Calcium oxide

Calcium Oxide

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

History

Calcium oxide is believed to have been produced and utilized by ancient civilizations. The ancient Romans, for example, were known to have used it in the preparation of concrete.

Production

Calcium oxide is produced by heating calcium carbonate (CaCO3) in a process known as calcination. The reaction is as follows:

CaCO3 → CaO + CO2

This process is commonly carried out in a rotary kiln.

Uses

Calcium oxide has a wide range of uses, including the production of cement, preparation of lime mortar, water treatment, and in the chemical industry.

Cement Production

Calcium oxide is a key ingredient in the production of cement. It is mixed with other compounds such as silicon dioxide, aluminum oxide, and iron(III) oxide to produce Portland cement.

Lime Mortar

In the preparation of lime mortar, calcium oxide is mixed with water to produce slaked lime (calcium hydroxide), which is then combined with sand.

Water Treatment

Calcium oxide is used in water treatment processes to adjust the pH and to remove impurities.

Chemical Industry

In the chemical industry, calcium oxide is used as a base in many chemical reactions due to its alkaline nature.

Safety

Calcium oxide is a strong irritant and can cause burns if it comes into contact with skin or eyes. It should be handled with care, using appropriate safety equipment.

See Also

• Calcium hydroxide
• Calcium carbonate
• Lime (material)
• Cement
• Concrete