Explain the process of producing alumina from bauxite.

1.	Explain the process of producing alumina from bauxite.
Answer» Bauxite is treated with hot concentrated NaOH. Aluminum oxide reacts with NaOH solution forming sodium aluminate solution (NaAlO₂). The unreacted impurities are removed from the solution. To the remaining solution of sodium aluminate, add Al(OH)₃ in small quantity and dilute with water. Then the whole aluminum in the solution gets precipitated as Al(OH)₃ . The Al(OH)₃ precipitated is separated from the solution. Then it is washed and heated strongly. Then Al(OH)₃ decomposes to give pure AL₂O₃ or alumina. 2Al(OH)_3(s) → Al₂O_3(s) + 3H₂O(1).

Answer»

Bauxite is treated with hot concentrated NaOH. Aluminum oxide reacts with NaOH solution forming sodium aluminate solution (NaAlO₂). The unreacted impurities are removed from the solution. To the remaining solution of sodium aluminate, add Al(OH)₃ in small quantity and dilute with water. Then the whole aluminum in the solution gets precipitated as Al(OH)₃ . The Al(OH)₃ precipitated is separated from the solution. Then it is washed and heated strongly. Then Al(OH)₃ decomposes to give pure AL₂O₃ or alumina.

2Al(OH)_3(s) → Al₂O_3(s) + 3H₂O(1).

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