高应力破裂矿柱阶梯式诱导崩落法回采实践

Practice of Step-induced Caving Mining in Fractured Pillar with High Stress

铜坑矿以采富留贫的方式对92#矿体进行回采,在高地压应力、多次开采扰动和空区冒落的影响下,预留的大量不规则矿柱大多呈破裂、不完整状态。矿柱群Ⅱ采区是高应力破裂矿柱的典型代表,由于多分层采准工程同时施工,严重削弱了矿柱的完整性,诱发区域性地压活动,大部分采准工程被破坏。针对矿柱群Ⅱ采区采准工程遭地压破坏的情况,通过对地压监测数据、各区域破坏类型进行系统分析,运用原地碎裂爆破技术,对高应力矿柱进行泄压,改善矿柱内部的应力环境,布置阶梯式出矿底部结构,大面积拉底,诱导顶部矿体垮落,实现破裂矿柱诱导崩落,矿石回收率达75%,贫化率为19.5%,取得了良好的开采效果。

In the 92# orebody of Tongkeng Mine, the rich ore is mined and the low-grade ore is retained. Under the influences of high ground pressure stress, repeated mining disturbance and goaf caving, a large number of reserved irregular pillars were mostly broken and incomplete. The pillar group II mining area was a typical representative of fractured pillar with high stress. Due to the simultaneous construction of mining preparation engineering in multiple layers, the integrity of pillar was seriously weakened, regional ground pressure activities were induced, and most of the mining preparation engineering was destroyed. In view of this situation, through the systematic analysis on the ground pressure monitoring data and the damage type in each region, by in-situ fragmentation blasting technology, the pressure of the pillar with high stress was relieved, the stress environment inside the pillar was improved, the stepped bottom structure was arranged, large area bottom pulling was achieved, and the top orebody was induced to collapse, so that the induced caving of broken pillars was realized. Finally, good mining effects have been obtained, with ore recovery rate of 75% and the dilution rate of 19.5%.