In the following question, a statement of assertion followed by a statement of reason is given. Choose the correct answer out of the following choices:
Assertion : Sulphide ores are concentrated by froth floatation process .
Reason : Cresols stabilize the froth in froth floatation process.
Answer & explanation
Correct answer: option 2
The froth flotation process is used to concentrate sulphide ores. In the froth floatation method, gangue particles are preferentially wetted by water, becoming heavier and settling down at the bottom of the tank, while sulphide ore particles are preferentially wetted by oil, becoming lighter and rising to the surface along with the froth. Cresols stabilise the froth in the latter case. The primary factor in metal extraction is froth formation. Froth and metal ore both emerge.