Thermochemistry and phase equilibria in calcium zeolites

Киселева, И. А.; Navrotsky, Alexandra; Belitsky, Igor A.; Fursenko, B. A.

doi:10.2138/am-1996-5-613

Cited by 84 publications

(28 citation statements)

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“…The thermodynamic properties of zeolites have been the subject of numerous experimental studies either using calorimetry or solution equilibria (Johnson et al, 1982(Johnson et al, , 1983(Johnson et al, , 1985(Johnson et al, , 1991(Johnson et al, , 1992Belitsky et al, 1982;Hemingway and Robie, 1984;Donahoe et al, 1990;Kiseleva et al, 1996Kiseleva et al, , 2001Shim et al, 1999;Drebushchak et al, 2000;Ogorodova et al, 2003;Neuhoff et al, 2004;Neuhoff and Wang, 2007). However, problems arise with the completeness of the thermodynamic datasets, for example with DH 0 f and S 0 (J mol À1 K À1 ) measured on minerals displaying slightly different compositions.…”

Section: Context Of the Selectionmentioning

confidence: 99%

ThermoChimie database developments in the framework of cement/clay interactions

Blanc

Vieillard

Gailhanou

et al. 2015

Applied Geochemistry

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Section: Context Of the Selectionmentioning

confidence: 99%

ThermoChimie database developments in the framework of cement/clay interactions

Blanc

Vieillard

Gailhanou

et al. 2015

Applied Geochemistry

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“…Higher Al content increases the basicity of the framework, which may cause stronger electrostatic interaction with cations and result in more stable Ref. [28]. b Ref.…”

Section: Comparison With Other Zeolitesmentioning

confidence: 99%

Thermodynamic study of alkali and alkaline-earth cation-exchanged natrolites

Navrotsky

Lee

2013

Microporous and Mesoporous Materials

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“…With the transposed-temperature drop calorimetry (TTDC), enthalpy of hydration data are obtained by measurements of the heat evolved from a sample dropped at room temperature into a calorimeter maintained at 700-800 °C, (Shim et al 1999;Yang et al 2001;Kiseleva et al 1996aKiseleva et al , 1996bKiseleva et al , 2001aSun et al 2006Sun et al , 2007Sun and Navrotsky 2008). One of the difficulties associated with this measurement method includes enthalpy effects due to irreversible structural changes at 700-800 °C (the effect depends on whether the collapse is exothermic or endothermic).…”

Section: Experimental Methodsmentioning

confidence: 99%

A predictive model for the enthalpies of hydration of zeolites

Vieillard

Mathieu

2009

American Mineralogist

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A compilation of the average hydration enthalpies per mole of water of 145 diversely originating zeolites measured using different technical methods [76 data from transposed-temperature drop calorimetry (TTDC), 57 data from immersion calorimetry (IC), 6 data from phase equilibria (PE), 5 data from gas-adsorption calorimetry (GAC), and 3 data from hydrofluoric acid solution calorimetry (HF)] was generated. Statistical regressions between three parameters involving the average hydration enthalpy per mole of water {∆H hyd-W , ∆H hyd-W /(Al/Si), ln[-∆H hyd-W /(Al/Si)]}and six parameters namely:(1) the charge defined by the Al/Si ratio; (2) the ratio of the framework charge to the number of H 2 O molecules (Al/H 2 O); (3) the framework density (FD) calculated from the molecular volume of the anhydrous zeolite, FD anh , and hydrated zeolite, FD hyd ; (4) the average cation electronegativity in the exchange site characterized by parameter ∆ H O = (site A) aq ; and (5) the intracrystalline water porosity (WP) determined from the volume of liquid water that can be recovered upon thorough outgassing of the hydrated zeolite. The regressions were performed by taking into account either the nature of the measurement technique, or the nature of the zeolite family. Within the zeolites from the TTDC and IC populations (133 data), the best results were obtained with ln[-∆H hyd-W /(Al/Si)] and Al/(Al + Si). Whatever the measurement technique, considering the nature of the zeolite family having a constant framework density of the anhydrous form (129 data), the Al/(Al + Si) ratio remains the best parameter and the enthalpy of hydration can be expressed as follows: ∆H hyd-w = -(Al/Si)*e {5.491 -4.674*[Al/(Al + Si)]}This general relationship can be improved by considering the following parameters: FD anh , ∆ H O = (site A) aq , WP and a new parameter that is the product of three parameters Al/Si, ∆ H O = (site A) aq , and WP weighing the variation of the water porosity related to the nature of the cation and to the total charge of the exchange site. Therefore, an understanding of the chemical formulae and unit-cell volumes of anhydrous and hydrated zeolites is required to evaluate the enthalpy of hydration with an accuracy of ±3.25 kJ/mol H 2 O.

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Thermochemistry and phase equilibria in calcium zeolites

Cited by 84 publications

References 0 publications

ThermoChimie database developments in the framework of cement/clay interactions

ThermoChimie database developments in the framework of cement/clay interactions

Thermodynamic study of alkali and alkaline-earth cation-exchanged natrolites

A predictive model for the enthalpies of hydration of zeolites

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