Recovery of rare-earth elements from nitric acid solutions by fullerene black impregnated with diphenyl(dibutylcarbamoylmethyl)phosphine oxide

The distribution of microamounts of La, Ce, Pr, Nd, Sm, Eu, Gd, Tb, Dy, Ho, Er, Tm, Yb, Lu, and Y nitrates between aqueous HNO₃ solutions and fullerene black impregnated with diphenyl(dibutylcarbamoylmethyl)phosphine oxide (L) was studied. The influence exerted on the efficiency of REE recovery by the HNO₃ concentration in the aqueous phase and concentration of L in the sorbent phase was examined. The degree of REE recovery increases on adding HClO₄ to the aqueous phase.     

Preconcentration of rare earth elements(III) by sorption from nitric acid solutions using carbamoylmethylphosphine oxide and an ionic liquid

Sorption of microamounts of rare earth elements(III) from HNO₃ solutions with complexing sorbents prepared by noncovalent immobilization of diphenyl(dibutylcarbamoylmethyl)phosphine oxide and an ionic liquid, 1-methyl-3-butylimidazolium bis[(trifluoromethyl)sulfonyl]imide, on the surface of carbon nanotubes was studied in relation to the component ratio in the sorbent and to the HNO₃ concentration in the aqueous phase. The efficiency of the recovery of rare earth elements considerably increases when the sorbent phase contains the ionic liquid.     

Extraction of U(VI) and Th(IV) from nitric acid solutions with tetraaryl-substituted (<Emphasis Type="Italic">o</Emphasis>-phenyleneoxymethylene)diphosphine dioxides

Extraction of U(VI) and Th(IV) from HNO₃ solutions in the form of complexes with tetraarylsubstituted (o-phenyleneoxymethylene)diphosphine dioxides is studied. The effect of substituents at the P atoms in the extractant molecule on its extraction ability and selectivity is considered. The stoichiometry of the extractable complexes is determined. The possibility of U(VI) and Th(IV) preconcentration with a complexing sorbent prepared by noncovalent immobilization of tetra-p-tolyl-substituted (o-phenyleneoxymethylene)-diphosphine dioxide on a polymeric matrix is demonstrated.     

Extraction of U(VI), Th(IV), and REE(III) from nitrate solutions with diaryl(dialkylcarbamoylalkyl)phosphine oxides containing a dialkylcarbamoylmethyl substituent in the alkylene bridge

The extraction of microamounts of U(VI), Th(IV), and REE(III) from HNO₃ and NH₄NO₃ solutions with solutions of diaryl(dialkylcarbamoylalkyl)phosphine oxides containing a dialkylcarbamoylmethyl substituent in the alkylene bridge was studied. The stoichiometry of the complexes extracted from nitric acid solutions with N,N,N',N'-tetrabutyl-2-(di-p-anisylphosphinyl)butanedioic diamide I was determined. The influence of the extractant structure and aqueous phase composition on the efficiency and selectivity of the extraction of U(VI), Th(IV), and REE(III) into the organic phase was examined. Introduction of the–CH₂C(O)NAlk₂ fragment into the methylene bridge of the diaryl(dialkylcarbamoylmethyl)phosphine oxide molecule considerably enhances the extraction of REE(III) from neutral nitrate solutions. Such modification of the extractant molecule only slightly influences the extraction of REE(III) from nitric acid solutions, but leads to a considerable increase in the U(VI) extraction and to a decrease in the Th(IV) extraction. The selectivity of the extraction of U(VI) and REE(III) is thus considerably increased.     

Extraction of Rare-Earth Elements from Nitric Acid Solutions with Ethylenediphosphine Dioxides

Extraction of microamounts of Y, La, Ce, Pr, Nd, Sm, Eu, Gd, Tb, Dy, Ho, Er, Tm, Yb, and Lu from HNO₃ aqueous solutions with ethylenediphosphine dioxides in organic diluents was studied. The effect of the dioxide structure on its extractive power and selectivity was considered. The stoichiometry of extractable solvates was determined.     

Influence of the Structure of (О-Phenylenoxymethylene)diphosphine Dioxides on Their Extraction Ability to U(VI), Th(IV), and REE(III) in Nitric Acid Media

Radiochemistry - Extraction of microquantites of U(VI), Th(IV), and REE(III) from nitric acid solutions with solutions of (o-phenyleneoxymethylene)diphosphine dioxides with phenyl and butyl...     

Influence of the Structure of Biscarbamoylmethylphosphine Oxides on the Extraction of REE(III), U(VI), and Th(IV) from Nitric Acid Solutions in the Presence of an Ionic Liquid

Radiochemistry - It was established that the extraction ability of bis[(diphenylphosphinyl)acetamido]alkanes, in the molecules of which two bidentate fragments Ph2P(O)CH2C(O)NAlk– are linked...     

Preconcentration of U(VI), Th(IV), and REE(III) from nitric acid solutions using carbon nanotubes modified with bis(dioctylphosphinylmethyl)phosphinic acid

The extraction of microamounts of U(VI) and Th(IV) from HNO₃ solutions in the form of complexes with bis(dioctylphosphinylmethyl)phenylphosphinic acid was studied. The stoichiometry of the extractable complexes was studied, and the influence of the extractant structure on the efficiency and selectivity of the U(VI) and Th(IV) extraction was examined. U(VI), Th(IV), and REE(III) can be preconcentrated from nitric acid solutions with a complexing sorbent prepared by noncovalent immobilization of bis(dioctylphosphinylmethyl) phosphinic acid on the surface of carbon nanotubes.     

Recovery of Rare-Earth Elements from Nitric Acid Solutions with a Polymeric Sorbent Impregnated with Diphenyl(dialkylcarbamoylmethyl)phosphine Oxides

The distribution of lanthanides (Ln), including also Y, between aqueous HNO₃ and a microporous styrene-divinylbenzene copolymer impregnated with diphenyl(dialkylcarbamoylmethyl)phosphine oxides (CMPOs) and their -substituted derivatives was studied in relation to the aqueous phase acidity and extractant content in the solid phase. Rare-earth elements pass into the sorbent phase in the form of complexes with the Ln : CMPO ratio of 1 : 2. The Ln distribution factors grow as the HNO₃ concentration in the aqueous phase is increased from 0.1 to 7.0 M.     

Extraction of REE(III), U(VI), and Th(IV) from Nitric Acid Solutions with Carbamoylmethylphosphine Oxides in the Presence of Dinonylnaphthalenesulfonic Acid

The extraction of REE(III), U(VI), and Th(IV) from nitric acid solutions with solutions of carbamoylmethylphosphine oxides (CMPOs) considerably increases in the presence of dinonylnaphthalenesulfonic acid. The stoichiometry of the extractable complexes was determined, and the influence of the aqueous phase composition, kind of organic diluent, and CMPO structure on the efficiency of the extraction of the metal ions was analyzed.