Production process
The raw material for the production of lime is limestone, a sedimentary rock rich in calcium carbonate (CaCO3) that is extracted from special quarries. The coarsely crushed material with a diameter in the order of centimetres is introduced into special furnaces where it is fired at 800-900°C.
During this phase, a reaction known as 'calcination' takes place, leading to the formation of calcium oxide with the release of carbon dioxide:
CaCO3 => CaO + CO2
The product, also known as Quicklime, is in the form of lumps of various grain sizes, which are subsequently ground and sieved. Hydrated lime (or slaked lime) is obtained by hydrating quicklime according to the reaction:
CaO + H2O => Ca(OH)2
The extinguishing of calcium oxide can take place by stoichiometrically dosing the water, with the formation of powdered hydrated lime, which in turn can be refined with specific wind separators to obtain Micro-lime (or lime flower).
When extinguishing occurs with excess water, the product obtained, subjected to adequate seasoning in tanks, is Lime Putty.
