The process of dressing (purification) of the ore which involves separation of ore from gangue due to preferential wetting is:

Froth flotation method

Reason — In the froth flotation method, the powdered ore is stirred with water and pine oil. The ore particles are preferentially wetted by the oil and rise up with the froth, while the gangue particles are wetted by water and settle down. This separation based on preferential wetting is the froth flotation method.