Improved comprehensive properties of Al2O3-MgO-C refractories containing lightweight tabular alumina aggregates

The lightweight of ladle lining refractories is of great significance to energy saving and consumption reduction. In this work, the lightweight alumina aggregates were selected to partially replace traditional tabular alumina aggregates to prepare lightweight Al2O3-MgO-C refractories used for steel ladle linings. And, the influence of lightweight alumina aggregates on the comprehensive properties of Al2O3-MgO-C refractories was investigated in detail. The results illustrated that the introduction of lightweight alumina aggregates can improve the strength of Al2O3-MgO-C refractories, due to the optimized interface bonding between aggregates and matrix. In addition, the thermal shock resistance of Al2O3-MgO-C refractories was also enhanced after adding lightweight alumina aggregates, which should be attributed to that the addition of lightweight alumina aggregates reduced the thermal expansion coefficient of such refractories, and micron-sized pores of lightweight alumina aggregates absorbed partial thermal stresses during thermal shock test. Furthermore, the addition of lightweight alumina aggregates improved the slag corrosion resistance of Al2O3-MgO-C refractories remarkably, which can be ascribed to the formation of continuous CA6 protective layer and densified matrix.