The iron is extracted in the blast furnace, from haematite ore (Fe2O3). To remove the impurities from the iron ore, carbon monoxide is needed to reduce the iron.
The process of extraction of iron starts with the burning of carbon because of the hot air blasted in the furnace.
The chemical reactions are as it follows below:
C + O2 -> CO2 (gas) + heat
CO2 + C -> 2CO
Carbon monoxide reacts with the iron in ore, reducing it to iron metal.
We'll write the balanced chemical reaction:
3CO + Fe2CO3 -> 3CO2 + 2Fe
Since the temperature of the furnace is very high, 2000 degrees Celsius, the state of the iron metal is liquid.