The extraction of cobalt(II) from lithium chloride solutions by aliquat 336R dissolved in chloroform

1982 ◽  
Vol 35 (11) ◽  
pp. 2345 ◽  
Author(s):  
R Paimin ◽  
RW Cattrall
Keyword(s):  
Ion Exchange ◽  
Aqueous Phase ◽  
Lithium Chloride ◽  
Organic Phase ◽  
Equilibrium Constants ◽  
Single Drop ◽  
Chloride Solutions ◽  
Rate Determining Step ◽  
Fast Ion ◽  
Drop Technique

The extraction of cobalt(II) by Aliquat 336R from 7 M lithium chloride solutions involves two species from the aqueous phase, COCl42 and CoCl3-, with the former being the predominant one. The equilibrium constants for the formation of the extracted complexes (R3MeN+)2 CoCl42- and R3MeN+CoCI3- are: logKll 5.01 and logK12 9.55. From the results of experiments by means of the single-drop technique, a mechanism is proposed based on the formation of interfacial complexes by fast ion-exchange with a rate-determining step which involves the replacement at the interface of the complex (R3MeN+)2 COCl42- by two molar proportions of reagent from the bulk organic phase.

The mechanism of extraction of zinc(II) from aqueous chloride solutions into chloroform solutions of methyltrioctylammonium chloride

1982 ◽  
Vol 35 (6) ◽  
pp. 1095 ◽  
Author(s):  
H Daud ◽  
RW Cattrall
Keyword(s):  
Organic Phase ◽  
Equilibrium Constants ◽  
Full Range ◽  
Single Drop ◽  
Exchange Reactions ◽  
Extraction Equilibrium ◽  
Rate Determining Step ◽  
Aqueous Chloride ◽  
Fast Ion ◽  
Drop Technique

The mechanism of the transfer of zinc(11) between 1.0 M HCl, 6.0 M HCl and 6.0 M LiCl and methyltrioctylammonium chloride in chloroform has been studied by using the single-drop technique. It is suggested that interfacial complexes are formed by fast ion-exchange reactions and that the rate-determining step, in the case of 1.0 M HCl and 6.0 M LiCl, involves the replacement at the interface of the complex R2ZnCl4 by two molecules of reagent from the bulk organic phase. For 6.0 M HCl the rate-determining step is the replacement of the interfacial complex RHZnCl4 by one molecule of reagent from the bulk organic phase. Support for this mechanism is obtained by comparing the extraction equilibrium constants for the complex R2ZnCl4 for 1.0 M HCl and 6.0 M LiCl from previous with the values calculated from the rate data. Interfacial tension measurements have shown that the interface is saturated with reagent over the full range of concentrations studied.

The mechanism of extraction of iron(III) from 6 M hydrochloric acid by long chain amines in chloroform

1983 ◽  
Vol 36 (7) ◽  
pp. 1319 ◽  
Author(s):  
MZ Ilic ◽  
RW Cattrall ◽  
DE Davey
Keyword(s):  
Organic Phase ◽  
Equilibrium Constants ◽  
Single Drop ◽  
Two Phase ◽  
Extraction Equilibrium ◽  
Rate Determining Step ◽  
Fast Reactions ◽  
Complex Forms ◽  
Fast Ion ◽  
Drop Technique

The mechanism of transfer of FellI between 6.0 M HCl and five amine chlorides in chloroform has been studied by means of the single-drop technique. It is suggested that the (1,1) complex forms at the interface by fast ion-exchange and that the rate determining step involves the replacement of the complex at the interface by one molecule of reagent monomer from the bulk organic phase. Additional heterogeneous aggregates are formed in the bulk organic phase by fast reactions with reagent monomer. Support for this mechanism is obtained through the excellent agreement between the extraction equilibrium constants calculated from the rate data for the (1,1) complexes and the values obtained previously by two phase titration studies.

Kinetics of solvent extraction of metal ions with HEDHP. III. The kinetics and mechanism of solvent extraction of Cr(III) from acidic aqueous solutions with bis-(2-ethyl hexyl) phosphoric acid in benzene

1979 ◽  
Vol 57 (23) ◽  
pp. 3011-3016 ◽  
Author(s):  
Muhammad Fakhrul Islam ◽  
Ranjit Kumar Biswas
Keyword(s):  
Solvent Extraction ◽  
Phosphoric Acid ◽  
Aqueous Phase ◽  
Organic Phase ◽  
Forward Rate ◽  
Nitrate Ions ◽  
Rate Determining Step ◽  
Ethyl Hexyl ◽  
Ph Range ◽  
Kinetics Of

The rate of solvent extraction of chromium(III) from aqueous sulphuric acid solutions (containing 0.05 mol dm−3 sulphate ion and 0.25 mol dm−3 acetate buffer, ionic strength, I = 0.40 mol dm−3) with bis-(2-ethyl hexyl) phosphoric acid (HDEHP or H2A2) in benzene has been measured under various conditions. The rate of backward extraction measurement of Cr(III) from organic phase to aqueous phase is not possible due to the inert property of Cr(III)–DEHP chelate. The forward rate is found to be first-order w.r.t. Cr(III) concentration in the aqueous phase and HDEHP concentration in the organic phase. The order w.r.t. H+ concentration varies from −1 to 1 over the pH range 1.5 to 5.25. The rate is found to decrease with increasing sulphate and nitrate ions concentrations in the aqueous phase. At (30 ± 1) °C, the rate expression, in the presence of sulphate, acetate, and nitrate ions, is found to be represented by:[Formula: see text]In the absence of the anions, the formation of CrHA22+ intermediate complex (Cr(OH)2+ + H2A2(0) → CrHA22+ + H2O) is the rate determining step at all acidities. The effects of the anions on the rate are discussed.

scholarly journals Extraction of steroidal glucosiduronic acids from aqueous solutions by anionic liquid ion-exchangers

1972 ◽  
Vol 126 (3) ◽  
pp. 533-543 ◽  
Author(s):  
V R Mattox ◽  
R. D. Litwiller ◽  
J E Goodrich
Keyword(s):  
Ion Exchange ◽  
Aqueous Phase ◽  
Organic Phase ◽  
Methyl Esters ◽  
Exchange Process ◽  
Amine Hydrochloride ◽  
Ion Exchangers ◽  
Ion Exchange Process ◽  
Ph Range ◽  
Organic Solutions

A pilot study on the extraction of three steroidal glucosiduronic acids from water into organic solutions of liquid ion-exchangers is reported. A single extraction of a 0.5mm aqueous solution of either 11-deoxycorticosterone 21-glucosiduronic acid or cortisone 21-glucosiduronic acid with 0.1m-tetraheptylammonium chloride in chloroform took more than 99% of the conjugate into the organic phase; under the same conditions, the very polar conjugate, β-cortol 3-glucosiduronic acid, was extracted to the extent of 43%. The presence of a small amount of chloride, acetate, or sulphate ion in the aqueous phase inhibited extraction, but making the aqueous phase 4.0m with ammonium sulphate promoted extraction strongly. An increase in the concentration of ion-exchanger in the organic phase also promoted extraction. The amount of cortisone 21-glucosiduronic acid extracted by tetraheptylammonium chloride over the pH range of 3.9 to 10.7 was essentially constant. Chloroform solutions of a tertiary, a secondary, or a primary amine hydrochloride also will extract cortisone 21-glucosiduronic acid from water. The various liquid ion exchangers will extract steroidal glucosiduronic acid methyl esters from water into chloroform, although less completely than the corresponding free acids. The extraction of the glucosiduronic acids from water by tetraheptylammonium chloride occurs by an ion-exchange process; extraction of the esters does not involve ion exchange.

Extraction of strontium with dicarbolide in the presence of polyethylene glycol

1979 ◽  
Vol 44 (1) ◽  
pp. 157-166 ◽  
Author(s):  
Petr Vaňura ◽  
Jiří Rais ◽  
Pavel Selucký ◽  
Miroslav Kyrš
Keyword(s):  
Experimental Data ◽  
Polyethylene Glycol ◽  
Ionic Strength ◽  
Aqueous Phase ◽  
Organic Phase ◽  
Distribution Ratio ◽  
Equilibrium Constants ◽  
Electrostatic Charge ◽  
Peg 400 ◽  
Order Of Magnitude

The extraction of microquantities of 85Sr in the presence of 3 . 10-4 - 0.25 mol l-1 polyethylene glycol (PEG 400) (L) with solutions of dicarbolide ({(π-(3)-1,2-B9C2H11)2Co}-) in nitrobenzene (10-3 - 10-2M) was investigated. The occurrence of the maxima (up to one order of magnitude) on the plots of the strontium distribution ratio vs the total PEG concentration was explained in terms of the competition between the charged strontium-PEG complex (SrL2+) and protonized PEG (HL+) during the balancing of the dicarbolide electrostatic charge in the organic phase. Theoretical relations were derived for the shape of this dependence, for the effect of the acid concentration in the aqueous phase and that of the dicarbolide concentration in the organic phase, as well as for the positions of the corresponding maxima. The theoretical dependences are in accordance with the experimental data. The values of the concentration equilibrium constants of the reactions Sr2+ + L + 2 H+ ##e SrL2+ + 2 H+ (Kex(SrL2+)) and H+ + L ##e HL+ (Kex(HL+)) (for variable ionic strength) are Kex(SrL2+) = 3.26 . 108 and Kex(HL+) = 538 at 25 °C.

Effect of aqueous acetic, oxalic and carbonic acids on the adsorption of americium onto α-alumina

2005 ◽  
Vol 93 (8) ◽  
Author(s):  
Cyrille Alliot ◽  
Lionel Bion ◽  
Florence Mercier ◽  
Pierre Vitorge ◽  
Pierre Toulhoat
Keyword(s):  
Ion Exchange ◽  
Aqueous Phase ◽  
Thermodynamic Equilibrium ◽  
Equilibrium Constants ◽  
Exchange Theory ◽  
Organic Ligands ◽  
Sorption Mechanism ◽  
Anionic Complexes ◽  
Carbonic Acids ◽  
Chemical Conditions

SummaryThe prediction of the migration for radionuclides in geologic media requires a quantitative knowledge of retardation phenomena. For this purpose, the sorption of Am(III) onto a model mineral — α-alumina — is studied here, including the effects of groundwater chemistry: pH and concentrations of small organic ligands (acetate, oxalate and carbonate anions). This work presents some experimental evidences for the synergic sorption mechanism of americium–ligand cationic complexes onto the alumina. As its anionic complexes were not sorbed, Am(III) cations were desorbed as a result of the formation of anionic complexes in the aqueous phase. By using the ion-exchange theory, and a corresponding restricted set of parameters — exchange capacities and thermodynamic equilibrium constants — the whole set of sorption experiments of Am(III) cationic species onto the α-alumina was modelled in various chemical conditions.

scholarly journals Liquid-Liquid Extraction of Transition Metal Cations by Glyoximes and Their Macrocyclic Glyoxime Ether Derivatives

2013 ◽  
Vol 2013 ◽  
pp. 1-7 ◽  
Author(s):  
Nazan Karapinar ◽  
Emin Karapinar ◽  
Emine Ozcan
Keyword(s):  
Transition Metal ◽  
Transition Metals ◽  
Crown Ether ◽  
Aqueous Phase ◽  
Organic Phase ◽  
Equilibrium Constants ◽  
Liquid Extraction ◽  
Extraction Equilibrium ◽  
Liquid Liquid Extraction ◽  
Extraction Constants

Liquid-liquid extraction of various alkalis (Li+, Na+, K+, and Cs+), transition metals (Co2+, Ni2+, Cu2+, Zn2+, Cd2+, and Hg2+), and Pb2+cations with phenylglyoxime (L1), p-tolylglyoxime (L2),N′-(4′-Benzo[15-crown-5])phenylaminoglyoxime (L3), andN′-(4′-Benzo[15-crown-5])-p-tolylaminoglyoxime (L4) from the aqueous phase into the organic phase was carried out. For comparison, the corresponding two glyoximes and their macrocyclic glyoxime ether derivatives were also examined. Crown ether groups having ligands (L3,L4) carry especially Na+cation from aqueous phase to organic phase. The extraction equilibrium constants (Kex) for complexes of ligands with Cu2+and Hg2+metal picrates between dichloromethane and water have been determined at 25°C. The values of the extraction constants (logKex) were determined to be 12.27, 13.37, 12.94, and 12.39 for Cu2+and 10.29, 10.62, 11.53, and 11.97 for Hg2+with L1–L4, respectively.

Extraction of hafnium(IV) with organophosphorus reagents from solutions of mineral acids mixtures

1979 ◽  
Vol 44 (12) ◽  
pp. 3656-3664
Author(s):  
Oldřich Navrátil ◽  
Jiří Smola ◽  
Rostislav Kolouch
Keyword(s):  
Ionic Strength ◽  
Aqueous Phase ◽  
Organic Phase ◽  
Perchloric Acid ◽  
Synergic Effect ◽  
Salting Out ◽  
Initial Concentration ◽  
Mixed Complexes ◽  
Synergic Extraction ◽  
Mineral Acids

Extraction of hafnium(IV) was studied from solutions of mixtures of perchloric and nitric acids and of perchloric and hydrochloric acids for constant ionic strength, I = 2, 4, 6, or 8, and for cHf 4 . 10-4 mol l-1. The organic phase was constituted by solutions of some acidic or neutral organophosphorus reagents or of 2-thenoyltrifluoroacetone, 1-phenyl-3-methyl-4-benzoyl-5-pyrazolone, or N-benzoyl-N-phenylhydroxylamine in benzene, chloroform, or n-octane. A pronounced synergic extraction of hafnium proceeds only on applying organophosphorus reagents from an aqueous phase whose acidity is not lower than 3M-(HClO4 + HNO3) or 5M-(HClO4 + HCl). The synergic effect was not affected markedly by a variation of the initial concentration of hafnium in the range 1 . 10-8 -4 .10-4 mol l-1, it lowered with increasing initial concentration of the organophosphorus reagent and decreasing concentration of the H+ ions. It is suggested that the hafnium passes into the organic phase in the form of mixed complexes, the salting-out effect of perchloric acid playing an appreciable part.

Extraction of strontium and barium salts by the nitrobenzene solution of dicarbolide in the presence of glymes

1985 ◽  
Vol 50 (3) ◽  
pp. 581-599 ◽  
Author(s):  
Petr Vaňura ◽  
Emanuel Makrlík
Keyword(s):  
Stability Constants ◽  
Organic Phase ◽  
Equilibrium Constants ◽  
Minor Role ◽  
Nitrobenzene Solution ◽  
Ligand Structure ◽  
Stability Constants Of Complexes ◽  
Separation Factors ◽  
The Stability ◽  
A Minor

Extraction of microamounts of Sr2+ and Ba2+ (henceforth M2+) from the aqueous solutions of perchloric acid (0.0125-1.02 mol/l) by means of the nitrobenzene solutions of dicarbolide (0.004-0.05 mol/l of H+{Co(C2B9H11)2}-) was studied in the presence of monoglyme (only Ba2+), diglyme, triglyme, and tetraglyme (CH3O-(CH2-CH2O)nCH3, where n = 1, 2, 3, 4). The distribution of glyme betweeen the aqueous and organic phases, the extraction of the protonized glyme molecule HL+ together with the extraction of M2+ ion and of the glyme complex with the M2+ ion, i.e., ML2+ (where L is the molecule of glyme), were found to be the dominating reactions in the systems under study. In the systems with tri- and tetraglymes the extraction of H+ and M2+ ions solvated with two glyme molecules, i.e., the formation of HL2+ and ML22+ species, can probably play a minor role. The values of the respective equilibrium constants, of the stability constants of complexes formed in the organic phase, and the theoretical separation factors αBa/Sr were determined. The effect of the ligand structure on the values of extraction and stability constants in the organic phase is discussed.

Europium and cerium extraction by the nitrobenzene solution of dicarbolide in the presence of polyethylene glycols

1986 ◽  
Vol 51 (3) ◽  
pp. 498-515 ◽  
Author(s):  
Emanuel Makrlík ◽  
Petr Vaňura
Keyword(s):  
Molecular Weight ◽  
Polyethylene Glycol ◽  
Organic Phase ◽  
Perchloric Acid ◽  
Equilibrium Constants ◽  
Polyethylene Glycols ◽  
Individual Species ◽  
Nitrobenzene Solution ◽  
Separation Factors ◽  
Equilibrium Data

Extraction of Eu3+ and Ce3+ microamounts from 0.1-0.4M perchloric acid by the nitrobenzene solution of dicarbolide H+[Co(C2B9H11)2]- in the presence of polyethylene glycols (Mr = 200, 300, 400) has been studied. The equilibrium data and the typical maxima on the dependence of the metal distribution ratio on the total analytical concentration of polyethylene glycol in the system can be explained assuming that the species ML3+org, ML3+2org, ML3+3org, MLH2+-1org, and HL+org (where M3+ = Eu3+, Ce3+; L = polyethylene glycol) are extracted into the organic phase. The values of extraction and equilibrium constants in the organic phase were determined and the effect of the polyethylene glycol molecular weight on the equilibrium constants and on the abundances of individual species in the organic phase is discussed. It has been found that the addition of polyethylene glycol to the acid - nitrobezene - dicarbolide system increases the values of the separation factors αCe/Eu.

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