6.13 How can you separate alumina from silica in a bauxite ore associated with silica? Give equations, if any.
Answers (1)
The separation of alumina carried out in the following steps-
The powdered ore is treated with the concentrated solution at 473K-523K and 35-36 bar pressure.
The gas is passed through the resulting solution to neutralise the aluminate, which results in ppt. of hydrated alumina.
The obtained hydrated alumina is filtered, dried and heated to get pure alumina.