Chemical synthesis and thermal evolution of MgAl2O4 spinel precursor prepared from industrial gibbsite and magnesia powder

International audienceA chemical route, using industrial raw materials, was developed for the synthesis of MgAl2O4 spinel precursor. The as-obtained powder was then calcined in air, up to 1200 °C for a period of 1 h. It was found that spinel single phase is formed at several hundred degrees lower than temperatures reported for the conventional powder preparation methods. Moreover, at 500 °C the degree of crystallinity is higher than that reported by other chemical processes at this temperature. The calcined powder reaches 83% of relative density at 1200 °C, indicating reactivity and good sintering behaviour. Scanning electron microscopy images revealed that the product consisted of fine spherical particles of magnesium aluminate spinel