Beneficiation of Coal from Impounded Coal Waste
Publication: Journal of Energy Engineering
Volume 123, Issue 1
Abstract
The potential for recovery and purification of fine coal particles from the impounded waste of a coal cleaning plant using a two-stage, two-solvent system was investigated. The two-solvent system consisted of a first-stage fluid (a mixture of n-dodecane and 2-propanol) used to separate fine coal particles from ash-forming impurities, and a second-stage fluid, the U.S. Environmental Protection Agency (EPA) toxicity characteristic leaching procedure (TCLP) solvents, used to remove sulfur and mineral impurities from the recovered coal. The degree of separation of organic matter from inorganic impurities was examined as a function of the fraction of n-dodecane in the first-stage fluid, and settling time. The results show a general trend of increasing organic matter recovery with increasing fraction of n-dodecane. The most ash removal was obtained with a first-stage fluid of 4% n-dodecane and 96% 2-propanol by volume. Mineral and sulfur removal from the recovered coal was negligible. Further treatment with TCLP solvents in the second stage showed significant removal from the recovered coal (over 70%) of iron, manganese, and sodium. Sulfur and calcium removal was poor (less than 50%); it is likely that these are bound in the organic matrix. The energy content of the final recovered coal product was 34.9 MJ/kg, an increase of 22.2% over the 28.59 MJ/kg of the impounded waste.
Get full access to this article
View all available purchase options and get full access to this article.
References
1.
Blanchar, R. W., Rehm, G., and Caldwell, A. C.(1965). “Sulfur in plant materials by digestion with nitric and perchloric acid.”Soil Sci. Soc. of Am. Proc., 29, 71–72.
2.
Brown, D. (1962). “Coal flotation.”Froth flotation, 50th anniversary volume, D. Fuerstneau, ed., The Am. Inst. of Min., Metallurgical, and Petr. Engrg., Inc., New York, N.Y.
3.
Capes, C. E., and Germain, R. J. (1982). “Selective oil agglomeration in fine coal beneficiation.”Physical cleaning of coal: present and developing methods, Y. A. Liu, ed., Marcel Dekker, Inc., New York, N.Y., 293–351.
4.
Hustwit, C. C., and Sykes, R. G. (1994). “Pipeline treatment of a metal mine drainage containing copper and zinc.”International land reclamation and mine drainage conference and third international conference on the abatement of acidic drainage; vol 1 of 4: mine drainage, Spec. Publ. SP 06A–94, U.S. Bureau of Mines, Washington, D.C., 233–240.
5.
Khoury, D. L., ed. (1981). Coal cleaning technology. Noyes Data Corporation, Park Ridge, N.J.
6.
Lai, R. W., Gray, M. L., Richardson, A. G., and Chiang, S. H. (1982). “Size reduction and selective agglomeration of coal: technical feasibility of cleaning Pittsburgh seam coal with isooctane.”Advances in coal mineral processing using flotation, Proc. Engrg. Found. Conf., The Engrg. Found., New York, N.Y., 120–129.
7.
“Method 1311: toxicity characteristic leaching procedure (TCLP).” (1986). Code of Federal Regulations, Title 40, Part 261, Appendix II.
8.
Osborne, D. G. (1988a). Coal preparation technology: volume one. Graham and Trotman, London, England.
9.
Parr Instrument Company. (1968). “Operating instructions for the 1341 oxygen bomb calorimeter.”Publ. No. 204M, Moline, Ill.
10.
Read, R. B., Camp, L. R., Summers, M. S., and Rapp, D. M.(1989). “The influence of reagent type on the kinetics of ultrafine coal flotation.”Powder technol., 59(3), 153–162.
11.
“Standard methods for the examination of water and wastewater, 17th Ed.” (1989). Am. Public Health Assoc., Washington, D.C.
12.
Wang, Z. Y., Ohtsuka, Y., and Tomita, A.(1986). “Removal of mineral matter from coal by alkali treatment.”Fuel processing technol., 13(3), 279–289.
13.
Welz, B. (1985). “Atomic absorption spectrometry.”Rep. D-6940, VCH Verlagsgesellschaft mbH, Weinheim, Germany.
14.
Wheelock, T. D. (1982). “Development and demonstration of selected fine coal beneficiation methods.”Physical cleaning of coal: present and developing methods, Y. A. Liu, ed., Marcel Dekker, Inc., New York, N.Y., 353–397.
Information & Authors
Information
Published In
Journal of Energy Engineering
Volume 123 • Issue 1 • April 1997
Pages: 20 - 32
Copyright
Copyright © 1997 American Society of Civil Engineers.
History
Published online: Apr 1, 1997
Published in print: Apr 1997
Authors
Metrics & Citations
Metrics
Citations
Download citation
If you have the appropriate software installed, you can download article citation data to the citation manager of your choice. Simply select your manager software from the list below and click Download.