The extraction of neodymium and samarium by di(2-ethylhexyl) phosphoric acid from aqueous chloride, perchlorate and nitrate systems

Lenz, Terry G.; Smutz, Morton

doi:10.1016/0022-1902(68)80488-9

Cited by 25 publications

(10 citation statements)

References 14 publications

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“…This ion may have formed by splitting off a DEHPA molecule from the neutral Nd(DEHPиDEHPA) 3 and the addition of H ϩ . The strongest signal in Figure 4 at m/z ϭ 2076 is due to [Nd(DEHPиDEHPA) 3 ϩ H] ϩ formed by the addition of H ϩ to a neutral Nd(DEHPиDEHPA) 3 . The presence of this species is in accord with the general opinion that the predominant molecule in not-completely-loaded lanthanide-DEHPA solutions is made up from one metal atom and three DEHPA dimers.…”

Section: The Esi and Maldi Spectrometric Investigations Of Neodymentioning

confidence: 97%

“…The set of signals at about m/z ϭ 1431 is probably mainly due to [Nd(DEHPи DEHPA) 2 ] ϩ , because the theoretical isotopic pattern of this species agrees with that measured (Figures 2 and 3). So, [Nd(DEHPиDEHPA) 2 ] ϩ may have formed from a neutral molecule Nd(DEHPиDEHPA) 3 or Nd(DEHPиDEHPA) 2 иDEHP by splitting off a (DEHPиDEHPA) Ϫ or (DEHP) Ϫ anion, respectively. The peak at about m/z ϭ 1752 may belong to [Nd(DEHPи DEHPA) 2 иDEHP ϩ H] ϩ , where two dimeric and one monomeric DEHPA molecules are bonded to the neodymium.…”

Section: The Esi and Maldi Spectrometric Investigations Of Neodymentioning

confidence: 99%

“…After evaporating the diluent toluene, an infrared spectroscopic analysis of the obtained solid matter yielded an Sc:DEHPA molar ratio of 1:2.8, which is close to the theoretical ratio of 1:3. Lenz and Smutz, [3] as well as Owens and Smutz, [4] stated that the transition to the gel occurs in a more complicated manner than usually assumed. That is, the gelatinous material may form at a RE:DEHPA ratio much less than 1:6.…”

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confidence: 98%

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Investigation of the structure of neodymium-di-(2-ethylhexyl) phosphoric acid combinations using electrospray ionization and matrix-assisted laser desorption ionization mass spectrometry and nuclear magnetic resonance spectroscopy

Scharf

Ditze

Schwerdtfeger

et al. 2005

Metall Mater Trans B

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Neodymium-di-(2-ethylhexyl) phosphoric acid (DEHPA) species forming in the organic phase during solvent extraction of neodymium with solutions of DEHPA have been studied. Two samples were prepared: one with a low molar ratio of neodymium to DEHPA, which is liquid and clear, and the other with a high molar ratio of neodymium to DEHPA (complete loading), which has the consistency of a gel. Electrospray ionization (ESI) and matrix-assisted laser desorption ionization (MALDI) mass spectrometric investigations show numerous compounds, in addition to the generally assumed species dimeric DEHPA and Nd(DEHPиDEHPA) 3 , in the liquid sample. The nuclear magnetic resonance (NMR) spectroscopic investigation of pure DEHPA and of a completely loaded sample confirm the formula of pure DEHPA and of the organic part of Nd(DEHP) 3 . Furthermore, chemical analysis of a dried, completely loaded sample also proves the existence of the species Nd(DEHP) 3 . Results of X-ray powder diffraction measurements of this sample agree well with literature data.

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Section: The Esi and Maldi Spectrometric Investigations Of Neodymentioning

confidence: 97%

Section: The Esi and Maldi Spectrometric Investigations Of Neodymentioning

confidence: 99%

mentioning

confidence: 98%

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Investigation of the structure of neodymium-di-(2-ethylhexyl) phosphoric acid combinations using electrospray ionization and matrix-assisted laser desorption ionization mass spectrometry and nuclear magnetic resonance spectroscopy

Scharf

Ditze

Schwerdtfeger

et al. 2005

Metall Mater Trans B

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“…The plotted points lie on a straight line as expected by eq. (8). From the slope and intercept of this line, the values of K m and K d were evaluated as shown in Table 1 together with the constants published in the literature 12,[14][15][16][17] for comparison.…”

Section: Distribution Of Pc-88amentioning

confidence: 99%

“…Thus, the experimental results were mathematically analyzed in order to obtain relevant conditional equilibrium constants. On the other hand, few studies have been carried out on the extraction equlibrium of RE metals in macro concentrations under practical and nonideal conditions, [8][9][10] where the nonideality of the aqueous phase was corrected by considering the appropriate complexations.…”

Section: Introductionmentioning

confidence: 99%

Modeling of the Equilibria of Yttrium(III) and Europium(III) Solvent Extraction from Nitric Acid with PC-88A

Tanaka

2006

Mater. Trans.

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The equilibria of yttrium(III) and europium(III) (RE) extraction with PC-88A dissolved in Shellsol D70 from nitric acid solutions were studied under nonideal conditions in order to develop a chemically-based model enabling the engineering prediction of the equilibrium distribution ratios. The distribution of the extractant between the nitrate solution and the diluent was also examined. As a result, it was found that (i) the majority of PC-88A is dimerized in the organic phase, (ii) the cation exchange extraction is predominant in the low-acidity region, and (iii) solvation extraction becomes appreciable in the high-acidity region. By using a model that considers these two extraction equilibria together with the complexation of the RE with NO 3 À , the nonideality of the PC-88A dimer, and the competing extraction of HNO 3 , the extraction equilibrium constants and the coefficient for the effective concentration of the extractant were determined by the nonlinear least-squares method. The proposed model can reproduce the experimental data with good accuracy for single-metal systems over wide feed concentration ranges of RE up to 0.1 kmolÁm À3 , nitric acid (0.05 to 3 kmolÁm À3 ), and the extractant (0.25 to 1 kmolÁm À3 ). Its applicability to the prediction of the extraction from a binary metal system was also confirmed.

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Extraction liquide‐liquide par des esters alkylphosphoriques. I. Extraction de l'yttrium par l'acide di‐(2‐éthylhexyl)phosphorique

Brunisholz

Hirsbrunner

Roulet

1972

Helvetica Chimica Acta

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IX 72)Summary. The extraction of macro-amounts of Yttrium from solutions of nitric and perchloric acids by di-(2-ethylhexyl)phosphoric acid has been studied. The extraction of Yttrium is more effective from the perchloric medium and takes place by two mechanisms: an ion-exchange reaction Y3+/H+ at low concentrations and a solvatation reaction at high concentrations of Yttrium. The stability constant of the mononitratocomplex YNOg+ has been estimated. 1 . Introduction. -La grande majorit6 des publications concernant la ¶tion des terres rares par extraction liquide-liquide au moyen d'esters dialkylphosphoriques (HG) sont consacrkes B des systkmes oh le mCtal est en concentration de traceur radioactif (< 1 0 -5~) [2]-[S]. Dans ces conditions, l'extraction a lieu par un mCcanisme selon: + n (HG)20rg * LnG, * (HG)zn-3,,, + 3 Ha'q (Ln = terre rare; (HG), = dim6re en solution organique; les indices aq et org indiquent la phase dans laquelle se trouve l'espkce) La valeur de n dCpend de la nature du diluant (hydrocarbures aliphatiques n = 2,5; hydrocarbures aromatiques n = 3,O). L'extraction h, des macroconcentrations n'a fait l'objet que de quelques travaux. Hamda & Smutz [9] ont CtudiC le systgme YC13-HC1-H,O-H(DEHP)/kCroskne H(DEHP) = acide di-(2Bthylhexyl)phosphorique) ; l'extraction par Cchange d'ions n'est mise en Cvidence que pour des faibles concentrations d'yttrium et dans un domaine d'acidit6 limit6 (2 h, 6~) . Un autre travail concerne l'extraction du chlorure d'yttrium par le meme extractant, en prCsence d'autres terres rares [lo]. La ¶tion de mClanges Ho-Y-Er en milieu nitrique ou chlorhydrique est reportCe par l)Extrait de la these de W . Hirsbrunner [l].

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The extraction of neodymium and samarium by di(2-ethylhexyl) phosphoric acid from aqueous chloride, perchlorate and nitrate systems

Cited by 25 publications

References 14 publications

Investigation of the structure of neodymium-di-(2-ethylhexyl) phosphoric acid combinations using electrospray ionization and matrix-assisted laser desorption ionization mass spectrometry and nuclear magnetic resonance spectroscopy

Investigation of the structure of neodymium-di-(2-ethylhexyl) phosphoric acid combinations using electrospray ionization and matrix-assisted laser desorption ionization mass spectrometry and nuclear magnetic resonance spectroscopy

Modeling of the Equilibria of Yttrium(III) and Europium(III) Solvent Extraction from Nitric Acid with PC-88A

Extraction liquide‐liquide par des esters alkylphosphoriques. I. Extraction de l'yttrium par l'acide di‐(2‐éthylhexyl)phosphorique

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