Cement serves as a crucial binder in construction, facilitating the setting, hardening, and adherence of various materials. Typically inorganic, cement used in construction primarily consists of lime or calcium silicate.
Cement grade limestone, a specific type of limestone, serves as a vital raw material in cement production. The quantity of limestone required correlates directly with estimated cement production, with each tonne of cement necessitating approximately 1.1 tonnes of cement grade limestone. This limestone variant is distinguished by its high calcium content, primarily in the form of calcium oxide (CaO) and calcium carbonate (CaCO3).
Limestone containing 40% (min) CaO and above is usually preferred in the manufacture of cement. Magnesia, sulphur and phosphorus are regarded as deleterious elements. Limestone should have less than 3% magnesium oxide (MgO), maximum tolerance being 5 percent. The presence of Phosphate (P) as P2O5 more than 1% slows down considerably the setting time of Portland cement.
The broad chemical specification of Cement Grade Limestone:
