露天煤矿抛掷爆破缓冲孔爆破优化与效益分析

Design optimization and benefit analysis about cushion blastholes in cast blasting of open-pit coal mine

黑岱沟露天煤矿高台阶抛掷爆破预裂孔前两排缓冲孔一直沿用气体间隔器分段装填现场混装多孔粒状铵油炸药，在5～lo天的装药过程中易产生炮孔塌陷，增加爆破成本。通过对此问题进行分析，采取了在缓冲孔内连续装填现场混装低密度铵油炸药，不仅提高了装填效率，缩短了装药时间，而且提高了炮孔利用率；实现了炸药能量在炮孔轴线上的均匀分布，对于预裂孔贯穿裂缝的形成及宽度的保持十分有利，也有利于边坡的稳定。同时，降低了爆破成本，创造了良好的经济效益，可为同类爆破提供参考。

Gas spacer block and site mixed porous granular ANFO explosive were used in the first two rows of cushion blastholes with divided charge in high bench cast blasting of Heidaigou open-pit coal mine.The charging process would last about 5to 10 days,so blastholes might be collapsed and the cost would be higher.Through the analysis of the problem,site mixed lowdesity ANFO explosive was continuously charged in the cushion blastholes.The charging efficiency was improved,the charging time was shorten and the utilization of blastholes was improved.The aim of blasting energy uniform distribution in blastholes axes was achieved.It was good for formation of cracks in presplitting blastholes and maintaining the width.Meanwhile,the blasting cost was reduced and the good economic benefit was created.It could provide a reference for similar blastings.