SEM observation of gibbsite precipitation with seeds from sodium aluminate solutions promoted by ultrasound
来源期刊：中国有色金属学报(英文版)2003年第3期
论文作者：陈国辉 陈启元 尹周澜 张平民
文章页码：708 - 714
Key words：ultrasound; sodium sluminate solution; SEM; secondary nuclei
Abstract: The microstructure of gibbsite precipitated with seeds from sodium aluminate solution was studied using SEM. The results show that there are a lot of fine secondary nuclei with diameter less than 1μm and the surfaces of seeds precipitated by low frequency ultrasound are very irregular. The new nuclei are pseudohexagonal slices with nanometer grade in thickness. At higher precipitation temperature, such as 75℃, SEM micrographs show that there exist something like colloid on joints of different small granules which have agglomerated to a large particle. It is suggested that the formation of such hexagonal crystalline units is promoted by low frequency ultrasound, while the colloids on the surface may be produced by imcompletely crystallization of the growth units.
