Question

Write the balanced chemical equation for concentrating alumina from bauxite by Baeyer's process.​

Answer 1

In the Bayer process, bauxite ore is heated in a pressure vessel along with a sodium hydroxide solution (caustic soda) at a temperature of 150 to 200 °C. At these temperatures, the aluminium is dissolved as sodium aluminate (primarily [Al(OH)4]−) in an extraction process.

2 NaOH + SiO2 → Na2SiO3 + H2O.