Question

The purest form of iron is prepared by oxidising impurities from cast iron in a reverberatory furnace. Which iron ore is used to line the furnace? Explain by giving reaction.

Answer 1

Haematite\[\ce{(Fe2O3)}\] is used. It supplies the oxygen and oxidises carbon, silicon, manganese and phosphorus present in the cast iron to \[\ce{CO}\], \[\ce{SiO2}\], \[\ce{MnO}\] and \[\ce{P2O5}\] respectively.

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

\[\ce{3Si + 2Fe2O3 -> 4Fe + 3SiO2}\]

\[\ce{3S + 2Fe2O3 -> 3SO2 + 4Fe}\]

\[\ce{CO}\] and \[\ce{SO2}\] escape and \[\ce{MnO}\] and \[\ce{SiO2}\] combine to form manganous silicate \[\ce{(MnSiO3)}\] as slag.

\[\ce{MnO + SiO2 ->[Heat] \underset{Manganous silicate (Slag)}{MnSiO3}}\]