Optimization Study Of The Mining Methods For The Upper Orebody Of The Second West Mining Area In Longshou Mine

The upper orebody of the second west mining area in Longshou Mine was originally mined by the downward slicing and cemented filling method,due to the change of economic condition of the second west mining area and the change of mining status of the upper orebody,the mine decided to change the existing mining method of the upper orebody and decided to mine the upper orebody by the caving method,so the natural caving and the non-pillar sublevel caving were considered preliminarily.In order to recover the upper orebody in a safe,economical and efficient way,this paper combined with its mining technical conditions and considered its current actual mining status,and the optimization study of its mining methods was carried out.Firstly,the technical feasibility of the mining methods that may be adopted in the mining of the upper orebody was analyzed,and the result shows that the technical feasibility is available when the downward slicing and cemented filling method,the natural caving and the non-pillar sublevel caving are applied to the upper orebody,but the ore loss of the former two methods is larger.Then,the mining methods of the upper orebody were optimized by the improved AHP,and the result shows that under the current and actual mining status of the upper orebody,the comprehensive effect of the non-pillar sublevel caving is the best when applied to the upper orebody,followed by the effect of the downward slicing and cemented filling method,and the effect of the natural caving is relatively poor.The non-pillar sublevel caving is suitable for mining the upper orebody.Finally,the stope structural parameters were optimized.The simulation experiment of the ore drawing was carried out to compare the ore recovery effect of the upper orebody under different stope structural parameters,and the stope stability of the upper orebody under different stope structural parameters was simulated by the FLAC-3D numerical simulation software.By means of the physical experiment and the numerical simulation,it can provide some references for optimizing stope structural parameters of the upper orebody.Then the stope structure parameters of the upper orebody were optimized by the improved AHP.The result shows that the ore recovery effect of the 12m×15m×2.0m structural parameter scheme is better than that of the 15m×15m×2.2m structural parameter scheme.Not only the ore recovery rate of the former is 2.0?2.4 percentage points higher than that of the latter,but also the waste rock mixing rate of the former is 0.4?1.5 percentage points lower than that of the latter;But when the mining conditions are the same,the former is less stable than the latter;When the non-pillar sublevel caving is applied to the upper orebody,the comprehensive effect of the latter is relatively good,and the stope structural parameter should adopt the 15m×15m×2.2m structural parameter scheme.The research result of this paper has been approved by the mine,and its research method has certain reference significance for other similar mines.