question_answer 60)

    Wrought iron is the purest form of. iron. Write a reaction used for the preparation of wrought iron from cast iron. How can the impurities of sulphur, silicon and phosphorus be removed from cast iron?

Answer:

                    (a) This reaction takes place in reverberatory furnace lined with haematite. (b) The haematite oxidises S to SO2, Si to SiO2 and P to P4 . Sometimes limestone is added as flux. Impurities of S, Si and P oxidise and pass into slag. The metal is removed and freed from slag by passing through rollers.