# Zirconium(IV) electrochemical behavior and electrorefining in molten fluoride salts

Abstract : Zirconium is a strategic metal used in various activity sectors and particularly for nuclear applications because of its physicochemical properties a low cross-section of neutron capture, corrosion resistance under extreme conditions (high temperature, aggressive media), excellent mechanical resistance and high pyrophoricity. Thus 90% of the production of zirconium metal is used in the nuclear field, as zirconium alloy claddings, UZr fuel, and dissolvers used for spent fuel reprocessing. Zirconium metal is commonly obtained in the form of zirconium sponges produced by Kroll process that consists in a chemical reduction of zirconium chlorides to zirconium metal. On the other hand, spent zircaloy claddings represent a consequent amount of zirconium considered nowadays as a waste. There could be an economic interest to recycle the irradiated zircaloy claddings in order to valorize Zr for further reuse within nuclear applications. One promising zircaloy recycling process consists of electrorefining in molten salt media. Although chloride salts seem not suitable to operate such process, mainly because of the several stable oxidation states of Zr coexisting in these media, the use of fluoride systems should stabilize Zr oxidation state as Zr$^{4+}$. A first step consists in investigating the feasibility of the electrochemical recovery of Zr metal in fluoride media. Thus, the present work focused on the electrochemical behavior study of zirconium in molten fluoride using transient electroanalytical techniques, e.g. Cyclic voltammetry, square wave voltammetry, and chronopotentiometry. These different technics allowed to understand the Zirconium reduction mechanism by determining the number of exchanged electrons and assessed the thermodynamic properties of Zr in the salt (diffusion coefficient, etc.). Zirconium electrocrystallisation process was also investigated by chronoamperometry and cyclic voltammetry. This set of data is of first importance in order to estimate the further potentialities of the process
Keywords :
Document type :
Conference papers
Domain :

https://hal-cea.archives-ouvertes.fr/cea-02328965
Submitted on : Monday, February 24, 2020 - 4:11:38 PM
Last modification on : Tuesday, April 28, 2020 - 11:28:12 AM
Long-term archiving on: : Monday, May 25, 2020 - 6:59:27 PM

### File

201800002902.pdf
Files produced by the author(s)

### Identifiers

• HAL Id : cea-02328965, version 1

### Citation

D. Quaranta, E. Mendes, L. Massot, M. Gibilaro, J. Serp. Zirconium(IV) electrochemical behavior and electrorefining in molten fluoride salts. IPRC 2018 - International Pyroprocessing Research Conference 2018, Oct 2018, Tokai-Mura, Japan. ⟨cea-02328965⟩

Record views