In the context of the Hall-Heroult process for the extreaction of Al

$\mathrm{Al}^{3+}$ is reduced at the cathode to form $\mathrm{Al}$

$\mathrm{Na}_{3} \mathrm{AlF}_{6}$ serves as the electrolyte

$\mathrm{CO}$ and $\mathrm{CO}_{2}$ are produced in this process

$\mathrm{Al}_{2} \mathrm{O}_{3}$ is mixed with $\mathrm{CaF}_{2}$ which lowers the melting point of the mixture and brings conductivity