Extraction of Americium and Neodymium from Perchloric and Hydrochloric Acid Solutions with Neat Diphenyl(dibutylcarbamoylmethyl)phosphine Oxide

Interaction of solid diphenyl(dibutylcarbamoylmethyl)phosphine oxide (Ph₂Bu₂) with perchloric and hydrochloric acid solutions was studied. On contact with the acids, this agent forms a liquid substance (liquid reagent, LR) exhibiting extractive power. The conditions of LR formation and extraction of Am(III) from HCl solutions with LR in the absence of organic diluent were studied. The solubility of Ph₂Bu₂ in 3 M HClO₄ is 2.5 mg l^{- 1}. The composition of the LR formed in HClO₄ solutions is 2Ph₂Bu₂·HClO₄·nH₂O. Perchloric acid is quantitatively backwashed from the LR phase with water. Formation of an Nd(III) complex with LR in HClO₄ solutions is accompanied by cementation (solidification) of the compound. The resulting complex has the 3 : 1 [Ph₂Bu₂ : Nd(III)] composition and mp 120°C. According to the IR spectrum, the coordination of Ph2Bu2 with the HClO₄ molecule is monodentate, and with the Nd(III) ion (in the absence of organic diluent) it is bidentate.