Microfluidic Solvent Extraction of Metal Ions and Complexes from Leach Solutions Containing Nanoparticles

Solvent extraction is often hindered by the presence of particles and surfactants that increase the stability of emulsion phases, i.e., crud, thus preventing full recovery of the organic phase and the valuable metal species. It is shown that bypassing the formation of a particle-stabilized crud using a stream-based microfluidic extraction approach has great potential for handling these more challenging and industry-relevant systems provided sufficient throughputs can be realized. Metal ions and complexes are extracted from copper oxide and chromite leach solutions at high efficiencies and extraction rates within the confinement of a microchannel and in the presence of silica nanoparticles. These findings and their implications for process intensification are discussed.