The ore depletion reasons analysise of sub-level caving method

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.