Abstract
Thiourea has been extensively used as a grain refiner in industrial copper electrorefining processes. The influence of thiourea on deposit structure and morphology has received considerable study; however, the effect of thiourea and its degradation chemistry on the passivation behavior of commercial copper anodes is still not fully understood. This study was conducted to provide useful information regarding the electrochemical response of a commercial copper anode in the absence and presence of thiourea. Chronopotentiometry measurements were performed in synthetic electrolytes containing different thiourea concentrations and in industrial electrolytes obtained directly from a commercial tank house. Passivation time (tp) and periodic passivation phenomena were found to be closely associated with thiourea concentration and degradation.