Electrochemistry of zirconium in molten chlorides

In this work, the electrochemical behavior of zirconium was studied on an inert molybdenum electrode at 550 °C in a LiCl-KCl-K₂ZrF₆ molten salt system, which is considered as an ideal electrolyte for the zirconium electrorefining process. Several transient electrochemical techniques were used such as cyclic voltammetry, chronopotentiometry, square wave voltammetry, and open circuit chronopotentiometry. The reduction of Zr (IV) was determined to follow a two-step mechanism of Zr (IV)/Zr (II) and Zr (II)/Zr. The diffusion coefficient of Zr (IV) was investigated with cyclic voltammetry and chronopotentiometry, and the results turned out to be in fair agreement from the both methods, as to be 4.26×10^-5 and 4.98×10^-5 cm²/s, respectively. The present study aims to provide a theoretical reference for the Zr electrorefining process.