Corrosion mechanism of magnesia-chrome refractory bricks with FetO-SiO₂-Cr₂O₃ copper converter slag

The paper investigates the effect of Cr2O3 on the resistance of magnesia-chrome refractory bricks to copper converter slag. The static crucible method was employed to carry out the slag resistance experiment. The corrosion of magnesia-chrome refractory bricks under the action of FetO-SiO2-xCr2O3 (x = 0-5 wt%) slag at 1300 degrees C was discussed. The microstructure of the corroded sample was analyzed by XRD and SEM-EDS to elucidate the corrosion mechanisms of magnesia-chrome refractory bricks with FetO-SiO2-Cr2O3 slag. The results indicated that the permeability index of the slag-resistant samples gradually decreased with increasing Cr2O3 content in the FetO-SiO2-Cr2O3 slag. Combined with SEM and XRD characterization, the MgO in the refractory reacted with FeO and SiO2 in the molten slag, leading to dissolution and reaction corrosion of the refractories. Meanwhile, forming a (Mg, Fe)O solid solution layer in corroded samples can prevent further chemical reactions and high-temperature dissolution between the FetO-SiO2-Cr2O3 slag and refractories. With the addition of Cr2O3 in the FetO-SiO2-Cr2O3 slag, the corrosion effect of slag on refractories was weakened, and the (Mg, Fe)O solid solution layer became thinner. The magnesia-chrome refractory bricks showed excellent slag resistance when the Cr2O3 content in the copper converter slag was 5 wt%.