The Formation of Barite and Celestite through the Replacement of Gypsum

Barite (BaSO4) and celestite (SrSO4) are the end-members of a nearly ideal solid solution. Most of the exploitable deposits of celestite occur associated with evaporitic sediments which consist of gypsum (CaSO4·2H2O) or anhydrite (CaSO4). Barite, despite having a broader geological distribution is r...

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Detalles Bibliográficos
Autores: Forjanes Pérez, Pablo Cayetano, Astilleros García-Monge, José Manuel, Fernández Díaz, María Lourdes
Tipo de recurso: artículo
Fecha de publicación:2020
País:España
Institución:Universidad Complutense de Madrid (UCM)
Repositorio:Docta Complutense
Idioma:inglés
OAI Identifier:oai:docta.ucm.es:20.500.14352/6214
Acceso en línea:https://hdl.handle.net/20.500.14352/6214
Access Level:acceso abierto
Palabra clave:549.76
Gypsum
Barite
Celestite
Dissolution-precipitation
Mineral replacement
Mineralogía (Geología)
2506.11 Mineralogía
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oai_identifier_str oai:docta.ucm.es:20.500.14352/6214
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repository_id_str
spelling The Formation of Barite and Celestite through the Replacement of GypsumForjanes Pérez, Pablo CayetanoAstilleros García-Monge, José ManuelFernández Díaz, María Lourdes549.76GypsumBariteCelestiteDissolution-precipitationMineral replacementMineralogía (Geología)2506.11 MineralogíaBarite (BaSO4) and celestite (SrSO4) are the end-members of a nearly ideal solid solution. Most of the exploitable deposits of celestite occur associated with evaporitic sediments which consist of gypsum (CaSO4·2H2O) or anhydrite (CaSO4). Barite, despite having a broader geological distribution is rarely present in these deposits. In this work, we present an experimental study of the interaction between gypsum crystals and aqueous solutions that bear Sr or Ba. This interaction leads to the development of dissolution-crystallization reactions that result in the pseudomorphic replacement of the gypsum crystals by aggregates of celestite or barite, respectively. The monitoring of both replacement reactions shows that they take place at very different rates. Millimeter-sized gypsum crystals in contact with a 0.5 M SrCl2 solution are completely replaced by celestite aggregates in less than 1 day. In contrast, only a thin barite rim replaces gypsum after seven days of interaction of the latter with a 0.5 M BaCl2 solution. We interpret that this marked difference in the kinetics of the two replacement reactions relates the different orientational relationship that exists between the crystals of the two replacing phases and the gypsum substrate. This influence is further modulated by the specific crystal habit of each secondary phase. Thus, the formation of a thin oriented layer of platy barite crystals effectively armors the gypsum surface and prevents its interaction with the Ba-bearing solution, thereby strongly hindering the progress of the replacement reaction. In contrast, the random orientation of celestite crystals with respect to gypsum guarantees that a significant volume of porosity contained in the celestite layer is interconnected, facilitating the continuous communication between the gypsum surface and the fluid phase and guaranteeing the progress of the gypsum-by-celestite replacement.MDPIUniversidad Complutense de Madrid20202020-01-0120202020-01-01journal articlehttp://purl.org/coar/resource_type/c_6501info:eu-repo/semantics/articleapplication/pdfhttps://hdl.handle.net/20.500.14352/6214reponame:Docta Complutenseinstname:Universidad Complutense de Madrid (UCM)Inglésengopen accesshttp://purl.org/coar/access_right/c_abf2Attribution 4.0 Internationalhttps://creativecommons.org/licenses/by/4.0/info:eu-repo/semantics/openAccessoai:docta.ucm.es:20.500.14352/62142026-06-02T12:44:21Z
dc.title.none.fl_str_mv The Formation of Barite and Celestite through the Replacement of Gypsum
title The Formation of Barite and Celestite through the Replacement of Gypsum
spellingShingle The Formation of Barite and Celestite through the Replacement of Gypsum
Forjanes Pérez, Pablo Cayetano
549.76
Gypsum
Barite
Celestite
Dissolution-precipitation
Mineral replacement
Mineralogía (Geología)
2506.11 Mineralogía
title_short The Formation of Barite and Celestite through the Replacement of Gypsum
title_full The Formation of Barite and Celestite through the Replacement of Gypsum
title_fullStr The Formation of Barite and Celestite through the Replacement of Gypsum
title_full_unstemmed The Formation of Barite and Celestite through the Replacement of Gypsum
title_sort The Formation of Barite and Celestite through the Replacement of Gypsum
dc.creator.none.fl_str_mv Forjanes Pérez, Pablo Cayetano
Astilleros García-Monge, José Manuel
Fernández Díaz, María Lourdes
author Forjanes Pérez, Pablo Cayetano
author_facet Forjanes Pérez, Pablo Cayetano
Astilleros García-Monge, José Manuel
Fernández Díaz, María Lourdes
author_role author
author2 Astilleros García-Monge, José Manuel
Fernández Díaz, María Lourdes
author2_role author
author
dc.contributor.none.fl_str_mv Universidad Complutense de Madrid
dc.subject.none.fl_str_mv 549.76
Gypsum
Barite
Celestite
Dissolution-precipitation
Mineral replacement
Mineralogía (Geología)
2506.11 Mineralogía
topic 549.76
Gypsum
Barite
Celestite
Dissolution-precipitation
Mineral replacement
Mineralogía (Geología)
2506.11 Mineralogía
description Barite (BaSO4) and celestite (SrSO4) are the end-members of a nearly ideal solid solution. Most of the exploitable deposits of celestite occur associated with evaporitic sediments which consist of gypsum (CaSO4·2H2O) or anhydrite (CaSO4). Barite, despite having a broader geological distribution is rarely present in these deposits. In this work, we present an experimental study of the interaction between gypsum crystals and aqueous solutions that bear Sr or Ba. This interaction leads to the development of dissolution-crystallization reactions that result in the pseudomorphic replacement of the gypsum crystals by aggregates of celestite or barite, respectively. The monitoring of both replacement reactions shows that they take place at very different rates. Millimeter-sized gypsum crystals in contact with a 0.5 M SrCl2 solution are completely replaced by celestite aggregates in less than 1 day. In contrast, only a thin barite rim replaces gypsum after seven days of interaction of the latter with a 0.5 M BaCl2 solution. We interpret that this marked difference in the kinetics of the two replacement reactions relates the different orientational relationship that exists between the crystals of the two replacing phases and the gypsum substrate. This influence is further modulated by the specific crystal habit of each secondary phase. Thus, the formation of a thin oriented layer of platy barite crystals effectively armors the gypsum surface and prevents its interaction with the Ba-bearing solution, thereby strongly hindering the progress of the replacement reaction. In contrast, the random orientation of celestite crystals with respect to gypsum guarantees that a significant volume of porosity contained in the celestite layer is interconnected, facilitating the continuous communication between the gypsum surface and the fluid phase and guaranteeing the progress of the gypsum-by-celestite replacement.
publishDate 2020
dc.date.none.fl_str_mv 2020
2020-01-01
2020
2020-01-01
dc.type.none.fl_str_mv journal article
http://purl.org/coar/resource_type/c_6501
dc.type.openaire.fl_str_mv info:eu-repo/semantics/article
format article
dc.identifier.none.fl_str_mv https://hdl.handle.net/20.500.14352/6214
url https://hdl.handle.net/20.500.14352/6214
dc.language.none.fl_str_mv Inglés
eng
language_invalid_str_mv Inglés
language eng
dc.rights.none.fl_str_mv open access
http://purl.org/coar/access_right/c_abf2
Attribution 4.0 International
https://creativecommons.org/licenses/by/4.0/
dc.rights.openaire.fl_str_mv info:eu-repo/semantics/openAccess
rights_invalid_str_mv open access
http://purl.org/coar/access_right/c_abf2
Attribution 4.0 International
https://creativecommons.org/licenses/by/4.0/
eu_rights_str_mv openAccess
dc.format.none.fl_str_mv application/pdf
dc.publisher.none.fl_str_mv MDPI
publisher.none.fl_str_mv MDPI
dc.source.none.fl_str_mv reponame:Docta Complutense
instname:Universidad Complutense de Madrid (UCM)
instname_str Universidad Complutense de Madrid (UCM)
reponame_str Docta Complutense
collection Docta Complutense
repository.name.fl_str_mv
repository.mail.fl_str_mv
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score 15,301603

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