An investigation into predispersed solvent extraction of nickel (II) ions from dilute aqueous solutions

This work investigated the extraction of nickel ions from dilute aqueous solutions using colloidal liquid aphrons. The effect of four experimental parameters (extractant concentration, phase volume ratio (PVR), water soluble surfactant concentration and equilibrium pH) on the extraction process at three different nickel concentrations was studied. Response surface method was used to determine the significance of various experimental parameters. The most significant factors were shown to be different for the various metal ion concentrations tested, which may have implication for industrial practice. The equilibrium pH of 5 was found to be optimum point for all concentrations studied. The recyclability of organic phase also shown through the reuse of stripped organic in a new extraction process. Reusing recycled organic in PDSE resulted in more than 99% nickel extraction, thus indicating the potential sustainability of a CLA-based extraction process.