Converters:

Cast iron, having the usual amounts of manganese, carbon and silicon might be converted into steel by blowing up air through or over molten iron. Molten iron, in operation is transferred from the cupola by ladles to an oval vessel known as a converter. The vessel is levelled and iron is poured into the open nose; as soon as the unit is tilted back into location air is blown up through tuyeres in the bottom or side. The air oxidizes the manganese, silicon and carbon. High carbon cast iron is decreased to very low-carbon cast iron fundamentally free of silicon and manganese; until the blow is continued carbon is reduced to 0.10-0.20 % to prevent undue oxidation of iron. The order of oxidation of elements and their rate of oxidation might be followed through the colour and length of flame issuing from the converter nose. No fuel is needed for converting; the oxidizing reactions are exothermic and more heat is added up to the metal than is eliminated by passing air through or over the charge. Ferroalloys of manganese carbon and silicon are added up to the molten iron as this is tapped into a pouring ladle, to adjust the metal to needed composition.