
Calcium oxide that survives processing without reacting in building products such as cement is called free lime.

By contrast, quicklime specifically applies to the single chemical compound calcium oxide.

The broadly used term " lime" connotes calcium-containing inorganic materials, in which carbonates, oxides and hydroxides of calcium, silicon, magnesium, aluminium, and iron predominate. It is a white, caustic, alkaline, crystalline solid at room temperature. Calcium oxide ( Ca O), commonly known as quicklime or burnt lime, is a widely used chemical compound.
