Abstract: Hydrous alumina(Al₂O₃)was obtained from aluminum isopropoxide as raw material.Influences of factors including end point temperature, heating rate,and holding times at end point temperature,277 ℃ and 590 ℃ on the properties of γ-Al₂O₃  powder were investigated through orthogonal experiment.Results showed that the end point temperature and heating rate had a clear effect on properties of γ-Al₂O₃.Degree of crystallinity,grain size,and BET were mainly influenced by the end point temperature,and the heating rate had an effect on grain size,and agglomerated size.Higher the end point temperature and the slower the heating rate,the bigger particle size of crystal,the crystal would tend to be more integrity,BET decreasing,and the agglomeration of powders could be improved clearly.Optimum conditions was obtained as follows:the end point temperature was 850 ℃ and its holding time was 30 min,the heating rate was 3 ℃/min,and the holding times at 277 ℃ and 590 ℃ were both 0 min.

Key words: &gamma, -Al₂O₃, calcination, orthogonal experiment, agglomeration, optimization