In the production of zirconium cladding tube, a pickling acid solution is used to remove surface contaminants, which generates tons of pickling acid waste. The waste pickling solution is a valuable resource of Hf-free Zr. Many studies have investigated separating the Hf-free Zr source from the waste pickling acid. The results showed that Ba2ZrF8 precipitates prepared from the waste pickling acid were useful as an electrolyte for the electrorefining of Zr in molten salt. In the present work, electrorefining was performed in a Ba2ZrF8-LiF binary electrolyte to recover Zr from a Hf-free CuZr ingot anode prepared by electroreduction. Before electrorefining, two pretreatments are performed. First, electrolyte melting was carried out to determine the eutectic temperature, and second, the electrolyte was treated to eliminate impurities, mainly hydride. After electrorefining, the cathode deposits were analyzed by O2 gas analyzer and SEM-EDX to explore the possibility of recovering nuclear-grade Zr metal. Moreover, the anode was analyzed by SEM-EDX to determine the Zr dissolution depth.

1. Introduction
 2. Experimental
  2.1 Materials and equipment
  2.2 Determination of salt melting points
  2.3 Cyclic voltammetry test
  2.4 Polarization behavior and electrorefining experiment
 3. Results and Discussion
  3.1 Salt melting points
  3.2 Electrochemical properties of the electrolyte
 4. Conclusions
 Acknowledgemnet
 References

• Seong Hun Lee(Graduate School of Department of Materials Science & Engineering, Chungnam National University)
• Jeong Hun Choi(Graduate School of Department of Materials Science & Engineering, Chungnam National University)
• Bung Uk Yoo(RASOM, Chungnam National University)
• Jong Hyeon Lee(1Graduate School of Department of Materials Science & Engineering, Chungnam National University, 2RASOM, Chungnam National University, 3Graduate School of Energy Science and Technology, Chungnam National University) Corresponding author