Optimization of coal water slurry properties through fine coal particle addition

For lowering energy consumption of low-concentration coal water slurry (CWS), this study investigates enhancing CWS performance through incorporation of micronized particles of coal as into the gasification raw material. Experimental results reveal that ultrafine particles of coal possess good physicochemical properties including low inherent moisture content, large specific surface area, and higher zeta potential. With the incorporation of 15 % fine coal particles, the concentration of CWS increased by 3 percentage points to 63.5 %, while the fractal dimension rose from 2.231 to 2.412, indicating improved packing efficiency of coal particles. Additionally, spread area per unit mass was increased by 21.2 %, and water separation rate was reduced by more than 50.3 %, depicting enhanced slurry stability. Further investigation indicated that fine particles lowered interparticle distance and increased ζ by 40.8 %, enhancing spatial resistance and electrostatic repulsion. The dynamic study indicated that incorporation of fine particles lowered activation energy by 1.42 %, the mean reaction rate ( K mean ) is increased by 188 %, and resulted in a forward shift in temperature of reaction. These observations reveal that incorporation of fine particles can be a means to enhance rheological and gasification properties of CWS and therefore improve energy efficiency in fuel applications on the basis of coal.