Solid oxide membrane-assisted electrolytic reduction of Cr2O3 in molten CaCl2
来源期刊：International Journal of Minerals Metallurgy and Materials2020年第12期
论文作者：Bo Wang Bo Wang Jun-qi Li Lin-zhu Wang Yuan-pei Lan Shi-yu Wang
摘 要：Solid oxide membrane-assisted electrolytic reduction of solid Cr2O3 to Cr in molten CaCl2 was performed using a sintered porous Cr2O3 cathode paired with an yttria-stabilized zirconia（YSZ） tube anode containing carbon-saturated liquid copper alloy. Analyses of the reduction mechanism, ion migration behavior, and effects of cathode pellet porosity and particle size on the electrolysis products and reduction rate revealed that the cathode microstructure and electrolytic conditions were key factors influencing the electrolysis process. Optimal results were obtained when the cathode was characterized by high porosity and a small particle size because this combination of features contributed to ion migration. Good electrochemical activation was observed when cathode pellets prepared by 4 MPa molding followed by 2 h of sintering at 1150°C were applied. The electrode reduction process(Cr3+ → Cr2+→ Cr) was promoted by high electrode voltages, and Cr metal was efficiently formed. The proposed method appears to be well suited for electrolytic Cr production because it does not require expensive pre-electrolysis techniques or generate harmful by-products.
Bo Wang1,2，Chao-yi Chen1,2，Jun-qi Li1,2，Lin-zhu Wang1,2，Yuan-pei Lan1,2，Shi-yu Wang1,2
1. College of Materials and Metallurgy, Guizhou University2. Guizhou Province Key Laboratory of Metallurgical Engineering and Process Energy Saving
摘 要：Solid oxide membrane-assisted electrolytic reduction of solid Cr2O3 to Cr in molten CaCl2 was performed using a sintered porous Cr2O3 cathode paired with an yttria-stabilized zirconia（YSZ） tube anode containing carbon-saturated liquid copper alloy. Analyses of the reduction mechanism, ion migration behavior, and effects of cathode pellet porosity and particle size on the electrolysis products and reduction rate revealed that the cathode microstructure and electrolytic conditions were key factors influencing the electrolysis process. Optimal results were obtained when the cathode was characterized by high porosity and a small particle size because this combination of features contributed to ion migration. Good electrochemical activation was observed when cathode pellets prepared by 4 MPa molding followed by 2 h of sintering at 1150°C were applied. The electrode reduction process(Cr3+ → Cr2+→ Cr) was promoted by high electrode voltages, and Cr metal was efficiently formed. The proposed method appears to be well suited for electrolytic Cr production because it does not require expensive pre-electrolysis techniques or generate harmful by-products.
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