Explain the method of froth floatation process of concentrating sulphide ore.

Explanation

In froth floatation process, the powdered ore of sulphide such as zinc blende (ZnS) and galena (PbS) etc., is mixed with water and pine oil in the tank known as cpllector. This suspen~ion is agitated (shaken) rapidly. Then compressed air draws through it. This will cause frothing. The ore particles which are wet by oils become lighter. Now these lighter particles rise to the surface along with the froth. The impurities wh!ch are wet by water being heavier, settle down in the tank. Lastly the froth is transferred to another tank and is washed again and again with water to get the concentrated ore.

Stabilizers and depressants :The froth formed during the froth floatation process may be stabilized by addition of certain organic compounds such as aniline etc. These are known as stabilizers. Sometimes certain reagents are used to suppress or depress the formation of froth. They are called depressants. For example, sodium cyanide (NaCN) acts as a depressant. It separates zinc sulphide (ZnS) and lead sulphide (PbS) from one another during the froth floatation process.