Quantification of Slag Carry Over & Its Effect on Melting Practice of Medium Carbon Re-Sulphur Steel

Slag carry over is an unwanted practice which cannot be completely prevented during tapping of liquid steel from primary steel making furnace. Steel making slag produced in the primary section and the secondary sections are very different in nature, even though the basicity of both is around 3. Therefore, the carry over slag from primary steel making furnace always causes some detrimental effect on the processing of liquid steel. Since the medium carbon re-sulphur steel grade is difficult to melt at ladle furnace, slag carry over from primary section makes the process very tedious. An approximate quantification of the slag carry over has been done by simple consideration of the mass/material balance for the materials involved in the ladle refining process. This paper mainly discusses the influence of slag carry over on melting practice (de-oxidation practice), ferro-alloy consumption at ladle furnace and castability of steel. This paper also gives some relevant feasible suggestions to process the liquid steel smoothly at ladle furnace and cast the liquid steel in a continuous caster.