拜什塔木铜矿位于新疆戈壁,矿山多年来采用无底柱分段崩落留矿采矿法进行回采,造成大面积地表塌陷。矿体顶板围岩为含细粉砂泥岩,泥质含量高、矿岩破碎、遇水泥化,导致矿体及围岩稳定性差。经过现场调查,针对拜什塔木铜矿存在问题,推荐选用膏体充填技术,但该全尾砂粒度细、且含大量粘土矿物,造成全尾砂制备的膏体存在凝结性能差、充填强度低等问题。研究从粘土矿物、戈壁集料堆积模型及膏体动态抗离析性能等角度,分析骨料级配及最大粒径对充填强度影响,推导并验证粗粒级膏体动态抗离析系数f及其增强措施,确定全尾砂添加戈壁集料的最大粒径d_(max)。通过对戈壁集料粒级的调整,在满足膏体充填假底强度4~5MPa前提下,控制充填成本,满足矿山安全、环保、经济的回采要求。
Baishitamu copper mine, located in the Gobi desert in Xinjiang, has been using non pillar continuous mining with sublevel caving stoping method for years, which results in a large area of surface subsidence. The roofs of the mine are mainly composed of fine silty mudstones and rich in clay, crushed rock and muddy, which make the stability of the ore and the surrounding rocks bad. According to the feasibility study, paste backfill was proposed to solve the problems in Baishitamu copper mine. However, the paste of unclassified tailings with a large proportion of fine content and clay minerals are of poor setting performance and have low strength. Considering the properties of clay mineral, Gobi aggregate packing model and dynamic segregation resistance of paste, the effects of aggregate gradation and the maximum particle size on the compressive strength of paste backfill were analyzed at the same time, the coarse paste dynamic segregation resistance coefficient f and its reinforcing measure were deduced and validated, and the maximum size d_(max) of Gobi aggregate added into tailings was confirmed. By adjusting the Gobi aggregate size, not only the basic requirements for paste strength of 4-5 MPa are satisfied, but also the operation costs decrease, the mining safety and environmental protection are guaranteed at the same time.