Gypsum is a mineral chemical composition of which is calcium sulphate. Gypsum (calcium sulphate) is added to control setting time of cement components during production.
Calcium sulphate may be gypsum (calcium sulphate dehydrate CaSO4.2H2O), hemihydrate CaSO4.1/2H2O or anhydride (dehydrated calcium sulphate, CaSO4) or their mixtures. Gypsum and anhydre is indigenous. Calcium sulphate can be supplied as the sub-product of some industrial processes.
Gypsum ore is purchased from producer company.