厚大磷矿体井下中深孔爆破参数优化研究

Research on Blast Parameters of Mid-deep Hole Underground Blasting in Thick and Large Phosphorite

瓮安大信北斗山磷矿矿层比较厚,主要为剩余矿体的开采,且地表允许塌陷,为提高矿岩回收率及矿山生产安全性,结合矿山开采技术条件及矿山生产经验,由原有房柱法开采改为扇形炮孔无底柱分段崩落法开采。利用有限元数值计算方法再现不同起爆方式的爆炸应力波传播过程,并在北斗山磷矿进行小型爆破试验,炸药的平均单耗0.478 kg/m3,矿石破碎效果很好。

The manto of Beidoushan phosphorite mining in Daxin,Weng′an city is thicher and mostly is remainder ore body,meanwhile,the earth′s surface is permitted to sink.In order to improve the ore recovery ratio and the production safety,the fanholes sublevel caving method without sill pillar substitutes the established room-and-pillar method on the basis of the technique condition and production experience.The finite element method is utilized to reappear the propagation of the blast wave under different initiation pattern.And the small blast test is done in Beidoushan phosphorite mining,the average specific charge is 0.478 kg/m3.