Electrochemical behavior of Nd was studied in NaCl-KCl melt on W and Cu electrodes via cyclic voltammetry and chronopotentiometry. Generally, the reduction of Nd 3+ takes place in two consecutive steps in molten chlorides, such as LiCl-CaCl 2 , LiCl-BaCl 2 , CaCl 2 -NaCl, LiCl-KCl melts. However, the reduction of Nd 3+ ions was found to be through a one-step process: Nd 3+ + 3e − → Nd. The co-reduction behavior of Nd 3+ and Cu 2+ ions and the mechanisms of alloy formation were investigated in NaCl-KCl melt on W electrodes at 988 K (715 °C). Four potential plateaus corresponding to four different kinds of Cu-Nd intermetallic compounds were detected. Cu-Nd alloys were prepared on Cu electrodes at 988 K (715 °C) and 1143 K (870 °C). At 988 K (715 °C), Cu 5 Nd phase was identified by X-ray diffraction. The morphology and micro-zone chemical analysis of the alloys were characterized by scanning electron microscopy equipped with energy-dispersive spectrometry. The alloy film was observed on the Cu electrodes. Moreover, at 1143 K (870 °C), a globate bulk Cu-Nd alloy with Cu 5 Nd, Cu 4 Nd, Cu 2 Nd, CuNd, and Cu phases, as liquid in the melt, was obtained at the bottom of the crucible.
The electrochemical reduction of Nd(III) was investigated on an inert W and a liquid Al electrode in molten NaCl–KCl eutectic salt. On both W and liquid Al electrodes, the reduction of Nd(III) ions to Nd(0) metal occurred in a single reaction step, which avoids the corrosion reaction: 2Nd(III) + Nd → 3Nd(II). Therefore, corrosion of Nd metal in this molten chloride media is not expected. The co-reduction behavior of Nd(III) and Al(III) ions was studied on a W electrode in NaCl–KCl–AlCl3–NdCl3 melts. Five kinds of Al–Nd intermetallic compound were detected via cyclic voltammetry and open circuit chronopotentiometry. Intermittent galvanostatic electrolysis was employed on liquid Al electrodes to extract Nd in the form of Al–Nd alloys in NaCl–KCl–NdCl3 melts. Nd, AlNd3, Al2Nd, and AlNd phases were identified by X-ray diffraction (XRD). With the increase of electrolytic time, the content of Nd-rich Al–Nd intermetallic compounds in the Al–Nd alloy increased. The morphology and micro-zone chemical analysis of the deposits were characterized by a scanning electron microscope (SEM) equipped with an energy dispersive spectrometer (EDS), and the Al11Nd3 phase was confirmed by EDS analysis.