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*, 宮ア 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