Fe-Ni-bearing serpentines from the saprolite horizon of Caribbean Ni-laterite deposits: new insights from thermodynamic calculations

Fe-Ni-bearing serpentine from the saprolite horizon is the main Ni ores in hydrous silicate-type Ni laterites and formed by chemical weathering of partially serpentinized ultramafic rocks under tropical conditions. During lateritization, Mg, Si, and Ni are leached from the surface and transported do...

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Detalhes bibliográficos
Autores: Villanova de Benavent, Cristina, Domènech Ortí, Cristina, Tauler i Ferré, Esperança, Galí Medina, Salvador, 1949-, Tassara, S., Proenza Fernández, Joaquín Antonio
Formato: artículo
Estado:Versión aceptada para publicación
Fecha de publicación:2017
País:España
Recursos:Varias* (Consorci de Biblioteques Universitáries de Catalunya, Centre de Serveis Científics i Acadèmics de Catalunya)
Repositorio:Recercat. Dipósit de la Recerca de Catalunya
OAI Identifier:oai:recercat.cat:2445/160423
Acesso em linha:https://hdl.handle.net/2445/160423
Access Level:acceso abierto
Palavra-chave:Níquel
Laterita
Compostos de níquel
Nickel
Laterite
Nickel compounds
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spelling Fe-Ni-bearing serpentines from the saprolite horizon of Caribbean Ni-laterite deposits: new insights from thermodynamic calculationsVillanova de Benavent, CristinaDomènech Ortí, CristinaTauler i Ferré, EsperançaGalí Medina, Salvador, 1949-Tassara, S.Proenza Fernández, Joaquín AntonioNíquelLateritaCompostos de níquelNickelLateriteNickel compoundsFe-Ni-bearing serpentine from the saprolite horizon is the main Ni ores in hydrous silicate-type Ni laterites and formed by chemical weathering of partially serpentinized ultramafic rocks under tropical conditions. During lateritization, Mg, Si, and Ni are leached from the surface and transported downwards. Fe2+ is oxidized to Fe3+ and fixed as insoluble Feoxyhydroxides (mostly goethite) that incorporate Ni. This Ni is later leached from goethite and incorporated in secondary serpentine and garnierite. As a result, a serpentine-dominated saprolite horizon forms over the ultramafic protolith, overlapped by a Fe-oxyhydroxide-dominated limonite horizon. The serpentine from the protolith (serpentine I) is of hydrothermal origin and yields similar Ni (0.10-0.62 wt.% NiO) and lower Fe (mostly 1.37-5.81 wt.% FeO) concentrations than the primary olivine. In contrast, Fe-Ni-bearing serpentine from the saprolite (serpentine II) shows significantly higher and variable Fe and Ni contents, typically ranging from 2.23 to 15.59 wt.% Fe2O3 and from 1.30 to 7.67 wt.% NiO, suggesting that serpentine get enriched in Fe and Ni under supergene conditions. This study presents detailed mineralogical, textural, and chemical data on this serpentine II, as well as new insights by thermodynamic calculations assuming ideal solution between Fe-, Ni- and Mg-pure serpentines. The aim is to assess if at atmospheric pressure and temperature Fe-Ni-bearing serpentine can be formed by precipitation. Results indicate that the formation of serpentine II under atmospheric pressure and temperature is thermodynamically supported, and pH, Eh, and the equilibrium constant of the reaction are the parameters that affect the results more significantly.Springer Verlag2020202020172020info:eu-repo/semantics/articleinfo:eu-repo/semantics/acceptedVersion35 p.application/pdfhttps://hdl.handle.net/2445/160423Articles publicats en revistes (Mineralogia, Petrologia i Geologia Aplicada)reponame:Recercat. Dipósit de la Recerca de Catalunyainstname:Varias* (Consorci de Biblioteques Universitáries de Catalunya, Centre de Serveis Científics i Acadèmics de Catalunya)InglésVersió postprint del document publicat a: https://doi.org/10.1007/s00126-016-0683-7Mineralium Deposita, 2017, vol. 52, p. 979-992https://doi.org/10.1007/s00126-016-0683-7(c) Springer Verlag, 2017info:eu-repo/semantics/openAccessoai:recercat.cat:2445/1604232026-05-29T05:05:01Z
dc.title.none.fl_str_mv Fe-Ni-bearing serpentines from the saprolite horizon of Caribbean Ni-laterite deposits: new insights from thermodynamic calculations
title Fe-Ni-bearing serpentines from the saprolite horizon of Caribbean Ni-laterite deposits: new insights from thermodynamic calculations
spellingShingle Fe-Ni-bearing serpentines from the saprolite horizon of Caribbean Ni-laterite deposits: new insights from thermodynamic calculations
Villanova de Benavent, Cristina
Níquel
Laterita
Compostos de níquel
Nickel
Laterite
Nickel compounds
title_short Fe-Ni-bearing serpentines from the saprolite horizon of Caribbean Ni-laterite deposits: new insights from thermodynamic calculations
title_full Fe-Ni-bearing serpentines from the saprolite horizon of Caribbean Ni-laterite deposits: new insights from thermodynamic calculations
title_fullStr Fe-Ni-bearing serpentines from the saprolite horizon of Caribbean Ni-laterite deposits: new insights from thermodynamic calculations
title_full_unstemmed Fe-Ni-bearing serpentines from the saprolite horizon of Caribbean Ni-laterite deposits: new insights from thermodynamic calculations
title_sort Fe-Ni-bearing serpentines from the saprolite horizon of Caribbean Ni-laterite deposits: new insights from thermodynamic calculations
dc.creator.none.fl_str_mv Villanova de Benavent, Cristina
Domènech Ortí, Cristina
Tauler i Ferré, Esperança
Galí Medina, Salvador, 1949-
Tassara, S.
Proenza Fernández, Joaquín Antonio
author Villanova de Benavent, Cristina
author_facet Villanova de Benavent, Cristina
Domènech Ortí, Cristina
Tauler i Ferré, Esperança
Galí Medina, Salvador, 1949-
Tassara, S.
Proenza Fernández, Joaquín Antonio
author_role author
author2 Domènech Ortí, Cristina
Tauler i Ferré, Esperança
Galí Medina, Salvador, 1949-
Tassara, S.
Proenza Fernández, Joaquín Antonio
author2_role author
author
author
author
author
dc.subject.none.fl_str_mv Níquel
Laterita
Compostos de níquel
Nickel
Laterite
Nickel compounds
topic Níquel
Laterita
Compostos de níquel
Nickel
Laterite
Nickel compounds
description Fe-Ni-bearing serpentine from the saprolite horizon is the main Ni ores in hydrous silicate-type Ni laterites and formed by chemical weathering of partially serpentinized ultramafic rocks under tropical conditions. During lateritization, Mg, Si, and Ni are leached from the surface and transported downwards. Fe2+ is oxidized to Fe3+ and fixed as insoluble Feoxyhydroxides (mostly goethite) that incorporate Ni. This Ni is later leached from goethite and incorporated in secondary serpentine and garnierite. As a result, a serpentine-dominated saprolite horizon forms over the ultramafic protolith, overlapped by a Fe-oxyhydroxide-dominated limonite horizon. The serpentine from the protolith (serpentine I) is of hydrothermal origin and yields similar Ni (0.10-0.62 wt.% NiO) and lower Fe (mostly 1.37-5.81 wt.% FeO) concentrations than the primary olivine. In contrast, Fe-Ni-bearing serpentine from the saprolite (serpentine II) shows significantly higher and variable Fe and Ni contents, typically ranging from 2.23 to 15.59 wt.% Fe2O3 and from 1.30 to 7.67 wt.% NiO, suggesting that serpentine get enriched in Fe and Ni under supergene conditions. This study presents detailed mineralogical, textural, and chemical data on this serpentine II, as well as new insights by thermodynamic calculations assuming ideal solution between Fe-, Ni- and Mg-pure serpentines. The aim is to assess if at atmospheric pressure and temperature Fe-Ni-bearing serpentine can be formed by precipitation. Results indicate that the formation of serpentine II under atmospheric pressure and temperature is thermodynamically supported, and pH, Eh, and the equilibrium constant of the reaction are the parameters that affect the results more significantly.
publishDate 2017
dc.date.none.fl_str_mv 2017
2020
2020
2020
dc.type.none.fl_str_mv info:eu-repo/semantics/article
info:eu-repo/semantics/acceptedVersion
format article
status_str acceptedVersion
dc.identifier.none.fl_str_mv https://hdl.handle.net/2445/160423
url https://hdl.handle.net/2445/160423
dc.language.none.fl_str_mv Inglés
language_invalid_str_mv Inglés
dc.relation.none.fl_str_mv Versió postprint del document publicat a: https://doi.org/10.1007/s00126-016-0683-7
Mineralium Deposita, 2017, vol. 52, p. 979-992
https://doi.org/10.1007/s00126-016-0683-7
dc.rights.none.fl_str_mv (c) Springer Verlag, 2017
info:eu-repo/semantics/openAccess
rights_invalid_str_mv (c) Springer Verlag, 2017
eu_rights_str_mv openAccess
dc.format.none.fl_str_mv 35 p.
application/pdf
dc.publisher.none.fl_str_mv Springer Verlag
publisher.none.fl_str_mv Springer Verlag
dc.source.none.fl_str_mv Articles publicats en revistes (Mineralogia, Petrologia i Geologia Aplicada)
reponame:Recercat. Dipósit de la Recerca de Catalunya
instname:Varias* (Consorci de Biblioteques Universitáries de Catalunya, Centre de Serveis Científics i Acadèmics de Catalunya)
instname_str Varias* (Consorci de Biblioteques Universitáries de Catalunya, Centre de Serveis Científics i Acadèmics de Catalunya)
reponame_str Recercat. Dipósit de la Recerca de Catalunya
collection Recercat. Dipósit de la Recerca de Catalunya
repository.name.fl_str_mv
repository.mail.fl_str_mv
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score 15,812429

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