ABSTRACT
Metals produced by the reduction of their halides are usually the reactive metals that cannot easily be prepared by the reduction of their oxides. Halides of these metals may be reduced by hydrogen or by metals. In the first case, the efficiency of reduction is low because a large volume of gas must be circulated at high temperatures. In the reduction of NbCl5 by hydrogen, for example, the molar ratio H2/NbCl5 for complete reduction is about 100 times that theoretically required. On the other hand, reduction by metals is used industrially but is challenged by fused salt electrolysis. In the case of TiCl4, which is liquid at room temperature, the liquid is injected into an evacuated air-tight heated reactor containing the reducing metal in the molten state. Titanium tetrachloride immediately evaporates and the vapors interact with the molten metal to deposit titanium crystals on the walls of the reactor at the liquid interface.
