Showing papers in "Solvent Extraction and Ion Exchange in 1990"
TL;DR: In this paper, Dicyclohexano-18-Crown-6 (DCH18C6) and its dimethyl and di-t-butyl derivatives have been evaluated as extractants for Sr (II) from nitric acid media.
Abstract: Dicyclohexano-18-Crown-6 (DCH18C6)and its dimethyl and di-t-butyl derivatives have been evaluated as extractants for Sr (II) from nitric acid media. As with DCH18C6, a correlation is observed between the extraction of strontium nitrate by the di-t-butyl compound dissolved in a variety of oxygenated, aliphatic solvents and the concentration of water in the organic phase. Comparison of the extractant dependencies of the three compounds using n-octanol as the diluent shows that the expected first power dependence of the strontium distribution ratio (Dsr) on crown concentration is observed only for the di-t-butyl derivative. DCH18C6 shows a marked deviation from first power dependence at crown concentrations greater -0.01 M. Dsr acid dependencies for DCHl8C6 and the di-t-butyl derivative do not exhibit the decrease in strontium distribution ratios at high acidities observed for DCH18C6 in chlorinated hydrocarbons.
136 citations
TL;DR: In this paper, the extraction of zinc was studied with solvents containing bis (2,4,4-trimethylpentyl)phosphinic acid and its monothio and dithio analogues.
Abstract: The extraction of zinc was studied with solvents containing bis (2,4,4-trimethylpentyl)phosphinic acid and its monothio and dithio analogues. Comparative data are presented to illustrate the effect of composition (sulphur substitution) on the extraction and stripping characteristics of the three reagents. Special emphasis is given to the selective separation of zinc from sulphate solutions containing calcium. The effect of aralkyl versus alkyl groups in the molecule is also illustrated and important extractant properties such as hydrolytic stability and aqueous solubility are discussed.
108 citations
TL;DR: A simple correlation has been observed between the extraction of strontium nitrate from nitric acid solution by cis-dicyclohexano-18-Crown-6 dissolved in a variety of oxygenated, aliphatic diluents and the molarity of water present in the organic phase.
Abstract: A simple correlation has been observed between the extraction of strontium nitrate from nitric acid solution by cis-dicyclohexano-18-Crown-6 dissolved in a variety of oxygenated, aliphatic diluents and the molarity of water present in the organic phase. This correlation is attributed to the extraction of the hydrated nitrate ion and its solvation by the diluent, facilitated by the high concentration of dissolved water. Of the solvents studied, ketones yield the largest values of the extraction constant for a given water content, although C5 and C6 alcohols give the highest overall values.
97 citations
TL;DR: In this article, the extraction of bis(2,4,4-trimethylpentyl)phosphinic acid (HBTMPP) from Isopar-H has been studied with relation to the total extractant concentration, the equilibrium pH and the total metal concentration in the aqueous phase.
Abstract: The extraction of Cd(II), Cu(II) and Zn(II) from 0.1 mol dmminus3 aqueous nitrate solutions with bis(2,4,4-trimethylpentyl)phosphinic acid (HBTMPP) dissolved in Isopar-H has been studied with relation to the total extractant concentration, the equilibrium pH and the total metal concentration in the aqueous phase. The stoichiometry of the extracted species and their equilibrium constants have been determined by graphical and numerical methods and appear to be CdA2 (HA)2 and CdA2 (HA)3 for Cd(II), CuA2(HA)2 for Cu(II) and ZnAzHA and ZnAz(HA)2 for Zn(II). The extraction efficiency follows the order Zn(II)
39 citations
TL;DR: In this paper, a study was made of the extraction of sodium into bis (2,4,4 -trimelhylpentyl) phosphinic acid and the following basic constants were measured at 25°C using two-phase titration techniques.
Abstract: A study has been made of the extraction of sodium into bis (2,4,4 -trimelhylpentyl) phosphinic acid. The following basic constants were measured at 25°C using two-phase titration techniques: the so...
36 citations
TL;DR: In this paper, a review of Mono-acidic liquid ion exchangers (extractants) containing the phosphonyl functional group arc is presented, with a focus on monophase.
Abstract: SUMMARY Mono-acidic liquid ion exchangers (extractants) containing the phosphonyl functional group arc reviewed.
35 citations
TL;DR: In this paper, the authors investigated the extraction of Au (III) from aqueous HCI solutions using the th-isobutyl phosphine sulfide (TIBPS) extractant in toluene.
Abstract: The extractant th-isobutyl phosphine sulfide (TIBPS ), Cyanex 471, in toluene has been investigated for the extraction of Au (III) from aqueous HCI solutions. Analysis of the equilibrium data shows that the extraction proceeds via a solvating type mechanism by the formation of the species AuCI3.FI and AuCl3.2R, for which formation constants are log 677 β= 34.84 and log β= 42.04 respectively (R =TIBPS).
33 citations
TL;DR: In this article, the separation of uranium from synthetic Hanford site groundwater by liquid-liquid extraction and by supported liquid membranes (SLM) was atudied, and a water soluble complexing agent, 1-hydroxyethane-1,1-diphoaphonic acid, HEDPA, was used as atrlpping agent.
Abstract: The separation of uranium from synthetic Hanford site groundwater by liquid-liquid extraction and by supported liquid membranes (SLM) was atudied. Bis(2,4,4-trimethylpentyl) phosphinic acid, H[DTMPeP], contained in the commercial extractant Cysnex 272, was selected for the membrane carrier because of its selectivity for uranium over calcium and magnesium. n-Dodecane was used as diluent and polypropylene membranea were used as the support. A water soluble complexing agent, 1-hydroxyethane-1,1-diphoaphonic acid, HEDPA, was used as atrlpping agent. The permeability coefficient of U(V1) was evaluated from a detailed study of the permeation of U(VI) through flat-sheet SLMs as a function of the membrane carrier concentration. The diffusion coefficient of the uranium complex in the organic phase was also evaluated from permeation experiments performed under loading conditions. Experiments were also carried out with Cs(II) and Fe(III) to measure the membrane selectivity for U(VI) over these two cations. ...
32 citations
ENEA1
TL;DR: In this article, a comparison between CMPO and D2EHPA for Eu(III) extraction has been carried out using mesitylene and dodecane as diluents.
Abstract: The extraction behavior of Eu(III) from nitric and hydrochloric acid By solutions of CMPO with and without TBP has been studied using mesitylene and dodecane as diluents. Compared to CMPO alone, the CMPO-TBP mixture shows a slight enhancement in the extraction of Eu(III) from nitric acid above 2M and lower DEu’ s from low acidity. The distribution ratios measured for Eu(III) between HN03 and CMPO-TBP in dodecane are higher than the corresponding values in mesitylene.Extractant dependency studies in the presence and absence of TBP show that at low HN03 concentrations, the extractant dependency curve obtained in the presence of TBP lies below the curve obtained in the absence of TBP. At high acidity, the opposite is observed. The extraction of Eu(III) from hydrochloric acid by CMPO-TBP in dodecane is much lower than from nitric acid. A comparison between CMPO and D2EHPA for Eu(III) extraction has been carried out.
25 citations
TL;DR: In this paper, the effects 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 water(2,4,4-trimethylpentyl)-phosphinic acid at various temperatures were investigated.
Abstract: 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 chlorof...
25 citations
TL;DR: In this article, a model for the polymers that invokes bridging of successive praseodymium atoms by the two functional groups of 0φD(iB)CMP0 is supported by: (a) the formation of polymers by two other Afunctional extractants, whereas a comparable mon-functional extractant fails to form polymers, and (b) the long and thin shape of most of the observed polymers exhibiting a radial extension.
Abstract: Octyl(phenyl)-N,N-diisobutylcarbamoylmethylphosphine oxide (OφD(iB)CMPO) and extracted praseodymium form large elongated polymers whose sizes and shapes were measured by small-angle neutron scattering (SANS). The particles were 17-40 Ȧ in diameter and up to 500 Ȧ long. The polymers are produced at low 0φD(iB)CMPO/Pr ratios, and their sizes decrease as OφD(iB)CMPO/Pr ratio increases. A model for the polymers that invokes bridging of successive praseodymium atoms by the two functional groups of 0φD(iB)CMP0 is supported by: (a) the formation of polymers by two other Afunctional extractants, whereas a comparable monofunctional extractant fails to form polymers, and (b) the long and thin shape of most of the observed polymers, exhibiting a radial extension that is consistent with the model. Four comparable carbamoyl-alkyl-phosphoryl extractants have been examined by SANS for their capacity to form polymers with praseodymium in C6D6. Consistent with the model, the extractants, having the more basic ami...
TL;DR: In this article, the extraction of Ag(I) and Hg(II) from chloride solutions of constant ionic strength (lM) by O,O-di-n-butyl a -phenylamino--phenylmethanethiophosphonate dissolved in trichloromethane has been studied.
Abstract: The extraction of Ag(I)and Hg(II) from chloride solutions of constant ionic strength (lM) by O,O-di-n-butyl a -phenylamino--phenylmethanethiophosphonate dissolved in trichloromethane has been studied. The extraction dependences of metals on the ligand, hydrogen and chloride ions concentrations have been analysed to determine the stoichiometry of the extracted complexes and their equilibrium constants. Evidence was found for the formation of the complexes
TL;DR: In this article, the thermodynamics of alkali and earth metal ion exchange on a layered zirconium sulphophosphonate having the general composition Zr(O3PC6H4SO3H) ×(HPO4) 2−× yH2O have been investigated.
Abstract: The thermodynamics of alkali and alkaline earth metal ion exchange on a layered zirconium sulphophosphonate having the general composition Zr(O3PC6H4SO3H) ×(HPO4) 2−× yH2O have been investigated. Enthalpy and entropy changes accompanying the M2+ - H+ exchange (M = Na+, Cs+, Mg2+ and Ba2+)were determined by the temperature variation method. For the monovalent ions, Na+ and Cs+, the enthalpy terms favor exchange whereas the entropy terms are unfavorable. In contrast, for the divalent ions, Mg2+ and Ba2+, the exchange is due to highly favorable entropy terms.
TL;DR: In this paper, the thermodynamics of the extraction of some lanthanide ions and bismuth, aluminium, calcium and zinc ions from perchloric acid into solutions of dinonylnaphthalenesulphonic acid have been studied.
Abstract: The thermodynamics of extraction of some lanthanide ions and bismuth, aluminium, calcium and zinc ions from perchloric acid into solutions of dinonylnaphthalenesulphonic acid have been studied. Extraction of the trivalent ions is dominated by the entropy of complexing. Electrostriction of large complex micelles by the complexed ion is postulated in order to account for the entropy effect. In the case of divalent ions, the enthalpy of dehydration of the ion is more important. A strategy for improving the separation factors is proposed.
TL;DR: In this article, a quantitative PMR study of synthetic solutions (Zn(L-8-L)(H2O) + × TOPO) was performed in wet CDC13.
Abstract: Zinc extraction from perchlorate medium, with 1, 10-bis[ 1-phenyl-3-methyl-5-hydroxy-4-pyrazolyl]-1,10-decanedione (HL-8-LH) and its mixtures with tri-n-octylphoaphine oxide (TOPO) in chloroform has been investigated and compared with the corresponding extraction systems with 1-phenyl-3-methyl-4-benzoyl-pyrazol-5-ol (HL*). The extraction processes are: Zn2+ + 2 HL-8-LH 3* 2 H+ + Zn(L-8-LH) (K ) -3.24(25°) and -2.80(30°); log K' 121= -2.35(25°); log Ki: ±0.1. HL-8-LH is a slightly better extractant than HL', due to the higher lipophilicity of the extracted complexes. For high values of [Zn], in both extraction systems, a third solid phase forms: it consists of the bis-chelate Zn(L-8-L)(H2O) (IR study). A quantitative PMR study of synthetic solutions “Zn(L-8-L)(H2O) + × TOPO”, in wet CDC13, gives evidence of the occurrence of the complexes Zn(L-8-L)(TOPO) and Zn(L-8-L)(TOPO)2. Only the former is clearly characterized in the extraction phases. In those systems, the influence of coordination upon TOP...
TL;DR: In this paper, several secondary cleanup procedures have been tested for hydrolytically and radiolyteically degraded TRUEX process solvent (0.2 m tributylphosphate (TBP) in n-dodecane).
Abstract: Several secondary cleanup procedures have been tested for hydrolytically and radiolytically degraded TRUEX process solvent (0.2 M. n-octyl(phenyl)N,N-diisobutylcarbamoylmethylphosphine oxide (CMPO)-1.2 M tributylphosphate (TBP) in n-dodecane). Sodium carbonate scrub was used as primary cleanup. For the secondary cleanup macroporous anion exchange resins and other solid adsorbents, such as goethite (a-FeOOH), alumina and activated charcoal were used. The effectiveness of a cleanup procedure was established by its capability to restore the original americium(III) distribution ratio from low HNO3 concentration, that is characteristic of pristine process solvent. Further information was obtained from the measurement of up to seven successive AmfJIT) distribution ratios with the regenerated solvent, using the stripping conditions of the TRUEX process. Although all the procedures tested proved to be effective in removing most of the unwanted acidic products from the degraded solvent, the use of a stron...
TL;DR: In this paper, the extraction of copper (II) from acidic sulfate solutions using commercial extractants LIX 84, P5100, and PT5050 was studied using a commercial equation-solving program on a personal computer.
Abstract: The Bureau of Mines studied the extraction of copper (II) from acidic sulfate solutions using commercial extractants LIX 84, P5100, and PT5050. Mathematical models, consisting of sets of nonlinear mass action and mass balance equations, were solved using a commercial equation-solving program on a personal computer. The models suggest that LIX 84 is a mixture of monomelic and dimeric extractant with an extraction equilibrium constant of 145 and a dimerization constant of 65 L/mol; PT5050 appears to be a monomeric extractant with an extraction equilibrium constant of 53; and P5100 shows more complex characteristics, with a monomeric extraction equilibrium constant of 400, a dimer formation constant of 3.7 L/mol, and a modifier-complex formation constant of 5.8 L/mol. For all models, the relative error of fit was less than 6%.
TL;DR: The thermodynamic parameters for the extraction of Am3+ with pyrazolones (HA=HPMBP or HPMTFP) alone as well as their mixtures with one of the crown ethers B15C5 or DCH18C6 have been calculated in this article.
Abstract: The thermodynamic parameters for the extraction of Am3+with pyrazolones (HA=HPMBP or HPMTFP) alone as well as their mixtures with one of the crown ethers B15C5 or DCH18C6 have been calculated In ch...
TL;DR: In this paper, the Gibbs, Szyszkowski,Frumkln and Temkin and polynomial were found as fits well to experimental interfacial tension isotherms for 2-hydroxy-5-alkylbenzaldehyde oximes at octane/water and xylene/water interfaces.
Abstract: Different adsorption isotherms such as the Gibbs, Szyszkowski,Frumkln and Temkin and polynomial were found as fits well to experimental interfacial tension isotherms for 2-hydroxy-5-alkylbenzaldehyde oximes at octane/water and xylene/water interfaces. The values of surface excess computed according to them increase as the length of the alkyl chain length increases for xylene/water system. Different behaviour was found at octane/water interface. The interfacial activity data were used to predict reaction orders against hydroxyoxime for different proposed mechanisms of copper extraction from acid sulphate solution.It was shown that an interfacial mechanism is very probable for compounds with long alkyl chains. For these compounds the extraction limiting step is the reaction between hydroxyoxime molecules present near the interface and the intermediate 1:1 complex.
TL;DR: In this paper, acid base couple extractants were used to extract sulfuric acid and zinc sulfate from zinc electrowinning waste streams, and they were used for treating zinc waste streams.
Abstract: Acid-base couple extractants extract sulfuric acid and zinc sulfate efficiently, selectively and reversibly. Their properties allowed development of a new, solvent extraction process for treating zinc electrowinning waste streams. In this process, about 95% of the sulfuric acid and 95% of the zinc can be recovered at concentrations high enough to be directly recycled to zinc production. Lime consumption and gypsum formation are substantially reduced. Only one extractant is used in the process, and zinc is recovered as zinc sulfate.
TL;DR: In this article, distribution equilibria were investigated for the adsorption of metal ions and acids on Sumichelate MC-10 resin, a polyethylene polyamine type of novel chelating resin.
Abstract: Distribution equilibria were investigated for the adsorption of metal ions and acids on Sumichelate MC-10 resin, a polyethylene polyamine type of novel chelating resin. The total exchange capacitie...
TL;DR: In this article, the authors show that the C-O-C stretching bands for the crown ether ligand shift to lower frequency when Mn2+ ion is extracted into a CC14 solution of HDDNS and tBC15C5.
Abstract: Addition of t-butylcyclohexano-15-crown-5 (tBC-15C5) induces a synergistic effect in the extraction of Mn2+ ion with didodecylnaphthalenesulfonic acid (HDDNS). This synergism is the result of the inner-sphere complexation of the crown ether to the manganese(II) ion. The formation of this complex, first suggested by distribution studies, has been confirmed by FTIR experiments. The C-O-C stretching bands for the crown ether ligand shift to lower frequency when Mn2+ ion is extracted into a CC14 solution of HDDNS and tBC15C5. A similar C-O-C Btretching band is observed for the crystalline complex [Mn(15C5 ) (Bu3CS03)2] (where 15C5 = 15-crown-5 and Bu = n-butyl).Formation of analogous complexes is not observed for Fe3+, co2+,N2+,cu2+, or zn2+ under similar conditions.
TL;DR: In this paper, a mathematical model of the shell progressive mechanism with changing bulk solution concentration and exchanger volume in ion exchange is presented and its conformity with experimental results is demonstrated, and the model is shown to be consistent with the experimental results.
Abstract: A mathematical model of the shell progressive mechanism with changing bulk solution concentration and exchanger volume in ion exchange is presented and its conformity with experimental results is demonstrated.
TL;DR: In this article, the synergistic solvent extraction of Am(III) and Eu(III), with the neutral soft donor TIBPS and HTTA, was investigated using cyclohexane as the organic solvent and at an ionic strength of 0.1 M (NaCIO4).
Abstract: The synergistic solvent extraction of Am(III) and Eu(III) with the neutral soft donor TIBPS and HTTA has been investigated using cyclohexane as the organic solvent and at an ionic strength of 0.1 M (NaCIO4). The extracted species are [M(TTA)2)] and [M(TTA)2 (Clo4) (TIBPS)] The extraction constants show that the synergistic factor is less than that for the analogous hard donor adducts (e.g., TBP and TOPO) and no preferential extraction of Am(III) over Eu(III) is observed.
TL;DR: In this paper, the authors reported the equilibrium data for the extraction of phenol at 288, 293 and 298 K with n-butyl acetate (NBA), acetophenone (AP), and mixtures of NBA + AP and methyl isobutyl ketone (MIK) + AP.
Abstract: Equilibrium data are reported for the extraction of phenol at 288, 293 and 298 K with n-butyl acetate (NBA), acetophenone (AP) and mixtures of NBA + AP and methyl isobutyl ketone (MIK) + AP. A synergistic behaviour is observed for the system phenol-water-(NBA/AP). Several equations have been used to correlate the experimental data: van't Hoff, Redlich-Kister and other polynomial equations. Reported data were compared with those available in the literature.
TL;DR: In this paper, the solvent extraction of gold cyanide from alkaline cyanide leach liquors by lauroimidazoline - a weak-base extractant - was investigated.
Abstract: The solvent extraction of gold cyanide from alkaline cyanide leach liquors by lauroimidazoline - a weak-base extractant - was investigated. The highly basic lauroimidazoline group extracted gold cyanide at a higher pH value than did Amberlite LA2 - a commercial alkylamine extractant with a pH value of protonation lower than that of the imidazoline group. The relative pH values where gold loading started to tail off were about 8 and 5 for the lauroimidazoline and the Amberlite LA2 extractants respectively. The pH value of extraction was higher for a higher concentration of lauroimidazoline in the organic phase with xylene as the diluent. The addition of tributylphosphate (an organic modifier) to the organic phase enhanced the basicity of imidazoline and hence the pH value of the extraction of gold cyanide by about two pH units. The extraction of gold cyanide passed through a minimum and increased above a pH value of 13. A synergistic solvation extraction mechanism, involving the sodium aurocyanide ...
TL;DR: In this article, the radiolysis of diisodecyl phosphoric acid (DIDPA) in n-dodecane containing tributyl phosphate (TBP) was examined by analyzing concentrations of acidic extractants and H3PO4, and its effect on the extraction of neptune was studied froi the aspect of the extraction rate.
Abstract: Radiolysis of diisodecyl phosphoric acid (DIDPA) in n-dodecane containing tributyl phosphate (TBP) was examined by analyzing concentrations of acidic extractants and H3PO4, and its effect on the extraction of neptuniua was studied froi the aspect of the extraction rate. For the solvent containing 0.5 fi DIDPA and 0.1 1 TBP Irradiated in the absence of HNO3, G-values for degradation of DIDPA and for production of dibutyl phosphoric acid (DBP)were found to be 0.47 and 0.14, respectively. For the solvent irradiated in stationary contact with 0.5 M HNO3, G-value for DIDPA degradation was found to be 0.78, which ras 1.7 tines larger than the value for the solvent irradiated in the absence of HNO3.
TL;DR: In this article, the extraction of copper(II) and lead (II) with a series of alkyloxy derivatives of N-benzoyl-N-phenylhydroxylamine(BPHA) in benzene has been studied.
Abstract: The extraction of copper(II) and lead(II) with a series of alkyloxy derivatives of N-benzoyl-N-phenylhydroxylamine(BPHA) in benzene has been studied. The extraction constants of these metal chelates did not change with increasing the carbon number of the substituted alkyloxy groups. Extraction behavior of these metal ions from strongly alkaline media with these extractants has also be investigated.
TL;DR: In this paper, the equilibrium and kinetics of the extraction of copper with 3-alkylpentane-2, 4-dione (-H, -C2H5, -Ph, and -C8H17) were studied.
Abstract: The equilibrium and kinetics of the extraction of copper with 3-alkylpentane-2, 4-dione (-H, -C2H5, -Ph, and -C8H17) were studied. It was found that the overall equilibrium constant is related to the proton disscoiation constant and that the ratio of the stability constants of the copper chelate, β2/β1 2was independent of the alkyl chain length of the β-diketone. The rate constants for the reactions between cupric ion and the β-diketones in the aqueous phase were obtained by the relaxation method. The values decreased in the order -H>-Ph>-C2H5. The observed extraction rates were explained by a kinetic model using the measured physicochemical properties.
TL;DR: In this article, the distribution of lanthanides and yttrium between o-xylene solutions of Adogen-464Cl and aqueous solutions of LiCl was investigated over a broad range of Li-Cl and extractant concentrations.
Abstract: The distribution of lanthanides and yttrium between o-xylene solutions of Adogen-464Cl and aqueous solutions of LiCl was investigated over a broad range of LiCl and extractant concentrations. It has been found that stability constants of inner sphere lantha-nide chloro complexes decrease across the series, whereas the equilibrium constants for the transfer of the negatively charged chloro complexes increase with increasing lanthanide atomic number.