Outline the principles of refining of metals by Vapour phase refining methods

Vapour refining is the process of refining metal by converting it into its volatile compound and then, decomposing it to obtain a pure metal. To carry out this process,

i)the metal should form a volatile compound with an available reagent, and

ii)The volatile compound should be easily decomposable so that the metal can be easily recovered.

iii)Nickel, Zircinium. And titanium are refined using this method.