Dongsheng Jiang,Zhuan Zhao,Huan Zhang,Ruifang Wang,Jianxun Song,Yusi Che,Jilin He
In this study, metallic niobium was produced by electrolysis in a NaCl-KCl melt using NbCxOy as a soluble anode. The anodic dissolution behavior of NbCxOy in the NaCl-KCl melt and the reduction mechanism of niobium ions were examined using cyclic voltammetry, linear sweep voltammetry, square wave voltammetry, electrochemical impedance spectroscopy, and chronopotentiometry. The results revealed that the electrode reduction process of niobium ion was Nb(Ⅴ) → Nb(Ⅲ) → Nb(Ⅰ) → Nb, with these reactions being diffusion-controlled. During successive multiturn scans, the reduction process of niobium ions favored the pathway of Nb(V) → Nb(III) → Nb. As the electrolytic voltage increased, the dissolution of niobium ions in NbCxOy also increased, with a tendency to oxidize into high-valence niobium ions. Constant-current electrolysis in a NaCl-KCl melt, using NbCxOy as the anode and Mo rods as the cathode resulted in the deposition of mainly metallic niobium on the Mo cathode, manifesting that NbCxOy can be used to extract metallic niobium. This study provides a theoretical foundation for the realization of a green and efficient extraction process for metallic niobium.
Buju Guo,Yaowu Wang,Ruoyu Li,Yifei Li,Boxiong Zhang,Jianping Peng,Yuezhong Di,Ke Wang,Chang Wang
Scrap aluminum (Al) alloy recycling is critical for energy conservation and decreasing carbon emissions. Conventional remelting process does not remove alloying elements, severely limiting the value and applications of recycled Al. To overcome this limitation, this study develops an efficient process for recovering pure Al from scrap Al alloys via soluble anode electrolysis in a designed MgCl 2 -KCl-NaCl (MKN) molten salt system. Real-time monitoring of the electrolysis process, time-dependent characterization of cathodic deposits, and electrochemical analyses reveal a three-stage cathodic deposition mechanism in the MKN molten salt system: initial underpotential deposition of Mg 2+ transitions to co-deposition of Mg 2+ and Al 3+ , and ultimately to exclusive reduction of Al 3+ , which is driven by progressive Al 3+ accumulation. The introduction of AlCl 3 proves pivotal, simultaneously enhancing Al 3+ deposition efficiency while effectively suppressing Mg 2+ co-reduction. Systematic optimization identifies 12.5 wt% AlCl 3 addition, 500 °C, and 0.15 A/cm 2 as the ideal operational parameters, achieving recycled Al with 99.84 wt% purity. The soluble anode electrolysis process in the MKN molten salt system represents an efficient and scalable alternative to conventional remelting. The developed process is capable of producing recycled Al with purity comparable to that of primary Al while addressing critical sustainability challenges in the Al industry.
危险品化学品经营许可证（带存储）