Question

what is the principle of froth flotation process?

Answer 1

This method is concentrating the sulphide ores.
A strong current of air is blown through the suspension, producing a heavy froth or foam on the surface. The metal sulphide is wetted by the oil but the gangues is not and the sulphide-oil mixture is carried to the surface by films of oil The froth is skimmed off, the gangue settles down on the bottom or remains underneath the froth. By this method it is possible to concentrate over 90% of a sulphite ore to 1/10 of its original bulk. Ex., Galena (PbS)