Extraction of trivalent lanthanides

Narita, H., Yaita, T., Tamura, K., Tachimori, S. 1998. Solvent extraction of trivalent lanthanide ions with N,N -dimethyl-N,N -diphenyl-3-oxapentanediamide. Radiochim. Acta 81 (4) 223-226. 

Jensen, M.P., Bond, A.H. 2002. Influence of aggregation on the extraction of trivalent lanthanide and actinide cations by purified Cyanex 272, Cyanex 301, and Cyanex 302. Radiochim. Acta 90 (4) 205-209. 

L. H. Delmau, Ph.D. Thesis, Strasbourg University, 1997. Extraction of Trivalent Lanthanides and Actinides by Functionalized Calixarenes. Study of the Structure of the Complexes in Solution by Nuclear Magnetic Resonance. 

Vanura, P. (1990) Extraction of trivalent lanthanides and actinides in the presence of crowns, polyethylene glycols and other polyoxonic compounds, Chem. Listy, 84(2), 141-163. 

Ensor DD, McDonald GR, Pippin CG, Extraction of trivalent lanthanides by a mixture of didodecylnaphthalenesulfonic acid and a crown ether. Anal. Chem 1986 58, 1814-1816. 

Fig. 9. Plot of the logarithm of the relative extraction coefficient vs L-quantum number for the extraction of trivalent lanthanides by HEH0P. Experimental data of static extraction at 25 "C69 ...

Cyanex-301 (bis(2,4,4-trimethyl pentyl) dithiophosphinic acid) has been extensively studied for lanthanide-actinide separation, either alone or in the presence of synergists [62,63], Solvent extraction studies using Cyanex-301 had indicated the following two-phase extraction equilibria for the extraction of trivalent lanthanides and actinides from aqueous nitrate medium [63] ... 

The in situ formation of ammonium carboxylate groups playing as bridging groups was proved by NMR and FT-IR spectroscopies. This material was proved to be very convenient for solid/liquid extraction of trivalent lanthanide ions (La, Eu, Gd, and Yb) by exchange reaction (see Section 12.4). Furthermore, this study... 

These oxygen-donor type extractants have potential for co-extraction of trivalent lanthanide and actinide ions. For the mutual separation between trivalent actinides and lanthanides, so-called soft-donor (nitrogen-donor type and sulfur-donor type) extractants are promising and widely investigated for the application of nuclear waste treatment as follows. 

Separation factors (relative to Am) for solvent extraction of trivalent lanthanides and actinides with 0.817 M DHDECMP/ DIPB/l.OM HNOj from Horwitz et al. (1981). 

In general, extraction of trivalent lanthanides/actinides by amine extractants suffer from many of the same limitations as the neutral organophosphorus extractants. In fact, they are more severely limited as metal complexes are extracted as anions, analogously with anion exchange resins. Of primary and secondary amine extractants, only Primene JM-T and n-benzyl heptadecyl amine (BzHp-DA) (Weaver 1974) showed any utility in separating lanthanides. 

Separation factors for TTA extraction of trivalent lanthanides and actinides from Stary (1966) (TTA/toluene) and Alstad etal. (1974) (TTA/Caj. 

Whereas previously attention was paid mainly to hard donors permitting only extraction of trivalent lanthanides and trivalent actinides (minor actinides, MA) as a group (Rais and Griiner, 2004), in the last five years mainly systems with soft donors (molecules containing S or N atoms) have been studied. 

As demonstrated, this family of extractants allows for a good extraction of trivalent lanthanides and actinides from most fission products present in the simulated PUREX feed. Most compounds... 

A fundamental study of the extraction of trivalent lanthanides and yttrium nitrates by carboxylic acids in xylene diluent was reported by duPreez and Preston (1992). The steric parameter E of the substituent alkyl group, representing the steric bulk of the carboxylic acid molecule, shows a definite relationship to the extractabilities of the lanthanides defined by their atomic numbers. The extraction reaction of a trivalent lanthanide Ln + by a carboxylic acid dimer is... 

The solvent extraction of trivalent lanthanides (La, Nd, Eu, Er, and Yb) in three calixarene-type cyclophanes was described by Ludwig et al. (1993). Calixarenes are (1, w)-cyclophanes with a cavity formed by bridged phenyl units and various derivatives are formed with the introduction of substituents onto the skeleton. The three calixarenes studied are /7-tert-butylcalix/6/arene hexacarboxylic acid (LI), /i-tert-butylcalix/4/arene tetracarboxylic acid (L2) and [3,1,3, l]-cyclophane (L3). LI, L2 and L3 have different cavity sizes and contain carboxylic acid groups at the lower rim to achieve a high coordination number for Ln and to prevent the phase transfer of counter anions. 

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