Electrochemical Separation of High-Purity Sb from Pb-Containing Sb Alloy in Choline Chloride-Ethylene Glycol Deep Eutectic Solvent

For the decontamination of Pb in a contaminated Sb alloy, the separation behaviors of Sb and Pb are investigated in choline chloride-ethylene glycol deep eutectic solvent (ChCl-EG DES) at 323–363 K. Linear sweep voltammetry measurements are recorded for determining the electrochemical behaviors of Sb and Pb in a 0.1-M SbCl 3 +ChCl-EG solution. The oxidation potentials of Sb and Pb are + 0.021 V and − 0.05 V at 323 K, respectively, which implies that the addition of SbCl 3 benefits the dissolution of Sb, while that of Pb is opposite. In addition, the reduction potential of Sb(III) is more positive than that of Pb(II), which suggests that the separation of Sb from the Pb-containing Sb alloy is feasible. The effects of temperature and current density are discussed during the electrorefining process. The results show that high-purity Sb powders (99.978%) can be obtained at 30 mA cm −2 and 343 K, and that the current efficiency is about 95.42%.