THERMODYNAMICS AND PHASE EQUILIBRIUM OF Cu－Y－O，Cu－Y－S，Cu－Y－O－S LIQUID SOLUTIONS
(Central Iron and Steel Research institute; Ministry of Metallurgical Industry; Beijing 100081)
Abstract: Thermodynamics of Cu-Y-O, Cu-Y-S and Cu-Y-O-S solutions at 1 200 ℃ were studied using solid electrolyte cell and chemical equilibrium method. The equilibrium constant of deoxidation,desulfurization and deoxysulfurization by Y, the Gibbs standard reaction free energies of the formation of Y2O3, YS and Y2O2S in Cu-base solution, activity interaction coefficients of S and Y, temperature dependence of standard free energy of solution of Y in Cu, self-interaction coefficients of Y in liquid Cu were obtained. The phase precipitation diagram for Cu-Y-O-S system was plotted. The thermodynamic condition of the existence of Y2O3, YS and Y2O2S in liquid Cu was determined.
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