During extraction of aluminium from bauxite, | Chemistry | SolveeIt

Question

During extraction of aluminium from bauxite,

the concentration of ore is done by gravity separation method

molten mixture of aluminium oxide, cryolite and fluorspar is electrolysed

impure aluminium is refined by liquation

molten aluminium is obtained at cathode while fluorine is liberated at anode.

Answer

molten mixture of aluminium oxide, cryolite and fluorspar is electrolysed

Explanation

Solution

Purified ${Al_2O_3}$ is mixed with ${Na_3AlF_6}$ and ${CaF_2}$ to improve conductivity of ${Al_2O_3}$ and to lower the melting point of the mixture.
${Al_2O_3 ->[Electrolysis] 2Al^{3+} + 3O^{2-}}$
At cathode : ${Al^{3+} + 3e^- ? Al}$
At anode : ${C + O^{2-} ? CO + 2e^-}$
${ C + 2O^{2-} \rightarrow CO_2 + 4e^-}$

Chemistry Question on General Principles and Processes of Isolation of Elements

Solution