Ferromanganese is a ferroalloy with high manganese content. It 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.