Beneficiation of Indian coal by chemical techniques

The high ash content of Indian coals affects the efficiency of operation (when used as fuel in boilers/furnaces) and also the quality of product (coking coals used for producing metallurgical coke). The experimental work conducted takes cognizance of the high silica content of the ash (over 50%) and aims at a selective attack on the silica portion, in order to achieve a substantial reduction in the mineral matter of coal. This was achieved by using certain fluxing agents for producing hydrofluoric acid in situ in the coal bed. The ash content of high ash Western coal fields coal was found to be reduced from 32.9 to about 10% after the treatment.