Limestone is extracted from quarries or mines. Part of the extracted stone, selected according to its chemical composition and granulometry, is calcinated at about 1000 °C in different types of lime kiln.
Quicklime is produced according to the reaction: CaCO3 + heat → CaO + CO2.
Quicklime can be hydrated, i.e., combined with water. Hydrated lime, known as slaked lime, is produced according to the reaction: CaO + H2O → Ca(OH)2.