摘要
研究了磷酸三丁酯（TBP，B）和三烷基胺萃取剂（N235，R，N，R=C8～C10）在HCl介质中对Zn^2＋的萃取，该混合体系对Zn^2＋存在明显的协同效应，协萃系数为12．34。用斜率法和恒摩尔法探讨了萃取机理，确定了萃合物的组成为（R3N）15·ZnCl2．B，协萃反应方程式：ZnCl2（n）＋1．5R3N（o）＋B（o）-（R3N）1.5·ZnCl2·B（o）。计算了该反应的平衡常数和热力学函数△H、△G和△S，证明反应为放热过程。比较了TBP-N235的混合体系萃取Zn^2＋和Cd^2＋的性能，并考察了TBP与另一种胺类萃取剂N,N′-二（1．甲庚基）乙酰胺（N503）的混合体系对Zn^2＋和Cd^2＋的萃取。结果表明：TBP-N235的混合体系对Cd^2＋没有明显的协同效应；TBP-N503的混合体系对Zn^2＋和Cd^2＋协同效应都不明显。计算了TBP-N235的混合体系对Zn^2＋和Cd^2＋的分离系数，证明此体系可以从富镉溶液中分离锌。
The extraction of Zn^2＋ by mixtures of tri-butyl-phosphate （TBP, B） and trialkyl amine （N235, RaN, R = Cs -Cl0） has been carried out. The mixtures have evident synergistic effects on Zn^2＋ with a synergistic enhancement factor of 12.34. The extraction mechanism was studied using the methods of slope analysis and constant mole. The extracted complex was determined as（ R3 N）1.5·ZnCl2B. The equilibrium constant and thermodynamic functions AH, AG and AS have been calculated, indicating that the reaction is exothermic driven. The extraction of Zn^2＋ and Cd^2＋ by the mixtures of TBP and N235 or N, N-di （ 1-methyl-heptyl ） acetamide（ N503 ） was also conducted. Results show that the mixtures of TBP and N235 do not have evident synergistic effects on Cd^2＋ , while TBP-NS03 mixing systems also do not have the synergistic effects on either Zn^2＋ or Cd^2＋ Moreover, the separation factors of Zn^2＋ and Cd^2＋ by TBP-N235 system was studied. It is feasible and advantageous to separate Zn^2＋ from bulk cadmium solutions.
出处
《分析化学》
SCIE
EI
CAS
CSCD
北大核心
2008年第5期619-622,共4页
Chinese Journal of Analytical Chemistry
基金
教育部留学回国人员科研启动基金资助项目(No.2006331)
