复杂边界条件下崩落矿岩流动特性

Flow characteristics of caved ore and rock under complex boundary conditions

基于颗粒元理论和PFC3D程序,构建放矿模型,开展对倾斜矿体复杂边界条件下崩落矿岩流动特性的研究,实现放出体(IEZ)形态的可视化。同时,将模拟结果与已有研究结论进行对比,验证基于PFC程序的放矿模型在崩落矿岩流动特性研究中的适用性与可靠性。研究结果表明:因受到倾斜边壁的限制,在复杂边界条件下放出体形态产生不同程度的变异,并不是一个规则的椭球体;在3类边界条件下,在放矿初始阶段,放出体高度呈指数形式快速增加,随着放矿量的增加,其增长率逐渐减小,随后,放出体高度将随放矿量的增加呈线性增长;下盘残留量随矿石层初始高度与矿石水平厚度之比(H/T)的增加而增加,其增长率逐渐降低,而随矿体倾角的增加而明显降低。

Based on particle flow theory and PFC3D code, draw model was constructed to study the flow characteristics of caved ore and rock at the complex boundary conditions in order to realize the visualization of the isolated extraction zone (IEZ) form. Simultaneously, the suitability and reliability of draw model based on PFC code and used in flow characteristics research of caved ore and rock were validated by comparative analysis between simulated results and existing research conclusions. The results show that the IEZ form produces different degrees of variation under complex boundary conditions due to the limit of tilting side walls, and thus the IEZ form is not a regular ellipsoid. The height of the IEZ increases rapidly in the form of index at the initiation of draw and its growth rate decreases with the increase of mass drawn, while the height of the IEZ increases linearly with the increase of mass drawn when mass drawn reaches a constant value. The footwall residual amounts increase as the ratio of initial ore layer height and ore level thickness (H/T) increases, and the increase rate decreases gradually but it reduces obviously as the increase of the orebody dips.