Pollet-Villard, M;
Daval, D;
Ackerer, P;
Saldi, GD;
Knauss, KG;
Wild, B;
Fritz, B;
(2017)
Experimental study of dissolution kinetics of K-feldspar as a function of crystal structure anisotropy under hydrothermal conditions.
Procedia Earth and Planetary Science
, 17
pp. 165-168.
10.1016/j.proeps.2016.12.042.
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Abstract
We present the results of an experimental study of the effect of anisotropy on the kinetics of K-Feldspar dissolution under hydrothermal conditions as encountered in the Soultz-sous-Forêts enhanced geothermal system. We try to quantify the impact of K-feldspar anisotropy on dissolution rates in order to develop a more comprehensive model of the evolution of the reactive surface of silicate minerals in order to propose alternate kinetic rate laws to be implemented into water-rock interaction models and reactive transport codes. Our results evidence a relation between K-spar dissolution rate and the Gibbs free energy of reaction (ΔGr) which clearly differs from the transition state theory usually implemented into geochemical codes: it depends on the crystallographic orientation of K-spar mineral with significant differences between the different crystal faces. As for the far-from-equilibrium dissolution rate, this result highlights that using a unique theoretical rate law to describe dissolution rate as a function of ΔGr remains highly questionable. These results are very important for our challenge of understanding and modelling the dissolution mechanisms and they evidence that the dissolution anisotropy plays a fundamental role in these mechanisms.
Type: | Article |
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Title: | Experimental study of dissolution kinetics of K-feldspar as a function of crystal structure anisotropy under hydrothermal conditions |
Event: | 15th Water-Rock Interaction International Symposium (WRI) |
Location: | Evora, PORTUGAL |
Dates: | 16 October 2016 - 21 October 2016 |
Open access status: | An open access version is available from UCL Discovery |
DOI: | 10.1016/j.proeps.2016.12.042 |
Publisher version: | http://doi.org/10.1016/j.proeps.2016.12.042 |
Language: | English |
Additional information: | Copyright © 2017 Published by Elsevier B.V. This is an open access article under the CC BY-NC-ND license (http://creativecommons.org/licenses/by-nc-nd/4.0/). |
Keywords: | experimental study; dissolution kinetics; anisotropy; K-feldspar; hydrothermal conditions |
UCL classification: | UCL UCL > Provost and Vice Provost Offices > UCL BEAMS UCL > Provost and Vice Provost Offices > UCL BEAMS > Faculty of Maths and Physical Sciences |
URI: | https://discovery.ucl.ac.uk/id/eprint/10056766 |
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