Hostname: page-component-848d4c4894-v5vhk Total loading time: 0 Render date: 2024-06-17T13:41:38.801Z Has data issue: false hasContentIssue false
  • English
  • Français

Calorimetric Measurement of the Enthalpy of Hydration of Clinoptilolite

Published online by Cambridge University Press:  28 February 2024

J. William Carey  and
David L. Bish
J. William Carey
Affiliation:
EES-1, MS D469, Los Alamos National Laboratory, Los Alamos, New Mexico 87545
David L. Bish
Affiliation:
EES-1, MS D469, Los Alamos National Laboratory, Los Alamos, New Mexico 87545
Get access Rights & Permissions [Opens in a new window]

Abstract

The enthalpy of hydration of natural clinoptilolite was determined by isothermal immersion calorimetry on Ca-, Na- and K-exchanged clinoptilolite (Fish Creek Mountains, Nevada). Heats of immersion of clinoptilolite were determined at initial H2O contents ranging from θ = 0.02 to 0.85 (where θ is the ratio [H2O content]/[maximum H2O content]). The heat of immersion (liquid H2O reference state) of Ca-clinoptilolite ranged from -7.5 (θ = 0.87) to -25.7 kJ/mol-H2O (θ = 0.19); values for Na-clinoptilolite ranged from -6.3 (θ = 0.85) to -21.8 kJ/mol-H2O (θ = 0.11); and values for K-clinoptilolite ranged from -7.7 (θ = 0.80) to -24.6 kJ/mol-H2O (θ = 0.02). Linear regression of the calorimetric data provided the following values for the complete heat of immersion (from θ = 0): Ca-clinoptilolite, -30.3 ± 2.0; Na-clinoptilolite, -23.4 ± 0.6; and K-clinoptilolite, -22.4 ± 0.8 kJ/mol-H2O.

The heat of immersion measurements were compared with the enthalpy of hydration results of Carey and Bish (1996) determined in a thermogravimetric study of the same samples. The heat of immersion data are similar but of smaller magnitude than the values of enthalpy of hydration and are believed to be more accurate because they represent direct measurements of this thermodynamic property.

The effect of dehydration of clinoptilolite on the thermal evolution of the potential high-level radioactive waste repository at Yucca Mountain was considered by comparing the amount of energy consumed by clinoptilolite dehydration with the amount of energy necessary to heat rocks lacking hydrous minerals. The extra energy consumed on heating clinoptilolite from 25 to 200 °C ranges between 70 and 80% in excess of that required for nondehydrating materials (that is, clinoptilolite acts as a heat sink). These results indicate that accurate thermohydrologic modeling of rock units at Yucca Mountain should consider the thermal effect of dehydration/hydration processes in clinoptilolite and other hydrous minerals, in addition to the water produced/adsorbed during heating/cooling.

Keywords

CalorimetryClinoptiloliteEnergeticsEnthalpyHydrationZeolite
Type
Research Article
Information
Clays and Clay Minerals , Volume 45 , Issue 6 , December 1997 , pp. 826 - 833
Copyright
Copyright © 1997, The Clay Minerals Society

Access options

Get access to the full version of this content by using one of the access options below. (Log in options will check for institutional or personal access. Content may require purchase if you do not have access.)

References

Barrer, R.M. Cram, P.J., Flanigen, E.M. and Sand, L.B., 1971 Heats of immersion of outgassed and ion-exchanged zeolites Molecular sieve zeolites—II Washington, DC Am Chem Soc 105–131 10.1021/ba-1971-0102.ch047.CrossRefGoogle Scholar
Bish, D.L., Kalló, D. and Sherry, H.S., 1988 Effects of composition on the dehydration behavior of clinoptilolite and heulandite Occurrence, properties and utilization of natural zeolites Budapest Akadémiai Kiadó 565–576.Google Scholar
Bish, D.L. and Chipera, S.J., 1989 Revised mineralogic summary of Yucca Mountain, Nevada Los Alamos Nat Lab Rept LA-1149-MS. .CrossRefGoogle Scholar
Carey, J.W. and Bish, D.L., 1996 Equilibrium in the clinoptilolite-H2O system Am Mineral 81 952–962 10.2138/am-1996-7-817.CrossRefGoogle Scholar
Carey, J.W. and Navrotsky, A., 1992 The molar enthalpy of dehydration of cordierite Am Mineral 77 930–936.Google Scholar
Chipera, S.J. Guthrie, G. J. Bish, D.L. and Guthrie, G M B, 1993 Preparation and purification of mineral dusts Health effects of mineral dusts Washington, DC Mineral Soc Am 235–249 10.1515/9781501509711-009.CrossRefGoogle Scholar
Deming, W.E., 1943 Statistical adjustment of data New York J Wiley..Google Scholar
Gottardi, G. and Galli, E., 1985 Natural zeolites Berlin Springer-Verlag. 10.1007/978-3-642-46518-5.CrossRefGoogle Scholar
Johnson, G.K. Tasker, I.R. and Jurgens, R O PAG, 1991 Thermodynamic studies of zeolites: Clinoptilolite J Chem Thermo 23 475–484 10.1016/S0021-9614(05)80135-1.CrossRefGoogle Scholar
Loeven, C., 1993 A summary and discussion of hydrologic data from the Calico Hills nonwelded Hydrogeologie unit at Yucca Mountain, Nevada Los Alamos Nat Lab Rept LA-12376-MS .CrossRefGoogle Scholar
Ross, S. and Olivier, J.P., 1964 On physical adsorption New York Interscience Publ.Google Scholar
Vaniman, D.T. Bish, D.L., Ming, D.W. and Mumpton, F.A., 1995 The importance of zeolites in the potential high-level radioactive waste repository at Yucca Mountain, Nevada Zeolites ’93 Brockport, NY Int Committee on Natural Zeolites 533–546.Google Scholar