Pb cathode assisted electrochemical extraction of Pr(III) by formation of Pb₃Pr in LiCl-KCl melts

In this paper, the electrochemical behaviors of Pb(II) and Pr(III) were investigated on W electrode in LiCl-KCl melts, respectively. The results illustrated that the reduction of Pb(II) and Pr(III) was a one step process. When the PbCl₂ and PrCl₃ co-existed in the molten salt, the cyclic voltammetry, square wave voltammetry and open circuit chronopotentiometry illustrated that four kinds of Pb-Pr intermetallic compounds were formed at 773 K. Whereafter, the electrochemical behavior of Pr(III) on liquid Pb cathode was studied by cyclic voltammetry in LiCl-KCl melts, and the result showed that only one kind of Pb-Pr intermetallic compound was formed at 773 K. The Pr element was extracted by galvanostatic and potentiostatic electrolysis with the assistance of Pb cathode in LiCl-KCl-PrCl₃ melts, respectively. Finally, the obtained alloys were analyzed by X-ray diffraction (XRD), scanning electron microscopy (SEM) equipped with energy dispersive spectroscopy (EDS), and the result illustrated that the prepared intermetallic compound mainly is Pb₃Pr. (author)