沉淀-共沸蒸馏法制备超细α-Al_2O_3粉体的研究  

Preparation of Ultrafine α-Al_2O_3 Using Precipitation-Azeotropic Distillation Method

作　　者：肖劲[1] 秦琪[1] 万烨[1] 陈燕彬[1] 周峰[1] 

机构地区：[1]中南大学冶金科学与工程学院,湖南长沙410083

出　　处：《湖南科技大学学报（自然科学版）》2007年第2期35-39,共5页Journal of Hunan University of Science And Technology：Natural Science Edition

基　　金：湖南省自然科学基金资助项目(5JJ30103)

摘　　要：以Al2(SO4)3为铝源,(NH4)2CO3为沉淀剂,利用沉淀-共沸蒸馏法制备出前驱物碳酸铝铵(AACH),并煅烧得到超细α-Al2O3粉末.研究了加料方式、表面活性剂、干燥方式等因素对产物分散性能的影响,分析了超细氧化铝粉末在热处理过程中的结构和性能变化.采用热重/差示扫描法(DTA/TGA)、扫描电镜(SEM)、X射线衍射(XRD)以及ICP等现代分析检测技术对样品性能进行了表征.结果表明,只有将Al2(SO4)3溶液雾化加入到(NH4)2CO3溶液中,添加适量PEG1000做为分散剂,同时采用正丁醇共沸蒸馏才能制备出粒度分布均匀、分散性能优异的超细α-Al2O3粉末.煅烧过程中,氧化铝的相变过程为:Al2O(3无定型)→γ-Al2O3→θ-Al2O3→α-Al2O3,且随着煅烧温度的提高,产物的晶粒尺寸不断增大,密度不断得到提高.在优化条件下合成的前驱物AACH于1200℃煅烧2h,能得到粒度分布均匀、分散性良好、形貌为类球形且纯度为99.97%以上的α-Al2O3粉体.图9,表1,参15.Ammonium aluminum carbonate hydroxide （AACH） was successfully prepared by precipitafion-azeotropic distillation method using aluminum sulfate as Al source, ammonium carbonate as a precipitant. The AACH was calcined to get ultrafine α-Al2O3 powder. The effect factors of reaction on dispersing property of ultrafine α-Al2O3 powder, such as methods of adding materials, surfactant, drying methods were discussed, and the structure and property changes of ultrafine alumina in thermal treatment process were also studied. The morphological structure and properties were characterized by DTA/TGA, SEM, XRD and ICP measurements. The results show that ultrafine α-Al2O3 powder with uniform particle size and well-distributed is synthesized with aluminum sulfate atomizing into ammonium carbonate, adding suitable amounts of PEG1000 as dispersant, and using azeotropic distillation. The phase transformation of alumina in calcination process is ：amorphous Al2O3→γ-Al2O3→θ-Al2O3→α-Al2O3, and the crystal gratal size and density of ultrafine alumina powder grow up with increasing of the calcination temperature. The ultrafine α-Al2O3 with uniform particle size that they are in spherical shape and well dispersed were obtained by AACH calcined at 1200℃ for 2h, and the purity of ultraline α-Al2O3 powder is high than 99.97%.9figs., 1tab., 15refs.

关 键 词：α-Al2O3粉末 共沸蒸馏 相变 分散性能 

分 类 号：TQ133.1[化学工程—无机化工]