Question

How to get pure alumina? explain with the reactions​

Answer 1

Okay I will explain you friend...

To get pure alumina, you should follow these below steps.

Step (1):- Impurity alumina is treated with conc. NaOH solution to form sodium aluminate.

`{ \green{ \tt{Al2O3 + 2NaOH + 3H2O → 2Na[Al(OH)4]}}}`

Step (2):- sodium aluminate is treated with carbon dioxide gas to form precipitated Al2O3

`{ \purple{ \tt{2Na[Al(OH)4] + CO2 → Al2O3.xH2O + NaHCO3}}}`

Step (3):- Precipitated Al2O3 separated by filtration and heated at 1470K to give pure alumina.

`{ \blue{ \tt{Al2O3.xH2O \: \: —(1470K)→ Al2O3 + xH2O}}}`