中深孔无井拉槽挤压爆破工艺参数优化

Optimization of Process Parameters of Medium-deep Hole Extrusion Slotting Blasting Without Cutting Well

切割拉槽爆破效果严重影响着地下矿山回采作业效率,为了解决某铁矿地下开采过程中无井拉槽爆破工艺效果不佳的问题,从传统的爆破工艺着手,首先对现场矿石颗粒进行挤压状态碎涨系数测试,然后通过数值模拟对爆破参数以及设计进行分析,最后结合现场爆破效果对爆破参数优化的合理性以及实用性进行验证。结果表明,传统爆破工艺存在补偿空间不足的问题,将爆破抵抗线1.2 m调整为1 m能够起到很好的爆破效果;通过爆破数值模拟分析,爆破过程中抵抗线方向最远单元点有效应力值大于矿石动态抗压强度61.3 MPa,同时挤压爆破过程中产生的应力波对矿石起到类似于挤压的作用,挤压强度达到试验要求,矿石碎胀系数小于1.333,满足爆破补偿空间要求;常规爆破条件下抵抗线计算公式并不适用于本次无井拉槽爆破,应考虑公式乘以一个补偿系数K 0,根据具体情况补偿空间比例确定,爆破参数修正后,爆破效果良好,达到本次爆破工程要求。本次试验为矿山地下开采无井拉槽爆破施工工艺提供了实用的理论及数据依据。

The effect of cutting and blasting affects the efficiency of underground mining operations.In the process of underground mining of an iron ore,there is a problem that the effect of the slotting blasting without cutting well process is not good.Starting from the traditional blasting process,first test the swelling coefficient of the ore particles in the squeezed state,then optimize the blasting parameters through numerical simulation,and finally verify the calculated results by comparing the field blasting effect.It was found that adjusting the blasting resistance line from 1.2 m to 1 m can overcome the problem of insufficient compensation space in the traditional blasting technology.Numerical simulation found that the effective stress value of the furthest unit point in the direction of the resistance line during the blasting process is greater than 61.3 MPa of the dynamic compressive strength of the ore.At the same time,the stress wave generated during the squeezing blasting process has a squeezing effect on the ore,meeting the test requirements.The ore crushing expansion coefficient is less than 1.333,meeting the blasting compensation space requirements.The traditional line of resistance calculation formula is not suitable for slotting blasting without well,and the compensation coefficient K0 should be considered.After the blasting parameters were revised,a good blasting effect was achieved.This test provides theoretical and data basis for mining construction technology of slotting blasting without cutting well in underground mining.