自然崩落法覆盖岩层下放矿贫化实验研究

自然崩落法放矿基本上都是在覆盖岩层下进行的。在放矿过程中，覆盖岩层废石会混杂在崩落矿石中从放矿漏斗一起放出，造成放出矿石贫化。经研究表明，覆盖岩层下放出矿石贫化的原因主要有两个：一是放矿高度到达矿岩接触面而引起的接触面上贫化；另外就是覆盖层中细小废石颗粒的渗透作用引起的矿岩提前贫化。从实验的角度出发，结合崩落矿岩散体性质及流动特点，分别采用不同矿石颗粒组成和废石颗粒组成，对覆盖岩层下放矿进行室内实验，探明崩落矿岩块度非均匀性对放矿贫化的影响，对放矿控制具有实践指导意义。

Study of Drawing Dilution under Overburden in Block Caving Based on Experiments

The process of ore- drawing in block caving is completed under overburden. In the process of ore- draw- ing, the waste will move out in the form of mixing into the drawing ore. In this case, drawing dilution appears. It makes clear that there are two reasons for drawing dilution based on the research, one is the dilution on the sur- face between ore and waste when the drawing reaches the interface, the other is the advanced dilution which is produced by osmosis of the small grain of waste. Research of the text is based on experiments, which use differ- ent compositions of ore and waste separately. Through the experiments of ore- drawing, the effect of the heteroge- neous degree of caved ore and rock on the drawing dilution is investigated, it can give guidance to control the ore- drawing.