粗颗粒对立式砂仓底流浓度及流变性的影响

尾砂充填是我国金属矿山生产中主要的充填技术，但以往研究侧重于探讨床层高度、料浆停留时间、絮凝剂单耗等因素对底流浓度产生的影响，有关添加粗尾砂颗粒对立式砂仓底流料浆性质产生的影响研究较少。为此，通过筛选3种粒径分布的粗颗粒尾砂，分析粗颗粒尾砂的添加量对床层沉降速度、底流浓度以及料浆流变性产生的影响。静态浓密试验结果表明：合适的絮凝条件下能够提高浓密效果评价值，且最佳絮凝剂单耗值随着絮凝剂浓度增加而增高；床层沉降速度和底流浓度随着粗颗粒尾砂添加量增加而增高，且-2 000 μm粒径粗颗粒尾砂提升效果更明显。动态浓密试验结果表明：立式砂仓模型底流料浆平均浓度与床层高度、料浆停留时间和粗颗粒尾砂添加量成正比关系，且底流料浆的静态屈服应力和动态屈服应力均随着粗颗粒尾砂添加量增加而降低、随着料浆浓度增加而增高，分析结果可为实现立式砂仓底流的高浓度稳定运行提供参考。

Effect of Coarse Particle on the Underflow Concentration and Rheology of Vertical Sand Bin

Tailings sand filling technology plays an important role in China′s mining enterprises,but previous studies have focused on the effects of bed height,slurry residence time and flocculant dosage on the underflow concentration,there are few studies on the effect of adding coarse tailings particles on the properties of underflow slurry in vertical sand bin.Therefore,three types of coarse grained tailing sand were selected and the effect of the addition of coarse grained tailing sand on bed settling velocity,bottom flow concentration and slurry rheology was analyzed.The results of static thickening test show that the evaluation value of thickening effect can be improved under suitable flocculation conditions,and the optimal flocculant dosage increases with the increase of flocculant concentration.The bed settling velocity and underflow concentration increase with the increase of coarse particle addition and the lifting effect of coarse grained tailings in the range of -2 000 μm is more obvious.The dynamic thickening test results show that the average concentration of the underflow slurry is positively related to the bed height,slurry residence time and the amount of coarse particles added,the static yield stress and dynamic yield stress of the underflow slurry both decrease with the increase of coarse particles content and increase with the slurry concentration,which provides reference for the stable operation of the underflow of the vertical sand bin with high concentration.