Crushing mechanism analysis of sintered ore and study of particle size distribution pattern after crushing

Abstract

To improve the crushing effect and reduce the range of particle size distribution after crushing, the crushing mechanism and the particle size distribution pattern after crushing of sintered ore under different roller rotation speeds are analysed in this paper. Based on the discrete element method, the microscopic parameters of sintered ore are calibrated and validated by uniaxial compression and the Brazilian splitting test. The initiation, propagation, and penetration of cracks inside the sintered ore are described by innovatively introducing the concept of compaction core and combining the force chain evolution. It reveals that the extension and penetration of radial cracks generated under the action of the tooth tip, along with the continuous formation and crushing of compacted cores, are the essence of crushing. The generation of new cracks originates from the tensile failure between particles in the region where tensile force chains are concentrated. Increasing the rotation speed properly can improve the crushing effect of sintered ore but also excessive rotation speed (4, 5, and 6 rad s−1) will hinder the main crack propagation path of sintered ore and deteriorate the crack penetration effect, which may inhibit the crushing effect of sintered ore in turn. The research results may have important implications for understanding the crushing mechanism of the sintered ore and optimising the crushing process.