覆盖层岩块容重对岩石混入的影响

Influence of Rock Weight Density of Overburden Stratum on Waste In-ore

针对无底柱分段崩落法端部放矿损失贫化大的问题,以理论力学为基础,分析岩块容重、合力大小、岩石混入三者之间的关系。同时以生产矿山采场参数为依据,设计制作实验模型,选取一定粒度和容重的岩石和矿石材料,对覆盖层岩块容重对岩石混入的影响进行了实验研究。研究表明:覆盖层岩块容重的大小对岩石混入率的影响较为明显。在其他条件一定的情况下,岩石混入率随着覆盖层岩块容重的增大而增加,随容重的减小而减少。生产矿山在形成覆盖层时,要考虑岩块容重对放矿的影响。如果覆盖层岩块容重较大,废石漏斗很快形成,废石过早混入,会使顶部矿石不能有效放出。在条件允许范围内,选用容重较小的岩石作为覆盖层,为矿山科学合理形成覆盖层提出了一条新的依据,对降低矿山矿石的损失贫化,提高经济效益具有指导意义。

Aiming at the problem of ore loss and dilution in bottom-pillarless sublevel caving method area-end ore drawing,based on theoretical mechanics,the relationship among rock weight density,resultant force and waste in-ore was analyzed. At the same time,based on the stope parameters of mine,the experimental model was designed and manufactured,rock and ore materials with certain grain size and weight density were selected,experimental study was conducted on influence of rock weight density of overburden stratum on waste in-ore.The results showed that the rock weight density of overburden stratum had a great impact on waste in-ore rate.Waste in-ore rate increases when the rock weight density of overburden stratum increases,vice versa, in the other same condition.The mine is supposed to take the influence on weight density of rock on drawing into consideration when forms overburden rock stratum.If the weight density of rock from overburden stratumis large,the waste funnel will form quickly and the waste will mix earlier,which result in not much ore on the top released.Stop drawing as soon as reaching cut-off grade. Within the limits of the conditions,selecting smaller weight density of rock as overburden stratum as much as possibleprovides a new reference for mines to form overburden scientifically and reasonably.It provides a new basis for the rational and scientificformation of the cover layer of the mine,which is of guiding significance for reducing the depletion of mine losses and improving economic benefits.