Abstract:
The rheological characteristics of three varieties of noncoking coals have been modulated by three starch-based additives, starch xanthate, starch xanthide, and starch phosphate. The apparent viscosity of the modified coal-water slurry has been measured by varying coal loading, additive percentage, pH, temperature, etc. Considerably stable concentrated coal-water slurry containing high weight fraction of coal could be achieved in each case, and slurry stays in a nonsettling form for 20-25 days with viscosity in a permissible low range. The effectiveness in reducing the apparent viscosity decreases in the order. Starch xanthide > Starch phosphate > starch xanthate. The plausible mechanism of slurry stabilization has been suggested considering the structural basis of an effective additive for the stabilization of coal-water slurry.