Question

Chemical leaching is useful in the concentration of:

Answer 1

Hint: An attempt to this question can be made by understanding the process of leaching. Try to identify the different types of leaching methods used and their properties. Based on this you can determine the ore that can be concentrated by this method and thus answer the question.

Complete Solution :
- Leaching is the process mainly used in extractive metallurgy where ore is treated with chemicals to convert the valuable metals within into soluble salts.
- On the other hand, the impurities remain insoluble. These can then be washed out and processed to give the final pure metal.
- Chemical leaching is preferred over pyrometallurgy as it is easier to perform. Along with that the energy requirement is relatively less.

There are 4 main types of leaching for 4 different types of mineral ores. They are listed below:
- Cyanide leaching : for gold ore
- Ammonia leaching : for crushed ore
- Alkali leaching : for bauxite ore
- Acid leaching : for sulfide ore
From the above statements we can conclude that chemical leaching is useful in the concentration of bauxite.
So, the correct answer is “Option A”.

Note: It is important to know that leaching although is easier to perform has some drawbacks. They are listed below:
- Low efficiency due to lack of energy/heat supplied
- Producing significant amounts of waste effluent and tailings produced. These waste substances are commonly observed to be toxic and highly acidic or basic in nature.