Question

Give reasons why:

Aluminium cannot be extracted by the reduction of its ores.

Answer 1

Aluminium cannot be reduced from its ore as:

• In the extraction of the aluminium from its bauxite ore, first it is converted to sodium aluminate known as alumina.
• The melting point of alumina is $2000{}^{\circ }C$ and it is a poor conductor of heat so it cannot be directly reduced to form pure aluminium.
• So, to the alumina the addition of cryolite, fluorspar and coke is done.
• By addition of these substances the melting point reduces to $900-950{}^{\circ }C$.

Due to the high melting point and poor conduction of heat, aluminium is not extracted by reduction of its ores.