A lime kiln is a kiln used for the calcination of limestone (calcium carbonate) to produce quicklime (calcium oxide). The process of calcination is carried out in a lime kiln at high temperatures, typically above 900°C.
Process of lime kiln
Limestone is heated in a preheating chamber to a temperature of around 800°C. This removes any moisture or impurities that may be present in the limestone.
The preheated limestone is fed into the lime kiln where it is heated to a temperature of around 1200-1300°C. At this temperature, the limestone breaks down into calcium oxide and carbon dioxide. The carbon dioxide is released into the atmosphere as a gas, while the calcium oxide, or quicklime, is collected at the bottom of the kiln.
The quicklime is then cooled in a cooling chamber to prevent it from reacting with the air and absorbing moisture. This is important because quicklime is a highly reactive substance that can react with water to produce heat and steam.
The cooled quicklime is then hydrated by adding water to it, which causes it to react and produce calcium hydroxide, also known as slaked lime.
The process of lime kiln is used to produce quicklime, which is widely used in various industries, including construction, steelmaking, agriculture, and water treatment. The process is energy-intensive and requires careful control of the temperature and other process variables to ensure that the quality of the quicklime produced is consistent and of the required purity.