Interactions in Two-Phase Systems of MgO(s)-(Na2O-SiO2)(l)
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Abstract: The corrosion drop tests were carried out on periclase plates MgO(s) by hot-melt testing of Na2O·2SiO2(l) (ratio of Na:Si = 1:1) in the viewing field of a high-temperature microscope. The corrosion tests at a temperature of 1300 °C lasted for 30, 60 and 120 min in air atmosphere. The corrosion of MgO(s) was evaluated by the SEM (scanning electron microscopy) method with local semi-quantitative EDX microanalysis. The attack on periclase crystal by the Na2O-SiO2 hot melt caused a penetration of the Na+ cations in MgO. Locally defective areas in periclase were observed up to a depth of 150-200 μm. The original cubic structure of periclase was deformed because of the differences in the ion size between Na+ and Mg2+. Silicon atoms were not detected. The Si4+ ions were fixed-bound in anion complexes ([SinO3n+1]-2(n+1)) in the melt.