Synthesis of Alumina Powders from Kaolin with and Without Ultrasounds

Alumina (Al2O3) powders were synthesized by extracting Al2O3 from kaolin via kaolin-H2SO4 reactions with and without ultrasounds. The amount of Al2O3 extracted from kaolin via the ultrasonic extraction process was investigated by comparing reaction time and reaction temperature with the same factors under the conventional extraction process. The time to obtaining a given amount of Al2O3 by the ultrasonic process was shorter than that by the conventional process, indicating that the application of ultrasound in the synthesis of Al2O3 powders is an efficient way to reduce synthesizing time.