Question

What is the concentration or enrichment of ore? Explain the method of enrichment of ore containing sulphide with diagram?

Answer 1

Concentration: The ores are concentrated on the basis of the type of impurities and their percentage proportions. As a result, most of the impurities are removed and the proportion of the ore is increased. This process is called concentration of the ore. For this, (i) concentration or centrifugation on the basis of the difference in the densities (ii) froth flotation and (iii) magnetic separation methods are used.
i. Froth floatation method is used for concentration of the ores of the metals whose ores are in sulphide form. The concentration of sulphide ores of copper, lead and zinc metal are carried out by this method.
ii. In this method, water and the fine powder of the ore are filled in a big vessel. Then, substances like pine, or turpentine oil are added to it. The sulphide particles of metals get wet and stick to it, while clay and particles of sand do not get wet. In this liquid mixture, air is passed with pressure through a tube.
iii. Hence, the froth is produced around the light particles of the sulphide ore and comes on the surface of the liquid mixture. Heavy particles like clay, sand etc. become wet by water and settled down at the bottom.
iv. The sulphide ore of the metal is removed with sieves in a second vessel and washed with water. By this method, ores like copper pyrites are concentrated and clay, sand etc. are removed.