Lime kiln

For other uses, see Lime kiln (disambiguation).

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[1]) is usually used to make the reaction proceed quickly.[2] Excessive temperature is avoided because it produces unreactive, "dead-burned" lime.

Slaked lime (calcium hydroxide) can be formed by mixing quicklime with water.

  1. ^ CRC Handbook of Chemistry and Physics, 54th Ed, p F-76
  2. ^ Parkes, G.D. and Mellor, J.W. (1939). Mellor's Modern Inorganic Chemistry London: Longmans, Green and Co.