Investigation on Carbon saturation in normal Cupola practice

Abstract

The optimum productivity of gray iron foundry cannot be attained due to the shortage of pig iron. The conversion of abundantly available steel scrap to an acceptable quality of iron in normal cupola practice is of great industrial significance. Extensive investigations were conducted to study the carbon saturation in progressively increasing steel scrap constituting the charge under different basicity degree of the slag during normal cupola practice employing cold air blast. For attaining neutral, acid and basic slag charges were melted in both acid and basic lined cupolas. The higher basicity degree of the slag favoured carbon saturation. The final carbon content of the melt depended on the average initial carbon in the charge and increased with the increase of steel scrap in the charge. The carbon saturation increased with the progress of melting in cupola. Finally the charge constituted entirely of mild steel scrap and no difficulties were experienced in the efficient working of cupola with cold blast. It was concluded that with requisite ladle additions of ferro-alloys, usable cast iron can be produced with 100 percent steel charge in a blast lined cupola employing cold air blast.