Zeitschriftenartikel: „U mine tailings“

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Troyer, Lyndsay D., James J. Stone und Thomas Borch. „Effect of biogeochemical redox processes on the fate and transport of As and U at an abandoned uranium mine site: an X-ray absorption spectroscopy study“. Environmental Chemistry 11, Nr. 1 (2014): 18. http://dx.doi.org/10.1071/en13129.

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Environmental context Uranium and arsenic, two elements of human health concern, are commonly found at sites of uranium mining, but little is known about processes influencing their environmental behaviour. Here we focus on understanding the chemical and physical processes controlling uranium and arsenic transport at an abandoned uranium mine. We find that the use of sedimentation ponds limits the mobility of uranium; however, pond conditions at our site resulted in arsenic mobilisation. Our findings will help optimise restoration strategies for mine tailings. Abstract Although As can occur in U ore at concentrations up to 10wt-%, the fate and transport of both U and As at U mine tailings have not been previously investigated at a watershed scale. The major objective of this study was to determine primary chemical and physical processes contributing to transport of both U and As to a down gradient watershed at an abandoned U mine site in South Dakota. Uranium is primarily transported by erosion at the site, based on decreasing concentrations in sediment with distance from the tailings. Sequential extractions and U X-ray absorption near-edge fine structure (XANES) fitting indicate that U is immobilised in a near-source sedimentation pond both by prevention of sediment transport and by reduction of UVI to UIV. In contrast to U, subsequent release of As to the watershed takes place from the pond partially due to reductive dissolution of Fe oxy(hydr)oxides. However, As is immobilised by adsorption to clays and Fe oxy(hydr)oxides in oxic zones and by formation of As–sulfide mineral phases in anoxic zones down gradient, indicated by sequential extractions and As XANES fitting. This study indicates that As should be considered during restoration of uranium mine sites in order to prevent transport.

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Reynier, Nicolas, Roselyne Gagné-Turcotte, Lucie Coudert, Sophie Costis, Rory Cameron und Jean-Francois Blais. „Bioleaching of Uranium Tailings as Secondary Sources for Rare Earth Elements Production“. Minerals 11, Nr. 3 (16.03.2021): 302. http://dx.doi.org/10.3390/min11030302.

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Tailings from inactive uranium mine sites represent a potential secondary source of rare earth elements (REEs). For this study, two mine tailings (DT and RAT) from restored uranium sites in Ontario, Canada, were used. Bioleaching experiments were conducted with a mix of native sulfur- and iron-oxidizing bacteria to test the solubilization of REEs, U and Th at different temperatures (20, 30 and 40 °C). The selective recovery of REEs from bioleaching solution was evaluated using different ion exchange resins. The mineralogical characterization revealed that DT tailings were mainly composed of quartz, pyrite, gypsum and silicates, whereas RAT tailings were mainly composed of quartz. The maximum solubilization of heavy and light REEs (HREEs and LREEs, respectively), Th and U reached 54%, 6%, 60% and 51% for RAT after 35 days at pH 2, T = 30 °C and pulp density = 10% (w/v). Higher extraction yields were obtained for DT, with 58% of HREEs, 14% of LREEs, 85% of Th and 89% of U solubilized under the same conditions. The use of Lewatit TP272 resin for the recovery of Sc (94%) and U (99%) followed by the Lewatit SP112 resin for the recovery of Th (57%) and REEs (81% LREEs and 65% HREEs) seemed a promising method for the co-extraction of the key elements from the bioleaching solution.

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Uzarowicz, Łukasz, und Alina Maciejewska. „Ocena Właściwości Technogenicznych Utworów Glebowych Technosols Zawierających Siarczki Żelaza / Assessment of Properties of Technogenic Soils Technosols Containing Iron Sulfides“. Soil Science Annual 63, Nr. 3 (01.12.2012): 37–42. http://dx.doi.org/10.2478/v10239-012-0031-2.

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Abstract Technogenic soils (Technosols) developed from mine tailings containing iron sulfides occurring in the area of the abandoned .Siersza. hard coal mine in Trzebinia and the abandoned .Staszic. pyrite mine in Rudki were investigated in order to assess their properties. The study revealed that the most adverse properties of the technogenic soils investigated are: strong acidity (pH below 3), the presence of large amounts of rock fragments containing unweathered sulfides, as well as the occurrence of heavy metals (e.g. Pb, As, and Tl) and radioactive elements (U and Th). All these properties should be taken into account during management of the studied mine tailings.

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Besançon, Clémence, Camille Chautard, Catherine Beaucaire, Sébastien Savoye, Paul Sardini, Martine Gérard und Michael Descostes. „The Role of Barite in the Post-Mining Stabilization of Radium-226: A Modeling Contribution for Sequential Extractions“. Minerals 10, Nr. 6 (29.05.2020): 497. http://dx.doi.org/10.3390/min10060497.

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Barite is ubiquitous and known to incorporate 226Ra through the formation of a solid-solution. In U mining mill tailings, barite is one of the dominant sulfate-binding minerals. In such environments, sequential extractions are generally used to identify the U- and 226Ra-binding phases and their associated reactivity. To better decipher the main processes governing the behavior of 226Ra during such sequential extractions, a geochemical model was developed with PHREEQC mimicking the sequential extraction of U and 226Ra from Bois-Noirs Limouzat U mine tailings, France. The model results were compared with a dataset produced by an experimental sequential extraction from the same mine tailings and including data on the solids and selective extraction results with the major elements, U and 226Ra. The simulations reproduced the results of the experimental chemical extractions accurately, with iron oxyhydroxides being the major U binding phase. However, the modeling indicated rather that barite would be the main 226Ra binding phase, instead of the iron oxyhydroxides identified by the experimental extractions. This is consistent with the 226Ra concentration measured in pore water, but in disagreement with the direct interpretation of the sequential extractions. The direct interpretation disregarded the role of barite in the geochemical behavior of 226Ra because barite was not specifically targeted by any of the extraction steps. However, the modeling showed that the dissolution of 226Ra-binding barite by reactants would lead to a 226Ra redistribution among the clay minerals, resulting in a skew in the experimental results. Similar results were achieved by referring simply to the bulk mineralogy of the tailings. This study highlights the importance of considering the mineralogy, mineral reactivity and retention capacity for more realistic interpretation of sequential extractions. Moreover, this paper provides new perspectives on the long-term consequences of these mill tailings in which barite controls the geochemical behavior of the 226Ra.

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Willett, IR, BN Noller und TA Beech. „Mobility of radium and heavy metals from uranium mine tailings in acid sulfate soils“. Soil Research 32, Nr. 2 (1994): 335. http://dx.doi.org/10.1071/sr9940335.

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This study was aimed at determining whether heavy metals in tailings from Ranger Uranium Mine (N.T.) change in chemical form in such a way that they will become more mobile, or bioavailable, after they are mixed with extremely acidic soils from downstream of the mine. Four soils were studied: two samples were acid sulfate (jarositic or pyritic) materials and two were acidic materials overlying acid sulfate horizons. Copper, iron, manganese, lead, uranium and zinc fractions were determined in soils to which uranium mill tailings had been added. Total and exchangeable 226Ra were also determined in selected samples. The tailings-soil mixtures were incubated for up to 4 months and included a comparison of reactions under continuously moist conditions and when subjected to a saturation and drying cycle. The tailings had considerably greater concentrations of total Mn, Pb, U and 226Ra than the soils. The heavy metals in the tailings occurred as relatively immobile forms. In the non-pyritic soils, the distribution of the metals between the fractions did not change much during 4 months of reaction. In the pyritic soil, which underwent oxidation and acidification during incubation, there were 2- to 3-fold increases in the exchangeable fractions of Fe, Mn, Cu and U. The metals in the tailings and soil behaved similarly. There appeared to be more likelihood of increased mobility of metals from oxidation of pyritic materials than from addition of tailings. The fraction of total 226Ra that was exchangeable decreased from 11% in the original tailings to 2-7% after reaction with three of the soils but increased to 44% in one soil. At estimated long-term erosion rates, the tailings are not likely to be a source of heavy metal pollution, but addition of 226Rato soils presents a possible radiological hazard.

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Marković, Marija, Biljana Nikolić, Tatjana Jakšić, Ljubinko Rakonjac, Mirjana Smiljić, Olivera Papović und Vesna Stankov-Jovanović. „Activity of enzyme catalase in plants from metal tailings of lead-zinc mine "Trepča"“. Sustainable Forestry: Collection, Nr. 85-86 (2022): 13–24. http://dx.doi.org/10.5937/sustfor2285013m.

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The environment of Northern Kosovo and Metohija has been remarkably influenced for a long time by the huge metallurgical complex "Trepča". The technological process of ore exploitation and processing in the Mining and Metallurgical Chemical Company "Trepča" has resulted in a large amount of discharged material, deposited on metal tailings that are mostly located in inappropriate areas, partially covered with vegetation, mostly consisted of several invasive plants. The activity of the enzyme catalase was investigated in plant species collected from abandoned metal tailings "Žitkovac" and compared with the same plant species from the environment from the vicinity of Niš city. Measurements of enzyme activity were carried out in the underground and above-ground parts of plant species Artemisia vulgaris, Cichorium intybus, Erigeron canadensis, Robinia pseudacacia, Medicago sativa, Teucrium chamaedrys, Plantago lanceolata, Rumex acetosella, Tanacetum vulgare and Euphorbia cyparissias using gasometric method. The results have indicated that an increase of catalase activity in tested plants from the metal tailings is possibly a consequence of stress caused by specific environmental conditions.

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Dhal, Paltu Kumar, und Pinaki Sar. „Microbial communities in uranium mine tailings and mine water sediment from Jaduguda U mine, India: A culture independent analysis“. Journal of Environmental Science and Health, Part A 49, Nr. 6 (12.02.2014): 694–709. http://dx.doi.org/10.1080/10934529.2014.865458.

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Kotlyar, L. S., B. D. Sparks, Y. LePage und J. R. Woods. „Effect of particle size on the flocculation behaviour of ultra-fine clays in salt solutions“. Clay Minerals 33, Nr. 1 (März 1998): 103–7. http://dx.doi.org/10.1180/000985598545309.

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AbstractThe Athabasca oil sands deposit in Alberta contains ~5 x 109 m3 of bitumen accessible by surface mining. During bitumen separation from the mined ore, ultra-fine (<300 nm) aluminosilicate clays only a few layers thick (U/F) are mobilized and become dispersed in the process water. In this water containing dissolved salts from natural deposits, U/F are capable of forming thixotropic gels. The consequence of this is the production of large volumes of mature fine tailings (MFT) with a high water holding capacity. For mine planning purposes, the objective of predicting and possibly mitigating MFT formation requires an understanding of the colloidal behaviour of U/F particles in salt solutions. In this work, photon correlation spectroscopy and the deuterium NMR method are used to provide an insight into the U/F floc formation process. These results are correlated with conventional analysis of settling data.

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Bamidele, L., und A. O. Edun. „Determination of Activity Concentration and Radiological Risks from Gold Mine Tailings around Ilahun-Ijesa in Obokun Local Government, Osun State, Nigeria“. Journal of Applied Sciences and Environmental Management 28, Nr. 4 (29.04.2024): 993–97. http://dx.doi.org/10.4314/jasem.v28i4.3.

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In this study, the activity concentrations and radiological risks associated with exposure to NORMS in soils around the gold mine tailings in Ilahun – Ijesa, Obokun Local Government, Osun State, Nigeria was evaluated. A Sodium Iodide (NaI) gamma spectroscopy was used to determine the activity concentrations of the natural radio nuclides in soil samples that were collected from the gold mine tailings. The mean activity concentration for 238 U, 232 Th and 40K were 14.50±2.40, 10.45±3.20 and 332.70±6.10 Bqkg-1 respectively. The average absorbed dose was calculated to be 26.4 nGy/h and the corresponding average annual effective dose was found to be 0.0031 mSv, which is less than the total annual effective dose of 1 mSv recommended by ICRP for public exposure control. Radiological hazard parameters were evaluated from activity concentrations and the average values were found to be lower than recommended safety limits.

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Eremin, Oleg, Olga Rusal, Maria Solodukhina, Ekaterina Epova und Georgy Yurgenson. „Thermodynamic equilibria of tailings dump pond water of Sherlovaya Gora tin-polymetallic deposit (Transbaikalia)“. E3S Web of Conferences 98 (2019): 01014. http://dx.doi.org/10.1051/e3sconf/20199801014.

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The potential toxic elements (Be, U, As, Cd, Pb, Sb, Bi) were detected for mine landscape of Sherlovaya Gora tin-polymetallic deposit. Thermodynamic calculation of equilibrium for tailings dump pond water was carried out by means of “Selektor” program complex based on Gibbs free energy minimization algorithm at 25°C and 1 bar total pressure. It turned out that the mine water is supersaturated with respect to many sulphates of Ca, Mg, Sr, Zn, K, Cu, Ni, Cd, Be, Al, Ce and Y, fluorides of (Ln and Y, Sc), and Y phosphate.

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DeWitt, Ted. „Chemistry and Biology of Solid Waste: Dredged Material and Mine Tailings. W. Salomons , U. Forstner“. Quarterly Review of Biology 64, Nr. 3 (September 1989): 363. http://dx.doi.org/10.1086/416426.

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You, Yue, Junfeng Dou, Yu Xue, Naifu Jin und Kai Yang. „Chelating Agents in Assisting Phytoremediation of Uranium-Contaminated Soils: A Review“. Sustainability 14, Nr. 10 (23.05.2022): 6379. http://dx.doi.org/10.3390/su14106379.

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Massive stockpiles of uranium (U) mine tailings have resulted in soil contamination with U. Plants for soil remediation have low extraction efficiency of U. Chelating agents can mobilize U in soils and, hence, enhance phytoextraction of U from the soil. However, the rapid mobilization rate of soil U by chelating agents in a short period than plant uptake rate could increase the risk of groundwater contamination with soluble U leaching down the soil profile. This review summarizes recent progresses in synthesis and application of chelating agents for assisting phytoremediation of U-contaminated soils. In detail, the interactions between chelating agents and U ions are initially elucidated. Subsequently, the mechanisms of phytoextraction and effectiveness of different chelating agents for phytoremediation of U-contaminated soils are given. Moreover, the potential risks associated with chelating agents are discussed. Finally, the synthesis and application of slow-release chelating agents for slowing down metal mobilization in soils are presented. The application of slow-release chelating agents for enhancing phytoextraction of soil U is still scarce. Hence, we propose the preparation of slow-release biodegradable chelating agents, which can control the release speed of chelating agent into the soil in order to match the mobilization rate of soil U with plant uptake rate, while diminishing the risk of residual chelating agent leaching to groundwater.

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Kaczowka, Andrew J., T. Kurt Kyser, Tom G. Kotzer, Matthew I. Leybourne und Daniel Layton-Matthews. „Geometallurgical ore characterization of the high-grade polymetallic unconformity-related uranium deposit“. Canadian Mineralogist 59, Nr. 5 (01.09.2021): 813–45. http://dx.doi.org/10.3749/canmin.2000050.

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ABSTRACT Cigar Lake is a polymetallic, unconformity-related uranium deposit with complex geochemistry and mineralogy located in the eastern Athabasca Basin of northern Saskatchewan, Canada. Variable concentrations and spatial distributions of elements of concern, such as As, Mo, Ni, Co, Se, and Zr, associated with the high-grade tetravalent uranium ores [UO2+x; U(SiO4)1–x(OH)4x] present unique mining, metallurgical, and environmental challenges. Sulfide and arsenide minerals have significant control over As, Mo, Ni, Co, and Se abundances and have properties that affect element of concern mobility, thus requiring consideration during mineral processing, mine-effluent water treatment, and long-term tailings management. The U-bearing (uraninite, coffinite) and metallic arsenide (nickeline, often called “niccolite” in the past), sulfarsenide (gersdorffite, cobaltite), and sulfide (chalcopyrite, pyrite, galena, bornite, chalcocite, sphalerite, pyrrhotite) minerals provide the main controls on the distributions of the elements of concern. Arsenic, Ni, and Co occur primarily in a reduced state as 1:1 molar ratio, Ni-Co:As, arsenide, and sulfarsenide minerals such as gersdorffite, nickeline, and cobaltite. Molybdenum occurs within molybdenite and uraninite. Selenium occurs within coffinite, sulfide, and sulfarsenide minerals. Zirconium is found within detrital zircon and coffinite. The spatial distribution and paragenesis of U-, As-, and S-bearing minerals are a result of the elemental composition, pH, and redox conditions of early formational and later meteoric fluids that formed and have modified the deposit through access along lithostratigraphic permeability and tectonic structures. Using the holistic geometallurgical paradigm presented here, the geochemistry and mineral chemistry at Cigar Lake can be used to optimize and reduce risk during long-term mine and mill planning.

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Jeran, Z., A. R. Byrne und F. Batič. „Transplanted Epiphytic Lichens as Biomonitors of Air-Contamination by Natural Radionuclides Around the Žirovski VRH Uranium Mine, Slovenia“. Lichenologist 27, Nr. 5 (September 1995): 375–85. http://dx.doi.org/10.1006/lich.1995.0035.

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AbstractSamples of Hypogymnia physodes were transplanted to the environment of the former uranium mine at Žirovski vrh, Slovenia for two exposure experiments. The levels of the long-lived radionuclides, 238U, 226Ra and 210Pb in lichen material were measured after 4 and 7 months in the first experiment, and 4, 8 and 12 months in the second, and compared with the levels in lichens growing in-situ from the same sampling locations. They were also compared with the nuclide levels found in air particulates by gamma spectrometry obtained at the regular site monitoring stations. The results showed that each of the radionuclides had its own distribution pattern in this environment. The highest 226Ra levels were found in lichens in the near vicinity of the dry-tailings pile, while U concentrations were high in the valley of the confluence of the Todraščica and Brebovščica streams close to the former yellow-cake production plant in Todraž, and then decreased downstream. 210Pb was the most uniformly distributed radionuclide and exhibited the highest level. The results also confirm that active biomonitoring with transplanted lichens can be a useful and cheap supplement to instrumental air pollution monitoring.

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Nišić, Dragana, Uroš Pantelić, Nikoleta Aleksić und Neda Nišić. „Classification of mining waste landfills according to legislation in Serbia“. Tehnika 76, Nr. 5 (2021): 575–83. http://dx.doi.org/10.5937/tehnika2105575n.

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Risk-based classification of mining waste landfills is a very important procedure that can suggest what measures should be taken to prevent failures at landfills. In many countries there is a legal obligation to classify landfills, while Serbia has included this practice in its legislation by adopting the Bylaw on the conditions and procedure for issuing waste management permits, as well as criteria, characterization, classification and reporting on mining waste in 2017. As the implementation of the Bylaw began in 2020, there are still frequent doubts during the interpretation of the criteria that can classify the landfill in the proposed category A. Starting from this issue, this paper explains in detail all the provisions of the Bylaw dealing with the terms of classification. It is determined that the landfill is classified based on the possibility of a potential failure and the character and composition of the waste disposed on it, while the process of classification according to the consequences of the failure runs through three iterations, through which endangered humanity, source-path-recipient chain and significance of consequences are analyzed. Although risk assessment is not imposed as an obligation through the Bylaw, procedures that directly or indirectly refer to the results of risk analysis and embankment breach calculation are suggested on several occasions through the classification process. By applying the classification on a specific example of flotation tailings management facility of copper mine, it was found that the realistic risk-based classification of landfills requires a very detailed analysis of all criteria leading to the final category.

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Zhang, Zehui, Zhenping Tang, Yong Liu, Haiyang He, Zhixin Guo, Peng Feng, Liang Chen und Qinglin Sui. „Study on the Ecotoxic Effects of Uranium and Heavy Metal Elements in Soils of a Uranium Mining Area in Northern Guangdong“. Toxics 11, Nr. 2 (20.01.2023): 97. http://dx.doi.org/10.3390/toxics11020097.

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To investigate the heavy metal contamination of soil in a uranium mining area in northern Guangdong, a physicochemical evaluation method was used to evaluate the contaminated soil near the pit and tailings pond of the uranium mining area, determine its heavy metal content and evaluate its ecological risk using the Nemerow integrated contamination index, ground accumulation index and potential ecological risk index. The results show that the average content of nine heavy metal elements in the soil of the uranium mining area exceeds the background value of red soil in Guangdong Province. Three pollution evaluation indices all indicate that Cd, As and U have serious pollution and high ecological risk, while the remaining elements are weakly polluted and the potential ecological risk of the six sampling sites all show very strong risk. On this basis, soil ecotoxicity was evaluated using ostracods (Cypridopsis vidua and Heterocypris sp.), Vibrio fischeri and Vicia faba L. Higher concentrations of heavy metals at individual sites (T1, T2, P2) resulted in higher mortality of ostracods, higher inhibition of Vibrio fischeri luminescence and a significant reduction in germination and pigmentation of broad beans. The results of the biotoxicity evaluation were consistent with the results of the physicochemical evaluation, allowing for a more direct and comprehensive evaluation of the ecotoxic effects of uranium and heavy metals in the mine soils.

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Dushyantha, Nimila, I. M. Saman K. Ilankoon, N. P. Ratnayake, H. M. R. Premasiri, P. G. R. Dharmaratne, A. M. K. B. Abeysinghe, L. P. S. Rohitha et al. „Recovery Potential of Rare Earth Elements (REEs) from the Gem Mining Waste of Sri Lanka: A Case Study for Mine Waste Management“. Minerals 12, Nr. 11 (07.11.2022): 1411. http://dx.doi.org/10.3390/min12111411.

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Sri Lanka is one of the wealthiest countries in terms of gems. Therefore, gem mining is extensively carried out in many areas of Sri Lanka, including districts such as Ratnapura, Monaragala, Matale, and Kalutara. During the mining process, only valuable gemstones are collected, and the remaining gravel fraction with many heavy minerals is discarded. Therefore, the gem mining industry produces a large amount of waste that is mainly used only for backfilling. To sustainably manage this waste stream, gem mining waste collected from a gem pit at Wagawatta in the Kalutara district in Sri Lanka was investigated for value recovery, specifically for rare-earth elements (REEs). The gem-bearing alluvial layer contained 0.3% rare-earth oxide (REO) that could easily be upgraded up to 2.8% (LREEs = 94%) with wet sieving and subsequent density separation via a shaking table. Therefore, the concentrates of gem mine tailings with REE-bearing minerals have the potential to be a secondary source for LREEs. The organic-rich clay layer underlying the gem-bearing alluvial layer contained 0.6% REO with 49% HREEs, including Gd, Dy, Er, Yb, and especially Y enrichments. Detailed explorations are thus necessary to assess the REE potential in Sri Lanka’s gem mining waste, and value recovery flowsheets should be subsequently developed to economically extract REEs. In addition, the presence of high U concentrations (800 mg/kg) in the concentrated samples could be alarming when considering the health and safety of the people engaged in gem mining. This aspect also requires detailed research studies.

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Johnson, Raymond H., Susan M. Hall und Aaron D. Tigar. „Using Fission-Track Radiography Coupled with Scanning Electron Microscopy for Efficient Identification of Solid-Phase Uranium Mineralogy at a Former Uranium Pilot Mill (Grand Junction, Colorado)“. Geosciences 11, Nr. 7 (16.07.2021): 294. http://dx.doi.org/10.3390/geosciences11070294.

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At a former uranium pilot mill in Grand Junction, Colorado, mine tailings and some subpile sediments were excavated to various depths to meet surface radiological standards, but residual solid-phase uranium below these excavation depths still occurs at concentrations above background. The combination of fission-track radiography and scanning electron microscope energy-dispersive X-ray spectroscopy (SEM-EDS) provides a uniquely efficient and quantitative way of determining mineralogic associations of uranium that can influence uranium mobility. After the creation of sample thin sections, a mica sheet is placed on those thin sections and irradiated in a nuclear research reactor. Decay of the irradiated uranium creates fission tracks that can be viewed with a microscope. The fission-track radiography images indicate thin section sample areas with elevated uranium that are focus areas for SEM-EDS work. EDS spectra provide quantitative elemental data that indicate the mineralogy of individual grains or grain coatings associated with the fission-track identification of elevated uranium. For the site in this study, the results indicated that uranium occurred (1) with coatings of aluminum–silicon (Al/Si) gel and gypsum, (2) dispersed in the unsaturated zone associated with evaporite-type salts, and (3) sorbed onto organic carbon. The Al/Si gel likely formed when low-pH waters were precipitated during calcite buffering, which in turn retained or precipitated trace amounts of Fe, As, U, V, Ca, and S. Understanding these mechanisms can help guide future laboratory and field-scale efforts in determining long-term uranium release rates to groundwater.

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Hubina, V. H., V. V. Pokalyuk, V. G. Verkhovtsev, V. G. Yatsenko und V. S. Zaborovskiy. „CHEMICAL COMPOSITION OF TAILINGS ENRICHMENT OF MAGNETITE QUARTZITES OF THE KRYVYI RIH BASIN“. Mineralogical Journal 45, Nr. 1 (2023): 59–71. http://dx.doi.org/10.15407/mineraljournal.45.01.059.

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The major and minor element compositions of the tailings at the Kryvyi Rih processing plants (i.e., Inguletsky, ArcelorMittal Kryvyi Rih, and Central) were studied. A good relationship between the composition of the tailings and the mined ore, which was to be enriched, was confirmed. The main trends in the techno geochemical changes in the process of enrichment were determined. Differences were measured of the tailings composition between various processing plants of the Kryvyi Rih basin. That is, the tailings from the Ingulets plant are more ferruginous with an iron content of 23.7 wt % and are almost twice as high compared to those of the Central and ArcelorMittal Kryvyi Rih plants. Tailings from ArcelorMittal Kryvyi Rih are more carbonaceous and aluminous and have low iron and silicon contents. Tailings of the Central plant are more siliceous and have minimum of alumina and carbonates and have the average iron content. In terms of the major elements, the tailings are generally enriched in silicon, aluminum, manganese, magnesium, calcium, sodium, potassium, phosphorus, sulfur, and depleted in iron and titanium, compared to the original ore. In terms of minor elements, the tailings are generally enriched in the some lithophile (including rare earth) elements Sr, Y, Sc, Li, and partially Zr, and depleted in elements that are concentrated in magnetite, Ni, Th, U, and Ge, compared to the original ore. The chalcophile elements Cu, Pb, Zn, Ag are characterized by an inhomogeneous and variable distribution. The most significant among them is Zn, which can have significant concentrations (up to 230 g/t in the tailings). These results can be used to determine the directions of tailing using and to assess the impact of tailings on the environment.

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Serafimovski, Todor, Goran Tasev und Trajce Stafilov. „The content of copper and heavy metals in the multilayer soil mud from the Buchim lake under the Buchim mine's waste dump, Republic North Macedonia“. Tehnika 75, Nr. 4 (2020): 297–304. http://dx.doi.org/10.5937/tehnika2003297s.

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The intense mineral extraction in mining areas during the last several decades has produced a large amount of waste material and tailings, which release toxic elements to the environment. The aim of the study was to determine in two vertical profiles/sections (1 and 2) the heavy metal contents of samples derived from six samples, three from each section located in the porphyry copper mine Buchim area, Republic North Macedonia. The results have been compared to new Dutchlist (DL) and Kabata-Pendias (KP) standards and the following was concluded: As values ranged 14.985÷60.131 mg kg-1 with 4 samples above the target value of the DL (29 mg kg-1 As) and 6 above standard values given in KP value (5 mg kg-1 As), in that context Co values ranged 11 ÷57 mg kg-1 with 6 values above the target value of the DL (9 mg kg-1 Co) and 5 above standard values given in KP value (12 mg kg-1 Co), Cr with range 29.32÷75.76 mg kg-1 with 6 over KP value (10 mg kg-1 Cr) and none above the target value of the DL (100 mg kg-1 Cr), Cu with range 2694÷6749 mg kg-1 with 6 samples above the target value of the DL (36 mg kg-1 Cu) and 6 above standard values given in KP value (20 mg kg-1 Cu), Ni with range 59.57÷105.98 mg kg-1 with 6 samples above the target value of the DL (35 mg kg-1 Ni) and 6 above standard values given in KP value (20 mg kg-1 Ni), Pb with range 27.06 ÷96.08 mg kg-1 with 1 sample above the target value of the DL (85 mg kg-1Pb) and 6 above standard values given in KP value (25 mg kg-1Pb), Zn with range 147÷273 mg kg-1 with 6 over target value of the DL (140 mg kg-1 Zn) and 6 above standard KP value (64 mg kg-1 Zn), V with range 34.44÷92.57 mg kg-1 with 5 over target value of the DL (42 mg kg-1 V) and one above KP value (90 mg kg-1 V).In order to compare the level of contamination, the contamination factor (𝐶𝑓 𝑖 ), degree of contamination (Cd), and pollution load index (PLI) were computed. Serious numbers were found for Cu, as, Zn, Co and Ni, which exceeded standard values at almost all samples from both vertical sections. Compared from section 1 and section 2, pollution load index increased by 13.43%, which in almost all samples was classified as heavily polluted to extremely polluted. The fact that mining activities at the Buchim Mine last for almost 40 years, the presence of heavy metals in soils at a serious level is understandable. The high level of contamination is a result of heavy metal persistence and non-biodegradability.

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Gibaga, Cris Reven, Jessie Samaniego, Alexandria Tanciongco, Rico Neil Quierrez, Mariel Montano, John Henry Gervasio, Rachelle Clien Reyes und Monica Joyce Peralta. „Pollution and radiological risk assessments of mine wastes from selected legacy and active mines in the Philippines“. Journal of Degraded and Mining Lands Management 9, Nr. 4 (01.07.2022): 3621. http://dx.doi.org/10.15243/jdmlm.2022.094.3621.

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In the Philippines, legacy mines and active mine wastes pose potential threats since these may contain elevated concentrations of potentially toxic elements (PTEs) and high natural radioactivity. In this study, legacy mine wastes from the Philippine Iron Mine (PIM), Barlo Mine (BM), and Rapu-Rapu Mine (RRM) and active mine tailing from Padcal Mine (PM) were analyzed to determine the concentrations of fifteen (15) PTEs and the activity concentrations of natural radionuclides. Several quantitative risk indicators and radiological health risk parameters were utilized to determine the potential effects of these mine wastes to the natural environment and to human health. Legacy mine wastes have higher contents of PTEs and are more polluted by PTEs than PM tailing. Both enrichment factor (EF) and geoaccumulation index (Igeo) values suggest that legacy mine wastes are strongly polluted by As, Cd, Cu, and Mo. BM and RM wastes are also polluted by Pb, Sb, and Zn; PIM waste is polluted by Ni and V; and BM waste is polluted by Tl. Padcal mine tailing is only moderately polluted by Cu and Mo. The natural radionuclide activity concentrations of legacy and active mine wastes are below the global background values and the radiological hazard indices are also all lower than their permissible limits, except for 40K, 238U, and absorbed gamma dose rate in PIM due to a geogenic source. Unlike the PTEs, radioactivity in the legacy and active mine wastes are not enhanced by mining activities and is not a significant risk factor to human health.

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Panchal, Sandeep, Debasis Deb und T. Sreenivas. „Mill tailings based composites as paste backfill in mines of U-bearing dolomitic limestone ore“. Journal of Rock Mechanics and Geotechnical Engineering 10, Nr. 2 (April 2018): 310–22. http://dx.doi.org/10.1016/j.jrmge.2017.08.004.

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23

Navarro, Andrés, und María Izabel Martínez da Matta. „Application of Magnesium Oxide for Metal Removal in Mine Water Treatment“. Sustainability 14, Nr. 23 (28.11.2022): 15857. http://dx.doi.org/10.3390/su142315857.

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In this study low-grade magnesium oxide (MgO) produced by calcinations of natural magnesite was used in mine water treatment using a laboratory-column device. The treatment of mine water from the abandoned Osor mine (NE Spain) with MgO showed the removal of metals from both mine water and tailing leachates. The PHREEQC numerical code and the Geochemist’s Workbench code (GWB) were used to evaluate the speciation of dissolved constituents and calculate the saturation state of the effluents. The analysis of the treated mine water showed the removal of As (from 1.59 to 0.31 μg/L), Cd (from 1.98 to <0.05 μg/L), Co (from 19.1 to <0.03 μg/L), F (from 2730 to 200 μg/L), Mn (from 841 to 0.6 μg/L), Ni (from 17.9 to <2 μg/L, U (from 9.16 to 0.08 μg/L), and Zn (from 2900 to 68.5 μg/L). Pb was also removed (from 98 to 35.2 μg/L) in the treatment of contaminated leachates from the mine waste. The mixing of MgO and water at room temperature may promote the formation of a stabilizing agent composed of hydroxides, carbonates, and magnesium-silicate-hydrates (MSH), which may remove Cd, Zn, and similar metals by sorption on MSH, substitution on the MSH lattice, and precipitation or co-precipitation with some of the hydrated phases.

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Paiva, Isabel, Rosa Marques, Marta Santos, Mário Reis, Maria Isabel Prudêncio, João Carlos Waerenborgh, Maria Isabel Dias et al. „Naturally occurring radioactive material and risk assessment of tailings of polymetallic and Ra/U mines from legacy sites“. Chemosphere 223 (Mai 2019): 171–79. http://dx.doi.org/10.1016/j.chemosphere.2019.02.057.

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Sillitoe, Richard H., Georgi Magaranov, Veselin Mladenov und Robert A. Creaser. „ROSEN, BULGARIA: A NEWLY RECOGNIZED IRON OXIDE-COPPER-GOLD DISTRICT“. Economic Geology 115, Nr. 3 (01.05.2020): 481–88. http://dx.doi.org/10.5382/econgeo.4731.

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Abstract The Rosen copper veins in southeastern Bulgaria are recognized for the first time as an iron oxide-copper-gold (IOCG) district. The veins are located in the East Srednogorie segment of the Carpathian-Balkan calc-alkaline volcano-plutonic arc and were formed during an end-stage interval of extreme slab rollback and intra-arc rifting, which gave rise farther east to seafloor spreading in the Western Black Sea basin. The resulting submarine volcano-sedimentary rift basin is dominated by intermediate to mafic shoshonitic to ultrapotassic volcanism and subsidiary gabbro to syenite intrusion. The E- to NE-striking veins define a NW-striking alignment along the western contact of the syenite-dominated Rosen pluton, inferred to be part of a large ring dike. More than 40 veins, the most important formerly mined to depths as great as 1,000 m, contain an early, pegmatoidal, calcic-potassic assemblage followed by predominant magnetite (including the mushketovite variety), chlorite, and carbonates but also quartz, chalcopyrite, pyrite, and numerous other metallic minerals, which combine to give an unusual Fe-Cu-Au-Mo-Co-Ni-U-light rare earth element (LREE)-W-Bi-Zn-Pb geochemical signature. The close correlation between Fe, Cu, U, and LREEs is evident even in the flotation tailings. Vein molybdenite was dated during this study at 80.6 ± 0.4 Ma, which is similar to a U-Pb zircon age for monzosyenite from the Rosen pluton. The mineralogic and compositional features of the Rosen district are comparable to those of well-known IOCG deposits worldwide and geometrically similar to the vertically extensive IOCG veins in the Coastal Cordillera province of northern Chile. The subsidiary granitophile signature that accompanies the characteristic siderophile IOCG suite was also recognized recently at the giant Olympic Dam deposit in South Australia and elsewhere. Although no exposed intrusion is definitively implicated in the genesis of the Rosen veins, coexisting gabbro and syenite fluid sources may be hypothesized at depth in or beneath the coeval ring dike.

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Manny Mathuthu und Vaino Indongo. „Measurements of Radiometric Concentrations for 222Ra, 238U, 232Th and 40K in Soil Samples from Two Uranium Mines’ Stockpiles, Erongo Region, Namibia“. International Journal of Scientific Research in Science, Engineering and Technology, 01.07.2023, 09–20. http://dx.doi.org/10.32628/ijsrset122951.

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The continuous exposures from radiations to human population has led to research studies on evaluating the radioactivity concentrations in most parts of the world. Naturally occurring radioactive materials (NORM) have been greatly regarded as the chief sources of both terrestrial and cosmological radiations. In this study a high-purity germanium well detector was used to measure the activity concentrations of samples from mines 1 and 2 considered in the study. The measured average activity concentration for 226Ra, 238U, 232Th and 40K in mine 1 were estimated at 2546±10, 557±13, 215±2 and 1079±26 Bq.kg-1, respectively. For mine 2, the estimated average values of the radionuclides of 226Ra, 238U, 232Th and 40K were calculated as 4414±27, 842±29, 436±5 and 2225±52 Bq.kg-1, respectively. The high concentration of radium in samples contributed to high rate of radon emanation into the atmosphere, ground and surface water as well and, if no remedial measures are put in place, this may contribute to plants, animals and eventually human exposures in the region. The study concludes that mine tailings contribute to an increase in background radiation in the environment due to the fact that they are uncovered and deposited in the open environment, resulting in wind-blown 226Ra carrying dust entering nearby residential dwellings. The exposures rates could also be increased by other possible transfer pathways, such as ingestions, inhalations and external gamma radiations. Mining companies are urged to decrease windblown atmospheric exposure by using water tanks mounted on mining equipment to sprinkle on top of the soil or covering the tailings with canvas sheet.

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Hudson-Edwards, Karen A. „Geochemistry and mineralogy of wastes from lithium-bearing granite-pegmatite mining: resource potential and environmental risks“. Frontiers in Geochemistry 2 (30.04.2024). http://dx.doi.org/10.3389/fgeoc.2024.1378996.

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The global need for lithium (Li) is increasing due to its use in batteries which are used to make electric vehicles, wind turbines and fuel cells to facilitate the world’s ‘green transition’ to low carbon economies. The mining of Li, like that of other Earth materials, produces large volumes of waste such as tailings and processing chemicals. A growing body of research is addressing the resource potential and environmental impacts of wastes from mining of Li-bearing granites and pegmatites that produce around 40% of the world’s Li. The wastes are dominated by SiO2 and Al2O3, with lesser Na2O, K2O and Fe2O3, that are hosted in quartz, feldspar and micas. They can contain around 1 wt% Li2O that is found in residual spodumene, lepidolite and zinnwaldite, and trace (<1 wt%) amounts of Rb, Cs, U and Be. Some exploitation of the Li from granite-pegmatite tailings is occurring on a commercial scale. There is also good potential for the waste quartz, feldspar and mica to be used in ceramics and building materials, and for the Rb, Cs and Be to be used for photovoltaic cells, alloys and other applications. Spodumene-bearing wastes can contain potentially toxic and/or radioactive U, Th and Tl, but the concentrations are generally low. Overall, Li-bearing granite-pegmatite mine wastes have good potential to be reused, remined and recycled. More research is required to characterize their geochemistry and mineralogy in detail to improve recovery and to understand how processing and weathering may affect environmental risk.

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Billon, Sophie, Sébastien Savoye, Paul Sardini, Martine Gérard, Catherine BEAUCAIRE und Michaël Descostes. „Sequential Extractions Versus Alpha Autoradiography: Mutually Complementary for the Identification of U- and Ra-Bearing Minerals in Mine Tailings“. SSRN Electronic Journal, 2022. http://dx.doi.org/10.2139/ssrn.4255388.

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Billon, Sophie, Sébastien Savoye, Paul Sardini, Martine Gérard, Catherine Beaucaire, Nathalie Coreau und Michael Descostes. „Sequential extractions versus alpha autoradiography: Mutually complementary for the identification of U- and Ra-bearing minerals in mine tailings“. Journal of Geochemical Exploration, Dezember 2023, 107368. http://dx.doi.org/10.1016/j.gexplo.2023.107368.

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Munkhsuld, Enkhuur, Takehiko Murayama, Keisuke Fukushi, Shigeo Nishikizawa, Baasansuren Gankhurel, Tserenkhand Batbold und Altansukh Ochir. „Heavy metal concentrations and water quality assessment of different types of drinking water wells in the Erdenet Cu–Mo mining area“. Discover Environment 2, Nr. 1 (26.02.2024). http://dx.doi.org/10.1007/s44274-024-00037-1.

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AbstractThe Erdenet mine (Erdenet, Mongolia) is a copper–molybdenum open pit mine with a huge tailing pond and is located next to a residential area. As the sources of drinking water in this area rely on groundwater and can be categorized into public or private wells, we aimed to assess the groundwater quality of the different types of drinking water wells. To accomplish our goal, we analyzed 18 trace metals (As, Ba, Bi, Cd, Co, Cr, Cs, Cu, Ga, Mo, Ni, Pb, Se, Sr, Th, U, V, Zn) and 8 major metals (Al, Ca, Fe, K, Mg, Mn, Na, Si) samples using ICP-MS and ICP-OES, and the heavy metal pollution index, heavy metal evaluation index, and degree of contamination were calculated. The most concerning point is that the Mo concentration of waste water in the Erdenet mine tailing pond and at a natural spring located 300 m from the tailing pond was 1100 μg/L, which greatly exceeds the WHO permissible concentration for Mo of 70 μg/L. Furthermore, high Ca and Mg concentrations at all private wells indicated that consumers of these wells are more vulnerable to any type of water pollution, as these wells are not built with any disinfection or treatment system. A modified categorization of the water quality indices showed that the public and private wells have low–medium contamination and that the tailing pond seepage water, along with its nearest spring, have a high degree of contamination. Because many private wells are located along the tailing pond and used directly without any treatment, we suggest a continuous evaluation and monitoring of the groundwater quality in this area.

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Xie, Gen, Henglei Chen, Peihong Mao und Guangwen Feng. „Equilibrium, kinetics and thermodynamics of biosorption of U(VI) by Jonesia quinghaiensis strain ZFSY-01 isolated from the wastewater of a uranium mine“. Journal of Water and Health, 12.07.2023. http://dx.doi.org/10.2166/wh.2023.108.

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Abstract The adsorption ability of a native Jonesia quinghaiensis strain ZFSY-01, a microorganism isolated from uranium tailing wastewater, to U(VI) in wastewater under different conditions was studied in this work. The results showed that 391.5 mg U/g and 78.3% of adsorption capacity and efficiency were achieved under an optimum adsorption condition, respectively. Especially, the adsorption capacity of this strain reached the maximum (Q=788.9 mg U/g) under 100 mg/L of strain dosage. Simultaneously, the linear regression coefficients for the used isothermal sorption model indicate that the biosorption process is compatible with the Freundlich isotherm, the Temkin isotherm and the Halsey isotherm model. Based on the fitted kinetic parameters, the data from the experiments fit well with models of pseudo-second-order kinetics and intraparticle diffusion, suggesting that the strain ZFSY-01 immobilized U(VI) by physical and chemical adsorption. In addition, thermodynamic parameters demonstrated that the sequestration of U(VI) by the strain is spontaneous and endothermic. Based on the above analysis, strain ZFSY-01 can effectively remove U(VI) ions from high- or low-concentration uranium-containing wastewater and is expected to become a promising biological adsorbent.

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Thomas, Kristen T., Anaïs Vermare, Suzannah O. Egleston, Yong-Dong Wang, Ashutosh Mishra, Tong Lin, Junmin Peng und Stanislav S. Zakharenko. „MicroRNA 3′ ends shorten during adolescent brain maturation“. Frontiers in Molecular Neuroscience 16 (14.04.2023). http://dx.doi.org/10.3389/fnmol.2023.1168695.

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MicroRNA (miRNA) dysregulation is well-documented in psychiatric disease, but miRNA dynamics remain poorly understood during adolescent and early adult brain maturation, when symptoms often first appear. Here, we use RNA sequencing to examine miRNAs and their mRNA targets in cortex and hippocampus from early-, mid-, and late-adolescent and adult mice. Furthermore, we use quantitative proteomics by tandem mass tag mass spectrometry (TMT-MS) to examine protein dynamics in cortex from the same subjects. We found that ~25% of miRNAs’ 3′ ends shorten with age due to increased 3′ trimming and decreased U tailing. Particularly, shorter but functionally competent isoforms (isomiRs) of miR-338-3p increase up to 10-fold during adolescence and only in brain. MiRNAs that undergo 3′ shortening exhibit stronger negative correlations with targets that decrease with age and stronger positive correlations with targets that increase with age, than miRNAs with stable 3′ ends. Increased 3′ shortening with age was also observed in available mouse and human miRNA-seq data sets, and stronger correlations between miRNAs that undergo shortening and their mRNA targets were observed in two of the three available data sets. We conclude that age-associated miRNA 3′ shortening is a well-conserved feature of postnatal brain maturation.

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