Zr electrorefining for the treatment of Zircaloy-4 cladding hull waste is demonstrated in LiCl-KCl-ZrCl_4 molten salts. Cyclic voltammetries using a W wire and a Zr rid as working and counter electrodes reveal that the Zr reduction process is an irreversible diffusion controlled mass transfer at 500 °C. For a 10-g scale treatment, electrochemical dissolution experiments of fresh and oxidized Zircaloy-4 cladding tube pieces in an anode basket resulted in a recovery of Zr on cathodes with purities of 99.54 wt.% and 99.74 wt.%, respectively, without any electrical contact issues. The effects of process parameters such as ZrCl_4 concentration and applied potential are also examined for an optimization of the Zr electrorefining process and an improvement of the Zr morphology.
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