Efficient extraction of cobalt and copper: Leveraging redox chemistry in oxide and sulfide copper-cobalt ores

Cobalt, a critical material for numerous important applications, faces supply risks due to the scarcity of cobalt ores and rising global demand. Copper-cobalt ore, a key source for cobalt extraction, presents significant processing challenges due to the distinct redox conditions required for sulfide and oxide ores. Here, we report a dualbenefit strategy that enables the simultaneous extraction of cobalt and copper from both ores by leveraging the strong oxidizing properties of Co (III) in oxide ore and the reducibility of sulfide ore. The method operates without additional oxidizing or reducing agents under the conditions of 120 degrees C, an initial concentration of 2.5 mol/L, a leaching time of 0.5 h, and a liquid-solid ratio of 5:1 mL/g with a mass ratio of 78:2 g/g (oxide to sulfide ore). The optimized process achieves recovery efficiency of 99.67 % for copper and 98.20 % for cobalt, respectively. Experiments, thermodynamic analysis, and detailed characterization clarify the interaction mechanism between the two ores, with trivalent cobalt from oxide ores playing a crucial role in the oxidative decomposition of sulfide ores. This research paves a way for sustainable cobalt recovery technology from complex copper-cobalt ores, aligning with the goals of efficient resource utilization.