Iron is used in bridges, buildings and other structures because it is strong.
The blast furnace
Iron is extracted from iron ore in a huge container called a blast furnace. Iron ores such as haematite contain iron(III) oxide, Fe2O3. The oxygen must be removed from the iron(III) oxide to leave the iron behind.
Reactions in which oxygen is removed are called reduction reactions.
It is so hot in the blast furnace that carbon monoxide is the reducing agent which reduces the iron(III) oxide. The equation for the reduction of iron(III) oxide in the blast furnace is:
iron(III) oxide + carbon monoxide → iron + carbon dioxide
Fe2O3(s) + 3CO(g) → 2Fe(l) + 3CO2(g)
Molten iron is tapped off at the bottom of the blast furnace.
Raw materials for the reaction
|Iron ore (haematite)||Iron(III) oxide||A compound that contains iron|
|Coke||Carbon||Burns in air to produce heat, and reacts to form carbon monoxide (needed to reduce the iron oxide)|
|Limestone||Calcium carbonate||Helps to remove acidic impurities from the iron by reacting with them to form molten slag|
|Air||Oxygen||Allows the coke to burn, and so produces heat|