焦家金矿全尾砂充填体三轴试验研究

充填采矿法可有效解护采矿生产过程中尾矿库塌陷和环境污染等问题,充填材料主要以水泥作为胶结剂,但普通水泥充填体强度低、充填成本高。鉴于此,以焦家金矿全尾砂为研究对象开展充填体常规三轴试验,以水泥作为对照,对比分析矿渣基胶结剂在不同龄期(3、7、14、28 d)和不同围压(0、50、100、300、500 kPa)下的力学特性。结果表明,矿渣基充填体可有效提升充填体早期强度,其不同龄期的抗压强度均大于水泥充填体。龄期的增加促使充填体从塑性向脆性的转化,围压的增加促使充填体从脆性向塑性的转化。Mogi-Coulomb强度准则比Mohr-Coulomb强度准则更适用于评估焦家金矿全尾砂充填体力学特性随着围压的增加,充填体的破坏特征从张拉破坏到剪切破坏,破坏裂纹分布密度减小；龄期对充填体破坏模式影响不大。试验结果表明矿渣基可解决充填体强度低、固体废弃物堆存等问题,有利于矿山企业可持续发展。

Investigation of Three-Axial Testing on Full Tailings Backfill at Jiaojia Gold Mine

Filling mining method can effectively solve the problems of tailing pond collapse and environmental pollution in mining production. Cement is the main filling material, but ordinary cement filling body has low strength and high filling cost. In view of this, conventional triaxial tests were carried out on the tailings of Jiaojia Gold Mine, and the mechanical properties of slag-based cementing agent at different ages (3, 7, 14 and 28 d) and different confining pressures (0, 50, 100, 300 and 500 kPa) were compared with cement. The results show that slag-based backfill can effectively improve the early strength of backfill, and its compressive strength at different ages is greater than that of cement backfill. The increase of age promotes the transition from plasticity to brittleness, and the increase of confining pressure promotes the transition from brittleness to plasticity. Mogi-Coulomb strength criterion is more suitable than Mohr-Coulomb strength criterion to evaluate the mechanical properties of full tailings filling in Jiaojia Gold Mine. With the increase of confining pressure, the failure characteristics of the filling body change from tensile failure to shear failure, and the distribution density of failure cracks decreases. Age has little effect on the failure mode of backfill. The test results show that slag base can solve the problems of low strength of filling body and solid waste storage, which is beneficial to the sustainable development of mining enterprises.