Solvent Extraction Of Lanthanum Research Articles

A novel method for synthesis of styryl phosphonate monoester and its application in La(III) extraction

Herein, styryl phosphonate monoester (SPE) was synthesized and first introduced as rare earth extractant. The solvent extraction of lanthanum (III) from nitrate solution using styryl phosphonate mono-iso-octyl ester (SPE108), di-2-ethylhexyl phosphoric acid (D2EHPA) and 2-ethylhexyl phosphonic acid-mono-2-ethylhexyl ester (EHEHPA) as extractants was investigated. The effects of experimental parameters including equilibrium time, extractant concentration, aqueous pH, phase ratio and salt concentration on the extraction process were studied. The results indicate that the extraction ability and capacity of the extractants follow the order: SPE108 > D2EHPA > EHEHPA. What's more, the extraction process is less affected by ammonium sulfate in the aqueous phase with SPE108. The results of the separation between lanthanum and adjacent lanthanides (Ce, Pr, Nd, Sm) show that SPE108 can separate lanthanides efficiently at low pH. The extraction mechanism of SPE108 is proved to be similar to D2EHPA, and the density functional theory (DFT) calculation results infer that SPE108 exhibits superior extraction ability due to its strong electron-accepting ability.

Solvent extraction of lanthanum(III) from chloride and nitrate aqueous solutions with dioctyldiglycolamates of dioctylammonium and trioctylammonium

The extraction of lanthanum(III) from chloride and nitrate aqueous solutions in the systems involving new binary extractants based on N,N-dioctyldiglycolamic acid (HA) and di-n-octylamine (R2NH) or tri-n-octylamine (R3N) in toluene was studied. The compositions of the extracted species in the lanthanum extraction with dioctyldiglycolamates of dioctylammonium and trioctylammonium were investigated based on the analysis of the extraction isotherms. The formation of the extracted species, LaA3, in the extraction of La(III) from chloride aqueous solutions with binary extractants was indicated. The extraction of lanthanum from nitrate aqueous solutions proceeds with the formation of 1:1 complexes between the binary extractants and La(III). The extractability of lanthanum nitrate was found to be significantly greater than that of lanthanum chloride, owing to differences in the compositions of the extracted compounds.

Solvent extraction of lanthanum (III) using PC88A extractant diluted in kerosene

Solvent extraction of lanthanum (III) using PC88A extractant diluted in kerosene

Solvent Extraction of Lanthanum(III) and Europium(III) from Nitrate Media by Aminooctyldimethylene Diphosphonic Acid

Solvent Extraction of Lanthanum(III) and Europium(III) from Nitrate Media by Aminooctyldimethylene Diphosphonic Acid

Solvent extraction of lanthanum and cerium ions from hydrochloric acidic aqueous solutions using partly saponified 2-ethylhexyl phosphonic acid mono-2-ethylhexyl ester

In order to clarify the extraction process with saponified extractant, the solvent extraction experiments of rare earth elements (REEs), lanthanum and cerium, by using partly saponified 2-ethylhexyl phosphoric acid mono-2-ethylhexyl ester (EHEHPA, HL) from hydrochloric acidic solutions have been performed. The concentration of initial aqueous rare earth ion was in a range of 0.0010–0.1000mol·L−1; EHEHPA in a range of 0.2877–0.8631mol·L−1with saponification rate of 0.3 (mole fraction), and the initial aqueous pH in a range of 1.00–4.00. Firstly, the extracted species were determined by the saturation extraction capacity method. Secondly, according to the equilibrium aqueous pH values, the extraction processes were divided into three different categories: extraction with saponified EHEHPA, extraction with un-saponified EHEHPA, and hydrolysis process. Finally, for the first two processes, in order to predict the distribution ratio, two semi-empirical calculation models were developed with. The calculation results are in good agreement well with the experimental data.

Studies on extraction and separation of La(III) with DEHPA and PC88A in petrofin

The solvent extraction of lanthanum(III) from nitrate solution using DEHPA and PC88A as extractants diluted with petrofin was investigated. The findings indicated that lanthanum extraction process follows a cation-exchange mechanism. The effect of experimental parameters like shaking time, extractant molarity, aqueous medium pH, presence of salt, phase volume ratio, and diluents on the extraction process has been studied. Extraction of 99.8% and 85% has been noticed with 0.5mol/L DEHPA and 0.6mol/L PC88A, respectively. Stripping of lanthanum from the loaded organic phase with mineral acids and separation of lanthanum(III) from Ce, Pr, Nd and Sm have also been reported.

Solvent extraction of lanthanum(III) by N-n-octylaniline from salicylate media

In this paper, solvent extraction of lanthanum(III) using N-n-octylaniline in salicylate media has been systematically investigated. The effect of various parameters, such as equilibrium time, aqueous pH, extractant concentration, weak acid concentration, aqueous to organic volume ratio, back strippant and organic solvent, on the extraction have been discussed. Lanthanum(III) is quantitatively extracted at pH 5.3–6.5 from 0.04 M sodium salicylate with 0.065 M N-n-octylaniline dissolved in xylene. Experimental data have been analysed graphically to determine the stoichiometry of extracted species [RR’NH+ 2 La(sal)- 2](org). The extracted metal ion was separated by using selective strippant and estimated spectrophotometrically with arsenazo I. The method is applicable for binary separation of lanthanum(III) from yttrium(III) and associated metal ions.

Selectivity of heterocyclic β-ketoenols toward trivalent lanthanoids: Semi-empirical molecular orbital calculations and solvent extraction from nitrate aqueous medium

The solvent extraction of lanthanum(III) and lutetium(III) from 0.1 M nitrate medium with monoacidic chelating extractants of various acidities and lipophilicities, in chloroform, at 25 °C, has been studied and compared with previously reported extraction data for europium. The extractants, “HL”, are either the 3-phenyl-4- p- tert-butylbenzoyl-isoxazol-5-one, “HPtbBI”, or the substituted 4-acyl-5-hydroxypyrazoles 1-( p-nitro-phenyl)-3-phenyl-4-lauroyl-5-hydroxypyrazole, “HNPPLP”, and 1-phenyl-3-methyl-4-( p-tert-butylbenzoyl)-5-hydroxy-pyrazole, “HPMtbBP”. Like europium, lanthanum and lutetium are extracted by cation exchange as LnL 3,org. Because of the higher acidity of the former ones, extractions performed with 4-acylisoxazol-5-ones occur at lower pH values than with 4-acyl-5-hydroxypyrazoles. The order of extraction efficiencies is: HPMtbBP (p K a = 4.2) < HNPPLP (p K a = 3.2) < HPtbBI (p K a = 1.3) < HPBI (p K a = 1.2) (HPBI: 3-phenyl-4-benzoyl-isoxazol-5-one). Moreover, for all these chelators, the extraction efficiency follows the order lanthanum < europium < lutetium, while their separation factors decrease with increasing extractant acidity. The extractions of other trivalent lanthanoids (Ln 3+ = Ce 3+, Nd 3+, Sm 3+, Tb 3+, Ho 3+ and Tm 3+) and yttrium(III) from nitrate medium with HNPPLP have also been investigated. The equilibrium constants and the intra-lanthanoidic separation factors show the same trends as those observed for other β-ketoenol extractants, HPMBP, 1-phenyl-3-methyl-4-benzoyl-5-hydroxypyrazole, and HTTA, thenoyltrifluoroacetone. The overall selectivity, SF(Lu/La), is discussed with respect to the extraction thermodynamics, the d(O⋯O) HL structural parameters, measured or calculated by semi-empirical methods, and the inner- or outer-sphere nature of the extracted complexes.

Solvent extraction of lanthanum(III), europium(III) and lutetium(III) by bis(4-acyl-5-hydroxypyrazoles) derivatives

The liquid–liquid extraction of some trivalent rare earths Ln(III) (Ln: La, Eu, Lu), performed from 0.1 M NaNO 3 aqueous solutions by two bis(4-acyl-5-hydroxypyrazoles), 1,12-bis(1′-phenyl-3′-methyl-5′-hydroxy-4′-pyrazolyl)-dodecane-1,12-dione (HL-10-LH) and 1,6-bis(1′-phenyl-3′-methyl-5′-hydroxy-4′-pyrazolyl)-hexane-1,6-dione (HL-4-LH), in chloroform, has been studied. The processes of extraction have been determined by the slope analysis method and by analyzing a function that allows the simultaneous treatment of all the experimental points obtained in different conditions. With HL-10-LH, the stoichiometries of the extracted species differ for the three lanthanides. The ligands are biscoordinated and tetracoordinated in the extracted complexes of lanthanum and europium, La 2(L-10-L) 2(L-10-LH) 2 and Eu n(L-10-L) n (L-10-LH) n ( n = 1,2). They are exclusively biscoordinated in the complex of lutetium, Lu(L-10-LH) 3. The complex of europium extracted by HL-4-LH at weak extraction yields, Eu(L-4-L)(L-4-LH), and the corresponding extraction constant are comparable to the ones obtained for HL-10-LH, whereas polynuclear species are extracted at high extraction yields. The extraction efficiency with HL-10-LH increases with the ascending atomic number of Ln (La < Eu < Lu). A comparison between HL-10-LH and HPMBP (1-phenyl-3-methyl-4-benzoyl-5-hydroxy-pyrazole) for the same concentration of complexation sites shows that the extraction by HL-10-LH is more effective. Moreover, a better selectivity of extraction was obtained with HL-10-LH.

Solvent extraction of lanthanum(III) from acidic nitrate-acetato medium by Cyanex 272 in toluene

The extraction behavior of La(III) from acidic nitrate-acetato medium by bis(2,4,4-trimethylpentyl)phosphinic acid (Cyanex 272, H 2A 2) in toluene either alone or in combination with trioctylphospine oxide (TOPO, B) has been investigated as a function of contact time, aqueous phase concentration of La 3+, H +, NO 3 − and Ac − (acetate), Cyanex 272 and TOPO concentration in the organic phase and temperature. The distribution coefficient is found to decrease with increasing La 3+ concentration up to 7.34 mM La 3+ in the aqueous phase, after which it increases up to 9.79 mM La 3+ concentration and again decreases. The pH and log extractant concentration dependencies suggest that [La(Ac) 2A·3HA] and [La(Ac)A 2·B] are extracted in the system without and with TOPO, respectively. The pH dependence of 1 indicates that one hydrogen ion is liberated in forming the complex for both the extraction system with TOPO and without TOPO. The distribution coefficient decreases with increasing acetate ion concentration at higher acetate ion concentrations with and without TOPO but is less dependent at low acetate concentrations. The synergistic effect of TOPO is found only at higher TOPO concentrations. These results suggest that the [La(Ac) 2A·3HA] (o) and [La(Ac)A 2·B] (o) species are extracted in the system without and with TOPO, respectively. The temperature dependence data give the enthalpy of extraction, Δ H, of 60 kJ/mol. The equilibrium constant, K ex, is 10 −2.16 with a standard deviation of log K ex of 0.096 in the system without TOPO and 10 −2.58 with a standard deviation of log K ex of 0.21 for the extraction system with TOPO. The loading capacity of Cyanex 272 is found to be 15.97 g La(III)/100 g Cyanex 272. The phosphorus to lanthanum ratio of the solid complex obtained is 3.

Solvent Extraction of Several Trivalent Metal Ions with 4-Isopropyltropolone into Chloroform

The solvent extraction of lanthanum(III), praseodymium(III). neodymium(III), samarium(III), europium(III), gadolinium(III), thulium(III), ytterbium(III), lutetium(III), scandium(III), and indium(III) (M(III)) in 0. mol dm 3 sodium nitrate solutions with 4-isopropyltropolone (Hipt) into chloroform was studied. From the dependence of extraction on the concentration of 4-isopropyltropolonate anions in the aqueous phase and also on the concentration of metal ions, it was concluded that scandium(III) and indium(III) were always extracted in the mononuclear form, M(ipt) 3 , But dinuclear lanthanoid(III) chelate complexes, M 2 (ipt) 6 nHipt where n=0 or 1, were also extracted with mononuclear ones even when the metal concentration in the organic phase was higher than about 10 -6 mol dm -3 . The degree of dinuclear species formation was greater in the following order: lutetium(III) to samarium(III)>neodymium(III)>praseodymium(III)>lanthanum(III) scandium(III) - indium(III). On the other hand, the stability of the self-adduct dinuclear chelate complexes in the organic phase was higher in the order: lanthanum(III) to gadolinium(III)>thulium( III)>ytterbium(III )>lutetium(III).

Polymerization and Adduct Formation of Some Lanthanide(III) Decanoates in the Extraction of Lanthanides(III) with Decanoic Acid Using 1-Octanol and Benzene as a Solvent.

The solvent extraction of lanthanum(III), cerium(III), neodymium(III), samarium(III), gadolinium(III), dysprosium(III), erbium(III) and ytterbium(III) with decanoic acid in 1-octanol and benzene was carried out at 25°C and at an aqueous ionic strength of 0.1 mol dm-3 (NaNO3). In extraction systems using 1-octanol as a solvent, all of the lanthanides were found to be extracted as two kinds of monomeric decanoates; in those using benzene, the monomeric, dimeric and tetrameric lanthanide(III) decanoates were proven to be responsible for the extraction, except for gadolinium(III), whose extracted species were the monomeric and dimeric species. The dimerization, tetramerization and adduct formation constants of lanthanide(III) decanoates in the organic phase were estimated. A so-called “gadolinium break” was observed for the polymerization constants of lanthanide(III) decanoates.

Effect of Changes in Structure of Phosphoric Acid Esters on Extractability of Rare Earths. Extraction of rare earths by phosphoric acid esters containing bulky alkyl groups. I.

Solvent extraction of lanthanum (III), samarium (III), and dysprosium (III) by kerosene solutions of phosphoric acid esters has been investigated to elucidate the structure effect of the phosphates on the extraction behaviors of these elements. As a result, it is found that the position of alkyl side chain in the organic groups of the phosphoric acid esters plays an important role in the extraction phenomena of the rare earths, and that the shorter the distance between the substituent and PO (OH) group, the greater the dependence of the extractability of rare earth on the pH of the aqueous phase is. It is also indicated that the separation factors between the elements are affected by the steric hindrance of the organic group of the phosphates. The factors of the substituent effect on the extraction phenomena are examined by using CNDO (Complete Neglect of Differential Overlap method) molecular orbital calculations.

Liquid–liquid extraction and separation of lanthanum(III) from titanium(IV), zirconium(IV), hafnium(IV), thorium(IV) and uranium(VI)

A method for the solvent extraction of lanthanum from salicylate media by using triphenylphosphine oxide is presented. Lanthanum is extracted quantitatively from 2.0 × 10–2–5.0 × 10–2 mol dm–3 sodium salicylate solution at pH 4.0–5.0 using 1.5% triphenylphosphine oxide dissolved in toluene. The extracted metal ion is stripped using water and estimated spectrophotometrically following complexation with Thoron-I. A possible mechanism of extraction is discussed. The method permits the separation of lanthanum from titanium, zirconium, hafnium, thorium and uranium.

Solvent extraction of lanthanum (III) and cerium (III) from aqueous chloride solutions by LIX 70

The extraction and separation of cerium (III) from aqueous NaCl solutions with LIX 70® dissolved in kerosene or in n-heptane was investigated. The extraction of both metals has been found to depend on pH and on extractant concentration but not to depend on metal or chloride concentrations. The extraction constants calculated experimentally are log K ex = −16.15 for cerium and log K ex= −16.85 for lanthanum, It was found that both lanthanides are extracted as 1:3, metal: reagent complexes.

Solvent extraction of lanthanum(III) and cerium(III) with dialkyldithiophosphoric acids. Separation from thorium(IV)

The extraction of lanthanum(III) and cerium(III) with dialkyldithiophosphoric acids, Hdtp, into different polar and nonpolar solvents (cyclohexane, benzene, carbon tetrachloride, chloroform, diethyl ether, dibutyl ether, n-butanol and cyclohexanone) from aqueous solutions containing perchlorate, nitrate and chloride anions has been investigated. The effect of various factors, such as nature of the solvent, pH, metal concentration and foreign anions present in the aqueous phase was investigated in order to establish the mechanism of extraction process. The data obtained suggest an ion-exchange mechanism. The anions present in the aqueous phase do not participate in the extraction process and do not influence significantly the magnitude of the extraction ratios either. The extracted species in the organic phase is a 1∶2 complex of lanthanide with Hdtp. The extraction efficiency (E%) is calculated and the possibility of Th-rare earths separation is discussed.

Solvent extraction of lanthanum(III), europium(III) and lutetium(III) with fluorinated 1-phenyl-3-methyl-4-benzoyl-5-pyrazolones into chloroform

A series of chelating reagents, 1-phenyl-3-methyl-4-(2-fluorobenzoyl)-5-pyrazolone, 1-phenyl-3-methyl-4-(3-fluorobenzoyl)-5-pyrazolone and 1-phenyl-3-methyl-4-(4-fluorobenzoyl)-5-pyrazolone, has been synthesized. The extraction of Ln(III), (Ln = La, Eu and Lu) into chloroform with these reagents at 30 ± 1° has been studied. The composition of the complexes extracted has been determined by the slope method, and the extraction constants K ex, were measured. The presence of the fluorine atom in the reagents does not make the K ex, values much different from those obtained with the parent pyrazolone.

Solvent extraction of lanthanum(III) from sulphuric acid solutions by Primene JMT

The distribution of lanthanum(III) between aqueous H 2SO 4 solutions and Primene JMT in the organic phase is described. The dependence of the extraction on acidity, extractant concentration and type of diluent was investigated. Aggregation numbers are calculated and a mechanism for the extraction is suggested. The separation of thorium(IV) from lanthanum(III), cerium(III) and cerium(IV) is outlined.