Foamability of stainless steelmaking slags in an EAF

The possible causes for the poor foamability of stainless steelmaking slags were examined in this research. Specifically the foam index of a simulated stainless steelmaking slag containing "Cr2O3" (CrO and Cr2O3) was measured and the rate at which carbon reacts with Cr2O3, CrO, and FeO was also measured. The experimental results show that the foam index of stainless steelmaking slags is comparable to carbon steelmaking slags provided that the amount of solid chrome oxide particles or complexes is not excessive. However, the experimental results demonstrate that the reaction rate of carbon with CrO or Cr2O3 dissolved in the slag and hence the generation of CO is significantly slower than for the reaction rate of carbon with FeO dissolved in slags. Therefore, the lack of FeO in stainless steelmaking slags is a primary reason for the poor foamability. Also, exploratory research indicates that waste oxides containing carbon and iron oxide produces high rates of CO evolution and consequently could improve foaming.