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Published on: May 20, 2019
Ion-pair extraction of uranyl ion from aqueous medium using crown ethers
1Radiochemistry Division, Bhabha Atomic Research Centre, Trombay, Bombay-400085, India.
Talanta
|October 31, 2008
Summary
Crown ethers were used for ion-pair extraction of uranyl ions, with specific ethers showing effective complexation. This method also enabled the separation of fission products and lanthanides from uranium.
Area of Science:
- Radiochemistry
- Separation Science
- Coordination Chemistry
Background:
- Uranyl ion (UO2^2+) is a key component in nuclear fuel cycles and waste.
- Efficient extraction and separation methods are crucial for nuclear material management and research.
- Crown ethers are known for their selective complexation of metal cations.
Purpose of the Study:
- To investigate the ion-pair extraction behavior of uranyl ions using various crown ethers.
- To determine the stoichiometry of the extracted uranyl-crown ether complexes.
- To explore the potential for separating fission products and lanthanides from uranyl ions.
Main Methods:
- Ion-pair extraction using crown ethers (benzo 15 crown 5, 18 crown 6, dibenzo 18 crown 6, dibenzo 24 crown 8) in chloroform.
- Studying uranyl ion extraction from aqueous solutions at pH 3.0 with picric acid as the counter anion.
- Analyzing the separation of fission products from an irradiated uranium target and trivalent lanthanides.
Main Results:
- Effective ion-pair extraction of uranyl ions was achieved with benzo 15 crown 5, 18 crown 6, and dibenzo 18 crown 6.
- The stoichiometry of extracted species was determined as [UO2(crown ether)n]2+.[pic(-)]2, with n=1.5 for B15C5 and n=1 for 18C6 and DB18C6.
- Dibenzo 24 crown 8 showed negligible extraction of uranyl ions.
- Successful separation of trivalent lanthanides from uranyl ions was observed.
Conclusions:
- Crown ethers, particularly 18-crown-6 and dibenzo-18-crown-6, are effective in the ion-pair extraction of uranyl ions.
- The study demonstrates a potential method for separating uranyl ions from fission products and lanthanides.
- Further research could optimize these crown ether-based extraction systems for nuclear applications.
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