Microfluidic extraction of uranium from dilute streams using TiAP in ionic liquid as the solvent

A microfluidic platform to extract uranium from HNO3 (nitric acid) medium using tri-isoamyl phosphate (TiAP) dissolved (30% v/v) in ionic liquid ([BMIM]PF6) is reported. PTFE microbore tubes serve as the microchannels. The quality of dispersion inside the translucent tubes was observed using a camera. The images obtained are used to understand the observed experimental trends. Overall volumetric mass transfer coefficient was determined considering the microchannel as a differential contactor with co-currently flowing phases. The effects of contact time, flow velocity, organic to aqueous (O/A) ratio and microchannel diameter on mass transfer performance are studied. Effect of different coiling configurations on mass transfer performance was compared. Under optimum conditions, 95.3% of uranium present in the feed (corresponding stage efficiency being 99.2%) could be extracted within a contact time of about 200 s in a single contact. Corresponding (KLa) was 0.024 s−1. Coiling was found to have a significant effect on values of KLa especially at low residence times.