尾矿泥浆沉降的微细观机制研究

Study on Micro-mesoscopic Mechanism of Tailings Slurry Settlement

由于堆存于尾矿库中的尾矿泥浆长期处于流动状态,是重大的危险源。因此针对尾矿泥浆进行了一系列沉降试验,利用Malvern-3000激光粒度仪对其沉降过程进行粒度分析,试样沉降稳定后进行了核磁共振(NMR)试验。结果表明,盐溶液增加了尾矿泥浆的絮凝和阻碍沉降阶段的持续时间,降低尾矿泥浆的初始平均沉降速度,尾矿泥浆在盐溶液中的稳定孔隙比小于在蒸馏水中的稳定孔隙比。激光粒度分析结果表明,在相互阻碍沉降阶段,随盐溶液中阳离子浓度增加,尾矿泥浆絮凝体直径变小。核磁共振试验结果表明,在盐溶液中的沉降稳定阶段,尾矿泥浆的结合水向自由水转变,对尾矿泥浆的沉降过程存在影响。可以考虑通过添加阳离子对絮凝剂继续改性,增加洗矿过程中的工作效率,加速尾矿泥浆在尾矿库中的自固结速度。

Because the tailings slurry piled in the tailings pond is in a flowing state for a long time,it is a major hazard source.Therefore,a series of sedimentation tests were carried out for the tailings slurry,and the Malvern-3000 laser particle size analyzer was used to analyze the particle size of the tailings slurry during the sedimentation process.Nuclear magnetic resonance(NMR)tests were carried out after the samples settled steadily.The results showed that salt solution increases the duration of flocculation and hinders the settling of the tailings slurry,reduced the initial average settling velocity of the tailings slurry,and the stable void ratio of the tailing slurry in salt solution was less than that in distilled water.The results of laser particle size analysis showed that the diameter of tailing mud flocs decreased with the increase of cation concentration in salt solution in the mutual obstruction settling stage.The results of NMR experiments showed that the bound water of tailings slurry changed to free water in the stable stage of settlement in salt solution,which had an impact on the settlement process of tailings slurry.It can be considered to continue to modify the flocculant by adding cations to increase the working efficiency in the process of ore washing and accelerate the self-consolidation speed of tailings slurry in the tailings reservoir.