Study On The Preparation Technology Of Vanadium

Vanadium, together with niobium and tantalum, belongs to group V of the periodic table. It has a high melting point and good corrosion resistance at low temperature, so it has been wild used from transitional aeronautics and astronautics industry to civil industries of metallurgy, energy source, transportation, chemic industry, biology and pharmacy. Because of complex manufacturing process and non-continuous production of the traditional process, production cost of vanadium is high, limiting greatly its application.FFC-Cambridge process proposed by the University of Cambridge is a new technology for producing metals and their alloys, the desired metal cations are reduced selectively at the cathode through control the electrode potential. Therefore, only metallic oxides take part in electrolytic reaction. It has the advantages of short manufacturing process, low cost and no pollution, and has been the potentials to take the place of the Kroll process.In this paper the preparation of vanadium by FFC process was studied. In view of some key problems existed in the electrolytic reduction process, the preparation of V2O3cathode and some premeters, such as the size of the anode, molten salts system, electrolyte temperature and electrolyte voltage, affacting the electro-reduction were discussed. The electro refining of vanadium in molten salts was also studied in this paper.V2O3pellets pressed at20MPa and sintered at1100℃for4h meet the the experimental requirements, when temperature is lower or higher than1100℃the pellets can not in accordance with the test requirements.The impact of experimental parameters, such as the size of the anode, molten salts system, electrolyte temperature and electrolyte voltage on the current, were studied by parallel experiments. The optimum parameters were determined as:graphite crucible was used as anode, CaCl2-NaCl (22:1, wt%) mixed salts were used as the electrolyte, electrolyte temperature is900℃, and electrolyte voltage is2.9V.The study on electro refining of vanadium in CaCl2-NaCl-CaO molten salts showed that the byproduct CaV2O4affects the quality of refined vanadium.