The kinetics of calcite dissolution/precipitation
- Oxford Univ., South Parks Road (United Kingdom). Physical Chemistry Lab.
The channel-flow cell method is used to establish the dissolution/precipitation kinetics of calcite under wide ranges of bulk Ca[sup 2+] concentration (0-10 mM) and solution flow rate (10[sup [minus]3]0.3 cm[sup 3]s[sup [minus]1]) for different bulk pH values. Detailed mathematical modeling of the heterogeneous reaction, and accompanying solution processes leads to the following rate equation based on a model in which Ca[sup 2+] and CO[sup 2][minus][sub 3] undergo Langmuirian adsorption on the calcite surface: D[sub net]/mol cm[sup [minus]2] s[sup [minus]1] = k[sub b]K[sub Ca]K[sub CO[sub 3]] [K[sub sp] [minus] (Ca[sup 2+])[sub 0](CO[sub 3][sup 2[minus]])[sub 0]/(1+K[sub Ca](Ca[sup 2+])[sub 0])(1+K[sub CO[sub 3]](CO[sub 3])[sub 0])]. Here D[sub net] is the net flux of dissolving calcium ions, k[sub b] is a rate constant, K[sub sp] is the solubility product of calcite corrected for the ionic strength of the solution, K[sub A] (A = Ca[sub 2+] or CO[sub 3][sup 2][minus]) are Langmuirian adsorption constants, and ( )[sub 0] denotes the concentration at the Outer Helmholtz Plane.
- OSTI ID:
- 5746954
- Journal Information:
- Journal of Colloid and Interface Science; (United States), Vol. 160:2; ISSN 0021-9797
- Country of Publication:
- United States
- Language:
- English
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