基于新型磁化助凝剂的超细泥化全尾砂动态絮凝沉降实验

摘要

In order to accelerate the sedimentation of super-large-scale argillized ultrafine tailings with bad features such as low settling velocity, muddy overflow water, and large flocculant dosage, a fly-ash-based magnetic coagulant (FAMC) was used in a dynamic experimental device. To obtain the best possible combination of the impact factors (magnetic intensity, FAMC dosage, flocculant dosage, and feed speed) for minimum overflow turbidity, a response surface methodology test coupled with a four-factor five-level central composite design was conducted. The synergy mechanism of FAMC and flocculant was analyzed based on the potential measurement and scanning electron microscopy. The results show that the flocculant dosage, overflow turbidity, and solid content can be reduced by 50%, 90%, and 80%, while the handling capacity per unit and efficiency of backfill and dry stacking can be promoted by 20%, 17%, and 13%, respectively, with a magnetic intensity of 0.3 T, FAMC dosage of 200 mL/t, flocculant dosage of 30 g/t, and feed speed of 0.6 t/(m2×h). Therefore, synergy of FAMC and flocculant has obvious efficiency in saving energy and protecting the environment by allowing 70×106 t/a of argillized ultrafine tailings slurry to be disposed safely and efficiently with a cost saving of more than 53×106 Yuan/a, which gives it great promise for use in domestic and foreign mines.%为解决司家营铁矿超大规模超细泥化全尾砂浆体沉降速度慢、溢流水浑浊、絮凝剂单耗高等问题，基于新型磁化助凝剂，进行了室内超细泥化全尾砂动态絮凝沉降实验。为获得各影响因子(磁场强度、助凝剂单耗、絮凝剂单耗和供料速度)作用下最小的溢流水浊度，基于响应面分析法，进行了四因素五水平的中心组合实验设计。采用电位分析和电镜扫描等方法分析了助凝剂和絮凝剂的协同作用机理。结果表明：在磁场强度为0.3 T，助凝剂单耗为200 mL/t，絮凝剂单耗为30 g/t，供料速度为0.6 t/(m2·h)时，絮凝剂单耗、溢流水浊度和含固量分别降低约50%、90%和80%；深锥单位面积处理能力、充填和干排效率分别提升约20%、17%和13%。新型磁化絮凝剂经济环保，在实现司家营铁矿7000万吨超细全尾砂浆体安全高效处置的基础上，可节约经济成本5300万元，在国内外矿山具有巨大的推广应用价值。