PHASE EQUILIBRIA AND THERMODYNAMICS IN THE AG ― PB ― S TERNARY SYSTEM

摘要

Within the Ag-Pb-S ternary system, the boundaries of the immiscibility region together with the tie-line distributions were re-established at 925℃ by the equilibrium-quenching technique where samples were kept in evacuated and sealed silica capsules. Activities of Pb were measured by the dew-point method along the Ag-Pb binary at 925℃, 1100°and 1200℃. positive deviations were observed and the results were modeled by the Krupkowski formalism. Activities of Ag, Pb, and S, along the ternary miscibility gap were calculated at 925℃ by utilizing the boundaries binary thermodynamics, phase equilibria and tie-lines. Activities of PbS within the pseudobinary Ag_2S―PbS mattes were also measured by the dew-point technique and the results were again modeled by the Krupkowski formation where negative deviations were observed.