The reaction between the magnesia–chrome brick and the molten slag of MgO–Al 2O 3–SiO 2–CaO–Fe tO and the resulting microstructure

Abstract

The reaction and microstructure at the interface of MgO–Cr 2O 3 brick and the molten slag of MgO–Al 2O 3–SiO 2–CaO–Fe tO after static slag corrosion at 1823–1923 K for various times and the resulting microstructure were investigated and characterized. After the static slag corrosion at 1923 K for 4 h, the XRD results show the major phases of periclase MgO, MgCr 2O 4 spinel, and CaMgSiO 4 as the minor phase. MgCr 2O 4 phase causes MgO to form a discontinuous phase in MgO–Cr 2O 4 brick. After static slag corrosion at 1923 K for 4 h, SEM micrographs show that brick interior cracks, MgO and dissolved MgO. MgO dissolved due to the molten plag penetrated into the brick interior and reaction with it, leading to a localized dissolution of brick slag. TEM micrographs and ED patterns demonstrate that the minor phase of (Mg, Fe)(Al, Cr) 2O 4 precipitates in the MgCr 2O 4 matrix.