普朗铜矿自然崩落法切割井形成技术研究

Study on the Formation Technique of the Cutting Shaft by Natural Caving Method of Pulang Copper Mine

中深孔一次爆破形成切割井是自然崩落法矿山聚矿槽爆破的先决条件。为实现普朗铜矿DU411潜孔台车施工φ762 mm空孔、SimbaH1354台车施工φ76 mm中深孔工艺条件下切割井的安全、稳定施工,在总结矿山含矿岩体物理力学性质的基础上,采用最大拉应力破坏准则和Mises准则,对矿山中深孔爆破作业在主要的4类含矿岩体中形成的破碎区、裂隙区进行了理论计算,认为切割井掏槽炮孔的设计应按破碎区范围布孔,辅助孔和周边炮孔应按裂隙区范围要求布孔,在此基础上确定了切割井中深孔设计参数。按照达到爆破效果需满足补偿空间要求的原则,结合电子雷管可随意确定爆破时间的优点,对各孔爆破时间按照岩石破碎、飞掷充满补偿空间、轴向移出高度范围形成新的补偿空间3个阶段进行了计算,提出了余波推动自由落体运动确定t;的方法,达到了随爆破不断创造补偿空间的效果。经过现场试验,实现了中深孔一次爆破形成高18 m、断面4 m×4 m的切割井。采用试验成功的技术方案,矿山已安全、高质量地完成了250个聚矿槽的中深孔爆破工作,过程中未发生安全和质量事故。

Prerequisite of forming a drawbell is that to make a cutting shaft with long hole blast by one time on block caving mine.In order to get cutting shaft safely and successfully construction technology under the production process of DU411 to construct φ762 mm empty hole and SimbaH1354 trolley construction φ76 mm long hole in Pulang Copper Mine Based on the summary of the physical and mechanical properties of ore-bearing rock mass,the maximum tensile stress failure criterion and Mises criterion were adopted to carry out the theoretical calculation of the fracture zone and fissure zone formed by long hole blasting in four main ore-bearing rock masses.The results showed that the design of cutting holes should be arranged according to the scope of the fracture zone.The auxiliary and peripheral holes should be arranged according to fracture area.On this basis,the design parameters of long hole in cutting shaft were determined.According to the principle of compensating space requirement to achieve blasting effect,combined with the advantage of electronic detonator can determine the blasting time at will,the blasting time of each hole was calculated according to three stages such as rock breaking,flying to fill the compensation space,and axial moving out of the height range to form a new compensation space,on the basis,a method of determining t;by the motion of free falling body driven by the aftershock was proposed,the effect of continuously creating compensation space with blasting was achieved.Through field tests,a cutting well with a height of 18 m and a section of 4 m×4 m was formed by a single medium-deep hole blasting.By using the technical scheme successfully tested,the mine has safely and high-quality completed the medium-deep hole blasting of 250 ore collecting slots,and no safety and quality accidents occurred in the process.