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Development and Use of Certain Flotation Reagents

Description: From Forward: "When the experiments described in this bulletin were begun many of the reagents were available only in trial quantities. Some of them are now available in commercial quantities and are of different compositions from those that were available for experimental work. It was not possible to determine the exact chemical composition of some of the reagents."
Date: 1944
Creator: Dean, R. S. & Ambrose, P. M.
Partner: UNT Libraries Government Documents Department

A Kinetic Model for Conventional Flotation of Coal

Description: 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 (j,2 3. Each set of coal data was represented by two constants, a and a, 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.
Date: 1995
Creator: Susko, Frank J. & Stanley, Don A.
Partner: UNT Libraries Government Documents Department

PROGRESS RELATING TO CIVILIAN APPLICATIONS DURING NOVEMBER 1958

Description: The effect of irradiation on the thermal conductivity and electrical resistivity of U and U0/sub 2/ is being investigated. The creep properties of 15% cold-worked Zircaloy-2 are being investigated in the 290 to 400 deg C temperature range for times exceeding 10,000 hr. The density distribution of crushed graphite is being investigated by the sink-float method. Centrifugal- casting techniques for the production of Al-35 wt.% U casting in the form of hollow cylinders are being investigated. A study of the processes involved in the solidification of U castings in graphite molds is being made. Work continued on electrolytic oxide and electroless oxide coatings on Croloy-2 1/4. Experimental work was continued to determine the effect of additive oxides on the oxidation characteristics and phase stability of U0/sub 2/. The fueled-moderator study has continued with the determination of additional hydrogen-absorption isotherms for the Zr-25 wt.% alloy and high-temperature x-ray diffraction patterns of hydrides of the 1 and 50 wt.% alloys. The irradiation of type 347 stainless steel at ETR process-water temperature. about 120 deg F and at 600 deg F, and subsequent determination of irradiation damage are being done in support of the KAPL-33 loop to be installed at the ETR. AIloys of U and Nb are being considered as possible high-temperature reactor fuels. Thorium-uranium base alloys are the subject of an investigation aimed at improving irradiation stability and corrosion resistance by ternary alloying and control of processing techniques Cermet fuel materials consisting of from 60 to 90 vol.% U0/sub 2/, UN, or UC dispersed in stainless steel are being investigated. Several types of 1 1/ 2-inch-diameter fueled graphite spheres containing 10 wt.% of fully enriched U0/ sub 2/ are being evaluated before and after irradiation in the BRR. Some localized attack has been observed after prolonged exposure of Ti steam tubes ...
Date: December 1, 1958
Creator: Dayton, R.W. & Tipton, C.R. Jr.
Partner: UNT Libraries Government Documents Department

Engineering Development of Advanced Physical Fine Coal Cleaing for Premium Fuel Applications

Description: The ash in six common bituminous coals, Taggart, Winifrede, Elkhorn No. 3, Indiana VII, Sunnyside and Hiawatha, could be liberated by fine grinding to allow preparation of clean coal meeting premium fuel specifications (< 1- 2 lb/ MBtu ash and <0.6 lb/ MBtu sulfur) by laboratory and bench- scale column flotation or selective agglomeration. Over 2,100 tons of coal were cleaned in the PDU at feed rates between 2,500 and 6,000 lb/ h by Microcel� column flotation and by selective agglomeration using recycled heptane as the bridging liquid. Parametric testing of each process and 72- hr productions runs were completed on each of the three test coals. The following results were achieved after optimization of the operating parameters: The primary objective was to develop the design base for commercial fine coal cleaning facilities for producing ultra- clean coals which can be converted into coal-water slurry premium fuel. The coal cleaning technologies to be developed were advanced column flotation and selective agglomeration, and the goal was to produce fuel meeting the following specifications -- Less than 2 pounds of ash per million Btu (860 grams per gigajoule) and
Date: September 26, 1997
Creator: Smit, Frank J.; Schields, Gene L.; Jha, Mehesh C. & Moro, Nick
Partner: UNT Libraries Government Documents Department

POC-Scale Testing of an Advanced Fine Coal Dewatering Equipment/Technique

Description: Froth flotation technique is an effective and efficient process for recovering of ultra-fine (minus 74 mm) clean coal. Economical dewatering of an ultra-fine clean coal product to a 20% level moisture will be an important step in successful implementation of the advanced cleaning processes. This project is a step in the Department of Energy's program to show that ultra-clean coal could be effectively dewatered to 20% or lower moisture using either conventional or advanced dewatering techniques. The cost-sharing contract effort is for 45 months beginning September 30, 1994. This report discusses technical progress made during the quarter from January 1 � March 31, 1998.
Date: August 28, 1998
Creator: Karekh, B. K.; Tao, D. & Groppo, J. G.
Partner: UNT Libraries Government Documents Department

An Advanced Control System For Fine Coal Flotation

Description: 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.
Date: August 25, 1998
Creator: Luttrell, G. H. & Adel, G. T.
Partner: UNT Libraries Government Documents Department

An Advanced Control System for Fine Coal Floatation

Description: 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 eighth quarter of this project, the analysis of data collected during Task 2 (Sampling and Data Analysis) was completed, and significant progress was made on Task 3 (Model Building and Computer Simulation). Previously, a plant sampling campaign had been conducted at Pittston�s Moss No. 3 preparation plant to provide data for the development of a mathematical process model and a model-based control system. During this campaign, a one-half factorial design experiment, blocked into low and high feed rates, was conducted to investigate the effects of collector, frother, and pulp level on model parameters. In addition, samples were collected during the transient period following each change in the manipulated variables to provide data for confirmation of the dynamic process simulator. A residence time distribution (RTD) test was also conducted to estimate the mean residence time. This is a critical piece of information since no feed flowrate measurement is available, and the mean residence time can be used to estimate the feed flowrate. Feed samples were taken at timed intervals and floated in a laboratory flotation cell to investigate the magnitude of feed property disturbances and their duration.
Date: June 1, 1998
Creator: Luttrell, G. H. & Adel, G. T.
Partner: UNT Libraries Government Documents Department

SURFACTANT SPRAY: A NOVEL TECHNOLOGY TO IMPROVE FLOTATION DEINKING PERFORMANCE

Description: 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.
Date: January 31, 2004
Creator: Deng, Yulin & Zhu, Junyong
Partner: UNT Libraries Government Documents Department

Removal of Wax and Stickies from OCC by Flotation

Description: 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 ...
Date: January 31, 2000
Creator: Doshi, M. R. & Dyer, J.
Partner: UNT Libraries Government Documents Department

An Ultracentrifugal Method for the Determination of Serum Lipoproteins

Description: A convenient method was developed for the ultracentrifugal analysis of all classes of serum lipoproteins which requires a minimum of time, work and materials. The method utilizes the principle of flotation of lipoproteins in a medium of greater density than their own hydrated density. In this procedure the isolation and the analysis of lipoproteins are done in a NaBr mediumn of density 1.20 g/ml. The advantages of this procedure are compared with other available methods, and its application to studies on serum lipoprotein is discussed. (auth)
Date: September 29, 1958
Creator: Del Gatto, L.; Lindgren, F. T. & Nichols, A. V.
Partner: UNT Libraries Government Documents Department

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

Description: 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.
Date: May 1, 1997
Creator: Honaker, R.Q. & Mohanty, M.K.
Partner: UNT Libraries Government Documents Department

Improvement of storage, handling, and transportability of fine coal. Final report

Description: The Mulled Coal process is a technology which has evolved from a line of investigations which began in the 1970`s. There was a major breakthrough in 1990, and since then, with significant support from DOE-PETC, the technology has progressed from the conceptual stage to a proven laboratory process. It is a simple process which involves the addition of a low cost specifically formulated reagent to wet fine coal by mixing the two in a pug mill. Although the converted material (Mulled Coal) retains some of its original surface moisture, it handles, transports, and stores like dry coal. But, unlike thermally dried fine coal Mulled Coal is not dusty, it will not rewet, and it causes no fugitive dust problems. This project was designed to advance the technology from the status of a process which works well in the laboratory to the status of a technology which is fully ready for commercialization. Project objectives were to: 1. Prove the concept that the technology can be used to produce Mulled Coal of a consistent quality, on a continuous basis, at a convincing rate of production, and at a major preparation plant which produces fine clean coal on a commercial basis. 2. Prove the concept that Mulled Coal, either as a blend with coarser clean coal or as a stand-alone fuel will successfully pass through a representative cross section of conventional coal storage, handling and transportation environments without causing any of the problems normally associated with wet fine coal. 3 Test the design and reliability of Mulled Coal circuit equipment and controls. 4. Test the circuit over a wide range of operating conditions. 5. Project scale-up designs for major equipment components and control circuits. 6. Forecast capital and operating costs for commercial circuits ranging from 25 TPH to 75 TPH. This report describes ...
Date: March 1, 1996
Creator: Maxwell, R.C. Jr. & Jamison, P.R.
Partner: UNT Libraries Government Documents Department

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

Description: Studies have indicated that the potentially hazardous trace elements found in coal have a strong affinity for coal pyrite. Thus, by maximizing the rejection of pyrite, one can minimize the trace element content of a given coal while also reducing sulfur emissions. The pyrite in most Illinois Basin coals, however, is finely disseminated within the coal matrix. Therefore, to remove the pyrite using physical coal cleaning techniques, the pyrite must be liberated by grinding the coal to ultrafine particle sizes. Fortunately, the coals being fed to pulverized coal boilers (PCB) are already ground to a very fine size, i.e., 70% passing 200 mesh. Therefore, this research project will investigate the use of advanced fine coal cleaning technologies for cleaning PCB feed as a compliance strategy. Work in this quarter has focused on the processing of a run-of-mine coal sample collected from Amax Coal Company`s Delta Coal mine using column flotation and an enhanced gravity separator as separate units and in circuitry arrangements. The {minus}60 mesh run-of-mine sample having an ash content of about 22% was cleaned to 6% while achieving a very high energy recovery of about 87% and a sulfur rejection value of 53% in a single stage column flotation operation. Enhanced gravity treatment is believed to be providing excellent total sulfur rejection values, although with inferior ash rejection for the {minus}400 mesh size fraction. The circuitry arrangement with the Falcon concentrator as the primary cleaner followed by the Packed-Column resulted in an excellent ash rejection performance, which out performed the release analysis. Trace element analyses of the samples collected from these tests will be conducted during the next report period.
Date: December 31, 1995
Creator: Honaker, R.Q.; Paul, B.C.; Mohanty, M.K. & Wang, D.
Partner: UNT Libraries Government Documents Department

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

Description: 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.
Date: November 9, 1993
Creator: Wen, Wu-Wey; Gray, M.L. & Champagne, K.J.
Partner: UNT Libraries Government Documents Department

Micro-agglomerate flotation for deep cleaning of coal. Quarterly progress report, July 1, 1995--September 30, 1995

Description: 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.
Date: July 1, 1995
Creator: Chander, S. & Hogg, R.
Partner: UNT Libraries Government Documents Department

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

Description: Goal is engineering development of two advanced physical fine coal cleaning processes, column flotation and selective agglomeration, for premium fuel applications. Scope includes laboratory research and bench-scale testing on 6 coals to optimize these processes, followed by design/construction/operation of a 2-t/hr PDU. During this quarter, parametric testing of the 30-in. Microcel{trademark} flotation column at the Lady Dunn plant was completed and clean coal samples submitted for briquetting. A study of a novel hydrophobic dewatering process continued at Virginia Tech. Benefits of slurry PSD (particle size distribution) modification and pH adjustment were evaluated for the Taggart and Hiawatha coals; they were found to be small. Agglomeration bench-scale test results were positive, meeting product ash specifications. PDU Flotation Module operations continued; work was performed with Taggart coal to determine scaleup similitude between the 12-in. and 6-ft Microcel{trademark} columns. Construction of the PDU selective agglomeration module continued.
Date: July 25, 1996
Creator: Moro, N.; Shields, G.L.; Smit, F.J. & Jha, M.C.
Partner: UNT Libraries Government Documents Department

A study of multistage/multifunction column for fine particle separation. Quarterly technical progress report, January 1, 1996-- March 31, 1996

Description: The overall objective of the proposed research program is to explore the potential application of a new invention involving a multistage column equipped with vortex-inducing loop-flow contactors (hereafter referred to as the multistage column) for fine coal cleaning process. The research work will identify the design parameters and their effects on the performance of the separation process. The results of this study will provide an engineering basis for further development of this technology in coal cleaning and in the general areas of fluid/particle separation. In the last quarter, we investigated the mixing and loop flow (circulation) behaviors around the contactors. In this quarter, the fine coal beneficiation tests were carried out in the multistage column and conventional column.
Date: April 20, 1996
Creator: Chiang, Shiao-Hung
Partner: UNT Libraries Government Documents Department

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

Description: 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.
Date: April 1, 1997
Creator: Honaker, R.Q., Mohanty, M.K.
Partner: UNT Libraries Government Documents Department

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

Description: 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.
Date: April 1, 1996
Creator: Chandler, S. & Hogg, R.
Partner: UNT Libraries Government Documents Department

Improvement of storage, handling, and transportability of fine coal. Quarterly technical progress report No. 4, October 1, 1994--December 31, 1994

Description: The objectives of this project are to demonstrate that: The Mulled Coal process, which has been proven to work on a wide range of wet fine coals at bench scale, will work equally well on a continuous basis, producing consistent quality at a convincing rate of production in a commercial coal preparation plant. The wet product from a fine coal cleaning circuit can be converted to a solid fuel form for ease of handling and cost savings in storage and rail car transportation. A wet fine coal product thus converted to a solid fuel form, can be stored, shipped, and burned with conventional fuel handling, transportation, and combustion systems. During this fourth quarter of the contract period, activities were underway under Tasks 2 and 3. Sufficient characterization of the bench-scale testing and pilot-plant testing results enabled the design and procurement activities to move forward. On that basis, activities in the areas of design and procurement that had been initiated during the previous quarter were conducted and completed.
Date: August 20, 1996
Partner: UNT Libraries Government Documents Department

Improvement of storage, handling, and transportability of fine coal. Quarterly technical progress report No. 7, July 1, 1995--September 30, 1995

Description: The Mulled Coal process was developed as a means of overcoming the adverse handling characteristics of wet fine coal without thermal drying. The process involves the addition of a low cost harmless reagent to wet fine coal using off-the-shelf mixing equipment. Based on laboratory- and bench-scale testing, Mulled Coal can be stored, shipped, and burned without causing any of the plugging, pasting, carryback and freezing problems normally associated with wet coal. The objectives of this project are to demonstrate that: The Mulled Coal process, which has been proven to work on a wide range of wet fine coals at bench scale, will work equally well in a commercial coal preparation plant. The wet product from a fine coal cleaning circuit can be converted to a solid fuel form for ease of handling and cost savings in storage and rail car transportation. A wet fine coal product thus converted to a solid fuel form can be stored, shipped, and burned with conventional fuel handling, transportation, and combustion systems. The Mulled Coal circuit was installed in an empty bay at the Chetopa Preparation Plant. Equipment has been installed to divert a 2.7 tonnes/hr (3 tons/hr) slipstream of the froth concentrate to a dewatering centrifuge. The concentrated wet coal fines from the centrifuge dropped through a chute directly into a surge hopper and feed system for the Mulled Coal circuit. The Mulled Coal product was gravity discharged from the circuit to a truck or product discharge area from which it will be hauled to a stockpile located at the edge of the clean coal stockpile area. During the 3-month operating period, the facility produced 870 tonnes (966 tons) of the Muffed Coal for evaluation in various storage, handling, and transportation equipment and operations. Immediately following the production demonstration, the circuit was disassembled and ...
Date: August 22, 1996
Partner: UNT Libraries Government Documents Department

Improvement of storage, handling, and transportability of fine coal. Quarterly technical progress report No. 5, January 1, 1995--March 31, 1995

Description: The Mulled Coal process was developed as a means of overcoming the adverse handling characteristics of wet fine coal without thermal drying. The process involves the addition of a low cost, harmless reagent to wet fine coal using off-the-shelf mixing equipment. Based on laboratory- and bench-scale testing, Mulled Coal can be stored, shipped, and burned without causing any of the plugging, pasting, carryback and freezing problems normally associated with wet coal. The objectives of this project are to demonstrate that: the Mulled Coal process, which has been proven to work on a wide range of wet fine coals at bench scale, will work equally well on a continuous basis, producing consistent quality at a convincing rate of production in a commercial coal preparation plant; the wet product from a fine coal cleaning circuit can be converted to a solid fuel form for ease of handling and cost savings in storage and rail car transportation; and a wet fine coal product thus converted to a solid fuel form, can be stored, shipped, and burned with conventional fuel handling, transportation, and combustion systems. During this reporting period, virtually all of the technical activities and progress was made in the areas of circuit installation and startup operations. Work in these activity areas are described.
Date: August 21, 1996
Partner: UNT Libraries Government Documents Department

A study of multistage/multifunction column for fine particle seperation

Description: The objective if this program is to explore the potential application of a multistage column equipped with concentric draft- tubes (multistage column) for fine coal cleaning. The aim is to identify design parameters of the separation process. In the last quarter we conducted the gas holdup measurement which is an essential part of the hydrodynamic experiments for establishing a process model for engineering design and scale-up.
Date: September 7, 1997
Creator: Chiang, S.
Partner: UNT Libraries Government Documents Department