Details

Autor(en) / Beteiligte

• Gaboreau, S.
• Gailhanou, H.
• Blanc, Ph
• Vieillard, Ph
• Made, B.

Titel

Clay mineral solubility from aqueous equilibrium: Assessment of the measured thermodynamic properties

Ist Teil von

• Applied geochemistry, 2020-02, Vol.113, p.104465, Article 104465

Ort / Verlag

Elsevier Ltd

Erscheinungsjahr

2020

Link zum Volltext

Quelle

Alma/SFX Local Collection

Beschreibungen/Notizen

• Clay minerals (kaolinite KGa-2, smectite MX-80, illite IMt-2, vermiculite SO and Chlorite Cca-2) were equilibrated in aqueous media during long-term batch experiments up to seven years. Dissolved element concentrations were measured, allowing calculation of the ionic activity product of the minerals. An improved protocol for equilibration has been established to limit evaporation over the seven years of the experiments and to optimize the analytical results accuracy. The protocol could be verified with respect to the solubility of kaolinite. For the other minerals, the equilibrium constants obtained could be compared with the values calculated after calorimetric measurements previously performed on the same samples. The ionic activity products extracted for illite, smectite and, to a lesser extent, vermiculite were found to agree with the values issued from the calorimetric measurements. For chlorite in particular, a discrepancy with calorimetric measurements still remains. This was interpreted in terms of dissolution rates getting slower for this mineral, formed at temperatures higher than 25 °C. •Long term clay dissolution batch experiments were conducted over seven years.•Clay minerals solubility from aqueous equilibrium was assessed by calculating the ionic activity product (IAP).•Thermodynamic properties for five clay minerals, kaolinite, smectite, vermiculite and chlorite were determined.•The equilibrium constants of smectite and vermiculite are provided in the anhydrous and the hydrated state.