Estimation of Thermodynamic Properties of Sodium Magnesium Silicates by the Polyhedron Method

摘要

A simple method for calculating thermodynamic properties such as enthalpy, entropy, and molar heat capacity of sodium magnesium silicates from their constituent polyhedra is introduced in this work. If it is assumed that the complex silicates are made up of different polyhedron constituents, the thermodynamic properties of complex compounds can be calculated from the linear combination of their polyhedron constituents. Thermodynamic properties of 18 polyhedra were obtained by weighted multiple linear regression analysis based on thermodynamic properties of 48 silicates compounds, which were collected from FactSage database. Standard enthalpy, entropy, Gibbs free energy, and molar hear capacity for the formation of five different sodium magnesium silicates (Na_2MgSiO_4, Na_2Mg_2Si_2O_7, Na_4Mg_2Si_3O_(10), Na_2MgSi_4O_(10), Na_2Mg_2Si_6O_(15)) provide the foundation for evaluating the possibilities and priorities of reactions involving these compounds.