Study Of Safety Mining Technology For Mining Gently Inclined Thin To Medium Thick Ore Under Broken Roof In GongBei Gold Mine

GongBei gold mine have many problems during the mining gently inclined thin to medium thick ore process, such as exist in mining, ore loss, safety problem. In order to solve those technology problems we do many research to mining the gently inclined thin to medium thick high grade ore, based on rock mechanics experiment and the rock stability classification of the roof of each stope, and mining method selected as the center of the whole research. We do the stability classification based on the roof of each stope, and mining method choice, and optimization of structural parameters of the mining stope, and architectural design of mining method. The main work is as follows:(1)Do many research such as site investigation, data collection, collecting ore samples on the ore geological conditions and mining technical condition; Do detailed statistics for mining empty eras; Do rock mechanics experiment and have the results of the mechanical parameters of rock, then reduced the rock mechanics parameters by using Hoek-Brown criterion, at last we have the rock mass parameters which attach for engineering mining process.(2)Spurac was used to build three-dimensional visual models of the surface mining, ore and roadway. Combined with the orebody model and cavity model built by Spurac, MIDAS/GTS was usd to make numerical simulations of roof stability in different cavity formed during the current mining within the mining area, and the numerical analysis results can be obtained.(3)The research on stope roof stability classification based on the analytical hierarchy process (AHP) and the fuzzy mathematic theory. Base on the numerical simulation and stope roof stability analysis by using GTS software, then using hierarchy process (AHP) and the fuzzy mathematic theory, we have the result of stope roof stability classification. Then according to the classification, we have diffident method to treat each empty areas.(4) We divided the ore body into three categories according to the inclination and thickness within the scope of the design of mining. By using hierarchy process (AHP) and the fuzzy mathematic theory, we choice that upward layred filling method is the best method that suit to GongBei gold mine mining process; The numerical simulation and stope stability analysis for the several kinds of orthogonal design scheme by using ANSYS software, and then we have the result that the rooms width is 10m and the pillars width is 12M, and two rooms are mining at the same time was the best method. And at last we have the mining method design for Au3 ore.(5) Through the indoor experiment, the first step was determined to use the cemented stowing with 1:6 cement filling,72% concentration for pillar stowing. The second step was also determined to use waste non-percha filling with gray sand ratio of 1:4, the concentration of 72% for Stope filling, which was the optimal filling ratio in the stoping process of Gongbei gold mine. According to the mine production requirements, the filling system was designed, and the location of the filling station was also determined. The economic benefit of the use of the filling method in the mine can be calculated.