초록
The molten salt electrolysis is applied to reduce titanium dioxide to titanium metal using calcium chloride as an electrolyte and the reaction mechanism of the reduction process is examined by analyzing the reaction products. The process conditions to obtain titanium metal for $900^{\circ}C$ correspond to 2.9~3.2 V and 24 hours. The reaction products for 2.9 V at $900^{\circ}C$ include irregular-shaped titanium oxides such as $Ti_4O_7$, $Ti_3O_5$ and $Ti_2O_3$ and polyhedral $CaTiO_3$. Using these microstructure analysis, the sequential reaction mechanism for the electrochemical reduction of titanium dioxide to titanium is proposed.