Specific features of temperature influence on the extraction of Am(III), Eu(III) and Lu(III) by N,N,N’,N’-tetraoctyldiglycolamide from mineral acid solutions

The influence of temperature on the extraction of Am(III), Eu(III) and Lu(III) by TODGA from nitric, hydrochloric and sulfuric acid solutions has been studied. The compositions of the extracted species were determined and the thermodynamic parameters of the extraction reactions were defined. On the basis of data on thermal effects of extraction processes, a method of Lu(III) concentrating at the stage of back-extraction was proposed. The influence of the nature of acid on the possibility of group separation of REE was evaluated.