Influencing factors on the flow characteristics of an isolated extraction zone in caving mining

Based on the particle flow theory and PFC^3D code, a draw model with the meso-mechanical properties of ore granular media was constructed to study influencing factors on the flow characteristics of an isolated extraction zone in caving mining. Major factors that have significant influence on the flow characteristics of the isolated extraction zone and their sensibility and relationships with the flow characteristics were determined by statistical knowledge. Simultaneously, the suitability and reliability of the draw model based on PFC^3D code and used in influencing factor research of the isolated extraction zone were validated by contrastive analysis between existing research conclusions and simulated results. The research results show that particle shape, friction coefficient, and drawpoint size are important parameters significantly influencing the flow characteristics of the caved ore and rock. In the initial stage of drawing, drawpoint size has the greatest influence on the form of the isolated extraction zone followed by friction coefficient and particle shape;in the following stage of drawing, particle shape has the greatest influence on the form of the isolated extraction zone followed by drawpoint size and friction coefficient. The drawing will be more difficult if the particle shape is more irregular, the inter-nal friction angle of particles is larger and the drawpoint size is smaller.