Preparation of Nanosized Alumina Powders by Microreactor of Mist Droplets

Nanosized Al2O3 powders were prepared by a new method of microreactor of mist droplets,using NH4Al(SO4)2 and NH4HCO3 as raw materials,and compared with Al2O3 powders prepared by normal precipitation method.The product was characterized by SEM and TEM and X-ray diffraction was used to analyze the phase structure.The results showed that the particle size of Al2O3 prepared by microreactor of mist droplets was much smaller and more homogeneous than that prepared by normal precipitation method.The precursor prepared by microreactor method can be transformed to α-Al2O3 at the temperature of 1 150 ℃ for 20 min completely.