Question

Write a note on bayer's process involved in leaching of alumina from bauxite ore.

Answer 1

The separation of the alumina from the impurities in the bauxite ore is usually accomplished by the Bayer Process. In this process the ground bauxite is leached with caustic soda (NaOH) to produce soluble sodium aluminate (NaAlO2), leaving the impurities in the insoluble residue

Answer 2

Answer:

1. This method is used in the extraction of metals such as aluminium, gold and silver from their ores.
2. During this process, the powdered ore is treated with certain reagent in which the ore is soluble due to chemical reaction, but the gangue is not soluble.
3. The undissolved gangue is separated by filtration.

Example: Concentration of bauxite which is an ore of aluminium is done by leaching. In this method, bauxite is soaked in aqueous NaOH or Na2CO3 which dissolves the main ingredient of ore i.e., alumina.