Froth flotation method. Explain.
Answers
In this method, water is added to powdered ore. To this, substances called collectors (such as pine oil ) are added so that the ore particles can be separated from the gangue particles. The ore particles become wet by oil while the gangue particles become wet by water. Air is blown in through a pipe and a rotating paddle agitates this mixture. This forms froth. The froth, being lighter, carries with it the ore particles and is separated from gangue. So, the ore particles float above water. The froth is then skimmed off, leaving behind the gangue. It is dried and metal is thus obtained.
Answer:
FROTH FLOATATION
Principle : The process of froth floatation depends on the preferential wettability of the ore with the oil (pine oil) and the gangue particles by water.
Method : The crushed ore is taken in a large tank containing pine oil and water. Potassium ethylxanthate is added to it, a current of compressed air is passed in the tank. The whole mass is agitated. The ore is wetted by the oil and gets seperated from the gangue in the form of froth.
The impurities get wetted by water and remain behind in the tank.
Since the ore is lighter, it comes on the surface with the froth and impurities are left behind.
Sulphide ores like zinc blende (ZnS) and galena(PbS) are lighter than the impurities present. They are concentrated by froth floatation process.
Explanation: