Green synthesis of MgAlON refractories with high strength and excellent slag corrosion resistance

The direct utilization of magnesite to synthesize magnesia-based refractories is a promising approach that not only shortens the mineral processing procedures, but also yields industrial products with high added value. In this work, we attempted to prepare MgAlON refractories with magnesite through a feasible solid-state reaction in a carbon-embedded atmosphere. Afterward, the influence of synthesis temperature and magnesite addition ratio on sintering and mechanical performance of as-synthesized MgAlON refractories was systematically investigated. Besides mechanical performance, the possible oxidation and slag corrosion mechanism of as-sintered MgAlON refractories was proposed. The results indicated that as-sintered refractories featured apparent porosity of 12.98%–39.29%, bulk density of 1.54–2.95 g cm−3, and cold compressive strength of 41.58–221.87 MPa. Additionally, it was found that the high magnesite content accelerated the sintering and densification process through the volume expansion effect. The slag resistance test results showed that the surface of the reacted refractory had a double-layer structure, namely the reacted slag layer and penetrated layer, indicating the slag corrosion process followed the mutual diffusion mechanism. Consequently, this work offers insight into the slag corrosion mechanism, paving the way for the cost-effective and facile synthesis of high-value MgAlON refractories from magnesite.