Benefication of the ore can be done by different ways. It is increasing the concentration of ore by removing impurities, while refining is the process by which concentration of metal is incresed in the final product.
The phase principle to apply vapour phase refining is/are:
A. The intermediate compound has to be volatile
B. The intermediate compound has to be relatively thermally unstable.
C. a and b both
D. Neither a nor b