The Solubility of Magnesia and Ferric-Ferrous Equilibrium in Liquid Fe<SUB>t</SUB>O-SiO<SUB>2</SUB>-CaO-MgO Slags

Abstract

The solubility limit of magnesia and the ferrous-ferric oxide equilibrium have been measured for the FetO-MgO, FetO-SiO2-MgO and FetO-SiO2-CaO-MgO slags in equilibrium of liquid iron at the temperature range from 1 550°to 1 650°C. The results obtained are summarized as follows ;1) The solubility limit of magnesia and the ferric oxide content in FetO-MgO slags are represented by the following empirical formulae.log(wt%MgO)=-6000/T+4.21 (±0.05) 1 536°-1 660°C ……(1) log(wt%Fe2O3)=3553/T-1.00 (±0.05) 1 536°-1 660°C ……(5)2) The solubility limit of magnesia in FetO-SiO2-MgO slags has been established at the temperatures of 1 550°, 1 600° and 1 650°C. The value of Λ=Fe3+/Fe2+ in this slags decreases with increasing silica content.3) The solubility limit of magnesia in FetO-SiO2-CaO-MgO slags decreases with increasing FetO content and slag basicity, and it becomes almost constant, 6.-8. wt% in the range of basicity higher than 2(=wt%CaO/wt%SiO2). The value of Λ=Fe3+/Fe2+ in these slags increases with increasing the slag basicity and with decreasing FetO content in basic slags.