Electrochemical Separation and Recovery of Metallic Zr from KCl-LiCl-K2ZrF6-PrCl3 Molten Salt System

Abstract

The electrochemical behavior of Zr(IV) and Pr(III) in LiCl-KCl melt on W and Sn electrodes was studied by various electrochemical methods. Electrochemical results indicated that the deposition potentials of Pr and Zr on Sn electrode shifted towards more positive value than that on W electrode due to forming different Sn-Zr and Sn-Pr intermetallic compounds. By means of cyclic voltammetry, square wave voltammetry, the deposited potentials of Pr and Zr on the Sn electrode were confirmed at -1.18 V and -0.8 V, respectively. Thus the selective potential range for separating Zr(IV) and Pr(III) was approximately -0.8 V to -1.1 V. The effects of applied potentials on separation were also studied and the optimal separation conditions were confirmed. The results of XRD and SEM-EDS indicated that the product consisted of Sn and Sn2Zr phases, and the separation of Zr and Pr could be achieved by potential electrolysis. Acknowledgement The work was financially supported by the National Natural Science foundation of China (11675044, 21790373, 21876034 and 11875116), and the International Exchange Program of Harbin Engineering University for Innovation−oriented Talents Cultivation.