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

Abstract

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(S 2 O 3 ) 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 CuNH 3 (S 2 O 3 ) 2 3− (s) complex.