Thermodynamic Study on the Ag–Pb–O System at 1273 K

The phase relations for the Ag–Pb–O system saturated with alumina and the activity coefficient of AgO0.5 in the PbO melt were investigated at 1273 K. A chemical equilibrium technique and an EMF method were applied to the measurement. In this system, there is a miscibility gap between a molten Ag–Pb alloy phase and a Pb–Ag–O oxide phase. The solubility of Ag in the oxide phase and that of Pb in the metal phase were studied as a relation of the partial oxygen pressure. These results suggest that component of silver oxide in liquid PbO phase should be represented as AgO0.5. The activity coefficient of AgO0.5 in the PbO based oxide melt at infinite dilution relative to pure solid AgO0.5 is 0.602 at 1273 K.