Solvent extraction of cadmium(II) from chloride solutions by pyridyl ketoximes

The solvent extraction of cadmium(II) from chloride solutions using 1-(2-pyridyl)-tridecane-1-one (2PC12), 1-(2-pyridyl)-pentadecane-1-one (2PC14), 1-(4-pyridyl)-tridecane-1-one (4PC12) and 1-(4-pyridyl)-pentadecane-1-one (4PC14) oximes has been investigated. The influence of extractant concentration, metal concentration, chloride ion concentrations and of various polar and non-polar diluents was studied. The results indicate that only 2-pyridyl ketoximes extract cadmium(II) from chloride solutions as a solvating dimer complex (CdCl2(2PC12 or 14)2) and the extraction depends on the diluent, reagent concentration and chloride ion concentration. Cadmium(II) was effectively extracted using a chloroform and hydrocarbons mixed with decan-1-ol as diluents and stripped from the loaded organic phase with water and ammonia aqueous solutions.

Research highlights
► The obtained results indicate that 2-pyridyl ketoximes extract cadmium(II) from chloride solutions.
► The extraction of cadmium(II) by 2-pyridyl ketoximes depends on the diluent, reagent concentration and chloride ion concentration.
► 2-pyridyl ketoximes form a solvating dimer complex (CdCl2(2PC12 or 14)2.