Simulation and Parameter Optimisation of Edge Effect in Ore Minerals Roll Crushing Process Based on Discrete Element Method

The edge effect is caused by poor use of confinement systems, different roll aspect ratios, operating conditions and other factors, which result in uneven pressure distribution between the two crushing rolls along the roll width direction, affecting the overall roll crushing process. To reduce the edge effect, this paper investigates the simulation of the edge effect and parameter optimisation in the roll-crushing process of ore materials based on the discrete element method (DEM). Firstly, the parameters of the iron ore crushing model are experimentally calibrated, and the working process of HPGR is simulated by DEM. Secondly, the effects of roll speed, roll gap, roll diameter and roll width on edge effect and crushing effect of HPGR are analysed by the one-factor experiment. Finally, the roll pressure optimisation model is established based on the Response Surface Methodology (RSM) to obtain the optimal roll pressure parameters. The results show that, with the roll speed and roll diameter increase, the edge effect also increases, the roll gap shows the opposite trend, and the roll width has less influence. The change in roll diameter has the greatest influence on the crushing effect, roll gap is second, and roll speed and roll width have less influence on the crushing effect. When the feed particles are iron ore with a particle size of 32 mm, the optimisation results show that the edge effect and crushing effect of HPGR are significantly improved when the roll speed is 1.25 rad/s, the roll gap is 38 mm, the roll diameter is 2000 mm and the roll width is 742 mm.