Influence of pitch coal surface treatment on the beneficiation of high water content coal and the rheological properties of CWS

Abstract

The influence of pitch coal surface treatment on the beneficiation of high water content coal and preparation of its highly concentrated coal-water slurry (CWS) has been investigated. Weak slurryability coal, containing a high water content, exhibited a high degree of hydrophilicity. Having been treated by pitch during milling, the surface of coal particles became increasingly hydrophobia Coal powders treated and untreated with pitch were beneficiated in the oil-water system for comparison. The value of ash reduction of the pitch treated coal powders was higher than that of the untreated ones after beneficiation. The untreated, treated and beneficiated coals were used to prepare highly concentrated CWS by adding additives. The results of rheological experiments show that the CWS of beneficiated coal after treatment with pitch had lower viscosities compared with the CWS of the untreated coal or treated coal without beneficiation.