Mining Method Study For Extremely Steep And Low Grade Medium Thickness Orebody Of Susong Phosphate Mine

Abstract:Phosphate rock resource of Anhui province is in a state of the demand scarcity long-term. The development of SuSong phosphate mine can not only ensure supply of raw material for the Liuguo chemical company, but also has significant economic and social benefits. Because of low grade phosphate rock and thin ore body, besides the mining technical conditions is complex, and the roof of some sections is seriously weathered and broken, and water inflow is big, moreover, the surface movement and deformation must be controlled within the scope of the permit, so suitable mining methods must be chosen to ensure mining of SuSong phosphate mine safely and efficiently. Based on the analysis of the mining technical conditions, through field investigation, experimental analysis, experimental research, numerical simulation and economic comparison, suitable mining scheme of Nanchong period is determined at the mining technical conditions; through theoretical analysis and numerical simulation methods, roof movement and deformation of the mining technology is predicted. Through the comparison with the maximum allowed value, influence degree of the roof movement and deformation for different mining process is evaluated. The following are results and conclusions:(1)Through the field investigation and data collection of Susong phosphate mine, the basic information and data is provided for theoretical analysis, numerical simulation and design.(2)According to the mining technical conditions, suitable mining methods is preliminary selected by studying the related theory of underground mine, the actual production data, and using for reference with the experience of similar mines, then the best scheme is selected through numerical simulation. Mechanization of arteries and veins on the outside to the horizontal slice stoping and backfilling method(single step) are determined for the main orebody of Susong phosphate mine;(3)Three-dimensional model of the mine is established through the three-dimensional digital mining software Surpac, using MIDAS/GTS and Mathews method the stope structure parameters is determined and optimized. Based on the analysis of calculation results and the factors such as economy, safety and so on, finally the parameters of ore block are determined as follows:bord is60m long, spike is5m long.(4)According to the optimization of mining scheme and calculation of the proceeds of the stope structure parameters, detailed mining scheme is designed.(5)The mining sequence of each level is determined by economic, technical and safety analysis, and the result is:The downward mining is used at the levels above-260m with upward mining under-260m. The-160m level and-210m level are mined first. In order to meet the ventilation, initial mining stoping sequence is:The retreating mining is used at the-160m level, with the advancing mining at the-210m level. The adjacent ore mining sequence is:According to the theory of natural equilibrium arch, mining of "pin" glyph structure is adopted.