Abstract: Ball mill is the key equipment in cement grinding system. Based on the Discrete Element Method and Rocky DEM software, the motion process of grinding medium and material during the operation of ball mill is numerically simulated. The effects of mill rotation speed, material properties of grinding medium, medium filling rate and gradation on the motion of material particles and equipment energy consumption are analyzed. The research shows that under different material characteristics and processing requirements, the mill rotation speed, the optimum filling rate and gradation of grinding medium are different. The use of ceramic balls instead of steel balls can significantly reduce the energy consumption of ball mills. Moreover, the influence of grinding medium gradation on the energy consumption utilization rate of ball mills is greater than that of the material properties of grinding medium, and the influence of restitution coefficient of grinding medium on the energy consumption utilization rate is greater than that of the density of grinding medium. Based on single factor analysis and multi-objective optimization design method, it is possible to not only improve the material and gradation of grinding medium but also achieve energy conservation and consumption reduction of cement grinding systems.
