Calcium oxide, commonly known as quicklime or burnt lime, is a chemical compound composed of calcium and oxygen. Its chemical formula is CaO. It is a white, caustic, crystalline solid that is highly reactive with water. Calcium oxide is produced by heating calcium carbonate (typically in the form of limestone) in a process called calcination.

Calcium oxide has a wide range of applications due to its physical and chemical properties. Some of its uses include:

• Industrial Applications: It is used in various industrial processes such as steel production, paper manufacturing, and sugar refining. It is also utilized in the production of cement, mortar, and plaster.
• Water Treatment: Calcium oxide is employed in water treatment systems to raise the pH levels and neutralize acidic water. It reacts with acidic impurities to form calcium hydroxide, which can be removed easily.
• Desiccant: Due to its strong affinity for water, calcium oxide is used as a desiccant or drying agent. It is employed to remove moisture from gases and liquids.
• Soil Amendment: In agriculture, calcium oxide is used as a soil amendment to neutralize acidic soils and increase pH levels. It improves the soil structure and provides essential calcium to plants.
• Chemical Industry: Calcium oxide serves as a precursor for the production of other chemicals, including calcium hydroxide (slaked lime), calcium carbonate, and various calcium salts.