Intensified extraction and separation Pr (III)/Nd (III) from chloride solution in presence of a complexing agent using a serpentine microreactor

The extraction and separation of Pr/Nd from chloride solution containing a complexing agent lactic acid (HLac) is assessed in the intensified serpentine microreactor using 2-ethylhexyl phosphoric acid-2-ethylhexyl ester (EHEHPA, P507) as the solvent phase. The investigations were carried out in micro channels having width of 0.3 mm to 1 mm different phase flow rates forming slug flow with the aqueous solution as the dispersed phase. Extraction and separation of Pr/Nd increased with increase in residence time, while decreased with increase in linear velocity and channel width. A better separation factor of 2.23 could be achieved in microfluidic extractor within 12 s of residence time, while only a separation factor of 2.19, could only be achieved for batch extractor, at a residence time 560 s. The overall volumetric mass transfer coefficient (k_La) was found to increase with increasing linear velocity, decrease in the channel width and decrease with channel length. The k_La of liquid–liquid microfluidic system was several orders of magnitude higher than the conventional extractors (1.01 × 10⁻² − 4.65 × 10⁻² s⁻¹), due to the decreased diffusion path and larger surface-to-volume ratio of microfluidic extractors.