An Investigation of Electro-deoxidation Process for Producing Titanium from Dense Titanium Dioxide Cathode

Abstract

The electrolytic method for directly extracting metals from the cathode of their its oxide has been called as “electro-deoxidation”. TiO2 cathode in molten CaCl2 has been developed more than 10 years. Two different mechanisms (“FFC Cambridge” and “OS”) were proposed to describe this electrochemical process. In order to further explore the mechanism, a dense cathode was designed in the present study, and an electrical conductor (Mo bar) was connected with the cathode, but without direct connection with molten salt to get rid of the possible electrochemical reaction between electrical conductor and melt. The experiments were carried out in a vertical electric resistance furnace at 900 °C in argon atm osphere w ith molten calciu chloride as electrolyte. The cathode was cylindrical in shape (about 35mm in height, and 8mm in diameter). The cathode after the electrolytic experiment was examined by using SEM technique. The SEM observation of the cathode showed a layer-structure with dense core and porous product in outer layer(s). The electrical resistance of the core was found much lower than that of the original cathode. The result of electro-deoxidation experiments by present authors indicated that the “FFC-Cambridge” mechanism may give a better explanation for the electro-deoxidation process of dense cathode at the initial time.