Blast Furnace Process: Iron Extraction from Haematite

Iron is extracted from the ore haematite (Fe₂O₃) by reduction. Carbon monoxide acts as a reducing agent because it is more reactive than iron.

Structure of the Blast Furnace

Chemical Reactions in the Furnace

Inside the blast furnace, several chemical reactions occur to produce molten iron:

• Combustion of Coke: Carbon reacts with oxygen (exothermic reaction)

C + O₂ → CO₂

• Carbon Reduction: CO₂ reacts with more coke to form carbon monoxide

CO₂ + C → 2CO

• Iron Ore Reduction: Carbon monoxide reduces iron(III) oxide to molten iron

Fe₂O₃ + 3CO → 2Fe + 3CO₂

• Slag Formation: Limestone decomposes and removes impurities

CaO + SiO₂ → CaSiO₃

Molten iron collects at the bottom of the furnace and slag floats above it, ready to be removed.