Phosphorus Distribution between Solid 2CaO·SiO₂ and Molten CaO-SiO₂-FeO-Fe₂O₃ Slags

Abstract

The equilibrium distribution ratio (Lp) of phosphorus between solid 2CaO·SiO₂ and molten CaO-SiO₂-Fe₂O₃ and CaO-SiO₃-FeO slags were determined in the temperature ranging from 1350°C to 1450°C.
It was found that Lp increased with increasing total iron content, regardless of the valency of iron. No dependence of Lp on temperature and CaO/SiO₂ in slags was observed.
These findings indicate that the ferrous and ferric oxides increase the activity coefficient of 3CaO·P₂O₅ in slags in the composition range studied. The data obtained by the present work confirmed that about 80% of phosphorus be removed from LD slags to 2CaO·SiO₂ which primarily precipitates on solidification.