk for living organisms. One of the most effective ways of limiting their ecological impact is by decreasing their mobility. In this study, the effect of introducing sewage sludge and fly ash mixtures (sluash material) into contaminated soil was evaluated. We tested the mixture in terms of the probability of its ecotoxicological impact on plant growth and development. The data obtained have shown that even low doses (3%) of sluash are effective in reducing the bioavailability of lead, cadmium and zinc, resulting in a decrease of their concentration in plants. The application of sluash also led to stabilize soil pH. It also had a positive impact on the total number of soil bacteria and soil fungi.

  7. New tool to manage coral reefs

    NASA Astrophysics Data System (ADS)

    Showstack, Randy

    The National Oceanic and Atmospheric Administration is making available a new tool for coral reef managers to monitor the cumulative thermal stress of several coral reefs around the world, including the Great Barrier Reef, and reefs by the Galapagos Islands, the agency announced on 25 February.The agency's "Degree Heating Weeks" product uses satellite-derived information to allow continuous monitoring of the extent and acuteness of thermal stress, which are key predictors of coral bleaching, and which contribute to coral reef degradation.

  8. Egg flotation estimates nest age for Pacific and Red-throated Loons

    USGS Publications Warehouse

    Rizzolo, Daniel; Schmutz, Joel A.

    2007-01-01

    We used Pacific Loon (Gavia pacifica) and Red-throated Loon (G. stellata) nests with known ages to gauge the efficacy of egg flotation for determining nest age in coastal Alaska. Egg flotation accurately estimated nest age for both species; the mean ± 1SD difference between known age and age determined with egg flotation was - 0.05 ± 2.00 d and -0.02 ± 1.63 d for Pacific and Red-throated Loons, respectively. Day of nest initiation did not influence the relationship between known nest age and nest age estimated with egg flotation, indicating incubation period was not shortened in nests initiated later in the season. Additionally, we found no difference in the ability of egg flotation to estimate nest age between two widely dispersed study sites for Pacific Loons, and only a small difference between two of three widely dispersed study sites for Red-throated Loons. Thus, our described relationships between egg flotation categories and nest age should be broadly applicable for these holarctic species. We conclude that for Pacific and Red-throated Loons, egg flotation is a useful technique for determining nest age in the field to better monitor nest fate, and to quantify nest age effects on nest daily survival rate.

  9. Removal of cadmium (II) from simulated wastewater by ion flotation technique.

    PubMed

    Salmani, Mohammad Hossein; Davoodi, Mojtaba; Ehrampoush, Mohammad Hassan; Ghaneian, Mohammad Taghi; Fallahzadah, Mohammad Hossein

    2013-01-01

    A separation technique which has recently received a sharp increase in research activities is "ion flotation". This technique has four important advantages for treating wastewaters: low energy consumption, small space requirements, small volume of sludge and acting selectively. The present study aims to optimize parameters of ion flotation for cadmium removal in simulated wastewater at laboratory scale. It was obtained on the reaction between Cd(2+) and sodium dodecylesulfate (SDS) collector followed by flotation with ethanol as frother. Test solution was prepared by combining the required amount of cadmium ion, SDS and necessary frother or sodium sulfate solution. All experiments were carried out in a flotation column at laboratory temperature (27°C), adjusted pH = 4 and 120 minutes. The different parameters (namely: flow rate, cadmium, SDS and frother concentrations and ionic strength) influencing the flotation process were examined. The best removal efficiency obtained at a collector-metal ratio of 3:1 in 60 min with flow rate of 150 mL/min was 84%. The maximum cadmium removal was 92.1% where ethanol was introduced at a concentration 0.4% to flotation column with above conditions. The obtained results were promising, as both cadmium and collector were effectively removed from wastewater. Hence, the application of ion flotation for metal ions removal from effluents seems to be efficient.

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

    PubMed

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

    2009-02-01

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

  11. Application of dissolved air flotation on separation of waste plastics ABS and PS.

    PubMed

    Wang, Hui; Chen, Xiao-Lei; Bai, Yang; Guo, Chao; Zhang, Li

    2012-07-01

    The aim of this research was to separate waste plastics acrylonitrile butadiene styrene (ABS) and polystyrene (PS) by dissolved air flotation in a self-designed dissolved air flotation apparatus. The effects of wetting agents, frother, conditioning time and flotation time on flotation behavior of waste plastics ABS (w-ABS) and PS (w-PS) were investigated and the optimized separation conditions were obtained. The results showed that when using 25 mgL(-1) tannic acid, 5 mgL(-1) terpineol, 15 min conditioning time and 15 min flotation time, mixtures of w-ABS and w-PS were separated successfully by dissolved air flotation in two stages, the results revealed that the purity and recovery rate of w-PS in the floated products were 90.12% and 97.45%, respectively, and the purity and recovery rate of w-ABS in the depressed products were 97.24% and 89.38%, respectively. Based on the studies of wetting mechanism of plastic flotation, it is found that the electrostatic force and hydrophobic attraction cannot be the main factor of the interaction between wetting agent molecules and plastic particles, which can be completed through water molecules as a mesophase, and a hydrogen bonding adsorption model with hydration shell as a mesophase was proposed.

  12. Recovery of fine coal from waste streams using advanced column flotation

    SciTech Connect

    Groppo, J.G.; Parekh, B.K. . Center for Applied Energy Research)

    1991-01-01

    The overall objective of this program is to evaluate the application of an advanced physical separation technique, namely Ken-Flote'' column flotation to recover clean coal with minimum sulfur and ash content at greater than 90 percent combustible recovery from two Illinois coal preparation plant fine waste streams. The project will optimize various operating parameters with particular emphasis on fine bubble generating devices and reagent packages to enhance the rejection of liberated ash and pyritic sulfur. During this contract period, column flotation testing was completed on the flotation feed slurry obtained from the Kerr-McGee Galatia Preparation Plant. The column flotation tests were conducted using three different bubble generating devices: Static, gas saver and foam jet spargers. Each of these devices was tested with three different frothers and various column operating variables to provide maximum combustible recovery, minimum product ash and maximum pyrite rejection. In general, the column flotation provided a clean coal containing about 4--6 percent ash at combustible recovery ranging from 88 to 92 percent while pyrite rejection was 70 to 75 percent. Flotation tests were also conducted on a slurry sample obtained from The Ziegler {number sign}26 Preparation Plant in Sesse, Illinois. Base-line flotation testing was completed using batch flotation to identify optimum reagent addition. Column flotation of the Ziegler slurry provided a clean coal containing 4--6 percent ash with a combustible recovery of 90--95 percent and pyrite rejection of 60--67 percent. Efforts are in progress in installing a 6-inc. I.D. pilot column at the Ziegler {number sign}26. 9 figs.

  13. COLLABORATIVE GUIDE: A REEF MANAGER'S GUIDE TO ...

    EPA Pesticide Factsheets

    Innovative strategies to conserve the world's coral reefs are included in a new guide released today by NOAA, and the Australian Great Barrier Reef Marine Park Authority, with author contributions from a variety of international partners from government agencies, non-governmental organizations, and academic institutions. Referred to as A Reef Manager's Guide to Coral Bleaching, the guide will provide coral reef managers with the latest scientific information on the causes of coral bleaching and new management strategies for responding to this significant threat to coral reef ecosystems. Innovative strategies to conserve the world's coral reefs are included in a new guide released today by NOAA, and the Australian Great Barrier Reef Marine Park Authority, with author contributions from a variety of international partners from government agencies, non-governmental organizations, and academic institutions. Dr. Jordan West, of the National Center for Environmental Assessment, was a major contributor to the guide. Referred to as

  14. A deep reef in deep trouble

    USGS Publications Warehouse

    Menza, Charles; Kendall, M.; Rogers, C.; Miller, J.

    2007-01-01

    The well-documented degradation of shallower reefs which are often closer to land and more vulnerable to pollution, sewage and other human-related stressors has led to the suggestion that deeper, more remote offshore reefs could possibly serve as sources of coral and fish larvae to replenish the shallower reefs. Yet, the distribution, status, and ecological roles of deep (>30 m) Caribbean reefs are not well known. In this report, an observation of a deep reef which has undergone a recent extensive loss of coral cover is presented. In stark contrast to the typical pattern of coral loss in shallow reefs, the deeper corals were most affected. This report is the first description of such a pattern of coral loss on a deep reef.

  15. Mineral chemical study of U-bearing minerals from the Dominion Reefs, South Africa

    NASA Astrophysics Data System (ADS)

    Rantzsch, Ulrike; Gauert, Christoph D. K.; van der Westhuizen, Willem A.; Duhamel, Isabelle; Cuney, Michel; Beukes, Gerhard J.

    2011-02-01

    The Neo-Archean Dominion Reefs (~3.06 Ga) are thin meta-conglomerate layers with concentrations of U- and Th-bearing heavy minerals higher than in the overlying Witwatersrand Reefs. Ore samples from Uranium One Africa's Rietkuil and Dominion exploration areas near Klerksdorp, South Africa, were investigated for their mineral paragenesis, texture and mineral chemical composition. The ore and heavy mineral assemblages consist of uraninite, other uraniferous minerals, Fe sulphides, Ni-Co sulfarsenides, garnet, pyrite, pyrrhotite, monazite, zircon, chromite, magnetite and minor gold. Sub-rounded uraninite grains occur associated with the primary detrital heavy mineral paragenesis. U-Ti, U-Th minerals, pitchblende (colloform uraninite) and coffinite are of secondary, re-mobilised origin as evidenced by crystal shape and texture. Most of the uranium mineralisation is represented by detrital uraninite with up to 70.2 wt.% UO2 and up to 9.3 wt.% ThO2. Re-crystallised phases such as secondary pitchblende (without Th), coffinite, U-Ti and U-Th phases are related to hydrothermal overprint during low-grade metamorphism and are of minor abundance.

  16. Kinetic model for conventional flotation of coal. Report of investigations/1995

    SciTech Connect

    Susko, F.J.; Stanley, D.A.

    1995-12-31

    The U.S. Bureau of Mines has developed a computer model to describe a flotation process. Coal data from conventional flotation has been converted to a simple two-parameter kinetic model developed by Reuter and van Deventer. Each set of coal data was represented by two constants, alpha and beta, and an average flotation rate. The success of the model was demonstrated when the calculated and experimental recoveries showed good correlation. The two-parameter model allows complex data to be defined much more efficiently than traditional knowledge-based models.

  17. Hydrophobic Agglomeration of Mineral Fines in Aqueous Suspensions and its Application in Flotation: a Review

    NASA Astrophysics Data System (ADS)

    Yang, Bingqiao; Song, Shaoxian

    2014-05-01

    Hydrophobic agglomeration is originated from the hydrophobic attraction between particles, which is essentially different from electrolyte coagulation and polymer flocculation. It is applied to mineral processing in floc-flotation process to improve the recovery of mineral fines. In this paper, the applications of this phenomenon in mineral fines were summarized, including the origin of hydrophobic agglomeration, the main factors affect hydrophobic agglomeration (particle hydrophobicity, shear rate and duration, nonpolar oil and tank geometry), as well as hydrophobic agglomeration based separation processes (carrier flotation and floc-flotation).

  18. Mining and beneficiation of lunar ores

    NASA Technical Reports Server (NTRS)

    Bunch, T. E.; Williams, R. J.; Mckay, D. S.; Giles, D.

    1979-01-01

    The beneficiation of lunar plagioclase and ilmenite ores to feedstock grade permits a rapid growth of the space manufacturing economy by maximizing the production rate of metals and oxygen. A beneficiation scheme based on electrostatic and magnetic separation is preferred over conventional schemes, but such a scheme cannot be completely modeled because beneficiation processes are empirical and because some properties of lunar minerals have not been measured. To meet anticipated shipping and processing needs, the peak lunar mining rate will exceed 1000 tons/hr by the fifth year of operation. Such capabilities will be best obtained by automated mining vehicles and conveyor systems rather than trucks. It may be possible to extract about 40 kg of volatiles (60 percent H2O) by thermally processing the less than 20 micron ilmenite concentrate extracted from 130 tons of ilmenite ore. A thermodynamic analysis of an extraction process is presented.

  19. Quantifying Coral Reef Ecosystem Services

    EPA Science Inventory

    Coral reefs have been declining during the last four decades as a result of both local and global anthropogenic stresses. Numerous research efforts to elucidate the nature, causes, magnitude, and potential remedies for the decline have led to the widely held belief that the recov...

  20. The future of coral reefs

    NASA Astrophysics Data System (ADS)

    Knowlton, Nancy

    2001-05-01

    Coral reefs, with their millions of species, have changed profoundly because of the effects of people, and will continue to do so for the foreseeable future. Reefs are subject to many of the same processes that affect other human-dominated ecosystems, but some special features merit emphasis: (i) Many dominant reef builders spawn eggs and sperm into the water column, where fertilization occurs. They are thus particularly vulnerable to Allee effects, including potential extinction associated with chronic reproductive failure. (ii) The corals likely to be most resistant to the effects of habitat degradation are small, short-lived "weedy" corals that have limited dispersal capabilities at the larval stage. Habitat degradation, together with habitat fragmentation, will therefore lead to the establishment of genetically isolated clusters of inbreeding corals. (iii) Increases in average sea temperatures by as little as 1°C, a likely result of global climate change, can cause coral "bleaching" (the breakdown of coral-algal symbiosis), changes in symbiont communities, and coral death. (iv) The activities of people near reefs increase both fishing pressure and nutrient inputs. In general, these processes favor more rapidly growing competitors, often fleshy seaweeds, and may also result in explosions of predator populations. (v) Combinations of stress appear to be associated with threshold responses and ecological surprises, including devastating pathogen outbreaks. (vi) The fossil record suggests that corals as a group are more likely to suffer extinctions than some of the groups that associate with them, whose habitat requirements may be less stringent.

  1. The future of coral reefs.

    PubMed

    Knowlton, N

    2001-05-08

    Coral reefs, with their millions of species, have changed profoundly because of the effects of people, and will continue to do so for the foreseeable future. Reefs are subject to many of the same processes that affect other human-dominated ecosystems, but some special features merit emphasis: (i) Many dominant reef builders spawn eggs and sperm into the water column, where fertilization occurs. They are thus particularly vulnerable to Allee effects, including potential extinction associated with chronic reproductive failure. (ii) The corals likely to be most resistant to the effects of habitat degradation are small, short-lived "weedy" corals that have limited dispersal capabilities at the larval stage. Habitat degradation, together with habitat fragmentation, will therefore lead to the establishment of genetically isolated clusters of inbreeding corals. (iii) Increases in average sea temperatures by as little as 1 degrees C, a likely result of global climate change, can cause coral "bleaching" (the breakdown of coral-algal symbiosis), changes in symbiont communities, and coral death. (iv) The activities of people near reefs increase both fishing pressure and nutrient inputs. In general, these processes favor more rapidly growing competitors, often fleshy seaweeds, and may also result in explosions of predator populations. (v) Combinations of stress appear to be associated with threshold responses and ecological surprises, including devastating pathogen outbreaks. (vi) The fossil record suggests that corals as a group are more likely to suffer extinctions than some of the groups that associate with them, whose habitat requirements may be less stringent.

  2. Bioindication in coral reef ecosystems.

    PubMed

    Yap, H T

    1986-01-01

    The concept of bioindication in the sense of the use of organisms for detecting environmental stress has been employed in coral reef conservation and management for the past several years. Important tools are coral growth rates and various community parameters, notably hard coral cover. The present need is the optimal coordination of international efforts for the earliest possible institution of an effective monitoring system.

  3. Proterozoic geology and ore deposits of Arizona

    USGS Publications Warehouse

    Karlstrom, Karl E.

    1991-01-01

    Proterozoic rocks in Arizona have been the focus of interest for geologists since the late 1800's. Early investigations, led by the U.S. Geological Survey, focused on the extensive ore deposits hosted by Proterozoic rocks. By the 1960's, these studies, combined with theses from academic institutions and the efforts of the Arizona Geological Survey, had produced a rich data base of geologic maps, primarily of the central part of the Transition Zone. The chronological significance of these maps became much better known with the application of U-Pb geochronology by L.Y. Silver and his students starting in the 1960's. The 1970's and early 1980's were marked by numerous contributions from Masters and Ph.D students at a variety of academic institutions, and continued work by the U.S. Geological Survey. Interest in ore deposits persisted and there was an increasing interest in interpretation of the tectonic history of Proterozoic rocks in terms of plate tectonic models, as summarized in papers by Phillip Anderson, Ed DeWitt, Clay Conway, Paul Lindberg, and J.L Anderson in the 1989 Arizona Geological Society Digest 17: "Geologic Evolution of Arizona". The present volume: "Proterozoic Geology and Ore deposits of Arizona" builds upon A.G.S. Digest 17, and presents the results of geologic investigations from the latter part of the 1980's. A number of the papers are condensed versions of MS theses done by students at Northern Arizona University. These papers are based upon 1:10,000 mapping and structural analysis of several areas in Arizona. The geologic maps from each of these studies are available separately as part of the Arizona Geological Survey Contributed Map Series. These detailed maps, plus the continuing mapping efforts of the U.S.G.S. and students at other academic institutions, form an ever improving data base for continuing attempts to understand the Proterozoic geology and ore deposits of Arizona

  4. A novel process for separation of polycarbonate, polyvinyl chloride and polymethyl methacrylate waste plastics by froth flotation.

    PubMed

    Wang, Chong-Qing; Wang, Hui; Huang, Luo-Luo

    2017-04-08

    A novel process was proposed for separation of ternary waste plastics by froth flotation. Pretreatment of plastics with potassium permanganate (KMnO4) solution was conducted to aid flotation separation of polycarbonate (PC), polyvinyl chloride (PVC) and polymethyl methacrylate (PMMA) plastics. The effect of pretreatment parameters including KMnO4 concentration, treatment time, temperature and stirring rate on flotation recovery were investigated by single factor experiments. Surface treatment with KMnO4 changes selectively the flotation behavior of PC, PVC and PMMA, enabling separation of the plastics by froth flotation. Mechanism of surface treatment was studied by Fourier transform infrared spectroscopy (FTIR), scanning electron microscopy (SEM) and X-ray photoelectron spectrum (XPS). Effect of frother concentration and flotation time on flotation behavior of plastic mixtures was further studied for flotation separation. The optimized conditions for separation of PC are KMnO4 concentration 2mmolL(-1), treatment time 10min, temperature 60°C, stirring rate 300rpm, flotation time 1min and frother concentration 17.5mgL(-1). Under optimum conditions, PVC and PMMA mixtures are also separated efficiently by froth flotation associated with KMnO4 treatment. The purity of PC, PVC and PMMA is up to 100%, 98.41% and 98.68%, while the recovery reaches 96.82%, 98.71% and 98.38%, respectively. Economic analysis manifests remarkable profits of the developed process. Reusing KMnO4 solution is feasible, enabling the process greener.

  5. 76 FR 82413 - Amendments to the Reef Fish, Spiny Lobster, Queen Conch and Coral and Reef Associated Plants and...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2011-12-30

    ... Part 622 Amendments to the Reef Fish, Spiny Lobster, Queen Conch and Coral and Reef Associated Plants... Amendments to the Reef Fish, Spiny Lobster, Queen Conch and Coral and Reef Associated Plants and... FMP), and Amendment 3 to the FMP for Corals and Reef Associated Plants and Invertebrates of...

  6. Contradictions to Darwin's Evolution of Reef Types in Barrier Reef Relationships

    NASA Astrophysics Data System (ADS)

    Purdy, E.; Winterer, E. L.

    2004-05-01

    The Darwinian progressive subsidence model for the evolution of fringing reefs, barrier reefs and atolls has been generally accepted following the indisputable proof of subsidence provided by drilling results in the Pacific. Nonetheless, there are data that do not fit the expectations of the model, such as the similar lagoon depths of barrier reefs and atolls as opposed to the subsidence theory's implicit prediction that atolls should have significantly greater depths. In contrast, much evidence supports the influence of meteoric-water solution on barrier reef morphology. For example, the maximum lagoon depth of the 56 modern barrier reefs is statistically correlated with the lagoon catchment area for modern annual rainfall. These modern rainfall patterns are a reasonable proxy for relative geographic differences in glacial lowstand rainfall, even though the absolute amounts of such rainfall are unknown. The correlation therefore stongly suggests the importance of Pleistocene subaerial solution in contributing to barrier reef morphology. Further support for antecedent influence occurs in the form of barrier reef passes in which the depth of the reef pass is correlated with onshore drainage volumes. On a larger scale, the Cook Island of Mangaia provides evidence that solution can produce barrier reef morphology independent of reef development. In contrast, there are no examples of the Darwinian subsidence-predicted lagoon transition of fringing reefs to barrier reefs to atolls. Moreover, the common occurrence of fringing reefs within barrier reefs negates subsidence as a causal factor in their presumed progressive evolutionary development. Consequently, the evidence points to a solution morphology template which has been accentuated by reef construction to produce the diagnostic barrier reef morphology we see today. Rapid subsidence of seamounts by flexural loading during their early history, combined with Pleistocene sealevel fluctuations results in permanent

  7. New evidence for the barrier reef model, Permian Capitan Reef complex, New Mexico

    SciTech Connect

    Kirkland, B.L.; Moore, C.H. Jr. )

    1990-05-01

    Recent paleontologic and petrologic observations suggest that the Capitan Formation was deposited as an organic or ecologic reef that acted as an emergent barrier to incoming wave energy. In outcrops in the Guadalupe Mountains and within Carlsbad Caverns, massive reef boundstone contains a highly diverse assemblage of frame-building and binding organisms. In modern reefs, diversity among frame builders decreases dramatically with depth. Marine cement is abundant in reef boundstone, but limited in back-reef grainstone and packstone. This cementation pattern is similar to that observed in modern emergent barrier reef systems. Based on comparison with modern analogs, these dasycladrominated back-reef sediments and their associated biota are indicative of shallow, hypersaline conditions. Few of these dasyclads exhibit broken or abraded segments and some thallus sections are still articulated suggesting that low-energy, hypersaline conditions occurred immediately shelfward of the reef. In addition, large-scale topographic features, such as possible spur and groove structures between Walnut Canyon and Rattlesnake Canyon, and facies geometries, such as the reef to shelf transition, resemble those found in modern shallow-water reefs. The organisms that formed the Capitan Reef appear to have lived in, and responded to, physical and chemical conditions similar to those that control the geometry of modern shallow-water reefs. Like their modern counterparts, they seem to have strongly influenced adjacent environments. In light of this evidence, consideration should be given to either modifying or abandoning the marginal mound model in favor of the originally proposed barrier reef model.

  8. Biological models for Mesozoic reef evolution

    SciTech Connect

    Kauffman, E.G. )

    1990-11-01

    Throughout the Mesozoic, shallow-water carbonate ramps and platforms of the circumequatorial Tethyan Ocean were characterized by extensive development of reef ecosystems, especially during times of eustatic highstand, expansion of the Tropics, and warm equable global climates. The greatest reef development was north of the paleoequator in the Caribbean and Indo-Mediterranean provinces. These reefs and associated debris facies comprise major petroleum reservoirs, in some cases with remarkable porosity and permeability normally attributed to a combination of sedimentologic, tectonic, and diagenetic factors. The biological evolution of Mesozoic reefs also has had an important, and in some cases dominant, role in determining reservoir quality. Three major biological factors are critical to mesozoic reef-associated reservoir development: (1) the replacement/competitive displacement of coral-algal dominated, highly integrated reef ecosystems by loosely packed rudistid bivalve-dominated reef ecosystems in the Barremian-Albian; (2) the evolution of dominantly aragonitic, highly porous shells among framework-building rudistids in the middle and Late Cretaceous; and (3) competitive strategies among rudistids that effectively prevented widespread biological binding of Cretaceous reefs, leading to the production of large marginal fans that comprise major carbonate reservoirs. Detailed studies of these evolutionary trends in reef/framework development and of the distribution of different groups of bioconstructors on reefs lead to predictive modeling for primary and secondary porosity development in mesozoic carbonate reservoirs. The competitive displacement of coral-algal communities by rudistids on Cretaceous reefs was so effective that, even after Maastrichtian mass extinction of rudistids and other important groups comprising Mesozoic reef/carbonate platform ecosystems, coral-algal reef-building communities did not evolve again until the late Eocene.

  9. Battelle developing reefs to ease habitat losses

    SciTech Connect

    Not Available

    1993-04-01

    Artificial reefs may be the answer to solving a worldwide problem of declining fish habitats, or they may only be good for creating fishing spots. Researchers at Battelle's Ocean Sciences Laboratory in Duxbury, Massachusetts, are studying artificial reefs in the Delaware River to determine if they are a solution to habitat losses in estuaries and coastal regions. [open quotes]Right now, we don't know if the fish are using the reefs simply as a grazing land, and then moving on, or if they're using the areas to colonize,[close quotes] said researcher Karen Foster. [open quotes]Ultimately, we hope to find they are colonizing.[close quotes] In 1989, Battelle researchers placed 16 prefabricated concrete reefs 45 feet deep in Delaware Bay. The reefs were placed in clusters of four, and monitoring began the following year. The federal government ordered the reefs placed in the bay as a mitigation technique for fish habitat that was lost when the river was dredged for navigational purposes. Researchers examined the reefs twice last summer. It will take five years, Foster said, before researchers can determine if the reefs are increasing the fish population. Early tests show, however, the populations of mussels, sponges, corals, and anemones increased by up to 150 percent over an area of bay bottom where the reefs were placed. Divers take crustacean samples from the reefs, and fish are caught near the reefs for examination. Researchers dissect the fish stomachs and analyze the contents to determine if they have been feeding at the reefs. [open quotes]If we find blue mussels in the stomach of the fish, that's great because we know that blue mussels are growing on the reef,[close quotes] Foster said.

  10. 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.

  11. Rule-based characterization of industrial flotation processes with inductive techniques and genetic algorithms

    SciTech Connect

    Gouws, F.S.; Aldrich, C.

    1996-11-01

    By making use of machine learning techniques, the features of flotation froths and other plant variables can be used as a basis for the development of knowledge-based systems for plant monitoring and control. probabilistic induction and genetic algorithms were used to classify different froth structures from industrial copper and platinum flotation plants, as well as recoveries from a phosphate flotation plant. Both algorithms were equally capable of classifying the different froths at least as well as a human expert. The genetic algorithm performed significantly better than the inductive algorithm but required more tuning before optimum results could be obtained. The classification rules produced by both algorithms can easily be incorporated into a supervisory expert system shell or decision support system for plant operators and could consequently make a significant impact on the way flotation plants are currently being controlled.

  12. 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

  13. Adsorption of Crystal Violet on Activated Carbon Prepared from Coal Flotation Concentrate

    NASA Astrophysics Data System (ADS)

    Aydogmus, Ramazan; Depci, Tolga; Sarikaya, Musa; Riza Kul, Ali; Onal, Yunus

    2016-10-01

    The objective of this study is firstly to investigate the floatability properties of Zilan- Van coal after microwave irradiation and secondly to produce activated carbon from flotation concentrate in order to remove Crystal Violet (CV) from waste water. The flotation experiments showed that microwave heating at 0.9 kW power level for 60 sec exposure time enhanced the hydrophobicity and increased the flotation yield. The activated carbon with remarkable surface area (696 m2/g) was produced from the flotation concentrate and used to adsorb CV from aqueous solution in a batch reactor at different temperature. The adsorption properties of CV onto the activated carbon are discussed in terms of the adsorption isotherms (Langmuir and Freundlich) and found that the experimental results best fitted by the Langmuir model.

  14. Physical-chemical conditions of ore deposition

    USGS Publications Warehouse

    Barton, P.B.

    1981-01-01

    Ore deposits form under a wide range of physical and chemical conditions, but those precipitating from hot, aqueous fluids-i.e. the hydrothermal deposits-form generally below 700??C and at pressures of only 1 or 2 kbar or less. Natural aqueous fluids in rocks may extract metal and sulfur from a variety of rock types or may acquire them as a residual heritage from a crystallizing silicate magma. Ore-forming hydrothermal fluids never appear as hot springs (except in deep, submarine situations) because they boil, mix with surface waters, and cool, thereby losing their ore-bearing ability before reaching the surface. Mineral systems function as chemical buffers and indicators just as buffers and indicators function in a chemical laboratory. By reading the record written in the buffer/indicator assemblages of minerals one can reconstruct many aspects of the former chemical environment. By studying the record of changing conditions one may deduce information regarding the processes functioning to create the succession of chemical environments and the ore deposits they represent. The example of the OH vein at Creede, Colorado, shows a pH buffered by the K-feldspar + muscovite + quartz assemblage and the covariation of S2 and O2 buffered by the assemblage chlorite + pyrite + quartz. Boiling of the ore fluid led to its oxidation to hematite-bearing assemblages and simultaneously produced an intensely altered, sericitic capping over the vein in response to the condensation of vapors bearing acidic components. The solubility of metals as calculated from experimental and theoretical studies of mineral solubility appears too low by at least one or two powers of ten to explain the mineralization at Creede. In contrast to Creede where the mineral stabilities all point to a relatively consistent chemistry, the Mississippi Valley type deposits present a puzzle of conflicting chemical clues that are impossible to reconcile with any single equilibrium situation. Thus we must

  15. In-plant testing of microbubble column flotation

    SciTech Connect

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

    1991-01-01

    Testing of micro-bubble column flotation continued. Work during this time frame was concentrated on completion of the automated control and data acquisition system and the factorial test plan for evaluating the performance of the 8-foot column (Tasks 2.5 and 3.3). Preliminary results obtained from the factorial test program indicate that higher frother addition and aeration rates result in a higher separation efficiency. Furthermore, an increase in collector dosage results in higher column yields under most conditions. The Allen-Bradley PLC has been installed and program development completed for control of the 8-foot column. A completely automated start-up and shut-down sequence has been developed. This sequence can be initiated by the operator from a plant floor industrial interface. Instrumentation of the 30-inch column has also been completed. Testing of this instrumentation is currently underway. 11 figs., 5 tabs.

  16. Hybrid first-principles/neural networks model for column flotation

    SciTech Connect

    Gupta, S.; Liu, P.H.; Svoronos, S.A.; Sharma, R.; Abdel-Khalek, N.A.; Cheng, Y.; El-Shall, H.

    1999-03-01

    A new model for phosphate column flotation is presented which for the first time relates the effects of operating variables such as frother concentration on column performance. This is a hybrid model that combines a first-principles model with artificial neural networks. The first-principles model is obtained from material balances on both phosphate particles and gangue (undesired material containing mostly silica). First-order rates of net attachment are assumed for both. Artificial neural networks relate the attachment rate constants to the operating variables. Experiments were conducted in a 6-in.-dia. (152-mm-dia.) laboratory column to provide data for neural network training and model validation. The model successfully predicts the effects of frother concentration, particle size, air flow rate and bubble diameter on grade and recovery.

  17. 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.

  18. 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.

  19. An Investigation of Variables in a Fecal Flotation Technique

    PubMed Central

    O'Grady, M. R.; Slocombe, J. O. D.

    1980-01-01

    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

  20. Molecular Loops in the Galactic Center: Evidence for Magnetic Flotation

    NASA Astrophysics Data System (ADS)

    Fukui, Yasuo; Yamamoto, Hiroaki; Fujishita, Motosuji; Kudo, Natsuko; Torii, Kazufumi; Nozawa, Satoshi; Takahashi, Kunio; Matsumoto, Ryoji; Machida, Mami; Kawamura, Akiko; Yonekura, Yoshinori; Mizuno, Norikazu; Onishi, Toshikazu; Mizuno, Akira

    2006-10-01

    The central few hundred parsecs of the Milky Way host a massive black hole and exhibit very violent gas motion and high temperatures in molecular gas. The origin of these properties has been a mystery for the past four decades. Wide-field imaging of the 12CO (rotational quantum number J = 1 to 0) 2.6-millimeter spectrum has revealed huge loops of dense molecular gas with strong velocity dispersions in the galactic center. We present a magnetic flotation model to explain that the formation of the loops is due to magnetic buoyancy caused by the Parker instability. The model has the potential to offer a coherent explanation for the origin of the violent motion and extensive heating of the molecular gas in the galactic center.

  1. Acid pre-treatment method for in situ ore leaching

    DOEpatents

    Mallon, R.G.; Braun, R.L.

    1975-10-28

    An acid leaching method is described for the recovery of a desired element from a subterranean rubblized body of primary ore containing the element and also having associated therewith a carbonate mineral wherein the rubblized ore body is flooded with an aqueous acidic solution in order to release carbon dioxide from the associated carbonate mineral. After a substantial portion of the available carbon dioxide is released and removed from the ore body, as by venting to the atmosphere, an oxidizing gas is introduced into the flooded, rubblized ore to oxidize the ore and form an acid leach solution effective in the presence of the dissolved oxidizing gas to dissolve the ore and cause the desired element to go into solution. The leach solution is then circulated to the surface where the metal values are recovered therefrom.

  2. 40 CFR 440.40 - Applicability; description of the mercury ore subcategory.

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... mercury ore subcategory. 440.40 Section 440.40 Protection of Environment ENVIRONMENTAL PROTECTION AGENCY... Mercury Ore Subcategory § 440.40 Applicability; description of the mercury ore subcategory. The provisions... produce mercury ores; and (b) mills beneficiating mercury ores by gravity separation methods or by...

  3. 40 CFR 440.40 - Applicability; description of the mercury ore subcategory.

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... mercury ore subcategory. 440.40 Section 440.40 Protection of Environment ENVIRONMENTAL PROTECTION AGENCY... Mercury Ore Subcategory § 440.40 Applicability; description of the mercury ore subcategory. The provisions... produce mercury ores; and (b) mills beneficiating mercury ores by gravity separation methods or by...

  4. 40 CFR 440.40 - Applicability; description of the mercury ore subcategory.

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ... mercury ore subcategory. 440.40 Section 440.40 Protection of Environment ENVIRONMENTAL PROTECTION AGENCY... Mercury Ore Subcategory § 440.40 Applicability; description of the mercury ore subcategory. The provisions... produce mercury ores; and (b) mills beneficiating mercury ores by gravity separation methods or by...

  5. 75 FR 48934 - Coral Reef Conservation Program Implementation Guidelines

    Federal Register 2010, 2011, 2012, 2013, 2014

    2010-08-12

    ... National Oceanic and Atmospheric Administration RIN 0648-ZC19 Coral Reef Conservation Program... Implementation Guidelines for the Coral Reef Conservation Program. SUMMARY: This document provides NOAA's revised Grant Program Implementation Guidelines (Guidelines) for the Coral Reef Conservation Program (CRCP...

  6. 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

  7. Pioneering studies on the flotation of corundum from a Montana gneiss

    SciTech Connect

    Smith, C.W.; Llewellyn, T.O.

    1987-01-01

    Bureau of Mines conducted laboratory-scale beneficiation tests on a sample of corundum gneiss from Montana to devise a method for beneficiating corundum for use as a substitute for refractory-grade bauxite. A flotation process utilizing petroleum sulfonate as the collector in an acid circuit was devised. Results showed that two flotation schemes each produced a concentrate exceeding the national stockpile specifications for calcined bauxite.

  8. 37. VIEW NORTH FROM EAST CRUDE ORE BIN TO CRUSHER ...

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

    37. VIEW NORTH FROM EAST CRUDE ORE BIN TO CRUSHER ADDITION AND CRUSHED OXIDIZED ORE BIN. VISIBLE ARE DINGS MAGNETIC PULLEY (CENTER), THE 100-TON STEEL CRUSHED UNOXIDIZED ORE BIN, AND UPPER PORTION OF THE STEPHENS-ADAMSON 25 TON/HR BUCKET ELEVATOR. THE UPPER TAILINGS POND LIES BEYOND THE MILL WITH THE UPPER TAILINGS DAM UNDER THE GRAVEL ROAD IN THE UPPER RIGHT CORNER. - Bald Mountain Gold Mill, Nevada Gulch at head of False Bottom Creek, Lead, Lawrence County, SD

  9. Delineating optimal settlement areas of juvenile reef fish in Ngederrak Reef, Koror state, Republic of Palau.

    PubMed

    Ticzon, Victor S; Foster, Greg; David, Laura T; Mumby, Peter J; Samaniego, Badi R; Madrid, Val Randolf

    2015-01-01

    Establishing the effectiveness of habitat features to act as surrogate measures of diversity and abundance of juvenile reef fish provides information that is critical to coral reef management. When accurately set on a broader spatial context, microhabitat information becomes more meaningful and its management application becomes more explicit. The goal of the study is to identify coral reef areas potentially important to juvenile fishes in Ngederrak Reef, Republic of Palau, across different spatial scales. To achieve this, the study requires the accomplishment of the following tasks: (1) structurally differentiate the general microhabitat types using acoustics; (2) quantify microhabitat association with juvenile reef fish community structure; and (3) conduct spatial analysis of the reef-wide data and locate areas optimal for juvenile reef fish settlement. The results strongly suggest the importance of branching structures in determining species count and abundance of juvenile reef fish at the outer reef slope of Ngederrak Reef. In the acoustic map, the accurate delineation of these features allowed us to identify reef areas with the highest potential to harbor a rich aggregation of juvenile reef fish. Using a developed spatial analysis tool that ranks pixel groups based on user-defined parameters, the reef area near the Western channel of Ngederrak is predicted to have the most robust aggregation of juvenile reef fish. The results have important implications not only in management, but also in modeling the impacts of habitat loss on reef fish community. At least for Ngederrak Reef, the results advanced the utility of acoustic systems in predicting spatial distribution of juvenile fish.

  10. Episodes of reef growth at Lord Howe Island, the southernmost reef in the southwest Pacific

    NASA Astrophysics Data System (ADS)

    Woodroffe, C. D.; Dickson, M. E.; Brooke, B. P.; Kennedy, D. M.

    2005-12-01

    Lord Howe Island lies at the present latitudinal limit to reef growth in the Pacific and preserves evidence of episodes of reef development over the Late Quaternary. A modern fringing reef flanks the western shore of Lord Howe Island, enclosing a Holocene lagoon, and Late Quaternary eolianites veneer the island. Coral-bearing beach and shallow-water calcarenites record a sea level around 2-3 m above present during the Last Interglacial. No reefs or subaerial carbonate deposits occur on, or around, Balls Pyramid, 25 km to the south. The results of chronostratigraphic studies of the modern Lord Howe Island reef and lagoon indicate prolific coral production during the mid-Holocene, but less extensive coral cover during the late Holocene. Whereas the prolific mid-Holocene reefs might appear to reflect warmer sea-surface temperatures, the pattern of dates and reef growth history are similar to those throughout the Great Barrier Reef and across much of the Indo-Pacific and are more likely correlated with availability of suitable substrate. Little direct evidence of a Last Interglacial reef is now preserved, and the only evidence for older periods of reef establishment comes from clasts of coral in a well-cemented limestone unit below a coral that has been dated to the Last Interglacial age in a core at the jetty. However, a massive reef structure occurs near the centre of the wide shelf around Lord Howe Island, veneered with Holocene coralline algae. Its base is 40-50 m deep and it rises to water depths of less than 30 m. This fossil reef is several times more extensive than either Holocene or Last Interglacial reefs appear to have been. Holocene give-up reef growth is inferred during the postglacial transgression, but an alternative interpretation is that this is a much older landform, indicating reefs that were much more extensive than modern reefs at this marginal site.

  11. Coral reefs. Limited scope for latitudinal extension of reef corals.

    PubMed

    Muir, Paul R; Wallace, Carden C; Done, Terence; Aguirre, J David

    2015-06-05

    An analysis of present-day global depth distributions of reef-building corals and underlying environmental drivers contradicts a commonly held belief that ocean warming will promote tropical coral expansion into temperate latitudes. Using a global data set of a major group of reef corals, we found that corals were confined to shallower depths at higher latitudes (up to 0.6 meters of predicted shallowing per additional degree of latitude). Latitudinal attenuation of the most important driver of this phenomenon-the dose of photosynthetically available radiation over winter-would severely constrain latitudinal coral range extension in response to ocean warming. Latitudinal gradients in species richness for the group also suggest that higher winter irradiance at depth in low latitudes allowed a deep-water fauna that was not viable at higher latitudes.

  12. Implementation of Microcel{trademark} column flotation for processing fine coal

    SciTech Connect

    Davis, V.L. Jr.

    1993-12-31

    Laboratory and pilot-scale test programs have been conducted in order to evaluate the performance of column and conventional flotation circuits for the processing of fine coal. The tests were conducted on-site at several operating coal preparation facilities by utilization of Pilot-scale conventional and column flotation cells. The feed to the test equipment in each case was classifying cyclone overflow material that was high in ash content (40%--50%) with solids content values in the 5%--10% range. The test results indicated that column flotation Provided superior metallurgical performance (approaching that attained by release analysis techniques) as compared to single pass and rougher/cleaner conventional flotation. The results of this study eventually led to the installation of 5--10 foot diameter column flotation cells at the Middle Fork pond reclaim facility. It was determined that the installation of the flotation columns at the Middle Fork facility led to a reduction in concentrate ash of approximately 7 percentage points and an increase in combustible recovery in excess of 15 percentage points.

  13. Sorbent flotation in trace metal analysis: Preconcentration of uranium traces on hydrophobized hyphan-cellulose

    SciTech Connect

    Braun, T.; Galsan, V.; Toelgyessy, J.

    1994-01-01

    The use of flotation in analytical chemistry has established itself as a reliable technique for the separation and preconcentration of trace elements. In most of the applications in situ generated inorganic and organic precipitates were used as trace element gatherers and floated to the surface of large volumes of solution with the aid of a rising stream of gas bubbles and well selected collector surfactants. This procedure of {open_quotes}precipitate flotation{close_quotes} has been well studied and applied to many problems of preconcentration chemistry. As far as the present authors are aware of solid preformed sorbents have not yet been separated from large volumes of solution by flotation after batch type sorption of trace elements on them. That is why the authors considered it worthwhile to explore the analytical potentialities of the separation of commercial and non-commercial solid sorbents by flotation. The new procedure the authors like to call {open_quotes}sorbent flotation{close_quotes} refers to the separation of preformed solid sorbents from large volumes of solution and can be viewed as an extension to the already known flotation of in situ formed inorganic and organic precipitates.

  14. The use of ion flotation for detoxification of metal-contaminated waters and process effluents

    SciTech Connect

    Doyle, F.M.; Duyvesteyn, S.; Sreenivasarao, K.

    1995-12-31

    Toxic metals entering surface or ground water from sources such as metal finishing shop spills and abandoned mines can pose a significant threat to public health and the environment. Ion flotation and similar foam separation techniques show great promise for treating dilute, metal-contaminated solutions, and could also be used to treat effluents from many minerals and metallurgical processing operations prior to discharge. In ion flotation, an appropriate collector is added to the solution to form hydrophobic complexes with the metal ions. These metal-bearing species are then removed by flotation, usually with trace addition of a frother to stabilize the foam. In an effort to better understand the underlying scientific and engineering principles that determine the performance of ion flotation, the removal of Cu(II), Pb(II), Cd(II), Cr(III) and Cr(VI) has been studied using laboratory scale flotation columns in batch mode. The effects of the superficial air velocity, solution and froth height, nature of the collector, collector:metal-ion ratio, ionic strength and several frothers at low concentrations on the flotation kinetics are reported. Finally, results are presented on methods that might allow regeneration of collector and recovery of by-product metal from the foam product.

  15. 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.

  16. Recovery of fine coal from waste streams using advanced column flotation

    SciTech Connect

    Groppo, J.G.

    1991-01-01

    The advanced flotation techniques, namely column flotation, have shown potential in obtaining a low ash, low pyritic sulfur fine size clean coal. The overall objective of this program is to evaluate applicability of an advanced flotation technique, 'Ken-Flote' column to recover clean coal with minimum mineral matter content at greater than 90 percent combustible recovery from two Illinois preparation plant waste streams. Column flotations tests were conducted on the flotation feed obtained from the Kerr-McGee Galatia and Ziegler No. 26 plants using three different bubble-generating devices: sparger, gas saver and foam jet. Each of these devices was tested with three different frothers and various column-operating variable to provide maximum combustible recovery, minimum product ash and maximum pyrite rejection. For the Galatia slurry, the column provided a clean coal containing 5 percent ash, 0.48 percent pyritic sulfur at combustible recovery averaging 90 percent. In other words, about 90 percent ash and about 75 percent pyritic sulfur rejection were attained for the Galatia slurry. Pilot plant studies on this slurry basically obtained results similar to the laboratory studies. For the Ziegler No. 26, slurry column flotation provided a clean coal containing about 5 percent ash, 0.44 percent pyritic sulfur at more than 90 percent combustible recovery. The ash and pyrite sulfur rejection was about 85 percent and 65 percent, respectively.

  17. 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.

  18. 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.

  19. 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.

  20. Effect of three typical sulfide mineral flotation collectors on soil microbial activity.

    PubMed

    Guo, Zunwei; Yao, Jun; Wang, Fei; Yuan, Zhimin; Bararunyeretse, P; Zhao, Yue

    2016-04-01

    The sulfide mineral flotation collectors are wildly used in China, whereas their toxic effect on soil microbial activity remains largely unexplored. In this study, isothermal microcalorimetric technique and soil enzyme assay techniques were employed to investigate the toxic effect of typical sulfide mineral flotation collectors on soil microbial activity. Soil samples were treated with different concentrations (0-100 μg•g - 1 soil) of butyl xanthate, butyl dithiophosphate, and sodium diethyldithiocarbamate. Results showed a significant adverse effect of butyl xanthate (p < 0.05), butyl dithiophosphate, and sodium diethyldithiocarbamate (p < 0.01) on soil microbial activity. The growth rate constants k decreased along with the increase of flotation collectors concentration from 20.0 to 100.0 μg•g(-1). However, the adverse effects of these three floatation collectors showed significant difference. The IC 20 of the investigated flotation reagents followed such an order: IC 20 (butyl xanthate) > IC 20 (sodium diethyldithiocarbamate) > IC 20 (butyl dithiophosphate) with their respective inhibitory concentration as 47.03, 38.36, and 33.34 μg•g(-1). Besides, soil enzyme activities revealed that these three flotation collectors had an obvious effect on fluorescein diacetate hydrolysis (FDA) enzyme and catalase (CAT) enzyme. The proposed methods can provide meaningful toxicological information of flotation reagents to soil microbes in the view of metabolism and biochemistry, which are consistent and correlated to each other.