Effects Of Relative Particle Size Of Loose Ore And Rock On Rock Mixed Rate

In non-pillar sublevel caving method,the extraction process was conducted under a loose cover-layer-rock.When in the process of ore drawing-out,it is easily to cause the ore loss and dilution,and,this is one of the problems existing in this kind of mining method.Because the loose cover layer rock and the caved ore is two important parts in sublevel caving method,it will have a direct impact on the mixed rate of rock into the ore,the recycling and utilization of mineral resources and the economic benefits of mine if the relative particle size of these two parts is reasonable or not.Based on the related theory of granular material mechanics,the movement law of loose ore and rock was analyzed.Also,an experimental device system was designed and manufactured.The experiment of effect on relative particle size of loose ore and rock on mixed rate of rock was carried out via this experimental device system,the experimental data was analyzed.Meanwhile,two evaluation methods were used to evaluate the results of the testing.The research of this paper achieved conclusions as follows:1?Factors which influencing on ore-rock mixed were analyzed based on granular material mechanics and the relative theory of "Brazil nut effect".Meanwhile,it is concluded,under a certain condition,that a good result can be obtained when the relative particle size of ore is smaller than a certain value.2.An automated device of monomer ore-drawing-out system is designed and manufactured.And,the device was used to the experiment on the impact of relative particle size of ore-rock on rock mixed rate.3?It is found in this experiment that the smaller relative particle size of rock and ore is,the lower mixed rate of rock is when at a certain condition.Otherwise,the higher is.And,the lower mixed rate of rock could be obtained when the relative particle size of ore and rock is less than 1:1.7.When the relative particle size of ore and rock is greater than 1:1.7,the rock mixed rate is relatively high.The results of this study have an important guiding significance for a mine,when using non-pillar sublevel caving method,to form a scientific and reasonable cover layer and ore caving,reduce the ore loss and dilution in the mining process.