The Effect of CaO–SiO ₂ –FeO _<i>x</i> –MgO Slag on the Erosion Behavior of MgO Refractory

To investigate the erosion mechanism of high‐FeO slag with low basicity on MgO refractories, this study uses high‐purity MgO rods to simulate the MgO phase in MgO–C bricks of converter lining refractories. These rods are immersed in slags of different compositions at 1600 °C. The research finds the following: 1) A decrease in slag basicity (CaO/SiO 2 ) promotes the further dissolution of MgO from the refractory into the slag, inducing the formation of pores in the refractory. This allows the liquid slag to penetrate into the refractory and react to form low‐melting‐point compounds such as CaMgSiO 4 , further accelerating the erosion of the refractory. 2) When the Fe 2 O 3 content ranges from 24 to 30 wt%, the dissolved MgO from the refractory reacts with FeO x , CaO, and SiO 2 in the slag to form high‐melting‐point compounds such as (Mg, Fe)O, Mg 2 SiO 4 , and Ca 2 SiO 4 . These compounds can slow down the erosion rate of the MgO refractory. 3) The dissolved MgO from the refractory reacts with FeO x in the slag to form a (Mg, Fe)O solid solution. As the FeO x content in the slag continuously increases, the MgO refractory continues to dissolve, significantly exacerbating the erosion of the refractory.