A comparative study on the slag resistance of MgO–C, low-carbon MgO–C, and MgO–SiC–C refractories

The corrosion of slag on refractories usually starts from the matrix, so improving the slag resistance of the matrix is of great significance for the slag resistance of the refractories. To clarify the influence of matrix on the slag resistance of magnesia–carbon refractories, the slag corrosion experiments were conducted at 1873 K on MgO–C refractories, low-carbon MgO–C refractories, and MgO–SiC–C refractories. The results showed that the slag resistance of MgO–C refractories was higher than that of low-carbon MgO–C refractories, and the slag resistance of MgO–SiC–C refractories was superior to that of low-carbon MgO–C refractories. The interaction between MgO–SiC–C refractories and slag generated high melting point phases such as forsterite and spinel, reducing the routes for the slag to infiltrate the inside of the refractories. MgO–SiC–C refractories reacted with slag to increase the viscosity of the slag, the viscosity being 86.3% and 51.9% higher than in the case of low-carbon MgO–C and MgO–C refractories, respectively. Compared with MgO–SiC–C refractories, MgO–C refractories did not exhibit overwhelming advantages in slag resistance. Due to the low-carbon content and good slag resistance, MgO–SiC–C refractories were promising low-carbon magnesia-based refractories for high-temperature industries.