金鼎钨钼矿露天台阶深孔爆破参数优化

为解决金鼎钨钼矿生产中存在的大块率过高、根底残留等问题,通过力学实验研究、数值模拟和现场试验,对该露天台阶深孔爆破参数进行优化。通过常规三轴试验研究,得到了该矿岩力学参数和矿岩性质,确定其矿岩炸药单耗0.68 kg/m~3;运用ANSYS/LS-DYNA软件对爆破参数进行优化,以炮孔密集系数m为变量,通过比较坡底、坡顶有效应力与岩石的动抗拉强度,判断相应炮孔密集系数下矿岩的爆破效果。结果表明:当炮孔密集系数m=1.5时,坡底和坡顶岩石均被破坏,大块明显减少,振动危害也小,达到预期爆破效果。将优化后的爆破参数(孔径d=20 cm,炸药单耗q=0.68 kg/m~3,炮孔密集系数m=1.5,孔排距为600 cm×400 cm)应用于生产现场,爆破效果大为改善,大块率低于5%。可以为类似极硬岩矿山提供参考经验。

Optimization of Deep-hole Bench Blasting Parameters in Jinding Tungsten Molybdenum Mine

In order to solve the problems of high boulder yield and toe rock residue in the production of Jinding tungsten molybdenum ore,the parameters of deep-hole bench blasting are optimized through mechanics experiment, numerical simulation and field application test.The rock mechanical parameters and rock properties are obtained by the conventional triaxial test,and the explosives specific charge of 0.68 kg/m3is determined.Taking borehole com-pression coefficient m as the variable,the blasting parameters were optimized by ANSYS/LS-DYNA,and the blasting effect under the corresponding hole density coefficient is determined by comparing the effective stress at the bottom and top of the slope with dynamic tensile strength of the rock.The results show that when m=1.5,the rocks at the bottom and the top of the slope are destroyed,the boulder are obviously reduced,and the vibration hazard gets smal-ler,and the expected effect is achieved.The optimized blasting parameters(hole diameter 20 cm,explosives specific charge 0.68 kg/m3,borehole compression coefficient 1.5,row space 600 cm and hole space 400 cm)are applied to the production field,the blasting effect is greatly improved,and the boulder yield is lower than 5%,which can pro-vide reference for similar extremely hard rock mine.