Controls on silicate dissolution rates in neutral and basic pH solutions at 25°C

https://doi.org/10.1016/0016-7037(89)90160-9Get rights and content

Abstract

The pH-dependence of far from equilibrium steady-state dissolution rates of silicates can be understood by considering the detachment rates of their oxide components through surface protonation-deprotonation reactions. At high pH, where Si surface sites are deprotonated and therefore carry negative charge, detachment of silicon appears to control overall silicate dissolution rates. At low pH, near the zero point of charge of SiO2 (where surface charge is dominated by the other oxide components), detachment of the non-silicon structure-forming oxides apparently controls dissolution rates of multi-oxide silicates. Correlations between metal-oxygen site potentials and pH-dependent surface detachment reactions permit estimation of dissolution rates of a large number of silicates from pH 5 to pH 12.

References (34)

  • G. Wirth et al.

    The initial kinetics of dissolution of vitreous silica in aqueous media

    J. Colloid Interface Sci.

    (1979)
  • B. Zinder et al.

    The coordinative chemistry of weathering: II. Dissolution of Fe(III) oxides

    Geochim. Cosmochim. Acta

    (1986)
  • C. Amrhein et al.

    The use of a surface complexation model to describe the kinetics of ligand promoted anorthite dissolution

    Geochim. Cosmochim. Acta

    (1988)
  • A. Bailey

    Effects of temperature on the reaction of silicates with aqueous solutions in the low temperature range

  • A. Blum et al.

    Role of surface speciation in the low-temperature dissolution of minerals

    Nature

    (1988)
  • A. Blum et al.

    The effect of dislocation density on the aqueous dissolution rate of quartz (abstr.)

  • G. Bolt

    Determination of the charge density of silica sols

    J. Phys. Chem.

    (1957)
  • Cited by (376)

    View all citing articles on Scopus
    View full text