Direct electrochemical reduction of solid vanadium oxide to metal vanadium at low temperature in molten CaCl₂-NaCl

Zhuo-fei Cai, Zhi-mei Zhang, Zhan-cheng Guo, and Hui-qing Tang State Key Laboratory of Advanced Metallurgy, University of Science and Technology Beijing, Beijing 100083, China

摘 要：V2O5 sintered pellets and graphite rods were employed as the cathode and the anode, respectively; a molten CaCl2-NaCl salt was used as the electrolyte. Then, V2O5 was directly reduced to metal vanadium by the Fray-Farthing-Chen （FFC） method at 873 K to realize low-temperature electrolysis. Two typical experimental conditions, electrolysis time and voltage, were taken into account to investigate the current efficiency and remaining oxygen content in electrolyzed products. The composition and microstructure of the products were charac-terized by X-ray diffraction （XRD） and scanning electron microscopy （SEM）. SEM observations show that a higher voltage （1.8-3.4 V） and a longer electrolysis time （2-5 h） can improve the product quality separately, that is, a lower remaining oxygen content and a more uniform microstructure. The products with an oxygen content of 0.205wt% are successfully obtained below 3.4 V for 10 h. However, the current effi-ciency is low, and further work is required.

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