Study Of Mining Technology For Medium-thick Steep Fractured Ore In Xu Jia Gou Copper Mine

Xu JiaGou copper deposit is located in the Mianxian-Lueyang-Yangpingguan triangle polymetallic mineralization area, belonging to the volcano sedimentary, magmatic reformed copper deposit. Ore bodies occur in foliated spilite belts, which is poor stability and low ore grade. According to the original design of the mining method for production, caving and collapse phenomenon is serious, security cannot be guaranteed, and ore which is difficult to be produced.This study based on engineering geological investigation, tech-economic evaluation and rock mechanics test on site, conducting the reduction of engineering quantity, guarantee the stability of the structural, reducing the difficulty of construction and other aspects, demonstrated a " self-pull slot extrusion blasting caving method " and "stage shrinkage caving method" in two kinds of mining method for the complex conditions, and has carried on the preliminary design.To optimize the two mining methods from the angle of system theory, the PFC2D-FLAC coupling numerical simulation method(application of discontinuous-continuous medium coupling theory) is used in the process, body will excavation near the joint development of rock mass is divided into discrete units, from a distance of rock mass as a continuum unit, thus the stress state and displacement of rock excavation area are calculation and analysis. Result that the self-pull slot extrusion blasting caving method may contribute to an increase in the rate of ore dilution and loss, but its final good for the hanging wall on the stability and deformation compared to the stage shrinkage caving method, which is more advantageous to the hanging wall of the surrounding rock control.Use the numerical results as an important factor indicators into the comprehensive evaluation, with TOPSIS method and analytic hierarchy process combined(both degree are 0.24 and 0.31 respectively), and the fuzzy comprehensive evaluation to verify(both membership are 0.24 and 0.31), concluded that "stage left caving method" for more in line with XuJia Gou copper mine safe, efficient, economic exploitation of the mining method, the results are more reliable conclusions to provide guidance for the mine’s production work, as well as similar conditions the mine design and production methods reference.