The effects of different clay addition amounts and zircon powder contents on the properties of steel-pouring brick were studied using bauxite particles, sintered mullite powder, and other materials as the main raw materials. The results showed that with the decrease of clay content, the bulk density of the samples changed slightly, but the cold modulus of rupture, compressive strength, hot modulus of rupture, and high-temperature volume stability were improved; the addition of zircon powder did not significantly change the basic properties, such as the bulk density of the brick, but significantly increased the high-temperature flexural strength. Therefore, under the addition of 5 wt.% clay and 1.5 wt.% zircon powder were used for the application. The results show that samples with this formula have good performance, and the surface of the cast steel is smooth. Therefore, the optimization of the mullite steel-pouring brick formula can adopt the strategy of the synergy effect of clay and zircon to improve its comprehensive performance.

To meet the stringent industrial service requirements of magnesia–chrome refractory bricks, this study adopts a technical approach that synergistically combines precise component ratio optimization with a vacuum-pressure MgSO₄ salt impregnation process to investigate the performance optimization of magnesia–chrome bricks. Samples were prepared by controlled formulation mixing, pressing at 250 MPa, drying at 110 °C, and firing at 1750 °C. Phase composition, microstructure, and physical–mechanical properties were characterized by XRD, SEM, and standard refractory test methods. The optimal additions of chromite powder and Cr₂O₃ micro-powder were determined to be 3 wt.% and 2 wt.%, respectively, which reacted with periclase to form a secondary composite spinel, creating a dense spinel bridge network that connected adjacent grains. Furthermore, when the proportion of sintered magnesia powder (MgO > 97 wt.%) was increased to 11 wt.%, the material achieved efficient densification facilitated by enhancing sintering performance. Based on this optimized formulation, and due to the high elemental compatibility between MgSO₄ and the magnesia–chrome brick matrix as well as the excellent permeability of the solution, the MgSO₄ vacuum-pressure salt impregnation process was subsequently applied. The salt solution filled the open pores and microcracks of the material, forming a crystalline salt micro-pillar reinforcing phase. Consequently, the apparent porosity of the material decreased to 10.98%, the bulk density increased to 3.23 g/cm³, and the cold compressive strength and cold modulus of rupture reached as high as 113.52 MPa and 24.91 MPa, respectively. This study innovatively establishes a new pathway for enhancing the mechanical properties of magnesia–chrome refractory bricks through the synergistic design of component ratio optimization and salt impregnation process. The prepared magnesia–chrome refractory bricks exhibit both excellent mechanical properties and volume stability.