6 research outputs found
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Fine coal fractionation using a magnetohydrostatic separation process CRADA 91-003. Final report
The magnetohydrostatic separation (MHS) process uses a magnetic fluid which has the ability to float a submerged particle in a magnetic field. The objective of this project was to develop a technique for laboratory gravity fractionation of coal using MHS
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Drying and reconstitution of subbituminous coal - CRADA 90-004. Final report
AMAX Coal Company (AMAX) has built a 200 tph, demonstration scale fluidized-bed drying process at their Belle Ayr Mine in Wyoming to dry the subbituminous coal of Wyodak seam from an average moisture content of 25-30 wt% to about 10 wt%. Currently, the dryer generates too many fines for proper transportation and handling. Though the raw coal is about 2-inch top size, about 80 wt% of the dryer product ends up finer than 28 mesh, and about 10 wt% of the dried coal is collected in the dryer bag house (minus 200 mesh). Paul Woessner, Director of Research and Development of AMAX, met with personnel from PETC Coal Preparation Division and expressed an interest in an investigation of the feasibility of applying the PETC`s humic acid binder to reconstitute the bag house fines from the dryer. This was an area in which PETC had been doing some research and had some expertise. As a result, AMAX and the U.S. Department of Energy`s Pittsburgh Energy Technology Center (PETC) signed a Cooperative Research and Development Agreement (CRADA, see appendix A) in June 1990 to produce, from fine subbituminous coal, economic low moisture reconstituted solid fuel forms that have suitable storage, handling, transportation, and combustion properties. PETC`s task in this agreement was to conduct broad, baseline studies in three areas: (1) to develop a humic acid binder from AMAX subbituminous coal using the PETC-developed Humic Acid Binder Process, (2) to reconstitute AMAX`s dried subbituminous coal fines from the bag house and the fluidized bed dryer product with humic acid binder, and (3) to produce low moisture, water-resistant pellets from raw subbituminous coal by the PETC-developed Lignipel Process. AMAX, on the other hand, agreed to produce 1-2 tons of reconstituted solid fuel for handleability and combustion tests and partially funded PETC`s efforts
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High-Temperature Water-Gas Shift Membrane Reactor Study
NETL’s Office of Research and Development is exploring the integration of membrane reactors into coal gasification plants as a way of increasing efficiency and reducing costs. Water-Gas Shift Reaction experiments were conducted in membrane reactors at conditions similar to those encountered at the outlet of a coal gasifier. The changes in reactant conversion and product selectivity due to the removal of hydrogen via the membrane reactor were quantified. Research was conducted to determine the influence of residence time and H2S on CO conversion in both Pd and Pd80wt%Cu membrane reactors. Effects of the hydrogen sulfide-to-hydrogen ratio on palladium and a palladium-copper alloy at high-temperature were also investigated. These results were compared to thermodynamic calculations for the stability of palladium sulfides
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Initial study of dry ultrafine coal beneficiation utilizing triboelectric charging with subsequent electrostatic separation
A novel, dry process using electrostatics to beneficiate ultrafine coal is being developed by the Coal Preparation Division at the Pittsburgh Energy Technology Center. The historical concept of triboelectricity and its eventual use as a means of charging coal for electrostatic separation will be discussed. Test data from a first-generation and a second-generation Tribo-Electrostatic separator are presented showing the effects of feed particle size, separator voltage, solids concentration in air, and particle velocity on separation performance. 10 refs., 10 figs., 9 tabs
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Fine Anthracite Coal Washing Using Spirals
The spiral performed well in cleaning the coarse 8 x 16 mesh size fraction, as demonstrated by the Ep ranging from 0.091 to 0.177. This is in line with typical spiral performance. In addition, the presence of the coarser size fraction did not significantly affect spiral performance on the typical 16 x 100 mesh fraction, in which the Ep ranged from 0.144 to 0.250. Changes in solids concentration and flow rate did not show a clear correlation with spiral performance. However, for difficult-to-clean coals with high near-gravity material, such as this anthracite, a single-stage spiral cleaning such a wide size fraction may not be able to achieve the clean coal ash and yield specifications required. In the first place, while the performance of the spiral on the coarse 8 x 16 mesh fraction is good with regard to Ep, the cutpoints (SG50s) are high (1.87 to 1.92), which may result in a clean coal with a higher-than-desired ash content. And second, the combination of the spiral's higher overall cutpoint (1.80) with the high near-gravity anthracite results in significant misplaced material that increases the clean coal ash error. In a case such as this, one solution may be to reclean the clean coal and middlings from the first-stage spiral in a second stage spiral
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Sulfur and ash reduction potential and selected chemical and physical properties of United States coals. [Contains glossary]
This report presents the washability and comprehensive characterization results of 543 raw coal samples collected from the Eastern Region of the United States. This is the first volume of a three-volume report on the coals of the United States. All the data are presented in six appendices. Statistical techniques and definitions are presented in Appendix A, and a glossary of terms is presented in Appendix B. The complete washability data and an in- depth characterization of each sample are presented alphbetically by state in Appendix C. In Appendix D, a statistical evaluation is given for the composited washability data, selected chemical and physical properties, and washability data interpolated at various levels of Btu recovery. This presentation is shown by state, section, and region where four or more samples were collected. Appendix E presents coalbed codes and names for the Eastern Region coals. Graphical summations are presented by state, section, and region showing the effects of crushing on impurity reductions, and the distribution of raw and clean coal samples meeting various levels of SO{sub 2} emissions. 14 refs., 27 figs., 3 tabs