The extraction of iron ore usually takes place in open quarries and extends over large areas, which means that the groundwater situation can change and local ecosystems can be damaged. One ton of iron ore usually produces 5 to 6 tons of waste materials. Extraction of coal in open quarries or deep mines causes similar environmental damage.

The conversion from iron ore to steel requires a series of processes. They begin with the breaking up of the ore, then cleaning, followed by sintering. The iron is smelted out and reduced in a blast furnace at 1700–1800 ^oC. A large, modern blast furnace can produce 1000 tons of pig iron every 24 hours. The amount of air needed is fourmillion cubic metres, and the coolingwater is equivalent to the amount a small town would use. It takes 440–600 tons of coal to produce 1 ton of iron. The total amount of coal needed can be halved if an oil spray is injected intothe furnace. Coal is used in the process to remove oxygen fromthe ore by forming carbon dioxide, leaving the pig iron behind. Limestone is added to the blast furnace charge in order to bind ash, silica, manganese, phosphor, sulphur and other impurities. This slag can, in turn, be used as pozzolana in the production of cements. Read more...

Iron was used in prehistoric times. Iron has been found in meteorites pure enough to be used without refining. Smelting iron from iron ore has been carried out for at least 5000 years. The first appearance of iron as a building material was in classical Greece, for reinforcing stone lintels and architraves. Uses in cramps, pivots, hinges and locks have been widespread. However, it is only from about the eighteenth century that we have seen more widespread uses for balustrades, balconies, furniture, stairs and various decorative items. The first structural iron girder was manufactured by Charles Bage in 1796 in England, and was used in a five-storey linen mill.Read more...