School of Resources and Safety Engineering, Central South University, Changsha, 410083, China; Sinosteel Maanshan Institute of Mining Research Company Limited, Maanshan, 243000, China.
School of Resources and Safety Engineering, Central South University, Changsha, 410083, China.
Chemosphere. 2022 Jan;286(Pt 1):131630. doi: 10.1016/j.chemosphere.2021.131630. Epub 2021 Jul 21.
Anionic polyacrylamide (APAM) has widely been employed in backfill mining to accelerate the sedimentation of fine tailings particles and increase the concentration of tailings slurry. However, APAM inevitably remains in thickened tailings, leading to a nonnegligible influence on the rheological, mechanical, and heavy metal leaching properties of tailings-based cemented paste backfill (CPB). In an effort to solve these issues, the influences of APAM on CPB properties were examined in the present study. Experimental tests such as rheology, uniaxial compressive strength (UCS), toxicity leaching, and microscopy were conducted. The results showed that the presence of APAM first significantly increased the yield stress and viscosity of CPB slurry. APAM slightly improved the early UCS of CPB curing for 7 days but hindered the UCS development of samples cured for 28 days. Moreover, the presence of APAM restrained the hydration reaction, reduced the amounts of hydrated products, increased pore size, and loosed the microstructure of the test samples. Finally, the addition of APAM effectively reduced the leaching of Ag and As, while incremented that of Cu and slightly affected the leaching of Ba. In sum, these findings look promising for the safe production and environmental protection of the mining industry.
阴离子型聚丙烯酰胺（APAM）广泛应用于回填采矿中，以加速细尾矿颗粒的沉降并提高尾矿浆的浓度。然而，APAM 不可避免地残留在增稠的尾矿中，对基于尾矿的胶结膏体充填料（CPB）的流变性、力学性能和重金属浸出特性产生不可忽视的影响。为了解决这些问题，本研究考察了 APAM 对 CPB 性能的影响。进行了流变学、单轴抗压强度（UCS）、毒性浸出和显微镜等实验测试。结果表明，APAM 的存在首先显著增加了 CPB 浆液的屈服应力和粘度。APAM 略微提高了 CPB 养护 7 天的早期 UCS，但阻碍了养护 28 天的样品的 UCS 发展。此外，APAM 的存在抑制了水化反应，减少了水化产物的量，增加了孔径，并使测试样品的微观结构变得疏松。最后，添加 APAM 可有效降低 Ag 和 As 的浸出，同时增加 Cu 的浸出量，并略微影响 Ba 的浸出。总之，这些发现为采矿业的安全生产和环境保护提供了有希望的前景。
