Abstract:

The basic principles of thermodynamics in multiple silicate systems were briefly reviewed with several typical approaches to mineral materials science.The thermodynamic calculations of the Gibbs free energies for typical multiple phase equilibria in silicate systems were performed,including (1)melting reactions of silicate reactant in processing of the glass-ceramics;(2)sintering reactions in utilizations of nepheline syenite and high-alumina flyash;(3)crystallizing reactions of tobermorite and xonotlite in both systems of SiO₂-CaO-H₂O and KAlSi₃O₈-CaO-H₂O;(4)dissolution reactions of the sintering products of the high-alumina flyash and nepheline syenite;and (5)crystallizing reaction of α-Al(OH)₃ and CaSO₄·2H₂O in  system of Na[Al(OH)₄]-Al(OH)₃-H₂Oand Na₂SO₄-Ca(OH)₂-H₂O, respectively.Approaches to reaction thermodynamics for multiple phase equilibria in silicate systems are in theory of significance for designing experimental scheme of preparing mineral materials,optimizing processing techniques in industry,enhancing the properties of mineral materials products.The current research could also be used for reference in approaching to the similar mineral materials.

Key words: mineral materials, silicate, thermodynamics, glass-ceramic, nepheline syenite, high-alumina flyash, tobermorite