Lime kiln

A lime kiln is used to produce quicklime through the calcination of limestone (calcium carbonate). The chemical equation for this reaction is

This reaction takes place at 900 °C (at which temperature the partial pressure of CO₂ is 1 atmosphere), but a temperature around 1000 °C (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.