Process for producing nodular cast iron

摘要

A process for producing nodular cast iron is proposed, wherein the treatment of the molten iron is carried out with metallic magnesium. By addition of CaSi, the sulphur content of the unstable compound MgS in the slag is converted into the stable compound CaS. This prevents a return of the sulphur, released from the compound MgS during prolonged standing times, back into the melt and a reaction therein with the dissolved magnesium, forming Mgs anew. The binding of the sulphur in the slag itself effectively prevents resulphurisation. The slag can remain on the surface of the melt for a prolonged period and has a heat-insulating effect, so that any longer standing times, caused by production conditions, can be accepted.