下盘铁矿矿柱爆破回采对上盘矾矿稳定性影响分析

Influence of Blasting and Mining of Footwall Iron Pillar on the Stability of Upper Bauxite Iron

根据七角井铁矿下盘铁矿体和上盘矾矿体的空间赋存关系,如果对铁矿体预留的矿柱进行回采,很有可能对矾矿体的稳定性造成重大影响。为了保障矾矿体的安全高效开采,在回收下盘铁矿体预留矿柱的同时,尽可能减小对矾矿体稳定性造成影响,提出了2种矿柱回收方案和空区处理方案,矿柱回采方案为间隔间柱抽采法和间隔间柱控制爆破堆坝法,并对2个方案进行了数值仿真模拟,模拟结果显示:采用方案一可有效控制上盘围岩的垂直位移量,最终位移量仅为10.83 mm,而采用方案二开挖上盘围岩的垂直位移量较大,达到17.45 mm,可能会造成上盘围岩的坍塌,最终确定方案一为矿柱回收和空区处理方案。

According to the spatial occurrence relationship of the footwall Iron ore-body and upper bauxite iron,it is pos-sible to impact the stability of the bauxite ore-body if the retained pillar footwall iron was recovered. In order to ensure the safe and efficient exploitation of bauxite ore,it is required to lower the influence on the stability of vanadium orebody when the re-mained iron ore-body is explored at footwall. Two kinds of pillar recovery methods and treatments of mine goaf were proposed, in which the mining schemes consisted of scheme 1 the interval mining between ore pillar and scheme 2 the controlled blasting between interval ore pillars. Numerical simulation analysis on the two programs was conducted. The results showed that the scheme 1 can effectively control the vertical displacement of the rock on the upper plate,with ultimate displacement of only 10. 83 mm. In the scheme 2,the larger vertical displacement reached 17. 45 mm after excavation of the upper surrounding rocks,which may cause the collapse of the upper surrounding rocks. It is determined that scheme 1 be the final program of pil-lar recovery and goaf treatment.