Advanced Coal Cleaning Technology for Challenges in Near future

Abstract

Beneficiation potential of a high ash (36%) medium coking coal to a low ash (12%) level is investigated. Characterization studies indicated that the coal must be processed after reducing the size to 1.18 mm in order to accomplish substantial yield of the clean coal. A gravity based flowsheet for the -1.18+0.5 mm fraction is developed to generate clean coal at 12% ash with 9.2% overall yield. Mechanical cell flotation circuit for the -0.5+0.15 mm size fraction resulted in additional 3.5% yield at the desired ash level. A flotation circuit for the fine fraction (-0.15 mm) is developed using Jameson Cell only that added further 3.0% yield in the overall mass recovery at 12% ash. Thus, a total of 15.7% yield of the clean coal with 12% ash is achieved by treating various size classes separately. Recycling of some of the intermediate product streams is recommended for continuous operation to enhance the overall yield of the clean coal significantly.