Question

The oil used as frothing agent in Froth flotation process is:
A. coconut oil
B. castor oil
C. palmitic oil
D. pine oil

Answer 1

Hint: In froth flotation, the ore particles come into froth and gangue settle down in the water. Thus, the ore is separated from the gangue. The separation is based upon the observation that ore is wetted by oil whereas the gangue is wetted by water.

Complete step by step answer:
The ore is converted into a fine powder and mixed with water and in this suspension collectors and a froth stabilizer are added. Froth stabilizers are added to stabilize the froth such as aniline. Collectors are added to increase the hydrophobicity of the metal such as pine oil.
Pine oil does not have an affinity for water, so it increases the hydrophobicity of ore. The pine oil is also known as a frothing agent.
Then the mixture is rotated and the air is supplied. The metal particles wrapped into the air come upward in froth whereas the gangue particles wrapped into water molecules settle down, and thus the ore is concentrated. The rotation makes the froth. The froth is separated and dried.
So, the oil used as a frothing agent in the Froth flotation process is pine oil.

Therefore option (D) pine oil is correct.

Note:
Froth floatation is mainly used for sulphide ores. Froth flotation separates the gangue from the ore but this method can also be used to separate the two sulphide ores. Froth flotation process method is used to concentrate the ore. Froth flotation process is based upon the density difference and affinity for water of ore and gangue. The metals are lightweight and hydrophobic whereas the gangue is heavy and hydrophilic.