Electrochemical Deposition of Titanium Ions in Molten Salts

The electrochemical deposition behaviors of titanium ions in titanium extraction by molten salts electrolysis were investigated.Different electrolytes were firstly prepared by adjusting the ratio of TiCl₄ to titanium sponge in NaCl-KCl melts then the electrochemical deposition behaviors of titanium ions were analyzed in the obtained electrolyte systems. According to XRD of the electrolytes of low valence titanium,the main products were TiCl₂ and NaCl-KCl-TiCl₂ electrolyte system can be formed when the mole ratio of TiCl₄ to Ti was 1:2 at 993 K in NaCl-KCl melts,while the TiCl₂ and K₃TiCl₆ with 2.57 of average valence and NaCl-KCl-TiCl₂-K₃TiCl₆ electrolyte system were obtained when the mole ratio of TiCl₄ to Ti was 2:1.The results of cyclic voltammetry for the electrolyte systems mentioned above indicated that the reduction course of titanium ions was Ti²⁺→Ti in NaCl-KCl-TiCl₂ influenced by diffusion with 2.93 × 10^-5cm²/s of diffusion coefficient and it was two steps of Ti³⁺→Ti²⁺and Ti²⁺→Ti in NaCl-KCl-TiCl₂-K₂TiCl₆ system.The morphology of titanium powder obtained in NaCl-KCl-TiCl₂ system was dendrite large particles,and with increase of current density and decrease in concentration of titanium ions the particle size of products decreased.Fine and porous titanium powder was prepared in NaCl-KCl-TiCl₂-K₂TiCl₆ melts.