Influence of magnesium-aluminum spinel on properties of spinel carbon refractories

Spinel carbon refractories exhibit outstanding thermal shock resistance and corrosion resistance by molten steel, rendering them well-suited for applications in continuous casting components. Two types of spinel carbon refractories were prepared using fused spinel, sintered spinel, graphite, and Al-Si alloy powders as primary raw materials, and the physical property and corrosion tests were carried out. The results show that: At relatively high temperatures（above 1 400 ℃）, the Al-Si alloy powders reacts with CO in vapor form to produce Al₂O₃ and SiC fibers, which strengthen the bonding of the matrix, and part of the silicon forms SiC with a granular morphology under corrosion conditions; Fused spinel, with its high density, can physically impede the infiltration of molten slag, and the erosion it undergoes is primarily characterized by chemical dissolution at the raw material boundary. In contrast, sintered spinel has a lower density than fused spinel, leading to weaker resistance against molten slag penetration. Nevertheless, it boasts higher activity compared to fused spinel and a stronger capacity to dissolve MnO and FeO in the slag, thereby demonstrating enhanced resistance to glass phase dissolution. As a result, both spinel carbon refractories exhibit excellent corrosion resistance.