应用化学 ›› 1985, Vol. 0 ›› Issue (4): 71-75.

• 研究简报 • 上一篇    下一篇

两相滴定法研究RE(Ⅲ)-HTTA-TBPO协萃体系

李声崇, 戴冈夫, 邹忠杰, 徐光宪   

  1. 北京大学化学系
  • 收稿日期:1984-11-15 修回日期:1985-03-09 出版日期:1985-12-10 发布日期:1985-12-10

STUDY ON THE SYNERGIC EXTRACTION OF RE(Ⅲ) IONS WITH HTTA-TBPO BY THE METHOD OF TWO-PHASE TITRATION

Li Shengchong, Dai Gangfu, Zou Zhongjie, Xu Guangxian   

  1. Department of Chemistry, Beijing University
  • Received:1984-11-15 Revised:1985-03-09 Published:1985-12-10 Online:1985-12-10

摘要: HTTA与中性膦类萃取剂协同萃取稀土元素的报导多数采用分配比法。用两相滴定法研究HTTA-TBPO协同萃取稀土元素,尚未见报导。本文用pH计测出滴定过程平衡水相的pH值,根据文献[1]的计算原理,求出HTTA的两相电离常数KaE及HTTA-TBPO在有机相中的缔合常数K,并确定有机相中稀土萃合物的组成及其稳定常数。两相滴定法省去了测定两相中稀土离子平衡浓度的繁杂手续,仪器和试剂简单,不仅节约时间,还可得到与分配法同样可靠的结果,是研究协萃体系的一种简便方法。

Abstract: The extraction system of RE(Ⅲ) (except Pm,including Y) with thenoyltriflouroacetone (HTTA) and tributylphosphine oxide (TBPO) was studied by two-phase titration method.The results showed that: (1) There is no association between HTTA and TBPO under experimental conditions. (2) The mixed ligand complexes of types RE (TTA)3(TBPO)2,RE(TTA)3(TBPO)3, RE(TTA)3(TBPO)4 were formed in the organic phase and their stability constants were determined. (3) The stability constants β30k of RE(TTA)3(TBPO)k increase with the atomic number of the lanthanide. logβ303 shows a clear tetrad effect.The position of logβ303 for Y is between that for Ho and Er.