What does quicklime mean?
Quicklime is the common name for calcium oxide, a dry white solid made by heating limestone or chalk. It is called “quick” because of its energetic chemical reaction with water: quicklime combines with moisture to form slaked lime, or calcium hydroxide, releasing considerable heat. In industry, it is used in the manufacture of cement, glass, paper, steel, and other products, while in agriculture it may be used to reduce soil acidity after being slaked. The word is mainly technical, and safety warnings often emphasize that quicklime should not be confused with the less caustic, more familiar slaked lime. Its importance is not merely historical: calcium oxide remains an important basic industrial chemical and a key intermediate in the production of many materials.
nounQuicklime is calcium oxide, a white, strongly alkaline solid obtained by heating limestone or chalk until carbon dioxide is driven off. It reacts vigorously with water to form slaked lime and is used in industry, construction, and agriculture.
- A white, dry, caustic substance consisting chiefly of calcium oxide, made by heating limestone or chalk.
- The process or industrial material known as quicklime, especially when referring to its manufacture or handling.
"The kiln produces quicklime, which is later slaked with water before use."
"Quicklime must be stored in airtight containers because it reacts with moisture in the air."
"The agricultural lime was applied in the form of quicklime after being properly slaked."
Usually treated as an uncountable mass noun; “quicklimes” is rare and is appropriate only when referring to separate batches or quantities.
"The plant stores separate grades of quicklimes for different industrial customers."
Quicklime is the industrial starting point for a remarkably reactive chemistry: add water, and the dry white solid becomes slaked lime while releasing substantial heat.
Reviewed by Deb Chak, Editor. AI-assisted content curated by RJS Tech Solutions LLP.
Where does quicklime come from?
The word is formed from “quick” and “lime.” “Lime” has Old English roots in a word referring to a sticky or limelike substance, while “quick” historically conveyed the sense of living or active, contrasting with dead or inert material. The compound developed in the context of lime production, where the distinction between the freshly burned, reactive material and its less reactive forms became important. Related forms include “limestone” and “limewash,” which belong to the same broad lime vocabulary.
How quicklime is actually used
The term is chiefly technical or industrial. It is normally used for the unslaked material; in general usage, “lime” may refer to either quicklime or slaked lime. Because quicklime is caustic and can generate heat when wetted, it requires careful handling.
Easily confused with quicklime
Quicklime is calcium oxide, whereas slaked lime is calcium hydroxide, the softer and more commonly handled product formed when quicklime reacts with water.
Lime can refer broadly to quicklime or slaked lime, while quicklime specifically means the unslaked calcium oxide used to make the latter.