Fabrication of Low-Oxygen Titanium Powder by Electrolysis of Molten Salt Containing LaCl3

Titanium and its alloys are widely used in aerospace and ocean engineering because of their excellent properties. Molten salt electrolysis is a cost-effective and efficient method for producing titanium powder. However, titanium powder prepared via this method contains high oxygen levels. To address this issue, a novel approach for producing low-oxygen titanium powder by molten salt electrolysis containing LaCl3 is proposed in this study. Molten salts were selected and their physicochemical properties determined. The density, viscosity, and surface tension of the molten salt increased with LaCl3 content and decreased with increase in temperature in the NaCl-KCl-MgCl2-LaCl3-TiClx molten salt system. For optimal separation of electrolytic products from the molten salt and electrolytic slag, lower LaCl3 content and higher temperatures are recommended. Electrochemical tests revealed that the Ti precipitation reaction was quasi-reversible and diffusion-controlled. Finally, molten salt electrolysis experiments were conducted, showing that the oxygen content of the titanium powder decreased with increased temperature, LaCl3 concentration, and electrolysis time. At 4 wt% LaCl3, titanium powder with a low oxygen content of 500 mass ppm oxygen was obtained by electrolysis at 850 °C and 2.5 V for 1 h. This study provides theoretical guidance for the low-cost, short-process preparation of low-oxygen titanium powder.