Extraction of Am(III) by mixture of dihexyl N,N-diethylcarbamoylmethyl phosphonate and tributyl phosphate in benzene from nitric acid solutions

Extraction of Am(III) by dihexyl N,N-diethylcarbamoylmethyl phosphonate (CMP) in benzene from nitric acid solutions (pH 2.0 to 6.0M) has been studied. High extraction of Am(III) by CMP from 2–3M HNO₃ was observed. The species extracted was found to be Am(NO₃)₃·3CMP. The extraction was also done with mixtures of CMP+TBP and CMP+TOPO, where mixed species were extracted in the organic phase. The back-extraction experiments gave an efficient back-extraction of Am(III) by pH 2.0 (HNO₃) from the loaded CMP+TBP phase but a poor back-extraction from the loaded CMP+TOPO phase. The loading of Nd(III) by mixture of CMP and TBP was 50% of the CMP concentrations at a total Nd(III) concentration of 0.182M. The thermodynamic parameters of Am(III) extraction by a mixture of CMP and TBP were evaluated by temperature variation method, which suggests that the two-phase reaction is stabilized by enthalpy and opposed by entropy.     

Extraction of tri- and tetravalent actinides with dihexyl N,N-diethylcarbamoylmethyl phosphonate (DHDECMP) and TBP from nitric acid solutions

Extraction of trivalent (Pu³⁺, Am³⁺, actinides and Eu³⁺, a representative of lanthanides) and tetravalent (Np⁴⁺ and Pu⁴⁺) actinides has been studied with dihexyl N,N-di-ethylcarbamoylmethyl phosphonate (DHDECMP) in combination with TBP in benzene from 2M nitric acid. The stoichiometries of the species extracted were found to be M(NO₃)₃·(3–n) TBP·n DHDECMP (for trivalent ions) and M(NO₃)₄·(2–n) TBP·n DHDECMP (for tetravalent ions) by the slope ratio method. The extraction constants evaluated (from the distribution data) indicate that for tetravalent ions (with solvation number two) the extraction constant increases when TBP (Kh=0.17) molecules are successively replaced by more basic DHDECMP (Kh=0.34) molecules. However, for trivalent ions (with solvation number three) when TBP molecules are totally replaced by DHDECMP molecules stereochemical factors appear and instead of increase, a substantial decrease in extraction constants is observed for Eu³⁺ and Am³⁺, a lesser decrease being observed for Pu³⁺ (larger ion).     

Extraction of ruthenium(III) by dihexyl sulfoxide from hydrochloric solutions

The extraction of ruthenium(III) by dihexyl sulfoxide (DHSO) from hydrochloric solutions is studied. Ruthenium(III) is first extracted by a hydration/solvation mechanism followed by the incorporation of extractant molecules into the inner coordination sphere of the ruthenium(III) ion. The composition of the extracted compound is suggested proceeding from the resuls of electronic, ¹H NMR spectroscopy, IR spectroscopy, and elemental analysis.     

Extraction of Eu(III) and Co(II) by dihexyl N,N-diethyl carbamoyl methyl phosphonate (DHDECMP) and thenoyl trifluoroacetone (HTTA)

The extraction of Eu(III) has been carried out from nitrate solutionusing DHDECMP. Different parameters affecting the distribution of metal ionhave been studied. The distribution of Eu(III) was found to be first orderdependent on pH and second order with respect to [DHDECMP]. DHDECMP showedhigh stability towards -radiation dose up to 26.5 megarad. The extractionof Co(II) by either DHDECMP or HTTA from acetate solution showed that it issecond order dependent on both the extractant concentration and the pH. Basedon the data of the distribution ratio obtained and the calculated thermodynamicparameters; reaction mechanisms are suggested.     

Extraction of iridium(IV) by dihexyl sulfoxide from hydrochloric acid solutions

The extraction of iridium(IV) by dihexyl sulfoxide from hydrochloric acid solutions was studied. Optimum conditions for the extraction of iridium(IV) were determined. It was found that an ion-association mechanism of iridium(IV) extraction took place in the test extraction systems at a phase contact time of 10 min. As the phase contact time was increased, the extraction took place by a mixed mechanism. One extractant molecule was incorporated into the inner coordination sphere of the iridium(IV) ion. This decreased the charge of the extracted complex to unity.     

Extraction of Dy(III) with N,N,N',N'-tetrabutylmalonamide

The extraction behavior of N,N,N',N'-tetrabutylmalonamide (TBMA) employing toluene as diluent toward Dy(III) has been investigated. The effect of the concentrations of nitric acid, lithium nitrate and extractant and also of the temperature on the distribution ratio has been studied. The stoichiometry found for the Dy(III) extracted species suggests a structure such as Dy(NO₃)₃ ^.3TBMA. An attempt has been made to establish the structure of the isolated extracted species recurring to the data of IR.     

Solvent extraction of yttrium(III) by TBP from acidic organic-aqueous solutions

Extraction by benzene solutions of TBP of carrier-free⁹⁰Y(III) from mixed aqueous-organic nitrate and perchlorate solutions was studied with special respect to the S-shaped D_Y versus acid concentration plots observed in aqueous systems. The presence of organic solvents in the aqueous phase enhanced the extraction of Y(III) and also influenced the shape of the D_Y vs. acid concentration plots in that the minimum was shifted towards lower acid concentration, became less pronounced, and eventually vanished completely.     

Extraction of protactinium(V) with 2-thenoyltrifluoroacetone from strongly acidic solutions

The extraction of Pa(V) from strongly acidic solutions of mineral acids is carried out with benzene solution of thenoyltrifluoroacetone. To interpret the data obtained, two extraction mechanisms representing the descending and ascending parts of the extraction curves are suggested. At lower acidity, the formation of PaO(TTA)₃·HTTA species predominates. In going to higher acidity, an ion-pair formation between anionic protactiniuminorganic complex species and H₂ TTA⁺ cation is assumed.     

Extraction of Am(III) in the presence of lanthanides and yttrium by benzyldimethyldodecylammonium nitrate from acidic nitrate solutions

We have investigated the effect of coextraction of lanthanides and yttrium on the distribution coefficients D_Am in the extraction of americium by benzyldimethyldodecylammonium nitrate (BDMLNNO₃) from nitrate solutions. In the coextraction of lanthanides, the extraction of Am(NO₃)₃ is suppressed, which is markedly manifested in the extraction of light lanthanides (La, Ce, Pr); of the series of lanthanides their extraction is the highest. The effect of nitric acid and the possibility of separation of lanthanides and americium by the application of three-stage multiple extraction is discussed.     

The complexation of (N,N-diethylcarbamoylmethyl)diphenylphosphine sulfide with silver nitrate

The crystalline complex [Ag(L ¹)NO₃]₂ (A) was isolated by the interaction of (N,N-diethylcaibamoylmethyl)diphenylphosphine sulfide Ph₂P(S)CH₂C(O)NEt₂ (L ¹) with AgNO₃ in different solvents at the ratios of metal:ligand = 11 and 12. According to the X-ray data, complexA is a center-symmetric dimer with bridge sulfur atoms. The cations of the metal are in a tetrahedral environment formed by two S atoms and the O atoms of CO and NO₃ groups. The interaction ofL ¹ with AgNO₃ was studied in solution by IR spectroscopy, and the structures of the complexes formed are discussed.Translated fromIzvestiya Akademii Nauk. Seriya Khimicheskaya, No. 4, pp. 708–713, April, 1994.The authors are grateful to B. V. Lokshin and his coworkers for help in measurement of the Raman spectra and for useful discussion.The present investigation was financially supported by the Russian Foundation for Basic Research (Project 93-03-4351).     

Extraction of indium(III) from sulfate solutions with organophosphorus acids

Extraction of indium(III) from sulfuric acid solutions with di-2-ethylhexyl hydrogen phosphate and isododecylphosphethanic and diisooctylphosphinic acids was studied. The effect of H₂SO₄ and In(III) concentrations in the aqueous phase, type and concentration of the extractant in the organic phase, temperature, and time of phase contact on the extraction of In(III) and impurity metal ions was considered. The In(III) extraction constants were estimated.Translated from Zhurnal Prikladnoi Khimii, Vol. 77, No. 10, 2004, pp. 1625–1629.Original Russian Text Copyright © 2004 by Travkin, Kubasov, Glubokov, Busygina, Kazanbaev, Kozlov.     

Extraction of rhodium(III) with sulfoxides from hydrochloric acid solutions

Extraction of rhodium(III) from hydrochloric acid solutions with dihexyl sulfoxide (DHSO) and with petroleum sulfoxides (PSOs) was studied, and the optimal conditions for its recovery were found. At a phase contact time of up to 0.5 h, the extraction of rhodium(III) with sulfoxides occurred mainly by an ionassociation scenario. If the phase contact time exceeds 0.5 h, a mixed extraction scenario predominated to form the extracted complexes (L · H⁺) · [RhCl₄L₂]-(DHSO)_o and PSO (LH⁺) · [RhCl₄(H₂O) · L]⁻. The protonation of the extraction agents occurred at the donor oxygen atoms of the sulfoxide group. When rhodium was extracted with PSOs, the coordination of the extractant molecule in the inner coordination sphere of the acido complex to the metal ion occurred through the donor sulfur atom of the sulfoxide group, while with the use of DHSO, through the donor atoms of sulfur and oxygen of the sulfoxide group. Electronic, ¹H NMR, and IR spectroscopy and elemental analysis were used to determine the composition of the extracted compounds and suggest their structure.     

Extraction of Ce(III) with naphthenic acid from nitrate solutions

Extraction of Ce(III) with naphthenic acid from nitrate solutions was studied. The composition of solvation complexes, extraction constants, and Gibbs energies of extraction were found from the dependences of the distribution coefficients on pH and compositions of the aqueous and organic phases.     

Extraction of uranium(VI) and thorium(IV) ions from nitric acid solutions by N,N,N′,N′-tetrabutyladipicamide

A new symmetrical diamide, the straight-chain alakyl substituted neutral tetrabutyladipicamide (TBAA) has been synthesized, characterized and used for the extraction of U(V) and Th(IV) from nitric acid solutions in a diluent composed of 50% 1,2,4-trimethylbenzene (TMB) and 50% kerosene (OK). Extraction distribution coefficients of U(VI) and Th(IV) as a function of aqueous nitric acid concentration, extractant concentration and temperature have been studied. Back-extraction of U(VI) and Th(IV) from organic phases by dilute nitric acid has been undertaken. From the data, the compositions of extracted species, equilibrium constants and enthalpies of extraction reactions have also been calculated.     

Dibutyl N,N-dibutylcarbamoylmethylphosphonate extraction of Eu(III) from perchlorate and nitrate solutions

Dibutyl N,N,-dibutylcarbamoylmethylphosphonate (DBDBCMP) has been used in the extraction study of Eu(III) from low acidic solutions. The different parameters affecting the distribution ratio have been studied. The reaction is considered as a chelate interaction and the extracted species are Eu(OH)₂ DBDBCMP·2HDBDBCMP and Eu(NO₃)₂ DBDBCMP. HDBDBCMP from perchlorate and nitrate, respectively. The equilibrium constants corresponding to the different species formed are calculated and discussed. The effect of changing diluent on extraction capacity of the phosphonate is also studied and discussed.     

Extraction of rhodium(III) with petroleum sulfoxides from hydrochloric acid solutions

Extraction of rhodium(III) from hydrochloric acid solutions with petroleum sulfoxides was studied. The optimal conditions of its recovery were found. The composition and structure of the compound being extracted was determined by electronic absorption, ¹H NMR, and IR spectroscopies and elemental analysis.     

Extraction of lanthanides(III) by phosphorylated naphthyridine ligands from carbonate solutions

The extraction capacities and selectivities of 1,8-naphthyridine-based neutral organophosphorus reagents in extracting trivalent lanthanides (Ln, Nd, Ho, Yb) from carbonate solutions were studied. The length and nature of the linker between the naphthyridine and phosphoryl moieties were found to have considerable influence on the efficiency and selectivity of lanthanide extraction.     

Radiochemical extraction of mercury(II) from acidic chloride solutions using dialkylsulphides

The liquid-liquid extraction behavior of Hg(II) from aqueous acidic chloride solutions has been investigated by tracer techniques using dialkylsulphides (R₂S) namely, dibutylsulphide (DBS) and dioctylsulphide (DOS) as extractants. These extraction data have been analyzed by both graphical and theoretical methods by taking into account complexation of the metal ion in the aqueous phase with inorganic ligands and all plausible complexes extracted into the organic phase. The results clearly indicate that Hg(II) is extracted into xylene as HgCl₂ ^. nDBS/nDOS (where n = 2 and 3). The equilibrium constants of the extracted complexes have been deduced by non-linear regression analysis. The separation possibilities of Hg(II) from other metal ions viz. Ca(II), Mg(II), Ba(II) and Fe((III), which are present in the industrial wastes of the chlor-alkali industry has also been discussed.     

Extraction kinetics of iron(III) from aqueous nitrate solutions to toluene solutions of tri-n-butylacetohydroxamic acid

The forward and reverse extraction rate of Fe³⁺ at time zero between aqueous nitrate solutions and toluene solutions of tri-n-butylacetohydroxamic acid, HX, has been studied as function of the composition of the system and the stirring speed of the two phases. Experimental information has been also obtained on the degree of aggregation of HX, its surface active properties, its solubility in the aqueous phase as well as on the equilibrium distribution of Fe(III). Rate equations have been derived. The rate determining step of the extraction reaction has been shown to be the reaction of the free and hydrolyzed iron ions, Fe³⁺ (hydrated) and FeOH⁺ (hydrated), with the HX undissociated molecules. The reactions occur simultaneously in the aqueous phase (homogeneous path) and at the interface (heterogeneous path). A correlation between the rate constants and the equilibrium constant of the extraction reaction of Fe(III) has been established.     

Phosphonium ionic liquids as extractants for recovery of ruthenium(III) from acidic aqueous solutions

The aim of this work is to investigate extraction of ruthenium(III) from acidic aqueous solutions with phosphonium ionic liquids such as trihexyl(tetradecyl)phosphonium chloride (Cyphos IL 101), trihexyl(tetradecyl)phosphonium bis(2,4,4-trimethylpentyl)phosphinate (Cyphos IL 104) and tributyl(tetradecyl)phosphonium chloride (Cyphos IL 167) as extractants. The influence of HCl content in the feed solutions on extraction of Ru(III) was investigated. The research was performed for model solutions containing Ru(III) and a mixture of waste solutions containing Ru(III) and Rh(III). In addition, investigation of the type of extractant and its concentration in the organic phase on extraction of Ru(III) was carried out. Co-extraction of protons to the organic phase was determined. To the best of our knowledge, the extraction of Ru(III) with Cyphos IL 167 (tributyl(tetradecyl)phosphonium chloride) as an extractant has not yet been described in the scientific literature.