Compounds Contained in Iron Ore
Other Metal:
Iron Ore are mostly oxides of iron with accompanying elements such as sulfur, phosphorus, manganese, silicon and earthy materials such as chalk, clays and silica. The elements which make up the Earth have formed compounds with each other under the widest possible range of conditions, e.g. heat, pressure, wind and water. Oxygen,
sulfur, phosphorus, silicon and carbon, for example, have combined with metals to form ores, The brownish-red color of the soil is often a sign of the presence of iron compounds.
Ores are minerals (rocks). Metals are present in these ores in chemically combined form, mixed with lumpy waste rock (mullock). The ores are smelted if they contain useful metals in proportions which make it economically viable to extract them. In the case of iron, the minimum content considered economically viable is 25% and for copper around 0.6%.
Ore are classified according to the extractable metal in them, e.g. iron, copper, tin, lead, zinc and nickel ores. Iron and oxygen combined chemically to form iron oxyde. Compound with oxygen are known as oxide.
Rust is regression of metallic iron to its ores state, Rust and brown haematite are essentially compounds of iron with atmospheric oxygen and water.
The principle elements with which iron has combined in the formation of ores are oxygen, sulfur and carbon. Iron ores which are smelled contain 25% to 70% iron. Important ore are magnetite (Fe
3O
4) with 50% to 75% iron, brown haematite (2 Fe
2O
3) with 30% to 50% iron and chalybite (FeCO
3) with 30% to 45% iron.