无底柱分段崩落法矿石贫化原因分析

The ore depletion reasons analysise of sub-level caving method

无底柱分段崩落法矿石贫化大,一直是个难以解决的问题。为了彻底分析无底柱分段崩落法发生矿石贫化的原因,本文首先根据随机介质端部放矿理论,分析了在端部放矿条件下,崩落矿岩散体的放出过程和贫化控制方式;其次,通过对国内外几个矿山现场出矿品位的取样标定,发现在崩落法爆破过程中,便发生了矿岩参杂现象。通过相似材料模型试验,对端部挤压爆破条件下引起矿岩参杂的过程及原因进行了进一步的分析。通过上述研究,本文认为,无底柱分段崩落法主要有两个发生矿岩掺杂的过程:一是扇形中深孔端部挤压爆破过程中发生的矿岩掺杂;二是放矿过程中发生的矿岩掺杂,这两个过程也正是造成无底柱分段崩落法矿石贫化的原因。因此,要降低无底柱分段崩落法矿石贫化率,就必须优化扇形中深孔爆破参数,并选取合理的放矿方式。

High ore depletion is a problem of sub-level caving method which is difficult to cope with.To analysis the reasons,this paper first analysise the ore drawing process and the control method based on the stochastic theory of ore drawing.Then the paper analysise the ore samples grade of sub-level caving method and find out that the ore and the rock mixing during the long-holes blasting.So the paper analysise the process and the reasons of ore and rock mixing during the long-holes blasting by the similar material model test.By these research,the paper conclude that the sub-level caving method have two processes which ore and rock mixing.First is the blasting process,second is the ore drawing process.That is the very reasons result in high depletion.So in order to reduce the rate of ore depletion,we must optimize the blasting parameters of long-holes and choose appropriate ore drawing method.