Explain electrometallurgy in detail.

(N/A) Electrometallurgy is the process of extracting electropositive metals from their ores or salts by electrolytic reduction,typically in a molten state or aqueous solution.
This method is based on electrochemical principles,governed by the Gibbs free energy equation:
$\Delta G^{\circ} = -nF E^{\circ}_{cell}$
Where:
$n = \text{number of electrons transferred}$
$F = \text{Faraday constant}$
$E^{\circ}_{cell} = \text{standard cell potential}$
For a spontaneous reaction,$\Delta G^{\circ}$ must be negative,which requires a positive $E^{\circ}_{cell}$. Highly reactive metals have large negative reduction potentials,making their reduction difficult. In such cases,electrolysis is employed where $M^{n+}$ ions are reduced at the cathode:
$M^{n+} + ne^{-} \rightarrow M_{(s)}$
Precautions are taken regarding the reactivity of the metal produced,and suitable electrodes are chosen. Flux is often added to the molten electrolyte to increase conductivity and lower the melting point.
Examples of processes based on these principles include the Hall-Heroult process (for $Al$),Castner's process (for $Na$),and Down's cell process (for $Na$).