Long-Term Evolution of Uranium Mobility within Sulfated Mill Tailings in Arid Regions: A Reactive Transport Study
| Autor: | Adrien Déjeant, Nicolas Seigneur, Michael Descostes, Vincent Lagneau, Laurent De Windt |
|---|---|
| Přispěvatelé: | Centre de Géosciences (GEOSCIENCES), MINES ParisTech - École nationale supérieure des mines de Paris, Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL), 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), ORANO, Mines Paris - PSL (École nationale supérieure des mines de Paris) |
| Jazyk: | angličtina |
| Rok vydání: | 2021 |
| Předmět: |
Gypsum
Evaporation chemistry.chemical_element Soil science uranium mill tailings 010501 environmental sciences engineering.material 010502 geochemistry & geophysics Dispersion (geology) 01 natural sciences evaporitic systems [SDU.STU.GC]Sciences of the Universe [physics]/Earth Sciences/Geochemistry Jarosite Uranium tailings HYTEC uranium mobility 0105 earth and related environmental sciences geochemistry Geology reactive transport modeling Uranium Geotechnical Engineering and Engineering Geology Mineralogy Tailings Arid uranyl sulfate chemistry engineering coupled processes Environmental science [SDU.STU.MI]Sciences of the Universe [physics]/Earth Sciences/Mineralogy QE351-399.2 |
| Zdroj: | Minerals, Vol 11, Iss 1201, p 1201 (2021) Minerals Minerals, MDPI, 2021, 11 (11), pp.1201. ⟨10.3390/min11111201⟩ Minerals, 2021, 11 (11), pp.1201. ⟨10.3390/min11111201⟩ Volume 11 Issue 11 |
| ISSN: | 2075-163X |
| Popis: | International audience; Management of mill tailings is an important part of mining operations that aims at preventing environmental dispersion of contaminants of concern. To this end, geochemical models and reactive transport modeling provide a quantitative assessment of the mobility of the main contaminants. In arid regions with limited rainfall and intense evaporation, solutes transport may significantly differ from the usual gravity-driven vertical flow. In the uranium tailings of the Cominak mine (Niger), these evaporative processes resulted in the crystallization of gypsum, and to a lesser extent jarosite, and in the formation of surface levels of sulfated gypcrete, locally enriched in uranium. We present a fully coupled reactive transport modeling approach using HYTEC, encompassing evaporation, to quantitatively reproduce the complex sequence of observed coupled hydrogeochemical processes. The sulfated gypcrete formation, porosity evolution and solid uranium content were successfully reproduced at the surface and paleosurfaces of the tailing deposit. Simulations confirm that high solubility uranyl-sulfate phase may form at the atmospheric boundary where evaporation takes place, which would then be transformed into uranyl-phosphate phases after being watered or buried under fresh tailings. As these phases usually exhibit a lower solubility, this transition is beneficial for mine operators and tailings management. |
| Databáze: | OpenAIRE |
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