垂直溜井中卸矿对物料的冲击夯实作用及其预防

垂直溜井中的矿岩运动会对井内储料产生冲击,使松散储料被夯实,进而引发溜井的悬拱堵塞。在总结垂直溜井中矿岩运动特征的基础上,分析了溜井中物料运动全过程的能量转化与耗散特征,讨论了物料运动对井内储料冲击夯实作用机理与冲击夯实过程,并给出了矿山预防冲击夯实作用的综合措施。研究表明:①矿岩块在垂直溜井中下落时,底部储料受冲击的能量大小与矿岩落差和矿岩块质量成正比关系;②下落矿岩块的冲击力在井内储料中矿块之间相互传递形成了一种"力链"的作用效果,冲击力越大,夯实的密实度和范围也越大,夯实范围大小与冲击过程中的能量耗散速度成反比关系;③控制进入溜井的矿岩块度和降低矿岩块在溜井中的落差,是预防井内储料被冲击夯实的有效措施。

Impact-ramming Effect of Unloading on Stored Materials and Its Prevention in Vertical Orepass

The impacting of the movement of ore or rock in a vertical orepass on the stored materials could ram the loose materials，draw the suspension arch and the blockage of orepass.On the basis of summing up the movement characteristics of ore or rock in vertical orepass，the energy conversion and dissipation characteristics of the whole process of material movement are analyzed，the mechanism and the process of moving ore or rock impact-ramming on stored materials in the orepass are discussed，and the comprehensive measures for preventing impact-ramming are given combined with an example on mines.The study results show that:①when the ore or rock block falls in a vertical orepass，the impact energy on the stored materials at the orepass bottom is proportional to the height of the ore or rock falling and the quality of the falling ore or rock block；②the impact force of falling ore or rock is transferred between ore or rock blocks in the orepass formed a “force chain” effect，the greater the impact force，the greater the ramming degree and scope of densification，the ramming range is inversely proportional to the velocity of the energy dissipation in the impact process；③the effective measures to prevent the impact-ramming of the material stored in the orepass is controlling the size of ore or rock entering the orepass and reducing the falling distance of ore-rock blocks in the orepass.