| Titre | An experimental investigation of the solubility and speciation of uranium in hydrothermal ore fluids |
| Télécharger | Téléchargement (publication entière) |
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| Licence | Veuillez noter que la Licence du gouvernement
ouvert - Canada remplace toutes les licences antérieures. |
| Auteur | Rempel, K U; Williams-Jones, A E; Fuller, K |
| Source | Targeted Geoscience Initiative 5: grant program final reports (2018-2020); par Targeted Geoscience Initiative Coordination Office; Commission géologique du Canada, Dossier public 8755, 2021 p. 281-288,
https://doi.org/10.4095/328995  Accès ouvert |
| Année | 2021 |
| Éditeur | Ressources naturelles Canada |
| Document | dossier public |
| Lang. | anglais |
| DOI | https://doi.org/10.4095/328995 |
| Media | en ligne; numérique |
| Référence reliée | Cette publication est contenue dans Targeted
Geoscience Initiative 5: grant program final reports (2018-2020) |
| Référence reliée | Cette publication est reliée à An experimental
investigation of the solubility and speciation of uranium in hydrothermal ore fluids |
| Formats | pdf |
| Sujets | gisements minéraux; uranium; gisements minéraux hydrothermaux; genèse des minerais; minéralisation; contrôles des minerais; établissement de modèles; géochimie de l'uranium; solubilités; cadre tectonique;
système hydrothermal; dynamique des fluides; oxydation; précipitation; fluorures; chlorure; alcalinité; acidité; oxydes; hydroxydes; Méthodologie; géologie économique; géochimie; Sciences et technologie; Nature et environnement |
| Illustrations | diagrammes schématiques; tableaux; graphiques |
| Programme | Initiative géoscientifique ciblée (IGC-5) Gestion de la connaissance de IGC |
| Diffusé | 2021 10 27 |
| Résumé | (disponible en anglais seulement)
Experimental data on the solubility and speciation of uranium in hydrothermal solution is required to improve genetic models for the formation of ore deposits,
yet very few data of this type have been published. Of particular interest is the oxidation state of the uranium in solution, as conventional wisdom suggests that U is dissolved in the oxidized U(VI) state and precipitated as reduced U(IV) minerals,
yet recent experiments have shown ppm-level solubility for U(IV).
This study investigated the mobility of reduced U(IV) and oxidized U(VI) in acidic (pH = 2), fluoride- bearing and alkaline (pH = 10), chloride-bearing solutions at 100-200°C and 1
to 15.8 bars (0.1-1.58 MPa). Preliminary data for the mobility of U(IV) in pH 2 fluids with 0.01 m F- show concentrations of 1.76 to 3.92 ppm U at 200°C, indicating that, contrary to common belief, the reduced U(IV) can be transported in solution. We
have also conducted experiments on U(VI) solubility in pH 2 fluoride-bearing, and pH 10 chloride-bearing solutions. Uranium concentrations in the F- -bearing experiments ranged from 624 to 1570 ppm (avg. 825 ppm, n = 6) at 100°C, 670 to 1560 ppm
(avg. 931 ppm, n = 4) at 150°C, and 3180 to 7550 ppm (avg. 5240, n = 9) at 200°C. In comparison, U concentrations in the Cl- -bearing runs range from 86.1 to 357 ppm (avg. 185 ppm, n = 15) at 200°C. Clearly, oxidized U(VI) is very readily mobilized
in hydrothermal fluids. However, the measured concentrations of U(VI) are independent of those of F- or Cl-, suggesting the formation of U oxide or hydroxide species rather than U chlorides or fluorides.
These experimental data will be verified
and supplemented in future experiments, which will be used to derive the stoichiometry and thermodynamic constants for the dominant uranium species in hydrothermal solutions. The data from this study will then be integrated into a comprehensive
genetic model for uranium ore-forming systems. |
| Sommaire | (Résumé en langage clair et simple, non publié)
L'Initiative des géosciences ciblées (IGC) est un programme fédéral collaboratif. Ce programme fournit à l'industrie ce qui est requis pour la
prochaine génération des connaissances géoscientifiques et des techniques novatrices. Le résultat est l'identification des dépôts de minéraux en profondeur. Ce compendium est le résultat des récipiendaires des subventions d'IGC 2018-2020. |
| GEOSCAN ID | 328995 |
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