Extracting iron from iron ore using a Blast Furnace
90% of all mining of metallic ores is for the extraction of iron. Industrially, iron is produced starting from iron ores, principally hematite and magnetite by a carbothermic reaction in a blast furnace at temperatures of about 2000 °C.
In a blast furnace, iron ore, carbon in the form of coke, and a flux such as limestone are fed into the top of the furnace, while a blast of heated air is forced into the furnace at the bottom.
In the furnace, the coke reacts with oxygen in the air blast to produce carbon monoxide:
2 C + O2 → 2 CO
The carbon monoxide reduces the iron ore to molten iron, becoming carbon dioxide in the process:
3 CO + Fe2O3 → 2 Fe + 3 CO2
The flux is present to melt impurities in the ore, principally silicon dioxide sand and other silicates. Common fluxes include limestone and dolomite. Other fluxes may be used depending on the impurities that need to be removed from the ore. In the heat of the furnace the limestone flux decomposes to calcium oxide:
CaCO3 → CaO + CO2
Then calcium oxide combines with silicon dioxide to form a slag.
CaO + SiO2 → CaSiO3
The slag melts in the heat of the furnace. In the bottom of the furnace, the molten slag floats on top of the denser molten iron, and apertures in the side of the furnace are opened to run off the iron and the slag separately. The iron once cooled, is called pig iron, while the slag can be used as a material in road construction or to improve mineral-poor soils for agriculture.
(Source from: http://en.wikipedia.org/wiki/Extraction_of_iron#Blast_furnace)
How Iron was extracted in the 19th century:
(Source from: http://en.wikipedia.org/wiki/File:Iron-Making.jpg)
EXPERIMENT!!!!!
Iron extraction-match head & reaction releasing CO2
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