Question

Write chemical reactions taking place in the extraction of iron from its ore.

Answer 1

The chief ore of iron is Haematite (Fe₂O₃). In the blast furnace, the following reactions take place:

Combustion reactions (lower part of furnace): Carbon monoxide is formed, which acts as the main reducing agent.

\[\ce{C + O2 -> CO2}\]

\[\ce{CO2 + C -> 2CO}\]

Reduction reactions (upper part of furnace): Haematite is stepwise reduced to metallic iron.

\[\ce{3Fe2O3 + CO -> 2Fe3O4 + CO2}\]

\[\ce{Fe3O4 + CO -> 3FeO + CO2}\]

\[\ce{FeO + CO -> Fe + CO2}\]

Slag formation reactions: Flux removes gangue by forming slag.

\[\ce{CaCO3 -> CaO + CO2}\]

\[\ce{CaO + SiO2 -> CaSiO3}\]

Reduction of other impurities: 

\[\ce{SiO2 + 2C -> Si + 2CO}\]

\[\ce{P4O10 + 10C -> 4P + 10CO}\]

\[\ce{MnO2 + 2C -> Mn + 2CO}\]