Continuous Reduction Process of Titanium Chloride by Magnesium

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A process to produce titanium metal in the molten salt was developed for continuous reduction. Titanium chloride and magnesium, which are used as raw materials for the conventional process, are separated into the two molten layers because of density difference. Titanium chloride gas is blown into the lower molten salt, and reduced by the upper magnesium. Titanium settled in the salt piles up on the vessel bottom, and it is extracted from the molten salt.The salt composition was chosen from KCI, NaCl and LiCl, to separate the molten salt and the reductant. The dense MgO was suitable for the crucible material. The obtained powder was about 1/10 finer than the titanium particle by the Kroll method. The main mechanism of reduction was the reduction by magnesium dissolved in the molten salt, and the reduction in the magnesium layer was additive. Considering this mechanism clarified here, a new technique that titanium chloride is blown without any direct contact with metallic magnesium was proposed. The yield was over 80%.On the other hand, the obtained particles were so small and well isolated that the separation from the salt became difficult. First solution was to adapt the condensification process such as liquid cyclone. The excess reductant adhered to titanium particles and enhanced the corsening. The second solution was to take a two-stepwise reduction. In the first step, the lower titanium chlorides are formed in the molten salt by resolving a part of formed titanium powder. In the second step, these highly concentrated chlorides are reduced by magnesium. This proposal are easily operated continuously, and the coarser particles were recovered easily.Similarly niobium and tantalum chlorides were reduced and their pure metallic powders were obtained. Their fine grain size was suitable for compact large capacity condensers.