Electrochemical co-deposition of Lu(III) with Bi(III) and extraction of Lu on Bi electrode

To extract Lu from LiCl–KCl molten salt, the electrochemical behavior of Lu(III) were explored by different electrochemical methods. Cyclic voltammetry (CV), reverse chronopotentiometry (RCP) and square-wave voltammetry (SWV) demonstrated that Lu metal was formed by one-step three-electron transfer when Lu(III) was reduced on W electrode, and the electrode reaction is reversible controlled by diffusion. The diffusion coefficient of Lu(III) in molten salt was calculated to be 1.68 × 10 –5 cm 2 s −1 by SWV. Only BiLu was formed when the co-deposition of Lu(III) and Bi(III) was conducted at 773 K, which was confirmed by anode chronopotentiometry. The influence of temperature on the types of Bi-Lu intermetallic compounds was also explored. In addition, the thermodynamic parameters of BiLu were estimated by open circuit chronopotentiometry. The extraction efficiency of Lu(III) reach up to 89.54% when the constant-current electrolysis continued for 12 h based on the result of ICP-OES, and the product was characterized by SEM–EDS.