Development of mullite/zirconia composites from a mixture of aluminum dross and zircon

In order to obtain mullite/zirconia composites, mixtures of aluminum dross and zircon were sintered. Aluminum dross was collected and purified by a milling, sieving and washing process. Stoichiometric mixtures of aluminum dross and zircon were sintered at several temperatures (1400, 1450 and 1500 °C) for several periods of time (2, 4 and 6 h). After the purifying treatment the dross contained mainly Al2O3, AlN, MgAl2O4, SiO2 and metallic Al. A homogeneous mullite matrix with small zirconia particles was obtained by sintering the aluminum dross–zircon samples at 1500 °C for 6 h.