Combined effect of amino and carboxyl group in α-alanine on seeded precipitation of sodium aluminate solution  

作　　者：吕保林 陈启元 尹周澜 胡慧萍 

机构地区：[1]School of Chemistry and Chemical Engineering, Central South University

出　　处：《中国有色金属学会会刊：英文版》2009年第3期745-750,共6页Transactions of Nonferrous Metals Society of China

基　　金：Project(20476107) supported by the National Natural Science Foundation of China;Project(2005CB623702) supported by the National Basic Research Program of China

摘　　要：α-alanine was adopted as a new additive to elucidate the seeded precipitation mechanism of sodium aluminate solution. α-alanine has the inhibitory effect at the initial period of reaction, but the favorable effect in subsequent reaction. The combined effect of amino and carboxyl group in α-alanine was confirmed by investigating the effect of propionic acid, ethamine and the mixture of propionic acid and ethamine (mole ratio 1-1) on the precipitation of sodium aluminate solution, respectively. The inhibitory effect derives from the adsorption of amino or carboxyl group in α-alanine on the active surface sites of gibbsite, which was confirmed by the alleviating inhibitory effects of propionic acid, ethamine and α-alanine due to the double crystal seed mass. The semi-quantitative IR spectrum analysis of the relative concentrations of Al2O(OH)62- with the band at about 550 cm-1 and polynuclear aluminate ion with the bands at about 880 cm-1 and 635 cm-1, indicates that the dynamic balance among some aluminate species present in sodium aluminate solution is broken due to the addition of α-alanine, thus resulting in the change of the seeded precipitation ratio of sodium aluminate solution.α-alanine was adopted as a new additive to elucidate the seeded precipitation mechanism of sodium aluminate solution. α-alanine has the inhibitory effect at the initial period of reaction, but the favorable effect in subsequent reaction. The combined effect of amino and carboxyl group in α-alanine was confirmed by investigating the effect of propionic acid, ethamine and the mixture of propionic acid and ethamine （mole ratio 1：1） on the precipitation of sodium aluminate solution, respectively. The inhibitory effect derives from the adsorption of amino or carboxyl group in α-alanine on the active surface sites of gibbsite, which was confirmed by the alleviating inhibitory effects of propionic acid, ethamine and α-alanine due to the double crystal seed mass. The semi-quantitative IR spectrum analysis of the relative concentrations of Al2O（OH）6^2- with the band at about 550 cm^-1 and polynuclear aluminate ion with the bands at about 880 cm^-1 and 635 cm^-1, indicates that the dynamic balance among some aluminate species present in sodium aluminate solution is broken due to the addition of α-alanine, thus resulting in the change of the seeded precipitation ratio of sodium aluminate solution.

关 键 词：铝酸钠溶液 种子质量 丙氨酸 氨基酸 羧基 沉淀 合作 降水机制 

分 类 号：O621.2[理学—有机化学]