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Title: Separation studies of yttrium(III) and lanthanide(III) ions with 4-benzoyl-2,4-dihydro-5-methyl-2-phenyl-3H-pyrazol-3-thione and trioctylphosphine oxide using a robotic extraction system

Journal Article · · Solvent Extraction and Ion Exchange

We studied the extraction of trivalent Y, La, Pr, Nd, Sm, Eu, Gd, Dy, Er, and Lu from aqueous perchlorate solutions using a mixture of 4-benzoyl-2,4-dihydro-5-methyl-2-phenyl-3H-pyrazol-3-thione (HBMPPT) and trioctylphosphine oxide (TOPO). The metal ion distribution coefficients (D-values) as a function of increasing lanthanide atomic number increased initially, reached a maximum value at Nd, then decreased to a nearly constant value for Gd and the later lanthanides. The D-values vary slightly across the lanthanide series, the maximum difference being a factor of 14 between La and Nd. Analysis of slopes of plots of log D versus pH, log [HBMPPT], and log [TOPO] indicated that the stoichiometries of the extraction complexes varied across the lanthanide series showing a decrease in the number of HBMPPT (and/or BMPPT) units and an increase in the number of TOPO molecules involved in the major extraction species. This extraction system can provide a good way to separate the trivalent actinides from the trivalent lanthanides. 21 refs., 2 figs., 3 tabs.

Sponsoring Organization:
USDOE
OSTI ID:
171569
Journal Information:
Solvent Extraction and Ion Exchange, Vol. 10, Issue 3; Other Information: PBD: Jul 1992
Country of Publication:
United States
Language:
English