Selective Separation of Rare Earth Metals by Solvent Extraction in the Presence of New Hydrophilic Chelating Polymers Functionalized with Ethylenediaminetetraacetic Acid. II. Separation Properties by Solvent Extraction

Hideto Matsuyama, Yoshikazu Miyamoto, Masaaki Teramoto, Masahiro Goto, Fumiyuki Nakashio

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The selective separation of rare earth metals by solvent extraction including chelating polymers in the aqueous phase was investigated. The chelating polymers were synthesized in this laboratory by introducing ethylenediaminetetraacetic acid (EDTA) onto water-soluble polyally lamine. The highest selectivity obtained for the Y/Er separation system was 14.7, which was much higher than that in conventional solvent extraction (about 1.4) and also higher than that in extraction including EDTA (about 5.0). This means that the number of extraction stages required can be considerably reduced by the addition of chelating polymers. The effects of several experimental conditions such as pH, extractant concentrations, chelating polymer concentrations, and initial total rare earth metal concentrations on the separation factors and the distribution ratios for the Y/Er system were studied in detail. Furthermore, this extraction method was applied to other separation systems (Y/Dy, Y/Ho, Y/Tm). A remarkably high separation factor (12.6) was obtained for the Y/Tm system and the Y/Er system, although the separation factors were comparable to those in the presence of EDTA in the Y/Dy and Y/Ho systems.

Original languageEnglish
Pages (from-to)799-810
Number of pages12
JournalSeparation Science and Technology
Issue number6
Publication statusPublished - Jan 1 1996


All Science Journal Classification (ASJC) codes

  • Chemistry(all)
  • Chemical Engineering(all)
  • Process Chemistry and Technology
  • Filtration and Separation

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