不同进液方式下铜电解槽内电解液流动特性的评价

摘要

铜电解槽的进液口布置方式对极板间的流场有着显著的影响,而流场的分布决定电解过程中的电流分布.为了深入了解电解液在竖直极板间复杂的流动行为,以铜电解槽为研究对象,建立了针对"一端进液"、"底部中心进液"、"上侧交错进液"和"底部交错进液"4种不同进液方式下电解槽内电解液的流动过程的三维计算流体动力学模型并进行数值模拟.结果表明:由于"底部中心进液"式电解槽中进液口的位置分布不均匀,其速度的极差较大,是交错进液时的4倍以上.另外,由于"底部交错进液"式电解槽内电解液的湍流强度较大,因此其体平均速度是"一端进液"式的4倍.综合来看,"底部交错进液"式电解槽能够将新鲜的电解液快速、均匀地补充到极板间,为提高电流密度和增加产能奠定了基础.%The arrangement of electrolyte inlet in the copper electro-refining (ER) cell has a great influence on the local flow field, which affects the distribution of electrical current density in consequence. In order to understand the complicated phenomena of electrolyte flow behavior in vertical counter electrodes in full-scale copper ER cell, the three-dimensional computational fluid dynamics (CFD) models with four different arrangements of electrolyte inlets, i.e., single inlet (SI), central bottom inlets (CBI), top side interlaced inlets (TII), and bottom side interlaced inlets (BII), were established to simulate the flow behavior. Simulation results have revealed that the parallel injection devices help to improve the electrolyte velocity between electrodes, and while the relative range of electrolyte velocity in CBI exceeds that of TII and BII, which is more than 4 times, indicating its severer unequal flow distribution. Meanwhile, the average velocity of electrolyte in BII is 4 times larger than that of SI due to its higher turbulence intensity. Generally, one of the efficient ways to supply fresh copper solution rapidly and uniformly into the inter-electrode space is to adapt the arrangement of BII. By utilizing such an arrangement, the electro-refining under high electrical current density is possible, and the productivity can be increased in sequence.