Multicomponent Phase Equilibria Study for Secondary Copper Recycling Applications

The present study focuses on the phase equilibria data in the multicomponent “CuO_0.5”–PbO–ZnO- “FeO_1.5”–SiO₂– “SnO₂”–NiO–(CaO–AlO_1.5–MgO–SbO_1.5) system in equilibrium with Cu/Sn/Ni metal. The equilibration and quenching approach, followed by the electron probe X-ray microanalysis was used to characterize the phase equilibria in the discussed system under various conditions. The composition of the slag selected for the present study was based on the industrial data for copper recycling processes. The applied method enabled the investigation of temperature effects, and the influence of oxygen partial pressures (pO₂). In addition, the effects of CaO, MgO, AlO_1.5, and SbO_1.5 on the phase equilibria in the “CuO_0.5”–PbO–ZnO– “FeO_1.5”–SiO₂– “SnO₂”–NiO–(CaO–AlO_1.5–MgO–SbO_1.5) system in the temperature range from 1170 to 1250 °C were experimentally characterized. The data obtained were used to improve the predictions of the developed thermodynamic model in the area of the industrial interest.