J.
Technology and Education, Vol.20, No.1, pp.1-5 (2013)
研究論文
梅調味廃液を用いたネオジムおよびサマリウムの分離回収
綱島 克彦*, 宮﨑 輝実, 前川 奈穂
和歌山工業高等専門学校物質工学科（〒644-0023和歌山県御坊市名田町野島77）
Separation
and Recovery of Neodymium and Samarium Using Waste
Solution
of Pickled Plum Production
Katsuhiko Tsunashima*, Terumi Miyazaki, Naho Maekawa
Department
of Materials Science, Wakayama National College of Technology
(77 Noshima, Nada-cho, Gobo, Wakayama
644-0023, Japan)
E-mail: tsunashima@wakayama-nct.ac.jp (K.
Tsunashima)
(Received November 26, 2012; Accepted January
17, 2013)
Recovery
processes of rare earth metals (neodymium and samarium) using waste solutions
of pickled plums (ume plums) on the basis of the
precipitation of rare earth metal complexes are presented in this report. A large
amount of pickled plums have been commercially produced in Wakayama, yielding
the corresponding amount of waste solutions in the production processes.
However, such waste solutions are almost unavailable, despite the fact that the
solutions frequently contain many useful organic compounds such as carboxylic
acids and polyphenols. On the other hand, the recycle processes of rare earth
metals using waste solutions have rarely been developed. In order to apply the
waste solutions to the metal recycle processes, we investigated the complex
formations between neodymium and samarium metals and organic acid components in
the waste solutions. The precipitations were observed when neodymium and
samarium chloride aqueous solutions were added into the concentrated waste
solutions of pickled plums. The presence of the neodymium and samarium in the
precipitates were indicated by the UV/visible spectroscopic measurements, which
suggests the formation of the complexes between the rare earth metals and
organic acid components. These results reveal that the precipitation processes
based on the complex formation might be regarded as a potential key process for
recycles of rare earth metals.
Key
Words : Rare
earth, Neodymium, Samarium, Pickled plums, Citric acid