云南金平长安金矿中深孔凿岩爆破参数优化研究

长安金矿1 520 m以下由露天转入地下开采,1 524 m分段挂帮矿采用无底柱分段崩落法开采,中深孔落矿存在眉线破坏严重、装药困难、大块率高等问题,严重影响了采矿生产安全和效率.针对上述问题,提出了相应的改进措施:优化采场结构参数和落矿参数,加强中深孔质量管理,改进爆破工艺.现场工业试验结果表明,1509分段1302...

Optimization of drilling and blasting parameters for medium and long holes in Jinping Chang'an Gold Mine,Yunnan

At the level of 1,520 m in Chang'an Gold Mine,the mining operation was transferred from open pit to underground,and the sublevel caving without sill pillar method was employed at sublevel 1,524 m for extraction of hanging wall ore.The ore drawing with medium and long holes presents such problems as serious damage of brow line,charging difficulty and many lumps,which influence the safety and efficiency of mining production seriously.The modification measures are proposed as follows:optimization of stope structure and ore drawing conditions,improvement on quality of medium-long hole and on blasting technology.Promising results have been obtained from the site commercial test,which are described as follows:as the row spacing in section 1302-1305 at sublevel 1509 increased from 1.5 m to 1.7 m,the ore recovery rate was 85%,the ore dilution rate was 25%,the lump rate was 5%,the unit consumption of primary explosive was 0.33 kg/t ore,thus the problem during blasting was solved by taking above measures and the blasting performance had been improved,which can be provided as a reference for the application of medium-long hole caving technology in gold mine.