Lime

Lime is an inorganic material made primarily of calcium oxides and hydroxides, usually in the form of calcium oxide or calcium hydroxide. It is produced by burning limestone, which is mainly composed of calcium carbonate, in a lime kiln at high temperatures. This process converts the calcium carbonate into quicklime (calcium oxide). Hydrating the quicklime by adding water produces slaked lime (calcium hydroxide).

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Lime has been used since prehistoric times for building materials like mortar and concrete, chemical feedstocks, and sugar refining. Limestone is quarried or mined, then crushed and burned in a lime kiln to make quicklime. Quicklime is caustic, but when water is added to make slaked lime, it becomes less caustic while still being alkaline. Both quicklime and slaked lime continue to have many industrial uses today, including in construction, engineering, wastewater treatment, and agriculture.