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Author Hebert, B.; Baron, F.; Robin, V.; Lelievre, K.; Dacheux, N.; Szenknect, S.; Mesbah, A.; Pouradier, A.; Jikibayev, R.; Roy, R.; Beaufort, D. url  openurl
  Title (down) Quantification of coffinite (USiO4) in roll-front uranium deposits using visible to near infrared (Vis-NIR) portable field spectroscopy Type Journal Article
  Year 2019 Publication Journal of Geochemical Exploration Abbreviated Journal  
  Volume 199 Issue Pages 53-59  
  Keywords Coffinite, Mineral quantification, Near infrared, Ore exploration, Portable field spectroscopy, Roll-front deposits  
  Abstract Coffinite (USiO4) is a common uranium-bearing mineral of roll-front uranium deposits. This mineral can be identified by the visible near infrared (Vis-NIR) portable field spectrometers used in mining exploration. However, due to the low detection limits and associated errors, the quantification of coffinite abundance in the mineralized sandstones or sandy sediments of roll-front uranium deposits using Vis-NIR spectrometry requires a specific methodological development. In this study, the 1135 nm absorption band area is used to quantify the abundance of coffinite. This absorption feature does not interfere with NIR absorption bands of any other minerals present in natural sands or sandstones of uranium roll-front deposits. The correlation between the 1135 nm band area and coffinite content was determined from a series of spectra measured from prepared mineral mixtures. The samples were prepared with a range of weighted amounts of arenitic sands and synthetic coffinite simulating the range of uranium concentration encountered in roll-front uranium deposits. The methodology presented in this study provides the quantification of the coffinite content present in sands between 0.03 wt% to 1 wt% coffinite with a detection limit as low as 0.005 wt%. The integrated area of the 1135 nm band is positively correlated with the coffinite content of the sand in this range, showing that the method is efficient to quantify coffinite concentrations typical of roll-front uranium deposits. The regression equation defined in this study was then used as a reference to predict the amount of natural coffinite in a set of mineralized samples from the Tortkuduk uranium roll-front deposit (South Kazakhstan).  
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  ISSN 0375-6742 ISBN Medium  
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  Notes Approved no  
  Call Number THL @ christoph.kuells @ hebert_quantification_2019 Serial 184  
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Author Pastukhov, A.M.; Rychkov, V.N.; Smirnov, A.L.; Skripchenko, S.Y.; Poponin, N.A. url  openurl
  Title (down) Purification of in situ leaching solution for uranium mining by removing solids from suspension Type Journal Article
  Year 2014 Publication Minerals Engineering Abbreviated Journal  
  Volume 55 Issue Pages 1-4  
  Keywords Bag filter, Firm particles, In situ leaching mining, Injection wells, Intake capacity, Purification  
  Abstract This study investigated the process of in situ leaching (ISL) method of uranium mining, and the removal of solid particles from the leaching solution. Investigations were carried out for 4months. The content of firm suspensions in the productive solutions arriving from the well field was up to standard of 3–5mg/l. After keeping in a settler of productive solutions within one hour concentration of suspensions decreases to 2–2.5mg/l. To increase the life of the wells requires more fine purification of the ISL solutions. The best results can be obtained but using filtration. Bag filters were used in experiments carried out at the extraction site. All samples of polypropylene bag filter was produced by the Tamfelt Corporation. The best results were obtained for fabrics S-51M03-L2K4 (pore size 3μm). After three month of trials following indicators of wells work were fixed: on the trial cell decrease in intake capacity did not occur; on the other cells of well field injectability of holes for the same period of time decreased for 15–40%. The results illustrated the high efficiency of this method, which allows injection wells to reach a constant intake capacity, making it possible for technological cells to achieve a constant productivity and balance. Purification of solutions allows to reduce acidulation term of new technological cells from 3–4 to 1.5–2months.  
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  ISSN 0892-6875 ISBN Medium  
  Area Expedition Conference  
  Notes Approved no  
  Call Number THL @ christoph.kuells @ pastukhov_purification_2014 Serial 204  
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Author Jroundi, F.; Descostes, M.; Povedano-Priego, C.; Sánchez-Castro, I.; Suvannagan, V.; Grizard, P.; Merroun, M.L. url  openurl
  Title (down) Profiling native aquifer bacteria in a uranium roll-front deposit and their role in biogeochemical cycle dynamics: Insights regarding in situ recovery mining Type Journal Article
  Year 2020 Publication Science of The Total Environment Abbreviated Journal  
  Volume 721 Issue Pages 137758  
  Keywords Bacterial diversity, Bioremediation, In-situ recovery, Natural attenuation, Network analysis, Uranium  
  Abstract A uranium-mineralized sandy aquifer, planned for mining by means of uranium in situ recovery (U ISR), harbors a reservoir of bacterial life that may influence the biogeochemical cycles surrounding uranium roll-front deposits. Since microorganisms play an important role at all stages of U ISR, a better knowledge of the resident bacteria before any ISR actuations is essential to face environmental quality assessment. The focus here was on the characterization of bacteria residing in an aquifer surrounding a uranium roll-front deposit that forms part of an ISR facility project at Zoovch Ovoo (Mongolia). Water samples were collected following the natural redox zonation inherited in the native aquifer, including the mineralized orebody, as well as compartments located both upstream (oxidized waters) and downstream (reduced waters) of this area. An imposed chemical zonation for all sensitive redox elements through the roll-front system was observed. In addition, high-throughput sequencing data showed that the bacterial community structure was shaped by the redox gradient and oxygen availability. Several interesting bacteria were identified, including sulphate-reducing (e.g. Desulfovibrio, Nitrospira), iron-reducing (e.g. Gallionella, Sideroxydans), iron-oxidizing (e.g. Rhodobacter, Albidiferax, Ferribacterium), and nitrate-reducing bacteria (e.g. Pseudomonas, Aquabacterium), which may also be involved in metal reduction (e.g. Desulfovibrio, Ferribacterium, Pseudomonas, Albidiferax, Caulobacter, Zooglea). Canonical correspondence analysis (CCA) and co-occurrence patterns confirmed strong correlations among the bacterial genera, suggesting either shared/preferred environmental conditions or the performance of similar/complementary functions. As a whole, the bacterial community residing in each aquifer compartment would appear to define an ecologically functional ecosystem, containing suitable microorganisms (e.g. acidophilic bacteria) prone to promote the remediation of the acidified aquifer by natural attenuation. Assessing the composition and structure of the aquifer’s native bacteria is a prerequisite for understanding natural attenuation and predicting the role of bacterial input in improving ISR efficiency.  
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  ISSN 0048-9697 ISBN Medium  
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  Notes Approved no  
  Call Number THL @ christoph.kuells @ jroundi_profiling_2020 Serial 177  
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Author Salbu, B. url  openurl
  Title (down) Preface: uranium mining legacy issue in Central Asia Type Journal Article
  Year 2013 Publication Journal of Environmental Radioactivity Abbreviated Journal  
  Volume 123 Issue Pages 1-2  
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  ISSN 0265-931x ISBN Medium  
  Area Expedition Conference  
  Notes Approved no  
  Call Number THL @ christoph.kuells @ salbu_preface_2013 Serial 125  
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Author Akter, A.; Tanim, A.H.; Islam, M.K. url  openurl
  Title (down) Possibilities of urban flood reduction through distributed-scale rainwater harvesting Type Journal Article
  Year 2020 Publication Water Science and Engineering Abbreviated Journal  
  Volume 13 Issue 2 Pages 95-105  
  Keywords Low-impact development (LID), SWMM, HEC-RAS, Remote sensing, Urban flooding, Inundation depth  
  Abstract Urban flooding in Chittagong City usually occurs during the monsoon season and a rainwater harvesting (RWH) system can be used as a remedial measure. This study examines the feasibility of rain barrel RWH system at a distributed scale within an urbanized area located in the northwestern part of Chittagong City that experiences flash flooding on a regular basis. For flood modeling, the storm water management model (SWMM) was employed with rain barrel low-impact development (LID) as a flood reduction measure. The Hydrologic Engineering Center’s River Analysis System (HEC-RAS) inundation model was coupled with SWMM to observe the detailed and spatial extent of flood reduction. Compared to SWMM simulated floods, the simulated inundation depth using remote sensing data and the HEC-RAS showed a reasonable match, i.e., the correlation coefficients were found to be 0.70 and 0.98, respectively. Finally, using LID, i.e., RWH, a reduction of 28.66% could be achieved for reducing flood extent. Moreover, the study showed that 10%–60% imperviousness of the subcatchment area can yield a monthly RWH potential of 0.04–0.45 m3 from a square meter of rooftop area. The model can be used for necessary decision making for flood reduction and to establish a distributed RWH system in the study area.  
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  ISSN 1674-2370 ISBN Medium  
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  Notes Approved no  
  Call Number THL @ christoph.kuells @ Akter202095 Serial 247  
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Author Zeng, S.; Shen, Y.; Sun, B.; Zhang, N.; Zhang, S.; Feng, S. url  openurl
  Title (down) Pore structure evolution characteristics of sandstone uranium ore during acid leaching Type Journal Article
  Year 2021 Publication Nuclear Engineering and Technology Abbreviated Journal  
  Volume 53 Issue 12 Pages 4033-4041  
  Keywords Acid method, In situ leaching, Nuclear magnetic resonance, Pore characteristic, Sandstone uranium ore  
  Abstract To better understand the permeability of uranium sandstone, improve the leaching rate of uranium, and explore the change law of pore structure characteristics and blocking mechanism during leaching, we systematically analyzed the microstructure of acid-leaching uranium sandstone. We investigated the variable rules of pore structure characteristics based on nuclear magnetic resonance (NMR). The results showed the following: (1) The uranium concentration change followed the exponential law during uranium deposits acid leaching. After 24 h, the uranium leaching rate reached 50%. The uranium leaching slowed gradually over the next 4 days. (2) Combined with the regularity of porosity variation, Stages I and II included chemical plugging controlled by surface reaction. Stage I was the major completion phase of uranium displacement with saturation precipitation of calcium sulfate. Stage II mainly precipitated iron (III) oxide-hydroxide and aluminum hydroxide. Stage III involved physical clogging controlled by diffusion. (3) In the three stages of leaching, the permeability of the leaching solution changed with the pore structure, which first decreased, then increased, and then decreased.  
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  ISSN 1738-5733 ISBN Medium  
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  Notes Approved no  
  Call Number THL @ christoph.kuells @ zeng_pore_2021 Serial 199  
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Author Su, X.; Liu, Z.; Yao, Y.; Du, Z. url  openurl
  Title (down) Petrology, mineralogy, and ore leaching of sandstone-hosted uranium deposits in the Ordos Basin, North China Type Journal Article
  Year 2020 Publication Ore Geology Reviews Abbreviated Journal  
  Volume 127 Issue Pages 103768  
  Keywords Geochemical composition, leach mining, Mineralogy, Ordos Basin, Sandstone-hosted uranium deposit  
  Abstract The Nalinggou–Daying uranium metallogenic belt is situated at the northern Ordos Basin, China. Petrographical, mineralogical and geochemical techniques were used to study the ore-bearing sandstones and host rocks in the Nalinggou–Daying uranium metallogenic belt. The present study shows that uranium minerals, i.e., coffinite, pitchblende, and brannerite, are mostly disseminated around pyrite and detrital particles. The ore-bearing sandstones are enriched in organic matter, with which this reductive environment influenced uranium leaching. The carbonate concentration of the uranium ores is markedly higher than that of the host rocks, and intense carbonatization occurs in the ore-bearing sandstones. In this case, the usage of the classical in-situ leach uranium mining technique by injecting H2SO4 + H2O2 solution produces calcium sulfate precipitate, which can lead to blocking of the ore-bearing strata. For this reason, laboratory and field uranium mining tests were conducted using CO2 + O2 in-situ leaching technology and were demonstrated to be successful, illustrating that this approach is technically feasible. Inhibiting ore bed blockage and increasing the amount of injected O2 are important for uranium leaching in this setting.  
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  ISSN 0169-1368 ISBN Medium  
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  Notes Approved no  
  Call Number THL @ christoph.kuells @ su_petrology_2020 Serial 120  
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Author Zhao, Y.; Li, X.; Lei, L.; Chen, L.; Luo, Z. url  openurl
  Title (down) Permeability evolution mechanism and the optimum permeability determination of uranium leaching from low-permeability sandstone treated with low-frequency vibration Type Journal Article
  Year 2023 Publication Journal of Rock Mechanics and Geotechnical Engineering Abbreviated Journal  
  Volume 15 Issue 10 Pages 2597-2610  
  Keywords Chemical reactive rate, Low-frequency vibration, Low-permeability sandstone, Optimum permeability, Permeability evolution mechanism, Uranium migration  
  Abstract Low-frequency vibrations can effectively improve natural sandstone permeability, and higher vibration frequency is associated with larger permeability. However, the optimum permeability and permeability evolution mechanism for uranium leaching and the relationship between permeability and the change of chemical reactive rate affecting uranium leaching have not been determined. To solve the above problems, in this study, identical homogeneous sandstone samples were selected to simulate low-permeability sandstone; a permeability evolution model considering the combined action of vibration stress, pore water pressure, water flow impact force, and chemical erosion was established; and vibration leaching experiments were performed to test the model accuracy. Both the permeability and chemical reactions were found to simultaneously restrict U6+ leaching, and the vibration treatment increased the permeability, causing the U6+ leaching reaction to no longer be diffusion-constrained but to be primarily controlled by the reaction rate. Changes of the model calculation parameters were further analyzed to determine the permeability evolution mechanism under the influence of vibration and chemical erosion, to prove the correctness of the mechanism according to the experimental results, and to develop a new method for determining the optimum permeability in uranium leaching. The uranium leaching was found to primarily follow a process consisting of (1) a permeability control stage, (2) achieving the optimum permeability, (3) a chemical reactive rate control stage, and (4) a channel flow stage. The resolution of these problems is of great significance for facilitating the application and promotion of low-frequency vibration in the CO2 + O2 leaching process.  
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  ISSN 1674-7755 ISBN Medium  
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  Notes Approved no  
  Call Number THL @ christoph.kuells @ zhao_permeability_2023 Serial 198  
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Author Heaton, T.H.E.; Talma, A.S.; Vogel, J.C. url  openurl
  Title (down) Origin and history of nitrate in confined groundwater in the western Kalahari Type Journal Article
  Year 1983 Publication Journal of Hydrology Abbreviated Journal  
  Volume 62 Issue 1 Pages 243-262  
  Keywords  
  Abstract Data are presented for nitrate, dinitrogen and argon concentrations and 15N14N ratios in groundwater, with radiocarbon ages up to 40,000 yr. for three confined sandstone aquifers in the western Kalahari of South West Africa/Namibia. The nitrate is probably generated within the soil of the recharge areas, and its production rate during the period 3000-40,000 B.P. has remained between 0.5 and 1.6 meq NO−3l−1 of recharge water, with ° 15N between + 4 and + 8‰. Variations in the amount of nitrate and of “excess air” in groundwater recharge are found, and can only reflect changes in the environmental conditions during recharge. They must therefore be caused by the climatic changes that have taken place during the past 25,000 yr.  
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  Series Volume Series Issue Edition  
  ISSN 0022-1694 ISBN Medium  
  Area Expedition Conference  
  Notes Approved no  
  Call Number THL @ christoph.kuells @ heaton_origin_1983 Serial 95  
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Author Heaton, T.H.E.; Talma, A.S.; Vogel, J.C. url  openurl
  Title (down) Origin and history of nitrate in confined groundwater in the western Kalahari Type Journal Article
  Year 1983 Publication Journal of Hydrology Abbreviated Journal  
  Volume 62 Issue 1 Pages 243-262  
  Keywords  
  Abstract Data are presented for nitrate, dinitrogen and argon concentrations and 15N14N ratios in groundwater, with radiocarbon ages up to 40,000 yr. for three confined sandstone aquifers in the western Kalahari of South West Africa/Namibia. The nitrate is probably generated within the soil of the recharge areas, and its production rate during the period 3000-40,000 B.P. has remained between 0.5 and 1.6 meq NO−3l−1 of recharge water, with ° 15N between + 4 and + 8‰. Variations in the amount of nitrate and of “excess air” in groundwater recharge are found, and can only reflect changes in the environmental conditions during recharge. They must therefore be caused by the climatic changes that have taken place during the past 25,000 yr.  
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  Series Editor Series Title Abbreviated Series Title  
  Series Volume Series Issue Edition  
  ISSN 0022-1694 ISBN Medium  
  Area Expedition Conference  
  Notes Approved no  
  Call Number THL @ christoph.kuells @ Heaton1983243 Serial 282  
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