Povar, IgorIgorPovarUbaldini, StefanoStefanoUbaldiniLupascu, TudorTudorLupascuSpinu, OxanaOxanaSpinuPintilie, BorisBorisPintilie2018-10-222018-10-222018L:1843-5831 (online); 2457-837110.21698/simi.2018.fp20http://hdl.handle.net/123456789/1238International Symposium "The Environment and the Industry", 20-21 September 2018, Bucharest, Romania, pp. 162-169The paper presents a new thermodynamic approach to studying mixed ligand complex formation reactions in multicomponent two-phase systems “solid phase saturated aqueous solution” under real conditions. The quintessence of developed approach consists in the thermodynamic analysis of concurrent reactions in the system Cu (II)-NH3-S2O32--H2O under real conditions on the basis of the introduced notion of the generalized reaction equation. The formation of mixed ligand complex species Cu(OH) i (NH3 ) j (S2O3 ) k is characterized by certain peculiarities in the behavior of studied two-phase heterogeneous systems. The new feature is to focus on the chemical description of the overall process of complex formation consisting of a series of concurrent reactions, where the nature and ratio of the concentrations of chemical species, formed in such reactions, depend on the ratio of the concentrations of the metal Cu2+ and ligands, temperature and other factors (thermodynamic parameters).AmmoniaCopper (II)LeachingThermodynamicsThiosulfateSymposium Proceedings