Inuit copper mine pillar mining

China is due to a deposition of copper ore deposits metamorphic, is divided into seven major transverse layers of ore independent segments, the major side of the mountain is one ore section, accounts for 43.2% of the whole metal mining. The face of the mountain section is 1000m long, and most of the thick ore body has a thickness of 7-20m and a dip angle of 55°~70°. The ore is stable and has good blasting properties. The lower plate is the purple layer of the people, f=7～9, medium stability. The upper plate is a falling snow dolomite , stable, f=10~12. The ore body has good continuity. The section is mined by the section rock drilling stage mining method, with a stage height of 60 m and a column width of 10 to 12 m. The ore body has good continuity. The section is mined by the section rock drilling stage mining method. The stage height is 60m, the column width is 10~12m, some is 22m, the bottom column height is 13~16m, the top column height is 6m, and the section height is 12~13m. The reserves of pillars account for 50-60% of the reserves of the ore. Use deep hole blasting to return to the mining column. Considering: 1. The inclination of the ore body is not steep enough and the grade is low (0.76%). The mine should be released as far as possible in the open field to reduce losses and depletion; 2. The effect of the pillars of several ore blocks in a stage blasting in stage IV Not good, because the exposed time of the goaf is long, the roof is seriously falling, the blasthole is deformed, and the charging is difficult, so the recovery rate is only 40-60%, and the construction organization management is complicated. To this end, in the V-stage pillar recovery, a scheme of blasting a ore pillar (a top column, a column) is used. In a ore block, the top column and the upper stage correspond to the lower part of the electric raft level of the bottom block of the ore block, and the ore is released under the empty field, and then the recovery column and the above-mentioned bottom column are above the electric level, and the upper plate It then collapsed and mined under the overburden rock. This recovery scheme reduces the loss of depletion, but the number of blasting is more, which has a certain impact on production. The blasting parameters are: aperture 95~105mm, minimum resistance line 2~2.5m, hole bottom distance 2.5~3.2m, 8~12t per metre of blasthole collapse. The unit explosive consumption is 0.5-0.7kg/t. Technical and economic indicators are: production capacity of 300t/d, rock drilling efficiency of 50.9 tons/shift, mining efficiency of 31.6 tons/work shift, loss rate of 26.2%, depletion rate of 28.2%, and cutting ratio of 3.2m /kt.