Corrosion behavior of MgO-C refractories with Al2O3-spinel addition by different low basicity slags

Low-carbon is the development trend in refractory industry. In order to improve the corrosion resistance of MgO-C refractories due to the reduction of carbon content, the Al 2 O 3 -spinel was used to improve their properties. The physical properties, oxidation resistance and corrosion resistance were tested to assess the influence of Al 2 O 3 -spinel on the MgO-C refractories, and thermodynamic calculation was used to investigate possible reactions during corrosion process. The introduction of Al 2 O 3 -spinel had no obvious effect on the physical properties of MgO-C refractories. However, Al 2 O 3 -spinel had adverse effects on the oxidation resistance due to the expansion caused by the in-situ formation of spinel from Al 2 O 3 -spinel and MgO-C refractories’ components. The different basicity of the slags affect its morphology and characteristics in the initial stage of corrosion and the reaction activity with refractories exhibiting different corrosion phenomena. Al 2 O 3 -spinel could improve the corrosion resistance by its inherent high temperature stability. In conclusion, MgO-C refractories with 3 wt% of Al 2 O 3 -spinel exhibited the better performance.