Abstract: The stirred mill is more suitable for fine grinding of ore than ball mill. In the actual grinding process,it is difficult to measure the internal working state of the stirred mill directly. It has become one of the important research methods to analyze the internal working state of the stirred mill with the help of simulation technology. In this study,a laboratory vertical stirred mill was taken as the prototype. The collision characteristics of media in stirred mill were analyzed using EDEM discrete element simulation software. The influences of process parameters,such as medium ratio,filling rate,and agitator speed,on the motion velocity of media,number of collisions,collision force,and collision energy were investigated systematically. The results showed that the motion velocity of the media,maximum normal force of collision,and collision energy increased with increasing the media ratio of ϕ5 mm and ϕ3 mm,but the number of collisions decreased. With increasing filling rate,the number of collisions was increased,but the motion velocity of media,maximum normal force of collision,and collision energy was decreased gradually. Meanwhile,a higher rotate speed of stirrer gave an increased motion velocity of the media,number of collisions,maximum normal force of collision,and collision energy. The results of this paper revealed the motion state of the media in the stirring mill,which also provided certain guiding for the selection of suitable grinding process parameters.

Key words: EDEM,stirred mill,media collision,medium ratio,filling rate,agitator speed