(北方工业大学 机械与材料工程学院，北京 100144)
摘 要: 铜电解精炼生产过程中，结瘤引起的阴阳极间短路会造成明显的电流效率损失和产品质量下降，检测阴极电流的变化趋势可以快速且准确地判断短路是否发生。本文通过在实验室构建铜电解系统对单个结瘤短路前后的现象进行研究，探究结瘤生长全过程的阴极电流变化规律，观察分析结瘤形貌的变化特点，并进一步利用COMSOL Multiphysics仿真软件模拟结瘤的生长过程，建立结瘤生长模型。结果表明：短路前阴极电流变化不显著，预测短路的难度较大；短路一旦发生，电流将以0.47~0.94 A/min的速率急剧增大，可以利用此特征对短路进行快速检测。通过电解实验发现，结瘤前端形成的冠状物的单侧径向生长速度为0.19 mm/h，而其前端局部形成的树枝状凸起促进了结瘤的轴向生长速度，使其达到了0.33 mm/h，两者共同作用造成电解过程中结瘤尺寸的显著增加。结合仿真和实验结果可知，电解后期高电流密度造成结瘤冠状前端局部发生铜的不均匀沉积，由此形成的快速生长接触阳极导致了短路的发生。
关键字: 铜电解精炼；极间短路；阴极电流；结瘤形貌；仿真模拟
（School of Mechanical and Materials Engineering, North China University of Technology, Beijing 100144, China）
Abstract:In the production of copper electro-refining, the short circuit between cathode and anode caused by nodulation leads to obvious loss of current efficiency and decrease of product quality. The occurrence of short circuit can be judged quickly and accurately by detecting cathode current. In this paper, a copper electrolysis system was constructed in the laboratory to simulate the short-circuit process caused by a single nodulation. The change of cathode current during the whole process of nodulation growing and the morphology of the nodulation were studied. Furthermore, the growth process of nodulation was simulated by COMSOL Multiphysics software to establish the nodulation growth model. The results show that, the change of cathode current before short circuit is not obvious, resulting in a difficulty to predict the short circuit. However, once the short circuit occurs, the current increases rapidly in rate range of 0.47-0.94 A/min, which can be used to detect the short circuit quickly. Based on the electrolysis experiment, the growth rate of coronal formed at the front of the nodulation is 0.19 mm/h along the radial direction, and the dendritic bulge formed locally at the front of the coronal accelerates the growth rate of the nodulation along the axial direction, reaching up to 0.33 mm/h, as a result of the significant increase of the nodulation size in the process of electrolysis. According to the results of experiment and simulation, in the later electrolysis process, the high current density around the nodulation will cause the nonuniform deposition of copper at the front of the coronal in some local regions. As a result, the nodulation will grow rapidly to contact the anode finally, leading to the interelectrode short circuit.
Key words: copper electro-refining; interelectrode short circuit; cathode current; nodulation morphology; simulation
