Absence of solid solution between Fe(II) and Mg(II) hydroxides and consequences on formation of fougerite and smectites
| Autor: | Georges Ona-Nguema, Fabienne Trolard, Guilhem Bourrié, Jihaine Ben Nacib |
|---|---|
| Přispěvatelé: | Académie d'Agriculture de France, Environnement Méditerranéen et Modélisation des Agro-Hydrosystèmes (EMMAH), Avignon Université (AU)-Institut National de Recherche pour l’Agriculture, l’Alimentation et l’Environnement (INRAE), Institut de minéralogie, de physique des matériaux et de cosmochimie (IMPMC), Muséum national d'Histoire naturelle (MNHN)-Institut de recherche pour le développement [IRD] : UR206-Sorbonne Université (SU)-Centre National de la Recherche Scientifique (CNRS) |
| Jazyk: | angličtina |
| Rok vydání: | 2019 |
| Předmět: |
lcsh:GE1-350
Chemistry Inorganic chemistry 0211 other engineering and technologies 02 engineering and technology 010501 environmental sciences engineering.material Fougèrite 01 natural sciences engineering 021108 energy lcsh:Environmental sciences 0105 earth and related environmental sciences Solid solution [SDU.STU.MI]Sciences of the Universe [physics]/Earth Sciences/Mineralogy |
| Zdroj: | E3S Web of Conferences E3S Web of Conferences, EDP Sciences, 2019, 16th International Symposium on Water-Rock Interaction (WRI-16) and 13th International Symposium on Applied Isotope Geochemistry (1st IAGC International Conference), 98, pp.04003. ⟨10.1051/e3sconf/20199804003⟩ E3S Web of Conferences, 2019, 16th International Symposium on Water-Rock Interaction (WRI-16) and 13th International Symposium on Applied Isotope Geochemistry (1st IAGC International Conference), 98, pp.04003. ⟨10.1051/e3sconf/20199804003⟩ E3S Web of Conferences, Vol 98, p 04003 (2019) |
| ISSN: | 2267-1242 2555-0403 |
| DOI: | 10.1051/e3sconf/20199804003⟩ |
| Popis: | International audience; As there exists extended solid solutions between ferrous and magnesian silicates, experiments were conducted to check if ferrous and magnesian hydroxides can co-precipitate in a solid solution. Results show that no solid solution forms and instead Fe(II) and Mg(II) hydroxides precipitate separately with the same solubilities as pure components. However, in fougerite, F(III), Fe(II) and Mg(II) coexist in a brucitic type hydroxide, with an extended solid solution. This implies that fougerite formation results from Fe(III) precipitation, Fe(III) being surrounded by divalent Fe(II) and Mg(II) to comply with the exclusion rule: Fe(III) ions cannot be direct neighbours. Consequently, Fe(III)-Fe(II)-Mg(II) smectites cannot form by oxidation of a ferrous-magnesian brucitic layer, but by silication of fougerite. The impossibility of formation of a solid solution between Fe(II) hydroxide and Mg(II) hydroxide, while their electric charge and ionic radii are identical can be explained by the differences of electronegativities of the elements. Fe(II) and Mg(II) can dimerize separately in aqueous solution, but an heterodimer cannot form. |
| Databáze: | OpenAIRE |
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