Carbonatation
Carbonatation is a chemical reaction in which calcium hydroxide reacts with carbon dioxide and forms insoluble calcium carbonate: Ca ( OH ) 2 + CO 2 ⟶ CaCO 3 + H 2 O {\displaystyle {\ce {Ca(OH)2{+}CO2->CaCO3{+}H_2O}}} The process of forming a carbonate is sometimes referred to as "carbonation", although this term usually refers to the process of dissolving carbon dioxide in water. == Concrete == Carbonatation is a slow process that occurs in concrete where lime (CaO, or Ca(OH)2(aq)) in the cement reacts with carbon dioxide (CO2) from the air and forms calcium carbonate.