Effective Processing of Low-Volatile Medium Coking Coal Fines of Indian Origin Using Different Process Variables of Flotation

Abstract

The low-volatile medium coking coal fines from the eastern part of the Indian coalfield was used for this study. The proximate analysis of the composite sample designates that the fines contain about 25% ash, 21.4% volatile matter, and 52.4% fixed carbon. The ash in the size fraction of −0.5 + 0.15 mm is lower (21.9%) than the −0.15 mm fraction (29.7%). The flotation characteristic of the composite coal reveals that recoverable combustible at 15% ash is 27% and 43% at the 17% ash level. The low yield of the concentrate is due to the presence of fines comprising high ash. To enhance the yield, the −0.5 + 0.15 mm and −0.15 mm fractions were subjected to flotation separately. The effects of reagent dosage and aeration rate were studied with a composite and the −0.5 + 0.15 mm fraction to produce low-ash clean coal. Release analysis carried out with −0.5 + 0.15 mm coal improves the recovery of combustibles to 42% at 15% ash%. The spilt flotation of −0.5 + 0.15 mm feed at the lower frother dosage and lower aeration favors generating the clean coal with low ash. The −0.15 mm fraction was floated with collector using sodium silicate as a depressant. The products having different ash levels could be used in specific purposes.