摘要：在碳酸铝铵法制备氧化铝工艺的基础上,通过加入晶体生长促进剂及改变热分解工艺等方法,有效控制了α-Al₂O₃颗粒的大小和形貌。结果表明:促进剂对α-Al₂O₃的相变过程影响很大,加入促进剂后使其相转变温度降低了200℃,至1000℃时已完全转变为α-Al₂O₃相;升温方式对α-Al₂O₃颗粒的形貌影响很大,将含促进剂的样品直接入高温炉煅烧时,倾向于形成六角片状颗粒;而先低温后高温煅烧时则会形成圆饼状颗粒。通过控制升温过程,可以控制得到粒径较小的圆饼状α-Al₂O₃颗粒,且分散性良好。

关键词：碳酸铝铵；氧化铝；促进剂；粒径

Abstract：α-Al₂O₃ powder was prepared by crystalline ammonium aluminum carbonate hydroxide(AACH) method,and particle size and shape of α-Al₂O₃ were controlled by adding crystal growing accelerant and changing the calcination process.The results showed that,the accelerant played a very important role of the phase transformation process and the particle size and shape of α-Al₂O₃,the phase transformation temperature of α-Al₂O₃ was lowered about 200 ℃,complete α-Al₂O₃ phase was achieved while calcination temperature over 1000 ℃.The well dispersed cake-like Al₂O₃ particles with small particle size can be synthesized through a two-step calcination process,while hexagonal flakey particles will be caused by directly high temperature calcinations.

Keywords：ammonium aluminum carbonate hydroxide;alumina;accelerant;particle size