Influence of FeO/SiO ₂ and CaO/SiO ₂ Ratios in Iron‐Saturated ZnO‐Rich Fayalite Slags on the Corrosion of MgO

Abstract

The corrosion behavior of MgO in iron‐saturated ZnO‐rich fayalite ( ZFS ) slags having various FeO/SiO 2 ratio and CaO/SiO 2 ratio was investigated using MgO crucible tests for 12 h at 1200°C. The FeO/SiO 2 and CaO/SiO 2 ratios in the ZFS slags were varied from 1.0 to 2.2, and from 0.04 to 0.32, respectively. In all of the tests, it was observed that MgO dissolves into ZFS slags and that (Zn,Fe,Mg) 2 SiO 4 olivine and (Zn,Fe,Mg)O solid solution are formed at the crucible/slag interface. The MgO dissolution decreased with the FeO/SiO 2 ratio up to a value of 1.7 and then slightly increased, whereas it continuously increased with the CaO/SiO 2 ratio. There is no obvious relationship between the amount of olivine and the FeO/SiO 2 ratio or CaO/SiO 2 ratio. In comparison, the formation of (Zn,Fe,Mg)O solid solution is enhanced by increasing the FeO/SiO 2 ratio or CaO/SiO 2 ratio in ZFS slags. The results suggest that MgO corrosion is the lowest for FeO/SiO 2 and CaO/SiO 2 ratios around 1.7 and 0, respectively.