Question

define the term leaching​

Answer 1

When solvents are used to remove substances from porous solids or sludges, the process is called leaching. Or. Leaching is the removal of a solute from a porous solid using a liquid solvent

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.