溜井储矿段储料缓冲性能离散元模拟研究

Discrete Element Simulation on Stock Buffer Performance in Storage Section of Ore-pass

为探究储料对溜井卸矿冲击的缓冲特性,采用离散元方法分析溜井卸矿冲击作用下储料缓冲过程,探究储料高度对储料缓冲效果、溜井侧壁受力特征的影响,引用缓冲率确定在当前溜井结构、矿岩粒径分布下的临界储料高度值。研究表明:(1)卸矿冲击作用下储料上部矿岩激烈碰撞,排列重新分布,分散、衰减了大部分冲击力;储料下部冲击力主要沿着初始力链网络传递,矿岩排列不变,摩擦阻力抵消了部分冲击力;(2)在指定颗粒粒径级配、储矿段直径(6m)等条件下,储料临界高度值是7m;总体上,储料缓冲效果随储料高度增加而变好,当储料高度低于7m时,储料缓冲效果受储料高度改变影响明显,当储料高度高于7m时,储料缓冲效果受储料高度改变影响较小;(3)井壁冲击力峰值随着储料高度、D值(所测井壁与储料面的距离)增加而降低。在距离储料面一个临界储料高度范围内,井壁冲击力降低速度较大,在该范围外,降低速度较小;(4)结合研究结果,在合理储料高度和卸矿、放矿管理3个方面提出了合理利用储料缓冲性能的具体措施,对矿山生产实践具有一定的指导意义。

To explore the stock buffer performance under unloading in the ore-pass,the discrete element method is used to analyze the stock buffer process under the impact of unloading in the ore-pass.The influence of the stock height on the stock buffer effect and the stress characteristics of the side wall in the ore-pass were explored.Then,the buffer ratio was introduced to determine the critical storage height under the current structure of the ore-pass and the particle size distribution of ore and rock.The study has obtained following results.Firstly,under the impact of ore unloading,the ore and rock in the upper part of the stock collide violently and change arrangement,which disperses and attenuates most of the impact force.The impact force at the lower part of the stock is mainly transmitted along the initial force chain network,the arrangement of ore and rock remains unchanged,and part of the impact force is offset by friction resistance.Secondly,under the conditions of specified particle size distribution and diameter of storage section(6 m),the critical height of stock is 7 m.On the whole,the stock buffer effect becomes better with the increase of stock height.The stock buffer effect is obviously affected by the change of stock height when the stock height is less than 7 m,but is less influenced when the height is more than 7 m.Thirdly,the peak value of wall impact force decreases with the increase of stock height and D value(the distance between the side wall and the stock surface).The wall impact force decreases rapidly in a critical stock height range from the stock surface,but decreases slowly outside this range.Finally,combined with the research results,the specific measures for reasonable utilization of stock buffer performance are proposed in three aspects,including reasonable storage height,ore unloading and drawing management.The study has a certain guiding significance for mine production practice.