Preparation of low-oxygen Ti powder from TiO2 through combining self-propagating high temperature synthesis and electrodeoxidation
(1. Key Laboratory of Ecological Metallurgy of Multi-metal Intergrown Ores of Ministry of Education, Northeastern University, Shenyang110819, China;
2. School of Metallurgy, Northeastern University, Shenyang 110819, China)
2. School of Metallurgy, Northeastern University, Shenyang 110819, China)
Abstract: An effective method was reported to prepare low-oxygen Ti powder, which included two experimental steps: the fast conversion of TiO2 to TiOx<1 powder by self-propagating high-temperature synthesis (SHS) process and the generation of low-oxygen Ti powder by electrodeoxidizing TiOx<1 powder at the cathode in molten CaCl2. The key intermediate steps were analyzed by XRD, SEM and electrochemical testing techniques. The results demonstrated that TiOx<1 powder (TiO0.325 and TiO0.97) was generated after acid leaching MgO in SHS products with TiO2/Mg molar ratio of 1:2, and the TiOx<1 powder with 16.3 wt.% oxygen could be transformed into pure titanium powder with 0.121 wt.% oxygen by electrodeoxidation at a constant potential of -3.3 V for 10 h. The electrodeoxidation of TiOx<1 powder in CaCl2 molten salt follows the step-by-step deoxidation mode, and the lattice of TiOx<1 powder after electrodeoxidation shrinks.
Key words: titanium metallurgy; self-propagating high temperature synthesis; titanium powder; electrochemical deoxidation