Quicklime is a white powder composed mainly of calcium oxides (CaO) obtained by pyrolysis of limestone.
Uses of quicklime
In the presence of water and the carbon dioxide in the air, quicklime forms calcium hydroxide (Ca(OH)2), also called air-slaked lime. This reaction can be used in processes to capture and sequester CO2.
Quicklime and air-slaked lime are used in industry to remove certain impurities from molten metals, to neutralise the acidity in smoke emissions and to process and depollute effluents.
This lime is also used in agriculture as a soil amendment to raise the pH of the soil, and in buildings as a render.
Old kilns used to produce quicklime from limestone. © David Shand CC by 2.0