Microstructural Refinement towards the Electrochemical Co–Deposition Recovery of Copper and Selenium

Abstract

Simultaneous recovery of selenium and copper from waste sulfuric acid electrolyte is of great importance for industrial treatment of electrorefining effluents. In this study we developed a cost‐effective electrochemical co‐deposition method for recovering selenium and copper with microstructural refinement. In order to enhance the recovery ratio and to control the deposit quality, the synergistic effect of mass transfer intensification and thiourea addition towards electrochemical co‐deposition was investigated systematically. We identified that the intensified mass transfer property has a beneficial effect from the kinetic considerations of electrodeposition while oscillation issues appear with the increase of the square root of the Reynolds number (Re1/2). Furthermore, adding thiourea has an integrated effect between grain refining and kinetics frustration, which can prevent the formation of dendritic products and confine the metal ions under a highly turbulent flow. As a result, the most uniform and compact deposited products were obtained in the presence of appropriate stirring and additives with a satisfied recovery ratio.

Selenium (Se) recovery for technological applications from environmental matrices based on biotic and abiotic mechanisms

“…Generally speaking, the oxidation half-reaction occurs at the anode, while the cathode is where reduction occurs and electrons are gained [165]. Se oxyanions can be removed by direct electrochemical reduction on the cathode surface or by indirect chemical or physicochemical transformations in the electrolyte, depending on the anode material [117,[166][167][168][169]. Comparison and mechanisms of direct electrochemical reduction (DER) and indirect Se removal by electrochemical systems are illustrated in Figure 5.…”