Extraction of actinides from chloride medium using pentaalkylpropanediamides

Pyrometallurgical processes for the purification of plutonium create waste solutions containing actinides, mainly americium, in chloride medium. Studies have been undertaken to study the extraction of actinides in chloride medium (hydrochloric acid mixed with concentrated salts such as LiCl, CaCl2, MgCl2, KCl) using pentaalkylpropanediamides as extractants. Plutonium (IV) is very easily extracted, Am (III) needs a salting out agent such as LiCl. Back extraction of trivalent cations is easy in HCl <5M. Plutonium(IV) and (VI) can be stripped by reduction either with ascorbic acid or hydroxylammonium salts in weak acid medium. Several diluents can be used (aromatic, chlorinated or even aliphatic) with addition of decanol to prevent third phase formation. In conclusion diamides can be used for various wastes declassification, they are potentially completely incinerable, and, as the synthesis has been optimized, they appear to be promising extractants