Effects of temperature, concentration, and uranium chloride mixture on zirconium electrochemical studies in LiCl-KCl eutectic salt

Experimental studies were performed to provide measurement and analysis of zirconium (Zr) electrochemistry in LiCl-KCl eutectic salt at different temperatures and concentrations using cyclic voltammetry (CV). An additional experimental set with uranium chloride added into the system forming UCl₃-ZrCl₄-LiCl-KCl was performed to explore the general behavior of these two species together. Results of CV experiments with ZrCl₄ show complicated cathodic and anodic peaks, which were identified along with the Zr reactions. The CV results reveal that diffusion coefficients (D) of ZrCl₄ and ZrCl₂ as the function of temperature can be expressed as D_Zr(IV) = 0.00046exp(-3716/T) and D_Zr(II) = 0.027exp(-5617/T), respectively. The standard rate constants and apparent standard potentials of ZrCl₄ at different temperatures were calculated. Furthermore, the results from the mixture of UCl₃ and ZrCl₄ indicate that high concentrations of UCl₃ hide the features of the smaller concentration of ZrCl₄ while Zr peaks become prominent as the concentration of ZrCl₄ increases.