Effect of lifters and mill speed on particle behaviour, torque, and power consumption of a tumbling ball mill: Experimental study and DEM simulation

Abstract

Crushing and grinding consume most of the energy in mineral processing. Ball mill is an important kind of grinding equipment used to decrease the size of ore particles. The power consumption of a ball mill is one of the most important parameters to consider in the design of a ball mill because it determines its economic efficiency. The power consumption is usually determined by charge fill level, lifter height, lifter number, and mill speed. However, almost all of the classical theories for calculating the power consumption of ball mills disregard the effect of lifters and only focus on rotation rate, charge fill level, as well as size and shape of grinding media, thereby may causing errors. Discrete element method (DEM) can simulate the motion and interaction of particle materials. Thus, this method is widely used to simulate the working process of ball mills, which yields many valuable research outcomes. Moreover, the results obtained from DEM usually should be validated with experiments. In this paper, simulation results of particle behaviour, mill torque, and power consumption obtained from DEM simulation are compared with experimental results in detail to validate the correctness of the simulation results. Especially, the particle behaviour is validated both qualitatively and quantitatively. The DEM results are shown to be highly consistent with the experimental results. The torque of liners and baffles are affected by lifter height, lifter number, and mill speed. Moreover, the changes in the torque and power consumption of a ball mill can be effectively explained using two important factors: lifter and particle area ratio.