Question

What is leaching process?​

Answer 1

Leaching is a process in which powdered ore is treated with suitable reagents like acids , bases or chemical compounds. Powdered ore is soluble whereas impurities remain insoluble in it. These undissolved impurities can be removed by filtration. For example, powdered ore of aluminium is leached with concentrated.

Answer 2

This method is based on chemical change. Under this the finely ground ore is reacted with the appropriate reagent. Due to which the state of solution changes and the impurities remain in solid state.

★ Example – To concentrate bauxite ore Al² O⁵

On treatment with NaOH, NaAlO2 is formed which is soluble in water and impurities

★ As- Silica, F e 2 O 3 precipitates out as solid below.

Al2O3 . 2H2O + 2 NaOH → 2 NaAlO2 + 3 H2O NaAlO2 + 2H2O → Al(OH)3 + NaOH .

Step-by-step explanation:

★ The Advantages of Leaching are :-

• It is not a harmful process in comparison to the other pyrometallurgical methods.

• It does not lead to any sorts of gaseous pollutants

★ The Disadvantages of Leaching are :-

The effluent of the leaching process is toxic.

The efficiency of the leaching process is entirely dependent on temperature