Biogenic non-crystalline U (IV) revealed as major component in uranium ore deposits

verfasst von

Amrita Bhattacharyya, Kate M. Campbell, Shelly D. Kelly, Yvonne Roebbert, Stefan Weyer, Rizlan Bernier-Latmani, Thomas Borch

Abstract

Historically, it is believed that crystalline uraninite, produced via the abiotic reduction of hexavalent uranium (U (VI)) is the dominant reduced U species formed in low-temperature uranium roll-front ore deposits. Here we show that non-crystalline U (IV) generated through biologically mediated U (VI) reduction is the predominant U (IV) species in an undisturbed U roll-front ore deposit in Wyoming, USA. Characterization of U species revealed that the majority (-1/458-89%) of U is bound as U (IV) to C-containing organic functional groups or inorganic carbonate, while uraninite and U (VI) represent only minor components. The uranium deposit exhibited mostly 238 U-enriched isotope signatures, consistent with largely biotic reduction of U (VI) to U (IV). This finding implies that biogenic processes are more important to uranium ore genesis than previously understood. The predominance of a relatively labile form of U (IV) also provides an opportunity for a more economical and environmentally benign mining process, as well as the design of more effective post-mining restoration strategies and human health-risk assessment.

Organisationseinheit(en)

Institut für Mineralogie
AG Geochemie

Externe Organisation(en)

Colorado State University
Lawrence Berkeley National Laboratory
Southwest Biological Science Center (SBSC)
EXAFS Analysis
Eidgenössische Technische Hochschule Lausanne (ETHL)

Typ

Artikel

Journal

Nature Communications

Band

8

ISSN

2041-1723

Publikationsdatum

01.06.2017

Publikationsstatus

Veröffentlicht

Peer-reviewed

Ja

ASJC Scopus Sachgebiete

Allgemeine Chemie, Allgemeine Biochemie, Genetik und Molekularbiologie, Allgemeine Physik und Astronomie

Ziele für nachhaltige Entwicklung

SDG 3 – Gute Gesundheit und Wohlergehen

Elektronische Version(en)

https://doi.org/10.1038/ncomms15538 (Zugang: Offen)