Abstract:High-purity copper (Cu) was recovered from waste cupronickel by electrolysis separation at 363 K in choline chloride-ethylene glycol deep eutectic solvent (ChCl-EG DES). The waste cupronickel and titanium sheets were served as anode and cathode, respectively. The effects of temperature and the concentration of cuprous chloride (CuCl) on the viscosity and conductivity of the DES were investigated systematically. Results showed that the viscosity of CuCl+ChCl-EG DES decreased with the increase of temperature and increased as the raising of CuCl concentration, whereas that of the conductivity was opposite. The anodic polarization curves showed that the potential difference between Cu and Ni can be increased by increasing CuCl concentration, which was conducive to the separation of Cu and Ni, but the anode dissolution rate can be slowed down with too high CuCl concentration. The electrolysis experiment showed that the DC power consumption decreased firstly and then increased as the increasing of CuCl concentration, while the current efficiency was opposite. When CuCl concentration was 1 M, the current efficiency was as high as 99.1 % during the electrolysis separation of waste cupronickel, and the DC power consumption was as low as 170.2 kW·h·t-1. Highly pure Cu (99.62 wt.%) can be obtained at cathode and the micromorphology was compact and flat.