基于FBRM和PVM技术的尾矿浓密过程絮团演化规律  

Aggregate evolution rule during tailings thickening based on FBRM and PVM

作　　者：周旭 阮竹恩 吴爱祥[2,3] 王洪江 王贻明[2,3] 尹升华 ZHOU Xu;RUAN Zhu-en;WU Ai-xiang;WANG Hong-jiang;WANG Yi-ming;YIN Sheng-hua(CRCC International investment Group Limited,Beijing 100000,China;School of Civil and Resources Engineering,University of Science and Technology Beijing,Beijing 100083,China;Key Laboratory of Efficient Mining and Safety of Metal Mines(Ministry of Education),University of Science and Technology Beijing,Beijing 100083,China)

机构地区：[1]中铁建国际投资有限公司,北京1000002 [2]北京科技大学土木与资源工程学院,北京1000833 [3]北京科技大学金属矿山高效开采与安全教育部重点实验室,北京100083

出　　处：《工程科学学报》2021年第11期1425-1432,共8页Chinese Journal of Engineering

基　　金：国家自然科学基金资助项目(51674012);中国博士后科学基金资助项目(2021M690011)。

摘　　要：在初始泥层高75 cm和耙架转速为0、0.1、1和10 r·min^(-1)条件,以及耙架转速为0.1 r·min^(-1)和初始泥层高度为75、45和25 cm条件下,采用FBRM和PVM实时在线监测技术,对动态浓密系统泥层脱水过程絮团结构演化进行原位连续观测,获得了泥层脱水过程中,絮团直径、数量分布特征和实时图像.研究结果表明,尾矿浓密过程中絮团直径和数量随剪切时间延长呈现先增长后降低,再保持稳定的状态.根据絮团直径变化程度,将絮团密实化过程分为絮团生长期、絮团重构期和絮团破碎期3个阶段.在剪切速率0.1 r·min^(-1)和初始泥层高度75 cm实验条件下,有利于絮团生长和絮团快速破裂重构,并提高絮团密实化程度,但过高的剪切速率作用对絮团结构影响程度下降.剪切速率的增加造成絮团平均直径减小,同时絮团平均直径减小的速率上升.随着初始泥层高度增大,絮团生长阶段时间更长,絮团直径峰值更大,重构期较长,絮团平均直径随初始泥层高度增加而增大.尾矿絮团分形维数可以反映絮团结构变化特征,结合PVM图像的分形维数和孔隙率计算,分析了剪切破坏力与絮团凝聚力存在的相互平衡关系,基于这种动态平衡对絮团破裂程度的影响,研究了尾矿浓密过程中的絮团密实化规律.The real-time inline monitoring technologies of focused beam reflectance measurement(FBRM) and particle video microscopy(PVM) were used to analyze the aggregate structure evolution during the operation of a dynamic thickening system. The tailings dewatering studies were performed under two series of conditions:(i) rake rotation speeds of 0, 0.1, 1, and 10 r·min^(-1) and an initial mud bed height of 75 cm and(ii) initial mud bed heights of 75, 45, and 25 cm and a rake rotation speed of 0.1 r·min^(-1). The aggregate diameter, particle size distribution, and real-time images of the tailings thickening process were obtained. The results show that with the increase in the shearing time, the diameter and counts of aggregate first increase, then decrease, and then become stable.According to the aggregate diameter variation, the aggregate evolution can be divided into three stages: growth, reconstruction, and densification periods. The condition of a shear rate of 0.1 r·min^(-1) and an initial mud bed height of 75 cm has the best effects on the aggregate growth, structure breaking acceleration, aggregate reconstruction, and aggregate densification improvement, as determined in the laboratory;however, high shear rate has a degrading effect on the aggregate structure evolution. The aggregate diameter progressively decreases with the increase in the shear rate. The longer the aggregate growth period, the larger the maximum aggregate diameter, and a longer reconstruction period is observed at higher initial mud bed heights. Moreover, the aggregate diameter increases with the increase in the initial mud bed height. The fractal dimension of tailings aggregate reflects the change characteristics of the aggregate structure. According to the calculation of fractal dimension and porosity of the PVM image, the dynamic equilibrium relastionship between the breaking force and cohesive force of aggregates was analyzed, the influence on the aggregate breaking was analyzed. The aggregate densification rule in the tailings thickening

关 键 词：动态浓密 实时原位监测 剪切速率 初始泥层高 絮团密实化 絮团破裂程度 

分 类 号：TD926.4[矿业工程—选矿]