(590991) EXPERIMENTAL AND THERMODYNAMIC MODELLING STUDY OF THE EFFECTS OF Al_2O_3, CaO AND MgO IMPURITIES ON GAS/SLAG/MATTE/SPINEL EQUILIBRIA IN THE “Cu_2O”-“FeO”-SiO2-S-Al_2O_3-CaO-MgO SYSTEM

摘要

The effects of the slagging components Al_2O_3, CaO and MgO on the thermodynamics and phase equilibria of the gas/slag/matte system with major elements “Cu_2O”-“FeO”-SiO_2-S are characterised using an integrated experimental and thermodynamic modelling approach. The experimental technique included high-temperature equilibration experiments using a spinel substrate in controlled gas atmosphere (CO/CO_2/SO_2/Ar), quenching of the sample and subsequent measurement of the compositions of equilibrium phases with Electron Probe X-ray Microanalysis (EPMA). Thermodynamic modelling is undertaken using the computer system FactSage. In previous experimental studies on this system, the separate effects of Al_2O_3, CaO and MgO were determined. In the present investigation, the combined effects of these additional components are investigated at 1200°C and P(SO_2) = 0.25 atm and a range of P(O_2)'s. Special attention is paid to ensuring chemical equilibrium is achieved in each case, for this reason possible kinetic factors are systematically analysed. The results obtained are presented in the form of graphs showing the compositions of matte and slag phases as functions of copper concentration (matte grade). The new experimental data are used for the improvement of the thermodynamic database for multicomponent copper-containing systems. The effects of the slagging elements on this multicomponent system will be presented in the paper.