金川二矿区上盘贫矿采矿方法优选及采动效应分析

Optimization of Mining Methods and Analysis of Mining Effect for Hanging Wall Low-Grade Ores in Jinchuan No.2 Mine Area

金川镍矿为我国最大的镍矿资源生产基地,随着二矿区富矿资源逐渐减少,为稳定矿区生产能力,亟需开采上盘贫矿资源。富矿开采过程破坏了原岩应力环境,造成上盘贫矿和围岩体变形破坏,严重影响贫矿资源开采的整体稳定性。针对上盘贫矿开采技术难题,研发了下向进路充填与分段中深孔嗣后充填联合采矿法等3种开采方法,采用未确知测度理论方法确定最优开采方案。通过构建二矿区整体数值模型及其可靠性验证,开展贫矿资源开采采动效应数值模拟分析,表明机械化盘区下向分层大进路胶结充填采矿法应力集中程度最小、总位移量相对最小,更有利于盘区的整体稳定。基于矿山生产实际,开展了机械化盘区下向分层大进路胶结充填采矿法现场试验,建立了矿区全数字型微震监测系统及多参数权重预警模型,实时预警并采取对策措施。采场开采损失率为7.0%,贫化率为6.5%。研究成果可为贫矿资源或二次资源高效安全开采提供技术支撑。

Jinchuan nickel mine is the largest nickel resource production base in China.With the rapid depletion of rich ore resources in Jinchuan No.2 mine area,it is urgently necessary to mine the hanging wall low-grade ore resources to stabilize the mining area's production capacity.The process of rich ore mining disrupts the original geo-stress field in the rock mass,causing the deformation and destruction of the hanging wall low-grade ores and surrounding rock mass,seriously affecting the overall stability of the mining of low-grade ore resources.Given the technical difficulties in mining the hanging wall low-grade ores,three technically feasible mining methods have been developed,including downward drift filling combined with subsection medium-deep hole subsequent filling mining method.In addition,the unascertained measure theory is employed to determine the optimal mining scheme.By constructing the whole numerical model of the Jinchuan No.2 mine area and verifying its reliability,a numerical simulation analysis of the mining effect of the low-grade ore resources mining plan was carried out.It was found that the mechanized panel downward layered large drift cemented filling mining method has the smallest stress concentration and the relative minimum total displacement,which is more conducive to the overall stability of the panel.Based on the practice of mine production,the industrial field test of mechanized panel downward layered large drift cemented filling mining method is carried.Established a full-digital microseismic monitoring system and multi-parameter weight early warning model in the mining area,real-time early warning and countermeasures.The mining site has a loss rate of 7.0% and a dilution rate of 6.5%.The research results can provide technical support for efficient and safe mining of low-grade ore resources or secondary resources and have broad application prospects.