Preparation of zirconium metal through electrolysis of zirconium oxycarbonitride anode

Abstract A single phase zirconium oxycarbonitride was prepared through a carbothermal reduction route at 1600℃ in nitrogen atmosphere using ZrO2 and graphite powder as raw materials. The hot-pressed zirconium oxycarbonitride block has good stability in the NaCl-KCl melt. The anodic dissolution behavior of zirconium oxycarbonitride and the reduction mechanism of zirconium ion in NaCl-KCl melt were studied by linear sweep voltammetry, electrochemical impedance spectrum, cyclic voltammetry and square wave voltammetry. The results show that zirconium in the anode is oxidized to Zr2+ ions and dissolved in the molten salt. The zirconium ions diffuse to the cathode and are reduced to zirconium metal by transferring two electrons in one step. Potentiostatic electrolysis at -2.9 V was performed between a Mo rod cathode and ZrCxOyNz anode. The cathode product was detected to be zirconium metal, which indicated that zirconium oxycarbonitride was a suitable consumable anode for the electrolytic preparation of zirconium metal.