A new kinetic approach to modeling water-rock interaction: The role of nucleation, precursors, and Ostwald ripening

Steefel, Carl I.; Cappellen, Philippe Van

doi:10.1016/0016-7037(90)90003-4

Cited by 480 publications

(349 citation statements)

References 75 publications

Supporting

Mentioning

324

Contrasting

Unclassified

Order By: Relevance

“…Here seeds may be created by nucleation, the seeds may growth via crystal growth and/or ripening and agglomeration (Steefel and Van Cappellen, 1990). Some proposed methods for including the evolution of reactive surface area are given in Section 5.4.5.…”

Section: Data Needs For Rate Lawsmentioning

confidence: 99%

“…If a mineral forms on existing surfaces (of the same mineral and/or on surfaces of existing precursors), the surface area can be assumed to evolve with some proportionality to the current volume fraction of the mineral (or precursor mineral(s)). However, if a mineral actually nucleates from solution, without precursors, a rigorous treatment of nucleation is required (Steefel and Van Cappellen, 1990). Such rigorous treatment, however, is deemed outside the scope of current model requirements, primarily because input parameters for nucleation models are scarce for most minerals.…”

Section: Reactive Surface Area Evolutionmentioning

confidence: 99%

“…(5.136) Such a procedure obviates the need for a more complicated formulation such as that found in Steefel and Van Cappellen (1990).…”

Section: Reactive Surface Area Evolutionmentioning

confidence: 99%

“…Thus the surface area A nucl (as the area of the spheres divided by the volume of the cube) can be computed as (5.137) where r is the average grain size of the mineral. A more comprehensive approach involving crystal size distributions has been proposed by Steefel and Van Cappellen (1990).…”

Section: Reactive Surface Area Evolutionmentioning

confidence: 99%

See 3 more Smart Citations

Mathematical Formulation Requirements and Specifications for the Process Models

Steefel¹,

Moulton²,

Pau³

et al. 2010

View full text Add to dashboard Cite

Section: Data Needs For Rate Lawsmentioning

confidence: 99%

Section: Reactive Surface Area Evolutionmentioning

confidence: 99%

“…(5.136) Such a procedure obviates the need for a more complicated formulation such as that found in Steefel and Van Cappellen (1990).…”

Section: Reactive Surface Area Evolutionmentioning

confidence: 99%

Section: Reactive Surface Area Evolutionmentioning

confidence: 99%

See 2 more Smart Citations

Mathematical Formulation Requirements and Specifications for the Process Models

Steefel¹,

Moulton²,

Pau³

et al. 2010

View full text Add to dashboard Cite

“…Thus Ostwald ripening involves a mass transfer from smaller particles to a lesser number of larger particles and this results in a net decrease in the number of particles in the system with the driving force for the process being the change in interfacial energy of the particles (Nielsen, 1964). At a given degree of supersaturation of the starting solution, δ, the critical radius of the resulting particles, r, can be expressed as a function of the molar volume, ν, the bulk solubility, S eq , the density, ρ, and the concentration, a c , and this represents the Gibbs-Kelvin equation (see also Steefel and Van Cappellen, 1990):…”

Section: Ostwald Ripeningmentioning

confidence: 99%

Nucleation, Growth, and Aggregation of Mineral Phases: Mechanisms and Kinetic Controls

Benning

Waychunas

2008

Kinetics of Water-Rock Interaction

View full text Add to dashboard Cite

The formation of any phase, whether natural or synthetic (Fig. 7.1), is usually a disequilibrium process that follows a series of steps until a thermodynamically stable state (equilibrium) is achieved. The first step in the process of creating a new solid phase from a supersaturated solution (either aqueous or solid) is called nucleation. A particle formed by the event of nucleation usually has a poorly ordered and often highly hydrated structure. This particle is metastable with respect to ordering into a well-defined phase, which can accompany growth of the particle. This process of initiation of a new phase is defined as a first order transition and can follow various pathways involving a host of mechanisms. One of these pathways occurs when individual nuclei coalesce into larger clusters, a process defined as aggregation, which itself can follow a series of different pathways. The new phase is thermodynamically defined when the growing nucleus or aggregate has distinct properties relative to its host matrix; for example, a well-defined crystal structure, composition and/or density. These processes depend on a plethora of chemical and physical parameters that control and strongly affect the formation of new nuclei, the growth of a new crystal, or the aggregation behavior of clusters, and it is these issues that will be the focus of this chapter. We will discuss the mechanisms and rates of each process as well as the methods of quantification or modeling from the point of view of existing theoretical understanding. Each step will be illustrated with natural examples or laboratory experimental quantifications. Complementary to the information in this chapter, a detailed analysis of the mechanisms and processes that govern dissolution of a phase are discussed in detail in Chap. 5 and more detailed information about molecular modeling approaches are outlined in Chap. 2.

show abstract

Influence of phosphate and iron on the extent of calcium carbonate precipitation during anaerobic digestion

Langerak

Beekmans

Beun

et al. 1999

J. Chem. Technol. Biotechnol.

View full text Add to dashboard Cite

The extent to which calcium carbonate deposition in an anaerobic reactor can be reduced by adding inhibitors (phosphate and iron) of calcium carbonate crystal growth was investigated. At several concentrations of the additive, the extent of precipitation was assessed in continuous experiments with laboratory-scale reactors. In the reactor, phosphate concentrations as low as 0.5± 5 mg total-P dm À3 were found to severely inhibit CaCO 3 precipitation. However, iron did not inhibit the deposition of CaCO 3 , which was found to be due to the fact that iron, in contrast to phosphate, only inhibits the growth of calcite and not the formation of aragonite. The results led to the conclusion that only additives which inhibit the formation of both aragonite and calcite can be used as effective inhibitors during anaerobic digestion. A chemical equilibrium model was developed and shown to be a useful tool to calculate the extent of calcium carbonate deposition during anaerobic digestion provided the proper apparent solubility product of calcium carbonate can be estimated.

show abstract

A new kinetic approach to modeling water-rock interaction: The role of nucleation, precursors, and Ostwald ripening

Cited by 480 publications

References 75 publications

Mathematical Formulation Requirements and Specifications for the Process Models

Mathematical Formulation Requirements and Specifications for the Process Models

Nucleation, Growth, and Aggregation of Mineral Phases: Mechanisms and Kinetic Controls

Influence of phosphate and iron on the extent of calcium carbonate precipitation during anaerobic digestion

Contact Info

Product

Resources

About