Feasibility study and performance optimization of sand-based cemented paste backfill materials
Feasibility study and performance optimization of sand-based cemented paste backfill materials
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DOI：
10.1016/j.jclepro.2020.120798
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发表时间：
2020-06
影响因子：
11.1
通讯作者：
N. Zhou;Jixiong Zhang;Ouyang Shenyang-;Xuejie Deng;Chaowei Dong;E. Du
中科院分区：
文献类型：
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作者：
N. Zhou;Jixiong Zhang;Ouyang Shenyang-;Xuejie Deng;Chaowei Dong;E. Du
膏体充填采矿法在我国煤矿中得到了广泛的应用，煤矸石是充填采矿中常用的骨料。然而，一些矿区的煤矸石供应并不充足。针对山东省赵官煤矿的开采条件，提出了一种以分布广泛、价格低廉的黄河砂为充填骨料，以水泥和粉煤灰为结合剂的砂基膏体充填材料。对物料的输送性能和力学性能进行了测试和优化。研究发现，SCPB初期泌水率大，早期和后期强度普遍较低，同时掺加聚羧酸盐和生石灰可显著改善充填料的工程性能，泌水率为3.2%~ 3.9%，早期强度为0.2-0.39 MPa，后期强度为7.53-8.86 MPa; SCPB浓度的最佳配比为78%，F/S比为0.6，C/S比为0.2，P/S比为0.004，L/S比为0.15。此外，X射线衍射（XRD）和扫描电子显微镜（SEM）结果表明，优化后的SCPB比初始的SCPB更致密，并且表现出更大程度的粉煤灰水化。
Cemented paste backfill (CPB) mining is widely applied in coal mines throughout China, where gangue rock is commonly used as an aggregate. However, some mining areas do not have an abundant supply of gangue. This paper proposes a sand-based cemented paste backfill material (SCPB) with widely distributed and low-cost Yellow River sand as the filling aggregate with cement and fly ash as the binders based on the mining conditions of the Zhaoguan Coal Mine located in the Shandong province of China. The conveying and mechanical properties of the material were tested and optimized. This study found that (i) the initial SCPB have a large bleeding rate, while the early and late strengths are generally low; (ii) simultaneously adding polycarboxylate and quicklime can significantly improve the engineering performance of the filling material, where the bleeding rate is 3.2%–3.9%, the early strength is 0.2–0.39 MPa, and the late strength is 7.53–8.86 MPa; and (iii) the optimal mixing ratio of the SCPB concentration is 78%, the F/S ratio is 0.6, the C/S ratio is 0.2, the P/S ratio is 0.004, and the L/S ratio is 0.15. Furthermore, the X-ray diffraction (XRD) and scanning electron microscopy (SEM) results show that the optimized SCPB was denser than the initial SCPB and exhibited a greater degree of fly ash hydration.