Reduction of Sulfur and Ash from Tabas Coal by Froth Flotation

Document Type: Research Article


Department of Chemical Engineering, Isfahan University of Technoogy, Isfahan 84156, I.R. IRAN


Tabas mines in Iran have coal sources which are suitable for use in metallurgy industries as coking coal. But the high sulfur content of this coal imposes severe limitations on its utilization as the sulfur oxide gases evolved from the combustion of high sulfur coals result in acid rains and corrosion of equipments. In this work, attempts have been made to reduce sulfur from high sulfur coal of Tabas by froth flotation. Laboratory tests were carried out in order to investigate the influence of various collectors, frothers, pyrite depressants and their consumption dosages on ash and sulfur reduction of Tabas coal. The use of kerosene as a collector and pine oil as a frother has decreased ash and sulfur content of coal more than other collectors and frothers. Although use of sodium polyacrylic acid as a pyrite depressant improved the total recovery of coal concentrate but did not enhance the reduction of sulfur.


Main Subjects

[1] Mukherjee, S., Mahiuddin, S., and Borthakur, P. C., Demineralization and Desulfurization of Subbi-tuminous Coal with Hydrogen Peroxide, Energy & Fuels, 15, 1418 (2001).

[2] Demirdas, A., Demineralization and Desulfurization of Coals via Column Froth Flotation and Different Methods, Energy Conversion and Management, 43, 885 (2002).

[3] Felici, P. F., Surface Energy and Induction Time of Fine Coal Treated with Various Levels of Dispersed Collector and their Correlation to Flotation Responses, Energy & Fuels, 10, 1202 (1996).

[4] Saleh, A. M., Ramadan, A.M., Moharam, M. R., Study on the Effect of Collector Type and Collector Mixing in Coal Flotation, XXI Int. Miner Process Cong., Rome, Italy, B8b177-184, (2000).

[5]Cebeci, Y.,  The  Investigation  of the  Floatability Improvement of Yozgat Ayridam Lignite Using Various Collectors, Fuel, 81, 281 (2002).

[6] Tao, D., Li, B., Johnson, S. and Parekh, B. K., A Flotation Study of Refuse Pond Coal Slurry, Fuel Processing Technology, 76, 201 (2002).

[7] Erol, M., Colduroglu, C. and Aktas, Z., The Effect of Reagents and Reagent Mixtures on Froth Flotation of Coal Fines, Int. J. Miner Process, 71, 131 (2003).

[8] American Society for Testing and Materials, Annual Book of ASTM Standards, Part 26, (Methods D3174-73 and D3177), Philadelphia, PA, USA, (1983).

[9] Kawatra, S. K. and Elisele, T. C., “Coal Desulfurization” 1st Ed., Taylor & Francis Inc., New York, USA, (2001).

[10] Klimpel, R.R., The Influence of Frother Structure on Industrial Coal Flotation, High-Efficiency Coal Preparation (Kawatra, Ed.), Society for Mining, Metallurgy, and Exploration, Littleton, Co, 141-151, (1995).

[11] Janczuk,  B.,  Wojcik,  W.,  Staszuk,  P., Bialo-piotrowicz, T., Chibowski, E., Detachment Forces of Air Bubble from Pyrite Surface Covered with Polar and Polar Liquids, Journal of Mines &Fuels, 37(9), 380 (1989).

[12] Kawatra, S. K., Eisele, T. C. and  Johnson,  H., “Recovery of Librated Pyrite in Coal Flotation: Entrainment or Hydrophobic?” Processing and Utilization of High Sulfur Coals ІV (Dugar, Quitley and Attia, Eds.), Elsevier, 255-277, (1991).

[13] Klimpel, R.R. and Hansen, R.D., Pyrite Depressants Useful in the Separation of Pyrite from Coal, United Stated Patent, Patent Number: 4830740, (1989).