Abstract: Two kinds of alumina powder prepared by different precipitants (urea and ammonium carbonate) with homogeneous precipitation method and ammonium aluminum sulfate as raw material were researched.Structure and morphology of precursor and alumina powder produced by two different precipitants were characterized by means of TEM,XRD,and TG/DTA etc.Results suggested that precursor Al(OH)₃ and alumina powder,using urea as precipitant,were superior to that using ammonium carbonate in dispersion，size,and shape of particle.Besides,the precursor Al(OH)₃,calcined in 1 200 ℃ for 2 h,turned into pure phase α-alumina with good degree of crystallization contrast with NH4Al(OH)₂CO₃ turned into mixed phase of θ- alumina and α- alumina under the same coditions.

Key words: α-alumina powder, homogeneous precipitation method;urea;ammonium carbonate