Selective removal of zinc(II) from spent pickling solutions in the presence of iron ions with phosphonium ionic liquid Cyphos IL 101

►Extraction of Zn(II) from model spent pickling solutions based on composition of real liquors. ►Cyphos IL 101/toluene mixture is tested as selective extractant of Zn(II). ►Multistage extraction-stripping system is proposed to separate Zn(II) from Fe(II). ►Selectivity of Zn(II) extraction depends on Zn(II) and Fe(II) content in the feed.