Extraction of Copper(II) Ions from Chloride and Sulphate Solutions Using Hydrophobic Pyridyl Ketoximes

Hydrophobic pyridyl ketoximes: 1-(2-pyridyl)tridecan-1-one oxime, 1-(3-pyridyl)tridecan-1-one oxime and 1-(4-pyridyl)tridecan-1-one oxime have been synthesized and investigated as extractants of copper(II) ions. Removal of metal ions was conducted from chloride, sulphate, and sulphate/chloride solutions. The influence of pH of aqueous solutions, copper(II), chloride, and sulphate ions and ligand concentration for extraction process were studied. Copper(II) extraction by hydrophobic 2-, 3-, and 4-pyridyl ketoximes from sulphate solutions is not possible. However, addition of chloride ions to initial sulphate media enables metal removal. The oxime of 1-(2-pyridyl)tridecane-1-one was determined as the strongest extractant of the tested oximes, but metal stripping was impossible. For the rest of the studied extractants the stripping process could be done using water or diluted mineral acid.