An experimental study of forsterite dissolution rates as a function of temperature and aqueous Mg and Si concentrations

摘要: Abstract Steady state forsterite dissolution rates, at far from equilibrium conditions and pH=2±0.04, were measured as a function of aqueous magnesium silica concentrations, temperatures 25°C to 65°C. All rates in mixed flow reactors exhibited stoichiometric dissolution. Measured are found be independent both concentrations. The temperature dependence the pH 2 obtained this study is consistent with an Arrhenius equation form r=A A exp (−E /RT) where r signifies overall steady rate, refers pre-exponential factor equal 0.190 mol cm −2 s −1 , E designates activation energy 63.8 kJ/mol, R represents gas constant, T denotes absolute temperature. observed variation composition interpreted originate its mechanism. structure consists isolated tetrahedra that branched together by octahedra chains. MgO bonds apparently break more rapidly than SiO structure. breaking chain linking bonds, which catalyzed hydrogen ion adsorption acidic conditions, leads directly destruction mineral. As rate-controlling precursor complex for mineral formed reaction, unaffected Mg Si activities.