无底柱分段崩落法放矿规律的PFC2D模拟仿真

PFC2D Numerical Simulation of Ore Drawing Rule with Pillarless Sublevel Caving

利用基于颗粒流的离散元方法,对无底柱分段崩落法覆岩下放矿的崩落矿岩移动规律以及矿石损失贫化过程进行了数值仿真。以矿石回收率和废石混入率为检测指标,对比分析平面放矿和立面放矿2个不同的放矿方案的优劣。研究发现,在相同的放矿条件下,平面放矿方案比立面放矿方案更加合理。在同一放矿模型中,通过对比5种不同摩擦性质颗粒在立面放矿方案下的放出体形态,发现在结构参数和放矿方案既定的情况下,矿岩散体内摩擦角会影响放矿效果：颗粒间摩擦系数越大,放出椭球体的偏心率越大。

By adopting the discrete element method based on the particles flow,the numerical simulation on the rocks movement rule of ore-drawing and the process of rocks loss and dilution with pillarless sublevel caving method is made.Taking the ore recovery rate and the waste rock mixture rate as checking index,the pros and cons of ore drawing with the flat hopper and with the facade hopper are analyzed respectively.The research found out that under the same ore-drawing conditions,the former was more reasonable than the latter.Putting them in the same model,and by comparing the drawing-body＇s shape with five different friction properties of particles under the facade program,and when the structural parameters an ore-drawing program are fixed,the ore-drawing effect that are influenced by the bulk friction angle are shown as follows：the greater the friction coefficient between the particles is,the larger the eccentricity of the ellipsoid becomes.