School of Mining Engineering, Anhui University of Science and Technology, Huainan, 232001, China.
School of Civil and Resource Engineering, University of Science and Technology Beijing, Beijing, 100083, China.
Environ Sci Pollut Res Int. 2023 Oct;30(46):102862-102879. doi: 10.1007/s11356-023-29455-z. Epub 2023 Sep 6.
By preparing fine tailings slurry with different mass concentration and fiber content, the rheological parameters of slurry with different fiber content and curing time were tested. In addition, the influence law of fiber content and curing time on compressive strength was analyzed through the prepared fine tailings backfill samples, and the microstructure characteristics of fine tailings backfill were further studied. The results show that when the fiber content is 0.2 ~ 1.2%, the yield stress and plastic viscosity of the slurry increase with the increase of fiber content, and the thixotropy of the slurry also shows the same change characteristics. The bridge effect of fiber makes it easier for forming network structure, which increase the slurry rheology. When the curing time ranges from 0 h to 2.5 h, the increasing of curing time leads to the increasing trend of rheological parameters, and also increases the thixotropy of slurry. However, the increase of rheological parameters will continuously decrease when the curing time exceeds 1 h, indicating that the influence of curing time on yield stress and thixotropy will gradually weaken with the continuous extension of curing time. When the curing age increases from 3 to 56 days, the compressive strength of the fine tailings backfill increases with the curing age, but the increasing range of compressive strength decreases gradually. When the fiber content ranges from 0.2 to 1.2%, the compressive strength of backfill increases first and then decreases with the increase of fiber content, and reaches the maximum value when the fiber content is 0.6%. The extension of curing time reduces the generation of large-scale pore structure, which promotes the formation of more compact microstructure of backfill.
通过制备不同质量浓度和纤维含量的细尾砂浆液，测试了不同纤维含量和养护时间下浆液的流变参数。此外，通过制备的细尾砂充填料样，分析了纤维含量和养护时间对抗压强度的影响规律，进一步研究了细尾砂充填料的微观结构特征。结果表明，当纤维含量为 0.21.2%时，浆液的屈服应力和塑性黏度随纤维含量的增加而增加，浆液的触变性也呈现出相同的变化特征。纤维的桥接作用使其更容易形成网络结构，从而增加了浆液的流变性。当养护时间从 0 h 增加到 2.5 h 时，流变参数呈增加趋势，且浆液的触变性也增加。然而，当养护时间超过 1 h 时，流变参数的增加会持续下降，表明养护时间对屈服应力和触变性的影响会随着养护时间的不断延长而逐渐减弱。当养护龄期从 3 天增加到 56 天时，细尾砂充填料的抗压强度随养护龄期的增加而增加，但抗压强度的增加幅度逐渐减小。当纤维含量在 0.21.2%范围内时，充填料的抗压强度随纤维含量的增加先增加后降低，当纤维含量为 0.6%时达到最大值。养护时间的延长减少了大尺寸孔隙结构的产生，促进了充填料更致密的微观结构的形成。
