Scrap-oxygen steelmaking in top-blown converter

Extensive investigations were conducted at NML for the conversion of solid scrap of assorted sizes and variable chemistry to molten steel by top blowing with oxygen in a basic-lined converter. The process was initiated in the presence of a solid fuel, and its minimum requirement was determined. The oxygen requirements and its efficiency, oxidation and yield for the conversion of molten pig iron or the conversion of solid scrap to steel were compared. The influence of scrap on the process was worked out. The use of calcium carbide, instead of solid fuel, was determined. The progressive oxidation on the metalloids was studied. The effects of different fluxes, basicity degrees of the slag and the bath temperatures on dephosphorization were comprehensively examined. The influence of manganese on desulphurization was noticed. The influence of the different process parameters on the efficiency of conversion of scrap to steel is outlined. The suitability of the developed process for industrial application has been discussed. (Shri S.K. Biswas, Scientist; Shri S.B. Ghosh, Senior Scientific Assistant; and Dr. A.B. Chatterjee, Deputy Director; National Metallurgical Laboratory