Abstract： In order to solve the problem that the settling speed of slime in a coal preparation plant is slow and the washing ability is affected, combined with the actual settlement of slime in the coal preparation plant, taking the feeding of the washing system after fractional roasting as the research object, the mineral composition in slime water, the water quality of slime water, the density of slime in slime water and the particle size of slime in slime water were analyzed by X-ray fluorescence spectrometry, pH method and conductivity method. It is concluded that the minerals of slime in the coal preparation plant are mainly kaolinite, and the pH value is acidic or neutral, the density of slime is 1.3 g/cm3, and the particle size of slime is more than 0.045. In what range, the coal preparation plant washing effect is the best, to provide data support for the next technical transformation.
