水平浅孔预裂爆破技术在新城金矿的应用

Application of level short hole pre-splitting blasting technology in Xincheng Gold Mine

为了准确获得地下水平浅孔条件下的预裂爆破参数,优化爆破效果,以新城金矿V#矿体二步采场为工程背景,应用理论分析和现场试验方法,开展预裂爆破参数优化研究。分析了预裂爆破技术的特点及其成缝机理,采用爆炸应力波与高压气体联合作用原理建立预裂爆破初始裂纹起裂、扩展和止裂的判据,并由此推导出用于地下水平浅孔条件下的预裂爆破主要参数的计算公式。根据该计算公式确定的试验采场预裂爆破参数进行现场工业试验,爆破后采场的顶板和两帮平整光滑,预裂炮孔孔壁清晰可见,验证了该计算公式的正确性,同时表明二步采场的回采过程中,采用预裂爆破的效果明显优于光面爆破,是一种安全、高效、经济的爆破落矿工艺,能够满足矿山的安全、高效开采。

Combining the application of theoretical analysis and field-test methods, a parameter optimization study was carried out based on V＂ orebody of Xincheng Gold Mine to obtain the parameters of pre-splitting blasting accurately in the condition of underground level short hole and to optimize the blasting effect. The paper analyzed the charac-teristics and cracking mechanism of pre-splitting blasting, established the criteria of pre-splitting blasting＇s startcrack,propagation and stop-crack by the theory of cooperation of explosive stress wave and high pressure gas,and derived the formula which can be used for the calculation of pre-splitting blasting parameters in the condition of undergrotmd level short hole. An industrial field test could be implemented with its parameters determined by this formula. The results show that the post-blasting roof and sides are smooth, and the blast hole is clearly visible, proving the formula correct. The effect by using pre-splitting blasting is significantly better than smooth blasting. Pre-splitting blasting is a kind of safe, efficient and economical process for ore blasting, which can meet the requirements of safe and efficient exploitation.