PHOSPHOGYPSUM AS A LAND AND WATER POLLUTANT

Sources of Phosphogypsum

Phosphogypsum is generated as a by-product of the phosphoric acid based fertiliser industry. The interaction of ground phosphate rock with sulphuric acid produces 10-40% free moisture along with phosphogypsym. 4.5 million tonnes is generated per year in India. Over 10 million tonnes has accumulated at plant sites.

Nature of Pollution

The fluoride content of phosphogypsum causes land and water pollution.

Recycling of Phosphogypsum

This pollutant by-product from the fertiliser industry can be used to make several building materials:

• Gypsum plaster, boards, tiles.

• As set controller in the manufacture of Portland cement.

• Non-shrinking cement, super sulphated/anhydride cement.

• As a hydraulic binder.

• As mineraliser.

• Simultaneous manufacture of cement and sulphuric acid.

• Artificial marble, fibre boards.