In this paper, microspheres were prepared by using Chinese bauxite as raw materials through
centrifugal spray drying method. The microstructure and composition of ceramic microsphere were
investigated by X-ray diffraction, scanning electron microscope and X-ray energy spectrum. The particle
size was 10~100#m. The XRD analysis reveals that the main crystalline phase of the ceramic microsphere
were α-Al2O3 and mullite (3Al2O3•2SiO2). The Al2O3 content (chemical composition) of the microspheres
was little more than 70%, and the molar ratio of Al2O3/SiO2 was near to the molar ratio of alumina
and silica of mullite.