In order to obtain fine mullite powders by a simple and inexpensive process, alpha aluminum hydroxide (alpha-Al(OH)(3)) was used as raw material, and heterogeneous nucleation-and-growth process was chosen for the preparation of powders. Composite coating particles consisting of alpha-Al(OH)(3) cores with outer amorphous silica shell were prepared by heterogeneous nucleation-and-growth process in the ethanol suspension containing ammonia. tetraethylorthosilicate (TEOS) and alpha-Al(OH)(3). Fine mullite powders (average particle size 0.67 mum) were fabricated by calcined composite coating particles at 1500 C for 2 h. (C) 2002 Elsevier Science B.V. All rights reserved.