干旱区露天矿爆破作用线理论与实践研究

Theoretical and practical study on blasting action line of open-pit mine in arid area

针对干旱区露天煤矿非构造裂隙岩体爆破过程中出现的大块率高、爆堆不规整等问题,提出了爆破作用线起爆技术,通过增加岩体内侧向爆破自由面、加强爆破作用方向及强化爆破作用破碎强度三方面,探讨了爆破作用线对非构造裂隙岩体爆破作用的影响。研究认为:对于深凹露天矿炮区中存在的非构造裂隙岩体,确定爆破作用线方向,设计采用非电导爆管加"四通"的斜线逐孔毫秒微差单侧或双侧向自由面不耦合集中或分段装药深孔爆破,可加强爆破作用线上炮孔对节理、裂隙发育岩体的破碎效果。对不同高度山体(>50m,35～50m,<35m)和倾角的山坡露天矿,采用分区、分段间隔爆破作用线逐孔毫秒微差上、下层分次或同时起爆、垂直深孔不耦合分段装药或倾斜孔散状耦合装药的爆破方式,可使爆破大块率降低。

Aiming at solving the problems of high block rate and irregularity of blasting, it is proposed that the blasting action line technology would play an important role in the blasting process of non-structural fractured rock mass in the open-pit coal mine. The effects of blasting line on the blasting action of non-structural fractured rock mass are discussed by increasing the blasting free surface of the rock mass, enhancing the blasting direction and strengthening the crushing strength of blasting. It is considered that, for the non-structural fractured rock mass in the deep open-pit mines, by determining the direction of the blasting action line, and designing the millisecond delay deep hole blasting with non-electric detonator plus "four links" by centralized or divided decoupling charge, the effect of blasting holes on the fractures of jointed and fractured rock mass along the blasting action line can be enhanced. For hillside open-pit mines with different heights(>50 m, 35~50 m,<35 m) and dip angle, the blasting block rate can be reduced by using the simultaneous or step-by-step blasting mode between the upper and the lower layers with millisecond delay by using vertical deep hole uncoupled divided charge or inclined hole scattered charge blasting.