Open Access

Quaternary phosphonium salts as effective extractants of zinc(II) and iron(III) ions from acidic pickling solutions


Extraction of zinc(II) and iron(III) from hydrochloric acid solutions using quaternary phosphonium salts, Cyphos® IL 101, Cyphos® IL 104, Cyphos® IL109 and Cyphos® IL 111 in mixtures with toluene, was studied. Trihexyl(tetradecyl)phosphonium chloride (Cyphos® IL 101) and trihexyl(tetradecyl)phosphonium bis(2,4,4-trimethylpentyl)phosphinate (Cyphos® IL 104) showed the best zinc(II) and iron(III) extraction abilities. After three stages of zinc(II) extraction with Cyphos® IL 101 and Cyphos® IL 104 the efficiencies were 100 and 93.6%, respectively. Total iron(III) transport to the organic phase was achieved after two separation stages and amounted to 82.1 and 100% for Cyphos® IL 101 and Cyphos® IL 104, respectively. Zinc(II) and iron(III) could be effectively stripped from the loaded organic phases with 0.5 mol dm-3 sulfuric acid. The more hydrophobic the character of the anion type of phosphonium salts, the lower the efficiency of extraction.

Publication timeframe:
4 times per year
Journal Subjects:
Industrial Chemistry, Biotechnology, Chemical Engineering, Process Engineering