Abstract: In order to reach the goal of realizing disposal of coal slime as rejected material, a quantitative analysis is made of the coal slime cyclone classifier′s feed and products. Result of analysis shows that the low ash and high calorific value of the coal slime are chiefly attributable to the low efficiencies and high rates of misplaced materials of the cyclone classifier, high-frequency screen, and the cyclone classifier for treating tailings of middlings magnetic separator. After the renovation of the high-frequency screen and the change of the flowsheet of the process for treating the tailings of middlings magnetic separator, the ash of coal slime is seen to go up to over 75%, well up to the standard of being discarded as reject, and the renovation work has led to increase of total yield of clean coal, improvement of composite economic performance of the plant and promotion of comprehensive utilization of coal resources.