Tazdin Amietszajew

Abstract:

Due to the growing industrial needs, the list of critical metals is ever growing, and so far includes Be, Co, Mn, Ni, and most of the Lanthanides. These metals are recovered by hydro- and pyrometallurgical methods, generating significant amounts of waste and lacking in performance. This work is focused on evaluating a clean molten-salts based electrochemical method of recovering valuable metals. In order to achieve high electroreduction efficiency, as well as high metal extraction rate, a novel mixed-salt system is proposed. Sodium borate salts are used to dissolve metals from waste feedstock. The valuable metal cations are transferred to the sodium chloride melt, where the electrolysis is conducted. Metals included in this analysis are Co, Cu, Mn and Ni. To evaluate the basic electrochemical and thermodynamical behaviour of the system, potentiodynamic electrochemical measurement methods were used. Cyclic voltammetry measurement data was analysed to find the best potentials for specific metals reduction and separation. Scanning electron microscopy with X-ray microanalysis was used to further analyse the reduced metal as the reaction product. As a result, the feasibility and efficiency of the electrochemical recovery of valuable metals from specific molten salts was evaluated.