How do mineral coatings affect dissolution rates? An experimental study of coupled CaCO3 dissolution—CdCO3 precipitation

Cubillas, Pablo; Köhler, Stephan Jürgen; Prieto, M.; Causserand, Carole; Oelkers, Eric H.

doi:10.1016/j.gca.2005.07.016

Cited by 111 publications

(60 citation statements)

References 76 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…P values of 0.5 indicate that dissolution or growth occur predominantly in two directions while P values of 0 indicate one direction (e.g., Witkamp et al, 1990). The reactive surface areas may also vary during experiments as a result of the extinction of highly reactive fine particles (Helgeson et al, 1984), change of the ratios of reactive and nonreactive sites (Gautier et al, 2001), mechanical disaggregation of particles (Nagy and Lasaga, 1992;Ganor et al, 1999), and formation of surface coating (Ganor et al, 1995;Nugent et al, 1998;Cubillas et al, 2005;Metz et al, 2005).…”

Section: Reactive Surface Areamentioning

confidence: 99%

Coupled alkali feldspar dissolution and secondary mineral precipitation in batch systems: 4. Numerical modeling of kinetic reaction paths

Zhu

Lü

Zheng

et al. 2010

Geochimica et Cosmochimica Acta

View full text Add to dashboard Cite

This paper explores how dissolution and precipitation reactions are coupled in batch reactor experimental systems at elevated temperatures. This is the fourth paper in our series of "Coupled Alkali Feldspar Dissolution and Secondary Mineral Precipitation in Batch Systems". In our third paper, we demonstrated via speciation-solubility modeling that partial equilibrium between secondary minerals and aqueous solutions was not attained in feldspar hydrolysis batch reactors at 90-300°C and that a strong coupling between dissolution and precipitation reactions follows as a consequence of the slower precipitation of secondary minerals ). Here, we develop this concept further by using numerical reaction path models to elucidate how the dissolution and precipitation reactions are coupled. Modeling results show that a quasi-steady state was reached. At the quasi-steady state, dissolution reactions proceeded at rates that are orders of magnitude slower than the rates measured at far from equilibrium. The quasi-steady state is determined by the relative rate constants, and strongly influenced by the function of Gibbs free energy of reaction (DG r ) in the rate laws.To explore the potential effects of fluid flow rates on the coupling of reactions, we extrapolate a batch system (Ganor et al., 2007) to open systems and simulated one-dimensional reactive mass transport for oligoclase dissolution and kaolinite precipitation in homogeneous porous media. Different steady states were achieved at different locations along the one-dimensional domain. The time-space distribution and saturation indices (SI) at the steady states were a function of flow rates for a given kinetic model. Regardless of the differences in SI, the ratio between oligoclase dissolution rates and kaolinite precipitation rates remained 1.626, as in the batch system case (Ganor et al., 2007). Therefore, our simulation results demonstrated coupling among dissolution, precipitation, and flow rates.Results reported in this communication lend support to our hypothesis that slow secondary mineral precipitation explains part of the well-known apparent discrepancy between lab measured and field estimated feldspar dissolution rates (Zhu et al., 2004). Here we show how the slow secondary mineral precipitation provides a regulator to explain why the systems are held close to equilibrium and show how the most often-quoted "near equilibrium" explanation for an apparent field-lab discrepancy can work quantitatively. The substantiated hypothesis now offers the promise of reconciling part of the apparent fieldlab discrepancy.

show abstract

Section: Reactive Surface Areamentioning

confidence: 99%

Coupled alkali feldspar dissolution and secondary mineral precipitation in batch systems: 4. Numerical modeling of kinetic reaction paths

Zhu

Lü

Zheng

et al. 2010

Geochimica et Cosmochimica Acta

View full text Add to dashboard Cite

show abstract

“…Giammar et al, 2005;Zakaznova-Herzog et al 2008;Olssen et al, 2012;Wang and Giammar, 2012;Hövelmann et al, 2013;Saldi et al, 2013). The degree to which secondary surface precipitates affect the dissolution rates of the primary mineral appears to depend on the structural match between the two minerals and the presence of interconnected porous pathways in the secondary phases (Hodson, 2003;Cubillas et al, 2005;Putnis, 2009;Stockmann, 2011Stockmann, , 2013Saldi et al, 2013). Finally, long-term olivine dissolution rates can also be limited by the slow precipitation rates of secondary minerals, which could lead the fluid to approach equilibrium with the dissolving mineral (e.g.…”

Section: Introductionmentioning

confidence: 99%

The efficient long-term inhibition of forsterite dissolution by common soil bacteria and fungi at Earth surface conditions

Oelkers

Benning

Lutz

et al. 2015

Geochimica et Cosmochimica Acta

Self Cite

View full text Add to dashboard Cite

“…Coating phases alter or ultimately obscure the reactive properties of mineral surfaces (Cubillas et al, 2005). For example, Martin and co-workers (Jun et al, 2005;Martin, 2008, 2009) showed, using scanning probe microscopy, that manganese oxide heteroepitaxial nanostructures grown on manganese carbonate surfaces exhibited vastly different interfacial forces than their substrate, indicative of different surface charges.…”

Section: Introductionmentioning

confidence: 99%

Kinetics and mechanisms of cadmium carbonate heteroepitaxial growth at the calcite (101¯4) surface

Xu¹,

Kovařík²,

Arey³

et al. 2014

Geochimica et Cosmochimica Acta

View full text Add to dashboard Cite

Elucidating the kinetics and mechanisms of heteroepitaxial nucleation and growth at mineral-water interfaces is essential to understanding surface reactivity in geochemical systems. In the present work, the formation of heteroepitaxial cadmium carbonate coatings at calcite-water interfaces was investigated by exposing calcite ð10 1 4Þ surfaces to Cd-bearing aqueous solutions. In situ atomic force microscopy (AFM) was employed as the primary technique. The AFM results indicate that the heteroepitaxial growth of cadmium carbonate proceeds via three different mechanisms depending on the initial supersaturation of the aqueous solution: advancement of existing steps, nucleation and growth of three-dimensional (3D) islands, and nucleation and spread of two-dimensional (2D) nuclei. The 3D islands and 2D nuclei exhibit different morphologies and growth kinetics. The effects of supersaturation on heteroepitaxial growth mechanisms can be interpreted in terms of the free energy barrier for nucleation. At low initial supersaturation, where 3D nucleation dominates, it is hypothesized, from the growth rate and morphology of the 3D islands observed with AFM, that the crystallization of the overgrowth follows a non-classical pathway involving the formation of a surface precursor that is not fully crystalline, whereas high supersaturation favors the formation of crystalline 2D nuclei whose morphology is based on the atomic structure of the calcite substrate. Cross-sectional transmission electron microscopy (TEM) images reveal that the atomic structure of the interface between the cadmium carbonate coating and calcite shows perfect, dislocation-free epitaxy.

show abstract

How do mineral coatings affect dissolution rates? An experimental study of coupled CaCO3 dissolution—CdCO3 precipitation

Cited by 111 publications

References 76 publications

Coupled alkali feldspar dissolution and secondary mineral precipitation in batch systems: 4. Numerical modeling of kinetic reaction paths

Coupled alkali feldspar dissolution and secondary mineral precipitation in batch systems: 4. Numerical modeling of kinetic reaction paths

The efficient long-term inhibition of forsterite dissolution by common soil bacteria and fungi at Earth surface conditions

Kinetics and mechanisms of cadmium carbonate heteroepitaxial growth at the calcite (101¯4) surface

Contact Info

Product

Resources

About