10.1021/es400658f.s001
M. A. Gomez
M. A.
Gomez
M. J. Hendry
M. J.
Hendry
J. Koshinsky
J.
Koshinsky
J. Essilfie-Dughan
J.
Essilfie-Dughan
S. Paikaray
S.
Paikaray
J. Chen
J.
Chen
Mineralogical Controls on Aluminum and Magnesium in
Uranium Mill Tailings: Key Lake, Saskatchewan, Canada
American Chemical Society
2013
hydrotalcite
EMPA
Key Lake
TEM
ED
CanadaThe mineralogy
raffinate neutralization process
Mineralogical Controls
oxic tailings body
XRD
Mg mineral phases
Key Lake U mill
phases show
Uranium Mill Tailings
EDX
Elemental analyses
Al
mineral samples
U mill tailings
2013-07-16 00:00:00
Journal contribution
https://acs.figshare.com/articles/journal_contribution/Mineralogical_Controls_on_Aluminum_and_Magnesium_in_Uranium_Mill_Tailings_Key_Lake_Saskatchewan_Canada/2395990
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.