Preparation of Nanoscale High-Purity a-Alumina Powders

摘要

High-purity nanoscale α-alumina powders with high specific surface area were prepared from boehmite powders synthesized by the method of aluminium isopropoxide hydrolysis. The physiochemical transformation of boehmite powders under heat-treatment was investigated. The results showed that the reaction progress of boehmite under heat-treatment is as follows: AlO(OH) → Al_2O_3 (amorphous) → γ-Al_2O_3 → δ-Al_2O_3 → αAl_2O_3. The phase transformation from δ-Al_2O_3 to α-Al_2O_3 begins at 1050℃, and the α-Al_2O_3 grains growth accelerates as temperature increases. High-purity α-Al_2O_3 nanometer powders with higher specific surface area can be obtained after incineration at 1100℃ for 4 h.