(1. 東北大學(xué) 冶金學(xué)院，沈陽110819；
2. Department of Chemical and Materials Engineering, University of Auckland, Auckland 1142, New Zealand)
摘 要: 鋁電解陽極氣泡行為對研究電解質(zhì)流場模擬和陽極效應(yīng)都至關(guān)重要。本文采用高溫透明電解槽觀測了底面積為50 cm2 (10 cm×5 cm)的石墨陽極上的氣泡行為，實驗溫度為924 ℃。結(jié)果表明：在陽極電流密度為0.3~1.7A/cm2范圍內(nèi)，最大氣體覆蓋率在48%~65%之間，與工業(yè)電解槽炭陽極上的最大氣體覆蓋率相近，低于文獻中小尺寸陽極上觀測到的60%~100%。通過SEM/EDS分析發(fā)現(xiàn)，氣泡成核的優(yōu)先位置與炭陽極表面的層狀結(jié)構(gòu)位置吻合，層狀碳結(jié)構(gòu)對CO2氣泡潤濕性好于致密碳結(jié)構(gòu)，并抑制二氧化碳氣泡的滑動，促進大氣泡的生成。
關(guān)鍵字: 鋁電解；透明電解槽；炭陽極對電解質(zhì)的潤濕性；氣泡行為；氣泡成核
（1. School of Metallurgy, Northeastern University, Shenyang 110819, China；
2. Department of Chemical and Materials Engineering, University of Auckland, Auckland 1142, New Zealand）
Abstract:In aluminum electrolysis, understanding the anodic bubble behavior has been critical for bath flow field simulation and anode effect investigation. In this paper, bubble behavior on graphite anodes with underside surface area of 50 cm2 (10 cm×5 cm) was studied in a transparent Hall-Heroult electrolytic cell at 924 ℃. The results indicate that the largest bubble coverage on the graphite anodes operated at 0.3-1.7 A/cm2 is in the range of 48%-65%, which agrees with the data obtained on industrial aluminum reduction cell, and lower than that of the smaller anodes, 60%-100%, reported in literatures. Priority sites for bubble nucleation were found to be linked to a highly layered carbon structure on the anode surface combined with SEM/EDS analysis. The layered carbon structure illustrates good wettability to CO2 bubbles, preventing adhered bubbles from gliding across the anode to result in the formation of large bubble.
Key words: aluminum electrolysis; transparent electrolytic cell; wettability of carbon anode to aluminum bath; bubble behavior; bubble nucleation
