Where Does Iron Come From?
Iron is the most abundant element in the Earth. The Earth’s core is mostly made up of an iron-nickel alloy. Iron also makes up about 5% of the Earth’s crust where it is the fourth most abundant element.
Because iron oxidizes when it comes into contact with air, most of the iron that is found on the surface of the Earth is in iron oxide minerals such as hematite and magnetite. Iron is also found in meteorites which can sometimes contain a large percentage of iron.
Most iron is mined from the ground in the form of iron ore. In making iron, the iron ore is mixed with coke and limestone. The iron ingredients are heated in a big blast furnace. Blasts of heated air make the coke burn so hot, it melts the iron ore. The limestone helps remove impurities from the ore.
The molten iron sinks to the bottom of the furnace and is drawn off. Most of the iron is used to make steel, but some is cooled in molds called “pigs.” The “pig iron” is shipped to a foundry, where it is used in the making of iron products such as pipes and machine parts.