絮凝剂和减水剂对尾砂浓密性能与充填体强度的影响

为提高溢流尾砂胶结充填效果，对溢流尾砂开展了添加和未添加减水剂沉降试验、湿堆密度测试、胶结料浆流变参数与抗压强度测试、胶结充填体总空隙率和微观结构测试，探究了絮凝剂与减水剂对溢流尾砂浓密性能和充填体强度的作用机理。研究表明：絮凝剂与减水剂具有“协同效应”，可提高尾砂浓密底流浓度，但效果与减水剂添加顺序和添加量相关。添加絮凝剂与减水剂使溢流尾砂湿堆密度增大，由0.559提高至0.591。絮凝剂添加使胶结充填体总空隙率与结构缺陷增加，造成充填体抗压强度降低；而含絮凝剂与减水剂的胶结充填体总空隙率降低，结构更致密，充填体抗压强度得到提高。尾砂浓密阶段添加减水剂可降低后续胶凝材料用量。相关研究成果可为优化尾砂高浓度胶结充填工艺提供借鉴。

Effects of Superplasticizer and Flocculants on Thickening Performance and Strengh of Overflow Tailings

In order to study thickening performance of overflow tailings slurry and improve filling effect of overflow tailings cemented backfills, the static sedimentation test,wet packing density test,rheological test , compressive strength test,total porosity test and scanning electron microscope (SEM) test were carried out on overflow tailings with or without superplasticizer.The influencing mechanism of the flocculants and superplasticizer on improving thickening performance of overflow tailings slurry was revealed. The results show that flocculants and superplasticizer had synergistic effect, the settling velocity and concentration of overflow tailings were increased,but the influence on overflow tailings depends on the adding order and dosage of the superplasticizer .The wet packing density of overflow tailings increasing from 0.559 to 0.591 when flocculants and superplasticizer were added. Flocculants in cemented tailings backfill slurry increased the total porosity of cemented tailings backfill and the structural defects such as holes and cracks, which reduced the compressive strength .When flocculants and superplasticizer adding ,the total porosity of cemented tailings backfill decreased and the structure become more compact lead to improved mechanical strengths.The addition of superplasticizer in the tailing thickening stage could reduce the addition amount of cementitious materials prepared by cemented tailings backfill slurry. The research results provide reference for the optimization of high concentration cemented filling of tailings.