“…39,40 However, the existing methods suffer from several drawbacks, such as long extraction time, multiple extraction stages, the need of masking agents and co-extraction of commonly associated ions, such as Zn(II) and Fe(III). 40 On the other hand, the extraction of Zn(II) from sulfate/chloride leachates or galvanizing liquors has been proposed as a route to zinc concentration and separation from impurities (such as Fe(III), Co(II), Cu(II) and Mn(II)). Both neutral and cation exchanger extractants such as TBP, D2EHPA, carboxylic acids, amines, Cyanex 923 (trialkylphosphine oxides) and Cyanex 302 (bis(2,4,4trimethylpentyl)monothiophosphinic acid) have been tested in acidic medium.…”