(北方工業(yè)大學(xué) 機(jī)械與材料工程學(xué)院，北京 100144)
摘 要: 銅電解精煉生產(chǎn)過程中，結(jié)瘤引起的陰陽極間短路會(huì)造成明顯的電流效率損失和產(chǎn)品質(zhì)量下降，檢測陰極電流的變化趨勢可以快速且準(zhǔn)確地判斷短路是否發(fā)生。本文通過在實(shí)驗(yàn)室構(gòu)建銅電解系統(tǒng)對單個(gè)結(jié)瘤短路前后的現(xiàn)象進(jìn)行研究，探究結(jié)瘤生長全過程的陰極電流變化規(guī)律，觀察分析結(jié)瘤形貌的變化特點(diǎn)，并進(jìn)一步利用COMSOL Multiphysics仿真軟件模擬結(jié)瘤的生長過程，建立結(jié)瘤生長模型。結(jié)果表明：短路前陰極電流變化不顯著，預(yù)測短路的難度較大；短路一旦發(fā)生，電流將以0.47~0.94 A/min的速率急劇增大，可以利用此特征對短路進(jìn)行快速檢測。通過電解實(shí)驗(yàn)發(fā)現(xiàn)，結(jié)瘤前端形成的冠狀物的單側(cè)徑向生長速度為0.19 mm/h，而其前端局部形成的樹枝狀凸起促進(jìn)了結(jié)瘤的軸向生長速度，使其達(dá)到了0.33 mm/h，兩者共同作用造成電解過程中結(jié)瘤尺寸的顯著增加。結(jié)合仿真和實(shí)驗(yàn)結(jié)果可知，電解后期高電流密度造成結(jié)瘤冠狀前端局部發(fā)生銅的不均勻沉積，由此形成的快速生長接觸陽極導(dǎo)致了短路的發(fā)生。
關(guān)鍵字: 銅電解精煉；極間短路；陰極電流；結(jié)瘤形貌；仿真模擬
（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
