Smelting
The reduction of a metal oxide to the metal by heating with a reducing agent, usually carbon or carbon monoxide.
Formula / equation
MO + C → M + CO
Unit
°C
In depth
Smelting is carried out in a blast furnace with a flux such as limestone, which combines with silica impurities to form a molten slag that floats on the denser metal and is drawn off separately. The process is only viable for metals below carbon in the reactivity series.
Examples in the real world
Fe₂O₃ + 3CO → 2Fe + 3CO₂ in a blast furnace; more reactive aluminium requires electrolysis instead.