摘要
以硫酸铝为铝源，氢氧化钠为沉淀剂，采用沉淀法制备水合氧化铝前驱物并研究其不同温度下的晶相变化。用TG—DTA分析前驱物的脱水过程，研究发现：前驱物在30℃-200℃、2∞℃～500℃和800℃～1000℃分别脱水显著。将前驱物在不同温度下煅烧后的粉末进行X射线衍射分析。由XRD谱图可知：前驱物为非晶相氢氧化铝，在550℃～700℃时Al2O3·xH2O已脱水转化为无定形一水铝石（AlOOH），800℃～900℃时出现γ-Al2O3，100℃时已出现α-Al2O3，1100℃时Al2O3已全部转化为α—Al2O3。并结合粒度分布、SEM对不同条件下的粉体进行表征，结果表明：在1100℃，α—Al2O3分散好，呈短棒状，粒径约为50nm-70nm。
Using aluminum sulfate as aluminum source and sodium hydroxide as precipitating agent, the precursor hydrated alunaina was prepared by chemical precipitation to study its crystalline phase change under different temperatures The dehydration process of precursor was investigated by TG--DTA. The study found that： the precursor dehydrated significantly at 30℃-200℃, 200℃-500℃ and 800℃ -1000℃, respectively. Precursor samples calcined at different temperatures were analyzed by the X--ray diffraction analysis. The result was as follows： the precursor was amorphous aluminum hydroxide; at 550℃ -700℃ Al2O3-xH2O was dehydrated into boehmite （AlOOH）, and at 8000C--900℃ it was γ-Al2O3, and -Al2O3 was obtained at 1000℃, and pure α--Al2O3 was prepared at 1100℃ heat treatment. In combination with the particle size distribution, SEM of the powder under different conditions, the results showed that： at 1100℃ α--Al2O3 was in stick--like shape with good distribution having a crystalline size of 50nm-70nm.
出处
《中国材料科技与设备》
2013年第2期28-30,共3页
Chinese Materials Science Technology & Equipment
