Efficient Electrochemical Recovery of Fine Tellurium Powder from Hydrochloric Acid Media Via Mass Transfer Enhancement

Recovery of tellurium from industrial waste streams is of significant importance for the supply of this scattered element. In order to overcome the bottlenecks of high reagents consumption and low recovery efficiency in conventional processes, a novel electrochemical recovery of Te from hydrochloric acid solution was first developed using low-cost stainless steel plate. Due to the high mobility of Te in HCl systems, there is a good electrodeposition behavior of Te(IV) from both the thermodynamic and kinetic considerations. It has been identified that Te electrodeposition is diffusion controlled quasi-reversible reaction, in which the mass transfer can significantly determine the recovery performance and deposit quality. Therefore, a cylinder turbulent reactor with larger surface area cathode was employed for the extraction of tellurium from dilute solution. Microscale Te powder was successfully obtained with a recovery ratio of 96.1% and a current efficiency of 84.3%, while the side reactions of chlorine evolution and TeO2 formation were efficiently inhibited. This mass transfer-enhanced electrodeposition may serve as a promising alternative to overcome the drawbacks of existing valuable element recovery and water purification