Solubility of anhydrite and gypsum at temperatures below 100°C and the gypsum-anhydrite transition temperature in aqueous solutions: a re-assessment
Anhydrite and gypsum are omnipresent in sedimentary rocks of all types. They occur as massive layers or are distributed within other geological formations as in clays. Understanding the conditions of formation and the stability of the hydrated and anhydrous form of calcium sulfate is crucial in an e...
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| Format: | Article |
| Language: | English |
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Frontiers Media S.A.
2023-09-01
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| Series: | Frontiers in Nuclear Engineering |
| Subjects: | |
| Online Access: | https://www.frontiersin.org/articles/10.3389/fnuen.2023.1208582/full |
| _version_ | 1797678081486356480 |
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| author | Wolfgang Voigt Daniela Freyer |
| author_facet | Wolfgang Voigt Daniela Freyer |
| author_sort | Wolfgang Voigt |
| collection | DOAJ |
| description | Anhydrite and gypsum are omnipresent in sedimentary rocks of all types. They occur as massive layers or are distributed within other geological formations as in clays. Understanding the conditions of formation and the stability of the hydrated and anhydrous form of calcium sulfate is crucial in an elucidation of the genesis of the geological formations envisaged as potential host rock for radioactive waste disposal. Estimations of the temperature, where gypsum is dehydrated to anhydrite in water vary between 30°C and 60°C. The extremely slow crystallization kinetics of anhydrite at T < 90°C prevents a direct determination of this transition temperature. In the present work the different approaches to fix this temperature are discussed. It is shown that careful assessment of solubility data and calorimetric measurements yields a transition temperature of 42°C ± 1°C. For results essentially deviating from this value methodic deficiencies are revealed and discussed. Thus, a long-standing discussion about the thermodynamic aspect of the gypsum-anhydrite conversion can be closed, not the kinetic part. |
| first_indexed | 2024-03-11T22:54:29Z |
| format | Article |
| id | doaj.art-4369d79eeec64a0888d869d8c0148788 |
| institution | Directory Open Access Journal |
| issn | 2813-3412 |
| language | English |
| last_indexed | 2024-03-11T22:54:29Z |
| publishDate | 2023-09-01 |
| publisher | Frontiers Media S.A. |
| record_format | Article |
| series | Frontiers in Nuclear Engineering |
| spelling | doaj.art-4369d79eeec64a0888d869d8c01487882023-09-21T17:26:25ZengFrontiers Media S.A.Frontiers in Nuclear Engineering2813-34122023-09-01210.3389/fnuen.2023.12085821208582Solubility of anhydrite and gypsum at temperatures below 100°C and the gypsum-anhydrite transition temperature in aqueous solutions: a re-assessmentWolfgang VoigtDaniela FreyerAnhydrite and gypsum are omnipresent in sedimentary rocks of all types. They occur as massive layers or are distributed within other geological formations as in clays. Understanding the conditions of formation and the stability of the hydrated and anhydrous form of calcium sulfate is crucial in an elucidation of the genesis of the geological formations envisaged as potential host rock for radioactive waste disposal. Estimations of the temperature, where gypsum is dehydrated to anhydrite in water vary between 30°C and 60°C. The extremely slow crystallization kinetics of anhydrite at T < 90°C prevents a direct determination of this transition temperature. In the present work the different approaches to fix this temperature are discussed. It is shown that careful assessment of solubility data and calorimetric measurements yields a transition temperature of 42°C ± 1°C. For results essentially deviating from this value methodic deficiencies are revealed and discussed. Thus, a long-standing discussion about the thermodynamic aspect of the gypsum-anhydrite conversion can be closed, not the kinetic part.https://www.frontiersin.org/articles/10.3389/fnuen.2023.1208582/fullsolubility equilibriumgypsumanhydritetransition temperaturethermodynamics |
| spellingShingle | Wolfgang Voigt Daniela Freyer Solubility of anhydrite and gypsum at temperatures below 100°C and the gypsum-anhydrite transition temperature in aqueous solutions: a re-assessment Frontiers in Nuclear Engineering solubility equilibrium gypsum anhydrite transition temperature thermodynamics |
| title | Solubility of anhydrite and gypsum at temperatures below 100°C and the gypsum-anhydrite transition temperature in aqueous solutions: a re-assessment |
| title_full | Solubility of anhydrite and gypsum at temperatures below 100°C and the gypsum-anhydrite transition temperature in aqueous solutions: a re-assessment |
| title_fullStr | Solubility of anhydrite and gypsum at temperatures below 100°C and the gypsum-anhydrite transition temperature in aqueous solutions: a re-assessment |
| title_full_unstemmed | Solubility of anhydrite and gypsum at temperatures below 100°C and the gypsum-anhydrite transition temperature in aqueous solutions: a re-assessment |
| title_short | Solubility of anhydrite and gypsum at temperatures below 100°C and the gypsum-anhydrite transition temperature in aqueous solutions: a re-assessment |
| title_sort | solubility of anhydrite and gypsum at temperatures below 100°c and the gypsum anhydrite transition temperature in aqueous solutions a re assessment |
| topic | solubility equilibrium gypsum anhydrite transition temperature thermodynamics |
| url | https://www.frontiersin.org/articles/10.3389/fnuen.2023.1208582/full |
| work_keys_str_mv | AT wolfgangvoigt solubilityofanhydriteandgypsumattemperaturesbelow100candthegypsumanhydritetransitiontemperatureinaqueoussolutionsareassessment AT danielafreyer solubilityofanhydriteandgypsumattemperaturesbelow100candthegypsumanhydritetransitiontemperatureinaqueoussolutionsareassessment |