Question

Sulphide ores are concentrated by froth floatation process.

a) Write the name or formula of any two sulphide ores of copper.

b) Explain froth floatation process.

Answer 1

a)

• Copper pyrites (CuFeS₂)
• Copper glance (Cu₂S)

b) This method is used for removing gangue from sulphide ores and is based on the principle of preferential wetting of solid surface by vanousliq ulds. i.e., the mineral particles become wet by oils while the gangue particles by water. Finely powered ore is agitated with water containing collectors (e.g. pine oils, fatty acids, xanthates, etc.) and froth stabilizers (e.g. cresols, aniline) by passing a forceful current of air. The collectors enhance non-wettability of the mineral particles and froth stabilisers stabilise the froth. The froth which is formed at the surface of water carries up lighter ore particles and heavier gangue particles are left to the bottom. The froth is skimmed off and then dried for recovery of the ore particles.