Melt speciation in the system Na2O–SiO2

摘要: The applicability of a speciation model to quantify the thermodynamic properties silicate liquids was evaluated in Na2O–SiO2 system. Based on spectroscopic data, four sodium-silicate species with various numbers bridging oxygen atoms were considered. We used that assumed ideal mixing between and temperature-independent, additive heat capacities species. Enthalpies entropies melt determined by fitting experimental data. Enthalpies for each either data from investigations or mineral–melt equilibrium assemblages. Results comparing calculated abundances temperature data. No compositional dependence quality fit observed. An independent check is provided fact enthalpies could be phase reproduce excellent overlap experiments values shows this system, approach accurately reproduces properties. This evaluation suggests it has significant potential describe physicochemical liquids. Moreover, compositions which cannot determined, information diagrams can resolve and, potentially, speciation-dependent (e.g., viscosity).