A Rigorous Calculation Method for Determining Potential-pH Diagrams Part I: Copper in Aqueous Solutions of Various Complexing Agents

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The main aim of this research is to determine optimal leaching conditions; Eh, pH and complexing agent concentrations, for recovery of Copper from hydroxide sludges such as those produced by electroplating shops, metal finishers, treatment of acid mine drainage, and industrial wastewater in general. This has been preceded by a theoretical approach and numerical and computer calculation. Potential-pH diagrams for the copper-water-ammonia, copper-water-cyanide, copper-water-glycine, copper-water-ethylenediamine (En) and copper-water-ethylene-diaminetetraacetic acid (EDTA) systems are derived at different total copper and complexing agent concentrations. The originality of our method is the introduction of a rigorous calculating method; we don’t neglect any equilibrium or species for Eh-pH diagrams and with the free concentration of complexing agent (pL-pH) diagram to show the stable regions of soluble copper species.