高等学校化学学报 ›› 2019, Vol. 40 ›› Issue (1): 1-10.doi: 10.7503/cjcu20180133

• 无机化学 • 上一篇    下一篇

二(2-乙基己基)二硫代次膦酸对硝酸溶液中Am3+和Eu3+的萃取

张利荣1, 王志鹏1, 刘莹1, 徐超2(), 陈靖2, 丁颂东1()   

  1. 1. 四川大学化学学院, 成都 610064
    2. 清华大学核能与新能源技术研究院, 北京 100084
  • 收稿日期:2018-02-12 出版日期:2019-01-10 发布日期:2018-12-12
  • 作者简介:

    联系人简介:丁颂东,男,博士,研究员,主要从事核燃料循环与材料方面的研究. E-mail: dsd68@163.com; 徐 超, 男, 博士, 副教授, 主要从事核化学化工方面的研究. E-mail: xuchao@tsinghua.edu.cn

  • 基金资助:
    国家自然科学基金(批准号: 91426302, 11675115, 91126016)资助.

Extraction of Trivalent Americium and Europiumfrom Nitric Acid Solution with Di(2-ethylhexyl)dithiophosphinic Acid

ZHANG Lirong1, WANG Zhipeng1, LIU Ying1, XU Chao2,*(), CHEN Jing2, DING Songdong1,*()   

  1. 1. College of Chemistry, Sichuan University, Chengdu 610064, China
    2. Institute of Nuclear and New Energy Technology, Tsinghua University, Beijing 100084, China
  • Received:2018-02-12 Online:2019-01-10 Published:2018-12-12
  • Contact: XU Chao,DING Songdong E-mail:xuchao@tsinghua.edu.cn;dsd68@163.com
  • Supported by:
    † Supported by the National Natural Science Foundation of China(Nos.91426302, 11675115, 91126016).

摘要:

以正十二烷作稀释剂, 研究了二(2-乙基己基)二硫代次膦酸(D2EHDTPA)对HNO3溶液中Am3+和Eu3+的萃取行为. 考察了酸度、 萃取剂及NO3-浓度和皂化度对萃取的影响. 在考察的pH范围(2.5~4.5)内, D2EHDTPA萃取Am3+和Eu3+的分配比(D)随pH值增大而增加; pH=3.65时, 分离因子(SFAm/Eu)值达到最大(4000). 随D2EHDTPA浓度的增加, DAmDEu值均增加. 斜率分析表明, D2EHDTPA萃取Am3+和Eu3+主要形成3:1和2:1型的萃合物. NO3-未直接参与D2EHDTPA对Am3+和Eu3+的萃取反应. D2EHDTPA经NaOH皂化后, 萃取能力显著增强, SFAm/Eu值提高到104量级, 萃取容量约为理论值的60%. 此外, 使用高分辨质谱、 红外光谱和等温微量热滴定方法研究了D2EHDTPA与Eu3+的配位化学行为, 得到了金属离子与配体的组成比、 络合物稳定常数以及配位热力学参数ΔH, ΔS和ΔG值.

关键词: 二(2-乙基己基)二硫代次膦酸, Am3+, Eu3+, 萃取, 选择性

Abstract:

The extraction of Am3+ and Eu3+ from HNO3 solution with di(2-ethylhexyl)dithiophosphinic acid(D2EHDTPA) were investigated using n-dodecane as diluent. Influences of acidity, ligand concentration, NO3- concentration and saponification on the extraction of Am3+ and Eu3+ were evaluated. The distribution ratio values of both Am3+ and Eu3+ increased with increasing pH values from 2.5 to 4.5, and also with increasing the ligand concentration from 0.10 mol/L to 0.50 mol/L. The maximum value of separation factor(SFAm/Eu) can reach 4000 at pH=3.65. Slope analyses indicated the main formation of 3:1 and 2:1 complexes of D2EHDTPA with Am3+ and Eu3+, respectively. The nitrate ion did not take part in the extraction reaction of D2EHDTPA with Am3+ or Eu3+. The extractability of D2EHDTPA was significantly enhanced through the saponification with NaOH solution. SFAm/Eu values could be improved to the magnitude of 104, and the extraction capacity was approximately 60% of the theoretical value. Furthermore, the complexation behaviors of D2EHDTPA with Eu3+ were also investigated by electrospray ionization mass spectrometry(ESI-MS), Fourier transform infrared(FTIR) and isothermal titration calorimetry(ITC). The composition and stability constants(lgβ) of the complex of D2EHDTPA with Eu3+, as well as the thermodynamic parameters(ΔH, ΔS and ΔG) were obtained.

Key words: Di(2-ethylhexyl)dithiophosphinic acid, Am3+, Eu3+, Extraction, Selectivity

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