Thermodynamic properties of SiO, HSiO and SiO

Walker, C.*; Anraku, Sohtaro ; Oda, Chie  ; Mitsui, Seiichiro  ; Mihara, Morihiro  

Equilibrium constants () describing the formation reactions of SiO, HSiO and SiO can be used to derive their thermodynamic properties. However, SiO was derived from inaccurate quartz solubility data, HSiO was not extrapolated to zero ionic strength and SiO is routinely ignored because of its restricted dominance to very high pH 13 solutions. Using quartz and water data as well known "anchor" points, values describing the formation reactions of SiO, HSiO and SiO were revised to derive new thermodynamic properties and revised Helgeson-Kirkham-Flowers equation of state (r-H-K-F EoS) parameters. These properties and parameters can be used in the derivation of the thermodynamic properties of other Si bearing aqueous species/complexes and the thermodynamic properties of cementitious, clay, zeolite, and rock forming minerals, and in calculating groundwater compositions relevant to the geological disposal of radioactive wastes.