Research on performance of a laboratory-scale SAG mill based on DEM-EMBD

Abstract

To explore the performance of a semi-autogenous (SAG) mill under different working conditions, in this paper, the working process of the laboratory-scale SAG mill is taken as the research object. Firstly, the electrical system and multi-body dynamics model (EMBD) of the SAG mill are established, the rock discrete element method (DEM) analysis model is obtained based on the multi-sphere filling method, and then the DEM-EMBD coupling model is created, and its effectiveness is verified through actual experiments. Secondly, the influences of fraction of critical speed, lifter face angle, and rock shape on particle motion characteristics, particle collision energy, and mill torque are studied by the method of DEM-EMBD coupling method. The results show that the particle motion characteristics are mainly determined by fraction of critical speed and lifter face angle. Particle collision energy is mainly determined by lifter face angle and rock shape. Further, when the SAG mill runs at a low speed, the lifter face angle and rock shape become the main influencing factors of the mill torque, and the fraction of critical speed becomes the dominant factor with a high running speed of the SAG mill. Finally, the electromechanical characteristics of the SAG mill are analysed, and the results show that the fluctuation of motor load torque, current, and SAG mill speed in the start-up stage is much larger than that in the stable running stage. The fraction of critical speed and the lifter face angle have a greater impact on the electromechanical characteristics, while the rock shape has little influence on the electromechanical characteristics as a whole.