Integrated experimental liquidus and modelling studies of the ternary AgO0.5-FeO1.5-SiO2 system in equilibrium with metallic Ag

Abstract

Phase equilibria of the AgO 0.5 -“FeO 1.5 ”-SiO 2 system was investigated in the range of 1563–1913 K (1290–1640 °C) for oxide liquid (slag) in equilibrium with the gas with controlled oxygen partial pressure, Ag metal or Ag-Au alloy, and solid oxide phases: (a) tridymite, cristobalite (SiO 2 ); (b) hematite (Fe 2 O 3 ), spinel (Fe 3 O 4 ) and wüstite (FeO 1+x ). High-temperature equilibration on silica, iridium or iron substrates, followed by quenching and direct measurement of the Ag, Au, Fe and Si concentrations in the liquid and solid phases with the electron probe X-ray microanalysis (EPMA) or laser ablation inductively coupled plasma mass spectrometry (LA-ICPMS) were used for accurate characterization of the system. Present data were used to develop the thermodynamic models for all phases in this system using FactSage computer package. The present study is a part of the investigation of the thermochemistry of complex multicomponent pyrometallurgical systems. • As a part of the recycling process, the copper and lead smelters require a reliable thermodynamic database for successful recovery of the precious metals such as Ag. • This article demonstrates the high temperature phase equilibria of the AgO 0.5 -“FeO 1.5 ″-SiO 2 ternary system. • This system is a part of the complex multicomponent pyrometallurgical systems (PbO-ZnO-Cu 2 O-FeO-Fe 2 O 3 -CaO-SiO 2 -Al 2 O 3 -MgO-S-As, Sn, Sb, Bi, Ag, Au, Ni, Cr) for the copper and lead smelting and recycling industries. • The data obtained in this study were used for developing FactSage thermodynamic database.