老龙山石灰岩矿深孔爆破参数优化试验

Optimization Experiment of Deep Hole Blasting Parameters in Laolongshan Limestone Mine

在露天开采过程中,深孔爆破参数直接影响爆破效果(大块率和根底)及爆破工序成本,且爆破工序成本占矿山露天开采综合成本比重较大。为了规范矿山穿孔爆破工序,提高矿山的实际生产效率和经济效益,老龙山石灰岩矿实施了深孔爆破参数优化试验:第一阶段在孔径保持90 mm不变情况下选定区域按照选定4.0 m×3.8 m、4.0 m×4.0 m、4.2 m×4.0 m,4.5 m×4.0 m四种测试孔排距参数进行爆破;第二阶段将钻孔孔径调整至110 mm,爆破孔排距增大至5.0 m×4.8 m、5.2 m×5.0 m。使用破碎锤对爆破后大块矿石进行二次破碎以满足生产矿石块度要求,以爆破设计参数达到的爆破效果和破碎锤二次破碎成本总和最低为要求最终测试出最合理爆破孔排距参数。通过试验过程中所实施的精细管控措施,实施前后爆破工序成本变化对比,摸索出90 mm、110 mm孔径下适合老龙山石灰岩矿深孔孔排距分别为4.0 m×3.8 m、5.0 m×4.8 m,为矿山下一步试验及其他矿山露天开采深孔爆破参数优化试验提供一些参考。

In the process of open pit mining,deep hole blasting parameters directly affect the blasting effects(boulder yield and bottom toe)and the blast cost which accounts for a large proportion of the overall cost of open-pit mining.In order to standardize the process of drilling and blasting and to improve the actual production efficiency and economic benefit,optimization tests of deep hole blasting parameters were carried out in Laolongshan limestone mine.In the first stage,blasts were conducted with hole diameter of 90 mm and four different blast hole layout patterns(hole spacing burden)of 4.0 m×3.8 m,4.0 m×4.4 m,4.2 m×4.4 m and 4.5 m×4.4 m.In the second stage,the hole diameter was adjusted to 110 mm,and the hole spacing and burden were increased to 5.0 m×4.8 m and 5.2 m×5.5 m.The crushing hammer is used for secondary crushing of boulders after blasting to meet the requirements of fragmentation.Finally,the most reasonable values of blasting hole spacing and burden were tested according to minimum overall cost of blasting and secondary crushing.By comparing the costs before and after the blast experiments,the optimum hole spacing and burden are 4.0 m and 3.8 m for hole diameter of 90 mm and 5.0 m and 4.8 m for hole diameter of 110 mm.