Demanganese Process from Molten Cast Iron by Sodium-Sulfide

Recently, Mn content in steel scrap is increasing due to the production of high strength steel for automobile body. The increase in Mn content particularly reduces the elongation of ductile cast iron. In the near future, this increase in Mn content is expected to make the production of high ductility cast iron in the cast condition extremely difficult. This paper aims at the removal of Mn from molten cast iron. First we confirmed that Mn in molten iron can be removed by adding sodium-sulfide in laboratory tests. The reproducibility was also checked in the manufacturing process. Furthermore, as a result of a study on the influence of each factor related to Mn removal, the optimal conditions for Mn removal processing were obtained.