Industrial Deployment of Reactive Transport Simulation: An Application to Uranium In situ Recovery

Lagneau, Vincent; Regnault, Olivier; Descostes, Michaël

doi:10.2138/rmg.2019.85.16

Cited by 54 publications

(31 citation statements)

References 49 publications

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“…During this process, the fluid continuously circulates between the injection and pumping wells in a loop both underground and at the surface. U is extracted from the pumped fluid, whose pH is monitored and readjusted before reinjection in order to maintain its ability to dissolve U in the rock (see Lagneau et al, 2019 for further details). A summarised description of the ISR test is available in Cardon et al (2016) andde Boissezon et al (2017).…”

Section: Samplesmentioning

confidence: 99%

“…The absolute difference of activity between the F and L samples could be explained by a variation of the initial U content on both samples, affecting hotspots and diffuse area activities similarly. Ra (de Boissezon et al, 2017;Lagneau et al, 2019). It appears that Fe-Ti minerals constitute an efficient trap for the "undetectable" U daughters.…”

Section: Implication For the Mobility Of 238 U Daughters Elementsmentioning

confidence: 99%

“…The leachate is then pumped out through recovery wells and transported to the treatment plant where U is extracted from the mineralized solution. In the absence of a significant amount of carbonate in the reservoir rocks, ISR proceeds by the injection of acidic (sulfuric acid, pH ~ 2) solutions and oxidizing solutions (Eh ~ 0.8 V/SHE) (Robin et al, 2015;Lagneau et al, 2019). This mining technique results in little surface disturbance and generates neither tailings nor waste rock.…”

Section: Introductionmentioning

confidence: 99%

“…The ISR method is based on the geochemical behaviour of uranium which is highly mobile under oxidizing and acidic conditions U(VI) and poorly mobile under reducing conditions U(IV) (Langmuir, 1978;Bourdon et al, 2003). As well as generating the production of a sulfate-rich plume which can contaminate the groundwater beyond the mineralized zones, the use of sulfuric acid as a leachate produces a strong radioactive disequilibrium state in the leached rocks (Lagneau et al, 2019). This disequilibrium is due to the almost total depletion by chemical extraction of the U isotopes which belong to the 238 U natural decay chain.…”

Section: Introductionmentioning

confidence: 99%

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Mobility of daughter elements of 238U decay chain during leaching by In Situ Recovery (ISR): New insights from digital autoradiography

Angileri

Sardini

Beaufort

et al. 2020

Journal of Environmental Radioactivity

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In highly permeable sedimentary rock formations, U extraction by in-situ leaching techniques (ISR  In-Situ Recovery) is generally considered to have a limited environmental impact at ground level. Significantly, this method of extraction produces neither mill tailings nor waste rocks. Underground, however, the outcome for 238 U daughter elements in aquifers is not well known because of their trace concentrations in the host rocks. Thus, understanding the in-situ mobility of these elements remains a challenge. Two samples collected before and after six months of ISR experiments (Dulaan Uul, Mongolia) were studied with the help of a digital autoradiography technique (DA) of alpha particles, bulk alpha spectrometry, and complementary petrographic observation methods. These techniques demonstrate that before and after leaching, the radioactivity is concentrated in altered and microporous Fe-Ti oxides.Most of the daughter elements of U remain trapped in the rock after the leaching process. DA confirms that the alpha activity of the Fe-Ti oxides remains high after uranium leaching, and the initial secular equilibrium of the 238 U series for 230 Th to 210 Po daughter elements (including 226 Ra) of the fresh rocks is maintained after leaching. While these findings should be confirmed by more systematic studies, they already identify potential mechanisms explaining why the U-daughter concentrations in leaching water are low.

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Section: Samplesmentioning

confidence: 99%

Section: Implication For the Mobility Of 238 U Daughters Elementsmentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

See 2 more Smart Citations

Mobility of daughter elements of 238U decay chain during leaching by In Situ Recovery (ISR): New insights from digital autoradiography

Angileri

Sardini

Beaufort

et al. 2020

Journal of Environmental Radioactivity

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“…Such variations could be explained by the activity of sulphate reducing bacteria (SRB) known to favour the reduction of sulphate concurrently to the oxidation of organic carbon (higher values observed in the mineralized and reduced parts of the aquifer, up to 3.67 mg/L for MOZO_0007) into carbonate and sulphide according to the overall simplified reaction, where redox conditions are here controlled by the solubility of ferric hydroxide (Fe(OH) 3 (s)) and pyrite (FeS 2 (s)), respectively, upstream and downstream the roll-front. 4 and, on the other hand, the affinity of cations towards clay minerals through sorption processes [27][28][29]. Concentrations of major anions (Cl, SO 4 ) are therefore also varying in the same way with respect to the electrical balance.…”

Section: Water Chemistrymentioning

confidence: 99%

Resident bacterial populations mediating biogeochemical dynamics in a Uranium roll front deposit

Jrou

Descostes

Povedano-Priego

et al. 2019

Preprint

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Background Uranium-mineralized sandy aquifer, planned for a mining by in situ recovery (U ISR), harbors a reservoir of bacterial life that may influence the biogeochemical cycles surrounding the Uranium roll front deposits. Since microorganisms are likely to 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 made on the characterization of the resident microbiome of an aquifer surrounding uranium roll-front deposit that is part of an ISR facility project at Zoovch Ovoo (Mongolia). Water samples were collected following the natural redox zonation inherited in the aquifer, including the native mineralized orebody, and both the upstream and downstream compartments.Results An imposed chemical zonation for all sensitive redox elements through the roll-front system was observed in all water samples. High-throughput sequencing showed that the bacterial community structure was shaped by the redox gradient and the oxygen availability. Several interesting bacteria were observed 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 be also involved in metal reduction (e.g. Desulfovibrio, Ferribacterium, Pseudomonas, Albidiferax, Caulobacter, Zooglea). The taxa residing in each aquifer compartment followed a strong redox zonation differentiation, although as a whole the population of each water section seems to define an ecologically functional ecosystem containing suitable microorganisms that are probably prone to promote the remediation of the acidified aquifer by natural attenuation. Co-occurrence patterns confirmed a strong correlations among the bacterial genera suggesting either a shared and preferred environmental conditions or the performance of functions similar or complementary to each other.Conclusions Assessing the composition, and structure of the resident bacterial communities is a prerequisite for understanding the natural attenuation and predicting bacterial input in the improvement of ISR efficiency.

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Uncertainty quantification for uranium production in mining exploitation by In Situ Recovery

et al. 2021

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Industrial Deployment of Reactive Transport Simulation: An Application to Uranium In situ Recovery

Cited by 54 publications

References 49 publications

Mobility of daughter elements of 238U decay chain during leaching by In Situ Recovery (ISR): New insights from digital autoradiography

Mobility of daughter elements of 238U decay chain during leaching by In Situ Recovery (ISR): New insights from digital autoradiography

Resident bacterial populations mediating biogeochemical dynamics in a Uranium roll front deposit

Uncertainty quantification for uranium production in mining exploitation by In Situ Recovery

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