Korean Journal of Materials Research ISSN:1225-0562(Print) 2287-7258(Online) 한국재료학회지

Zirconium(Zr) nuclear fuel cladding tubes are made using a three-time pilgering and annealing process. In order to remove the oxidized layer and impurities on the surface of the tube, a pickling process is required. Zr is dissolved in HF and HNO₃ mixed acid during the process and pickling waste acid, including dissolved Zr, is totally discarded after being neutralized. In this study, the waste acid was recycled by adding BaF₂, which reacted with the Zr ion involved in the waste acid; Ba₂ZrF₈ was subsequently precipitated due to its low solubility in water. It is very difficult to extract zirconium from the as-recovered Ba₂ZrF₈ because its melting temperature is 1031 °C. Hence, we tried to recover Zr using an electrowinning process with a low temperature molten salt compound that was fabricated by adding ZrF₄ to Ba₂ZrF₈ to decrease the melting point. Change of the Zr redox potential was observed using cyclic voltammetry; the voltage change of the cell was observed by polarization and chronopotentiometry. The structure of the electrodeposited Zr was analyzed and the electrodeposition characteristics were also evaluated.