At Sigma, chemical grade Limestone of Rajasthan belt are mined.
Lime is extensively used to treat municipal waste waters and industrial liquid wastes. In wastewater treatment plants (both urban or industrial) Hydrated Lime and Quick Lime are widely used for correcting the pH balance of acidic water, for precipitating heavy metals and phosphates, and for its flocculating action.
Lime is widely used for stabilizing industrial residual sludge or dredging sludge and for treating urban biosolids before agricultural re-use or incineration.
In addition, lime is used to treat soils polluted with hydrocarbons.
Lime has long been used in the construction industry to make mortar and plaster, serving as a binder in these substances. During the hardening process, the lime combines with carbon dioxide from the air to form rocklike calcium carbonate, while water is released by evaporation. Hydraulic lime is used to make a special kind of mortar that hardens under water. Besides this, Quick Lime Powder is also used immensely for manufacturing AAC Blocks (Autoclaved Aerated Concrete).
A cleaning agent in the leather manufacture process, lime is used to remove raw skin and thus obtain clean leather.