Pore Connectivity and Dewatering Mechanism of Tailings Bed in Raking Deep-Cone Thickener Process
Pore Connectivity and Dewatering Mechanism of Tailings Bed in Raking Deep-Cone Thickener Process
复制标题
耙式深锥浓密机尾矿床孔隙连通性及脱水机理
DOI：
10.3390/min10040375
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发表时间：
2020-04-01
期刊：
影响因子：
2.5
通讯作者：
Liu, Juanhong
中科院分区：
文献类型：
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作者：
Chen, Xinming;Jin, Xiangfei;Liu, Juanhong
膏体浓缩尾矿（PTT）技术可以提高选矿厂尾矿的利用和管理水平。在耙式剪切作用下，厚层尾矿床的孔隙尺寸分布（PSD）和微观结构演化是产生高密度尾矿底流的关键。通过连续增厚和计算机断层扫描（CT）测试来研究有和无剪切的PSD。通过对孔隙形貌的研究，揭示了尾矿床层的剪切脱水性能。结果表明，当絮凝剂浓度为0.01wt%，料浆浓度为10wt%时，有剪切和无剪切时底流浓度分别可达58.5wt%和55.8wt%。CT图像重建模型表明，剪切尾矿床的孔隙度随床层高度的增加而增加。当床层高度从2.5 cm增加到10 cm时，孔隙度从35.1%增加到41.9%，孔隙分形维数从1.8-1.95增加到2.1-2.15，孔隙数量减少了21.39%。平均孔容随高度的增加而增加，分别为13.93%、16.57%和12.07%。随着床层高度的增加，孔隙结构变得更加复杂，孔隙间连通性增强，形成水流通道，有利于封闭水的排出。
Paste and thickened tailings (PTT) technology can improve the utilization and management of tailings from processing plants. The pore size distribution (PSD) and microstructure evolution affected by the rake shear in thickening tailings beds are essential to produce a high-density tailings underflow. Continuous thickening and computed tomography (CT) scanning tests were conducted to study the PSD with and without shear. The pore morphology was studied to reveal the shearing-dewatering performance of the tailings bed. The results show that at a flocculant solution concentration of 0.01 wt % and a feed slurry concentration of 10 wt%, the underflow concentration with and without shear can reach 58.5 wt %and 55.8 wt %, respectively. The CT image reconstruction models demonstrated that the porosity of the sheared tailings bed increased with the bed height. When the bed height increased from 2.5 to 10 cm, the porosity increased from 35.1% to 41.9%, the pore fractal dimension increased from the range 1.8–1.95 to the range 2.1–2.15, and the pore quantity decreased by 21.39%. The average pore volume increased with increasing height by 13.93%, 16.57% and 12.07%. The pore structure became more complex with the bed height, and the connectivity between pores increased to form water-flow channels, which were beneficial to the drainage of sealed water.