Calcination

Calcination is <a href="/facts/Thermal_treatment/aTB6PvIM">thermal treatment</a> of a solid chemical compound (e.g. mixed <a href="/facts/Carbonate/FES1QHkN">carbonate</a> <a href="/facts/Ore/kgc9DssX">ores</a>) whereby the compound is raised to high temperature without melting under restricted supply of ambient <a href="/facts/Oxygen/acyn6o8r">oxygen</a> (i.e. gaseous O2 fraction of air), generally for the purpose of removing impurities or <a href="/facts/Volatility_(chemistry)/90r3ep6w">volatile</a> substances and/or to incur <a href="/facts/Thermal_decomposition/Qqx9RqkW">thermal decomposition</a>.
The root of the word calcination refers to its most prominent use, which is to remove carbon from <a href="/facts/Limestone/8ntvtFnR">limestone</a> (calcium carbonate) through <a href="/facts/Combustion/ohQoWj8z">combustion</a> to yield <a href="/facts/Calcium_oxide/Wh9C8l7j">calcium oxide (quicklime)</a>. This calcination reaction is CaCO3(s) → CaO(s) + CO2(g). Calcium oxide is a crucial ingredient in modern <a href="/facts/Cement/VfDMkk12">cement</a>, and is also used as a chemical <a href="/facts/Flux_(metallurgy)/ruKFTPGD">flux</a> in <a href="/facts/Smelting/Ghdvhlga">smelting</a>. Industrial calcination generally emits <a href="/facts/Carbon_dioxide/xGzpppEp">carbon dioxide</a> (CO2). 
A calciner is a steel cylinder that rotates inside a heated furnace and performs indirect high-temperature processing (550–1150 °C, or 1000–2100 °F) within a controlled atmosphere.

Calcination open-in-new

Calcination