露天煤矿的台阶高度对抛掷率的影响

Influences of bench height of an open-pit coal mine on cast percentage

以黑岱沟露天煤矿为例,在理论分析和现场实验的基础上,探讨台阶高度对抛掷爆破效果的影响。现场实验结果表明:爆堆最远抛距和抛掷率随台阶高度的增加而增大,爆堆形态也变得更平滑;随台阶高度的进一步增加,抛掷率增大的幅度逐渐减小。当炸药单耗q=0.70 kg/m3,台阶高度H>37 m时,随台阶高度的增大,抛掷率的提高不明显,甚至是停留在47%左右,此时单靠提高台阶高度来获取较高抛掷率的方法将受采场条件和钻采机械设备的限制。

Heidaigou open-pit coal mine was chosen as an example to explore the influences of bench height on cast blasting in open-pit coal mines.Theoretical analyses and site tests were carried out,respectively.Investigated results display that with the increase of the bench height,the maximum cast distance of the blast muckpile as well as the cast percentage increases,and the shape of the blast muckpile becomes smoother,on the other hand,the higher the bench,the more slowly the cast percentage increases.When the unit explosive consumption is equal to 0.70 kg/m3 and the bench is higher than 37 m,with the increase of the bench height,the cast percentage increases slowly,even stays at 47 percent.Here,it is subject to mine conditions and mining equipments,which simply raises the bench height to obtain a higher cast percentage.