Separation of ultrafine chalcogenide particles using Fe3O4 magnetic nanoparticles and ligands with metal selectivity

Abstract

The role of magnetic nanoparticles on the separation of chalcogenide fine particles from their mixture was investigated for the first time using the selective chelation property of ligands with metals. The need of the study lies in the fact that the finer sized ore particles do not respond to the conventional froth flotation technique of separation. The separation study has been carried out by synthesizing Fe3O4 magnetic nanoparticles and then using it in a model mineral mixture of ZnS and PbS added previously with a chelating ligand 8-hydroxyquinoline (HQ) in aqueous medium. The % of collected ZnS and PbS per mg of magnetically separated sample has been estimated as 95% and 0.28% respectively. Such kind of efficient separation has become feasible because of the fact that addition of 8-HQ induces simultaneous complexation with Zn2+ and Fe3+ ions but not with Pb2+ ions. This selective chelation has been studied by vibrational, fluorescence, XPS spectroscopic techniques and zeta potential measurements. Along with these results, controlled experiments were performed to confirm the selective chelation of 8-HQ ligands.