In situ electro-oxidation and liquid-liquid extraction of cerium(IV) from nitric acid medium using tributyl phosphate and 2-ethylhexyl hydrogen 2-ethylhexyl phosphonate
In situ electro-oxidation and liquid-liquid extraction of cerium(IV) from nitric acid medium using tributyl phosphate and 2-ethylhexyl hydrogen 2-ethylhexyl phosphonate
复制标题
使用磷酸三丁酯和 2-乙基己基氢 2-乙基己基膦酸酯从硝酸介质中进行原位电氧化和液液萃取
DOI：
10.1007/bf02034260
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发表时间：
1997
影响因子：
1.6
通讯作者：
A. Ramanujam
中科院分区：
文献类型：
--
作者：
C. Kedari;S. S. Pandit;A. Ramanujam
研究了Ce（III）原位电氧化成Ce（IV），然后萃取到有机相中的过程，考察了其在硝酸盐介质中分离Ce的适用性。用磷酸三丁酯（TBP）和2-乙基己基膦酸氢2-乙基己酯（KSM-17，相当于PC-88 A）从电氧化至四价态的硝酸中萃取铈。测定了不同硝酸浓度和不同电极电位下萃取剂的萃取效率。研究了盐酸羟胺、亚硝酸钠、硫酸亚铁等还原剂和EDTA、草酸等络合剂对铈的反萃作用。将开发的用于萃取铈的方法进一步扩展到从PUREX高活度废物（HAW）溶液的基于KSM-17的萃取色谱元素分级期间获得的铈-Am混合物中分配铈。在间歇和连续流动有机相萃取实验中获得的Ce的回收率>95%，具有良好的放射化学纯度。
The process of in situ electro-oxidation of Ce(III) to Ce(IV) followed by its extraction into the organic phase has been investigated for its applicability in the separation of Ce from nitrate medium. Solvent extraction of cerium from nitric acid after its electro-oxidation to fourth valency state was carried out using tributyl phosphate (TBP) and 2-ethylhexyl hydrogen 2-ethylhexyl phosphonate (KSM-17, equivalent to PC-88A). The efficiency of the extractants at different aqueous phase nitric acid concentrations and different electrode potentials were determined. Various reducing agents such as hydroxylamine hydrochloride, sodium nitrite, ferrous sulphate as well as complexing agents like EDTA, oxalic acid etc, were studied as strippants for the back extraction of cerium from the loaded organic phase. The method developed for the extraction of cerium was further extended to the partitioning of cerium from Ce-Am mixture obtained during the KSM-17 based extraction chromatographic elemental fractionation of PUREX High Activity Waste (HAW) solutions. Recovery of Ce obtained in the extraction experiments by batch as well as by continuous flow organic phase was >95% with good radiochemical purity.