Selective Extraction of Cu2+ and Ag+ Ions from Sulfuric Acid by Synergistic Combinations of Tetradentate Thia Macrocycles with Dioodecylnaphthalene Sulfonic Acid

The aqueous-insoluble thia macrocycles tetrathia-14-crown-4 (TT14C4) and tetrathia-16-crown-4 (TT16C4) strongly and selectively synergize the extraction of Cu 2+ and Ag + ions from aqueous sulfuric acid solutions by the organophilic cation exchanger didodecylnaphthalene sulfonlc acid (HDDNS) in toluene diluent. Over a range of sulfuric acid concentrations, the selectivity is given by the order Ag 2 > Cu 2+ > Mn 2+ , Fe 2+ , Fe 3+ , Co 2+ , Ni 2+ , and Zn 2+ , where synergism occurs only for Ag + and Cu 2+ . Selectivity factors greater than 300 have been achieved for Cu 2+ over ubiquitous Fe 3+ . The synergistic extraction of Cu 2+ and Ag + was explored as a function of sulfuric acid concentration, relative concentration of macrocycle vs. HDDNS, and loading.