This invention covers the method and equipment for the continuous or discontinuous addition of reaction/inoculation materials necessary for desulphurization or the production of ductile iron obtainable during the passage of the base iron through a basin containing the chamber for melting, vaporizing and distributing the reaction-inoculation materials into the melt (e.g. magnesium vapor-Ferrum Silicon). The treatment can be conducted continuously for unlimited or freely definable quantities of iron.