Anodic dissolution behavior of Zr‐Dy alloy in LiCl‐KCl molten salt

Abstract

To research Zr-Dy alloy dissolution behavior at anode, the electrode process of LiCl-KCl-K 2 ZrF 6 -DyCl 3 on an inert W electrode was firstly explored through a group of electrochemical techniques. The depolarization phenomenon was observed owing to the formation of Zr-Dy solid solution, and the redox potentials of Dy(III)/Dy, Zr(II)/Zr-Dy solid solution, Zr(IV)/Zr(II) and Zr(II)/Zr (0) were determined. Then, Zr and Zr-Dy alloy dissolution behaviors at anode were explored by cyclic voltammetry and linear sweep voltammetry. It was confirmed that the rapid dissolution potentials of Zr and Zr-Dy solid solution were observed at À0.86 V and À 1.90 V, and the passivation phenomena of Zr and Zr-Dy solid solution were also observed. Zr-Dy alloy dissolution at anode was conducted employing constant potential (CP) and current (CC) electrolysis. It was found that both Dy and Zr could be dissolved by CC electrolysis. However, Zr dissolution could be controlled by CP electrolysis. Furthermore, Zr-Dy alloy dissolution process was monitored online at different current densities, the dissolution rate increased with the increase of the applied current density.

Optical monitoring of the anodic dissolution of zirconium and the agglomeration of potassium hexachlorozirconate during transpassive dissolution in molten LiCl–KCl salt

“…Sakamura 7 employed Zr metal as the working electrode in a cyclic-voltammetry (CV) analysis and found that Zr undergoes a passivation process during anodic dissolution. Ghosh et al 21 and Han et al 19 advanced similar suggestions. Koyama et al 22 and Iizuka et al 23 pointed out that the anodic dissolution of a Zr-rich alloy leaves a dense salt layer on the alloy surface.…”

“…One promising methodology for recycling spent fuel Zralloy cladding is an electrometallurgical process that uses molten LiCl-KCl salt as a medium. [7][8][9][10][11][12][13][14][15][16][17][18][19] For such a process, the direct anodic dissolution of Zr-alloy cladding is the most straightforward strategy for administering Zr reactants into molten LiCl-KCl salts. 8,16 Since Zr-alloy cladding is generally composed of 97% or more of Zr; 8 it is essential to rigorously understand the anodic dissolution behavior of Zr in molten LiCl-KCl salt.…”

Preparation and Electrochemical Dissolution of a Soluble Uranium Oxycarbide Anode

“…Evidently, the initial dissolution potential, rapid dissolution potential, and passivation potential of UC 0.4 O 0.6 were observed at −0.14, 0.27, and 1.25 V, respectively. 19,20 With the increase of cycle times, the initial dissolution potential of UC 0.4 O 0.6 remained basically unchanged, while the dissolution current intensity continuously increased, indicating that the electrode area of the UC 0.4 O 0.6 anode was continuously changing.…”