急斜薄矿脉崩落矿岩散体流动规律研究

Research on granular flow laws of caved ore and rock for steeply dipping thin vein

基于内蒙古某金矿实际地质条件及矿岩物理性质,采用颗粒离散元法,对急斜薄矿脉崩落矿岩散体的流动规律进行数值模拟研究。研究结果表明,其颗粒的运动模型可分为倾斜边壁控制区、过渡区及自由下落区;其力的传递模型可分为均匀接触力区、卸压区及不稳定力拱区。在此基础上分析了矿岩摩擦角的变化对放矿过程的影响,尤其是对放矿过程中贫化三角矿体的大小及颗粒间接触力的影响。分析结果表明:1)上下盘围岩的摩擦角δ与矿石散体的摩擦角φ之比越大,贫化三角矿体积越大;2)颗粒间摩擦角越大,则颗粒间接触力越大,放矿过程中不稳定力拱的产生与崩塌越频繁,越容易产生稳定拱。最终,根据所得研究结果,提出了优化采场结构参数,降低矿石损失贫化的方法。

Based on the geological conditions and ore-rock physical properties of a gold mine in Inner Mongolia, the numerical simulation research of granule flowing laws of the steeply inclined and narrow veins is analyzed by using discrete element method of the particle flow. The results of the analysis show that the flow patterns of particle can be divided into side wall control zone, transition zone and free fall zone. The patterns of stress transmission can be divided into homogeneous stress zonel decompression and unstable arches. Based on what is mentioned above, the author analyzes the effect of the changes of ore friction angle on ore drawing process, especially the effect on the size of dilution triangle ore body and contact force between particles in ore drawing process. The results of the analysis are as follows： 1） The greater the ratio of the friction angle δ and the friction angle φ of ore is, the bigger the dilution triangle ore body will be; 2） The greater the friction angle of particles is, the more frequent the production and collapse of the unstable arches will be and the easier to produce stable arch. Based on the research results, a method of optimizing the mining structural parameters and reducing the ore loss and dilution is put forward.