北洺河铁矿改进装药结构试验研究

北洺河铁矿采用大结构参数无底柱分段崩落法开采，多年来大块率高、爆破隔墙事故与眉线破坏等爆破问题，一直没有得到很好解决。通过对扇形炮孔爆破机理的分析得出，形成推墙现象的主要原因，是扇形面内炮孔过于密集。以减小扇面炮孔的密度，将炮孔爆破的主导方向调整到抵抗线方向为出发点，进行了改进装药结构的现场试验，通过优化装药结构，改进了爆破效果。

Experimental Study on Improving Charge Structure of Blast Hole in Beiminghe Iron Mine

Beiminghe iron mine adopted the sublevel caving mining method with large parameters. Such problems in blasting as higher bulk rate，accident in partition wall and the destruction of the eyebrow line have not been well solved for many years. This paper drew a conclusion from analyzing the fan-patterned holes blasting mechanism that the dense holes in fan-patterned plan is the basic reason for the problem above. Based on decreasing the dense of holes and changing the blast direction into the least resistant line，the in-sit experiment on improving the charge structure of blast hole was carried out and an optimization scheme was put forward to improve the blast effect.