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Kinetic model for the short-term dissolution of a rhyolitic glass

Chemical Geology

By:
,
DOI: 10.1016/0009-2541(80)90038-8

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Abstract

Aqueous dissolution experiments with the vitric phase of a rhyolitic tuff were performed at 25??C and constant pH in the range 4.5-7.5. Results suggest interchange of aqueous hydrogen ions for cations situated both on the surface and within the glass. At time intervals from 24 to 900 hr., dissolution kinetics are controlled by ion transport to and from sites within the glass. Experimental data indicate that parabolic diffusion rate of a chemical species from the solid is a nonlinear function of its aqueous concentration. A numerical solution to Fick's second law is presented for diffusion of sodium, which relates it's aqueous concentration to it's concentration on glass surface, by a Freundlich adsorption isotherm. The pH influence on sodium diffusion in the model can be accounted for by use of a pH-dependent diffusion coefficient and a pH-independent adsorption isotherm. ?? 1980.

Additional Publication Details

Publication type:
Article
Publication Subtype:
Journal Article
Title:
Kinetic model for the short-term dissolution of a rhyolitic glass
Series title:
Chemical Geology
DOI:
10.1016/0009-2541(80)90038-8
Volume
28
Issue:
C
Year Published:
1980
Language:
English
Publisher:
Elsevier
Larger Work Type:
Article
Larger Work Subtype:
Journal Article
First page:
91
Last page:
109
Number of Pages:
19