中深孔爆破在西藏某矿山高分段采场的试验研究

Experimental Study of Medium-depth Hole Blasting in a High Sublevel Stope in a Tibet Mine

中深孔分段空场采矿法广泛应用于国内外中厚及以上矿体开采中。随着凿岩设备日趋大型化,分段空场法的分段高度也在逐渐加大,在减少开拓工程量、提高矿山生产能力的同时,也带来了因中深孔施工偏差造成的矿体开采贫损指标难以控制等问题,直接影响矿山经济效益。以西藏某矿山高分段采场开采为例,通过分析中深孔爆破参数设计原理及国内外正在实施中深孔爆破的采场技术参数,并考虑高分段造成钻机偏斜加大等因素,确定了中深孔爆破试验参数,通过多次爆破试验及生产过程中的参数优化,得到了适宜该矿山二期地下开采范围内矿岩特性的中深孔爆破参数,最终得到了大块率为4.75%,开采损失率为7.34%,贫化率为3.28%等指标,可为二期地下采场中深孔高效爆破提供技术参考。

Sublevel stoping method with medium-depth hole blasting has been widely used in the mining of mediumthickness or thicker orebody at home and abroad. With the Large-scale development of drilling equipment, the sublevel height in the sublevel stoping method is gradually increasing, which can reduce the mine development amount and improve the production capacity, but simultaneously result in difficulty in controlling mining loss and dilution from drilling deviation and affect mine economic benefit directly. In the paper, taking a high-level sublevel stope of a metal mine in Tibet for example, the test parameters of medium-depth hole blasting are determined comprehensively by investigating the designing principle of medium-depth hole blasting parameters and the blasting design parameters of medium-depth hole stope being implemented at home and abroad, and considering the factors such as the deviation of drilling rig caused by high sublevel. Through the repeated blasting tests and the parameters optimization in production process, the suitable medium-depth hole blasting parameters for ore-rock features of stage-2 underground mining area in this mine. Such indicators as the block rate of 4.75%, the mining loss rate of 7.34%, and the dilution rate of 3.28% have been obtained in the end. It can provide technical reference for the efficient blasting of medium and deep holes in the stage-2 underground stope.