超细全尾砂胶结充填体的强度特征分析

以中关铁矿全尾砂为充填骨料、水泥为胶凝材料制作胶结充填体,采用单因素四水平试验设计,分析了全尾砂的物理化学性质,探讨了全尾砂胶结充填体强度与灰砂比、料浆质量浓度和养护龄期之间的定量关系,并对其敏感程度进行了研究。研究结果表明：中关铁矿全尾砂中值粒径仅为14.2μm,碱度系数为2.31,活性系数为2.12,属于碱性超细全尾砂,级配良好、活性较高；全尾砂胶结充填体的强度随灰砂比的增加和料浆质量浓度的增加呈指数函数增长,随养护龄期的增加呈线性增长,拟合相关系数平均值分别为0.97、0.96和0.92；充填体强度对养护龄期的敏感程度最高,灰砂比次之,料浆质量浓度最小。

Analysis on Strength Characteristics of Super-fine Unclassified Tailiings Cemented Backfills

Cemented-tailing backfills were produced by taking unclassified tailings of Zhongguan Iron Mine as filling aggregate, and ordinary Portland cement as cementing agent. Physicochemical properties of unclassified tailings were analyzed, quantitative relationships between backfill strength and cement-tailing ratio, slurry concentration, and curing age were discussed by using single-factor four-level experiment, and sensitivity of backfill strength to these factors were also studied. The results show that, unclassified tailings of test, whose median diameter, alkalinity coefficient and activity coefficient are 14. 2 μm, 2. 31 and 2. 12 respectively, belongs to alkaline super-fine tailings with high activity. Strength of full tailings cemented backfill follows exponential function with cemented-tailing ratio and slurry concentration, but linear function with curing age, and the the corresponding correlation coefficients are 0. 97, 0. 96 and 0. 92 respectively. Sensitivity of backfill strength to curing age is the maximum, followed by cement-tailing ratio, and slurry concentration is the minimum.