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Sample records for air flotation process

  1. Optimizing the air flotation water treatment process. Final report, May 1997

    SciTech Connect

    Barnett, B.

    1998-09-01

    The injection water for the Nelson Project is a combination of produced and make-up water, typical of many Eastern Kansas operations. The make-up water is a low-salinity salt water from the Arbuckle Formation and contains dissolved minerals and sulfides. The produced water contains suspended oil, suspended clay and silt particles, along with a combination of other dissolved minerals. The combination of the two waters causes several undesirable reactions. The suspended solids load contained in the combined waters would plug a 75-micron plant bag filter within one day. Wellhead filters of 75-micron size were also being used on the injection wells. The poor water quality resulted in severe loss of injectivity and frequent wellbore cleaning of the injection wells. Various mechanical and graded-bed filtration methods were considered for cleaning the water. These methods were rejected due to the lack of field equipment and service availability. A number of vendors did not even respond to the author`s request. The air flotation process was selected as offering the best hope for a long-term solution. The objective of this work is to: increase the cost effectiveness of the process through optimizing process design factors and operational parameters. A vastly modified air flotation system is the principal tool for accomplishing the project objective. The air flotation unit, as received from manufacturer Separation Specialist, was primarily designed to remove oil from produced water. The additional requirement for solids removal necessitated major physical changes in the unit. Problems encountered with the air flotation unit and specific modifications are detailed in the body of the report.

  2. Dissolved air flotation as a potential treatment process to remove Giardia cysts from anaerobically treated sewage.

    PubMed

    Santos, Priscila Ribeiro Dos; Daniel, Luiz Antonio

    2016-11-30

    Controlling Giardia cysts in sewage is an essential barrier for public health protection, reducing possible routes of protozoa transmission. The aim of this study was to evaluate the capability of dissolved air flotation (DAF), on a bench scale, to remove Giardia cysts from anaerobic effluent. Moreover, removals of indicator microorganisms and physical variables were also investigated. Flocculation conditions were studied, associating different flocculation times with different mean velocity gradients. DAF treatment achieved mean log removals in the range of 2.52-2.62 for Giardia cysts, depending on the flocculation condition. No statistical differences were observed among the flocculation conditions in terms of cyst removal. Low levels of turbidity and apparent color obtained from the treated effluent may indicate good treatment conditions for the DAF process in cyst removal. Indicator microorganisms were not able to predict the parasitological quality of the wastewater treated by flotation in terms of cyst concentrations. The DAF process provided an effective barrier to control cysts from sewage, which is an important parasite source.

  3. Effects of floc and bubble size on the efficiency of the dissolved air flotation (DAF) process.

    PubMed

    Han, Mooyoung; Kim, Tschung-il; Kim, Jinho

    2007-01-01

    Dissolved air flotation (DAF) is a method for removing particles from water using micro bubbles instead of settlement. The process has proved to be successful and, since the 1960s, accepted as an alternative to the conventional sedimentation process for water and wastewater treatment. However, limited research into the process, especially the fundamental characteristics of bubbles and particles, has been carried out. The single collector collision model is not capable of determining the effects of particular characteristics, such as the size and surface charge of bubbles and particles. Han has published a set of modeling results after calculating the collision efficiency between bubbles and particles by trajectory analysis. His major conclusion was that collision efficiency is maximum when the bubbles and particles are nearly the same size but have opposite charge. However, experimental verification of this conclusion has not been carried out yet. This paper describes a new method for measuring the size of particles and bubbles developed using computational image analysis. DAF efficiency is influenced by the effect of the recycle ratio on various average floc sizes. The larger the recycle ratio, the higher the DAF efficiency at the same pressure and particle size. The treatment efficiency is also affected by the saturation pressure, because the bubble size and bubble volume concentration are controlled by the pressure. The highest efficiency is obtained when the floc size is larger than the bubble size. These results, namely that the highest collision efficiency occurs when the particles and bubbles are about the same size, are more in accordance with the trajectory model than with the white water collector model, which implies that the larger the particles, the higher is the collision efficiency.

  4. Advanced water recycling through electrochemical treatment of effluent from dissolved air flotation unit of food processing industry.

    PubMed

    Yoo, Sukjoon; Hsieh, Jeffery S

    2010-01-01

    This study elucidates the feasibility of electrochemical treatment as a water recycling process in the dissolved air flotation (DAF) unit in the food industry. Effects of operation parameters such as current density, electrolysis time, initial pH of effluent, and mixing process were investigated on the removal of COD, TSS, and TDS of the DAF pretreated effluent. An increase of current density enhances the removal rates and reduces the electrolysis time to reach the maximum performance. The initial pH less than 7 and the addition of mixing process were proven to increase the efficiency of EC treatment. About 80% of COD, 100% of TSS, and 60% of TDS were successfully removed at 500 mA current for 1 hour of electrolysis. The final treated effluent was found to meet the discharge standard from the US Environmental Protection Agency. It was concluded that EC process could be effective as an advanced water resourcing technology in the food industry.

  5. 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...

  6. 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...

  7. 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...

  8. 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...

  9. 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...

  10. 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...

  11. 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)...

  12. 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...

  13. 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)...

  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. 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.

  18. 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)...

  19. 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...

  20. 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.

  1. 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.

  2. Hydrocarbon-oil encapsulated air bubble flotation of fine coal. 1st Quarterly report, October 1, 1990--December 31, 1990

    SciTech Connect

    Peng, F.F.

    1995-01-01

    In the froth flotation process, whether accomplished In a conventional stirred tank flotation cell, in a column flotation cell, in an air sparged cyclone flotation or in a static-tube cell by using microbubbles, it requires the addition of large quantity of surfactants such as frother and/or collector (or promoter). In coarse coal flotation, special reagents are used such as high molecular weight frothers, the collector with a non-ionic, low foam emulsifier, Sherex Shur Coal 159 or Sherex Shur Coal 168 blended with fuel oil No. 2. These reagents in liquid forms are directly added into the coal pulp in the flotation cell. Frequently, a conditioning tank is required to achieve the dispersion of the reagents. The dispersion of the collector such as hydrocarbon-oil (insoluble or partially soluble) by a mechanical mixer in the coal pulp is often inadequate. In this work, in order to demonstrate the effectiveness of collector droplet size and dispersion on froth flotation processes, a unique gasified collector dispersion and oil-coated bubble generation system was used. The hydrocarbon oil collector was gasified at a temperature approximately 40 degrees C above the fractionation temperature of the collector to avoid pyrolysis. Gasified collector is first mixed in the air stream and transported to the air diffusion hood in the flotation cell. The oil-coated air bubbles were then generated and diffused into solid-water phases.

  3. 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...

  4. Dissolved air flotation (DAF) for primary and tertiary treatment of municipal wastewaters.

    PubMed

    Koivunen, J; Heinonen-Tanski, H

    2008-01-01

    Tertiary treatment of municipal wastewater by dissolved air flotation was studied on a pilot-scale. The effects of coagulant dose, flocculation pattern, dispersion water recycle ratio and hydraulic surface load on process performance were evaluated. The treatment of primary effluents by dissolved air flotation was investigated to assess the suitability of this process for the treatment of heavily polluted effluents and wastewater treatment plant by-passes. The tertiary dissolved air flotation process typically achieved 90-99% reductions in the numbers of enteric microbes (total coliforms, enterococci and F-RNA coliphages). The average reductions of total phosphorus and chemical oxygen demand were 55-81% and 28-39%, respectively. Increasing the polyaluminium chloride coagulant dose from 2 to 10 mgAl(3+) l(-1) and the dispersion water recycle ratio from 11 to 22% improved the efficiency of the process. Changes in the flocculation conditions (range of G-values 10-55 s(-1); retention time 4-8 min) and hydraulic surface load (5 or 10 m h(-1)) did not clearly affect the process efficiency. The dissolved air flotation process decreased the numbers of enteric microbes and reduced total phosphorus, chemical oxygen demand and suspended solids from the primary treated wastewaters on average by 98-99.8%, 90%, 47% and 77%, respectively. The dissolved air flotation process was demonstrated to be a suitable method for efficient tertiary treatment of wastewaters, as well as for the elimination of peak pollution loads or by-pass wastewaters during the treatment plant overloading situations.

  5. 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.

  6. Removal of hydrocarbons from petrochemical wastewater by dissolved air flotation.

    PubMed

    Galil, N I; Wolf, D

    2001-01-01

    The dissolved air flotation (DAF) method has an important role in the removal of hydrocarbons, as well as in the protection of the biological treatment, which usually follows the DAF. The aims of this study were to evaluate the removal efficiencies of suspended solids, general organic matter, hydrocarbons and phenols by DAF, as influenced by the flocculant type, aluminum sulfate (alum) or a cationic polyelectrolyte. Laboratory batch experiments included chemical flocculation followed by DAF, controlling the flocculant dose and the air to solids ratio. The characterization of the influent and effluent was based on general analysis of organic matter (COD), suspended solids, hydrocarbons and phenols. The influent to all experiments was supplied daily from the outlet of a full scale oil-water gravitational separation unit at a petrochemical complex in Haifa, Israel. The influent contained hydrocarbons in the range of 20 to 77 mg/L. Usually less than 10% were found in "free" form, 70 to 80% were emulsified and 10 to 20% were dissolved. The DAF process enabled us to reduce the general hydrocarbon content by 50 to 90%. The effluent was characterized by stable and uniform levels of suspended solids, and oil, almost without depending on the influent concentrations. The results indicate that the chemical flocculation followed by DAF removed efficiently the emulsified phase, which could be aggregated and separated to the surface. However, it was found that the process could also remove substantial amounts of dissolved organic matter. This mechanism could be explained by the hydrophobic characteristics of some of the substances, which could bind to the solid surfaces. It was found that aggregates created by the flocculation with the cationic polyelectrolite (C-577) could remove up to 40% from the dissolved hydrocarbon. Alum flocs also indicated removal of soluble materials, mainly phenols. The results obtained in this study indicated the possibility to improve the protection

  7. Elimination of TiO₂ nanoparticles with the assist of humic acid: influence of agglomeration in the dissolved air flotation process.

    PubMed

    Zhang, Ming; Guiraud, Pascal

    2013-09-15

    With recent advances in nanotechnology, environmental and health consequences of nanomaterial disposal merit close attention. In the search for environmentally-friendly reagent, this study investigates the use of humic acid (HA) as an assist of dissolved air flotation (DAF) in the TiO₂ nanoparticle (TNP) elimination. To determine mechanisms of TNPs interacting with HA, surface modification experiments were firstly carried out; thereafter, laboratory scaled DAF tests were applied to remove TNPs with HA assisting. Results of surface modification experiments showed that the zeta potential of TNP suspension system had a reversal trend due to counter ions of TNP and anions offered by the HA stock solution. The surface modified suspension was not easy to restabilize because of the close combination of TNPs and HA through sphere linkages or hydrogen-bonded surface complexes. Agglomeration took place more readily along with increasing HA concentration in the optimum dosage range (7.8-9.15 mg/L DOC). The flotation performance revealed that HA could improve the DAF efficiency in the optimum dosage range of HA. The interaction between TNPs and HA (Na(+)-humate), including surface charge neutralization (electrostatic interactions), sphere linkages or hydrogen-bonded surface complexes, hydrophobic interactions, and van der Waals interactions, played dominant roles.

  8. Evaluation on simultaneous removal of particles and off-flavors using population balance for application of powdered activated carbon in dissolved air flotation process.

    PubMed

    Kwak, D H; Yoo, S J; Lee, E J; Lee, J W

    2010-01-01

    Most of the water treatment plants applying the DAF process are faced with off-flavors control problems. For simultaneous control of particles of impurities and dissolved organics that cause pungent taste and odor in water, an effective method would be the simple application of powdered activated carbon (PAC) in the DAF process. A series of experiments were carried out to explore the feasibility for simultaneous removal of kaolin particles and organic compounds that produce off-flavors (2-MIB and geosmin). In addition, the flotation efficiency of kaolin and PAC particles adsorbing organics in the DAF process was evaluated by employing the population balance theory. The removal efficiency of 2-MIB and geosmin under the treatment condition with kaolin particles for simultaneous treatment was lower than that of the individual treatment. The decrease in the removal efficiency was probably caused by 2-MIB and geosmin remaining in the PAC particle in the treated water of DAF after bubble flotation. Simulation results obtained by the population balance model indicate, that the initial collision-attachment efficiency of PAC particles was lower than that of kaolin particles.

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

    PubMed

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

    2009-06-15

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

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

    SciTech Connect

    Peng, F.F.

    1995-01-01

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

  11. 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.

  12. 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.

  13. Axial flow reversal and its significance in air-sparged hydrocyclone (ASH) flotation

    SciTech Connect

    Miller, J.D.; Das, A.; Yin, D.

    1995-12-31

    In recent years the potential of air-sparged hydrocyclone (ASH) flotation for fine coal cleaning has been demonstrated both in pilot plant testing and in a plant-site demonstration program. Further improvements in the ASH technology will depend, to some extent, on improved understanding of the complex multiphase fluid flow. Froth transport plays a very important role in determining the efficiency of fine coal cleaning by ASH flotation. It should be noted that the surface of zero axial velocity is of particular significance in froth transport because the location of this surface actually accounts for the amount of froth being transported to the overflow. In this regard, the axial flow reversal has been examined based on specially designed tracer experiments. On the basis of these experimental results, modeling efforts were made to characterize the flow pattern in the ASH. The theoretical predictions based on turbulent fluid dynamic considerations were found to describe experimental observations regarding the surface of zero axial velocity. These results that define the surface of zero axial velocity together with froth phase features established from X-ray CT measurements provide an excellent description of the flow characteristics in ASH flotation and explain the effect of various process variables, such as dimensionless area (A*), dimensionless flowrate (Q*), inlet pressure, percent solids, etc., on flotation recovery. On this basis it is expected that further advances in the design and operation of the ASH system can be made, leading to more efficient use of the ASH technology for fine coal cleaning.

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

    PubMed

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

    2013-05-01

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

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

    PubMed

    Kwak, Dong-Heui; Lee, Ki-Cheol

    2015-01-01

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

  16. 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.

  17. 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.

  18. 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.

  19. 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.

  20. 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.

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

    PubMed

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

    2016-07-01

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

  2. Air-Sparged Hydrocyclone/Advanced Froth Flotation fine coal cleaning

    SciTech Connect

    Stoessner, R.D. ); Shirey, G.A.; Zawadzki, E.A. ); Welsh, C.F. ); Miller, J.D. ); Shell, W.P. )

    1990-05-27

    In May 1988, the Pennsylvania Electric Company (Penelec) and New York State Electric and Gas Corporation (NYSEG) were awarded a contract from the Department of Energy's Pittsburgh Energy and Technology Center (DOE-PETC) to evaluate the performance of a two-inch Air-Sparged Hydrocyclone (ASH) for cleaning fine minus-100-mesh coal. A 24-month study was successfully completed, optimizing the performance of the ASH for cleaning raw classified, naturally-occurring minus-100-mesh Upper Freeport coal, and comparing its performance with Advanced Froth Flotation (AFF), a procedure utilizing conventional flotation equipment operated in an advanced manner (low impeller speeds, starvation float, multiple-stage cleaning, etc.) with highly selective reagents to optimize ash and pyritic sulfur rejection. The economics of cleaning fine coal by both processes at commercial scale, for retrofit and greenfield applications were found to be comparable within the accuracy of the study. Technical performance of the two processes were also found to be essentially identical. Thus, the ASH would be the best choice for a retrofit installation into an existing plant because of requiring less space. Both processes were successful in achieving excellent separations when cleaning the Upper Freeport coal. Both the ASH and AFF circuits were able to produce a clean-coal product of yield (65--80 percent weight recovery) and quality (5--6 percent ash) equivalent to that as theoretically determined by float-sink washability analyses. Combining either of the two fine coal flotation processes with a classifying cyclone circuit resulted in pyritic sulfur rejection values of about 85 percent. 47 refs., 109 figs., 75 tabs.

  3. Air-Sparged Hydrocyclone/Advanced Froth Flotation fine coal cleaning

    SciTech Connect

    Shirey, G.A.; Stoessner, R.D.; Pennsylvania Electric Co., Johnstown, PA )

    1988-12-30

    The objective of the project is to evaluate the Air-Sparged Hydrocyclone (ASH) and Advanced Froth Flotation (AFF) procedures for their effectiveness in cleaning fine (minus 100 mesh) coal. The two processes will be tested in a circuit capable of processing 0.124 to 0.15 tons per hour of coal at the EPRI-CQDC. Performance of the two processes will be evaluated, and the economics of fine coal cleaning by both processes will be determined. During the past quarter, efforts were concentrated on the following tasks: installation of process equipment and characterization of the test feed coal; start-up of the ASH and AFF circuits; and initialization of the AFF Test Program. 4 figs., 7 tabs.

  4. Comparison of coagulants and coagulation aids for treatment of meat processing wastewater by column flotation.

    PubMed

    de Sena, Rênnio F; Moreira, Regina F P M; José, Humberto J

    2008-11-01

    The physicochemical treatment of the wastewater from a meat processing industry was studied using three ferric salts as coagulants in conjunction with four different polymers as coagulation aids by batch column flotation. The effluent was characterized in terms of pH (6.5-6.7), turbidity (1000-12000 NTU), total solids (TS) (2300-7000mgl(-1)), oils and greases (OG) (820-1050mgl(-1)), and biochemical and chemical oxygen demands (BOD(5) and COD) (1200-1760 and 2800-3230mgl(-1)), respectively. The treatments achieved typical organic load reductions of oils and greases, and total solids (up to 85%), as well as biochemical and chemical oxygen demands (between 62.0-78.8% and 74.6-79.5%, respectively). The research also found that the utilization of a column flotation achieved high efficiency of organic matter removal and its operation as a primary treatment showed no significant dependence of pollutant removal and air flow rate.

  5. Advanced treatment of oilfield production wastewater by an integration of coagulation/flotation, catalytic ozonation and biological processes.

    PubMed

    Chen, Ke-Yong; Zhang, Xiao-Bing; Li, Jun

    2016-10-01

    In this study, advanced treatment of heavily polluted oilfield production wastewater (OPW) was investigated employing the combination of coagulation/dissolved air flotation, heterogeneous catalytic ozonation and sequencing batch reactor (SBR) processes. Two SBR reactors were separately set up before and after the ozonation unit. The results show that microbubble flotation was more efficient than macrobubble flotation in pollutant removal. Catalytic ozonation with the prepared Fe/activated carbon catalyst significantly enhanced pollutant removal in the second SBR by improving wastewater biodegradability and reducing wastewater microtoxicity. The treatment technique decreased oil, chemical oxygen demand and NH3-N by about 97%, 88% and 91%, respectively, allowing the discharge limits to be met. Therefore, the integrated process with efficient, economical and sustainable advantages was suitable for advanced treatment of real OPW.

  6. Integrated processes for produced water polishing: Enhanced flotation/sedimentation combined with advanced oxidation processes.

    PubMed

    Jiménez, Silvia; Micó, María M; Arnaldos, Marina; Ferrero, Enrique; Malfeito, Jorge J; Medina, Francisco; Contreras, Sandra

    2017-02-01

    In this study, bench scale dissolved air flotation (DAF) and settling processes have been studied and compared to a novel flotation technology based on the use of glass microspheres of limited buoyancy and its combination with conventional DAF, (Enhanced DAF or E-DAF). They were evaluated as pretreatments for advanced oxidation processes (AOPs) to polish produced water (PW) for reuse purposes. Settling and E-DAF without air injection showed adequate turbidity and oil and grease (O&G) removals, with eliminations higher than 87% and 90% respectively, employing 70 mg L(-1) of FeCl3 and 83 min of settling time, and 57.9 mg L(-1) of FeCl3, 300 mg L(-1) of microspheres and a flocculation rate of 40 rpm in the E-DAF process. A linear correlation was observed between final O&G concentration and turbidity after E-DAF. In order to polish the O&G content of the effluent even further, to remove soluble compounds as phenol and to take advantage of residual iron after these treatments, Fenton and photo-Fenton reactions were essayed. After 6 h of the Fenton reaction at pH 3, the addition of 1660 mg L(-1) of H2O2 and 133 mg L(-1) of iron showed a maximum O&G elimination of 57.6% and a phenol removal up to 80%. Photo-Fenton process showed better results after 3 h, adding 600 mg L(-1) of H2O2 and 300 mg L(-1) of iron, at pH 3, with a higher fraction of elimination of the O&G content (73.7%) and phenol (95%) compared to the conventional Fenton process.

  7. 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

  8. 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.

  9. 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.

  10. 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.

  11. 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.

  12. An approach to mineral particle-air bubble interaction in turbulent flow of flotation cell

    SciTech Connect

    Lu, S.; Song, S.; Gou, J.; Pan, Y.

    1995-12-31

    The calculated potential energies of interaction between hydrophobic particle of three minerals (rhodochrosite, quartz and talc) and air bubble show that the energy of hydrophobic interaction is the dominant factor for their attachment. An attachment rate equation, integrating particle-bubble collision and adhesion by introducing a capture efficiency, has been put forward. It was found that the hydrophobic particle-bubble aggregates can not be disconnected in the bulk zone of flotation cell, whereas in the impeller zone the breakup may occur, particularly for the coarser particles captured by bubble. Finally, the flotation rate constant was estimated theoretically and verified by experiments.

  13. Dissolved air flotation and centrifugation as methods for oil recovery from ruptured microalgal cells.

    PubMed

    Ghasemi Naghdi, Forough; Schenk, Peer M

    2016-10-01

    Solvent-free microalgal lipid recovery is highly desirable for safer, more sustainable and more economical microalgal oil production. Dispersed air flotation and centrifugation were evaluated for the ability to separate oil and debris from a slurry mixture of osmotically fractured Chaetoceros muelleri cells with and without utilizing collectors. Microalgal oil partially phase-separated as a top layer and partially formed an oil-in-water emulsion. Although collectors, such as sodium dodecyl sulphate enhanced selective flotation, by just adjusting the pH and cell concentration of the mixture, up to 78% of the lipids were recovered in the froth. Using centrifugation of fractured microalgal slurry resulted in removal of 60% cell debris and up to 68.5% of microalgal oil was present in the supernatant. Both methods, centrifugation and flotation provided options for separation of microalgal oil from C. muelleri slurry with similar fatty acid recoveries of 57% and 60%, respectively.

  14. 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.

  15. Dissolved air flotation primary clarifier improves performance of biological waste treatment at a latex manufacturing facility

    SciTech Connect

    Miller, D.R.; Kerecz, B.J.; Davis, M.N.

    1996-12-31

    Air Products and Chemicals, Inc. operates a chemical manufacturing facility in Piedmont, SC which generates a high strength COD emulsion wastewater from latex manufacturing. The on-site wastewater treatment facility consisted of flow equalization, activated sludge treatment and gravity clarification. The inability of the biological system to assimilate the high strength emulsion wastwater loadings led to incomplete conversion within the activated sludge process and poor settling waste sludge with turbid final effluent high in COD, BOD and TSS. The facility installed a dissolved air flotation (DAF) clarifier to effectively remove greater than 99 percent of the wastewater emulsion solids ahead of the activated sludge system. An organic coagulant is used for emulsion destabilization instead of iron or aluminum metal coagulants, improving DAF clarifier performance and minimizing operational cost and system complexity. An innovative DAF float solids collection and handling system produces disposal solids concentrations of 50 - 60% total solids resulting in further waste disposal cost savings. By removing more than 99 percent of the emulsion solids with the DAF clarifier ahead of the activated sludge process, the waste-water treatment facility now consistently produces a high quality effluent low in COD, BOD, TSS and turbidity. Wastewater treatment performance improved dramatically, as evident by the facility receiving the Western Carolina Regional Sewer Authority`s {open_quotes}Best Pollution Prevention Program{close_quotes} award. In addition, the wastewater treatment facility can now process three times the pre-DAF waste loads.

  16. 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.

  17. Fine coal flotation in a centrifugal field with an air sparged hydrocyclone

    SciTech Connect

    Miller, J.D.; van Camp, M.C.

    1982-11-01

    Preliminary results are reported for the design and development of a pilot-scale air-sparged hydrocyclone for cleaning fine coal (590 ..mu..m, - 28 mesh) containing 24% ash and 1.6% sulphur. The principle of separation is the flotation of hydrophobic coal particles in the centrifugal field generated by the fluid flow in the air-sparged hydrocyclone. This 152 mm hydrocyclone has a nominal capacity of 0.9 ton/h, and experimental results suggest that separations vastly superior to a water-only cyclone are possible. In addition, the separation efficiency is as good, if not better, than that achieved with conventional flotation cells. Typical results indicate that 75% clean coal can be recovered at 15% ash leaving a tailing product of almost 50% ash.

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

    PubMed

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

    2010-05-15

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

  19. Improving the removal of anions by coagulation and dissolved air flotation in wastewater reclamation.

    PubMed

    Chuang, S H; Chang, W C; Chang, T C; You, S J

    2006-05-01

    This study investigated the feasibility of improving the removal of anions from a secondary effluent by coagulation/flocculation (Coag/Floc) and dissolved air flotation (DAF) using a pilot-scale wastewater reclamation plant in a high-tech industrial park. The pilot plant was equipped with units of Coag/Floc, DAF, activated carbon beds (AC), microfiltration modules (MF) and a reverse-osmosis membrane (RO). It was operated in-situ continuously for around one year to evaluate the performance of anion removal in two processes - the AC-RO process and the DAF-AC-RO process. Long-term experimental results indicated that combining Coag/Floc, DAF and AC units increased the potential of pretreatment to remove anions. The removal efficiencies in Coag/Floc-DAF units were in the order phosphate > fluoride > chloride > sulfate > silicate. The charged complex of PACl flocs revealed a higher affinity for adsorption onto phosphate and fluoride than on chloride, sulfate and silicate. Comparison of the performance of Coag/Floc-DAF-AC units in the DAF-AC-RO process with that of a single AC unit in the AC-RO process demonstrated that adding Coag/Floc-DAF units increased the removal efficiencies of phosphate, fluoride and silicate by approximately 70.0%, 42.7% and 70.1%, respectively. Most of the phosphate and fluoride were removed in Coag/Floc-DAF units, while most of the silicate escaped from the Coag/Floc-DAF units, and was adsorbed and/or trapped in the AC unit. The quality of reclaimed water in the DAF-AC-RO process complied with the requirements of high-tech industries in cleaning processes. Combined units of Coag/Floc-DAF-AC were therefore recommended for use in pretreatment in wastewater reclamation in high-tech industrial parks.

  20. 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.

  1. 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.

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

    DOEpatents

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

    1991-01-01

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

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

    DOEpatents

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

    1991-01-01

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

  4. 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.

  5. 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.)

  6. Flotation process for removal of precipitates from electrochemical chromate reduction unit

    DOEpatents

    DeMonbrun, James R.; Schmitt, Charles R.; Williams, Everett H.

    1976-01-01

    This invention is an improved form of a conventional electrochemical process for removing hexavalent chromium or other metal-ion contaminants from cooling-tower blowdown water. In the conventional process, the contaminant is reduced and precipitated at an iron anode, thus forming a mixed precipitate of iron and chromium hydroxides, while hydrogen being evolved copiously at a cathode is vented from the electrochemical cell. In the conventional process, subsequent separation of the fine precipitate has proved to be difficult and inefficient. In accordance with this invention, the electrochemical operation is conducted in a novel manner permitting a much more efficient and less expensive precipitate-recovery operation. That is, the electrochemical operation is conducted under an evolved-hydrogen partial pressure exceeding atmospheric pressure. As a result, most of the evolved hydrogen is entrained as bubbles in the blowdown in the cell. The resulting hydrogen-rich blowdown is introduced to a vented chamber, where the entrained hydrogen combines with the precipitate to form a froth which can be separated by conventional techniques. In addition to the hydrogen, two materials present in most blowdown act as flotation promoters for the precipitate. These are (1) air, with which the blowdown water becomes saturated in the course of normal cooling-tower operation, and (2) surfactants which commonly are added to cooling-tower recirculating-water systems to inhibit the growth of certain organisms or prevent the deposition of insoluble particulates.

  7. Review of pollutants removed by electrocoagulation and electrocoagulation/flotation processes.

    PubMed

    Emamjomeh, Mohammad M; Sivakumar, Muttucumaru

    2009-04-01

    The word "electrocoagulation" (EC) will be sometimes used with "electroflotation" (EF) and can be considered as the electrocoagulation/flotation (ECF) process. Through the process of electrolysis, coagulating agents such as metal hydroxides are produced. When aluminium electrodes are used, the aluminium dissolves at the anode and hydrogen gas is released at the cathode. The coagulating agent combines with the pollutants to form large size flocs. As the bubbles rise to the top of the tank they adhere to particles suspended in the water and float them to the surface. In fact, a conceptual framework of the overall ECF process is linked to coagulant generation, pollutant aggregation, and pollutant removal by flotation and settling when it has been applied efficiently to various water and wastewater treatment processes. This review paper considers a significant number of common applications of EC and ECF processes which have been published in journal and conference papers.

  8. Selection of feed coals for production of premium fuel using column flotation and selective agglomeration processes

    SciTech Connect

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

    1995-10-01

    Column flotation and selective agglomeration are promising advanced physical cleaning processes that can be developed for preparing premium quality coal-water slurry fuel from coal fines. Such a fuel could either replace oil or natural gas in certain industrial and utility boilers or else could be burned in advanced combustors currently under development. These applications require coal cleaned to sulfur and ash contents below 258 g/GJ and 430--860 g/GJ (0.6 lb/million Btu and 1--2 lb/million Btu), respectively, to meet clean air emission requirements. A highly loaded slurry must be produced in order to avoid derating the boilers, and the total cost of the fuel must be below $2.37/GJ ($2.50/million Btu) in order to penetrate the market by the turn of the century. Achieving these technical and economic goals depend critically on the selection of suitable feed coals. This paper describes the identification and evaluation of 18 coals and final selection of six coals from different regions of the United States as potential feedstock for preparation of premium fuel. The work is being performed under a cost-shared DOE project.

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

    DOEpatents

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

    1992-12-01

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

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

    DOEpatents

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

    1998-09-29

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

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

    DOEpatents

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

    1992-01-01

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

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

    DOEpatents

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

    1998-01-01

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

  13. Characterization of multiphase fluid flow during air-sparged hydrocyclone flotation by x-ray CT. Final report, 14 August 1990--13 August 1994

    SciTech Connect

    Miller, J.D.

    1994-10-18

    Air sparged hydrocyclone (ASH) flotation is a new particle separation technology that has been developed at the University of Utah. This technology combines froth flotation principles with the flow characteristics of a hydrocyclone such that the ASH system can perform flotation separations in less than a second. This feature provides the ASH with a high specific capacity, 100 to 600 times greater than the specific capacity of conventional flotation machines. In an effort to develop a more detailed understanding of ASH flotation, multiphase flow characteristics of the air sparged hydrocyclone were studied and the relationship of these characteristics with flotation performance was investigated. This investigation was divided into four phases. In the first phase, the time-averaged multiphase flow characteristics of the ASH during its steady state operation were studied using x-ray computed tomography (x-ray CT). In this regard, a model system, mono-sized quartz flotation with dodecyl amine as collector, using a 2 in. diameter ASH unit (ASH-2C), was selected for study. Various flow regimes, namely, the air core, the froth phase, and the swirl layer, were identified and their spatial extent established for different experimental conditions by x-ray CT analysis. In the second phase, a detailed parametric study of flotation response of the ASH for the same system was carried out in order to establish the effect of various operating variables on flotation response. The findings of this phase of investigation were then correlated with the multiphase flow characteristics as revealed by x-ray CT in the first phase. Thus, the impact of various operating variables on the flow regimes, and hence, on flotation response was established.

  14. Comparison of inclined plate sedimentation and dissolved air flotation for the minimisation of subsequent nitrogenous disinfection by-product formation.

    PubMed

    Chu, Wen-Hai; Gao, Nai-Yun; Templeton, Michael R; Yin, Da-Qiang

    2011-04-01

    The formation of disinfection by-products (DBPs), including both nitrogenous disinfection by-products (N-DBPs) and carbonaceous disinfection by-products (C-DBPs), was investigated upon chlorination of water samples following two treatment processes: (i) coagulation-inclined plate sedimentation (IPS)-filtration and (ii) coagulation-dissolved air flotation (DAF)-filtration. The removal of algae, dissolved organic nitrogen (DON), dissolved organic carbon (DOC) and UV(254) by coagulation-DAF-filtration was superior to coagulation-IPS-filtration. On average, 53%, 53% and 31% of DOC, DON and UV(254) were removed by coagulation-DAF-filtration process, which were higher than 47%, 31% and 27% of that by coagulation-IPS-filtration process. Additionally, coagulation-IPS-filtration performed less well at removing the low molecular weight organics than coagulation-DAF-filtration process. The concentrations of chloroform, dichloroacetamide (DCAcAm) and dichloroacetonitrile (DCAN) formed during chlorination after coagulation-DAF-filtration reached their maximum values of 13, 1.5 and 4.7μgL(-1), respectively, and were lower than those after coagulation-IPS-filtration with the maximum detected levels of 17, 2.9 and 6.3μgL(-1). However, the trichloronitromethane (TCNM) concentration after the two processes was similar, suggesting that DON may have less of a contribution to TCNM formation than DCAcAm and DCAN.

  15. 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.

  16. Ambient froth flotation process for the recovery of bitumen from tar sand

    SciTech Connect

    Smith, S.L.

    1984-01-10

    A method is disclosed for upgrading the bitumen content of tar sands, wherein a raw tar sand slurry admixture of tar sands, water, collectors, and dispersing/wetting agents is milled; conditioned and then separated by a series of froth flotations at ambient temperatures from about 2/sup 0/ C. to about 25/sup 0/ C. to recover a concentrated bitumen tar sand product which may be processed by conventional means to recover oil from the bitumen. Enhanced recovery of bitumen may be accomplished by moderate heating in one or more of the flotation zones to about 50/sup 0/ C. The method permits recovery and recycle of various components used in processing of the tar sand.

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

    PubMed

    Jin, Xin; Jin, Pengkang; Wang, Xiaochang

    2015-01-01

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

  18. Optimization of Fenton's reagent coupled to Dissolved Air Flotation to remove cyanobacterial odorous metabolites and suspended solids from raw surface water.

    PubMed

    Elías-Maxil, Jorge A; Rigas, Fotis; Orta de Velásquez, María Teresa; Ramírez-Zamora, Rosa-María

    2011-01-01

    Ferrous salts are commonly used as coagulants in Water Treatment Plants (WTPs). When these salts are combined with hydrogen peroxide in acidic conditions - besides coagulation - an additional Advanced Oxidation Process (Fenton's reagent) can take place. Using a response surface methodology, this paper presents the optimization of a novel treatment system constituted by Fenton's reagent (FE) and Dissolved Air Flotation (DAF) for removing 2-Methylisoborneol (MIB), geosmin and Total Suspended Solids (TSS) from raw water. FE was proven able to remove completely both micro pollutants found in the influent of a drinking water treatment plant. Moreover, higher clarification rate was achieved by coupling FE-DAF with respect FE-Sedimentation.

  19. 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.

  20. Critical evaluation and modeling of algal harvesting using dissolved air flotation. DAF Algal Harvesting Modeling

    SciTech Connect

    Zhang, Xuezhi; Hewson, John C.; Amendola, Pasquale; Reynoso, Monica; Sommerfeld, Milton; Chen, Yongsheng; Hu, Qiang

    2014-07-14

    In our study, Chlorella zofingiensis harvesting by dissolved air flotation (DAF) was critically evaluated with regard to algal concentration, culture conditions, type and dosage of coagulants, and recycle ratio. Harvesting efficiency increased with coagulant dosage and leveled off at 81%, 86%, 91%, and 87% when chitosan, Al3+, Fe3+, and cetyl trimethylammonium bromide (CTAB) were used at dosages of 70, 180, 250, and 500 mg g-1, respectively. The DAF efficiency-coagulant dosage relationship changed with algal culture conditions. In evaluating the influence of the initial algal concentration and recycle ratio revealed that, under conditions typical for algal harvesting, we found that it is possible that the number of bubbles is insufficient. A DAF algal harvesting model was developed to explain this observation by introducing mass-based floc size distributions and a bubble limitation into the white water blanket model. Moreover, the model revealed the importance of coagulation to increase floc-bubble collision and attachment, and the preferential interaction of bubbles with larger flocs, which limited the availability of bubbles to the smaller sized flocs. The harvesting efficiencies predicted by the model agree reasonably with experimental data obtained at different Al3+ dosages, algal concentrations, and recycle ratios. Based on this modeling, critical parameters for efficient algal harvesting were identified.

  1. Critical evaluation and modeling of algal harvesting using dissolved air flotation. DAF Algal Harvesting Modeling

    DOE PAGES

    Zhang, Xuezhi; Hewson, John C.; Amendola, Pasquale; ...

    2014-07-14

    In our study, Chlorella zofingiensis harvesting by dissolved air flotation (DAF) was critically evaluated with regard to algal concentration, culture conditions, type and dosage of coagulants, and recycle ratio. Harvesting efficiency increased with coagulant dosage and leveled off at 81%, 86%, 91%, and 87% when chitosan, Al3+, Fe3+, and cetyl trimethylammonium bromide (CTAB) were used at dosages of 70, 180, 250, and 500 mg g-1, respectively. The DAF efficiency-coagulant dosage relationship changed with algal culture conditions. In evaluating the influence of the initial algal concentration and recycle ratio revealed that, under conditions typical for algal harvesting, we found that itmore » is possible that the number of bubbles is insufficient. A DAF algal harvesting model was developed to explain this observation by introducing mass-based floc size distributions and a bubble limitation into the white water blanket model. Moreover, the model revealed the importance of coagulation to increase floc-bubble collision and attachment, and the preferential interaction of bubbles with larger flocs, which limited the availability of bubbles to the smaller sized flocs. The harvesting efficiencies predicted by the model agree reasonably with experimental data obtained at different Al3+ dosages, algal concentrations, and recycle ratios. Based on this modeling, critical parameters for efficient algal harvesting were identified.« less

  2. Characterization of multiphase fluid flow during air-sparged hydrocyclone flotation by x-ray CT. Fifteenth quarterly report, 14 February 1994--13 May 1994

    SciTech Connect

    Miller, J.D.

    1994-08-10

    During this quarter of the DOE project, ``Characterization of Multiphase Fluid Flow During Air-Sparged Hydrocyclone Flotation``, the x-ray CT measurements were correlated with the results from the flotation experiments reported in the 13th quarterly report. In this regard the axial view of the flow regimes in the ASH during steady state operation were constructed from the radial density profiles as revealed by x-ray CT measurements. Construction of the axial view of the flow regimes was explained in the last quarterly report. By studying the characteristics of the flow regimes from these axial views and relating them with flotation recovery data, a phenomenological description of ASH flotation was possible. The effect of two operating variables, inlet pressure and dimensionless flow rate ratio (A* = air flow rate/slurry flow rate), are reported in this quarterly report.

  3. 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.

  4. 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.

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

    NASA Astrophysics Data System (ADS)

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

    2016-06-01

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

  6. Flotation process for sludge recovery and energy conversion

    SciTech Connect

    Hammel, G.

    1987-09-08

    This patent describes a process for offshore sewage treatment comprising: () separating sewage into a watery effluent and a sludge; (b) placing the sludge in flexible buoyant balloon storage tanks for anaerobic digestion; (c) recovering and drying methane produced from the sludge during the digestion; (d) transferring the sludge to drying barges; (e) drying the sludge; and (f) supplying the watery effluent to surrounding seaweed farms as a nutrient.

  7. Improved GSO Optimized ESN Soft-Sensor Model of Flotation Process Based on Multisource Heterogeneous Information Fusion

    PubMed Central

    Wang, Jie-sheng; Han, Shuang; Shen, Na-na

    2014-01-01

    For predicting the key technology indicators (concentrate grade and tailings recovery rate) of flotation process, an echo state network (ESN) based fusion soft-sensor model optimized by the improved glowworm swarm optimization (GSO) algorithm is proposed. Firstly, the color feature (saturation and brightness) and texture features (angular second moment, sum entropy, inertia moment, etc.) based on grey-level co-occurrence matrix (GLCM) are adopted to describe the visual characteristics of the flotation froth image. Then the kernel principal component analysis (KPCA) method is used to reduce the dimensionality of the high-dimensional input vector composed by the flotation froth image characteristics and process datum and extracts the nonlinear principal components in order to reduce the ESN dimension and network complex. The ESN soft-sensor model of flotation process is optimized by the GSO algorithm with congestion factor. Simulation results show that the model has better generalization and prediction accuracy to meet the online soft-sensor requirements of the real-time control in the flotation process. PMID:24982935

  8. Improved GSO optimized ESN soft-sensor model of flotation process based on multisource heterogeneous information fusion.

    PubMed

    Wang, Jie-sheng; Han, Shuang; Shen, Na-na

    2014-01-01

    For predicting the key technology indicators (concentrate grade and tailings recovery rate) of flotation process, an echo state network (ESN) based fusion soft-sensor model optimized by the improved glowworm swarm optimization (GSO) algorithm is proposed. Firstly, the color feature (saturation and brightness) and texture features (angular second moment, sum entropy, inertia moment, etc.) based on grey-level co-occurrence matrix (GLCM) are adopted to describe the visual characteristics of the flotation froth image. Then the kernel principal component analysis (KPCA) method is used to reduce the dimensionality of the high-dimensional input vector composed by the flotation froth image characteristics and process datum and extracts the nonlinear principal components in order to reduce the ESN dimension and network complex. The ESN soft-sensor model of flotation process is optimized by the GSO algorithm with congestion factor. Simulation results show that the model has better generalization and prediction accuracy to meet the online soft-sensor requirements of the real-time control in the flotation process.

  9. Characterization of multiphase fluid flow during air-sparged hydrocyclone flotation by x-ray CT. Fourteenth quarterly report, 14 November 1993--13 February 1994

    SciTech Connect

    Miller, J.D.

    1994-08-10

    During this quarter of the DOE project, ``Characterization of Multiphase Fluid Flow During Air-Sparged Hydrocyclone Flotation``, efforts were made to correlate the x-ray CT measurements with the flotation experiments reported in the last. quarterly report. In this regard the axial view of the flow regimes in the ASH during steady state operation were constructed from the radial density profiles as revealed by x-ray CT measurements. By studying the characteristics of the flow regimes from these axial views and relating them with flotation recovery data, a more detailed understanding of ASH flotation was possible. Construction of the axial view of the flow regimes and the effect of two operating variables, dimensionless area ratio (A* = overflow opening area/underflow opening area) and percent solids in the feed, are reported in this quarterly report.

  10. Distribution and leaching ability of some heavy metals in products of flotation processing of fine-grained coal slurries

    SciTech Connect

    Klika, Z.; Weiss, Z.; Lach, K.

    1994-12-31

    Coal from the Ostrava-Karvina mines is processed in 19 coal preparation plants, 6 of which are not equipped with flotation technology. Generally, all fine-grained coal is transported into sedimentary coal slurry ponds. Depending on processing technology, coal slurries contain from 5 to 95% coal matter. Sedimentary coal slurry ponds occupy large areas, deteriorate the landscape, and ar great sources of dust in a dry summer. Moreover, some components from coal slurries scan be leached and can penetrate into underground water. This research project sampled 13 coal slurry ponds to determine the composition of coal slurries, the distribution of some heavy metals in the flotation process, and leaching behavior.

  11. Removal of pharmaceutical residue in municipal wastewater by DAF (dissolved air flotation)-MBR (membrane bioreactor) and ozone oxidation.

    PubMed

    Choi, Miyoung; Choi, Dong Whan; Lee, Jung Yeol; Kim, Young Suk; Kim, Bun Su; Lee, Byoung Ho

    2012-01-01

    Growing attention is given to pharmaceutical residue in the water environment. It is known that pharmaceuticals are able to survive from a series of wastewater treatment processes. Concerns regarding pharmaceutical residues are attributed to the fact that they are being detected in water and sediment environment ubiquitously. Pharmaceutical treatment using a series of wastewater treatment processes of the DAF (dissolved air flotation)-MBR (membrane bioreactor)-ozone oxidation was conducted in the study. DAF, without addition of coagulant, could remove COD(cr) (chemical oxygen demand by Cr) up to over 70%, BOD 73%, SS 83%, T-N 55%, NH₄(+) 23%, and T-P 65% in influent of municipal wastewater. Average removal rates of water quality parameters by the DAF-MBR system were very high, e.g. COD(cr) 95.88%, BOD₅ 99.66%, COD(mn) (chemical oxygen demand by Mn) 93.63%, T-N 69.75%, NH₄-N 98.46%, T-P 78.23%, and SS 99.51%, which satisfy effluent water quality standards. Despite the high removal rate of the wastewater treatment system, pharmaceuticals were eliminated to be about 50-99% by the MBR system, depending on specific pharmaceuticals. Ibuprofen was well removed by MBR system up to over 95%, while removal rate of bezafibrate ranged between 50 and 90%. With over 5 mg/l of ozone oxidation, most pharmaceuticals which survived the DAF-MBR process were removed completely or resulted in very low survival rate within the range of few micrograms per litre. However, some pharmaceuticals such as bezafibrate and naproxen tended to be resistant to ozone oxidation.

  12. 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.

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

    DOEpatents

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

    1995-01-01

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

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

    DOEpatents

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

    1995-03-14

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

  15. 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.

  16. Hydrophobically-associating cationic polymers as micro-bubble surface modifiers in dissolved air flotation for cyanobacteria cell separation.

    PubMed

    Yap, R K L; Whittaker, M; Diao, M; Stuetz, R M; Jefferson, B; Bulmus, V; Peirson, W L; Nguyen, A V; Henderson, R K

    2014-09-15

    Dissolved air flotation (DAF), an effective treatment method for clarifying algae/cyanobacteria-laden water, is highly dependent on coagulation-flocculation. Treatment of algae can be problematic due to unpredictable coagulant demand during blooms. To eliminate the need for coagulation-flocculation, the use of commercial polymers or surfactants to alter bubble charge in DAF has shown potential, termed the PosiDAF process. When using surfactants, poor removal was obtained but good bubble adherence was observed. Conversely, when using polymers, effective cell removal was obtained, attributed to polymer bridging, but polymers did not adhere well to the bubble surface, resulting in a cationic clarified effluent that was indicative of high polymer concentrations. In order to combine the attributes of both polymers (bridging ability) and surfactants (hydrophobicity), in this study, a commercially-available cationic polymer, poly(dimethylaminoethyl methacrylate) (polyDMAEMA), was functionalised with hydrophobic pendant groups of various carbon chain lengths to improve adherence of polymer to a bubble surface. Its performance in PosiDAF was contrasted against commercially-available poly(diallyl dimethyl ammonium chloride) (polyDADMAC). All synthesised polymers used for bubble surface modification were found to produce positively charged bubbles. When applying these cationic micro-bubbles in PosiDAF, in the absence of coagulation-flocculation, cell removals in excess of 90% were obtained, reaching a maximum of 99% cell removal and thus demonstrating process viability. Of the synthesised polymers, the polymer containing the largest hydrophobic functionality resulted in highly anionic treated effluent, suggesting stronger adherence of polymers to bubble surfaces and reduced residual polymer concentrations.

  17. Evaluation of flow hydrodynamics in a pilot-scale dissolved air flotation tank: a comparison between CFD and experimental measurements.

    PubMed

    Lakghomi, B; Lawryshyn, Y; Hofmann, R

    2015-01-01

    Computational fluid dynamics (CFD) models of dissolved air flotation (DAF) have shown formation of stratified flow (back and forth horizontal flow layers at the top of the separation zone) and its impact on improved DAF efficiency. However, there has been a lack of experimental validation of CFD predictions, especially in the presence of solid particles. In this work, for the first time, both two-phase (air-water) and three-phase (air-water-solid particles) CFD models were evaluated at pilot scale using measurements of residence time distribution, bubble layer position and bubble-particle contact efficiency. The pilot-scale results confirmed the accuracy of the CFD model for both two-phase and three-phase flows, but showed that the accuracy of the three-phase CFD model would partly depend on the estimation of bubble-particle attachment efficiency.

  18. Capillary-rheological effects at liquid-gas interfaces containing oil films, and their relation to the flotation process

    SciTech Connect

    Belova, N.S.; Leonov, S.B.

    1995-03-01

    In spite of many years of practical experience in the use of nonpolar reagents in the technology of mineral beneficiation, there are still a number of open questions regarding the mechanism of action of these reagents in the flotation process. No clear, unambiguous explanation has been forthcoming for certain effects that are observed in flotation practice - reduced recovery of mineral particles as a result of an increase of reagent consumption or dispersity of the emulsion. It is believed that a lowering of the strength of particle-bubble adhesion upon increasing the quantity of oil, and the lower flotation activity that is observed with increasing size of the emulsion drops, are related to localization of the reagent on the surface of the solid phase and a consequent change in the conditions of formation and fixation of the three-phase contact of particle and bubble. However, a flotation-active mineral oils also spread on the surfaces of bubbles, where, acting through a capillary mechanism, they influence the balance of forces in the particle-bubble system, strengthening their contact under dynamic conditions of froth flotation. This effect is a consequence of the creation of a nonequilibrium state of the surface close to the three-phase contact when it stretches by the forces detaching the particle from the bubble. The mineral oils that are used in flotation as nonpolar reagents are obtained by fractional distillation of crude oil; they consist mainly of hydrocarbons with various lengths of the hydrocarbon chain. The spreading of these oils on a water surface depends on the concentration of polar molecules in the oil, which thus determined the thickness of the films that are formed. Therefore, mineral oils can be regarded as solutions in which the solvents are components having very little adhesion to water, whereas the surfactants dissolved in these solvents are components with a high degree of adhesion to water.

  19. Characterization of multiphase fluid flow during air-sparged hydrocyclone flotation by X-ray CT. Thirteenth quarterly report: 14 August--13 November, 1993

    SciTech Connect

    Miller, J.D.

    1993-11-16

    The research activities during this quarter of the DOE project, {open_quotes}Characterization of Multiphase Fluid Flow During Air-Sparged Hydrocyclone Flotation{close_quotes}, involved a detailed parametric study of the flotation response of the ASH, establishing an empirical correlation between flotation response and operating variables, and development of a phenomenological description of the observed responses. In these experiments with quartz particles, flotation response is essentially characterized by recovery of the solids to the overflow. Dimensionless variables such as the ratio of overflow opening area to underflow opening area, the ratio of air flow rate to slurry flow rate, percent solids in the feed suspension, particle size, inlet velocity (i.e. slurry pressure) are all of paramount importance. A series of experiments were designed to systematically study the effects of these variables on the flotation response. The radial density distribution profiles obtained from x-ray CT measurements (presented in earlier quarterly reports) reflect the fluid flow behavior of the ASH to a great extent. Based on the results of the experimental tests an empirical model has been developed correlating recovery with the operating variables.

  20. Hydrocarbon-oil encapsulated air bubble flotation of fine coal. Technical progress report for the fifth quarter, October 1, 1991--December 30, 1991

    SciTech Connect

    Peng, F.F.

    1995-01-01

    A main portion of this reporting period has been consumed in the following tasks: (i) Contact angle measurement using gasified collector encapsulated bubble; (ii) wettability measurement using film flotation method; (iii) induction time measurement; (iv) conducting atomized collector flotation tests in a stirred tank cell; (v) developing the experimental design and conducting a column flotation test. The coal samples used in this period of work are five ranks of coal samples from Mammoth, Lower Kittanning, Upper Freeport, Pittsburgh No. 8 and Wyodak seam coals. To better understand the fundamental steps involved in the modes of collector addition techniques in the froth flotation, contact angle, wettability and induction time were measurement. It was found increasing in the contact angles and decreasing in the induction time for a hydrocarbon-oil encapsulated air bubble compared to those for an oil-free bubble for all the coal samples measured. These observations may account for the improved flotation kinetics and, hence, the recovery with the hydrocarbon-oil encapsulated bubbles. Two level fractional factorial experimental design were developed for conducting the column flotation tests to obtain the optimal operating conditions. In the first series of the tests, seven operating parameters were considered with 16 runs. Based on those results, subsequently, the second experimental design was developed for six operating parameters with 16 runs. The third experiment design was formulated with three most significant operating parameters with 8 runs. A high combustible recovery was obtained for -200 mesh Upper Freeport coal sample. However, the results indicated that for further reduction of the ash content of the froth product, the height of column flotation cell needed to be increased.

  1. The influence of contact zone configuration on the flow structure in a dissolved air flotation pilot plant.

    PubMed

    Lundh, Måns; Jönsson, Lennart; Dahlquist, Jan

    2002-03-01

    The dissolved air flotation process is used in water and wastewater treatment. Among many parameters the fluid dynamics determine the capacity of the process. The contact zone is assumed to be important for the removal function, as it is believed to be the location for the aggregation of bubbles and flocs. This paper presents an experimental study on the flow structure in a contact zone of a DAF pilot tank and the influence of contact zone configuration. The flow structure in the contact zone was examined for different horizontal lengths of the zone and for different heights and inclinations of the shaft wall. The hydraulic surface loading was 11 m/h over the total tank surface area and the recycle rate was constant at 10% of the main flow. The examined hydraulic surface loading over the contact zone ranged from 40 to 98 m/h. Water velocities in the longitudinal, central section of the tank were measured with an acoustical Doppler velocimeter in a grid net for the different contact zone configurations, giving an insight into the flow structure. The result showed that the flow structure in the contact zone was characterised by a turbulent lower region and a plug-flow higher region. The hydraulic surface loading, a function of the length of the contact zone, seemingly determined the extension of the turbulent region. A higher hydraulic surface loading decreased the turbulent region while the lower loading increased it. A hydraulic surface loading of 65 m/h was suggested for design. It was not possible to determine the turbulent intensity quantitatively due to the measurement method. The height and inclination of the shaft wall did not seem to have a significant influence on the turbulent region. However, an increased height of the contact zone enhanced the higher, plug flow region and a recommended height of 0.81 m or higher for the recommended hydraulic surface loading was suggested when both mixing and plug-flow are desired. The separation zone was characterised by

  2. 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.

  3. Partial removal of PCDD/Fs, coplanar PCBS, and PCBS from municipal solid waste incineration fly ash by a column flotation process.

    PubMed

    Huang, Ying; Takaoka, Masaki; Takeda, Nobuo; Oshita, Kazuyuki

    2007-01-01

    Municipal solid waste incineration (MSWI) fly ash has recently attracted much attention because of its large quantity and enrichment of high toxic combustion generating organohalogen contaminants such as polychlorinated dibenzo-p-dioxins (PCDDs), dibenzofurans (PCDFs), coplanar polychlorinated biphenyls (coplanar PCBs), and polychlorinated biphenyls (PCBs). Since the organohalogen contaminants in MSWI fly ash are known to be enriched in the unburnt carbon (UC) fraction, the organohalogen contaminants can therefore be removed by the removal of UC. In this research, we used a modified column flotation technique to remove the organic contaminants from MSWI fly ash. UC was removed for 27.7% under the flotation condition without chemical flotation aids. The removal efficiencies of UC, PCDD/Fs, coplanar PCBs, and PCBs are further improved by adding flotation aids during the flotation process. UC was removed for 49.0% by adding a collector assistant with a HLB value of 13.5 and a concentration in the kerosene of 3% during the flotation process. In addition,the UC removal efficiencies are increased with the decrease of the diameter of the micropores in the gas spargers. By optimizing the flotation condition, 41.9% total PCDD/Fs, 40.8% coplanar PCBs, and 44.1% PCBs with 64.0% UC have been successfully removed from MSWI fly ash. The total toxic equivalent (TEQ) of the fly ash was decreased from 6.2 ng/g to 4.2 ng/g in the residue.

  4. 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.

  5. Process air quality data

    NASA Technical Reports Server (NTRS)

    Butler, C. M.; Hogge, J. E.

    1978-01-01

    Air quality sampling was conducted. Data for air quality parameters, recorded on written forms, punched cards or magnetic tape, are available for 1972 through 1975. Computer software was developed to (1) calculate several daily statistical measures of location, (2) plot time histories of data or the calculated daily statistics, (3) calculate simple correlation coefficients, and (4) plot scatter diagrams. Computer software was developed for processing air quality data to include time series analysis and goodness of fit tests. Computer software was developed to (1) calculate a larger number of daily statistical measures of location, and a number of daily monthly and yearly measures of location, dispersion, skewness and kurtosis, (2) decompose the extended time series model and (3) perform some goodness of fit tests. The computer program is described, documented and illustrated by examples. Recommendations are made for continuation of the development of research on processing air quality data.

  6. 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.

  7. 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.

  8. 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.

  9. Replacing synthetic with microbial surfactants as collectors in the treatment of aqueous effluent produced by acid mine drainage, using the dissolved air flotation technique.

    PubMed

    Menezes, Carlyle T B; Barros, Erilson C; Rufino, Raquel D; Luna, Juliana M; Sarubbo, Leonie A

    2011-02-01

    Dissolved air flotation (DAF) is a well-established separation process employing micro bubbles as a carrier phase. The application of this technique in the treatment of acid mine drainage, using three yeast biosurfactants as alternative collectors, is hereby analyzed. Batch studies were carried out in a 50-cm high acrylic column with an external diameter of 2.5 cm. High percentages (above 94%) of heavy metals Fe(III) and Mn(II) were removed by the biosurfactants isolated from Candida lipolytica and Candida sphaerica and the values were found to be similar to those obtained with the use of the synthetic sodium oleate surfactant. The DAF operation with both surfactant and biosurfactants, achieved acceptable turbidity values, in accordance with Brazilian standard limits. The best ones were obtained by the biosurfactant from C. lipolytica, which reached 4.8 NTU. The results obtained with a laboratory synthetic effluent were also satisfactory. The biosurfactants removed almost the same percentages of iron, while the removal percentages of manganese were slightly higher compared with those obtained in the acid mine drainage effluent. They showed that the use of low-cost biosurfactants as collectors in the DAF process is a promising technology for the mining industries.

  10. 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.

  11. 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.

  12. Air Quality Management Process Cycle

    EPA Pesticide Factsheets

    Air quality management are activities a regulatory authority undertakes to protect human health and the environment from the harmful effects of air pollution. The process of managing air quality can be illustrated as a cycle of inter-related elements.

  13. 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...

  14. 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...

  15. Lamella dissolved air flotation treatment of fish farming effluents as a part of an integrated farming and effluent treatment concept.

    PubMed

    Jokela, Petri; Lepistö, Raghida

    2014-01-01

    Nutrient emissions from fish farming can be reduced by a bag pen, i.e., a floating circular basin which serves simultaneously both as a fish cultivation tank and a swirl separation tank. Solid matter (excreta and uneaten feed) is collected at the bottom of the bag pen and pumped as an underflow to a dissolved air flotation (DAF) unit for nutrient removal. DAF equipped with lamella elements was studied in real conditions. Altogether 3000 rainbow trout females (2.0 kg each) were cultivated. Solid-water mixture was pumped from the bottom of the bag pen to an equalizing basin using a sequence of 2-min pumping followed by a 4-min pause. In some tests the influent was pumped directly and continuously from the bag pen to DAF. The influent quality changed substantially: average suspended solids (SS) and phosphorus (P) concentrations were 290 mg l⁻¹ ± 110 mg l⁻¹ and 3.2 mg l⁻¹ ± 1.2 mg l⁻¹, respectively. When the influent was fresh and P strongly associated with SS, DAF without precipitation chemicals produced up to 86% SS and 83% P removals. The influence of chemical doses was studied using 6.4-29.2 mg Fe l⁻¹ with hydraulic loadings (HLs) of 11.0-11.7 m h⁻¹. SS and P removal did not change substantially and the effluent concentration levelled at 30 mg SS l⁻¹ and 0.20-0.30 mg P l⁻¹, respectively. The lamella DAF, coupled with ferric precipitation, produced up to 90% P and 80% nitrogen reductions. HLs, excluding recycle water flow and lamella projection, up to 21 m h⁻¹ could be used.

  16. Characterization of multiphase fluid flow during air-sparged hydrocyclone flotation by x-ray CT

    SciTech Connect

    Miller, J.D.

    1993-03-01

    During this quarter a new set of experiments was carried out with and without collector in order to understand the flow patterns inside the ASH unit for both hydrophilic and hydrophobic particles. These tests were designed to study the effects of percent solids in the feed, A* - the nondimensional ratio of overflow opening area to underflow opening area, and the effect of collector addition on the flow characteristics. These experiments were done with 0%, 5% and 15% solids in the feed. The latter two cases were studied for three different A* values and also with and without the addition of collector. The value of Q*, the dimensionless ratio of air f low rate and slurry flow rate was maintained at the same level (Q* 4.55). Quartz particles of size [minus]100 +200 mesh were used for this study rather than coal particles because they did not abrade and were of a higher density. The reagents and their dosages used were 40 ppm (water basis) of frother (MIBC) and 800 g of collector (dodecyl amine) per ton of solids in the suspension. At room temperature, quartz is intrinsically hydrophilic while addition of the amine collector renders the quartz particles hydrophobic. The absence of collector will be referred to as the hydrophilic case and the presence of collector will be referred to as the hydrophobic case.A total of 11 scans was taken over the entire length of the ASH unit. Software has now been developed to analyze the CT images obtained from these tests and is able to account for any offset of the air core from the axis of the ASH. In this way, the image is reconstructed and a radial density profile of the time averaged flow is generated. Some experimental results are presented graphically in Figures 1 through 4 at 0% and 5% solids in the suspension for both hydrophilic and hydrophobic cases.

  17. Use of multiple radiotracers produced from intrinsic elements to trace float-sink components of coal in the flotation process for cleaning coal

    SciTech Connect

    Agyemang-Boateng, K.

    1985-01-01

    The multiple radioisotope tracer method has been delineated, developed, and demonstrated for automating the research on and characterization of the froth flotation process for a New Mexico subbituminous coal. The method allows a real-time measurement of the amounts of three specific float-sink coal components of interest. A rational basis for this method was that the two short-lived radioisotopes, Na-24 and Mn-56, produced by a 5-minute neutron irradiation of the intrinsic elements in the coal in a nuclear reactor must have constant, but different concentrations in each of the three coal components as a requirement for their usage. An impulse tracer injection was made in a conditioner leading to a single flotation cell. Then, the instantaneous tracer component amounts in the feed, the froth product, and the slurry product of the cell were monitored simultaneously using an external microcomputer-based data logging system which is capable of obtaining gamma-ray spectra almost continuously. The determination of the transient amounts of each float-sink component from the composite pulse-height spectra was accomplished by the application of a standard library least-squares method. A phenomenological model for a single flotation cell based on the cross flow finite stage residence time distribution model with a first-order flotation rate constant is used to determine the flotation rate constants and the transport and dispersion properties of the float-sink components. The results indicate the model and tracer methods developed to extract the model parameters are valid for the coal flotation process.

  18. Characterization of multiphase fluid flow during air-sparged hydrocyclone flotation by x-ray CT

    SciTech Connect

    Miller, J.D.

    1992-08-17

    The effect of A* (the dimensionless ratio of overflow opening area to underflow opening area) on the fluid flow behavior of the 2 inch ASH-2C unit was studied for different percentage of solids in the suspension. Limestone, a hydrophilic solid was chosen for study. The particle size of the solids was taken as [minus]100 [plus]200 mesh. Three different concentrations of solids in the suspension were considered, 5, 10 and 20% by weight. The corresponding pulp densities of the feed suspension for these three cases are 1.09, 1.18 and 1.36 g/cc respectively. Since no collector was added to the suspension, all the solids are expected to report to the underflow. For all these studies the Q* value was maintained at the same level (Q* = 2.28). Reconstructed images from the CT scanner were analyzed using the graphics software developed at the University of Utah. Assuming the air core to be cylindrical in shape and using the previously generated calibration curve, the average density of the swirl layer and its average thickness were estimated for each slice. These results are presented graphically in the accompanying figures along the axis of the ASH unit from bottom to top.

  19. 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.

  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. Treatment of drinking water residuals: comparing sedimentation and dissolved air flotation performance with optimal cation ratios.

    PubMed

    Bourgeois, J C; Walsh, M E; Gagnon, G A

    2004-03-01

    Spent filter backwash water (SFBW) and clarifier sludge generally comprise the majority of the waste residual volume generated and in relative terms, these can be collectively referred to as combined filter backwash water (CFBW). CFBW is essentially a low-solids wastewater with metal hydroxide flocs that are typically light and slow to settle. This study evaluates the impact of adding calcium and magnesium carbonates to CFBW in terms of assessing the impacts on the sedimentation and DAF separation processes. Representative CFBW samples were collected from two surface water treatment plants (WTP): Lake Major WTP (Dartmouth, Nova Scotia, Canada) and Victoria Park WTP (Truro, Nova Scotia, Canada). Bench-scale results indicated that improvements in the CFBW settled water quality could be achieved through the addition of the divalent cations, thereby adjusting the monovalent to divalent (M:D) ratios of the wastewater. In general, the DAF process required slightly higher M:D ratios than the sedimentation process. The optimum M:D ratios for DAF and sedimentation were determined to be 1:1 and 0.33:1, respectively. It was concluded that the optimisation of the cation balance between monovalent cations (e.g., Na(+), K(+)) and added divalent cations (i.e., Ca(2+), Mg(2+)) aided in the settling mechanism through charge neutralisation-precipitation. The increase in divalent cation concentrations within the waste residual stream promoted destabilisation of the negatively charged colour molecules within the CFBW, thereby causing the colloidal content to become more hydrophobic.

  2. 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.

  3. A stepwise recovery of metals from hybrid cathodes of spent Li-ion batteries with leaching-flotation-precipitation process

    NASA Astrophysics Data System (ADS)

    Huang, Yanfang; Han, Guihong; Liu, Jiongtian; Chai, Wencui; Wang, Wenjuan; Yang, Shuzhen; Su, Shengpeng

    2016-09-01

    The recovering of valuable metals in spent lithium-ion battery cathodes brings about economic and environmental benefits. A stepwise leaching-flotation-precipitation process is adopted to separate and recover Li/Fe/Mn from the mixed types of cathode materials (hybrid wastes of LiFePO4 and LiMn2O4). The optimal operating conditions for the stepwise recovery process are determined and analyzed by factorial design, thermodynamics calculation, XRD and SEM characterization in this study. First, Li/Fe/Mn ions are released from the cathode using HCl assisted with H2O2 in the acid leaching step. The leachability of metals follows the series Li > Fe > Mn in the acidic environment. Then Fe3+ ions are selectively floated and recovered as FeCl3 from the leachate in the flotation step. Finally, Mn2+/Mn3+ and Li+ ions are sequentially precipitated and separated as MnO2/Mn2O3 and Li3PO4 using saturated KMnO4 solution and hot saturated Na3PO4 solution, respectively. Under the optimized and advisable conditions, the total recovery of Li, Fe and Mn is respectively 80.93 ± 0.16%, 85.40 ± 0.12% and 81.02 ± 0.08%. The purity for lithium, ferrum and manganese compounds is respectively 99.32 ± 0.07%, 97.91 ± 0.05% and 98.73 ± 0.05%. This stepwise process could provide an alternative way for the effective separation and recovery of metal values from spent Li-ion battery cathodes in industry.

  4. 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.

  5. 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.

  6. 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.

  7. 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.

  8. 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.

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

    ERIC Educational Resources Information Center

    Klopping, Paul H.

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

  10. Hydrocarbon-oil encapsulated bubble flotation of fine coal. Technical progress report for the fourth quarter, July 1, 1991--September 30, 1991

    SciTech Connect

    Peng, F.F.

    1995-01-01

    This report is concerned with the progress made during the fourth period of the research Project, Grant no. DE-FG22-90-PC90314. A main portion of this reporting period has been consumed in the following tasks: (i) induction time measurement for the coal particles prepared by using various modes of collector addition techniques; (ii) ultrasonic energy dispersed collector flotation tests; (iii) natural floatability measurement using Hallimond tube flotation cell; (iv) preparation and operation of 3-inch column cell, and (v) preparation of wettability measurement using film flotation method. The coal samples used in this period of work are four ranks of coal samples from Mammoth (Anthracite), Lower Kittanning, Upper Freeport and Pittsburgh No. 8 seam coals. The results showed that a drastic improvement in the flotation rate and yield were achieved by using the ultrasonic energy dispersed collector flotation compared to that of conventional flotation. The techniques of direct liquid addition and addition of ultrasonic energy dispersed collector are mainly for alteration of the hydrophobicity distribution of coal particle surfaces. On the contrary, the gasified collector addition to the gas phase technique is for alteration of the chemical properties of bubble surfaces. Among these techniques, however, the results showed that the hydrocarbon oil encapsulated bubble flotation is more selective than either ultrasonic energy dispersed collector flotation process or conventional flotation process. Induction time measurement was continued and extended to the coal samples received in this period of work, using oil free air bubble and oil-coated air bubbles. Induction time for oil-coated bubbles is significantly shorter than that of oil-free bubbles for all the coal samples used. A good agreement between flotation responses and induction time were obtained for all the coal samples under the conditions of various modes of collector dispersion.

  11. Feed-Forward Neural Network Soft-Sensor Modeling of Flotation Process Based on Particle Swarm Optimization and Gravitational Search Algorithm

    PubMed Central

    Wang, Jie-Sheng; Han, Shuang

    2015-01-01

    For predicting the key technology indicators (concentrate grade and tailings recovery rate) of flotation process, a feed-forward neural network (FNN) based soft-sensor model optimized by the hybrid algorithm combining particle swarm optimization (PSO) algorithm and gravitational search algorithm (GSA) is proposed. Although GSA has better optimization capability, it has slow convergence velocity and is easy to fall into local optimum. So in this paper, the velocity vector and position vector of GSA are adjusted by PSO algorithm in order to improve its convergence speed and prediction accuracy. Finally, the proposed hybrid algorithm is adopted to optimize the parameters of FNN soft-sensor model. Simulation results show that the model has better generalization and prediction accuracy for the concentrate grade and tailings recovery rate to meet the online soft-sensor requirements of the real-time control in the flotation process. PMID:26583034

  12. Compact secondary treatment train combining a lab-scale moving bed biofilm reactor and enhanced flotation processes.

    PubMed

    Brosseau, Catherine; Émile, Bettina; Labelle, Marc-André; Laflamme, Édith; Dold, Peter L; Comeau, Yves

    2016-12-01

    High-rate wastewater processes are receiving a renewed interest to obtain energy positive/efficient water resource recovery facilities. An innovative treatment train combining a high-rate moving bed biofilm reactor (HR-MBBR) with an enhanced flotation process was studied. The two objectives of this work were 1) to maximize the conversion of soluble organics to particulate matter in an HR-MBBR and 2) to maximize the particulate matter recovery from the HR-MBBR effluent by green chemicals to enhance biogas production by anaerobic digestion. To achieve these objectives, lab-scale MBBRs fed with synthetic soluble wastewater were operated at organic loading rates (OLRs) between 4 and 34 kg COD m(-3) reactor d(-1) corresponding to hydraulic retention times (HRTs) between 6 and 54 min. Colloidal and soluble chemical oxygen demand (COD) removal efficiency in the HR-MBBR increased with HRT to reach a plateau of 85% at an HRT longer than 27 min. Carrier clogging observed at an OLR higher than 16 kg COD m(-3) d(-1) (HRT < 13 min) resulted in about 23% loss in colloidal and soluble COD removal efficiency. Thus, the recommended parameters were between 22 and 37 min and between 6 and 10 kg COD m(-3) d(-1) for the HRT and the OLR, respectively, to maximize the conversion of soluble organics to particulate matter. Total suspended solids (TSS) recovery of 58-85% and 90-97% were achieved by enhanced flotation using green and unbiodegradable chemicals, respectively, corresponding to a TSS effluent concentration below 14 and 7 mg TSS/L. Among the synthetic polymers tested, a high molecular weight and low charge density cationic polyacrylamide was found to give the best results with less than 2 mg TSS/L in the clarified effluent (97% TSS recovery). Green chemicals, although performing slightly less for solids separation than unbiodegradable chemicals, achieved a mean TSS concentration of 10 ± 3 mg/L in the clarified effluent.

  13. Testing of the 15-inch air-sparged hydrocyclone for fine coal flotation at the Homer City preparation plant

    SciTech Connect

    Miller, J.D.; Yi, Y.; Gopalakrishnan, S.; Battista, J.J.

    1993-12-31

    Previous plant testing had been limited to the processing of minus 100 mesh classifier overflow (Upper Freeport Coal {approximately} 20% ash) with the 6-inch air-sparged hydrocyclone (ASH-6C) as reported at Coal Prep 92. The ASH-6C unit was found to provide separation efficiencies equivalent, or superior, to separations with the ASH-2C system. During the summer of 1992 the construction of the first 15-inch air-sparged hydrocyclone prototype was completed by the Advanced Processing Technologies, Inc. Installation at the Homer City Coal Preparation Plant was accomplished and testing began in October 1992. The ASH-15C unit can operate at a flowrate as high as 1,000 gpm. Experimental results are reported with respect to capacity, combustible recovery and clean coal quality.

  14. Reengineering the Air Travel Process

    DTIC Science & Technology

    1999-04-01

    Thesis 3. DATES COVERED (FROM - TO) xx-xx-1999 to xx-xx-1999 4. TITLE AND SUBTITLE Reengineering the Air Travel Process Unclassified 5a. CONTRACT...RELEASE , 13. SUPPLEMENTARY NOTES 14. ABSTRACT Every year, Department of Defense (DOD) travelers make thousands of trips that include air transportation

  15. Flotation of algae for water reuse and biomass production: role of zeta potential and surfactant to separate algal particles.

    PubMed

    Kwak, Dong-Heui; Kim, Mi-Sug

    2015-01-01

    The effect of chemical coagulation and biological auto-flocculation relative to zeta potential was examined to compare flotation and sedimentation separation processes for algae harvesting. Experiments revealed that microalgae separation is related to auto-flocculation of Anabaena spp. and requires chemical coagulation for the whole period of microalgae cultivation. In addition, microalgae separation characteristics which are associated with surfactants demonstrated optimal microalgae cultivation time and separation efficiency of dissolved CO2 flotation (DCF) as an alternative to dissolved air flotation (DAF). Microalgae were significantly separated in response to anionic surfactant rather than cationic surfactant as a function of bubble size and zeta potential. DAF and DCF both showed slightly efficient flotation; however, application of anionic surfactant was required when using DCF.

  16. 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.

  17. Removal of emulsified fuel oils from brackish and pond water by dissolved air flotation with and without polyelectrolyte use: pilot-scale investigation for estuarine and near shore applications.

    PubMed

    Tansel, Berrin; Pascual, Beth

    2011-11-01

    In coastal areas, estuaries, and inland waters, dispersant use after oil spills is not allowed due to sensitivity of the ecosystems. The purpose of this study was to investigate the removal of emulsified fuel oils from brackish and pond water by dissolved air flotation (DAF) with and without use of coagulants. Experiments were conducted with a 60L DAF system. Fuel oil-water emulsions were prepared with regular unleaded gasoline, jet fuel, and diesel fuel mixed at 1:1:1 (v/v/v) ratio. Batch and continuous runs were conducted at air pressurization of 354.6kPa. During both batch and continuous modes, significant petroleum hydrocarbon (PHC) removal was achieved within 10 min. Coagulant addition initially increased the PHC removal by about 5-15%. However, effectiveness of the coagulant was not significant after 20 min due to breakage of the aggregates. In general, the pond water had higher PHC removal than the brackish water. With longer run times, PHC removal improved slightly and the effluent contained increasing fractions of higher molecular weight compounds indicating that PHC removal was due to both DAF and stripping processes. Results indicate that DAF process can be effective both with and without the use of coagulants for removing PHCs from brackish and pond waters.

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

    PubMed

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

    2016-09-01

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

  19. 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.

  20. Treatment of combined acid mine drainage (AMD)--flotation circuit effluents from copper mine via Fenton's process.

    PubMed

    Mahiroglu, Ayse; Tarlan-Yel, Esra; Sevimli, Mehmet Faik

    2009-07-30

    The treatability of a copper mine wastewater, including heavy metals, AMD, as well as flotation chemicals, with Fenton process was investigated. Fenton process seems advantageous for this treatment, because of Fe(2+) content and low pH of AMD. First, optimum Fe(2+) condition under constant H(2)O(2) was determined, and initial Fe(2+) content of AMD was found sufficient (120 mg/L for removal of chemical oxygen demand (COD) of 6125 mg/L). In the second step, without any additional Fe(2+), optimum H(2)O(2) dosage was determined as 40 mg/L. Fe(2+)/H(2)O(2) molar ratio of 1.8 was enough to achieve the best treatment performance. In all trials, initial pH of AMD was 4.8 and pH adjustment was not performed. Utilization of existing pH and Fe(2+), low H(2)O(2) requirements, and up to 98% treatment performances in COD, turbidity, color, Cu(2+), Zn(2+) made the proposed treatment system promising. Since the reaction occurs stepwise, a two-step kinetic model was applied and calculated theoretical maximum removal rate was consistent to experimental one, which validates the applied model. For the optimum molar ratio (1.8), 140 mL/L sludge of high density (1.094 g/mL), high settling velocity (0.16 cm/s) with low specific resistance (3.15 x 10(8)m/kg) was obtained. High reaction rates and easily dewaterable sludge characteristics also made the proposed method advantageous.

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

    SciTech Connect

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

    1990-01-01

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

  2. 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.

  3. 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.

  4. Evaluation of column flotation in the downstream processing of fermentation products: recovery of a genetically engineered alpha-amylase.

    PubMed

    Miranda, E A; Berglund, K A

    1993-01-01

    Flotation is a simple, inexpensive, and versatile unit operation with a largely unexplored potential in biotechnology. There is a general lack of research concerning biotechnological applications in this area, especially in the recovery of fermentation products. Moreover, the few reports in the literature do not consider the modern concept of column flotation as practiced in the mineral industry. We report herein the application of column flotation for the recovery of a Bacillus stearothermophilus alpha-amylase expressed in Escherichia coli by the use of a food-grade polymer, (hydroxypropyl)methylcellulose (HPMC), and ammonium sulfate. First, the enzyme was removed from the liquid phase by partition to a salted-out HPMC phase. The enzyme-containing polymer flocs were then floated from the liquid. Recovery of active enzyme was as high as 90%, with throughput as high as 94 m3/(h.m2). The floatability of the enzyme from a periplasmic extract was higher than extracellular enzyme in the broth due to the presence of depressors of molecular weight lower than 10,000 in the broth.

  5. Hydrocarbon-oil encapsulate bubble flotation of fine coal. Technical progress report for the thirteenth quarter, October 1--December 30, 1993

    SciTech Connect

    Peng, F.F.

    1993-12-31

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

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

    SciTech Connect

    Peng, F.F.

    1993-12-31

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

  7. Physical cleaning of waste coal by dissolved-CO{sub 2} flotation. Final technical report, September 1, 1992--August 31, 1993

    SciTech Connect

    Shiao, S.Y.

    1993-12-31

    The coal wastes generated from coal mining operations and coal cleaning processes contain fine and ultrafine coals. Recovery of the fine/ultrafine coal from the coal wastes reduces the loss of useable fuels and the environmental impact. The objective of this project was to use dissolved-CO{sub 2} technology to generate ultrafine bubbles to separate fine/ultrafine coal from pyrite and other mineral matter in the coal wastes. The Illinois No. 6 coal waste used in the project was the underflow from a refuse thickener. The concentrations of the major trace metals are much higher than those found in Illinois Basin Coal database for Illinois No. 6 coals. Bench-scale conventional flotation tests of the waste coal were performed under various conditions using a 4-liter Wemco flotation cell. The tests were performed to determine the chemical dosages and flotation conditions used in dissolved-CO{sub 2} column flotation. The waste coal samples were subjected to dissolved-CO{sub 2} flotation in a 2-inch diameter microbubble column under various test conditions. The flotation performance as affected by each test variable was compared. For most of the tests, the Btu recovery was above 80%, the pyrite rejection was about 60%, and the ash rejection varied from about 45% to 76%. Dissolved air was used in one test for comparison. The waste coal samples were also subjected to typical microbubble flotation. As compared to microbubble flotation, the dissolved-CO{sub 2} had higher yield, higher Btu recovery, less pyrite rejection, and less ash rejection. Almost all of the major trace metals had a substantial reduction in concentration by dissolved-CO{sub 2} flotation, particularly for cadmium, chromium, nickel, and lead.

  8. 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.

  9. 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.

  10. Hydrocarbon-oil encapsulated air bubble flotation of fine coal. Technical progress report for the second quarter, January 1, 1991--March 31, 1991

    SciTech Connect

    Peng, F.F.

    1995-01-01

    The objective of the present work is to have a good understanding on the fundamentals of modes of reagent/collector dispersion and adsorbing collector on the bubbles to improve the selectivity and recovery of fine coal flotation. A portion of this reporting period has been consumed in building experimental apparatus and equipment. These include an automated flotation machine, a computer-based induction time apparatus, a bubble charge measuring apparatus, continuous flotation column, etc. An automated flotation machine was constructed for Denver model D-12 with 2- and 4-liter cells. The standard test procedure was established for using the machine with improved pulp level control and constant frother removal to minimize the human error. The flotation results of Upper Freeport coal sample showed a good reproducibility for using the improved automatic flotation machine/cell. The reagentless flotation was conducted in a Hallimond tube to determine the hydrophobicity of coal particles. Upper Freeport coal samples were used for all of the tests including -30 mesh, -200 mesh and -400 mesh U.S. sieves coal samples. High floatability was obtained for Upper Freeport coal samples. The significant entrainment of fine particles were observed for coal samples with -200 mesh and -400 mesh U.S. Sieve samples. The electrokinetic properties of coal particles from Upper Freeport seam was determined as the function of pH, frother or collector concentrations. The IEP of -200 mesh coal particle was at pHaw.53. The zeta potential of the coal particles with or without addition of MIBC or kerosene were exhibited negative values for pH greater than 3 and decreased with increasing pH values. The coal particles with kerosene has the higher zeta-potential value than that of particles with MIBC or free of frother/collector. The negative zeta-potential of coal sample was also observed regardless of MIBC concentration employed.

  11. Characterization of multiphase fluid flow during air-sparged hydrocyclone flotation by x-ray CT. Sixteenth quarterly report, 14 May--13 August 1994

    SciTech Connect

    Miller, J.D.

    1994-10-10

    The axial flow reversal was studied using tracer injection and results correlation with x-ray CT and flotation. Effects of dimensionless area ratio and flow rate ratio, percent solids in feed, and inlet pressure on location of surface of zero axial velocity in the ASH were studied. 4 figs.

  12. A novel capillary electrophoresis method with pressure assisted field amplified sample injection in determination of thiol collectors in flotation process waters.

    PubMed

    Sihvonen, T; Aaltonen, A; Leppinen, J; Hiltunen, S; Sirén, H

    2014-01-17

    A new capillary electrophoresis method was developed for the quantification of diisobutyldithiophosphate (DTP), diisobutyldithiophosphinate (DTPI) and ethyl and isobutyl xanthates (EX, IBX) all of which are used as thiol collectors in froth flotation. This method uses pressure assisted field amplified sample injection (PA-FASI) to concentrate the analytes at the capillary inlet. The background electrolyte in electrophoretic separation was 60millimolar (mM) from 3-(cyclohexylamino)propane-1-sulfonic acid (CAPS) in 40mM NaOH solution. The similar CAPS electrolyte solution has earlier been used for screening for diuretics that contained sulphonamide and/or carboxylic groups. In this study, the functional groups are xanthate, phosphate and phosphinate. The method was developed using actual flotation process waters. The results showed that the water delivered from the plant did not contain significant amount of collectors; therefore, method development was accomplished by spiking analytes in these waters. Separation of analytes was achieved in 15min. The range of quantification was 0.27-66.6mg/L (R(2) 0.9991-0.9999) for all analytes other than ethyl xanthate, for which the range was 0.09-66.6mg/L (R(2) 0.9999). LOD (S/N=3) and LOQ (S/N=10) values for DTP, DTPI, IBX and EX were 0.05, 0.07, 0.06 and 0.01mg/L and 0.16, 0.25, 0.21 and 0.04mg/L, respectively. No interference from the matrices was observed, when the method was tested at a gold concentrator plant.

  13. 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.

  14. Micro-agglomerate flotation for deep cleaning of coal. Quarterly progress report, July 1--September 30, 1994

    SciTech Connect

    Chander, S.; Hogg, R.

    1994-10-01

    The goals of this research program are to demonstrate the technical and economic feasibility of a micro-agglomerate flotation process and to establish the essential criteria for reagent selection and system design and operation. 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. The research program has been organized into several specific tasks : interfacial studies; emulsification; agglomerate growth and structure; and agglomerate flotation. Accomplishments are reported.

  15. 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.

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

    PubMed

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

    2016-01-01

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

  17. 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.

  18. 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.

  19. 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.

  20. 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.

  1. 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.

  2. Micro-agglomerate flotation for deep cleaning of coal. Quarterly progress report, January 1--March 31, 1993

    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.

  3. Micro-agglomerate flotation for deep cleaning of coal. Quarterly progress report, September 30--December 31, 1992

    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.

  4. Processing AIRS Scientific Data Through Level 3

    NASA Technical Reports Server (NTRS)

    Granger, Stephanie; Oliphant, Robert; Manning, Evan

    2010-01-01

    The Atmospheric Infra-Red Sounder (AIRS) Science Processing System (SPS) is a collection of computer programs, known as product generation executives (PGEs). The AIRS SPS PGEs are used for processing measurements received from the AIRS suite of infrared and microwave instruments orbiting the Earth onboard NASA's Aqua spacecraft. Early stages of the AIRS SPS development were described in a prior NASA Tech Briefs article: Initial Processing of Infrared Spectral Data (NPO-35243), Vol. 28, No. 11 (November 2004), page 39. In summary: Starting from Level 0 (representing raw AIRS data), the AIRS SPS PGEs and the data products they produce are identified by alphanumeric labels (1A, 1B, 2, and 3) representing successive stages or levels of processing. The previous NASA Tech Briefs article described processing through Level 2, the output of which comprises geo-located atmospheric data products such as temperature and humidity profiles among others. The AIRS Level 3 PGE samples selected information from the Level 2 standard products to produce a single global gridded product. One Level 3 product is generated for each day s collection of Level 2 data. In addition, daily Level 3 products are aggregated into two multiday products: an eight-day (half the orbital repeat cycle) product and monthly (calendar month) product.

  5. Micro-agglomerate flotation for deep cleaning of coal. Quarterly progress report, 1 April--30 June 1994

    SciTech Connect

    Chander, S.; Hogg, R.

    1994-07-01

    The authors are investigating the use of a hybrid process--Micro-agglomerate flotation--which is a combination of oil-agglomeration and froth flotation. The basic concepts is to use small quantities of oil to promote the formation of dense micro-agglomerates with minimal entrapment of water and mineral particles, and to use froth flotation to extract these micro-agglomerates from the water/dispersed-mineral phase. Since the floating units are agglomerates (about 30--50 {mu}m in size) rather than individual coal particles (1--10 {mu}m) the problems of froth overload water/mineral carryover should be significantly alleviated. The process involves at least five phases: two or more solids (coal and mineral), two liquids (oil and water) and one gas (air). It is necessary to maintain precise control over the chemistry of the liquid phases in order to promote the interfacial reactions and interactions between phases necessary to ensure selectivity. Kinetics as well as thermodynamic factors may be critical in determining overall system response. The research program has been organized into several specific tasks: Task 1, interfacial studies; Task 2, emulsification; Task 3, agglomerate growth and structure; and Task 4, agglomerate flotation. This report summarizes the status of Tasks 2, 3, and 4.

  6. Air separation by the Moltox process

    SciTech Connect

    Erickson, D. C.

    1981-04-01

    The report describes results of a development program on a new and energy saving process for air separation. The Moltox process involves reversibly reacting oxygen in air with a recirculating salt solution, such that oxygen is extracted without depressurizing the remaining nitrogen. Energy savings of approximately 50% are indicated for this process compared to conventional cryogenic air separation. The development program consisted of design, construction, and operation of a 6 liter/minute pilot plant; optimization of the process flowsheet through computer modelling; investigation of engineering aspects of the process including corrosion, safety, and NO/sub x/ generation; and an economic comparison to conventional cryogenic practice. All objectives were satisfactorily achieved except for continuous operation of the pilot plant, and the modifications necessary to achieve that have been identified. Economically the Moltox process shows a substantial advantage over large scale cryogenic plants which are powered by fuel vice electricity.

  7. Micro-agglomerate flotation for deep cleaning of coal. Final report

    SciTech Connect

    Chander, S.; Hogg, R.

    1997-01-15

    The development of practical technologies for the deep cleaning of coal has been seriously hampered by the problems of carrying out efficient coal/mineral separations at the very fine sizes (often finer than 10 {micro}m) needed to achieve adequate liberation of the mineral matter from the coal matrix. In this investigation a hybrid process--Micro-agglomerate flotation--which is a combination of oil-agglomeration and froth flotation was studied. The basic concept is to use small quantities of oil to promote the formation of dense micro-agglomerates with minimal entrapment of water and mineral particles and to use froth flotation to separate these micro-agglomerates from the water/dispersed-mineral phase. Since the floating units will be relatively large agglomerates (30--50 {micro}m in size) rather than fine coal particles (1--10 {micro}m) the problems of froth overload and water/mineral carryover should be significantly alleviated. There are, however, complications. The process involves at least five phases: two or more solids (coal and mineral), two liquids (oil and water) and one gas (air). It is demonstrated in this study that the process is very sensitive to fluctuations in operating parameters. It is necessary to maintain precise control over the chemistry of the liquid phases as well as the agitation conditions in order to promote selectivity. Both kinetics as well as thermodynamic factors play a critical role in determining overall system response.

  8. 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.

  9. 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.

  10. 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.

  11. 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.

  12. 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.

  13. 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.

  14. AIRS Maps from Space Processing Software

    NASA Technical Reports Server (NTRS)

    Thompson, Charles K.; Licata, Stephen J.

    2012-01-01

    This software package processes Atmospheric Infrared Sounder (AIRS) Level 2 swath standard product geophysical parameters, and generates global, colorized, annotated maps. It automatically generates daily and multi-day averaged colorized and annotated maps of various AIRS Level 2 swath geophysical parameters. It also generates AIRS input data sets for Eyes on Earth, Puffer-sphere, and Magic Planet. This program is tailored to AIRS Level 2 data products. It re-projects data into 1/4-degree grids that can be combined and averaged for any number of days. The software scales and colorizes global grids utilizing AIRS-specific color tables, and annotates images with title and color bar. This software can be tailored for use with other swath data products for the purposes of visualization.

  15. 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.

  16. 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.

  17. 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.

  18. Column flotation monitoring based on electrical capacitance volume tomography: A preliminary study

    NASA Astrophysics Data System (ADS)

    Haryono, Didied; Harjanto, Sri; Nugraha, Harisma; Huda, Mahfudz Al; Taruno, Warsito Purwo

    2017-01-01

    A preliminary study of column flotation monitoring process using electrical capacitance volume tomography (ECVT) was conducted. ECVT was one of the monitoring systems which based on the capacitance measurement. It was used to understand the phenomenon that occurs inside the column in a three-dimensional (3-D) image. A linear back projection (LBP) algorithm technique was used to reconstruct the 3-D ECVT images from all measurement data obtained in this study. As a preliminary study, the effect of gas injection in the two-phase (liquid and gas) system was conducted. This study is conducted to assess the possibility of ECVT system in the monitoring of column flotation process. The experiments were conducted by using column flotation with 5 cm diameter and 150 cm height in which a sparger was installed at the bottom of column to inject air inside the column. 32-CH rectangular ECVT sensor was installed at 13 cm above the sparger and placed around the column. The gas injection variations used were 2-7 l/min with interval 1 l/min and all experiments were conducted at room temperature. Based on the signal and image analysis, the signals and 3-D ECVT images showed differences when the gas injection was varied. An increase in gas injection will decrease the fluctuation of signal intensity which correlates to the 3-D ECVT images. Average signals obtained by ECVT when given gas injection variations were in the range of 440.09 to 453.62 mV from high to low gas injection. Based on these results, ECVT has a prospect as an imaging tool to monitor the column flotation process. And also, hopefully, based on the analysis of 3-D images generated by ECVT system, the metallurgical performance would be analyzed in the further researches.

  19. 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.

  20. Processing AIRS Scientific Data Through Level 2

    NASA Technical Reports Server (NTRS)

    Oliphant, Robert; Lee, Sung-Yung; Chahine, Moustafa; Susskind, Joel; arnet, Christopher; McMillin, Larry; Goldberg, Mitchell; Blaisdell, John; Rosenkranz, Philip; Strow, Larrabee

    2007-01-01

    The Atmospheric Infrared Spectrometer (AIRS) Science Processing System (SPS) is a collection of computer programs, denoted product generation executives (PGEs), for processing the readings of the AIRS suite of infrared and microwave instruments orbiting the Earth aboard NASA s Aqua spacecraft. AIRS SPS at an earlier stage of development was described in "Initial Processing of Infrared Spectral Data' (NPO-35243), NASA Tech Briefs, Vol. 28, No. 11 (November 2004), page 39. To recapitulate: Starting from level 0 (representing raw AIRS data), the PGEs and their data products are denoted by alphanumeric labels (1A, 1B, and 2) that signify the successive stages of processing. The cited prior article described processing through level 1B (the level-2 PGEs were not yet operational). The level-2 PGEs, which are now operational, receive packages of level-1B geolocated radiance data products and produce such geolocated geophysical atmospheric data products such as temperature and humidity profiles. The process of computing these geophysical data products is denoted "retrieval" and is quite complex. The main steps of the process are denoted microwave-only retrieval, cloud detection and cloud clearing, regression, full retrieval, and rapid transmittance algorithm.

  1. 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...

  2. 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...

  3. The effect of operational parameters on electrocoagulation-flotation process followed by photocatalysis applied to the decontamination of water effluents from cellulose and paper factories.

    PubMed

    Boroski, Marcela; Rodrigues, Angela Cláudia; Garcia, Juliana Carla; Gerola, Adriana Passarella; Nozaki, Jorge; Hioka, Noboru

    2008-12-15

    Cellulose and paper pulp factories utilize a large amount of water generating several undesirable contaminants. The present work is a preliminary investigation that associates the electrocoagulation-flotation (EC) method followed by photocatalysis to treat such wastewater. For EC, the experiment with aluminium and iron electrodes showed similar efficiency. Iron electrodes (anode and cathode) were chosen. By applying 30min of EC/Fe(0), 153A m(-2) and pH 6.0, the COD values, UV-vis absorbance and turbidity underwent an intense decrease. For the subsequent UV photocatalysis (mercury lamps) TiO(2) was employed and the favourable operational conditions found were 0.25g L(-1) of the catalyst and solution pH 3.0. The addition of hydrogen peroxide (50mmol L(-1)) highly increased the photo-process performance. By employing the UV/TiO(2)/H(2)O(2) system, the COD reduction was 88% compared to pre-treated effluents and complete sample photobleaching was verified. The salt concentration on EC (iron electrodes) showed that the electrolysis duration can be reduced from 30 to 10min by the addition of 5.0g L(-1) of NaCl. The biodegradability index (BOD/COD) increased from 0.15 (pre-treated) to 0.48 (after EC) and to 0.89 (after EC/photocatalysis irradiated for 6h), showing that the employed sequence is very helpful to improve the water quality. This result was confirmed by biotoxicity tests performed with microcrustaceous Artemia salina.

  4. 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.

  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. Removal of carbon constituents from hospital solid waste incinerator fly ash by column flotation.

    PubMed

    Liu, Hanqiao; Wei, Guoxia; Zhang, Rui

    2013-01-01

    Hospital solid waste incinerator (HSWI) fly ash contains a large number of carbon constituents including powder activated carbon and unburned carbon, which are the major source of polychlorinated dibenzo-p-dioxins and dibenzofurans (PCDD/Fs) in fly ash. Therefore, the removal of carbon constituents could reduce PCDD/Fs in fly ash greatly. In this study, the effects of the main flotation parameters on the removal of carbon constituents were investigated, and the characteristics of the final product were evaluated. The results showed that loss on ignition (LOI) of fly ash increased from 11.1% to 31.6% during conditioning process. By optimizing the flotation parameters at slurry concentration 0.05 kg/l, kerosene dosage 12 kg/t, frother dosage 3 kg/t and air flow rate 0.06 m(3)/h, 92.7% of the carbon constituents were removed from the raw fly ash. Under these conditions, the froth product has LOI of 56.35% and calorific values of 12.5 MJ/kg, LOI in the tailings was below 5%, and the total toxic equivalent (TEQ) of PCDD/Fs decreased from 5.61 ng-TEQ/g in the raw fly ash to 1.47 ng-TEQ/g in the tailings. The results show that column flotation is a potential technology for simultaneous separation of carbon constituents and PCDD/Fs from HSWI fly ash.

  7. Understanding the role of ion interactions in soluble salt flotation with alkylammonium and alkylsulfate collectors.

    PubMed

    Ozdemir, Orhan; Du, Hao; Karakashev, Stoyan I; Nguyen, Anh V; Celik, M S; Miller, Jan D

    2011-03-15

    There is anecdotal evidence for the significant effects of salt ions on the flotation separation of minerals using process water of high salt content. Examples include flotation of soluble salt minerals such as potash, trona and borax in brine solutions using alkylammonium and alkylsulfate collectors such as dodecylamine hydrochloride and sodium dodecylsulfate. Although some of the effects are expected, some do not seem to be encompassed by classical theories of colloid science. Several experimental and modeling techniques for determining solution viscosity, surface tension, bubble-particle attachment time, contact angle, and molecular dynamics simulation have been used to provide further information on air-solution and solid-solution interfacial phenomena, especially with respect to the interfacial water structure due to the presence of dissolved ions. In addition atomic force microscopy, and sum frequency generation vibrational spectroscopy have been used to provide further information on surface states. These studies indicate that the ion specificity effect is the most significant factor influencing flotation in brine solutions.

  8. 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.

  9. An advanced control system for fine coal flotation. Final technical progress report, October 1, 1995--June 30, 1996

    SciTech Connect

    1996-11-26

    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 reagent dosage, air addition rate, pulp density and pulp level are adjusted using model-based control algorithms to compensate for feed variations and other process disturbances. Recent developments in video-based sensor technology are being applied for on-line determination of slurry ash content. During the third quarter of this project, work continued on the testing and calibration of the video-based ash analyzer, and a plant sampling campaign was conducted to provide data for the development of a mathematical process model and the model-based control algorithms.

  10. 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.

  11. 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.

  12. Environmental Analysis of the Air Bending Process

    NASA Astrophysics Data System (ADS)

    Kellens, Karel; Dewulf, Wim; Duflou, Joost R.

    2011-05-01

    This paper presents the results of a data collection effort, allowing to assess the overall environmental impact of the air bending process using the CO2PE!-Methodology. First the different modes of the air bending process are investigated, including both productive and non-productive modes. In particular consumption of electric power is recorded for the different modes. Subsequently, time studies allow determining the importance of productive and nonproductive modes of the involved process. The study demonstrates that the influence of standby losses can be substantial. In addition to life cycle analysis, in depth process analysis also provides insight in achievable environmental impact reducing measures towards machine tool builders and eco-design recommendations for product developers. The energy consumption of three different machine tool architectures are analysed and compared within this paper.

  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. 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°.

  15. 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.

  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. 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.

  18. 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.

  19. A comparison study of column flotation technologies for cleaning Illinois coal. Final technical report, September 1, 1993--November 30, 1994

    SciTech Connect

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

    1994-12-31

    Six commercially-available column technologies were compared on the basis of their separation performance, throughput capacity and operational characteristics for treating Illinois Basin coal fines. The flotation column technologies included in this study were the Jameson Cell, Flotaire, Turboair, Packed-Column, Microcel and the Canadian Column. The coal samples treated in this study were a {minus}100 mesh flotation feed slurry, a {minus}40 mesh coal, and a refuse pond coal sample. This investigation found that the Packed Column, Jameson Cell, and Microcel are the best flotation columns for cleaning the Illinois Basin coals treated in this study. The Packed-Column was found to provide superior selectivity, although requiring the highest amount of air and frother concentration. The superior performance is believed to be related to the extensive reflux action and selective detachment mechanism that are more prevalent in the Packed-Column due to its unique ability to support a full froth column. Among the conventional open columns, the Microcel provided the best selectivity, most likely due to its lower aeration requirement which results in a more plug-flow environment within the cell. Both the Packed-Column and the Microcel appeared to have nearly equal throughput capacities. The Jameson Cell, which also has a relatively high throughput capacity, was found to require the least amount of frother while supplying a self-inducing air system. Another important finding of this investigation is that the traditional release analysis procedure is inadequate for predicting the optimum performance of advanced froth flotation processes and, thus, requires further investigation.

  20. Process for recovering organic vapors from air

    DOEpatents

    Baker, Richard W.

    1985-01-01

    A process for recovering and concentrating organic vapor from a feed stream of air having an organic vapor content of no more than 20,000 ppm by volume. A thin semipermeable membrane is provided which has a feed side and a permeate side, a selectivity for organic vapor over air of at least 50, as measured by the ratio of organic vapor permeability to nitrogen permeability, and a permeability of organic vapor of at least 3.times.10.sup.-7 cm.sup.3 (STP) cm/cm.sup.2 sec.cm Hg. The feed stream is passed across the feed side of the thin semipermeable membrane while providing a pressure on the permeate side which is lower than the feed side by creating a partial vacuum on the permeate side so that organic vapor passes preferentially through the membrane to form an organic vapor depleted air stream on the feed side and an organic vapor enriched stream on the permeate side. The organic vapor which has passed through the membrane is compressed and condensed to recover the vapor as a liquid.

  1. 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...

  2. 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...

  3. 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...

  4. 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...

  5. 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.

  6. 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)....

  7. 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...

  8. 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...

  9. 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...

  10. 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...

  11. 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.

  12. Bio-processing of copper from combined smelter dust and flotation concentrate: a comparative study on the stirred tank and airlift reactors.

    PubMed

    Vakylabad, Ali Behrad; Schaffie, Mahin; Ranjbar, Mohammad; Manafi, Zahra; Darezereshki, Esmaeel

    2012-11-30

    To scrutinize the influence of the design and type of the bioreactors on the bioleaching efficiency, the bioleaching were evaluated in a batch airlift and a batch stirred tank bioreactors with mixed mesophilic and mixed moderately thermophilic bacteria. According to the results, maximum copper recoveries were achieved using the cultures in the stirred tank bioreactors. It is worth noting that the main phase of the flotation concentrate was chalcopyrite (as a primary sulphide), but the smelter dust mainly contained secondary copper sulphides such as Cu(2)S, CuS, and Cu(5)FeS(4).Under optimum conditions, copper dissolution from the combined flotation concentrate and smelter dust (as an environmental hazard) reached 94.50% in the STR, and 88.02% in the airlift reactor with moderately thermophilic, after 23 days. Also, copper extractions calculated for the bioleaching using mesophilic bacteria were 48.73% and 37.19% in the STR (stirred tank reactor) and the airlift bioreactor, respectively. In addition, the SEM/EDS, XRD, chemical, and mineralogical analyses and studies confirmed the above results.

  13. Engineering development of advanced physical fine coal cleaning technolgies: Froth flotation. Quarterly technical progress report No. 10, January 1, 1991--March 31, 1991

    SciTech Connect

    Not Available

    1991-12-31

    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.

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

    SciTech Connect

    Chandler, S.; Hogg, R.

    1996-04-01

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

  15. 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.

  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. 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. Micro-agglomerate flotation for deep cleaning of coal. Quarterly progress report, January 1, 1995--March 31, 1995

    SciTech Connect

    Chander, S.; Hogg, R.

    1995-04-01

    The development of practical technologies for the deep cleaning of coal has been seriously hampered by the problems of carrying out efficient coal/mineral separations at the very fine sizes (often finer than 10 mm) needed to achieve adequate liberation of the mineral matter from the coal matrix. In froth flotation, selectivity is substantially reduced at fine sizes due, primarily, to overloading of the froth phase which leads to excessive carryover of water and entrained mineral matter. Oil agglomeration, on the other hand, can provide good selectivity at low levels of oil addition but the agglomerates tend to be too fragile for separation by the screening methods normally used. The addition of larger amounts of oil can yield large, strong agglomerates which are easily separated but the selectivity is reduced and reagent costs can become excessive. 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 mm in size) rather than individual coal particles (1-10 mm) the problems of froth overload and water/mineral carryover should be significantly alleviated. There are, however, complications. The process involves at least five phases: two or more solids (coal and mineral), two liquids (oil and water) and one gas (air). It is 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.

  19. 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.

  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. 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.

  2. 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.

  3. Selective separation of virgin and post-consumer polymers (PET and PVC) by flotation method

    SciTech Connect

    Burat, Firat; Gueney, Ali; Olgac Kangal, M.

    2009-06-15

    More and more polymer wastes are generated by industry and householders today. Recycling is an important process to reduce the amount of waste resulting from human activities. Currently, recycling technologies use relatively homogeneous polymers because hand-sorting waste is costly. Many promising technologies are being investigated for separating mixed thermoplastics, but they are still uneconomical and unreliable. At present, most waste polymers cause serious environmental problems. Burning polymers for recycling is not practiced since poisonous gases are released during the burning process. Particularly, polyvinyl chloride (PVC) materials among waste polymers generate hazardous HCl gas, dioxins containing Cl, etc., which lead to air pollution and shorten the life of the incinerator. In addition, they make other polymers difficult to recycle. Both polyethylene terephthalate (PET) and PVC have densities of 1.30-1.35 g/cm{sup 3} and cannot be separated using conventional gravity separation techniques. For this reason, polymer recycling needs new techniques. Among these techniques, froth flotation, which is also used in mineral processing, can be useful because of its low cost and simplicity. The main objective of this research is to recycle PET and PVC selectively from post-consumer polymer wastes and virgin polymers by using froth flotation. According to the results, all PVC particles were floated with 98.8% efficiency in virgin polymer separation while PET particles were obtained with 99.7% purity and 57.0% efficiency in post-consumer polymer separation.

  4. Selective separation of virgin and post-consumer polymers (PET and PVC) by flotation method.

    PubMed

    Burat, Firat; Güney, Ali; Olgaç Kangal, M

    2009-06-01

    More and more polymer wastes are generated by industry and householders today. Recycling is an important process to reduce the amount of waste resulting from human activities. Currently, recycling technologies use relatively homogeneous polymers because hand-sorting waste is costly. Many promising technologies are being investigated for separating mixed thermoplastics, but they are still uneconomical and unreliable. At present, most waste polymers cause serious environmental problems. Burning polymers for recycling is not practiced since poisonous gases are released during the burning process. Particularly, polyvinyl chloride (PVC) materials among waste polymers generate hazardous HCl gas, dioxins containing Cl, etc., which lead to air pollution and shorten the life of the incinerator. In addition, they make other polymers difficult to recycle. Both polyethylene terephthalate (PET) and PVC have densities of 1.30-1.35g /cm(3) and cannot be separated using conventional gravity separation techniques. For this reason, polymer recycling needs new techniques. Among these techniques, froth flotation, which is also used in mineral processing, can be useful because of its low cost and simplicity. The main objective of this research is to recycle PET and PVC selectively from post-consumer polymer wastes and virgin polymers by using froth flotation. According to the results, all PVC particles were floated with 98.8% efficiency in virgin polymer separation while PET particles were obtained with 99.7% purity and 57.0% efficiency in post-consumer polymer separation.

  5. DESCRIPTION OF ATMOSPHERIC TRANSPORT PROCESSES IN EULERIAN AIR QUALITY MODELS

    EPA Science Inventory

    Key differences among many types of air quality models are the way atmospheric advection and turbulent diffusion processes are treated. Gaussian models use analytical solutions of the advection-diffusion equations. Lagrangian models use a hypothetical air parcel concept effecti...

  6. Clean Air Act Standards and Guidelines for Mineral Processing

    EPA Pesticide Factsheets

    This page contains the stationary sources of air pollution for the mineral processing industries, and their corresponding air pollution regulations. To learn more about the regulations for each industry, just click on the links below.

  7. Characterization of multiphase fluid flow during air-sparged hydrocyclone flotation by x-ray CT. Tenth quarterly report, 14 November 1992--13 February 1993

    SciTech Connect

    Miller, J.D.

    1993-03-01

    During this quarter a new set of experiments was carried out with and without collector in order to understand the flow patterns inside the ASH unit for both hydrophilic and hydrophobic particles. These tests were designed to study the effects of percent solids in the feed, A* - the nondimensional ratio of overflow opening area to underflow opening area, and the effect of collector addition on the flow characteristics. These experiments were done with 0%, 5% and 15% solids in the feed. The latter two cases were studied for three different A* values and also with and without the addition of collector. The value of Q*, the dimensionless ratio of air f low rate and slurry flow rate was maintained at the same level (Q* 4.55). Quartz particles of size {minus}100 +200 mesh were used for this study rather than coal particles because they did not abrade and were of a higher density. The reagents and their dosages used were 40 ppm (water basis) of frother (MIBC) and 800 g of collector (dodecyl amine) per ton of solids in the suspension. At room temperature, quartz is intrinsically hydrophilic while addition of the amine collector renders the quartz particles hydrophobic. The absence of collector will be referred to as the hydrophilic case and the presence of collector will be referred to as the hydrophobic case.A total of 11 scans was taken over the entire length of the ASH unit. Software has now been developed to analyze the CT images obtained from these tests and is able to account for any offset of the air core from the axis of the ASH. In this way, the image is reconstructed and a radial density profile of the time averaged flow is generated. Some experimental results are presented graphically in Figures 1 through 4 at 0% and 5% solids in the suspension for both hydrophilic and hydrophobic cases.

  8. 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.

  9. Characterization of multiphase fluid flow during air-sparged hydrocyclone flotation by x-ray CT. Eighth quarterly report, 14 May 1992--13 August 1992

    SciTech Connect

    Miller, J.D.

    1992-08-17

    The effect of A* (the dimensionless ratio of overflow opening area to underflow opening area) on the fluid flow behavior of the 2 inch ASH-2C unit was studied for different percentage of solids in the suspension. Limestone, a hydrophilic solid was chosen for study. The particle size of the solids was taken as {minus}100 {plus}200 mesh. Three different concentrations of solids in the suspension were considered, 5, 10 and 20% by weight. The corresponding pulp densities of the feed suspension for these three cases are 1.09, 1.18 and 1.36 g/cc respectively. Since no collector was added to the suspension, all the solids are expected to report to the underflow. For all these studies the Q* value was maintained at the same level (Q* = 2.28). Reconstructed images from the CT scanner were analyzed using the graphics software developed at the University of Utah. Assuming the air core to be cylindrical in shape and using the previously generated calibration curve, the average density of the swirl layer and its average thickness were estimated for each slice. These results are presented graphically in the accompanying figures along the axis of the ASH unit from bottom to top.

  10. Characterization of multiphase fluid flow during air-sparged hydrocyclone flotation by x-ray CT. Twelfth quarterly report, 14 May--13 August 1993

    SciTech Connect

    Miller, J.D.

    1993-08-13

    During this quarter some experiments from the previous set were repeated to check the reproducibility of the results. Also, a new set of experiments was carried out to study the effects of (1) collector dosage, (2) Q* -- the nondimensional ratio of air flow rate to slurry flow rate, and (3) slurry pressure on the flow characteristics. Four different Q* values with hydrophobic particles in the feed slurry were studied. The value of A*, the dimensionless ratio of overflow opening area to underflow opening area, was maintained at the same level (A* 1.00). Quartz particles of size {sup {minus}}100 {sup +}200 mesh were used for this study rather than coal particles because they did not abrade and were of a higher density. The reagents used were 40 ppM (water basis) of MIBC frother and 800 g of dodecyl amine collector per ton of dry solids in the suspension. In other experiments with no solids in the feed suspension, collector level in the water was varied at 0, 10 and 20 ppM. At room temperature, quartz is intrinsically hydrophilic while addition of the amine collector renders the quartz particles hydrophobic. The absence of collector will be referred to as the hydrophilic case and the presence of collector will be referred to as the hydrophobic case.

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

    ERIC Educational Resources Information Center

    Venditti, Richard A.

    2004-01-01

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

  12. 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.

  13. 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

  14. 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.

  15. 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.

  16. 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.

  17. 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.

  18. Sewage treatment-flotation apparatus

    SciTech Connect

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

    1981-03-03

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

  19. 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.

  20. Effect of operating parameters on desulphurization of mine tailings by froth flotation.

    PubMed

    Alam, Raquibul; Shang, Julie Q

    2012-04-30

    A site-specific study is carried out to assess the suitability of froth flotation for desulphurization of reactive mine tailings at the Musselwhite Mine, Northern Ontario, Canada, to prevent acid mine drainage (AMD). The results from pilot scale flotation tests on an Outokumpu flotation unit are presented, which confirm that froth flotation is effective to reduce sulphide contents of tailings. The factors affecting the treatment effectiveness, such as the froth depth, air flow rate, pulp density and impeller speed are studied. The sulphur recoveries after 0.25, 0.5, 1, 2, 5, and 12 min of flotation time are fitted to a second-order kinetic model. It is found that the second order rate constant, k(2) is negatively correlated with the froth depth and positively correlated with the air flow rate. Based on the data presented in this study; the maximum recovery of total sulphur was achieved when the operational parameters were set to the froth depth of 5 cm, air flow rate 125 L/min, impeller speed 1300 rpm and pulp density 35%.

  1. 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.

  2. 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.

  3. 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.

  4. 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....

  5. 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....

  6. 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....

  7. 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....

  8. 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....

  9. 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

  10. 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.

  11. 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...

  12. 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...

  13. 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...

  14. 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...

  15. 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...

  16. 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...

  17. Effects of organic and inorganic additives on flotation recovery of washed cells of Saccharomyces cerevisiae resuspended in water.

    PubMed

    DeSousa, Sandro Rogério; Laluce, Cecilia; Jafelicci, Miguel

    2006-03-01

    Separation of microbial cells by flotation recovery is usually carried out in industrial reactors or wastewater treatment systems, which contain a complex mixture of microbial nutrients and excretion products. In the present study, the separation of yeast cells by flotation recovery was carried out using a simple flotation recovery systems containing washed yeast cells resuspended in water in order to elucidate the effects of additives (defined amounts of organic and inorganic acids, ethanol, surfactants and sodium chloride) on the cellular interactions at interfaces (cell/aqueous phase and cell/air bubble). When sodium chloride, organic acids (notably propionic, succinic and acetic acids) and organic surfactants (sodium dodecyl sulphate (SDS), cetyltrimethylammonium bromide (CTAB) and Nonidet P40) were added to the flotation recovery system, significant increases in the cell recovery of yeast hydrophobic cells (Saccharomyces cerevisiae, strain FLT-01) were observed. The association of ethanol to acetic acid solution (a minor by-product of alcoholic fermentation) in the flotation recovery system, containing washed cells of strain FLT-01 resuspended in water, leading to an increased flotation recovery at pH 5.5. Thus, the association among products of the cellular metabolism (e.g., ethanol and acetic acid) can improve yeast cell recovery by flotation recovery.

  18. 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.

  19. 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.

  20. 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.

  1. 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.

  2. Air Force research in optical processing

    NASA Technical Reports Server (NTRS)

    Neff, J.

    1981-01-01

    Optical and optical electronic hybrid processing especially in the application area of image processing are emphasized. Real time pattern recognition processors for such airborne missions as target recognition, tracking, and terminal guidance are studied.

  3. 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.

  4. 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.

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

    PubMed

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

    2016-05-01

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

  6. Characterization of process air emissions in automotive production plants.

    PubMed

    D'Arcy, J B; Dasch, J M; Gundrum, A B; Rivera, J L; Johnson, J H; Carlson, D H; Sutherland, J W

    2016-01-01

    During manufacturing, particles produced from industrial processes become airborne. These airborne emissions represent a challenge from an industrial hygiene and environmental standpoint. A study was undertaken to characterize the particles associated with a variety of manufacturing processes found in the auto industry. Air particulates were collected in five automotive plants covering ten manufacturing processes in the areas of casting, machining, heat treatment and assembly. Collection procedures provided information on air concentration, size distribution, and chemical composition of the airborne particulate matter for each process and insight into the physical and chemical processes that created those particles.

  7. 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.

  8. Laser processing of polytetrafluoroethylene (Teflon) in air

    NASA Astrophysics Data System (ADS)

    Wang, Z. B.; Hong, Ming Hui; Lu, Yong Feng; Chong, Tow Chong

    2003-02-01

    Teflon, polytetrafluorethylene (PTFE), is an important material in bioscience and medical application due to its special characteristics (non-flammable, anti-adhesive, heat-resistant and bio-compatible). The advantages of ultrashort laser processing of Teflon include a minimal thermal penetration region and low processing temperatures, precision removal of material, and good-quality feature definition. In this paper, laser processing of Teflon by Ti:Sapphire femtosecond laser (780 nm, 110 fs), Nd:YAG laser (532 nm, 7 ns) and CO2 laser (10.6 μm, 10 μs) has been investigated. For femtosecond laser processing, clear ablation takes place and provides high-quality groove on Teflon surface. Both the groove depth and the width increase as the laser fluence increase, and decrease almost linearly as the scanning speed increase for laser fluence below 5.0 J/cm2. For Nd:YAG processing, Teflon surface roughness is improved but no clean ablation is accessible, which makes it difficult to micromachine Teflon by Nd:YAG laser. For CO2 laser processing, laser-induced bumps were formed on Teflon surface with controlled laser parameters. The physics mechanisms for different pulse duration laser processing of Teflon are also discussed.

  9. Air separation by the Moltox process. Interim final report

    SciTech Connect

    Erickson, D.C.

    1981-04-01

    Results are described of a development program on a new and energy-saving process for air separation. The Moltox process involves reversibly reacting oxygen in air with a recirculating salt solution, such that oxygen is extracted without depressurizing the remaining nitrogen. Energy savings of approximately 50% are indicated for this process compared to conventional cryogenic air separation. The development program consisted of design, construction, and operation of a 6 liter/minute pilot plant; optimization of the process flowsheet through computer modelling; investigation of engineering aspects of the process including corrosion, safety, and NO/sub x/ generation; and an economic comparison to conventional cryogenic practice. All objectives were satisfactorily achieved except for continuous operation of the pilot plant, and the modifications necessary to achieve that have been identified. Economically the Moltox process shows a substantial advantage over large scale cryogenic plants which are powered by fuel vice electricity.

  10. Engineering development of advanced physical fine coal cleaning technologies: Froth flotation. Quarterly technical progress report No. 9, October 1, 1990--December 31, 1990

    SciTech Connect

    Not Available

    1992-12-31

    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.

  11. 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.

  12. 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.

  13. 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.

  14. 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.

  15. 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.

  16. 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.

  17. A comparison study of column flotation technologies for cleaning Illinois coal. [Quarterly] technical report, December 1, 1993--February 28, 1994

    SciTech Connect

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

    1994-06-01

    The objectives of this research project are to optimize the performance of six commercially available column technologies for the treatment of Illinois Basin coal fines and to compare their performance on the basis of the recovery-grade curve and column throughput capacity. A statistically-designed, experimental program will be conducted to optimize the critical operating performance values of each flotation column. During the previous reporting period, construction and installation of the six flotation columns were completed. The flotation feed sample that will be used for the tests in this investigation was collected from a coal preparation plant treating the Illinois No. 5 seam coal. During this reporting period, the flotation feed sample was characterized on a size-by-size basis for its ash, total sulfur, and BTU content. A release analysis was also conducted to obtain the best possible recovery versus product grade curve that can be achieved by a froth flotation process for the treatment of the Illinois No. 5 flotation feed sample. Experiments were initiated on the Jameson Cell. The preliminary results indicate that the Jameson Cell achieves a separation performance that is close to the release data. The experimental program on the Jameson Cell and the other flotation technologies will be performed during the next reporting period.

  18. 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.

  19. 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.

  20. 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

  1. Comparing the effect of biosurfactant and chemical surfactant on bubble hydrodynamics in a flotation column.

    PubMed

    Wang, Huanran; Yang, Jingjing; Lei, Shaomin; Wang, Xinbing

    2013-01-01

    Bubble hydrodynamics is fundamental to the performance of the flotation process widely used in the separation industry. To compare the effect of biosurfactants and chemical synthetic surfactants on bubble hydrodynamics in the flotation process, the motion of a single bubble and the size distribution of bubble swarms in various surfactants (rhamnolipid, tea saponin and Triton X-100) solutions were observed directly using a high-speed video camera in a laboratory scale flotation column. Bubble trajectory, dimensions, velocity and size distribution were then determined through image analysis. The results indicated that the addition of biosurfactants had the same significant effects on bubble motion and size distribution as chemosynthetic surfactants. The biosurfactant effect on bubble behavior was also found to depend on their type and concentration. In general, the effect of tea saponin was stronger than another biosurfactant (rhamnolipid) used in the present study. The present findings implied that some biosurfactants like tea saponin can replace chemosynthetic surfactants in controlling bubble behavior in flotation operation. This will contribute to promoting the use of green environmentally friendly flotation agents in the separation industry.

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

    SciTech Connect

    Not Available

    1991-01-01

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

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

    PubMed

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

    2014-08-15

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

  4. Micro-agglomerate flotation for deep cleaning of coal. Quarterly progress report, July 1-September 30, 1996

    SciTech Connect

    Chander, S.; Hogg, R.

    1996-12-01

    The goals of this research program are to demonstrate the technical and economic feasibility of a micro-agglomerate flotation process and to establish the essential criteria for reagent selection and system design and operation. 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 mm in size) rather than individual coal particles (1-10 mm) the problems of froth overload and water/mineral carryover should be significantly alleviated.

  5. [Electro-flotation using in solid-liquid separation of activated sludge].

    PubMed

    Chen, Jin-Luan; Wan, Jing; Shi, Han-Chang

    2006-11-01

    The separation of suspended solids (SS) from activated sludge was carried out in an electro-flotation cell which has two sets of electrodes,three Ti/RuO2-IrO2-TiO2 anodes and three Ti screen cathodes. The effect of operating parameters on the performance of the electro-flotation system was examined. The parameters investigated were hydraulic retention time (HRT), current density, initial SS concentration and initial pH. The results show that electro-flotation cell is a unit of high performance in solid-liquid separation. HRT and current density are the main affecting factors. The removal ratio of SS increases with increment of HRT and current density; and it decreases with the increment of sludge loading. The pH value affects the size of tiny bubbles generated from water electrolysis and the character of sludge, but it has little effect on the removal of SS. The pH value is not need to be adjusted during the electro-flotation. Under the conditions with initial SS about 1 000 mg/L, HRT 20 min, a current density 5 mA/cm2 in contacting zone, a current density 2.5 mA/cm2 in separating zone, the removal ratio of SS can reach up to 97%, at this point, the electrolysis energy consumption is 0.4 - 0.5 (kW x h)/m3 wastewater. The water content of the sludge from electro-flotation is much lower than that from dissolved air flotation and secondary sedimentation tank, which has significant in the decrement and final disposal of the sludge.

  6. Hydrocarbon-oil encapsulated bubble flotation of fine coal. Technical progress report for the ninth quarter, October 1, 1992--December 31, 1992

    SciTech Connect

    Peng, F.F.

    1995-01-01

    A main portion of this reporting period has been consumed in the following tasks to establish the base line for hydrocarbon oil encapsulated bubble flotation: (1) to measure the residence time distribution and formulate the axial dispersion model of 1-in. I.D. flotation column, (2) to obtain the optimum operating conditions using three phase experiment design approach followed the fractional factorial design, (3) to develop the column scale-up procedure and formulate recovery predicting model for flotation column, (4) to apply the models developed to design a 3-in. ID flotation column and predicting the cleaning results, (5) to test the collector gasification system installed on the 3-in. I.D. flotation column for hydrocarbon-oil capsulated bubble flotation of fine coal. Column flotation of minus 47 {mu}m (-400 US sieve) Pittsburgh No. 8 seam coal was carried out to study the column scale-up procedure using one-inch column. The dispersion model of nonideal flow was applied to describe the hydrodynamic state within the column. This model may be used to predict the collection zone recovery of column flotation in scale-up procedure if the column flotation is a first-order rate process. Residence Time Distribution (RTD) data of the column flotation were measured to determine the parameters of the model. It was found that an empirical distribution, logarithmic normal distribution can describe the RTD curve well. The effects of operating variables and column geometry on the Peclet number, Pe, which measure the extent of axial dispersion were studied and an empirical expression of Pe was obtained. Using the dispersion model, the column flotation of fine coal recovery can be predicted.

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

    SciTech Connect

    Xie Hua; Huang Bo; Xia Qing

    1998-12-31

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

  8. 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.

  9. Experimental Air Pressure Tank Systems for Process Control Education

    ERIC Educational Resources Information Center

    Long, Christopher E.; Holland, Charles E.; Gatzke, Edward P.

    2006-01-01

    In process control education, particularly in the field of chemical engineering, there is an inherent need for industrially relevant hands-on apparatuses that enable one to bridge the gap between the theoretical content of coursework and real-world applications. At the University of South Carolina, two experimental air-pressure tank systems have…

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

    PubMed

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

    2006-01-01

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

  11. Determination of molybdenum (VI) in sea water with preliminary concentration by the method of ion flotation

    SciTech Connect

    Andreeva, I. Yu.; Drapchinskaya, O.L.; Lebedeva, L.I.

    1985-10-01

    The purpose of this paper is to assess the feasibility of using the method of ion flotation for the concentration of microamounts of molybdenum (VI) during determination in sea water. The ion flotation method is used for the purification of industrial sewage from the ions of nonferrous metals, including molybdenum (VI) with its content of up to 50 mg/liter. A 1.10/sup -4/M solution of sodium molybdate in 0.1M NaOH was used. The effect of different factors on the ion flotation process of molybdenum (VI) was investigated: pH of the solution, flotation times, concentrations of surface-active substances (SAS), molybdenum (IV), extraneous salts. Data presented show that the ion flotation method in conjunction with the photometric method of determining molybdenum with brompyrogallol red (BPR) and cetylpridinium chloride (CP) (limit of detection 0.02 micrograms/liter) allows the content of molybdenum (VI) in sea water to be established with sufficient reliability and reproducibility.

  12. 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...

  13. 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...

  14. 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...

  15. 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...

  16. 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...

  17. 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...

  18. 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...

  19. 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...

  20. 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...

  1. 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...

  2. 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...

  3. 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...

  4. 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...

  5. 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...

  6. 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...

  7. 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.

  8. 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...

  9. 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...

  10. 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...

  11. 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...

  12. 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...

  13. Combustion Technology for Incinerating Wastes from Air Force Industrial Processes.

    DTIC Science & Technology

    1984-02-01

    Conservation and Recovery Act and are properly disposed at cost to the Air Force. Onsite incineration with heat recovery is being considered as a...the heat released during thermal processing could reduce the costs of waste incineration. 0 * Normally, relatively small amounts of individual wastes...wastes. Task 3: Combustion Analysis. Determine and quantify the essential combustion parameters of industrial process wastes with respect to heat

  14. Microwave-assisted surface modification for the separation of polycarbonate from polymethylmethacrylate and polyvinyl chloride waste plastics by flotation.

    PubMed

    Huang, Luoluo; Wang, Hui; Wang, Chongqing; Zhao, Junyao; Zhang, Bo

    2017-03-01

    Microwave-assisted potassium permanganate modification (MPPM) was used for the flotation separation of polycarbonate (PC) from polyvinyl chloride (PVC) and polymethylmethacrylate (PMMA) waste plastics. The separation process was optimized by investigating the potassium permanganate concentration, treatment time, flotation time and frother concentration. MPPM selectively reduced the flotation recovery of PC. The optimum conditions were determined to be: potassium permanganate concentration, 2 mM/L; treatment time, 1 min; frother concentration, 17.57 g/L; and flotation time, 1 min. PC was efficiently separated from PVC and PMMA under the optimum conditions. The purity of the separated PC was 97.71%. The purity and recovery of PVC and PMMA were both >95%. The modification mechanism was investigated using the water contact angles, Fourier transform infrared spectrometry and scanning electron microscopy. This work provides technical insights into the industrial recycling of waste plastics.

  15. 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.

  16. 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.

  17. Process to manufacture effervescent tablets: air forced oven melt granulation.

    PubMed

    Yanze, F M; Duru, C; Jacob, M

    2000-12-01

    In the present study we apply melt granulation in an air forced oven, called "are forced oven melt granulation" to the single-stage manufacture of effervescent granules consisting of anhydrous citric acid (43.2%) and sodium bicarbonate (56.8%) in order to make tablets. This study established that process parameters such as concentration of PEG 6000, residence time in the air forced oven, fineness of PEG 6000, fineness of the initial effervescent mix and efficiency of two lubricants markedly influenced several granule and tablet characteristics. The granules ready to be compressed into tablets were stable for 7 days at 60% RH/18 degrees C. It is a dry, simple, rapid, effective, economical, reproducible process particularly well suited to the manufacture of effervescent granules which are easily compressed into effervescent tablets. Of all the formulations tested, only formulations B2 and E2 melt granulated for 30 minutes gave tablets which had optimum compression characteristics without processing problems during compression.

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

    SciTech Connect

    Carvalho, Teresa; Durao, Fernando; Ferreira, Celia

    2010-11-15

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

  19. Direct recovery of cyclodextringlycosyltransferase from Bacillus cereus using aqueous two-phase flotation.

    PubMed

    Lin, Yu Kiat; Show, Pau Loke; Yap, Yee Jiun; Tan, Chin Ping; Ng, Eng-Poh; Ariff, Arbakariya B; Mohamad Annuar, Mohamad Suffian B; Ling, Tau Chuan

    2015-12-01

    Purification of cyclodextrin glycosyl transferase (CGTase) from Bacillus cereus using polyethylene glycol (PEG)-potassium phosphates aqueous two-phase flotation (ATPF) system was studied in this paper. The effects of varying PEG molecular weight, tie-line length (TLL) value, volume ratio (VR), pH value, crude concentration and gas nitrogen flotation time were investigated. The optimal condition for purification of CGTase was attained at 18.0% (w/w) PEG 8000, 7.0% (w/w) potassium phosphates, VR of 3.0, 20% (w/w) crude load at pH 7, and 80 min nitrogen flotation time at a flow rate of 5 L/min. With this optimal condition, purification factor (PFT) of 21.8 and a yield (YT) of 97.1% were attained. CGTase was successfully purified in a single downstream processing step using the ATPF.

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

    PubMed

    Carvalho, Teresa; Durão, Fernando; Ferreira, Célia

    2010-11-01

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

  1. Materials, design and processing of air encapsulated MEMS packaging

    NASA Astrophysics Data System (ADS)

    Fritz, Nathan T.

    This work uses a three-dimensional air cavity technology to improve the fabrication, and functionality of microelectronics devices, performance of on-board transmission lines, and packaging of micro-electromechanical systems (MEMS). The air cavity process makes use of the decomposition of a patterned sacrificial polymer followed by the diffusion of its by-products through a curing polymer overcoat to obtain the embedded air structure. Applications and research of air cavities have focused on simple designs that concentrate on the size and functionality of the particular device. However, a lack of guidelines for fabrication, materials used, and structural design has led to mechanical stability issues and processing refinements. This work investigates improved air gap cavities for use in MEMS packaging processes, resulting in fewer fabrication flaws and lower cost. The identification of new materials, such as novel photo-definable organic/inorganic hybrid polymers, was studied for increased strength and rigidity due to their glass-like structure. A novel epoxy polyhedral oligomeric silsesquioxane (POSS) material was investigated and characterized for use as a photodefineable, permanent dielectrics with improved mechanical properties. The POSS material improved the air gap fabrication because it served as a high-selectivity etch mask for patterning sacrificial materials as well as a cavity overcoat material with improved rigidity. An investigation of overcoat thickness and decomposition kinetics provided a fundamental understanding of the properties that impart mechanical stability to cavities of different shape and volume. Metallization of the cavities was investigated so as to provide hermetic sealing and improved cavity strength. The improved air cavity, wafer-level packages were tested using resonator-type devices and chip-level lead frame packaging. The air cavity package was molded under traditional lead frame molding pressures and tested for mechanical

  2. 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.

  3. A review of factors that affect contact angle and implications for flotation practice.

    PubMed

    Chau, T T; Bruckard, W J; Koh, P T L; Nguyen, A V

    2009-09-30

    Contact angle and the wetting behaviour of solid particles are influenced by many physical and chemical factors such as surface roughness and heterogeneity as well as particle shape and size. A significant amount of effort has been invested in order to probe the correlation between these factors and surface wettability. Some of the key investigations reported in the literature are reviewed here. It is clear from the papers reviewed that, depending on many experimental conditions such as the size of the surface heterogeneities and asperities, surface cleanliness, and the resolution of measuring equipment and data interpretation, obtaining meaningful contact angle values is extremely difficult and such values are reliant on careful experimental control. Surface wetting behaviour depends on not only surface texture (roughness and particle shape), and surface chemistry (heterogeneity) but also on hydrodynamic conditions in the preparation route. The inability to distinguish the effects of each factor may be due to the interplay and/or overlap of two or more factors in each system. From this review, it was concluded that: Surface geometry (and surface roughness of different scales) can be used to tune the contact angle; with increasing surface roughness the apparent contact angle decreases for hydrophilic materials and increases for hydrophobic materials. For non-ideal surfaces, such as mineral surfaces in the flotation process, kinetics plays a more important role than thermodynamics in dictating wettability. Particle size encountered in flotation (10-200 microm) showed no significant effect on contact angle but has a strong effect on flotation rate constant. There is a lack of a rigid quantitative correlation between factors affecting wetting, wetting behaviour and contact angle on minerals; and hence their implication for flotation process. Specifically, universal correlation of contact angle to flotation recovery is still difficult to predict from first principles

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

    SciTech Connect

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

    1995-02-16

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

  5. A modified release analysis procedure using advanced froth flotation mechanisms: Technical report, March 1, 1996-May 31, 1996

    SciTech Connect

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

    1997-04-01

    Recent studies indicate that the optimum separation performances achieved by multiple stage cleaning using various column flotation technologies and single stage cleaning using a Packed-Flotation Column are superior to the performance achieved by the traditional release procedure, especially in terms of pyritic sulfur rejection. This superior performance is believed to be the result of the advanced flotation mechanisms provided by column flotation technologies. Thus, the objective of this study is to develop a suitable process utilizing the advanced froth flotation mechanisms to characterize the true flotation response of a coal sample. Work in this reporting period concentrated on developing a modified coal flotation characterization procedure, termed as Advanced Flotation Washability (AFW) technique. The new apparatus used for this procedure is essentially a batch operated packed-column device equipped with a controlled wash water system. Several experiments were conducted using the AFW technique on a relatively high sulfur, -100 mesh Illinois No. 5 run-of-mine coal sample collected from a local coal preparation plant. Similar coal characterization experiments were also conducted using the traditional release and tree analysis procedures. The best performance curve generated using the AFW technique was found to be superior to the optimum curve produced by the traditional procedures. For example, at a combustible recovery of 80%, a 19% improvement in the reduction of the pyritic sulfur content was achieved by the AFW method while the ash reduction was also enhanced by 4%. Several tests are on-going to solidify the AFW procedure and verify the above finding by conducting Anova analyses to evaluate the repeatability of the AFW method and the statistical significance of the difference in the performance achieved from the traditional and modified coal characterization procedures.

  6. A modified release analysis procedure using advanced froth flotation mechanisms. Final technical report, September 1, 1995--August 31, 1996

    SciTech Connect

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

    1997-05-01

    Recent studies indicate that the optimum separation performances achieved by multiple stage cleaning using various column flotation technologies and single stage cleaning using a Packed-Flotation Column are superior to the performance achieved by the traditional release procedure, especially in terms of pyritic sulfur rejection. This superior performance is believed to be the result of the advanced flotation mechanisms provided by column flotation technologies. Thus, the objective of this study was to develop a suitable process utilizing the advanced froth flotation mechanisms to characterize the true flotation response of a coal sample. This investigation resulted in the development of a modified coal flotation characterization procedure, termed as the Advanced Flotation Washability (AFW) technique. The apparatus used for this procedure is a batch operated Packed-Column device which provides enhanced selectivity due to a plug-flow environment and a deep froth zone. The separation performance achieved by the AFW procedure was found to be superior to those produced by the conventional tree and release procedures for three nominally -100 mesh coal samples and two micronized samples. The largest difference in separation performance was obtained on the basis of product pyritic sulfur content. A comparison conducted between the AFW and the release procedures at an 80% recovery value showed that the AFW technique provided a 19% improvement in the reduction of pyritic sulfur. For an Illinois No. 5 coal sample, this improvement corresponded to a reduction in pyritic sulfur content from 1.38% to 0.70% or a total rejection of 66%. Micronization of the sample improved the pyritic sulfur rejection to 85% while rejecting 92% of the ash-bearing material. In addition, the separation performance provided by the AFW procedure was superior to that obtained from multiple cleaning stages using a continuous Packed-Column under both kinetic and carrying-capacity limiting conditions.

  7. Word Processing: The Air Force Administrators’ Handbook

    DTIC Science & Technology

    1979-05-01

    LEYEL > WORD PROCESSING ERRORCOP Qis 4 pL THE? ~ AIR FORCE ADMINISTRATOR$.! ’--s..HANDBOOK 400 Zi LUPRED F~ Fiir [rLT The views and opinions...INSTRUCTIONSBEFORE COMPLETING FORM I. REPORT NUMBER .O.Vk Er.;. NO. R CIPIENT’S CATALOG NUMBER 4. TITLE (and Subtitle) S. ’TYPE OF REPORT & PERIOD COVERED WORD ...Accession No. ADB 040882 L 19. KEY WORDS (Continue on reverse aide it necessary and identify by block number) Administration / / Administrative Systems

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

    SciTech Connect

    Meryem Ozmak; Zeki Aktas

    2006-05-15

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

  9. Removal of pyrite and trace elements from waste coal by dissolved-CO{sub 2} flotation and chelating agents. Final technical report, September 1, 1993--August 31, 1994

    SciTech Connect

    Shiao, S.Y.; Ho, K.

    1994-12-31

    The overall objective of this project was to use ultrafine bubbles generated by dissolved C0{sub 2} to recover useable fuel, and reject pyrite and other minerals from a waste coal in flotation. In addition, a chelating agent was used to remove trace metals from the froth products. Illinois No. 6 waste coal obtained from a refuse thickener of a coal cleaning circuit was used as the feed in flotation. The as-received waste coal had a top size of 2400 microns. The waste coal was ground to {minus}75 microns ({minus}200 mesh) and {minus}44 microns ({minus}325 mesh). The as-received and the ground waste coal samples were subjected to flotation. Dissolved-CO{sub 2} flotation tests were performed mainly in a 3-inch diameter by 8 feet high packed column under various test conditions. Some tests were also performed in a 2-inch diameter microbubble column for comparison. The flotation performance of the waste coal in the microbubble column was higher than that for the packed column. The packing in the packed column hindered the coal flotation. The separation efficiency of the ground coal was less than that for the asreceived coal. Flotation of the waste coal was also performed in the packed column using coarser bubbles generated by dispersed C0{sub 2} and air. The separation efficiency of the ground waste coal of 44 microns top size was higher than that for dissolved-CO{sub 2} flotation. Additives were used to modify the waste coal surfaces. Triton-X 100, a nonionic surfactant and EDTA, a chelating agent, increased the separation efficiency of the waste coal.Most of the trace metals in coal were reduced in different degrees by flotation. Triton X-100 or EDTA enhanced removal of chromium, nickel, and selenium. Applying EDTA to the froth products further removed lead significantly.

  10. 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.

  11. 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.

  12. In situ aeration: Air sparging, bioventing, and related remediation process

    SciTech Connect

    Hinchee, R.E.; Miller, R.N.; Johnson, P.C.

    1995-12-31

    This volume is part of a ten volume set of papers derived from the Third International In Situ and On-Site Bioreclamation Symposium which was held in San Diego, California, in April 1995. The purpose of the conference was to provide a multidisciplinary forum for exchange of state-of-the-art information on bioremediation. This volume focuses on the use of air sparging, bioventing, and other aeration processes to remediate hydrocarbon-contaminated soils and groundwater. Individual papers have been processed separately for inclusion in the appropriate data bases.

  13. 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.

  14. Beneficiation of oil shales by froth flotation and heavy media separation: Volume 1, Summary and main report: Final report

    SciTech Connect

    Krishnan, G.N.

    1987-08-01

    An experimental program was conducted to determine the feasibility of upgrading US oil shales by froth flotation and heavy media separation (HMS) techniques. The results of the experiments along with other available information were used to analyze technical and economic aspects of a process scheme in which a mined shale will be beneficiated and then retorted. The experimental program and economic analysis indicate that whereas beneficiation processes do not offer any clear incentive at the current time, these processes may become essential when lean deposits are to be exploited. Froth flotation process appears to be significantly superior than the HMS process. The significant deterrents to developing a beneficiation process based on froth flotation are grinding costs and lack of suitable retorts. 15 refs., 13 figs., 13 tabs.

  15. Supporting the Future Air Traffic Control Projection Process

    NASA Technical Reports Server (NTRS)

    Davison, Hayley J.; Hansman, R. John, Jr.

    2002-01-01

    In air traffic control, projecting what the air traffic situation will be over the next 30 seconds to 30 minutes is a key process in identifying conflicts that may arise so that evasive action can be taken upon discovery of these conflicts. A series of field visits in the Boston and New York terminal radar approach control (TRACON) facilities and in the oceanic air traffic control facilities in New York and Reykjavik, Iceland were conducted to investigate the projection process in two different ATC domains. The results from the site visits suggest that two types of projection are currently used in ATC tasks, depending on the type of separation minima and/or traffic restriction and information display used by the controller. As technologies improve and procedures change, care should be taken by designers to support projection through displays, automation, and procedures. It is critical to prevent time/space mismatches between interfaces and restrictions. Existing structure in traffic dynamics could be utilized to provide controllers with useful behavioral models on which to build projections. Subtle structure that the controllers are unable to internalize could be incorporated into an ATC projection aid.

  16. Flotation and Survival Equipment Studies

    DTIC Science & Technology

    1978-01-01

    resubmerged, made a maximum exhalation, and turned the air control valve to the spirometer position. The subject made three maximum inhalations and...exhalations and then turned the air control valve from the spirometer to snorkel position. After the final weight was obtained, the subject emerged from the...recording on the spirometer drum. The residual volume (VR) and body density (DI) were calculated as follows: VITO 22 E VCO iV ANGLA =0 -o 90 VINTIC,. _ _j It

  17. Mathematical Modeling and Computer Simulation of Molten Aluminum Purification by Flotation in Stirred Reactor

    NASA Astrophysics Data System (ADS)

    Mirgaux, O.; Ablitzer, D.; Waz, E.; Bellot, J. P.

    2009-06-01

    The removal of inclusions by flotation in mechanically agitated vessels is widely used in liquid aluminum treatments. Originating from different sources (oxide skins, refractory, or recycling wastes), inclusions may have disastrous repercussions such as deterioration of the physical properties of the cast products or difficulties during forging processes. With the aim of both a better understanding of the physical processes acting during flotation and the optimization of the refining process, a mathematical modeling of the behavior of the population of inclusions has been set up. Transport phenomena, agglomeration of inclusions, and flotation are considered here. The model combines population balance with convective transport of the inclusions, in order to calculate the time evolution of the inclusion size distribution. An operator-splitting technique is employed to solve the coupled population balance equation (PBE) and the transport equation. The transport equation is solved using a finite volume technique associated with a total variation diminishing scheme, whereas the PBE resolution relies on the fixed pivot technique developed by Kumar and Ramkrishna. A laboratory-scale flotation vessel is modeled and the results of a two-dimensional (2-D) simulation are presented.

  18. Generation of low-temperature air plasma for food processing

    NASA Astrophysics Data System (ADS)

    Stepanova, Olga; Demidova, Maria; Astafiev, Alexander; Pinchuk, Mikhail; Balkir, Pinar; Turantas, Fulya

    2015-11-01

    The project is aimed at developing a physical and technical foundation of generating plasma with low gas temperature at atmospheric pressure for food industry needs. As known, plasma has an antimicrobial effect on the numerous types of microorganisms, including those that cause food spoilage. In this work an original experimental setup has been developed for the treatment of different foods. It is based on initiating corona or dielectric-barrier discharge in a chamber filled with ambient air in combination with a certain helium admixture. The experimental setup provides various conditions of discharge generation (including discharge gap geometry, supply voltage, velocity of gas flow, content of helium admixture in air and working pressure) and allows for the measurement of the electrical discharge parameters. Some recommendations on choosing optimal conditions of discharge generation for experiments on plasma food processing are developed.

  19. Effects of air flow directions on composting process temperature profile

    SciTech Connect

    Kulcu, Recep; Yaldiz, Osman

    2008-07-01

    In this study, chicken manure mixed with carnation wastes was composted by using three different air flow directions: R1-sucking (downward), R2-blowing (upward) and R3-mixed. The aim was to find out the most appropriate air flow direction type for composting to provide more homogenous temperature distribution in the reactors. The efficiency of each aeration method was evaluated by monitoring the evolution of parameters such as temperature, moisture content, CO{sub 2} and O{sub 2} ratio in the material and dry material losses. Aeration of the reactors was managed by radial fans. The results showed that R3 resulted in a more homogenous temperature distribution and high dry material loss throughout the composting process. The most heterogeneous temperature distribution and the lowest dry material loss were obtained in R2.

  20. Process study and exergy analysis of a novel air separation process cooled by LNG cold energy

    NASA Astrophysics Data System (ADS)

    Xu, Wendong; Duan, Jiao; Mao, Wenjun

    2014-02-01

    In order to resolve the problems of the current air separation process such as the complex process, cumbersome operation and high operating costs, a novel air separation process cooled by LNG cold energy is proposed in this paper, which is based on high-efficiency heat exchanger network and chemical packing separation technology. The operating temperature range of LNG cold energy is widened from 133K-203K to 113K-283K by high-efficiency heat exchanger network and air separation pressure is declined from 0.5MPa to about 0.35MPa due to packing separation technology, thereby greatly improve the energy efficiency. Both the traditional and novel air separation processes are simulated with air handling capacity of 20t·h-1. Comparing with the traditional process, the LNG consumption is reduced by 44.2%, power consumption decrease is 211.5 kWh per hour, which means the annual benefit will be up to 1.218 million CNY. And the exergy efficiency is also improved by 42.5%.

  1. Ozone Generation in Air during Electron Beam Processing

    NASA Astrophysics Data System (ADS)

    Cleland, Marshall R.; Galloway, Richard A.

    Ozone, the triatomic form of oxygen, can be generated by exposing normal diatomic oxygen gas to energetic electrons, X-rays, nuclear gamma rays, short-wavelength ultraviolet radiation (UV) and electrical discharges. Ozone is toxic to all forms of life, and governmental regulations have been established to protect people from excessive exposures to this gas. The human threshold limit values (TLV) vary from 60 to 100 parts per billion (ppb) in air, depending on the agency or country involved. Much higher concentrations can be produced inside industrial electron beam (EB) facilities, so methods for ozone removal must be provided. Equations for calculating the ozone yield vs absorbed energy, the production rate vs absorbed power, and the concentration in the air of an EB facility are presented in this paper. Since the production rate and concentration are proportional to the EB power dissipated in air, they are dependent on the design and application of the irradiation facility. Examples of these calculations are given for a typical EB process to cross-link insulated electrical wire or plastic tubing. The electron energy and beam power are assumed to be 1.5 MeV and 75 kW.

  2. Corrosion study in the chemical air separation (MOLTOX trademark ) process

    SciTech Connect

    Kang, Doohee; Wong, Kai P.; Archer, R.A.; Cassano, A.A.

    1988-12-01

    This report presents the results of studies aimed at solving the corrosion problems encountered during operation of the MOLTOX{trademark} pilot plant. These studies concentrated on the screening of commercial and developmental alloys under conditions simulating operation conditions in this high temperature molten salt process. Process economic studies were preformed in parallel with the laboratory testing to ensure that an economically feasible solution would be achieved. In addition to the above DOE co-funded studies, Air Products and Chemicals pursued proprietary studies aimed at developing a less corrosive salt mixture which would potentially allow the use of chemurgically available alloys such as stainless steels throughout the system. These studies will not be reported here; however, the results of corrosion tests in the new less corrosive salt mixtures are reported. Because our own studies on salt chemistry impacts heavily on the overall process and thereby has an influence on the experimental work conducted under this contract, some of the studies discussed here were impacted by our own proprietary data. Therefore, the reasons behind some of the experiments presented herein will not be explained because that information is proprietary to Air Products. 14 refs., 42 figs., 21 tabs.

  3. 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.

  4. A modified release analysis procedure using advanced froth flotation mechanisms. Technical report, September 1--November 30, 1995

    SciTech Connect

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

    1995-12-31

    The objective of this study is to reinvestigate the release analysis procedure, which is traditionally conducted using a laboratory Denver cell, and to develop a modified process that can be used for all froth flotation technologies. Recent studies have found that the separation performance achieved by multiple stage cleaning and, in some cases, single stage cleaning using column flotation is superior to the performance achieved by the traditional release procedure. These findings are a result of the advanced flotation mechanisms provided by column flotation, which will be incorporated into a modified release analysis procedure developed in this study. A fundamental model of an open column has been developed which incorporates the effects of system hydrodynamics, froth drop-back, selective and non-selective detachment, operating parameters, feed solids content, and feed component flotation kinetics. Simulation results obtained during this reporting period indicate that the ultimate separation that can be achieved by a column flotation process can only be obtained in a single cleaning stage if the detachment mechanism in the froth phase is highly selective, which does not appear to occur in practice based on experimental results. Two to three cleaning stages were found to be required to obtain the ultimate performance if non-selective detachment or kinetic limiting conditions are assumed. this simulated finding agrees well with the experimental results obtained from the multiple stage cleaning of an Illinois No. 5 seam coal using the Packed-Column. Simulated results also indicate that the separation performance achieved by column flotation improves with increasing feed solids content after carrying-capacity limiting conditions are realized. These findings will be utilized in the next reporting period to modify the traditional release analysis procedure.

  5. Air

    MedlinePlus

    ... do to protect yourself from dirty air . Indoor air pollution and outdoor air pollution Air can be polluted indoors and it can ... this chart to see what things cause indoor air pollution and what things cause outdoor air pollution! Indoor ...

  6. 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.

  7. Micro-agglomerate flotation for deep cleaning of coal. Quarterly progress report, April 1--June 30, 1993

    SciTech Connect

    Chander, S.; Hogg, R.

    1993-07-01

    The goals of this research program are to demonstrate the technical and economic feasibility of a micro-agglomerate flotation process and to establish the essential criteria for reagent selection and system design and operation. The development of practical technologies for the deep cleaning of coal has been seriously hampered by the problems of carrying out efficient coal/mineral separations at the very fine sizes (often finer than 10 {mu}m) needed to achieve adequate liberation of the mineral matter from the coal matrix. It is generally recognized that surface-based separation processes such as froth flotation or selective agglomeration offer considerable potential for such applications but there remain many problems in obtaining the required selectivity with acceptable recovery of combustible matter. In froth flotation, selectivity is substantially reduced at fine sizes due, primarily, to overloading of the froth phase which leads to excessive carryover of water and entrained mineral matter. Oil agglomeration, on the other hand, can provide good selectivity at low levels of oil addition but the agglomerates tend to be too fragile for separation by the screening methods normally used. The addition of larger amounts of oil can yield large, strong agglomerates which are easily separated but the selectivity is reduced and reagent costs can become excessive. 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.

  8. 32 CFR 806.29 - Administrative processing of Air Force FOIA requests.

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ... 32 National Defense 6 2012-07-01 2012-07-01 false Administrative processing of Air Force FOIA... FORCE ADMINISTRATION AIR FORCE FREEDOM OF INFORMATION ACT PROGRAM § 806.29 Administrative processing of Air Force FOIA requests. (a) This section is a checklist format of processing steps and...

  9. 32 CFR 806.29 - Administrative processing of Air Force FOIA requests.

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... 32 National Defense 6 2011-07-01 2011-07-01 false Administrative processing of Air Force FOIA... FORCE ADMINISTRATION AIR FORCE FREEDOM OF INFORMATION ACT PROGRAM § 806.29 Administrative processing of Air Force FOIA requests. (a) This section is a checklist format of processing steps and...

  10. 32 CFR 806.29 - Administrative processing of Air Force FOIA requests.

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... 32 National Defense 6 2013-07-01 2013-07-01 false Administrative processing of Air Force FOIA... FORCE ADMINISTRATION AIR FORCE FREEDOM OF INFORMATION ACT PROGRAM § 806.29 Administrative processing of Air Force FOIA requests. (a) This section is a checklist format of processing steps and...

  11. 32 CFR 806.29 - Administrative processing of Air Force FOIA requests.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... 32 National Defense 6 2010-07-01 2010-07-01 false Administrative processing of Air Force FOIA... FORCE ADMINISTRATION AIR FORCE FREEDOM OF INFORMATION ACT PROGRAM § 806.29 Administrative processing of Air Force FOIA requests. (a) This section is a checklist format of processing steps and...

  12. 32 CFR 806.29 - Administrative processing of Air Force FOIA requests.

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... 32 National Defense 6 2014-07-01 2014-07-01 false Administrative processing of Air Force FOIA... FORCE ADMINISTRATION AIR FORCE FREEDOM OF INFORMATION ACT PROGRAM § 806.29 Administrative processing of Air Force FOIA requests. (a) This section is a checklist format of processing steps and...

  13. Investigation of ammonia air-surface exchange processes in a ...

    EPA Pesticide Factsheets

    Recent assessments of atmospheric deposition in North America note the increasing importance of reduced (NHx = NH3 + NH4+) forms of nitrogen (N) relative to oxidized forms. This shift in in the composition of inorganic nitrogen deposition has both ecological and policy implications. Deposition budgets developed from inferential models applied at the landscape scale, as well as regional and global chemical transport models, indicate that NH3 dry deposition contributes a significant portion of inorganic N deposition in many areas. However, the bidirectional NH3 flux algorithms employed in these models have not been extensively evaluated for North American conditions (e.g, atmospheric chemistry, meteorology, biogeochemistry). Further understanding of the processes controlling NH3 air-surface exchange in natural systems is critically needed. Based on preliminary results from the Southern Appalachian Nitrogen Deposition Study (SANDS), this presentation examines processes of NH3 air-surface exchange in a deciduous montane forest at the Coweeta Hydrologic Laboratory in western North Carolina. A combination of measurements and modeling are used to investigate net fluxes of NH3 above the forest and sources and sinks of NH3 within the canopy and forest floor. Measurements of biogeochemical NH4+ pools are used to characterize emission potential and NH3 compensation points of canopy foliage (i.e., green vegetation), leaf litter, and soil and their relation to NH3 fluxes

  14. [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.

  15. [PAH removal from black sludge from aluminium industry by flotation using non-ionic surfactants].

    PubMed

    Dhenain, A; Mercier, G; Blais, J F; Bergeron, M

    2006-09-01

    The valorization of black sludge is an environmental problem of the aluminium industry because of Polycyclic Aromatic Hydrocarbon (PAH), fluoride and alumina contents. A soil washing operated in a cell flotation with non-ionic surfactants (Brij 35, Igepal CA-720, Triton X-100, Tween 80) at different concentrations has been tested in order to remove the PAH (benzo(a)anthracene, benzo(a)pyrene, benzo(b)fluoranthene, benzo(j)fluoranthene, benzo(k)fluoranthene, fluoranthene) detected in black sludge. The Tween 80 at 0.5% gave the best results with PAH removal rates between 35 and 50%. These percentages remain low due to the presence in large quantity of fine solid particles (45%) in the PAH concentrate produced by the flotation process. The substitution of the cell flotation by a column flotation allowed the reduction of this problem. Thus, the PAH removal rates reached 60%. This removal yield has been obtained with the lowest wash water flow-rate (150 ml min(-1)) and pulp total solids (10% p p(-1)) tested.

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

    PubMed

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

    2015-01-01

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

  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. Hydrocarbon-oil encapsulate bubble flotation of fine coal. Technical progress report for the seventh quarter, April 1, 1992--June 30, 1992

    SciTech Connect

    Peng, F.F.

    1995-01-01

    This reporting period has been devoted in the study of lyophobic characteristics of six ranks of coals which were selected for the study of hydrocarbon-oil encapsulated bubble flotation of fine coals. Additionally, the coal particle surfaces treated with collector using various collector dispersion techniques are also tested in the film flotation. The experimental techniques and instruments used for the measurement of hydrophobicity and floatability of fine coals include (1) Film flotation, (2) Induction timer, (3) Hallimond cell and (4) stirred tank flotation cell are given. The static float and sink test known as the film flotation process were used to characterize the wetting behaviors of the fine coal surfaces. In this flotation technique, the coal particles were tested on the interface of a series of aqueous methanol solution of different surface tensions. The distributions of lyophobic particles as the function of the wetting surface tensions of the particles were obtained. From the frequency distribution of critical surface tensions, the parameters such as the mean critical surface tension, dispersion and average contact angle for the coal particle surfaces were calculated. These parameters characterized the heterogeneity of the coal particle surfaces and correlated well with the induction time, floatability and flotation response data obtained from Hallimond cell and a stirred tank cell. Furthermore, the frequency distributions of hydrophobic surface sites of the particle surfaces were also derived from the results of film flotation tests. These frequency distributions were extended to interpret and predict the flotation rates and recoveries for the coal samples without treating and coal samples treated with collector using various collector dispersion techniques.

  19. 32 CFR 806.27 - Samples of Air Force FOIA processing documents.

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ... 32 National Defense 6 2012-07-01 2012-07-01 false Samples of Air Force FOIA processing documents. 806.27 Section 806.27 National Defense Department of Defense (Continued) DEPARTMENT OF THE AIR FORCE ADMINISTRATION AIR FORCE FREEDOM OF INFORMATION ACT PROGRAM § 806.27 Samples of Air Force FOIA...

  20. 32 CFR 806.27 - Samples of Air Force FOIA processing documents.

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... 32 National Defense 6 2014-07-01 2014-07-01 false Samples of Air Force FOIA processing documents. 806.27 Section 806.27 National Defense Department of Defense (Continued) DEPARTMENT OF THE AIR FORCE ADMINISTRATION AIR FORCE FREEDOM OF INFORMATION ACT PROGRAM § 806.27 Samples of Air Force FOIA...

  1. 32 CFR 806.27 - Samples of Air Force FOIA processing documents.

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... 32 National Defense 6 2013-07-01 2013-07-01 false Samples of Air Force FOIA processing documents. 806.27 Section 806.27 National Defense Department of Defense (Continued) DEPARTMENT OF THE AIR FORCE ADMINISTRATION AIR FORCE FREEDOM OF INFORMATION ACT PROGRAM § 806.27 Samples of Air Force FOIA...

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

    PubMed

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

    2007-08-25

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

  3. Distribution of chemical elements in attic dust as reflection of their geogenic and anthropogenic sources in the vicinity of the copper mine and flotation plant.

    PubMed

    Balabanova, Biljana; Stafilov, Trajče; Sajn, Robert; Bačeva, Katerina

    2011-08-01

    The main aim of this article was to assess the atmospheric pollution with heavy metals due to copper mining Bučim near Radoviš, the Republic of Macedonia. The open pit and mine waste and flotation tailings are continually exposed to open air, which leads to winds carrying the fine particles into the atmosphere. Samples of attic dust were examined as historical archives of mine emissions, with the aim of elucidating the pathways of pollution. Dust was collected from the attics of 29 houses, built between 1920 and 1970. Nineteen elements (Ag, Al, As, Ba, Ca, Cd, Co, Cr, Cu, Li, Fe, K, Mg, Mn, Na, Ni, Pb, Sr, and Zn) were analyzed by atomic emission spectrometry with inductively coupled plasma. The obtained values of the investigated elements in attic dust samples were statistically processed using nonparametric and parametric analysis. Factor analysis revealed three factors governing the source of individual chemical elements. Two of them grouping Ca, Li, Mg, Mn, and Sr (Factor 1) and Co, Cr, and Ni (Factor 2) can be characterized as geogenic. The third factor grouping As, Cu, and Pb is anthropogenic and mirrors dust fallout from mining operation and from flotation tailings. Maps of areal deposition were prepared for this group of elements, from which correlation of these anthropogenic born elements was confirmed.

  4. Value enhancement of olivine process dust through air classification

    NASA Astrophysics Data System (ADS)

    Kleiv, R. A.

    2012-03-01

    As a result of the production of dry olivine sand products at A/S Olivin's production plant at Åheim in western Norway, an annual quantity of some 20000-30000 t of process dust is produced. The bulk of this material is currently being sold as a slag conditioner at a relatively low price; hence, alternative uses of the process dust are now being sought. Information regarding the chemical composition of the material as a function of particle size facilitates product modifications through exclusion or mixing of individual size fractions. This paper demonstrates how such information can be obtained from air classification experiments when these are combined with chemical analysis of the produced size fractions. The classification and subsequent analysis of the olivine process dust revealed that the finer size fractions had high loss on ignition (LOI) values and were relatively low in MgO when compared with the bulk analysis. Removal of the finer fractions resulted in a remaining coarse product of significantly higher quality. The coarse material could be used as a raw material for further processing; it could be recycled or it could constitute a new product in itself.

  5. Evaluation of rhamnolipid (RL) as a biosurfactant for the removal of chromium from aqueous solutions by precipitate flotation.

    PubMed

    Salmani Abyaneh, Ali; Fazaelipoor, Mohammad Hassan

    2016-01-01

    Rhamnolipid (RL) is a biosurfactant which is produced by the bacterial species Pseudomonas aeruginosa. Although applications of this material have been examined in various fields, its applications in the flotation of heavy metals remain to be explored. In this research, rhamnolipid was applied as a collector in the flotation of Cr(III) from aqueous solutions. FeSO4 was used for the precipitation of Cr(VI) to Cr(III) which was subsequently removed by flotation. A two level full factorial design (with center points) was used to evaluate the effects of pH, air flow rate, RL/Cr and Fe/Cr molar ratios on the performance of the flotation system. The results showed that the biosurfactant was highly effective in the removal of chromium, and all of the factors had significant effects on the flotation performance. The chromium removal efficiencies of greater than 95% were obtained with the initial chromium concentration of 40 ppm within 5 min. Kinetic studies showed that a first order kinetic model was appropriate to describe the precipitate flotation of Cr(III) using rhamnolipid as a collector. The interference of NaCl, CaCl2, CaSO4, and CaCO3 on the Cr removal was also investigated, and it was demonstrated that CaSO4 and CaCO3 as sparingly water soluble salts, and CaCl2 as a contributor to water hardness had significant negative impacts on Cr removal efficiency of rhamnolipid.

  6. 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.

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

    PubMed

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

    2013-12-01

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

  8. 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

  9. Hydrocarbon-oil encapsulate bubble flotation of fine coal. Technical progress report for the eighth quarter, July 1, 1992--September 30, 1992

    SciTech Connect

    Peng, F.F.

    1995-01-01

    A portion of this reporting period has been consumed in the following tasks: (1) development of air-water-frother sparging system using an assemble of two sets of atomizers; (2) conducting the column flotation tests followed 2{sup 6} {times} 1/4 fractional factorial design; (3) to develop a collector gasifier system for formation of hydrocarbon-oil encapsulated bubbles. To effectively remove sulfur and mineral matters from coal, the coal particles must be ground to minus 75 {mu}m (minus 200 U.S. sieve) or less to liberate the pyrite and mineral matters from the coal matrix. As reported in a previous report (Fifth Quarterly report), in order to effectively reduce ash content in fine clean coal products using a 3-in. flotation column, the height of the column must be increased to increase the depth of the frother and the residence time of coal particles in the flotation column. In this study, a series of column flotation tests were conducted on freshly ground minus 75 {mu}m Upper Freeport seam coal. The flotation column is equipped with froth washing device as well as two sets of atomizers for sparging the air-water and frother mixture. The operation of column flotation involves the multiplicity of control variables. Thus, three phases of work plan were used to minimize the number of tests. In this report, the results of column flotation tests obtained in the third phase of the experiment work are reported. The column flotation is capable of achieving 90 percent or more of combustible recovery and 70 percent or more of ash rejection from the raw coal contained 20 percent or greater ash content. The main objectives of this reporting period are: (1) to establish a test procedure, and to determine the optimal height of flotation column and operating conditions for cleaning minus 75 {mu}m Upper Freeport seam coal, and (2) to extend the test procedure and the operating conditions established to clean various seam coals using a hydrocarbon-oil encapsulated bubble flotation.

  10. Wastewater treatment using flocculation, coagulation, and flotation. (Latest citations from the NTIS bibliographic database). Published Search

    SciTech Connect

    1995-12-01

    The bibliography contains citations concerning the design, development, and evaluation of flocculation coagulation and flotation processes for the treatment of sewage and industrial wastes. Citations examine technology requirements and limitations, activated sludge and anaerobic processes, chlorination, runoff pollution control, wastewater recycling and reuse, and materials recovery.(Contains 50-250 citations and includes a subject term index and title list.) (Copyright NERAC, Inc. 1995)

  11. Wastewater treatment using flocculation, coagulation, and flotation. (Latest citations from the NTIS bibliographic database). Published Search

    SciTech Connect

    1996-11-01

    The bibliography contains citations concerning the design, development, and evaluation of flocculation coagulation and flotation processes for the treatment of sewage and industrial wastes. Citations examine technology requirements and limitations, activated sludge and anaerobic processes, chlorination, runoff pollution control, wastewater recycling and reuse, and materials recovery.(Contains 50-250 citations and includes a subject term index and title list.) (Copyright NERAC, Inc. 1995)

  12. Fact Sheet - Final Air Toxics Rule for Gold Mine Ore Processing and Production

    EPA Pesticide Factsheets

    Fact sheet summarizing main points of National Emissions Standards for Hazardous Air Pollutants for gold ore processing and production facilities, the seventh largest source of mercury air emission in the United States.

  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. 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...

  15. 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...

  16. 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...

  17. 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...

  18. 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...

  19. 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...

  20. 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...

  1. 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...

  2. 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...

  3. Wastewater treatment using flocculation, coagulation, and flotation. (Latest citations from the NTIS bibliographic database). NewSearch

    SciTech Connect

    Not Available

    1994-10-01

    The bibliography contains citations concerning the design, development, and evaluation of flocculation coagulation and flotation processes for the treatment of sewage and industrial wastes. Citations examine technology requirements and limitations, activated sludge and anaerobic processes, chlorination, runoff pollution control, wastewater recycling and reuse, and materials recovery. (Contains 250 citations and includes a subject term index and title list.)

  4. 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.

  5. Froth flotation of oil-bearing metal sulfide wastes

    SciTech Connect

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

    1991-01-01

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

  6. Mobile Air Monitoring Data Processing Strategies and Effects on Spatial Air Pollution Trends

    EPA Science Inventory

    The collection of real-time air quality measurements while in motion (i.e., mobile monitoring) is currently conducted worldwide to evaluate in situ emissions, local air quality trends, and air pollutant exposure. This measurement strategy pushes the limits of traditional data an...

  7. Wintertime air-sea interaction processes across the Gulf Stream

    NASA Astrophysics Data System (ADS)

    Bane, John M.; Osgood, Kenric E.

    1989-08-01

    Aircraft, buoy and satellite measurements have been used to study the wintertime air-sea interaction processes across the Gulf Stream during January 25-30, 1986. The turbulent flux regime in the marine atmospheric boundary layer exhibited considerable spatial and temporal variability during this 6-day period, which was related to both the evolution of the synoptic scale atmospheric conditions and the sea surface temperature (SST) field. During the pre-storm conditions prior to January 25, the spatial structure of the SST field played an important role in generating a shallow atmospheric frontal zone along the Gulf Stream front by causing differential heating of the marine atmospheric boundary layer over the stream versus over the cooler shelf waters. As this front moved shoreward on January 25, the warm, moist, maritime air flowing northwestward behind the front induced moderate ocean-to-atmosphere heat fluxes (˜300 W m-2 total heat flux measured over the core of the Gulf Stream). The subsequent outbreak of eastward flowing cold, dry, continental air over the ocean on January 27 and 28 generated high total heat fluxes (˜1060 W m-2 over the core of the Stream), as did a second, somewhat weaker outbreak which followed on January 30 (˜680 W2 over the core of the Stream). During each of these outbreaks, with air flowing from land out over the continental shelf, Gulf Stream and Sargasso Sea waters, the SST field again affected the spatial structure of the flux fields. The near-surface fluxes of both sensible and latent heat were found to be relatively low over the cool continental shelf waters, while higher fluxes were seen over the Gulf Stream and Sargasso Sea. Similar spatial structure was seen in the near-surface momentum flux values, but relative changes were typically smaller from one location to another on a particular day. The most noticeable responses of the Gulf Stream to these surface fluxes were the deepening of its mixed layer and a loss of upper layer

  8. Micro-agglomerate flotation for deep cleaning of coal. Quarterly technical progress report, April 1, 1995--June 30, 1995

    SciTech Connect

    Chander, S.; Hogg, R.

    1995-07-01

    The development, of practical technologies for the deep cleaning of coal has been seriously hampered by the problems of carrying out efficient coal/mineral separations at the very fine sizes (often finer than 10 mm) needed to achieve adequate liberation of the mineral matter from the coal matrix. In froth flotation, selectivity is substantially reduced at fine sizes due, primarily, to overloading of the froth phase which leads to excessive carryover of water and entrained mineral matter. Oil agglomeration, on the other hand, can provide good selectivity at low levels of oil addition but the agglomerates tend to be too fragile for separation by the screening methods normally used. This project is concerned with a hydrid process, micro-agglomerate flotation, which is a combination of oil agglomeration and froth flotation.

  9. The removal of heavy metals from contaminated soil by a combination of sulfidisation and flotation.

    PubMed

    Vanthuyne, Mathias; Maes, André

    2002-05-06

    The possibility of removing cadmium, copper, lead and zinc from Belgian loamy soil by a combination of sulfidisation pre-treatment and Denver flotation was investigated. The potentially available--sulfide convertible--metal content of the metal polluted soil was estimated by EDTA (0.1 M, pH 4.65) extraction and BCR sequential extraction. EDTA extraction is better at approximating the metal percentage that is expected to be convertible into a metal sulfide phase, in contrast to the sequential extraction procedure of 'Int. J. Environ. Anal. Chem. 51 (1993) pp. 135-151' in which transition metals present as iron oxide co-precipitates are dissolved by hydroxylammoniumchloride in the second extraction step. To compare the surface characteristics of metal sulfides formed by sulfidisation with those of crystalline metal sulfides, two types of synthetic sediments were prepared and extracted with 0.1 M EDTA (pH 4.65) in anoxic conditions. Separate metal sulfides or co-precipitates with iron sulfide were formed by sulfide conditioning. The Denver flotation of both types of synthetic sediments (kerosene as collector at high background electrolyte concentrations) resulted in similar concentrating factors for freshly formed metal sulfides as for fine-grained crystalline metal sulfides. The selective flotation of metal sulfides after sulfide conditioning of a polluted soil, using kerosene or potassium ethyl xanthate as collectors and MIBC as frother, was studied at high background electrolyte concentrations. The sulfidisations were made in ambient air and inside an anoxic glove box. The concentrating factors corrected by the potentially available metal percentage, determined by 0.1 M EDTA extraction, lie between 2 and 3. The selective flotation of these finely dispersed, amorphous, metal sulfides can possibly be improved by optimising the bubble-particle interaction.

  10. In-plant testing of microbubble column flotation. Third quarter technical progress report, April 1, 1990--June 30, 1990

    SciTech Connect

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

    1990-12-31

    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.

  11. 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

  12. Continuous Process Improvement at Tinker Air Logistics Complex

    DTIC Science & Technology

    2013-03-01

    Abstract The Air Logistics Complexes (ALC) represent the Air Force’s largest Maintenance, Repair, and Overhaul ( MRO ) Operations. The ALCs strive to...this problem is important to the ALCs because it provides a roadmap for how to sustain Maintenance, Repair and Overhaul ( MRO ) actions with less...ALC) represent the Air Force’s largest Maintenance, Repair, and Overhaul ( MRO ) Operations. The ALCs strive to become leaner by reducing Work In

  13. Micro-agglomerate flotation for deep cleaning of coal. Quarterly progress report, October 1, 1994--December 31, 1994

    SciTech Connect

    Chander, S.; Hogg, R.

    1995-01-01

    The development of practical technologies for the deep cleaning of coal has been seriously hampered by the problems of carrying out efficient coal/mineral separations at the very fine sizes (often finer than 10 mm) needed to achieve adequate liberation of the mineral matter from the coal matrix. It is generally recognized that surface-based separation processes such as froth flotation or selective agglomeration offer considerable potential for such applications but there remain many problems in obtaining the required selectivity with acceptable recovery of combustible matter. In froth flotation, selectivity is substantially reduced at fine sizes due, primarily, to overloading of the froth phase which leads to excessive carryover of water and entrained mineral matter. Oil agglomeration, on the other hand, can provide good selectivity at low levels of oil addition but the agglomerates tend to be too fragile for separation by the screening methods normally used. The addition of larger amounts of oil can yield large, strong agglomerates which are easily separated but the selectivity is reduced and reagent costs can become excessive. 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 mm in size) rather than individual coal particles (1-10 mm) 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.

  14. Removal of wax and stickies from OCC by flotation. Progress report No. 3, July 1--September 30, 1998

    SciTech Connect

    Doshi, M.R.; Dyer, J.; Heise, O.; Cao, B.

    1998-11-01

    In this quarter we completed low consistency laboratory pulping trials. Pulping results were analyzed in terms of defibering index or yield and the concentration of free wax. The objective of these trials is to identify pulping conditions that will give higher yield and higher concentration of free wax. The yields from low consistency pulping trials ranged from 90 to 99% based on 6-cut laboratory screen rejects. In general, high temperatures (140-150{degree}F) and high pH (9.5-10) conditions resulted in higher yield and the generation of free wax. Factors such as rotor speed and the gap (between the rotor and grate) were not significant in affecting defibering. Generally, the turbidities of filtrates from wax-contaminated pulps increased with increase in temperature and/or pH. The filtrate turbidity indicated the relative concentration of finely dispersed wax that could be removed from pulp dewatered on a 30 {micro}m filter paper. Preliminary experiments were conducted to study flotation conditions necessary for effective removal of wax from pulp. Factors which are important for effective flotation include flotation time, volume of air, surfactant concentration and type, and low temperature. Future plans include additional flotation trials to better optimize conditions. Other contaminant types include pressure sensitive adhesives and hot melts will also be examined. This will be followed by pilot plant and mill trials.

  15. Removal of wax and stickies from OCC by flotation. Progress report No. 3, July 1--September 30, 1998

    SciTech Connect

    Dosh, M.R.; Dyer, J.; Heise, O.; Cao, B.

    1998-11-01

    In this quarter we completed low consistency laboratory pulping trials. Pulping results were analyzed in terms of defibering index or yield and the concentration of free wax. The objective of these trials is to identify pulping conditions that will give higher yield and higher concentration of free wax. The yields from low consistency pulping trials ranged from 90 to 99% based on 6-cut laboratory screen rejects. In general, high temperatures (140-150{degrees}F) and high pH (9.5-10) conditions resulted in higher yield and the generation of free wax. Factors such as rotor speed and the gap (between the rotor and grate) were not significant in affecting defibering. Generally, the turbidities of filtrates from wax-contaminated pulps increased with increase in temperature and/or pH. The filtrate turbidity indicated the relative concentration of finely dispersed wax that could be removed from pulp dewatered on a 30 {micro}m filter paper. Preliminary experiments were conducted to study flotation conditions necessary for effective removal of wax from pulp. Factors which are important for effective flotation include flotation time, volume of air, surfactant concentration and type, and low temperature. Future plans include additional flotation trials to better optimize conditions. Other contaminant types include pressure sensitive adhesives and hot melts will also be examined. This will be followed by pilot plant and mill trials.

  16. EMISSIONS PROCESSING FOR THE ETA/ CMAQ AIR QUALITY FORECAST SYSTEM

    EPA Science Inventory

    NOAA and EPA have created an Air Quality Forecast (AQF) system. This AQF system links an adaptation of the EPA's Community Multiscale Air Quality Model with the 12 kilometer ETA model running operationally at NOAA's National Center for Environmental Predication (NCEP). One of the...

  17. 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.

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

    DOEpatents

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

    1995-01-01

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

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

    PubMed

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

    2013-09-01

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

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

    PubMed

    Besson, Alexandre; Guiraud, Pascal

    2013-11-01

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

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

    SciTech Connect

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

    1993-11-09

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

  2. Characterization of air pollutants from an activated sludge process

    SciTech Connect

    Scheff, P.A.; Holden, J.A.; Wadden, R.A.

    1981-02-01

    An eight-month monitoring study was conducted to characterize air pollutants near a large activated sludge plant in a Chicago suburb. Air pollutants detected include aerobic bacteria-containing particles, total suspended particulates, nitrogen dioxide, sulfur dioxide, chloride, hydrogen sulfides, and trace elements. The wastewater treatment plant is concluded to be a significant source of total coliforms and atmospheric bacteria-containing particles. (6 maps, 23 references, 6 tables)

  3. 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.

  4. 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.

  5. 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.

  6. 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

  7. 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.

  8. 76 FR 54528 - Standard Operating Procedures (SOP) of the Aircraft Certification Service (AIR) Process for the...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2011-09-01

    ... (AIR) Process for the Sequencing of Certification and Validation Projects AGENCY: Federal Aviation...) standard operating procedure (SOP) describing the process used to sequence certification projects that are... Procedure--Aircraft Certification Service Project Sequencing to: Federal Aviation Administration,...

  9. 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.

  10. 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.

  11. 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.

  12. Effects of surfactant on bubble hydrodynamic behavior under flotation-related conditions in wastewater.

    PubMed

    Li, Yanpeng; Zhu, Tingting; Liu, Yanyan; Tian, Ye; Wang, Huanran

    2012-01-01

    Bubble behavior is fundamental to the performance of froth flotation operations used in wastewater treatment processes. To fully understand and characterize bubble behavior under flotation-related conditions in wastewater, the high-speed photographic method has been employed to examine the motion of single bubbles and size distribution of bubble swarms with intermediate sizes ranging from 1 to 4 mm in the presence of surfactants in a laboratory scale flotation column. Both distilled water and synthetic municipal wastewater have been used to make solutions as well as two types of common surfactants. The instantaneous bubble motion has been recorded by a high speed camera. Subsequently, bubble trajectory, dimensions, velocity and distribution have been determined from the recorded frames using the image analysis software. The experimental results show that the addition of surfactant into wastewater has similar effects on bubble hydrodynamic behavior as in pure water (e.g., improving trajectory stabilization, dampening bubble deformation, slowing down terminal velocity, reducing bubble size and increasing the specific surface area of bubble swarm) due to the Marangoni effect. However, it is interesting to note that surfactant effects on single bubble hydrodynamics in wastewater are slightly stronger than those in pure water while surfactant effects on size parameters of bubble swarms in wastewater are significantly stronger than those in pure water. This finding suggests that besides surfactant, inorganic salts present in synthetic wastewater have an important influence on bubble dispersion.

  13. Adsorption of modified dextrins on molybdenite: AFM imaging, contact angle, and flotation studies.

    PubMed

    Beaussart, Audrey; Parkinson, Luke; Mierczynska-Vasilev, Agnieszka; Beattie, David A

    2012-02-15

    The adsorption of three dextrins (a regular wheat dextrin, Dextrin TY, carboxymethyl (CM) Dextrin, and hydroxypropyl (HP) Dextrin) on molybdenite has been investigated using adsorption isotherms, tapping mode atomic force microscopy (TMAFM), contact angle measurements, and dynamic bubble-surface collisions. In addition, the effect of the polymers on the flotation recovery of molybdenite has been determined. The isotherms revealed the importance of molecular weight in determining the adsorbed amounts of the polymers on molybdenite at plateau coverage. TMAFM revealed the morphology of the three polymers, which consisted of randomly dispersed domains with a higher area fraction of surface coverage for the substituted dextrins. The contact angle of polymer-treated molybdenite indicated that polymer layer coverage and hydration influenced the mineral surface hydrophobicity. Bubble-surface collisions indicated that the polymers affected thin film rupture and dewetting rate differently, correlating with differences in the adsorbed layer morphology. Direct correlations were found between the surface coverage of the adsorbed layers, their impact on thin film rupture time, and their impact on flotation recovery, highlighting the paramount role of the polymer morphology in the bubble/particle attachment process and subsequent flotation.

  14. Guidance Regarding Sample Collection and Refinement of Fecal Flotation Exam for the Isolation of Aspiculuris tetraptera.

    PubMed

    Goodroe, Anna E; Baxter, Victoria K; Watson, Julie

    2016-01-01

    Aspiculuris tetraptera continues to be a problem in rodent vivaria, in part due to difficulties in parasite detection. Although PCR testing is highly sensitive, it is expensive and does not always provide immediate results. Consequently, many institutions rely on passive fecal flotation as a quick inhouse exam for diagnosing A. tetraptera infections. To increase the sensitivity of this test, we examined multiple parameters to determine the optimal test protocol. A 30-min soaking period prior to fecal flotation for 15 min allowed fecal pellets to soften and facilitated efficient egg isolation. We also evaluated the effect of time of day, sample size, age, sex, and housing status on egg isolation. No evidence of cyclical egg shedding was found, and although larger fecal sample sizes did not result in more eggs isolated, their use reduced the incidence of false-negative exams. The most eggs were isolated from 8- and 12-wk-old mice, and as mice aged, the number of eggs isolated declined. Overall, neither sex nor housing status influenced the number of eggs isolated. Finally, examination of multiple diagnostic tests (fecal flotation exam, direct examination of cecal and colonic contents, and fecal PCR) revealed that no single test was definitive, thus indicating that multiple tests might be required to successfully screen mice with low pinworm burdens. These findings provide guidance regarding sample selection, collection, and processing to efficiently detect A. tetraptera.

  15. Guidance Regarding Sample Collection and Refinement of Fecal Flotation Exam for the Isolation of Aspiculuris tetraptera

    PubMed Central

    Goodroe, Anna E; Baxter, Victoria K; Watson, Julie

    2016-01-01

    Aspiculuris tetraptera continues to be a problem in rodent vivaria, in part due to difficulties in parasite detection. Although PCR testing is highly sensitive, it is expensive and does not always provide immediate results. Consequently, many institutions rely on passive fecal flotation as a quick inhouse exam for diagnosing A. tetraptera infections. To increase the sensitivity of this test, we examined multiple parameters to determine the optimal test protocol. A 30-min soaking period prior to fecal flotation for 15 min allowed fecal pellets to soften and facilitated efficient egg isolation. We also evaluated the effect of time of day, sample size, age, sex, and housing status on egg isolation. No evidence of cyclical egg shedding was found, and although larger fecal sample sizes did not result in more eggs isolated, their use reduced the incidence of false-negative exams. The most eggs were isolated from 8- and 12-wk-old mice, and as mice aged, the number of eggs isolated declined. Overall, neither sex nor housing status influenced the number of eggs isolated. Finally, examination of multiple diagnostic tests (fecal flotation exam, direct examination of cecal and colonic contents, and fecal PCR) revealed that no single test was definitive, thus indicating that multiple tests might be required to successfully screen mice with low pinworm burdens. These findings provide guidance regarding sample selection, collection, and processing to efficiently detect A. tetraptera. PMID:27657708

  16. 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.

  17. 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.

  18. 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.

  19. Transfer Processes at the Air--Sea Interface

    NASA Astrophysics Data System (ADS)

    Guymer, T. H.; Businger, J. A.; Katsaros, K. B.; Shaw, W. J.; Taylor, P. K.; Large, W. G.; Payne, R. E.

    1983-02-01

    Near-surface data from ships, buoys, aircraft and a microwave remote-sensing satellite have been used to estimate the fluxes of momentum, heat and water vapour at the sea surface over a 200 km × 200 km area during the Joint Air--Sea Interaction Experiment of 1978. In particular, daily means of the surface heat balance and the wind stress are presented. Generally, the sensible heat flux was found to be less than 25% of the latent heat flux. Over periods of a day the total upward heat flux was about a third of the net radiation, implying that a significant proportion of the available energy went into heating the ocean. The Ekman pumping accounted for most of the divergence in the atmospheric boundary layer but only 10% at most of that in the upper ocean. Some case studies of the horizontal variation of the fluxes in relation to larger scales are also discussed and it is suggested that the fluxes are modulated by mesoscale patterns in sea-surface temperature. Surface turbulent fluxes and SST have been examined on scales from several kilometres to 200 km and for days to weeks by using a combination of ships, buoys, aircraft and microwave remote sensing. The net radiative flux had been obtained at the corners of the 200 km meteorological triangle either by direct measurements of the shortwave and longwave components or by parametrization techniques. This has enabled the surface heat budget to be examined on a daily basis. About 70% of the net flux (typically 100 W m-2 in phase 1 and 70 W m-2 in phase 2) is available for heating the ocean and, of the remainder, over 75% goes into the atmosphere as latent heat. In these near-neutral conditions the mean surface wind speed across the triangle was 77% of the geostrophic wind speed and the cross-isobar flow angle was 11 degrees (down-gradient). Significant variations in the thermodynamic fluxes across the area were found, associated partly with the SST distribution and also with the fact that the coldest and driest air was

  20. Modeling of membrane processes for air revitalization and water recovery

    NASA Technical Reports Server (NTRS)

    Lange, Kevin E.; Foerg, Sandra L.; Dall-Bauman, Liese A.

    1992-01-01

    Gas-separation and reverse-osmosis membrane models are being developed in conjunction with membrane testing at NASA JSC. The completed gas-separation membrane model extracts effective component permeabilities from multicomponent test data, and predicts the effects of flow configuration, operating conditions, and membrane dimensions on module performance. Variable feed- and permeate-side pressures are considered. The model has been applied to test data for hollow-fiber membrane modules with simulated cabin-air feeds. Results are presented for a membrane designed for air drying applications. Extracted permeabilities are used to predict the effect of operating conditions on water enrichment in the permeate. A first-order reverse-osmosis model has been applied to test data for spiral wound membrane modules with a simulated hygiene water feed. The model estimates an effective local component rejection coefficient under pseudosteady-state conditions. Results are used to define requirements for a detailed reverse-osmosis model.

  1. Heat-transfer processes in air-cooled engine cylinders

    NASA Technical Reports Server (NTRS)

    Pinkel, Benjamin

    1938-01-01

    From a consideration of heat-transfer theory, semi-empirical expressions are set up for the transfer of heat from the combustion gases to the cylinder of an air-cooled engine and from the cylinder to the cooling air. Simple equations for the average head and barrel temperatures as functions of the important engine and cooling variables are obtained from these expressions. The expressions involve a few empirical constants, which may be readily determined from engine tests. Numerical values for these constants were obtained from single-cylinder engine tests for cylinders of the Pratt & Whitney 1535 and 1340-h engines. The equations provide a means of calculating the effect of the various engine and cooling variables on the cylinder temperatures and also of correlating the results of engine cooling tests. An example is given of the application of the equations to the correlation of cooling-test data obtained in flight.

  2. Recent advances in improvement of forecast skill and understanding climate processes using AIRS Version-5 products

    NASA Astrophysics Data System (ADS)

    Susskind, Joel; Molnar, Gyula; Iredell, Lena; Rosenberg, Robert

    2012-10-01

    The NASA Goddard Earth Sciences (GES) Data and Information Services Center (DISC) generates products derived from AIRS/AMSU-A observations, starting from September 2002 when the AIRS instrument became stable, using the AIRS Science Team Version-5 retrieval algorithm. This paper shows results of some of our research using Version-5 products from the points of view of improving forecast skill as well as aiding in the understanding of climate processes.

  3. In-plant testing of microbubble column flotation

    SciTech Connect

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

    1989-01-01

    A project to evaluate the performance of the Virginia Tech Microbubble Column Flotation (MCF) process in an operating coal preparation plant was initiated during this past quarter. The project is concerned with the collection of process operating data using a 30-inch diameter column, and using this data to scale-up to a prototype, full-scale plant column. The work is being carried out at the Marrowbone Preparation Plant owned by the Shell Mining Corporation. Work has primarily concentrated on finalizing the project work plan (Task 2.1 -- Project Planning), instrumenting the 30-inch diameter column (Task 2.2 -- Advanced Instrumentation) and conducting a preliminary parametric study to evaluate the performance of the column (Task 2.3 -- Detailed Testing). To date, the column has been consistently capable of producing a 9.5% ash product at a 61% combustible recovery from a -150 mesh classifying cyclone overflow containing 55--60% ash at 3--5% solids. Tests conducted over an extended period of time indicate that the column consistently maintains grade in spite of fluctuations in the feed characteristics. 12 figs.

  4. In-plant testing of microbubble column flotation

    SciTech Connect

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

    1990-01-01

    A project to evaluate the performance of the Virginia Tech Microbubble Column Flotation (MCF) process in an operating coal preparation plant was continued during this past quarter. The project is concerned with the collection of process operating data using a 30-inch diameter column, and using these data to scale-up to a prototype, full-scale plant column. The work is being carried out at the Marrowbone Preparation Plant owned by the Shell Mining Corporation. Work during the past reported period primarily concentrated on the completion of a parametric study to evaluate the performance of the 30-inch diameter column. The preliminary results obtained from the parametric study suggest that higher gas flow rates and frother additions appear to have a beneficial effect on separation efficiency. However, under these conditions, a larger wash water flow rate was necessary to offset the increased flow of feed water to the product stream. The parametric testing results indicated that the height of the stabilized froth zone had only a limited impact on the separation efficiency, except under conditions of high feed rates. A more detailed analysis of the response surface data is currently under way. Work in other areas (Task 2.5 - Control systems and Task 3.3 - Column Testing) is continuing, but has progressed at a slower pace than originally anticipated. The appendix contains data on energy recovery, product ash content, sulfur rejection, and separation efficiency. 32 figs., 5 tabs.

  5. Air plasma processing of poly(methyl methacrylate) micro-beads: Surface characterisations

    NASA Astrophysics Data System (ADS)

    Liu, Chaozong; Cui, Nai-Yi; Osbeck, Susan; Liang, He

    2012-10-01

    This paper reports the surface processing of poly(methyl methacrylate) (PMMA) micro-beads by using a rotary air plasma reactor, and its effects on surface properties. The surface properties, including surface wettability, surface chemistry and textures of the PMMA beads, were characterised. It was observed that the air plasma processing can improve the surface wettability of the PMMA microbeads significantly. A 15 min plasma processing can reduce the surface water contact angle of PMMA beads to about 50° from its original value of 80.3°. This was accompanied by about 8% increase in surface oxygen concentration as confirmed by XPS analysis. The optical profilometry examination revealed the air plasma processing resulted in a rougher surface that has a “delicate” surface texture. It is concluded that the surface chemistry and texture, induced by air plasma processing, co-contributed to the surface wettability improvement of PMMA micro-beads.

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

    SciTech Connect

    Not Available

    1991-12-31

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

  7. Air Vehicle Technology Integration Program (AVTIP). Delivery Order 0004: Advanced Sol-Gel Adhesion Processes

    DTIC Science & Technology

    2002-04-01

    AFRL-ML-WP-TR-2003-4173 AIR VEHICLE TECHNOLOGY INTEGRATION PROGRAM (AVTIP) Delivery Order 0004: Advanced Sol-Gel Adhesion Processes Kay Y...2001 – 03/31/2002 5a. CONTRACT NUMBER F33615-00-D-3052 5b. GRANT NUMBER 4. TITLE AND SUBTITLE AIR VEHICLE TECHNOLOGY INTEGRATION PROGRAM

  8. Building Sustainability into the Air Force Remediation Process

    DTIC Science & Technology

    2010-06-16

    Technology  GSR Through Optimization  In-depth Case Study : Travis AFB  Necessary  Optimization  GSR Treatment Train  In situ Bioreactor...y - S e r v i c e - E x c e l l e n c e Case Study : Travis AFB 12 Goals  Out of necessity  Reduce energy consumption, air emissions, material... Phytoremediation Biobarrier  Wrap-up  Future Direction 2 I n t e g r i t y - S e r v i c e - E x c e l l e n c e AF Environmental Restoration

  9. Features extraction of flotation froth images and BP neural network soft-sensor model of concentrate grade optimized by shuffled cuckoo searching algorithm.

    PubMed

    Wang, Jie-sheng; Han, Shuang; Shen, Na-na; Li, Shu-xia

    2014-01-01

    For meeting the forecasting target of key technology indicators in the flotation process, a BP neural network soft-sensor model based on features extraction of flotation froth images and optimized by shuffled cuckoo search algorithm is proposed. Based on the digital image processing technique, the color features in HSI color space, the visual features based on the gray level cooccurrence matrix, and the shape characteristics based on the geometric theory of flotation froth images are extracted, respectively, as the input variables of the proposed soft-sensor model. Then the isometric mapping method is used to reduce the input dimension, the network size, and learning time of BP neural network. Finally, a shuffled cuckoo search algorithm is adopted to optimize the BP neural network soft-sensor model. Simulation results show that the model has better generalization results and prediction accuracy.

  10. Features Extraction of Flotation Froth Images and BP Neural Network Soft-Sensor Model of Concentrate Grade Optimized by Shuffled Cuckoo Searching Algorithm

    PubMed Central

    Wang, Jie-sheng; Han, Shuang; Shen, Na-na; Li, Shu-xia

    2014-01-01

    For meeting the forecasting target of key technology indicators in the flotation process, a BP neural network soft-sensor model based on features extraction of flotation froth images and optimized by shuffled cuckoo search algorithm is proposed. Based on the digital image processing technique, the color features in HSI color space, the visual features based on the gray level cooccurrence matrix, and the shape characteristics based on the geometric theory of flotation froth images are extracted, respectively, as the input variables of the proposed soft-sensor model. Then the isometric mapping method is used to reduce the input dimension, the network size, and learning time of BP neural network. Finally, a shuffled cuckoo search algorithm is adopted to optimize the BP neural network soft-sensor model. Simulation results show that the model has better generalization results and prediction accuracy. PMID:25133210

  11. Evaluating Membrane Processes for Air Conditioning; Highlights in Research and Development, NREL (National Renewable Energy Laboratory)

    SciTech Connect

    2015-06-01

    This NREL Highlight discusses a recent state-of-the-art review of membrane processes for air conditioning that identifies future research opportunities. This highlight is being developed for the June 2015 S&T Alliance Board meeting.

  12. 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.

  13. 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.

  14. Cleaner production in a remanufacturing process of air compressors.

    PubMed

    Esquer, Javier; Arvayo, Jose Angel; Alvarez-Chavez, Clara Rosalia; Munguia-Vega, Nora Elba; Velazquez, Luis

    2017-03-01

    This article provides relevant results of a cleaner production program conducted in a company dedicated to remanufacturing air compressors in the city of Hermosillo, Sonora, Mexico. The overall study design was based on an integration of acknowledged cleaner production and pollution prevention programs. Although this kind of program also involves environmental issues, this study focused on occupational health and safety by addressing different aspects of the work environment: ergonomic, physical (noise and lighting), and chemical. Particularly, ergonomic aspects were evaluated through the Modular Arrangement of Predetermined Time Standards (MODAPTS) method. For physical aspects, noise and lighting were addressed through Standard No. NOM-011-STPS-2001 and Standard No. NOM-025-STPS-2008 respectively. In addition, chemical aspects were analyzed through material safety data sheets and different search tools. Root causes of each risk were identified, and options to prevent, eliminate, and/or reduce each risk have been provided.

  15. A perspective of stepwise utilisation of Bayer red mud: Step two--Extracting and recovering Ti from Ti-enriched tailing with acid leaching and precipitate flotation.

    PubMed

    Huang, Yanfang; Chai, Wencui; Han, Guihong; Wang, Wenjuan; Yang, Shuzhen; Liu, Jiongtian

    2016-04-15

    The extraction and recovery of Ti from Ti-enriched tailing with acid leaching and precipitate flotation, as one of the critical steps, was proposed for the stepwise utilization of red mud. The factors influencing acid leaching and precipitate flotation were examined by factorial design. The leaching thermodynamics, kinetics of Ti(4+), Al(3+) and Fe(3+), and the mechanism of selectively Fe(3+) removal using [Hbet][Tf2N] as precipitating reagent were discussed. The extracting of Ti(4+), Al(3+) and Fe(3+) in concentrated H2SO4 is controlled by diffusion reactions, depending mainly upon leaching time and temperature. The maximum extracting efficiency of Ti(4+) is approximately 92.3%, whereas Al(3+) and Fe(3+) leaching are respectively 75.8% and 84.2%. [Hbet][Tf2N], as a precipitating reagent, operates through a coordination mechanism in flotation. The pH value is the key factor influencing the flotation recovery of Ti(4+), whereas the dosage of precipitating reagent is that for Al(3+) recovery. The maximum flotation recovery of Ti(4+) is 92.7%, whereas the maximum Al(3+) recovery is 93.5%. The total recovery rate for extracting and recovering titanium is 85.5%. The liquor with Ti(4+) of 15.5g/L, Al(3+) of 30.4g/L and Fe(3+) of 0.48g/L was obtained for the following hydrolysis step in the integrated process for red mud utilisation.

  16. Removal of copper (II) from aqueous solutions by flotation using polyaluminum chloride silicate (PAX-XL60 S) as coagulant and carbonate ion as activator.

    PubMed

    Ghazy, S E; Mahmoud, I A; Ragab, A H

    2006-01-01

    Flotation is a separation technology for removing toxic heavy metal ions from aqueous solutions. Here a simple and rapid flotation procedure is presented for the removal of copper(II) from aqueous solutions. It is based on the use of polyaluminum chloride silicate (PAX-XL60 S) as coagulant and flocculent, carbonate ion as activator and oleic acid (HOL) as surfactant. Both ion and precipitate flotation are included depending on the solution pH. Ion and precipitate flotation in the aqueous HOL-PAX-XL60 S-Cu2+-CO3(2-) system gave powerful preferential removal of Cu2+ (F -100%) over the HOL-PAX-XL60 S-Cu2+ system containing no CO3(2+) ion (F approximately 86%). The role of CO3(2-) ion is also evident from decreasing the dose of PAX-XL60 S from 700 mg l(-1) to 200 mg l(-1). The other parameters, influencing the flotation process, namely: metal ion, surfactant and PAX-XL60 S concentrations, ionic strength, temperature and foreign ions were examined. Moreover, the procedure was successfully applied to recover Cu2+ ions from different volumes up to 11 and from natural water samples.

  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. 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...

  7. 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...

  8. 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...

  9. 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...

  10. 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.

  11. 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...

  12. 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...

  13. 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,...

  14. 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,...

  15. 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...

  16. 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...

  17. 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...

  18. 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...

  19. 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...

  20. 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...

  1. 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...

  2. 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...

  3. 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...

  4. Controls Over the Air Force Contract Augmentation Program Payment Process Need Improvement

    DTIC Science & Technology

    2015-01-28

    No. DODIG-2015-075 J A N U A R Y 2 8 , 2 0 1 5 Controls Over the Air Force Contract Augmentation Program Payment Process Need Improvement Report...2. REPORT TYPE 3. DATES COVERED 00-00-2015 to 00-00-2015 4. TITLE AND SUBTITLE Controls Over the Air Force Contract Augmentation Program...Controls Over the Air Force Contract Augmentation Program Payment Process Need Improvement Visit us at www.dodig.mil Objective To determine whether DoD was

  5. Air processed organic photovoltaic devices incorporating a MoOx anode buffer layer

    NASA Astrophysics Data System (ADS)

    Bovill, Edward S. R.; Griffin, Jonathan; Wang, Tao; Kingsley, James W.; Yi, Hunan; Iraqi, Ahmed; Buckley, Alastair R.; Lidzey, David G.

    2013-05-01

    Molybdenum oxide (MoOx) has been shown to act as an efficient hole extraction layer in organic photovoltaic (OPV) devices. However, exposing MoOx films to air is problematic as it is hygroscopic; the uptake of moisture having a negative impact on its electronic properties. Here, we use spectroscopic ellipsometry to characterise the uptake of water, and fabricate PCDTBT:PC70BM based OPVs to determine its effects on device performance. We then show that thermally annealing MoOx reduces its hygroscopicity, permitting it to be processed in air. Using this process, we create air-processsed OPVs having PCEs (power conversion efficiencies) of up to 5.36%.

  6. Moisture content, processing yield, and surface color of broiler carcasses chilled by water, air, or evaporative air.

    PubMed

    Jeong, J Y; Janardhanan, K K; Booren, A M; Karcher, D M; Kang, I

    2011-03-01

    This study was conducted to investigate the effects of water chilling (WC), air chilling (AC), and evaporative air chilling (EAC) on the moisture content, processing yield, surface color, and visual appearance of broiler carcasses. For the WC treatment, 1 group of birds was hard scalded and submersed into ice slush, whereas for AC, 1 group of birds was soft scalded and exposed to blowing air (1.0 m/s at 0°C) and for EAC, or 1 group of birds was soft scalded and exposed to blowing air and a cold water spray (every 5 min). During chilling, carcass temperature was reduced most effectively by WC (55 min), followed by EAC (120 min) and AC (155 min). After chilling, both WC and EAC carcasses picked up moisture at 4.6 and 1.0% of their weights, respectively, whereas AC carcasses lost 1.5% of their weight. On cutting at 5 h postmortem, WC carcasses showed the highest (2.5%), EAC showed the second highest (0.4%), and AC showed the least (0.3%) moisture loss. After 24 h of storage, almost 83% of the absorbed water in the WC carcass parts was released as purge, whereas EAC and AC carcasses maintained weights close to the prechilled weights. In an instrumental color evaluation and a visual evaluation by panelists, AC carcasses showed a darker appearance, a more yellow color, and more surface discoloration compared with WC or EAC carcasses.

  7. 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.

  8. Analyzing the Air Operations Center (AOC) Air Tasking Order (ATO) Process Using Theory of Constraints (TOC)

    DTIC Science & Technology

    2005-06-13

    Theory of Constraints (TOC), as espoused by Israeli physicist Dr. Eliyahu Goldratt , defines a process in which throughput-limiting constraints can...the “longest chain of dependent events where the dependency is either task or resource related [17].” In The Goal and Its Not Luck, Dr. Goldratt ...intensive process such as ATO development. It is not possible to use physical evidence such as raw materials or subassemblies, so Goldratt suggests

  9. 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.

  10. 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.

  11. 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.

  12. Air Stripping Designs and Reactive Water Purification Processes for the Lunar Surface

    NASA Technical Reports Server (NTRS)

    Boul, Peter J.; Lange, Kevin; Conger, Bruce; Anderson, Molly

    2010-01-01

    Air stripping designs are considered to reduce the presence of volatile organic compounds in the purified water. Components of the wastewater streams are ranked by Henry's Law Constant and the suitability of air stripping in the purification of wastewater in terms of component removal is evaluated. Distillation processes are modeled in tandem with air stripping to demonstrate the potential effectiveness and utility of these methods in recycling wastewater on the Moon. Scaling factors for distillation and air stripping columns are presented to account for the difference in the lunar gravitation environment. Commercially available distillation and air stripping units which are considered suitable for Exploration Life Support are presented. The advantages to the various designs are summarized with respect to water purity levels, power consumption, and processing rates. An evaluation of reactive distillation and air stripping is presented with regards to the reduction of volatile organic compounds in the contaminated water and air. Among the methods presented, an architecture is presented for the evaluation of the simultaneous oxidation of organics in air and water. These and other designs are presented in light of potential improvements in power consumptions and air and water purities for architectures which include catalytic activity integrated into the water processor. In particular, catalytic oxidation of organics may be useful as a tool to remove contaminants that more traditional distillation and/or air stripping columns may not remove. A review of the current leading edge at the commercial level and at the research frontier in catalytically active materials is presented. Themes and directions from the engineering developments in catalyst design are presented conceptually in light of developments in the nanoscale chemistry of a variety of catalyst materials.

  13. 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.

  14. 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.

  15. 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.

  16. The role of sea spray in cleansing air pollution over ocean via cloud processes.

    PubMed

    Rosenfeld, Daniel; Lahav, Ronen; Khain, Alexander; Pinsky, Mark

    2002-09-06

    Particulate air pollution has been shown to strongly suppress precipitation from convective clouds over land. New observations show that precipitation from similar polluted clouds over oceans is much less affected, because large sea salt nuclei override the precipitation suppression effect of the large number of small pollution nuclei. Raindrops initiated by the sea salt grow by collecting small cloud droplets that form on the pollution particles, thereby cleansing the air. Therefore, sea salt helps cleanse the atmosphere of the air pollution via cloud processes. This implies that over oceans, the climatic aerosol indirect effects are significantly smaller than current estimates.

  17. Land Surface Process and Air Quality Research and Applications at MSFC

    NASA Technical Reports Server (NTRS)

    Quattrochi, Dale; Khan, Maudood

    2007-01-01

    This viewgraph presentation provides an overview of land surface process and air quality research at MSFC including atmospheric modeling and ongoing research whose objective is to undertake a comprehensive spatiotemporal analysis of the effects of accurate land surface characterization on atmospheric modeling results, and public health applications. Land use maps as well as 10 meter air temperature, surface wind, PBL mean difference heights, NOx, ozone, and O3+NO2 plots as well as spatial growth model outputs are included. Emissions and general air quality modeling are also discussed.

  18. 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.

  19. Process for removal of hazardous air pollutants from coal

    DOEpatents

    Akers, David J.; Ekechukwu, Kenneth N.; Aluko, Mobolaji E.; Lebowitz, Howard E.

    2000-01-01

    An improved process for removing mercury and other trace elements from coal containing pyrite by forming a slurry of finely divided coal in a liquid solvent capable of forming ions or radicals having a tendency to react with constituents of pyrite or to attack the bond between pyrite and coal and/or to react with mercury to form mercury vapors, and heating the slurry in a closed container to a temperature of at least about 50.degree. C. to produce vapors of the solvent and withdrawing vapors including solvent and mercury-containing vapors from the closed container, then separating mercury from the vapors withdrawn.

  20. Analysis of processes in DC arc plasma torches for spraying that use air as plasma forming gas

    NASA Astrophysics Data System (ADS)

    Frolov, V.; Ivanov, D.; Toropchin, A.

    2014-11-01

    Developed in Saint Petersburg State Polytechnical University technological processes of air-plasma spraying of wear-resistant, regenerating, hardening and decorative coatings used in number of industrial areas are described. The article contains examples of applications of air plasma spraying of coatings as well as results of mathematical modelling of processes in air plasma torches for spraying.

  1. MEASUREMENT OF INDOOR AIR EMISSIONS FROM DRY-PROCESS PHOTOCOPY MACHINES

    EPA Science Inventory

    The article provides background information on indoor air emissions from office equipment, with emphasis on dry-process photocopy machines. The test method is described in detail along with results of a study to evaluate the test method using four dry-process photocopy machines. ...

  2. Carboxymethylcellulose adsorption on molybdenite: the effect of electrolyte composition on adsorption, bubble-surface collisions, and flotation.

    PubMed

    Kor, Mohammad; Korczyk, Piotr M; Addai-Mensah, Jonas; Krasowska, Marta; Beattie, David A

    2014-10-14

    The adsorption of carboxymethylcellulose polymers on molybdenite was studied using spectroscopic ellipsometry and atomic force microscopy imaging with two polymers of differing degrees of carboxyl group substitution and at three different electrolyte conditions: 1 × 10(-2) M KCl, 2.76 × 10(-2) M KCl, and simulated flotation process water of multicomponent electrolyte content, with an ionic strength close to 2.76 × 10(-2) M. A higher degree of carboxyl substitution in the adsorbing polymer resulted in adsorbed layers that were thinner and with more patchy coverage; increasing the ionic strength of the electrolyte resulted in increased polymer layer thickness and coverage. The use of simulated process water resulted in the largest layer thickness and coverage for both polymers. The effect of the adsorbed polymer layer on bubble-particle attachment was studied with single bubble-surface collision experiments recorded with high-speed video capture and image processing and also with single mineral molybdenite flotation tests. The carboxymethylcellulose polymer with a lower degree of substitution resulted in almost complete prevention of wetting film rupture at the molybdenite surface under all electrolyte conditions. The polymer with a higher degree of substitution prevented rupture only when adsorbed from simulated process water. Molecular kinetic theory was used to quantify the effect of the polymer on the dewetting dynamics for collisions that resulted in wetting film rupture. Flotation experiments confirmed that adsorbed polymer layer properties, through their effect on the dynamics of bubble-particle attachment, are critical to predicting the effectiveness of polymers used to prevent mineral recovery in flotation.

  3. Martian Air Separation for In-Situ Resource Utilization Processes

    NASA Astrophysics Data System (ADS)

    MacArthur, J. R.; Way, J. D.; Baldwin, R. M.; Mason, L. W.

    2002-01-01

    We will introduce the concept of using synthetic organic and inorganic membranes for the separation and purification of carbon dioxide (CO2) from mixtures of gases, such as those found in the Martian atmosphere. The class of applications targeted in this project are known as In Situ Resource Utilization (ISRU). ISRU involves the use of resources present on Mars, such as atmospheric gases, a concept that will dramatically reduce the amount of material that must be transferred from Earth to support a mission. ISRU technologies will provide many of the consumables required for a manned mission, such as rocket propellant, water, oxygen and buffer gases. The Martian atmosphere is primarily CO2, and also contains a few percent nitrogen and argon. Martian CO2 is a principal component of several ISRU processes that may be used in a manned Mars mission. For example, the Sabatier/Electrolysis (SE) process reacts atmospheric CO2 with hydrogen to produce methane (fuel), water, and oxygen. Pure gas and mixed gas permeation tests with CO2, Ar, N2, and O2 were performed over the temperature range 243 K to 295 K with a several candidate membrane materials including rubbery polymers (silicone rubber and PEBAX) and supported faujasite zeolite membranes. In experiments with commercially available silicone rubber membranes, the pure gas CO2 permeance (flux/driving force) increases from 460 GPUs to 655 GPUs as the temperature decreases from 295 K to 243 K. A GPU is a commonly used unit of permeance and is defined as 10-6 cm3(STP)/cm2-s-cm Hg. The ideal carbon dioxide/nitrogen separation factor (ratio of pure gas permeances) increases from 7.5 to 17.5 over the same temperature range. However, in mixed gas experiments, the CO2/N2 separation factor was much lower, increasing from 4.5 to 6 as the temperature decreased from 295 K to 243 K. This difference was attributed to plasticization of the rubbery polymer membrane by CO2.

  4. Desulfurization of coal. Final report. [Flotation followed by olefin and vinyl monomer treatment

    SciTech Connect

    Dichter, M.; Sanduja, M.

    1980-10-01

    Ohio coal, like many other types of coal, has a high sulfur as well as ash content. We at PRCA, through a series of steps involving the treatment of coal with an olefin-catalyst and/or catalyzed oxidizing system, have established the following: (1) Crushing and pulverizing of coal to a size of 150 to 200 mesh is an important factor in the process of desulfurization, as this allows improvement of the efficiency of flotation and chemical desulfurization. (2) Flotation results in a significant reduction of sulfur and ash content of the coal and reduces the amount of water absorbed on the pulverized coal when petroleum fractions are introduced into the flotation process. Coal containing 4.3% and 2.7% sulfur have been desulfurized to 2.8% to 3.0% and 1.5% to 1.9%, respectively. The ash content has been reduced after flotation from 10.7% to 6.5% of the Pittsburgh No. 8 coal and from 16.5% to 10.5% of a coal provided by Consolidation Coal Co. (3) Chemical treatment with olefins and monomers allows complete removal of the rest of the pyritic sulfur and part of the organic sulfur. The higher molecular weight olefins give better results and an introduction of some maleic anhydride monomer helps to get a higher reduction of the sulfur in the coal. The presence of an alkaline medium (NaOH or Na/sub 2/CO/sub 3/) enhances the sulfur removal efficiency. (4) Elevated temperatures and pressures allows reduction of the time of reaction to obtain lower sulfur content coal. However, the pressure in the range of 100 to 200 psi allows achievement of an optimum desulfurization of treated coal. Even 25 to 30 psi has shown satisfactory results in the same time. (5) The results of desulfurization by a monomer (olefin) treatment are given. Further work on the desulfurization of the Ohio coals is recommended in a small scale pilot plant on a continuous basis. This pilot plant will represent an approximation of a real plant which will allow the necessary insight needed for scale up.

  5. 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.

  6. 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...

  7. 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...

  8. 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.

  9. 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 §...

  10. 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 §...

  11. 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 §...

  12. 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...

  13. 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...

  14. 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 §...

  15. 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 §...

  16. 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.

  17. 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.

  18. 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.

  19. 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.

  20. 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...