THE EXTRACTION OF NEPTUNIUM(V) BY METHYLTRIOCTYLAMMONIUM CHLORIDE AND 1-PHENYL-3-METHYL-4-BENZOYL-5-PYRAZOLONE

The synergistic effect of methyltrioctylammonium chloride (QCI) on the extraction of Np(V) by 1-phenyl-3-methyl-4-benzoyl-pyrazolone(HP) in benzene is studied over the pH range 2-6. This system extracts Np(V) better than any previously reported. The interaction of the extractants and monomer-dimer equilibria affect the distribution behavior of Np(V) in a complicated manner. Analysis of the results suggests that NpO₂ ⁺ (M⁺) is extracted as mixed dimers, (QMP₂QCl)_o and (QMP₂QP)_o.     

SOLVENT EXTRACTION OF URANIUM(VI) AND THORIUM(IV) WITH A TETRA-CARBOXYLATED CALIX[4]ARENE AND EFFECT OF ALKALI IONS (Na+, K+)

ABSTRACT

The solvent extraction of uranium(VI) and thorium(IV) with a tetra-carboxylated calix[4]arene (LH₄) in chloroform has been studied in the presence or absence of alkali ions (M⁺=Na⁺, K⁺). When studied alone, UO₂ ²⁺ and Th⁴⁺ were extracted into chloroform as 2:2 and 1:1 metal:ligand complexes, respectively. The efficiency of extraction increases in the presence of alkali ions, due to the formation of heteronuclear complexes. For uranium(VI), the extracted species are found to be both 2:2:2 and 1:1:1 (uoi₂ ²⁺:M⁺:LH₄,) mixed complexes. For Th(IV) in the presence of Na⁺, the formation of a mixed complex in 1:1:1 (Th(IV):Na⁺:LH₄,) proportions has been evidenced. However, the exact nature of this species could not be determined. In practical grounds, LH. may be useful as a selective extracting agent for Th(IV) with respect to U(VI) since separation factor Th(IV)/U(VI) close to 1000 have been measured in competitive extraction, in the presence or absence of alkali ions.     

EXTRACTION AND SEPARATION OF ZIRCONIUM(IV) WITH 3-HYDROXY-2-METHYL-1-PHENYL-4-PYRIDONE

ABSTRACT The extraction of zirconium(IV) from aqueous hydrochloric, sulphuric and perchloric acid solutions with 3-hydroxy-2-methyl--1-phenyl-4-pyridone (HX) dissolved in chloroform is described. Perchlorate and thiocyanate ions show a synergistic effect on zirconium extraction with HX. The synergistic effect of thiocyanate is stronger than the effect of perchlorate.

The composition of the extracted zirconium(IV) complexes is studied and a simple and rapid method for the separation of zirconium from niobium is described.     

SYNERGISTIC SOLVENT EXTRACTION OF LANTHANIDES WITH MIXTURES OF 1-PHENYL-3-METHYL-4-BENZOYL-PYRAZOL-5-ONE AND ALIQUAT 336

The solvent extraction of Pr(III),Gd(III) and Yb(III) With 1-phenyl-3-methyl-4-benzoyl-pyrazol-5-one (HP) and Aliquat 336(QCl) in CCl₄.C₆H₆ and CHCl₃, has been studied.The composition of the extracted species has been determined as LnP₄ ^?.Q⁺ (Ln=Pr,Gd and Yb).The values of the equilibrium constants have been calculated. The extraction mechanism has been discussed.     

SOLVENT EXTRACTION OF SOME TERVALENT LANTHANOIDS WITH 4-ACYL-3-PHENYL-5-ISOXAZOLONES

ABSTRACT

The solvent extraction of some tervalent lanthanoid ions (Ln³⁺) with five 4-acyl-3-phenyl-5-isoxazolones (AcyPI or HL),i.e. 4-acetyl-, 4-benzoyl-, 4- (4-toluoyl)-, 4- (4-fluorobenzoyl) - and 4-(4-nitrobenzoyl)-3-phenyl-5-isoxazolones (API,BPI, TPI, FBPI and NBPI respectively) into benzene was studied in the presence of tri-n-butylphosphate (TBP). The extracted species were (Ln³⁺) (L^-)₃ (TBP)₂ for AcyPI.     

SOLVENT EXTRACTION OF SOME LANTHANIDES WITH MIXTURES OF 1-PHENYL-3-METHYL-4-BENZOYL-FYRAZOL-5-ONE AND 1-(2-PYRIDYLAZO)-2-NAPHTOL

The solvent extraction of Pr(IIl),Gd(III) and Yb (III) with 1-phenyl-3-methyl-4-benzoyl-pyrazol-5-one (PMBP,HP) and with mixtures of PMBP and 1-(2-pyridyl-azo)-2-naphtol(PAN,S) in-CCI?4?,C?6?H?6? and CHCI?3?, has been studied..The composition of the extracted complexes has been determined as LnP?3?.HP and LnP?3?.S(Ln=Pr,Gd and Yb) The values of the equilibrium constants have been calculated.Weak synergistic effects were found when the metals were extracted with mixtures of the extractants     

THE EFFECT OF TEMPERATURE ON THE SYNERGISTIC EXTRACTION OF THORIUM( IV) AND URANIUM( VI) BY 2-ETHYLHEXYL PHENYLPHOSPHONIC ACID AND MICELLES OF DINONYL NAPHTHALENE SULPHONIC ACID

ABSTRACT

The influence of temperature in the range 15 to 75° C on the extraction of thorium( IV) and uranium( VI) from nitric acid solutions into ligroine solutions of 2-ethylhexyl phenylphosphonic acid ( HEHφ P) micellar dinonyl naphthalene sulphonic acid ( HDNNS) extractants and mixture of the two extractants is reported. From the variation of the distribution ratio with temperature, the enthalpy changes associated with the extraction were determined, and an attempt was made to estimate the free energy and entropy changes associated with the extraction process. The results indicate that the extraction of thorium is favored by both entropy change and enthalpy change when the solvent is HEHφ P and the mixture of HEHOP and HDNNS, but entropy controlled when HDNNS is the extractant. On the other hand, the extraction of uranium by HEHφ P is enthalpy controlled but favored by entropy change when the solvent is HDNNS or a mixture of the two ligands. Temperature did not affect the extraction stoichiometry.     

SYNERGIC EXTRACTION OF DIVALENT TRANSITION METALS WITH MIXTURES OF 1-PHENYL-3-METHYL-4 BENZOYL- PYRAZOL-5-ONE AND CROWN ETHERS IN PRESENCE OF ALKALI OR ALKALINE EARTH IONS

The extraction of divalent transition metals (M = Cu, Zn, Co, Cd) with mixtures of 1-phenyl-3-methyl-4-benzoylpyrazol-5-one (HL) and crown-ethers (E = B15C5, 18C6, DC18C6, DB18C6, DC24C8, DB24C8 with B = benzo, DB = dibenzo, DC = dicyclohexyl) in chloroform has been studied. From 1.0 M K aqueous solutions, EK.ML₃ ion pairs have been extracted with 18C6 - type crown ethers that have a good correspondence between their cavity size and the K⁺ diameter, _and with M = Co and Cd, metals with a higher stability of the ML- anion. With B15C5, which has a cavity size too small to accomodate K⁺, the synergic extraction of Co is explained by the formation of E₂.K.CoL₃. Both CoL₂E and EBa(CoL₃.) ₂ (E = DBl8C6)were extracted from 0.33M Ba(No₃ ) ₂. In all otHer experiments - extractions from 1.0M LiCl, NaCl, NaNO with B15C5     

EXTRACTION AND COMPLEX FORMATION OF PLUTONIUM(IV) WITH 1-PHENYL-2-METHYL-3-HYDROXY-4-PYRIDONE

Abstract

At a ionic strength of 1.0 and mineral acid concentrations of 0.1 to 1M, l-phenyl-2-methyl-3-hydroxy-4-pyridone (HX, 0.001 to 0.01M in chloroform) extracts plutonium(IV) effectively from nitrate solutions, somewhat less effectively from perchlorate solutions and markedly less effectively from chloride solutions. The extractant distributes between the phases in a monomeric form, as an undisso-ciated molecule and a cationic species. The stoichiometries of the complexes extracted from the respective ionic media are PuX₂(NO₃)₂, PuX₃(Clo₄)₂HX and PuX₂(Clo₄)₂.HX, and PuX₂Cl₂.     

EXTRACTION OF HEAVY METAL IONS WITH 3-[(DIOCTYLAMINO)METHYL]ALIZARIN

3-[(Dioctylamino)methyl]alizarin (C₈AL), which is endowed with high solubility in nonpolar organic solvents through introduction of dioctylaminomethyl group into the alizarin nucleus was studied for extracting heavy metal ions such as Cu(II), Zn(II), Cd(II), Co(II), Mn(II), and Ni(II), from aqueous solution.Cu(II) was most readily extracted into chlorobenzene at low pH and thus was separated from other metal ions. The metal ions stabilized in alkaline solution in the presence of water-soluble chelating agents were found to be extracted by this, alizarin-type extraction agent into chlorobenzene with the assistance by lipophilic quaternary ammonium salt, Capriquat? (methyltrioctylammonium chloride, Q^?C1^?).The proton dissociation process of CRAL was studied, and the mechanism of these metal extractions was discussed.The separation of Cu(II) and Ni(II) from the mixture with other divalent metal ions was also studied.     

DILUENT AND EXTRACTANT EFFECTS ON THE ENTHALPY OF EXTRACTION OF URANIUM(VI) AND AMERICIUM(III) NITRATES BY TRIALKYL PHOSPHATES

ABSTRACT

The effect of various diluents such as n-hexane, n-heptane n-octane, isooctane, n-decane, n-undecane, n-dodecane, n-tetradecane, n-hexadecane, cyclohexane, benzene, toluene, p-xylene, mesitylene and o-dichlorobenzene on the enthalpy of extraction of uranyl nitrate by tri-n-amyl phosphate (TAP) over the temperature range 283 K - 333 K has been studied. The results indicate that the enthalpy of extraction does not vary significantly with the diluents studied. Also enthalpies of extraction of uranyl nitrate and americium(III) nitrate by neutral organo phosphorous extractants such as tri-n-butyl phosphate (TBP), tri-n-amyl phosphate (TAP), tri-sec-butyl phosphate (TsBP), tri-isoamyl phosphate )TiAP) and tri-n-hexyl phosphate (THP) have been studied. An attempt has been made to explain the trends, on the basis of the nature of the solvate formed and the different terms which contribute to the overall enthalpy change.     

SOLVENT EXTRACTION OF METALS WITH 4-DINITROBENZOYL-2, 4-DIHYDRO-5-METHYL-2-PHENYL-3H-PYRAZOL-3-ONE (DMPP)

ABSTRACT

The mechanism of the extraction of copper (II), nickel (II), cobalt (II) and thorium (IV) from aqueous buffer media with 4-dinitrobenzoyl1-2, 4-dihydro-5-methyl-2-phenyl-311-pyrazol-3-one (DMPP) in benzene has been investigated. The values of log K^*where K^*refers to the extraction equilibrium Mn⁺+-nHL ? MD_n+ nH⁺are Cu(II)& lpar; + 0.3), Co(II) (?6.65), Ni(II) (?5.04) and Th(IV) ( + 6.1). Solid complexes synthesized have the composition CuL₂· 2H₂O, NiL₂· 2H₂O and ThL₄respectively (L = anion of the ligand). DMPP seems to be superior to the corresponding 4-benzoyland 4-nitrobenzoyl derivatives of 2,4-dihydro-5-methyl-2-phenyl1-3 H-pyrazol1-3-one (MPP) and also better than thenoyltrifluoroacetone, the popularly employed fluorinated β-dike tone in the system investigated.     

SYNERGISTIC EXTRACTION OF CADMIUM AND ZINC WITH 1-PHENYL-3-METHYL-4-BENZOYLPYRAZOL-5-OL AND n-DODBCYLAMINE MIXTURES,EMULSION FORMATION.

The synergistic extraction of zinc and cadmium (M^2*) from sulphate, nitrate and perchlorate media with mixtures of 1-phenyl-3-methyl-4-benzoylpyra2ol-5-ol (HL) and n-dodecylammoniura salts (DDAH^*,X^?) in toluene has been studied. In sulphate medium, the lipophilic ammonium pyrazololate (DDAK^*L^?) is the predominating ammonium species : the synergy observed can be considered as the addition of (DDAH^*,L^?) on HL₂ perchlorate and nitrate media, the amphiphilic ammonium salts {DDAH^*, CIO₄?) and (DDAH⁺N0₃ ^?) predominate, leading to the formation of an aqueous emulsion in equilibrium with a clear organic phase. Metal distribution curves show that the formation of the lipophilic synergistic species (DDAH⁺ML₂ ^?) results from a X^?/ML₃ ^? exchange in the interfacial region between the aqueous and the organic phase. The addition of n-octanol or 4-nonylphenol in the organic phase turns the emulsion into a micro-emulsion whereas the substitution of toluene by chloroform largely decreases the emulsion stability.     

SOLVENT EXTRACTION OF HAFNIUM( IV) WITH 3-HYDR0XY-2-METHYL-1-PHENYL-4-PYRIDONE

The extraction of hafnium(IV ) from aqueous hydrochloric, sulphuric and perchloric acid solutions with 3-hydroxy-2-methyl--1-phenyl-4-pyridone(HX) dissolved in chloroform is described. Perchlorate and thiocyanate ions show a synergistic effect on hafnium extraction with HX. Hafnium can be quantitatively extracted with HX from more acidic solutions and with less excess of HX if the extraction is carried out from a hydrochloric, sulphuric or perchloric acid solution containing an excess of perchlorate or thiocyanate ions. A mixed Hf-NCS-HX complex is more stable than a mixed Hf-ClO₄-HX complex and thiocyanate ions show a stronger synergistic effect than perchlorate ions.     

EXTRACTION OF INDIUM( III) FROM BROMIDE AND THIOCYANATE MEDIA WITH 1-PHENYL-3-HETHYL-1-BENZOYLPYRAZOL-5-ONE; EFFECT OF LIPOPHILIC AMMONIUM SALTS

1-phenyl-3-methyl-4-benzoylpyrazol-5-one (HL) in toluene extracts In(III) from ClO₄ ^?, (Br^?, CIO ClO₄ ^?, ) and Br^? media according to the extraction equilibria (1) and (2). Tri-n-octylmethylammonium bromide (B⁺Br^?) induces a medium synergic effect for Br^? and (Br^?,NO₃ ^?) media, which is cancelled in ClO₄ ^?medium. It corresponds to the extraction of (B⁺InBr_xL_4-x) ion pairs. On the contrary, from SCN^? or (SCN^?,ClO₄ ^?) media, In is extracted by HL according to only (1) and no synergism is obtained with tri-n-octylammonium salt.

These results are compared with those obtained with Cl^? and (C1^?,ClO₄ ^?) aqueous media. They are to a great extent explained by taking into account the complexing of In³⁺ by aqueous inorganic anions, the lipophilicity of the diverse species and the anionic exchanges in the B⁺X^? ion pairs.     

NEW XANTHIC ACID DERIVATIVES AS POTENTIAL REAGENTS IN THE SOLVENT EXTRACTION OF PRECIOUS METAL IONS: EXTRACTION OF PALLADIUM(II) WITH 13-BIS(0-BUTYLXANTHATO)PROPANE

ABSTRACT

Two series of new xanthic acid derivatives namely, the bis (O-butylxanthato) alkanes ( abbreviated as BBXAs or simply as bis-xanthates in this paper) have been synthesized in connection with the solvent extraction of precious metal ions. From an aqueous medium containing 0.1 M NaC10₄ (1 M=l mol dm^-3), these compounds exhibited high selectivity for extraction of Pd(II) and Ag(I) in dichloroethane, over most of the base metals as well as Pt(IV) and Au(III) ions. Towards Pd(II) and Ag(I) ions, the bis compounds act as SS chelating agents where the stabilities of the extractable complexes are determined by the length of the alkylene chain existing between the donor atoms. Pd(II) extraction has been studied in detail taking 13-bis(O-n-butylxanthato)propane (BnBXP) as the representative member of the series of bis-xanthates synthesized in this work. The extraction of palladium(II) was found to be quite slow in pure chloride medium. But, a mixed acid medium containing H₂SO₄ or HNO₃ in the presence of smaller amount of chloride ion provided optimum reversible extraction of palladium in dichloroethane, where Pd(II) forms 1:1 extractabic complexes with BnBXP. Pd(II) extraction is described in terms of the aqueous phase compositions, extraction and back-extraction data, extraction equilibrium, selectivity considerations and probable mechanisms of extraction.     

金属离子对溴碘化银乳剂微晶体的掺杂效应——Ⅰ.Fe~(3+)的掺杂

应用常规感光测定法、电镜法、介电损耗仪和微波光导仪研究了Fe~(3+)对卤化根乳剂微晶的掺杂效应,结果表明:Fe~(3+)使卤化银乳剂的感光度降低,灰雾降低,而反差变化不大。电镜观察和介电损耗测量表明:Fe~(3+)在物理成熟过程中对乳剂颗粒大小和离子电导率的影响不大,而微波光导数据表明,掺杂对电子电导的影响是明显的。上述结果表明:在AgBr中,Fe~(3+)起了深的电子陷阱作用,使光电子徙动路程缩短,影响潜影的形成效率。     

POLYNITROGEN REAGENTS,IN METAL SEPARATION. PART 5 THE EXTRACTION OF URANIUM(VI) FROM SULPHURIC,NITRIC AND HYDROCHLORIC ACID MEDIA WITH ALKYLDIAMHONIUM EXTRACTANTS.

ABSTRACT

A variety of a1kyldiammonium extractants (tertiary and quaternary) were used to extract uranium(VI) from sulphuric, nitric and hydrochloric acid media. The performance of these extractants was compared with that of Aliquat-336 and Alamine-336. Extractions from dilute uranium(VI) solutions were carried out in order to simulate conditions employed in the local mining industry     

THE EQUILIBRIUM REACTION OF THE EXTRACTION OF URANIUM(VI) WITH DI-(2-ETHYLHEXYL) PHOSPHORIC ACID FROM NITRIC ACID SOLUTIONS

The equilibrium reactions for the extraction of uranium(VI) with di(2-ethylhexyl)phosphoric acid from nitric acid solutions is investigated. In this work, proton NMR technique was used to verify that the nitrate ligand in the resulting complexes originated from the complexing of nitric acid. Organic solutions of 0.05 M (dimeric HDEHP, the upper bar denotes the species in the organic phase) in kerosene were used to extract aqueous solutions containing various concentrations of uranyl nitrate and nitric acid. The concentrations of nitric acid and uranium(VI) in the organic phase were measured, and used to determine the composition of the resulting complex. Which were found to be varied with the uranium(VI) loading and the nitric acid loading of HDEHP. Parallel reactions of forming UO were proposed to describe this extraction system. The proposed reactions elucidate the equilibrium behavior consistently, for the loadings of uranium(VI) and nitric acid ranging from very low value to the vicinity of saturation.     

THE EFFECT OF TRIOCTYLPHOSPHINE OXIDE ON PHASE AND EXTRACTION EQUILIBRIA IN SYSTEMS CONTAINING BIS( 2,4,4-TRIMETHYLPENTYL) PHOSPHINIC ACID

The metal extractant Cyanex© 272 contains bis(2,4,4-trimethylpentyl)-phosphinic acid (BTMPPA) as the main component and trioctylphosphine oxide as an impurity. As-received Cyanex 272 and pure BTMPPA were observed to significantly differ in respect to both their phase behavior during saponification and to their copper extraction ability. The differences were elucidated by investigating the effects of an addition of small amounts of tri(n-octyl)phosphine oxide (TOPO) on the phase equilibria in the system Water(2.4M NaOH)/BTMPPA/n-Hexane at 25?°C as well as in the system Water(2.4M NaOH)/BTMPPA at various temperatures. In the absence of TOPO a large microemulsion region and a small region of lyotropic liquid crystalline phase with lamellar structure are formed. When TOPO is added into the system the lamellar phase gradually disappears. The effects of TOPO on metal extraction equilibria were studied by measuring the distribution of copper(II) between a perchloric acid solution and a BTMPPA in chloroform solution in the presence and absence of tri(n-octyl)phosphine oxide.