Experimental Liquidus Studies of the ZnO-“CuO0.5” and ZnO-“CuO0.5”-SiO2 Liquidus in Equilibrium with Cu-Zn Metal

Phase equilibria in the ZnO-“CuO0.5”-SiO2 system have been investigated at 1403-1948 K (1130-1675 °C) for oxide liquid in equilibrium with Cu-Zn metal (> 99% Cu) and solid oxide phases: (a) tridymite or cristobalite SiO2; (b) willemite Zn2SiO4; (c) zincite ZnO; and (d) cuprite Cu2O. Two-liquid immiscibility range in the high-SiO2 slags has also been studied. High-temperature equilibration on primary phase (SiO2, Cu2O), inert metal (platinum-iridium wire), or ceramic (Al2O3 for high-Cu2O slags) substrates, followed by quenching and direct measurement of Zn, Cu, Si and possible impurities (Al, Pt, Ir) concentrations in the phases with the electron probe x-ray microanalysis (EPMA) has been used to accurately characterize the system in equilibrium with metal. All results are projected onto the ZnO-“CuO0.5”-SiO2 plane for presentation purposes.