化工学报Issue(8)：2863-2868,6.DOI:10.3969/j.issn.0438-1157.2014.08.001
Mg-Al水滑石的溶解动力学及热力学
Dissolution kinetics and thermodynamics of Mg-Al hydrotalcites
摘要
Abstract
The dissolution of Mg-Al hydrotalcites in aqueous solution and its mechanism were investigated, with the dissolution kinetics and thermodynamics at different temperatures and pH. The kinetic model with the outer diffusion and chemical reaction control can be used to describe the dissolution process appropriately, with different controlling steps in various pH ranges. In the pH range from 1.0 to 3.8, the hydrotalcites dissolve completely and the dissolution rate decreases as pH increases, with the dissolution controlled by desorption. In the pH range from 4.2 to 9.4, the hydrotalcites partly dissolve, independent of pH, with the dissolution controlled by surface exchange reaction. On the other hand, the Gibbs free energy change of the dissolution reaction from the Mg-Al hydrotalcite is estimated as 29.516 kJ·mol-1 at 298 K. The result is consistent with the experimental evidence.关键词
镁铝水滑石/溶解/动力学/热力学/动力学模型Key words
Mg-Al hydrotalcite/dissolution/kinetics/thermodynamics/kinetic modeling分类
化学化工引用本文复制引用
徐圣,廖梦尘,曾虹燕,朱培函,张治青,黄清军,刘小军,张伟..Mg-Al水滑石的溶解动力学及热力学[J].化工学报,2014,(8):2863-2868,6.基金项目
湖南省自然科学基金重点项目(12JJ2008)；湖南省高校创新平台开放基金项目(12K048)；2012年湖南省大学生创新性实验计划项目(2012)。@@@@supported by the Key Program of the Natural Science Foundation of Hunan Province (12JJ2008), the Open Project of Hunan Provincial University Innovation Platform (12K048) and Hunan Province Undergraduate Innovative Experiment Program(2012) （12JJ2008）
