“极端假设-校正”法研究BEHDTPA-TOA萃取镉的机理  

Study on Mechanism of Extracting Cadmium with BEHDTPA-TOA by Extreme Hypothesis/Correction Method

作　　者：张大力[1] 柯家骏[1] 卢立柱[1] 

机构地区：[1]中国科学院过程工程研究所

出　　处：《化学学报》2006年第11期1106-1110,共5页Acta Chimica Sinica

基　　金：国家自然科学基金(No.20276074)资助项目.

摘　　要：用BEHDTPA[二(2-乙基己基)二硫代磷酸]-TOA(三辛胺)庚烷溶剂萃取硫酸盐溶液中的镉时,pH的减小既可引起萃取率降低又可引起萃取率升高.萃取中可能存在多个机理的转换.依据极端假设,分别讨论了三个萃取机理对萃取的作用,并得到了初步的萃取方程.分析了三种机理的作用随pH而变化的性质,并将粗略的萃取方程校正为较精确的方程.萃取相对贡献曲线可比较直观地反映三机理的复杂关系.研究结果表明,在一定pH范围三种机理以相互交叉的方式影响着萃取结果.极端假设:在多机理作用的体系中,可认为在一定情况下某一机理起主要作用而其他机理则忽略.In extracting cadmium from aqueous solution of sulfate with bis（2-ethylhexyl）dithiophosphoric acid-trioctylarnine in heptane, a reduction in pH could cause the decrease of extraction rate, then its increase. There were the transitions among several mechanisms in the extraction. On the basis of an extreme hypothesis, the effects of three mechanisms on extraction were discussed separately, with a preliminary equation of the extraction got. The action of such three mechanisms changing with pH was analyzed, and the rough and preliminary equation was corrected into a comparatively precise equation. The complex relationship among the three extraction mechanisms could be revealed by the mechanism contribution curves with a direct vision method. In certain pH ranges, the three mechanisms affected extraction result by the overlapping ways. The extreme hypothesis can be described below： in the system of several mechanisms, it could be considered extremely that under some conditions a certain mechanism takes key effect and others can be neglected.

关 键 词：极端假设 校正 萃取 机理 BEHDTPA-TOA 镉 

分 类 号：TQ028[化学工程]