KINETICS OF THE DESULFURIZATION OF MOLTEN IRON

APIRUKSA SAELIM, University of Pennsylvania

Abstract

Experimental work has involved the fabrication of impervious slip-cast CaO crucibles, measurement of the rate of desulfurization of liquid iron by solid CaO and measurement of the rate of desulfurization of liquid iron by CaO-saturated liquid FeO at 1600(DEGREES)C. The rate of desulfurization by solid CaO is determined by diffusion of sulfur in the liquid iron. Above some minimum sulfur level, which is in the range 0.088 wt%S, the activity of FeS is high enough to form a liquid phase in the system CaO-Fe-S. With lower sulfur levels CaO does not cause any desulfurization of the liquid iron. When CaO-saturated liquid FeO is brought into contact with a liquid Fe-S alloy a rapid initial rate of desulfurization occurs due to surface tension-induced local convection at the slag/metal interface. After this initial period, the rate of desulfurization is determined by diffusion of sulfur in the metal. No change occurs in the oxygen content of the metal during desulfurization and hence the half cell reactions occurring in the electrochemical transfer process are {Fe} (--->) (Fe('2+)) + 2e('-) and {S} + 2e('-) (--->) (S('2-)). The sulfur content of liquid iron in equilibrium with CaO-saturated liquid FeO at 1600(DEGREES)C is 0.012wt% and the equilibrium distribution ratio, (wt%S)/{wt%S}, is 5.8. The addition of 4wt% CaF(,2) to the CaO-saturated slag has no effect on the kinetics of the desulfurization reaction.

Subject Area

Metallurgy

Recommended Citation

SAELIM, APIRUKSA, "KINETICS OF THE DESULFURIZATION OF MOLTEN IRON" (1981). Dissertations available from ProQuest. AAI8127068.
https://repository.upenn.edu/dissertations/AAI8127068

Share

COinS