Thermodynamic corrosion behavior of Al2O3, ZrO2 and MgO refractories in contact with high basicity refining slag

Abstract Al 2 O 3 , MgO, and ZrO 2 containing refractories are widely used in the steel industry. The corrosion behavior of high basicity refining slag on three kinds of refractory materials was studied. Regarding the Al 2 O 3 refractory, Al 2 O 3 crucible would partially dissolve into the slag, and form a transition layer composed of CaAl 12 O 19 and CaAl 4 O 7 at the same time. For ZrO 2 refractories, the refining slag and the ZrO 2 crucible produce a transition layer composed of calcium zirconate with the high melting point of CaZrO 3 , CaZr 4 O 9 and Ca 6 Zr 19 O 44 , which prevents the contact between the ZrO 2 crucible and the refining slag to inhibit the further corrosion of the crucible. There is no chemical reaction between the MgO crucible and the refining slag. However, the pores in the MgO crucible matrix are filled with liquid slag. The corrosion mechanisms were studied by experiments combined with thermodynamic calculations, and the relative corrosion model has been established.