Reaction sintering of alumina-rich magnesium aluminate spinel

The alumina-rich magnesium aluminate spinels were reaction-sintered by changing the reactivity of alumina through calcination. The starting materials, sintered seawater magnesia, and commerical alumina, were first characterized using chemical analysis, specific gravity and specific area measurement, and phase analysis. Spinel batches containing 90 percent alumina were prepared by mixing magnesia and alumina, which was calcined at various temperatures, in an alumina-lined pot mill for 30 min. Maximum densification of alumina-rich spinel can be achieved when the starting alumina has a surface area of 2 m 2/g