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.     

Extraction of REE(III), U(VI), and Th(IV) from Nitric Acid Solutions with Diphenyl(dibutylcarbamoylmethyl)phosphine Oxide in the Presence of Quaternary Ammonium Bis[(trifluoromethyl)sulfonyl]imides

Radiochemistry - The extraction of REE(III), U(VI), and Th(IV) from nitric acid solutions with solutions of diphenyl(dibutylcarbamoylmethyl)phosphine oxide considerably increases in the presence of...     

Extraction of U(VI), Th(IV), and REE(III) from Nitric Acid Solutions with Bis[(diphenylphosphoryl)acetamido]alkanes

Radiochemistry - It was found that combining two bidentate fragments Ph2P(O)CH2C(O)NAlk– in the same molecule via an amide atom with an alkylene bridge leads to a noticeable increase in the...     

Extraction of REE(III), U(VI), and Th(IV) from Nitric Acid Solutions with N-Akyl(aryl)carbamoylmethylphosphine Oxides in the Presence of an Ionic Liquid

Radiochemistry - It was found that the extraction of REE(III), U(VI), and Th(IV) from nitric acid solutions with N-alkyl(aryl)carbamoylmethyl phosphine oxides Ph2P(O)CH2C(O)NHR (R = C9H19, Ph,...     

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...     

Extraction of REE(III), U(VI), and Th(IV) from Perchloric Acid Solutions with 2,6-Bis(diphenylphosphorylmethyl)pyridine N-Oxide

Radiochemistry - The extraction of microamounts of REE(III), U(VI), and Th(IV) from HClO4 solutions with solutions of 2,6-bis(diphenylphosphorylmethyl) pyridine N-oxide (I) in 1,2-dichloroethane...     

Extraction of REE(III), U(VI), and Th(IV) from Perchlorate Solutions with Tetraphenyl(o-oxyphenylenemethylene)diphosphine Dioxide

Radiochemistry - The extraction of microamounts of REE(III), U(VI), and Th(IV) from perchlorate solutions with solutions of tetraphenyl(o-oxyphenylenemethylene)diphosphine dioxide (I) in...     

Extraction of U(VI), Th(IV), and REE(III) from Nitric Acid Solutions with 2,6-Bis(diphenylphosphorylmethyl)pyridine <Emphasis Type="Italic">N</Emphasis>-Oxide

The extraction of microamounts of U(VI), Th(IV), and REE(III) from HNO₃ solutions in the form of complexes with 2,6-bis(diphenylphosphorylmethyl)pyridine N-oxide (I) was studied in relation to the kind of organic diluent and to the HNO₃ concentration in the equilibrium aqueous phase. The stoichiometry of the extractable complexes was determined. With respect to the ability to extract Th(IV) and REE(III), compound I considerably surpasses tetraphenylmethylenediphosphine dioxide and tetraalkyl-substituted analogs of I.     

Extraction and sorption preconcentration of U(VI), Th(IV), and REE(III) from nitric acid solutions using amine-substituted tetraarylethylenediphosphine dioxides

Extraction of U(VI), Th(IV), and REE(III) from HNO₃ solutions in the form of complexes with amine-substituted tetraarylethylenediphosphine dioxides was studied. The effect of substituents at the P atoms in the extractant molecule on its extraction ability was examined. The stoichiometry of the extractable complexes was determined. The possibility of preconcentration of U(VI), Th(IV), and REE(III) with the complexing sorbent prepared by noncovalent immobilization of the examined extractants on a polymer matrix was demonstrated.     

Extraction of Am(III) from Nitric Acid Solutions with Bis(diphenylphosphinylmethyl)phosphinic Acid

Extraction of trace quantities of Am(III) from aqueous HNO₃ solutions with solutions of bis(diphenylphosphinylmethyl)phosphinic acid (I), bis[2-(diphenylphosphinyl)phenoxymethyl]phosphinic acid (II), and bis[2-(diphenylphosphinylmethyl)phenoxymethyl]phosphinic acid (III) in dichloroethane was studied. The stoichiometry of the extractable complexes was determined; the effect of organic diluent on the extraction was considered. The extractive power of the reagents toward Am(III) grows in the order III < II < I. Acid I surpasses in the extractive power a neutral bidentate extractant, tetraphenylmethylenediphosphine dioxide (TPMDPD), by three orders of magnitude. A synergistic effect in extraction of Am with mixtures of TPMDPD and acid I was revealed.     

1,3-Bis[(diphenylphosphorylacetamido)methyl]benzene as reagent for extraction and sorption preconcentration of REE(III), U(VI), and Th(IV) from nitric acid solutions

The extraction of microamounts of REE(III), U(VI), and Th(IV) from HNO₃ solutions in the form of complexes with a polyfunctional neutral organophosphorus compound, 1,3-bis[(diphenylphosphorylacetamido)-methyl]benzene, was studied. The influence exerted by the structure of the bridge binding two carbamoylmethyl-phosphine oxide fragments on the efficiency of the extraction of REE(III), U(VI), and Th(IV) and on the stoichiometry of the extractable complexes was analyzed. The possibility of recovering and concentrating REE(III), U(VI), and Th(IV) from nitric acid solutions with a complexing sorbent prepared by noncovalent immobilization of 1,3-bis[(diphenylphosphorylacetamido)methyl]benzene on the surface of carbon nanotubes was examined.     

Extraction of U(VI), Th(IV), Pu(IV), and Am(III) from nitric acid solutions with polyfunctional organophosphorus acids

Extraction of microamounts of U(VI), Th(IV), Pu(IV), and Am(III) nitrates from aqueous HNO₃ solutions with solutions of (diphenylphosphinylmethyl)phenylphosphinic, (di-p-tolylphosphinylmethyl)phenylphosphinic, and (dioctylphosphinylmethyl)phosphinic acids and of butyl hydrogen (diphenylphosphinylmethyl)phosphonate in organic diluents was studied. The metal: extractant stoichiometric ratio in the extractable complexes was determined, and the diluent effect on the extraction efficiency was examined. The possibility of using a macroporous polymeric sorbent impregnated with (dioctylphosphinylmethyl)phenylphosphinic acid for concentrating metal ions from HNO₃ solutions was demonstrated.     

Extraction of U(VI), Th(IV), and REE(III) from nitric acid solutions with (N,N-dialkylcarbamoylmethyl)- and (N-alkylcarbamoylmethyl)phenylphosphinic acids

Extraction of microamounts of U(VI), Th(IV), and REE(III) from HNO₃ solutions with solutions of (N,N-dialkylcarbamoylmethyl)- and (N-alkylcarbamoylmethyl)phenylphosphinic acids in dichloroethane was studied. The stoichiometry of the extractable complexes was determined, and the influence exerted on the efficiency of the U(VI), Th(IV), and REE(III) recovery into the organic phase by the extractant structure, organic diluent, and aqueous phase composition was examined. The possibility of selective recovery and concentration of U(VI), Th(IV), and REE(III) from nitric acid solutions with a complexing sorbent prepared by noncovalent immobilization of the examined polyfunctional organophosphorus acids on a macroporous polymeric matrix was demonstrated.     

Extraction and sorption preconcentration of U(VI), Th(IV), and REE(III) from nitric acid solutions using bis[2-(diphenylphosphinyl)phenoxymethyl]phosphinic acid

Extraction of microamounts of U(VI) and Th(IV) from HNO₃ solutions in the form of complexes with polyfunctional organophosphorus acids was studied. The influence of the extractant structure on the efficiency and selectivity of the extraction of U(VI) and Th(IV) was examined, and the stoichiometry of the extractable complexes was determined. The possibility of preconcentration of U(VI), Th(IV), and REE(III) from nitric acid solutions with a complexing sorbent prepared by noncovalent immobilization of bis[2-(diphenylphosphinyl) phenoxymethyl]phosphinic acid on a macroporous polymeric matrix was demonstrated.     

Extraction of Am(III), U(VI), and Pu(IV) from HCl Solutions with Diphenyl(dibutylcarbamoylmethyl)phosphine Oxide

Extraction of Am(III), U(VI), and Pu(IV) from HCl solutions with solutions of diphenyl(dibutylcarbamoylmethyl)phosphine oxide in dichloroethane and m-nitrobenzotrifluoride was studied. The curves of the Am(III) and U(VI) extraction as a function of the acid concentration pass through a minimum at [HCl] = 1 M, followed by a steep ascent at the acid concentration increased further. The logarithmic dependences of the distribution factors on the extractant concentration are nonlinear, with the slope of the upper portions close to 2 for Am(III) and 1 for U(VI). Pu(IV) is extracted noticeably worse than U(VI). A significant anomalous aryl strengthening effect is observed in HCl solutions.     

Extraction of REEs(III), U(VI), and Th(IV) with acidic phosphoryl-containing podands from nitric acid solutions

The extraction of microamounts of REEs(III), U(VI), and Th(IV) from HNO₃ solutions with solutions of acidic phosphoryl-containing podands in 1,2-dichloroethane was studied. The stoichiometry of the extractable complexes was determined. The influence of the extractant structure and aqueous phase composition on the efficiency and selectivity of the recovery of REEs(III), U(VI), and Th(IV) into the organic phase was considered.     

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.     

Selectivity of extraction of U(VI), Th(IV), and REE(III) from perchloric acid solutions with bidentate phosphoryl-substituted butyl phenylphosphinates

Extraction of microamounts of U(VI), Th(IV), and REE(III) from HClO₄ solutions with solutions of bidentate phosphoryl-substituted butyl phenylphosphinates R₂P(O)CH₂P(O)Ph(OBu) [R = phenyl (I), octyl (II)] in dichloroethane was studied. The effect of substituents at the phosphorus atom in the phosphine oxide moiety of these compounds on their extraction ability and selectivity was examined, and the stoichiometry of the extractable complexes was determined. In going from nitric to perchloric acid solutions, the efficiency of the extraction of U(VI) and REE(III) considerably increases, the U/REE separation factors increase, but the Th/U separation factors decrease.     

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.     

Effect of Fe(III) on the extraction of U(VI), Th(IV), and REE(III) from HCl solutions with diphenyl(dibutylcarbamoylmethyl)phosphine oxide

The extraction of U(VI), Th(IV), and REE(III) from HCl solutions with solutions of diphenyl(dibutylcarbamoylmethyl)phosphine oxide in dichloroethane in the presence of Fe(III) was studied. An increase in the Fe concentration in the organic phase leads to a considerable increase in the distribution ratios of U(VI), Th(IV), and REE(III), which is caused by transfer into the organic phase of mixed complexes MCl _m?n (FeCl₄) _n solvated by the extractant molecules. A macroporous styrene-divinylbenzene copolymer impregnated with diphenyl(dibutylcarbamoylmethyl)phosphine oxide can be used for concentrating U(VI), Th(IV), and REE(III) from HCl solutions in the presence of Fe(III).