低密度炸药对露天矿煤层爆破关键指标的影响研究

Effect of low density explosives on key indicators in surface coal seam blasting

为进一步改善煤岩爆破效果,从煤岩爆破破碎机理分析了减少爆破药柱粉碎区的途径,提出了将低密度炸药用于露天煤矿煤岩爆破。通过对低密度炸药不同装药结构、不同炸药单耗量的煤岩爆破试验,分析了采掘效率、块煤率及沫煤率等重要指标。结果表明:低密度炸药爆炸能量传递过程中更加均匀,有利于降低炸药单耗,减少沫煤率。研究中发现在一定范围内,炸药单耗量与采掘效率、大块率、块煤率及沫煤率成比例关系,综合优化四者之间的关系,给出了适合于露天煤矿爆破炸药单耗量的最佳范围区间是0.171~0.190 kg/m^3。

In order to improve the blasting effect of coal-rock,on the base of rock blasting theory,blasting mechanism of coal-rock and the way to reduce the crushing zone of blasting are analyzed,and low-density explosive is proposed for coal-rock blasting in surface coal mine.The effects of low-density explosives on the bulk rate,extraction efficiency,lump coal rate and foamed coal rate are studied by testing the coal-rock blasting of different charge structures and explosive charge of low-density explosives.The results show that the density of low-density explosive charge is low,the continuous charge can be achieved in the blast hole,which is beneficial to reduce the explosive consumption,energy transmission is more uniform than other explosives.In a certain extent,explosive unit consumption is proportional to the mining efficiency,bulk rate,lump coal rate and foam coal ratio,and the relationship among them is comprehensively optimized.The optimum range is 0.171-0.190 kg/m^3,which provides the basis for engineering blasting design.