Investigation of oscillatory baffled reactors for the hydrometallurgical separation of cobalt and nickel

Oscillatory baffled reactors (OBRs) utilise strategically placed baffles that interact with fluid pulsations to generate specific flow patterns, yielding exceptional mixing control independent of the net flow rate and residence time. In this study, the mixing performance of oscillatory baffled reactors (OBRs) for the hydrometallurgical separation of cobalt and nickel is systematically explored using a 3D-printed reactor. The impact of operational parameters such as oscillation frequency, oscillation amplitude and residence time on the overall extraction and stripping is investigated. High-speed imaging and velocimetry are employed to examine droplet size and flow behaviour of the two-phase system. The overall findings highlight the advantages of oscillatory baffled reactors over conventional systems, such as mixer-settlers, and successfully demonstrate, for the first time, the application of oscillatory baffled reactors for the hydrometallurgical separation of cobalt and nickel. • Separation of cobalt and nickel using 3D-printed oscillatory baffled reactors. • Near-equilibrium efficiency in 36 s for extraction and 72 s for stripping using continuous process. • High-speed imaging and droplet image velocimetry providing additional insights. • Performance comparison of space–time yield and productivity to state-of-the-art.