| Project/Area Number |
01550517
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| Research Category |
Grant-in-Aid for General Scientific Research (C)
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| Allocation Type | Single-year Grants |
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| Research Field |
金属精錬・金属化学
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| Research Institution | Tohoku University |
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Principal Investigator |
UMETSU Yoshiaki Tohoku University, Research Institute of Mineral Dressing and Metallurgy, Associate Prof., 選鉱製錬研究所, 助教授 (10005423)
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| Project Period (FY) |
1989 – 1990
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| Project Status |
Completed (Fiscal Year 1990)
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| Budget Amount *help |
¥2,100,000 (Direct Cost: ¥2,100,000)
Fiscal Year 1990: ¥400,000 (Direct Cost: ¥400,000)
Fiscal Year 1989: ¥1,700,000 (Direct Cost: ¥1,700,000)
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| Keywords | Complex formation, / Solvent extraction, / Separation, / Rare earth metal ions, / DTPA, / Transfer, / D2EHPA, / HEH (EHP) |
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| Research Abstract |
In order to improve the separation of rare earth metal ions in the solvent extraction, the addition of a chelating reagent in the aqueous phase was investigated for Ce, Pr, and Nd. The extractants considered in this work were D2EHPA (di(2-ethylhexyl phosphorous acid) and HEH (EHP) (2-ethylhexyl hydrogen 2-ethylhexyl phosphonate) and a chelating reagent DTPA (diethylene triamine pentaacetate) was added into the aqueous phase. In such systems the extraction is considered to be depending on the relative strength between complex-forming in aqueous phase and the combination of the ion with the extractant in the organic phase.
In the extraction with D2EHPA, the extraction was onli slightly affected by the presence of the chelating reagent, DTPA over the whole range of pH probably due to strong affinity between D2EHPA and metal ions in question.
The formation of DTPA complex of the rare earth metal ions in the aqueous phase significantly enhanced the separation of the ions in the solvent extraction using HEH (EHP). At higher pH, the extractoin of the ions was higher in the order of Ce, Pr and Nd and the separation was promoted in high pH range.
Also in the transfer of the extracted ions from the aqueous phase to the organic was found to be suppressed to different extent according to the stability of the complex ions in the aqueous phase.
The addition of chelating reagent in the aqueous phase was shown to be effective in mutual separation of Ce, Pr and Nd ions both in equilibrium of extraction and in the transfer of the ions into the organic phase.
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