Calcination

The act or process of disintegrating a substance, or rendering it friable by the action of heat, esp. by the expulsion of some volatile matter, as when carbonic and acid is expelled from carbonate of calcium in the burning of limestone in order to make lime.

The act or process of reducing a metal to an oxide or metallic calx; oxidation.

the conversion of metals into their oxides as a result of heating to a high temperature