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Title: Characterization of cores from an in-situ recovery mined uranium deposit in Wyoming: Implications for post-mining restoration

Abstract

© 2014. In-situ recovery (ISR) of uranium (U) from sandstone-type roll-front deposits is a technology that involves the injection of solutions that consist of ground water fortified with oxygen and carbonate to promote the oxidative dissolution of U, which is pumped to recovery facilities located at the surface that capture the dissolved U and recycle the treated water. The ISR process alters the geochemical conditions in the subsurface creating conditions that are more favorable to the migration of uranium and other metals associated with the uranium deposit. There is a lack of clear understanding of the impact of ISR mining on the aquifer and host rocks of the post-mined site and the fate of residual U and other metals within the mined ore zone. We performed detailed petrographic, mineralogical, and geochemical analyses of several samples taken from about 7m of core of the formerly the ISR-mined Smith Ranch-Highland uranium deposit in Wyoming. We show that previously mined cores contain significant residual uranium (U) present as coatings on pyrite and carbonaceous fragments. Coffinite was identified in three samples. Core samples with higher organic (>1wt.%) and clay (>6-17wt.%) contents yielded higher 234U/238U activity ratios (1.0-1.48) than those with lower organic and claymore » fractions. The ISR mining was inefficient in mobilizing U from the carbonaceous materials, which retained considerable U concentrations (374-11,534ppm). This is in contrast with the deeper part of the ore zone, which was highly depleted in U and had very low 234U/238U activity ratios. This probably is due to greater contact with the lixiviant (leaching solution) during ISR mining. EXAFS analyses performed on grains with the highest U and Fe concentrations reveal that Fe is present in a reduced form as pyrite and U occurs mostly as U(IV) complexed by organic matter or as U(IV) phases of carbonate complexes. Moreover, U-O distances of ~. 2.05. Å were noted, indicating the potential formation of other poorly defined U(IV/VI) species. We also noted a small contribution from U. O at 1.79. Å, which indicates that U is partially oxidized. There is no apparent U-S or U-Fe interaction in any of the U spectra analyzed. However, SEM analysis of thin sections prepared from the same core material reveals surficial U associated with pyrite which is probably a minor fraction of the total U present as thin coatings on the surface of pyrite.Our data show the presence of different structurally variable uranium forms associated with the mined cores. U associated with carbonaceous materials is probably from the original U mobilization that accumulated in the organic matter-rich areas under reducing conditions during shallow burial diagenesis. U associated with pyrite represents a small fraction of the total U and was likely deposited as a result of chemical reduction by pyrite. Our data suggest that areas rich in carbonaceous materials had limited exposure to the lixiviant solution, continue to be reducing, and still hold significant U resources. Because of their limited access to fluid flow, these areas might not contribute significantly to post-mining U release or attenuation. Areas with pyrite that are accessible to fluids seem to be more reactive and could act as reductants and facilitate U reduction and accumulation, limiting its migration.« less

Authors:
; ; ; ; ; ; ; ; ; ; ; ; ; ; ;
Publication Date:
Research Org.:
Los Alamos National Laboratory (LANL), Los Alamos, NM (United States); Lawrence Berkeley National Laboratory (LBNL), Berkeley, CA (United States)
Sponsoring Org.:
USDOE Office of Science (SC), Basic Energy Sciences (BES)
OSTI Identifier:
1377664
Alternate Identifier(s):
OSTI ID: 1212144; OSTI ID: 1721627
Grant/Contract Number:  
AC52-06NA25396; AC02-05CH11231
Resource Type:
Published Article
Journal Name:
Chemical Geology
Additional Journal Information:
Journal Name: Chemical Geology Journal Volume: 390 Journal Issue: C; Journal ID: ISSN 0009-2541
Publisher:
Elsevier
Country of Publication:
Netherlands
Language:
English
Subject:
11 NUCLEAR FUEL CYCLE AND FUEL MATERIALS; uranium; pyrite; carbonaceous; in-situ recovery (ISR); post-mining; restoration

Citation Formats

WoldeGabriel, G., Boukhalfa, H., Ware, S. D., Cheshire, M., Reimus, P., Heikoop, J., Conradson, S. D., Batuk, O., Havrilla, G., House, B., Simmons, A., Clay, J., Basu, A., Christensen, J. N., Brown, S. T., and DePaolo, D. J. Characterization of cores from an in-situ recovery mined uranium deposit in Wyoming: Implications for post-mining restoration. Netherlands: N. p., 2014. Web. doi:10.1016/j.chemgeo.2014.10.009.
WoldeGabriel, G., Boukhalfa, H., Ware, S. D., Cheshire, M., Reimus, P., Heikoop, J., Conradson, S. D., Batuk, O., Havrilla, G., House, B., Simmons, A., Clay, J., Basu, A., Christensen, J. N., Brown, S. T., & DePaolo, D. J. Characterization of cores from an in-situ recovery mined uranium deposit in Wyoming: Implications for post-mining restoration. Netherlands. https://doi.org/10.1016/j.chemgeo.2014.10.009
WoldeGabriel, G., Boukhalfa, H., Ware, S. D., Cheshire, M., Reimus, P., Heikoop, J., Conradson, S. D., Batuk, O., Havrilla, G., House, B., Simmons, A., Clay, J., Basu, A., Christensen, J. N., Brown, S. T., and DePaolo, D. J. Mon . "Characterization of cores from an in-situ recovery mined uranium deposit in Wyoming: Implications for post-mining restoration". Netherlands. https://doi.org/10.1016/j.chemgeo.2014.10.009.
@article{osti_1377664,
title = {Characterization of cores from an in-situ recovery mined uranium deposit in Wyoming: Implications for post-mining restoration},
author = {WoldeGabriel, G. and Boukhalfa, H. and Ware, S. D. and Cheshire, M. and Reimus, P. and Heikoop, J. and Conradson, S. D. and Batuk, O. and Havrilla, G. and House, B. and Simmons, A. and Clay, J. and Basu, A. and Christensen, J. N. and Brown, S. T. and DePaolo, D. J.},
abstractNote = {© 2014. In-situ recovery (ISR) of uranium (U) from sandstone-type roll-front deposits is a technology that involves the injection of solutions that consist of ground water fortified with oxygen and carbonate to promote the oxidative dissolution of U, which is pumped to recovery facilities located at the surface that capture the dissolved U and recycle the treated water. The ISR process alters the geochemical conditions in the subsurface creating conditions that are more favorable to the migration of uranium and other metals associated with the uranium deposit. There is a lack of clear understanding of the impact of ISR mining on the aquifer and host rocks of the post-mined site and the fate of residual U and other metals within the mined ore zone. We performed detailed petrographic, mineralogical, and geochemical analyses of several samples taken from about 7m of core of the formerly the ISR-mined Smith Ranch-Highland uranium deposit in Wyoming. We show that previously mined cores contain significant residual uranium (U) present as coatings on pyrite and carbonaceous fragments. Coffinite was identified in three samples. Core samples with higher organic (>1wt.%) and clay (>6-17wt.%) contents yielded higher 234U/238U activity ratios (1.0-1.48) than those with lower organic and clay fractions. The ISR mining was inefficient in mobilizing U from the carbonaceous materials, which retained considerable U concentrations (374-11,534ppm). This is in contrast with the deeper part of the ore zone, which was highly depleted in U and had very low 234U/238U activity ratios. This probably is due to greater contact with the lixiviant (leaching solution) during ISR mining. EXAFS analyses performed on grains with the highest U and Fe concentrations reveal that Fe is present in a reduced form as pyrite and U occurs mostly as U(IV) complexed by organic matter or as U(IV) phases of carbonate complexes. Moreover, U-O distances of ~. 2.05. Å were noted, indicating the potential formation of other poorly defined U(IV/VI) species. We also noted a small contribution from U. O at 1.79. Å, which indicates that U is partially oxidized. There is no apparent U-S or U-Fe interaction in any of the U spectra analyzed. However, SEM analysis of thin sections prepared from the same core material reveals surficial U associated with pyrite which is probably a minor fraction of the total U present as thin coatings on the surface of pyrite.Our data show the presence of different structurally variable uranium forms associated with the mined cores. U associated with carbonaceous materials is probably from the original U mobilization that accumulated in the organic matter-rich areas under reducing conditions during shallow burial diagenesis. U associated with pyrite represents a small fraction of the total U and was likely deposited as a result of chemical reduction by pyrite. Our data suggest that areas rich in carbonaceous materials had limited exposure to the lixiviant solution, continue to be reducing, and still hold significant U resources. Because of their limited access to fluid flow, these areas might not contribute significantly to post-mining U release or attenuation. Areas with pyrite that are accessible to fluids seem to be more reactive and could act as reductants and facilitate U reduction and accumulation, limiting its migration.},
doi = {10.1016/j.chemgeo.2014.10.009},
journal = {Chemical Geology},
number = C,
volume = 390,
place = {Netherlands},
year = {Mon Dec 01 00:00:00 EST 2014},
month = {Mon Dec 01 00:00:00 EST 2014}
}

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https://doi.org/10.1016/j.chemgeo.2014.10.009

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Works referenced in this record:

In Situ Fe K-Edge X-ray Absorption Fine Structure of a Pyrite Electrode in a Li/Polyethylene Oxide(LiClO 4 )/FeS 2 Battery Environment
journal, November 1997

  • Totir, Dana A.; Bae, In Tae; Hu, Yining
  • The Journal of Physical Chemistry B, Vol. 101, Issue 47
  • DOI: 10.1021/jp971470r

Facies distribution in uranium host rocks of the southern Powder River basin, Wyoming
report, January 1981


A spectroscopic study of uranium(VI) interaction with magnetite
journal, August 2007


FULLPAT : a full-pattern quantitative analysis program for X-ray powder diffraction using measured and calculated patterns
journal, November 2002


X-ray absorption spectroscopy studies of reactions of technetium, uranium and neptunium with mackinawite
journal, January 2004

  • Livens, Francis R.; Jones, Mark J.; Hynes, Amanda J.
  • Journal of Environmental Radioactivity, Vol. 74, Issue 1-3
  • DOI: 10.1016/j.jenvrad.2004.01.012

Electrochemical Insertion of Lithium into Pyrite from Nonaqueous Electrolytes at Room Temperature: An in Situ Fe K-Edge X-ray Absorption Fine Structure Study
journal, March 1995

  • Tryk, Donald A.; Kim, Sunghyun; Hu, Yining
  • The Journal of Physical Chemistry, Vol. 99, Issue 11
  • DOI: 10.1021/j100011a047

Sorption of Uranium(VI) onto Ferric Oxides in Sulfate-Rich Acid Waters
journal, July 2003

  • Walter, Marcus; Arnold, Thuro; Reich, Tobias
  • Environmental Science & Technology, Vol. 37, Issue 13
  • DOI: 10.1021/es025749j

Hydrothermal synthesis and crystal structure of pyrite
journal, June 2004


Redox processes in the LixFeS2/Li electrochemical system studied through crystal, Mössbauer, and EXAFS analyses
journal, May 1989


Uranium(VI) Interactions with Mackinawite in the Presence and Absence of Bicarbonate and Oxygen
journal, June 2013

  • Gallegos, Tanya J.; Fuller, Christopher C.; Webb, Samuel M.
  • Environmental Science & Technology, Vol. 47, Issue 13
  • DOI: 10.1021/es400450z

Reductive Immobilization of Uranium(VI) by Amorphous Iron Sulfide
journal, December 2008

  • Hua, Bin; Deng, Baolin
  • Environmental Science & Technology, Vol. 42, Issue 23
  • DOI: 10.1021/es801225z

Age of uranium mineralization at the Highland Mine, Powder River basin, Wyoming, as indicated by U-Pb isotope analyses
journal, May 1983


Trace element affinities in two high-Ge coals from China
journal, January 2011


An EXAFS study of uranium(VI) sorption onto silica gel and ferrihydrite
journal, November 1998


1994 Compilation of Working Values and Sample Description for 383 Geostandards
journal, July 1994


Uranyl Incorporation into Calcite and Aragonite:  XAFS and Luminescence Studies
journal, February 2000

  • Reeder, Richard J.; Nugent, Melissa; Lamble, Geraldine M.
  • Environmental Science & Technology, Vol. 34, Issue 4
  • DOI: 10.1021/es990981j

Pretreatment technique for siderite removal for organic carbon isotope and C:N ratio analysis in geological samples
journal, January 2008

  • Larson, Toti E.; Heikoop, Jeffrey M.; Perkins, George
  • Rapid Communications in Mass Spectrometry, Vol. 22, Issue 6
  • DOI: 10.1002/rcm.3432

activity ratio disequilibrium technique for studying uranium mobility in the Opalinus Clay at Mont Terri, Switzerland
journal, June 2010


Ge distribution in the Wulantuga high-germanium coal deposit in the Shengli coalfield, Inner Mongolia, northeastern China
journal, March 2009

  • Du, Gang; Zhuang, Xinguo; Querol, Xavier
  • International Journal of Coal Geology, Vol. 78, Issue 1
  • DOI: 10.1016/j.coal.2008.10.004

Spectroscopic Confirmation of Uranium(VI)−Carbonato Adsorption Complexes on Hematite
journal, July 1999

  • Bargar, John R.; Reitmeyer, Rebecca; Davis, James A.
  • Environmental Science & Technology, Vol. 33, Issue 14
  • DOI: 10.1021/es990048g

Treatment of simulated wastewater from in situ leaching uranium mining by zerovalent iron and sulfate reducing bacteria
journal, December 2009


Modeling in-situ uranium(VI) bioreduction by sulfate-reducing bacteria
journal, June 2007


Nano-FeS Inhibits UO 2 Reoxidation under Varied Oxic Conditions
journal, December 2013

  • Bi, Yuqiang; Hayes, Kim F.
  • Environmental Science & Technology, Vol. 48, Issue 1
  • DOI: 10.1021/es4043353

Shale gas reservoir characterisation: A typical case in the southern Sichuan Basin of China
journal, November 2011


Mobile uranium(IV)-bearing colloids in a mining-impacted wetland
journal, December 2013

  • Wang, Yuheng; Frutschi, Manon; Suvorova, Elena
  • Nature Communications, Vol. 4, Issue 1
  • DOI: 10.1038/ncomms3942

234U/238U signatures associated with uranium ore bodies: part 3 Koongarra
journal, April 2013


Number of relevant independent points in x-ray-absorption fine-structure spectra
journal, October 1993


Uranium(IV) remobilization under sulfate reducing conditions
journal, March 2014


Identifying the Sources of Subsurface Contamination at the Hanford Site in Washington using High-Precision Uranium Isotopic Measurements
journal, June 2004

  • Christensen, John N.; Dresel, P. Evan; Conrad, Mark E.
  • Environmental Science & Technology, Vol. 38, Issue 12
  • DOI: 10.1021/es034700q