我矿的矿石以磁铁石英岩为主,有少量的磁铁富矿和赤铁矿,岩石为顶盘混合岩和底盘角闪岩。由于矿岩结构呈致密块状、片状及松散状,节理裂隙较发育,韧性强,因而坚韧难爆;又由于矿体倾角为39～45°左右,采用从顶盘至底盘推进、工作面沿走向布置的开采方法。在这样条件下,当工作台阶爆破时,矿岩沿层面滑落,形成了缓倾斜工作台阶,给穿爆工作造成困 The ore of mine is dominated by magnetite quartzite with a small amount of magnetite rich ore and hematite. The rock is composed of top-plate mixed rock and amphibolite. Due to the fact that the structure of ore rock is dense, flaky and loose, the joint fissures develop well and the toughness is strong, so it is tough and hard to explode. Because the orebody inclination is about 39 ~ 45 °, Along the direction of the layout of the mining method. Under such conditions, when the working bench is demolished, the ore rock slides along the surface and forms a gently inclined work bench, which causes the sleepy work