What is the difference between gangue and non wettebility?
The earthly and undesirable substances present in an ore besides the metal of interest is the gangue. Gangue is soluble/wettable in water. Sulphide ores on the other hand are soluble in oil and not in water and are therefore non-wettable. This difference in the property of gangue and mineral is exploited to separate out gangue from the mineral in an ore.