絮团稠化对全尾砂浓密性能的影响

Effects of aggregate densification on unclassified tailings thickening performance

基于全尾砂浓密过程料浆质量分数高,尾矿絮团无法直接观测,而取样稀释再进行测试分析难以避免误差,借助FBRM和PVM实时在线监测和分析系统,观测全尾砂浓密过程耙架剪切应力和重力耦合作用下絮团颗粒结构和粒度的变化。研究结果表明:在泥层高度分别为25,45和70cm的3个全尾砂浓密阶段内均保持耙架转速为15r/min的试验条件下,直径在100μm以上的絮团逐渐破裂重构而数量减少,直径在10μm以下絮团数量相应增加,松散的大絮团逐渐演化成为密实的小絮团;絮团有效直径随剪切时间延长和泥层高度增加而减小,絮团稠化速程度随泥层高度上升而加快;有效干涉沉降系数是基于絮团有效直径的函数,随剪切时间延长和泥层高度增加呈现先增大后稳定的趋势。

Due to the high concentration of unclassified tailings slurry thickening process,flocculated aggregates of tailings particles can't be directly observed,and the deviation of sampling and diluted analyzing is unavoidable.Based on focused beam reflectance measurement (FBRM) and particle vision microscope (PVM) real-time online monitoring and analysis system,the study of aggregate densification under rake shear stress coupled with gravity during unclassified tailings thickening process was accomplished.The results show that in three thickening test stages of mud bed height 25, 45 and 70 cm with the same rake shear ratio 15 r/min,the amount of aggregates diameter over 100 μm decreases,while the amount of aggregates diameter under 10 μm increases,because the large and loosen aggregates are reconstructed and deformed into small and denser aggregates.Effective aggregate diameter decreases as shear time mud bed height increases,and the aggregate densification accelerates with mud bed height rises.As the function of effective aggregate diameter,the effective hinder settling factor rapidly increases first and then becomes stable when shear time increase and mud bed height rises.