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Sources and Processes
Steel must be developed from iron ore. There are four main sources of ore: magnetite, meteorites, limonite, and hematite. Magnetite (Fe3O4) has magnetic properties, wherein each iron crystal behaves as independent magnets organized in a uniform fashion in order to have a strong magnetic force. Iron is well-known for its magnetic capabilities since the atoms of the iron will align itself so that there are two poles on the mass. Meteorites are also a large source of iron ore. The concentration of iron is very high in meteorites, almost up to 90%. Huge meteor crash sites are the ideal place to find iron ore. Hematite (Fe2O3) represents the ore for most iron. Found near rivers or seas, this red ore takes many years to develop since it undergoes a repeating cycle of erosion and evaporation. Mines containing these ores are increasingly found near the arctic circle. Iron must be refined for proper use. Basic refining requires iron ore, coke, and limestone. The coke is burned to provide heat and CO2 for the furnace. The carbon dioxide then interacts with the iron oxide to form pure liquid iron. This interaction may require temperatures up to 2000°C. Anyhow, the limestone can also provide some carbon dioxide. More importantly, however, the limestone binds with the silica in the iron ore so that the iron will not attach to the silica to form iron silicate. Then the iron would be useless. The calcium silicate will drop out of the furnace at the bottom in a slag.
Oxidation
of Coke: C(s) + O2(G)-->CO2(g)
Reduction of Iron Oxide: Fe2O3(s) + 3CO(g)-->2Fe(l) + 3CO2(g) Silicon is Oxidized: 2Fe(s) + Si(s) + CaO(s)-->2Fe(s) + CaSiO3(s)
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