Distribution of Sulphur between Liquid Iron and Fe_tO-(CaO+MgO)-(SiO₂+P₂O₅) Phosphate Slags

Abstract

Equilibrium sulphur distribution between slag and liquid iron has been studied at the temperature range from 1 573 to 1 953 K. The slag systems studied were of Fe_tO-P₂O₅-M_xO_y (M_xO_y=CaO, MgO, SiO₂) ternary and of Fe_tO-P₂O₅-CaO-M_xO_y (M_xO_y= MgO, SiO₂) quaternary. The data were obtained in our previous works concerning the effect of additives on the phosphorus equilibrium and the approximate validity of the regular solution model for the phosphate slag.
The distibution ratios, (% S)/a_S, and the sulphide capacities, C_S, of those slags were determined as the function of the slag composition. The results obtained were summarized as follows:
log C_S = -4.210 + 3.645 (BI)
(BI) = N_CaO + N_FeO + 0.5N_MgO - 0.5N_P2O5
log{(% S)/ a_S} = log C_S - log a_FetO + 5 685/ T - 1.430
It was confirmed that these equations were applicable to all the experimental results, not only on the phosphate slags, which was obtained in the present work and were reported by the others, but also on the silicate slags by the other investigators.