Which of the following methods is primarily used for the concentration of sulphide ores?
Correct: C
Froth flotation is a selective method primarily used for concentrating sulphide ores. In this process, the finely powdered ore is mixed with water and a frothing agent (like pine oil) and a collecting agent. Air is blown through the mixture, creating a froth that selectively carries the sulphide ore particles to the surface, while the gangue settles down. Gravity separation is for heavy oxide ores, magnetic separation for magnetic ores, and leaching for certain specific ores like bauxite or silver/gold ores.