Characteristics of Wet Grinding of Highly Concentrated Coal Water Slurry

The wet grinding characteristics of CWM (Coal Water Mixture) at high concentrations was investigated by conducting batch preparation tests using a laboratory-scale ball mill. Although the grindability became worse with the increase of slurry concentration, it was found possible to prepare CWM of 65 to 75% by use of the proper dispersant. The improvement of grindability was caused by the improved movement of balls owing to the decrease of apparent viscosity at low shear rates. The grindability greatly changed with coal type. The difference of grindability among coal types was mainly due to the difference of flocculation force.