SOLVENT EXTRACTION OF SOME TERVALENT LANTHANOIDS WITH SALICYLALDEHYDE n-ALKANOHYDRAZONES

Sal icylaldehyde n-alkanohydrazones (SAAH or H₂L) having 1 to 13 carbon atoms in their alkyl chains were synthesized and used for the extraction of some lanthanoid ions (Ln³⁺) including praseodymium, europium and ytterbium ions from aqueous solutions containing both tri-n-butyIphosphate (TBP) and perchlorate into I,2-dichloroethane The extracted species were (Ln³⁺) (HL-)₂(TBP)₃(C10₁,-) for all SAAH. The partition coefficients, Kd, of SAAH increased with an increase in the carbon number of the alkyl chain, the increment of log Kb being 0.64 per a carbon atom. The acid dissociation constants of SAAH also increased slightly with an increase in the carbon number, but the extraction constants of their lanthanoid complexes were almost independent of the length of the alkyl chain.     

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.     

EXTRACTION AND SEPARATION OF LANTKANIDE METALS WITH 2-(3,5-DIBROMO-2-PYRIDYLAZO)-5-DIETHYLAMINOPHENOL

A study of the equilibrium extraction behavior of a series of representative tervalent lanthanide ions, La, Pr, Eu and Yb, was conducted using a CC1 solution containing either 2-( 3, 5-dibromo-2-pyridyxazo) -5-di-ethyl-aminophenol (DBPADAP or HL) alone or combined with TOPO. With HL,the lanthanides are extracted as simple chelates LnL?. In the presence of both HL and TOPO, the extracted species may be Ln(OH)L₂(TOPO).. Solvent extraction equilibrium constants of the lan-thanide-DBPADAP complexes are reported. the extractant, DBPADAP, displays good selectivity for the lighter lanthanides.     

SOLVENT EXTRACTION OF CERTAIN TERVALENT LANTHANIDES WITH OXINE IN THE PRESENCE OP 4,4'-DI-(5-NONYL)-2-2'-BIPYRIDINE

Extraction behavior of certain tervalent lanthanides with chloroform solutions which contain 8-quinolinol (oxine), (HQ) and 4,4'-di(5-nonyl)-2,2'-bipyridine (DNBP) was studied. The stoichiometry, extraction constants and separation factors were determined. Yb, Ho, Eu and Pr are extracted as mixed adduct compounds, LnQ₃·HQ·DNBP, whereas La is extracted as a simple compound, LaQ₃. A difference between DNBP and 1,10-phenanthroline (phen) is the number of neutral oxine molecules In the extracted species. In oxine-phen systems, the extracted species is LnQ₃·2HQ·phen. This difference may be due to the steric effect of the nonyl-groups in DNBP.     

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     

SOME METHODS FOR ANALYSIS OF SOLVENT EXTRACTION DATA AND THEIR APPLICATIONS

Abstract

Three programs develpoed to analyze data for liquid-liquid extraction of metal have been applied to the calculation of the stability constants of aqueous cadmium(II)-thiocyanato complexes by using the data for the extraction of tricaprylmethylammonium salt in benzene. The resulting stability constants of the aqueous thiocyanato complexes determined were: for the trial and error method log β₁ = 2·97, log β₂ = 3·70, log β₃ =3·50 and log β₄ =3·28; for the Gauss method log β₁ = 2·91, log β₂ = 3·70, log β₃ =3·35 and log β₄ = 3·29; for the Newton-Gauss method for log β₁ = 2·47, log β₂ =3·24, log β₃ =2·29 and log β₄ = 2·85     

SOLVENT EXTRACTION OF LANTHANIDES WITH N-m-AND N-p-METHOXYBENZOYL-N-PHENYLHYDROXYLAMINE

The solvent extraction of lanthanides with N-o-methoxy-(o-MBPHA), N-m-methoxy- (m-MBPHA) and N-p-methoxybenzoyl-N-phenylhydroxylamine (p-MBPHA), respectively, in chloroform was studied. The selected lanthanides (Yb, Ho, Eu, Pr and La) were all found extract with m- and p-MBPHA as self-adducts of the form LnL-2HL, where L and HL denote the ligand anion and neutral ligand, respectively. The extraction constant and separation factors for the lanthanides with m- and p-MBPHA were evaluated.     

EXTRACTION OF LINCOMYCIN WITH LONG-CHAIN ALCOHOLS AS SOLVENT

ABSTRACT

The extraction of lincomycin with long-chain alcohols as solvent was studied. The experimental results indicated that the power of n-alkyl alcohols for the extraction of lincomycin depends mainly on the molarity of alcohols in solvent used. For alcohols with short carbon chain, the steric hindrance of alkyl groups in alcohols with different structure has only little influence on the extraction of lincomycin. The chemistry of extraction of lincomycin with alcohols as solvent was discussed.     

SOLVENT EXTRACTION OF NITRIC,HYDROCHLORIC AND SULFURIC ACID AND THEIR URANYL SALTS WITH TRI-n-OCTYLPHOSPHINE OXIDE

ABSTRACT

The equilibrium constants of the extraction of nitric, hydrochloric and sulfuric acid and of their uranyl salts with trl-n-octylphoophlne oxide (TOPO), dissolved In different diluents, have been determined. Obtained extraction constants have been correlated with the corresponding dissociation constants of mineral aclda used. The more mineral acid dissociated, the less undlssoclated molecules of acid available and, as a consequence, the extraction process is less expressed.     

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 EQUILIBRIA OF LEAD(II) WITH ACIDIC ORGANOPHOSPHATE AND PHOSPHONATE

Distribution equilibria of lead(II) in the extraction with di(2-ethylhexyl)phosphoric acid and 2-ethylhexyl 2-ethylhexylphosphonic acid in toluene from aqueous ammonium nitrate solutions were measured at 303 K to elucidate the concentration dependencies of the reactant species on the distribution ratio. It was found that lead(II) is extracted as the mononuclear complex, PbR₂2HR, with the former extrac-tant while it is extracted not only as the complex, PbR₂2HR, but also as the complex, Pb(NO₃)R;HR, accompanied by simultaneous transfer of nitrate anion with the latter ex-tractant. The extraction equilibrium constants of these complexes were evaluated as well as the stability constants of lead(II) -nitrato complexes, Pb(NO₃)⁺, Pb(NO₃)₂and Pb(NO₃)^? ₃.     

SOLVENT EXTRACTION OF PHENOL WITH MINERAL ACID SALTS OF HIGH-MOLECULAR-WEIGHT AMINES

Distribution equilibria in the solvent extractions of phenol with various mineral acid salts of high-molecular-amines were measured at 30°C to examine the effects of types of amines and mineral acids on the distribution equilibria.

It was found that the extraction is greatly enhanced by converting the free base amines into their hydrochloric acid salts in the cases of secondary and tertiary amines while it is decreased in the case of a primary amine. On the effect of types of mineral acids, sulfuric acid and hydrochloric acid salts of trioctylamine can much more effectively extract phenol than the free base amine and the order of the efficiency for phenol extraction was found to be as follows: Aliquat 336 > sulfuric acid salt of trioctylamine i its hydrochloric acid salt ≥ its nitric acid salt > its perchloric acid salt ? free base amine.     

SOLVENT EXTRACTION OF COPPER (II) WITH AN ALDOXIME FROM HYDROCHLORIC AND HYDROBROMIC ACIDS

2-ethylhexanal oxime was synthesized to examine the selectivities for various metals in the extractions from hydrochloric acid. It was found to be highly selective for palladium(II) over platinum(II and IV) and other base metals including copper(II), zinc and aluminum, especially in the low concentration region of chloride ions.     

SOLVENT EXTRACTION ENHANCED MICROFILTRATION OF STRONTIUM AND TECHNETIUM WITH DI-2-ETHYLHEXYLPHOSPHORIC ACID AND QUATERNARY AMMONIUM SALTS

ABSTRACT

Application of extractants in form of microphase (micelles or microdrops) separated from aqueous matrix by microfiltration, “solvent extraction enhanced microfiltration (SEEMF)” is closely related to micellar enhanced ultrafiltration (MEUF) technique.

Uptake of strontium from aqueous solutions with microphase di-2-ethylhexylphosphoric acid (DEHPA) and pertechnetate with quaternary ammoniumsalts (QAS): trioctylmethylammonium chloride, benzyldodecyl-dimethylammonium bromide, and n-(α-carbethoxypenthadecyl)trimetyl-ammonium chloride was investigated as a function of microphase concentration and composition, pH and salinity of aqueous phase. Recovery of microfiltration on cellulose acetate 200 nm filters reached 95% for strontium with 4×10^?3 M DEHPA and 99% for technetium with 10^?4 M trioctyl-methylammonium chloride. A substantial part of 88-99% retention of technetium with investigated quaternary ammonium salts on microfilter may be caused by the filter wetting or sorption phenomena.     

SOLVENT EXTRACTION OF ZINC FROM CHLORIDE MEDIA WITH SECONDARY LONG-CHAIN ALKYLAMINE

In the solvent extraction of zinc from chloride media with a secondary long-chain alkylamine, Amberlite LA-2, aggregations of ammonium chloride salt of alkylamine and zinc-complex with alkylamine and distribution equilibrium of zinc were investigated at 30 "C using n-hexane as a diluent. The ammonium chloride salt of alkylamine exists as monomeric, dimeric, trimeric and tetrameric species (BHCl, (BHCl)₂, (BHCl)₃ and (BHCl)₄, respectively). The zinc-complex exists as monomeric and dimeric species ((BH)₂ZnCl₄ and ((BH)₂ZnCl₄)₂, respectively). Zinc is extracted according to the extraction reaction in the lower loading region of zinc to alkylamine and according to the extraction reaction in the higher loading region.     

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.     

INFLUENCE OF THE AMMONIUM SALT ANION ON THE SYNERGISTIC SOLVENT EXTRACTION OF LANTHANIDES WITH MIXTURES OF THENOYLTRDJLUOROACETONE AND TRIDECYLAMINE

ABSTRACT

The synergistic solvent extraction of Pr, Gd and Yb with mixtures of thenoyltnfluoroacetone ( HTTA) and primary ammonium salt ( tridecylammonium chloride or perchlorate, TDAH( C1, CI0) in dHhas been studied. The composition of the extracted species have been determined as Ln( TTA)₃ TDAHA( A= CI or CIO⁴ ) The values of the equilibrium constant K_{T. s} have been calculated. The influence of the ammonium salt anion on the extraction process has been discussed. The separation factors of the pairs Gd/ Pr and Yb/ Gd have been determined.     

SOLVENT EXTRACTION OF SILVER BY CYANEX 272, CYANEX 302 AND CYANEX 30

ABSTRACT

The solvent extraction of silver from nitrate media by the extractants Cyanex 272 (bis)2,4,4-trimethylpentyl)phosphinic acid), Cyanex 302 ( bis(2,4,4-trimethylpentyl)thiophosphinic acid) and Cyanex 301 ( bis( 2,4,4-trimethyl-pentyl)dithiophosphinic acid) is characterized. Extraction shifts to lower pH with increasing sulfur substitution in the phosphinic acid, in accordance with the increased extractant acidity imparted by the soft nature of the sulfur donor atoms. The effects of extractant concentration, aqueous-phase ionic strength and organic-phase diluent on the extraction behavior are examined. The stoichiometry of the extraction reactions and the geometry of the extracted complexes are postulated based on slope analysis and spectroscopic measurements. All three extractants behave as bidentate ligands and combine in a 1:1 stoichiometric ratio with silver. The sulfur-containing ligands form multi-nuclear oligomeric complexes in which the ligands bridge between metal centers.     

SOLVENT EXTRACTION OF Ni(ll) WITH THE ACTIVE COMPONENT OF LIX 54

ABSTRACT

The solvent extraction of Ni(II) with the active component of the commercial extractant Lix 54 in different synergic mixtures, using tri-n-octylphosphine oxide (TOPO), tri-n-laurylamine (TLA), di-(2-ethylhexyl)phosphoric acid (HDEHP), tributylphosphate (TBP) and 4-methylpyridine as synergic reagents is compared in this work, the highest synergic effects corresponding to the presence of TOPO and 4-methylpyridine. For this reason, the extraction of Ni(ll) from a 1.0 mol.dnr³ KN0₃media by the mixture of the active component of Lix 54 and 4-methylpyridine has been extensively studied in this work. The results have been treated both graphically and numerically in order to find a suitable chemical model of the species responsible for the extraction as well as their extraction constants.