水厂铁矿采场东帮预裂爆破质量的改进措施

水厂铁矿采场东帮地质条件复杂，节理裂隙发育，影响到界边坡预裂爆破质量。通过对影响该部位的穿孔质量、爆破设计等四方面因素进行调查分析，采取适当增加预裂爆破炮孔直径、合理控制上水平主缓冲孔超深、分段泄水预裂爆破、在预裂爆破区域的两端各留下1～2个空炮孔不爆破、清碴爆破及适当增加预裂爆破药量、减少缓冲爆破药量等措施。结果表明，L8钻机150 mm孔径预裂爆破半壁孔率提高到70%以上，最高达到85%，复杂地质条件部位孔深合格率、角度合格率、半壁孔率分别较F9钻机提升了10%、7%、20%，2种钻机预裂爆破平均半壁孔率达到65%，整体爆破质量得到明显改善，有效降低采矿成本，相关经验对类似条件矿山具有借鉴作用。

Improvement Measures of Pre-spliting Blasting Quality of The East Boundary of the Stope of Shuichang Iron Mine

The geological conditions of the east boundary of the stope of Shuichang Iron Mine is complex,the joint sand fissures are well developed,the pre-spliting blasting quality of the boundary is influenced.Through investigation and analysis of the influence factors of drilling quality and blasting design,the improvement measures are proposed.The blasting quality can be improved by increasing the hole diameter of pre-spliting blasting appropriately,controlling the overdepth of the main horizontal buffer hole reasonably,sub-level drainage pre-spliting blasting,retaining 1~2 empty holes at each end of the pre-spliting blasting area without blasting,cleaning slag blasting and increasing the amount of pre-spliting blasting charge appropriately and reducing the charge of buffer blasting.The results show that half porosity of pre-spliting blasting of L8 drilling machine with 150 mm diameter can be improved to more than 70%,the maximum value is 85％,compared with F9 drilling machine,the hole depth qualified rate,angle qualified rate and half hole rate of the areas with complex geological condition of L8 drilling machine is improved by 10%,7% and 20% respectively,the average half porosity is 65％,the whole blasting quality is improved effectively,the mining cost is reduced significantly,the above study experience can provide some reference for the similar mines.