Iron ore, such as hematite and magnetite, are where most of the iron that is used for industrial purposes comes from. Hematite is composed of the iron (III) oxide, and magnetite is composed of the iron (II, III) oxide. The iron is isolated from these minerals through a carbon reaction that is carried out in a blast furnace.
The furnace is heated to 3632 °F, coke which serves as the carbon source is added to furnace with the iron ore, and a flux like limestone is fed through the top of the furnace. Heated air is continually pushed into the bottom of the furnace to maintain the high temperatures. In the furnace, the coke and oxygen react to form carbon monoxide. The carbon monoxide reduce the iron ore resulting in pure iron and carbon dioxide. The limestone, or flux, melts other impurities inside the iron to further purify the iron ore.