Electrochemical Formation of RE Alloys (RE = Dy, Nd) in a Molten LiCl-KCl System and Separation of Dy
Potentiostatic electrolysis were conducted at 0.55 V (vs. Li+ / Li) for 0.5, 1, 2, 3, 4 and 6 h with Ni plate cathodes at 723 K to confirm the formation of Nd-Ni alloys in LiCl-KCl eutectic melts added NdCl3 (0.50 mol％) at 723 K. All samples obtained after electrolysis at 0.55 V were identified as NdNi2 by XRD analysis. The growth rate of NdNi2 seems to be almost linear, 9.8 μm h-1. In order to investigate the electrolysis potential for the separation of Dy and Nd, cyclic voltammetry was conducted on a Ni electrode in LiCl-KCl eutectic melts added NdCl3 or DyCl3 at 723 K. In the cathodic scanning for the Ni electrode, cathodic current was observed from 1.00 V due to the formation of Dy-Ni alloys in LiCl-KCl eutectic melts added DyCl3. On the other hand, cathodic current due to the formation of Nd-Ni alloys was observed from 0.60 V in LiCl-KCl eutectic melts added NdCl3. From these results, it was suggested that separation of Dy and Nd could be achieved in the potential region of 0.60-1.0 V. Based on the result of cyclic voltammetry, an alloy sample was prepared by potentiostatic electrolysis at 0.65 V for 1 h with a Ni plate cathode in LiCl-KCl eutectic melts added NdCl3 and DyCl3. From the result of ICP-AES analysis, the mass ratio of Dy/Nd in the alloy sample was found to be 72. This result indicated a possibility of selective separation of Dy in a molten LiCl-KCl-DyCl3-NdCl3 system.
Molten salt Separation Recycle Rare earth Electrochemical process
Hirokazu KONISHI Hideki ONO Tetsuo OISHI Toshiyuki NOHIRA
Graduate School of Engineering, Osaka University, 2-1 Yamadaoka, Suita, Osaka 565-0871, Japan National Institute of Advanced Industrial Science and Technology, 16-1 Onogawa, Tsukuba, Ibaraki 305 Graduate School of Energy Science, Kyoto University, Sakyo-ku, Kyoto 606-8501, Japan
国际会议
Ninth International Conference on Molten Slags,Fluxes and Salts(第九届国际熔渣、溶剂与熔盐学术会议 MOLTEN12)
北京
英文
1-8
2012-05-27（万方平台首次上网日期，不代表论文的发表时间）