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The dissolution of calcite in CO2-saturated solutions at 25°C and 1 atmosphere total pressure

Geochimica et Cosmochimica Acta

By:
and
DOI: 10.1016/0016-7037(76)90176-9

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Abstract

The dissolution of Iceland spar in CO2-saturated solutions at 25°C and 1 atm total pressure has been followed by measurement of pH as a function of time. Surface concentrations of reactant and product species have been calculated from bulk fluid data using mass transport theory and a model that accounts for homogeneous reactions in the bulk fluid. The surface concentrations are found to be close to bulk solution values. This indicates that calcite dissolution under the experimental conditions is controlled by the kinetics of surface reaction. The rate of calcite dissolution follows an empirical second order relation with respect to calcium and hydrogen ion from near the initial condition (pH 3.91) to approximately pH 5.9. Beyond pH 5.9 the rate of surface reaction is greatly reduced and higher reaction orders are observed. Calculations show that the rate of calcite dissolution in natural environments may be influenced by both transport and surface-reaction processes. In the absence of inhibition, relatively short times should be sufficient to establish equilibrium.

Additional Publication Details

Publication type:
Article
Publication Subtype:
Journal Article
Title:
The dissolution of calcite in CO2-saturated solutions at 25°C and 1 atmosphere total pressure
Series title:
Geochimica et Cosmochimica Acta
DOI:
10.1016/0016-7037(76)90176-9
Volume
40
Issue:
2
Year Published:
1976
Language:
English
Publisher:
Elsevier
Description:
12 p.
First page:
191
Last page:
202
Online Only (Y/N):
N
Additional Online Files(Y/N):
N