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.

Explanation

Haematile `(Fe_2 O_3)` is used. It supplies the oxygen and oxidises carbon , silicon, manganese and phosphorus present in the cast iron to CO, `SiO_2` , MnO and `P_2 O_5` respectively.
`Fe_2 O_3 + 3C overset("Heat")to 2Fe + 3CO`
`3Si + 2Fe_2 O_3 to 4Fe + 3Si O_2 `
`3S + 2Fe_2 O_3 to 3SO_2 + 4Fe`
CO and `SO_2` escape and MnO and `SiO_2` combine to form manganous silicate `(MnSiO_3)` as long.
`MnO + SiO_2 overset("Heat")to underset("Manganous silicate (Slag)")(MnSiO_3)`