Abstract: The differentiated effect of adding rare earth CeO₂ and La₂O₃ on the strength and anti-slag erosion capacity was studied. After the addition of rare earth CeO₂, the porosity rate of low carbon magnesia carbon brick was decreased, the volume density and normal temperature compressive strength were increased, and the slag erosion resistance was improved. After the addition of CeO₂, low carbon magnesia carbon bricks were more dense, the volume density increased from 3.00 g/cm³ to 3.04 g/cm³, and the porosity rate decreased from 3.57% to 3.16%. With the addition of rare earth CeO₂, the strength of low carbon magnesia carbon brick also increased, and the compressive strength increased from 34.7 MPa to 41.3 MPa. However, after the addition of La₂O₃, low carbon magnesiacarbon brick self-powdered, the volume density decreased from 3.00 g/cm³ to 2.62 g/cm³, and the porosity rate increased from 3.57% to 8.2%. With the addition of rare earth La₂O₃, the strength of low carbon magnesia carbon brick also decreased, and the compressive strength decreased from 34.7 MPa to 9.6 MPa. The slag erosion resistance of low carbon magnesia carbon bricks was enhanced after adding rare earth CeO₂ and La₂O₃. After 1 600 ℃ for 3 h, the melting loss thickness of low carbon magnesia carbon bricks without the rare earth mixture was 0.83 mm, the  melting loss thickness after adding CeO₂ was 0.40 mm, and the  melting loss thickness after adding La₂O₃ was 0.18 mm.

Key words: low carbon magnesia carbon brick, rare earth oxide, microstructure, strength, anti-slag erosion ability