Mineralogical Controls on Aluminum and Magnesium in Uranium Mill Tailings: Key Lake, Saskatchewan, Canada

Gomez, MA; Hendry, MJ; Koshinsky, J; Essilfie-Dughan, J; Paikaray, S; Chen, J

HERO ID

1760213

Reference Type

Journal Article

Year

2013

Language

English

PMID

23802943

HERO ID 1760213
In Press No
Year 2013
Title Mineralogical Controls on Aluminum and Magnesium in Uranium Mill Tailings: Key Lake, Saskatchewan, Canada
Authors Gomez, MA; Hendry, MJ; Koshinsky, J; Essilfie-Dughan, J; Paikaray, S; Chen, J
Journal Environmental Science & Technology
Volume 47
Issue 14
Page Numbers 7883-7891
Abstract The mineralogy and evolution of Al and Mg in U mill tailings are poorly understood. Elemental analyses (ICP-MS) of both solid and aqueous phases show that precipitation of large masses of secondary Al and Mg mineral phases occurs throughout the raffinate neutralization process (pH 1-11) at the Key Lake U mill, Saskatchewan, Canada. Data from a suite of analytical methods (ICP-MS, EMPA, laboratory- and synchrotron-based XRD, ATR-IR, Raman, TEM, EDX, ED) and equilibrium thermodynamic modeling showed that nanoparticle-sized, spongy, porous, Mg-Al hydrotalcite is the dominant mineralogical control on Al and Mg in the neutralized raffinate (pH ≥ 6.7). The presence of this secondary Mg-Al hydrotalcite in mineral samples of both fresh and 15-year-old tailings indicates that the Mg-Al hydrotalcite is geochemically stable, even after >16 years in the oxic tailings body. Data shows an association between the Mg-Al hydrotalcite and both As and Ni and point to this Mg-Al hydrotalcite exerting a mineralogical control on the solubility of these contaminants.
Doi 10.1021/es400658f
Pmid 23802943
Wosid WOS:000322059800040
Is Certified Translation No
Dupe Override No
Is Public Yes
Language Text English