The content of calcium oxide in clinker is the highest and the mixture is complex. Except limestone and mineral powder, the calcium oxide content of other mixtures (volcanic ash, slag, fly ash, etc.). ) is generally less than 15%.

Calcium oxide is an inorganic compound with chemical formula of CaO, commonly known as quicklime. Physical properties: the surface is white powder, grayish white when it is impure, pale yellow or gray when it contains impurities, and it is hygroscopic.