自然崩落法放矿中覆盖层冰碛物穿流特征与控制试验研究

Experimental Study on Inflow Characteristics and Control of Overburden Moraine During Ore Drawing by Natural Caving Method

为解决自然崩落法放矿中覆盖层冰碛物细颗粒穿流混入带来的高贫化损失难题,采用室内放矿相似模拟试验,选取自然堆积与固结改性两种覆盖层冰碛物状态进行试验,对放矿过程中细颗粒的混入率进行统计分析。研究结果表明:自然堆积覆盖层冰碛物状态下,混入率随放矿高度增加呈幂指数增加,混入率与覆盖层细颗粒含量成正比,冰碛物覆盖层下放矿可划分为纯矿石放出、少量细颗粒快速穿流、细颗粒与矿石混合和细颗粒大量穿流放出4个阶段;固结改性覆盖层冰碛物状态下,细颗粒混入率可降低50%以上,放出矿量增加30%,固结改性是控制覆盖层冰碛物细颗粒穿流混入的有效手段。

In order to solve the problem of high depletion loss caused by the inflow of fine particles of overburden moraine during ore drawing by natural caving method,the similar simulation test of indoor ore drawing was adopted,and two overburden moraine states of natural accumulation and consolidation modification were selected for test,and the mixing rate of fine particles during ore drawing was statistically analyzed.The research results show that under the overburden moraine state of natural accumulation,the mixing rate increases exponentially with the increase of ore drawing height,and the mixing rate is proportional to the content of fine particles in the overburden.The ore drawing under the moraine overburden can be divided into four stages,including pure ore discharge,rapid inflow of a small amount of fine particles,mixing of fine particles with ore and large inflow of fine particles.Under the overburden moraine state of consolidation modification,the mixing rate of fine particles can be reduced by more than 50%,and the amount of ore drawing can be increased by 30%.Consolidation modification is an effective means to control the inflow mixing of fine particles of overburden moraine.