Mechanical characteristics of roll crushing of ore materials based on discrete element method

Abstract

The application of high-pressure grinding rolls for ore crushing is considered to be one of the effective ways to save energy and reduce emissions in the ore processing industry. The crushing effect is directly determined by the forces of ore material during roll crushing. However, the mechanical state of ore material in roll crushing and the effect of roll structure, process parameters, feed particle size, on the force during the crushing of ore material needs to be expanded. Therefore, this paper intends to use the discrete element method to study the mechanical characteristics of roll crushing of ore materials. Firstly, the contact parameters of an ore material and the parameters of the Tavares UFRJ Breakage model are calibrated through tests. Then, considering different roll structures, process parameters, and feed particle sizes of high-pressure grinding rolls, a simulation of the industry high-pressure grinding roll crushing process is developed. The force state of ore material, rolls and cheek plates is studied. The main factors and laws are also investigated, which affect the crushing effect and wear of high-pressure grinding rolls. The results show that the material in the roll-crushing process is mainly subject to the normal force. The forces on particles at different locations in the compression zone are related to average velocity. Specific effects of different parameter levels on the forces on the material, rolls, and cheek plates. The wear between the material and the rolls due to extrusion is slightly lower than the shear effect. Besides, the wear of the cheek plates is mainly dominated by the shear effect of the ore material.