Safety evaluation on room pillar mining of steep thick orebody

After the integration of Xiapingtian calcite mine, it is urgent to evaluate the process parameters under the new mining conditions.Based on the condition of open stope mining method for steeply inclined thick orebody, the stability of the width of rock(vertical) pillar is calculated and analyzed according to the theory of limit equilibrium of strata.The deeper the mining depth is, the larger the width of rock pillar is, leaving 8.0m in the +200 m section, 9.0 m in the +150 m section and 10.0 m in the +100 m section.According to the theory of rock mechanics, the open field span is calculated and analyzed.The deeper the mining depth is, the smaller the open field span is.The span is 60 m in +200 m section, 45 m in +150 m section and +100 m section.UDEC software is used to analyze the mining process.The bearing arch structure formed in the roof of each section after mining makes the empty field and rock pillar stable.The engineering practice shows that it is safe and reliable to mine with the optimized mining process parameters.