Precipitation of spherical boehmite from concentrated sodium aluminate solution by adding gibbsite as seed
来源期刊：International Journal of Minerals Metallurgy and Materials2017年第8期
论文作者：Gui-hua Liu Zheng Li Xiao-bin Li Tian-gui Qi Zhi-hong Peng Qiu-sheng Zhou
文章页码：954 - 963
摘 要：The precipitation of spherical boehmite was studied by surface energy calculations, measurements of precipitation ratios, Fourier transform infrared spectroscopy, X-ray diffraction, scanning electron microscopy, and transmission electron microscopy. The surface energy calculation results show that the（001） and（112） planes of gibbsite surfaces are remarkably stable because of their low surface energies. In addition, the（010） plane of boehmite grows preferentially during precipitation because of its low surface energy. Thus, we propose a method to precipitate spherical boehmite from a supersaturated sodium aluminate solution by adding gibbsite as seed in a heterogeneous system. In this method, gibbsite acts as the preliminary seed and saturation modifier. The results show that the fine boehmite first nucleates on the（001） and（112） planes of gibbsite and then grows vertically on the（001） and（112） basal planes of gibbsite via self-assembly, thereby forming spherical boehmite. Simultaneously, gibbsite is dissolved into the aluminate solution to maintain the saturation for the precipitation of boehmite. The precipitation ratio fluctuates（forming an M-shaped curve） because of gibbsite dissolution and boehmite precipitation. The mechanism of boehmite precipitation was further discussed on the basis of the differences in surface energy and solubility between gibbsite and boehmite. This study provides an environmentally friendly and economical method to prepare specific boehmite in a heterogeneous system.
Gui-hua Liu，Zheng Li，Xiao-bin Li，Tian-gui Qi，Zhi-hong Peng，Qiu-sheng Zhou
School of Metallurgy and Environment, Central South University
摘 要：The precipitation of spherical boehmite was studied by surface energy calculations, measurements of precipitation ratios, Fourier transform infrared spectroscopy, X-ray diffraction, scanning electron microscopy, and transmission electron microscopy. The surface energy calculation results show that the（001） and（112） planes of gibbsite surfaces are remarkably stable because of their low surface energies. In addition, the（010） plane of boehmite grows preferentially during precipitation because of its low surface energy. Thus, we propose a method to precipitate spherical boehmite from a supersaturated sodium aluminate solution by adding gibbsite as seed in a heterogeneous system. In this method, gibbsite acts as the preliminary seed and saturation modifier. The results show that the fine boehmite first nucleates on the（001） and（112） planes of gibbsite and then grows vertically on the（001） and（112） basal planes of gibbsite via self-assembly, thereby forming spherical boehmite. Simultaneously, gibbsite is dissolved into the aluminate solution to maintain the saturation for the precipitation of boehmite. The precipitation ratio fluctuates（forming an M-shaped curve） because of gibbsite dissolution and boehmite precipitation. The mechanism of boehmite precipitation was further discussed on the basis of the differences in surface energy and solubility between gibbsite and boehmite. This study provides an environmentally friendly and economical method to prepare specific boehmite in a heterogeneous system.
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