MgO飽和BaO-Fe_tO-SiO₂系スラグ-溶鉄間のりんの分配平衡

抄録

In order to meet the recent demand for low phosphorus steels, highly basic slags must be used to increase the refining efficiency. In this study, the equilibrium partition ratio of phosphorus (L_P) between MgO saturated BaO-Fe_tO-SiO₂ slags and liquid iron was measured at 1600°C as a function of slag composition. The results are summarized as follows.
(1)The MgO solubility of BaO-Fe_tO-SiO₂ slags is lower than those for the CaO-Fe_tO-SiO₂ and Na₂O-Fe_tO-SiO₂ systems.
(2)The maximum value of the phosphate capacity of this system is higher than that for the CaO system and not less than that of the Na₂O system.
(3)There is a FeO content to give the maximum L_P value at constant BaO/SiO₂ ratios. This is in accord with the well known fact applicable for the CaO-FeO-SiO₂ system.
(4)The activity coefficients of FeO and FeO_1.5 have been measured and discussed in terms of slag composition.