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Chemical Cleaning of Coal with Hot Alkaline Solutions
Fossil Fuels Utilization, Environmental Concerns
  • C.Y. Chi, Iowa State University
  • C.W. Fan, Iowa State University
  • Richard Markuszewski, Iowa State University
  • Thomas D. Wheelock, Iowa State University
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Book Chapter
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Published Version
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Various bituminous coals were demineralized by an experimental two-step leaching process in which the ballmilled coals were first treated with a hot alkaline solution and then with a dilute mineral acid. Different alkalis and acids were studied to determine their relative effectiveness. In addition, the effects of alkali concentration, treatment temperature, and treatment time were evaluated. Under the best conditions, the process reduced the ash content of the coals by 85-90% and the total sulfur content by 70-90%. As the temperature of the alkaline treatment was raised from 150 to 345°C, the removal of sulfur increased greatly whereas the recovery of organic matter declined. When a 1 M sodium carbonate solution was employed for the treatment, the recovery of organic matter was 91-97% for various coals treated at 250°C and 79-89% for the same coals treated at 300°C.

Reprinted (adapted) with permission from Fossil Fuels Utilization, Chapter 3, pp 30–41. Copyright 1986 American Chemical Society.

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American Chemical Society
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Citation Information
C.Y. Chi, C.W. Fan, Richard Markuszewski and Thomas D. Wheelock. "Chemical Cleaning of Coal with Hot Alkaline Solutions" Fossil Fuels Utilization, Environmental Concerns Vol. 319 (1986) p. 30 - 41
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