Question

Class XII problem

What is the significance of leaching in the extraction of aluminium?

Answer 1

Leaching.
1. Heat the boxite
2.Add some NaOH to it. and wash it.
3.Na3AlO3 will get.
4.wash this and add Al(OH)2. and clean it
5.we will get al(OH)2 now
6.heat it.
7.Now we get alumina(al2O3)

we can't extract Aluminium without this steps. Then again heat this alumina with krayolite

Answer 2

Leaching removes impurities like SiO2 which cannot be removed by any other method.