Electrorefining of nickel from nickel–chromium alloy in molten LiCl–KCl

Electrorefining of nickel in LiCl–KCl melt was investigated using electrochemical techniques. Nickel products after electrorefining were characterized by X-ray diffraction, X-ray fluorescence, and scanning electron microscopy. Both cyclic voltammetry and square wave voltammetry results suggested that Niwas directly reduced to Ni metal in Li Cl–KCl. Based on a preliminary study on the electrochemical behavior of nickel and chromium, electrorefining was carried out under constant potential, whereupon deposits were formed on the cathode.The purity of nickel increased from 72.62% in the original alloy to 99.83% in cathodic deposits, as determined by inductively coupled plasma atomic emission spectroscopy analysis. Almost all the nickel in the alloy could be recovered during the electrochemical process with [ 90%current efficiency. A lower concentration of Ni Clin Li Cl–KCl was found to be favorable for nickel electrorefining, as increased Ni Clconcentration caused severe corrosion of the nickel anode at the gas–liquid interface due to the accumulation of Clgas.