FCI Aravali Gypsum & Minerals India Ltd.

	APPLICATIONS OF GYPSUM

	The Gypsum powder as per the standards specified in IS Specifiation No.-6046-1982 is used as a agriculture grade Gypsum. In agriculture it is used:-

	As a source of Sulphur:-

		In general, each tonne of grain production of cereal removes 3-4 Kg ; pulses 8Kg; oilseeds 12Kg sulphur per hectare from the soil. Use of sulphur deficient Fertilizers is aggrevating this deficiency of the soil. Natural Gypsum contains 13% sulphur; as such this can be used as a source of sulphur to the soil. This has encouraged farmers of Punjab, Haryana, Rajasthan, etc. to use mineral gypsum as a source of sulphur to substantially increase the yield of patato, sugarcane, oil seeds and Pulses.



	Reclamation of Sodic land:-

		Gypsum neutralises alcaline soils and improves the soil permeability and also help the penetration of water and air which are mainly prevented from circulating in alkaline soils. It also provides sulphur and calcium and gives catalytic support for maximum fertilizer utilization. Gypsum can also reduce the harmful effects of sodium salts.


		Mineral Gypsum (IS : 6046-1982) which should pass through a 2mm sieve but at least 50% of it should pass through a 0.25 mm (60 mesh) sieve and contain not less than 70% calcium sulphate dihydrade (CaSO₄2H₂O) and the sodium content of the mineral should not be more than 0.75% could be used effectively for reclaiming alcali soil.

	Use of Gypsum in Cement :-

		The major consumers of the Gypsum at present are cement industry. By weight about 4% to 6% gypsum in crushed condition is utilised in portland cement manufacture after mixing with cement/clinker. Gypsum acts as a retarder and controls the setting time of cement. Gypsum also findes use in cementitons formulations with non OPC products like in the manufacture of high alumina cement, super sulphated cement etc.



	Use of Gypsum in Plaster of Paris:-

		Gypsum (CaSO₄2H₂O) looses three fourth of it's water molecules when heated to about 1500 ^oC & converting itself into hemihydrate form (CaSO₄.1/2 H₂O) which is known as Plaster of Paris. This is used in construction industry for making wall boards, decorative roofing etc.