| Project/Area Number |
24686101
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| Research Category |
Grant-in-Aid for Young Scientists (A)
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| Allocation Type | Partial Multi-year Fund |
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| Research Field |
Recycling engineering
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| Research Institution | Yokohama National University |
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Principal Investigator |
MATSUMIYA Masahiko 横浜国立大学, 環境情報研究科(研究院), 准教授 (00370057)
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| Project Period (FY) |
2012-04-01 – 2015-03-31
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| Project Status |
Completed (Fiscal Year 2014)
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| Budget Amount *help |
¥8,060,000 (Direct Cost: ¥6,200,000、Indirect Cost: ¥1,860,000)
Fiscal Year 2014: ¥1,040,000 (Direct Cost: ¥800,000、Indirect Cost: ¥240,000)
Fiscal Year 2013: ¥2,860,000 (Direct Cost: ¥2,200,000、Indirect Cost: ¥660,000)
Fiscal Year 2012: ¥4,160,000 (Direct Cost: ¥3,200,000、Indirect Cost: ¥960,000)
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| Keywords | 有価物回収 / イオン液体 / レアアース / リサイクル / イオン液体電析法 / 応用電気化学 / 環境電気化学 |
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| Outline of Final Research Achievements |
In this study, we developed a novel recycling process of rare earth metals from Nd-Fe-B magnets, which was composed of the following steps: pretreatment, wet separation and electrodeposition using ionic liquids. The leaching ratio of Nd3+ and Fe3+ was 91.5% and 5.8%, respectively. Then, Fe(OH)3 precipitate was generated by adding Ca(OH)2 at pH～4.5 on deironization process. As a result, Fe(OH)3 was perfectly removed by solid-liquid separation and the separation factor of Fe was >99.9%. This result allowed us to demonstrate that the electrodeposition energy of residual Fe was 0 kJ/mol. The electrodeposition of Nd metal was performed in ionic liquids under potentiostatic condition of -3.25V at 393K. As for the Nd deposits, Nd metal layer at the depth of 0.62um was confirmed by XPS analysis. Finally, the total recovery energy of Nd-1t was estimated at 1.8MWh/t, which was extremely low compared with the conventional technology and we contributed to the development of energy-saving process.
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