(N/A) Method: In this method,the impure metal is made to act as the anode. $A$ strip of the same metal in pure form is used as the cathode. They are put in a suitable electrolytic bath containing a soluble salt of the same metal. The more basic metal remains in the solution and the less basic metal goes to the anode mud.
This process can be explained on the basis of electrode potential,overpotential,and Gibbs energy concepts.
Reaction:
Anode: $M \rightarrow M^{n+} + n e^-$
Cathode: $M^{n+} + n e^- \rightarrow M$
Copper is refined using this electrolytic method.
Anode is made of impure copper. $A$ strip of pure copper is taken as the cathode.
The electrolyte is an acidic solution of copper sulfate,and the net result of electrolysis is the transfer of copper from the anode to the cathode as pure copper.
Anode: $Cu \rightarrow Cu^{2+} + 2e^-$
Cathode: $Cu^{2+} + 2e^- \rightarrow Cu$
Impurities from blister copper deposit as anode mud,which contains antimony,selenium,tellurium,silver,gold,and platinum. The recovery of these elements may meet the cost of refining.