Froth floatation method is used for the concentration of sulphide ores and depends upon the non-wettability of mineral particles in water. In this process, a suspension of the powdered ore is made with water and it is agitated by using paddle and air is passed. Consequently, froth is formed, ore particles goes with froth' sometime two sulphide ore may also be present together. Froth floatation method is also helpful in their separation. A mixture contains sulphides of lead and zinc. These two sulphides can be separated by the use of