Gas Generation Reactions during TiO₂ Reduction Using Molten Salt

Abstract

Titanium dioxides were reduced to metallic titanium via molten salt electrolysis using CaCl 2. It was reported that the ef ciency was low because some side reactions produced carbon precipitates. To produce titanium more ef ciently, these electrochemical side reactions were examined by cyclic voltammetry CV. O 2 reacted with the carbon anode to form CO and CO 2 gas bubbles, which easily dissolved into the molten salt and formed CO 3 2 , subsequently generating carbon powder. CV was performed after interrupting electrolysis temporarily. The electrochemical reduction of CO 3 2 in the cathodic scan was not observed, suggesting that CO 3 2 was spontaneously reduced by Ca during electrolysis. Anodic reactions preceding Cl 2 gas generation occurred in three steps: CO and CO 2 gas generation related to O 2 , and successive CO 2 generation related to CO 3 2 .

Recent Studies on Titanium Refining: 2017–2020

“…42 mass% O could be directly achieved as a porous powder starting from TiO 2 .3133) Haraguchi et al34) studied electrochemical side reactions via cyclic voltammetry. The O 2¹ in the CaCl 2 melt reacted with the carbon anode, forming CO and CO 2 gas bubbles, which are essential components of the OS process.…”