Explain the purification of sulphide ore by froth floatation method.

1) This process is mainly used to concentrate low grade sulphide ores
2) Finely powdered ore is suspended in water taken in a tank

3) To the suspension, oils like pine oil (or) olive oil is added. frothing agent like sodium ethyl xanthate is also added.
4) Froth is formed when suspension is agitated by bubbling air through it. ore particles adhere to the froth and gangue particles settle down at the bottom of the tank.
5) The principle of this process is that the mineral particles are wetted by oils and gangue particles by water
6) Froth is stabilized by adding collectors. To the suspension conditioner substances like, lime, sodium carbonate are added which help the froth to float.
7) Finally froth is allowed to collapse and dry to recover ore particles
Ex: copper pyrites, Iron pyrite s, zinc blende