Explain the Froth Flotation?

Explain the Froth Flotation?

Froth Floatation : This method is widely used for concentration of sulphide ores. Such as copper pyrites (CuFeS2), Galena (Pbs), zinc blende (Zns).

The finely powered ore is mixed with water in a tank. A small amount of pine oil or xanthates is added to it makes the ore particles non-wettable. Air is now blown violently into the mixture. A froth of scum is formed at the surface. The ore particles are carried by the froth to the surface. The earthy impurities sink to the bottom of the tank. The froth in skimmed off. An acid is added to break up the froth and the concentrated are is filtered and dried.