增布卫星孔降低大块率的露天深孔爆破方案研究

Research on Bulk Rate Reduction of Deep-Hole Step Blasting Scheme in Open-Pit Mine by Increasing Satellite Holes

为解决新疆金宝矿业露天深孔台阶爆破大块率高的问题,通过分析大块产生的部位及原因,提出在原爆破方案孔网参数不变的条件下,增布卫星孔的爆破优化方案,卫星孔直径为115 mm,孔深为4.5 m,孔网参数由4.5 m×3.5 m改为4.5 m×1.75 m。通过增布卫星孔,增加台阶顶部炮孔堵塞段装药量,使得更多的爆炸能量作用在台阶顶部区域。因卫星孔的存在,斜线起爆过程中排距减小,台阶顶部岩石爆破的抵抗线降低50%。结果表明,增布卫星孔的爆破优化方案的爆堆大块率平均值为13.8%,大块产出降低约40%,爆破质量明显改善。尽管炸药单耗有所增加,但考虑二次破碎、铲装运输等的综合成本,优化后的方案较原方案仍然更为经济。

In order to solve the problems of high bulk rate in deep-hole step blasting of Xinjiang Jinbao open-pit mine,based on analyzing the location and the reasons of bulk output,a blasting optimization scheme was proposed to increase the distribution of satellite holes under the condition of unchanged hole network parameters in the original blasting scheme.The satellite hole diameter was 115 mm,the hole depth was 4.5 m,and the hole network parameters were changed from 4.5 m × 3.5 m to 4.5 m×1.75 m.By increasing the number of satellite holes and increasing the charge amount in the blockage section at the top holes of the step,more explosive energy was applied to the top area of the step.Due to the presence of satellite holes,the row spacing decreased during the oblique detonation process,and the resistance line of rock blasting at the top of the step was reduced by 50%.The results show that the average bulk rate in the blasting optimization scheme with increased satellite holes is about 13.8%,and the bulk output is reduced by about 40%,resulting in a significant improvement in blasting quality.Aithough the explosive consumption has increased,considering the comprehensive costs of secondary crushing,shovel loading and transportation,the optimized scheme is still more economical than the original scheme.