wAbstract
@Steady-state dissolution rates of basaltic glass were measured
in mixed-flow reactors at 50 and 3pH10 in HCl-NaCl-NH4OH bearing bearing solutions having an ionic
strength of 0.01 M, or higher, as a function of aqueous sulphate
concentration. Sulphate was added to reactive aqueous solutions
in the form of Na2SO4.
Measured dissolution rates increase with increased sulphate concentration
in acid conditions, but little effect was found in basic conditions.
At pH 5, the presence of 0.01 mol/kg sulphate doubled the dissolution
rate while 0.10 mol/kg of sulphate tripled the dissolution rate
compared to that measured in sulphate-free solutions. This rate
increase is found to be consistent with that calculated using
an equation previously proposed by Gislason and Oelkers (2003),
where the observed rate increase stems from the formation of aqueous
Al-sulphate complexes. As the release of divalent cations is thought
to be the rate limiting step for CO2 mineralization
in basalt, adding aqueous sulphate to injected CO2
could accelerate carbonization processes in this rock during carbon
sequestration efforts.
keywords: Basaltic glass; Dissolution rates; CO2
sequestration; Kinetics; Aqueous sulphate; Martian weatheringx
1. Introduction
2. Theoretical background
3. Materials and methods
4. Results
5. Discussion
6. Conclusions
Acknowledgements
References