Improvement of Mullite and Magnesia-Based Refractory Castables Through Addition of Nano-Spinel Powder

Two different commercial refractory castables based on mullite or magnesia aggregates have been improved through addition of 0–25 wt.% nano‐magnesium aluminate spinel (MA) powder. Physico‐mechanical and refractory properties were tested at different firing temperatures. The phase composition, thermal analysis, and microstructure of these refractory castables were detected using X‐ray diffraction (XRD), differential thermal analysis (DTA), as well as scanning electron microscope (SEM) attached with energy dispersive X‐ray unit, respectively. The castable sample mix containing 10 wt.% nano‐MA spinel powder was chosen as an optimum composition according to its good sintering, mechanical as well as refractory properties.