Reduction is widely used in metallurgical industries to reduce the metal oxide to metals. One of the best examples of reduction is reduction of iron oxide to iron in the blast furnace. The reaction is as follows:

3Fe₂O₃ + CO → CO₂ + 2Fe₃O₄

Fe₃O₄ + CO → CO₂ + 3FeO

FeO + CO → CO₂ + Fe