Effect of rare earth oxides doping on MgAl2O4 spinel obtained by sintering of secondary aluminium dross

Abstract Secondary aluminium dross has been widely generated due to the extensive development of the secondary aluminium industry. In this study, reutilization of secondary aluminium dross and the effect of rare earth oxides (REO) doping on the MgAl2O4 were studied. The results showed that secondary aluminium dross can be used to produce MgAl2O4 spinel, and that the densification behaviour of the spinel can be improved by doping with Y2O3, Eu2O3, La2O3, and CeO2. The densification of doped MgAl2O4 was higher than that of MgAl2O4 without REO in the temperature ranged from 1473 to 1773 K. Especially, the density of the spinel with 3 wt% La2O3 at 1673 K for 3 h was 2.13 g cm−3. The improvement of the spinel densification was attributed to the solubility of rare earth ion and the formation of liquid phases such as YAlO3, Y2Ti2O7, Ca2Eu8(SiO4)6O2, Al2Ca0.5La0.5, and CeO2. The results suggested that the secondary aluminium dross doping with REO for the MgAl2O4 spinel can be broadened its reutilization.