崩落法采矿中放出体流动特性的影响因素

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

  • 摘要: 基于颗粒元理论和PFC3D程序,构建具有矿石散体细观力学性质的放矿模型,开展崩落法采矿中放出体流动特性影响因素研究.运用统计学知识确定对放出体流动特性有显著影响的主要因素及其敏感性,得出其与放出体流动特性的关系,并通过已有研究结论与模拟结果的对比分析,验证了基于PFC3D程序的放矿模型在放出体流动特性影响因素研究中的适宜性与可靠性.研究表明:放出体颗粒形状、摩擦系数及放矿口尺寸三种因素是显著影响崩落矿岩流动特性的重要参数.在放矿初始阶段,放矿口尺寸对放出体形态影响最大,其次为摩擦系数,颗粒形状对其影响最小;在之后的放矿过程中,颗粒形状对放出体形态影响最大,其次为放矿口尺寸和摩擦系数.散体颗粒形状越不规则、散体内摩擦角越大以及放矿口尺寸越小则放矿越困难.

     

    Abstract: Based on the particle flow theory and PFC3D 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 PFC3D 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.

     

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