倾斜中厚矿体阶段空场嗣后充填采矿工艺优化研究

Optimization of mining method for stage open-stoping with backfill of inclined medium-thick orebody

分段凿岩阶段空场嗣后充填法是倾斜中厚矿体的高效采矿方法,但爆破、充填与采场稳定性之间关系复杂,可能存在地表塌陷、顶底板垮塌和回采损失率高的问题。采用工程类比、工业试验等手段,从回采顺序、切割方式、底部结构布置等方面对倾斜中厚矿体分段凿岩阶段空场嗣后充填法进行了工艺优化,并提出采场内不留间柱的布置方法。该方法在一步骤充填后将充填体侧帮直接与矿房相连接,并采用挤压爆破提高充填体强度和矿块的回采率。实施时间是该方法的关键,ANSYS/LS-DYNA数值模拟表明:采用中深孔挤压爆破形成切割槽时,应在采场充填及充填体养护7~9 d后进行。工程实践表明该方法具有可行性,能够为矿山生产提供技术支撑。

The open field subsequent filling method in segmented drilling stage is an efficient mining method for inclined medium thick ore bodies.However,blasting,filling and stope stability show complex relationships,causing surface subsidence,roof and floor collapse,and high mining loss rate.This study adopts engineering analogy and industrial experiments to optimize the process of the sublevel drilling and stage open-stoping with backfill of inclined medium thick ore bodies in the aspects of mining se-quence,cutting method,and bottom structure layout,and propose a layout method without leaving pillars in the stope.This method directly connects the side walls of the filling body to the chamber after one-step of filling,and improves the strength of the filling body and the recovery rate of the ore block through extrusion blasting.As the key to this method lies in the implementation time,numerical simula-tion using ANSYS/LS-DYNA shows that medium-depth hole extrusion blasting is used to form cutting grooves,it should be carried out between 7~9 d after filling and curing of the filling body in the stope.Engineering practice has proved the feasibility of this method,which provides technical support for mining production.