Calcination
The heating of an ore or compound to high temperature in the absence or limited supply of air to drive off volatile matter.
Formula / equation
MCO₃ →(Δ) MO + CO₂
Unit
°C
In depth
Calcination is applied to carbonate and hydroxide ores to convert them into oxides, which are far easier to reduce to the metal. It also removes moisture and organic matter, leaving a porous product with a greatly increased surface area.
Examples in the real world
Roasting limestone in a lime kiln to give quicklime; calcining bauxite to remove water before aluminium extraction.