Removal of organic carbon in coal-series kaolin using gravity separation

Abstract

ABSTRACTCoal-series kaolin, a precious associated nonmetal mineral in coal mines, shows high industrial value. However, it usually contains organic carbon and a small amount of impurities including iron and titanium elements, which seriously decrease the whiteness of final kaolin products. In this investigation, gravity separation method was adopted to remove organic carbon from coal-series kaolin (decarbonized kaolin) based on the differences in density. It was found that compared with the raw kaolin, the loss on ignition (LOI) of decarbonized kaolin was decreased by 44.22%, and the contents of Fe2O3 and TiO2 were also decreased by 48.57% and 59.57%, respectively. The decarbonized kaolin was of high purity, and the whiteness of the decarbonized kaolin was much higher than that of the raw kaolin. The organic carbon separated from the coal-series kaolin can also be used in various ways depending on its coal rank and quality, which avoids the waste of coal resources. The coal-series kaolin can obtain a better use after removing the organic carbon using the gravity separation.