Skip to main content Accessibility help
×
Home

Kinetic and structural constraints during glauconite dissolution: implications for mineral disposal of CO2

  • S. Fernandez-Bastero (a1), C. Gil-Lozano (a1), M. J. I. Briones (a2) and L. Gago-Duport (a1)

Abstract

The kinetics of glauconite dissolution have been determined in the pH range 2—10 (T = 25°C) using flow-batch reactor experiments. Besides the kinetic characteristics, the structural and textural aspects which could influence its long-term reactivity have also been characterized by means of X-ray diffraction (XRD), high-resolution transmission electron microscopy (HRTEM), scanning electron microscopy (SEM) and BET surface area measurements. The results from these analyses showed that glauconite follows a dual dissolution pathway which is pH-dependent, being more stable at neutral or slightly alkaline pH values. Under acidic conditions, glauconite is slightly more soluble than other ubiquitous silicates present in the marine sediments. The dissolution mechanism is incongruent at very acid pH values and tends to be congruent for intermediate and neutral ones. In addition, the results from the structural analyses suggest that the dissolution is a two-step process: the first one involves the disorder of the octahedral and tetrahedral layers, probably following a turbostratic mechanism which is evident in the XRD spectra as selective broadening of several reflections. In the second step, the dissolution of the cations from interlayer positions takes place and leads to the formation of an amorphous residue which acts as a passivating layer and reduces the reactive surface considerably. The influence of these aspects on CO2 capture via carbonation reactions is discussed.

Copyright

Corresponding author

References

Hide All
Blum, A.E. and Stillings, L.L. (1995) Feldspar dissolution kinetics. Pp. 291–351 in: Chemical Weathering Rates of Silicate Mineral. (White, A.F. and Brantley, S.L., editors). Reviews in Mineralogy 31, Mineralogical Society of America, Washington, D.C.
Fernandez-Bastero, S., Garcia, T., Santos, A. and Gago-Duport, L. (2005) Geochemical potentiality of glauconitic shelf sediments for sequestering atmospheric CO2 of antropogenic origin. Ciencias Marinas, 31, 593–615.
Guthrie, G.D., Carey, J.W., Bergfeld, D., Byler, D., Chipera, S., Ziock, H.J. and Lackner, K.S. (2001) Geochemical aspects of the carbonation of magnesium silicates in an aqueous medium. NETL Conference on Carbon Sequestration.
Malmstrom, M. and Banwart, S. (1997) Biotite dissolution at 25“C: the pH dependence of dissolution rate and stoichiometry. Geochimica et Cosmochimica Ada, 61, 2779–2799.
Santos, A., Toledo-Fernandez, J.A., Roberto Mendoza-Serna, R., Gago-Duport, L., de la Rosa-Fox, N., Pinero, M. and Esquivias, L. (2007) Chemically active silica aerogel-wollastonite composites for CO2fixation by carbonation reactions. Industrial and Engineering Chemical Research, 46, 103–107.
Wu, J.C.S., Sheen, ID., Chen, S.Y. and Fan, Y.C. (2001) Feasibility of CO2 fixation via artificial rock weathering. Industrial and Engineering Chemical Research, 40, 3902–3905.

Kinetic and structural constraints during glauconite dissolution: implications for mineral disposal of CO2

  • S. Fernandez-Bastero (a1), C. Gil-Lozano (a1), M. J. I. Briones (a2) and L. Gago-Duport (a1)

Metrics

Full text views

Total number of HTML views: 0
Total number of PDF views: 0 *
Loading metrics...

Abstract views

Total abstract views: 0 *
Loading metrics...

* Views captured on Cambridge Core between <date>. This data will be updated every 24 hours.

Usage data cannot currently be displayed