Properties of magnesium‐aluminate spinel derived from bauxite and magnesia

Abstract The synthesis of magnesium‐aluminate spinel divided from bauxites and magnesias, the starting materials with different molar mass ratios (Al ₂ O ₃ : MgO) of 3, 1, and 0.6 were developed using solid‐state reaction sintering at 1350‐1500°C. The effects of different mass ratios and sintering temperatures on the phase composition, densification behavior, shrinkage, flexural strength, and microstructure of the synthetic materials were studied. It was found that as the relative content of bauxite decreased, the flexural strength first decreased before increasing. When n(Al ₂ O ₃ )/n(MgO) was 1, the spinel was the primary phase and the sample was dense. When the temperature became 1450°C, the flexural strength became maximized at 106.48 MPa.