Thermodynamic modeling of lead distribution among matte, slag, and liquid copper

摘要

Recently, a thermodynamic database was developedfor the calculation of equilibria involved in the production ofcopper. The present study is concerned with the furtherdevelopment of the thermodynamic models and the database ofmodel parameters for the matte, slag, and blister copper phaseswith a view to including Pb in the database and permittingcalculations in the seven-component system Pb-Cu-Ca-Fe-Si-O-S.Thermodynamic and phase equilibrium data available in theliterature are reviewed, critically assessed, and optimized with themodified quasi-chemical model. When used with the Gibbs energyminimization software and other databases of the FACTthermodynamic computing system, the database developed in thepresent study can be used for the calculation of matte-slag-copper-gas phase equilibria during copper smelting and converting.The distribution of lead among these phases can be computed. Forexample, the distribution of lead among matte, silica-saturated slag,and copper has been calculated at metal saturation, or under fixedpartial pressure of S02, and has been compared with the availableexperimental data. The Pb distributions among the equilibriumphases have been calculated under various conditions, which aredifficult to study experimentally, such as at magnetite saturation orunder various oxygen partial pressures and iron to silica ratios in the slag.