Separation of americium (III) and strontium (II) using TEHDGA and 18-crown-6

• Published in: Radiochimica acta Vol. 105; no. 4; pp. 265 - 273
• Main Authors: Sinharoy, Prithwish, Khan, Pasupati Nath, Nair, Deepika, Jagasia, Poonam, Anitha, M., Dhami, P.S., Sharma, J.N., Kaushik, C.P., Banerjee, Kalyan
• Format: Journal Article
• Language: English
• Published: De Gruyter 01.04.2017
• Subjects: 18-crown-6; HLW; selective stripping; sr(II); TEHDGA
• ISSN: 0033-8230; 2193-3405
• DOI: 10.1515/ract-2016-2646

This work describes extraction of Am(III) and Sr(II) together with tetra(2-ethylhexyl) diglycolamide (TEHDGA) and selective back-extraction of strontium with a strontium complexant, 18-crown-6, leading to their separation from each other. 0.3 M TEHDGA+5% isodecyl alcohol/ -dodecane was used to extract Am(III) and Sr(II) from 4 M nitric acid into organic phase with very high ( =1000, =22) and 0.1 M 18-crown-6 dissolved in 4 M nitric acid is used for selective stripping of Sr(II) from loaded extract phase. Am(III) left in the extract phase was then stripped with 0.01 M nitric acid. Stripping of Sr(II) was found to increase with increase in 18-crown-6 concentration, at 0.1 M 18-crown-6 dissolved in 4 M nitric acid, 83% of the loaded strontium ( =0.20) was back-extracted in a single contact while loss of Am(III) was 0.8% ( =122.45). Stoichiometry limit of 1:1 was observed between strontium and 18-crown-6. Strontium was precipitated and separated from the complexant by Na SO or Na CO . This process was tested with simulated solution of high level waste and found suitable for quantitative recovery of strontium with high purity.