Wrought iron is obtained from cast iron by a process called puddling process. In this process, cast iron along with some scrap iron is heated in a reverberatory furnace lined with hematite. The molten mass is stirred or puddle throughout with iron rods to ensure the contact of the mass with hematite lining. Hematite oxidizes carbon, sulphur, silicon, manganese and phosphorus present as impurity in cast iron, converting them to their oxides.
3C + Fe2O3 → 2Fe + 3CO
3S + 2Fe2O3 → 4Fe + 3SO2
3Si + 2Fe2O3 → 4Fe + 3SiO2 (slag)
4P + 5O2 → 2P2O5 (slag)
When the oxidation of the impurities is complete, the materiel is taken out of the furnace in the form of balls or blooms. The slag is easily removed by hammering. The iron obtained is called wrought iron and is 99.5 percent pure. It is soft, ductile and malleable. It can be welded. Wrought iron is used in making anchors, bolts, wires and agricultural equipments as it is resistant towards rusting and corrosion.