The impact behavior between the charge and lifter has significant effect to address the mill processing, and is affected by various factors including mill speed, mill filling, lifter height and media shape. To investigate the multi-body impact load behavior, a series of experiments and Discrete Element Method (DEM) simulations were performed on a laboratory-scale mill, in order to improve the grinding efficiency and prolong the life of the lifter. DEM simulation hitherto has been extensively applied as a leading tool to describe diverse issues in granular processes. The research results shown as follows: The semi-empirical power draw of Bond model in this paper does not apply very satisfactorily for the ball mills, while the power draw determined by DEM simulation show a good approximation for the measured power draw. Besides, the impact force on the lifter was affected by mill speed, grinding media filling, lifter height and iron ore particle. The maximum percent of the impact force between 600 and 1400 N is at 70–80% of critical speed. The impact force can be only above 1400 N at the grinding media filling of 20%, and the maximum percent of impact force between 200 and 1400 N is obtained at the grinding media filling of 20%. The percent of impact force ranging from 0 to 200 N decreases with the increase of lifter height. However, this perfect will increase above 200 N. The impact force will decrease when the iron ore particles are added. Additionally, for the 80% of critical speed, the measured power draw has a maximum value. Increasing the grinding media filling increases the power draw and increasing the lifter height does not lead to any variation in power draw.

Friction and wear are the primary factors for the failure of liners, which affects the lifting capacity and milling cost in ball mills. However, there are no effective methods to measure and evaluate the friction and wear behavior of the liner. Therefore, it is vital to understand the friction and wear mechanisms of liners in ball mills. In this article, the multibody friction and wear properties of a liner in the fracture region and grinding region were investigated using an impact friction test rig and a rolling friction test rig. Three types of evaluation indicators, namely, the coefficient of impact friction (u_i), coefficient of rolling friction (u_r) and 3D morphology, were applied to describe the friction and wear behavior. Results showed that adding ore powder results in an increase in the impact friction coefficient from 0.041 to 0.042 and an increase in the rolling friction coefficient from 0.342 to 0.611 at a contact load of W = 300 N·rpm. However, the addition of slurry leads to an increase in the impact friction coefficient from 0.041 to 0.045 and a decrease in the rolling friction coefficient from 0.342 to 0.112 at a contact load of W = 300 N·rpm. Additionally, the 3D morphology of the wear region shows that the wear of liners in ball mills will generate plastic deformation, scratches, and abrasive behavior. Wear of the liner in dry conditions is faster than that in wet conditions and adding ore powder or slurry in ball mills will be helpful to reduce liner consumption.