Upgrading low-rank coals (Çan, Çanakkale/Turkey) by float-sink separation in dense media

Abstract

ABSTRACTTurkey coal reserves are mainly lignite (brown coal) and the majority of these reserves contain high-ash/sulfur coals, therefore, it is important to evaluate these low-quality lignite coals. Most of the produced lignite is utilized at the coal power stations in Turkey. The polluting gases containing sulfur dioxide after burning of low-quality coals are the main reason for air pollution, acid rain, and some respiratory systems diseases. In order to avoid these problems, high ash and sulfur-containing coal in our country need to be improved. In this study, the sink-float tests (heavy media separation) were applied to increase the quality of coal samples so that the ash and the impurities could be removed using a high ash-sulfur content coal sample (36.96% ash, 6.94% S and calorific value 3185 kcal.kg−1) taken from TKI (Turkish Coal Enterprises) Çan (Çanakkale, Turkey) lignite coalfield. The results of the float-sink tests showed that the most convenient washing operating density was 1.6 g/cm3, and the weight yield of the clean coal was 53.16%wt. (70.94% coal recovery) with 16.46% ash, 6.14% S with calorific value 5000 kcal.kg−1 using 10–0.5 mm size fraction of the coal.