Mechanistic Model-Based Speciation of Copper Complexes Adsorbed on Resin in an Ammoniacal Thiosulphate Resin-Solution System

Leaching and adsorption of copper complexes simultaneously occur in ammoniacal thiosulphate resin-solution systems. The reaction requires good control-independent variables to minimize reagent consumption as well as to obtain optimal adsorption of copper complexes on resin. This work proposed the development of a mechanistic model for the speciation of copper complexes in such a system. A set of experiments was conducted to validate the mechanistic model, and a comparison of the results showed that the mechanistic model is in very good agreement with the measurement-based result with the correlation coefficient (R-2) being 0.997. In addition, the effect of independent variables was investigated. The effect of initial thiosulphate concentration on the most dominant copper complex species of Cu(S2O3)(3)(5-) ((S)) on resin and the possibility to minimize the reagent for the optimal concentration of species were investigated. In addition, a constraint was needed in the concentration of ammonia in solution to achieve the optimal adsorption of CuNH3(S2O3)(2)(3-) ((S)) complex.