Cobalt Recovery from Copper Solvent Extraction Raffinate Using Ion Exchange Resins

This study investigates the recovery of cobalt and copper from copper solvent extraction raffinate, as approached by Dow Water & Process Solutions for ASARCO Inc. The objective was to develop an efficient methodology to extract valuable metals from leach or raffinate streams, particularly given cobalt's high market price and its role in copper electrowinning tankhouses. Two different chelating resins, XUS-43578 and XUS-43605, were employed to selectively recover cobalt and copper, respectively, from a solution containing varying concentrations of metals. Initial laboratory testing demonstrated the potential for effective metal recovery, although further optimization, including the determination of optimal pH for maximum metal loading and the assessment of stripping conditions, is necessary. A larger-scale proof-of-concept pilot trial confirmed the feasibility of the proposed ion exchange techniques. The findings suggest that with additional testing, the process can be refined to enhance product recovery efficiency and reduce operational costs, thus enabling ASARCO Inc. to capture cobalt and copper from their copper solvent extraction raffinate streams successfully.