Solvent extraction of copper(II) from ammonium chloride and hydrochloric acid solutions with hydrophobic pyridineketoximes

The main goal of this work was to study the extraction of copper(II) ions from ammonia/ammonium chloride solutions with hydrophobic pyridineketoximes. The effect of different variables on the extraction of copper(II) ions such as the pH of aqueous feed, the concentration of metal ion and kind of oxime has been investigated. The oxime of 1-(2-pyridyl)tridecan-1-one was determined as the strongest extractant and metal stripping depends on the extraction conditions. The oxime of 1-(3-pyridyl)nonan-1-one extracts copper(II) from acidic and weak acidic solutions though the stripping process could be done using water or diluted mineral acid.

► Pyridineketoximes can extract of copper from ammoniacal spent etching solutions.
► Results suggest an affinity of the oxime to chloride-copper-complexes.
► Complexation is by chelating or/and solvating mechanism.
► The extraction capacity increases to 1 mol Cu/mol extractant .
► The stripping process depends on the type of extractant used.