Effect of hercynite spinel content on the properties of magnesia-calcium zirconate dense refractory composite

Hercynite spinel was added to magnesia-calcium zirconate refractory compositions in the range of 0-8 wt%. Refractory specimens were obtained by solid state sintering at 1500 °C in an electric furnace. The effect of different contents of spinel (FeAl2O4) as a microstructural elastifier in the refractory matrix was studied. Refractory specimens were characterized by density, porosity, cold crushing strength, crystalline phase formation (XRD), microstructural analysis (SEM), and microhardness. Spinel (0.5 wt%) containing a magnesia-calcium zirconate composition was found to have superior properties. The mechanical behaviour of the MgO-CaZrO3 was enhanced by c.a. 95% by the hercynite addition.