Question

Give the principle of:

1. Hydrolytic method
2. Froth floatation
3. Electromagnetic separation

Answer 1

The principle the following are:

(a) Hydrolytic method: It works on the principle of differences in the densities of metallic ore and the gangue particles.

• Gangue is the unwanted earthly impurities such as mud, sand, stone, etc. associated with ore.
• This method is used for those ores that are much heavier than the gangue particles present within them.

(b) Froth floatation process: It depends on the difference in the wetting characteristics of the ore and gangue with pine oil and water used to extract the ore.

• Sulphide ores are treated in this process, e.g. $\mathrm{ZnS},\mathrm{PbS}$.

(c) Electromagnetic separation: It works on the magnetic properties of the ore. A magnet separates the magnetic ore particles from the non-magnetic ore particles.

• This method is useful for those ores that are magnetic in nature.
• Magnetic ores of iron are concentrated by this method e.g. ${\mathrm{Fe}}_2{\mathrm{O}}_3$.