Lime kiln

kiln used for the calcination of limestone (calcium carbonate) to produce the form of lime called quicklime (calcium oxide)

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

A preserved lime kiln in Burgess Park, London
CaCO3 + heat → CaO + CO2

Limestone is poured into one side of the kiln, it is then heated up with hot air and quicklime [Calcium Oxide] comes out the other end. Waste Gases come out of the top of the kiln.