Question

What is the principle of vapour phase refining?

Answer 1

The element must be easily converted to volatile compound with available reagent.
2)furthur it should decompose easily for recovery of original element.

ex:Ni+4CO-->Ni(CO)4.
NI(CO)4-->Ni+4CO.

Answer 2

 Vapour phase refining. (i) Zonerefining: This method is based on theprinciple that impurities are more soluble in the molten state of metal (the melt) than in the solid state. ... (ii) Electrolytic refining; Electrolyticrefining is the process of refiningimpure metals by using electricity.