 Iron Ore: About 98% of iron ore is used to make steel - one of the greatest inventions and most useful materials ever created. While the other uses for iron ore and iron are only a very small amount of the consumption, they provide excellent examples of the ingenuity and the multitude of uses that man can create from our natural resources. Powdered iron: used in metallurgy products, magnets, high-frequency cores, auto parts, catalyst. Radioactive iron (iron 59): in medicine, tracer element in biochemical and metallurgical research. Iron blue: in paints, printing inks, plastics, cosmetics (eye shadow), artist colors, laundry blue, paper dyeing, fertilizer ingredient, baked enamel finishes for autos and appliances, industrial finishes. Black iron oxide: as pigment, in polishing compounds, metallurgy, medicine, magnetic inks, in ferrites for electronics industry. Major producers of iron ore include Australia, Brazil, China, Russia, and India.
Smelting
Main articles: blast furnace and bloomery
Iron ores consists of oxygen and iron atoms bonded together into molecules. To convert it to metallic iron it must be smelted or sent through a direct reduction process to remove the oxygen. Oxygen-iron bonds are strong, and to remove the iron from the oxygen, a stronger elemental bond must be presented to attach to the oxygen. Carbon is used because the strength of a carbon-oxygen bond is greater than that of the iron-oxygen bond, at high temperatures. Thus, the iron ore must be powdered and mixed with coke, to be burnt in the smelting process.
However, it is not entirely as simple as that; carbon monoxide is the primary ingredient of chemically stripping oxygen from iron. Thus, the iron and carbon smelting must be kept at an oxygen deficient (reducing) state to promote burning of carbon to produce CO not CO2.
Air blast and charcoal (coke): 2C + O2  2CO.
Carbon monoxide (CO) is the principal reduction agent.
- Stage One: 3Fe2 O3 + CO
 2Fe3 O4 + CO2
- Stage Two: Fe3 O4 + CO
 3Fe O + CO2
- Stage Three: FeO + CO
 Fe + CO2
Limestone fluxing chemistry: CaCO3  CaO + CO2 |
