Original paper

Thermodynamic properties of some 2:1 layer clay minerals from solution-equilibration data

Aja, Stephen U.

European Journal of Mineralogy Volume 7 Number 2 (1995), p. 325 - 334

41 references

published: Mar 29, 1995
manuscript accepted: Oct 1, 1994
manuscript received: Mar 31, 1993

DOI: 10.1127/ejm/7/2/0325

BibTeX file

ArtNo. ESP147050702008, Price: 29.00 €

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Abstract

Abstract In recent solution-equilibration experiments with several natural illites, solubility was controlled by mica-like phases [Kx(MgyAl2-y) (Alx-ySi4-(x-y))O10(OH)2] including the following: smectite x = 0.29 + 0.04, y = 0.26 ±0.02; IS or illite (0.50 K), x = 0.50±0.05, y = 0.22 ±0.14; ISII or illite(0.69K), x = 0.69 ± 0.08, y = 0.16 ±0.03 and endmember illite or illite(0.85K), x = 0.85±0.05, y = 0.12±0.04. ΔG°f,298 retrieved for smectite, IS, ISII and endmember illite are -5316.8 ±5.6, -5407.7 ±5.0, -5452.3 ±6.8 and -5502.2 ± 8.4kJ/mol, respectively. Third-law entropy and enthalpy of formation have also been determined for these phases

Keywords

equilibrium constantstandard-state thermodynamic propertiesendmember illitesmectiteISII.