Chemical and Mineralogical Examination of a 4Cr2O3.MgO Coating Applied to a Bloating Fireclay Brick

AbstractA basic oxide coating has been applied to the working face of a bloating fireclay ladle brick to increase chemical resistance to a basic steelmaking slag. The expansion characteristics of various Cr2O3 and MgO coating mixtures have been measured with a 4:1 molar ratio Cr2O3 to MgO being most compatible with the refractory over 25–1450°C. Evidence of a reaction between this coating and refractory to form a chromium-rich layer is presented, and associated mineralogical changes in the parent refractory are described. It is postulated that this increase in basicity should reduce refractory corrosion at the slag-refractory- gas interface.