Electrorefining of aluminum in urea-imidazole chloride-aluminum chloride ionic liquids  

尿素-氯化咪唑-氯化铝离子液体电解精炼金属铝

作　　者：JIANG Yan-ying LIU Ai-min TANG Zi-rui LU Xiao-qing LIU Feng-guo HU Xian-wei SHI Zhong-ning 蒋严莹;刘爱民;唐子瑞;鲁小青;刘风国;胡宪伟;石忠宁(Key Laboratory of Ecological Metallurgy of Multimetallic Mineral,Northeastern University,Shenyang 110819,China)

机构地区：[1]Key Laboratory of Ecological Metallurgy of Multimetallic Mineral,Northeastern University,Shenyang 110819,China

出　　处：《Journal of Central South University》2024年第9期3079-3089,共11页中南大学学报（英文版）

基　　金：Project(52004062)supported by the National Natural Science Foundation of China;Project(2020-MS-084)supported by the Natural Science Foundation of Liaoning Province,China;Project(N2125014)supported by the Fundamental Research Funds for the Central Universities,China。

摘　　要：The electrochemical behavior of Al(Ⅲ)in urea-1-butyl-3-methylimidazolium chloride-aluminum chloride(urea-BMIC-AlCl_(3))ionic liquids,and the effect of potential and temperature on the characterization of cathode products,current efficiency and energy consumption of aluminum electrorefining have been investigated.Cyclic voltammetry showed that the electrochemical reduction of Al(Ⅲ)was a one-step three-electron-transfer irreversible reaction,and the electrochemical reaction was controlled by diffusion.The diffusion coefficient of Al(Ⅲ)in urea-BMIC-AlCl_(3)ionic liquids at 313 K was 1.94×10^(−7)cm^(2)/s.The 7075 aluminum alloy was used as an anode for electrorefining,and the cathode products were analyzed by XRD,SEM and EDS.The results from XRD analysis indicated that the main phase of the cathode products was aluminum.The results from SEM and EDS characterization revealed that the cathode product obtained by electrorefining−1.2 V(vs.Al)was dense and uniform,and the mass fraction of aluminum decreased from 99.61%to 99.10%as the experimental temperature increased from 313 K to 333 K.In this work,the optimum experimental conditions were−1.2 V(vs.Al)and 313 K.At this time,the cathode current efficiency was 97.80%,while the energy consumption was 3.72 kW·h/kg.本文研究了尿素-1-丁基-3-甲基氯化咪唑-氯化铝(urea-BMIC-AlCl_(3))离子液体中电沉积金属铝的电化学行为,以及电位和温度对铝电解精炼阴极产物、电流效率和能耗的影响。循环伏安研究表明,Al(Ⅲ)的电化学还原为一步转移三个电子的不可逆反应,且电化学反应受扩散控制;在313 K下urea-BMIC-AlCl_(3)离子液体中Al(Ⅲ)的扩散系数为9.72×10^(-7)cm^(2)/s。以7075铝合金为阳极进行电解精炼,并对阴极产物进行XRD、SEM和EDS分析。XRD分析结果表明,阴极产物的主要成分为铝。SEM和EDS分析结果表明,在-1.2 V(vs.Al)下电解精炼得到的阴极产物致密且均匀,当实验温度从313 K升至333 K时,产物铝的质量分数从99.61%降至99.10%;在-1.2 V(vs.Al)和313 K下进行电解精炼时,阴极电流效率为97.80%,能耗仅为3.72 kW·h/kg。

关 键 词：ionic liquids ELECTROREFINING ALUMINUM cyclic voltammetry 

分 类 号：TF821[冶金工程—有色金属冶金]