| Project/Area Number |
14350406
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| Research Category |
Grant-in-Aid for Scientific Research (B)
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| Allocation Type | Single-year Grants |
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| Section | 一般 |
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| Research Field |
化学工学一般
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| Research Institution | TOKYO INSTITUTE OF TECHNOLOGY |
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Principal Investigator |
NAKANO Yoshio Tokyo Institute of Technology, Interdisciplinary Graduate School of Science and Technology, Professor, 大学院・総合理工学研究科, 教授 (30092563)
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| Co-Investigator(Kenkyū-buntansha) |
MIYAZAKI Akane Tokyo Institute of Technology, Interdisciplinary Graduate School of Science and Technology, Assistant Professor, 大学院・総合理工学研究科, 助手 (80293067)
HIROKAWA Yoshitsugu Tokyo Institute of Technology, Interdisciplinary Graduate School of Science and Technology, Professor, 大学院・総合理工学研究科, 連携客員教授
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| Project Period (FY) |
2002 – 2003
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| Project Status |
Completed (Fiscal Year 2003)
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| Budget Amount *help |
¥7,000,000 (Direct Cost: ¥7,000,000)
Fiscal Year 2003: ¥3,300,000 (Direct Cost: ¥3,300,000)
Fiscal Year 2002: ¥3,700,000 (Direct Cost: ¥3,700,000)
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| Keywords | Gold ion / Silver ion / Palladium ion / Gel / Tannin molecule / novel metals / Extraction / Redox / 銀イオン |
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| Research Abstract |
We succeeded in developing a novel recovery system of gold(Au), silver(Ag), and palladium(Pd) contained in the electric parts of mobile phones, utilizing tannin gel particles. Tannin gel particles were prepared by cross-linking natural condensed tannin molecules which is ubiquitous and inexpensive material having a lot of hydroxyl groups. The adsorption mechanisms of those novel metals onto the tannin gel particles was investigated in detail to establish the polymer gel/liquid extraction method. The following results were obtained.
(1)The adsorption of Au, Ag and Pd onto the tannin gel particles was found to take place through the two steps : the reduction of Au, Ag and Pd ions to the metals on the surface of tannin gel particles and the oxidization of tannin molecules.
(2)The maximum capacity of metallic silver adsorbed was extremely high as 930mg-Ag/(g-dry-tannin-gel). The adsorption rate of Ag was accelerated in the presence of small amount of Cu ions and Ag ions were recovered selectively in Ag-Cu mixtures.
(3)The tannin gel showed the most highest adsorption capacity (8000mg-Au/g-dry-tannin gel that) for Au among the previous reports.
(4)As for Pd, the Pd species containing fewer Cl such as PdCl^+ and PdCl_2, were more adsorbable onto the tannin gel particles than PdCl_3^-and PdCl_4^<2->.
(5)It was elucidated that the separation of Au and Pd occurred perfectly depending on the conditions of Au-Pd aqueous solution.
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