6.12 Describe a method for refining nickel.

 

Nickel is refined by Mond’s process. In this process, nickel is heated in the presence of carbon monoxide to form nickel tetracarbonyl, which is a volatile complex.                                                          Ni+4CO330-350KNi(CO)4
Nickeltetracarbonyl

Then, the obtained nickel tetracarbonyl is decomposed by subjecting it to a higher temperature (450 − 470 K) to obtain pure nickel metal.
                                                               Ni(CO)4450-470KNi+4CO
NickelNickel
tetracarbonyl