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

Description: In the last quarterly report, it was noticed that the baseline dewatering data varied significantly. This abnormality was attributed to the use of house vacuum which varied significantly during the testing. This quarter tests were repeated using a portable vacuum pump which provided a constant vacuum of 25 inches of mercury. Using 30 secs cake drying time and 30 secs cake formation time, the high- and low-porosity ceramic leaf filters provided 21.5% and 18.0% filter cake moistures, respectively. The solids loading on the high- and low-porosity filters were 0.8 Kg/m 2 and 0.44 Kg/m 2 , respectively. Addition of 10 g/t of an anionic flocculant lowered the filter cake moisture from 22.0% to 14.0% using the high-porosity filter, and 18.0% to 13.5% using the low-porosity filter. Addition of 15 g/t of a cationic flocculant lowered filter cake moisture from 18.0% to 16.0% using the low-porosity filter. High-porosity filter did not provide any lowering of filter cake moisture, however, the solids loading increased from 1.5 kg/m 2 to 5.8 kg/m 2 at a flocculant dosage of 25 g/t. This high solids loading indicated thicker filter cake which would retain a high moisture. Among the three surfactants studied, only the non-ionic and the cationic were effective in lowering the filter cake moisture. 0.4 kg/t of a non-ionic surfactant (octyl phenoxy polyethoxy ethanol) lowered filter cake moisture from 19.5% to 16.8%; and 1 kg/t of the cationic surfactant CPCL, lowered the filter cake moisture from 19.0% to 15.8%. Addition of 0.4 kg/t of copper ions or 0.3 kg/t of aluminum ions lowered the filter cake moisture from 20.5% to 17.0%, using the low-porosity filter. The high-porosity filter which showed increase solids loading (thicker filter cakes) did not provide any lowering of the filter cake moisture. Low-porosity filter was found to be more effective ...
Date: October 21, 1998
Creator: Parekh, B.K.; Tao, D. & Groppo, J.G.
Partner: UNT Libraries Government Documents Department


Description: The next generation of forming elements based on acoustic excitation to increase drainage and enhances formation both with on-line control and profiling capabilities has been investigated in this project. The system can be designed and optimized based on the fundamental experimental and computational analysis and investigation of acoustic waves in a fiber suspension flow and interaction with the forming wire.
Date: November 30, 2007
Creator: Aidun, Cyrus K
Partner: UNT Libraries Government Documents Department

Evaluation of hyperbaric filtration for fine coal dewatering. Eleventh quarterly technical progress report, April 1, 1995--June 30, 1995

Description: The main objectives of the project are to investigate the fundamental aspects of particle-liquid interaction in fine coal dewatering, to conduct laboratory and pilot plant studies on the applicability of hyperbaric filter systems and to develop process conditions for dewatering of fine clean coal to less than 20 percent moisture. The program consist of three phases, namely Phase I - Model Development, Phase II - Laboratory Studies, Phase III - Field Testing. The Pennsylvania State University is leading efforts in Phase I, the University of Kentucky in Phase II, and Consol Inc. in Phase III of the program. All three organizations are involved in all the three phases of the program. The Pennsylvania State University is developing a theoretical model for hyperbaric filtration systems, whereas the University of Kentucky is conducting experimental studies to investigate fundamental aspects of particle-liquid interaction and application of high pressure filter in fine coal dewatering. The optimum filtration conditions identified in Phase I and II will be tested in a Consol Inc. coal preparation plant using an Andritz Ruthner portable hyperbaric filtration unit.
Date: December 1, 1995
Creator: Parekh, B.K.; Hogg, R. & Fonseca, A.
Partner: UNT Libraries Government Documents Department

Effects of particle size on the desorption kinetics of water from Beulah-Zap lignite coal: Differential scanning calorimetry results

Description: The drying kinetics of water from three particle-sized Beulah-Zap lignite coal samples were probed using the differential scanning calorimetry technique at 295 < T < 480 K. The measurements undertaken under flowing N{sub 2} gas environment indicate that water is lost from this coal by two independent but simultaneously operative kinetic mechanisms. Our results suggest that the unimolecular decay kinetics are obeyed by those water molecules which are near the mouths of large pores and/or surround the coal particles. Most of the water, about 80% of the water lost in our experiments, was removed via a 2nd-order diffusion mechanism. As expected, the desorption activation energies of the 2nd-order diffusion kinetics were much larger than the decay mechanism`s activation energies. Our results also suggest, at least for particle sizes < 841 {mu}m, < 106 {mu}m, and < 37 {mu}m, that the coal particle size has little effect on the desorption activation barriers.
Date: March 1996
Creator: Dang, Yuhong; Malhotra, V. M. & Vorres, K. S.
Partner: UNT Libraries Government Documents Department

Subtask 3.16 - Low-Cost Coal-Water Fuel for Entrained-Flow Gasification

Description: The specific objective of this research project is to assess the potential process efficiency and pollution control benefits that may occur by applying the hydrothermal, or hot water-drying, process to low-rank coals as related to entrained-flow gasification systems. Project emphasis is on identifying more efficient coal dewatering and CWF formulation methods prior to gasification. A favorable estimate of incremental cost for integrated hydrothermal drying depends, in part, on increasing the particle size of the feed coal from minus 100 to minus 28 mesh for the purpose of simplifying the slurry concentration process. Two options will be reviewed for dewatering or concentrating the processed slurry: (1) repressurization and then concentration with sieve bends or (2) partial dewatering at system pressure with hydroclones. Both have their own merits, sieve bends being a low-cost alternative, while hydroclone application would not require additional pumping sections prior to gasification. Various CWF samples with different particle-size distributions and solids concentrations will be sent to equipment vendors for application review. Also, EERC cost models will be used to calculate the integral cost of adding the partial dewatering to the hydrothermal technology for a commercial-size facility.
Date: October 1, 1997
Creator: Anderson, C.M.
Partner: UNT Libraries Government Documents Department

Application of the Granuflow Process to Pipeline-Transported Coal Slurry CRADA PC96-010, Final Report

Description: In light of the current difficulties in processing fine coal and the potential for a significant increase in fines due to more demanding quality specifications, the U.S. Department of Energy's Federal Energy Technology Center (FETC) has been involved in the reconstitution of the fine clean coal resulting from advanced fine coal cleaning technologies. FETC has invented and developed a new strategy that combines fine-coal dewatering and reconstitution into one step. The process reduces the moisture content of the clean coal, and alleviates handling problems related to dustiness, stickiness, flowability, and freezing. This process has been named the GranuFlow Process. Early work successfully demonstrated the feasibility of the process for laboratory-scale vacuum filtration dewatering using asphalt emulsion. Further tests focused on the application of the process to a screen-bowl centrifuge via batch mode tests at 300 lb/hr. These tests produced roughly the same results as the laboratory filtration tests did, and they included some testing using Orimulsion, a bitumen emulsion. The Orimulsion seemed to offer greater potential for moisture reduction and was less affected by colder slurry temperatures. Most recently, FETC has conducted several series of tests in its Coal Preparation Process Research Facility. These tests dramatically showed the visible difference in the dewatered product by applying the GranuFlow Process, turning it from a clumpy, wet, sticky material into a granular, dry free-flowing product. In addition, it verified previous results with improvements in moisture content, dustiness, stickiness, and freezing. Orimulsion showed a significant benefit over asphalt emulsion in moisture reduction at additions more than 5%. The overall goal of this project was to successfully apply FETC'S GranuFlow Process to improve coal slurry pipeline operations. Williams Technologies, Inc. (WTI), a leader in pipeline technology, has an interest in reducing the moisture content of the coal at the end of a coal slurry ...
Date: September 24, 1997
Creator: Killmeyer, Richard P. & Wen, Wu-Wey
Partner: UNT Libraries Government Documents Department

POC-scale testing of an advanced fine coal dewatering equipment/technique: Quarterly technical progress report,January--March 1997

Description: Laboratory centrifugal dewatering tests were conducted to study the effects of anionic and cationic flocculants on filtration of PMCC compliance (low sulfur) and non-compliance (high sulfur) ultrafine coal slurry. The results obtained with compliance coal indicated that use of 30 g/t anionic flocculant reduced filter cake moisture from 32. 3 to 29.0 percent and increased solids recovery by two absolute percentage points. Use of cationic flocculant had no effects on solids recovery but lowered cake moisture to 27 percent at a dosage of 15 g/t. With the non-compliance coal slurry addition of 15 g/t anionic flocculant lowered cake moisture from 30 to 28.5 percent with marginal effects on solids recovery; addition of cationic flocculant reduced cake moisture by one absolute percentage point. Both flocculants showed marginal effects on solids recovery. Laboratory vacuum filter leaf filtration studies showed that use of flocculants considerably increased filtration kinetics. For example, addition of 15 g/t anionic flocculant to the compliance coal slurry increased filtration kinetics by 10 times and addition of 15 g/t.
Date: May 7, 1997
Creator: Tao, D.; Grappo, J.G. & Parekh, B.K.
Partner: UNT Libraries Government Documents Department

Thermal denitration and mineralization of waste constituents

Description: In order to produce a quality grout from LLW using hydraulic cements, proper conditioning of the waste is essential for complete cement curing. Several technologies were investigated as options for conditions. Since the LLW is dilute, removal of all, or most, of the water will significantly reduce the final waste volume. Neutralization of the LLW is also desirable since acidic liquids to not allow cement to cure properly. The nitrate compounds are very soluble and easily leached from solid waste forms; therefore, denitration is desirable. Thermal and chemical denitration technologies have the advantages of water removal, neutralization, and denitration. The inclusion of additives during thermal treatment were investigated as a method of forming insoluable waste conditions.
Date: August 1, 1997
Creator: Nenni, J.A. & Boardman, R.D.
Partner: UNT Libraries Government Documents Department

Hydrophobic Dewatering of Fine Coal. Topical report, March 1, 1995-March 31, 1997

Description: Many advanced fine coal cleaning technologies have been developed in recent years under the auspices of the U.S. Department of Energy. However, they are not as widely deployed in industry as originally anticipated. An important reason for this problem is that the cleaned coal product is difficult to dewater because of the large surface area associated with fine particles. Typically, mechanical dewatering, such as vacuum filtration and centrifugation, can reduce the moisture to 20-35% level, while thermal drying is costly. To address this important industrial problem, Virginia Tech has developed a novel dewatering process, in which water is displaced from the surface of fine particulate materials by liquid butane. Since the process is driven by the hydrophobic interaction between coal and liquid butane, it was referred to as hydrophobic dewatering (HD). A fine coal sample with 21.4 pm median size was subjected to a series of bench-scale HD tests. It was a mid-vol bituminous coal obtained from the Microcel flotation columns operating at the Middle Fork coal preparation plant, Virginia. All of the test results showed that the HD process can reduce the moisture to substantially less than 10%. The process is sensitive to the amount of liquid butane used in the process relative to the solids concentration in the feed stream. Neither the intensity nor the time of agitation is critical for the process. Also, the process does not require long time for phase separation. Under optimal operating conditions, the moisture of the fine coal can be reduced to 1% by weight of coal.
Date: December 31, 1997
Creator: Yoon, R.; Sohn, S.; Luttrell, J. & Phillips, D.
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 pm) 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 36 months beginning September 30, 1994. This report discusses technical progress made during the quarter from July 1 - September 30, 1997.
Date: September 1, 1998
Partner: UNT Libraries Government Documents Department


Description: The main objective of the proposed program is to evaluate a novel surface modification technique, which utilizes the synergistic effect of metal ions-surfactant combination, for dewatering of ultra-fine clean coal on a proof-of-concept scale of 1 to 2 tph. The novel surface modification technique developed at the UKCAER will be evaluated using vacuum, centrifuge, and hyperbaric filtration equipment. Dewatering tests will be conducted using the fine clean-coal froth produced by the column flotation units at the Powell Mountain Coal Company, Mayflower Preparation Plant in St. Charles, Virginia. The POC-scale studies will be conducted on two different types of clean coal, namely, high-sulfur and low-sulfur clean coal. The Mayflower Plant processes coals from five different seams, thus the dewatering studies results could be generalized for most of the bituminous coals.
Date: February 3, 1998
Creator: PAREKH, B.K.; TAO, D. & GROPPO, J.G.
Partner: UNT Libraries Government Documents Department


Description: The major aspects of this project are proceeding toward completion. Prior to this quarter, design criteria, tentative site selection, facility layout, and preliminary facility cost estimates were completed and issued. Processing of bio-solids was completed, providing material for the pilot operations. Pilot facility design, equipment selection, and modification were completed during the fourth quarter of 2000. Initial pilot facility shakedown was completed during the fourth quarter. After some unavoidable delays, a suitable representative supply of MSW feed material was procured. During this first quarter of 2001, shredding of the feed material and final feed conditioning were completed. Pilot facility hydrolysis production was completed to produce lignin for co-fire testing. During this quarter, TVA completed the washing and dewatering of the lignin material produced from the MSW hydrolysis. Seven drums of lignin material were washed to recover the acid and sugar from the lignin and provide an improved fuel for steam generation. Samples of both the lignin and bio-solids fuel materials for co-fire testing were sent to the co-fire facility (EERC) for evaluation. After sample evaluation, EERC approved sending the material and all of the necessary fuel for testing was shipped to EERC. EERC has requested and will receive coal typical of the fuel to the TVA-Colbert boilers. This material will be used at EERC as baseline material and for mixing with the bio-fuel for combustion testing. EERC combustion testing of the bio based fuels is scheduled to begin in August of 2001. The TVA-Colbert facility has neared completion of the task to evaluate the co-location of the Masada facility on the operation of the power generation facility. The TVA-Colbert fossil plant is fully capable of providing a reliable steam supply. The preferred steam supply connection points and steam pipeline routing have been identified. The environmental review of the pipeline routing ...
Date: July 1, 2001
Creator: Berglund, Ted; Ranney, Jeffrey T.; Babb, Carol L. & Broder, Jacqueline G.
Partner: UNT Libraries Government Documents Department

Relationship of shale dewatering and smectite dehydration to undercompaction occurrence

Description: The cause(s) of abnormal fluid pressures in sedimentary basins are not clearly understood. One step in determining the mechanism(s) of abnormal pressure generation in sedimentary basins is to develop an understanding of the relationship among undercompacted shale, abnormal pressure, and temperature. Our research focused on understanding undercompaction and how it related to smectite-illite conversion. A series of carefully designed experiments were used to help clarify and evaluate the relationship of smectite-illite transformation to undercompaction.
Date: December 1, 1996
Creator: Leftwich, J.T. Jr.
Partner: UNT Libraries Government Documents Department


Description: It is the objective of the project to further develop the triboelectrostatic separation (TES) process developed at the Federal Energy Technology Center (FETC) and to test the process at a proof-of-concept (POC) scale. This process has a distinct advantage over other coal cleaning processes in that it does not entail costly steps of dewatering. The POC-scale unit is to be developed based on (i) the charging characteristics of coal and mineral matter that can be determined using the novel on-line tribocharge measuring device developed at Virginia Tech and (ii) the results obtained from bench-scale TES tests conducted on three different coals. During the past quarter, most of the personnel assigned to this project have been performing work elements associated with the engineering design (Task 3) of the TES process. This activity has been subdivided into three subtasks, i.e., Charger Tests (Subtask 3.1), Separator Tests (Subtask 3.2), and Final POC Design (Subtask 3.3). In Subtask 3.1, several different tribocharging devices have been constructed using materials of various work functions. They are currently being tested to establish the best materials to be used for designing and manufacturing the optimum tribochargers that can maximum charge differences between coal and mineral matter. In Subtask 3.2, bench-scale cleaning tests have been conducted to study the effects of the various operating and design parameters on the performance of the electrostatic separator. Two different TES units have been tested to date. One uses drum-type electrodes to separate charged particles, while the other uses plate-type electrodes for the separation. The test results showed that a major improvement in separation efficiency can be achieved by recycling the middlings back to the feed stream. It has also been established that the major source of inefficiency arises from the difficulty in separating ultrafine particles. Understanding the behavior of the ultrafine particles ...
Date: March 10, 1999
Creator: Yan, E.S.; Luttrell, G.H.; Adel, G.T. & Yoon, R.-H.
Partner: UNT Libraries Government Documents Department

Utilization of lightweight materials made from coal gasification slags. Quarterly report, June--August 1995

Description: Integrated-gasification combined-cycle (IGCC) technology is an emerging technology that utilizes coal for power generation and production of chemical feedstocks. However, the process generates large amounts of solid waste, consisting of vitrified ash (slag) and some unconverted carbon. In previous projects, Praxis investigated the utilization of {open_quotes}as-generated{close_quotes} slags for a wide variety of applications in road construction, cement and concrete production, agricultural applications, and as a landfill material. From these studies, we found that it would be extremely difficult for {open_quotes}as-generated{close_quotes} slag to find large-scale acceptance in the marketplace even at no cost because the materials it could replace were abundantly available at very low cost. It was further determined that the unconverted carbon, or char, in the slag is detrimental to its utilization as sand or fine aggregate. It became apparent that a more promising approach would be to develop a variety of value-added products from slag that meet specific industry requirements. This approach was made feasible by the discovery that slag undergoes expansion and forms a lightweight material when subjected to controlled heating in a kiln at temperatures between 1400 and 1700{degrees}F. These results indicated the potential for using expanded slag as a substitute for conventional lightweight aggregates (LWA). The technology to produce lightweight and ultra-lightweight aggregates (ULWA) from slag was subsequently developed by Praxis with funding from the Electric Power Research Institute (EPRI), Illinois Clean Coal Institute (ICCI), and internal resources. The major objectives of the subject project are to demonstrate the technical and economic viability of commercial production of LWA and ULWA from slag and to test the suitability of these aggregates for various applications.
Date: September 1, 1995
Partner: UNT Libraries Government Documents Department


Description: The project involves the development of an efficient, environmentally friendly system for the economical recovery of carbon from fine-coal refuse ponds. The project will be conducted in two phases. Phase I was involved in the development and evaluation of process equipment and techniques to be used in carbon recovery, product dewatering and reconstitution, and refuse management. Phase II will integrate the various units into a continuously operating circuit that will be demonstrated at a site selected based on the results presented in this study.
Date: July 1, 2000
Creator: Chugh, Y.P.; Patil, D.; Patwardhan, A.; Honaker, R.Q.; Parekh, B.K.; Tao, D. et al.
Partner: UNT Libraries Government Documents Department


Description: West Carney Field produces from Hunton Formation. All the wells produce oil, water and gas. The main objective of this study is to understand the unique behavior observed in the field. We would also like to extend the analysis to other similar fields. This report specifically addresses two issues relevant to our understanding of the West Carney reservoir. In the first part, we discuss our efforts to develop the geological model which can help us understand how the depositional environment affects the producing behavior. In the previous Budget Period, we described fourteen cores. In this report, we present preliminary analysis of several additional cores and conodont work. Based on the additional data collected, it is clear that the earlier geological model is simplified and needs to be updated. The complexity in geological environment can explain some of the unusual behavior observed in the field production. The second issue deals with how to develop a model for gauging a potential success of a dewatering project. We have a developed hypothesis regarding what makes it successful, however, we need to test it against the available data. We have started collecting data from other fields producing from Hunton formation so that we can test this hypothesis. In this report, we provide the details of our effort to collect additional information.
Date: July 1, 2003
Creator: Kelkar, Mohan
Partner: UNT Libraries Government Documents Department

D-Zero Central Calorimeter Inner Vessel Pumpdown Information

Description: The information presented in this engineering note can be of value to others who wish to predict pumping times and water content of vessels containing G-IO material. Four predictions of the water content of the G-IO in the D-Zero Central Calorimeter (CC) are given. Experience from pumping on the NW A cryostat was used to help predict the pumpdown time required for the CC. The actual pumpdown time and water removal from the CC agrees quite well with those predicted which gives confidence for future predictions done using the information presented in this engineering note. A listing of the predictions and actual CC pumpdown particulars is given.
Date: December 10, 1990
Creator: Rucinski, R.
Partner: UNT Libraries Government Documents Department

Modeling and High-Resolution-Imaging Studies of Water-Content Profiles in a Polymer-Electrolyte-Fuel-Cell Membrane-Electrode Assembly

Description: Water-content profiles across the membrane electrode assembly of a polymer-electrolyte fuel cell were measured using high-resolution neutron imaging and compared to mathematical-modeling predictions. It was found that the membrane held considerably more water than the other membrane-electrode constituents (catalyst layers, microporous layers, and macroporous gas-diffusion layers) at low temperatures, 40 and 60 C. The water content in the membrane and the assembly decreased drastically at 80 C where vapor transport and a heat-pipe effect began to dominate the water removal from the membrane-electrode assembly. In the regimes where vapor transport was significant, the through-plane water-content profile skewed towards the cathode. Similar trends were observed as the relative humidity of the inlet gases was lowered. This combined experimental and modeling approach has been beneficial in rationalizing the results of each and given insight into future directions for new experimental work and refinements to currently available models.
Date: March 6, 2008
Creator: Stevenson, Cynthia; Weber, A.Z. & Hickner, M.A.
Partner: UNT Libraries Government Documents Department

Evaluation of hyperbaric filtration for fine coal dewatering. Second Quarterly technical progress report, December 1, 1992--February 28, 1993

Description: The normal practice in the coal preparation plant is to remove the water from the fine coal slurry by vacuum filtration and drying. Conventional vacuum filtration typically produces filter cake moisture containing in the range of 25 to 30 weight percent from minus 28 mesh coal slurries. Although the desired product quality can be obtained by using thermal dryers, there are problems associated with these equipment such as high capital costs and the greatest potential source of air pollution in a coal cleaning plant. In the present research project, an alternative to thermal drying, hyperbaric filtration which has shown potential in lowering moisture content in fine coal to about 20 percent level, is being investigated in detail. This project will essentially focus on developing fundamental information on particle-liquid interaction during hyperbaric filtration and applying the knowledge in developing optimum conditions for the pilot plant testing of the hyperbaric filter system.
Date: June 1, 1993
Creator: Parekh, B. K.; Hogg, R. & Fonseca, A.
Partner: UNT Libraries Government Documents Department

Dewatering studies of fine clean coal. Technical report, September 1, 1991--November 30, 1991

Description: Physical cleaning of ultra-fine coal using an advanced froth flotation technique provides a low ash product, however, the amount of water associated with clean coal is high. Economic removal of water from the froth will be important for commercial applicability of advanced froth flotation processes. The main objective of the present research program is to study and understand the dewatering characteristics of ultra-fine clean coal and to develop the process parameters to effectively reduce the moisture to less than 20 percent in the clean coal product. The research approach under investigation utilizes synergistic effects of metal ions and surfactant to lower the moisture of clean coal using a conventional vacuum dewatering technique. During the last year`s effort, it was reported that a combination of metal ion and surfactant provided a 22 percent moisture filter cake.
Date: December 31, 1991
Creator: Parekh, B. K.
Partner: UNT Libraries Government Documents Department

Evaluation of hyperbaric filtration for fine coal dewatering. First quarterly technical progress report, September 1, 1992--November 30, 1992

Description: Most of the coal presently used by the utility industry is cleaned at preparation plants employing wet processes. Water, while being the mainstay of coal washing, is also one of the least desirable components in the final product. Coarse coal (+3/4 inch) is easily dewatered to a 3--4 percent moisture level using conventional vibrating screens and centrifuges. However, the main problem of excess product moisture occurs in fine (minus 28 mesh) coal and refuse. Even though fines may constitute only about 20 percent of a contemporary cleaning plant feed, they account for two-thirds of the product surface moisture. This high surface moisture offsets many of the benefits of coal cleaning, and can easily undercut the ongoing programs on recovery of fine clean coal from refuse as well as producing an ultra-fine super clean coal fuel. Currently, most of the coal preparation plants utilize vacuum disk type technology for dewatering of the fine coal, providing dewatered product containing about 25 percent moisture. The coal industry would prefer to have a product moisture in the range of 10 to 15 percent, thereby avoiding thermal drying of coal. Hyperbaric filtration. has shown potential in lowering moisture in fine coal to about 20 percent level. This project will develop fundamental information on particle-liquid interaction during hyperbaric filtration and apply the knowledge in developing optimum conditions for the pilot plant testing of the hyperbaric filter system.
Date: December 31, 1992
Creator: Parekh, B. K.; Hogg, R. & Fonseca, A.
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