The effect of aqueous sulphate on basaltic glass dissolution rates

摘要

Steady-state dissolution rates of basaltic glass were measured in mixed-flow reactors at 50 deg C at pH 3 and 4 as a function of aqueous sulphate concentration. Dissolution rates in the presence of 0.1 moles/kg SO_4~(2-) were found to be approx 3 times greater than those in corresponding SO_4~(2-) free solutions. This rate increase is found to be approximately consistent with that calculated using a rate equation previously proposed by Gislason and Oelkers (2003). These results suggest that the addition of sulphate to injected CO_2 may facilitate CO_2 sequestration in basalts by accelerating basaltic glass dissolution rates thus more rapidly releasing aqueous Ca and Mg to solution.