Vaporization Processes and Thermodynamic Properties of Oxide Systems Studied by High Temperature Mass Spectrometry

摘要

Information on the vaporization processes and thermodynamic properties of the ternary silicate systems Na_2O-B_2O_3-SiO_2, Cs_2O-B_2O_3-SiO_2, Rb_2O-B_2O_3-SiO_2, MgO-B_2O_3-SiO_2, CaO-B_2O_3-SiO_2, SrO-B_2O_3-SiO_2, BaO-B_2O_3-SiO_2, MgO-Al_2O_3-SiO_2, CaO-Al_2O_3-SiO_2, CaO-TiO_2-SiO_2, BaO-TiO_2-SiO_2, PbO-B_2O_3-SiO_2 and ZnO-B_2O_3-SiO_2 together with previously obtained data is discussed. Various types of vapour species were found over the oxide systems studied such as the associated, dissociated and polymerized products of vaporization. The systematic trends in the vaporization of binary and multicomponent oxide systems are illustrated and discussed from the point of view of the acid-base concept. Results on determination of thermodynamic functions in oxide systems were considered taking into account the main requirements for the confirmation of their reliability. The general lattice theory of associated solutions was used for the calculation of thermodynamic properties of the ternary silicate melts studied. Some industrial applications of multicomponent oxide systems are also illustrated.