School of Resource and Environmental Engineering, Wuhan University of Science and Technology, Wuhan, 430081, China.
State Key Laboratory of Nickel and Cobalt Resources Comprehensive Utilization, Jinchang, 737100, Gansu, China.
Environ Sci Pollut Res Int. 2023 Apr;30(19):55143-55157. doi: 10.1007/s11356-023-26298-6. Epub 2023 Mar 8.
Cemented tailings backfill (CTB) is the most cost-effective and environmentally friendly method to recycle tailings for filling mining. It is of great significance to study the fracture mechanism of CTB for safe mining. In this study, three cylindrical CTB samples with a cement-tailings ratio of 1:4 and a mass fraction of 72% were prepared. An acoustic emission (AE) test under uniaxial compression (UC) with WAW-300 microcomputer electro-hydraulic servo universal testing machine and DS2 series full information AE signal analyzer was carried out to discuss the AE characteristics of CTB, such as hits, energy, peak frequency, and AF-RA. Combined with particle flow and moment tensor theory, a meso AE model of CTB was constructed to reveal the fracture mechanism of CTB. The results show that (1) the AE law of CTB under UC has periodic characteristics, which can be divided into the rising stage, stable stage, booming stage, and active stage. (2) The peak frequency of the AE signal is mainly focused on three frequency bands. The ultra-high frequency AE signal may be the precursor information for CTB failure. (3) The low frequency band AE signals represent shear crack, while the medium and high frequency band AE signals represent tension crack. The shear crack initially decreases and then increases, and the tension crack is the opposite. (4) The fracture types of the AE source are divided into tension crack, mixed crack, and shear crack. The tension crack is dominant, while a larger magnitude AE source is frequently shear crack. The results can provide a basis for the stability monitoring and fracture prediction of CTB.
胶结尾矿充填料（CTB）是回收尾矿进行充填采矿最具成本效益和环境友好的方法。研究 CTB 的断裂机制对于安全采矿具有重要意义。在这项研究中，制备了三个水泥-尾矿比为 1:4、质量分数为 72%的圆柱形 CTB 样品。采用 WAW-300 微机电液伺服万能试验机和 DS2 系列全信息声发射（AE）信号分析仪进行单轴压缩（UC）下的 AE 测试，讨论了 CTB 的 AE 特征，如 hits、energy、peak frequency 和 AF-RA。结合颗粒流和矩张量理论，构建了 CTB 的细观 AE 模型，揭示了 CTB 的断裂机制。结果表明：（1）UC 下 CTB 的 AE 规律具有周期性特征，可分为上升阶段、稳定阶段、繁荣阶段和活跃阶段。（2）AE 信号的峰值频率主要集中在三个频带。超高频率 AE 信号可能是 CTB 失效的前兆信息。（3）低频带 AE 信号代表剪切裂纹，而中高频带 AE 信号代表拉伸裂纹。剪切裂纹最初减少，然后增加，而拉伸裂纹则相反。（4）AE 源的断裂类型分为拉伸裂纹、混合裂纹和剪切裂纹。拉伸裂纹占主导地位，而较大幅值的 AE 源则频繁为剪切裂纹。研究结果可为 CTB 的稳定性监测和断裂预测提供依据。
