METAL-PROTON EQUILIBRIUM RELATIONS IN A CHELATING IMINODIACETIC RESIN

A model of equilibrium including the pH effect was proposed and tested with experimental data of the Na-H-metal systems onto chelating resins. The protonation constants were used to calculate the complexing capacity of the metals Cu, Ni, Co, and Zn in the iminodiacetic type resin. This equilibrium model that considers two stoichiometries for the retention of divalent nonferrous metals was extended for simultaneous multimetallic uptake and applied to a real hydrometallurgical effluent. Another simplified equilibrium model that only requires one equilibrium constant for each metal has shown to fit fairly well the experimental results.