Ferromanganese, a ferroalloy with high content of manganese, is made by heating a mixture of the oxides MnO₂ and Fe₂O₃, with carbon, usually as coal and coke, in either a blast furnace or an electric arc furnace-type system, called a submerged arc furnace. The oxides undergo carbothermal reduction in the furnaces, producing the ferromanganese. Ferromanganese is used as a deoxidizer for steel.