Integrated experimental and thermodynamic modeling study of phase equilibria in the 'CuO0.5'-MgO-SiO2 system in equilibrium with liquid Cu metal for characterizing refractory-slag interactions. Issue 16 (15th August 2022)

• Record Type: Journal Article
• Authors: Abdeyazdan, Hamed; Shevchenko, Maksym; Hayes, Peter C.; Jak, Evgueni
• Is Part Of: Ceramics international. Volume 48:Issue 16(2022)
• Page Start: 22699
• Page End: 22711
• Publication Date: 2022-08-15
• Subjects: Copper oxide -- Magnesium oxide -- Silica -- 'CuO0.5'-MgO-SiO2 -- Phase equilibria -- Liquidus -- Refractory -- Periclase -- Copper converting -- Recycling -- Corrosion -- Slag; Ceramics -- Periodicals; Céramique industrielle -- Périodiques; Ceramics; Periodicals; Electronic journals; 666
• DOI: 10.1016/j.ceramint.2022.03.183
• Languages: English
• ISSNs: 0272-8842

Abstract

Abstract: An integrated experimental and thermodynamic modeling study of the phase equilibria in the 'CuO0.5 '-MgO-SiO2 system in equilibrium with liquid Cu metal has been undertaken to better understand the reactions between MgO-based refractories and liquid slag in copper converting and refining processes. New experimental phase equilibria data at 1250–1680 °C were obtained for this system using a high-temperature equilibration of synthetic mixtures with predetermined compositions in silica ampoules or magnesia crucibles, a rapid quenching technique, and electron probe X-ray microanalysis of the equilibrated phase compositions. The system has been shown to contain primary phase fields of cristobalite (SiO2 ), tridymite (SiO2 ), pyroxene/protoenstatite (MgSiO3 ), olivine/forsterite (Mg2 SiO4 ), periclase (MgO), and cuprite (Cu2 O). Three regions of 2-liquid immiscibility were found—two in the high-silica range of compositions above the cristobalite primary phase field (close to 'CuO0.5 '-SiO2 and MgO–SiO2 binaries) and one in the low-SiO2, high-'CuO0.5 ' compositional region above the periclase and olivine phase fields. The results obtained in this study indicate that silica in high-copper refining slags likely led to olivine and pyroxene phase formation, increased solubility of MgO in liquid slag, and decline in the performance of MgO-based refractories. New experimental data were used in the development of a thermodynamic database describing this pseudo-ternary system.