On the Phase Equilibria of Fe–O–CaO–SiO2–(Na2O, Al2O3) Slags and Metallic Copper at 1200 °C and pO2 of 10−7.0–10−4.5 atm

Abstract The equilibrium phase relations between metallic copper and silica-saturated FeO–CaO–SiO 2 –(Na 2 O, Al 2 O 3 ) slags were investigated at 1200 °C and p O2 from 10 −7.0 to 10 −4.5 atm. An advanced experimental technique was employed, involving high-temperature isothermal equilibration in controlled CO–CO 2 –N 2 gas atmospheres, followed by quenching in ice-water mixtures. Quantitative measurements of the equilibrated phase compositions were conducted using electron probe X-ray microanalysis. The equilibrium compositions of metal and slag were displayed as a function of p O2 , and the copper solubilities in three different slags were compared and discussed in the context of fire refining. The experimental results were compared with data from the literature as well as thermodynamic databases of MTDATA and FactSage thermodynamic software. This study enhances the understanding of slag chemistry in copper anode furnace refining, contributing to the optimization of industrial fire refining operations.