Calcium oxide

Calcium oxide (CaO), commonly known as quicklime or lime, is an inorganic alkali produced by thermal decomposition of limestone. It carries CAS number 1305-78-8 and EC number 215-138-9, and is traded under names including calx and burnt lime. No E-code designation applies to this substance.

In water treatment, calcium oxide raises pH by reacting with water to form calcium hydroxide, neutralising acidic effluents and precipitating heavy metals. In building and construction, it serves as a binding agent in mortars through a carbonation reaction with atmospheric CO2. Agricultural applications rely on its strong alkalinity to correct acidic soils and suppress microbial activity.

Calcium oxide is available in technical and industrial grades as powder or granular form, with particle size specifications varying by application. It falls under REACH regulation and requires a current Safety Data Sheet for EU procurement. Standard packaging includes bulk bags and loose bulk delivery; food or feed-grade certification should be confirmed with the supplier.