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Effect of Cation Chloride Concentration on the Dissolution Rates of Basaltic Glass and Labradorite at pH 3.6 and 25°C and Applica-Tion to Subsurface Carbon Storage
Mesfin, K.G.; Wolff-Boenisch, D.; Gislason, S.R.; Oelkers, E.H. Effect of Cation Chloride Concentration on the Dissolution Rates of Basaltic Glass and Labradorite: Application to Subsurface Carbon Storage. Minerals2023, 13, 682.
Mesfin, K.G.; Wolff-Boenisch, D.; Gislason, S.R.; Oelkers, E.H. Effect of Cation Chloride Concentration on the Dissolution Rates of Basaltic Glass and Labradorite: Application to Subsurface Carbon Storage. Minerals 2023, 13, 682.
Mesfin, K.G.; Wolff-Boenisch, D.; Gislason, S.R.; Oelkers, E.H. Effect of Cation Chloride Concentration on the Dissolution Rates of Basaltic Glass and Labradorite: Application to Subsurface Carbon Storage. Minerals2023, 13, 682.
Mesfin, K.G.; Wolff-Boenisch, D.; Gislason, S.R.; Oelkers, E.H. Effect of Cation Chloride Concentration on the Dissolution Rates of Basaltic Glass and Labradorite: Application to Subsurface Carbon Storage. Minerals 2023, 13, 682.
Abstract
The steady-state dissolution rates of basaltic glass and labradorite have been measured in the presence of 10 to 700 x 10-3 mol kgw-1 aqueous NaCl, KCl, CaCl2, and MgCl2 at 25 oC. All rates were measured in mixed flow reactors, and at pH~3.6 by the addition of HCl to the reactive fluids. Steady-state basaltic glass dissolution rates based on Si release increased by ~0.3 log units in the presence of 1 x 10-2 mol kgw-1 of CaCl2 or MgCl2, compared to their rates in 10 x 10-3 mol kgw-1 of NaCl, and KCl. In contrast, the steady-state dissolution rates of labradorite decreased by ~0.4 log units in the presence of 10 x 10-3mol kgw-1 of CaCl2 or MgCl2, compared to their rates in 10 x 10-3 mol kgw-1 of NaCl, and KCl. These contrasting behaviours likely reflect the varying effects of these cations on the stability of rate controlling Si-rich activated complexes on the surface of the solids. On average, the Si release rates of these solids are similar to each other and increase slightly with increasing ionic strength. As the pH of water charged with 10 to 30 bars CO2 is ~3.6, the results of this study indicate that both basaltic glass and labradorite dissolution will likely be effective at increasing pH and adding Ca to the aqueous phase in saline fluids. This observation supports potential efforts to store carbon through its mineralization in saline aquifers containing Ca-bearing feldspar and in submarine basalts.
Keywords
Labradorite; basaltic glass; mineral carbonation; dissolution rates
Subject
Environmental and Earth Sciences, Geochemistry and Petrology
Copyright:
This is an open access article distributed under the Creative Commons Attribution License which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited.
