Quicklime powder, also known as calcium oxide (CaO), is a white, alkaline powder produced by heating limestone at high temperatures in a process called calcination. It is a highly reactive material that releases heat when mixed with water, forming slaked lime. Quicklime is widely used in construction, steel manufacturing, water treatment, and chemical industries. In construction, it improves soil stabilization and mortar strength. It is also used for pH control, waste treatment, and flue gas desulfurization. Due to its strong reactivity, quicklime must be handled carefully and stored in dry conditions to maintain its effectiveness and safety.