Addition of preformed spinels to both Al2O3–C orMgO–C bricks also led to
improved slag corrosion resistance. For example, addition of 20 wt% preformed
stoichiometric spinel to MgO–C refractories improved their slag corrosion resistance
by 48% (72). When MgO and Al2O3 are added to Al2O3–C (i.e., Al2O3–
MgO–C) and MgO–C (i.e., MgO–Al2O3–C) refractories, respectively, in-situ
spinel forms in both refractories; as a result, both refractories show improved
slag corrosion resistance although the MgO–Al2O3–C refractories are more slag
resistant than Al2O3–MgO–C refractories. For this reason, the former are usually
used in the slag lines of steel ladles whereas the latter are used in the wall.