Mill scale is a steelmaking co-product from the rolling mill in the steel hot rolling process. Mill scale contains both iron in elemental form and three types of iron oxides: Wustite, Hematite and Magnetite. The chemical composition of mill scale varies according to the type of steel produced and the process used. Rolling mill scale is a solid co-product of the steelmaking industry that contains metallic iron and three types of iron oxides: wustite, hematite and magnetite. It also contains traces of non-ferrous metals, alkaline compounds and oils from the rolling process. A study is made of the reduction of mill scale to sponge iron using coke at different temperatures and times. The reduced samples are studied by X-ray diffraction and scanning electron microscopy. Oxygen analysis is carried out by combustion in a LECO oven. The reduction of mill scale allows the new use and development of this material to obtain sponge iron that can be re-used to the electric furnace as metallic load in steel manufacturing. It can also used as a raw material for the production of various parts made of iron through powder metallurgy.