Lime kiln

Kiln used for the calcination of limestone Rotary lime kiln (rust-colored horizontal tube at right) with preheater, Wyoming, 2010 Traditional lime kiln in Sri Lanka A lime kiln is a kiln used for the calcination of limestone (calcium carbonate) to produce the form of lime called quicklime (calcium oxide). The chemical equation for this reaction is: CaCO3 + heat → CaO + CO2 This reaction can take place at anywhere above 840 °C (1,540 °F), but is generally considered to occur at 900 °C (1,650 °F) (at which temperature the partial pressure of CO2 is 1 atmosphere), but a temperature around 1,000 °C (1,830 °F) (at which temperature the partial pressure of CO2 is 3.8 atmospheres) is usually used to make the reaction proceed quickly. Excessive temperature is avoided because it produces unreactive, "dead-burned" lime. Slaked lime (calcium hydroxide) can be formed by mixing quicklime with water. History Pre-pottery Neolithic In plaster, proto-pottery, and mortar An archaeologist at Çatalhöyük Because it is so readily made by heating limestone, lime must have been known from the earliest times, and all the early civilizations used it in building mortars and as a stabilizer in mud