Influence of pre-synthesized Al₂O₃–SiC composite powder from clay on properties of low-carbon MgO–C refractories

To improve the properties of low-carbonization of MgO–C refractories, the introduction of composite additives is an effective strategy. Al₂O₃–SiC composite powder was prepared from clay using electromagnetic induction heating and carbon embedded methods. Further, the Al₂O₃–SiC composite powder synthesized by electromagnetic induction heating at 600 A was added into low-carbon MgO–C refractories (4 wt.%) to improve their properties. The results showed that when the addition amount of Al₂O₃–SiC composite powder is within the range of 2.5–5.0 wt.%, the properties of low-carbon MgO–C samples were significantly improved, e.g., the apparent porosity of 7.58%–8.04%, the bulk density of 2.98–2.99 g cm⁻³, the cold compressive strength of 55.72–57.93 MPa, the residual strength after three air quenching at 1100 °C of 74.86%–78.04%, and the decarburized layer depth after oxidized at 1400 °C for 2 h of 14.03–14.87 mm. Consequently, the idea for the rapid synthesis of Al₂O₃–SiC composite powder provides an alternative low-carbon MgO–C refractories performance optimization strategy.