(中南大学 化学化工学院，长沙 410083)
摘 要: 研究L-白氨酸对铝酸钠溶液种分分解率及其产物Al(OH)3粒度和形貌的影响，并结合表面张力和27Al NMR检测手段探讨L-白氨酸对铝酸钠溶液种分过程影响的作用机制。结果表明：在所选实验条件下，L-白氨酸可以强化分解过程，并在低浓度下可使种分产品细化；L-白氨酸的加入可以降低溶液的表面张力，27Al NMR特征峰峰形和化学位移均无显著改变，但半峰宽缩小；结合种分实验，认为添加剂主要是通过吸附在晶种表面，降低了氢氧化铝结晶活化能，促进氢氧化铝的快速析出。
关键字: L-白氨酸；铝酸钠溶液；晶种分解；分解率
sodium aluminate solution
（School of Chemmistry and Chemical engineering ,Central South University, Changsha 410083, China）
Abstract:The effects of L-leucine on the seeded precipitation rate of sodium aluminate solution, the particle size and morphology of the products were studied. The surface tension and 27Al NMR were used in order to investigate the interaction mechanism of L-leucine on the seeded precipitation. The results indicate that L-leucine can promote the precipitation at low concentration and the product becomes finer. The surface tension of sodium aluminate solution decreases with the addition of L-leucine. According to the 27Al NMR spectra, the peak profile and chemical shift of the characteristic peak have no obvious change compared with the blank solution, however, the half-peak width reduces. From the results of seed agglomeration, it can be inferred that the precipitation of Al(OH)3 is promoted by the adsorption of additive molecules on the surface of seed particles, thus the crystallization activation energy decreases.
Key words: L-leucine; sodium aluminate solution; seeded precipitation; precipitation rate
