Question

Write the different reactions that occur in a blast furnace.

Answer 1

The key chemical reactions occurring at different zones inside the blast furnace during the extraction of Iron are:

Zone of Combustion (Lower region): Coke burns in oxygen to produce heat and carbon dioxide.

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

Zone of Reduction (Upper region): Carbon dioxide is reduced to carbon monoxide, which then reduces the iron ore (Fe₂O₃) to iron.

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

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

Zone of Slag Formation (Middle region): Limestone (CaCO₃) decomposes, and the resulting flux reacts with silica gangue to form fusible slag.

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

\[\ce{CaO (Flux) + SiO2 (Gangue) -> CaSiO3 (Slag)}\]