The XRD analysis in Fig. 8
showed that the sample Al-3 and sample Al-7 calcined at 1000 C
for different time. As show in Fig. 8, with the increasing of calcining
time, the diffraction peaks of g-Al2O3 became weaker. The sample
Al-7 with 3.5% seed showed the pure diffraction peaks of a-Al2O3
when calcined at 1000 C for 1.5 h, While, the sample Al-3 without
seed showed the diffraction peaks of g-Al2O3 when calcined at
1000 C for 2.5 h. Although the addictive of seed has no impact on