Study On Titanium Dioxide To Titanium In Molten Salt

Titanium is a kind of excellent structural materials and specific functional materials, and has played a very important role in the material industry and high tech areas. To overcome disadvantages of the conventional preparing processes of titanium metal powders such as complex technology, high cost, big energy consumption and severe pollution to the environment, a novel method for producing metals from metal oxides was put forward by researchers in University of Cambridge (called FFC process) in 2000. The process has advantages of short process and little pollution. The direct electrochemical reduction of TiO₂ is one of the most promising processes, which could replace the conventional Kroll process. Although it is difficult to produce titanium from TiO₂ or titanium concentrate, the direct electrochemical reduction of TiO₂ is a simple green process with low energy consumption and non-pollution compared with conventional Kroll process. The process is still in early stage of development and more work should be done in both depth and extent.Preparation of the cathode, choice and pretreatment of the salt, improvement of the electrolysis equipment and control of the parameters during electrolysis were carefully investigated in home-made equipment, the reduction reaction mechanism of titanium dioxide in molten calcium chloride is studied emphasisly.The TiO₂ electrodes for preparing spongy titanium metal in molten CaCl2 system were prepared, and the conductivity of TiO₂ cathode was studied. The products of sintering and electrochemical reduction of TiO₂ were examined by SEM and XPS.The results show that the conductivity of titanium dioxide cathode can be changed by high-temperature sintering, electric double layer and molten salt. The TiO₂ of energy band structure can be changed by high-temperature sintering, and production massive electric conduction vacancy can enhance the conductivity of electrode. The electric double layer can be formed in molten salt, and formation the TiO₂-x structure that enhance the conductivity of electrode. The ions infiltrate to the electrode in molten salt, and increase the numbers of conduction ion that enhance the conductivity of electrode.The formation of O₂^- and the migration process in the cathode was studied preliminarity in this paper, think that high-temperature structure of TiO₂ to the lack of oxygen in the formation. In molten-salts system O₂^- formed by the lack of movement in the cathode, the calcium titanium ore is electrolysis process necessity centre outcome, the metal titanium that the negative electrode generates outside has hindered O₂^-from going to the outer layer migration tier from negative electrode inner.