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Sample records for albarrana uranium ores

  1. Processing of Sierra Albarrana uranium ores; Tratamiento de los minerales de uranio de Sierra Albarrana

    Energy Technology Data Exchange (ETDEWEB)

    Gutierrez Jodra, L.; Perez Luina, A.; Perarnau, M.

    1960-07-01

    Uranium recovery by hydrometallurgy from brannerite, found in Hornachuelos (Cordoba) is described. It has been studied the acid and alkaline leaching and salt roasting, proving as more satisfactory the acid leaching. Besides the uranium solubilization by acid leaching, is described the further process to obtain pure uranyl nitrate. (Author)

  2. Uranium mill ore dust characterization

    Energy Technology Data Exchange (ETDEWEB)

    Knuth, R.H.; George, A.C.

    1980-11-01

    Cascade impactor and general air ore dust measurements were taken in a uranium processing mill in order to characterize the airborne activity, the degree of equilibrium, the particle size distribution and the respirable fraction for the /sup 238/U chain nuclides. The sampling locations were selected to limit the possibility of cross contamination by airborne dusts originating in different process areas of the mill. The reliability of the modified impactor and measurement techniques was ascertained by duplicate sampling. The results reveal no significant deviation from secular equilibrium in both airborne and bulk ore samples for the /sup 234/U and /sup 230/Th nuclides. In total airborne dust measurements, the /sup 226/Ra and /sup 210/Pb nuclides were found to be depleted by 20 and 25%, respectively. Bulk ore samples showed depletions of 10% for the /sup 226/Ra and /sup 210/Pb nuclides. Impactor samples show disequilibrium of /sup 226/Ra as high as +-50% for different size fractions. In these samples the /sup 226/Ra ratio was generally found to increase as particle size decreased. Activity median aerodynamic diameters of the airborne dusts ranged from 5 to 30 ..mu..m with a median diameter of 11 ..mu..m. The maximum respirable fraction for the ore dusts, based on the proposed International Commission on Radiological Protection's (ICRP) definition of pulmonary deposition, was < 15% of the total airborne concentration. Ore dust parameters calculated for impactor duplicate samples were found to be in excellent agreement.

  3. Start of exploration and mining of uranium ores in Hungary

    Energy Technology Data Exchange (ETDEWEB)

    Mikolay, I.; Szomolanyi, G. (Mecseki Ercbanyaszati Vallalat, Pecs II (Hungary))

    1983-09-01

    The mining of uranium ores is the youngest branch in the history of the Hungarian ore mining. The exploration for uranium ores started in Hungary in the decade from 1947, using simple methods at the beginning to apply more developed technologies later on. From the year 1952 Soviet geologists and geophysicists joined the explorations using the most advanced instruments, in co-operation with the Hungarian experts. From 1953 explorations and developments have been concentrated on the SW area of Mountain Mecsek so that by 1957 the preliminary conditions of a successful Hungarian uranium mining were established.

  4. Uranium and thorium recovery in thorianite ore-preliminary results

    Energy Technology Data Exchange (ETDEWEB)

    Gaiotte, Joao V.M. [Universidade Federal de Alfenas, Pocos de Caldas, MG (Brazil); Villegas, Raul A.S.; Fukuma, Henrique T., E-mail: rvillegas@cnen.gov.br, E-mail: htfukuma@cnen.gov.br [Comissao Nacional de Energia Nuclear (CNEN), Pocos de Caldas, MG (Brazil). Lab. de Pocos de Caldas

    2011-07-01

    This work presents the preliminary results of the studies aiming to develop a hydrometallurgical process to produce uranium and thorium concentrates from thorianite ore from Amapa State, Brazil. This process comprises two major parts: acid leaching and Th/U recovery using solvent extraction strategies. Thorianite ore has a typical composition of 60 - 70% of thorium, 8 - 10% lead and 7 - 10% uranium. Sulfuric acid leaching operational conditions were defined as follows: acid/ore ratio 7.5 t/t, ore size below 65 mesh (Tyler), 2 hours leaching time and temperature of 100 deg C. Leaching tests results showed that uranium and thorium recovery exceeded 95%, whereas 97% of lead ore content remained in the solid form. Uranium and thorium simultaneous solvent extraction is necessary due to high sulfate concentration in the liquor obtained from leaching, so the Primene JM-T primary anime was used for this extraction step. Aqueous raffinate from extraction containing sulfuric acid was recycled to the leaching step, reducing acid uptake around 60%, to achieve a net sulfuric acid consumption of 3 t/t of ore. Uranium and thorium simultaneous stripping was performed using sodium carbonate solution. In the aqueous stripped it was added sulfuric acid at pH 1.5, followed by a second solvent extraction step using the tertiary amine Alamine 336. The following stripping step was done with a solution of sodium chloride, resulting in a final solution of 23 g L-1 uranium. (author)

  5. Evaluation of the effectiveness of the filtration leaching for uranium recovery from uranium ore

    OpenAIRE

    2015-01-01

    The physical and chemical processes taking place in filtration leaching of uranium from uranium ore sample by sulphuric acid solution have been studied by modern physico-chemical methods (X-ray diffraction, scanning electron spectroscopy, electron probe microanalysis, optical emission spectroscope, ICP OES). Column leaching test was carried out for ore samples obtained from a uranium in-situ leaching (ISL) mining site using deluted sulphuricacid to study the evolution of various elements conc...

  6. Uranium recovery from Uro area phosphate ore, Nuba Mountains, Sudan

    Directory of Open Access Journals (Sweden)

    Abdelmajid A. Adam

    2014-11-01

    Full Text Available This study was carried out in a laboratory scale to recover uranium from Uro area phosphate ore in the eastern part of Nuba Mountains in Sudan. Phosphate ore samples were collected, and analyzed for uranium abundance. The results showed that the samples contain a significant concentration of uranium with an average of 310.3 μg/g, which is 2.6 times higher than the world average of phosphate. The green phosphoric acid obtained from the samples was found to contain uranium in the range of 186–2049 μg/g, with an average of 603.3 μg/g, and about 98% of uranium content of the phosphate ore was rendered soluble in the phosphoric acid. An extraction process using 25% tributylphosphate, followed by stripping process using 0.5 M sodium carbonate reported that more than 98% of uranium in the green phosphoric acid exists as uranyl tricarbonate complex, moreover, sodic decomposition using 50% sodium hydroxide showed that about 98% of the uranium was precipitated as sodium diuranate concentrate that is known as the yellow cake (Na2U2O7. Further purification and calcinations of the yellow cake led to the formation of the orange powder of uranium trioxide (UO3. The chemical analysis of the obtained uranium concentrates; yellow cake and uranium trioxide proved their nuclear purity and that they meet the standard commercial specification. The obtained results proved that uranium from Uro phosphate ore was successfully recovered as uranium trioxide with an overall recovery percentage of 93%.

  7. Summary of the mineralogy of the Colorado Plateau uranium ores

    Science.gov (United States)

    Weeks, Alice D.; Coleman, Robert Griffin; Thompson, Mary E.

    1956-01-01

    In the Colorado Plateau uranium has been produced chiefly from very shallow mines in carnotite ores (oxidized vanadiferous uranium ores) until recent deeper mining penetrated black unoxidized ores in water-saturated rocks and extensive exploration has discovered many deposits of low to nonvanadiferous ores. The uranium ores include a wide range from highly vanadiferous and from as much as one percent to a trace of copper, and contain a small amount of iron and traces of lead, zinc, molybdenum, cobalt, nickel, silver, manganese, and other metals. Recent investigation indicates that the carnotite ores have been derived by progressive oxidation of primary (unoxidized) black ores that contain low-valent uranium and vanadium oxides and silicates. The uranium minerals, uraninite and coffinite, are associated with coalified wood or other carbonaceous material. The vanadium minerals, chiefly montroseite, roscoelite, and other vanadium silicates, occur in the interstices of the sandstone and in siltstone and clay pellets as well as associated with fossil wood. Calcite, dolomite, barite and minor amounts of sulfides, arsenides, and selenides occur in the unoxidized ore. Partially oxidized vanadiferous ore is blue black, purplish brown, or greenish black in contrast to the black or dark gray unoxidized ore. Vanadium combines with uranium to form rauvite. The excess vanadium is present in corvusite, fernandinite, melanovanadite and many other quadrivalent and quinquevalent vanadium minerals as well as in vanadium silicates. Pyrite and part or all of the calcite are replaced by iron oxides and gypsum. In oxidized vanadiferous uranium ores the uranium is fixed in the relatively insoluble minerals carnotite and tyuyamunite, and the excess vanadium commonly combines with one or more of the following: calcium, sodium, potassium, magnesium, aluminum, iron, copper, manganese, or barium, or rarely it forms the hydrated pentoxide. The relatively stable vanadium silicates are little

  8. Radon emanation from low-grade uranium ore.

    Science.gov (United States)

    Sahu, Patitapaban; Mishra, Devi Prasad; Panigrahi, Durga Charan; Jha, Vivekanand; Patnaik, R Lokeswara

    2013-12-01

    Estimation of radon emanation in uranium mines is given top priority to minimize the risk of inhalation exposure due to short-lived radon progeny. This paper describes the radon emanation studies conducted in the laboratory as well as inside an operating underground uranium mine at Jaduguda, India. Some of the important parameters, such as grade/(226)Ra activity, moisture content, bulk density, porosity and emanation fraction of ore, governing the migration of radon through the ore were determined. Emanation from the ore samples in terms of emanation rate and emanation fraction was measured in the laboratory under airtight condition in glass jar. The in situ radon emanation rate inside the mine was measured from drill holes made in the ore body. The in situ(222)Rn emanation rate from the mine walls varied in the range of 0.22-51.84 × 10(-3) Bq m(-2) s(-1) with the geometric mean of 8.68 × 10(-3) Bq m(-2) s(-1). A significant positive linear correlation (r = 0.99, p 222)Rn emanation rate and the ore grade was observed. The emanation fraction of the ore samples, which varied in the range of 0.004-0.089 with mean value of 0.025 ± 0.02, showed poor correlation with ore grade and porosity. Empirical relationships between radon emanation rate and the ore grade/(226)Ra were also established for quick prediction of radon emanation rate from the ore body.

  9. Mining and processing of uranium ores at the Streltsovsky ore field

    Energy Technology Data Exchange (ETDEWEB)

    Ovseytchuk, V.A.; Litvinenko, V.G.; Kultishev, V.I. [Joint Stock Company, Priargunsky Industrial Mining and Chemical Union, Krasnokamensk, Chita Region (Russian Federation)

    2000-07-01

    The uranium deposits of Streltsovsky ore fields provide raw materials for Russian nuclear industry. For this region, it is important to achieve continued and increased activities in the recovery of mineral resources of uranium. Similarly, maintaining the mining and processing of uranium ores ensures the supply of raw materials for the nuclear industry. With the current operations, increasing the mining and processing activities would increase the cost of production of uranium oxides due to decreasing grades of ore body. After a review of the existing economic, technological and natural factors, a solution was proposed based on the joint application of underground mining and ore enrichment and processing with the help of hydrometallurgical process, in-situ leaching. Reduction of operation coasts and creation of radiation-safe working conditions could be achieved with the application of these systems involving concrete hardening in the mines and in-situ leaching of ore. With the help of economic-mathematical modeling, methods for rational application of various technologies could be determined and their processing parameters were specified. A reduction of coasts could be obtained and favorable conditions could be established for improvement in the treatment of lower grade ores by heap leaching. Application of purification of mine waters and tailing pond reduces the influence of the radiation and the impact on the natural environment. (author)

  10. Evaluation of the effectiveness of the filtration leaching for uranium recovery from uranium ore

    Directory of Open Access Journals (Sweden)

    Bolat Uralbekov

    2015-09-01

    Full Text Available The physical and chemical processes taking place in filtration leaching of uranium from uranium ore sample by sulphuric acid solution have been studied by modern physico-chemical methods (X-ray diffraction, scanning electron spectroscopy, electron probe microanalysis, optical emission spectroscope, ICP OES. Column leaching test was carried out for ore samples obtained from a uranium in-situ leaching (ISL mining site using deluted sulphuricacid to study the evolution of various elements concentration in the pregnant leach solution. It has been shown that the uranium in pregnant solutions appears by dissolution of calcium and magnesium carbonates and uranium minerals as well. It was found the decreasing of filtration coefficient from 0.099 m day-1 to 0.082 m day-1, due to the presence of mechanical and chemical mudding. Partial extraction of uranium (85% from the ore has been explained by the slow diffusion of sulfuric acid to the uranium minerals locates in the cracks of silicate minerals. It was concluded that the studied uranium ore sample according to adverse geotechnical parameters is not suitable for uranium extraction by filtration leaching.

  11. PROCESS FOR THE RECOVERY OF URANIUM FROM PHOSPHATIC ORE

    Science.gov (United States)

    Long, R.L.

    1959-04-14

    A proccss is described for the recovery of uranium from phosphatic products derived from phosphatic ores. It has been discovered that certain alkyl phosphatic, derivatives can be employed in a direct solvent extraction operation to recover uranium from solid products, such as superphosphates, without first dissolving such solids. The organic extractants found suitable include alkyl derivatives of phosphoric, pyrophosphoric, phosof the derivative contains from 4 to 7 carbon atoms. A diluent such as kerosene is also used.

  12. 40 CFR 440.30 - Applicability; description of the uranium, radium and vanadium ores subcategory.

    Science.gov (United States)

    2010-07-01

    ... for the extraction of uranium, radium and vanadium. Only vanadium byproduct production from uranium... uranium, radium and vanadium ores subcategory. 440.30 Section 440.30 Protection of Environment... SOURCE CATEGORY Uranium, Radium and Vanadium Ores Subcategory § 440.30 Applicability; description of...

  13. Method and set-up for uranium ore sorting

    Energy Technology Data Exchange (ETDEWEB)

    Dragulescu, E.; Ivascu, M.; Popescu, D.; Semenescu, G. (Institutul de Fizica si Inginerie Nucleara, Bucharest (Romania)); Gherea, Gh. (Intreprinderea metalelor rare, Bucuresti (Romania)); Draga, Z.; Funaru, Gh. (Exploatarea miniera Oravita, Oravita (Romania))

    1981-01-01

    A method was studied for uranium ore sorting. After the discussion of the principle, some particular conditions of the sorting are pointed out. A radiometric assembly is described and some results obtained on the simulator and in industrial conditions are reported.

  14. Continued Multicolumns Bioleaching for Low Grade Uranium Ore at a Certain Uranium Deposit

    Directory of Open Access Journals (Sweden)

    Gongxin Chen

    2016-01-01

    Full Text Available Bioleaching has lots of advantages compared with traditional heap leaching. In industry, bioleaching of uranium is still facing many problems such as site space, high cost of production, and limited industrial facilities. In this paper, a continued column bioleaching system has been established for leaching a certain uranium ore which contains high fluoride. The analysis of chemical composition of ore shows that the grade of uranium is 0.208%, which is lower than that of other deposits. However, the fluoride content (1.8% of weight is greater than that of other deposits. This can be toxic for bacteria growth in bioleaching progress. In our continued multicolumns bioleaching experiment, the uranium recovery (89.5% of 4th column is greater than those of other columns in 120 days, as well as the acid consumption (33.6 g/kg. These results indicate that continued multicolumns bioleaching technology is suitable for leaching this type of ore. The uranium concentration of PLS can be effectively improved, where uranium recovery can be enhanced by the iron exchange system. Furthermore, this continued multicolumns bioleaching system can effectively utilize the remaining acid of PLS, which can reduce the sulfuric acid consumption. The cost of production of uranium can be reduced and this benefits the environment too.

  15. Laser-induced breakdown spectroscopy measurements of uranium and thorium powders and uranium ore

    Energy Technology Data Exchange (ETDEWEB)

    Judge, Elizabeth J. [Chemistry Division, Los Alamos National Laboratory, Los Alamos, NM 87545 (United States); Barefield, James E., E-mail: jbarefield@lanl.gov [Chemistry Division, Los Alamos National Laboratory, Los Alamos, NM 87545 (United States); Berg, John M. [Manufacturing Engineering and Technology Division, Los Alamos National Laboratory, Los Alamos, NM 87545 (United States); Clegg, Samuel M.; Havrilla, George J.; Montoya, Velma M.; Le, Loan A.; Lopez, Leon N. [Chemistry Division, Los Alamos National Laboratory, Los Alamos, NM 87545 (United States)

    2013-05-01

    Laser-induced breakdown spectroscopy (LIBS) was used to analyze depleted uranium and thorium oxide powders and uranium ore as a potential rapid in situ analysis technique in nuclear production facilities, environmental sampling, and in-field forensic applications. Material such as pressed pellets and metals, has been extensively studied using LIBS due to the high density of the material and more stable laser-induced plasma formation. Powders, on the other hand, are difficult to analyze using LIBS since ejection and removal of the powder occur in the laser interaction region. The capability of analyzing powders is important in allowing for rapid analysis of suspicious materials, environmental samples, or trace contamination on surfaces since it most closely represents field samples (soil, small particles, debris etc.). The rapid, in situ analysis of samples, including nuclear materials, also reduces costs in sample collection, transportation, sample preparation, and analysis time. Here we demonstrate the detection of actinides in oxide powders and within a uranium ore sample as both pressed pellets and powders on carbon adhesive discs for spectral comparison. The acquired LIBS spectra for both forms of the samples differ in overall intensity but yield a similar distribution of atomic emission spectral lines. - Highlights: • LIBS analysis of mixed actinide samples: depleted uranium oxide and thorium oxide • LIBS analysis of actinide samples in powder form on carbon adhesive discs • Detection of uranium in a complex matrix (uranium ore) as a precursor to analyzing uranium in environmental samples.

  16. Application of neodymium isotope ratio measurements for the origin assessment of uranium ore concentrates

    NARCIS (Netherlands)

    Krajko, J.; Varga, Z.; Yalcintas, E.; Wallenius, M.; Mayer, K.

    2014-01-01

    A novel procedure has been developed for the measurement of 143Nd/144Nd isotope ratio in various uranium-bearing materials, such as uranium ores and ore concentrates (UOC) in order to evaluate the usefulness and applicability of variations of 143Nd/144Nd isotope ratio for provenance assessment in nu

  17. Standard practices for sampling uranium-Ore concentrate

    CERN Document Server

    American Society for Testing and Materials. Philadelphia

    2010-01-01

    1.1 These practices are intended to provide the nuclear industry with procedures for obtaining representative bulk samples from uranium-ore concentrates (UOC) (see Specification C967). 1.2 These practices also provide for obtaining a series of representative secondary samples from the original bulk sample for the determination of moisture and other test purposes, and for the preparation of pulverized analytical samples (see Test Methods C1022). 1.3 These practices consist of a number of alternative procedures for sampling and sample preparation which have been shown to be satisfactory through long experience in the nuclear industry. These procedures are described in the following order. Stage Procedure Section Primary Sampling One-stage falling stream 4 Two-stage falling stream 5 Auger 6 Secondary Sampling Straight-path (reciprocating) 7 Rotating (Vezin) 8, 9 Sample Preparation 10 Concurrent-drying 11-13 Natural moisture 14-16 Calcination 17, 18 Sample Packaging 19 Wax s...

  18. Behavior of uranium under conditions of interaction of rocks and ores with subsurface water

    Science.gov (United States)

    Omel'Yanenko, B. I.; Petrov, V. A.; Poluektov, V. V.

    2007-10-01

    The behavior of uranium during interaction of subsurface water with crystalline rocks and uranium ores is considered in connection with the problem of safe underground insulation of spent nuclear fuel (SNF). Since subsurface water interacts with crystalline rocks formed at a high temperature, the mineral composition of these rocks and uranium species therein are thermodynamically unstable. Therefore, reactions directed toward the establishment of equilibrium proceed in the water-rock system. At great depths that are characterized by hindered water exchange, where subsurface water acquires near-neutral and reducing properties, the interaction is extremely sluggish and is expressed in the formation of micro- and nanoparticles of secondary minerals. Under such conditions, the slow diffusion redistribution of uranium with enrichment in absorbed forms relative to all other uranium species is realized as well. The products of secondary alteration of Fe- and Ti-bearing minerals serve as the main sorbents of uranium. The rate of alteration of minerals and conversion of uranium species into absorbed forms is slow, and the results of these processes are insignificant, so that the rocks and uranium species therein may be regarded as unaltered. Under reducing conditions, subsurface water is always saturated with uranium. Whether water interacts with rock or uranium ore, the equilibrium uranium concentration in water is only ≤10-8 mol/l. Uraninite ore under such conditions always remains stable irrespective of its age. The stability conditions of uranium ore are quite suitable for safe insulation of SNF, which consists of 95% uraninite (UO2) and is a confinement matrix for all other radionuclides. The disposal of SNF in massifs of crystalline rocks at depths below 500 m, where reducing conditions are predominant, is a reliable guarantee of high SNF stability. Under oxidizing conditions of the upper hydrodynamic zone, the rate of interaction of rocks with subsurface water

  19. AMS of natural 236U and 239Pu produced in uranium ores

    Science.gov (United States)

    Wilcken, K. M.; Barrows, T. T.; Fifield, L. K.; Tims, S. G.; Steier, P.

    2007-06-01

    The rare isotopes 236U and 239Pu are produced naturally by neutron capture in uranium ores. Here we measure 236U and 239Pu by accelerator mass spectrometry (AMS) in the same ore samples for the first time. To ensure efficient extraction of both elements and isotopic equilibrium between the 239Pu in the ore and a 242Pu spike, we developed a new sample preparation protocol. AMS has clear advantages over previous methods because it achieves better discrimination against molecular interferences with higher sensitivity and shorter counting times. Measurements of 236U and 239Pu hold considerable promise as proxy indicators of neutron flux and uranium concentration.

  20. Modeling and experimental examination of water level effects on radon exhalation from fragmented uranium ore.

    Science.gov (United States)

    Ye, Yong-Jun; Dai, Xin-Tao; Ding, De-Xin; Zhao, Ya-Li

    2016-12-01

    In this study, a one-dimensional steady-state mathematical model of radon transport in fragmented uranium ore was established according to Fick's law and radon transfer theory in an air-water interface. The model was utilized to obtain an analytical solution for radon concentration in the air-water, two-phase system under steady state conditions, as well as a corresponding radon exhalation rate calculation formula. We also designed a one-dimensional experimental apparatus for simulating radon diffusion migration in the uranium ore with various water levels to verify the mathematical model. The predicted results were in close agreement with the measured results, suggesting that the proposed model can be readily used to determine radon concentrations and exhalation rates in fragmented uranium ore with varying water levels.

  1. Respiratory tract carcinogenesis in large and small experimental animal following daily inhalation of radon daughters and uranium ore dust

    Energy Technology Data Exchange (ETDEWEB)

    Stuart, B.O.; Palmer, R.F.; Filipy, R.E.; Dagle, G.E.; McDonald, K.E.

    1977-01-01

    Uranium ore miners of the Colorado plateau suffer more than 6 times the normal incidence of lung cancer, and their mortality rates due to pneumoconiosis and emphysema are 5 times greater than in the general population. Inhalation exposures of beagle dogs and rodents to radon daughters and uranium ore dust were undertaken to determine which of these uranium mine air contaminants, and at what levels, are responsible for the high incidences of these diseases. Results are discussed.

  2. Application of lead and strontium isotope ratio measurements for the origin assessment of uranium ore concentrates.

    Science.gov (United States)

    Varga, Zsolt; Wallenius, Maria; Mayer, Klaus; Keegan, Elizabeth; Millet, Sylvain

    2009-10-15

    Lead and strontium isotope ratios were used for the origin assessment of uranium ore concentrates (yellow cakes) for nuclear forensic purposes. A simple and low-background sample preparation method was developed for the simultaneous separation of the analytes followed by the measurement of the isotope ratios by multicollector inductively coupled plasma mass spectrometry (MC-ICPMS). The lead isotopic composition of the ore concentrates suggests applicability for the verification of the source of the nuclear material and by the use of the radiogenic (207)Pb/(206)Pb ratio the age of the raw ore material can be calculated. However, during data interpretation, the relatively high variation of the lead isotopic composition within the mine site and the generally high contribution of natural lead as technological contamination have to be carefully taken into account. The (87)Sr/(86)Sr isotope ratio is less prone to the variation within one mine site and less affected by the production process, thus it was found to be a more purposeful indicator for the origin assessment and source verification than the lead. The lead and strontium isotope ratios measured and the methodology developed provide information on the initial raw uranium ore used, and thus they can be used for source attribution of the uranium ore concentrates.

  3. Culture-dependent and -independent molecular analysis of the bacterial community within uranium ore.

    Science.gov (United States)

    Islam, Ekramul; Sar, Pinaki

    2011-08-01

    The bacterial community structure within a uranium ore was investigated using culture-dependent and -independent clone library analysis and denaturing gradient gel electrophoresis of 16S rRNA genes. The major aerobic heterotrophic bacteria were isolated and identified, and their resistance to uranium and other heavy metals was characterized. Together with near neutral pH, moderate organic carbon content, elevated U and other heavy metals (V, Ni, Mn, Cu, etc.), the ore showed high microbial counts and phylotype richness. The bacterial community mainly consisted of uncultured Proteobacteria, with the predominance of γ - over β - and α -subdivisions, along with Actinobacteria and Firmicutes. A phylogenetic study revealed that nearly one-third of the community was affiliated to as yet uncultured and unidentified bacteria having a closer relationship to Pseudomonas. Lineages of Burkholderiaceae and Moraxellaceae were relatively more abundant in the total community, while genera affiliated to Xanthomonadaceae and Microbacteriaceae and Exiguobacterium were detected in the culturable fraction. More than 50% of the bacterial isolates affiliated to Stenotrophomonas, Microbacterium, Acinetobacter, Pseudomonas and Enterobacter showed resistance to uranium and other heavy metals. The study showed for the first time that uranium ore harbors major bacterial groups related to organisms having a wide range of environmentally significant functional attributes, and the most abundant members are possibly new groups/taxa. These findings provide new insights into U-ore geomicrobiology that could be useful in biohydrometallurgy and bioremediation applications.

  4. Application of neodymium isotope ratio measurements for the origin assessment of uranium ore concentrates.

    Science.gov (United States)

    Krajkó, Judit; Varga, Zsolt; Yalcintas, Ezgi; Wallenius, Maria; Mayer, Klaus

    2014-11-01

    A novel procedure has been developed for the measurement of (143)Nd/(144)Nd isotope ratio in various uranium-bearing materials, such as uranium ores and ore concentrates (UOC) in order to evaluate the usefulness and applicability of variations of (143)Nd/(144)Nd isotope ratio for provenance assessment in nuclear forensics. Neodymium was separated and pre-concentrated by extraction chromatography and then the isotope ratios were measured by multi-collector inductively coupled plasma mass spectrometry (MC-ICP-MS). The method was validated by the measurement of standard reference materials (La Jolla, JB-2 and BCR-2) and the applicability of the procedure was demonstrated by the analysis of uranium samples of world-wide origin. The investigated samples show distinct (143)Nd/(144)Nd ratio depending on the ore type, deposit age and Sm/Nd ratio. Together with other characteristics of the material in question, the Nd isotope ratio is a promising signature for nuclear forensics and suggests being indicative of the source material, the uranium ore.

  5. Heap leaching of clay ish uranium ores; Lixiviacion estatica de minerales arcillosos de uranio

    Energy Technology Data Exchange (ETDEWEB)

    Gonzalez, E.; Sedano, A.

    1973-07-01

    This paper describes an experimental facility, built near El Lobo mine. In it we study the beneficiation of low-grade uranium ore. The mineral has a great amount of clay and fines. The flow-sheet used has four steps: head leaching, ph-ajustement, ion-exchange and participation. We show, also, the most interesting results. (Author)

  6. Determination of uranium content in phosphate ores using different measurement techniques

    Directory of Open Access Journals (Sweden)

    Mohammad A. Al-Eshaikh

    2016-01-01

    Full Text Available The most important unconventional source of uranium is found in phosphate deposits; unfortunately, nowadays its exploitation is limited by economic constraints. The uranium concentrations in phosphate ores in the world vary regionally and most countries with large phosphate deposits have either plant in operation to extract uranium or are at the stage of pilot extraction plants. The aim of this investigation is to evaluate uranium content in the Saudi phosphate ores for, at least, two reasons: firstly, upgrading the phosphate quality by removing the uranium content in order to reduce the radioactivity in the fertilizer products. Secondly, getting benefit from the extracted uranium for its domestic use as a fuel in nuclear power and desalination plants. The results of this study show that the uranium concentration in Saudi phosphate rocks is relatively low (less than 100 ppm, which is not economically encouraging for its direct extraction. However, its extraction as a byproduct from the phosphoric acid, which will have higher concentration could be quite promising and worth exploiting.

  7. AMS of natural {sup 236}U and {sup 239}Pu produced in uranium ores

    Energy Technology Data Exchange (ETDEWEB)

    Wilcken, K.M. [Department of Nuclear Physics, RSPhysSE, Australian National University, Canberra, ACT 0200 (Australia)]. E-mail: k.wilcken@suerc.gla.ac.uk; Barrows, T.T. [Department of Nuclear Physics, RSPhysSE, Australian National University, Canberra, ACT 0200 (Australia); Fifield, L.K. [Department of Nuclear Physics, RSPhysSE, Australian National University, Canberra, ACT 0200 (Australia); Tims, S.G. [Department of Nuclear Physics, RSPhysSE, Australian National University, Canberra, ACT 0200 (Australia); Steier, P. [VERA Laboratory, Institute for Isotopic Research and Nuclear Physics, University of Vienna, Waehringer Strasse 17, A-1090 Vienna (Austria)

    2007-06-15

    The rare isotopes {sup 236}U and {sup 239}Pu are produced naturally by neutron capture in uranium ores. Here we measure {sup 236}U and {sup 239}Pu by accelerator mass spectrometry (AMS) in the same ore samples for the first time. To ensure efficient extraction of both elements and isotopic equilibrium between the {sup 239}Pu in the ore and a {sup 242}Pu spike, we developed a new sample preparation protocol. AMS has clear advantages over previous methods because it achieves better discrimination against molecular interferences with higher sensitivity and shorter counting times. Measurements of {sup 236}U and {sup 239}Pu hold considerable promise as proxy indicators of neutron flux and uranium concentration.

  8. Investigation of sulphur isotope variation due to different processes applied during uranium ore concentrate production.

    Science.gov (United States)

    Krajkó, Judit; Varga, Zsolt; Wallenius, Maria; Mayer, Klaus; Konings, Rudy

    The applicability and limitations of sulphur isotope ratio as a nuclear forensic signature have been studied. The typically applied leaching methods in uranium mining processes were simulated for five uranium ore samples and the n((34)S)/n((32)S) ratios were measured. The sulphur isotope ratio variation during uranium ore concentrate (UOC) production was also followed using two real-life sample sets obtained from industrial UOC production facilities. Once the major source of sulphur is revealed, its appropriate application for origin assessment can be established. Our results confirm the previous assumption that process reagents have a significant effect on the n((34)S)/n((32)S) ratio, thus the sulphur isotope ratio is in most cases a process-related signature.

  9. Assessment of natural radioactivity in aquifer medium bearing uranium ores in Koprubasi, Turkey

    Science.gov (United States)

    Simsek, Celalettin

    2008-10-01

    Koprubasi, located within Manisa Province near the Izmir, is the biggest uranium mine where uranium ores originate from Neogene aged altered sandstone and conglomerate layers. The main objective of this study is to determine the radiation hazard associated with radioactivity levels of uranium ores, and the rocks and sediments around Koprubasi. In this regard, measured activity levels of 226Ra, 232Th and 40K were compared with world averages. The average activity levels of 226 Ra, 232Th and 40K were measured to be 5369.75, 124.78 and 10.0 Bq/kg in uranium ores, 24.32, 52.94 and 623.38 Bq/kg in gneiss, 46.24, 45.13 and 762.26 Bq/kg in sandstone and conglomerate, 73.11, 43.15 and 810.65 Bq/kg in sediments, respectively. All samples have high 226Ra and 40K levels according to world average level. As these sediments are used as construction materials and in agricultural activities within the study area, the radiation hazard are calculated by using dose rate (D), annual effective dose rate (He), radium equivalent activity (Raeq) and radiation hazard index (Iyr). All the samples have Raeq levels that are lower than the world average limit of 370 Bq/kg. On the other hand, D, He and Iyr values are higher than world average values. These results indicate that the uranium ores in the Koprubasi is the most important contributor to the natural radiation level. The radioactivity levels of sediments and rocks make them unsuitable for use as agricultural soil and as construction materials. Moreover, it is determined that shallow groundwater in sediments and deep groundwater in conglomerate rocks and also surface water sources in the Koprubasi have high 226Ra content. According to environmental radioactive baseline, some environmental protection study must be taken in Koprubasi uranium site and the environment.

  10. Leaching of molybdenum and arsenic from uranium ore and mill tailings

    Science.gov (United States)

    Landa, E.R.

    1984-01-01

    A sequential, selective extraction procedure was used to assess the effects of sulfuric acid milling on the geochemical associations of molybdenum and arsenic in a uranium ore blend, and the tailings derived therefrom. The milling process removed about 21% of the molybdenum and 53% of the arsenic initially present in the ore. While about one-half of the molybdenum in the ore was water soluble, only about 14% existed in this form in the tailings. The major portion of the extractable molybdenum in the tailings appears to be associated with hydrous oxides of iron, and with alkaline earth sulfate precipitates. In contrast with the pattern seen for molybdenum, the partitioning of arsenic into the various extractable fractions differs little between the ore and the tailings. ?? 1984.

  11. Petrographic-geochemical characteristics of granitoids and their epigenetic alteration products in paleovalley fields (Vitim uranium-ore site)

    Science.gov (United States)

    Kuznetsova, E. S.; Domarenko, V. A.; Matveenko, I. A.

    2016-09-01

    The study describes the results of the mineral and element composition of granitoids in basement and weathering crust of Khiagdinsk ore field in Vitim uranium ore site. It has been stated that granitoids in basement consist of leucocratic biotite granite of subalkaline group. The major rock-forming, accessory (apatite, zircon, sphene (titanite), magnetite, monazite, xenotime), and uranium-bearing minerals have been determined. Weathering crust is composed of unlithified or weakly lithified sediments, among which sandy and sandy medium gravel deposits have been distinguished in terms of mineralogical and granulometric texture. High radioactivity of granitoids was revealed in thorium-uranium basement and natural uranium. The combination of the specified factors presupposes that granitoids of Vitim uranium ore site may be a source of uranium in the fields of the paleovalley type.

  12. Leaching of radionuclides from uranium ore and mill tailings ( Ra- 226, Tn-230).

    Science.gov (United States)

    Landa, E.R.

    1982-01-01

    The major part of the extractable uranium is associated with a readily acid-soluble fraction in both ore and tailings. The major part of the extractable 226Ra was associated with an iron, manganese hydrous-oxide fraction in the ore and tailings. Thorium-230 was the least leachable of the radionuclides studied. The major portion of the extractable 230Th was associated with alkaline-earth sulphate precipitates, organic matter, or both. The specific effects of milling on each of the nuclides are discussed.-Author

  13. An Overview of Process Monitoring Related to the Production of Uranium Ore Concentrate

    Energy Technology Data Exchange (ETDEWEB)

    McGinnis, Brent [Innovative Solutions Unlimited, LLC

    2014-04-01

    Uranium ore concentrate (UOC) in various chemical forms, is a high-value commodity in the commercial nuclear market, is a potential target for illicit acquisition, by both State and non-State actors. With the global expansion of uranium production capacity, control of UOC is emerging as a potentially weak link in the nuclear supply chain. Its protection, control and management thus pose a key challenge for the international community, including States, regulatory authorities and industry. This report evaluates current process monitoring practice and makes recommendations for utilization of existing or new techniques for managing the inventory and tracking this material.

  14. Determination of specific activity of 230Th in uranium ore samples

    Institute of Scientific and Technical Information of China (English)

    2000-01-01

    A new method suitable for determining specific activity of 230Th in uranium ore samples is built. The method is characterized by adding the 230Th/ 232Th standard dilution agent with lower activity ratio (Its 230Th/ 232Th activity ratio and 230Th have been known) to the samples and using isotopic dilution analysis. The method can be applied to analyses of 230Th specific activity in various 230Th/ 232Th activity ratio samples. The precision can also be improved.

  15. Evolutionary and geological factors controlling endogenic uranium mineralization and the potential for the discovery of new ore districts

    Science.gov (United States)

    Mashkovtsev, G. A.; Miguta, A. K.; Shchetochkin, V. N.

    2015-03-01

    The exhaustion of known surface and near-surface high-grade uranium deposits poses the serious problem of prospecting and exploration of new large endogenic deposits. A comparison of large data sets for endogenic deposits from the world's major uranium districts allowed the authors to develop an evolutionary geological model of large-scale uranium ore genesis, which reflects the succession and nature of preore, ore-forming, and post-ore processes. The study reveals a combination of general (recurrent) factors controlling the formation of ore districts with large-scale uranium mineralization regardless of the genesis and timing of the mineralization. At the same time, these factors depend on the regional setting and can vary considerably among deposits of the same type localized in different tectonic blocks with different characteristics and structural evolution. In connection with this, the exploration of major genetic types of deposits requires the application of specified criteria. Along with the consideration of the evolutionary geological model of ore formation, the study discusses a variety of tectono-magmatic, mineralogical, geochemical, radiogeochemical, and physicochemical factors and indications in three uranium districts (the Streltsovskoe, Elkon, and Central Ukrainian districts), which can form the basis for further uranium prospecting and exploration. Using a combination of favorable prerequisite conditions the study compares the possibilities for the discovery of large endogenic uranium deposits in several regions of Russia.

  16. Effect of Groundwater Radiolysis on the Wall—rock Alteration of Uranium Ore Deposits

    Institute of Scientific and Technical Information of China (English)

    闵茂中; 吴俊奇; 等

    1994-01-01

    Reported for the first time in this paper are the results of simulating experiments on the γ-irradiation-induced oxidation of Fe2+ under the physicochemical conditions(T=200℃,P=50MPa,Eh=-0.1V,pH=7.2)simial to those under which moderate-low temperature hydrothermal uranium deposits are formed.Evdence shows that the effect of groundwater radiolysis seems to be the major mechanism of wall-rock alteration(hematitizaton)of hydrothermal uranium deposits.Moreover,adiscussion was made of possible effects of radiolysis of the water-rock system on wall-rock alterations including argillization and decoloration of uranium ore deposits on the basis of the experimental results.

  17. Diversity, metal resistance and uranium sequestration abilities of bacteria from uranium ore deposit in deep earth stratum.

    Science.gov (United States)

    Islam, Ekramul; Sar, Pinaki

    2016-05-01

    Metal resistance and uranium (U) sequestration abilities of bacteria residing in subsurface U ore was investigated using 122 pure culture strains isolated through enrichment. The cumulative frequencies of isolates resistant to each metal tested were as follows: As(V), 74%; Zn, 58%; Ni, 53%; Cd, 47%; Cr(VI), 41%; Co, 40%; Cu, 20%; and Hg, 4%. 16S rRNA gene analysis revealed that isolated bacteria belonged to 14 genera with abundance of Arthrobacter, Microbacterium, Acinetobacter and Stenotrophomonas. Cobalt did not interfere with the growth of most of the bacterial isolates belonging to different groups while U allowed growth of four different genera of which Stenotrophomonas and Microbacterium showed high U tolerance. Interestingly, tolerance to Ni, Zn, Cu, and Hg was observed only in Microbacterium, Arthrobacter, Paenibacillus¸ and Acinetobacter, respectively. However, Microbacterium was found to be dominant when isolated from other five different metal enrichments including U. Uranium removal study showed that 84% of the test bacteria could remove more than 50mgUg(-1) dry weight from 80 or 160mgL(-1) U within 48h. In general, Microbacterium, Arthrobacter and Acinetobacter could remove a higher amount of U. High resolution transmission electron microscopy (HRTEM) study of U exposed cells revealed that accumulated U sequestered mostly around the cell periphery. The study highlights that indigenous U ore deposit bacteria have the potential to interact with U, and thus could be applied for bioremediation of U contaminated sites or wastes.

  18. PHASE ANALYSES OF URANIUM-BEARING MINERALS FROM THE HIGH GRADE ORE, NOPAL I, PENA BLANCA, MEXICO

    Energy Technology Data Exchange (ETDEWEB)

    M. Ren; P. Goodell; A. Kelts; E.Y. Anthony; M. Fayek; C. Fan; C. Beshears

    2005-07-11

    The Nopal I uranium deposit is located in the Pena Blanca district, approximately 40 miles north of Chihuahua City, Mexico. The deposit was formed by hydrothermal processes within the fracture zone of welded silicic volcanic tuff. The ages of volcanic formations are between 35 to 44 m.y. and there was secondary silicification of most of the formations. After the formation of at least part of the uranium deposit, the ore body was uplifted above the water table and is presently exposed at the surface. Detailed petrographic characterization, electron microprobe backscatter electron (BSE) imagery, and selected x-ray maps for the samples from Nopal I high-grade ore document different uranium phases in the ore. There are at least two stages of uranium precipitation. A small amount of uraninite is encapsulated in silica. Hexavalent uranium may also have been a primary precipitant. The uranium phases were precipitated along cleavages of feldspars, and along fractures in the tuff. Energy dispersive spectrometer data and x-ray maps suggest that the major uranium phases are uranophane and weeksite. Substitutions of Ca and K occur in both phases, implying that conditions were variable during the mineralization/alteration process, and that compositions of the original minerals have a major influence on later stage alteration. Continued study is needed to fully characterize uranium behavior in these semi-arid to arid conditions.

  19. An investigation into heterogeneity in a single vein-type uranium ore deposit: Implications for nuclear forensics.

    Science.gov (United States)

    Keatley, A C; Scott, T B; Davis, S; Jones, C P; Turner, P

    2015-12-01

    Minor element composition and rare earth element (REE) concentrations in nuclear materials are important as they are used within the field of nuclear forensics as an indicator of sample origin. However recent studies into uranium ores and uranium ore concentrates (UOCs) have shown significant elemental and isotopic heterogeneity from a single mine site such that some sites have shown higher variation within the mine site than that seen between multiple sites. The elemental composition of both uranium and gangue minerals within ore samples taken along a single mineral vein in South West England have been measured and reported here. The analysis of the samples was undertaken to determine the extent of the localised variation in key elements. Energy Dispersive X-ray spectroscopy (EDS) was used to analyse the gangue mineralogy and measure major element composition. Minor element composition and rare earth element (REE) concentrations were measured by Electron Probe Microanalysis (EPMA). The results confirm that a number of key elements, REE concentrations and patterns used for origin location do show significant variation within mine. Furthermore significant variation is also visible on a meter scale. In addition three separate uranium phases were identified within the vein which indicates multiple uranium mineralisation events. In light of these localised elemental variations it is recommended that representative sampling for an area is undertaken prior to establishing the REE pattern that may be used to identify the originating mine for an unknown ore sample and prior to investigating impact of ore processing on any arising REE patterns.

  20. Early Phanerozoic trace fossils from the Sierra Albarrana quartzites (Ossa-Morena Zone, Southwest Spain)

    NARCIS (Netherlands)

    Marcos, A.; Azor, A.; González, F.; Simancas, F.

    1991-01-01

    Three ichnogenera are described from a 50 to 500 m thick shallow-water sandstone-shale sequence (Sierra Albarrana Quartzites). The ichnofauna consists of the burrows of worm-like animals (Arenicolites, Monocraterion, and Skolithos). The age of this formation, previously considered to be Precambrian

  1. Enhanced Uranium Ore Concentrate Analysis by Handheld Raman Sensor: FY15 Status Report

    Energy Technology Data Exchange (ETDEWEB)

    Bryan, Samuel A. [Pacific Northwest National Lab. (PNNL), Richland, WA (United States); Johnson, Timothy J. [Pacific Northwest National Lab. (PNNL), Richland, WA (United States); Orton, Christopher R. [Pacific Northwest National Lab. (PNNL), Richland, WA (United States)

    2015-11-11

    High-purity uranium ore concentrates (UOC) represent a potential proliferation concern. A cost-effective, “point and shoot” in-field analysis capability to identify ore types, phases of materials present, and impurities, as well as estimate the overall purity would be prudent. Handheld, Raman-based sensor systems are capable of identifying chemical properties of liquid and solid materials. While handheld Raman systems have been extensively applied to many other applications, they have not been broadly studied for application to UOC, nor have they been optimized for this class of chemical compounds. PNNL was tasked in Fiscal Year 2015 by the Office of International Safeguards (NA-241) to explore the use of Raman for UOC analysis and characterization. This report summarizes the activities in FY15 related to this project.

  2. Release of uranium and thorium from monazite ores: implications for phosphatic wasteforms

    Energy Technology Data Exchange (ETDEWEB)

    Read, D. [Reading Univ. (United Kingdom); Jarvis, N.V.; Andreoli, M.A.G. [Atomic Energy Corp. of South Africa Ltd., Pretoria (South Africa)

    1998-12-31

    Monazite is an important economic source of uranium, thorium, and the rare earth elements. Economically viable concentrations occur in placer deposits and as massive ore bodies in igneous and metamorphic provinces throughout the world. This and its refractory nature has led to speculation that artificial phosphate-based matrices similar in composition to monazite may prove useful as wasteforms for high level radioactive waste. Before a detailed evaluation can be made, however, it is worthwhile to assess the long term degradation behaviour of natural monazites in diverse hydrogeochemical environments. This paper focusses on the Steenkampskraal monazite mine, South Africa and compares findings with those from monazite occurrences in the Palaeozoic rocks of Britain and Western France. In all cases where the monazite has altered, a marked fractionation of the lanthanide series elements is apparent, together with substantial redistribution of uranium and thorium. The implications for waste encapsulation are discussed in terms of the potential for groundwater transport away from the source. (orig.)

  3. Nucleogenic {sup 36}Cl, {sup 236}U and {sup 239}Pu in uranium ores

    Energy Technology Data Exchange (ETDEWEB)

    Wilcken, K.M. [Department of Nuclear Physics, RSPhysSE, Australian National University, Canberra, ACT 0200 (Australia); Scottish Universities Environmental Research Centre, Scottish Enterprise Technology Park, Rankine Avenue, East Kilbride G75 0QF (United Kingdom)], E-mail: K.Wilcken@suerc.gla.ac.uk; Fifield, L.K.; Barrows, T.T.; Tims, S.G.; Gladkis, L.G. [Department of Nuclear Physics, RSPhysSE, Australian National University, Canberra, ACT 0200 (Australia)

    2008-08-15

    The nucleogenic isotopes {sup 36}Cl, {sup 236}U and {sup 239}Pu are produced naturally in subsurface environments via neutron capture of thermal and epithermal neutrons. Concentrations are, however, very low and accelerator mass spectrometry (AMS) is required for quantitative measurements. A particular challenge is presented by the measurement of {sup 236}U/{sup 238}U ratios down to the level of 10{sup -13} that is expected from rocks with low uranium concentration. Here, we present the AMS methodology that has been developed at the ANU for measuring {sup 236}U/{sup 238}U ratios at this level. The more established methodologies for {sup 36}Cl and {sup 239}Pu measurements are also summarised. These capabilities are then used to characterize the {sup 36}Cl, {sup 236}U and {sup 239}Pu concentrations in a range of uranium ores. A simple model of the neutron production and capture processes in subsurface environments has been developed and is presented. It is shown that nucleogenic {sup 36}Cl, {sup 236}U and {sup 239}Pu can be used to determine both thermal and epithermal neutron fluxes in subsurface environments. Potential applications include uranium exploration and monitoring of the environmental impact of uranium mining.

  4. Nucleogenic 36Cl, 236U and 239Pu in uranium ores

    Science.gov (United States)

    Wilcken, K. M.; Fifield, L. K.; Barrows, T. T.; Tims, S. G.; Gladkis, L. G.

    2008-08-01

    The nucleogenic isotopes 36Cl, 236U and 239Pu are produced naturally in subsurface environments via neutron capture of thermal and epithermal neutrons. Concentrations are, however, very low and accelerator mass spectrometry (AMS) is required for quantitative measurements. A particular challenge is presented by the measurement of 236U/ 238U ratios down to the level of 10 -13 that is expected from rocks with low uranium concentration. Here, we present the AMS methodology that has been developed at the ANU for measuring 236U/ 238U ratios at this level. The more established methodologies for 36Cl and 239Pu measurements are also summarised. These capabilities are then used to characterize the 36Cl, 236U and 239Pu concentrations in a range of uranium ores. A simple model of the neutron production and capture processes in subsurface environments has been developed and is presented. It is shown that nucleogenic 36Cl, 236U and 239Pu can be used to determine both thermal and epithermal neutron fluxes in subsurface environments. Potential applications include uranium exploration and monitoring of the environmental impact of uranium mining.

  5. Investigation of the {sup 236}U/{sup 238}U isotope abundance ratio in uranium ores and yellow cake samples

    Energy Technology Data Exchange (ETDEWEB)

    Srncik, M. [Vienna Univ. (Austria). Dept. of Inorganic Chemistry; European Commission, Joint Research Centre, Karlsruhe (Germany). Institute for Transuranium Elements; Mayer, K.; Hrnecek, E.; Wallenius, M.; Varga, Z. [European Commission, Joint Research Centre, Karlsruhe (Germany). Institute for Transuranium Elements; Steier, P. [Vienna Univ. (Austria). VERA Lab.; Wallner, G. [Vienna Univ. (Austria). Dept. of Inorganic Chemistry

    2011-07-01

    Uranium ores and yellow cake samples of known geographic origin were investigated for their n({sup 236}U)/n({sup 238}U) isotope abundance ratio. Samples from four different uranium mines in Australia, Brazil and Canada were selected. Uranium was separated by UTEVA {sup registered} Resin and was measured by Accelerator Mass Spectrometry (AMS) at the Vienna Environmental Research Accelerator (VERA). The measurement of the isotope abundance ratio n({sup 236}U)/n({sup 238}U) will be used to investigate possible correlations between the original mineral (uranium ore) and the intermediate product (yellow cake). Such correlations are useful indicators for nuclear forensic or for non-proliferation purposes. (orig.)

  6. Nuclear forensic analysis of an unknown uranium ore concentrate sample seized in a criminal investigation in Australia.

    Science.gov (United States)

    Keegan, Elizabeth; Kristo, Michael J; Colella, Michael; Robel, Martin; Williams, Ross; Lindvall, Rachel; Eppich, Gary; Roberts, Sarah; Borg, Lars; Gaffney, Amy; Plaue, Jonathan; Wong, Henri; Davis, Joel; Loi, Elaine; Reinhard, Mark; Hutcheon, Ian

    2014-07-01

    Early in 2009, a state policing agency raided a clandestine drug laboratory in a suburb of a major city in Australia. During the search of the laboratory, a small glass jar labelled "Gamma Source" and containing a green powder was discovered. The powder was radioactive. This paper documents the detailed nuclear forensic analysis undertaken to characterise and identify the material and determine its provenance. Isotopic and impurity content, phase composition, microstructure and other characteristics were measured on the seized sample, and the results were compared with similar material obtained from the suspected source (ore and ore concentrate material). While an extensive range of parameters were measured, the key 'nuclear forensic signatures' used to identify the material were the U isotopic composition, Pb and Sr isotope ratios, and the rare earth element pattern. These measurements, in combination with statistical analysis of the elemental and isotopic content of the material against a database of uranium ore concentrates sourced from mines located worldwide, led to the conclusion that the seized material (a uranium ore concentrate of natural isotopic abundance) most likely originated from Mary Kathleen, a former Australian uranium mine.

  7. 铀矿大型矿集区与成矿作用%Large ore-concentrated area of uranium deposits and uranium metellogeny

    Institute of Scientific and Technical Information of China (English)

    仉宝聚

    2001-01-01

    The formation of large ore-concentated are results from the anomalous concentration of multi-mineral resources and large amount of ore materials during the process of geologic evolution history. Different ore-concentrated areas are characterized by different typical mineral resources and typical ore deposits. This paper, taking uranium deposit as on example, recognizes 14 large ore-concentrated areas of uranium deposit in the world, and studies the time-space constraints of large ore-concentrated areas of uranium deposits and their relation with geodynamic evolution, and on the above basis, discusses the unusual concentration of ore elements in large ore-concentrated areas of uranium deposits, as well as proposes the characteristics of “unusual concentration in certain points and areas” and “explosion metallogeny in a short period of time” of multiple mineral resources. According to the three basic “links”, i.e. “source, transportation and precipitation”, this paper proposes the metallogeny of large ore-concentrated areas of uranium deposits. Of them, the study on the deep-source metallogeny, water-rock intereaction of special alkaline fluid and precipitation environment has made a fundation for the establishment of prospecting model of large uranium ore-concentration arcas.%大型矿集区的形成,是在地质历史演化进程中,多矿种大矿量超常聚集的结果。不同的矿集区有不同的典型矿种和典型矿床。本文仅以铀矿为例,在世界范围内厘定出14个铀矿大型矿集区。本文研究铀矿大型矿集区时空分布规律与地球动力学演化的关系,在此基础上探讨了铀矿大型矿集区元素超常聚集规律,提出多矿种“点区超常聚集”和“短时限爆发成矿”特征。本文按照“源、运、积”3个环节,探讨铀矿大型矿集区的成矿作用,其中有关深源成矿、特殊碱质流体的水岩反应以及元素淀积环境的研究,为建立铀

  8. Multivariate approach to the chemical mapping of uranium in sandstone-hosted uranium ores analyzed using double pulse Laser-Induced Breakdown Spectroscopy

    Science.gov (United States)

    Klus, Jakub; Mikysek, Petr; Prochazka, David; Pořízka, Pavel; Prochazková, Petra; Novotný, Jan; Trojek, Tomáš; Novotný, Karel; Slobodník, Marek; Kaiser, Jozef

    2016-09-01

    The goal of this work is to provide high resolution mapping of uranium in sandstone-hosted uranium ores using Laser-Induced Breakdown Spectroscopy (LIBS) technique. In order to obtain chemical image with highest possible spatial resolution, LIBS system in orthogonal double pulse (DP LIBS) arrangement was employed. Owing to this experimental arrangement the spot size of 50 μm in diameter resulting in lateral resolution of 100 μm was reached. Despite the increase in signal intensity in DP LIBS modification, the detection of uranium is challenging. The main cause is the high density of uranium spectral lines, which together with broadening of LIBS spectral lines overreaches the resolution of commonly used spectrometers. It results in increased overall background radiation with only few distinguishable uranium lines. Three different approaches in the LIBS data treatment for the uranium detection were utilized: i) spectral line intensity, ii) region of apparent background and iii) multivariate data analysis. By utilizing multivariate statistical methods, a specific specimen features (in our case uranium content) were revealed by processing complete spectral information obtained from broadband echelle spectrograph. Our results are in a good agreement with conventional approaches such as line fitting and show new possibilities of processing spectral data in mapping. As a reference technique to LIBS was employed X-ray Fluorescence (XRF). The XRF chemical images used in this paper have lower resolution (approximately 1-2 mm per image point), nevertheless the elemental distribution is apparent and corresponds to presented LIBS experiments.

  9. Assessment of (222)Rn emanation from ore body and backfill tailings in low-grade underground uranium mine.

    Science.gov (United States)

    Mishra, Devi Prasad; Sahu, Patitapaban; Panigrahi, Durga Charan; Jha, Vivekanand; Patnaik, R Lokeswara

    2014-02-01

    This paper presents a comparative study of (222)Rn emanation from the ore and backfill tailings in an underground uranium mine located at Jaduguda, India. The effects of surface area, porosity, (226)Ra and moisture contents on (222)Rn emanation rate were examined. The study revealed that the bulk porosity of backfill tailings is more than two orders of magnitude than that of the ore. The geometric mean radon emanation rates from the ore body and backfill tailings were found to be 10.01 × 10(-3) and 1.03 Bq m(-2) s(-1), respectively. Significant positive linear correlations between (222)Rn emanation rate and the (226)Ra content of ore and tailings were observed. For normalised (226)Ra content, the (222)Rn emanation rate from tailings was found to be 283 times higher than the ore due to higher bulk porosity and surface area. The relative radon emanation from the tailings with moisture fraction of 0.14 was found to be 2.4 times higher than the oven-dried tailings. The study suggested that the mill tailings used as a backfill material significantly contributes to radon emanation as compared to the ore body itself and the (226)Ra content and bulk porosity are the dominant factors for radon emanation into the mine atmosphere.

  10. Detailed mineral and chemical relations in two uranium-vanadium ores

    Science.gov (United States)

    Garrels, Robert M.; Larsen, E. S.; Pommer, A.M.; Coleman, R.G.

    1956-01-01

    Channel samples from two mines on the Colorado Plateau have been studied in detail both mineralogically and chemically. A channel sample from the Mineral Joe No. 1 mine, Montrose County, Colo., extends from unmineralized rock on one side, through a zone of variable mineralization, into only weakly mineralized rock. The unmineralized rock is a fairly clean quartz sand cemented with gypsum and contains only minor amounts of clay minerals. One boundary between unmineralized and mineralized rock is quite sharo and is nearly at right angles to the bedding. Vanadium clay minerals, chiefly mixed layered mica-montmorillonite and chlorite-monmorillonite, are abundant throughout the mineralized zone. Except in the dark "eye" of the channel sample, the vanadium clay minerals are accompanied by hewettite, carnotite, tyuyamunite, and probably unidentified vanadates. In the dark "eye," paramontroseite, pyrite, and marcasite are abundant, and bordered on each side by a zone containing abundant corvusite. No recognizable uranium minerals were seen in the paramontroseite zone although uranium is abundant there. Coaly material is recognizable throughout all of the channel but is most abundant in and near the dark "eye." Detailed chemical studies show a general increase in Fe, Al, U, and V, and a decrease in SO4 toward the "eye" of the channel. Reducing capacity studies indicate that V(IV) and Fe(II) are present in the clay mineral throughout the channel, but only in and near the "eye" are other V(IV) minerals present (paramontroseite and corvusite). The uranium is sexivalent, although its state of combination is conjectural where it is associated with paramontroseite. Where the ore boundary is sharp, the boundary of introduced trace elements is equally sharp. Textural and chemical relations leave no doubt that the "eye: is a partially oxidized remnant of a former lower-valence ore, and the remainder of the channel is a much more fully oxidized remnant. A channel sample from the

  11. Gamma-ray spectrometer measurement of 238U/235U in uranium ore from a natural reactor at Oklo, Gabon

    Science.gov (United States)

    Moxham, Robert M.

    1976-01-01

    About 20 years ago, Kuroda theorized that a high-grade uranium deposit emplaced about 2x109 years ago could achieve criticality and sustain a nuclear chain reaction, given a sufficient thickness of high-grade ore and an appropriate water content. Such a natural reactor was found in 1972 at the Oklo deposit, Gabon. The ore contains as much as 60 percent uranium, but the isotopic abundance of 235U is as little as 0.4 percent in contrast to the normal abundance of 0.7110 percent 235U. A sample from the Oklo deposit containing about 0.51 atom percent 235U (by mass spectrometer) was analyzed by a gamma-ray spectrometer system, using a high-purity planar germanium detector. The 235U was determined from its daughter's (234Th) 63.3 keV photopeak; the 235U was determined from its 143.8 and 163.4 keV photopeaks. The ratios of these photopeaks were compared with that from a standard having normal uranium isotopic content; the resulting calculations give a 235U abundance of 0.54 atom percent in the Oklo sample. The gamma-ray spectrum also contains lines from five other isotopes in the uranium series, which indicate the Oklo sample to be at or near secular equilibrium, as the time elapsed since the nuclear reaction ended was sufficient to permit the daughters to achieve equilibrium.

  12. Origin of gray-green sandstone in ore bed of sandstone type uranium deposit in north Ordos Basin

    Institute of Scientific and Technical Information of China (English)

    2007-01-01

    Dongsheng sandstone-type uranium deposit is located in the northern part of Ordos Basin, occurring in the transitional zones between gray-green and gray sandstones of Jurassic Zhiluo Formation. Sandstones in oxidized zone of the ore bed look gray-green, being of unique signature and different from one of ordinary inter-layered oxidation zone of sandstone-type uranium deposits. The character and origin of gray-green sandstones are systematically studied through their petrology, mineralogy and geochemistry. It is pointed out that this color of sandstones is originated from secondary oil-gas reduction processes after paleo-oxidation, being due to acicular-leaf chlorite covering surfaces of the sandstone grains. To find out the origin of gray-green sandstone and recognize paleo-oxidation zones in the ore bed are of not only theoretical significance for understanding metallogenesis of this kind of sandstone-type uranium deposit, but also very importantly practical significance for prospecting for similar kind of sandstone-type uranium deposit.

  13. 660铀矿田成矿地质特征及成矿预测%Geological characteristics and metallogenic prediction of No.660 uranium ore field

    Institute of Scientific and Technical Information of China (English)

    雷遥鸣

    2012-01-01

    火山岩型铀矿在我国铀矿资源中占有较大份额.660铀矿田是一个典型的火山岩型铀矿聚集区,对该区已发现的矿床、矿点以及成矿异常点(带)的地质特征进行研究分析,找出其矿化特征、矿体分布规律,总结出其控矿因素、成矿规律及成矿地质作用,并根据其成矿地质特征和找矿标志等,提出660铀矿田新一轮找矿预测区和方向.%Volcanic-type uranium deposits account for a large share in uranium ore resources of China. No. 660 uranium ore field is the metallogenie area of typical volcanic-type uranium deposits. The geo- logical features of discovered deposits, occurrences and metallogenic outliers (belt) in the region are studied in order to identify the mineralization characteristics and ore body distribution, and sum up its ore-controlling factors, regularities and geological roles of mineralization. According to its geological characteristics and mineralization abnormalities, a new target and direction of prospecting in No. 660 uranium ore field are pointed out.

  14. Radon and radioactivity at a town overlying Uranium ores in northern Greece.

    Science.gov (United States)

    Kourtidis, K; Georgoulias, A K; Vlahopoulou, M; Tsirliganis, N; Kastelis, N; Ouzounis, K; Kazakis, N

    2015-12-01

    Extensive measurements of (222)Rn in the town of Xanthi in N Greece show that the part of the town overlying granite deposits and the outcrop of a uranium ore has exceptionally high indoor radon levels, with monthly means up to 1500 Bq m(-3). A large number of houses (40%) in this part of the town exhibit radon levels above 200 Bq m(-3) while 11% of the houses had radon levels above 400 Bq m(-3). Substantial interannual variability as well as the highest in Europe winter/summer ratios (up to 12) were observed in this part of the town, which consist of traditional stone masonry buildings of the late 19th-early 20th century. Measurements of (238)U and (232)Th content of building materials from these houses as well as radionuclide measurements in different floors show that the high levels of indoor radon measured in these buildings are not due to high radon emanation rates from the building materials themselves but rather due to high radon flux from the soil because of the underlying geology, high radon penetration rates into the buildings from underground due to the lack of solid concrete foundations in these buildings, or a combination thereof. From the meteorological variables studied, highest correlation with indoor (222)Rn was found with temperature (r(2) = 0.65). An indoor radon prognostic regression model using temperature, pressure and precipitation as input was developed, that reproduced indoor radon with r(2) = 0.69. Hence, meteorology is the main driving factor of indoor radon, with temperature being the most important determinant. Preliminary flux measurements indicate that the soil-atmosphere (222)Rn flux should be in the range 150-250 Bq m(-2) h(-1), which is in the upper 10% of flux values for Europe.

  15. Technical Report on the Behavior of Trace Elements, Stable Isotopes, and Radiogenic Isotopes During the Processing of Uranium Ore to Uranium Ore Concentrate

    Energy Technology Data Exchange (ETDEWEB)

    Marks, N. E. [Lawrence Livermore National Lab. (LLNL), Livermore, CA (United States); Borg, L. E. [Lawrence Livermore National Lab. (LLNL), Livermore, CA (United States); Eppich, G. R. [Lawrence Livermore National Lab. (LLNL), Livermore, CA (United States); Gaffney, A. M. [Lawrence Livermore National Lab. (LLNL), Livermore, CA (United States); Genneti, V. G. [Lawrence Livermore National Lab. (LLNL), Livermore, CA (United States); Hutcheon, I. D. [Lawrence Livermore National Lab. (LLNL), Livermore, CA (United States); Kristo, M. J. [Lawrence Livermore National Lab. (LLNL), Livermore, CA (United States); Lindvall, R. E. [Lawrence Livermore National Lab. (LLNL), Livermore, CA (United States); Ramon, C. [Lawrence Livermore National Lab. (LLNL), Livermore, CA (United States); Robel, M. [Lawrence Livermore National Lab. (LLNL), Livermore, CA (United States); Roberts, S. K. [Lawrence Livermore National Lab. (LLNL), Livermore, CA (United States); Schorzman, K. C. [Lawrence Livermore National Lab. (LLNL), Livermore, CA (United States); Sharp, M. A. [Lawrence Livermore National Lab. (LLNL), Livermore, CA (United States); Singleton, M. J. [Lawrence Livermore National Lab. (LLNL), Livermore, CA (United States); Williams, R. W. [Lawrence Livermore National Lab. (LLNL), Livermore, CA (United States)

    2015-07-09

    The goals of this SP-1 effort were to understand how isotopic and elemental signatures behave during mining, milling, and concentration and to identify analytes that might preserve geologic signatures of the protolith ores. The impurities that are preserved through the concentration process could provide useful forensic signatures and perhaps prove diagnostic of sample origin.

  16. The uranium ore deposits in Ciudad Rodrigo Phyllites. about the possibility of new deposits; Los yacimientos uraniferos en las pizarras paleozoicas de Ciudad Rodrigo. sobre la posible existencia de nuevas mineralizaciones

    Energy Technology Data Exchange (ETDEWEB)

    Mingarro Martin, E.; Marin Benavente, C.

    1969-07-01

    The main features of the genesis of uranium deposits of the Fe mine type, are discussed in this paper. Pitchblende ore is related with phyllites bearing organic material and with geomorphological level, fossilized by eocene sediments. As a result, new uranium ore deposits are possible under Ciudad Rodrigo tertiary basin, tertiary cover depth being little more than three hundred feet. (Author)

  17. Geochemical evidence for contribution of ore-forming materials from peraluminous granite basement-- Taking Fucheng pluton and No. 6722 uranium deposit in southern Jiangxi Province as examples

    Institute of Scientific and Technical Information of China (English)

    ZHANG; Bangtong(章邦桐); CHEN; Peirong(陈培荣); YANG; Dongsheng(杨东生); KONG; Xinggong(孔兴功)

    2003-01-01

    Using the induced fission-track method, mobile uranium leaching and lead isotope analysis, this work obtianed geochemical features of the peraluminous Fucheng granite basement and the host rock (shoshonite) of the No. 6722 uranium deposit in southern Jiangxi Province. (i) Uranium contents of the leucocratic rock-forming minerals (0.18 ?g/g for quartz, 0.36 ?g/g for feldspar) are lower than the uranium content of the whole rock (4.6 ?g/g). Biotite and some accessory mineral inclusions (zircon, monazite and uraninite) are the main uranium carriers of the Fucheng granite pluton. The fissure uranium in altered minerals (hydromica and chlorite) increased evidently. (ii) Leachable rate of mobile uranium in the biotite granite is 10.4%, while that in the altered granite increased to 31%. (iii) Caculation based on lead isotopes shows that during alteration the Fucheng granite lost uranium (?U = ?37% - ?65%), whereas the Caotaobei shoshonite gained uranium (?U = +37%- +58%). These features suggest that the ore-forming material of the No. 6722 uranium deposit was mainly derived from the altered peraluminous granite basement of Fucheng pluton.

  18. Uranium determination in the red blood cells of workers engaged in the chemical treatment of uranium ore

    Energy Technology Data Exchange (ETDEWEB)

    Nosek, J.; Simkova, M.; Kukula, F.; Musil, K.

    1973-10-01

    Using the neutron activation analysis method, the uranium levels were determined in red blood cells of venous blood samples from persons occupationally exposed to this metal in chemical processing plants using wet methods (6.5+-2.1ppb U) or dry methods (37.2+-20.2ppb U), and of controls (4.1+-2.6ppb U).

  19. Genesis and formation conditions of deposits in the unique Strel'tsovka Molybdenum-Uranium ore field: New mineralogical, geochemical, and physicochemical evidence

    Science.gov (United States)

    Aleshin, A. P.; Velichkin, V. I.; Krylova, T. L.

    2007-10-01

    The ambiguity of genetic interpretations of uranium ore formation at Mo-U deposits of the Strel’tsovka ore field led us to perform additional geochemical, mineralogical, and thermobarogeochemical studies. As a result, it has been established that closely related U and F were progressively gained in the Late Mesozoic volcanic rocks from the older basic volcanics (170 Ma) to the younger silicic igneous rocks (140 Ma). The Early Cretaceous postmagmatic hydrothermal epoch (140-125 Ma) is subdivided into preore, uranium ore, and first and second postore stages. The primary brannerite-pitchblende ore was formed in association with fluorite. At the first postore stage, this assemblage was replaced by a U-Si metagel, which was previously identified as coffinite. The metagel shows a wide compositional variation; its fine structure has been studied. The preore metasomatic alteration and related veined mineralization were formed under the effect of sodium (bicarbonate)-chloride solution at a temperature of 250-200°C. The uranium ore formation began with albitization and hematitization of rocks affected by supercritical fluid at 530-500°C; brannerite and pitchblende precipitated at 350-300°C. The chondrite-normalized REE patterns of pitchblende hosted in trachybasalt, trachydacite, and granite demonstrate a pronounced Sm-Nd discontinuity and a statistically significant tetrad effect of W type. These attributes were not established in REE patterns of rhyolites derived from the upper crustal magma chamber. This circumstance and a chronological gap of 5 Ma between silicic volcanism and ore formation do not allow us to suggest that uranium was derived from this magma chamber. According to the proposed model, the evolved silicic Li-F magma was a source of uranium. U4+, together with REE, was fractionated into the fluid phase as complex fluoride compounds. The uranium mineralization was deposited at a temperature barrier. It is suggested that hydromica alteration and the

  20. Molecular marker and stable carbon isotope analyses of carbonaceous Ambassador uranium ores of Mulga Rock in Western Australia

    Science.gov (United States)

    Jaraula, C.; Schwark, L.; Moreau, X.; Grice, K.; Bagas, L.

    2013-12-01

    Mulga Rock is a multi-element deposit containing uranium hosted by Eocene peats and lignites deposited in inset valleys incised into Permian rocks of the Gunbarrel Basin and Precambrian rocks of the Yilgarn Craton and Albany-Fraser Orogen. Uranium readily adsorbs onto minerals or phytoclasts to form organo-uranyl complexes. This is important in pre-concentrating uranium in this relatively young ore deposit with rare uraninite [UO2] and coffinite [U(SiO4)1-x(OH)4x], more commonly amorphous and sub-micron uranium-bearing particulates. Organic geochemical and compound-specific stable carbon isotope analyses were conducted to identify possible associations of molecular markers with uranium accumulation and to recognize effect(s) of ionizing radiation on molecular markers. Samples were collected from the Ambassador deposit containing low (2000 ppm) uranium concentrations. The bulk rock C/N ratios of 82 to 153, Rock-Eval pyrolysis yields of 316 to 577 mg hydrocarbon/g TOC (Hydrogen Index, HI) and 70 to 102 mg CO2/g TOC (Oxygen Index, OI) are consistent with a terrigenous and predominantly vascular plant OM source deposited in a complex shallow water system, ranging from lacustrine to deltaic, swampy wetland and even shallow lake settings as proposed by previous workers. Organic solvent extracts were separated into saturated hydrocarbon, aromatic hydrocarbon, ketone, and a combined free fatty acid and alcohol fraction. The molecular profiles appear to vary with uranium concentration. In samples with relatively low uranium concentrations, long-chain n-alkanes, alcohols and fatty acids derived from epicuticular plant waxes dominate. The n-alkane distributions (C27 to C31) reveal an odd/even preference (Carbon Preference Index, CPI=1.5) indicative of extant lipids. Average δ13C of -27 to -29 ‰ for long-chain n-alkanes is consistent with a predominant C3 plant source. Samples with relatively higher uranium concentrations contain mostly intermediate-length n

  1. (234)U/(238)U signatures associated with uranium ore bodies: part 3 Koongarra.

    Science.gov (United States)

    Lowson, Richard T

    2013-04-01

    The Koongarra ore body is an early Proterozoic U ore body in the Alligator Rivers U province, Northern Territory, Australia. It has surface expression with a redox front located ∼30 m below the surface. The (234)U/(238)U activity ratios (AR) for the ground water and the amorphous phase of the solid have been analysed for the ore zone and dispersion halo as a function of depth. The results display a (234)U/(238)U AR signature with depth which may be common to all U ore bodies. The (234)U/(238)U AR is depressed below secular equilibrium in the weathered material above the redox front; rises significantly above secular equilibrium in the vicinity of the redox front; and is followed by a gradual decrease with depth below the redox front. The amplitude of the profile is a function of local conditions. A model is proposed for the signature in which oxidising waters preferentially leach the (234)U sites at the redox front due to preconditioning of the (234)U sites by α recoil during the decay of (23)(8)U to (23)(4)U. Mass balance requires the solid material left behind the redox front to have a (234)U/(238)U AR reduced below 1. Local second order effects may be superimposed on the signature. The signature may have application to calibrating scenarios for nuclear waste repositories, assisting in understanding historical climates, economic evaluation of U ore bodies and U exploration.

  2. (234)U/(238)U signatures associated with uranium ore bodies: part 2 Manyingee.

    Science.gov (United States)

    Lowson, Richard T; McIntyre, Mark G

    2013-04-01

    The Manyingee ore body is a roll-front U ore body located at depth in the Cretaceous sandstone sediments of a Proterozoic palaeo valley. It is located in a confined aquifer. The aquifer is recharged 4 km upstream by the Ashburton River. Groundwater samples were collected at and up to 4.7 km downstream of the ore body. The ground water (234)U/(238)U activity ratios (AR) were elevated to 1.86 in the vicinity of the ore body and then declined to 1.06 over the 4.7 km transect. The elevated (234)U/(238)U ARs are attributed to selective leaching of (234)U sites by oxidising waters, with α recoil as a necessary precursor to produce activated (234)U sites. Direct ejection into another phase following α recoil is considered to be a minor contributor to (234)U -(238)U disequilibrium in this environment. The profile is considered to be typical of the (234)U/(238)U AR profile at and down gradient of the redox front of a U ore body.

  3. Chemical treatment of uranium ores in France; Le traitement chimique des minerais d'uranium en France

    Energy Technology Data Exchange (ETDEWEB)

    Mouret, P.; Sartorius, R. [Commissariat a l' Energie Atomique, Saclay (France). Centre d' Etudes Nucleaires

    1958-07-01

    The various processes of chemical treatmenturanium ores, from the oldest to the more recent, are exposed, considering the following conditions: economics, geography, techniques and safety. The interest of obtaining a final concentrate as uranyl nitrate is discussed. (author)Fren. [French] Les differents procedes de traitement chimique des minerais uraniferes sont exposes depuis les premiers jusqu'aux plus recents, en tenant compte des facteurs economiques, geographiques, techniques et de salubrite. L'interet d'obtenir un concentre final a l'etat de nitrate d'uranyle est discute. (auteur)

  4. Disposal of residue from uranium ore processing in France; Les stockages de residus de traitement de minerais d'uranium en France

    Energy Technology Data Exchange (ETDEWEB)

    Crochon, Ph. [AREVA NC, Business Group Mines, Dir. de la responsabilite environnementale et societale, 75 -Paris (France)

    2011-02-15

    Between 1949 and 2001, French mines produced 76, 000 metric tons of uranium and 50 million metric tons of ore, processing residues are stored at 17 sites (in ponds enclosed by dykes or in former open-cast mines) subject to ICPE (classified facility for environment protection) regulation. These disposal sites cover surface areas of between one and several tens of hectares and several thousands to several millions of metric tons of waste are stored at them. When uranium mining stopped in France, these sites were redeveloped, with caps placed over the residue to provide mechanical and radiological protection. All these sites are still monitored by AREVA. In the last fifteen years, these sites have been the subject of a number of studies, especially regarding the long-term evolution and impact of the residue. These studies are now being pursued within the framework of the national plan for the management of nuclear materials and waste (PNGMDR). A regulatory and institutional framework regarding long-term management of these disposal sites needs to be defined. (author)

  5. (234)U/(238)U signatures associated with uranium ore bodies: part 1 Ranger 3.

    Science.gov (United States)

    Lowson, Richard T; McIntyre, Mark G

    2013-04-01

    The Ranger 3 ore body is an early Proterozoic U ore body in the Alligator Rivers U province, Northern Territory, Australia. It has surface expression with a redox front located between 30 and 50 m below the surface. The ground water U concentration and (234)U/(238)U AR signature in the top 10 m of the weathered zone are reported for 357 samples collected over 4 wet seasons, at 5 depths, along a transect in-line with the hydraulic gradient and along the centre line of the ore body and its associated dispersion halo. The results show that the weathered zone displays a general U isotope feature for this type of ore body with the (234)U/(238)U AR for the ground water and amorphous phase of the solid matrix being less than 1. The ground water (234)U/(238)U AR is independent of the annual monsoonal climate and depth within the range surface to 10 m. In the vicinity of the U ore body the ground water (234)U/(238)U AR is 0.75 and is very similar to the (234)U/(238)U AR of the amorphous phase of the solid (0.76). The (234)U/(238)U ARs of the amorphous phase and ground water rise and separate to values of 0.88 and 1.02 at the end of the transect. The rise and separation in (234)U/(238)U AR are interpreted as evidence that the source of the U in the ground water is from the water-soluble sub-phase of the amorphous phase and that the ground water flow is too fast to allow the processes occurring across the solid-water interface to reach chemical equilibrium. The data set is a robust characterisation of the coarse and fine detail of the (234)U/(238)U AR signature in the weathered zone of U ore bodies.

  6. Uptake of uranyl ions from uranium ores and sludges by means of Spirulina platensis, Porphyridium cruentum and Nostok linckia alga.

    Science.gov (United States)

    Cecal, Alexandru; Humelnicu, Doina; Rudic, Valeriu; Cepoi, Liliana; Ganju, Dumitru; Cojocari, Angela

    2012-08-01

    In this paper was studied the uranyl ions biosorption on three types of alga: Nostok linckia, Porphyridium cruentum and Spirulina platensis. These ions were supplied either from a pure solution of uranyl nitrate, or after leaching process of uranium ore, or from the sludge resulting in the output of pure UO(2) technology. It was investigated the retention degree versus contact time and afterwards the Langmuir and Freundlich biosorption isotherms of uranyl ions on the three alga types. The retention of UO(2)(2+) ions on alga was proved through FTIR spectra plotted before and after biosorption processes. From the experimental data it was found that regardless of origin of uranyl ions, the retention degree on alga decreased in the series. Spirulina platensis > Porphyridium cruentum ≥ Nostok linckia.

  7. Effects of barium chlorine treatment of uranium ore on /sup 222/Rn emanation and /sup 226/Ra leachability from mill tailings

    Energy Technology Data Exchange (ETDEWEB)

    Ibrahim, S.A.; Church, S.L.; Whicker, F.W.

    1985-01-01

    The purpose of this laboratory study was to investigate the effectiveness of barium chloride treatment of uranium ore on /sup 222/Rn emanation from mill tailings, /sup 226/Ra level in waste-water, and the leachability of radium from tailings. It has been shown that barium sulfate is an excellent carrier for radium and that barium sulfate crystals have high retention capacity for radon gas produced by radium trapped within the lattice. Ground uranium ore from a mine in Wyoming was mixed with water to form a 1:1 ratio before barium and potassium chlorides were added at concentrations of 0, 10, 25, 50, and 100 mg per liter of slurry. The ore was then subjected to a simulated mill process using sulfuric acid leaching. The liquid representing tailings pond water was separated and analyzed for /sup 226/Ra and the solid fraction, representing mill tailings, was tested for radon emanation and the leachability of radium by deionized water. This study suggests that barium treatment of uranium ore prior to sulfuric acid leaching could be effective in reducing radon emanation from tailings and also in reducing the /sup 226/Ra concentration of waste-water. Leachability of radium from treated tailings was markedly reduced.

  8. X-Ray Fluorescence Spectrometry. II Determination of Uranium in ores; Espectrometria de fluorescencia de Rayos X. II-Aplicacion a la determinacion de uranio en minerales

    Energy Technology Data Exchange (ETDEWEB)

    Bermudez Polonio, J.; Crus Castillo, F. de la; Fernandez Cellini, R.

    1961-07-01

    A method of analysis of uranium in ores by X-ray spectrometry was developed, using the internal standard technique. Strontium was found to be the most suitable internal standard for general use. A Norelco Philips X-ray fluorescent spectrometer was used in this work, equipped with a lithium fluoride crystal acting as a diffraction grating analyzer. The intensity of the uranium-L {alpha}{sub 1} spectral line is calculated and related to corresponding strontium-K{sub {alpha}} spectral line, both detected with a Scintillation Counter. (Author) 31 refs.

  9. Study of Character and Trace of REE in Xiangshan Uranium Ore Field%相山铀矿田稀土元素地球化学特征及示踪研究

    Institute of Scientific and Technical Information of China (English)

    廖宇华

    2000-01-01

    Xiangshan Uranium ore fieled is a famous Volcanic type hydrothermal uranium ore field. The author studysgeochemical character of samples of REE of 4 reprentive uranium ores,of which are ore-host rock, uranium mine andpitchblende. This paper discusses material resource of rock-forming ore-forming, unveilings REE of uranium ore andmineralization of uranium of two difference geochemical types of mine,bring out relation of direct ratio, especialy urani-um and heavy REE in rich mine ore, which come from inner oviginal fluid and bring ont Co-precipitation. The strongeruranium-hydrothermal differntiation evolution is, the richer minerarli zation of uranium is.%相山铀矿田是我国著名的火山岩型热液铀矿田。作者对矿田4个有代表性的铀矿床的赋矿主岩、铀矿石、沥青铀矿样品稀土元素地球化学特征进行了研究,探讨了其成岩、成矿的物质来源,揭示了两种不同地球化学类型铀矿床的稀土元素与铀矿化呈正消长关系,尤其是富矿床中铀与重稀土元素,主要来自深部原生流体,并呈现出共沉淀的特点,含铀热液分异演化愈强,则铀矿化愈富。

  10. 从某铀矿石硫酸浸出液中回收铀、铜试验研究%Experiment Research on Recovery of Uranium and Copper From Leaching Solution of Uranium Ore With Sulfuric Acid

    Institute of Scientific and Technical Information of China (English)

    刘辉; 周根茂; 孟运生; 郑英; 师留印; 程浩

    2013-01-01

      某铀矿石硫酸浸出液中含有铀和铜,研究了从中综合回收铀和铜。试验结果表明:采用201×7树脂吸附铀,用酸性氯化钠溶液淋洗负载树脂,然后用氢氧化钠溶液从淋洗液中沉淀铀,铀回收率为98.4%;对铀的吸附尾液,采用循环铁粉置换法回收铜,铜回收率为90%。采用该方法可实现铀、铜的综合回收。%Recovery of uranium and copper from sulfuric acid leaching solution of a uranium ore has been studied .The results showed that uranium recovery was 98 .4% by adsorption uranium using 201 × 7 resin from the leaching solution ,and desorption uranium using acidic sodium chloride solution from loaded resin ,then precipitating uranium from the stripping liquid .The copper in the adsorption tail liquid was be replaced using iron powder ,recovery of copper was 90% .Comprehensive recovery of uranium and copper can be realized by the method .

  11. Determination of elemental impurities and U and O isotopic compositions with a view to identify the geographical and industrial origins of uranium ore concentrates

    Science.gov (United States)

    Salaun, A.; Hubert, A.; Pointurier, F.; Aupiais, J.; Pili, E.; Richon, P.; Fauré, A.; Diallo, S.

    2012-12-01

    First events of illicit trafficking of nuclear and radiological materials occurred 50 years ago. Nuclear forensics expertise are aiming at determining the use of seized material, its industrial history and provenance (geographical area, place of production or processing), at assisting in the identification and dismantling of illicit trafficking networks. This information is also valuable in the context of inspections of declared facilities to verify the consistency of operator's declaration. Several characteristics can be used to determine the origin of uranium ore concentrates such as trace elemental impurity patterns (Keegan et al., 2008 ; Varga et al., 2010a, 2010b) or uranium, oxygen and lead isotopic compositions (Tamborini et al., 2002a, 2002b ; Wallenius et al., 2006; Varga et al., 2009). We developed analytical procedures for measuring the isotopic compositions of uranium (234U/238U and 235U/238U) and oxygen (18O/16O) and levels of elemental impurities (e.g. REE, Th) from very small amounts of uranium ore concentrates (or yellow cakes). Micrometer particles and few milligrams of material are used for oxygen isotope measurements and REE determination, respectively. Reference materials were analyzed by mass spectrometry (TIMS, SF-ICP-MS and SIMS) to validate testing protocols. Finally, materials of unknown origin were analyzed to highlight significant differences and determine whether these differences allow identifying the origin of these ore concentrates. References: Keegan, E., et al. (2008). Applied Geochemistry 23, 765-777. Tamborini, G., et al. (2002a). Analytical Chemistry 74, 6098-6101. Tamborini, G., et al. (2002b). Microchimica Acta 139, 185-188. Varga, Z., et al. (2009). Analytical Chemistry 81, 8327-8334. Varga, Z., et al. (2010a). Talanta 80, 1744-1749. Varga, Z., et al. (2010b). Radiochimica Acta 98, 771-778 Wallenius, M., et al. (2006). Forensic Science International 156, 55-62.

  12. Experimental design and optimization of leaching process for recovery of valuable chemical elements (U, La, V, Mo, Yb and Th) from low-grade uranium ore

    Energy Technology Data Exchange (ETDEWEB)

    Zakrzewska-Koltuniewicz, Grażyna, E-mail: g.zakrzewska@ichtj.waw.pl [Institute of Nuclear Chemistry and Technology, Dorodna 16, 03-195 Warsaw (Poland); Herdzik-Koniecko, Irena [Institute of Nuclear Chemistry and Technology, Dorodna 16, 03-195 Warsaw (Poland); Cojocaru, Corneliu [Institute of Macromolecular Chemistry “Petru Poni”, Aleea Grigore Ghica Voda, nr. 41A, 700487 Iasi (Romania); Chajduk, Ewelina [Institute of Nuclear Chemistry and Technology, Dorodna 16, 03-195 Warsaw (Poland)

    2014-06-30

    Highlights: • The experimental design for optimization of leaching process of uranium from low-grade ores was applied. • Multi-objective optimization method based on desirability approach was employed. • The recovery of associated metals like vanadium, molybdenum and lanthanides was considered. • The effects of factors were identified by 3-D surface plots. • The optimum condition for valuable metals: P = 5 bar, T = 120 °C and t = 90 min has been determined. - Abstract: The paper deals with experimental design and optimization of leaching process of uranium and associated metals from low-grade, Polish ores. The chemical elements of interest for extraction from the ore were U, La, V, Mo, Yb and Th. Sulphuric acid has been used as leaching reagent. Based on the design of experiments the second-order regression models have been constructed to approximate the leaching efficiency of elements. The graphical illustrations using 3-D surface plots have been employed in order to identify the main, quadratic and interaction effects of the factors. The multi-objective optimization method based on desirability approach has been applied in this study. The optimum condition have been determined as P = 5 bar, T = 120 °C and t = 90 min. Under these optimal conditions, the overall extraction performance is 81.43% (for U), 64.24% (for La), 98.38% (for V), 43.69% (for Yb) and 76.89% (for Mo) and 97.00% (for Th)

  13. Foreign current situation of radioactive sorting of uranium ores%国外铀矿石放射性分选的现状

    Institute of Scientific and Technical Information of China (English)

    汪淑慧

    2013-01-01

    经放射性分选提高矿石品位后可以降低铀的加工成本,还可以使一些低品位资源得以利用.近年来放射性分选的发展重新受到重视,以俄罗斯于2008年投产的一个大型放射性分选厂为例进行介绍.%The distribution of uranium in the earth's crust is more extensive, but the high-grade uranium deposit is very few. The processing costs of uranium can be reduced and some low-grade resources can be taken advantage of after the ore grade is raised by radioactive sorting. In recent years, the development of radioactive sorting receives attentions again. A large radioactive sorting plant in Russia, which was put into operation in 2008, is introduced,including process flow of ore treatment and technical parameters.

  14. 某铀矿石多桶串联细菌溶浸试验%Bacterial Leaching Experiment on Uranium Ore with Series Connection

    Institute of Scientific and Technical Information of China (English)

    周仲魁; 高峰; 孙占学; 高柏

    2012-01-01

    对某铀矿石进行了多桶串联细菌溶浸试验,分析了串联装置和充气时间对浸出率、酸耗的影响.结果表明,该矿石三桶串联、两桶串联和单桶的铀平均浸出率分别为82.33%、81.42%和83.62%,同一串联工艺中,越靠后的桶的铀浸出率越低,耗酸也越低;另外,充气可以明显加快离子交换速度,提高细菌活性.%The bacterial leaching experiment was carried out for uranium ore under series connection conditions. The effects of series connection equipment and air inflation time on uranium leaching rate and acid consumption were analyzed. The results show that the average uranium leaching rates of three-barrels-series connection, two-barrels-series connection and single-barrel are 82. 33%,81. 42% and 83. 62% respectively. The uranium leaching rate and acid consumption of the barrel rely on the latter are lower. Inflation can accelerate ion exchange speed and improve bacterial activity obviously.

  15. Column Bioleaching of Low-grade Uranium Ore%低品位铀矿石微生物柱浸试验

    Institute of Scientific and Technical Information of China (English)

    李江; 刘亚洁; 周谷春; 车江华

    2012-01-01

    Column bioleaching of a low-grade uranium ore with a variety of spraying methods was carried out. The results show that the mixed culture of acidophilic microorganisms in use have a high adaptation to the uranium minerals, and the average uranium leaching rates are 87. 70% and 88. 53%, the acid consumption is 5.36% and 5.37% within 172 days, at 5% and 10% spraying condition, respectively. A bigger spray liquid quantity could increase uranium leaching rate at the bioleaching stage, however, the ratio of liquid to solid rises greatly as well, which resulted in a rise of cost for uranium recovery. Therefore, the optimum spray liquid quantity should be confirmed with a consideration of both uranium recovery and leaching cost.%对某低品位铀矿石进行了不同喷淋条件的微生物柱浸试验.结果表明,试验用混合菌群对目标铀矿石具有较强适应性,浸出周期172 d,菌浸期间5%和10%喷淋量条件下渣计平均浸出率分别为87.70%和88.53%,耗酸率分别为5.36%和5.37%.菌浸阶段采用较大喷淋量可提高浸出率,但液固比会显著增加,综合成本相应提高.因此,喷淋量的选择应综合考虑铀资源回收率与浸出成本.

  16. Experimental study of leaching parameters on extracting uranium from a uranium ore%从某铀矿石中回收铀的浸出工艺条件试验研究

    Institute of Scientific and Technical Information of China (English)

    邓锦勋; 李建华; 程威; 周磊

    2012-01-01

    根据某矿床铀矿石的化学组成和矿物形式,分别进行酸法、碱法搅拌浸出及酸法柱浸试验,以探索处理该矿石的工艺条件.试验结果表明:在适当条件下,酸法搅拌授出时,铀浸出率达到88.44%;酸法柱浸时,铀浸出率达到87.63%;碱法搅拌浸出时,铀浸出率较低.综合考虑,工业上宜采用酸法堆浸工艺处理该矿石.%Based on the investigation of the mineral form and chemical compositions, the processing method and leaching parameters were selected through acid stirring leaching, alkaline stirring leaching and acid column leaching experiments. Under suitable conditions, the leaching rate of acid stirring leaching can reach 88. 44%, and leaching rate of acid column leaching is 87. 65%. Alkaline stirring leaching is not suitable for the ore for its low leaching rate. In the final analysis acid heap leaching is available for extracting uranium from the uranium ore in the industrial production.

  17. Resources evaluation of layer-shaped volcanic lava-type uranium deposits in Dazhou ore-field,Gan-Hang uranium metallogenic belt%赣杭铀成矿带大洲矿田层状火山熔岩型铀矿资源评价

    Institute of Scientific and Technical Information of China (English)

    毛孟才

    2001-01-01

    本文全面总结了大洲铀矿田成矿地质背景及铀矿特征,分析了溶浸采矿条件,论述了大洲铀矿田溶浸采矿的可行性,并指明应用溶浸采矿技术重新评价赣杭铀成矿带硬岩型铀矿资源的必要性。%According to the technological requirements, using theory ofsolution mining, the author makes a resources evaluation of layer-shaped volcanic lava-type uranium deposits in Dazhou ore-field, Gan-Hang uranium metallogenic belt. This paper comprehensively summarizes the metallogenic geologic background and characteristics of uranium deposits in Dazhou uranium ore-field, analyses the conditions of solution mining and describes the feasibility of solution mining in Dazhou uranium ore-field, then proposes the necessity to reevaluate hard rock uranium resources in Gan-Hang uranium metallognic belt.

  18. Study of the combined effects of smoking and inhalation of uranium ore dust, radon daughters and diesel oil exhaust fumes in hamsters and dogs. Final report

    Energy Technology Data Exchange (ETDEWEB)

    Cross, F.T.; Palmer, R.F.; Filipy, R.E.; Busch, R.H.; Stuart, B.O.

    1978-09-01

    Exposure to particulates from uranium ore dust and diesel exhaust soot provoked inflammatory and proliferative responses in lungs. Also exposure to radon and radon daughters yielded increased occurrences of bronchiolar epithelial hyperplasia and metaplastic changes of alveolar epithelium. The data suggest that this cellular change is also a precursor of premalignant change in hamsters. The authors suggest an animal model other than the hamster based on two observations: (1) the Syrian golden hamster has been shown to be highly refractory to carcinoma induction; and (2) that when exposed to realistic levels of agents in life-span exposure regimens, the hamster does not develop lesions. Dog studies with cigarette smoke exposure showed mitigating effects on radon daughter induced respiratory tract cancer. Two reasons are suggested although no empirical evidence was gathered. A strict comparison of human and animal exposures and interpolative models are not possible at this time. (PCS)

  19. Uranium industry in Canada

    Energy Technology Data Exchange (ETDEWEB)

    1983-01-01

    Current state of uranium industry in Canada has been considered. It is shown that in Canada, which is the major supplier of uranium, new methods of prospecting, mining and processing of uranium are developed and the old ones are improved. Owing to automation and mechanization a higher labour productivity in uranium ore mining is achieved. The uranium industry of Canada can satisfy the future demands in uranium but introduction of any new improvement will depend completely on the rate of nuclear power development.

  20. Experimental design and optimization of leaching process for recovery of valuable chemical elements (U, La, V, Mo, Yb and Th) from low-grade uranium ore.

    Science.gov (United States)

    Zakrzewska-Koltuniewicz, Grażyna; Herdzik-Koniecko, Irena; Cojocaru, Corneliu; Chajduk, Ewelina

    2014-06-30

    The paper deals with experimental design and optimization of leaching process of uranium and associated metals from low-grade, Polish ores. The chemical elements of interest for extraction from the ore were U, La, V, Mo, Yb and Th. Sulphuric acid has been used as leaching reagent. Based on the design of experiments the second-order regression models have been constructed to approximate the leaching efficiency of elements. The graphical illustrations using 3-D surface plots have been employed in order to identify the main, quadratic and interaction effects of the factors. The multi-objective optimization method based on desirability approach has been applied in this study. The optimum condition have been determined as P=5 bar, T=120 °C and t=90 min. Under these optimal conditions, the overall extraction performance is 81.43% (for U), 64.24% (for La), 98.38% (for V), 43.69% (for Yb) and 76.89% (for Mo) and 97.00% (for Th).

  1. Uranium conversion; Urankonvertering

    Energy Technology Data Exchange (ETDEWEB)

    Oliver, Lena; Peterson, Jenny; Wilhelmsen, Katarina [Swedish Defence Research Agency (FOI), Stockholm (Sweden)

    2006-03-15

    FOI, has performed a study on uranium conversion processes that are of importance in the production of different uranium compounds in the nuclear industry. The same conversion processes are of interest both when production of nuclear fuel and production of fissile material for nuclear weapons are considered. Countries that have nuclear weapons ambitions, with the intention to produce highly enriched uranium for weapons purposes, need some degree of uranium conversion capability depending on the uranium feed material available. This report describes the processes that are needed from uranium mining and milling to the different conversion processes for converting uranium ore concentrate to uranium hexafluoride. Uranium hexafluoride is the uranium compound used in most enrichment facilities. The processes needed to produce uranium dioxide for use in nuclear fuel and the processes needed to convert different uranium compounds to uranium metal - the form of uranium that is used in a nuclear weapon - are also presented. The production of uranium ore concentrate from uranium ore is included since uranium ore concentrate is the feed material required for a uranium conversion facility. Both the chemistry and principles or the different uranium conversion processes and the equipment needed in the processes are described. Since most of the equipment that is used in a uranium conversion facility is similar to that used in conventional chemical industry, it is difficult to determine if certain equipment is considered for uranium conversion or not. However, the chemical conversion processes where UF{sub 6} and UF{sub 4} are present require equipment that is made of corrosion resistant material.

  2. Potential impact of former Zn ore extraction activities on dissolved uranium distribution in the Riou-Mort watershed (France).

    Science.gov (United States)

    Saari, Hanna-Kaisa; Schmidt, Sabine; Coynel, Alexandra; Huguet, Stéphanie; Schäfer, Jörg; Blanc, Gérard

    2007-09-01

    The industrial basin of Decazeville (Riou-Mort watershed, South-West France) is well known for its heavy metal pollution and its subsequent environmental effects on the Lot-Garonne River system. The source of this pollution is the Riou-Mort River, which drains smelting waste areas. A first survey after remediation works has revealed elevated dissolved uranium (U(D)) concentrations in the outlet of the Riou-Mort River. The objective of this research is to identify the origin of U(D) in the Riou-Mort watershed and to evaluate the impact of industrial activities on this element. Uranium was measured at 10 water sampling sites, located upstream and downstream the industrial basin, and in three smelting waste deposits. Uranium concentrations in the smelting waste deposits reach up to 14.4 mg kg(-1) and (234U/238U) activity ratios (AR) are near unity. Dissolved U concentrations in the Riou-Mort River and its main tributaries ranges over two orders of magnitude from 0.02 to 6.1 microg L(-1). The highest levels were measured in a site with no anthropogenic pollution, upstream from the industrial area. This observation suggests that U(D) is mainly linked to weathering; the elevated U concentrations originate from the naturally occurring radioactive materials (NORM) located in the Permian bedrock and no significant U pollution exists, at present, in the Riou-Mort watershed. This work demonstrates that spatial monitoring coupled with a long time-series are an essential prerequisite in assessment of spatiotemporal variations of U(D), prior to a diagnostic of pollution in a small watershed.

  3. Behaviour of the pH adjustment, Ion exchange and concentrate precipitation stages in the acid leaching of uranium phosphate ores; Tratamiento de disoluciones de lixiviacion de minerales de uranio en presencia de fosfatos. Comportamiento en las etapas de ajuste de PH, cambio de ion y precipitacion de concentrados

    Energy Technology Data Exchange (ETDEWEB)

    Estrada Aguilar, J.; Uriarte Hueda, A.

    1962-07-01

    The uranium recovery from acid leach solutions of uranium-phosphate ores has been studied. Relations have been found between the solution characteristics and the results obtained at different stages of the process. The following data can thus be predicted: solids to remove and uranium recovery in the pH adjustment stage, uranium capacity of the resin, more suitable eluating agent, elution velocity and uranium concentration in the eluate in the ion exchange stage, and composition of the concentrate produced by direct precipitation of the eluate in the concentrate precipitation stage. (Author) 8 refs.

  4. Application of the angle measure technique as image texture analysis method for the identification of uranium ore concentrate samples: New perspective in nuclear forensics.

    Science.gov (United States)

    Fongaro, Lorenzo; Ho, Doris Mer Lin; Kvaal, Knut; Mayer, Klaus; Rondinella, Vincenzo V

    2016-05-15

    The identification of interdicted nuclear or radioactive materials requires the application of dedicated techniques. In this work, a new approach for characterizing powder of uranium ore concentrates (UOCs) is presented. It is based on image texture analysis and multivariate data modelling. 26 different UOCs samples were evaluated applying the Angle Measure Technique (AMT) algorithm to extract textural features on samples images acquired at 250× and 1000× magnification by Scanning Electron Microscope (SEM). At both magnifications, this method proved effective to classify the different types of UOC powder based on the surface characteristics that depend on particle size, homogeneity, and graininess and are related to the composition and processes used in the production facilities. Using the outcome data from the application of the AMT algorithm, the total explained variance was higher than 90% with Principal Component Analysis (PCA), while partial least square discriminant analysis (PLS-DA) applied only on the 14 black colour UOCs powder samples, allowed their classification only on the basis of their surface texture features (sensitivity>0.6; specificity>0.6). This preliminary study shows that this method was able to distinguish samples with similar composition, but obtained from different facilities. The mean angle spectral data obtained by the image texture analysis using the AMT algorithm can be considered as a specific fingerprint or signature of UOCs and could be used for nuclear forensic investigation.

  5. 某低品位含钼钒碳质页岩型铀矿石浸出工艺研究%Study on the uranium and molybdenum and vanadium extraction technology for a low grade carbonaceous shale type uranium ore

    Institute of Scientific and Technical Information of China (English)

    周根茂; 曾毅君; 武翠莲; 贾秀敏; 王亮; 孟舒

    2012-01-01

    The processing technologies for extracting uranium and molybdenum and vanadium from a carbonaceous shale type uranium ore which contains vanadium and molybdenum were studied. The research results show that the ore is a polymetal associated uranium ore difficult to leaching. Uranium and molybdenum and vanadium in the ore were not synchronously extracted by H2SO4 or Na2CO3 leaching directly. With high-pressure leaching or acid curing, the contents of uranium and molybdenum in the residue were reduced to 0. 01% and 0. 02% respectively, and the vanadium leaching rate was over 50%.%对某含钼、钒碳质页岩型铀矿石开展铀、钼、钒综合提取工艺试验.研究结果表明:该铀矿石属于难浸出的多金属矿石,直接采用硫酸或碳酸钠浸出时,均不能实现铀、钼、钒的综合提取;采用加压酸浸或拌酸熟化搅拌浸出时,矿石中铀、钼、钒3种元素均可获得比较满意的浸出效果,渣中铀品位可降至0.01%左右,钼品位可降至0.02%以下,钒的浸出率达50%以上.

  6. 相山矿田铀矿地质研究进展与趋势%Progress and trend in the research on uranium geology in Xiangshan ore field

    Institute of Scientific and Technical Information of China (English)

    张万良

    2012-01-01

    相山铀矿是华南最大的产于火山一侵入杂岩体中的热液脉型铀矿田。文章对相山铀矿地质研究的历史进行了简略回顾,重点阐述了铀矿地质研究的新进展,主要有:火山杂岩时代为早白垩世、火山岩浆具有反方向演化特点,成矿作用是一个相对连续的演化过程,铀矿类型归属斑岩型,属于与燕山晚期火山一斑岩作用有关的铀或铀一多金属矿床成矿系列。最后,文章展望了未来的研究方向。%Xiangshan ore field occurred in volcanic-intrusive complex body is the largest nyaromerinnl wein type uranium deposit in south China. This paper briefly reviews the history of geological research on Xiangshan uranium ore field' and mainly focuses on the new progress in the research on the uranium geology as fol- lows: the age of volcanic complex is confirmed as early Cretaceous, the magma of volcanic rocks is charac- terized by a reversal evolution, the mineralization shows a relatively continuous evolution process, the uranium deposit belongs to a porphyry type that can be classified into the uranium or uranium-polymetallogenic series related with the late Yanshanian volcano-porphyry. Finally, the future research trend is precllotocl_

  7. The Influence of Geologic Feature of Ores on Kinetics of Uranium Leaching from Some Granite Uranium Deposit in South China%华南某花岗岩型铀矿床矿石地质特征对铀浸出动力学的影响

    Institute of Scientific and Technical Information of China (English)

    蒋卫士; 谭凯旋; 谢焱石; 胡杨

    2014-01-01

    华南花岗岩型铀矿床是我国重要的铀资源之一,主要采用堆浸法提取铀。本文实验研究了铀矿石的地质地球化学特征对铀浸出的影响。根据地质地球化学特征,铀矿石可以分为2个类型,Ⅰ类是发育赤铁矿化,呈暗红色,Fe2 O3含量较高,Ca、Ma、Al含量较低;Ⅱ类是发育绢云母化和碳酸盐化,呈灰绿色,Fe2 O3含量较低,Ca、Ma、Al含量较高。铀浸出动力学受表面化学反应控制,矿石的地质地球化学特征对铀的浸出有显著影响,Ⅰ类矿石铀的浸出率、铀浓度和浸出速率常数显著高于Ⅱ类矿石。矿石中的赤铁矿为铀浸出提供氧化剂Fe3+,从而促进铀的浸出;碳酸盐矿物一方面消耗酸,另一方面形成沉淀物,从而对铀浸出产生不利影响。%The granite uranium deposits in south China are one of important uranium re-sources,and uranium is mainly extracted using heap leaching. The influence of geological and geochemical characteristics of ores on uranium leaching was experimentally studied in this paper. Accrrding to geological and geochemical characteristics,uranium ores can be di-vided into two types:type Ⅰ is kermesinus with hematization,and high content of Fe2 O3 , low content of Ca,Mg,Al-bearing minerals;typeIIis grayish-green with sericitization,car-bonatation,low content of Fe2 O3 ,and high content of Ca,Mg,Al-bearing minerals. The ki-netics of uranium leaching are controlled by surface chemical reaction. The uranium leac-hing is affected obviously by geological and geochemical characteristoics of ores. The leac-hing efficiency, concentration and leaching rate constant of uranium for typeⅠores are higher than for type II ores. The dissolution of hematite from ores provide oxidant Fe3+which promote uranium leaching. But carbonate minerals can consume acid and form new precipitates thus be unfavourable to uranium leaching.

  8. Redevelopment of the legacies of the uranium ore mining industry in Saxony and Thuringia - 15 years of Wismut GmbH; Sanierung der Hinterlassenschaften des Uranerzbergbaus in Sachsen und Thueringen - 15 Jahre Wismut GmbH

    Energy Technology Data Exchange (ETDEWEB)

    Beschorner, F. [Wismut GmbH, Chemnitz (Germany). Belegschafts- und Kaufmaennisches Ressort; Koenig, A. [Wismut GmbH, Chemnitz (Germany). Abteilung Beschaffung/Materialwirtschaft; Lersow, M. [Wismut GmbH, Chemnitz (Germany). Technisches Ressort; Leupold, D. [Wismut GmbH, Chemnitz (Germany). Abteilung Ausfuehrung

    2006-12-14

    Since 1991 the state-owned company Wismut GmbH has been redeveloping the legacies of the 40 years or uranium ore mining in Saxony and Thuringia. The Federal government included 13 nb DM (about 6.3 bn EUR) in the Federal budget for this major environmental protection project in 1991. The balance-sheet of the previous shutdown and redevelopment activities of Wismut GmbH as an important prerequisite for the socio-economic development n the previous uranium ore mining areas is positive without exception. Development of the municipality of Schlema to a spa and the creation of BUGA 2007 in Gera and Ronneburg can be mentioned as examples. As an important economic factor for the region Wismut GmbH has awarded contracts worth about 1.6 bn EUR to other firms with application of the public contract award procedure since 1992. With a proportion of 13% Wismut GmbH is one of the largest vocational training companies in the region. The acquired Wismut know-how is marketed via the subsidiary company WISUTEC Wismut Umwelttechnik established in 2002. (orig.)

  9. Method for determining microamounts of uranium in solutions from copper ores, by liquid-liquid extraction and spectrophotometry with arsenazo III.; Metodo para determinar microcantidades de uranio en disoluciones de minerales de cobre, por extraccion liquido-liquido y espectrofotometria con arsenazo III

    Energy Technology Data Exchange (ETDEWEB)

    Rodriguez, B.

    1972-07-01

    A spectrophotometric method is described for determining small amounts of uranium in aqueous solutions from copper ores. Uranium is quantitatively separated in a single extraction by a solution of tri-n-octylphosphine oxide in benzene, using ethylendiaminetetracetic acid and sodium fluoride as complexing agents, for improving the selectivity of the procedure. An aliquot of the extract is diluted with a hydrocolloidal solution of arsenazo III. Optical density is measured at 650 nm. (Author) 3 refs.

  10. Processing of lateritic ores

    Energy Technology Data Exchange (ETDEWEB)

    Collier, D.E.; Ring, R.J. [Environment Division, Australian Nuclear Science and Technology Organisation, Menai, New South Wales (Australia); McGill, J.; Russell, H. [Energy Resources of Australia Ltd., Ranger Mine, Jabiru, Northern Territory (Australia)

    2000-07-01

    Highly weathered or lateritic ores that contain high proportions of fine clay minerals present specific problems when they are processed to extract uranium. Of perhaps the greatest significance is the potential of the fine minerals to adsorb dissolved uranium (preg-robbing) from leach liquors produced by processing laterites or blends of laterite and primary ores. These losses can amount to 25% of the readily soluble uranium. The clay components can also restrict practical slurry densities to relatively low values in order to avoid rheology problems in pumping and agitation. The fine fractions also contribute to relatively poor solid-liquid separation characteristics in settling and/or filtration. Studies at ANSTO have characterised the minerals believed to be responsible for these problems and quantified the effects of the fines in these types of ores. Processing strategies were also examined, including roasting, resin-in-leach and separate leaching of the laterite fines to overcome potential problems. The incorporation of the preferred treatment option into an existing mill circuit is discussed. (author)

  11. The Application of Reconstruction Prediction Technology of Chaotic Phase Space in Heap Leaching Process of Uranium Ores%混沌相空间重构预测技术在铀矿堆浸中的应用

    Institute of Scientific and Technical Information of China (English)

    韩静; 刘光萍

    2012-01-01

    将混沌理论引入到铀矿堆浸工艺中,分析工艺中产生的数据,得出铀矿堆浸工艺具有混沌特性的结论,并在此基础上,应用新的局部预测方法,对铀矿的累计浸出率进行了几组多维预测分析,为建立合理的堆浸工艺数学模型提供了新的思路.%The chaos theory is applied to the heap leaching process of uranium ores. The analysis on the data generated in the process showed that the heap leaching process of uranium has chaotic property. Based on this, several groups of multi-dimensional prediction analysis on the uranium extraction rate are made by using an new local forecasting method. It provides a new concept to establish a reasonable mathematical model in heap leaching process.

  12. Development of an extractive spectrophotometric method for estimation of uranium in ore leach solutions using 2-ethylhexyl phosphonic acid-mono-2-ethylhexyl ester (PC88A) and tri-n-octyl phosphine oxide (TOPO) mixture as extractant and 2-(5-bromo-2-pyridylozo)-5-diethyl aminophenol (Br-PADAP) as chromophore.

    Science.gov (United States)

    Biswas, Sujoy; Pathak, P N; Roy, S B

    2012-06-01

    An extractive spectrophotometric analytical method has been developed for the determination of uranium in ore leach solution. This technique is based on the selective extraction of uranium from multielement system using a synergistic mixture of 2-ethylhexyl phosphonic acid-mono-2-ethylhexyl ester (PC88A) and tri-n-octyl phosphine oxide (TOPO) in cyclohexane and color development from the organic phase aliquot using 2-(5-Bromo-2-pyridylazo)-5-diethyl aminophenol (Br-PADAP) as chromogenic reagent. The absorption maximum (λ(max)) for UO(2)(2+)-Br-PADAP complex in organic phase samples, in 64% (v/v) ethanol containing buffer solution (pH 7.8) and 1,2-cyclohexylenedinitrilotetraacetic acid (CyDTA) complexing agent, has been found to be at 576 nm (molar extinction coefficient, ɛ: 36,750 ± 240 L mol(-1)cm(-1)). Effects of various parameters like stability of complex, ethanol volume, ore matrix, interfering ions etc. on the determination of uranium have also been evaluated. Absorbance measurements as a function of time showed that colored complex is stable up to > 24h. Presence of increased amount of ethanol in colored solution suppresses the absorption of a standard UO(2)(2+)-Br-PADAP solution. Analyses of synthetic standard as well as ore leach a solution show that for 10 determination relative standard deviation (RSD) is ore leach solutions and results were compared with standard methods like inductively coupled plasma emission spectrometry (ICPAES). The determined values of uranium concentrations by these methods are within ± 2%. This method can be used to determine 2.5-250 μg mL(-1) uranium in ore leach solutions with high accuracy and precision.

  13. An evaporated seawater origin for the ore-forming brines in unconformity-related uranium deposits (Athabasca Basin, Canada): Cl/Br and δ 37Cl analysis of fluid inclusions

    Science.gov (United States)

    Richard, Antonin; Banks, David A.; Mercadier, Julien; Boiron, Marie-Christine; Cuney, Michel; Cathelineau, Michel

    2011-05-01

    Analyses of halogen concentration and stable chlorine isotope composition of fluid inclusions from hydrothermal quartz and carbonate veins spatially and temporally associated with giant unconformity-related uranium deposits from the Paleoproterozoic Athabasca Basin (Canada) were performed in order to determine the origin of chloride in the ore-forming brines. Microthermometric analyses show that samples contain variable amounts of a NaCl-rich brine (Cl concentration between 120,000 and 180,000 ppm) and a CaCl 2-rich brine (Cl concentration between 160,000 and 220,000 ppm). Molar Cl/Br ratios of fluid inclusion leachates range from ˜100 to ˜900, with most values between 150 and 350. Cl/Br ratios below 650 (seawater value) indicate that the high salinities were acquired by evaporation of seawater. Most δ 37Cl values are between -0.6‰ and 0‰ (seawater value) which is also compatible with a common evaporated seawater origin for both NaCl- and CaCl 2-rich brines. Slight discrepancies between the Cl concentration, Cl/Br, δ 37Cl data and seawater evaporation trends, indicate that the evaporated seawater underwent secondary minor modification of its composition by: (i) mixing with a minor amount of halite-dissolution brine or re-equilibration with halite during burial; (ii) dilution in a maximum of 30% of connate and/or formation waters during its migration towards the base of the Athabasca sandstones; (iii) leaching of chloride from biotites within basement rocks and (iv) water loss by hydration reactions in alteration haloes linked to uranium deposition. The chloride in uranium ore-forming brines of the Athabasca Basin has an unambiguous dominantly marine origin and has required large-scale seawater evaporation and evaporite deposition. Although the direct evidence for evaporative environments in the Athabasca Basin are lacking due to the erosion of ˜80% of the sedimentary pile, Cl/Br ratios and δ 37Cl values of brines have behaved conservatively at the basin

  14. 野外现场铀矿石中铀的快速准确测定方法研究——TOPO萃取α计数法%Rapid and Accurate Determination of Uranium in Uranium Ores in the Field Using TOPO Extraction and α-counting Method

    Institute of Scientific and Technical Information of China (English)

    黄秋红; 刘立坤; 郭冬发; 王玉学; 武朝晖; 汤三星; 李红光

    2011-01-01

    研究了野外现场快速准确测定铀矿石中铀的三辛基氧膦(TOPO)萃取α计数法.目前野外现场铀的测量主要采用γ谱法,即利用铀子体的γ射线强度来计算铀的含量,当样品中铀镭处于不平衡状态时,γ谱法测铀存在着较大的测量误差.本文将铀的核性质与化学性质结合起来,采用密闭酸溶法快速溶解样品中的铀,酸溶后的样品不经分离直接在溶样罐中用TOPO萃取,进而测定样品中铀产生的α射线强度获得铀的含量,避免了γ谱法的不足.方法检出限为铀含量2.41 μg/g;当铀含量为大约为100μg/g时,测量相对偏差为5.93%;铀的测定范围为7.23μg/g~ n%.密闭酸溶法试剂用量少,溶样速度快,且对环境和操作人员污染小;酸溶后的样品用TOPO萃取2 min后即可达到萃取平衡,铀萃取效率在97%以上;所需的仪器设备可以车载形式用于野外现场铀矿石中铀的准确测定,野外应用操作简单、快速、精密度和准确性较高.%The method of TOPO extraction followed by a-counting has been developed for field determination of uranium in uranium ores. The traditional method of field uranium determination is by spectrometry. The content of uranium using that method is determined by the intensity of the ray, therefore, results have larger errors when uranium and radium are in equilibrium. The method researched by this article combines the nuclear and chemical properties of uranium. The content of the uranium is determined directly by the intensity recorded by an a counter after following dissolution and extraction processes. The detection limit of uranium is 2.41 μg/g. When the content of uranium is about 100 μg/g, the relative standard deviation ( RSD) is 5. 93% . The determining range of uranium is 7. 23 μg/g - n%. The dissolution method requires less reagents, has better dissolving efficiency and less pollution. The extraction method has the advantage and efficiency ( >97

  15. OXYGEN ISOTOPE FRACTION ATION IN URANIUM OXIDES

    Institute of Scientific and Technical Information of China (English)

    郑永飞

    1995-01-01

    Thermodynamic oxygen isotope factors for uranium oxides have been calculated by means of the modified increment method.The sequence of 18O-enrichment in the uranium oxides with respect to the common rock-forming minerals is predicted as follows:spineluranium blacks≤coffiniteuranium oxides and water and between the uranium oxides and the other minerals have been obtained for 0-1200℃.The theoretical results are applicable to the isotopic geothermometry of uranium ores when pairing with other gangue minerals in hydrothermal uranium deposits.

  16. Kellad orelis

    Index Scriptorium Estoniae

    2000-01-01

    18. VI Tallinna toomkirikus organist Ines Maidre (kaastegev Kristjan Mäeots) kontsert "Kellad orelis". Kontserdiga esitleb I. Maidre ka oma samanimelist CD-d (kujundaja Margus Haavamägi), mis on osaliselt sisse mängitud Tallinna toomkiriku Ladegasti-Saueri orelil. Tänavu tähistatakse toomkiriku Maarja kella ja Lunastaja kella 315. aastapäeva.

  17. Zircon U-Pb geochronology,Hf isotopic composition and geological implications of the rhyodacite and rhyodacitic porphyry in the Xiangshan uranium ore field,Jiangxi Province,China

    Institute of Scientific and Technical Information of China (English)

    2010-01-01

    The Xiangshan uranium ore field is the largest volcanic rock hosted uranium deposit in China.The host rock is a volcanic intrusive complex,including rhyodacite,porphyroclastic lava and late stage sub-volcanic rocks.In this study,zircons from an early stage rhyodacite and a late stage rhyodacite porphyry were dated by SHRIMP and LA-ICP-MS U-Pb methods,and their Hf isotopic compositions were measured by LA-MC-ICP-MS.206Pb/238U ages of 135.1±1.7 and 134.8±1.1 Ma were obtained for the rhyodacite and rhyodacitic porphyry,respectively.These accurate ages indicate that the Xiangshan volcanic-intrusive complex formed in the Early Cretaceous rather than in the Late Jurassic,as concluded in some previous studies.By the Early Cretaceous,the tectonic setting of the area has evolved into a back-arc extensional setting,possibly related to subduction of the paleo-Pacific plate.The close ages of the(early) eruptive rhyodacite and the(late) hypabyssal rhyodacitic porphyry shows that the Xiangshan volcanism was intensive and concentrated in a short time.Zircons from the rhyodacite show negative εHf(t) values of-5.7 to-8.5,with Hf depleted mantle model ages between 1550 and 1720 Ma,whereas zircons from the rhyodacitic porphyry yield εHf(t) values of-6.9 to-10.1 and Hf model ages between 1621 and 1823 Ma.These zircon Hf model ages are similar to the whole rock Nd model ages(1486 to 1911 Ma).Combined with other geochemical characteristics,the Xiangshan rhyodacite and rhyodacitic porphyry may have been derived from partial melting of the Paleo-Mesoproterozoic metamorphic rocks from the Xiangshan basement,without any significant addition of mantle-derived magma.Contribution of basement of this age is also supported by finding a Paleoproterozoic xenocrystic zircon core in the rhyodacite sample.

  18. 高纯锗(HPGe)γ谱仪测定铀矿石中镭的方法研究%The Experiment Study on the Radium Measurment in Uranium ore with High Purity Germanium(HPGe) γSpectrometer

    Institute of Scientific and Technical Information of China (English)

    薛志伟; 高明明; 乔宁强; 王强; 朱晓贤

    2014-01-01

    为了改善由样品密度不同、厚度不同引起的测量误差,笔者采用压片法制样,然后密封于样品盒达到平衡,通过152 Eu对外界的电磁干扰进行内标校正,在高纯锗( HPGe)γ谱仪上测定铀矿石中镭的含量。测定结果的相对标准偏差( RSD/%)为2.43%,与射气法结果进行比较,相对误差在-5.31%~6.62%之间,方法的精密度和准确度均能满足实际生产需求,可操作性强,简便快速。%In order to reduce the measurement error caused by different sample thickness and density , the author uses compression method to get detection sample .The sample is sealed in a sample box to achieve balance , then we measure the radium content of uranium ore by using High purity germanium (HPGe) γspectrometer. The result is corrected by 152 Eu to avoid the electromagnetic disturbances .The relative standard deviation ( RSD%) of the determination results is 2.43%.Comparing with the emanation method results , the relative error are between -5.31%~6.62%.The method is able to meet the demands due to its advantages of easy operation and rapidness , the high precision and accuracy .

  19. Biomining: metal recovery from ores with microorganisms.

    Science.gov (United States)

    Schippers, Axel; Hedrich, Sabrina; Vasters, Jürgen; Drobe, Malte; Sand, Wolfgang; Willscher, Sabine

    2014-01-01

    Biomining is an increasingly applied biotechnological procedure for processing of ores in the mining industry (biohydrometallurgy). Nowadays the production of copper from low-grade ores is the most important industrial application and a significant part of world copper production already originates from heap or dump/stockpile bioleaching. Conceptual differences exist between the industrial processes of bioleaching and biooxidation. Bioleaching is a conversion of an insoluble valuable metal into a soluble form by means of microorganisms. In biooxidation, on the other hand, gold is predominantly unlocked from refractory ores in large-scale stirred-tank biooxidation arrangements for further processing steps. In addition to copper and gold production, biomining is also used to produce cobalt, nickel, zinc, and uranium. Up to now, biomining has merely been used as a procedure in the processing of sulfide ores and uranium ore, but laboratory and pilot procedures already exist for the processing of silicate and oxide ores (e.g., laterites), for leaching of processing residues or mine waste dumps (mine tailings), as well as for the extraction of metals from industrial residues and waste (recycling). This chapter estimates the world production of copper, gold, and other metals by means of biomining and chemical leaching (bio-/hydrometallurgy) compared with metal production by pyrometallurgical procedures, and describes new developments in biomining. In addition, an overview is given about metal sulfide oxidizing microorganisms, fundamentals of biomining including bioleaching mechanisms and interface processes, as well as anaerobic bioleaching and bioleaching with heterotrophic microorganisms.

  20. The radon 222 transport in soils. The case of the storage of residues coming from uranium ores processing; La migration du radon 222 dans un sol. Application aux stockages de residus issus du traitement des minerais d'uranium

    Energy Technology Data Exchange (ETDEWEB)

    Ferry, C

    2000-07-01

    Uranium Mill Tailings (UMT) contain comparatively large quantities of radium-226. This radionuclide yields, by radioactive decay, the radioactive gas radon-222. Tailing piles are routinely covered to reduce the radon release-rate into the atmosphere. In order to assess the long term environmental impact of a UMT repository, mechanisms governing radon exhalation at the soil surface must be deciphered and understood. A model of radon transport in the unsaturated zone is developed for this purpose: water- and air-flow in the porous material are determined, as well as radon transport by diffusion in the pore space and advection by the gas phase. The radon transport model in the unsaturated zone - TRACI (which stands, in French, for Radon Transport within the Unsaturated Layer) - calculates moisture contents in the soil, Darcy's velocities of the liquid and gas phases, radon concentrations in the gas phase and radon flux at the soil surface. TRACI's results are compared with observations carried out on a UMT and a cover layer. Input parameters are derived from the textural analysis of the material under study, whereas upper boundary conditions are given by meteorological data. If we consider measurement errors and uncertainties on the porous medium characterisation, model's results are generally in good agreement with observations, at least on the long run. Moreover, data analysis shows hat transient phenomena are understood as well, in most situations. (author)

  1. Uranium industry annual 1993

    Energy Technology Data Exchange (ETDEWEB)

    1994-09-01

    Uranium production in the United States has declined dramatically from a peak of 43.7 million pounds U{sub 3}O{sub 8} (16.8 thousand metric tons uranium (U)) in 1980 to 3.1 million pounds U{sub 3}O{sub 8} (1.2 thousand metric tons U) in 1993. This decline is attributed to the world uranium market experiencing oversupply and intense competition. Large inventories of uranium accumulated when optimistic forecasts for growth in nuclear power generation were not realized. The other factor which is affecting U.S. uranium production is that some other countries, notably Australia and Canada, possess higher quality uranium reserves that can be mined at lower costs than those of the United States. Realizing its competitive advantage, Canada was the world`s largest producer in 1993 with an output of 23.9 million pounds U{sub 3}O{sub 8} (9.2 thousand metric tons U). The U.S. uranium industry, responding to over a decade of declining market prices, has downsized and adopted less costly and more efficient production methods. The main result has been a suspension of production from conventional mines and mills. Since mid-1992, only nonconventional production facilities, chiefly in situ leach (ISL) mining and byproduct recovery, have operated in the United States. In contrast, nonconventional sources provided only 13 percent of the uranium produced in 1980. ISL mining has developed into the most cost efficient and environmentally acceptable method for producing uranium in the United States. The process, also known as solution mining, differs from conventional mining in that solutions are used to recover uranium from the ground without excavating the ore and generating associated solid waste. This article describes the current ISL Yang technology and its regulatory approval process, and provides an analysis of the factors favoring ISL mining over conventional methods in a declining uranium market.

  2. Uranium in cassiterites of tin deposits

    Energy Technology Data Exchange (ETDEWEB)

    Zagruzina, I.A.; Pinskij, Eh.M.; Savinova, I.B.

    1986-01-01

    For the purpose of elucidation of physico-chemical features of uranium and tin behaviour in ore deposition zones uranium determinations (1000 determ) in cassiterite grains from 55 tin-ore deposits of different formation types of several separate regions are carried out by means of fission radiography. It is shown that uranium content in cassiterites is a genetic sign. Peculiarities of uranium concentration and migration in tin deposits permit to use them as prognostic radiogeochemical criteria. Radiogeochemical prognostic-search signs confirm the antagonism between uranium and tin deposits of cassiterite-silicate and cassiterite-sulfide formations and paragenetic of certain types of uranium hydrothermal deposits with tin deposits of cassiterite-quartz formation.

  3. Cenozoic Tectonic Evolution and its Influence on Uranium Ore-forming Processes in the Xiazhuang Ore Field, Northern Guangdong Province%粤北下庄矿田新生代构造演化及其对铀成矿的影响

    Institute of Scientific and Technical Information of China (English)

    王军; 赖中信; 张辉仁; 汤世凯; 杨坤光

    2011-01-01

    The Nanling area in northern Guangdong Province is important for its granitic uranium deposits. The characteristics of the structures and ESR ages of the hydrothermal quartz show that the ore field underwent three stages of structural deformation in Cenozoic; (65. 5 -55. Oma) differential uplifting of land mass and colossal faults movements; Ⅱ (40.3 The Earth is a dynamic system in which rocks deform under various physical and chemical conditions. A continuous improvement of the related testing and analysis techniques during the past decades has enabled the rheology of the Earth materials to be studied successfully in the laboratory and made important advances in the interpretation of natural deformation and structure in the crust and upper mantle. The goal of this paper is to provide a succinct overview on technical developments of experimental rock deformation equipment with a particular focus on the Paterson High-Pressure High-Temperature Testing System ( HPT). The HPT is an internally-heated gas-confining medium high temperature (up to~1500℃ ) and high pressure (up to 700MPa) triaxial deformation apparatus. Unlike the solidmedium Criggs apparatus, the HPT can measure temperature, confine pressure, differential stress and strain with great accuracy and precision so that high quality mechanical data can be obtained. The HPT allows various types of tests to be carried out in compression, extension and torsion: constant strain rate, creep (constant stress), relaxation, etc. , depending on the capabilities of the actuator system fitted. Using the pore fluid system equipped with the apparatus, one can also automatically control the pore fluid pressure and measure the volume of pore fluid entering or leaving the specimen, and subsequently the volume change of the specimen during an experimental deformation. The apparatus is regarded as the most powerful testing tool in the research of mechanical behavior and physical properties of minerals and rocks. This paper

  4. Inherently safe in situ uranium recovery

    Science.gov (United States)

    Krumhansl, James L; Brady, Patrick V

    2014-04-29

    An in situ recovery of uranium operation involves circulating reactive fluids through an underground uranium deposit. These fluids contain chemicals that dissolve the uranium ore. Uranium is recovered from the fluids after they are pumped back to the surface. Chemicals used to accomplish this include complexing agents that are organic, readily degradable, and/or have a predictable lifetime in an aquifer. Efficiency is increased through development of organic agents targeted to complexing tetravalent uranium rather than hexavalent uranium. The operation provides for in situ immobilization of some oxy-anion pollutants under oxidizing conditions as well as reducing conditions. The operation also artificially reestablishes reducing conditions on the aquifer after uranium recovery is completed. With the ability to have the impacted aquifer reliably remediated, the uranium recovery operation can be considered inherently safe.

  5. Kinetics of Uranium Extraction from Uranium Tailings by Oxidative Leaching

    Science.gov (United States)

    Zhang, Biao; Li, Mi; Zhang, Xiaowen; Huang, Jing

    2016-07-01

    Extraction of uranium from uranium tailings by oxidative leaching with hydrogen peroxide (H2O2) was studied. The effects of various extraction factors were investigated to optimize the dissolution conditions, as well as to determine the leaching kinetic parameters. The behavior of H2O2 in the leaching process was determined through scanning electron microscopy-energy dispersive x-ray spectroscopy (SEM-EDX) and x-ray diffraction analysis of leaching residues. Results suggest that H2O2 can significantly improve uranium extraction by decomposing the complex gangue structures in uranium tailings and by enhancing the reaction rate between uranium phases and the leaching agent. The extraction kinetics expression was changed from 1 - 3(1 - α)2/3 + 2(1 - α) = K 0(H2SO4)-0.14903(S/L)-1.80435( R o)0.20023 e -1670.93/T t ( t ≥ 5) to 1 - 3(1 - α)2/3 + 2(1 - α) = K 0(H2SO4)0.01382(S/L)-1.83275( R o)0.25763 e -1654.59/T t ( t ≥ 5) by the addition of H2O2 in the leaching process. The use of H2O2 in uranium leaching may help in extracting uranium more efficiently and rapidly from low-uranium-containing ores or tailings.

  6. The uranium bearing shale ore-body at St-Hippolyte (Haut-Rhin). An example of research with statistical methods; Le gisement des schistes uraniferes de St-Hippolyte (Haut-Rhin). Exemple d'etude par calculs statistiques

    Energy Technology Data Exchange (ETDEWEB)

    Carlier, A. [Commissariat a l' Energie Atomique, Saclay (France). Centre d' Etudes Nucleaires

    1958-07-01

    The uranium bearing shale ore-body at St-Hippolyte was mainly proved by drillings, the results of which were studied through statistical methods. The author gives an account of his conclusions regarding the distribution of mineralization, its origin and, the estimate of reserves. The uranium mineralization is irregularly distributed in shales. On a vertical line, levels could be singled out: they are similar, as far as lithology is concerned, but each of them is characterized by a grade-population, according to a lognormal distribution. Horizontally, a connection is noted between grades and the overlying barren sandstone bed. These considerations, as well as a statistical study of U/Ra ratio, induced the author to consider that the mineralization of the richest level has an hydrothermal origin. It is only through an uranium diffusion from that level that the others are mineralized. The uranium which is contained in poorest beds has a syn-genetic origin. Furthermore, statistical methods bring us to an evaluation of reserves. In such a case, the evaluation is equivalent to the ore obtained by common arithmetical methods. Moreover, we are able to state precisely the upper and lower limits where a true tonnage or a true grade could be given with a definite value of statistical certainty. Then the author has been able to study the separation of reserves in grade-groups and to foresee the effect of sorting in connection with the lower possible grade and with extraction units (wagons, lorries, etc...), on which the sorting will be done. To conclude, the author indicates the value of both classical and statistical methods. These two techniques are completing each other and they solve different problems. (author) [French] Le gisement des schistes uraniferes de St-Hippolyte a ete reconnu essentiellement par sondages, dont les resultats ont ete etudies par les methodes du calcul statistique. L'auteur expose les conclusions auxquelles il a ete amene et qui concernent: la

  7. Speciation and Precipitation of Uranium Complexes in Hydrothermal Solutions Related to Granite—type Uranium Deposits

    Institute of Scientific and Technical Information of China (English)

    陈培荣; 章邦桐; 等

    1992-01-01

    Uranium-bearing hydrothermal solutions during the stage of ore deposition are weakly alkaline and of the Ca2+ -Na+/HCO3- -F- type.UO2(CO3)22- and UO2F4-, are dominant in the hydrothermal solutions with respect to their activity.Wall-rock hydrothermal alterations ,temperature and pressure drop and the reducing capability of rock assemblage (Δeh) led to a decrease in Eh of the hydrothermal solutions and an increase in Eh at which uranium began precipitating.Therefore,the mechanism of uranium precipitation is essentially the reduction of uranium complexes.The granite-type uranium deposits are the most important type of uranium resources in China.Discussions will be made in this paper concerning the hydrothermal speciation and precipitation mech-anisms of uranium complexes in the light of fluid inclusion and geological data from some major de-posits of this type in South China.

  8. 10 CFR 40.66 - Requirements for advance notice of export shipments of natural uranium.

    Science.gov (United States)

    2010-01-01

    ... 10 Energy 1 2010-01-01 2010-01-01 false Requirements for advance notice of export shipments of natural uranium. 40.66 Section 40.66 Energy NUCLEAR REGULATORY COMMISSION DOMESTIC LICENSING OF SOURCE... natural uranium. (a) Each licensee authorized to export natural uranium, other than in the form of ore...

  9. On the Genesis of Uranium Deposit 720 with Special Reference to the Double Solution—Mixing Model

    Institute of Scientific and Technical Information of China (English)

    李振球; 胡中林

    1991-01-01

    Presented in this paper is an approach to the analysis of "series-stage"division.The processes of hydrothermal evolution involved in ore deposition,the factors affecting the enrichment of uranium and the source of ore forming elements in uranium deposit 720 are also discussed .In addition,the ore-forming tem-perature and pressure as well as the pH,Eh and chemical composition of ore-forming medium are studied with reference to the fluid inclusion data available.A double solution-mixing model has been proposed to explain the genesis of the uranium deposit studied.

  10. The physical hydrogeology of ore deposits

    Science.gov (United States)

    Ingebritsen, Steven E.; Appold, M.S.

    2012-01-01

    Hydrothermal ore deposits represent a convergence of fluid flow, thermal energy, and solute flux that is hydrogeologically unusual. From the hydrogeologic perspective, hydrothermal ore deposition represents a complex coupled-flow problem—sufficiently complex that physically rigorous description of the coupled thermal (T), hydraulic (H), mechanical (M), and chemical (C) processes (THMC modeling) continues to challenge our computational ability. Though research into these coupled behaviors has found only a limited subset to be quantitatively tractable, it has yielded valuable insights into the workings of hydrothermal systems in a wide range of geologic environments including sedimentary, metamorphic, and magmatic. Examples of these insights include the quantification of likely driving mechanisms, rates and paths of fluid flow, ore-mineral precipitation mechanisms, longevity of hydrothermal systems, mechanisms by which hydrothermal fluids acquire their temperature and composition, and the controlling influence of permeability and other rock properties on hydrothermal fluid behavior. In this communication we review some of the fundamental theory needed to characterize the physical hydrogeology of hydrothermal systems and discuss how this theory has been applied in studies of Mississippi Valley-type, tabular uranium, porphyry, epithermal, and mid-ocean ridge ore-forming systems. A key limitation in the computational state-of-the-art is the inability to describe fluid flow and transport fully in the many ore systems that show evidence of repeated shear or tensional failure with associated dynamic variations in permeability. However, we discuss global-scale compilations that suggest some numerical constraints on both mean and dynamically enhanced crustal permeability. Principles of physical hydrogeology can be powerful tools for investigating hydrothermal ore formation and are becoming increasingly accessible with ongoing advances in modeling software.

  11. Newly discovered uranium mineralization at 2.0 Ma in the Menggongjie granite-hosted uranium deposit, South China

    Science.gov (United States)

    Luo, Jin-Cheng; Hu, Rui-Zhong; Fayek, Mostafa; Bi, Xian-Wu; Shi, Shao-Hua; Chen, You-Wei

    2017-04-01

    The southeastern part of the Nanling metallogenic province, South China contains numerous economically important granite-hosted, hydrothermal vein-type uranium deposits. The Miao'ershan (MES) uranium ore field is one of the most important uranium sources in China, hosts the largest Chanziping carbonaceous-siliceous-pelitic rock-type uranium deposit and several representative granite-hosted uranium deposits. The geology and geochemistry of these deposits have been extensively studied. However, accurate and precise ages for the uranium mineralization are scarce because uranium minerals in these deposits are usually fine-grained, and may have formed in several stages, thus hindering the understanding of the uranium metallogenesis of this province. The Menggongjie (MGJ) uranium deposit is one of the largest granite-hosted uranium deposits in the MES ore field. Uranium mineralization in this deposit occurs at the central part of the MES granitic complex, accompanied with silicification, fluorination, K-metasomatism and hematitization. The ore minerals are dominated by uraninite, occurring in quartz or fluorite veinlets along fractures in altered granite. In-situ SIMS U-Pb dating on the uraninite yields the U-Pb isotopic age of 1.9 ± 0.7 Ma, which is comparable to the chemical U-Th-Pbtol uraninite age of 2.3 ± 0.1 Ma. Such ages agree well with the eruption ages of the extension-related Quaternary volcanics (2.1-1.2 Ma) in South China, suggesting that the uranium mineralization have formed at an extensional setting, possibly related to the Quaternary volcanic activities. Therefore, our robust, new dating results of the MGJ uranium deposit make it the youngest granite-hosted uranium deposit reported so far in South China and the mineralization event represents a newly identified mineralization epoch.

  12. Uncertainty Evaluation on the Determination of Uranium Ores by Volumetry of Ammonium Vanadate%钒酸铵容量法测定岩石矿物中铀的不确定度评定

    Institute of Scientific and Technical Information of China (English)

    马立奎; 王垚; 罗媛媛; 黎金标; 朱乐杰

    2012-01-01

    Uncertainty evaluation on the criteria of "ferrous sulfate deoxidization / ammonium vanadate oxidation titrimetry to measure uranium" (EJ267. 2-84) issued by Ministry of Nuclear Industry was analyzed. The uncertainty brought by the method itself was obtained through the identification of uncertainty sources, quantification of uncertainty components and determination of uranium content by titration with calibrated ammonium vanadate solution. With the analytical study to uncertainty sources of entire process and components, and the application of statistical treatment based on scientific data, the combined standard uncertainty and expanded uncertainty about different levels of uranium content was reported.%根据核工业行业标准“硫酸亚铁还原/钒酸铵氧化滴定法测铀”(EJ267.2-84)进行不确定度评定.通过不确定度来源识别,不确定度分量的量化,并以标定好的钒酸铵溶液滴定铀质量分数,得出方法本身带来数据的不确定度.对整个过程的不确定度来源和大小进行分析研究,应用统计学基础对数据进行科学处理.报告出了不同铀质量分数的合成标准不确定度和扩展不确定度.

  13. Bioprocessing of ores: Application to space resources

    Science.gov (United States)

    Johansson, Karl R.

    The role of microorganisms in the oxidation and leaching of various ores (especially those of copper, iron, and uranium) is well known. This role is increasingly being applied by the mining, metallurgy, and sewage industries in the bioconcentration of metal ions from natural receiving waters and from waste waters. It is concluded that bioprocessing using bacteria in closed reactors may be a variable option for the recovery of metals from the lunar regolith. Obviously, considerable research must be done to define the process, specify the appropriate bacteria, determine the necessary conditions and limitations, and evaluate the overall feasibility.

  14. Uranium from seawater

    Energy Technology Data Exchange (ETDEWEB)

    Gregg, D.; Folkendt, M.

    1982-09-21

    A novel process for recovering uranium from seawater is proposed and some of the critical technical parameters are evaluated. The process, in summary, consists of two different options for contacting adsorbant pellets with seawater without pumping the seawater. It is expected that this will reduce the mass handling requirements, compared to pumped seawater systems, by a factor of approximately 10/sup 5/, which should also result in a large reduction in initial capital investment. Activated carbon, possibly in combination with a small amount of dissolved titanium hydroxide, is expected to be the preferred adsorbant material instead of the commonly assumed titanium hydroxide alone. The activated carbon, after exposure to seawater, can be stripped of uranium with an appropriate eluant (probably an acid) or can be burned for its heating value (possible in a power plant) leaving the uranium further enriched in its ash. The uranium, representing about 1% of the ash, is then a rich ore and would be recovered in a conventional manner. Experimental results have indicated that activated carbon, acting alone, is not adequately effective in adsorbing the uranium from seawater. We measured partition coefficients (concentration ratios) of approximately 10/sup 3/ in seawater instead of the reported values of 10/sup 5/. However, preliminary tests carried out in fresh water show considerable promise for an extraction system that uses a combination of dissolved titanium hydroxide (in minute amounts) which forms an insoluble compound with the uranyl ion, and the insoluble compound then being sorbed out on activated carbon. Such a system showed partition coefficients in excess of 10/sup 5/ in fresh water. However, the system was not tested in seawater.

  15. Uranium mining operations in Spain

    Energy Technology Data Exchange (ETDEWEB)

    Rios, J.-M.; Arnaiz, J.; Criado, M.; Lopez, A.

    1995-12-31

    The Empresa Nacional del Uranio, SA (ENUSA) was founded in 1972 to undertake and develop the industrial and procurement activities of the nuclear fuel cycle in Spain. Within the organisation of ENUSA, the Uranium Division is directly responsible for the uranium mining and production operations that have been carried out since 1973 in the area of Ciudad Rodrigo in the province of Salamanca. These activities are based on open pit mining, heap leaching and a hydrometallurgical plant (Elefante) for extracting uranium concentrates from the ore. This plant was shut down in 1993 and a new plant was started up on the same site (Quercus) with a dynamic leaching process. The nominal capacity of the new plant is 950 t U{sub 3}O{sub 8} per year. Because of the historically low uranium prices which have recently prevailed, the plant is currently running at a strategic production rate of 300 t U{sub 3}O{sub 8} per year. From 1981 to 1990, in the area of La Haba (Badajoz province), ENUSA also operated a uranium production site, based on open pit mining, and an experimental extraction plant (Lobo-G). ENUSA is currently decommissioning these installations. This paper describes innovations and improvements that ENUSA has recently introduced in the field of uranium concentrates production with a view to cutting production costs, and to improving the decommissioning and site restoration processes in those sites where production is being shut down or resources have been worked out. (author).

  16. Potential aquifer vulnerability in regions down-gradient from uranium in situ recovery (ISR) sites.

    Science.gov (United States)

    Saunders, James A; Pivetz, Bruce E; Voorhies, Nathan; Wilkin, Richard T

    2016-12-01

    Sandstone-hosted roll-front uranium ore deposits originate when U(VI) dissolved in groundwater is reduced and precipitated as insoluble U(IV) minerals. Groundwater redox geochemistry, aqueous complexation, and solute migration are important in leaching uranium from source rocks and transporting it in low concentrations to a chemical redox interface where it is deposited in an ore zone typically containing the uranium minerals uraninite, pitchblende, and/or coffinite; various iron sulfides; native selenium; clays; and calcite. In situ recovery (ISR) of uranium ores is a process of contacting the uranium mineral deposit with leaching and oxidizing (lixiviant) fluids via injection of the lixiviant into wells drilled into the subsurface aquifer that hosts uranium ore, while other extraction wells pump the dissolved uranium after dissolution of the uranium minerals. Environmental concerns during and after ISR include water quality degradation from: 1) potential excursions of leaching solutions away from the injection zone into down-gradient, underlying, or overlying aquifers; 2) potential migration of uranium and its decay products (e.g., Ra, Rn, Pb); and, 3) potential mobilization and migration of redox-sensitive trace metals (e.g., Fe, Mn, Mo, Se, V), metalloids (e.g., As), and anions (e.g., sulfate). This review describes the geochemical processes that control roll-front uranium transport and fate in groundwater systems, identifies potential aquifer vulnerabilities to ISR operations, identifies data gaps in mitigating these vulnerabilities, and discusses the hydrogeological characterization involved in developing a monitoring program.

  17. 77 FR 25193 - Notice of Availability of the Draft Environmental Impact Statement for the Lost Creek Uranium In...

    Science.gov (United States)

    2012-04-27

    ... Creek Uranium In Situ Recovery Project, Wyoming AGENCY: Bureau of Land Management, Interior. ] ACTION... (EIS) for the Lost Creek Uranium In Situ Recovery (ISR) Project and by this notice is announcing the... subpart 3809 regulations to construct a uranium ore recovery plant, an access road to the site, and...

  18. The chemical industry of uranium in France; L'industrie chimique de l'uranium en France

    Energy Technology Data Exchange (ETDEWEB)

    Goldschmidt, B. [Commissariat a l' Energie Atomique, Paris (France). Centre d' Etudes Nucleaires

    1955-07-01

    The actual CEA program is concerned with the construction of two large graphite reactors, each of those containing at least one hundred tons of uranium metal with nuclear purity. The uranium for these two reactors will be regularly supplied by new resources discovered in France and Madagascar in the last five years. The working and treatment of such ore have led to the creation of an important french industry of which the general outline and principle are described. The operated ores have got different natures and concentration, individual characteristics are described for the main ores.The most high-grade ore are transported to a central plant in Bouchet near Paris; the low-grade ore are concentrated by physical methods or chemical processes of which principles and economy are studied with constancy. The acid processes are the only used until now, although the carbonated alkaline processes has been studied in France. The next following steps after the acid process until the obtention of uranium rich concentrate are described. The purification steps of uranium compounds to nuclear purity material are described as well as the steps to elaborate metal of which the purity grade will be specify. Finally, the economic aspects of uranium production difficulty will be considered in relation with technical progresses which we can expect to achieve in the future. (M.P.)

  19. The measurement test of uranium in a uranium-contaminated waste by passive gamma-rays measurement method

    CERN Document Server

    Sukegawa, Y; Ohki, K; Suzuki, S; Yoshida, M

    2002-01-01

    This report is completed about the measurement test and the proofreading of passive gamma - rays measurement method for Non - destructive assay of uranium in a uranium-contaminated waste. The following are the results of the test. 1) The estimation of the amount of uranium by ionization survey meter is difficult for low intensity of gamma-rays emitted from uranium under about 50g. 2) The estimation of the amount of uranium in the waste by NaI detector is possible in case of only uranium, but the estimation from mixed spectrums with transmission source (60-cobalt) is difficult to confirm target peaks. 3) If daughter nuclides of uranium and thorium chain of uranium ore exist, measurement by NaI detector is affected by gamma-rays from the daughter nuclides seriously-As a result, the estimation of the amount of uranium is difficult. 4) The measurement of uranium in a uranium-contaminated waste by germanium detector is possible to estimate of uranium and other nuclides. 5) As to estimation of the amount of uranium...

  20. Limno-chemical and microbiology aspects in Uranium Pit Mine Lake (Osamu Utsumi), in Antas and Bortolan reservoirs under the influence of effluent Ore Treatment Unit, Caldas - Minas Gerais State, Brazil

    Energy Technology Data Exchange (ETDEWEB)

    Ronqui, Leilane B.; Nasciment, Marcos R.L. do; Roque, Claudio V.; Bruschi, Armando; Borba Junior, Palvo J.; Nascimento, Heliana A. F. do, E-mail: leilanebio@yahoo.com.br, E-mail: pmarcos@cnen.gov.br, E-mail: cvroque@cnen.gov.br, E-mail: abruschi@cnen.gov.br, E-mail: jouber_borba@hotmail.com, E-mail: hazevedo@cnen.gov.br [Comissao Nacional de Energia Nuclear (LAPOC/CNEN), Pocos de Caldas, MG (Brazil). Laboratorio de Pocos de Caldas; Almeida, Tito C.M. de, E-mail: titoalmeida2008@gmail.com [Universidade do Vale do Itajai (CTT-Mar/UNIVALI), SC (Brazil). Centro de Ciencias Tecnologicas da Terra e do Mar

    2013-07-01

    Due to high natural radioactivity there in Pocos de Caldas Plateau (Minas Gerais State, Brazil) and the existence of the first uranium mine in Brazil (Pit Mine Osamu Utsumi - Mineral Treatment Unit/Brazilian Nuclear Industries, MTU/BNI), which is characterized by an open-pit mine presents as increased environmental liability the formation of acid mine drainage, this study was conducted to evaluate the limno-chemicals and microbiology aspects (protozooplankton and bacterioplankton) belonging to uranium pit mine lake (PM) and evaluate the possible effects of acid effluents treated and discharged by MTU/BNI in Antas reservoir-AR and downstream of this, the Bortolan reservoir-BR. Besides the realization of abiotic and microbiology analysis of protozooplankton and bacterioplankton; was held standardization and deployment of the Fluorescence 'In Situ' Hybridization (FISH) technical using oligonucleotide probes for extremophile Archaea and Bacteria. According to the results, the PM showed the highest values for the chemical variables, lower pH values, lower protozooplankton density, however, protozooplanktonic high biomass showing the presence of tolerant species in this extreme environment. Antas and Bortolan reservoirs showed differences in the abiotic and biotic variables, AR showed suffer greater interference of acid effluents released at P41point and downstream of this at P14 point, lower protozooplankton biomass, lower bacterial density and pollution characteristics of inorganic sources. Using the FISH technique standard in this study to water bodies evaluated, it was possible to detect the presence of the extremophile bacteria of the Archaea domain in the three water bodies. The results of this study contribute to the knowledge of the pit mine lakes limnology which have become a major concern due to increased mining in the open. (author)

  1. Uranium deposits in France and in French overseas territories; Les gisements d'uranium de la France metropolitaine et des territoires francais d'Outre-Mer

    Energy Technology Data Exchange (ETDEWEB)

    Roubault, M. [Commissariat a l' Energie Atomique, Saclay (France). Centre d' Etudes Nucleaires

    1955-07-01

    The discover of radium element by Pierre and Marie Curie in 1898 activated the uranium ores prospecting in France and its overseas territories. Before 1945, rare and poor deposits were found with only one being operated in Madagascar and the production of nobiantalates from washing of pegmatitic eluvium. Since the setting up of the Research and Mines Department in the C.E.A. and the training of specialized exploration teams as well as the use of Geiger counters, the uranium ores prospecting has been largely developed in France. The mineralogical data resulting from studies during the pre-war period led to the discover of four main uranium ores content areas: La Crouzille deposit in Limousin characterized by large presence of pitchblende, the Bauzot deposit with massive presence of pitchblende as well, discover of mineralization traces in the Bois Noirs area where a rich uranium ore lodes were discovered afterwards and finally the madagascar deposit. Few other areas have been prospected and have got good evidences of uranium ores presence. The majority of French uranium deposits have got an 'hydrothermal' vein type with localized pitchblende or a secondary mineralization type. It described the different deposits by region and in chronological order of discover. The structural aspect and petrographic studies are discussed. The metallogenic study shows the presence of large mineralization in the French Hercynian massif. After ten years of uranium ores prospecting and mines work, it shows that France possesses numerous uranium deposits which can be qualified as large deposits and the minerals ores prospecting revealed that many deposits sites would be payable in the near future. (M.P.)

  2. A study of the efficiency of different spectrochemical buffers applied to the uranium ore analysis; Estudio de la eficiencia de diversos reguladores espectroqimicos aplicados al analisis de minerales de uranio

    Energy Technology Data Exchange (ETDEWEB)

    Roca, M.; Diaz Guerra, J. P.

    1981-07-01

    A direct-reading emission spectroscopy method allowing the determination of Al, Ca, Fe, Mg, Mn, Na, P, Si and Ti in geological materials, that are of interest for the prospecting and recovery of uranium, is proposed. Direct-current are between graphite electrodes Is used as the excitation source. Efficiency of Ag{sub 2}O, BaCO{sub 3}, Bi{sub 2}O{sub 3}, CuF{sub 2}, CuO, Ga{sub 2}0{sub 3}, Ge0{sub 2}, graphite, K{sub 2}CO{sub 3}, H{sub 2}B{sub 4}O{sub 7}, Li{sub 2}CO{sub 3}, Ni, PbS, Sb{sub 2}o{sub 4} , SrC0{sub 3}, Ti{sub 2}O{sub 3} and ZnO as spectrochemical buffers has been studied. It has been inferred that through a sample dilution with Li{sub 2}CO{sub 3}, SrC0{sub 3} and graphite powder in the rations 1:10:10:20, respectively, the highest reduction of the matrix effects is achieved. Phosphorus determination Is better performed with PbS as spectrochemical buffer Instead of the indicated above. The action of the selected compounds Is completed by using Co, In, Li and Sr as internal standards, and, as a whole, satisfactory accuracy and reproducibility are attained. (Author) 7 refs.

  3. Uranium, depleted uranium, biological effects; Uranium, uranium appauvri, effets biologiques

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    2001-07-01

    Physicists, chemists and biologists at the CEA are developing scientific programs on the properties and uses of ionizing radiation. Since the CEA was created in 1945, a great deal of research has been carried out on the properties of natural, enriched and depleted uranium in cooperation with university laboratories and CNRS. There is a great deal of available data about uranium; thousands of analyses have been published in international reviews over more than 40 years. This presentation on uranium is a very brief summary of all these studies. (author)

  4. Potential Aquifer Vulnerability in Regions Down-Gradient from Uranium In Situ Recovery (ISR) Sites

    Science.gov (United States)

    Sandstone-hosted roll-front uranium ore deposits originate when U(VI) dissolved in groundwater is reduced and precipitated as insoluble U(IV) minerals. Groundwater redox geochemistry, aqueous complexation, and solute migration are instrumental in leaching uranium from source rock...

  5. Uranium deposit in Kumsan area (1979)

    Energy Technology Data Exchange (ETDEWEB)

    Han, Jong Yun; Kim, Jeong Taek; Kim, Dai Oap [Korea Inst. of Geology Mining and Materials, Taejon (Korea, Republic of)

    1995-12-01

    The survey on the nuclear raw mineral (uranium) deposits had been carried out for a long time from early 1960`s to late 1980`s by the Geological and Mineral Institute of Energy and Resources. Unpublished data of the uranium ore deposits of Kumsan area is published on this paper. Geology on the Ogcheon System have been controversial by many geologists, therefore we have reviewed on the geology and stratigraphy. Particularly, we have interpreted the host root rock on the magnetite bearing banded gneiss, which is named so called Kyemeongsan Formation. (author). 5 maps.

  6. Uranium deposit in Yongyuri Miwon area (1978)

    Energy Technology Data Exchange (ETDEWEB)

    Kim, Jeong Taek; Han, Jong Yun; Kim, Dai Oap; Im Hyun Chul [Korea Inst. of Geology Mining and Materials, Taejon (Korea, Republic of)

    1995-12-01

    The survey on the nuclear raw mineral (uranium) deposits had been carried out for a long time from early 1960`s to late 1980`s by the Geological and Mineral Institute of Energy and Resources. Unpublished data of the uranium ore deposit of Yongyuri Miwon area is published on this paper. Geology on the Ogcheon System have been controversial by many geologists, therefore we have reviewed on the geology and stratigraphy. Particularly, we have interpreted the host root rock on the magnetite bearing banded gneiss, which is named so called Kyemeongsan Formation. (author). 5 refs., 1 tab., 2 maps.

  7. Uranium deposit in Yiheonri area (1978)

    Energy Technology Data Exchange (ETDEWEB)

    Kim, Jeong Taek; Kim, Dai Oap [Korea Inst. of Geology Mining and Materials, Taejon (Korea, Republic of)

    1995-12-01

    The survey on the nuclear raw mineral (uranium) deposits had been carried out for a long time from early 1960`s to late 1980`s by the Geological and Mineral Institute of Energy and Resources. Unpublished data of the uranium ore deposit of Yiheonri area is published on this paper. Geology on the Ogcheon System have been controversial by many geologists, therefore we have reviewed on the geology and stratigraphy. Particularly, we have interpreted the host root rock on the magnetite bearing banded gneiss, which is named so called Kyemeongsan Formation. (author). 4 tabs., 3 maps.

  8. Uranium deposit in Geosan B area (1978)

    Energy Technology Data Exchange (ETDEWEB)

    Kim, Gil Seung; Kim, Dai Oap; Kim, Jong Hwan [Korea Inst. of Geology Mining and Materials, Taejon (Korea, Republic of)

    1995-12-01

    The survey on the nuclear raw mineral (uranium) deposits had been carried out for a long time from early 1960`s to late 1980`s by the Geological and Mineral Institute of Energy and Resources. Unpublished data of the uranium ore deposit of Goesan Deokpyeongri B area is published on this paper. Geology on the Ogcheon System have been controversial by many geologists, therefore we have reviewed on the geology and stratigraphy. Particularly, we have interpreted the host root rock on the magnetite bearing banded gneiss, which is named so called Kyemeongsan Formation. (author). 8 maps.

  9. URANIUM-SERIES CONSTRAINTS ON RADIONUCLIDE TRANSPORT AND GROUNDWATER FLOW AT NOPAL I URANIUM DEPOSIT, SIERRA PENA BLANCA, MEXICO

    Energy Technology Data Exchange (ETDEWEB)

    S. J. Goldstein, S. Luo, T. L. Ku, and M. T. Murrell

    2006-04-01

    Uranium-series data for groundwater samples from the vicinity of the Nopal I uranium ore deposit are used to place constraints on radionuclide transport and hydrologic processes at this site, and also, by analogy, at Yucca Mountain. Decreasing uranium concentrations for wells drilled in 2003 suggest that groundwater flow rates are low (< 10 m/yr). Field tests, well productivity, and uranium isotopic constraints also suggest that groundwater flow and mixing is limited at this site. The uranium isotopic systematics for water collected in the mine adit are consistent with longer rock-water interaction times and higher uranium dissolution rates at the front of the adit where the deposit is located. Short-lived nuclide data for groundwater wells are used to calculate retardation factors that are on the order of 1,000 for radium and 10,000 to 10,000,000 for lead and polonium. Radium has enhanced mobility in adit water and fractures near the deposit.

  10. Metallogenesis of Devonian—Carboniferous Strata—bound Carbonate—type Uranium Deposits in South China

    Institute of Scientific and Technical Information of China (English)

    庞玉蕙

    1990-01-01

    This paper deais with the geological conditions.mineralization characteristics,genetic types and space-time distribution of the Devonian-Carboniferous strata-bound carbonate-type uranium deposits in South China.These ore deposits are genetically classified as the leaching type and the leaching-hydrothermal superimposed type,These ore deposits are confined mainly to the strata (D2-3,C1)of platform-lagoon carbonate facies.Unique tectonic settings are a vital factor leading to the formation of these uranium deposits.A metallogenetic model for these uranium deposits has been proposed.

  11. Geochemical characteristics of Dongsheng sandstone-type uranium deposit, Ordos Basin

    Institute of Scientific and Technical Information of China (English)

    SUN Yuzhuang; LIU Chiyang; DAI Shifeng; QIN Peng

    2007-01-01

    Generally, sandstone-type uranium deposits can be divided into three zones according to their redox conditions: oxidized zone, ore zone and reduced zone. The Dongsheng uranium deposit belongs to this type. In order to study its geochemical characteristics, 11 samples were taken from the three zones of the Dongsheng uranium deposit. Five samples of them were collected from the oxidized zone, four samples from the ore zone and two samples from the reduced zone. These samples were analyzed using organic and inorganic geochemical methods. The results of GC traces and ICP-MASS indicate that the three zones show different organic and inorganic geochemical characteristics.

  12. Statistical data of the uranium industry

    Energy Technology Data Exchange (ETDEWEB)

    None

    1979-01-01

    The Statistical Data of the Uranium Industry is a compilation of historical facts and figures through 1978. These statistics are based primarily on information provided voluntarily by the uranium exploration, mining, and milling companies. This publication is compiled and updated annually by the Grand Junction Office (GJO). Most of the numbers reported herein have been rounded. The production, reserves, drilling, and production capability information has been reported in a manner which avoids disclosure of proprietary information. The nomenclature of DOE's forward cost ore reserve estimates has been changed to reserve estimates because ore usually connotes material which can be extracted at a profit. Also, because of some confusion, we emphasize that this book follows the common industry practice of reporting mine production, reserves, and potential resources as tons of U/sub 3/O/sub 8/ in ore and reporting mill production as tons of U/sub 3/O/sub 8/ in concentrate. Uranium inventories for Texas have been added. The distribution of $50 reserves by mining method in producing and nonproducing properties has been newly included. An analysis of costs associated with production capability has been added (Appendix B). A probabilistic analysis of reserves has been introduced this year. The technical methodology for this analysis is outlined, and probability distribution curves for the 1/1/79 $30 and $50 reserves are presented.

  13. Lime, agent to uranium concentration; La chaux comme agent de concentration de l'uranium

    Energy Technology Data Exchange (ETDEWEB)

    Mouret, P.; Le Bris, J.; Kremer, M. [Commissariat a l' Energie Atomique, Saclay (France). Centre d' Etudes Nucleaires; Gautier, R. [Etablissement Kuhlmann, Service d' Etudes et de Pilotages Industriels (France)

    1958-07-01

    Choice of the process according to health requirements. Description of the process: dissolution of uranium by sulfuric leaching of ores, precipitation of uranium by lime, re-dissolution of the concentrate with nitric ions, purification by T.B.P. finally resulting in pure uranyl nitrate solution containing 400 g/litre. (author)Fren. [French] Les raisons du choix du procede en fonction des imperatifs d'hygiene, sont exposees ainsi que le procede qui consiste en une dissolution de l'uranium des minerais par lixiviation sulfurique, precipitation de l'uranium par la chaux et redissolution du concentre en presence d'ions nitriques, purification par le T.B.P. et obtention d'un concentre final de nitrate d'uranyle pur a 400 g/litre. (auteur)

  14. The history of uranium mining and the Navajo people.

    Science.gov (United States)

    Brugge, Doug; Goble, Rob

    2002-09-01

    From World War II until 1971, the government was the sole purchaser of uranium ore in the United States. Uranium mining occurred mostly in the southwestern United States and drew many Native Americans and others into work in the mines and mills. Despite a long and well-developed understanding, based on the European experience earlier in the century, that uranium mining led to high rates of lung cancer, few protections were provided for US miners before 1962 and their adoption after that time was slow and incomplete. The resulting high rates of illness among miners led in 1990 to passage of the Radiation Exposure Compensation Act.

  15. The History of Uranium Mining and the Navajo People

    Science.gov (United States)

    Brugge, Doug; Goble, Rob

    2002-01-01

    From World War II until 1971, the government was the sole purchaser of uranium ore in the United States. Uranium mining occurred mostly in the southwestern United States and drew many Native Americans and others into work in the mines and mills. Despite a long and well-developed understanding, based on the European experience earlier in the century, that uranium mining led to high rates of lung cancer, few protections were provided for US miners before 1962 and their adoption after that time was slow and incomplete. The resulting high rates of illness among miners led in 1990 to passage of the Radiation Exposure Compensation Act. PMID:12197966

  16. Morphological Comparison of U3O8 Ore Concentrates from Canada Key Lake and Namibia Sources

    Energy Technology Data Exchange (ETDEWEB)

    Schwartz, Daniel S. [Los Alamos National Lab. (LANL), Los Alamos, NM (United States); Tandon, Lav [Los Alamos National Lab. (LANL), Los Alamos, NM (United States); Martinez, Patrick Thomas [Los Alamos National Lab. (LANL), Los Alamos, NM (United States)

    2016-03-11

    Uranium ore concentrates from two different sources were examined using scanning electron microscopy (SEM) and energy dispersive spectroscopy (EDS). The ore powders are referred to as Namibia (id. no. 90036, LIMS id. no. 18775) and Canada Key Lake (id. no. 90019, LIMS id. no. 18774). Earlier work identified the ores as the U₃O₈ phase of uranium oxide using x-ray diffraction. Both sets of powders were in the form of dark brown to black powder fines. However, the Canada Key Lake concentrates contained larger chunks of material on the millimeter scale that were easily visible to the unaided eye. The powders were mounted for SEM examination by hand dispersing a small amount onto conductive sticky tape. Two types of applicators were used and compared: a fine-tipped spatula and a foam-tipped applicator. The sticky tape was on a standard SEM “tee” mount, which was tapped to remove loose contamination before being inserted into the SEM.

  17. Determination of {sup 2}30Th (Ionium) in uranium ores and wastes from uranium reprocessing. IV. Calculation of ionium separation yield; Determinacion de {sup 2}39Th (Ionio) en minerales y residuos del procesado de Uranio. IV: Determinacion del rendimiento en la separacion del {sup 2}30 Th

    Energy Technology Data Exchange (ETDEWEB)

    Galiano Sedano, J. A.; Acena Barrenechea, M. L.

    1974-07-01

    For determining ionium ({sup 2}30Th) in minerals and uranium processing wastes by precipitation with fluorhidric acid, using lanthanum as carrier, and selective extraction with tenoytrifluoroacetone (TTA) followed by radiometric determination of the isolated nuclide, it is necessary the use of a tracer since the chemical yield of the separation ranges between wide limits. In this paper, the use of the beta-emitter {sup 2}34Th as the most convenient tracer is discussed. Equations are derived for correcting for counting errors introduced by other thorium isotopes which are present either in the sample or in the tracer, as well as for calculating the chemical yield of the separation. These equations have been experimentally checked by ionium determinations carried out with different types of samples. (Author) 18 refs.

  18. Complexing and hydrothermal ore deposition

    CERN Document Server

    Helgeson, Harold C

    1964-01-01

    Complexing and Hydrothermal Ore Deposition provides a synthesis of fact, theory, and interpretative speculation on hydrothermal ore-forming solutions. This book summarizes information and theory of the internal chemistry of aqueous electrolyte solutions accumulated in previous years. The scope of the discussion is limited to those aspects of particular interest to the geologist working on the problem of hydrothermal ore genesis. Wherever feasible, fundamental principles are reviewed. Portions of this text are devoted to calculations of specific hydrothermal equilibriums in multicompone

  19. Statistical data of the uranium industry

    Energy Technology Data Exchange (ETDEWEB)

    None

    1977-01-01

    The ''Statistical Data of the Uranium Industry'' is a compilation of historical facts and figures through 1976. These statistics are based primarily on information provided voluntarily by the uranium exploration, mining, and milling companies. This publication is compiled and revised annually by the Grand Junction Office. The production and ore reserve information has been compiled in a manner which avoids disclosure of proprietary information. Due to increased interest in higher-cost and lower-grade resources, four new categories of information are provided: (1) an estimate of the $50 per pound or less reserves and potential resources (p. 21-22, 26, 43), (2) preproduction and postproduction uranium mineral inventories (p. 34-39), (3) size-depth-thickness and size-grade matrices (p. 64-70), and (4) average U/sub 3/O/sub 8/ prices for delivery commitments (p. 97-98).

  20. Uranium deposits of the world. Europe

    Energy Technology Data Exchange (ETDEWEB)

    Dahlkamp, Franz J.

    2016-07-01

    Uranium Deposits of the World, in three volumes, comprises an unprecedented compilation of data and descriptions of the uranium regions in Asia, USA, Latin America and Europe structured by countries. With this third, the Europe volume, Uranium Deposits of the World presents the most extensive data collection of the set. It covers about 140 uranium regions in more than 20 European countries with nearly 1000 mentioned uranium deposits. Each country and region receives an analytical overview followed by the geologically- and economically-relevant synopsis of the individual regions and fields. The presentations are structured in three major sections: (a) location and magnitude of uranium regions, districts, and deposits, (b) principal features of regions and districts, and (c) detailed characteristics of selected ore fields and deposits. This includes sections on geology, alteration, mineralization, shape and dimensions of deposits, isotopes data, ore control and recognition criteria, and metallogenesis. Beside the main European uranium regions, for example in the Czech Republic, Eastern Germany, France, the Iberian Peninsula or Ukraine, also small regions an districts to the point of singular occurrences of interest are considered. This by far the most comprehensive presentation of European uranium geology and mining would not be possible without the author's access to extensive information covering the countries of the former Eastern Bloc states, which was partly not previously available. Abundantly illustrated with information-laden maps and charts throughout, this reference work is an indispensable tool for geologists, mining companies, government agencies, and others with an interest in European key natural resources. A great help for the reader's orientation are the substantial bibliography of uranium-related publications and the indices, latter containing about 3900 entries in the geographical part alone. The three volumes of Uranium Deposits of the

  1. Selective Removal of Uranium from the Washing Solution of Uranium-Contaminated Soil

    Energy Technology Data Exchange (ETDEWEB)

    Kim, Seung Soo; Han, G. S.; Kim, G. N.; Koo, D. S.; Jeong, J. W.; Choi, J. W. [Korea Atomic Energy Research Institute, Daejeon (Korea, Republic of)

    2015-10-15

    This study examined selective removal methods of uranium from the waste solution by ion exchange resins or solvent extraction methods to reduce amount of the 2{sup nd} waste. Alamine-336, known as an excellent extraction reagent of uranium from the leaching solution of uranium ore, did not remove uranium from the acidic washing solution of soil. Uranyl ions in the acidic waste solution were sorbed on ampholyte resin with a high sorption efficiency, and desorbed from the resin by a washing with 0.5 M Na{sub 2}CO{sub 3} solution at 60 .deg. C. However, the uranium dissolved in the sulfuric acid solution was not sorbed onto the strong anion exchanger resins. A great amount of uranium-contaminated (U-contaminated) soil had been generated from the decommissioning of a uranium conversion plant. Our group has developed a decontamination process with washing and electrokinetic methods to decrease the amount of waste to be disposed of. However, this process generates a large amount of waste solution containing various metal ions.

  2. Borehole Logging for Uranium by Gamma-Ray Spectrometry

    DEFF Research Database (Denmark)

    Løvborg, Leif; Nyegaard, P.; Christiansen, E. M.

    1980-01-01

    The resources in a large syngenetic deposit of low-grade uranium (U) ore with thorium at Kvanefjeld, South Greenland, were evaluated by spectrometric gamma-ray logging of 23 boreholes, 46 mm in diameter and 200 m deep. The borehole probe's detector contained 22 cm3 of sodium-iodide, and the photo......The resources in a large syngenetic deposit of low-grade uranium (U) ore with thorium at Kvanefjeld, South Greenland, were evaluated by spectrometric gamma-ray logging of 23 boreholes, 46 mm in diameter and 200 m deep. The borehole probe's detector contained 22 cm3 of sodium...... of the spectrometer system were determined by calculating the average number of U and thorium (Th) counts per meter of borehole and comparing these with the U-Th concentrations in 1-m sections of analyzed drill core. The sensitivity and the background count rate in the uranium window varied appreciably from one hole...

  3. Field Testing of Downgradient Uranium Mobility at an In-Situ Recovery Uranium Mine

    Science.gov (United States)

    Reimus, P. W.; Clay, J. T.; Rearick, M.; Perkins, G.; Brown, S. T.; Basu, A.; Chamberlain, K.

    2015-12-01

    In-situ recovery (ISR) mining of uranium involves the injection of O2 and CO2 (or NaHCO3) into saturated roll-front deposits to oxidize and solubilize the uranium, which is then removed by ion exchange at the surface and processed into U3O8. While ISR is economical and environmentally-friendly relative to conventional mining, one of the challenges of extracting uranium by this process is that it leaves behind a geochemically-altered aquifer that is exceedingly difficult to restore to pre-mining geochemical conditions, a regulatory objective. In this research, we evaluated the ability of the aquifer downgradient of an ISR mining area to attenuate the transport of uranium and other problem constituents that are mobilized by the mining process. Such an evaluation can help inform both regulators and the mining industry as to how much restoration of the mined ore zone is necessary to achieve regulatory compliance at various distances downgradient of the mining zone even if complete restoration of the ore zone proves to be difficult or impossible. Three single-well push-pull tests and one cross-well test were conducted in which water from an unrestored, previously-mined ore zone was injected into an unmined ore zone that served as a geochemical proxy for the downgradient aquifer. In all tests, non-reactive tracers were injected with the previously-mined ore zone water to allow the transport of uranium and other constituents to be compared to that of the nonreactive species. In the single-well tests, it was shown that the recovery of uranium relative to the nonreactive tracers ranged from 12-25%, suggesting significant attenuation capacity of the aquifer. In the cross-well test, selenate, molybdate and metavanadate were injected with the unrestored water to provide information on the transport of these potentially-problematic anionic constituents. In addition to the species-specific transport information, this test provided valuable constraints on redox conditions within

  4. The prospection of uranium and thorium ores in desert country and in equatorial forest regions of the Union Francaise; La prospection des minerais d'uranium et de thorium dans les pays desertiques et dans les regions de foret equatoriale de l'Union Francaise

    Energy Technology Data Exchange (ETDEWEB)

    Lecoq, J.J.; Bigotte, G.; Hinault, J.; Leconte, J.R. [Commissariat a l' Energie Atomique, Saclay (France). Centre d' Etudes Nucleaires

    1958-07-01

    Since it was founded, the D.R.E.M. has carried out important prospection work in the overseas territories which now make up the Communaute Francaise. This work, now involving almost a million km{sup 2}, represents an experiment scarcely equalled throughout the world. Research in these territories presents both general and technical difficulties, which are especially severe in countries with extreme climates: deserts or dense equatorial forests. The adaptation of various methods of radioactive ore prospection to these regions is described, and also the results obtained. Three particular examples are given in detail: - general exploration in the Hoggar, and reconnoitring of particular indications; - general exploration in the equatorial forest of French Guyana; - detailed study of a sign of uraniferous occurrences and its surroundings in the equatorial zone (Mounana deposit near Franceville (Gabon)). (author) [French] Depuis sa creation, la D.R.E.M. poursuit un effort important de prospection dans les territoires d'outre-mer qui constituent maintenant la Communaute Fran ise. Ces travaux qui interessent maintenant pres d'un million de km{sup 2} constituent une experience qui a peu d'equivalent dans le monde. Les recherches dans ces territoires presentent des difficultes, sur le plan general et sur le plan technique, particulierement ardues dans les pays a climats excessifs: deserts ou forets equatoriales denses. On decrit l'adaptation des diverses methodes de prospection des minerais radioactifs a ces regions et les resultats qu'elles ont fournis. Trois exemples particuliers sont donnes en detail: - Exploration generale au Hoggar, et reconnaissance d'indices particuliers. - Exploration generale en foret equatoriale en Guyane fran ise. - Etude detaillee d'un indice uranifere et de ses environs en zone equatoriale (gisement de Mounana pres de France-ville (Gabon)). (auteur)

  5. Uranium industry annual 1996

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    1997-04-01

    The Uranium Industry Annual 1996 (UIA 1996) provides current statistical data on the US uranium industry`s activities relating to uranium raw materials and uranium marketing. The UIA 1996 is prepared for use by the Congress, Federal and State agencies, the uranium and nuclear electric utility industries, and the public. Data on uranium raw materials activities for 1987 through 1996 including exploration activities and expenditures, EIA-estimated reserves, mine production of uranium, production of uranium concentrate, and industry employment are presented in Chapter 1. Data on uranium marketing activities for 1994 through 2006, including purchases of uranium and enrichment services, enrichment feed deliveries, uranium fuel assemblies, filled and unfilled market requirements, uranium imports and exports, and uranium inventories are shown in Chapter 2. A feature article, The Role of Thorium in Nuclear Energy, is included. 24 figs., 56 tabs.

  6. Hunting for Iron Ore Bargains

    Institute of Scientific and Technical Information of China (English)

    2009-01-01

    One of China’s leading steel mills has turned to smaller mines for long-term, lowcost iron ore supplies china’s oldest steel producer is looking to South America to fulfill its iron ore needs in the face of rising prices from

  7. Development of Novel Sorbents for Uranium Extraction from Seawater

    Energy Technology Data Exchange (ETDEWEB)

    Lin, Wenbin; Taylor-Pashow, Kathryn

    2014-01-08

    As the uranium resource in terrestrial ores is limited, it is difficult to ensure a long-term sustainable nuclear energy technology. The oceans contain approximately 4.5 billion tons of uranium, which is one thousand times the amount of uranium in terrestrial ores. Development of technologies to recover the uranium from seawater would greatly improve the uranium resource availability, sustaining the fuel supply for nuclear energy. Several methods have been previously evaluated including solvent extraction, ion exchange, flotation, biomass collection, and adsorption; however, none have been found to be suitable for reasons such as cost effectiveness, long term stability, and selectivity. Recent research has focused on the amidoxime functional group as a promising candidate for uranium sorption. Polymer beads and fibers have been functionalized with amidoxime functional groups, and uranium adsorption capacities as high as 1.5 g U/kg adsorbent have recently been reported with these types of materials. As uranium concentration in seawater is only ~3 ppb, great improvements to uranium collection systems must be made in order to make uranium extraction from seawater economically feasible. This proposed research intends to develop transformative technologies for economic uranium extraction from seawater. The Lin group will design advanced porous supports by taking advantage of recent breakthroughs in nanoscience and nanotechnology and incorporate high densities of well-designed chelators into such nanoporous supports to allow selective and efficient binding of uranyl ions from seawater. Several classes of nanoporous materials, including mesoporous silica nanoparticles (MSNs), mesoporous carbon nanoparticles (MCNs), meta-organic frameworks (MOFs), and covalent-organic frameworks (COFs), will be synthesized. Selective uranium-binding liagnds such as amidoxime will be incorporated into the nanoporous materials to afford a new generation of sorbent materials that will be

  8. Environmental Radioactive Impact Associated to Uranium Production

    Directory of Open Access Journals (Sweden)

    Fernando P. Carvalho

    2011-01-01

    Full Text Available Problem statement: One century of uranium mining in Europe and North-America created a legacy of ore mining and milling sites needing rehabilitation for environmental and human safety. In the last decades developments of uranium mining displaced the core of this activity to Australia, Canada and African countries. In the coming years, uranium mining is expected to grow further, in those countries and elsewhere, due to the possible increase of nuclear power production and thus the amount of radioactive and toxic tailing materials will grow. Approach: International radiation protection guidelines and legislation have known recent developments and set the radiation dose limit applied to members of the public at 1 mSv y-1. Taking into account past and present uranium waste management and environmental remediation measures adopted already in some countries, we assessed the implications of enforcing this new dose limit in uranium milling and mining areas. Results: The radioactive impact of uranium mining and milling was illustrated through case studies. Environmental radioactivity monitoring and surveillance carried out in areas impacted by uranium mining and milling industry showed generally that dose limit for members of the public was exceeded. The compliance with this dose limit is nowadays the main goal for environmental remediation programs of legacy sites implemented in European Union countries. Taking into account the new radiation protection regulations, a change is required in mining practices from traditionally reactionary (problem solving to proactive (integrated management and life-cycle approach. Conclusion: A new paradigm in uranium mining should be implemented worldwide to ensure reduced environmental radioactivity impact current and future reduced radiation risk exposure of population.

  9. Apache Trail uranium prospect, White Signal district, Grant County, New Mexico

    Science.gov (United States)

    Bauer, Herman L.

    1951-01-01

    The Apache Trail uranium prospect in the White Signal district, Grant County. N. Mex., was mapped by the Geological Survey in May 1950. Pre-Cambrian granite is cut by a diabase dike and a parallel quartz-hematite vein, both of which strike easterly and dip 60 to 65 degrees north. Small quantities of copper carbonates and bismuth-gold ore have been mined. The quartz-hematite vein is moderately radioactive and, although no uranium minerals were seen, two samples contained about 0.01 percent uranium. The diabase dike locally contains torbernite. Two samples of diabase contained about 0.04 percent uranium.

  10. Evaluation of in vitro dissolution rates of thorium in uranium mill tailings.

    Science.gov (United States)

    Reif, R H

    1994-11-01

    Dissolution rates of thorium from the uranium mill tailings piles at two Department of Energy Uranium Mill Tailings Remedial Action Project (UMTRAP) sites have been evaluated. The thorium dissolution rates were evaluated in vitro using simulated lung fluid. The former uranium mills at the UMTRAP sites employed different chemical processes (acid leach and alkaline pressure leach) to extract the uranium from the ore, and the thorium dissolution rates at these sites were found to be markedly different. A site specific annual limit on intake (ALI) value for 230Th was calculated for the UMTRAP site that was associated with a multiple component dissolution curve.

  11. Monte Carlo Simulation of EDXRF Spectrometer for Uranium Ores

    Institute of Scientific and Technical Information of China (English)

    ZHAO; Jiang-bin

    2013-01-01

    Energy dispersive X-ray fluorescence spectrometry(EDXRF)is an important nondestructive analytical technology,which can be used for elements recognition and measurement.Before the design of the EDXRF spectrometer,it’s necessary to perform MC simulation with MCNP code about the X-ray tube high voltage,thickness of Beryllium window,geometry of filter and collimator,as well as the geometric

  12. National uranium resource evaluation. Geology and recognition criteria for sandstone uranium deposits of the salt wash type, Colorado Plateau Province. Final report

    Energy Technology Data Exchange (ETDEWEB)

    Thamm, J.K.; Kovschak, A.A. Jr.; Adams, S.S.

    1981-01-01

    The uranium-vanadium deposits of the Salt Wash Member of the Morrison Formation in the Colorado Plateau are similar to sandstone uranium deposits elsewhere in the USA. The differences between Salt Wash deposits and other sandstone uranium deposits are also significant. The Salt Wash deposits are unique among sandstone deposits in that they are dominantly vanadium deposits with accessory uranium. The Salt Wash ores generally occur entirely within reduced sandstone, without adjacent tongues of oxidized sandstone. They are more like the deposits of Grants, which similarly occur in reduced sandstones. Recent studies of the Grants deposits have identified alteration assemblages which are asymmetrically distributed about the deposits and provide a basis for a genetic model for those deposits. The alteration types recognized by Shawe in the Slick Rock district may provide similar constraints on ore formation when expanded to broader areas and more complete chemical analyses.

  13. Electrolytic extraction of uranium from Egyptian phosphorites

    Energy Technology Data Exchange (ETDEWEB)

    Madkour, L.H. [Dept. of Chemistry, Faculty of Science, Tanta Univ. (Egypt)

    1995-02-01

    Nile Valley phosphate deposits (East Luxor locality), considered in Egypt as a rather rich source of uranium, is subjected to mineralogical, chemical, spectral and infrared spectrometric analyses. A process is proposed for the hydrometallurgical treatment of the phosphate rock for the recovery of uranium and the production of phosphatic fertilizers, without polluting the environment with radioactive materials. A uraniferous iron phosphate concentrate (2.5% U) which is produced as a by-product, is separately processed in an alkaline leaching step using a high concentration of both Na{sub 2}CO{sub 3} and NaHCO{sub 3} under oxidizing conditions. The product, sodium uranyl tricarbonate complex Na{sub 4}UO{sub 2}(CO{sub 3}){sub 3} liquor, is converted into the conventional uranium concentrate of sodium diuranate Na{sub 2}U{sub 2}O{sub 7} through sodic decomposition treatment. Uranium metal is cathodically deposited from a number of solutions containing the ore metal concentrate liquor, and a complexing agent at controlled pH. The effects of various factors on the deposition of uranium are discussed. The results of spectrophotometric and chemical analyses revealed that the purity of the deposited metal is > 99%. (orig.)

  14. Uranium Industry Annual, 1992

    Energy Technology Data Exchange (ETDEWEB)

    1993-10-28

    The Uranium Industry Annual provides current statistical data on the US uranium industry for the Congress, Federal and State agencies, the uranium and electric utility industries, and the public. The feature article, ``Decommissioning of US Conventional Uranium Production Centers,`` is included. Data on uranium raw materials activities including exploration activities and expenditures, resources and reserves, mine production of uranium, production of uranium concentrate, and industry employment are presented in Chapter 1. Data on uranium marketing activities including domestic uranium purchases, commitments by utilities, procurement arrangements, uranium imports under purchase contracts and exports, deliveries to enrichment suppliers, inventories, secondary market activities, utility market requirements, and uranium for sale by domestic suppliers are presented in Chapter 2.

  15. Uranium: War, Energy and the Rock That Shaped the World; Uranium: la biographie

    Energy Technology Data Exchange (ETDEWEB)

    Zoellner, T.

    2009-07-01

    Having traveled extensively through the savannah of Africa, the mountains of Eastern Europe, and the deserts of Utah, the author delves into the complex science, politics and history of uranium, which presents the best and worst of mankind: the capacity for scientific progress and political genius; the capacity for nihilism, exploitation, and terror. Because the author covers so much ground, from the discovery of radioactivity, through the development of the atomic bomb, he does not go into great depth on any one topic. Nonetheless, he paints vivid pictures of uranium's impact, including forced labor in Soviet mines and lucky prospectors who struck it rich in harsh environments, the spread of uranium smuggling, as well as an explanation of why it was absurd to claim that Saddam Hussein was attempting to purchase significant quantities of uranium from Niger. The only shortcoming is the author's omission of the issue of radioactive wastes generated by nuclear power. The author knows well what uranium looks like, why peril pulses in its every atom, and how scientists exploit its nuclear volatility. The drama is found in the weaponry uranium has spawned as demonstrated at Hiroshima and Nagasaki. In pursuit of this raw power, the U.S. let Navajos die extracting needed ore and let southwestern cities sicken beneath clouds from reckless testing. The Soviet Union sentenced tens of thousands to lethal gulag mines. Israel diverted ore through deception on the high seas. Pakistan stole European refining technology. Alive with devious personalities, the author's narrative ultimately exposes the frightening vulnerability of a world with too many sources of a dangerous substance and too little wisdom to control it

  16. Microbial reduction of iron ore

    Science.gov (United States)

    Hoffmann, Michael R.; Arnold, Robert G.; Stephanopoulos, Gregory

    1989-01-01

    A process is provided for reducing iron ore by treatment with microorganisms which comprises forming an aqueous mixture of iron ore, microorganisms operable for reducing the ferric iron of the iron ore to ferrous iron, and a substrate operable as an energy source for the microbial reduction; and maintaining the aqueous mixture for a period of time and under conditions operable to effect the reduction of the ore. Preferably the microorganism is Pseudomonas sp. 200 and the reduction conducted anaerobically with a domestic wastewater as the substrate. An aqueous solution containing soluble ferrous iron can be separated from the reacted mixture, treated with a base to precipitate ferrous hydroxide which can then be recovered as a concentrated slurry.

  17. Total-Count Calibration Blocks for use in uranium Exploration

    DEFF Research Database (Denmark)

    Løvborg, Leif

    Transportable calibration blocks for field scintillometers and borehole probes were manufactured from concrete and installed at calibration sites in Denmark and Greece. The concrete mixes were prepared from aggregates of quartz sand and crushed uranium-thorium ore. Hater-reducing agents and silica...... dust added to the cement paste produced concretes of acceptable porosity and pore structure. The content of ore was adjusted to provide block grades of approximately 2, 140, and 540 units of radioelement concentration (Ur). Thorium was estimated to contribute 0.39 ± 0.02 Ur per ppm Th. The adopted...

  18. Statistical model of global uranium resources and long-term availability

    Directory of Open Access Journals (Sweden)

    Monnet Antoine

    2016-01-01

    Full Text Available Most recent studies on the long-term supply of uranium make simplistic assumptions on the available resources and their production costs. Some consider the whole uranium quantities in the Earth's crust and then estimate the production costs based on the ore grade only, disregarding the size of ore bodies and the mining techniques. Other studies consider the resources reported by countries for a given cost category, disregarding undiscovered or unreported quantities. In both cases, the resource estimations are sorted following a cost merit order. In this paper, we describe a methodology based on “geological environments”. It provides a more detailed resource estimation and it is more flexible regarding cost modelling. The global uranium resource estimation introduced in this paper results from the sum of independent resource estimations from different geological environments. A geological environment is defined by its own geographical boundaries, resource dispersion (average grade and size of ore bodies and their variance, and cost function. With this definition, uranium resources are considered within ore bodies. The deposit breakdown of resources is modelled using a bivariate statistical approach where size and grade are the two random variables. This makes resource estimates possible for individual projects. Adding up all geological environments provides a repartition of all Earth's crust resources in which ore bodies are sorted by size and grade. This subset-based estimation is convenient to model specific cost structures.

  19. Geological and geochemical aspects of uranium deposits: a selected, annotated bibliography

    Energy Technology Data Exchange (ETDEWEB)

    Thomas, J.M.; Brock, M.L.; Garland, P.A.; White, M.B.; Daniel, E.W. (comps.)

    1978-06-01

    A compilation of 490 references is presented which is the second in a series compiled from the National Uranium Resource Evaluation (NURE) Bibliographic Data Base. This data base is one of six created by the Ecological Sciences Information Center, Oak Ridge National Laboratory, for the Grand Junction Office of the Department of Energy. Major emphasis for this volume has been placed on uranium geology, encompassing deposition, genesis of ore deposits, and ore controls; and prospecting techniques, including geochemistry and aerial reconnaissance. The following indexes are provided to aid the user in locating references of interest: author, geographic location, quadrangel name, geoformational feature, taxonomic name, and keyword.

  20. Uranium processing and properties

    CERN Document Server

    2013-01-01

    Covers a broad spectrum of topics and applications that deal with uranium processing and the properties of uranium Offers extensive coverage of both new and established practices for dealing with uranium supplies in nuclear engineering Promotes the documentation of the state-of-the-art processing techniques utilized for uranium and other specialty metals

  1. Uranium market as well as production and processing of reactor fuel, 1995/1996; Rynek uranu oraz produkcji i przerobu paliw reaktorowych, 1995/1996

    Energy Technology Data Exchange (ETDEWEB)

    Dembinski, W. [Institute of Nuclear Chemistry and Technology, Warsaw (Poland)

    1997-12-01

    The worldwide uranium market has been analysed in period of 1995/1996. The uranium reserves, production of reactor fuel from natural ores and from fuel recycling have been presented.The worldwide price tendency have been discussed on that background. 3 refs, 1 fig., 3 tabs.

  2. Borehole survey of uranium deposit in Yongyuri Miwon area (1979)

    Energy Technology Data Exchange (ETDEWEB)

    Kim, Dai Oap [Korea Inst. of Geology Mining and Materials, Taejon (Korea, Republic of)

    1995-12-01

    The survey on the nuclear raw mineral (uranium) deposits had been carried out for a long time from early 1960`s to late 1980`s by the Geological and Mineral Institute of Energy and Resources. Unpublished data of the uranium ore deposit of Yongyuri Miwon area is published on this paper. Geology on the Ogcheon System have been controversial by many geologists, therefore we have reviewed on the geology and stratigraphy. Particularly, we have interpreted the host root rock on the magnetite bearing banded gneiss, which is named so called Kyemeongsan Formation. (author). 5 maps.

  3. Uranium deposit in Geosan Deokpyeongri C area (1978)

    Energy Technology Data Exchange (ETDEWEB)

    Kim, Jeong Taek; Han, Jong Yun; Kim, Jong Hwan [Korea Institute of Geology Mining and Materials, Taejon (Korea, Republic of)

    1995-12-01

    The survey on the nuclear raw mineral (uranium) deposits had been carried out for a long time from early 1960`s to late 1980`s by the Geological and Mineral Institute of Energy and Resources. Unpublished data of the uranium ore deposit of Goesan Deokpyeongri C area is published on this paper. Geology on the Ogcheon System have been controversial by many geologists, therefore we have reviewed on the geology and stratigraphy. Particularly, we have interpreted the host root rock on the magnetite bearing banded gneiss, which is named so called Kyemeongsan Formation. (author). 1 fig., 4 maps.

  4. Morphology Characterization of Uranium Particles From Laser Ablated Uranium Materials

    Institute of Scientific and Technical Information of China (English)

    2011-01-01

    In the study, metallic uranium and uranium dioxide material were ablated by laser beam in order to simulate the process of forming the uranium particles in pyrochemical process. The morphology characteristic of uranium particles and the surface of

  5. Urinary excretion of uranium in adult inhabitants of the Czech Republic.

    Science.gov (United States)

    Malátová, Irena; Bečková, Věra; Kotík, Lukáš

    2016-02-01

    The main aim of this study was to determine and evaluate urinary excretion of uranium in the general public of the Czech Republic. This value should serve as a baseline for distinguishing possible increase in uranium content in population living near legacy sites of mining and processing uranium ores and also to help to distinguish the proportion of the uranium content in urine among uranium miners resulting from inhaled dust. The geometric mean of the uranium concentration in urine of 74 inhabitants of the Czech Republic was 0.091 mBq/L (7.4 ng/L) with the 95% confidence interval 0.071-0.12 mBq/L (5.7-9.6 ng/L) respectively. The geometric mean of the daily excretion was 0.15 mBq/d (12.4 ng/d) with the 95% confidence interval 0.12-0.20 mBq/d (9.5-16.1 ng/d) respectively. Despite the legacy of uranium mines and plants processing uranium ore in the Czech Republic, the levels of uranium in urine and therefore, also human body content of uranium, is similar to other countries, esp. Germany, Slovenia and USA. Significant difference in the daily urinary excretion of uranium was found between individuals using public supply and private water wells as a source of drinking water. Age dependence of daily urinary excretion of uranium was not found. Mean values and their range are comparable to other countries, esp. Germany, Slovenia and USA.

  6. The roles of organic matter in the formation of uranium deposits in sedimentary rocks

    Science.gov (United States)

    Spirakis, C.S.

    1996-01-01

    Because reduced uranium species have a much smaller solubility than oxidized uranium species and because of the strong association of organic matter (a powerful reductant) with many uranium ores, reduction has long been considered to be the precipitation mechanism for many types of uranium deposits. Organic matter may also be involved in the alterations in and around tabular uranium deposits, including dolomite precipitation, formation of silicified layers, iron-titanium oxide destruction, dissolution of quartz grains, and precipitation of clay minerals. The diagenetic processes that produced these alterations also consumed organic matter. Consequently, those tabular deposits that underwent the more advanced stages of diagenesis, including methanogenesis and organic acid generation, display the greatest range of alterations and contain the smallest amount of organic matter. Because of certain similarities between tabular uranium deposits and Precambrian unconformity-related deposits, some of the same processes might have been involved in the genesis of Precambrian unconformity-related deposits. Hydrologic studies place important constraints on genetic models of various types of uranium deposits. In roll-front deposits, oxidized waters carried uranium to reductants (organic matter and pyrite derived from sulfate reduction by organic matter). After these reductants were oxidized at any point in the host sandstone, uranium minerals were reoxidized and transported further down the flow path to react with additional reductants. In this manner, the uranium ore migrated through the sandstone at a rate slower than the mineralizing ground water. In the case of tabular uranium deposits, the recharge of surface water into the ground water during flooding of lakes carried soluble humic material to the water table or to an interface where humate precipitated in tabular layers. These humate layers then established the chemical conditions for mineralization and related

  7. Application of alkaline leaching to the extraction of uranium from shale of the Vosges; Application de la lixiviation alcaline a l'extraction de l'uranium du schiste des Vosges

    Energy Technology Data Exchange (ETDEWEB)

    Mouret, P.; Pottier, P.; Le Bris, J. [Commissariat a l' Energie Atomique, Saclay (France). Centre d' Etudes Nucleaires; Soudan, P. [Centre d' Etude de Lalumine, Compagnie Pechiney (France)

    1958-07-01

    Description of chemical treatment of Vosges shales to obtain uranium by alkaline leaching. Mineralogy aspects of ore, physical and chemical conditions of leaching, solid/liquid separation, uranium recovery by either ion exchange process or electrolytic precipitation. (author)Fren. [French] Description du traitement chimique des schistes des Vosges pour extraire l'uranium en milieu alcalin. L'aspect mineralogique, les conditions physiques et chimiques de la lixiviation, la separation solide/liquide et la recuperation de l'uranium soit par echangeurs d'ions, soit par precipitation electrolytique y sont exposes. (auteur)

  8. Uranium Provinces in China

    Institute of Scientific and Technical Information of China (English)

    2000-01-01

    Three uranium provinces are recognized in China, the Southeast China uranium province, the Northeast China-lnner Mongolia uranium province and the Northwest China (Xinjiang) uranium province. The latter two promise good potential for uranium resources and are major exploration target areas in recent years. There are two major types of uranium deposits: the Phanerozoic hydrothermal type (vein type) and the Meso-Cenozoic sandstone type in different proportions in the three uranium provinces. The most important reason or prerequisite for the formation of these uranium provinces is that Precambrian uranium-enriched old basement or its broken parts (median massifs) exists or once existed in these regions, and underwent strong tectonomagmatic activation during Phanerozoic time. Uranium was mobilized from the old basement and migrated upwards to the upper structural level together with the acidic magma originating from anatexis and the primary fluids, which were then mixed with meteoric water and resulted in the formation of Phanerozoic hydrothermal uranium deposits under extensional tectonic environments. Erosion of uraniferous rocks and pre-existing uranium deposits during the Meso-Cenozoic brought about the removal of uranium into young sedimentary basins. When those basins were uplifted and slightly deformed by later tectonic activity, roll-type uranium deposits were formed as a result of redox in permeable sandstone strata.

  9. Uranium industry annual 1994

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    1995-07-05

    The Uranium Industry Annual 1994 (UIA 1994) provides current statistical data on the US uranium industry`s activities relating to uranium raw materials and uranium marketing during that survey year. The UIA 1994 is prepared for use by the Congress, Federal and State agencies, the uranium and nuclear electric utility industries, and the public. It contains data for the 10-year period 1985 through 1994 as collected on the Form EIA-858, ``Uranium Industry Annual Survey.`` Data collected on the ``Uranium Industry Annual Survey`` (UIAS) provide a comprehensive statistical characterization of the industry`s activities for the survey year and also include some information about industry`s plans and commitments for the near-term future. Where aggregate data are presented in the UIA 1994, care has been taken to protect the confidentiality of company-specific information while still conveying accurate and complete statistical data. A feature article, ``Comparison of Uranium Mill Tailings Reclamation in the United States and Canada,`` is included in the UIA 1994. Data on uranium raw materials activities including exploration activities and expenditures, EIA-estimated resources and reserves, mine production of uranium, production of uranium concentrate, and industry employment are presented in Chapter 1. Data on uranium marketing activities, including purchases of uranium and enrichment services, and uranium inventories, enrichment feed deliveries (actual and projected), and unfilled market requirements are shown in Chapter 2.

  10. Uranium industry annual 1998

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    1999-04-22

    The Uranium Industry Annual 1998 (UIA 1998) provides current statistical data on the US uranium industry`s activities relating to uranium raw materials and uranium marketing. It contains data for the period 1989 through 2008 as collected on the Form EIA-858, ``Uranium Industry Annual Survey.`` Data provides a comprehensive statistical characterization of the industry`s activities for the survey year and also include some information about industry`s plans and commitments for the near-term future. Data on uranium raw materials activities for 1989 through 1998, including exploration activities and expenditures, EIA-estimated reserves, mine production of uranium, production of uranium concentrate, and industry employment, are presented in Chapter 1. Data on uranium marketing activities for 1994 through 2008, including purchases of uranium and enrichment services, enrichment feed deliveries, uranium fuel assemblies, filled and unfilled market requirements, and uranium inventories, are shown in Chapter 2. The methodology used in the 1998 survey, including data edit and analysis, is described in Appendix A. The methodologies for estimation of resources and reserves are described in Appendix B. A list of respondents to the ``Uranium Industry Annual Survey`` is provided in Appendix C. The Form EIA-858 ``Uranium Industry Annual Survey`` is shown in Appendix D. For the readers convenience, metric versions of selected tables from Chapters 1 and 2 are presented in Appendix E along with the standard conversion factors used. A glossary of technical terms is at the end of the report. 24 figs., 56 tabs.

  11. Geochemical hosts of solubilized radionuclides in uranium mill tailings

    Science.gov (United States)

    Landa, E.R.; Bush, C.A.

    1990-01-01

    The solubilization and subsequent resorption of radionuclides by ore components or by reaction products during the milling of uranium ores may have both economic and environmental consequences. Particle-size redistribution of radium during milling has been demonstrated by previous investigators; however, the identification of sorbing components in the tailings has received little experimental attention. In this study, uranium-bearing sandstone ore was milled, on a laboratory scale, with sulfuric acid. At regular intervals, filtrate from this suspension was placed in contact with mixtures of quartz sand and various potential sorbents which occur as gangue in uranium ores; the potential sorbents included clay minerals, iron and aluminum oxides, feldspar, fluorspar, barite, jarosite, coal, and volcanic glass. After equilibration, the quartz sand-sorbent mixtures were separated from the filtrate and radioassayed by gamma-spectrometry to determine the quantities of 238U, 230Th, 226Ra, and 210Pb sorbed, and the radon emanation coefficients. Sorption of 238U was low in all cases, with maximal sorptions of 1-2% by the bentonite- and coal-bearing samples. 230Th sorption also was generally less than 1%; maximal sorption here was observed in the fluorspar-bearing sample and appears to be associated with the formation of gypsum during milling. 226Ra and 210 Pb generally showed higher sorption than the other nuclides - more than 60% of the 26Ra solubilized from the ore was sorbed on the barite-bearing sample. The mechanism (s) for this sorption by a wide variety of substrates is not yet understood. Radon emanation coefficients of the samples ranged from about 5 to 30%, with the coal-bearing samples clearly demonstrating an emanating power higher than any of the other materials. ?? 1990.

  12. Natural radionuclide concentrations in two phosphate ores of east Algeria

    Energy Technology Data Exchange (ETDEWEB)

    Lakehal, Ch. [Department of Physics, Mentouri Constantine University, 25000 Constantine (Algeria); Ramdhane, M., E-mail: ramdhane@hotmail.co [Department of Physics, Mentouri Constantine University, 25000 Constantine (Algeria); Boucenna, A. [Department of Physics, Ferhat-Abbas University, 19000 Setif (Algeria)

    2010-05-15

    Ore is considered as an important source of many elements such as the iron, phosphorus, and uranium. Concerning the natural radionuclides, their concentrations vary from an ore to other depending on the chemical composition of each site. In this work, two phosphate ores found in East of Algeria have been chosen to assess the activity concentration of natural radionuclides represented mainly by three natural radioactive series {sup 238}U, {sup 235}U and {sup 232}Th, and the primordial radionuclide {sup 40}K where they were determined using ultra-low background, high-resolution gamma-ray spectroscopy. The measured activity concentrations of radioactive series ranged from 6.2 +- 0.4 to 733 +- 33 Bq.kg{sup -1} for the {sup 232}Th series, from 249 +- 16 to 547 +- 39 Bq.kg{sup -1} for the {sup 238}U series, around 24.2 +- 2.5 Bq.kg{sup -1} for the {sup 235}U series, and from 1.4 +- 0.2 to 6.7 +- 0.7 Bq.kg{sup -1} for {sup 40}K. To assess exposure to gamma radiation in the two ores, from specific activities of {sup 232}Th, {sup 40}K and {sup 226}Ra, three indexes were determined: Radium equivalent (Ra{sub eq}), external and internal hazard indexes (H{sub ex} and H{sub in}), their values ranged from 831 +- 8 to 1298 +- 14 Bq.kg{sup -1} for Ra{sub eq}, from 2.2 +- 0.4 to 3.5 +- 0.7 Bq.kg{sup -1} for H{sub ex}, and from 4.2 +- 0.7 to 4.5 +- 0.7 Bq.kg{sup -1} for H{sub in}.

  13. Uranium-series constraints on radionuclide transport and groundwater flow at the Nopal I uranium deposit, Sierra Pena Blanca, Mexico.

    Science.gov (United States)

    Goldstein, Steven J; Abdel-Fattah, Amr I; Murrell, Michael T; Dobson, Patrick F; Norman, Deborah E; Amato, Ronald S; Nunn, Andrew J

    2010-03-01

    Uranium-series data for groundwater samples from the Nopal I uranium ore deposit were obtained to place constraints on radionuclide transport and hydrologic processes for a nuclear waste repository located in fractured, unsaturated volcanic tuff. Decreasing uranium concentrations for wells drilled in 2003 are consistent with a simple physical mixing model that indicates that groundwater velocities are low ( approximately 10 m/y). Uranium isotopic constraints, well productivities, and radon systematics also suggest limited groundwater mixing and slow flow in the saturated zone. Uranium isotopic systematics for seepage water collected in the mine adit show a spatial dependence which is consistent with longer water-rock interaction times and higher uranium dissolution inputs at the front adit where the deposit is located. Uranium-series disequilibria measurements for mostly unsaturated zone samples indicate that (230)Th/(238)U activity ratios range from 0.005 to 0.48 and (226)Ra/(238)U activity ratios range from 0.006 to 113. (239)Pu/(238)U mass ratios for the saturated zone are 1000 times lower than the U mobility. Saturated zone mobility decreases in the order (238)U approximately (226)Ra > (230)Th approximately (239)Pu. Radium and thorium appear to have higher mobility in the unsaturated zone based on U-series data from fractures and seepage water near the deposit.

  14. Uranium-series constraints on radionuclide transport and groundwater flow at the Nopal I uranium deposit, Sierra Pena Blanca, Mexico

    Energy Technology Data Exchange (ETDEWEB)

    Goldstein, S.J.; Abdel-Fattah, A.I.; Murrell, M.T.; Dobson, P.F.; Norman, D.E.; Amato, R.S.; Nunn, A. J.

    2009-10-01

    Uranium-series data for groundwater samples from the Nopal I uranium ore deposit were obtained to place constraints on radionuclide transport and hydrologic processes for a nuclear waste repository located in fractured, unsaturated volcanic tuff. Decreasing uranium concentrations for wells drilled in 2003 are consistent with a simple physical mixing model that indicates that groundwater velocities are low ({approx}10 m/y). Uranium isotopic constraints, well productivities, and radon systematics also suggest limited groundwater mixing and slow flow in the saturated zone. Uranium isotopic systematics for seepage water collected in the mine adit show a spatial dependence which is consistent with longer water-rock interaction times and higher uranium dissolution inputs at the front adit where the deposit is located. Uranium-series disequilibria measurements for mostly unsaturated zone samples indicate that {sup 230}Th/{sup 238}U activity ratios range from 0.005-0.48 and {sup 226}Ra/{sup 238}U activity ratios range from 0.006-113. {sup 239}Pu/{sup 238}U mass ratios for the saturated zone are <2 x 10{sup -14}, and Pu mobility in the saturated zone is >1000 times lower than the U mobility. Saturated zone mobility decreases in the order {sup 238}U{approx}{sup 226}Ra > {sup 230}Th{approx}{sup 239}Pu. Radium and thorium appear to have higher mobility in the unsaturated zone based on U-series data from fractures and seepage water near the deposit.

  15. URANIUM RECOVERY PROCESS

    Science.gov (United States)

    Bailes, R.H.; Long, R.S.; Olson, R.S.; Kerlinger, H.O.

    1959-02-10

    A method is described for recovering uranium values from uranium bearing phosphate solutions such as are encountered in the manufacture of phosphate fertilizers. The solution is first treated with a reducing agent to obtain all the uranium in the tetravalent state. Following this reduction, the solution is treated to co-precipitate the rcduced uranium as a fluoride, together with other insoluble fluorides, thereby accomplishing a substantially complete recovery of even trace amounts of uranium from the phosphate solution. This precipitate usually takes the form of a complex fluoride precipitate, and after appropriate pre-treatment, the uranium fluorides are leached from this precipitate and rccovered from the leach solution.

  16. Radionuclides in sheep grazing near old uranium mines

    Energy Technology Data Exchange (ETDEWEB)

    Carvalho, Fernando P.; Oliveira, Joao M.; Malta, M. [Instituto Superior Tecnico/Campus Tecnologico e Nuclear/ (IST/CTN), Universidade de Lisboa, Estrada Nacional 10 - ao km 139,7, - 2695-066 Bobadela LRS (Portugal); Lemos, M.E. [Servicos de Alimentacao e Veterinaria da Regiao Centro, Bairro Na Sra dos Remedios, 6300 Guarda (Portugal); Vala, H.; Esteves, F. [Escola Superior Agraria de Viseu, Quinta da Alagoa, Estrada de Nelas, Ranhados,3500-606 Viseu (Portugal)

    2014-07-01

    During the past century extensive uranium mining took place in Portugal for radium and uranium production. Many uranium deposits were mined as open pits and after ore extraction and transportation to milling facilities, mining wastes were left on site. One uranium ore mining site, Boco Mine, was extracted in the 1960's and 70's and mining waste and open pits were left uncovered and non-remediated since closure of uranium mining activities. During the nineties a quarry for sand extraction was operated in the same site and water from a local stream was extensively used in sand sieving. Downstream the mine areas, agriculture soils along the water course are currently used for cattle grazing. Water from this stream, and water wells, soil, pasture and sheep meat were analyzed for radionuclides of the uranium series. The U- series radionuclide {sup 226}Ra was generally the highest in concentrations especially in soil, pasture, and in internal organs of sheep. Ra-226 concentrations averaged 1093±96 Bq/kg (dry weight) in soil, 43±3 Bq/kg (dw) in pasture, and 0.76±0.41 Bq/kg (dw) in muscle tissue of sheep grown there. Other sheep internal organs displayed much higher {sup 226}Ra concentrations, such as the brain and kidneys with 7.7±2.3 Bq/kg (dw) and 28±29 Bq/kg (dw), respectively. Results of tissue sample analysis for sheep grown in a comparison area were 2 to 11 times lower, depending on the tissue. Absorbed radiation doses for internal organs of sheep were computed and may exceed 20 mSv/y in the kidney. Although elevated, this absorbed radiation dose still is below the threshold for biological effects on mammals. Nevertheless, enhanced environmental radioactive contamination mainly due to radium was observed in the area of influence of this legacy uranium mine and there is potential food chain transfer for humans (authors)

  17. 1株分离于铀矿的可利用玉米秸秆高效产氢的芽孢杆菌%Biohydrogen production by a newly strain of Bacillus isolated from uranium ore using cornstalk as feedstock

    Institute of Scientific and Technical Information of China (English)

    张晓; 何晓锐; 庞园涛; 朱艳杰; 黄建新

    2015-01-01

    A newly bacterial strain w-14,efficiently transforming cornstalk to hydrogen,had been isolated from uranium ore samples with strictly anaerobic culturing method.It was finally nomenclatured as Clostridium butyricum on the basis of series of standard identification methods.The influences of glycolysis temperature,glycolysis time,glycolysis pH,bran koji concentration of Trichoderma koningii and Aspergillus bran koji e.t.c on the the substrate saccharification efficiency and hydrogen production by the strain w-14 were investigated.Two periods of fermentation were used to discuss the effect of glycolysis (glycolysis temperature,glycolysis time,glycolysis pH,bran koji concentration of Trichoderma koningii and Aspergillus bran koji) on the substrate saccharification efficiency and hydrogen production by the strain w-14.At the optimum of variables combination,such as 20 g/L of bran koji,an initial pH of 5.0,incubating at 45 ℃ for 84 h by the Two stages of fermentation technology,the maximum reducing sugar content (402 mg/g-cs) and cumulative H2 yield of 99.7 mL/g-cs were obtained.Orthogonal design were used to optimize bio-hydrogen production from cornstalk glycolytic substrates by submerged fermentation.The maximum cumulative H2 yield of 140.24 mL/g-cs,increased by 41.38%,was achieved at the optimized hydrogen production conditions from the assistance of orthogonal design.Furthermore,it demonstrated that maximum cumulative H2 and the hydrogen content could reach 140.24 mL/g-cs,55.63% respectively in 5 L batch fermentation tank.%采用二重叠皿隔绝空气培养法从铀矿中分离获得1株可利用玉米秸秆高效产氢的菌株w-14,经生理生化及16S rRNA基因序列分析鉴定为丁酸梭菌(Clostridium butyricum);通过两段发酵技术,研究了用木霉、曲霉菌制备的纤维素酶麸曲酵解玉米秸秆的温度、时间、pH、麸曲用量对底物的糖化效率和w-14菌株利用玉米秸秆酵解物产氢的影

  18. Uranium Processing Facility

    Data.gov (United States)

    Federal Laboratory Consortium — An integral part of Y‑12's transformation efforts and a key component of the National Nuclear Security Administration's Uranium Center of Excellence, the Uranium...

  19. Cathodoluminescence of uranium oxides

    Energy Technology Data Exchange (ETDEWEB)

    Winer, K.; Colmenares, C.; Wooten, F.

    1984-08-09

    The cathodoluminescence of uranium oxide surfaces prepared in-situ from clean uranium exposed to dry oxygen was studied. The broad asymmetric peak observed at 470 nm is attributed to F-center excitation.

  20. Uranium industry annual 1995

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    1996-05-01

    The Uranium Industry Annual 1995 (UIA 1995) provides current statistical data on the U.S. uranium industry`s activities relating to uranium raw materials and uranium marketing. The UIA 1995 is prepared for use by the Congress, Federal and State agencies, the uranium and nuclear electric utility industries, and the public. It contains data for the period 1986 through 2005 as collected on the Form EIA-858, ``Uranium Industry Annual Survey``. Data collected on the ``Uranium Industry Annual Survey`` provide a comprehensive statistical characterization of the industry`s plans and commitments for the near-term future. Where aggregate data are presented in the UIA 1995, care has been taken to protect the confidentiality of company-specific information while still conveying accurate and complete statistical data. Data on uranium raw materials activities for 1986 through 1995 including exploration activities and expenditures, EIA-estimated reserves, mine production of uranium, production of uranium concentrate, and industry employment are presented in Chapter 1. Data on uranium marketing activities for 1994 through 2005, including purchases of uranium and enrichment services, enrichment feed deliveries, uranium fuel assemblies, filled and unfilled market requirements, uranium imports and exports, and uranium inventories are shown in Chapter 2. The methodology used in the 1995 survey, including data edit and analysis, is described in Appendix A. The methodologies for estimation of resources and reserves are described in Appendix B. A list of respondents to the ``Uranium Industry Annual Survey`` is provided in Appendix C. For the reader`s convenience, metric versions of selected tables from Chapters 1 and 2 are presented in Appendix D along with the standard conversion factors used. A glossary of technical terms is at the end of the report. 14 figs., 56 tabs.

  1. Research on Magnesite Ore Purification

    Directory of Open Access Journals (Sweden)

    Berisha, K.

    2009-12-01

    Full Text Available Magnesite ore, consisting mainly of magnesite, MgCO3 is a chief mineral source for production of high quality refractory materials based on highly pure MgO. However, the presence of calcium and silicium mineral impurities in the ore adversely affect refractoriness. The removal of silicate minerals is now a routine process but it is not so for calcium minerals impurities. In this work, the new method for the removal of calcium mineral impurities from magnesite ore has been investigated. It is based on extraction of calcium hydroxide from the calcined hydrated ore with the solution of magnesium nitrate. The results show that it is possible to remove up to 65–83 % of calcium oxide (CaO within five minutes, and up to 88–95 % within an hour. The process itself is complex, but mainly under mass transfer control. It is possible to use waste materials produced as fertilizer in agriculture thus helping in environmental protection.

  2. Geological and geochemical aspects of uranium deposits: a selected, annotated bibliography. Vol. 2, Rev. 1. [490 references

    Energy Technology Data Exchange (ETDEWEB)

    Thomas, J.M.; Brock, M.L.; Garland, P.A.; White, M.B.; Daniel, E.W. (comps.)

    1979-07-01

    This bibliography, a compilation of 490 references, is the second in a series compiled from the National Uranium Resource Evaluation (NURE) Bibliographic Data Base. This data base is one of six data bases created by the Ecological Sciences Information Center, Oak Ridge National Laboratory, for the Grand Junction Office of the Department of Energy. Major emphasis for this volume has been placed on uranium geology, encompassing deposition, genesis of ore deposits, and ore controls; and prospecting techniques, including geochemistry and aerial reconnaissance. The following indexes are provided to aid the user in locating references of interest: author, geographic location, quadrangle name, geoformational feature, taxonomic name, and keyword.

  3. Statistical data of the uranium industry

    Energy Technology Data Exchange (ETDEWEB)

    None

    1978-01-01

    This document is a compilation of historical facts and figures through 1977. These statistics are based primarily on information provided voluntarily by the uranium exploration, mining, and milling companies. The production, ore reserve, and production capability information has been reported in a manner which avoids disclosure of proprietary information. Due to mining and milling cost increases, references to $10 per pound reserves and potential resources have been deleted, and statistics for $50 per pound have been added for 1/1/78. Also, the size-depth-thickness and the size-grade matrices have been revised to present $50 rather than $30 per pound resources. The graphic distribution of reported future U/sub 3/O/sub 8/ prices has been replaced by a table of historical and projected average prices for U/sub 3/O/sub 8/ delivery commitments. The results of a survey of capital investment for uranium production and the history of annual U.S. nuclear plant ordering have been included for the first time. A new section, Production Capability of the Uranium Industry, presents the results of a 1977 GJO assessment of the nation's ability to produce U/sub 3/O/sub 8/ from the 1/1/77 $30 per pound reserves and probable potential. Appendices give the historical AEC uranium procurement statistics, World Uranium Resources and Production Capability by Continent, a distribution of 1/1/77 $30 reserves and potential by land status, and a diagram of the nuclear fuel cycle.

  4. Virtual phosphorus ore requirement of Japanese economy.

    Science.gov (United States)

    Matsubae, Kazuyo; Kajiyama, Jun; Hiraki, Takehito; Nagasaka, Tetsuya

    2011-08-01

    Phosphorus is indispensable for agricultural production. Hence, the consumption of imported food indirectly implies the import of phosphorus resources. The global consumption of agricultural products depends on a small number of ore-producing countries. For sustainable management of phosphorus resources, the global supply and demand network should be clarified. In this study, we propose the virtual phosphorus ore requirement as a new indicator of the direct and indirect phosphorus requirements for our society. The virtual phosphorus ore requirement indicates the direct and indirect demands for phosphorus ore transformed into agricultural products and fertilizer. In this study, the virtual phosphorus ore requirement was evaluated for the Japanese economy in 2005. Importantly, the results show that our society requires twice as much phosphorus ore as the domestic demand for fertilizer production. The phosphorus contained in "eaten" agricultural products was only 12% of virtual phosphorus ore requirement.

  5. Importance of Organic Matter-Uranium Biogeochemistry to Uranium Plume Persistence in the Upper Colorado River Basin

    Science.gov (United States)

    Bargar, J.; Janot, N.; Jones, M. E.; Bone, S. E.; Lezama-Pacheco, J.; Fendorf, S. E.; Long, P. E.; Williams, K. H.; Bush, R. P.

    2014-12-01

    Recent evidence suggests that biologically driven redox reactions, fueled by sedimentary lenses enriched in detrital organic matter, play major roles in maintaining the persistent uranium groundwater plume in the subsurface at the U.S. Department of Enery's Rifle, CO field research site. Biogeochemical cycling of C, N, Fe, and S is highly active in these organic-rich naturally reduced zones (NRZs), and uranium is present as U(IV). The speciation of these elements profoundly influences the susceptibility of uranium to be reoxidized and remobiliized and contribute to plume persistence. However, uranim speciation in particular is poorly constrained in these sytems. To better evaluate the importance of NRZs to uranium mobility and plume persistence at the Rifle site, the DOE-BER-funded SLAC SFA team has characterized vertical concentration profiles and speciation of uranium, iron, sulfur, and NOM in well bores at high spatial resolution (4 inch intervals). Up to 95% of the sedimentary uranium pool was found to be concentrated in NRZs, where it occurs dominantly as non-crystalline forms of U(IV). Uranium accumulation and the presence of the short-lived sulfide mackinawite (FeS) at NRZ-aquifer interfaces indicate that NRZs actively exchange solutes with the surrounding aquifer. Moreover, sediment textures indicate that NRZs are likely to be abundant in riparian zones throughout the upper Colorado River basin (U.S.A.), which contains most of the contaminated DOE legacy uranium ore processing sites in the U.S. These results suggest that NRZ-uranium interactions may be important to plume persistence regionally and emphasize the importance of understanding molecular-scale processes.

  6. Identifying anthropogenic uranium compounds using soft X-ray near-edge absorption spectroscopy

    Energy Technology Data Exchange (ETDEWEB)

    Ward, Jesse D.; Bowden, Mark; Tom Resch, C.; Eiden, Gregory C.; Pemmaraju, C. D.; Prendergast, David; Duffin, Andrew M.

    2017-01-01

    Uranium ores mined for industrial use are typically acid-leached to produce yellowcake and then converted into uranium halides for enrichment and purification. These anthropogenic chemical forms of uranium are distinct from their mineral counterparts. The purpose of this study is to use soft X-ray absorption spectroscopy to characterize several common anthropogenic uranium compounds important to the nuclear fuel cycle. Non-destructive chemical analyses of these compounds is important for process and environmental monitoring and X-ray absorption techniques have several advantages in this regard, including element-specificity, chemical sensitivity, and high spectral resolution. Oxygen K-edge spectra were collected for uranyl nitrate, uranyl fluoride, and uranyl chloride, and fluorine K-edge spectra were collected for uranyl fluoride and uranium tetrafluoride. Interpretation of the data is aided by comparisons to calculated spectra. These compounds have unique spectral signatures that can be used to identify unknown samples.

  7. Exploration for uranium deposits in the Spring Creek Mesa area, Montrose County, Colorado

    Science.gov (United States)

    Roach, Carl Houston

    1954-01-01

    The U.S. Geological Survey explored the Spring Creek Mesa area from July 11, 1951, to August 14, 1953. During that period, 280 diamond-drill holes were completed for a total of 180,287 feet. Sedimentary rocks of Mesozoic age are exposed in and adjacent to the Spring Creek Mesa area. These rocks consist of, from oldest to youngest: the Upper Jurassic Morrison formation, the Lower Cretaceous Burro Canyon formation, and the Upper Cretaceous Dakota formation. The Morrison formation consists of two members in the Spring Creek Mesa area: the lower is the Salt Wash member and the upper is the Brusby Basin member. All of the large uranium-bearing deposits discovered by the Geological Survey drilling in the Spring Creek Mesa area are in a series of coalescing sandstone lenses in the uppermost part of the Salt Wash member of the Morrison formation. Most of the ore deposits are believed to be irregular tabular or lens-shaped masses and probably lie parallel to the bedding, although in detail, they may crosscut the bedding. Also, ore deposits that take the form of narrow elongate concretionary-like structures, locally called “rolls”, may be present in the Spring Creek Mesa area. The mineralized material consists mostly of sandstone which has been selectively impregnated and in part replaced by uranium and vanadium minerals. Also, rich concentrations of uranium and vanadium are commonly associated with thin mudstone seams, beds of mudstone pebbles, and carbonaceous material of various types. Two suites of ore minerals are present in the ore deposits - - an oxidized suite of secondary uranium and vanadium minerals and a relatively unoxidized suite of “primary” uranium and vanadium minerals. The following geologic criteria are useful as guides to ore in the Spring Creek Mesa area:

  8. Elemental Geochemistry of the Interlayer Oxidation Zone in the Shihongtan Sandstone Type Uranium Deposit, Xinjiang

    Institute of Scientific and Technical Information of China (English)

    CAI Genqing; ZHANG Zimin; LI Shengxiang

    2005-01-01

    According to the oxidation intensity of ore-hosting sandstone, the interlayer oxidation zone of the Shihongtan sandstone-type uranium deposit in the Turpan-Hami basin can be divided into 4 geochemical subzones, namely, intensely-oxidized, weakly-oxidized, redox and unoxidized primary subzones. The elemental geochemical characteristics of the four subzones have been studied in detail, and the results show that U, together with other elements such as Re, Mo, Se, Sr, S,REE, Corganic etc., is enriched in the redox subzone. Re and U have similar geochemical properties in the reduction-oxidation process. The geochemical properties of Mo and Se are similar to those of U in the reduction condition, but different from those of U in the oxidation condition. It is proposed that the ore-hosting layers can provide a curtain mount of uranium for uranium mineralization.

  9. 31 CFR 540.317 - Uranium feed; natural uranium feed.

    Science.gov (United States)

    2010-07-01

    ... 31 Money and Finance: Treasury 3 2010-07-01 2010-07-01 false Uranium feed; natural uranium feed... (Continued) OFFICE OF FOREIGN ASSETS CONTROL, DEPARTMENT OF THE TREASURY HIGHLY ENRICHED URANIUM (HEU) AGREEMENT ASSETS CONTROL REGULATIONS General Definitions § 540.317 Uranium feed; natural uranium feed....

  10. 用FeCl3作为反应剂超临界CO2浸取砂岩型铀矿中的铀%Supercritical CO2 fluid leaching of uranium from sandstone type ores using FeCl3 as reactant

    Institute of Scientific and Technical Information of China (English)

    王艳龙; 谭凯旋; 屈慧琼; 李春光; 胡杨; 李咏梅

    2014-01-01

    铀是重要的核能燃料,而超临界CO2是一种新型高效且环境安全性的铀提取方法。在FeCl3作为反应剂的前提下,考察了主要因素压力和时间对浸取效果的影响。恒定时间下随着压力的增加浸出率是先增加后减少,恒定压力下随着时间的增加浸出率是先增加然后是到稳定状态。最佳浸出条件为压力10MPa,浸出率可达90%。与传统的酸碱浸取铀相比,浸取效果要明显高于常规采铀。所以超临界 CO2流体浸取有望应用于低品位砂岩铀矿的地浸采铀中。%Uranium is an important nuclear fuel,and supercritical CO2 fluid leaching is a new,efficient and environmentally safe uranium extraction method. The aim of this experiment was to investigate the impact of pressure and time on uranium leaching efficiency with FeCl3 as reactant. Leaching efficiency first increased and then decreased with the increase of pressure. Under a constant specific pressure leaching efficiency first increased with increasiing time and then stabilized at a fixed value. The optimum leaching pressure was 10MPa,and leaching efficiency could reach 90%. Compared with the traditional acid-alkali leaching of uranium,leaching effect was significantly higher. Supercritical CO2 fluid leaching could be used for in-situ uranium leaching of low grade sandstone-type uranium deposits.

  11. Ecological condition around the uranium tailing pits in Tajikistan

    Energy Technology Data Exchange (ETDEWEB)

    Mirsaidov, I.; Mirsaidov, U.; Khakimov, N.; Nazarov, Kh. [Nuclear and Radiation Safety Agency under the Academy of Sciences of the Republic of Tajikistan, 33 Rudaki avenue, Dushanbe 734025 (Tajikistan)

    2010-07-01

    One of the basic sectors of the economy in Tajikistan is the mining industry. Its development in the past led to an accumulation of large amounts of waste mainly associated with the uranium milling facilities. These wastes contain radionuclides in high concentrations (basically uranium- thorium series) and other hazardous substances. These facilities are often located in residential areas and in the upper side of the main watersheds of the region, such as Amu-Daria and Syr-Daria. Tajikistan has a number of uranium ore deposits and mining and milling facilities, which operated in the past. This country's own ores and imported raw materials were processed mainly at the former Leninabad Geochemical Combine facility (currently State Enterprise (SE) 'Vostokredmet') and also at other hydro-metallurgical plants located in the vicinity of uranium ore extraction sites (Adrasman, Taboshar, Isphara etc.). Presently the only operating enterprise in the Republic of Tajikistan, which still has the potential to process Uranium ores, using an acid leach extraction process, is the SE 'Vostokredmet'. It is interesting is to note that the mine wastes at the Adrasman site were recently successfully reprocessed to produce a lead concentrate. Otherwise, all underground and open pit mines and old radium and uranium facilities have been decommissioned, but most of them are still not remediated. Due to the recent significant increase in the price of uranium, the uranium mining residues have become a focus of interest for various different investors and commercial companies who are considering reprocessing the waste rock piles and mill tailings of Northern Tajikistan. Based on estimates from SE 'Vostokredmet', the total amount of residual uranium in the tailings and waste rock piles in the Republic of Tajikistan is about 55 million tons. The total activity of these wastes is estimated to be approximately 240-285 10{sup 12} Bq. The total volume of waste

  12. Uranium hexafluoride public risk

    Energy Technology Data Exchange (ETDEWEB)

    Fisher, D.R.; Hui, T.E.; Yurconic, M.; Johnson, J.R.

    1994-08-01

    The limiting value for uranium toxicity in a human being should be based on the concentration of uranium (U) in the kidneys. The threshold for nephrotoxicity appears to lie very near 3 {mu}g U per gram kidney tissue. There does not appear to be strong scientific support for any other improved estimate, either higher or lower than this, of the threshold for uranium nephrotoxicity in a human being. The value 3 {mu}g U per gram kidney is the concentration that results from a single intake of about 30 mg soluble uranium by inhalation (assuming the metabolism of a standard person). The concentration of uranium continues to increase in the kidneys after long-term, continuous (or chronic) exposure. After chronic intakes of soluble uranium by workers at the rate of 10 mg U per week, the concentration of uranium in the kidneys approaches and may even exceed the nephrotoxic limit of 3 {mu}g U per gram kidney tissue. Precise values of the kidney concentration depend on the biokinetic model and model parameters assumed for such a calculation. Since it is possible for the concentration of uranium in the kidneys to exceed 3 {mu}g per gram tissue at an intake rate of 10 mg U per week over long periods of time, we believe that the kidneys are protected from injury when intakes of soluble uranium at the rate of 10 mg U per week do not continue for more than two consecutive weeks. For long-term, continuous occupational exposure to low-level, soluble uranium, we recommend a reduced weekly intake limit of 5 mg uranium to prevent nephrotoxicity in workers. Our analysis shows that the nephrotoxic limit of 3 {mu}g U per gram kidney tissues is not exceeded after long-term, continuous uranium intake at the intake rate of 5 mg soluble uranium per week.

  13. Bioremediation of uranium contamination with enzymatic uranium reduction

    Science.gov (United States)

    Lovley, D.R.; Phillips, E.J.P.

    1992-01-01

    Enzymatic uranium reduction by Desulfovibrio desulfuricans readily removed uranium from solution in a batch system or when D. desulfuricans was separated from the bulk of the uranium-containing water by a semipermeable membrane. Uranium reduction continued at concentrations as high as 24 mM. Of a variety of potentially inhibiting anions and metals evaluated, only high concentrations of copper inhibited uranium reduction. Freeze-dried cells, stored aerobically, reduced uranium as fast as fresh cells. D. desulfuricans reduced uranium in pH 4 and pH 7.4 mine drainage waters and in uraniumcontaining groundwaters from a contaminated Department of Energy site. Enzymatic uranium reduction has several potential advantages over other bioprocessing techniques for uranium removal, the most important of which are as follows: the ability to precipitate uranium that is in the form of a uranyl carbonate complex; high capacity for uranium removal per cell; the formation of a compact, relatively pure, uranium precipitate.

  14. Measurement of moisture in mill feed ore

    Energy Technology Data Exchange (ETDEWEB)

    Timm, A.R.; Moench, P.; Moisel, E. (Council for Mineral Technology, Randburg (South Africa))

    1985-04-01

    The control of the moisture in the feed to a mill is very important for efficient mill operation. Water is added continuously to the ore fed to a mill to maintain a suitable mix of ore and moisture in the mill. However, problems arise because of the large variation in the moisture content of the ore, which affects the efficiency of the grind. If too little moisture is present, the mill is unable to grind the ore finely enough, creating instead a thick 'porridge' that causes the mill to choke up. On the other hand, too much moisture results in inefficient grinding because the ore is flushed through the mill too quickly. Several techniques are available for measuring moisture and Mintek undertook an investigation in an attempt to develop a reliable robust moisture meter suitable for monitoring the moisture content of ore, which include the following: neutron backscattering, infrared absorption, microwaves, capacitance and moisture as a function of conductivity.

  15. ANALYSIS ON THE ORE-FORMING CONDITIONS OF THE SANDSTONE TYPE URANIUM DEPOSIT IN THE NORTHEAST UPLIFT OF SONGLIAO BASIN%松辽盆地东北隆起区砂岩型铀矿成矿条件分析

    Institute of Scientific and Technical Information of China (English)

    杨海波; 钟延秋

    2011-01-01

    运用水成矿理论,对松辽盆地东北隆起区砂岩型铀矿成矿的铀源、构造、沉积、水文地质、古气候等条件进行了分析,认为该区具有良好的砂岩型铀矿成矿地质条件.具体表现在区内存在受构造运动影响地层隆起遭受剥蚀的构造天窗,在盆地边缘发育向南西倾斜的斜坡带;有利铀成矿的河流相、三角洲相砂体发育;泥岩-砂岩-泥岩结构层发育良好,有含水透水层和隔水层;补-径-排机制较完善,水动力条件较好,具有渗入型自流水盆地特征.该区具有良好的勘探前景.%With the theory of hydrogenic uranium deposit, the conditions of uranium source, geological structure, hydrology, sedimentation and paleo-climate for the metallogenesis of sandstone type uranium deposits in the northeast uplift of Songliao Basin are analyzed. The following geological conditions are considered favorable for the metallogenesis of sandstone type uranium deposits in this area: Influenced by tectonic movements, stratum uplifting and erosion, a structural inlier is formed in the area; A SW-trending slope belt is developed in the margin of the basin; The well developed sand bodies of fluvial facies and delta facies are deposited; an interlayer zone of mudstone-sandstone-mudstone is developed with permeable bed and impermeable bed; The supply-passage-discharge system is complete with favorable hydraulic condition and the characteristics of secondary seeping artesian basin. As a result, the prospects of uranium in the northeast uplift of Songliao Basin are encouraging.

  16. Evolution of ore deposits on terrestrial planets

    Science.gov (United States)

    Burns, R. G.

    1991-01-01

    Ore deposits on terrestrial planets materialized after core formation, mantle evolution, crustal development, interactions of surface rocks with the hydrosphere and atmosphere, and, where life exists on a planet, the involvement of biological activity. Core formation removed most of the siderophilic and chalcophilic elements, leaving mantles depleted in many of the strategic and noble metals relative to their chondritic abundances. Basaltic magma derived from partial melting of the mantle transported to the surface several metals contained in immiscible silicate and sulfide melts. Magmatic ore deposits were formed during cooling, fractional crystallization and density stratification from the basaltic melts. Such ore deposits found in earth's Archean rocks were probably generated during early histories of all terrestrial planets and may be the only types of igneous ores on Mars. Where plate tectonic activity was prevalent on a terrestrial planet, temporal evolution of ore deposits took place. Repetitive episodes of subduction modified the chemical compositions of the crust and upper mantles, leading to porphyry copper and molybdenum ores in calc-alkaline igneous rocks and granite-hosted tin and tungsten deposits. Such plate tectonic-induced mineralization in relatively young igneous rocks on earth may also have produced hydrothermal ore deposits on Venus in addition to the massive sulfide and cumulate chromite ores associated with Venusian mafic igneous rock. Sedimentary ore deposits resulting from mechanical and chemical weathering in reducing atmospheres in Archean earth included placer deposits (e.g., uraninite, gold, pyrite ores). Chromite, ilmenite, and other dense unreactive minerals could also be present on channel floors and in valley networks on Mars, while banded iron formations might underlie the Martian northern plains regions. As oxygen evolved in earth's atmosphere, so too did oxide ores. By analogy, gossans above sulfide ores probably occur on Mars

  17. Dictyonema black shale and Triassic sandstones as potential sources of uranium

    Directory of Open Access Journals (Sweden)

    Kiegiel Katarzyna

    2015-09-01

    Full Text Available The main objective of the present study was an assessment of the possibility of uranium recovery from domestic resources in Poland. In the first stage uranium was leached from the ground uranium ore by using acidic (sulfuric acid or hydrochloric acid or alkaline (carbonate solutions. The leaching efficiencies of uranium were dependent on the type of ore and it reached 81% for Dictyonemic shales and almost 100% for sandstones. The novel leaching routes, with the application of the helical membrane contactor equipped with rotating part were tested. The obtained postleaching solutions were concentrated and purified using solvent extraction or ion exchange chromatography. New methods of solvent extraction, as well as hybrid processes for separation and purification of the product, were studied. Extraction with the use of membrane capillary contactors that has many advantages above conventional methods was also proposed as an alternative purification method. The final product U3O8 could be obtained by the precipitation of ‘yellow cake’, followed by calcination step. The results of precipitation of ammonium diuranate and uranium peroxide from diluted uranium solution were presented

  18. Up-dated ore composition data (Central ore-field, Kuznetsk Alatau

    Directory of Open Access Journals (Sweden)

    Bushmanov A.

    2016-01-01

    Full Text Available Applying scanning electron microscope (SEM, energy-dispersive microanalyzer and X-ray ray fluorescence microscope the ore mineral composition in Central gold-ore field ore field (Kuznetsk Alatau was investigated. Eleven new minerals were detected in this ore field. The differentiated behavior of mineral formation stages in veinsand near-veined beresites was determined. The composition of native gold was studied, as well as the distribution of trace elements in pyrite.

  19. Hageri alustas oreli taastamisega / Inge Põlma

    Index Scriptorium Estoniae

    Põlma, Inge

    2009-01-01

    1851. aastal eesti orelimeistri Carl Tantoni valmistatud ja 1892. aastal Gustav Terkmanni poolt kohendatud Hageri Lambertuse kiriku oreli restaureerimisest, ekspertiisi tegi rootsi organist Göran Grahn

  20. CHEMICAL TOXICITY OF URANIUM

    Directory of Open Access Journals (Sweden)

    Sermin Cam

    2007-06-01

    Full Text Available Uranium, occurs naturally in the earth’s crust, is an alpha emitter radioactive element from the actinide group. For this reason, U-235 and U-238, are uranium isotopes with long half lives, have got radiological toxicity. But, for natural-isotopic-composition uranium (NatU, there is greater risk from chemical toxicity than radiological toxicity. When uranium is get into the body with anyway, also its chemical toxicity must be thought. [TAF Prev Med Bull 2007; 6(3.000: 215-220

  1. METHOD OF ROLLING URANIUM

    Science.gov (United States)

    Smith, C.S.

    1959-08-01

    A method is described for rolling uranium metal at relatively low temperatures and under non-oxidizing conditions. The method involves the steps of heating the uranium to 200 deg C in an oil bath, withdrawing the uranium and permitting the oil to drain so that only a thin protective coating remains and rolling the oil coated uranium at a temperature of 200 deg C to give about a 15% reduction in thickness at each pass. The operation may be repeated to accomplish about a 90% reduction without edge cracking, checking or any appreciable increase in brittleness.

  2. PRODUCTION OF URANIUM

    Science.gov (United States)

    Ruehle, A.E.; Stevenson, J.W.

    1957-11-12

    An improved process is described for the magnesium reduction of UF/sub 4/ to produce uranium metal. In the past, there have been undesirable premature reactions between the Mg and the bomb liner or the UF/sub 4/ before the actual ignition of the bomb reaction. Since these premature reactions impair the yield of uranium metal, they have been inhibited by forming a protective film upon the particles of Mg by reacting it with hydrated uranium tetrafluoride, sodium bifluoride, uranyl fluoride, or uranium trioxide. This may be accomplished by adding about 0.5 to 2% of the additive to the bomb charge.

  3. Study of uranium leaching from industrial residues of Industrias Nucleares do Brazil S.A. (INB), Caetite, Bahia, Brazil

    Energy Technology Data Exchange (ETDEWEB)

    Formiga, Thiago S.; Morais, Carlos A., E-mail: cmorais@cdtn.b [Centro de Desenvolvimento da Tecnologia Nuclear (CDTN/CNEN-MG), Belo Horizonte, MG (Brazil); Gomiero, Luiz A., E-mail: gomiero@inb.gov.b [Industrias Nucleares do Brasil S/A (INB), Caetite, BA (Brazil)

    2011-07-01

    The uraniferous district of Lagoa Real, located in the south-central region of the state of Bahia, has reserves estimated at 100,000 tons of uranium, which is enough to supply Angra I, II and III for 100 more years. The process adopted for the beneficiation of the uranium ore from Lagoa Real is heap leaching, a static process in which the ore is crushed, disposed in heaps and irrigated with a sulfuric acid solution to remove the uranium. This technique has a relatively low cost of implementation, although the yield of uranium recovery is low, with an uranium content in the leached residue of 700 {mu}g/g U{sub 3}O{sub 8} for ores with an initial content of 2,700 {mu}g/g U{sub 3}O{sub 8}. With the deepening of the mine pit, an increase in the carbonate content in the ore was noted, which required a higher acid consumption in the leaching. In order to reduce the concentration of carbonates, a study of the ore concentration by flotation column was accomplished. The flotation reject had high carbonate content, with a uranium content of about 2,300 {mu}g/g U{sub 3}O{sub 8} for flotation in one column and 1,100 {mu}g/g U{sub 3}O{sub 8} for flotation in two columns. This paper presents the study of the leaching process for the recovery of the uranium present in the residue of the heap leaching and in the carbonated residue from the flotation of the anomaly 13 ore. The results indicate the feasibility of treating the waste of the heap leaching through dynamic leaching. The study of the uranium leaching from the flotation residue through acid leaching technique indicated a recovery of 96% of uranium, however with a high consumption of acid, around 450 kg/t, showing that for this case, the most suitable technique for the process is alkaline leaching. (author)

  4. FROM THE SIGNIFICANT ST. JOACHIMSTAL SILVER AND URANIUM PIT, JÁCHYMOV, TO RADON SPA IN SAXON CZECH „RUDNA GORA“

    Directory of Open Access Journals (Sweden)

    Branislav Šebečić

    2006-12-01

    Full Text Available At he beginning of the 16th century Saxon miners discovered silver ore in the small settlement Konnradsgrűn at south-west slopes of Erzgebirge in the valley Joachimsthal named after the patron saint St. Joachim. The silver coin was named Jochymst(haler. The mine and the settlement became a free royal mining city where, thanks to the mint, one of the richest noble families von Schlick arose. 554,44 tons of silver were produced from 1517 till 1900. Together with silver ore cobalt and lead ore were exploited ( in significant quantities from 18th till 19th century and after that period nickel, bismuth and arsenic ore (19th century. From the listed ores cobalt was produced in largest quantities for enamel production; 1824,23 tons in the period from 1775 till 1851. Next to these ores uranite ore (urani/ni/t was discovered in the mine. The ore was first used to produce uranium colours used for ceramics, glass and paintings and later to obtain uranium; 8500 tons since 1853 till 1964, a part of which was worked up into radium, to obtain 100gr Ra-. Thanks to the discovery of radioactive- radon water the mine is still active because 20 miners are employed to maintain the part of it from which the radon water is exploited. Jachymov and its surroundigs have become a famous radioactive thermal sanatorium in Europe (the paper is published in Croatian.

  5. Uraniferous opal, Virgin Valley, Nevada: conditions of formation and implications for uranium exploration

    Science.gov (United States)

    Zielinski, R.A.

    1982-01-01

    Uraniferous, fluorescent opal, which occurs in tuffaceous sedimentary rocks at Virgin Valley, Nevada, records the temperature and composition of uranium-rich solutions as well as the time of uranium-silica coprecipitation. Results are integrated with previous geologic and geochronologic data for the area to produce a model for uranium mobility that may be used to explore for uranium deposits in similar geologic settings. Uraniferous opal occurs as replacements of diatomite, or silicic air-fall ash layers in tuffaceous lakebeds of the Virgin Valley Formation (Miocene) of Merriam (1907). Fission-track radiography shows uranium to be homogeneously dispersed throughout the opal structure, suggesting coprecipitation of dissolved uranium and silica gel. Fluid inclusions preserved within opal replacements of diatomite have homogenization temperatures in the epithermal range and are of low salinity. Four samples of opal from one locality all have U-Pb apparent ages which suggest uraniferous opal precipitation in late Pliocene time. These ages correspond to a period of local, normal faulting, and highangle faults may have served as vertical conduits for transport of deep, thermalized ground water to shallower levels. Lateral migration of rising solutions occurred at intersections of faults with permeable strata. Silica and some uranium were dissolved from silica-rich host strata of 5-20 ppm original uranium content and reprecipitated as the solutions cooled. The model predicts that in similar geologic settings, ore-grade concentrations of uranium will occur in permeable strata that intersect high-angle faults and that contain uranium source rocks as well as efficient reductant traps for uranium. In the absence of sufficient quantities of reductant materials, uranium will be flushed from the system or will accumulate in low-grade disseminated hosts such as uraniferous opal. ?? 1982.

  6. Maintaining the uranium resources data system and assessing the 1989 US uranium potential resources

    Energy Technology Data Exchange (ETDEWEB)

    McCammon, R.B. (Geological Survey, Reston, VA (USA)); Finch, W.I.; Grundy, W.D.; Pierson, C.T. (Geological Survey, Denver, CO (USA))

    1990-12-31

    Under the Memorandum of Understanding (MOU) between the EIA, US Department of Energy, and the US Geological Survey (USGS), US Department of the Interior, the USGS develops estimates of uranium endowment for selected geological environments in the United States. New estimates of endowment are used to update the Uranium Resources Assessment Data (URAD) System which, beginning in 1990, is maintained for EIA by the USGS. For 1989, estimates of US undiscovered resources were generated using revised economic index values (current to December 1989) in the URAD system's cost model. The increase in the estimates for the Estimated Additional Resources (EAR) and Speculative Resources (SR) classes resulted primarily from increases in the estimates of uranium endowment for the solution-collapse, breccia-pipe uranium deposit environment in the Colorado Plateau resource region. The mean values for $30-, $50-, and $100-per-pound U{sub 3}O{sub 8} forward-cost categories of EAR increased by about 8, 48, and 32 percent, respectively, as compared to 1988. Estimates of the 1989 undiscovered resources in the SR class also increased in all three forward-cost categories by 10, 5, and 9 percent, respectively. The original cost equations in the URAD System were designed to cover drilling costs related to extensive flat-lying tabular ore bodies. The equations do not adequately treat drilling costs for the smaller areas of vertical breccia pipe uranium deposits in the Colorado Plateau resource region. The development of appropriate cost equations for describing the economics of mining this type of deposit represents a major new task. 12 refs., 4 figs., 5 tabs.

  7. Risk evaluation of uranium mining: A geochemical inverse modelling approach

    Science.gov (United States)

    Rillard, J.; Zuddas, P.; Scislewski, A.

    2011-12-01

    It is well known that uranium extraction operations can increase risks linked to radiation exposure. The toxicity of uranium and associated heavy metals is the main environmental concern regarding exploitation and processing of U-ore. In areas where U mining is planned, a careful assessment of toxic and radioactive element concentrations is recommended before the start of mining activities. A background evaluation of harmful elements is important in order to prevent and/or quantify future water contamination resulting from possible migration of toxic metals coming from ore and waste water interaction. Controlled leaching experiments were carried out to investigate processes of ore and waste (leached ore) degradation, using samples from the uranium exploitation site located in Caetité-Bahia, Brazil. In experiments in which the reaction of waste with water was tested, we found that the water had low pH and high levels of sulphates and aluminium. On the other hand, in experiments in which ore was tested, the water had a chemical composition comparable to natural water found in the region of Caetité. On the basis of our experiments, we suggest that waste resulting from sulphuric acid treatment can induce acidification and salinization of surface and ground water. For this reason proper storage of waste is imperative. As a tool to evaluate the risks, a geochemical inverse modelling approach was developed to estimate the water-mineral interaction involving the presence of toxic elements. We used a method earlier described by Scislewski and Zuddas 2010 (Geochim. Cosmochim. Acta 74, 6996-7007) in which the reactive surface area of mineral dissolution can be estimated. We found that the reactive surface area of rock parent minerals is not constant during time but varies according to several orders of magnitude in only two months of interaction. We propose that parent mineral heterogeneity and particularly, neogenic phase formation may explain the observed variation of the

  8. Structural control on uranium mineralization in South China: Implications for fluid flow in continental strike-slip faults

    Institute of Scientific and Technical Information of China (English)

    LI; Jianwei(李建威); ZHOU; Meifu(周美夫); LI; Xianfu(李先福); FU; Zhaoren(傅昭仁); LI; Zijin(李紫金)

    2002-01-01

    South China is the most important uranium producer in the country. Much of the Mesozoic-Cenozoic geology of this area was dominated by NNE-trending intracontinental strike-slip faulting that resulted from oblique subduction of the paleo-Pacific plate underneath the eastern China continent. This strike-slip fault system was characterized by transpression in the early-mid Jurassic and by transtension from the latest Jurassic through Cretaceous to early Tertiary. Most uranium ore deposits in South China are strictly fault-hosted and associated with mid-late Mesozoic granitic intrusions and volcanic rocks, which formed under transpression and transtension regimes, respectively. Various data demonstrate that the NNE-trending strike-slip faults have played critical roles in the formation and distribution of hydrothermal uranium deposits. Extensive geochronological studies show that a majority of uranium deposits in South China formed during the time period of 140-40 Ma with peak ages between 87-48 Ma, coinciding well with the time interval of transtension. However, hydrothermal uranium deposits are not uniformly distributed along individual strike-slip fault. The most important ore-hosting segments are pull-apart stepovers, splay structures, extensional strike-slip duplexes, releasing bends and fault intersections. This non-uniform distribution of ore occurrences in individual fault zone reflects localization of hydrothermal fluids within those segments that were highly dilational and thus extremely permeable. The unique geometric patterns and structural styles of strike-slip faults may have facilitated mixing of deeply derived and near-surface fluids, as evidenced by stable isotopic data from many uranium deposits in South China. The identification of fault segments favorable for uranium mineralization in South China is important for understanding the genesis of hydrothermal ore deposits within continental strike-slip faults, and therefore has great implications for

  9. Sandbox experiments on Uraninite Ore: ERT and SP measurments.

    Science.gov (United States)

    Singh, R. K.

    2015-12-01

    Nuclear energy, considering its own intrinsic merits, would be a leading source for meeting the energy requirement in present and future scenario. Concealed Uranium deposits under sedimentary cover, with poor surface indications calls for reorientation of survey with large inputs involving integrated geophysical approach. Sand Box experiments have been carried out over Uraninite ore. The tank is a glass fish tank (height 39 cm, length 75 cm, width 30 cm). It was filled with sand up to 35 cm high. The sand was saturated from below to minimize the entrapment of the gas bubbles. The average size for sand grains is ~ 0.295mm. The formation factor of the sand is 3.5, with a negligible surface conductivity because of the coarse nature of the sand grains. The dimension of considered Uraninite ore sample is 4cm x 4cm x 4cm. The depth of top of the ore sample is kept at 3cm. In this paper both resistivity and self-potential measurements were carried out for possible detection of Uraninite. The resistivity measurements were made with 64 non-polarizable electrodes using Electrical Resistivity Tomography (ERT) equipment of FlashRes Universal developed by ZZ Resistivity Imaging Pty. Ltd. We have used screws of length 3cm as electrodes. The separation between these electrodes are ~ 1cm. The resistivity tomography results clearly outlines the target Uraninite body. The resistivity tomography results also detects small heterogeneities associated with air bubbles possibly due to unsaturated pore spaces. SP measurements were made using two non-polarizing Pb/PbCl2 electrodes and a Fluke 289 voltmeter (sensitivity 0.001 mV, internal impedance 100 MOhm). The reference electrode was located on the corner of the sandbox. The other electrode was used to scan the electrical potential at the surface of the sand. SP measurements were made with a spacing of 3 cm over the same ERT profile. The SP results also shows a dip (or a low SP anomaly) over the target ore body sample. Thus, both SP and

  10. Preliminary investigation of the elemental variation and diagenesis of a tabular uranium deposit, La Sal Mine, San Juan County, Utah

    Science.gov (United States)

    Brooks, Robert A.; Campbell, John A.

    1976-01-01

    Ore in the La Sal mine, San Juan County, Utah, occurs as a typical tabular-type uranium deposit of the-Colorado Plateau. Uranium-vanadium occurs in the Salt Wash Member of the Jurassic Morrison Formation. Chemical and petrographic analyses were used to determine elemental variation and diagenetic aspects across the orebody. Vanadium is concentrated in the dark clay matrix, which constitutes visible ore. Uranium content is greater above the vanadium zone. Calcium, carbonate carbon, and lead show greater than fifty-fold increase across the ore zone, whereas copper and organic carbon show only a several-fold increase. Large molybdenum concentrations are present in and above the tabular layer, and large selenium concentrations occur below the uranium zone within the richest vanadium zone. Iron is enriched in the vanadium horizon. Chromium is depleted from above the ore and strongly enriched below. Elements that vary directly with the vanadium content include magnesium, iron, selenium, zirconium, strontium, titanium, lead, boron, yttrium, and scandium. The diagenetic sequence is as follows: (1) formation of secondary quartz overgrowths as cement; (2) infilling and lining of remaining pores with amber opaline material; (3) formation of vanadium-rich clay matrix, which has replaced overgrowths as well as quartz grains; (4) replacement of overgrowths and detrital grains by calcite; (5) infilling of pores with barite and the introduction of pyrite and marcasite.

  11. Assessment of a Hydroxyapatite Permeable Reactive Barrier to Remediate Uranium at the Old Rifle Site Colorado.

    Energy Technology Data Exchange (ETDEWEB)

    Moore, Robert C.; Szecsody, James (PNNL); Rigali, Mark J.; Vermuel, Vince (PNNL); Leullen, Jon (AECOM)

    2016-02-01

    We have performed an initial evaluation and testing program to assess the effectiveness of a hydroxyapatite (Ca10(PO4)6(OH)2) permeable reactive barrier and source area treatment to decrease uranium mobility at the Department of Energy (DOE) former Old Rifle uranium mill processing site in Rifle, western Colorado. Uranium ore was processed at the site from the 1940s to the 1970s. The mill facilities at the site as well as the uranium mill tailings previously stored there have all been removed. Groundwater in the alluvial aquifer beneath the site still contains elevated concentrations of uranium, and is currently used for field tests to study uranium behavior in groundwater and investigate potential uranium remediation technologies. The technology investigated in this work is based on in situ formation of apatite in sediment to create a subsurface apatite PRB and also for source area treatment. The process is based on injecting a solution containing calcium citrate and sodium into the subsurface for constructing the PRB within the uranium plume. As the indigenous sediment micro-organisms biodegrade the injected citrate, the calcium is released and reacts with the phosphate to form hydroxyapatite (precipitate). This paper reports on proof-of-principle column tests with Old Rifle sediment and synthetic groundwater.

  12. Uranium: abundance or shortage?

    Energy Technology Data Exchange (ETDEWEB)

    Steyn, J. [Energy Resources International, Inc., Washington, DC (United States)

    1997-09-01

    With large uranium stockpiles, particularly in the form of HEU, continuing to be the dominant factor in the world uranium market, buyers should be able to enter into attractive long-term commitments for the future. Nevertheless, producers are now able to see forward with some degree of certainty and are expected to meet their planned levels of production and demand. (author).

  13. SULPHUR DIOXIDE LEACHING OF URANIUM CONTAINING MATERIAL

    Science.gov (United States)

    Thunaes, A.; Rabbits, F.T.; Hester, K.D.; Smith, H.W.

    1958-12-01

    A process is described for extracting uranlum from uranium containing material, such as a low grade pitchblende ore, or mill taillngs, where at least part of the uraniunn is in the +4 oxidation state. After comminuting and magnetically removing any entrained lron particles the general material is made up as an aqueous slurry containing added ferric and manganese salts and treated with sulfur dioxide and aeration to an extent sufficient to form a proportion of oxysulfur acids to give a pH of about 1 to 2 but insufficient to cause excessive removal of the sulfur dioxide gas. After separating from the solids, the leach solution is adjusted to a pH of about 1.25, then treated with metallic iron in the presence of a precipitant such as a soluble phosphate, arsonate, or fluoride.

  14. The Luster of Iron Ore Prices

    Institute of Scientific and Technical Information of China (English)

    2009-01-01

    China battles its way out of an iron ore stalemate by finding alternative supplier After months of seesawing, China’s iron ore negotiators appear to be breaking through the tight encirclement of suppliers. On August 17, the China Iron and Steel Association (CISA) announced that Fortescue

  15. Fuzzy Comprehensive Appraisal of Concealed Ore Deposits

    Institute of Scientific and Technical Information of China (English)

    2000-01-01

    In this paper, the transformation from the fuzzy to the accurate process is exemplified by the Jiaodong gold ore deposits concentrated region where the mathematical analysis is used to appraise and forecast regional concealed gold ore deposits. In this sense, this paper presents a new way to the appraisal of the non-traditional mineral resources.

  16. Iron from Zealandic bog iron ore -

    DEFF Research Database (Denmark)

    Lyngstrøm, Henriette Syrach

    2011-01-01

    og geologiske materiale, metallurgiske analyser og eksperimentel arkæologiske forsøg - konturerne af en jernproduktion med udgangspunkt i den sjællandske myremalm. The frequent application by archaeologists of Werner Christensen’s distribution map for the occurrence of bog iron ore in Denmark (1966...... are sketched of iron production based on bog iron ore from Zealand....

  17. Biomass for iron ore sintering

    Energy Technology Data Exchange (ETDEWEB)

    Zandi, M.; Martinez-Pacheco, M.; Fray, T.A.T. [Corus Research Development & Technology, Rotherham (United Kingdom)

    2010-11-15

    Within an integrated steelworks, iron ore sinter making is an energy intensive process. In recent years, biomass is becoming an attractive alternative source of energy to traditional fossil fuels such as coal. In this study, commercially available biomass materials suited to sinter making have been identified as an alternative source of fuel to coke breeze. Olive residues, sunflower husk pellets, almond shells, hazelnut shells and Bagasse pellets have been characterised and prepared for sintering. A laboratory sinter pot has been employed for studying sintering behaviour of biomass material. On average, the calorific values of selected biomass materials, on a dry basis, are about 65% of dry coke breeze. It was found that less of this energy would be available in sinter making due to the evaporation of some of the volatile matter ahead of the flame front. At a replacement rate of 25%, the crushed sunflower husk pellets showed the closest thermal profile to that of coke breeze alone in the size range of -0.8 to +0.6 mm. A specification of less than 1 mm has been recommended for the studied biomass materials when co-firing biomass with coke breeze for iron ore sintering.

  18. Production of Solar Cells in Space from Non Specific Ores by Utilization of Electronically Enhanced Sputtering

    Science.gov (United States)

    Curreri, Peter A.

    2009-01-01

    An ideal method of construction in space would utilize some form of the Universal Differentiator and Universal Constructor as described by Von Neumann (1). The Universal Differentiator is an idealized non ore specific extractive device which is capable of breaking any ore into its constituent elements, and the Universal Constructor can utilize these elements to build any device with controllability to the nanometer scale. During the Human Exploration Initiative program in the early 1990s a conceptual study was done (2) to understand whether such devices were feasible with near term technology for the utilization of space resources and energy. A candidate system was proposed which would utilize electronically enhanced sputtering as the differentiator. Highly ionized ions would be accelerated to a kinetic energy at which the interaction between them and the lattice elections in the ore would be at a maximum. Experiments have shown that the maximum disintegration of raw material occurs at an ion kinetic energy of about 5 MeV, regardless of the composition and structure of the raw material. Devices that could produce charged ion beams in this energy range in space were being tested in the early 1990s. At this energy, for example an ion in a beam of fluorine ions yields about 8 uranium ions from uranium fluoride, 1,400 hydrogen and oxygen atoms from ice, or 7,000 atoms from sulfur dioxide ice. The ions from the disintegrated ore would then be driven by an electrical field into a discriminator in the form of a mass spectrometer, where the magnetic field would divert the ions into collectors for future use or used directly in molecular beam construction techniques. The process would require 10-7 Torr vacuum which would be available in space or on the moon. If the process were used to make thin film silicon solar cells (ignoring any energy inefficiency for beam production), then energy break even for solar cells in space would occur after 14 days.

  19. Uranium triamidoamine chemistry.

    Science.gov (United States)

    Gardner, Benedict M; Liddle, Stephen T

    2015-07-01

    Triamidoamine (Tren) complexes of the p- and d-block elements have been well-studied, and they display a diverse array of chemistry of academic, industrial and biological significance. Such in-depth investigations are not as widespread for Tren complexes of uranium, despite the general drive to better understand the chemical behaviour of uranium by virtue of its fundamental position within the nuclear sector. However, the chemistry of Tren-uranium complexes is characterised by the ability to stabilise otherwise reactive, multiply bonded main group donor atom ligands, construct uranium-metal bonds, promote small molecule activation, and support single molecule magnetism, all of which exploit the steric, electronic, thermodynamic and kinetic features of the Tren ligand system. This Feature Article presents a current account of the chemistry of Tren-uranium complexes.

  20. Uranium dioxide electrolysis

    Science.gov (United States)

    Willit, James L.; Ackerman, John P.; Williamson, Mark A.

    2009-12-29

    This is a single stage process for treating spent nuclear fuel from light water reactors. The spent nuclear fuel, uranium oxide, UO.sub.2, is added to a solution of UCl.sub.4 dissolved in molten LiCl. A carbon anode and a metallic cathode is positioned in the molten salt bath. A power source is connected to the electrodes and a voltage greater than or equal to 1.3 volts is applied to the bath. At the anode, the carbon is oxidized to form carbon dioxide and uranium chloride. At the cathode, uranium is electroplated. The uranium chloride at the cathode reacts with more uranium oxide to continue the reaction. The process may also be used with other transuranic oxides and rare earth metal oxides.

  1. Characterization of uranium bearing material using x-ray fluorescence and direct gamma-rays measurement techniques

    Energy Technology Data Exchange (ETDEWEB)

    Mujaini, M., E-mail: madihah@uniten.edu.my; Chankow, N. [Faculty of Engineering, Chulalongkorn University Phyathai Rd., Wang Mai, Patumwan, Bangkok 10330 (Thailand); Yusoff, M. Z.; Hamid, N. A. [College of Engineering, Universiti Tenaga Nasional 43000 Kajang, Selangor (Malaysia)

    2016-01-22

    Uranium ore can be easily detected due to various gamma-ray energies emitted from uranium daughters particularly from {sup 238}U daughters such as {sup 214}Bi, {sup 214}Pb and {sup 226}Ra. After uranium is extracted from uranium ore, only low energy gamma-rays emitted from {sup 235}U may be detected if the detector is placed in close contact to the specimen. In this research, identification and characterization of uranium bearing materials is experimentally investigated using direct measurement of gamma-rays from {sup 235}U in combination with the x-ray fluorescence (XRF) technique. Measurement of gamma-rays can be conducted by using high purity germanium (HPGe) detector or cadmium telluride (CdTe) detector while a {sup 57}Coradioisotope-excited XRF spectrometer using CdTe detector is used for elemental analysis. The proposed technique was tested with various uranium bearing specimens containing natural, depleted and enriched uranium in both metallic and powder forms.

  2. Evolution of uranium and thorium minerals

    Science.gov (United States)

    Hazen, R. M.; Ewing, R. C.; Sverjensky, D. A.

    2009-12-01

    led to non-marine organic-rich sediments that promoted new sandstone-type ore deposits. The modes of accumulation and even the compositions of uraninite, as well as the multiple oxidation states of U (4+, 5+, and 6+), are a sensitive indicator of global redox conditions. In contrast, the behavior of thorium, which has only a single oxidation state (4+) that has a very low solubility in the absence of aqueous F-complexes, cannot reflect changing redox conditions. Geochemical concentration of Th relative to U at high temperatures is therefore limited to special magmatic-related environments, where U4+ is preferentially removed by chloride or carbonate complexes, and at low temperatures by mineral surface reactions. The near-surface mineralogy of uranium and thorium provide a measure of a planet’s geotectonic and geobiological history. In the absence of extensive magmatic-related fluid reworking of the crust and upper mantle, uranium and thorium will not become sufficiently concentrated to form their own minerals or ore deposits. Furthermore, in the absence of surface oxidation, all but a handful of the known uranium minerals are unlikely to form.

  3. Assessment of the Radiological Impact of the Inactive Uranium-Mill Tailings at Mexican Hat, Utah

    OpenAIRE

    Haywood, F. F.; Goldsmith, W. A.; Ellis, B. S.; Hubbard Jr., H. M.; Fox, W. F.; Shinpaugh, W. H.; Oak Ridge National Laboratory

    1980-01-01

    High surface soil concentrations of 226Ra and high above-ground measurements of gamma-ray intensity in the vicinity of the inactive uranium-mill tailings at Mexican Hat show both wind and water erosion of the tailings. The former mill area, occupied by a trade school at the time of this survey, shows a comparatively high level of contamination, probably from unprocessed ore on the surface of the ore storage area near the location of the former mill buildings. However, the estimated health e...

  4. A literature review of interaction of oxidized uranium species and uranium complexes with soluble organic matter

    Science.gov (United States)

    Jennings, Joan K.; Leventhal, J.S.

    1978-01-01

    Organic material is commonly found associated with uranium ores in sandstone-type deposits. This review of the literature summarizes the classes and separations of naturally occurring organic material but the emphasis is on soluble organic species. The main class of materials of interest is humic substances which are high-molecular-weight complex molecules that are soluble in alkaline solution. These humic substances are able to solubilize (make soluble) minerals and also to complex [by ion exchange and (or) chelation] many cations. The natural process of soil formation results in both mineral decomposition and element complexing by organic species. Uranium in solution, such as ground water, can form many species with other elements or complexes present depending on Eh and pH. In natural systems (oxidizing Eh, pH 5-9) the uranium is usually present as a complex with hydroxide or carbonate. Thermodynamic data for these species are presented. Interacting metals and organic materials have been observed in nature and studied in the laboratory by many workers in diverse scientific disciplines. The results are not easily compared. Measurements of the degree of complexation are reported as equilibrium stability constant determinations. This type of research has been done for Mn, Fe, Cu, Zn, Pb, Ni, Co, Mg, Ca, Al, and to a limited degree for U. The use of Conditional Stability Constants has given quantitative results in some cases. The methods utilized in experiments and calculations are reviewed.

  5. Glances on uranium. Tome 2. Exploration, production; Regards sur l`uranium. Tome 2. Exploration, production

    Energy Technology Data Exchange (ETDEWEB)

    Valsardieu, C

    1997-12-31

    This book is an homage to all participants of uranium prospecting and mining exploitation who have contributed to satisfy the nuclear energy needs during the last 50 years. The first chapter describes the economical, administrative and environmental constraints of uranium mining projects. The second chapter describes the different steps of the exploration (permits, inventory, mineralisation, quality, resource estimation, quantifying), the direct and indirect exploratory techniques and methods (radiometry, geochemistry, drillings and well logging, mapping, tele-detection, geophysical surveys..) and the exploration costs. The third chapter deals with the legal, administrative, technical, socio-economical and financial aspects which must be taken into account in the risk evaluation of a mining project. Chapter 4 concerns the start up of the project while the development and production methods are detailed in chapter 5 (opencast and underground mining, in-situ lixiviation, ore processing, chemical extraction etc.). The last chapter is devoted to the environmental aspects of uranium mining: legal aspects, nuisances, dusts, contamination, the case of in-situ lixiviation, the rehabilitation of sites. (J.S.) 106 refs.

  6. Uranium from Seawater Program Review; Fuel Resources Uranium from Seawater Program DOE Office of Nuclear Energy

    Energy Technology Data Exchange (ETDEWEB)

    None

    2013-07-01

    For nuclear energy to remain sustainable in the United States, economically viable sources of uranium beyond terrestrial ores must be developed. The goal of this program is to develop advanced adsorbents that can extract uranium from seawater at twice the capacity of the best adsorbent developed by researchers at the Japan Atomic Energy Agency (JAEA), 1.5 mg U/g adsorbent. A multidisciplinary team from Oak Ridge National Laboratory, Lawrence Berkeley National Laboratory, Pacific Northwest National Laboratory, and the University of Texas at Austin was assembled to address this challenging problem. Polymeric adsorbents, based on the radiation grafting of acrylonitrile and methacrylic acid onto high surface-area polyethylene fibers followed by conversion of the nitriles to amidoximes, have been developed. These poly(acrylamidoxime-co-methacrylic acid) fibers showed uranium adsorption capacities for the extraction of uranium from seawater that exceed 3 mg U/g adsorbent in testing at the Pacific Northwest National Laboratory Marine Sciences Laboratory. The essence of this novel technology lies in the unique high surface-area trunk material that considerably increases the grafting yield of functional groups without compromising its mechanical properties. This technology received an R&D100 Award in 2012. In addition, high surface area nanomaterial adsorbents are under development with the goal of increasing uranium adsorption capacity by taking advantage of the high surface areas and tunable porosity of carbon-based nanomaterials. Simultaneously, de novo structure-based computational design methods are being used to design more selective and stable ligands and the most promising candidates are being synthesized, tested and evaluated for incorporation onto a support matrix. Fundamental thermodynamic and kinetic studies are being carried out to improve the adsorption efficiency, the selectivity of uranium over other metals, and the stability of the adsorbents. Understanding

  7. High resolution remote sensing information identification for characterizing uranium mineralization setting in Namibia

    Science.gov (United States)

    Zhang, Jie-Lin; Wang, Jun-hu; Zhou, Mi; Huang, Yan-ju; Xuan, Yan-xiu; Wu, Ding

    2011-11-01

    The modern Earth Observation System (EOS) technology takes important role in the uranium geological exploration, and high resolution remote sensing as one of key parts of EOS is vital to characterize spectral and spatial information of uranium mineralization factors. Utilizing satellite high spatial resolution and hyperspectral remote sensing data (QuickBird, Radarsat2, ASTER), field spectral measurement (ASD data) and geological survey, this paper established the spectral identification characteristics of uranium mineralization factors including six different types of alaskite, lower and upper marble of Rössing formation, dolerite, alkali metasomatism, hematization and chloritization in the central zone of Damara Orogen, Namibia. Moreover, adopted the texture information identification technology, the geographical distribution zones of ore-controlling faults and boundaries between the different strata were delineated. Based on above approaches, the remote sensing geological anomaly information and image interpretation signs of uranium mineralization factors were extracted, the metallogenic conditions were evaluated, and the prospective areas have been predicted.

  8. Uranium in the Wyoming Landscape Conservation Initiative study area, southwestern Wyoming

    Science.gov (United States)

    Wilson, Anna B.

    2015-10-20

    Wyoming has led the nation as the producer of uranium ore since 1995 and contains the largest reserves of any state. Approximately one third of Wyoming’s total production came from deposits in, or immediately adjacent to, the Wyoming Landscape Conservation Initiative (WLCI) study area in the southwestern corner of the state including all of Carbon, Lincoln, Sublette, Sweetwater, Uinta, and parts of southern Fremont Counties. Conventional open-pit and underground mining methods were employed in the study area until the early 1990s. Since the early 1990s, all uranium mining has been by in-situ recovery (also called in-situ leach). It is estimated that statewide remaining resources of 141,000 tonnes of uranium are about twice the 84,000 tonnes of uranium that the state has already produced.

  9. Application of waste frying oil as an extractant for uranium from sulfate leach liquor

    Directory of Open Access Journals (Sweden)

    Enass Mohamed El-Sheikh

    2016-04-01

    Full Text Available The possibility of using the waste frying oil (WFO as an extractant for uranium from its sulfate liquor has been studied. Several experiments were conducted to determine the relevant factors affecting both the extraction and stripping of the uranium from a synthetic solution. At the optimum conditions, it was found that the maximum uranium uptake would attain 54 mg/g at a solution pH of 3.5. Kinetic characteristics of the loading process have been found to satisfactorily fitting to the pseudo-first-order equation. The obtained optimum conditions have also been applied to investigate the potentiality of the working WFO for the recovery of uranium from the actual sulfate leach liquor of El-Sela ore material (South Eastern Desert of Egypt.

  10. Uranium mineralization in fluorine-enriched volcanic rocks

    Energy Technology Data Exchange (ETDEWEB)

    Burt, D.M.; Sheridan, M.F.; Bikun, J.; Christiansen, E.; Correa, B.; Murphy, B.; Self, S.

    1980-09-01

    Several uranium and other lithophile element deposits are located within or adjacent to small middle to late Cenozoic, fluorine-rich rhyolitic dome complexes. Examples studied include Spor Mountain, Utah (Be-U-F), the Honeycomb Hills, Utah (Be-U), the Wah Wah Mountains, Utah (U-F), and the Black Range-Sierra Cuchillo, New Mexico (Sn-Be-W-F). The formation of these and similar deposits begins with the emplacement of a rhyolitic magma, enriched in lithophile metals and complexing fluorine, that rises to a shallow crustal level, where its roof zone may become further enriched in volatiles and the ore elements. During initial explosive volcanic activity, aprons of lithicrich tuffs are erupted around the vents. These early pyroclastic deposits commonly host the mineralization, due to their initial enrichment in the lithophile elements, their permeability, and the reactivity of their foreign lithic inclusions (particularly carbonate rocks). The pyroclastics are capped and preserved by thick topaz rhyolite domes and flows that can serve as a source of heat and of additional quantities of ore elements. Devitrification, vapor-phase crystallization, or fumarolic alteration may free the ore elements from the glassy matrix and place them in a form readily leached by percolating meteoric waters. Heat from the rhyolitic sheets drives such waters through the system, generally into and up the vents and out through the early tuffs. Secondary alteration zones (K-feldspar, sericite, silica, clays, fluorite, carbonate, and zeolites) and economic mineral concentrations may form in response to this low temperature (less than 200 C) circulation. After cooling, meteoric water continues to migrate through the system, modifying the distribution and concentration of the ore elements (especially uranium).

  11. 内蒙古多伦义盛店铀银多金属矿地质特征及控矿因素分析%Geological Characteristics and Ore-controlling Factors of Duolun Yishengdian Uranium-Silver Polymetallic Deposit,Inner Mongolia

    Institute of Scientific and Technical Information of China (English)

    薛兰花; 史老虎

    2016-01-01

    多伦义盛店铀银多金属矿位于沽源—多伦铀多金属成矿带的北段,矿体赋存于上侏罗统满克头鄂博组三段蚀变钾长流纹岩和满克头鄂博组次流纹岩体内的隐爆角砾岩中。银矿体呈脉状产出,铀矿体呈似层状产出,受角砾岩带控制明显,属低硫型浅成低温热液矿床。结合前人研究成果,通过对银铀矿成矿地质特征、矿体定位及分布规律的分析研究,认为区内矿化与硅化、萤石化、菱锰矿化、水云母化和碳酸盐化等关系密切,矿化受火山—次火山岩体和 NW-NWW 向断裂带控制。NW-NWW 向构造角砾岩带是银多金属矿的有利储存空间;NW-NNW 向构造角砾岩带、次火山岩接触带及隐爆角砾岩带叠加复合部位是银铀多金属矿的最佳赋存部位。因此,构造角砾岩带、次火山岩接触带和隐爆角砾岩带可作为区内地质标志,结合地球化学异常和地球物理异常,指导区内找矿工作。%Duolun Yishengdian uranium-silver polymetallic deposit is located at the north of Guyuan-Duolun polymetallic metallogenic belt,which is a low sulfide,epithermal deposit,orebodies of this deposit are hosted in alteration potash-liparite of the third stage of Maotouebo in Jurassic and liparite of Mantouebo period,silver orebodies are veined,uranium orebodies are platelike,both are controlled by breccia zone.Combined to the study about geological character,orebodies,positon and distribution law of uranium-silver deposit,we state that alterations are closely related to silicification,fluorite,rhodochrosite,hydromica,carbonatation,which are controlled by volcanic,secondary volcanic and NW-NWW fault belt.NW-NWW pressure breccia belt is the profitable position of silver polymetallic deposit,the overlapped part of NW-NWW pressure breccia belt,secondary volcanic contact zone and hydrothermal breccia is the perfect zone for uranium-silver polymetallic deposit

  12. Advances in research of sulphide ore textures and their implications for ore genesis

    Institute of Scientific and Technical Information of China (English)

    GU Lianxing; ZHENG Yuanchuan; TANG Xiaoqian; WU Changzhi; HU Wenxuan

    2006-01-01

    Important advances in research of sulphide ore textures in recent years have deepened our understanding of ore genesis of related mineral deposits. Pressure solution of sulphide minerals has been suggested as a mechanism for remobilization of ore materials,whereas pressure solution of the gangues is believed to raise the grade of the primary ores. We have known that precipitation of base metal sulphides from fluids prefers crystal and crack surfaces of pyrite to form overgrowth. Therefore, pyrite-bearing embryo beds in a sedimentary sequence can be acted as effective crystal seed beds and are favorable for fluid overprinting to form huge statabound deposits. Texture studies of various sulphides can be used to interpret the entire history of sedimentation, diagenesis, deformation and metamorphism of the ores. The study of chalcopyrite disease in sphalerite has brought about the idea of zone refining, and given a new explanation to metal zonation in massive sulphide deposits. Ductile shearing of sulphide ores may form ore mylonites, which will become oreshoots enriched in Cu, Au and Ag during late-stage fluid overprinting. Despite that various modern analytical techniques are being rapidly developed, ore microscopy remains to be an unreplaceable tool for ore geologists. Combined with these modern techniques, this tool will help accelerate the development of theories on ore genesis.

  13. The structural and genetic position uranium-thorium mineralization of Azov megablock

    Directory of Open Access Journals (Sweden)

    Katalenets A.I.

    2014-12-01

    Full Text Available The genetic characteristics of development and placement uranium-thorium mineralization and distribution of their concentrations in Azov megablock areas are examined. The main structures of Azov megablock areas controlling of distribution of metasomatic types and ore occurrence related with them are set. Preliminary basis for the allocation of boundaries and areas of ore districts is created. Considered theoretical and practical problem associated with the establishment of regional characteristics, genetic types of mineralization, its structural and temporary accommodation, the development of search criteria and characteristics of mineralization, the release of potentially mineralized areas and study areas of prospecting for Azov megablock of Ukrainian shield. The research is based on data on the geological structure of the PM, and the structural control of the placement lithochemical uranium and thorium anomalies occurrences and deposits, typomorphic properties of minerals, the phase distribution of uranium, thorium. Distribution of uranium and thorium mineralization in areas considered structure is: own minerals, isomorphic impurity in minerals associated with them, or turn on the first to the last. Uranium and thorium PM mineralization is characterized by a genetic (paragenetic involving mineral associations exogenous and metasomatic rocks.

  14. Spatial analysis techniques applied to uranium prospecting in Chihuahua State, Mexico

    Science.gov (United States)

    Hinojosa de la Garza, Octavio R.; Montero Cabrera, María Elena; Sanín, Luz H.; Reyes Cortés, Manuel; Martínez Meyer, Enrique

    2014-07-01

    To estimate the distribution of uranium minerals in Chihuahua, the advanced statistical model "Maximun Entropy Method" (MaxEnt) was applied. A distinguishing feature of this method is that it can fit more complex models in case of small datasets (x and y data), as is the location of uranium ores in the State of Chihuahua. For georeferencing uranium ores, a database from the United States Geological Survey and workgroup of experts in Mexico was used. The main contribution of this paper is the proposal of maximum entropy techniques to obtain the mineral's potential distribution. For this model were used 24 environmental layers like topography, gravimetry, climate (worldclim), soil properties and others that were useful to project the uranium's distribution across the study area. For the validation of the places predicted by the model, comparisons were done with other research of the Mexican Service of Geological Survey, with direct exploration of specific areas and by talks with former exploration workers of the enterprise "Uranio de Mexico". Results. New uranium areas predicted by the model were validated, finding some relationship between the model predictions and geological faults. Conclusions. Modeling by spatial analysis provides additional information to the energy and mineral resources sectors.

  15. Some concepts of favorability for world-class-type uranium deposits in the northeastern United States

    Energy Technology Data Exchange (ETDEWEB)

    Adler, H.H.

    1981-03-01

    An account is given of concepts of favorability of geologic environments in the eastern United States for uranium deposits of several major types existing elsewhere in the world. The purpose is to convey some initial ideas about the interrelationships of the geology of the eastern United States and the geologic settings of certain of these world-class deposits. The study and report include consideration of uranium deposits other than those generally manifesting the geologic, geochemical and genetic characteristics associated with the conventional sandstone-type ores of the western United States.

  16. Analysis of the gamma spectra of the uranium, actinium, and thorium decay series

    Energy Technology Data Exchange (ETDEWEB)

    Momeni, M.H.

    1981-09-01

    This report describes the identification of radionuclides in the uranium, actinium, and thorium series by analysis of gamma spectra in the energy range of 40 to 1400 keV. Energies and absolute efficiencies for each gamma line were measured by means of a high-resolution germanium detector and compared with those in the literature. A gamma spectroscopy method, which utilizes an on-line computer for deconvolution of spectra, search and identification of each line, and estimation of activity for each radionuclide, was used to analyze soil and uranium tailings, and ore.

  17. Borehole survey of uranium deposit in Geosan Deokpyeongri A area (1977)

    Energy Technology Data Exchange (ETDEWEB)

    Kim, Jeong Taek; Han, Jong Yun; Kim, Dai Oap; Im, Hyun Chul [Korea Inst. of Geology Mining and Materials, Taejon (Korea, Republic of)

    1995-12-01

    The survey on the nuclear raw mineral (uranium) deposits had been carried out for a long time from early 1960`s to late 1980`s by the Geological and Mineral Institute of Energy and Resources. Unpublished data of the uranium ore deposit of Goesan Deokpyeongri A area is published on this paper. Geology on the Ogcheon System have been controversial by many geologists, therefore we have reviewed on the geology and stratigraphy. Particularly, we have interpreted the host root rock on the magnetite bearing banded gneiss, which is named so called Kyemeongsan Formation. (author). 4 maps.

  18. Borehole survey and reserves of uranium deposit in Geosan Deokpyeongri A area (1978)

    Energy Technology Data Exchange (ETDEWEB)

    Park, Joong Kwon; Kim, Jong Hwan; Kim, Jeong Taek [Korea Institute of Geology Mining and Materials, Taejon (Korea, Republic of)

    1995-12-01

    The survey on the nuclear raw mineral (uranium) deposits had been carried out for a long time from early 1960`s to late 1980`s by the Geological and Mineral Institute of Energy and Resources. Unpublished data of the uranium ore deposit of Goesan Deokpyeongri A area is published on this paper. Geology on the Ogcheon System have been controversial by many geologists, therefore we have reviewed on the geology and stratigraphy. Particularly, we have interpreted the host root rock on the magnetite bearing banded gneiss, which is named so called Kyemeongsan Formation. (author). 12 maps.

  19. Clay vein and its implication for uranium exploration activity in the northern part of the Alligator Rivers Uranium Field, northern Australia

    Energy Technology Data Exchange (ETDEWEB)

    Sasao, Eiji [Japan Nuclear Cycle Development Inst., Toki, Gifu (Japan). Tono Geoscience Center

    2003-07-01

    -forming fluid was possibly related to the uranium mineralization, judging from similarity of mineral and chemical compositions between the clay vein and the inner clay alteration zone, and of nature of vein- and ore-forming fluids. In the uranium deposits in ARUF, ferrous iron in Fe chlorite and mafic mineral such as amphibole have acted as an important reductant against oxidized ore-forming fluid. No uranium mineralization in the clay vein is estimated to have resulted due to the lack of Fe chlorite. Therefore, alteration accompanying Fe chlorite needs to be confirmed to find a uranium mineralization. In the Jabiluka deposit, a general spatial correlation between the intensity of chlorite in the sandstone and the close proximity to ore below has been suggested. Because the mode of occurrence, mineral and chemical compositions of the clay vein resemble those of the chlorite vein, deeper parts of the distributed area of the clay vein are most prospective as an exploration target. Conclusively, confirmation of following points should be important in any future exploration to reach uranium ore; more frequent occurrence of the clay vein, a strongly altered zone below the clay vein and an alteration zone accompanying Fe chlorite. (author)

  20. Oolitic ores in the Bakchar iron-ore cluster (Tomsk Oblast)

    Science.gov (United States)

    Rudmin, M. A.; Mazurov, A. K.

    2016-12-01

    Oolitic iron ores are typified, and their morphology and composition are studied. Special attention is focused on the character of distribution of valuable and harmful admixtures and determination of the principal minerals concentrating these elements. As a result of this study, three types of ores are identified, such as "loose" ores, cemented ores with glauconite-chlorite-clay cement, and well-cemented ores with siderite cement. The morphology and composition of the ore oolites are characterized. The forms of occurrence of calcium phosphates (anapaite) and phosphates of rare-earth elements (monazite, cularite) that are related to the harmful phosphorus admixture are described. According to the analysis of the elemental composition, the fractions of (-1…+0.2) and (-1…+0.1) mm in the western and eastern segments, respectively, may be promising for processing.

  1. Alteration and vein mineralization, Schwartzwalder uranium deposit, Front Range, Colorado

    Science.gov (United States)

    Wallace, Alan R.

    1983-01-01

    The Schwartzwalder uranium deposit, in the Front Range west of Denver, Colorado, is the largest vein-type uranium deposit in the United States. The deposit is situated in a steeply dipping fault system that cuts Proterozoic metamorphic rocks. The host rocks represent a submarine volcanic system with associated chert and iron- and sulfide-rich pelitic rocks. Where faulted, the more competent garnetiferous and quartzitic units behaved brittlely and created a deep, narrow conduit. The ores formed 70-72 m.y. ago beneath 3 km of Phanerozoic sedimentary rocks. Mineralization included two episodes of alteration and three stages of vein-mineralization. Early carbonate-sericite alteration pseudomorphically replaced mafic minerals, whereas the ensuing hematite-adularia episode replaced only the earlier alteration assemblage. Early vein mineralization produced a minor sulfide-adularia-carbonate assemblage. Later vein mineralization generated the uranium ores in two successive stages. Carbonates, sulfides, and adularia filled the remaining voids. Clastic dikes composed of fault gouge and, locally, ore were injected into new and existing fractures. Geologic and chemical evidence suggest that virtually all components of the deposit were derived from major hornblende gneiss units and related rocks. The initial fluids were evolved connate/metamorphic water that infiltrated and resided along the extensive fault zones. Complex fault movements in the frontal zone of the eastern Front Range caused the fluids to migrate to the most permeable segments of the fault zones. Heat was supplied by increased crustal heat flow related to igneous activity in the nearby Colorado mineral belt. Temperatures decreased from 225?C to 125?C during later mineralization, and the pressure episodically dropped from 1000 bars. The CO2 fugacity was initially near 100 bars, and uranium was carried as a dicarbonate complex. Sudden decreases in confining pressure during fault movement caused evolution of CO2

  2. Uranium Location Database

    Data.gov (United States)

    U.S. Environmental Protection Agency — A GIS compiled locational database in Microsoft Access of ~15,000 mines with uranium occurrence or production, primarily in the western United States. The metadata...

  3. Uranium in alkaline rocks

    Energy Technology Data Exchange (ETDEWEB)

    Murphy, M.; Wollenberg, H.; Strisower, B.; Bowman, H.; Flexser, S.; Carmichael, I.

    1978-04-01

    Geologic and geochemical criteria were developed for the occurrence of economic uranium deposits in alkaline igneous rocks. A literature search, a limited chemical analytical program, and visits to three prominent alkaline-rock localities (Ilimaussaq, Greenland; Pocos de Caldas, Brazil; and Powderhorn, Colorado) were made to establish criteria to determine if a site had some uranium resource potential. From the literature, four alkaline-intrusive occurrences of differing character were identified as type-localities for uranium mineralization, and the important aspects of these localities were described. These characteristics were used to categorize and evaluate U.S. occurrences. The literature search disclosed 69 U.S. sites, encompassing nepheline syenite, alkaline granite, and carbonatite. It was possible to compare two-thirds of these sites to the type localities. A ranking system identified ten of the sites as most likely to have uranium resource potential.

  4. Sustainability of uranium mining and milling: toward quantifying resources and eco-efficiency.

    Science.gov (United States)

    Mudd, Gavin M; Diesendorf, Mark

    2008-04-01

    The mining of uranium has long been a controversial public issue, and a renewed debate has emerged on the potential for nuclear power to help mitigate against climate change. The central thesis of pro-nuclear advocates is the lower carbon intensity of nuclear energy compared to fossil fuels, although there remains very little detailed analysis of the true carbon costs of nuclear energy. In this paper, we compile and analyze a range of data on uranium mining and milling, including uranium resources as well as sustainability metrics such as energy and water consumption and carbon emissions with respect to uranium production-arguably the first time for modern projects. The extent of economically recoverable uranium resources is clearly linked to exploration, technology, and economics but also inextricably to environmental costs such as energy/water/chemicals consumption, greenhouse gas emissions, and social issues. Overall, the data clearly show the sensitivity of sustainability assessments to the ore grade of the uranium deposit being mined and that significant gaps remain in complete sustainability reporting and accounting. This paper is a case study of the energy, water, and carbon costs of uranium mining and milling within the context of the nuclear energy chain.

  5. Radiological impact of surface water and sediment near uranium mining sites.

    Science.gov (United States)

    Ivanova, K; Stojanovska, Z; Badulin, V; Kunovska, B; Yovcheva, M

    2015-12-01

    The aim of this study is to assess the radiological impact of surface water and sediment around uranium mining sites 20 years after their closing. The areas under observations are 31 former classical underground uranium mining and exploratory sites in Bulgaria, named as objects. The extraction and processing of uranium ores in the Republic of Bulgaria were ended in 1992. To assess the radiological impact of radionuclides field expeditions were performed to sample water and bottom sediment. The migration of uranium through surface water was examined as one of the major pathways for contamination spread. The range of uranium concentration in water flowing from the mining sites was from 0.012 to 6.8 mgU l(-1) with a geometric mean of 0.192 mgU l(-1). The uranium concentrations in water downstream the mining sites were approximately 3 times higher than the background value (upstream). The concentrations of Unat, (226)Ra, (210)Pb, and (232)Th in the sediment of downstream river were higher than those upstream by 3.4, 2.6, 2, and 1.7 times, respectively. The distribution coefficient of uranium reflects its high mobility in most of the sites. In order to evaluate the impact on people as well as site prioritization for more detailed assessment and water management, screening dose assessments were done.

  6. Structural changes in amber due to uranium mineralization.

    Science.gov (United States)

    Havelcová, Martina; Machovič, Vladimír; Mizera, Jiří; Sýkorová, Ivana; René, Miloš; Borecká, Lenka; Lapčák, Ladislav; Bičáková, Olga; Janeček, Oldřich; Dvořák, Zdeněk

    2016-07-01

    The presence of uranium, with a bulk mass fraction of about 1.5 wt% and radiolytic alterations are a feature of Cenomanian amber from Křižany, at the northeastern edge of the North Bohemian Cretaceous uranium ore district. Pores and microcracks in the amber were filled with a mineral admixture, mainly in the form of Zr-Y-REE enriched uraninite. As a result of radiolytic alterations due to the presence of uranium, structural changes were observed in the Křižany amber in comparison with a reference amber from Nové Strašecí in central Bohemia; this was of similar age and botanical origin but did not contain elevated levels of uranium. Structural changes involved an increase in aromaticity due to dehydroaromatization of aliphatic cyclic hydrocarbons, loss of oxygen functional groups, an increase in the degree of polymerization, crosslinking of CC bonds, formation of a three-dimensional hydrocarbon network in the bulk organic matrix, and carbonization of the organic matrix around the uraninite infill.

  7. Radionuclides from past uranium mining in rivers of Portugal.

    Science.gov (United States)

    Carvalho, Fernando P; Oliveira, João M; Lopes, Irene; Batista, Aleluia

    2007-01-01

    During several decades and until a few years ago, uranium mines were exploited in the Centre of Portugal and wastewaters from uranium ore milling facilities were discharged into river basins. To investigate enhancement of radioactivity in freshwater ecosystems, radionuclides of uranium and thorium series were measured in water, sediments, suspended matter, and fish samples from the rivers Vouga, Dão, Távora and Mondego. The results show that these rivers carry sediments with relatively high naturally occurring radioactivity, and display relatively high concentrations of radon dissolved in water, which is typical of a uranium rich region. Riverbed sediments show enhanced concentrations of radionuclides in the mid-section of the Mondego River, a sign of past wastewater discharges from mining and milling works at Urgeiriça confirmed by the enhanced values of (238)U/(232)Th radionuclide ratios in sediments. Radionuclide concentrations in water, suspended matter and freshwater fish from that section of Mondego are also enhanced in comparison with concentrations measured in other rivers. Based on current radionuclide concentrations in fish, regular consumption of freshwater species by local populations would add 0.032 mSv a(-1) of dose equivalent (1%) to the average background radiation dose. Therefore, it is concluded that current levels of enhanced radioactivity do not pose a significant radiological risk either to aquatic fauna or to freshwater fish consumers.

  8. Endogenic Au-Ag polymetallic ore deposits and ore-bearing potentiality of strata

    Institute of Scientific and Technical Information of China (English)

    WANG Baode; NIU Shuyin; SUN Aiqun; XIE Yan; LUO Yi; LIU Hailong; WANG Yanhua

    2010-01-01

    The problem of ore-bearing potentiality of the strata involves metallogenic theory and ore-search orientation. Studies of the spatial distribution of endogenic Au-Ag polymetallic ore deposits in North Hebei indicated that the strata in which ore deposits occurred range in age from Paleozoic, Proterozoic to Mesozoic. In addition the ore deposits are characterized as being strata-bound in nature. The arise and establishment of "extracting" viewpoint may be attributed to the following three reasons: 1) influence by the idea of "ore-source bed"; 2) limitation of analytical techniques in the 1980s' (especially gold element); and 3) a small number of samples (sampling locations were mostly disturbed by mineralization). Studies have shown that ore-forming materials would most probably come from the deep interior of the Earth. Deep-seated ore-bearing materials including Au-Ag polymetals were brought to the shallow levels by way of mantle plume-mantle sub-plume-mantle branch structure multi-stage evolution, finally leading to the formation of ore deposits.

  9. Geological Characteristics of Epithermal Ore Concentrated Areas and Epithermal Ore Deposits in China

    Institute of Scientific and Technical Information of China (English)

    1999-01-01

    The epithermal ore concentrated area is located in Southwestern China. We systematically study the regional geological characteristics such as the basement of Proterozoic, the capping bed, Moho, geothermal feature and tectonics, and discuss the relationship between distributed characteristics of the epithermal ore deposits and ore-control factors in this paper. It is concluded that the conditions, under which the epithermal ore deposits form, are huge thick basement of Proterozoic, long-time and wide-scope developed capping bed and weak magmatic activity. The basement of Proterozoic that enriches volcanic matters and carbon and the carbonaceous-bearing and paleo-pool-bearing capping bed provides main ore source. The large and deep faults and paleopool accordance with gravity anomaly gradient control the distribution of epithermal ore deposits. The lithologic assembles of microclastic rocks and carbonate rocks in the capping bed provide spaces of ore precipitation and create conditions of ore precipitation. The coincidence of many geological factors above forms the epithermal ore concentrated area.

  10. Research of Geochemical Associations of Nephelin Ores

    Science.gov (United States)

    Vulf, M.; Simonov, K.; Sazonov, A.

    The instant paper concerns research of distribution petrogenic chemical members in urtit ore body of Kia-Shaltyrsk deposit. Rocks of the deposit are ore for producing alum earth. Actuality of the subject based on outlooks of detection noble metal ore-bearing (Au, Pt, Pd, Rh, Ru) in alkaline rocks of Siberia, including rocks of Kia-Shaltyrsk deposit (Kuznetsk Alatau). The main purpose of analysis of distribution of members is directed to detection of a non-uniformity of distribution of substance and segments enriched with alum earth and noble members. The basic solved problems are following: o Creation regression models of ore body; o Definition of cumulative distribution functions of members in a contour of ore body; o The analysis of the obtained outcomes in geologic terms. For construction regression models the full-scale data was used, which was presented by the results of the spectral and silicate analyses of gold and petrogenic members containing 130 assays arranged in ore body. A non-linear multiparameter model of the ore body based on components of nephelin ore using neural net approach was constructed. For each member the corresponding distribution function is produced. The model is constructed on the following members: Au, Al2O3, SiO2, Fe2O3, CaO, MgO, SO3, R2O ((Na2O+K2O) -1) and losses of burning. The error of model forecasting membersS concentrations was from 0.02 up to 20%. Large errors basically connected with assays located near contact of ore body and ad- jacent strata or with very high concentrations of members; also they can be connected with different genesis of rocks or superposition of other processes. The analysis of concentrations of members and normalised absolute errors of the fore- cast has shown, that all members can be sectioned into two groups: first: Al2O3, SiO2, R2O, Fe2O3 and second: Au, losses of burning, CaO, MgO, SO3. The distribution of 1 gold is tightly connected with calcium and losses of burning and spatially linked with zones

  11. 澳大利亚铀矿资源考察%Overview of Australia Uranium Resources

    Institute of Scientific and Technical Information of China (English)

    金若时; 苏永军

    2013-01-01

    Australia is rich in uranium resources, and it is the largest uranium resources country in the world. The article focuses on types of Australia uranium deposits and distribution of uranium resources, through determining the distribution of Australia uranium deposits, master the geological background of uranium deposit, the metallo-genic regulation and ore-controlling factors, thus it has extremely important significance for uranium exploration and prediction of prospecting target zone, and it provides more opportunities for prospecting uranium deposit. The uranium exploration is in the new period of development in China, use Australia’s prospecting ideas and successful experiences for reference to prospecting in new area or adjacent area, and advances the domestic break-through in uranium prospecting.%澳大利亚铀矿资源丰富,是世界上最大的铀矿资源国。本文重点介绍了澳大利亚铀矿床类型和铀矿资源分布情况。了解澳大利亚铀矿产出的地质背景、成矿规律和控矿因素,对寻找铀矿资源具有十分重要的意义,这些经验可为勘查人员提供更多寻找铀矿的思路。我国铀矿勘查正处于新的发展时期,借鉴澳大利亚找铀矿思路和成功经验,开辟新区和矿区外围铀矿勘查,推进国内铀资源找矿突破。

  12. Mechanism of mechanical activation for sulfide ores

    Institute of Scientific and Technical Information of China (English)

    HU Hui-ping; CHEN Qi-yuan; YIN Zhou-lan; HE Yue-hui; HUANG Bai-yun

    2007-01-01

    Structural changes for mechanically activated pyrite, sphalerite, galena and molybdenite with or without the exposure to ambient air, were systematically investigated using X-ray diffraction analysis(XRD), particle size analysis, gravimetrical method, X-ray photo-electron spectroscopy(XPS) and scanning electron microscopy(SEM), respectively. Based on the above structural changes for mechanically activated sulfide ores and related reports by other researchers, several qualitative rules of the mechanisms and the effects of mechanical activation for sulfide ores are obtained. For brittle sulfide ores with thermal instability, and incomplete cleavage plane or extremely incomplete cleavage plane, the mechanism of mechanical activation is that a great amount of surface reactive sites are formed during their mechanical activation. The effects of mechanical activation are apparent. For brittle sulfide ores with thermal instability, and complete cleavage plane, the mechanism of mechanical activation is that a great amount of surface reactive sites are formed, and lattice deformation happens during their mechanical activation. The effects of mechanical activation are apparent. For brittle sulfide ores with excellent thermal stability, and complete cleavage plane, the mechanism of mechanical activation is that lattice deformation happens during their mechanical activation. The effects of mechanical activation are apparent. For sulfide ores with high toughness, good thermal stability and very excellent complete cleavage plane, the mechanism of mechanical activation is that lattice deformation happens during their mechanical activation, but the lattice deformation ratio is very small. The effects of mechanical activation are worst.

  13. How Many Ore-Bearing Asteroids?

    CERN Document Server

    Elvis, Martin

    2013-01-01

    A simple formalism is presented to assess how many asteroids contain ore, i.e. commercially profitable material, and not merely a high concentration of a resource. I apply this formalism to two resource cases: platinum group metals (PGMs) and water. Assuming for now that only Ni-Fe asteroids are of interest for PGMs, then 1% of NEOs are rich in PGMs. The dearth of ultra-low delta-v (= US$1 B and the population of near-Earth objects (NEOs) larger than 100 m diameter is ~20,000 (Mainzer et al. 2011) the total population of PGM ore-bearing NEOs is roughly 10. I stress that this is a conservative and highly uncertain value. For example, an order of magnitude increase in PGM ore-bearing NEOs occurs if delta-v can as large as 5.7 km s-1. Water ore for utilization in space is likely to be found in ~1/1100 NEOs. NEOs as small as 18 m diameter can be water-ore-bodies because of the high richness of water (~20%) expected in ~25% of carbonaceous asteroids, bringing the number of water-ore-bearing NEOs to ~9000 out of th...

  14. Meeting of the French geological society - Uranium: geology, geophysics, chemistry. Book of abstracts; Reunion de la Societe Geologique de France - Uranium: geologie, geophysique, chimie. Recueil des resumes

    Energy Technology Data Exchange (ETDEWEB)

    Zakari, A.A.; Mima, S.; Bidaud, A.; Criqui, P.; Menanteau, P.; David, S.; Pagel, M.; Chagnes, A.; Cote, G.; Courtaud, B.; Thiry, J.; Miehe, J.M.; Gilbert, F.; Cuney, M.; Bruneton, P.; Ewington, D.; Vautrin-Ul, C.; Cannizzo, C.; Betelu, S.; Chausse, A.; Ly, J.; Bourgeois, D.; Maynadie, J.; Meyer, D.; Clavier, N.; Costin, D.T.; Cretaz, F.; Szenknect, S.; Ravaux, J.; Poinssot, C.; Dacheux, N.; Durupt, N.; Blanvillain, J.J.; Geffroy, F.; Aparicio, B.; Dubessy, J.; Nguyen-Trung, C.; Robert, P.; Uri, F.; Beaufort, D.; Lescuyer, J.L.; Morichon, E.; Allard, T.; Milesi, J.P.; Richard, A.; Rozsypal, C.; Mercadier, J.; Banks, D.A.; Boiron, M.C.; Cathelineau, M.; Dardel, J.; Billon, S.; Patrier, P.; Wattinne, A.; Vanderhaeghe, O.; Fabre, C.; Castillo, M.; Salvi, S.; Beziat, D.; Williams-Jones, A.E.; Trap, P.; Durand, C.; Goncalves, P.; Marquer, D.; Feybesse, J.L.; Richard, Y.; Orberger, B.; Hofmann, A.; Megneng, M.; Orberger, B.; Bouttemy, M.; Vigneron, J.; Etcheberry, A.; Perdicakis, M.; Prignon, N.; Toe, W.; Andre-Mayer, A.S.; Eglinger, A.; Jordaan, T.; Hocquet, S.; Ledru, P.; Selezneva, V.; Vendryes, G.; Lach, P.; Cuney, M.; Mercadier, J.; Brouand, M.; Duran, C.; Seydoux-Guillaume, A.M.; Bingen, B.; Parseval, P. de; Guillaume, D.; Bosse, V.; Paquette, J.L.; Ingrin, J.; Montel, J.M.; Giot, R.; Maucotel, F.; Hubert, S.; Gautheron, C.; Tassan-Got, L.; Pagel, M.; Barbarand, J.; Cuney, M.; Lach, P.; Bonhoure, J.; Leisen, M.; Kister, P.; Salaun, A.; Villemant, B.; Gerard, M.; Komorowski, J.C.; Michel, A.; Riegler, T.; Tartese, R.; Boulvais, P.; Poujols, M.; Gloaguen, E.; Mazzanti, M.; Mougel, V.; Nocton, G.; Biswas, B.; Pecaut, J.; Othmane, G.; Menguy, N.; Vercouter, T.; Morin, G.; Galoisy, L.; Calas, G.; Fayek, M.

    2010-11-15

    -temperature, and metallogenic provinces; 21 - Magmatic-hydrothermal transition in the Roessing pegmatite: implications for uranium mineralisation; 22 - Deformation and partial fusion of a Archean-paleo-Proterozoic crust: implication on uraniferous ores mobilization and deposition, Torngats orogenesis, Ungava bay; 23 - Black chert pebbles of the Pongola basin conglomerates ({approx}2, 9 Ga - South Africa): a potential uranium source?; 24 - origin and evolution of detrital pyrites in meso-Archean conglomerates (3.08-2.64 Ga) of South Africa: uranium source or trap?; 25 - Experimental study of U(VI) carbonates with respect to 3 parameters: pH, carbonate concentration, temperature, using vibrational (Raman, FTIR, ATR) and optical (UV-visible) spectroscopy; 26 - Nature and significance of the contact between the Abbabis gneiss complex and the meta-sedimentary sequences of the Damara orogenic belt; 27 - Metallogenic potentialities of Proterozoic orogenic belts accreted to Archean basements: the Damara/Lufilien orogen - Namibia and Zambia; 28 - Contribution of the Geological Exploration to the development of the KATCO ISR mine - Chu-Sarysu basin, Kazakhstan; 29 - Remarks about some remarkable events which occurred during the Francevillien formation; 30 - Geochemical signature of different mineral phases obtained by ICP-MS laser ablation (trace elements and rare earths): Application Uranium deposits; 31 - Role of fluids and irradiation in complex pegmatite euxenite/zircon assemblies from Norway and their U-Pb geochronological consequences; 32 - Mechanical modeling of rupture around metamictic minerals; 33 - Helium diffusion in apatite: Effect alpha recoil-linked damages; 34 - Rare earth spectra in uranium oxides: a marker of the uranium deposit type; 35 - Rare earths: tracers of uranium behaviour during acid sulphated hydrothermal weathering - the Guadeloupe example; 36 - What metallogenic model for the Kiggavik-Andrew Lake trend? Nunavut, Canada; 37 - Uranium mobility in the Southern

  15. REE geochemical characteristics of the No. 302 uranium deposit in northern Guangdong, South China

    Institute of Scientific and Technical Information of China (English)

    2007-01-01

    The No. 302 uranium deposit, located in Guangdong Province, is a typical granite-type uranium ore deposit. REE geochemical characteristics of the wall rocks, pitchblende, altered rocks, calcite and fluorite from this deposit have been systematically studied in this paper. The result showed that the alkali-metasomatic granites and other altered rocks have the same REE distribution patterns as Indosinian granites. It is indicated that the hydrothermal ore-forming solution had altered the Indosinian granites, and ore-forming materials may directly originate from the Indosinian granites. Calcite and fluorite of different stages are the products derived from the same source but different stages. The evolution and degassing of the mineralizing solution might induce LREE enrichment to varying degree. Mantle fluid and a large volume of mineralizer may be the crucial factors controlling uranium mineralization, and the hydrothermal solution with mineralizer played an important role in U transport and concentration. Meanwhile, the degassing of CO2 might promote U and REE precipitation.

  16. Ores and Climate Change - Primary Shareholders

    Science.gov (United States)

    Stein, Holly J.; Hannah, Judith L.

    2015-04-01

    Many in the economic geology community concern themselves with details of ore formation at the deposit scale, whether tallying fluid inclusion data to get at changes in ore-forming fluids or defining structures that aid and abet mineralization. These compilations are generally aimed at interpretation of events at the site of ore formation, with the goal being assignment of the deposit to a sanctioned ore deposit model. While providing useful data, this approach is incomplete and does not, by itself, serve present-day requirements for true interdisciplinary science. The ore-forming environment is one of chaos and disequilibrium at nearly all scales (Stein, 2014). Chaos and complexity are documented by variably altered rocks, veins or disseminated mineralization with multi-generational fluid histories, erratic and unusual textures in host rocks, and the bitumen or other hydrocarbon products entwined within many ore deposits. This should give pause to our drive for more data as a means to find "the answer". The answer lies in the kind of data collected and more importantly, in the way we interpret those data. Rather than constructing an ever-increasing catalog of descriptive mutations on sanctioned ore deposit models (e.g., IOGC or Iron-Oxide Copper Gold deposits), the way forward is to link source and transport of metals, sulfur, and organic material with regional and ultimately whole Earth chemical evolution. Important experimental work provides chemical constraints in controlled and behaved environments. To these data, we add imagination and interpretation, always tying back to field observations. In this paper, several key points are made by way of ore deposit examples: (1) many IOCG deposits are outcomes of profound changes in the chemistry of the Earth's surface, in the interplay of the atmosphere, hydrosphere, biosphere, and lithosphere; (2) the redox history of Fe in deep earth may be ultimately expressed in the ore-forming sequence; and (3) the formation of

  17. PREDICTION OF LOCATION OF HIDDEN ORE DEPOSITS IN THE AGED ORE FIELDS:AN EXAMPLE FROM FENGHUANGSHAN ORE FIELD,TONGLING,CHINA

    Institute of Scientific and Technical Information of China (English)

    LIU; Liang-ming; PENG; Sheng-lin; YIANG; Qun-zhou; SHAO; Yong-jun; WANG; Zhi-qiang

    2001-01-01

    This paper discusses the strategy for successfully predicting the location of potential hidden ore bodies in aged ore field,and presents the result of location prediction of hidden ore bodies in Fenghuangshan ore field,Tongling.Innovative conceptual targeting procedures based on a genetic understanding of mineralization systems,carefully geological investigation and correct deduction,together with new geochemical and geophysical technology and integrating of comprehensive information are all very important for the successful prediction.In the aged Fenghuangshan ore field,through researching by application of the metallogenic theory of polygenetic compound ore deposits and triple-frequency induced polarization method and exploration tectono-geochemical method,we predicted location and quality of hidden ore bodies.According to the prediction,hidden high quality Cu-Au ore bodies of skarn type and porphyry type have been discovered.

  18. ASTER, ALI and Hyperion sensors data for lithological mapping and ore minerals exploration.

    Science.gov (United States)

    Beiranvand Pour, Amin; Hashim, Mazlan

    2014-01-01

    This paper provides a review of the Advanced Spaceborne Thermal Emission and Reflection Radiometer (ASTER), Advanced Land Imager (ALI), and Hyperion data and applications of the data as a tool for ore minerals exploration, lithological and structural mapping. Spectral information extraction from ASTER, ALI, and Hyperion data has great ability to assist geologists in all disciplines to map the distribution and detect the rock units exposed at the earth's surface. The near coincidence of Earth Observing System (EOS)/Terra and Earth Observing One (EO-1) platforms allows acquiring ASTER, ALI, and Hyperion imagery of the same ground areas, resulting accurate information for geological mapping applications especially in the reconnaissance stages of hydrothermal copper and gold exploration, chromite, magnetite, massive sulfide and uranium ore deposits, mineral components of soils and structural interpretation at both regional and district scales. Shortwave length infrared and thermal infrared bands of ASTER have sufficient spectral resolution to map fundamental absorptions of hydroxyl mineral groups and silica and carbonate minerals for regional mapping purposes. Ferric-iron bearing minerals can be discriminated using six unique wavelength bands of ALI spanning the visible and near infrared. Hyperion visible and near infrared bands (0.4 to 1.0 μm) and shortwave infrared bands (0.9 to 2.5 μm) allowed to produce image maps of iron oxide minerals, hydroxyl-bearing minerals, sulfates and carbonates in association with hydrothermal alteration assemblages, respectively. The techniques and achievements reviewed in the present paper can further introduce the efficacy of ASTER, ALI, and Hyperion data for future mineral and lithological mapping and exploration of the porphyry copper, epithermal gold, chromite, magnetite, massive sulfide and uranium ore deposits especially in arid and semi-arid territory.

  19. Licensing of the Process Uranium Plant Mineral, Retortillo-Santidad; Licenciamiento de la Planta de Proceso de Mineral de Uranio Retortillo-Sanidad

    Energy Technology Data Exchange (ETDEWEB)

    Blazquez Arroyo, E.; Colilla Peletero, J.; Bellon del Rosal, F.; Mancipe Jimenez, D. C.; Garrido Delgado, C.; Garcia-Bermejo Fernandez, R.

    2013-07-01

    Berkeley Minera Spain, S.A. provides for the operation of the concession Retortillo-Santidad (Salamanca) mining and construction of a beneficiation plant of uranium ore, for the production of uranium concentrate (Yellow cake). In Spain, the project Quercus, ENUSA, obtained the last prior authorization in 1979. Since then, there has been a continuous evolution in the aspects technical and regulatory. This paper is the documentation and content necessary for the licensing of a uranium production plant. In particular, to obtain the prior authorization as radioactive installation of 1st category (RINR).

  20. Contrasting REE Signatures on Manganese Ores of Iron Ore Group in North Orissa, India

    Institute of Scientific and Technical Information of China (English)

    2007-01-01

    The distribution pattern of Rare Earth Elements (REE) in three categories of manganese ores viz.stratiform, stratabound-replacement, and detrital of Precambrian Iron Ore Group from north Orissa, India was reported.These categories of Mn-ore differed in their major and trace chemistry and exhibited contrasting REE signature.The stratiform ores were relatively enriched in REE content (697 μg·g-1) and their normalized pattern showed both positive Ce and Eu anomalies, whereas the stratabound-replacement types were comparatively depleted in REE content (211 μg·g-1) and showed negative Ce and flat Eu signatures.The detrital categories showed mixed REE pattern.The data plotted in different discrimination diagrams revealed a mixed volcaniclastic and chemogenic source of material for stratiform categories, and LREE (Light Rare Earth Elements) and HREE (Heavy Rare Earth Elements) are contributed by such sources, respectively.In contrast, the stratabound ore bodies were developed during the remobilization of stratiform ores, and associated Mn-containing rocks under supergene condition followed by the redeposition of circulating mineralized colloidal solutions in structurally favorable zones.During this process, some of the constituents were found only in very low concentration within stratabound ores, and this is attributed to their poor leachability/mobility.The detrital ores did not exhibit any significant characteristic in respect of REE as their development was via a complex combination of processes involving weathering, fragmentation, recementation, and burial under soil cover.

  1. Mobility factors of cracked ore in vibrating-ore draw shafts

    Institute of Scientific and Technical Information of China (English)

    WU Ai-xiang; JIANG Li-chun; CHEN Jia-sheng

    2005-01-01

    The mobile factors of cracked ore in vibrating-ore draw shafts were analyzed. The results show that the mobile coefficient of cracked ores will be mainly influenced by the combination of ore physical factors if the structure dimension and parameters of vibrating ore-draw shafts are sure. It decreases with increasing the cohesion, lump content, lump size and powder content and increases with increasing the porosity. The coefficient decreases with increasing the moisture content, but increases after the moisture content reaches a certain value. Uniform grain leads to better mobility, non-uniform grain leads to worse mobility. The value of the mobile coefficient should be in a range of 0.31.1 when designing the vibrating ore-draw shafts. According to correlation degree of grey system theory, the effects of factors on the mobility of cracked ore are given in the weight decreasing consequence as follows: moisture content, lump content, distribution of grain size, lump size, porosity, cohesion and powder ore content. It is unreasonable to neglect any one because the values of their weights are not obvious.

  2. Uranium hexafluoride handling. Proceedings

    Energy Technology Data Exchange (ETDEWEB)

    1991-12-31

    The United States Department of Energy, Oak Ridge Field Office, and Martin Marietta Energy Systems, Inc., are co-sponsoring this Second International Conference on Uranium Hexafluoride Handling. The conference is offered as a forum for the exchange of information and concepts regarding the technical and regulatory issues and the safety aspects which relate to the handling of uranium hexafluoride. Through the papers presented here, we attempt not only to share technological advances and lessons learned, but also to demonstrate that we are concerned about the health and safety of our workers and the public, and are good stewards of the environment in which we all work and live. These proceedings are a compilation of the work of many experts in that phase of world-wide industry which comprises the nuclear fuel cycle. Their experience spans the entire range over which uranium hexafluoride is involved in the fuel cycle, from the production of UF{sub 6} from the naturally-occurring oxide to its re-conversion to oxide for reactor fuels. The papers furnish insights into the chemical, physical, and nuclear properties of uranium hexafluoride as they influence its transport, storage, and the design and operation of plant-scale facilities for production, processing, and conversion to oxide. The papers demonstrate, in an industry often cited for its excellent safety record, continuing efforts to further improve safety in all areas of handling uranium hexafluoride. Selected papers were processed separately for inclusion in the Energy Science and Technology Database.

  3. Systematic evaluation of satellite remote sensing for identifying uranium mines and mills.

    Energy Technology Data Exchange (ETDEWEB)

    Blair, Dianna Sue; Stork, Christopher Lyle; Smartt, Heidi Anne; Smith, Jody Lynn

    2006-01-01

    In this report, we systematically evaluate the ability of current-generation, satellite-based spectroscopic sensors to distinguish uranium mines and mills from other mineral mining and milling operations. We perform this systematic evaluation by (1) outlining the remote, spectroscopic signal generation process, (2) documenting the capabilities of current commercial satellite systems, (3) systematically comparing the uranium mining and milling process to other mineral mining and milling operations, and (4) identifying the most promising observables associated with uranium mining and milling that can be identified using satellite remote sensing. The Ranger uranium mine and mill in Australia serves as a case study where we apply and test the techniques developed in this systematic analysis. Based on literature research of mineral mining and milling practices, we develop a decision tree which utilizes the information contained in one or more observables to determine whether uranium is possibly being mined and/or milled at a given site. Promising observables associated with uranium mining and milling at the Ranger site included in the decision tree are uranium ore, sulfur, the uranium pregnant leach liquor, ammonia, and uranyl compounds and sulfate ion disposed of in the tailings pond. Based on the size, concentration, and spectral characteristics of these promising observables, we then determine whether these observables can be identified using current commercial satellite systems, namely Hyperion, ASTER, and Quickbird. We conclude that the only promising observables at Ranger that can be uniquely identified using a current commercial satellite system (notably Hyperion) are magnesium chlorite in the open pit mine and the sulfur stockpile. Based on the identified magnesium chlorite and sulfur observables, the decision tree narrows the possible mineral candidates at Ranger to uranium, copper, zinc, manganese, vanadium, the rare earths, and phosphorus, all of which are

  4. Assessment of radiation exposure around abandoned uranium mining area of Stara planina Mt., Serbia

    Directory of Open Access Journals (Sweden)

    Tanić Milan N.

    2014-01-01

    Full Text Available The aim of this work was to estimate the health and radiation hazard due to external irradiation from terrestrial radionuclides in the Stara planina Mt. region, which is important because of past uranium mining activities on the mountain. Soil samples were collected inside the flotation processing facilities, their surroundings and more distant locations, i.e. from areas considered certainly affected, potentially affected, and unaffected by former mining and uranium ore processing activities. The radiological and health risk assessments were done by calculating the six main parameters, based on the activity concentration of 238U, 232Th, and 40K in soil samples as determined by gamma-ray spectrometry. Increased values of the risk parameters were observed only for sites where uranium ore was processed, while the location surrounding these compounds showed values that are usual for this mountain or slightly above them. Calculations of the risk parameters for the background area showed no radiation risk for the local and seasonal population. The presence of U and Th was detected in all water samples from creeks surrounding the facilities, but only in the water from the facility drainage pipe did their concentration exceed the limits given for the uranium content in drinking water. In conclusion, the results obtained in this study fall within the range of values in similar studies conducted worldwide and are below the values which can cause a significant radiation hazard. [Projekat Ministarstva nauke Republike Srbije, br. III43009 i br. III41005

  5. Isolation of uranium mill tailings and their component radionuclides from the biosphere; some earth science perspectives

    Science.gov (United States)

    Landa, Edward

    1980-01-01

    Uranium mining and milling is an expanding activity in the. Western United States. Although the milling process yields a uranium concentrate, the large volume of tailings remaining contains about 85 percent of the radioactivity originally associated with the ore. By virtue of the physical and chemical processing of the ore and the redistribution of the contained radionuclides at the Earth's surface, these tailings constitute a technologically enhanced source of natural radiation exposure. Sources of potential human radiation exposure from uranium mill tailings include the emanation of radon gas, the transport of particles by wind and water, and the transport of soluble radionuclides, seeping from disposal areas, by ground water. Due to the 77,000 year half-life of thorium-230, the parent of radium-226, the environmental effects associated with radionuclides contained in these railings must be conceived of within the framework of geologic processes operating over geologic time. The magnitude of erosion of cover materials and tailings and the extent of geochemical mobilization of the contained radionuclides to the atmosphere and hydrosphere should be considered in the evaluation of the potential, long-term consequences of all proposed uranium mill tailings management plans.

  6. Summary of the radiological assessment of the fuel cycle for a thorium-uranium carbide-fueled fast breeder reactor

    Energy Technology Data Exchange (ETDEWEB)

    Tennery, V.J.; Bomar, E.S.; Bond, W.D.; Meyer, H.R.; Morse, L.E.; Till, J.E.; Yalcintas, M.G.

    1980-01-01

    A large fraction of the potential fuel for nuclear power reactors employing fissionable materials exists as ores of thorium. In addition, certain characteristics of a fuel system based on breeding of the fissionable isotope {sup 233}U from thorium offer the possibility of a greater resistance to the diversion of fissionable material for the fabrication of nuclear weapons. This report consolidates into a single source the principal content of two previous reports which assess the radiological environmental impact of mining and milling of thorium ore and of the reprocessing and refabrication of spent FBR thorium-uranium carbide fuel.

  7. Uranium Conversion & Enrichment

    Energy Technology Data Exchange (ETDEWEB)

    Karpius, Peter Joseph [Los Alamos National Lab. (LANL), Los Alamos, NM (United States)

    2017-02-06

    The isotopes of uranium that are found in nature, and hence in ‘fresh’ Yellowcake’, are not in relative proportions that are suitable for power or weapons applications. The goal of conversion then is to transform the U3O8 yellowcake into UF6. Conversion and enrichment of uranium is usually required to obtain material with enough 235U to be usable as fuel in a reactor or weapon. The cost, size, and complexity of practical conversion and enrichment facilities aid in nonproliferation by design.

  8. Corrosion-resistant uranium

    Science.gov (United States)

    Hovis, V.M. Jr.; Pullen, W.C.; Kollie, T.G.; Bell, R.T.

    1981-10-21

    The present invention is directed to the protecting of uranium and uranium alloy articles from corrosion by providing the surfaces of the articles with a layer of an ion-plated metal selected from aluminum and zinc to a thickness of at least 60 microinches and then converting at least the outer surface of the ion-plated layer of aluminum or zinc to aluminum chromate or zinc chromate. This conversion of the aluminum or zinc to the chromate form considerably enhances the corrosion resistance of the ion plating so as to effectively protect the coated article from corrosion.

  9. Baseline risk assessment of ground water contamination at the uranium mill tailings site Salt Lake City, Utah

    Energy Technology Data Exchange (ETDEWEB)

    1994-09-01

    This baseline risk assessment of groundwater contamination at the uranium mill tailings site near Salt Lake City, Utah, evaluates potential public health or environmental impacts resulting from ground water contamination at the former uranium ore processing site. The tailings and other contaminated material at this site were placed in a disposal cell located at Clive, Utah, in 1987 by the US Department of Energy`s Uranium Mill Tailings Remedial Action (UMTRA) Project. The second phase of the UMTRA Project is to evaluate residual ground water contamination at the former uranium processing site, known as the Vitro processing site. This risk assessment is the first site-specific document under the Ground Water Project. It will help determine the appropriate remedial action for contaminated ground water at the site.

  10. Scientific basis for risk assessment and management of uranium mill tailings

    Energy Technology Data Exchange (ETDEWEB)

    1986-01-01

    A National Research Council study panel, convened by the Board on Radioactive Waste Management, has examined the scientific basis for risk assessment and management of uranium mill tailings and issued this final report containing a number of recommendations. Chapter 1 provides a brief introduction to the problem. Chapter 2 examines the processes of uranium extraction and the mechanisms by which radionuclides and toxic chemicals contained in the ore can enter the environment. Chapter 3 is devoted to a review of the evidence on health risks associated with radon and its decay products. Chapter 4 provides a consideration of conventional and possible new technical alternatives for tailings management. Chapter 5 explores a number of issues of comparative risk, provides a brief history of uranium mill tailings regulation, and concludes with a discussion of choices that must be made in mill tailing risk management. 211 refs., 30 figs., 27 tabs.

  11. Remediation of uranium mill tailings by an integrated biological and chemical process

    Energy Technology Data Exchange (ETDEWEB)

    Torma, A.E.

    1992-01-01

    Dilute calcium chloride brine solution was found to be effective in the solubilization of toxic heavy metals and long half-life radionuclides (Th-230, Ra-226 and Pb-210) from uranium ores and mill tailings. The recovery of heavy metals and radionuclides from uranium mill tailing effluents was studied with calcium alginate beads. The maximum cadmium and zinc uptakes by calcium alginate beads were determined to be 2.8 [times] 10[sup [minus]3] and 2.3 [times] 10[sup [minus]3] mol/dry weight of alginate. The kinetic values, V[sub m] and K, were calculated for uranium uptake by calcium alginate to be 96.2 mg/l/s and 0.125 g/l, respectively.

  12. Remediation of uranium mill tailings by an integrated biological and chemical process

    Energy Technology Data Exchange (ETDEWEB)

    Torma, A.E.

    1992-12-31

    Dilute calcium chloride brine solution was found to be effective in the solubilization of toxic heavy metals and long half-life radionuclides (Th-230, Ra-226 and Pb-210) from uranium ores and mill tailings. The recovery of heavy metals and radionuclides from uranium mill tailing effluents was studied with calcium alginate beads. The maximum cadmium and zinc uptakes by calcium alginate beads were determined to be 2.8 {times} 10{sup {minus}3} and 2.3 {times} 10{sup {minus}3} mol/dry weight of alginate. The kinetic values, V{sub m} and K, were calculated for uranium uptake by calcium alginate to be 96.2 mg/l/s and 0.125 g/l, respectively.

  13. Evolution of uranium distribution and speciation in mill tailings, COMINAK Mine, Niger.

    Science.gov (United States)

    Déjeant, Adrien; Galoisy, Laurence; Roy, Régis; Calas, Georges; Boekhout, Flora; Phrommavanh, Vannapha; Descostes, Michael

    2016-03-01

    This study investigated the evolution of uranium distribution and speciation in mill tailings from the COMINAK mine (Niger), in production since 1978. A multi-scale approach was used, which combined high resolution remote sensing imagery, ICP-MS bulk rock analyses, powder X-ray diffraction, Scanning Electron Microscopy, Focused Ion Beam--Transmission Electron Microscopy and X-ray Absorption Near Edge Spectroscopy. Mineralogical analyses showed that some ore minerals, including residual uraninite and coffinite, undergo alteration and dissolution during tailings storage. The migration of uranium and other contaminants depends on (i) the chemical stability of secondary phases and sorbed species (dissolution and desorption processes), and (ii) the mechanical transport of fine particles bearing these elements. Uranium is stabilized after formation of secondary uranyl sulfates and phosphates, and adsorbed complexes on mineral surfaces (e.g. clay minerals). In particular, the stock of insoluble uranyl phosphates increases with time, thus contributing to the long-term stabilization of uranium. At the surface, a sulfate-cemented duricrust is formed after evaporation of pore water. This duricrust limits water infiltration and dust aerial dispersion, though it is enriched in uranium and many other elements, because of pore water rising from underlying levels by capillary action. Satellite images provided a detailed description of the tailings pile over time and allow monitoring of the chronology of successive tailings deposits. Satellite images suggest that uranium anomalies that occur at deep levels in the pile are most likely former surface duricrusts that have been buried under more recent tailings.

  14. Aluminum substitution in goethite in lake ore

    Directory of Open Access Journals (Sweden)

    Carlson, L.

    1995-06-01

    Full Text Available The extent of substitution of Fe by Al in goethite in 32 lake ore samples collected from 11 lakes in Finland varied between 0 and 23 mol-%. The data indicated a negative relationship between Al-substitution and the particle size of lake ore. Differences in the Al-substitution were apparent between sampling sites, suggesting that kinetic and environmental variation in lake ore formation influences the substitution. Non-substituted goethite is formed in coarse-grained sediments with locally high concentrations of Fe due to iron-rich springs. Unit cell edge lengths and volumes of goethite varied as function of Al-subsitution but deviated from the Vegard relationship towards higher values.

  15. Groundwater prospecting for sandstone-type uranium deposits: the merits of mineral-solution equilibria versus single element tracer methods. Volume II

    Energy Technology Data Exchange (ETDEWEB)

    Wanty, R.B.; Langmuir, D.; Chatham, J.R.

    1981-08-01

    This report presents the results of further research on the groundwater geochemistry of 96 well waters in two uraniferous aquifers in Texas and Wyoming, and is a continuation of the work presented by Chatham et al. (1981). In this study variations in concentrations of U, As, Mo, Se and V were compared with the saturation state of the groundwater with respect to mineral phases of these elements known or expected to occur in each area. The non-radiogenic trace elements exhibited strong redox dependence consistent with thermodynamic predictions, but their variations did not pinpoint existing uranium ore bodies, because of a shift in groundwater flow patterns since the time of ore emplacement. Saturation levels of trace element minerals such as realgar, native Se, and molybdenite showed broad anomalies around the ore-bearing areas, similar to patterns found for U minerals by Langmuir and Chatham (1980), and Chatham et al. (1981). The radiogenic elements Ra and Rn showed significant anomalies directly within the ore zones. Helium anomalies were displaced in the direction of groundwater flow, but by their magnitude and areal extent provided strong evidence for the existence of nearby uranium accumulations. Uranium isotope ratios showed no systematic variations within the two aquifers studied. Saturation maps for kaolinite, illite, montmorillonite and the zeolites analcime and clinoptilolite provided 1 to 2 km anomalies around the ore at the Texas site. Saturation values for the gangue minerals pyrite and calcite defined the redox interface and often suggested the position of probable uranium mineralization. When properly used, the groundwater geochemical concepts for exploration can accurately pinpoint uranium mineralization at a fraction of the cost of conventional methods that involve test drilling and geophysical and core logging.

  16. Radioactive contamination of the environment as a result of uranium production: a case study at the abandoned Lincang uranium mine, Yunnan Province, China

    Institute of Scientific and Technical Information of China (English)

    XU; Lechang(

    2002-01-01

    [1]Gillmore, G. K., Grattan, J., Pyatt, F. B. et al., Radon, water and abandoned metalliferous mines in the UK: Environmental and Human Health Implications, in Uranium in the Aquatic Environment, Proceedings of the International Conference Uranium Mining and Hydrogeology III and the International Mine Water Association Symposium (eds. Merkel, B. J., Planer-Friedrich, B., Wolkersdorfer, C.), Berlin: Springer, 2002, 65-76.[2]GB/T 16146-1995, Standards for Controlling Radon Concentration in Dwellings (in Chinese).[3]Kinze, M., Dose limits and maximum concentration limits (MCL's) for radionuclides--Implication on remediation of uranium mining and milling facilities in Saxony Germany, in Uranium in the Aquatic Environment, Proceedings of the International Conference Uranium Mining and Hydrogeology III and the International Mine Water Association Symposium (eds. Merkel, B. J., Planer-Friedrich, B., Wolkersdorfer, C.), Berlin: Springer, 2002, 1-7.[4]Xu, L. C., Wang, Y. X., Environmental issues and remedial actions of the abandoned Lincang uranium mine in China, in Uranium in the Aquatic Environment, Proceedings of the International Conference Uranium Mining and Hydrogeology III and the International Mine Water Association Symposium (eds. Merkel, B. J., Planer-Friedrich, B., Wolkersdorfer, C.), Berlin: Springer, 2002, 709-718.[5]International Atomic Energy Agency, Decommissioning of Facilities for Mining and Milling of Radioactive Ores and Closeout of Residues, Technical Report Series No. 362, Vienna: IAEA, 1994, 70.[6]OECD/NEA (Nuclear Energy Agency), Environment Activities in Uranium Mining and Milling, A Joint NEA/IAEA Report, Paris: Pubie en Francais Sous le Titre, 1999, 23-26.[7]Xu, L. C., Dai, X., Tan, T. et al., Environment Impact Report on Environmental Treatment Engineering of Decommissioning Lincang Uranium Mine (Feasibility studies stages) ( in Chinese), 1999.[8]Zhang Zhihui, Measurement Methods of Radon and Its Daughters in

  17. Uranium-bearing lignite and its relation to the White River and Arikaree formations in northwestern South Dakota and adjacent states

    Science.gov (United States)

    Denson, N.M.; Bachman, G.O.; Zeller, H.D.

    1954-01-01

    In northwestern South Dakota and adjacent areas uranium-bearing lignite beds occur at many horizons in the Hell Creek formation of late Cretaceous age and the overlying Ludlow, Tongue River, and Sentinel Butte members of the Fort Union formation of Paleocene age. Uranium analyses of 275 surface and auger samples and about 1,000 core samples show that many of the lignite beds contain 0. 005 to 0. 02 percent uranium with concentrations of 0. 05 to 0.10 percent uranium in the lignite ash. Analytical data indicate that the region contains an aggregate of at least 47,500, 000 tons of lignite with an average grade of slightly more than .0. 008 percent containing 3, 900 tons of uranium. Almost a fifth of the estimated reserves are adapted to strip mining and are in beds averaging about 4 feet in thickness. Uranium concentrations of this magnitude in lignite indicate that these deposits upon the development of proper utilization techniques and processes may be an important future source of uranium. Recent discoveries of ore-grade deposits of autunite-bearing lignite and secondary uranium minerals in carbonaceous sandstone at Cave Hills and Slim Buttes indicate that northwestern South Dakota and adjacent areas may containimportant reserves of uranium-ore. The stratigraphic units containing the uraniferous lignite beds have a combined thickness of about 1, 500 feet and are unconformably overlapped by 300 feet or more of tuffaceous sandstone and bentonitic claystone of the White River and Arikaree formations of Oligocene and Miocene age. The stratigraphically highest lignite beds in the local sequence have the greatest concentration of uranium,, and the uranium content is greatest at the top of thick lignite beds, diminishing progressively downward to a vanishing point in their lower parts. Variations in permeability of the rock overlying the mineralized lignite beds seem to be reflected in the intensity of uranium mineralization. Most of the known uranium-bearing lignite

  18. The neurotoxicology of uranium.

    Science.gov (United States)

    Dinocourt, Céline; Legrand, Marie; Dublineau, Isabelle; Lestaevel, Philippe

    2015-11-01

    The brain is a target of environmental toxic pollutants that impair cerebral functions. Uranium is present in the environment as a result of natural deposits and release by human applications. The first part of this review describes the passage of uranium into the brain, and its effects on neurological functions and cognitive abilities. Very few human studies have looked at its cognitive effects. Experimental studies show that after exposure, uranium can reach the brain and lead to neurobehavioral impairments, including increased locomotor activity, perturbation of the sleep-wake cycle, decreased memory, and increased anxiety. The mechanisms underlying these neurobehavioral disturbances are not clearly understood. It is evident that there must be more than one toxic mechanism and that it might include different targets in the brain. In the second part, we therefore review the principal mechanisms that have been investigated in experimental models: imbalance of the anti/pro-oxidant system and neurochemical and neurophysiological pathways. Uranium effects are clearly specific according to brain area, dose, and time. Nonetheless, this review demonstrates the paucity of data about its effects on developmental processes and the need for more attention to the consequences of exposure during development.

  19. METALLOGENIC SYSTEM OF DACHANG TINPOLYMETALLIC ORE FIELD

    Institute of Scientific and Technical Information of China (English)

    WU Xiang-bin; DAI Ta-gen; WANG Zhi-bin; FANG Sheng-kui

    2001-01-01

    The Dachang tin-polymetallic ore field in northern Guangxi,China,lies in a mid-late Paleozoic rift that borders up the southern boundary of the Jiangnan-Xuefeng Massif.As a giant ore deposit,it deposited in middle of the Nandang-Hechi metallogenic zone.The orehosting strata are of the Devonion,which shows the evident characteristics of polymetallic elements,i.e: ,Sn,Zn,Pb,Sb,As,Cu,Ag,In,Ge,Cd,et al.,and over 1 000 000 t tin reserves.

  20. A new radiation shielding material: Amethyst ore

    Energy Technology Data Exchange (ETDEWEB)

    Korkut, Turgay, E-mail: turgaykorkut@hotmail.co [Faculty of Science and Art, Department of Physics, Ibrahim Cecen University, Agri (Turkey); Korkut, Hatun [Faculty of Science and Art, Department of Physics, Ibrahim Cecen University, Agri (Turkey); Karabulut, Abdulhalik; Budak, Goekhan [Faculty of Science, Department of Physics, Atatuerk University, Erzurum (Turkey)

    2011-01-15

    This paper describes a new radiation shielding material, amethyst ore. We have determined the elemental composition of amethyst using WDXRF spectroscopy technique. To see the shielding capability of amethyst for several photon energies, these results have been used in simulation process by FLUKA Monte Carlo radiation transport code. Linear attenuation coefficients have been calculated according to the simulation results. Then, these values have been compared to a fine shielding concrete material. The results show that amethyst shields more gamma beams than concrete. This investigation is the first study about the radiation shielding properties of amethyst ore.

  1. Partitioning properties of rare earth ores in China

    Institute of Scientific and Technical Information of China (English)

    CHI Ru'an; LI Zhongjun; PENG Cui; ZHU Guocai; XU Shengming

    2005-01-01

    The properties of rare earth partitioning in Chinese industrial rare earth ores were analyzed. Rare earth ores can be divided into the single-mineral type ore with bastnaesite, the multi-mineral type ore with bastnaesite and monazite, and the weathering crust type. Both the Bayan Obo rare earth ore and the Zhushan rare earth ore are a kind of mixed ore, consisting of bastnaesite and monazite. Their rare earth partitionings are strongly enriched in light rare earths, where CeO2 is 50% and the light rare earth partitioning is totally over 95%. The Mianning rare earth ore as well as the Weishan rare earth is a kind of rare earth ore only having bastnaesite. Their rare earth partitionings are also strongly enriched in light rare earths,in which CeO2 is 47% and the light rare earth partitioning is totally over 94%. For the weathering crust type rare earth ore,there are the Longnan rare earth ore, the Xunwu rare earth ore, and the middle yttrium and rich europium ore. In the Longnan rare earth ore, which is strongly enriched in heavy rare earths, Y2O3 is 64.83%, and the heavy and light rare earth partitionings are 89.40% and 10.53%, respectively. In the Xunwu rare earth ore, which is strongly enriched in light rare earths, CeO2 is 47.16%, and the light rare earth partitioning is totally 93.25%. Y and Eu are enriched in the middle yttrium and rich europium ore. Its middle rare earth partitioning is totally over 10%, and Eu2O3 and Y2O3 are over 0.5% and 20%,respectively, which are mainly industrial resources of the middle and the heavy rare earths.

  2. Final Environmental assessment for the Uranium Lease Management Program

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    1995-07-01

    The US Department of Energy (DOE) has prepared a programmatic environmental assessment (EA) of the proposed action to continue leasing withdrawn lands and DOE-owned patented claims for the exploration and production of uranium and vanadium ores. The Domestic Uranium Program regulation, codified at Title 10, Part 760.1, of the US Code of Federal Regulations (CFR), gives DOE the flexibility to continue leasing these lands under the Uranium Lease Management Program (ULMP) if the agency determines that it is in its best interest to do so. A key element in determining what is in DOE`s ``best interest`` is the assessment of the environmental impacts that may be attributable to lease tract operations and associated activities. On the basis of the information and analyses presented in the EA for the ULMP, DOE has determined that the proposed action does not constitute a major Federal action significantly affecting the quality of the human environment, as defined in the National Environmental Policy Act (NEPA) of 1969 (42 United States Code 4321 et seq.), as amended.Therefore, preparation of an environmental impact statement is not required for the ULMP,and DOE is issuing this Finding, of No Significant Impact (FONSI).

  3. Sintering Properties and Optimal Blending Schemes of Iron Ores

    Institute of Scientific and Technical Information of China (English)

    Dauter0liveira; WUSheng—li; DAIYu—ming; XUJian; CHEN Hong

    2012-01-01

    In order to obtain good sintering performance, it is important to understand sintering properties of iron ores. Sintering properties including chemical composition, granulation and high-temperature behaviors of ores from China, Brazil and Australia. Furthermore, several indices were defined to evaluate sintering properties of iron ores. The results show that: for chemical composition, Brazilian ores present high TFe, low SiOz, and low Alz03 con- tent. For granulation, particle diameter ratio of Brazilian ores are high; particle intermediate fraction of Chinese con- centrates are low; and average particle size and clay type index of Australian ores are high. For high-temperature properties, ores from China, Brazil and Australia present different characteristics. Ores from different origins should be mixed together to obtain good high-temperature properties. According to the analysis of each ore's sintering prop- erties, an ore blending scheme (Chinese concentrates 20 ~-1- Brazilian ores 400//oo -k Australian ores 40 ~) was sugges- ted. Moreover, sinter pot test using blending mix was performed, and the results indicated that the ore blending scheme led to good sintering performance and sinter quality.

  4. Uranium Potential and Regional Metallogeny in China

    Institute of Scientific and Technical Information of China (English)

    ZHANG Jindai; LI Ziying

    2008-01-01

    This paper is briefly involved in distributions of China's uranium metallogenic types,provinces, regions and belts. Eight target regions have been pointed out to be worthy of prospectingfor uranium resources. The regional uranium metallogeny is discussed and great uranium potentialpointed out from many aspects. Generally speaking, there are favorable conditions for uraniummineralization and good perspective to explore for uranium resources.

  5. Method of preparation of uranium nitride

    Science.gov (United States)

    Kiplinger, Jaqueline Loetsch; Thomson, Robert Kenneth James

    2013-07-09

    Method for producing terminal uranium nitride complexes comprising providing a suitable starting material comprising uranium; oxidizing the starting material with a suitable oxidant to produce one or more uranium(IV)-azide complexes; and, sufficiently irradiating the uranium(IV)-azide complexes to produce the terminal uranium nitride complexes.

  6. 31 CFR 540.309 - Natural uranium.

    Science.gov (United States)

    2010-07-01

    ... 31 Money and Finance: Treasury 3 2010-07-01 2010-07-01 false Natural uranium. 540.309 Section 540... FOREIGN ASSETS CONTROL, DEPARTMENT OF THE TREASURY HIGHLY ENRICHED URANIUM (HEU) AGREEMENT ASSETS CONTROL REGULATIONS General Definitions § 540.309 Natural uranium. The term natural uranium means uranium found...

  7. Safety requirements and radiological protection for ore installations; Requisitos de seguranca e protecao radiologica para instalacoes minero-industriais

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    2003-06-15

    This norm establishes the safety and radiological protection requirements for mining installations which manipulates, process and storing ores, raw materials, steriles, slags and wastes containing radionuclides of the uranium and thorium natural series, simultaneously or separated, and which can cause undue exposures to the public and workers, at anytime of the functioning or pos operational stage. This norm applies to the mining installations activities, suspended or which have ceased their activities before the issue date of this norm, destined to the mining, physical, chemical and metallurgical processing, and the industrialization of raw materials and residues containing associated radionuclides from the natural series of uranium and thorium, including the stages of implantation, operation and decommissioning of the installation.

  8. Comparison of potential radiological consequences from a spent-fuel repository and natural uranium deposits

    Energy Technology Data Exchange (ETDEWEB)

    Wick, O.J.; Cloninger, M.O.

    1980-09-01

    A general criterion has been suggested for deep geological repositories containing spent fuel - the repositories should impose no greater radiological risk than due to naturally occurring uranium deposits. The following analysis investigates the rationale of that suggestion and determines whether current expectations of spent-fuel repository performance are consistent with such a criterion. In this study, reference spent-fuel repositories were compared to natural uranium-ore deposits. Comparisons were based on intrinsic characteristics, such as radionuclide inventory, depth, proximity to aquifers, and regional distribution, and actual and potential radiological consequences that are now occurring from some ore deposits and that may eventually occur from repositories and other ore deposits. The comparison results show that the repositories are quite comparable to the natural ore deposits and, in some cases, present less radiological hazard than their natural counterparts. On the basis of the first comparison, placing spent fuel in a deep geologic repository apparently reduces the hazard from natural radioactive materials occurring in the earth's crust by locating the waste in impermeable strata without access to oxidizing conditions. On the basis of the second comparison, a repository constructed within reasonable constraints presents no greater hazard than a large ore deposit. It is recommended that if the naturally radioactive environment is to be used as a basis for a criterion regarding repositories, then this criterion should be carefully constructed. The criterion should be based on the radiological quality of the waters in the immediate region of a specific repository, and it should be in terms of an acceptable potential increase in the radiological content of those waters due to the existence of the repository.

  9. Improving the neutronic characteristics of a boiling water reactor by using uranium zirconium hydride fuel instead of uranium dioxide fuel

    Energy Technology Data Exchange (ETDEWEB)

    Galahom, Ahmed Abdelghafar [Higher Technological Institute, Ramadan (Egypt)

    2016-06-15

    The present work discusses two different models of boiling water reactor (BWR) bundle to compare the neutronic characteristics of uranium dioxide (UO{sub 2}) and uranium zirconium hydride (UZrH{sub 1.6}) fuel. Each bundle consists of four assemblies. The BWR assembly fueled with UO{sub 2} contains 8 × 8 fuel rods while that fueled with UZrH{sub 1.6} contains 9 × 9 fuel rods. The Monte Carlo N-Particle Transport code, based on the Mont Carlo method, is used to design three dimensional models for BWR fuel bundles at typical operating temperatures and pressure conditions. These models are used to determine the multiplication factor, pin-by-pin power distribution, axial power distribution, thermal neutron flux distribution, and axial thermal neutron flux. The moderator and coolant (water) are permitted to boil within the BWR core forming steam bubbles, so it is important to calculate the reactivity effect of voiding at different values. It is found that the hydride fuel bundle design can be simplified by eliminating water rods and replacing the control blade with control rods. UZrH{sub 1.6} fuel improves the performance of the BWR in different ways such as increasing the energy extracted per fuel assembly, reducing the uranium ore, and reducing the plutonium accumulated in the BWR through burnup.

  10. Characteristics of polymetallic ore-forming fluid and metallogenesis of the Xiangshan ore-field in Jiangxi%江西相山矿田多金属成矿流体特征与成矿作用

    Institute of Scientific and Technical Information of China (English)

    聂江涛; 李子颖; 王健; 郭建

    2015-01-01

    Fluid inclusions of polymetallic mineralization in the Xiangshan uranium orefield were studied for the first time in this pa⁃per. A large number of polymetallic mineralizations were discovered recently with the deepening of geological exploration in the Xiangshan uranium orefield and the implementation of uranium scientific deep drilling. Based on studying petrography, microther⁃mometry, pressure of ore-forming processes, composition and metallogenic depth of fluid inclusions as well as sulfur, carbon, oxygen isotopic composition, the authors hold that the lead and zinc ore-forming temperatures are mainly concentrated on 230~300℃, the metallogenic pressures are concentrated on 12~51MPa, and the salinities are concentrated on 4%~12%NaCleqv. The fluid inclusions are enriched in CO2 and to a lesser extent in CH4 and N2. The mineral assemblage is mainly sphalerite+gelenite+pyrite. The cop⁃per ore-forming temperatures are mainly concentrated on 320~380℃,metallogenic pressures on 33~95MPa , and salinities on 4%~12%NaCleqv. The fluid inclusions are enriched in CO2 and to a lesser extent in CH4 and N2. The mineral assemblage is mainly chal⁃copyrite+pyrrhotite+arsenikstein. All these data indicate that ore-forming fluids were characterized by medium-high temperature, high pressure, medium-high salinity, low oxygen fugacity and high content of CO 2. The lead, zinc, copper and uranium ore-form⁃ing fluids were characterized by deep source, but there were obvious different in stage, space, alteration and fluid inclusion characteris⁃tics of lead, zinc, copper and uranium mineralization, so they were formed in different ore-forming stages and occurred in different separate hydrothermal mineralization processes in early-middle Cretaceous in South China.%随着相山铀矿矿田勘探深度的增加和铀矿科学深钻的实施,在矿田内揭露了大量多金属矿化,流体包裹体和地球化学研究表明,铅锌矿成矿期温度集中在230~300

  11. A cohort study of uranium millers and miners of Grants, New Mexico, 1979-2005

    Energy Technology Data Exchange (ETDEWEB)

    Boice, John D Jr; Cohen, Sarah S; Mumma, Michael T; Chadda, Bandana; Blot, William J [International Epidemiology Institute, 1455 Research Boulevard, Suite 550, Rockville, MD 20850 (United States)], E-mail: john.boice@vanderbilt.edu

    2008-09-01

    A cohort mortality study of workers engaged in uranium milling and mining activities near Grants, New Mexico, during the period from 1955 to 1990 was conducted. Vital status was determined through 2005 and standardised mortality ratio (SMR) analyses were conducted for 2745 men and women alive after 1978 who were employed for at least six months. Overall, mortality from all causes (SMR 1.15; 95% CI 1.07-1.23; n = 818) and all cancers (SMR 1.22; 95% CI 1.07-1.38; n = 246) was greater than expected on the basis of US mortality rates. Increased mortality, however, was seen only among the 1735 underground uranium miners and was due to malignant (SMR 2.17; 95% CI 1.75-2.65; n = 95) and non-malignant (SMR 1.64; 95% CI 1.23-2.13; n = 55) respiratory diseases, cirrhosis of the liver (SMR 1.79; n = 18) and external causes (SMR 1.65; n = 58). The lung cancer excess likely is attributable to the historically high levels of radon in uranium mines of the Colorado Plateau, combined with the heavy use of tobacco products. No statistically significant elevation in any cause of death was seen among the 904 non-miners employed at the Grants uranium mill. Among 718 mill workers with the greatest potential for exposure to uranium ore, no statistically significant increase in any cause of death of a priori interest was seen, i.e., cancers of the lung, kidney, liver, or bone, lymphoma, non-malignant respiratory disease, renal disease or liver disease. Although the population studied was relatively small, the follow-up was long (up to 50 yrs) and complete. In contrast to miners exposed to radon and radon decay products, for uranium mill workers exposed to uranium dusts and mill products there was no clear evidence of uranium-related disease.

  12. Hydrogen Plasma Processing of Iron Ore

    Science.gov (United States)

    Sabat, Kali Charan; Murphy, Anthony B.

    2017-03-01

    Iron is currently produced by carbothermic reduction of oxide ores. This is a multiple-stage process that requires large-scale equipment and high capital investment, and produces large amounts of CO2. An alternative to carbothermic reduction is reduction using a hydrogen plasma, which comprises vibrationally excited molecular, atomic, and ionic states of hydrogen, all of which can reduce iron oxides, even at low temperatures. Besides the thermodynamic and kinetic advantages of a hydrogen plasma, the byproduct of the reaction is water, which does not pose any environmental problems. A review of the theory and practice of iron ore reduction using a hydrogen plasma is presented. The thermodynamic and kinetic aspects are considered, with molecular, atomic and ionic hydrogen considered separately. The importance of vibrationally excited hydrogen molecules in overcoming the activation energy barriers, and in transferring energy to the iron oxide, is emphasized. Both thermal and nonthermal plasmas are considered. The thermophysical properties of hydrogen and argon-hydrogen plasmas are discussed, and their influence on the constriction and flow in the of arc plasmas is considered. The published R&D on hydrogen plasma reduction of iron oxide is reviewed, with both the reduction of molten iron ore and in-flight reduction of iron ore particles being considered. Finally, the technical and economic feasibility of the process are discussed. It is shown that hydrogen plasma processing requires less energy than carbothermic reduction, mainly because pelletization, sintering, and cokemaking are not required. Moreover, the formation of the greenhouse gas CO2 as a byproduct is avoided. In-flight reduction has the potential for a throughput at least equivalent to the blast furnace process. It is concluded that hydrogen plasma reduction of iron ore is a potentially attractive alternative to standard methods.

  13. Origin of the Mariano Lake uranium deposit, McKinley County, New Mexico

    Science.gov (United States)

    Fishman, Neil S.; Reynolds, Richard L.

    1982-01-01

    introduced amorphous organic matter and uranium residence in this organic matter) indicate that the Mariano Lake orebody is a tabular-type uranium deposit. Oxidative processes have not noticeably redistributed and reconcentrated primary uranium in the immediate vicinity of the deposit nor have they greatly modified geochemical characteristics in the ore. Preservation of the Mariano Lake deposit may not only be related to its position along the synclinal trough, where oxidative destruction of the orebody has been inhibited by stagnation of oxidizing ground waters by the structure, but also due to the deflection of ground waters (resulting from low orebody porosity) around the orebody.

  14. ELECTROLYSIS OF THORIUM AND URANIUM

    Science.gov (United States)

    Hansen, W.N.

    1960-09-01

    An electrolytic method is given for obtaining pure thorium, uranium, and thorium-uranium alloys. The electrolytic cell comprises a cathode composed of a metal selected from the class consisting of zinc, cadmium, tin, lead, antimony, and bismuth, an anode composed of at least one of the metals selected from the group consisting of thorium and uranium in an impure state, and an electrolyte composed of a fused salt containing at least one of the salts of the metals selected from the class consisting of thorium, uranium. zinc, cadmium, tin, lead, antimony, and bismuth. Electrolysis of the fused salt while the cathode is maintained in the molten condition deposits thorium, uranium, or thorium-uranium alloys in pure form in the molten cathode which thereafter may be separated from the molten cathode product by distillation.

  15. Radiochemistry of uranium

    Energy Technology Data Exchange (ETDEWEB)

    Gindler, J.E.

    1962-03-01

    This volume which deals with the radiochemistry of uranium is one of a series of monographs on radiochemistry of the elements. There is included a review of the nuclear and chemical features of particular interest to the radiochemist, a discussion of problems of dissolution of a sample and counting technique, and finally, a collection of radiochemical procedures for the element as found in the literature.

  16. Uranium Critical Point Location Problem

    CERN Document Server

    Iosilevskiy, Igor

    2013-01-01

    Significant uncertainty of our present knowledge for uranium critical point parameters is under consideration. Present paper is devoted to comparative analysis of possible resolutions for the problem of uranium critical point location, as well as to discussion of plausible scheme of decisive experiment, which could resolve existing uncertainty. New calculations of gas-liquid coexistence in uranium by modern thermodynamic code are included in the analysis.

  17. URANIUM MARKET TRENDS

    Directory of Open Access Journals (Sweden)

    Serghei MĂRGULESCU

    2016-06-01

    Full Text Available The recent UN Climate Talks in Paris have put forward the goal of limiting the global temperature rise to two degrees Celsius by the end of the century. This is providing a strong political base for expanding the nuclear power capacity because of the critical role that nuclear power plants play in the production of electricity without emissions of greenhouse gases. In all, more than a dozen countries get over 25% of their energy from nuclear power, with 437 nuclear reactors operating around the world. On top of that, there are another 71 reactors under construction, 165 planned, and 315 proposed. Global uranium demand is expected to rise 40% by 2025 and 81% by 2035. Mined supply of uranium will struggle to keep pace amid rising demand and falling secondary supplies. A cumulative supply deficit is expected to emerge by 2021 while 2016 marks a huge inflection point for the industry, beeing the first year that demand will actually exceed supplies, creating a 60,000-tonne shortfall by 2018. Over the next 10 years, we're going to see uranium prices more than double while the bull run will begin in earnest in 2016.

  18. High-rate behaviour of iron ore pellet

    Directory of Open Access Journals (Sweden)

    Gustafsson Gustaf

    2015-01-01

    Full Text Available Iron ore pellets are sintered, centimetre-sized spheres of ore with high iron content. Together with carbonized coal, iron ore pellets are used in the production of steel. In the transportation from the pelletizing plants to the customers, the iron ore pellets are exposed to different loading situations, resulting in degradation of strength and in some cases fragmentation. For future reliable numerical simulations of the handling and transportation of iron ore pellets, knowledge about their mechanical properties is needed. This paper describes the experimental work to investigate the dynamic mechanical properties of blast furnace iron ore pellets. To study the dynamic fracture of iron ore pellets a number of split Hopkinson pressure bar tests are carried out and analysed.

  19. METHOD FOR RECOVERING URANIUM FROM OILS

    Science.gov (United States)

    Gooch, L.H.

    1959-07-14

    A method is presented for recovering uranium from hydrocarbon oils, wherein the uranium is principally present as UF/sub 4/. According to the invention, substantially complete removal of the uranium from the hydrocarbon oil may be effected by intimately mixing one part of acetone to about 2 to 12 parts of the hydrocarbon oil containing uranium and separating the resulting cake of uranium from the resulting mixture. The uranium in the cake may be readily recovered by burning to the oxide.

  20. SEPARATION OF THORIUM FROM URANIUM

    Science.gov (United States)

    Bane, R.W.

    1959-09-01

    A description is given for the separation of thorium from uranium by forming an aqueous acidic solution containing ionic species of thorium, uranyl uranium, and hydroxylamine, flowing the solution through a column containing the phenol-formaldehyde type cation exchange resin to selectively adsorb substantially all the thorium values and a portion of the uranium values, flowing a dilute solution of hydrochloric acid through the column to desorb the uranium values, and then flowing a dilute aqueous acidic solution containing an ion, such as bisulfate, which has a complexing effect upon thortum through the column to desorb substantially all of the thorium.

  1. Hydrocarbon-mediated gold and uranium concentration in the Witwatersrand Basin, South Africa

    Science.gov (United States)

    Fuchs, Sebastian; Williams-Jones, Anthony; Schumann, Dirk; Couillard, Martin; Murray, Andrew

    2016-04-01

    The Witwatersrand deposits in South Africa represent the largest repository of gold in the World and a major resource of uranium. The genesis of the gold and uranium ores in the quartz-pebble conglomerates (reefs), however, is still a matter of considerable discussion. Opinion has been divided over whether they represent paleo-placers that have been partly remobilised by hydrothermal fluids or if the mineralisation is entirely hydrothermal in origin. In addition, recently published models have proposed a syngenetic origin for the gold involving bacterially-mediated precipitation from meteoric water and shallow seawater. An important feature of the gold and uranium mineralisation in the reefs is the strong spatial association with organic matter. In some reefs, up to 70% of the gold and almost the entire uranium resource is spatially associated with pyrobitumen seams, suggesting a genetic relationship of the gold-uranium mineralisation with hydrocarbons. Here we report results of a study of the Carbon Leader Reef, using high-resolution scanning and transmission electron microscopy (SEM / TEM) and LA-ICP-MS that provide new insights into the role of hydrocarbons in the concentration of the gold and uranium. A detailed examination revealed gold monocrystals containing numerous rounded or elliptical inclusions filled with pyrobitumen. We interpret these inclusions to record the crystallisation of the gold around droplets of a hydrocarbon liquid that migrated through the Witwatersrand basin, and was converted to pyrobitumen by being heated. We propose that the gold was transported in a hydrothermal fluid as a bisulphide complex and that this fluid mixed with the hydrocarbon liquid to form a water-oil emulsion. The interaction between the two fluids caused a sharp reduction in fO2 at the water-oil interface, which destabilised the gold-bisulphide complexes, causing gold monocrystals to precipitate around the oil droplets. In contrast to the gold, uraninite, the principal

  2. Geology and recognition criteria for sandstone uranium deposits in mixed fluvial-shallow marine sedimentary sequences, South Texas. Final report

    Energy Technology Data Exchange (ETDEWEB)

    Adams, S.S.; Smith, R.B.

    1981-01-01

    Uranium deposits in the South Texas Uranium Region are classical roll-type deposits that formed at the margin of tongues of altered sandstone by the encroachment of oxidizing, uraniferous solutions into reduced aquifers containing pyrite and, in a few cases, carbonaceous plant material. Many of the uranium deposits in South Texas are dissimilar from the roll fronts of the Wyoming basins. The host sands for many of the deposits contain essentially no carbonaceous plant material, only abundant disseminated pyrite. Many of the deposits do not occur at the margin of altered (ferric oxide-bearing) sandstone tongues but rather occur entirely within reduced, pyurite-bearing sandstone. The abundance of pyrite within the sands probably reflects the introduction of H/sub 2/S up along faults from hydrocarbon accumulations at depth. Such introductions before ore formation prepared the sands for roll-front development, whereas post-ore introductions produced re-reduction of portions of the altered tongue, leaving the deposit suspended in reduced sandstone. Evidence from three deposits suggests that ore formation was not accompanied by the introduction of significant amounts of H/sub 2/S.

  3. Quantifying uranium transport rates and storage of fluvially eroded mine tailings from a historic mine site in the Grand Canyon Region

    Science.gov (United States)

    Skalak, K.; Benthem, A. J.; Walton-Day, K. E.; Jolly, G.

    2015-12-01

    The Grand Canyon region contains a large number of breccia pipes with economically viable uranium, copper, and silver concentrations. Mining in this region has occurred since the late 19th century and has produced ore and waste rock having elevated levels of uranium and other contaminants. Fluvial transport of these contaminants from mine sites is a possibility, as this arid region is susceptible to violent storms and flash flooding which might erode and mobilize ore or waste rock. In order to assess and manage the risks associated with uranium mining, it is important to understand the transport and storage rates of sediment and uranium within the ephemeral streams of this region. We are developing a 1-dimensional sediment transportation model to examine uranium transport and storage through a typical canyon system in this region. Our study site is Hack Canyon Mine, a uranium and copper mine site, which operated in the 1980's and is currently experiencing fluvial erosion of its waste rock repository. The mine is located approximately 40km upstream from the Colorado River and is in a deep, narrow canyon with a small watershed. The stream is ephemeral for the upper half of its length and sediment is primarily mobilized during flash flood events. We collected sediment samples at 110 locations longitudinally through the river system to examine the distribution of uranium in the stream. Samples were sieved to the sand size and below fraction (system to determine where uranium is preferentially stored in canyon systems. This information will quantify the downstream transport of constituents associated with the Hack Canyon waste rock and contribute to understanding the risks associated with fluvial mobilization of uranium mine waste.

  4. Thermodynamics of uranium/organic matter interactions in hydrothermal systems

    Science.gov (United States)

    Richard, L.

    2003-04-01

    Organic matter is commonly encountered in and around uranium and other ore deposits, which raises the question of the role played by organic compounds in the formation of these deposits (Landais and Gize, 1997). One of the best known examples is the observation of uraninite crystals entrapped within solid bitumens in the Oklo natural reactors. This observation led Nagy et al. (1991) to propose that a liquid, aliphatic-rich bitumen may have acted as a reductant to precipitate uraninite from hydrothermal solutions according to the reaction VIUO2+2(aq)+H_2O(l)=IVUO2(c)+2H^+(aq)+0.5 O2(g). The liquid bitumen was simultaneously oxidized into a polyaromatic solid, which may be represented by the reaction 2.7n- C20H42(l) + 17.85 O2(g) = C54H42(c)+35.7 H_2O(l) where n-C20H42(l) denotes n-eicosane present in the liquid bitumen, and C54H42(c) represents an idealized polyaromatic solid. Recent advances in theoretical organic geochemistry made it possible to generate a comprehensive thermodynamic database for hundreds of crystalline, liquid, gas and aqueous organic compounds of geochemical interest (Shock and Helgeson, 1990; Shock, 1995; Amend and Helgeson, 1997; Helgeson et al., 1998; Richard and Helgeson, 1998; Richard, 2001), which can be used together with thermodynamic properties for uranium-bearing minerals and aqueous species (Grenthe et al., 1992; Shock et al., 1997) to characterize uranium/organic matter interactions in hydrothermal systems as a function of temperature, pressure, oxygen fugacity, and organic matter composition. Activity-fO_2 diagrams have been constructed at a series of temperatures and pressures to investigate possible genetic relationships between uranium mineralizations and solid bitumens of various compositions.

  5. Timing of ore-related magmatism in the western Alaska Range, southwestern Alaska

    Science.gov (United States)

    Taylor, Ryan D.; Graham, Garth E.; Anderson, Eric D.; Selby, David

    2014-01-01

    This report presents isotopic age data from mineralized granitic plutons in an area of the Alaska Range located approximately 200 kilometers to the west-northwest of Anchorage in southwestern Alaska. Uranium-lead isotopic data and trace element concentrations of zircons were determined for 12 samples encompassing eight plutonic bodies ranging in age from approximately 76 to 57.4 millions of years ago (Ma). Additionally, a rhenium-osmium age of molybdenite from the Miss Molly molybdenum occurrence is reported (approx. 59 Ma). All of the granitic plutons in this study host gold-, copper-, and (or) molybdenum-rich prospects. These new ages modify previous interpretations regarding the age of magmatic activity and mineralization within the study area. The new ages show that the majority of the gold-quartz vein-hosting plutons examined in this study formed in the Late Cretaceous. Further work is necessary to establish the ages of ore-mineral deposition in these deposits.

  6. Ore fluid geochemistry of the Jinlongshan Carlin type gold ore belt in Shaanxi Province, China

    Institute of Scientific and Technical Information of China (English)

    2006-01-01

    The Jinlongshan gold ore belt in southern Shaanxi Province contains a number of Carlin-type gold deposits in the Qinling collisional orogenic belt. Their fluid inclusions are of the Na+ - Cl- type. From the main metallogenic stage to later stages, the total quantity of anions and cations, temperature and deoxidation parameter (R) for fluid inclusions all gradu ally decreased, suggesting the gradual intensification of fluid oxidation, the reduction of met allogenic depth and the input of meteoric water and organic components. The deposits were formed during crustal uplifting and hence had similar tectonic settings to orogenic gold depos its. The CO2 contents and CO2/H2O values of the ore fluid increased from early to late sta ges, and the wall-rock alteration is represented by decarbonation, which is inconsistent with the characteristics of orogenic gold deposits. It is also discovered that Na + , K + ,SO42-, Cl-and the total amounts of anions and cations in the inclusions in quartz are higher than those in the coexisting calcite. The H, O and C isotope ratios indicate that the ore fluid was sourced from meteoric water and metamorphic devolatilisation of the sedimentary rocks that host the ores. The high background δ18O and δ13C values of wall rocks resulted in high δ18O and δ13 C values of ore fluid and also high δ 18 O and δ 13 C values of hydrothermal minerals such as quartz and carbonate. The carbon in ore fluid stemmed largely from the hosting strata. The δ 18O and δ13C values of Fe-calcite and the δD values of fluid inclusions are lower than those of calcite and quartz. In terms of the theory of coordination chemistry, all these differences can be ascribed to water-rock interaction in the same fluid system, instead, to the multi source of ore fluid.

  7. Identifying anthropogenic uranium compounds using soft X-ray near-edge absorption spectroscopy

    Science.gov (United States)

    Ward, Jesse D.; Bowden, Mark; Tom Resch, C.; Eiden, Gregory C.; Pemmaraju, C. D.; Prendergast, David; Duffin, Andrew M.

    2017-01-01

    Uranium ores mined for industrial use are typically acid-leached to produce yellowcake and then converted into uranium halides for enrichment and purification. These anthropogenic chemical forms of uranium are distinct from their mineral counterparts. The purpose of this study is to use soft X-ray absorption spectroscopy to characterize several common anthropogenic uranium compounds important to the nuclear fuel cycle. Chemical analyses of these compounds are important for process and environmental monitoring. X-ray absorption techniques have several advantages in this regard, including element-specificity, chemical sensitivity, and high spectral resolution. Oxygen K-edge spectra were collected for uranyl nitrate, uranyl fluoride, and uranyl chloride, and fluorine K-edge spectra were collected for uranyl fluoride and uranium tetrafluoride. Interpretation of the data is aided by comparisons to calculated spectra. The effect of hydration state on the sample, a potential complication in interpreting oxygen K-edge spectra, is discussed. These compounds have unique spectral signatures that can be used to identify unknown samples.

  8. Fractal and Chaos Analysis for Dynamics of Radon Exhalation from Uranium Mill Tailings

    Science.gov (United States)

    Li, Yongmei; Tan, Wanyu; Tan, Kaixuan; Liu, Zehua; Xie, Yanshi

    2016-08-01

    Tailings from mining and milling of uranium ores potentially are large volumes of low-level radioactive materials. A typical environmental problem associated with uranium tailings is radon exhalation, which can significantly pose risks to environment and human health. In order to reduce these risks, it is essential to study the dynamical nature and underlying mechanism of radon exhalation from uranium mill tailings. This motivates the conduction of this study, which is based on the fractal and chaotic methods (e.g. calculating the Hurst exponent, Lyapunov exponent and correlation dimension) and laboratory experiments of the radon exhalation rates. The experimental results show that the radon exhalation rate from uranium mill tailings is highly oscillated. In addition, the nonlinear analyses of the time series of radon exhalation rate demonstrate the following points: (1) the value of Hurst exponent much larger than 0.5 indicates non-random behavior of the radon time series; (2) the positive Lyapunov exponent and non-integer correlation dimension of the time series imply that the radon exhalation from uranium tailings is a chaotic dynamical process; (3) the required minimum number of variables should be five to describe the time evolution of radon exhalation. Therefore, it can be concluded that the internal factors, including heterogeneous distribution of radium, and randomness of radium decay, as well as the fractal characteristics of the tailings, can result in the chaotic evolution of radon exhalation from the tailings.

  9. Volumetric determination of uranium using titanous sulfate as reductant before oxidimetric titration

    Science.gov (United States)

    Wahlberg, James S.; Skinner, Dwight L.; Rader, Lewis F.

    1956-01-01

    A new method for determining uranium in samples containing 0.05 percent or more U3O8, using titanous sulfate as reducing agent, is much shorter, faster, and has fewer interferences than conventional methods using reductor columns. The sample is dissolved with sulfuric, nitric, perchloric, and hydrofluoric acids. Elements that would otherwise form insoluble fluorides are kept in solution by complexing the fluoride ion with boric acid. A precipitation is made with cupferron to remove interfering elements. The solution is filtered to remove the precipitated cupferrates instead of extracting them with chloroform as is usually done. Filtration is preferred to extraction because any niobium that may be in solution forms an insoluble cupferrate that may be removed by filtering but is very difficult to extract with chloroform. Excess cupferron is destroyed by oxidizing with nitric and perchloric acids, and evaporating to dense fumes of sulfuric acid. The uranium is reduced to U(IV) by the addition of titanous sulfate, with cupric sulfate used as an indicator of the completeness of the reduction. Metallic copper is formed when all the uranium is reduced. The reduced copper is then reoxidized by the addition of mercuric perchlorate, an excess of ferric sulfate added, and the solution titrated immediately with standard ceric sulfate with ferroin as an indicator. Precision of the method compared favorable with methods in common use, both for uranium ores and for most types of uranium-rich materials.

  10. Assessment of Prospecting Potentiality for Superlarge Continental Volcanic Rock—Type Uranium Deposits in China

    Institute of Scientific and Technical Information of China (English)

    陈贵华; 陈名佐; 等

    1999-01-01

    The superlarge continental volcanic rock-type uranium deposits,which were discovered abroad long ago,have not ye been reported up to now in China.This is an important problem that needs to be urgently solved by uranium geologists at present.In this paper,on the basis of analyzing the metallogenic settings and geological conditions of the superlarge continental volcanic rock-type uranium deposits discovered in the world along with the metallogenic characteristics of those of the same type in China,the space-time distribution patterns of continental volcanics and the metallogenic potential of main tectono-volcanic belts in China are discussed,and a synthetic conclusion has been drawn that there is a possibility to discover the superlarge continental volcanic rock-type uranium deposits in China.Moreover,it is evidenced that the Ganhang,Nanling,Yanliao,Da Hinggan Ling and other tectono-volcanic belts possess favorable geological conditions for the formation of ssuperlarge ore deposits of the continental volcanic rock type.The intersecting and overlapping locations of the aforementioned main belts with other tectono-volcanic(-intrusive)belts are the most potential areas where the superlarge continental volcanic rock-type uranium deposits would be found.

  11. Geochemical reconnaissance for uranium occurrences in the Notch Peak intrusive area, House Range, Millard County, Utah

    Science.gov (United States)

    Cadigan, R.A.; Robinson, Keith

    1982-01-01

    Samples collected from the contact metamorphic zone of the Notch Peak intrusive area, House Range, Millard County, Utah, indicate the occurrence of low-grade uranium and thorium ore. Maximum abundances in the altered mineralized rocks in the contact zone are 450 ppm uranium and 480 ppm thorium. Interpretation of factor analysis of the spectrochemical and delayed neutron analytical data suggests the presence of five geological factors which account for 82 percent of element covariance of 34 elements in 61 samples. The factors are identified as (1) limestone source rock reactions; (2) monzonite source rock reactions; (3) hydrothermal element group 1; (4) rare earth group; and (5) hydrothermal element group 2. The last factor effects the distribution of, primarily, beryllium, uranium, copper, molybdenum, tungsten, niobium, and secondarily, thorium, tin, and zinc; it is identified as the prime mineralization factor. The Notch Peak intrusive area has been a tungsten producing area since before the 1940's and the location of small-scale gold placer operations. This reconnaissance study was a 'follow-up' of uranium anomaly data which were developed during the U.S. Dept. of Energy National Uranium Resource Evaluation (NURE) program in 1978-80.

  12. Environmental assessment of remedial action at the Naturita uranium processing site near Naturita, Colorado: Revision 5

    Energy Technology Data Exchange (ETDEWEB)

    1994-10-01

    Title 1 of the Uranium Mill Tailings Radiation Control Act (UMTRCA) of 1978, Public Law (PL) 95-604, authorized the US Department of Energy (DOE) to perform remedial action at the inactive Naturita, Colorado, uranium processing site to reduce the potential health effects from the radioactive materials at the site and at vicinity properties associated with the site. Title 2 of the UMTRCA authorized the US Nuclear Regulatory Commission (NRC) or agreement state to regulate the operation and eventual reclamation of active uranium processing sites. The uranium mill tailings at the site were removed and reprocessed from 1977 to 1979. The contaminated areas include the former tailings area, the mill yard, the former ore storage area, and adjacent areas that were contaminated by uranium processing activities and wind and water erosion. The Naturita remedial action would result in the loss of 133 acres (ac) of contaminated soils at the processing site. If supplemental standards are approved by the NRC and the state of Colorado, approximately 112 ac of steeply sloped contaminated soils adjacent to the processing site would not be cleaned up. Cleanup of this contamination would have adverse environmental consequences and would be potentially hazardous to remedial action workers.

  13. Uranium deposits in the Eureka Gulch area, Central City district, Gilpin County, Colorado

    Science.gov (United States)

    Sims, P.K.; Osterwald, F.W.; Tooker, E.W.

    1954-01-01

    The Eureka Gulch area of the Central City district, Gilpin County, Colo., was mined for ores of gold, silver, copper, lead, and zinc; but there has been little mining activity in the area since World War I. Between 1951 and 1953 nine radioactive mine dumps were discovered in the area by the U.S. Geological Survey and by prospectors. the importance of the discoveries has not been determined as all but one of the mines are inaccessible, but the distribution, quantity, and grade of the radioactive materials found on the mine dumps indicate that the area is worth of additional exploration as a possible source of uranium ore. The uranium ans other metals are in and near steeply dipping mesothermal veins of Laramide age intrusive rocks. Pitchblende is present in at least four veins, and metatorbernite, associated at places with kosolite, is found along two veins for a linear distance of about 700 feet. The pitchblends and metatorbernite appear to be mutually exclusive and seem to occur in different veins. Colloform grains of pitchblende were deposited in the vein essentially contemporaneously with pyrite. The pitchblende is earlier in the sequence of deposition than galena and sphalerite. The metatorbernite replaces altered biotite-quartz-plagioclase gneiss and altered amphibolite, and to a lesser extent forms coatings on fractures in these rocks adjacent to the veins; the kasolite fills vugs in highly altered material and in altered wall rocks. Much of the pitchblende found on the dumps has been partly leached subsequent to mining and is out of equilibrium. Selected samples of metatorbernite-bearing rock from one mine dump contain as much as 6.11 percent uranium. The pitchblende is a primary vein mineral deposited from uranium-bearing hydrothermal solutions. The metatorbernite probably formed by oxidation, solution, and transportation of uranium from primary pitchblende, but it may be a primary mineral deposited directly from fluids of different composition from these

  14. The terrestrial uranium isotope cycle.

    Science.gov (United States)

    Andersen, Morten B; Elliott, Tim; Freymuth, Heye; Sims, Kenneth W W; Niu, Yaoling; Kelley, Katherine A

    2015-01-15

    Changing conditions on the Earth's surface can have a remarkable influence on the composition of its overwhelmingly more massive interior. The global distribution of uranium is a notable example. In early Earth history, the continental crust was enriched in uranium. Yet after the initial rise in atmospheric oxygen, about 2.4 billion years ago, the aqueous mobility of oxidized uranium resulted in its significant transport to the oceans and, ultimately, by means of subduction, back to the mantle. Here we explore the isotopic characteristics of this global uranium cycle. We show that the subducted flux of uranium is isotopically distinct, with high (238)U/(235)U ratios, as a result of alteration processes at the bottom of an oxic ocean. We also find that mid-ocean-ridge basalts (MORBs) have (238)U/(235)U ratios higher than does the bulk Earth, confirming the widespread pollution of the upper mantle with this recycled uranium. Although many ocean island basalts (OIBs) are argued to contain a recycled component, their uranium isotopic compositions do not differ from those of the bulk Earth. Because subducted uranium was probably isotopically unfractionated before full oceanic oxidation, about 600 million years ago, this observation reflects the greater antiquity of OIB sources. Elemental and isotope systematics of uranium in OIBs are strikingly consistent with previous OIB lead model ages, indicating that these mantle reservoirs formed between 2.4 and 1.8 billion years ago. In contrast, the uranium isotopic composition of MORB requires the convective stirring of recycled uranium throughout the upper mantle within the past 600 million years.

  15. Dose calculations for intakes of ore dust

    Energy Technology Data Exchange (ETDEWEB)

    O`Brien, R.S

    1998-08-01

    This report describes a methodology for calculating the committed effective dose for mixtures of radionuclides, such as those which occur in natural radioactive ores and dusts. The formulae are derived from first principles, with the use of reasonable assumptions concerning the nature and behaviour of the radionuclide mixtures. The calculations are complicated because these `ores` contain a range of particle sizes, have different degrees of solubility in blood and other body fluids, and also have different biokinetic clearance characteristics from the organs and tissues in the body. The naturally occurring radionuclides also tend to occur in series, i.e. one is produced by the radioactive decay of another `parent` radionuclide. The formulae derived here can be used, in conjunction with a model such as LUDEP, for calculating total dose resulting from inhalation and/or ingestion of a mixture of radionuclides, and also for deriving annual limits on intake and derived air concentrations for these mixtures. 15 refs., 14 tabs., 3 figs.

  16. Tectonophysics of hydrothermal ore formation: an example of the Antei Mo-U deposit, Transbaikalia

    Science.gov (United States)

    Petrov, V. A.; Rebetsky, Yu. L.; Poluektov, V. V.; Burmistrov, A. A.

    2015-07-01

    The Antei deposit of the southeastern Transbaikalian region is one of the largest uranium mines in Russia. It is hosted by the Late Paleozoic granitic basement of the Streltsovskaya caldera and was formed as a result of Late Mesozoic tectonothermal activity. Vein and stockwork-disseminated molybdenum-uranium mineralization at this deposit is controlled by zones of intense hydrothermal alteration, cataclasis, brecciation, and intense fracturing along steeply dipping faults, which acted as conduits for mineralizing fluids and hosts to the ore bodies. The upper edge of the ore-bearing zone is located at a depth of 400 m, and its lower edge was intersected at a depth of 1300 m from the day surface. The conditions of ore localization were determined using structural-geological and petrophysical studies coupled with numerical modeling of the effects of gravitational body forces at purely elastic and postcritical elastoplastic deformational stages. The dynamics of the tectonic stress field in the rock massif was reconstructed using the results of mapping of morphogenetic and kinematic characteristics of fault and fracture systems, as well as data on petrography and mineralogy of rocks and vein-filling material. It was shown that the fault framework of the deposit was formed in four tectonic stages, three of which took place in the geologic past and one of which reflects recent geologic history. Each tectonic stage was characterized by different parameters of the tectonic stress-strain field, fault kinematics, and conditions of mineral formation. The following types of metasomatic rocks are recognized within the deposit: high-temperature K-feldspar rocks and albitites (formed during the Late Paleozoic as the primary structural elements of a granitic massif) and Late Mesozoic low-temperature preore (hydromicatized rocks), synore (hematite, albite, chlorite, and quartz) and postore (kaolinite-smectite) rocks. The following petrophysical parameters were determined for all

  17. Repository criticality control for {sup 233}U using depleted uranium

    Energy Technology Data Exchange (ETDEWEB)

    Forsberg, C.W.; Elam, K.R.; Hopper, C.M.

    1999-07-01

    The US is evaluating methods for the disposition of excess weapons-usable {sup 233}U, including disposal in a repository. Isotopic dilution studies were undertaken to determine how much depleted uranium (DU) would need to be added to the {sup 233}U to minimize the potential for nuclear criticality in a repository. Numerical evaluations were conducted to determine the nuclear equivalence of different {sup 235}U enrichments to {sup 233}U isotopically diluted with DU containing 0.2 wt% {sup 235}U. A homogeneous system of silicon dioxide, water, {sup 233}U, and DU, in which the ratio of each component was varied, was used to determine the conditions of maximum nuclear reactivity. In terms of preventing nuclear criticality in a repository, there are three important limits from these calculations. 1. Criticality safe in any nonnuclear system: The required isotopic dilution to ensure criticality under all conditions, except in the presence of man-made nuclear materials (beryllium, etc.), is {approximately}1.0% {sup 235}U in {sup 238}U. The equivalent {sup 233}U enrichment level is 0.53 wt% {sup 233}U in DU. 2. Critically safe in natural systems: The lowest {sup 235}U enrichment found in a natural reactor at shutdown was {approximately}1.3%. French studies, based on the characteristics of natural uranium ore bodies, indicate that a minimum enrichment of {approximately}1.28% {sup 235}U is required for criticality. These data suggest that nuclear criticality from migrating uranium is not realistic unless the {sup 235}U enrichments exceed {approximately}1.3%, which is a result that is equivalent to 0.72% {sup 233}U in DU. 3. Criticality safety equivalent to light water reactor (LWR) spent nuclear fuel (SNF): The {sup 233}U can be diluted with DU so that the uranium criticality characteristics match SNF uranium. Whatever repository criticality controls are used for SNF can then be used for {sup 233}U. The average LWR SNF assay (after decay of plutonium isotopes to uranium

  18. Uranium in soils and water; Uran in Boden und Wasser

    Energy Technology Data Exchange (ETDEWEB)

    Dienemann, Claudia; Utermann, Jens

    2012-07-15

    The report of the Umweltbundesamt (Federal Environmental Agency) on uranium in soils and water covers the following chapters: (1) Introduction. (2) Deposits and properties: Use of uranium; toxic effects on human beings, uranium in ground water and drinking water, uranium in surface waters, uranium in soils, uranium in the air. (3) Legal regulations. (4) Uranium deposits, uranium mining, polluted area recultivation. (5) Diffuse uranium entry in soils and water: uranium insertion due to fertilizers, uranium insertion due to atmospheric precipitation, uranium insertion from the air. (6) Diffuse uranium release from soils and transfer in to the food chain. (7) Conclusions and recommendations.

  19. SOLVENT EXTRACTION OF URANIUM VALUES

    Science.gov (United States)

    Feder, H.M.; Ader, M.; Ross, L.E.

    1959-02-01

    A process is presented for extracting uranium salt from aqueous acidic solutions by organic solvent extraction. It consists in contacting the uranium bearing solution with a water immiscible dialkylacetamide having at least 8 carbon atoms in the molecule. Mentioned as a preferred extractant is dibutylacetamide. The organic solvent is usually used with a diluent such as kerosene or CCl/sub 4/.

  20. Biodiversity and interactions of acidophiles: Key to understanding and optimizing microbial processing of ores and concentrates

    Institute of Scientific and Technical Information of China (English)

    D.B.JOHNSON

    2008-01-01

    Mining companies have become increasingly aware of the potential of microbiological approaches for recovering base and precious metals from low-grade ores,and for remediating acidic,metal-rich wastewaters that drain from both operating and abandoned mine sites.Biological systems offer a number of environmental and (sometimes) economical advantages over conventional approaches,such as pyrometallurgy,though their application is not appropriate in every situation.Mineral processing using micro-organisms has been exploited for extracting gold,copper,uranium and cobalt,and current developments are targeting other base metals.Recently,there has been a great increase in our knowledge and understanding of both the diversity of the microbiology of biomining environments,and of how the microorganisms interact with each other.The results from laboratory experiments which have simulated both stirred tank and heap bioreactor systems have shown that microbial consortia are more robust than pure cultures of mineral-oxidizing acidophiles,and also tend to be more effective at bioleaching and bio-oxidizing ores and concentrates.The paper presented a concise review of the nature and interactions of microbial consortia that are involved in the oxidation of sulfide minerals,and how these might be adapted to meet future challenges in biomining operations.

  1. Vertical mill simulation applied to iron ores

    Directory of Open Access Journals (Sweden)

    Douglas Batista Mazzinghy

    2015-04-01

    Full Text Available The application of vertical mills in regrind circuits is consolidated. This type of mill is now attracting interest in primary grinding applications, due to its higher efficiency when compared to ball mills, which are usually used at this stage. In this study, a coarse sample of iron ore was tested in a pilot scale grinding circuit with a vertical mill. Other three samples of pellet feed had already been tested with the methodology used in this study. The sample of coarse iron ore was characterized in laboratory tests carried out in a small batch ball mill. Selection and breakage function parameters were determined from the laboratory tests. The parameters were then used for simulating the pilot scale tests using Modsim™ software. The model previously implemented in Modsim™ has been successfully applied to represent the vertical mill operated with different ores. The simulations produced particle size distributions that were very close to the actual size distributions, and the predictions were accomplished only by imputing the calibrated parameters from the batch tests, the power draw and the feed size distribution of the pilot tests. The methodology is therefore useful for scale-up and simulation of vertical mills, only requiring laboratory tests that can be carried out in standard laboratory batch ball mills with small amounts of samples.

  2. 华南产铀花岗岩体铀矿化特征及其铀成矿规律分析%Anglysis on Features and Rules of Uranium Mineralization of the Uranium Granite Rock in South China

    Institute of Scientific and Technical Information of China (English)

    张莹

    2012-01-01

    Granite-type uranium deposit is one of the four main uranium ore types of our country. It plays an very important role in researching the Uranium resources in China. South China is one of the most significant ura- nium field. This paper analyses the features of uranium mineralization of the main Uranium granite rock in South China. Then it summarizes the rules of uranium mineralization in this area.%花岗岩型铀矿床为我国四大主要铀矿床类型之一,对我国寻找铀矿资源起到了重要作用。华南地区是我国最重要的铀资源供给地之一。本文将对华南主要产铀花岗岩体的铀矿化特征进行分析阐述,并总结该地区铀成矿规律。

  3. Isotopic Characteristics of Mesozoic Au-Ag Polymetallic Ore Deposits in Northern Hebei and Their Ore-Forming Materials Source

    Institute of Scientific and Technical Information of China (English)

    王宝德; 牛树银; 孙爱群; 李红阳

    2003-01-01

    It has long been a controversy about the source of ore-forming materials of Au-Agpolymetallic deposits both in metallogenic theory and in ore-searching practice. In terms of alarge wealth of the isotopic statistics data from Indosinian-Yanshanian endogenic ore deposits innorthern Hebei (generally referring to the areas along the northern part of Taihang Mountainsand northern Hebei, the same below) , it is considered that the ore-forming materials came fromthe deep interior of the Earth, which had migrated through plumes to the Earth surface while ex-perienced multi-stage evolution and then emplaced progressively in favorable structural loci toform ores. Their isotope data show that 559 sulfur isotopic data from 40 ore deposits are, for themost part, within the range of - 5‰ - 5‰, with a high degree of homogenization, indicatingthat the sulfur is derived mainly from magma; 200 lead isotope data from 37 ore deposits indi-cate that the ore-forming materials are principally of mantle source though some crust-source ma-terial was involved; 96 oxygen, hydrogen and carbon isotope data from 34 ore deposits illustratethat the ore-forming fluids are dominated by magmatic water while other sources of water wouldbe involved. It may therefore be seen that the formation of endogenic deposits has nothing to dowith the strata.

  4. Physical-chemical conditions of ore deposition

    Science.gov (United States)

    Barton, P.B.

    1981-01-01

    Ore deposits form under a wide range of physical and chemical conditions, but those precipitating from hot, aqueous fluids-i.e. the hydrothermal deposits-form generally below 700??C and at pressures of only 1 or 2 kbar or less. Natural aqueous fluids in rocks may extract metal and sulfur from a variety of rock types or may acquire them as a residual heritage from a crystallizing silicate magma. Ore-forming hydrothermal fluids never appear as hot springs (except in deep, submarine situations) because they boil, mix with surface waters, and cool, thereby losing their ore-bearing ability before reaching the surface. Mineral systems function as chemical buffers and indicators just as buffers and indicators function in a chemical laboratory. By reading the record written in the buffer/indicator assemblages of minerals one can reconstruct many aspects of the former chemical environment. By studying the record of changing conditions one may deduce information regarding the processes functioning to create the succession of chemical environments and the ore deposits they represent. The example of the OH vein at Creede, Colorado, shows a pH buffered by the K-feldspar + muscovite + quartz assemblage and the covariation of S2 and O2 buffered by the assemblage chlorite + pyrite + quartz. Boiling of the ore fluid led to its oxidation to hematite-bearing assemblages and simultaneously produced an intensely altered, sericitic capping over the vein in response to the condensation of vapors bearing acidic components. The solubility of metals as calculated from experimental and theoretical studies of mineral solubility appears too low by at least one or two powers of ten to explain the mineralization at Creede. In contrast to Creede where the mineral stabilities all point to a relatively consistent chemistry, the Mississippi Valley type deposits present a puzzle of conflicting chemical clues that are impossible to reconcile with any single equilibrium situation. Thus we must

  5. Physical-chemical conditions of ore deposition

    Science.gov (United States)

    Barton, Paul B.

    Ore deposits form under a wide range of physical and chemical conditions, but those precipitating from hot, aqueous fluids-i.e. the hydrothermal deposits-form generally below 700°C and at pressures of only 1 or 2 kbar or less. Natural aqueous fluids in rocks may extract metal and sulfur from a variety of rock types or may acquire them as a residual heritage from a crystallizing silicate magma. Ore-forming hydrothermal fluids never appear as hot springs (except in deep, submarine situations) because they boil, mix with surface waters, and cool, thereby losing their ore-bearing ability before reaching the surface. Mineral systems function as chemical buffers and indicators just as buffers and indicators function in a chemical laboratory. By reading the record written in the buffer/indicator assemblages of minerals one can reconstruct many aspects of the former chemical environment. By studying the record of changing conditions one may deduce information regarding the processes functioning to create the succession of chemical environments and the ore deposits they represent. The example of the OH vein at Creede, Colorado, shows a pH buffered by the K-feldspar + muscovite + quartz assemblage and the covariation of S 2 and O 2 buffered by the assemblage chlorite + pyrite + quartz. Boiling of the ore fluid led to its oxidation to hematite-bearing assemblages and simultaneously produced an intensely altered, sericitic capping over the vein in response to the condensation of vapors bearing acidic components. The solubility of metals as calculated from experimental and theoretical studies of mineral solubility appears too low by at least one or two powers of ten to explain the mineralization at Creede. In contrast to Creede where the mineral stabilities all point to a relatively consistent chemistry, the Mississippi Valley type deposits present a puzzle of conflicting chemical clues that are impossible to reconcile with any single equilibrium situation. Thus we must

  6. Synthesis of Uranium nitride powders using metal uranium powders

    Energy Technology Data Exchange (ETDEWEB)

    Yang, Jae Ho; Kim, Dong Joo; Oh, Jang Soo; Rhee, Young Woo; Kim, Jong Hun; Kim, Keon Sik [Korea Atomic Energy Research Institute, Daejeon (Korea, Republic of)

    2012-10-15

    Uranium nitride (UN) is a potential fuel material for advanced nuclear reactors because of their high fuel density, high thermal conductivity, high melting temperature, and considerable breeding capability in LWRs. Uranium nitride powders can be fabricated by a carbothermic reduction of the oxide powders, or the nitriding of metal uranium. The carbothermic reduction has an advantage in the production of fine powders. However it has many drawbacks such as an inevitable engagement of impurities, process burden, and difficulties in reusing of expensive N{sup 15} gas. Manufacturing concerns issued in the carbothermic reduction process can be solved by changing the starting materials from oxide powder to metals. However, in nitriding process of metal, it is difficult to obtain fine nitride powders because metal uranium is usually fabricated in the form of bulk ingots. In this study, a simple reaction method was tested to fabricate uranium nitride powders directly from uranium metal powders. We fabricated uranium metal spherical powder and flake using a centrifugal atomization method. The nitride powders were obtained by thermal treating those metal particles under nitrogen containing gas. We investigated the phase and morphology evolutions of powders during the nitriding process. A phase analysis of nitride powders was also a part of the present work.

  7. Genesis of Gold- Silver Deposits in Qingchengzi Ore Field

    Institute of Scientific and Technical Information of China (English)

    Wei Min

    2001-01-01

    The gold - silver complex ore field of Qingchengzi is located in Liaohe group of Liaodong rift. The gold - silver ore bodies mainly lie in Dashiqiao group and Gaixian group, which provides ore - forming materials for the mineralization. For taking place multi - period and multi - stage magmatic activities, the ore - forming materials in the formation had had dynamothermal metamorphism for a long time and enriched and formed ore bodies after magmatism in Indo- Chinese and Yanshan epoch. The ore bodies are controlled by stratigraphic formation and stored in the interformational faults and schistosity belts. Silicalite is the most important indicator for searching them. Although the Pb - Zn and the gold - silver deposits are the same series of mineralized products, their positions are different, resulting from the differences of elements nature and mineralized conditions. The gold silver deposits belong to strata - bound and hysterogenetic mesothermal - epithermal deposit.

  8. EXPLANATORY MODEL OF SPOT PRICE OF IRON ORE

    Directory of Open Access Journals (Sweden)

    Juan Enrique Villalva A.

    2015-11-01

    Full Text Available The objective of this study was to construct an explanatory model of the spot price of iron ore in the international market. For this, the method of multiple linear regressions was used. As a dependent variable, the spot price of iron ore (62% Fe China Tianjin port was taken, between 2010 and 2013. As independents variables were taken seven variables of international iron ore market. The resulting model includes variables: Iron ore inventory in Chinese ports, Baltic Dry Index (BDI, Iron ore exports from Brazil & Australia and Chinese Rebar Steel Price, as explanatory variables of the behavior of the spot price of iron ore in the international market. The model has an adjusted coefficient of determination R2 of 0.90, and was validated by comparing its predictions vs. known values of 2014.

  9. Manhattan Project Technical Series: The Chemistry of Uranium (I)

    Energy Technology Data Exchange (ETDEWEB)

    Rabinowitch, E. I. [Argonne National Lab. (ANL), Argonne, IL (United States); Katz, J. J. [Argonne National Lab. (ANL), Argonne, IL (United States)

    1947-03-10

    This constitutes Chapters 11 through 16, inclusive, of the Survey Volume on Uranium Chemistry prepared for the Manhattan Project Technical Series. Chapters are titled: Uranium Oxides, Sulfides, Selenides, and Tellurides; The Non-Volatile Fluorides of Uranium; Uranium Hexafluoride; Uranium-Chlorine Compounds; Bromides, Iodides, and Pseudo-Halides of Uranium; and Oxyhalides of Uranium.

  10. 31 CFR 540.316 - Uranium enrichment.

    Science.gov (United States)

    2010-07-01

    ... 31 Money and Finance: Treasury 3 2010-07-01 2010-07-01 false Uranium enrichment. 540.316 Section... FOREIGN ASSETS CONTROL, DEPARTMENT OF THE TREASURY HIGHLY ENRICHED URANIUM (HEU) AGREEMENT ASSETS CONTROL REGULATIONS General Definitions § 540.316 Uranium enrichment. The term uranium enrichment means the process...

  11. PURIFICATION OF URANIUM FROM URANIUM/MOLYBDENUM ALLOY

    Energy Technology Data Exchange (ETDEWEB)

    Pierce, R; Ann Visser, A; James Laurinat, J

    2007-10-15

    The Savannah River Site will recycle a nuclear fuel comprised of 90% uranium-10% molybdenum by weight. The process flowsheet calls for dissolution of the material in nitric acid to a uranium concentration of 15-20 g/L without the formation of precipitates. The dissolution will be followed by separation of uranium from molybdenum using solvent extraction with 7.5% tributylphosphate in n-paraffin. Testing with the fuel validated dissolution and solubility data reported in the literature. Batch distribution coefficient measurements were performed for the extraction, strip and wash stages with particular focus on the distribution of molybdenum.

  12. Alligator Rivers Analogue project. Geochemical modelling of secondary uranium ore formation. Final Report - Volume 11

    Energy Technology Data Exchange (ETDEWEB)

    Sverjensky, D. [The John Hopkins Univ, Dept of Earth and Planetary Sciences, Baltimore (United States); Bennett, D.G.; Read, D. [W.S. Atkins Science and Technology, Epsom Surrey, (United Kingdom)

    1992-12-31

    The purpose of the present study was to establish how the uranyl phosphate zone at the Koongarra site was formed. The overall approach taken in the present study employed theoretical chemical mass transfer calculations and models that permit investigation and reconstruction of the kinds of waters that could produce the uranyl phosphate zone. These calculations have used the geological and mineralogical data for the Koongarra weathered zone (Volumes 2, 8, and 9 of this series), to constrain the initial compositions and reactions undergone by groundwater during the formation of the uranyl phosphate zone. In carrying out these calculations the present-day analyses of Koongarra waters are used only as a guide to the possible initial composition of the fluids associated with the formation of the phosphate zone. Aqueous speciation, saturation state and chemical mass transfer calculations were carried out using the computer programs EQ3NR and EQ6 (Wolery, 1983; Wolery et al., 1984) and a thermodynamic database generated at The Johns Hopkins University over the last eight years which is tabulated in the Appendix 1 to Volume 12 of this series. Despite uncertainties in the thermodynamic characterisation of species, all the above calculations suggest that the uranyl phosphate zone at Koongarra has not formed from present-day groundwaters (Volume 12 of this series). The present-day groundwaters in the weathered zone (eg. at 13 m depth) appear to be undersaturated with respect to saleeite. Furthermore, as present-day groundwaters descend below the water table they rapidly lose their atmospheric oxygen imprint, as is typical of most groundwaters, and become even more reducing in character. Under these circumstances, the groundwaters become more undersaturated with respect to saleeite than the shallow groundwaters. Because much of the phosphate zone is currently below the water table, under saturated zone conditions, it is suggested in the present study that the uranyl phosphate zone must have formed in the geologic past under unsaturated zone conditions

  13. Source of ore-forming material for the Huangtuliang gold deposit, Hebei Province and ore prospecting in the deep periphery

    Institute of Scientific and Technical Information of China (English)

    NIU Shuyin; SUN Aiqun; WANG Baode; HAN Yuchou; WEI Minghui; ZHANG Hai; ZHANG Ge; SHI Ping; WANG Wenxing

    2008-01-01

    The Huangtuliang gold deposit is characterized by its wide and large ore belt, stable extension and closely spaced orebodies. Unfortunately, no orebody was found by deep drilling. As a result, ore prospecting in this region was once put into dilemma. Detailed analysis of ore-forming and ore-controlling structures in the mining district by the authors has revealed that the ore-forming and ore-controlling structure in this mining district is a steeply dipping (85°-110°/∠70°-85° N-NNE), spade-shaped ductile shear zone, and the ore-controlling structures are a series of nearly erected second-ordered faults which are developed in the upper part of the ductile shear zone, intersecting with the ductile shear zone. Deep cutting of the ductile shear zone made it possible the ascending of ore fluids from the mantle plume at depth and these ore fluids would migrate upwards along the ductile shear zone under certain temperature and pressure conditions. Along their ascending path, the ore fluids would extract ore-forming elements from the country rocks and the extracted ore-forming elements would be deposited as ores in the hanging-wall second-ordered faults. The reason why no orebody was found in early prospecting at depth is that northward-dipping drilling in the southern part of the shear zone extended so deeply as to be beneath the shear zone. Only shallow-level orebodies could be found by southward-dipping drilling practice in the northern part of the shear zone.The location where deep-seated orebodies occurred shifted northwards and the orebodies occurred at greater depth.Therefore, it is natural that no orebody could be found when drill core passed through the shear zone. After the ore-forming and ore-controlling structures were well understood, the focus of ore prospecting was placed on the deep-level, northward-penetrating veins. In this way a number of new blind orebodies of great thickness have been found. On the basis of research development in the mining

  14. Uranium mineralization and unconformities: how do they correlate? - A look beyond the classic unconformity-type deposit model?

    Science.gov (United States)

    Markwitz, Vanessa; Porwal, Alok; Campbell McCuaig, T.; Kreuzer, Oliver P.

    2010-05-01

    varies from strata- to structure-bound and occurs above regional unconformities. The Proterozoic basins in the Mount Isa Inlier rest unconformably on Palaeoproterozoic basement accompanied by volcanic and igneous rocks, which were deformed and metamorphosed in the Mesoproterozoic. Uranium occurrences in the Western Succession of Mount Isa are either hosted in clastic metasediments or mafic volcanics that belong to the Palaeoproterozoic Eastern Creek Volcanics. Uranium and vanadium mineralization occur in metasomatised and hematite-magnetite-carbonate alteration zones, bounded by major faults and regional unconformities. The results of this study highlight the importance of unconformities in uranium minerals systems as possible fluid pathways and/or surfaces of physico-chemical contrast that could have facilitated the precipitation of uranium, not only in classical unconformity style uranium deposits but in several other styles of uranium mineralization as well. References Cuney, M., 2009. The extreme diversity of uranium deposits. Mineralium Deposita, 44, 3-9. Dahlkamp, F. J., 1993. Uranium ore deposits. Springer, Berlin, p 460. OECD / NEA Red Book & IAEA, 2000. Uranium 1999: Resources, Production and Demand. OECD Nuclear Energy Agency and International Atomic Energy Agency, Paris.

  15. US Geological Survey research on the environmental fate of uranium mining and milling wastes

    Science.gov (United States)

    Landa, E.R.; Gray, J.R.

    1995-01-01

    Studies by the US Geological Survey (USGS) of uranium mill tailings (UMT) have focused on characterizing the forms in which radionuclides are retained and identifying factors influencing the release of radionuclides to air and water. Selective extraction studies and studies of radionuclide sorption by and leaching from components of UMT showed alkaline earth sulfate and hydrous ferric oxides to be important hosts of radium-226 (226Ra) in UMT. Extrapolating from studies of barite dissolution in anerobic lake sediments, the leaching of 226Ra from UMT by sulfate-reducing bacteria was investigated; a marked increase in 226Ra release to aqueous solution as compared to sterile controls was demonstrated. A similar action of iron(III)-reducing bacteria was later shown. Ion exchangers such as clay minerals can also promote the dissolution of host-phase minerals and thereby influence the fate of radionuclides such as 226Ra. Radon release studies examined particle size and ore composition as variables. Aggregation of UMT particles was shown to mask the higher emanating fraction of finer particles. Studies of various ores and ore components showed that UMT cannot be assumed to have the same radon-release characteristics as their precursor ores, nor can 226Ra retained by various substrates be assumed to emanate the same fraction of radon. Over the last decade, USGS research directed at offsite mobility of radionuclides from uranium mining and milling processes has focused on six areas: the Midnite Mine in Washington; Ralston Creek and Reservoir, Colorado; sites near Canon City, Colorado; the Monument Valley District of Arizona and Utah; the Cameron District of Arizona; and the Puerco River basin of Arizona and New Mexico.

  16. The future of Yellowcake: A global assessment of uranium resources and mining

    Energy Technology Data Exchange (ETDEWEB)

    Mudd, Gavin M., E-mail: Gavin.Mudd@monash.edu

    2014-02-01

    Uranium (U) mining remains controversial in many parts of the world, especially in a post-Fukushima context, and often in areas with significant U resources. Although nuclear proponents point to the relatively low carbon intensity of nuclear power compared to fossil fuels, opponents argue that this will be eroded in the future as ore grades decline and energy and greenhouse gas emissions (GGEs) intensity increases as a result. Invariably both sides fail to make use of the increasingly available data reported by some U mines through sustainability reporting — allowing a comprehensive assessment of recent trends in the energy and GGE intensity of U production, as well as combining this with reported mineral resources to allow more comprehensive modelling of future energy and GGEs intensity. In this study, detailed data sets are compiled on reported U resources by deposit type, as well as mine production, energy and GGE intensity. Some important aspects included are the relationship between ore grade, deposit type and recovery, which are crucial in future projections of U mining. Overall, the paper demonstrates that there are extensive U resources known to meet potential short to medium term demand, although the future of U mining remains uncertain due to the doubt about the future of nuclear power as well as a range of complex social, environmental, economic and some site-specific technical issues. - Highlights: • An extensive data set on global uranium resources and classified by deposit type. • Comprehensive analysis of key trends, such as ore grades and recovery rates. • Energy and carbon intensity of production shows an increase as ore grades decline. • Mine rehabilitation often shows poor success or accounts of long-term effectiveness. • Real constraints on nuclear power remain safety and costs compared to alternatives.

  17. US Geological Survey research on the environmental fate of uranium mining and milling wastes

    Science.gov (United States)

    Landa, E. R.; Gray, J. R.

    1995-07-01

    Studies by the US Geological Survey (USGS) of uranium mill tailings (UMT) have focused on characterizing the forms in which radionuclides are retained and identifying factors influencing the release of radionuclides to air and water. Selective extraction studies and studies of radionuclide sorption by and leaching from components of UMT showed alkaline earth sulfate and hydrous ferric oxides to be important hosts of radium-226 (226Ra) in UMT. Extrapolating from studies of barite dissolution in anerobic lake sediments, the leaching of226Ra from UMT by sulfate-reducing bacteria was investigated; a marked increase in226Ra release to aqueous solution as compared to sterile controls was demonstrated. A similar action of iron(III)-reducing bacteria was later shown. Ion exchangers such as clay minerals can also promote the dissolution of host-phase minerals and thereby influence the fate of radionuclides such as226Ra. Radon release studies examined particle size and ore composition as variables. Aggregation of UMT particles was shown to mask the higher emanating fraction of finer particles. Studies of various ores and ore components showed that UMT cannot be assumed to have the same radon-release characteristics as their precursor ores, nor can226Ra retained by various substrates be assumed to emanate the same fraction of radon. Over the last decade, USGS research directed at offsite mobility of radionuclides from uranium mining and milling processes has focused on six areas: the Midnite Mine in Washington; Ralston Creek and Reservoir, Colorado; sites near Canon City, Colorado; the Monument Valley District of Arizona and Utah; the Cameron District of Arizona; and the Puerco River basin of Arizona and New Mexico.

  18. Pros and Cons,Iron Ore Price Hikes

    Institute of Scientific and Technical Information of China (English)

    Tang Jingtao

    2008-01-01

    @@ Backaround Baostecl and CVRD reached an agreement on the price hikes of 65 percent and 71 percent in February.And in June Baosteel and Rio Tinto which is the largest iron ore company in Australia reached an agreement on the price hikes of 79.88 percent on the iron ore fines and 96.5 percent on the iron ore lumps.This is the first time that two kinds of the iron ore price grew at the same time in Asian market.

  19. Tectonomagmatic Metallogenic System of Dexing Ore Field, Jiangxi, China

    Institute of Scientific and Technical Information of China (English)

    1999-01-01

    13 ore deposits and a large number of ore occurrences cluster in Dexing ore field which is 20 km long and 12 km wide. The tectonic evolution, magmatism, as well as the metallogeny are controlled by the Northeast Jiangxi deep-seated fracture belt (NJDFB). The source is believed to have been derived from the Meso-Neoproterozoic marine volcanism. The magmatic activity of Mesozoic I-type granite could have provided the metal elements, thermal fluid, heat, and the space for ore-forming processes. A unified geological model is proposed, which combines the tectonism, magmatism and metallogeny as the basic control of the giant metal mineralizations.

  20. Sulfuric acid leaching of mechanically activated manganese carbonate ore

    Directory of Open Access Journals (Sweden)

    Kenan Yıldız

    2010-06-01

    Full Text Available Acidic leaching of mechanically activated manganese ore from Denizli – Tavas was investigated. The ore was activated mechanically in a planetary mill and the amorphisation in manganese structure was analyzed with X-ray diffraction. The parameters in acidic leaching of the ore were milling time, acid concentration and time. All experiments were performed at 25°C with solid to liquid ratio: 1/10. The activation procedure led to amorphization and structural disordering in manganese ore and accelerated the dissolution of manganese in acidic media.

  1. Assessment of potential migration of radionuclides and trace elements from the White Mesa uranium mill to the Ute Mountain Ute Reservation and surrounding areas, southeastern Utah

    Science.gov (United States)

    Naftz, David L.; Ranalli, Anthony J.; Rowland, Ryan C.; Marston, Thomas M.

    2011-01-01

    In 2007, the Ute Mountain Ute Tribe requested that the U.S. Environmental Protection Agency and U.S. Geological Survey conduct an independent evaluation of potential offsite migration of radionuclides and selected trace elements associated with the ore storage and milling process at an active uranium mill site near White Mesa, Utah. Specific objectives of this study were (1) to determine recharge sources and residence times of groundwater surrounding the mill site, (2) to determine the current concentrations of uranium and associated trace elements in groundwater surrounding the mill site, (3) to differentiate natural and anthropogenic contaminant sources to groundwater resources surrounding the mill site, (4) to assess the solubility and potential for offsite transport of uranium-bearing minerals in groundwater surrounding the mill site, and (5) to use stream sediment and plant material samples from areas surrounding the mill site to identify potential areas of offsite contamination and likely contaminant sources. The results of age-dating methods and an evaluation of groundwater recharge temperatures using dissolved-gas samples indicate that groundwater sampled in wells in the surficial aquifer in the vicinity of the mill is recharged locally by precipitation. Tritium/helium age dating methods found a "modern day" apparent age in water samples collected from springs in the study area surrounding the mill. This apparent age indicates localized recharge sources that potentially include artificial recharge of seepage from constructed wildlife refuge ponds near the mill. The stable oxygen isotope-ratio, delta oxygen-18, or δ(18O/16O), known as δ18O, and hydrogen isotope-ratio, delta deuterium, or δ(2H/1H), known as δD, data indicate that water discharging from Entrance Spring is isotopically enriched by evaporation and has a similar isotopic fingerprint as water from Recapture Reservoir, which is used as facilities water on the mill site. Water from Recapture

  2. Geochronology and Fluid-Rock Interaction Associated with the Nopal I Uranium Deposit, Pena Blanca, Mexico

    Energy Technology Data Exchange (ETDEWEB)

    M. Fayek; P. Goodell; M. Ren; A. Simmons

    2005-07-11

    The Nopal I uranium (U) deposit, Pena Blanca District, Mexico, largely consists of secondary U{sup 6+} minerals, which occur within a breccia pipe mainly hosted by the 44 Ma Nopal and Colorados volcanic formations. These two units overly the Pozos conglomerate formation and Cretaceous limestone. Three new vertical diamond drill holes (DDHs) were recently drilled at Nopal I. DDH-PB1 with continuous core was drilled through the Nopal I deposit and two additional DDHs were drilled {approx}50 m on either side of the cored hole. These DDHs terminate 20 m below the current water table, thus allowing the detection of possible gradients in radionuclide contents resulting from transport from the overlying uranium deposit. Primary uraninite within the main ore body is rare and fine-grained ({approx}50 micrometers), thus making geochronology of the Nopal I deposit very difficult. Uranium, lead and oxygen isotopes can be used to study fluid-uraninite interaction, provided that the analyses are obtained on the micro-scale. Secondary ionization mass spectrometry (SIMS) permits in situ measurement of isotopic ratios with a spatial resolution on the scale of a few {micro}m. Preliminary U-Pb results show that uraninite from the main ore body gives an age of 32 {+-} 8 Ma, whereas uraninite from the uraniferous Pozos conglomerate that lies nearly 100 m below the main ore body and 25 meters above the water table, gives a U-Pb age that is <1 Ma. Oxygen isotopic analyses show that uraninite from the ore body has a {delta}{sup 18}O = -10.8{per_thousand}, whereas the uraninite within the Pozos conglomerate has a {delta}{sup 18}O = +1.5{per_thousand}. If it is assumed that both uraninites precipitated from meteoric water ({delta}{sup 18}O = -7{per_thousand}), then calculated precipitation temperatures are 55 C for the uraninite from the ore body and 20 C for uraninite hosted by the Pozos conglomerate. These temperatures are consistent with previous studies that calculated precipitation

  3. A study of uranium uptake in plants

    Energy Technology Data Exchange (ETDEWEB)

    Kaur, A.; Singh, Surinder; Virk, H.S. (Guru Nanak Dev Univ., Amritsar (India). Dept. of Physics)

    1988-01-01

    A fission track technique has been used to study the uptake of uranium in Tomato Plant. Lexan plastic has been employed as the external detector for recording induced fission tracks due to uranium. The uranium uptake rate is found to increase as the growth proceeds. The uranium concentration is also determined in Phlox, Calendula and Dog Flower, grown under normal conditions. The uranium content is found to vary in different parts of the plants. (author).

  4. Remobilisation features and structural control on ore grade distribution at the Konkola stratiform Cu-Co ore deposit, Zambia

    OpenAIRE

    Torremans, K.; Gauquie, J.; Boyce, A. J.; Barrie, C.D.; Sikazwe, O.; Muchez, P.H.

    2013-01-01

    The Konkola deposit is a high grade stratiform Cu–Co ore deposit in the Central African Copperbelt in Zambia. Economic mineralisation is confined to the Ore Shale formation, part of the Neoproterozoic metasedimentary rocks of the Katanga Supergroup. Petrographic study reveals that the copper–cobalt ore minerals are disseminated within the host rock, sometimes concentrated along bedding planes, often associated with dolomitic bands or clustered in cemented lenses and in layer-parallel and irre...

  5. SEPARATION OF URANIUM FROM THORIUM

    Science.gov (United States)

    Hellman, N.N.

    1959-07-01

    A process is presented for separating uranium from thorium wherein the ratio of thorium to uranium is between 100 to 10,000. According to the invention the thoriumuranium mixture is dissolved in nitric acid, and the solution is prepared so as to obtain the desired concentration within a critical range of from 4 to 8 N with regard to the total nitrate due to thorium nitrate, with or without nitric acid or any nitrate salting out agent. The solution is then contacted with an ether, such as diethyl ether, whereby uranium is extracted into ihe organic phase while thorium remains in the aqueous phase.

  6. Pyrophoric behaviour of uranium hydride and uranium powders

    Energy Technology Data Exchange (ETDEWEB)

    Le Guyadec, F., E-mail: fabienne.leguyadec@cea.f [CEA Marcoule DEN/DTEC/SDTC, 30207 Bagnols sur Ceze, BP 17171 (France); Genin, X.; Bayle, J.P. [CEA Marcoule DEN/DTEC/SDTC, 30207 Bagnols sur Ceze, BP 17171 (France); Dugne, O. [DEN/DTEC/SGCS, 30207 Bagnols sur Ceze, BP 17171 (France); Duhart-Barone, A.; Ablitzer, C. [CEA Cadarache DEN/DEC/SPUA, 13108 St. Paul lez Durance (France)

    2010-01-31

    Thermal stability and spontaneous ignition conditions of uranium hydride and uranium metal fine powders have been studied and observed in an original and dedicated experimental device placed inside a glove box under flowing pure argon. Pure uranium hydride powder with low amount of oxide (<0.5 wt.%) was obtained by heat treatment at low temperature in flowing Ar/5%H{sub 2}. Pure uranium powder was obtained by dehydration in flowing pure argon. Those fine powders showed spontaneous ignition at room temperature in air. An in situ CCD-camera displayed ignition associated with powder temperature measurement. Characterization of powders before and after ignition was performed by XRD measurements and SEM observations. Oxidation mechanisms are proposed.

  7. Predictive analysis of shaft station radon concentrations in underground uranium mine: A case study.

    Science.gov (United States)

    Zhao, Guoyan; Hong, Changshou; Li, Xiangyang; Lin, Chunping; Hu, Penghua

    2016-07-01

    This paper presented a method for predicting shaft station radon concentrations in a uranium mine of China through theoretical analysis, mathematical derivation and Monte-Carlo simulation. Based upon the queuing model for tramcars, the average waiting time of tramcars and average number of waiting tramcars were determined, which were further used in developing the predictive model for calculating shaft station radon concentrations. The results exhibit that the extent of variation of shaft station radon concentration in the case study mine is not significantly affected by the queuing process of tramcars, and is always within the allowable limit of 200 Bq m(-3). Thus, the empirical limit of 100,000 T annual ore-hoisting yields has no value in ensuring radiation safety for this mine. Moreover, the developed model has been validated and proved useful in assessing shaft station radon levels for any uranium mine with similar situations.

  8. Characterization of PAH matrix with monazite stream containing uranium, gadolinium and iron

    Science.gov (United States)

    Pal, Sangita; Meena, Sher Singh; Goswami, D.

    2016-05-01

    Uranium (U) gadolinium(Gd) and iron (Fe) containing alkaline waste simulated effluent (relevant to alkaline effluent of monazite ore) has been treated with a novel amphoteric resin viz, Polyamidehydroxamate (PAH) containing amide and hydroxamic acid groups. The resin has been synthesized in an eco-friendly manner by polymerization nad conversion to functional groups characterized by FT-IR spectra and architectural overview by SEM. Coloration of the loaded matrix and de-coloration after extraction of uranium is the special characteristic of the matrix. Effluent streams have been analyzed by ICP-AES, U loaded PAH has been characterized by FT-IR, EXAFS, Gd and Fe by X-ray energy values of EDXRF at 6.053 Kev and 6.405 Kev respectively. The remarkable change has been observed in Mössbauer spectrum of Fe-loaded PAH samples.

  9. Autoradiography of geological fluorite samples for determination of uranium and thorium distribution using nuclear track methodology

    Energy Technology Data Exchange (ETDEWEB)

    Pi, T.; Sole, J. [Instituto de Geologia, UNAM, Cd. Universitaria, Coyoacan, 04510 Mexico DF (Mexico); Golzarri, J.I; Rickards, J.; Espinosa, G. [IFUNAM, AP 20-364, 01000 Mexico DF (Mexico)]. e-mail: espinosa@fisica.unam.mx

    2007-07-01

    In this paper we present the uranium and thorium distribution analysis of several samples of the 'La Azul' an epithermal fluorspar deposit in southern Mexico, using nuclear track methodology (NTM), in the alpha-autoradiography mode, by placing the mineral sample in contact with a polycarbonate detector. This constitutes a non-destructive analysis, with sufficient sensitivity to provide valuable information about textural and para genetic characteristics of the geological samples. The selected nuclear track detector was CR-39 (Landauer). The region of interest of the geological samples was polished and put in contact with the detector material surface for 45 days in a vacuum chamber (10-3 torr). After this period of time, the detectors were chemically etched, revealing the auto radiograph of the radioactive material. The results show a clear distribution of bands of uranium and thorium in the fluorite samples. This is valuable information for the genetic or geochronological studies of the ore deposits. (Author)

  10. Alteration and vein mineralization, Ladwig uranium mine, Jefferson County, Colorado

    Science.gov (United States)

    Wallace, Alan R.

    1979-01-01

    Uranium ore at the Ladwig mine, Jefferson County, Colo., occurs in steeply dipping, northwest-striking faults and related fractures with a carbonate-adularia assemblage that forms in altered wallrocks and fills veins. The faults occur between large intrusive pegmatites and garnetiferous gneisses of Precambrian age, and were reactivated as the result of the early Paleocene uplift of the Front Range foothills. Mineralization in the deposit includes both wallrock alteration and vein filling. Alteration was intense but local, and chiefly involved the carbonatization of mafic minerals in the wallrocks. Felsic minerals in the wallrocks are relatively unaltered. The veins are filled with an adularia-pitchblende-carbonate assemblage with minor related sulfides and coffinite. Many of the iron-bearing carbonates in both the alteration and vein assemblages have been altered to hematite. The mineralization and alteration are believed to have formed in response to initially high amounts of CO2 and the subsequent release of dissolved CO2 by boiling or effervescence. Uranium, carried in a dicarbonate complex, was precipitated directly as pitchblende when the CO2 was released. The expulsion of H+ during boiling created a net oxidizing environment which oxidized the iron-bearing carbonates. Late stage calcite and sulfides were deposited in existing voids in the veins.

  11. Role of ore mineralogy in optimizing conditions for bioleaching low-grade complex sulphide ores

    Institute of Scientific and Technical Information of China (English)

    P. A. OLUBAMBI; S. NDLOVU; J. H. POTGIETER; J. O. BORODE

    2008-01-01

    The role that ore mineralogy plays in understanding and optimizing the conditions favouring the bioleaching of complex sulphide ore containing high amounts of siderite was studied using mixed cultures of mesophilic bacteria, with emphasis on zinc,lead and copper recoveries. The influencing parameters investigated include particle size, stirring speed, volume of inoculum, pulp density, and pH. The results show that the mixed mesophilic cultures can extract about two and a half times the amount of zinc than copper over an equivalent period of time. The highest zinc and copper recoveries of 89.2% and 36.4% respectively are obtained at particle size of 75 μm, stirring speed of 150 r/min, pulp density of 10% (w/v), 12% (v/v) inoculum concentration, and a pH of 1.6. Variations in elemental composition within different particle sizes resulting from the mineralogy of the ore account for the bioleaching behaviour at varying particle sizes. The dissolution at varying pulp density, volume of inoculum, solution pH and the low solution potential observed are also influenced by ore mineralogy.

  12. A Metal Stable Isotope Approach to Understanding Uranium Mobility Across Roll Front Redox Boundaries

    Science.gov (United States)

    Brown, S. T.; Basu, A.; Christensen, J. N.; DePaolo, D. J.; Heikoop, J. M.; Reimus, P. W.; Maher, K.; Weaver, K. L.

    2015-12-01

    Sedimentary roll-front uranium (U) ore deposits are the principal source of U for nuclear fuel in the USA and an important part of the current all-of-the-above energy strategy. Mining of roll-front U ore in the USA is primarily by in situ alkaline oxidative dissolution of U minerals. There are significant environmental benefits to in situ mining including no mine tailings or radioactive dust, however, the long-term immobilization of U in the aquifer after the completion of mining remains uncertain. We have utilized the metal stable isotopes U, Se and Mo in groundwater from roll-front mines in Texas and Wyoming to quantify the aquifer redox conditions and predict the onset of U reduction after post mining aquifer restoration. Supporting information from the geochemistry of groundwater and aquifer sediments are used to understand the transport of U prior to and after in situ mining. Groundwater was collected across 4 mining units at the Rosita mine in the Texas coastal plain and 2 mining units at the Smith Ranch mine in the Powder River Basin, Wyoming. In general, the sampled waters are moderately reducing and ore zone wells contain the highest aqueous U concentrations. The lowest U concentrations occur in monitoring wells downgradient of the ore zone. 238U/235U is lowest in downgradient wells and is correlated with aqueous U concentrations. Rayleigh distillation models of the 238U/235U are consistent with U isotope fractionation factors of 1.0004-1.001, similar to lab-based studies. Based on these results we conclude that redox reactions continue to affect U distribution in the ore zone and downgradient regions. We also measured aqueous selenium isotope (δ82Se) and molybdenum isotope (δ98Mo) compositions in the Rosita groundwater. Se(VI) primarily occurs in the upgradient wells and is absent in most ore zone and downgradient wells. Rayleigh distillation models suggest reduction of Se(VI) along the groundwater flow path and when superimposed on the U isotope data

  13. Project StORe: Social Science report

    OpenAIRE

    Burton, Guy

    2006-01-01

    There was widespread support across the social science research community regarding the aims of the StORe Project Nearly half of social science respondents claimed that both source-to-output and out-put-to source repositories would offer a ‘significant advantage to my work’; a third in both cases claimed it would be ‘useful but not of major significance’ Postgraduate students were generally more enthusiastic about source-to-output and output-to-source repositories than acade...

  14. Uranium hexafluoride bibliography

    Energy Technology Data Exchange (ETDEWEB)

    Burnham, S.L.

    1988-01-01

    This bibliography is a compilation of reports written about the transportation, handling, safety, and processing of uranium hexafluoride. An on-line literature search was executed using the DOE Energy files and the Nuclear Science Abstracts file to identify pertinent reports. The DOE Energy files contain unclassified information that is processed at the Office of Scientific and Technical Information of the US Department of Energy. The reports selected from these files were published between 1974 and 1983. Nuclear Science Abstracts contains unclassified international nuclear science and technology literature published from 1948 to 1976. In addition, scientific and technical reports published by the US Atomic Energy Commission and the US Energy Research and Development Administration, as well as those published by other agencies, universities, and industrial and research organizations, are included in the Nuclear Science Abstracts file. An alphabetical listing of the acronyms used to denote the corporate sponsors follows the bibliography.

  15. Uranium Occurrences and Its Mineral Combination Characteristics in Uranium Deposit No.302%302铀矿床矿石中铀的存在形式及矿物组合特征

    Institute of Scientific and Technical Information of China (English)

    赵奇峰; 夏菲; 潘家永; 陈黎明; 林坤

    2015-01-01

    Electronic probe analysis indicated that uranium in uranium deposit No.302 mainly existed as independent uranium minerals and minors occurred as isomorphism of thorium in zircon and rutile and other accessory minerals.The independent uranium ore minearal mainly as pitchblende,some as coffinG ite,uranothorite, brannerite and the second uranium minerals of uranophane, autunite, chalcolite. The ore consist of five kind mineral combination,the diversity of uranium ore mineral combination reG flects the long term and complex activity of hydrothermal fluid in the deposit,which also indicate the multiphases and variety of fluid composition and forming environment in hydrothermal activity. Alteration related with uranium mineralization are siliconization,hematization,purple black fluoritizaG tion,pyritization,calcitization,sericitization and chloritization,etc.%电子探针分析显示,302铀矿床矿石中铀的存在形式以独立铀矿物为主,少量呈类质同像赋存于钍石、锆石及金红石等副矿物之中。独立铀矿物以沥青铀矿为主,其次有铀石、铀钍石、钛铀矿等原生铀矿物和硅钙铀矿、钙铀云母、铜铀云母等次生铀矿物。铀矿石具有5种不同的矿物组合,这种矿物组合的多样性,反映了该矿床热液流体活动的长期性和复杂性,即成矿热液流体作用具有多阶段性,以及热液流体组成和成矿环境的多变性。与铀矿化相关的蚀变有硅化、赤铁矿化、紫黑色萤石化、黄铁矿化、方解石化、绢云母化及绿泥石化等。

  16. Mixed State and High Effective Utilization of Pilbara Blending Iron Ore Powder%Mixed State and High Effective Utilization of Pilbara Blending Iron Ore Powder

    Institute of Scientific and Technical Information of China (English)

    CAO Yong-guo; WU Sheng-li; HAN Hong-liang; WANG Hong-wei; XUE Fang; LIU Xiao-qin

    2011-01-01

    Pilbara blending iron ore powder (PB powder) is blending ores with good and poor quality iron ores, so how to use PB power effectively is a problem. The self-characteristics of PB powder and its single-components were studied respectively such as the macroscopic properties, microscopic properties, and high-temperature properties the behavior and effect in the sintering were mastered. Then based on the new ore-proportioning idea of iron ores sintering characteristics complementary, the principles on the effective use of PB powder were discussed, and was fur ther validated through the sintering pot test and industrial production. The results show that PB powder is composed of three kinds of iron ore, and the sintering characteristics of different iron ores are obviously discrepant. With the ore-proportioning optimization based on the iron ores sintering characteristics complementary, the proportion of PB iron ore powder can be increased to more than 45 %.

  17. Baseline risk assessment of ground water contamination at the Monument Valley uranium mill tailings site Cane Valley, Arizona

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    1996-03-01

    The U.S. Department of Energy (DOE) Uranium Mill Tailings Remedial Action (UMTRA) Project consists of the Surface Project (Phase I) and the Ground Water Project (Phase II). Under the UMTRA Surface Project, tailings, radioactive contaminated soil, equipment, and materials associated with the former uranium ore processing at UMTRA Project sites are placed into disposal cells. The cells are designed to reduce radon and other radiation emissions and to minimize further contamination of ground water. Surface cleanup at the Monument Valley UMTRA Project site near Cane Valley, Arizona, was completed in 1994. The Ground Water Project evaluates the nature and extent of ground water contamination that resulted from the uranium ore processing activities. The Ground Water Project is in its beginning stages. Human health may be at risk from exposure to ground water contaminated by uranium ore processing. Exposure could occur by drinking water pumped out of a hypothetical well drilled in the contaminated areas. Adverse ecological and agricultural effects may also result from exposure to contaminated ground water. For example, livestock should not be watered with contaminated ground water. A risk assessment describes a source of contamination, how that contamination reaches people and the environment, the amount of contamination to which people or the ecological environment may be exposed, and the health or ecological effects that could result from that exposure. This risk assessment is a site-specific document that will be used to evaluate current and potential future impacts to the public and the environment from exposure to contaminated ground water. The results of this evaluation and further site investigations will be used to determine a compliance strategy to comply with the UMTRA ground water standards.

  18. Baseline risk assessment of ground water contamination at the Uranium Mill Tailings Sites near Rifle, Colorado. Revision 2

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    1996-02-01

    The U.S. Department of Energy (DOE) Uranium Mill Tailings Remedial Action (UMTRA) Project consists of the Surface Project (Phase I) and the Ground Water Project (Phase II). Under the UMTRA Surface Project, tailings, radioactive contaminated soil, equipment, and materials associated with the former uranium ore processing sites are placed into disposal cells. The cells are designed to reduce radon and other radiation emissions and to prevent further ground water contamination. The Ground Water Project evaluates the nature and extent of ground water contamination resulting from the uranium ore processing activities. Two UMTRA Project sites are near Rifle, Colorado: the Old Rifle site and the New Rifle site. Surface cleanup at the two sites is under way and is scheduled for completion in 1996. The Ground Water Project is in its beginning stages. A risk assessment identifies a source of contamination, how that contamination reaches people and the environment, the amount of contamination to which people or the environment may be exposed, and the health or environmental effects that could result from that exposure. This report is a site-specific document that will be used to evaluate current and future impacts to the public and the environment from exposure to contaminated ground water. This evaluation and further site characterization will be used to determine if action is needed to protect human health or the environment. Human health risk may result from exposure to ground water contaminated from uranium ore processing. Exposure could occur from drinking water obtained from a well placed in the areas of contamination. Furthermore, environmental risk may result from plant or animal exposure to surface water and sediment that have received contaminated ground water.

  19. Baseline risk assessment of ground water contamination at the Uranium Mill Tailings Site near Lakeview, Oregon. Revision 2

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    1996-03-01

    The U.S. Department of Energy (DOE) Uranium Mill Tailings Remedial Action (UMTRA) Project consists of the Surface Project (Phase I) and the Ground Water Project (Phase II). Under the UMTRA Surface Project, tailings, contaminated soil, equipment, and materials associated with the former uranium ore processing at UMTRA Project sites are placed into disposal cells. The cells are designed to reduce radon and other radiation emissions and to minimize further contamination of ground water. Surface cleanup at the UMTRA Project site near Lakeview, Oregon, was completed in 1989. The mill operated from February 1958 to November 1960. The Ground Water Project evaluates the nature and extent of ground water contamination that resulted from the uranium ore processing activities. The Ground Water Project is in its beginning stages. Human health may be at risk from exposure to ground water contaminated by uranium ore processing. Exposure could occur by drinking water pumped out of a hypothetical well drilled in the contaminated areas. Ecological risks to plants or animals may result from exposure to surface water and sediment that have received contaminated ground water. A risk assessment describes a source of contamination, how that contamination reaches people and the environment, the amount of contamination to which people or the ecological environment may be exposed, and the health or ecological effects that could result from that exposure. This risk assessment is a site-specific document that will be used to evaluate current and potential future impacts to the public and the environment from exposure to contaminated ground water. The results of this evaluation and further site characterization will determine whether any action is needed to protect human health or the ecological environment.

  20. Uranium-polymetallic combination characteristics and significance of volcanic type uranium deposits in China%我国火山岩型铀矿床中铀-多金属组合特征及其意义

    Institute of Scientific and Technical Information of China (English)

    李海东; 钟福军; 张志勇; 沈滔; 黄广文

    2015-01-01

    火山岩型铀矿床是我国四大工业类型铀矿床之一,在部分铀矿床中存在铀矿与多金属矿共生或伴生组合关系。文章在前人研究基础上,以我国几个典型火山岩型铀矿床为例,综合分析铀-多金属组合的时空关系、成矿规律、矿化分带等特征,结果显示:(1)铀与多金属在区域成矿带上共存,在单个矿床中存在垂向矿化分带现象。(2)在矿床范围内,多金属矿化晕比铀矿化晕范围更大。铀多金属组合特征研究对铀-多金属矿联合勘查具有重要的指导意义。%Volcanic type uranium deposit is one of the four industrial types of uranium deposits in China,and parts of them have uranium and polymetallic intergrowth and associated combination relations.On the basis of previous studies,the space and time relationship of uranium-polymetallic combination,metallogenic regu-larities and ore tumble belt characteristics for several typical volcanic type uranium deposits as examples have been analysis comprehensively in this paper.It is concluded that:(1)the uranium and polymetallic coexist in the regional metallogenic belt,combine with vertical zoning phenomenon in a single deposit;(2)in the range of the ore deposit,the halo of polymetallic mineralization is larger than that of uranium mineralization.The study of uranium-polymetallic combination characteristic has important guiding significance for uranium-polymetallic joint exploration.

  1. Experimental study of the uranium mobility due to the weathering action at the uraniferous district of Caetite/Lagoa Real, Bahia, Brazil; Estudo experimental da mobilidade do uranio por acao intemperica, distrito uranifero de Caetite/Lagoa Real, Bahia, Brasil

    Energy Technology Data Exchange (ETDEWEB)

    Scislewski, Alexandro Rocha

    2004-01-15

    In the present research, the proposal was to develop a preliminary study about the geochemical behavior of determined chemical elements, mainly the uranium, during the action of weathering processes in the rocks that bear the uranium mineralizations of the Caetite-Lagoa Real region, State of Bahia, more specifically of the Jazida Cachoeira uranium mine. To reach this purpose were used samples that represent several stages of the milling process of the uranium ore, so selecting representatives of the host rock, the ore and the treated ore (waste from the milling plant) to be used in the laboratory-controlled experiments. The samples were dried, sieved and finally introduced in the reactors, these adapted from the Flow-Through Reactor of Brantley and Chen. In the geochemical point of view, the results of the experiments showed a distinct behavior between the samples. It was observed that the treated ore, in relation to the host rocks of the ore and the own ore, shown a faster and homogeneous interaction with the leaching solution; it was also noted that in the output solution of the treated ore samples existed a significant complexation of the uranium by the sulfate (S0{sub 4}{sup -2}), ), instead of the non treated samples (host rock and ore) that were complexed mainly by the carbonate (C0{sub 3}{sup -2}). These different results are attributed to the alterations imposed to the rock during the milling process, and occur mainly, during the acid attack in the leaching process of the milling plant. The results and conclusions of this research, in spite of been preliminary, are essential to understand the behavior of the geochemical speciation of the effluent solutions; to understand the alterations of a rock matrix, and finally, to understand the migration chemical behavior of the related chemical elements. It is expected that these results contribute, in the future, to a deeper knowledge of the processes that control the chemical composition of the natural waters from

  2. The geology of uranium in the Saint-Sylvestre granite district (Limousin, Massif Central, France); La geologie de l'uranium dans le massif granitique de Saint-Sylvestre (Limousin - Massif Central Francais)

    Energy Technology Data Exchange (ETDEWEB)

    Marquaire, C.; Moreau, M.; Barbier, J.; Ranchin, G.; Carrat, H.G.; Coppens, R.; Senecal, J.; Koszotolanyi, C.; Dottin, H

    1969-07-01

    This report concerns the geology of uranium in Limousin, more particularly in the St-Sylvestre massif, and the related phenomena: regional geology, petrographic and geochemical zonal distribution observed in various granite massifs, uranium movement in connection with surface alteration, geochronology of uranium ore. The work is made up of six articles covering the various scientific aspects listed above. Each article is headed with an abstract. The paper comprises the following chapters: Foreword by Marcel ROUBAULT. 1. Ch. MARQUAIRE, M. MOREAU Outline of geological conditions in Northern Limousin and distribution of uraniferous occurrences. 2. J. BARBIER, G. RANCHIN, H. G. CARRAT and R. COPPENS Geology of the St-Sylvestre Massif and uranium geochemistry - Introduction to laboratory studies - Problems of methodology. 3. J. BARBIER and G. RANCHIN Petrographical and geochemical zones in the St-Sylvestre granite massif (Limousin - French 'Massif Central'). 4. J. BARBIER and G. RANCHIN Uranium geochemistry in the St-Sylvestre Massif (Limousin - French 'Massif Central') - Occurrences of primary geochemical uranium and replacement processes. 5. J. SENEGAL Monograph of the Brugeaud orebody. 6. R. COPPENS, Ch. KOSZTOLANYI and H. DOTTIN Geochronological study of the Brugeaud mine. 1969. (authors) [French] Ce memoire est consacre a la geologie de l'uranium dans le Limousin, plus specialement dans le massif de St-Sylvestre, et aux phenomenes qui s'y rattachent: geologie regionale, phenomenes de zonalite petrographique et geochimique dans certains massifs granitiques, mouvements de l'uranium lies a l'alteration superficielle, geochronologie du minerai d'uranium. L'ouvrage comprend six articles qui recouvrent les differents aspects scientifiques enumeres. Chacun de ces six articles est precede d'un resume. La composition du memoire st la suivante: Marcel ROUBAULT, Preface. 1. Ch. MARQUAIRE, M. MOREAU Esquisse geologique du

  3. An evaluation of health risk to the public as a consequence of in situ uranium mining in Wyoming, USA.

    Science.gov (United States)

    Ruedig, Elizabeth; Johnson, Thomas E

    2015-12-01

    In the United States there is considerable public concern regarding the health effects of in situ recovery uranium mining. These concerns focus principally on exposure to contaminants mobilized in groundwater by the mining process. However, the risk arising as a result of mining must be viewed in light of the presence of naturally occurring uranium ore and other constituents which comprise a latent hazard. The United States Environmental Protection Agency recently proposed new guidelines for successful restoration of an in situ uranium mine by limiting concentrations of thirteen groundwater constituents: arsenic, barium, cadmium, chromium, lead, mercury, selenium, silver, nitrate (as nitrogen), molybdenum, radium, total uranium, and gross α activity. We investigated the changes occurring to these constituents at an ISR uranium mine in Wyoming, USA by comparing groundwater quality at baseline measurement to that at stability (post-restoration) testing. Of the groundwater constituents considered, only uranium and radium-226 showed significant (p Uranium concentrations increased by a factor of 5.6 (95% CI 3.6-8.9 times greater) while radium-226 decreased by a factor of about one half (95% CI 0.42-0.75 times less). Change in risk was calculated using the RESRAD (onsite) code for an individual exposed as a resident-farmer; total radiation dose to a resident farmer decreased from pre-to post-mining by about 5.2 mSv y(-1). Higher concentrations of uranium correspond to increased biomarkers of nephrotoxicity, however the clinical significance of this increase is unclear.

  4. Carcinogenesis of Depleted Uranium Fragments.

    Science.gov (United States)

    1996-02-01

    P. W. Morrow, B. J. Panner and R. B. Baggs (eds.): Nephrotoxicity of Uranyl Fluoride and Reversibility of Renal Injury in the Rat. NUREG /CR-4951...Accidental Exposure to Uranium Hexafluoride. NUREG /CR-5566, PNL-7328, Prepared for U.S. Nuclear Regulatory Commission, Washington, DC, 1990. Foulkes, E. C...Hydrolysis Products of Uranium Hexafluoride, NUREG /CR-2268, RH, Prepared for Division of Health Siting and Waste Management, Washington, DC, 1982. 20 Nothdurft

  5. A multi-instrumental geochemical study of anomalous uranium enrichment in coal.

    Science.gov (United States)

    Havelcová, Martina; Machovič, Vladimír; Mizera, Jiří; Sýkorová, Ivana; Borecká, Lenka; Kopecký, Lubomír

    2014-11-01

    Contents of uranium in coals from Odeř in the northernmost part of the Sokolov Basin, Czech Republic, in the vicinity of the well known St. Joachimsthal uranium ore deposits, reach extremely high values. In the present work, coal samples with contents of uranium ranging from 0.02 to 6 wt.% were studied. The study employing a whole complex of analytical techniques has been aimed at identification of changes in the structure of coal organic matter, which are associated with the high contents of uranium in coal. The study includes proximate and ultimate analyses, multielement analysis by instrumental neutron and photon activation analyses, micropetrographic analysis by optical microscopy, ESEM/EDX analysis of mineral matter, infrared and Raman spectroscopies, solvent extraction followed by gas chromatography with mass spectroscopy (GC/MS), and analytical pyrolysis (Py-GC/MS). The study has confirmed previously proposed explanation of uraniferous mineralization in sedimentary carboniferous substances by the mechanism of reduction and fixation of soluble U(VI) (uranyl, UO2(2+)) species (e.g., humic, carbonate/hydroxo/phosphate complexes) by sedimentary organic matter under diagenetic or hydrothermal conditions, and formation of insoluble U(IV) species as phosphate minerals and uraninite. The process is accompanied with alteration and destruction of the coal organic matter. The changes in the structure of coal organic matter involve dehydrogenation and oxidation mainly in the aliphatic, aromatic and hydroxyl structures, and an increase in aromaticity, content of ether bonds, and the degree of coalification.

  6. Early signals of environmental and health impacts caused by uranium mining in Caetite, Bahia, Brazil

    Energy Technology Data Exchange (ETDEWEB)

    Brito, Adelson S. de; Rego, Rita de Cassia Franco [Universidade Federal da Bahia (UFBA), Salvador, BA (Brazil). Dept. de Medicina Preventiva. Programa de Pos-Graduacao em Saude, Ambiente e Trabalho; Zucchi, Maria do Rosario [Universidade Federal da Bahia (UFBA), Salvador, BA (Brazil). Dept. de Fisica da Terra. Lab. de Fisica Nuclear Aplicada; Navarro, Marcus V. Teixeira, E-mail: mvtn@ifba.edu.b [Instituto Federal da Bahia (LAFIR/NTS/IFBA) Salvador, BA (Brazil). Nucleo de Tecnologia em Saude. Lab. de Fisica Radiologica

    2011-07-01

    Uranium mining and processing at Lagoa Real (Bahia, Brazil) in the southwest of Bahia state started in the year 2000.The processing of uranium ore for obtaining U3O8 (yellowcake) is done today in the processing unit of the Brazilian Nuclear Industries INB located in the area of the same municipality above mentioned. The production capacity is 400 tons / year of U3O8, and the reserves in this region are estimated at 100.000 tons of uranium without any other associated minerals, enough to supply the demand for nuclear power plants Angra I and II for over 100 years. Since the granting of AOP (Permanent Operation Authorization) by CNEN (National Commission on Nuclear Energy) in the year 2009, there were some incidents at the facility, such as: solvents and liquid containing uranium overflow; pipes rupture, causing indiscriminate dispersion of toxic acids and other chemical agents; collapse of parts of the slope of the open pit. CNEN admitted in an official press release on April 1, 2011 that 'INB has no capacity to produce annual reports on environmental monitoring (unable to perform radiometric measurements, etc.). The last time a report was released happened in the year 2008. These reports are vital to the environmental impact assessment of the facility'. Another potential source of environmental and health negative impacts on the local population could be linked to radon emission. What are the levels of this important pollutant in the affected areas? (author)

  7. Radon releases from Australian uranium mining and milling projects: assessing the UNSCEAR approach.

    Science.gov (United States)

    Mudd, Gavin M

    2008-02-01

    The release of radon gas and progeny from the mining and milling of uranium-bearing ores has long been recognised as a potential radiological health hazard. The standards for exposure to radon and progeny have decreased over time as the understanding of their health risk has improved. In recent years there has been debate on the long-term releases (10,000 years) of radon from uranium mining and milling sites, focusing on abandoned, operational and rehabilitated sites. The primary purpose has been estimates of the radiation exposure of both local and global populations. Although there has been an increasing number of radon release studies over recent years in the USA, Australia, Canada and elsewhere, a systematic evaluation of this work has yet to be published in the international literature. This paper presents a detailed compilation and analysis of Australian studies. In order to quantify radon sources, a review of data on uranium mining and milling wastes in Australia, as they influence radon releases, is presented. An extensive compilation of the available radon release data is then assembled for the various projects, including a comparison to predictions of radon behaviour where available. An analysis of cumulative radon releases is then developed and compared to the UNSCEAR approach. The implications for the various assessments of long-term releases of radon are discussed, including aspects such as the need for ongoing monitoring of rehabilitation at uranium mining and milling sites and life-cycle accounting.

  8. Radionuclide migration at the Koongarra uranium deposit, Northern Australia Lessons from the Alligator Rivers analogue project

    Science.gov (United States)

    Payne, Timothy E.; Airey, Peter L.

    The Koongarra uranium deposit in Northern Australia provides a ‘natural analogue’ for processes that are of relevance for assessing the safety of radioactive waste disposal. In an international project extending over two decades, the Koongarra ore body was studied to increase the understanding of radionuclide migration and retention mechanisms that might occur in the vicinity of a geological repository. The research effort included extensive characterisation of the geological, hydrological and geochemical conditions at the site. Patterns of the distribution of radionuclides (predominantly members of the 238U decay chain, but also the rare isotopes 239Pu, 99Tc and 129I) were studied in both solid and groundwater phases. The project included detailed studies of uranium adsorption on mineral surfaces, and of subsequent processes that may lead to long-term uranium immobilisation. Numerous models for uranium migration were developed during the project. This paper provides a comprehensive review of the research at Koongarra, and assesses the value of the site for integrating the results of a complex series of laboratory, modelling and field studies. The insights gained from this review of the Koongarra project may assist in maximising the potential scientific benefit of future natural analogue studies.

  9. Evolution of uranium distribution and speciation in mill tailings, COMINAK Mine, Niger

    Energy Technology Data Exchange (ETDEWEB)

    Déjeant, Adrien, E-mail: adrien.dejeant@normalesup.org [Institut de Minéralogie, de Physique des Matériaux et de Cosmochimie, Case 115, 4 place Jussieu, 75005 Paris (France); Université Paris Diderot — Paris VII, 5 rue Thomas Mann, 75013 Paris (France); Galoisy, Laurence [Institut de Minéralogie, de Physique des Matériaux et de Cosmochimie, Case 115, 4 place Jussieu, 75005 Paris (France); Université Pierre et Marie Curie — Paris VI, 4 place Jussieu, 75005 Paris (France); Roy, Régis [AREVA Mines — Geoscience Department, Tour AREVA, 1 place Jean Millier, 92084 Paris, La Défense (France); Calas, Georges; Boekhout, Flora [Institut de Minéralogie, de Physique des Matériaux et de Cosmochimie, Case 115, 4 place Jussieu, 75005 Paris (France); Université Pierre et Marie Curie — Paris VI, 4 place Jussieu, 75005 Paris (France); Phrommavanh, Vannapha; Descostes, Michael [AREVA Mines — R& D Department, BAL 0414C-2, Tour AREVA, 1 place Jean Millier, 92084 Paris, La Défense (France)

    2016-03-01

    This study investigated the evolution of uranium distribution and speciation in mill tailings from the COMINAK mine (Niger), in production since 1978. A multi-scale approach was used, which combined high resolution remote sensing imagery, ICP-MS bulk rock analyses, powder X-ray diffraction, Scanning Electron Microscopy, Focused Ion Beam — Transmission Electron Microscopy and X-ray Absorption Near Edge Spectroscopy. Mineralogical analyses showed that some ore minerals, including residual uraninite and coffinite, undergo alteration and dissolution during tailings storage. The migration of uranium and other contaminants depends on (i) the chemical stability of secondary phases and sorbed species (dissolution and desorption processes), and (ii) the mechanical transport of fine particles bearing these elements. Uranium is stabilized after formation of secondary uranyl sulfates and phosphates, and adsorbed complexes on mineral surfaces (e.g. clay minerals). In particular, the stock of insoluble uranyl phosphates increases with time, thus contributing to the long-term stabilization of uranium. At the surface, a sulfate-cemented duricrust is formed after evaporation of pore water. This duricrust limits water infiltration and dust aerial dispersion, though it is enriched in uranium and many other elements, because of pore water rising from underlying levels by capillary action. Satellite images provided a detailed description of the tailings pile over time and allow monitoring of the chronology of successive tailings deposits. Satellite images suggest that uranium anomalies that occur at deep levels in the pile are most likely former surface duricrusts that have been buried under more recent tailings. - Highlights: • The evolution of U distribution and speciation in mill tailings is investigated. • High resolution satellite images provide useful information on tailings evolution. • U and many other elements are enriched in a sulfate-rich duricrust. • Formation of

  10. PRACTICAL AND PREDICTIVE MODELLING OF ORE DEPOSITS IN HYDROTHERMAL SYSTEMS

    Institute of Scientific and Technical Information of China (English)

    ZHAO Chong-bin; B.E.Hobbs; H.B.Muhlhaus; A.Ord

    2001-01-01

    @@ Over the past five years,we have been making efforts to develop a practical and predictive tool to explore for giant ore deposits in hydrothermal systems.Towards this goal,a significant progress has been made towards a better understanding of the basic physical and chemical processes behind ore body formation and mineralization in hydrothermal systems.

  11. PRACTICAL AND PREDICTIVE MODELLING OF ORE DEPOSITS IN HYDROTHERMAL SYSTEMS

    Institute of Scientific and Technical Information of China (English)

    ZHAO; Chong-bin; B.E.Hobbs; H.B.Muhlhaus; A.Ord

    2001-01-01

    Over the past five years,we have been making efforts to develop a practical and predictive tool to explore for giant ore deposits in hydrothermal systems.Towards this goal,a significant progress has been made towards a better understanding of the basic physical and chemical processes behind ore body formation and mineralization in hydrothermal systems.……

  12. Experimental study of ore gabbro liquid immiscibility

    Institute of Scientific and Technical Information of China (English)

    SANG; Zunan; XIA; Bin; ZHOU; Yongsheng; JIN; Zhenmin

    2005-01-01

    In this paper, the authors present the results of a preliminary experimental study on partial melting of fine-grained gabbro, Panzhihua, Sichuan Province, China. Experiments were conducted under (confining) pressure ranging from 450 to 500 MPa and temperature of 900-1200℃. The results show that the initial melt is distributed along grain boundaries and triple junctions. Liquid immiscibility phenomena are noted in the melt with two compositional different melt phases, i.e. matrix and sphere phases. The matrix phase is relatively rich in Si, Al and K, and is depleted in Mg, Fe, Ca, Na and Ti, whereas the sphere phase shows opposite trends. The calculation of the melt free energy indicates that the liquid immiscibility is governed by the rule of thermodynamics, as the liquid immiscibility would result in the decrease in free energy of the melt system. The field relationships suggest that the liquid immiscibility may have played an important role in the generation of ore magma of Panzhihua V-Ti magnetite ore deposit. This study thus provides experimental constraints on the mechanism of the formation of V-Ti magnetite deposite.

  13. Uranium uptake by hydroponically cultivated crop plants

    Energy Technology Data Exchange (ETDEWEB)

    Soudek, Petr; Petrova, Sarka [Laboratory of Plant Biotechnologies, Joint Laboratory of Institute of Experimental Botany AS CR, v.v.i. and Crop Research Institute, v.v.i., Rozvojova 263, 162 05 Prague 6 (Czech Republic); Benesova, Dagmar [Laboratory of Plant Biotechnologies, Joint Laboratory of Institute of Experimental Botany AS CR, v.v.i. and Crop Research Institute, v.v.i., Rozvojova 263, 162 05 Prague 6 (Czech Republic); Faculty of Environment Technology, Institute of Chemical Technology, Technicka 5, 166 28 Prague 6 (Czech Republic); Dvorakova, Marcela [Laboratory of Plant Biotechnologies, Joint Laboratory of Institute of Experimental Botany AS CR, v.v.i. and Crop Research Institute, v.v.i., Rozvojova 263, 162 05 Prague 6 (Czech Republic); Vanek, Tomas, E-mail: vanek@ueb.cas.cz [Laboratory of Plant Biotechnologies, Joint Laboratory of Institute of Experimental Botany AS CR, v.v.i. and Crop Research Institute, v.v.i., Rozvojova 263, 162 05 Prague 6 (Czech Republic)

    2011-06-15

    Hydroponicaly cultivated plants were grown on medium containing uranium. The appropriate concentrations of uranium for the experiments were selected on the basis of a standard ecotoxicity test. The most sensitive plant species was determined to be Lactuca sativa with an EC{sub 50} value about 0.1 mM. Cucumis sativa represented the most resistant plant to uranium (EC{sub 50} = 0.71 mM). Therefore, we used the uranium in a concentration range from 0.1 to 1 mM. Twenty different plant species were tested in hydroponic solution supplemented by 0.1 mM or 0.5 mM uranium concentration. The uranium accumulation of these plants varied from 0.16 mg/g DW to 0.011 mg/g DW. The highest uranium uptake was determined for Zea mays and the lowest for Arabidopsis thaliana. The amount of accumulated uranium was strongly influenced by uranium concentration in the cultivation medium. Autoradiography showed that uranium is mainly localized in the root system of the plants tested. Additional experiments demonstrated the possibility of influencing the uranium uptake from the cultivation medium by amendments. Tartaric acid was able to increase uranium uptake by Brassica oleracea and Sinapis alba up to 2.8 times or 1.9 times, respectively. Phosphate deficiency increased uranium uptake up to 4.5 times or 3.9 times, respectively, by Brassica oleracea and S. alba. In the case of deficiency of iron or presence of cadmium ions we did not find any increase in uranium accumulation. - Highlights: > The uranium accumulation in twenty different plant species varied from 0.160 to 0.011 mg/g DW. > Uranium is mainly localized in the root system. > Tartaric acid was able to increase uranium uptake by Brassica oleracea and Sinapis alba. > The phosphates deficiency increase the uranium uptake.

  14. Excited response of granular ores in vibrating field

    Institute of Scientific and Technical Information of China (English)

    2001-01-01

    The dynamical theory was utilized to probe into the law of the excited response of granular ores generated by the exciting action of exciter and the influence of wave propagation in vibrating field. The exciter with double axes was presented as an example, and the principle of exciter and its mathematical expression of the excitation force were given. The granular ores have viscidity and damping speciality, on the basis of which the motion equation of excited response of ores was established and the approximate expression of mode-displacement by harmonic excitation and the steady effect solution of coordinate response were deduced. Utilizing the step-by-step integration method, the recursion relation matrix of displacement, velocity and acceleration of the excited response of ores were obtained, and the computational flow chart and a computational example were given. The results show that the excited response can change the dynamical character and the flowing characteristic of granular ores.

  15. A Multifaceted Sampling Approach to Better Understanding Biogeochemical and Hydrogeological Controls on Uranium Mobility at a Former Uranium Mill Tailings Site in Riverton, Wyoming

    Science.gov (United States)

    Dam, W. L.; Johnson, R. H.; Campbell, S.; Bone, S. E.; Noel, V.; Bargar, J.

    2015-12-01

    Understanding uranium mobility in subsurface environments is not trivial. Obtaining sufficient data to accurately represent soil and aquifer characteristics can require unique approaches that evolve with added site knowledge. At Riverton, the primary source of uranium mill tailings remaining from ore processing was removed but contaminant plumes have persisted longer than predicted by groundwater modeling. What are the primary mechanisms controlling plume persistence? DOE is conducting new characterization studies to assist our understanding of underlying biogeochemical and hydrogeological mechanisms affecting secondary sources. A variety of field sampling techniques are being sequentially employed including augering, trenching, pore water sampling, and installing multi-level wells. In August 2012, vadose zone soil samples from 34 locations and groundwater from 103 boreholes were collected with Geoprobe ® direct push rods. Lower than expected uranium concentrations in composited shallow soils indicated the need for more focused and deeper samples. In May 2014, soil samples containing evaporites were collected along the bank of the Little Wind River; elevated uranium concentrations in evaporite minerals correlated with plume configurations and reflect contaminated groundwater discharge at the river. In September 2014, hand anger samples collected by the river and oxbow lake also indicated the presence of organic rich zones containing elevated uranium (>50 mg/kg). Subsequent samples collected from five backhoe trenches in May 2015 revealed a highly heterogeneous vadose zone composed of clay, silt, sand and cobbles containing evaporites and organic rich zones which may interact with groundwater plumes.Plans for August 2015 include sonic drilling to obtain continuous cores from the surface down to the base of the surficial aquifer with multi-level monitoring wells constructed in each borehole to assess vertical variation in groundwater chemistry. Temporary well

  16. Microbial accumulation of uranium, radium, and cesium

    Energy Technology Data Exchange (ETDEWEB)

    Strandberg, G.W.; Shumate, S.E. II; Parrott, J.R. Jr.; North, S.E.

    1981-05-01

    Diverse microbial species varied considerably in their ability to accumulate uranium, cesium, and radium. Mechanistic differences in uranium uptake by Saccharomyces cerevisiae and Pseudomonas aeruginosa were indicated. S. serevisiae exhibited a slow (hours) surface accumulation of uranium which was subject to environmental factors, while P. aeruginosa accumulated uranium rapidly (minutes) as dense intracellular deposits and did not appear to be affected by environmental parameters. Metabolism was not required for uranium uptake by either organism. Cesium and radium were concentrated to a considerably lesser extent than uranium by the several species tested.

  17. Exposure pathways and biological receptors: baseline data for the canyon uranium mine, Coconino County, Arizona

    Science.gov (United States)

    Hinck, Jo E.; Linder, Greg L.; Darrah, Abigail J.; Drost, Charles A.; Duniway, Michael C.; Johnson, Matthew J.; Méndez-Harclerode, Francisca M.; Nowak, Erika M.; Valdez, Ernest W.; Van Riper, Charles; Wolff, S.W.

    2014-01-01

    Recent restrictions on uranium mining within the Grand Canyon watershed have drawn attention to scientific data gaps in evaluating the possible effects of ore extraction to human populations as well as wildlife communities in the area. Tissue contaminant concentrations, one of the most basic data requirements to determine exposure, are not available for biota from any historical or active uranium mines in the region. The Canyon Uranium Mine is under development, providing a unique opportunity to characterize concentrations of uranium and other trace elements, as well as radiation levels in biota, found in the vicinity of the mine before ore extraction begins. Our study objectives were to identify contaminants of potential concern and critical contaminant exposure pathways for ecological receptors; conduct biological surveys to understand the local food web and refine the list of target species (ecological receptors) for contaminant analysis; and collect target species for contaminant analysis prior to the initiation of active mining. Contaminants of potential concern were identified as arsenic, cadmium, chromium, copper, lead, mercury, nickel, selenium, thallium, uranium, and zinc for chemical toxicity and uranium and associated radionuclides for radiation. The conceptual exposure model identified ingestion, inhalation, absorption, and dietary transfer (bioaccumulation or bioconcentration) as critical contaminant exposure pathways. The biological survey of plants, invertebrates, amphibians, reptiles, birds, and small mammals is the first to document and provide ecological information on .200 species in and around the mine site; this study also provides critical baseline information about the local food web. Most of the species documented at the mine are common to ponderosa pine Pinus ponderosa and pinyon–juniper Pinus–Juniperus spp. forests in northern Arizona and are not considered to have special conservation status by state or federal agencies; exceptions

  18. High-temperature performance prediction of iron ore fines and the ore-blending programming problem in sintering

    Institute of Scientific and Technical Information of China (English)

    Bing-ji Yan; Jian-liang Zhang; Hong-wei Guo; Ling-kun Chen; Wei Li

    2014-01-01

    The high-temperature performance of iron ore fines is an important factor in optimizing ore blending in sintering. However, the application of linear regression analysis and the linear combination method in most other studies always leads to a large deviation from the desired results. In this study, the fuzzy membership functions of the assimilation ability temperature and the liquid fluidity were proposed based on the fuzzy mathematics theory to construct a model for predicting the high-temperature performance of mixed iron ore. Comparisons of the prediction model and experimental results were presented. The results illustrate that the prediction model is more accurate and effec-tive than previously developed models. In addition, fuzzy constraints for the high-temperature performance of iron ore in this research make the results of ore blending more comparable. A solution for the quantitative calculation as well as the programming of fuzzy constraints is also introduced.

  19. The end of cheap uranium.

    Science.gov (United States)

    Dittmar, Michael

    2013-09-01

    Historic data from many countries demonstrate that on average no more than 50-70% of the uranium in a deposit could be mined. An analysis of more recent data from Canada and Australia leads to a mining model with an average deposit extraction lifetime of 10±2 years. This simple model provides an accurate description of the extractable amount of uranium for the recent mining operations. Using this model for all larger existing and planned uranium mines up to 2030, a global uranium mining peak of at most 58±4 ktons around the year 2015 is obtained. Thereafter we predict that uranium mine production will decline to at most 54±5 ktons by 2025 and, with the decline steepening, to at most 41±5 ktons around 2030. This amount will not be sufficient to fuel the existing and planned nuclear power plants during the next 10-20 years. In fact, we find that it will be difficult to avoid supply shortages even under a slow 1%/year worldwide nuclear energy phase-out scenario up to 2025. We thus suggest that a worldwide nuclear energy phase-out is in order. If such a slow global phase-out is not voluntarily effected, the end of the present cheap uranium supply situation will be unavoidable. The result will be that some countries will simply be unable to afford sufficient uranium fuel at that point, which implies involuntary and perhaps chaotic nuclear phase-outs in those countries involving brownouts, blackouts, and worse.

  20. Uranium series, volcanic rocks

    Science.gov (United States)

    Vazquez, Jorge A.

    2014-01-01

    Application of U-series dating to volcanic rocks provides unique and valuable information about the absolute timing of crystallization and differentiation of magmas prior to eruption. The 238U–230Th and 230Th-226Ra methods are the most commonly employed for dating the crystallization of mafic to silicic magmas that erupt at volcanoes. Dates derived from the U–Th and Ra–Th methods reflect crystallization because diffusion of these elements at magmatic temperatures is sluggish (Cherniak 2010) and diffusive re-equilibration is insignificant over the timescales (less than or equal to 10^5 years) typically associated with pre-eruptive storage of nearly all magma compositions (Cooper and Reid 2008). Other dating methods based on elements that diffuse rapidly at magmatic temperatures, such as the 40Ar/39Ar and (U–Th)/He methods, yield dates for the cooling of magma at the time of eruption. Disequilibrium of some short-lived daughters of the uranium series such as 210Po may be fractionated by saturation of a volatile phase and can be employed to date magmatic gas loss that is synchronous with volcanic eruption (e.g., Rubin et al. 1994).

  1. 40 CFR 421.320 - Applicability: Description of the secondary uranium subcategory.

    Science.gov (United States)

    2010-07-01

    ... secondary uranium subcategory. 421.320 Section 421.320 Protection of Environment ENVIRONMENTAL PROTECTION... CATEGORY Secondary Uranium Subcategory § 421.320 Applicability: Description of the secondary uranium... uranium (including depleted uranium) by secondary uranium facilities....

  2. Ceramic colorant from untreated iron ore residue.

    Science.gov (United States)

    Pereira, Oscar Costa; Bernardin, Adriano Michael

    2012-09-30

    This work deals with the development of a ceramic colorant for glazes from an untreated iron ore residue. 6 mass% of the residue was added in suspensions (1.80 g/cm(3) density and 30s viscosity) of white, transparent and matte glazes, which were applied as thin layers (0.5mm) on engobeb and not fired ceramic tiles. The tiles were fired in laboratory roller kiln in a cycle of 35 min and maximum temperatures between 1050 and 1180°C. The residue and glazes were characterized by chemical (XRF) and thermal (DTA and optical dilatometry) analyses, and the glazed tiles by colorimetric and XRD analyses. The results showed that the colorant embedded in the transparent glaze results in a reddish glaze (like pine nut) suitable for the ceramic roof tile industry. For the matte and white glazes, the residue has changed the color of the tiles with temperature.

  3. Improved polynomial remainder sequences for Ore polynomials.

    Science.gov (United States)

    Jaroschek, Maximilian

    2013-11-01

    Polynomial remainder sequences contain the intermediate results of the Euclidean algorithm when applied to (non-)commutative polynomials. The running time of the algorithm is dependent on the size of the coefficients of the remainders. Different ways have been studied to make these as small as possible. The subresultant sequence of two polynomials is a polynomial remainder sequence in which the size of the coefficients is optimal in the generic case, but when taking the input from applications, the coefficients are often larger than necessary. We generalize two improvements of the subresultant sequence to Ore polynomials and derive a new bound for the minimal coefficient size. Our approach also yields a new proof for the results in the commutative case, providing a new point of view on the origin of the extraneous factors of the coefficients.

  4. Exact linear modeling using Ore algebras

    CERN Document Server

    Schindelar, Kristina; Zerz, Eva

    2010-01-01

    Linear exact modeling is a problem coming from system identification: Given a set of observed trajectories, the goal is find a model (usually, a system of partial differential and/or difference equations) that explains the data as precisely as possible. The case of operators with constant coefficients is well studied and known in the systems theoretic literature, whereas the operators with varying coefficients were addressed only recently. This question can be tackled either using Gr\\"obner bases for modules over Ore algebras or by following the ideas from differential algebra and computing in commutative rings. In this paper, we present algorithmic methods to compute "most powerful unfalsified models" (MPUM) and their counterparts with variable coefficients (VMPUM) for polynomial and polynomial-exponential signals. We also study the structural properties of the resulting models, discuss computer algebraic techniques behind algorithms and provide several examples.

  5. Rigid Ideals and Radicals of Ore Extensions

    Institute of Scientific and Technical Information of China (English)

    Chan Yong Hong; Tai Keun Kwak; S. Tariq Rizvi

    2005-01-01

    For an endomorphism σ of a ring R, Krempa called σ a rigid endomorphism if aσ(a) = 0 implies a= 0 for a ∈ R. A ring R is called rigid if there exists a rigid endomorphism of R. In this paper, we extend the σ-rigid property of a ring R to an ideal of R. For a σ-ideal Ⅰ of a ring R, we call Ⅰ a σ-rigid ideal if aσ(a) ∈Ⅰ implies a ∈Ⅰ for a ∈ R. We characterize σ-rigid ideals and study related properties. The connections of the prime radical and the upper nil radical of R with the prime radical and the upper nil radical of the Ore extension R[x; σ, δ], respectively, are also investigated.

  6. Direct Biohydrometallurgical Extraction of Iron from Ore

    Energy Technology Data Exchange (ETDEWEB)

    T.C. Eisele

    2005-10-01

    A completely novel approach to iron extraction was investigated, based on reductive leaching of iron by anaerobic bacteria. Microorganisms were collected from an anaerobic bog where natural seepage of dissolved iron was observed. This mixed culture was used to reduce insoluble iron in a magnetite ore to the soluble ferrous (Fe{sup +2}) state. While dissolution rates were slow, concentrations of dissolved iron as high as 3487 mg/l could be reached if sufficient time was allowed. A factorial study of the effects of trace nutrients and different forms of organic matter indicated that the best dissolution rates and highest dissolved iron concentrations were achieved using soluble carbohydrate (sucrose) as the bacterial food source, and that nutrients other than nitrogen, phosphorus, potassium, sodium, and acetate were not necessary. A key factor in reaching high levels of dissolved iron was maintaining a high level of carbon dioxide in solution, since the solubility of iron carbonates increases markedly as the quantity of dissolved carbon dioxide increases. Once the iron is dissolved, it has been demonstrated that the ferrous iron can then be electroplated from solution, provided that the concentration of iron is sufficiently high and the hydrogen ion concentration is sufficiently low. However, if the leaching solution is electrolyzed directly, organic matter precipitates at the cathode along with the metallic iron. To prevent this problem, the ferrous iron should be separated from the bulk solution in a more concentrated, purified form. One route to accomplishing this is to take advantage of the change in solubility of ferrous iron as a function of carbon dioxide concentration. By cycling the concentration of carbon dioxide in solution, it is possible to produce an iron-rich concentrate that should be suitable for electrolysis. This represents the first viable hydrometallurgical method for leaching iron directly from ore and producing metallic iron.

  7. Occurrence and fluctuations of Acidithiobacillus ssp. in uranium mine effluents, Caldas, MG

    Energy Technology Data Exchange (ETDEWEB)

    Campos, Michelle Burato de; Roque, Claudio Vitor; Gomes, Heliana de Azevedo [Brazilian Nuclear Energy Commission (CNEN-MG), Pocos de Caldas, MG (Brazil)]. E-mail: michelle_borato@hotmail.com; cvroque@cnen.gov.br; hgomes@cnen.gov.br

    2007-07-01

    Sulphide ores that are present in mining areas can cause serious environmental problems because of the action of chemolithotrophic bacteria of the Acidithiobacillus genera, mainly A. ferroxidans and A. thiooxidans. These microorganisms are capable of oxidizing sulphide minerals, elemental sulphur and ferrous ion, possibly mobilizing radionuclides such as uranium into the environment. In this context, the present study was undertaken in order to determine the occurrence and fluctuations of populations of A. ferroxidans and A. thiooxidans in effluents from an uranium mine, part of the Ore Treatment Unit (UTM) in Caldas, MG - Brazil, analyzing samples from 9 sampling points (CM, BS, D3, 25, 27, 32, 41, 75, and 76). The results showed that the population of A. thiooxidans occurs more often (44.4%) than the population of A. ferroxidans (31.5%). In the sample points within the UTM-environment interface, points 25 and 76 were considered the most susceptible to acid mine drainage and activity of bacteria involved in metal bioleaching. The seasonal behavior of some of the variables observed at points CM, D3, and BS, when evaluated simultaneously, such as high Eh values, low pH values, the detection of greater percentages of incidence and higher counts of A. ferroxidans and A. thiooxidans, showed that these points are the main locations for the occurrence of acid mine drainage and bacterial bioleaching in the UTM and should be considered as critical points for a possible decommissioning action. (author)

  8. Uranium Determination by Delayed Neutron Counting

    Institute of Scientific and Technical Information of China (English)

    2008-01-01

    <正>Uranium is a very important resource in nuclear industry, especially in the exploiture of nuclear energy. Determination of uranium using delayed neutron counting (DNC) is simple, non-destructive, and

  9. The economics of uranium 1991. 3. ed

    Energy Technology Data Exchange (ETDEWEB)

    1991-01-01

    The new Roskill report on the economics of uranium, 1991, gives essential facts and figures on five main topics; background, supply and demand; prices and uranium and nuclear activities by country and company. (author).

  10. Uranium 2007 resources, production and demand

    CERN Document Server

    Organisation for Economic Cooperation and Development. Paris

    2008-01-01

    Based on official information received from 40 countries, Uranium 2007 provides a comprehensive review of world uranium supply and demand as of 1st January 2007, as well as data on global uranium exploration, resources, production and reactor-related requirements. It provides substantive new information from major uranium production centres in Africa, Australia, Central Asia, Eastern Europe and North America. Projections of nuclear generating capacity and reactor-related uranium requirements through 2030 are also featured, along with an analysis of long-term uranium supply and demand issues. It finds that with rising demand and declining inventories, uranium prices have increased dramatically in recent years. As a result, the uranium industry is undergoing a significant revival, bringing to an end a period of over 20 years of underinvestment.

  11. Super-Enrichment of Dispersed Elements and Associated Ore Deposits

    Institute of Scientific and Technical Information of China (English)

    高振敏; 姚林波

    2004-01-01

    Dispersed elements do not always occur as associated elements in the ore deposits of other elements. Instead, they can constitute independent ore deposits. The focus of this paper is placed on the mechanism of super-enrichment of the four dispersed elements TI, Ge, Se, and Te under favorable geological conditions, where their enrichment coefficients are so high that their abundances can reach n×103-n×104, sometimes even up to n×106 times (e. g. Te) those of the crust. As a result, they can form their independent ore deposits. Studies have shown that such independent ore deposits are mostly distributed in the southwestern part of China, most of which belong to low-temperature ore deposits, ranging in age from Yanshanian to Himalayan(Cretaceous to Cenozoic), with a significant time gap with the host strata. Moreover, this paper also deals with the existing forms (as independent minerals, occurring isomorphously and being adsorbed) of the dispersed elements in those independent ore deposits. The discovery of independent ore deposits of dispersed elements is a great breakthrough in the study of dispersed element metallogenesis.

  12. Leaching hydrodynamics of weathered elution-deposited rare earth ore

    Institute of Scientific and Technical Information of China (English)

    2001-01-01

    Both porosity (φ) and permeability (k) of the weathered elution-deposited rare earth ores are basic hydrodynamic parameters for RE leaching. The relationship between k and φ of two typical rare earth ores of South China in the packed bed was investigated by measuring the flow (Q) under various leaching pressure difference (Δp). The experimental results show that the relationship between k and φ is unique, moreover the relationship between Q and Δp is in accord with the Darcy's law. The effects of the type of ores, the leaching reagents and its concentration, the granule ore size on the leaching permeability have also been investigated. It is demonstrated that kH (for heavy RE ore, kH=35.98 mm2)>kM-H (for middle-heavy RE ore,kM-H=28.50 mm2), whereas k(NH4NO3)>k(NH4Cl)>k[(NH4)2SO4], and the k value increases with increasing leaching reagents concentration and granule ore size(k0.60~0.75 mm=99.96 mm2,k0.125~0.60 mm=11.83 mm2, k0.074~0.125 mm=0.84 mm2).

  13. Baseline risk assessment of ground water contamination at the uranium mill tailings site near Lakeview, Oregon. Revision 1

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    1995-12-01

    Surface cleanup at the Uranium Mill Tailings Remedial Action (UMTRA) Project site near Lakeview, Oregon was completed in 1989. The Ground Water Project evaluates the nature and extent of ground water contamination that resulted from the uranium ore processing activities. The Ground Water Project is in its beginning stages. Human health may be at risk from exposure to ground water contaminated by uranium ore processing. Exposure could occur by drinking water pumped out of a hypothetical well drilled in the contaminated areas. Ecological risks to plants or animals may result from exposure to surface water and sediment that have received contaminated ground water. A risk assessment describes a source of contamination, how that contamination reaches people and the environment, the amount of contamination to which people or the ecological environment may be exposed, and the health or ecological effects that could result from that exposure. This risk assessment is a site-specific document that will be used to evaluate current and potential future impacts to the public and the environment from exposure to contaminated ground water. The results of this evaluation and further site characterization will determine whether any action is needed to protect human health or the ecological environment.

  14. Baseline risk assessment of ground water contamination at the uranium mill tailings sites near Rifle, Colorado. Revision 1

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    1995-08-01

    The US Department of Energy (DOE) Uranium Mill Tailings Remedial Action (UMTRA) Project consists of the Surface Project (Phase 1) and the Ground Water Project (Phase 2). Under the UMTRA Surface Project, tailings, radioactive contaminated soil, equipment, and materials associated with the former uranium ore processing sites are placed into disposal cells. The cells are designed to reduce radon and other radiation emissions and to prevent further ground water contamination. The Ground Water Project evaluates the nature and extent of ground water contamination resulting from the uranium ore processing activities. Two UMTRA Project sites are near Rifle, Colorado: the Old Rifle site and the New Rifle site. Surface cleanup at the two sites is under way and is scheduled for completion in 1996. The Ground Water Project is in its beginning stages. A risk assessment identifies a source of contamination, how that contamination reaches people and the environment, the amount of contamination to which people or the environment may be exposed, and the health or environmental effects that could result from that exposure. This report is a site-specific document that will be used to evaluate current and future impacts to the public and the environment from exposure to contaminated ground water. This evaluation and further site characterization will be used to determine if action is needed to protect human health or the environment.

  15. Baseline risk assessment of ground water contamination at the uranium mill tailings site near Riverton, Wyoming. Revision 1

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    1995-09-01

    The Uranium Mill Tailings Remedial Action (UMTRA) Project consists of two phases: the Surface Project and the Ground Water Project. At the UMTRA Project site near Riverton, Wyoming, Surface Project cleanup occurred from 1988 to 1990. Tailings and radioactively contaminated soils and materials were taken from the Riverton site to a disposal cell in the Gas Hills area, about 60 road miles (100 kilometers) to the east. The surface cleanup reduces radon and other radiation emissions and minimizes further ground water contamination. The UMTRA Project`s second phase, the Ground Water Project, will evaluate the nature and extent of ground water contamination at the Riverton site that has resulted from the uranium ore processing activities. Such evaluations are used at each site to determine a strategy for complying with UMTRA ground water standards established by the US Environmental Protection Agency (EPA) and if human health risks could result from exposure to ground water contaminated by uranium ore processing. Exposure could hypothetically occur if drinking water were pumped from a well drilled in an area where ground water contamination might have occurred. Human health and environmental risks may also result if people, plants, or animals are exposed to surface water that has mixed with contaminated ground water.

  16. Uranium briquettes for irradiation target

    Energy Technology Data Exchange (ETDEWEB)

    Saliba-Silva, Adonis Marcelo; Garcia, Rafael Henrique Lazzari; Martins, Ilson Carlos; Carvalho, Elita Fontenele Urano de; Durazzo, Michelangelo, E-mail: saliba@ipen.b [Instituto de Pesquisas Energeticas e Nucleares (IPEN/CNEN-SP), Sao Paulo, SP (Brazil)

    2011-07-01

    Direct irradiation on targets inside nuclear research or multiple purpose reactors is a common route to produce {sup 99}Mo-{sup 99m}Tc radioisotopes. Nevertheless, since the imposed limits to use LEU uranium to prevent nuclear armament production, the amount of uranium loaded in target meats has physically increased and new processes have been proposed for production. Routes using metallic uranium thin film and UAl{sub x} dispersion have been used for this purpose. Both routes have their own issues, either by bringing difficulties to disassemble the aluminum case inside hot cells or by generating great amount of alkaline radioactive liquid rejects. A potential route might be the dispersion of powders of LEU metallic uranium and nickel, which are pressed as a blend inside a die and followed by pulse electroplating of nickel. The electroplating provides more strength to the briquettes and creates a barrier for gas evolution during neutronic disintegration of {sup 235}U. A target briquette platted with nickel encapsulated in an aluminum case to be irradiated may be an alternative possibility to replace other proposed targets. This work uses pulse Ni-electroplating over iron powder briquette to simulate the covering of uranium by nickel. The following parameters were applied 10 times for each sample: 900Hz, -0.84A/square centimeters with duty cycle of 0.1 in Watts Bath. It also presented the optical microscopy analysis of plated microstructure section. (author)

  17. The End of Cheap Uranium

    CERN Document Server

    Dittmar, Michael

    2011-01-01

    Historic data from many countries demonstrate that on average no more than 50-70% of the uranium in a deposit could be mined. An analysis of more recent data from Canada and Australia leads to a mining model with an average deposit extraction lifetime of 10+- 2 years. This simple model provides an accurate description of the extractable amount of uranium for the recent mining operations. Using this model for all larger existing and planned uranium mines up to 2030, a global uranium mining peak of at most 58 +- 4 ktons around the year 2015 is obtained. Thereafter we predict that uranium mine production will decline to at most 54 +- 5 ktons by 2025 and, with the decline steepening, to at most 41 +- 5 ktons around 2030. This amount will not be sufficient to fuel the existing and planned nuclear power plants during the next 10-20 years. In fact, we find that it will be difficult to avoid supply shortages even under a slow 1%/year worldwide nuclear energy phase-out scenario up to 2025. We thus suggest that a world...

  18. Sulfur isotope geochemistry of ore and gangue minerals from the Silesian-Cracow Mississippi Valley-type ore district, Poland

    Science.gov (United States)

    Leach, D.L.; Vets, J.G.; Gent, C.A.

    1996-01-01

    Studies of the sulfur isotopic composition of ore and gangue minerals from the Silesian-Cracow Zn-Pb district were conducted to gain insights into processes that controlled the location and distribution of the ore deposits. Results of this study show that minerals from the Silesian-Cracow ore district have the largest range of sulfur isotope compositions in sulfides observed from any Mississippi Valley-type ore district in the world. The ??34S values for sulfide minerals range from +38 to -32 per mil for the entire paragenetic sequence but individual stages exhibit smaller ranges. There is a well developed correlation between the sulfur isotope composition and paragenetic stage of ore deposition. The first important ore stage contains mostly positive ??34S values, around 5 per mil. The second stage of ore formation are lower, with a median value of around -5 to -15 per mil, and with some values as low as -32 per mil. Late stage barite contains isotopically heavy sulfur around +32 per mil. The range in sulfur isotope compositions can be explained by contributions of sulfur from a variety of source rocks together with sulfur isotope fractionations produced by the reaction paths for sulfate reduction. Much of the variation in sulfur isotope compositions can be explained by bacterial reduction of sedimentary sulfate and disequilibrium reactions by intermediate-valency sulfur species, especially in the late-stage pyrite and sphalerite. Organic reduction of sulfate and thermal release of sulfur from coals in the Upper Silesian Coal Basin may have been important contributors to sulfur in the ore minerals. The sulfur isotopic data, ore mineral textures, and fluid inclusion data, are consistent with the hypothesis that fluid mixing was the dominant ore forming mechanism. The rather distinct lowering of ?? 34S values in sulfides from stage 2 to stage 3 is believed to reflect some fundamental change in the source of reduced sulfur and/or hydrology of the ore

  19. Uranium 2003 resources, production and demand

    CERN Document Server

    Organisation for Economic Cooperation and Development. Paris

    2004-01-01

    Uranium 2003: Resources, Production and Demand paints a detailed statistical profile of the world uranium industry in the areas of exploration, resource estimates, production and reactor-related requirements. It provides substantial new information from all major uranium production centres in Africa, Australia, Eastern Europe and North America and for the first time, a report for Turkmenistan. Also included are international expert analyses and projections of nuclear generating capacity and reactor-related uranium requirements through 2020.

  20. Statistical data of the uranium industry

    Energy Technology Data Exchange (ETDEWEB)

    None

    1981-01-01

    Data are presented on US uranium reserves, potential resources, exploration, mining, drilling, milling, and other activities of the uranium industry through 1980. The compendium reflects the basic programs of the Grand Junction Office. Statistics are based primarily on information provided by the uranium exploration, mining, and milling companies. Data on commercial U/sub 3/O/sub 8/ sales and purchases are included. Data on non-US uranium production and resources are presented in the appendix. (DMC)

  1. Tourmaline as a recorder of ore-forming processes

    Science.gov (United States)

    Slack, J.F.; Trumbull, R.B.

    2011-01-01

    Tourmaline occurs in diverse types of hydrothermal mineral deposits and can be used to constrain the nature and evolution of ore-forming fl uids. Because of its broad range in composition and retention of chemical and isotopic signatures, tourmaline may be the only robust recorder of original mineralizing processes in some deposits. Microtextures and in situ analysis of compositional and isotopic variations in ore-related tourmaline provide valuable insights into hydrothermal systems in seafl oor, sedimentary, magmatic, and metamorphic environments. Deciphering the hydrothermal record in tourmaline also holds promise for aiding exploration programs in the search for new ore deposits.

  2. The uranium in the environment; L'uranium dans l'environnement

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    2001-07-01

    The uranium is a natural element omnipresent in the environment, with a complex chemistry more and more understood. Many studies are always today devoted to this element to better improve the uranium behavior in the environment. To illustrate this knowledge and for the public information the CEA published this paper. It gathers in four chapters: historical aspects and properties of the uranium, the uranium in the environment and the impacts, the metrology of the uranium and its migration. (A.L.B.)

  3. 40 CFR 440.110 - Applicability; description of the platinum ore subcategory.

    Science.gov (United States)

    2010-07-01

    ... platinum ore subcategory. 440.110 Section 440.110 Protection of Environment ENVIRONMENTAL PROTECTION AGENCY (CONTINUED) EFFLUENT GUIDELINES AND STANDARDS ORE MINING AND DRESSING POINT SOURCE CATEGORY Platinum Ores Subcategory § 440.110 Applicability; description of the platinum ore subcategory. The provisions of...

  4. 40 CFR 440.10 - Applicability; description of the iron ore subcategory.

    Science.gov (United States)

    2010-07-01

    ... ore subcategory. 440.10 Section 440.10 Protection of Environment ENVIRONMENTAL PROTECTION AGENCY (CONTINUED) EFFLUENT GUIDELINES AND STANDARDS ORE MINING AND DRESSING POINT SOURCE CATEGORY Iron Ore Subcategory § 440.10 Applicability; description of the iron ore subcategory. The provisions of this subpart...

  5. 40 CFR 440.90 - Applicability; description of the antimony ore subcategory.

    Science.gov (United States)

    2010-07-01

    ... antimony ore subcategory. 440.90 Section 440.90 Protection of Environment ENVIRONMENTAL PROTECTION AGENCY (CONTINUED) EFFLUENT GUIDELINES AND STANDARDS ORE MINING AND DRESSING POINT SOURCE CATEGORY Antimony Ore Subcategory § 440.90 Applicability; description of the antimony ore subcategory. The provisions of...

  6. 40 CFR 440.20 - Applicability; description of the aluminum ore subcategory.

    Science.gov (United States)

    2010-07-01

    ... aluminum ore subcategory. 440.20 Section 440.20 Protection of Environment ENVIRONMENTAL PROTECTION AGENCY (CONTINUED) EFFLUENT GUIDELINES AND STANDARDS ORE MINING AND DRESSING POINT SOURCE CATEGORY Aluminum Ore Subcategory § 440.20 Applicability; description of the aluminum ore subcategory. The provisions of...

  7. 40 CFR 440.50 - Applicability; description of the titanium ore subcategory.

    Science.gov (United States)

    2010-07-01

    ... titanium ore subcategory. 440.50 Section 440.50 Protection of Environment ENVIRONMENTAL PROTECTION AGENCY (CONTINUED) EFFLUENT GUIDELINES AND STANDARDS ORE MINING AND DRESSING POINT SOURCE CATEGORY Titanium Ore Subcategory § 440.50 Applicability; description of the titanium ore subcategory. The provisions of...

  8. 40 CFR 440.70 - Applicability; description of the nickel ore subcategory.

    Science.gov (United States)

    2010-07-01

    ... nickel ore subcategory. 440.70 Section 440.70 Protection of Environment ENVIRONMENTAL PROTECTION AGENCY (CONTINUED) EFFLUENT GUIDELINES AND STANDARDS ORE MINING AND DRESSING POINT SOURCE CATEGORY Nickel Ore Subcategory § 440.70 Applicability; description of the nickel ore subcategory. The provisions of this...

  9. 40 CFR 440.40 - Applicability; description of the mercury ore subcategory.

    Science.gov (United States)

    2010-07-01

    ... mercury ore subcategory. 440.40 Section 440.40 Protection of Environment ENVIRONMENTAL PROTECTION AGENCY (CONTINUED) EFFLUENT GUIDELINES AND STANDARDS ORE MINING AND DRESSING POINT SOURCE CATEGORY Mercury Ore Subcategory § 440.40 Applicability; description of the mercury ore subcategory. The provisions of subpart...

  10. 40 CFR 440.60 - Applicability; description of the tungsten ore subcategory.

    Science.gov (United States)

    2010-07-01

    ... tungsten ore subcategory. 440.60 Section 440.60 Protection of Environment ENVIRONMENTAL PROTECTION AGENCY (CONTINUED) EFFLUENT GUIDELINES AND STANDARDS ORE MINING AND DRESSING POINT SOURCE CATEGORY Tungsten Ore Subcategory § 440.60 Applicability; description of the tungsten ore subcategory. The provisions of...

  11. The Itataia phosphate-uranium deposit (Ceará, Brazil) new petrographic, geochemistry and isotope studies

    Science.gov (United States)

    Veríssimo, César Ulisses Vieira; Santos, Roberto Ventura; Parente, Clóvis Vaz; Oliveira, Claudinei Gouveia de; Cavalcanti, José Adilson Dias; Nogueira Neto, José de Araújo

    2016-10-01

    The Itataia phosphate-uranium deposit is located in Santa Quitéria, in central Ceará State, northeastern Brazil. Mineralization has occurred in different stages and involves quartz leaching (episyenitization), brecciation and microcrystalline phase formation of concretionary apatite. The last constitutes the main mineral of Itatiaia uranium ore, namely collophane. Collophanite ore occurs in massive bodies, lenses, breccia zones, veins or episyenite in marble layers, calc-silicate rocks and gneisses of the Itataia Group. There are two accepted theories on the origin of the earliest mineralization phase of Itataia ore: syngenetic (primary) - where the ore is derived from a continental source and then deposited in marine and coastal environments; and epigenetic (secondary) - whereby the fluids are of magmatic, metamorphic and meteoric origin. The characterization of pre- or post-deformational mineralization is controversial, since the features of the ore are interpreted as deformation. This investigation conducted isotopic studies and chemical analyses of minerals in marbles and calc-silicate rocks of the Alcantil and Barrigas Formations (Itataia Group), as well as petrographic and structural studies. Analysis of the thin sections shows at least three phosphate mineral phases associated with uranium mineralizaton: (1) A prismatic fluorapatite phase associated with chess-board albite, arfvedsonite and ferro-eckermannite; (2) a second fluorapatite phase with fibrous radial or colloform habits that replaces calcium carbonate in marble, especially along fractures, with minerals such as quartz, chlorite and zeolite also identified in calc-silicate rocks; and (3) an younger phosphate phase of botryoidal apatite (fluorapatite and hydroxyapatite) related with clay minerals and probably others calcium and aluminum phosphates. Detailed isotopic analysis carried out perpendicularly to the mineralized levels and veins in the marble revealed significant variation in isotopic

  12. 77 FR 14837 - Bioassay at Uranium Mills

    Science.gov (United States)

    2012-03-13

    ... COMMISSION Bioassay at Uranium Mills AGENCY: Nuclear Regulatory Commission. ACTION: Draft regulatory guide... for public comment draft regulatory guide (DG), DG-8051, ``Bioassay at Uranium Mills.'' This guide describes a bioassay program acceptable to the NRC staff for uranium mills and applicable portions...

  13. 77 FR 12880 - Uranium From Russia

    Science.gov (United States)

    2012-03-02

    ... COMMISSION Uranium From Russia Determination On the basis of the record \\1\\ developed in the subject five... investigation on uranium from Russia would be likely to lead to continuation or recurrence of material injury to... Publication 4307 (February 2012), entitled Uranium from Russia: Investigation No. 731-TA-539-C (Third...

  14. The Chemistry and Toxicology of Depleted Uranium

    Directory of Open Access Journals (Sweden)

    Sidney A. Katz

    2014-03-01

    Full Text Available Natural uranium is comprised of three radioactive isotopes: 238U, 235U, and 234U. Depleted uranium (DU is a byproduct of the processes for the enrichment of the naturally occurring 235U isotope. The world wide stock pile contains some 1½ million tons of depleted uranium. Some of it has been used to dilute weapons grade uranium (~90% 235U down to reactor grade uranium (~5% 235U, and some of it has been used for heavy tank armor and for the fabrication of armor-piercing bullets and missiles. Such weapons were used by the military in the Persian Gulf, the Balkans and elsewhere. The testing of depleted uranium weapons and their use in combat has resulted in environmental contamination and human exposure. Although the chemical and the toxicological behaviors of depleted uranium are essentially the same as those of natural uranium, the respective chemical forms and isotopic compositions in which they usually occur are different. The chemical and radiological toxicity of depleted uranium can injure biological systems. Normal functioning of the kidney, liver, lung, and heart can be adversely affected by depleted uranium intoxication. The focus of this review is on the chemical and toxicological properties of depleted and natural uranium and some of the possible consequences from long term, low dose exposure to depleted uranium in the environment.

  15. Grade-Tonnage, Ore Value-Tonnage, and Enrichment Ratio-Tonnage Models for Resource Assessment

    Institute of Scientific and Technical Information of China (English)

    2001-01-01

    According to grade-tonnage diagrams of nickel and zinc deposits, their critical grades are 0.4 % and 3.4 %, respectively, and hence the former resources can be considered optimistic and the latter pessimistic. The grade-tonnage diagram of gold deposits is convex downwards suggesting that the critical grade is 1×10-6 in the low-grade part. The ore value (OV)-tonnage diagram of all deposits in the world consists of three parts: high, middle and low value classes. The enrichment ratio (ER)-tonnage diagram of all deposits in the world also consists of three parts: high, middle and low ratio classes. Nine quality categories defined by ER and OV are characterized by some keywords indicating deposit types as follows: category HH (high ER-high OV: 0.7 %) by “unconformity” and “Mississippi Valley”, category HM (high ER-middle OV: 0.7 %) by “vein”, category ML (middle ER-low OV: 0 %) by “sandstone”, “stockwork” and “dissemination”, category LM by “orthomagmatic”, “laterite”, komatiite“ and ”chemical“, and category LL by “porphyry”, “dissemination” and “placer”. Category MM is not characterized by any keyword. If the commodities of a deposit are defined by both the enrichment ratio and the ore value, the defined commodities are relatively coincident for gold and nickel, but different for copper, silver and zinc, and greatly different for molybdenum and lead. Deposits containing lead and/or zinc are complimentary. If the commodity Pb+Zn is applied, most lead or zinc deposits are classified as Pb+Zn by both definitions. Accessory metals are commonly expected for deposits of kuroko-type zinc, epithermal silver, massive sulfide-type zinc and volcanogenic zinc, but uncommon for deposits of orthomagmatic chromium, chemically precipitated copper and sandstone-type uranium.

  16. Electroformation of uranium hemispherical shells

    Energy Technology Data Exchange (ETDEWEB)

    Marshall, S.L.; Redey, L.; Vandegrift, G.F.; Vissers, D.R.

    1989-11-01

    This effort was directed at developing an electrochemical process for forming uniform and dendrite-free deposits of uranium from molten salts. This process is to be used for the electroformation of free-standing hemispherical shells of uranium for nuclear applications. Electrodeposition of uranium onto a substrate was accomplished with a fused chloride mixture containing 42 wt% UCl{sub 3} and a fused chloride-fluoride mixture containing 4 wt % UF{sub 4}. Under pulsed potential control at 504{degree}C, the chloride-fluoride mixture yielded the widest range of plating conditions for which dendrites could be avoided. Bipolar current pulse plating with both electrolytes gave good results, and successful application of this technique to a large tubular cathode has been demonstrated. 24 refs., 10 figs.

  17. Y-12 Uranium Exposure Study

    Energy Technology Data Exchange (ETDEWEB)

    Eckerman, K.F.; Kerr, G.D.

    1999-08-05

    Following the recent restart of operations at the Y-12 Plant, the Radiological Control Organization (RCO) observed that the enriched uranium exposures appeared to involve insoluble rather than soluble uranium that presumably characterized most earlier Y-12 operations. These observations necessitated changes in the bioassay program, particularly the need for routine fecal sampling. In addition, it was not reasonable to interpret the bioassay data using metabolic parameter values established during earlier Y-12 operations. Thus, the recent urinary and fecal bioassay data were interpreted using the default guidance in Publication 54 of the International Commission on Radiological Protection (ICRP); that is, inhalation of Class Y uranium with an activity median aerodynamic diameter (AMAD) of 1 {micro}m. Faced with apparently new workplace conditions, these actions were appropriate and ensured a cautionary approach to worker protection. As additional bioassay data were accumulated, it became apparent that the data were not consistent with Publication 54. Therefore, this study was undertaken to examine the situation.

  18. Geochemistry of Rare Earth Elements in Xikeng Ag-Pb-Zn Ore Deposit, South Anhui, China

    Institute of Scientific and Technical Information of China (English)

    2000-01-01

    In this paper, a comparative study is done on the geochemical charateristics of REE in ore, ore-hosted rocks of Lantian group, granite related to ore deposit, and altered rocks for tracing origin of ore-forming materials. The result indicates that the ore-forming fluid and ore-forming materials for Xikeng silver-polymetallic ore deposit were derived from Yixian granite's magmatic activity. Water-rock reaction of the hydrothermal fluid with the carbonate-rich stratum led the altered rock to relatively enrich in HREE.

  19. Studies on Sulfating Roasting Process for Mianning Bastnasite and Baotou Mixed RE Concentrate Ore

    Institute of Scientific and Technical Information of China (English)

    Miao Guangli

    2004-01-01

    Some processes of sulfating roasting and water leaching of crude Mianning RE concentrate ore, of fine Mianning RE concentrate ore, of Baotou RE concentrate ore and of their mixture were investigated.The result shows that the mixture of Mianning and Baotou RE concentrate ore has the optimum leaching rate and rate of recovery when the mixture ratio is 1:4.The recovery rate of the mixture is higher by 14.76% than that of crude Mianning RE concentrate ore, by 5.0 % than that of Mianning fine RE concentrate ore and by 2.4 % than that of Baotou RE concentrate ore.

  20. Experimental study on preferential solution flow during dump leaching of low-grade ores

    Institute of Scientific and Technical Information of China (English)

    YIN Sheng-hua; WU Ai-xiang; SU Yong-ding; ZHANG Jie

    2007-01-01

    The phenomenon of preferential solution flow during dump leaching of low-grade ores was studied. The formative mechanism of preferential solution flow was investigated through analyzing the relationship between permeability and ore diameter,and the relationship between surface tension and ore diameter. The preferential solution flow happened within the fine ore area when the dump was unsaturated. And it could happen within the coarse ore area when the dump became saturated. The results of experiment show that the outflow of coarse ore area increases sharply with higher applied rate. The outflow of fine ore area is greater than that of coarse ore area when the applied rate is below 3.2 L/min, and the preferential solution flow happens in fine ore area. But the preferential solution flow happens in coarse ore area when the applied rate is higher than 3.2 L/min. The result of the experiment is consistent with the mechanism analyzing.

  1. RECOVERY OF URANIUM FROM TUNGSTEN

    Science.gov (United States)

    Newnam, K.

    1959-02-01

    A method is presented for the rccovery of uranium which has adhered to tungsten parts in electromagnetic isotope separation apparatus. Such a tungsten article is dissolved electrolytically in 20% NaOH by using the tungsten article as the anode. The resulting solution, containing soluble sodium lungstate and an insoluble slime, is then filtered. The slime residue is ignited successively with sodium nitrate and sodium pyrosulfate and leashed, and the resulting filtrates are combined with the original filtrate. Uranium is then recovered from the combined flltrates by diuranate precipitation.

  2. Nuclear, uranium, reserves, sustainability, independence; Nucleaire, Uranium, reserves, durabilite, independance

    Energy Technology Data Exchange (ETDEWEB)

    Acket, C

    2007-06-15

    In order to evaluate the energy independence concerning the nuclear energy, the author takes the state of the art about the uranium. He details the fuel needs, the reserves on the base of the today available techniques, the reserves on the base of the future techniques and concludes positively on the energy independence for the nuclear. (A.L.B.)

  3. Metallogenic model of the Las Termas uranium deposit at Fiambala, Province of Catamarca, Argentina; Modelo metalogenetico del yacimiento de uranio Las Termas, Fiambala, Catamarca, Argentina

    Energy Technology Data Exchange (ETDEWEB)

    Morello, O.; Rubinstein, N.; Hongn, F.; Ferreira, L.; Anesa, J.; Arias, A.

    2011-07-01

    The Las Termas uranium-ore deposit, located in the geological province of Sierras Pampeanas, Argentina, is contained within the Precambrian metamorphic basement close to the contact with the Los Ratones Carboniferous granite. This deposit was originally linked to greisenization associated with Carboniferous magmatic activity. Nevertheless, recent data concerning pitchblende-type uraninite (113.6 Ma and 51.4 Ma) and the spatial relationship between the mineralization and Cretaceous rifting volcanism lead us to suggest a new genetic model, developed in two stages. During the first stage Carboniferous greisenization included the leaching of uranium from granite, whilst during the second stage Cretaceous rift-magmatism led to a hydrothermal system, which would have been responsible for uranium mineralization. (Author)

  4. Searching for Rich Uranium Layers of Volcanic Rocks by Measuring Potential Difference%测定电位差圈定火山岩富铀层位

    Institute of Scientific and Technical Information of China (English)

    袁富蕴; 刘峰

    2000-01-01

    (2.岩石的电位差(△Eh)控制着变价元素的地球化学行为,用差减电位法对330铀矿区393个火山岩△Eh值测量结果表明:火山岩的△Eh值可以准确地圈出铀的富集层位,铀矿化只产在△Eh值高的岩石中。%The potential difference(P.D) of rocks controls geochemical behavior of the element whose valence can change.393volcanic rocks are survied in the 330 uranium ore district by the potential difference method. The result shows: volcanic rocks P.D. accuratly the concetration place of uranium accumtly and uranium mineralize only in the rocks where P.D. value is high.

  5. Release behavior of uranium in uranium mill tailings under environmental conditions.

    Science.gov (United States)

    Liu, Bo; Peng, Tongjiang; Sun, Hongjuan; Yue, Huanjuan

    2017-02-28

    Uranium contamination is observed in sedimentary geochemical environments, but the geochemical and mineralogical processes that control uranium release from sediment are not fully appreciated. Identification of how sediments and water influence the release and migration of uranium is critical to improve the prevention of uranium contamination in soil and groundwater. To understand the process of uranium release and migration from uranium mill tailings under water chemistry conditions, uranium mill tailing samples from northwest China were investigated with batch leaching experiments. Results showed that water played an important role in uranium release from the tailing minerals. The uranium release was clearly influenced by contact time, liquid-solid ratio, particle size, and pH under water chemistry conditions. Longer contact time, higher liquid content, and extreme pH were all not conducive to the stabilization of uranium and accelerated the uranium release from the tailing mineral to the solution. The values of pH were found to significantly influence the extent and mechanisms of uranium release from minerals to water. Uranium release was monitored by a number of interactive processes, including dissolution of uranium-bearing minerals, uranium desorption from mineral surfaces, and formation of aqueous uranium complexes. Considering the impact of contact time, liquid-solid ratio, particle size, and pH on uranium release from uranium mill tailings, reducing the water content, decreasing the porosity of tailing dumps and controlling the pH of tailings were the key factors for prevention and management of environmental pollution in areas near uranium mines.

  6. Aluminium phosphate sulphate minerals (APS) associated with proterozoic unconformity-type uranium deposits: crystal-chemical characterisation and petrogenetic significance; Les sulfates phosphates d'aluminium hydrates (APS) dans l'environnement des gisements d'uranium associes a une discordance proterozoique: caracterisation cristallochimique et signification petrogenetique

    Energy Technology Data Exchange (ETDEWEB)

    Gaboreau, St

    2005-07-01

    Aluminium phosphate sulfate minerals (APS) are particularly widespread and spatially associated with hydrothermal clay alteration in both the East Alligator River Uranium Field (Northern Territory, Australia) and the Athabasca basin (Saskatchewan, Canada), in the environment of proterozoic unconformity-related uranium deposits (URUD). The purpose of this study is both: 1) to characterize the nature and the origin of the APS minerals on both sides of the middle proterozoic unconformity between the overlying sandstones and the underlying metamorphic basement rocks that host the uranium ore bodies, 2) to improve our knowledge on the suitability of these minerals to indicate the paleo-conditions (redox, pH) at which the alteration processes relative to the uranium deposition operated. The APS minerals result from the interaction of oxidising and relatively acidic fluids with aluminous host rocks enriched in monazite. Several APS-bearing clay assemblages and APS crystal-chemistry have also been distinguished as a function of the distance from the uranium ore bodies or from the structural discontinuities which drained the hydrothermal solutions during the mineralisation event. One of the main results of this study is that the index mineral assemblages, used in the recent literature to describe the alteration zones around the uranium ore bodies, can be theoretically predicted by a set of thermodynamic calculations which simulate different steps of fluid-rock interaction processes related to a downward penetrating of hyper-saline, oxidizing and acidic diagenetic fluids through the lower sandstone units of the basins and then into the metamorphic basement rocks. The above considerations and the fact that APS with different crystal-chemical compositions crystallized in a range of fO{sub 2} and pH at which uranium can either be transported in solution or precipitated as uraninite in the host-rocks make these minerals not only good markers of the degree of alteration of the

  7. By lithology Zbruch deposits (Lower Sarmatian Nikopol manganese ore Basin

    Directory of Open Access Journals (Sweden)

    Bogdanovich V.V.

    2010-06-01

    Full Text Available Based on lithologic-paleogeographic study Zbruch layers of Nikopol manganese ore Basin sediments described lithological and genetic types of rocks and facies conditions of formation of deposits.

  8. Microstructure of bentonite in iron ore green pellets.

    Science.gov (United States)

    Bhuiyan, Iftekhar U; Mouzon, Johanne; Schröppel, Birgit; Kaech, Andres; Dobryden, Illia; Forsmo, Seija P E; Hedlund, Jonas

    2014-02-01

    Sodium-activated calcium bentonite is used as a binder in iron ore pellets and is known to increase strength of both wet and dry iron ore green pellets. In this article, the microstructure of bentonite in magnetite pellets is revealed for the first time using scanning electron microscopy. The microstructure of bentonite in wet and dry iron ore pellets, as well as in distilled water, was imaged by various imaging techniques (e.g., imaging at low voltage with monochromatic and decelerated beam or low loss backscattered electrons) and cryogenic methods (i.e., high pressure freezing and plunge freezing in liquid ethane). In wet iron ore green pellets, clay tactoids (stacks of parallel primary clay platelets) were very well dispersed and formed a voluminous network occupying the space available between mineral particles. When the pellet was dried, bentonite was drawn to the contact points between the particles and formed solid bridges, which impart strength to the solid compact.

  9. ITABIRITE IRON ORE CONCENTRATION BY PNEUMATIC FLOTATION CELL

    Directory of Open Access Journals (Sweden)

    Angelo Quintiliano Nunes da Silva

    2015-06-01

    Full Text Available The main iron ore processing plants in Brazil operate through reverse cationic flotation. Many studies have been conducted in order to improve flotation efficiency by optimization process variables. The pneumatic flotation cell stands out due to the simplicity to and to the intense contact particle/bubble promoted by the pulp feeding system. In this study, laboratory scale and pilot were conducted using a sample of itabirite iron ore. The objectives are evaluating the performance of this device using low grade iron ore, and drawing a comparison with laboratory scale tests on conventional flotation cell. The results indicate the potential application of pneumatic flotation cell to the ore tested. Adjustments in the feed particle size and process optimizations can be performed on the concentrate, reaching Fe and SiO2 grades used by the industry

  10. Radioanalysis of RE enrichment of ion adsorption type RE ores

    CERN Document Server

    Zhao Shu Quan; Hu He Ping; Li Fu Sheng; Chen Ying Min; LiuShiMing

    2002-01-01

    Objective: To analyze the radioactivity in Rare Earth (RE) enrichment of ion adsorption type RE ores. Methods: Using HPGe-gamma spectrometer to analyze the activity ratio of gamma radionuclides in kind of samples, using FJ-2603 low background alpha, beta measurement apparatus to measure their total alpha and total beta activities, and using X-ray fluorescence spectrometer to analyze contents of La sub 2 O sub 3 and Y sub 2 O sub 3 , respectively. Results: HPGe gamma spectroscopy and X-ray fluorescence spectroscopy are simple, convenient and non-destructive methods of analyzing radionuclides and La sub 2 O sub 3 , Y sub 2 O sub 3 in RE enrichment of ion adsorption type RE ores, respectively. Conclusion: The basic data were provided for radiation protection and treatment of gas, liquid and solid waste in RE production of ion adsorption type RE ores; method and experience were provided for studying ion adsorption type RE ores

  11. Development of pulsed neutron uranium logging instrument

    Energy Technology Data Exchange (ETDEWEB)

    Wang, Xin-guang, E-mail: wangxg@upc.edu.cn [School of Geosciences, China University of Petroleum, Qingdao 266580 (China); Engineering Research Center of Nuclear Technology Application (East China Institute of Technology), Ministry of Education, Nanchang 330013 (China); Liu, Dan [China Institute of Atomic Energy, Beijing 102413 (China); Zhang, Feng [School of Geosciences, China University of Petroleum, Qingdao 266580 (China)

    2015-03-15

    This article introduces a development of pulsed neutron uranium logging instrument. By analyzing the temporal distribution of epithermal neutrons generated from the thermal fission of {sup 235}U, we propose a new method with a uranium-bearing index to calculate the uranium content in the formation. An instrument employing a D-T neutron generator and two epithermal neutron detectors has been developed. The logging response is studied using Monte Carlo simulation and experiments in calibration wells. The simulation and experimental results show that the uranium-bearing index is linearly correlated with the uranium content, and the porosity and thermal neutron lifetime of the formation can be acquired simultaneously.

  12. A geochemical assessment of possible lunar ore formation

    Science.gov (United States)

    Haskin, Larry A.; Colson, Russell O.; Vaniman, David

    The Moon apparently formed without appreciable water or other relatively volatile materials. Interior concentrations of water or other volatile substances appear to be extremely low. On Earth, water is important to the genesis of nearly all types of ores. Thus, some have reasoned that only abundant elements would occur in ore concentrations. The definition and recognition of ores on the Moon challenge the imaginations and the terrestrial perceptions of ore bodies. Lunar ores included solar-wind soaked soils, which contain abundant but dilute H, C, N, and noble gases (including He-3). Oxygen must be mined; soils contain approximately 45 percent (wt). Mainstream processes of rock formation concentrated Si, Mg, Al, Fe, and Ca, and possibly Ti and Cr. The highland surface contains approximately 70 percent (wt) feldspar (mainly CaAl2Si2O8), which can be separated from some highland soils. Small fragments of dunite were collected; dunite may occur in walls and central peaks of some craters. Theoretical extensions of observations of lunar samples suggest that the Moon may have produced ores of trace elements. Some small fragments have trace-element concentrations 104 times higher than the lunar average, indicating that effective geochemical separations occurred; processes included fractional crystallization, silicate immiscibility, vaporization and condensation, and sulfide metamorphism. Operations of these processes acting on indigenous materials and on meteoritic material in the regolith could have produced ores. Infalling carbonaceous meteorites and comets have added water and hydrocarbons that may have been cold-trapped. Vesicles in basalts, pyroclastic beads, and reported transient events suggest gag emission from the lunar interior; such gas might concentrate and transport rare elements. Large impacts may disperse ores or produce them through deposition of heat at depth and by vaporization and subsequent condensation. The main problem in assessing lunar resources is

  13. Domestic utility attitudes toward foreign uranium supply

    Energy Technology Data Exchange (ETDEWEB)

    1981-06-01

    The current embargo on the enrichment of foreign-origin uranium for use in domestic utilization facilities is scheduled to be removed in 1984. The pending removal of this embargo, complicated by a depressed worldwide market for uranium, has prompted consideration of a new or extended embargo within the US Government. As part of its on-going data collection activities, Nuclear Resources International (NRI) has surveyed 50 domestic utility/utility holding companies (representing 60 lead operator-utilities) on their foreign uranium purchase strategies and intentions. The most recent survey was conducted in early May 1981. A number of qualitative observations were made during the course of the survey. The major observations are: domestic utility views toward foreign uranium purchase are dynamic; all but three utilities had some considered foreign purchase strategy; some utilities have problems with buying foreign uranium from particular countries; an inducement is often required by some utilities to buy foreign uranium; opinions varied among utilities concerning the viability of the domestic uranium industry; and many utilities could have foreign uranium fed through their domestic uranium contracts (indirect purchases). The above observations are expanded in the final section of the report. However, it should be noted that two of the observations are particularly important and should be seriously considered in formulation of foreign uranium import restrictions. These important observations are the dynamic nature of the subject matter and the potentially large and imbalanced effect the indirect purchases could have on utility foreign uranium procurement.

  14. Uranium 2011 resources, production and demand

    CERN Document Server

    Organisation for Economic Cooperation and Development. Paris

    2012-01-01

    In the wake of the Fukushima Daiichi nuclear power plant accident, questions are being raised about the future of the uranium market, including as regards the number of reactors expected to be built in the coming years, the amount of uranium required to meet forward demand, the adequacy of identified uranium resources to meet that demand and the ability of the sector to meet reactor requirements in a challenging investment climate. This 24th edition of the “Red Book”, a recognised world reference on uranium jointly prepared by the OECD Nuclear Energy Agency and the International Atomic Energy Agency, provides analyses and information from 42 producing and consuming countries in order to address these and other questions. It offers a comprehensive review of world uranium supply and demand as well as data on global uranium exploration, resources, production and reactor-related requirements. It also provides substantive new information on established uranium production centres around the world and in countri...

  15. Uranium 2014 resources, production and demand

    CERN Document Server

    Organisation for Economic Cooperation and Development. Paris

    2014-01-01

    Published every other year, Uranium Resources, Production, and Demand, or the "Red Book" as it is commonly known, is jointly prepared by the OECD Nuclear Energy Agency and the International Atomic Energy Agency. It is the recognised world reference on uranium and is based on official information received from 43 countries. It presents the results of a thorough review of world uranium supplies and demand and provides a statistical profile of the world uranium industry in the areas of exploration, resource estimates, production and reactor-related requirements. It provides substantial new information from all major uranium production centres in Africa, Australia, Central Asia, Eastern Europe and North America. Long-term projections of nuclear generating capacity and reactor-related uranium requirements are provided as well as a discussion of long-term uranium supply and demand issues. This edition focuses on recent price and production increases that could signal major changes in the industry.

  16. Uranium 2005 Resources, Production and Demand

    CERN Document Server

    Organisation for Economic Cooperation and Development. Paris. Nuclear Energy Agency

    2006-01-01

    Published every other year, Uranium Resources, Production, and Demand, or the "Red Book" as it is commonly known, is jointly prepared by the OECD Nuclear Energy Agency and the International Atomic Energy Agency. It is the recognised world reference on uranium and is based on official information received from 43 countries. This 21st edition presents the results of a thorough review of world uranium supplies and demand as of 1st January 2005 and provides a statistical profile of the world uranium industry in the areas of exploration, resource estimates, production and reactor-related requirements. It provides substantial new information from all major uranium production centres in Africa, Australia, Central Asia, Eastern Europe and North America. Projections of nuclear generating capacity and reactor-related uranium requirements through 2025 are provided as well as a discussion of long-term uranium supply and demand issues. This edition focuses on recent price and production increases that could signal major c...

  17. Study on the multi-sources of ore-forming materials and ore-forming fluids in the Huize lead-zinc ore deposit

    Institute of Scientific and Technical Information of China (English)

    ZHANG Zhenliang; HUANG Zhilong; GUAN Tao; YAN Zaifei; GAO Derong

    2005-01-01

    The Huize large-sized Pb-Zn deposit in Yunnan Province, China, is characterized by favorable metallogenic background and particular geological settings. This suggested that the ore-forming mechanism is relatively unique. On the basis of geological features such as the contents of mineralization elements, the REE concentrations of gangue calcites, the REE concentrations of calcite veins in the NE-trending tectonic zone and the Pb, Sr, C, H and O isotopic compositions of different minerals, this paper presents that the ore-forming materials and ore-forming fluids of the deposit were derived from various types of strata or rocks. This is a very significant conclusion for us to further discuss the mineralization mechanism of the deposit at depth and establish an available genetic model.

  18. KEY ROLE OF METALLOGENIC THEORY OF POLYGENETIC COMPOUND ORE DEPOSITS IN LOCATION PREDICTION OF HIDDEN ORE DEPOSITS IN DIWA REGIONS

    Institute of Scientific and Technical Information of China (English)

    PENG; Sheng-lin; LIU; Liang-ming; LAI; Jian-qing

    2001-01-01

    The metallogenic theory of polygenetic compound ore deposit is the Important basis for location prediction of hidden ore deposits in diwa regions.It can play an important role in each step of prediction research,targeting procedure,acquiring information and integrating information.In this paper,the authors discusses how to construct geological concept by using of the metallogenic theory of polygenetic ore deposits for predicting targeting area,to arrange investigation and detection for getting enough useful information,and to analyze and integrate information for reaching a trustful prediction conclusion.According to these strategies,we conduct a successful prediction of location of hidden ore bodies in the outer of the Fenghuangshan copper mine,a principal producing mine in Tongling Cu-Au district.

  19. Transport network and flow mechanism of shallow ore-bearing magma in Tongling ore cluster area

    Institute of Scientific and Technical Information of China (English)

    DENG; Jun; WANG; Qingfei; HUANG; Dinghua

    2006-01-01

    Abundant studies revealed that shallow intrusions of the Yanshanian epoch resulted in the mass mineralization of the Tongling region. Various evidences showed there existed a concealed magma chamber at -10 km depth in the middle part of this region during Yanshanian epoch, from which the ore-forming magma was generated and then transported to the superficial layer. Yet the transport network and flow mechanism of the shallow ore-bearing magma, the key problem associ- ated with ore-forming process, was relatively little focused on. Integrate analysis of structural me- chanics, statistical fractal and geological facts suggested that NE trending high-angle fold-related thrust faults and the tessellated basement ones served as the main pathways for the shallow magma's transporting, moreover, the saddle void spaces among adjacent strata in the folds upon this fault system provided the place for magma's emplacement. So the folds in the upper part and faults in the lower part of the upper crust constituted the fluid's transport and emplacement network. During the deformation of geologic body with multi-layer structure, the layers in the upper part tended to fold when received the jacking stress from the lower part, while the lower one inclined to fault undergoing loads of the upper part. And the producing probability of this structure assemblage was highly increased in the condition, such as in the Tongling area, that the mechanic rigidity of the lower layers was stronger than that of the upper ones. For the pre-existence of fluid-conducting network, the top magma with high volatile in the magma chamber transported rapidly to the superficial layer in dyking pattern, located in the void spaces of folds, filled and reconstructed them. The sudden drop of pressure caused the fluid unmixing from the magma and mass ore-forming elements concentration. Pulse activity of the dyking may be the principal reason why magmatic bodies in the Tongling area were spatially

  20. Synthesis of uranium fluorides from uranium dioxide with ammonium bifluoride and ammonolysis of uranium fluorides to uranium nitrides

    Science.gov (United States)

    Yeamans, Charles Burnett

    This work presents the chemical conversion of uranium oxides to uranium fluorides, and their subsequent conversion to uranium nitrides. Uranium dioxide reacts with ammonium bifluoride at 20°C to form compound in the ammonium-uranium fluoride chemical system. This reaction occurs between solid uranium dioxide at the surface of the particles and ammonium fluoride vapor. A shrinking-sphere model demonstrated surface reaction kinetics, not mass transport by diffusion through the product layer, limit the reaction rate when the starting material consists of 100 mum uranium dioxide particles. Powder x-ray diffraction showed the reaction to be complete within 8 hours, with (NH4) 4UF8 the reaction product. High-resolution electron microcopy revealed the product is largely amorphous on a micrometer-scale, but contains well-formed crystal domains on the order of 10x10 nm. X-ray diffraction showed the reaction progresses though beta-NH4UF5, delta-(NH 4)2UF6, and gamma-(NH4)2UF6 intermediate phases before finally forming (NH4)4UF 8. Modeling the system as a series of first-order reaction suggested a fourth intermediate, possibly UF4, is likely to occur. The reaction of (NH4)4UF8 with ammonia gas at 800°C forms alpha-U2N3/UN2 solid solution products with a composition of UN1.83. The x-ray powder diffraction pattern of this product is the fcc pattern commonly referenced as that of UN2 and the lattice parameter was 0.53050 nm. Surface area increased by a factor of ten during ammonolysis, consistent with the action of a hydriding agent. The alpha-U2N 3/UN2 solid solution system formed contained 1 wt% UO 2 as an impurity. Upon subsequent heating to 1150°C for 4.5 hours under argon, the nitride sample formed UN with a UO2 impurity of 9 wt%. Based on the HRTEM images, oxidation in the UN product appears to be limited to within 20 nm of particle surfaces and grain boundaries.

  1. Ferrite grade iron oxides from ore rejects

    Indian Academy of Sciences (India)

    K S Rane; V M S Verenkar; P Y Sawant

    2001-06-01

    Iron oxyhydroxides and hydroxides were synthesized from chemically beneficiated high SiO2/Al2O3 low-grade iron ore (57.49% Fe2O3) rejects and heated to get iron oxides of 96–99.73% purity. The infrared band positions, isothermal weight loss and thermogravimetric and chemical analysis established the chemical formulas of iron-oxyhydroxides as -FeOOH.0.3H2O; -FeOOH.0.2H2O and amorphous FeOOH. The thermal products of all these were -Fe2O3 excepting that of -FeOOH.0.3H2O which gave mainly -Fe2O3 and some admixture of -Fe2O3. The hydrazinated iron hydroxides and oxyhydroxides, on the other hand, decomposed autocatalytically to mainly -Fe2O3. Hydrazine method modifies the thermal decomposition path of the hydroxides. The saturation magnetization, s, values were found to be in the range 60–71 emu g–1 which are close to the reported values for -Fe2O3. Mechanism of the -Fe2O3 formation by hydrazine method is discussed.

  2. Uranium Immobilization in Wetland Soils

    Science.gov (United States)

    Jaffe, Peter R.; Koster van Groos, Paul G.; Li, Dien; Chang, Hyun-Shik; Seaman, John C.; Kaplan, Daniel I.; Peacock, Aaron D.; Scheckel, Kirk

    2014-05-01

    In wetlands, which are a major feature at the groundwater-surface water interface, plants deliver oxygen to the subsurface to keep root tissue aerobic. Some of this oxygen leaches into the rhizosphere where it will oxidize iron that typically precipitates on or near roots. Furthermore, plans provide carbon via root exudates and turnover, which in the presence of the iron oxides drives the activity of heterotrophic iron reducers in wetland soils. Oxidized iron is an important electron acceptor for many microbially-driven transformations, which can affect the fate and transport of several pollutants. It has been shown that heterotrophic iron reducing organisms, such as Geobacter sp., can reduce water soluble U(VI) to insoluble U(IV). The goal of this study was to determine if and how iron cycling in the wetland rhizosphere affects uranium dynamics. For this purpose, we operated a series of small-scale wetland mesocosms in a greenhouse to simulate the discharge of uranium-contaminated groundwater to surface waters. The mesocosms were operated with two different Fe(II) loading rates, two plant types, and unplanted controls. The mesocosms contained zones of root exclusion to differentiate between the direct presence and absence of roots in the planted mesocosms. The mesocosms were operated for several month to get fully established, after which a U(VI) solution was fed for 80 days. The mesocosms were then sacrificed and analyzed for solid-associated chemical species, microbiological characterization, micro-X-ray florescence (µ-XRF) mapping of Fe and U on the root surface, and U speciation via X-ray Absorption Near Edge Structure (XANES). Results showed that bacterial numbers including Geobacter sp., Fe(III), as well as total uranium, were highest on roots, followed by sediments near roots, and lowest in zones without much root influence. Results from the µ-XRF mapping on root surfaces indicated a strong spatial correlation between Fe and U. This correlation was

  3. Contribution to the methods for estimating uranium deposits (1963); Contribution aux methodes d'estimation des gisements d'uranium (1963)

    Energy Technology Data Exchange (ETDEWEB)

    Carlier, A. [Commissariat a l' Energie Atomique, Fontenay-aux-Roses (France). Centre d' Etudes Nucleaires

    1964-02-15

    Having defined a deposit of economic value according to the marginal theory, the author discriminates several categories of ore reserves according to the degree of knowledge of the deposit and according to the mining stage where the ore is considered. He dismisses the conventional French classification of 'on sight', 'probable' and 'possible' ore categories and suggests more suitable ones. The 'sensu stricto', ore reserves are those for which the random error can be calculated. The notion of the natural contrast of grades in an ore deposit (absolute dispersion coefficient {alpha}) is introduced in relation to this topic. The author considers three types of mining exploration. The first is the random exploration so often met; the second is the logical exploration based on a systematic location of underground works, bore-holes, etc. The third, and hardest to achieve, is the one which minimizes exploration costs for a given level of accuracy. Part of the publication deals with sampling errors such as those resulting from the quartering of a heap of ore (theory of Pierre GY) or those resulting from the use of radiometric measurement of grade. Another part deals with the extension error (entailed by the assimilation of samples to the deposit they are issued from) and gives the essential formulae in order to appraise the random error (Geo-statistics of Matheron). As to the estimator itself the work shows how the disharmony between the ore sample and the associated influence zone can be solved by the way of 'kriging'. The thesis gives numerous examples of the various numerical parameters, characteristics of an uranium deposit (absolute dispersion coefficient) or of an uranium ore (liberation parameter) as well as a few examples of linear correlations between gamma radioactivity and uranium grade. Three complete examples of reserve evaluation are given. The end of the thesis deals with the notion of ruin risk which has to

  4. Uranium isotopes fingerprint biotic reduction

    Science.gov (United States)

    Stylo, Malgorzata; Neubert, Nadja; Wang, Yuheng; Monga, Nikhil; Romaniello, Stephen J.; Weyer, Stefan; Bernier-Latmani, Rizlan

    2015-01-01

    Knowledge of paleo-redox conditions in the Earth’s history provides a window into events that shaped the evolution of life on our planet. The role of microbial activity in paleo-redox processes remains unexplored due to the inability to discriminate biotic from abiotic redox transformations in the rock record. The ability to deconvolute these two processes would provide a means to identify environmental niches in which microbial activity was prevalent at a specific time in paleo-history and to correlate specific biogeochemical events with the corresponding microbial metabolism. Here, we demonstrate that the isotopic signature associated with microbial reduction of hexavalent uranium (U), i.e., the accumulation of the heavy isotope in the U(IV) phase, is readily distinguishable from that generated by abiotic uranium reduction in laboratory experiments. Thus, isotope signatures preserved in the geologic record through the reductive precipitation of uranium may provide the sought-after tool to probe for biotic processes. Because uranium is a common element in the Earth’s crust and a wide variety of metabolic groups of microorganisms catalyze the biological reduction of U(VI), this tool is applicable to a multiplicity of geological epochs and terrestrial environments. The findings of this study indicate that biological activity contributed to the formation of many authigenic U deposits, including sandstone U deposits of various ages, as well as modern, Cretaceous, and Archean black shales. Additionally, engineered bioremediation activities also exhibit a biotic signature, suggesting that, although multiple pathways may be involved in the reduction, direct enzymatic reduction contributes substantially to the immobilization of uranium. PMID:25902522

  5. Reactive transport modeling at uranium in situ recovery sites: uncertainties in uranium sorption on iron hydroxides

    Science.gov (United States)

    Johnson, Raymond H.; Tutu, Hlanganani; Brown, Adrian; Figueroa, Linda; Wolkersdorfer, Christian

    2013-01-01

    Geochemical changes that can occur down gradient from uranium in situ recovery (ISR) sites are important for various stakeholders to understand when evaluating potential effects on surrounding groundwater quality. If down gradient solid-phase material consists of sandstone with iron hydroxide coatings (no pyrite or organic carbon), sorption of uranium on iron hydroxides can control uranium mobility. Using one-dimensional reactive transport models with PHREEQC, two different geochemical databases, and various geochemical parameters, the uncertainties in uranium sorption on iron hydroxides are evaluated, because these oxidized zones create a greater risk for future uranium transport than fully reduced zones where uranium generally precipitates.

  6. Characteristics and origin of ore-forming fluids of Jinchangqing gold (copper) ore deposit (s) in Xiangyun, Yunnan Province

    Institute of Scientific and Technical Information of China (English)

    HE Mingqin; SONG Huanbin; LIU Jiajun; LI Chaoyang

    2005-01-01

    On the basis of results of the studies of primary fluid inclusions, and the hydrogen and oxygen isotope data, the authors concluded that the early-stage ore-forming fluid from the Jinchangqing gold (copper) ore deposit is a kind of sulfate type hot brine characterized by medium temperature and salinity, genetically related to the late-stage ore-forming fluid derived from an acidic and more reductive environment. However, the late-stage ore-forming fluid is a sort of low temperature and low salinity chloride-type hot brine which originated from a lower pressure, acidic and more oxidative environment. In general, the ore fluids were derived from the late-stage, or largely from the early-stage groundwater-derived meteoric water, which has a 12‰-17‰ heavier oxygen isotopic composition than the original rain water (δ 18 O= -15.3‰ ), and were formed during gold mineralization as a product of oxygen isotope exchange during the reaction between ore-forming fluid and wall rocks under a lower water/rock ratio condition.

  7. Uranium exploration in the vicinity of abandoned fluorite mines, in northern Thailand, using cellulose nitrate films

    Energy Technology Data Exchange (ETDEWEB)

    Wattananikorn, K.; Asnachinda, P.; Lamphunphong, S. (Chiangmai Univ. (Thailand))

    1990-01-01

    Ground radon measurements using LR-115 type 2 as detectors were carried out covering an area of approx. 3.5 km{sup 2} in the vicinity of abandoned fluorite mines in northern Thailand. Each detector was enclosed in a PVC tube buried at a constant depth at each measuring station. Nine anomalies of {alpha}-track values were found covering an area of approx. 12000 m{sup 2}. Most of the anomalies were related closely to quartz veins, fluorite veins and faults. Three out of these nine anomalies showed corresponding distinct {gamma}-ray activities. The maximum {alpha}-track anomaly occurred at station P18, having a track density of 58685 t/cm{sup 2}.d. A small uranium-bearing quartz vein, about 10 cm wide and 2 m long, was subsequently discovered outcropping close to the station. The vein consists of quartz, fluorite and a secondary uranium mineral, torbernite. The maximum uranium content in the ore samples was found to be as much as 14%. (author).

  8. Uranium Isotope Fractionation during Adsorption, (Co)precipitation, and Biotic Reduction.

    Science.gov (United States)

    Dang, Duc Huy; Novotnik, Breda; Wang, Wei; Georg, R Bastian; Evans, R Douglas

    2016-12-06

    Uranium contamination of surface environments is a problem associated with both U-ore extraction/processing and situations in which groundwater comes into contact with geological formations high in uranium. Apart from the environmental concerns about U contamination, its accumulation and isotope composition have been used in marine sediments as a paleoproxy of the Earth's oxygenation history. Understanding U isotope geochemistry is then essential either to develop sustainable remediation procedures as well as for use in paleotracer applications. We report on parameters controlling U immobilization and U isotope fractionation by adsorption onto Mn/Fe oxides, precipitation with phosphate, and biotic reduction. The light U isotope ((235)U) is preferentially adsorbed on Mn/Fe oxides in an oxic system. When adsorbed onto Mn/Fe oxides, dissolved organic carbon and carbonate are the most efficient ligands limiting U binding resulting in slight differences in U isotope composition (δ(238)U = 0.22 ± 0.06‰) compared to the DOC/DIC-free configuration (δ(238)U = 0.39 ± 0.04‰). Uranium precipitation with phosphate does not induce isotope fractionation. In contrast, during U biotic reduction, the heavy U isotope ((238)U) is accumulated in reduced species (δ(238)U up to -1‰). The different trends of U isotope fractionation in oxic and anoxic environments makes its isotope composition a useful tracer for both environmental and paleogeochemical applications.

  9. Pollution of the stream waters and sediments associated with the Crucea uranium mine (East Carpathians, Romania)

    Science.gov (United States)

    Petrescu, L.; Bilal, E.; Iatan, E. L.

    2009-04-01

    Uranium and thorium are omnipresent in our environment. Various anthropogenic activities involving the processing or use of materials rich in uranium may modify the natural abundance of uranium in water. The study is related to uranium mineralization located within Crucea ore deposit, in the East Carpathians, Romania. The Crucea uranium ore deposit is located in the eastern part of the Bistrita Mountains (40 Km southeast of the town of Vatra Dornei) in the headwaters of Crucea, Lesu and Livezi valleys. At present, this is the largest uranium mine in the country. In the past, the mining area covered 18 km2, but was gradually overtaken by logging activities. The exploration and mining facilities include thirty-two galleries, situated between 780 and 1040 m above sea level. Radioactive waste resulted from mining are disposed next to the mining facilities. The waste rock was disposed in piles of variable size that are spread over an area of 364,000 m2. Older dumps (18) have been already naturally reclaimed by forest vegetation. The vegetation cover played an important role in stabilizing the waste dump cover and in slowing down the uranium migration processes. A number of 46 water samples were taken in order to evaluate the impact of ore deposit (including its exploitation process) on the chemical composition of waters down to the exploitation galleries. The sediment samples were collected at 16 sampling points from the bottom of the studied stream waters. ICP-OES, XRF and IC methods was used to evaluate the impact of uranium mine dumps on the surface waters from Crucea region. According to the analytical data the stream waters showed a Ca - carbonate character. In relation to salinity, the pH and the anion NO3-, CO32-and SO42- contents display generally non-linear relationships with chloride. Uranium is the most significant trace element in the river waters nearby the waste rock dumps, sometimes reaching levels up to 1-mgṡL-1, well in excess of the Romanian

  10. Inherently safe in situ uranium recovery.

    Energy Technology Data Exchange (ETDEWEB)

    Krumhansl, James Lee; Beauheim, Richard Louis; Brady, Patrick Vane; Arnold, Bill Walter; Kanney, Joseph F.; McKenna, Sean Andrew

    2009-05-01

    Expansion of uranium mining in the United States is a concern to some environmental groups and sovereign Native American Nations. An approach which may alleviate some problems is to develop inherently safe in situ uranium recovery ('ISR') technologies. Current ISR technology relies on chemical extraction of trace levels of uranium from aquifers that, once mined, can still contain dissolved uranium and other trace metals that are a health concern. Existing ISR operations are few in number; however, high uranium prices are driving the industry to consider expanding operations nation-wide. Environmental concerns and enforcement of the new 30 ppb uranium drinking water standard may make opening new mining operations more difficult and costly. Here we propose a technological fix: the development of inherently safe in situ recovery (ISISR) methods. The four central features of an ISISR approach are: (1) New 'green' leachants that break down predictably in the subsurface, leaving uranium, and associated trace metals, in an immobile form; (2) Post-leachant uranium/metals-immobilizing washes that provide a backup decontamination process; (3) An optimized well-field design that increases uranium recovery efficiency and minimizes excursions of contaminated water; and (4) A combined hydrologic/geochemical protocol for designing low-cost post-extraction long-term monitoring. ISISR would bring larger amounts of uranium to the surface, leave fewer toxic metals in the aquifer, and cost less to monitor safely - thus providing a 'win-win-win' solution to all stakeholders.

  11. Occurrence of fungus Rhizopus sp in bioassays with Allium cepa germinated in the presence of uranium to study the effect of natural radioactivity

    Energy Technology Data Exchange (ETDEWEB)

    Xavier, Magno N.; Oliveira, Andressa L.; Maffei, Eliane M.D.; Campos, Simara S., E-mail: simaracampos@gmail.com [Universidade Estadual do Sudoeste da Bahia (UESB), Vitoria da Conquista, BA (Brazil). Departamento de Ciencias Exatas e Tecnologicas; Gennari, Roseli F. [Universidade de Sao Paulo (USP), SP (Brazil). Instituto de Fisica. Departamento de Fisica Nuclear

    2015-07-01

    The demographic and global economic growth has promoted increasing power consumption. In this context, several studies point to nuclear energy as being promising to meet such demand. Although Brazil composes the seventh position in the world ranking of uranium reserves, the ore is still little explored in Brazil, considering its vast existing arsenal. On the one hand, despite nuclear energy has brought great benefits, technological and socio-economic development, it generates controversy about environmental contamination and risks to public health. Studies on this subject indicate that areas where uranium ore concentration is high, natural environmental radiation exposure levels are already higher than in other regions. The aim of this study is to observe the simple germination of the bio-indicator (Allium cepa), typically used to assess potential chromosomal aberrations, suffer any adverse effect caused by natural radiation uranium. The choice of this bio-indicator is based on its potential for evaluating the mutation caused by countless chemical compounds. Four treatments with three replicates were designed. In each treatment, 10 seeds of onion A. cepa without any pesticides were packed in the Petri dish lined with germination paper and room temperature (25°C) was kept until the root reaches approximately 1cm long. As a result, growth of the fungus Rhizopus sp was observed, in the experiments where uranium ore was added. It is important to mention according to the literature, this fungus can cause serious infections (and often fatal) in humans and animals, due to its high growth rate and also to their ability on surviving in relatively high temperatures. (author)

  12. Fluorosilicone and silicone o-ring aging study.

    Energy Technology Data Exchange (ETDEWEB)

    Bernstein, Robert; Gillen, Kenneth T.

    2007-10-01

    Fluorosilicone o-ring aging studies were performed. These studies examined the compressive force loss of fluorosilicone o-rings at accelerated (elevated) temperatures and were then used to make predictions about force loss at room temperature. The results were non-Arrhenius with evidence for a lowering in Arrhenius activation energies as the aging temperature was reduced. The compression set of these fluorosilicone o-rings was found to have a reasonably linear correlation with the force loss. The aging predictions based on using the observed curvature of the Arrhenius aging plots were validated by field aged o-rings that yielded degradation values reasonably close to the predictions. Compression set studies of silicone o-rings from a previous study resulted in good correlation to the force loss predictions for the fluorosilicone o-rings from this study. This resulted in a preliminary conclusion that an approximately linear correlation exists between compression set and force decay values for typical fluorosilicone and silicone materials, and that the two materials age at similar rates at low temperatures. Interestingly, because of the observed curvature of the Arrhenius plots available from longer-term, lower temperature accelerated exposures, both materials had faster force decay curves (and correspondingly faster buildup of compression set) at room temperature than anticipated from typical high-temperature exposures. A brief study on heavily filled conducting silicone o-rings resulted in data that deviated from the linear relationship, implying that a degree of caution must be exercised about any general statement relating force decay and compression set.

  13. Studying uranium migration in natural environment: experimental approach and geochemical modeling; Etude de la migration de l'uranium en milieu naturel: approche experimentale et modelisation geochimique

    Energy Technology Data Exchange (ETDEWEB)

    Phrommavanh, V.

    2008-10-15

    The present study deals with characterizing uranium migration in a limited zone of Le Bouchet site, a former uranium ore treatment facility, which is dismantled and the rehabilitation of which is under process. Some wastes are packed in a rehabilitated disposal nearby, called the Itteville site. In the framework of the monitoring of the deposit environment (air, water, sediment) set by prefectorial decrees, a piezometer (PZPK) located downstream to the latter, has shown total dissolved uranium peaks each winter since the 1990's. PZPK collects both the interstitial water of a calcareous peat formation, between the surface and 3 m, and an alluvial aquifer near 6 m of depth. Firstly, a hydrogeochemical characterization of the site has evidenced the uranium source term, which is present in the peat soil near 0.8 m, hence excluding any leaching from the waste disposal. Actually, a few microparticles of uranium oxide and mixed uranium-thorium oxide have been detected, but they do not represent the major part of the source term. Secondly, water chemistry of the peat soil water and PZPK has been monitored every two months from 2004 to 2007 in order to understand the reasons of the seasonal fluctuations of [U]tot.diss.. Completed with geochemical modeling and a bacterial identification by 16S rDNA sequence analysis, water chemistry data showed an important sulfate-reducing bacterial activity in summertime, leading to reducing conditions and therefore, a total dissolved uranium content limited by the low solubility of uraninite U{sup IV}O{sub 2}(s). In wintertime, the latter bacterial activity being minimal and the effective pluviometry more important, conditions are more oxidant, which favors U(VI), more soluble, notably as the Ca{sub 2}UO{sub 2}(CO{sub 3}){sub 3}(aq) complex, evidenced by TRLFS. Finally, bacterial activity has been reproduced in laboratory in order to better characterize its impact on uranium solubility in the peat soil. Various parameters were tested

  14. Depleted uranium: Metabolic disruptor?; Uranium appauvri: perturbateur metabolique?

    Energy Technology Data Exchange (ETDEWEB)

    Souidi, Maamar; Dublineau, Isabelle; Lestaevel, Philippe [Institut de Radioprotection et de Surete Nucleaire - IRSN, Direction de la radioprotection de l' homme, Laboratoire de radiotoxicologie experimentale, Service de radiobiologie et d' epidemiologie, BP 17, 92262 Fontenay-aux-Roses cedex (France)

    2011-11-15

    The presence of uranium in the environment can lead to long-term contamination of the food chain and of water intended for human consumption and thus raises many questions about the scientific and societal consequences of this exposure on population health. Although the biological effects of chronic low-level exposure are poorly understood, results of various recent studies show that contamination by depleted uranium (DU) induces subtle but significant biological effects at the molecular level in organs including the brain, liver, kidneys and testicles. For the first time, it has been demonstrated that DU induces effects on several metabolic pathways, including those metabolizing vitamin D, cholesterol, steroid hormones, acetylcholine and xenobiotics. This evidence strongly suggests that DU might well interfere with many metabolic pathways. It might thus contribute, together with other man-made substances in the environment, to increased health risks in some regions. (authors)

  15. Reports on investigations of uranium anomalies. National Uranium Resource Evaluation

    Energy Technology Data Exchange (ETDEWEB)

    Goodknight, C.S.; Burger, J.A. (comps.)

    1982-10-01

    During the National Uranium Resource Evaluation (NURE) program, conducted for the US Department of Energy (DOE) by Bendix Field Engineering Corporation (BFEC), radiometric and geochemical surveys and geologic investigations detected anomalies indicative of possible uranium enrichment. Data from the Aerial Radiometric and Magnetic Survey (ARMS) and the Hydrogeochemical and Stream-Sediment Reconnaissance (HSSR), both of which were conducted on a national scale, yielded numerous anomalies that may signal areas favorable for the occurrence of uranium deposits. Results from geologic evaluations of individual 1/sup 0/ x 2/sup 0/ quadrangles for the NURE program also yielded anomalies, which could not be adequately checked during scheduled field work. Included in this volume are individual reports of field investigations for the following six areas which were shown on the basis of ARMS, HSSR, and (or) geologic data to be anomalous: (1) Hylas zone and northern Richmond basin, Virginia; (2) Sischu Creek area, Alaska; (3) Goodman-Dunbar area, Wisconsin; (4) McCaslin syncline, Wisconsin; (5) Mt. Withington Cauldron, Socorro County, New Mexico; (6) Lake Tecopa, Inyo County, California. Field checks were conducted in each case to verify an indicated anomalous condition and to determine the nature of materials causing the anomaly. The ultimate objective of work is to determine whether favorable conditions exist for the occurrence of uranium deposits in areas that either had not been previously evaluated or were evaluated before data from recent surveys were available. Most field checks were of short duration (2 to 5 days). The work was done by various investigators using different procedures, which accounts for variations in format in their reports. All papers have been abstracted and indexed.

  16. Uranium triflate complexes; Complexes triflates de l'uranium

    Energy Technology Data Exchange (ETDEWEB)

    Berthet, J.C.; Ephritikhine, M. [CEA Saclay, Dept. de Recherche sur l' Etat Condense, les Atomes et les Molecules, Lab. de Chimie de Coordination, 91 - Gif sur Yvette (France); Nierlich, M. [CEA Saclay, Dept. de Recherche sur l' Etat Condense, les Atomes et les Molecules, Lab. de Cristallochimie, 91 - Gif sur Yvette (France)

    2002-02-01

    Uranium triflate complexes. We review here the different preparations of uranium triflates that we have developed in the course of these last years in our laboratory. Protonation of [U]-R and [U]-NR{sub 2} (R=alkyl) bonds with pyridinium triflate constitutes a general and efficient route towards triflate complexes. This method is very suitable for the preparation of organometallic compounds such as U(Cp){sub 3}(OTf), U(Cp){sub 2}(OTf){sub 2}(py), U(Cp{sup *}){sub 2}(OTf){sub 2}, and U(Cot)(OTf){sub 2}(py), which have been crystallographically characterised. The homoleptic species U(OTf){sub n} (n=3,4) are easily prepared by heating a mixture of uranium turnings or UH{sub 3} in triflic acid. By adjusting the temperature to 120 or 180 deg C, either U(OTf){sub 3} or U(OTf){sub 4} is isolated. Treatment of UO{sub 3} with pure or aqueous solution of triflic acid leads to the non-solvated uranyl triflate UO{sub 2}(OTf){sub 2}, which is more conveniently obtained by heating a suspension of UO{sub 3} in triflic anhydride. This reactant is an excellent dehydrating agent and enables the preparation of UO{sub 2}(OTf){sub 2} and Ce(OTf){sub 4} from the hydrated starting materials. (authors)

  17. Derivation of residual radioactive material guidelines for uranium in soil at the Middlesex Sampling Plant Site, Middlesex, New Jersey

    Energy Technology Data Exchange (ETDEWEB)

    Dunning, D.E. [Argonne National Lab., IL (United States). Environmental Assessment Div.

    1995-02-01

    Residual radioactive material guidelines for uranium in soil were derived for the Middlesex Sampling Plant (MSP) site in Middlesex, New Jersey. This site has been designated for remedial action under the Formerly Utilized Sites Remedial Action Program (FUSRAP) of the US Department of Energy. The site became contaminated from operations conducted in support of the Manhattan Engineer District (MED) and the Atomic Energy Commission (AEC) between 1943 and 1967. Activities conducted at the site included sampling, storage, and shipment of uranium, thorium, and beryllium ores and residues. Uranium guidelines for single radioisotopes and total uranium were derived on the basis of the requirement that the 50-year committed effective dose equivalent to a hypothetical individual living or working in the immediate vicinity of the MSP site should not exceed a dose of 30 mrem/yr following remedial action for the current-use and likely future-use scenarios or a dose of 100 mrem/yr for less likely future-use scenarios. The RESRAD computer code, which implements the methodology described in the DOE manual for establishing residual radioactive material guidelines, was used in this evaluation. Four scenarios were considered for the site. These scenarios vary regarding future land use at the site, sources of water used, and sources of food consumed.

  18. Assessment of trace ground-water contaminants release from south Texas in-situ uranium solution-mining sites

    Energy Technology Data Exchange (ETDEWEB)

    Kidwell, J.R.; Humenick, M.J.

    1981-01-01

    The future of uranium solution mining in south Texas depends heavily on the industry's ability to restore production zone ground water to acceptable standards. This study investigated the extent of trace contaminant solubilization during mining and subsequent restoration attempts, first through a literature search centered on uranium control mechanisms, and then by laboratory experiments simulating the mining process. The literature search indicated the complexity of the situation. The number of possible interactions between indigenous elements and materials pointed on the site specificity of the problem. The column studies evaluated three different production area ores. Uranium, molybdenum, arsenic, vanadium, and selenium were analyzed in column effluents. After simulated mining operations were completed, uranium was found to be the most persistent trace element. However, subsequent ground water flushing of the columns could restore in-situ water to EPA recommended drinking water concentrations. Limited data indicated that ground water flowing through mined areas may solubilize molybdenum present in down gradient areas adjacent to the production zone due to increased oxidation potential of ground water if adequate restoration procedures are not followed.

  19. Determination of the concentration of radionuclides in soil and water next the uranium mine of Caetite, Bahia, Brazil

    Energy Technology Data Exchange (ETDEWEB)

    Almeida, Geangela M.; Souza, Susana O. [Federal University of Sergipe (UFS), Sao Cristovao, SE (Brazil). Dept. of Physics; Campos, Simara S.S. [State University of Southwest Bahia (UESB), Itapetinga, BA (Brazil). Dept. of Basic and Instrumental Studies; Gennari, Roseli F., E-mail: rgennari@dfn.if.usp.b [University of Sao Paulo (USP), Sao Paulo, SP (Brazil). Inst. of Physics. Dept. of Nuclear Physics

    2011-07-01

    The economic growing in Brazil is responsible for an urgent demand for energy. Uranium is the fuel used to generate nuclear power. Brazil has the sixth largest reserve of the uranium ore in the world and, nowadays there is only one mine under exploration (Uraniferous District of Lagoa Real - Caetite-BA). Some Non-Governmental Organizations (NGOs), such as Greenpeace, state that the explored uranium mine is dangerous and polluting, causing water contamination by uranium. So, the population would be receiving radiation doses above permissible limits. However, Industrias Nucleares do Brasil (INB) the company in charge of the complex extraction and production of yellow cake rejected these accusations. The main purpose of this work is the determination of the composition of natural radionuclides in the Uraniferous District of Lagoa Real in order to determine if the nearest population is exposed to environmental radiation. It was checked if there is water contamination due to the natural transport in the uranium mining surroundings. Soil and water samples from Caetite mine and also from nearby town were collected. Only one water sample collected had concentrations higher than the limits recommended by World Health Organization. The presence of radionuclides in soil samples is considered independent of mineral exploration. The effective dose rates in almost all samples are above the world average which is 2.4 mSv/y. To sum up, the presence of uranium in water and soil of the tested areas is probably due to the nature of the soil and not to the exploration of mine. (author)

  20. Maximum permissible concentrations of uranium in air

    CERN Document Server

    Adams, N

    1973-01-01

    The retention of uranium by bone and kidney has been re-evaluated taking account of recently published data for a man who had been occupationally exposed to natural uranium aerosols and for adults who had ingested uranium at the normal dietary levels. For life-time occupational exposure to uranium aerosols the new retention functions yield a greater retention in bone and a smaller retention in kidney than the earlier ones, which were based on acute intakes of uranium by terminal patients. Hence bone replaces kidney as the critical organ. The (MPC) sub a for uranium 238 on radiological considerations using the current (1959) ICRP lung model for the new retention functions is slightly smaller than for earlier functions but the (MPC) sub a determined by chemical toxicity remains the most restrictive.

  1. Deposit model for volcanogenic uranium deposits

    Science.gov (United States)

    Breit, George N.; Hall, Susan M.

    2011-01-01

    Volcanism is a major contributor to the formation of important uranium deposits both close to centers of eruption and more distal as a result of deposition of ash with leachable uranium. Hydrothermal fluids that are driven by magmatic heat proximal to some volcanic centers directly form some deposits. These fluids leach uranium from U-bearing silicic volcanic rocks and concentrate it at sites of deposition within veins, stockworks, breccias, volcaniclastic rocks, and lacustrine caldera sediments. The volcanogenic uranium deposit model presented here summarizes attributes of those deposits and follows the focus of the International Atomic Energy Agency caldera-hosted uranium deposit model. Although inferred by some to have a volcanic component to their origin, iron oxide-copper-gold deposits with economically recoverable uranium contents are not considered in this model.

  2. Uranium 2009 resources, production and demand

    CERN Document Server

    Organisation for Economic Cooperation and Development. Paris

    2010-01-01

    With several countries currently building nuclear power plants and planning the construction of more to meet long-term increases in electricity demand, uranium resources, production and demand remain topics of notable interest. In response to the projected growth in demand for uranium and declining inventories, the uranium industry – the first critical link in the fuel supply chain for nuclear reactors – is boosting production and developing plans for further increases in the near future. Strong market conditions will, however, be necessary to trigger the investments required to meet projected demand. The "Red Book", jointly prepared by the OECD Nuclear Energy Agency and the International Atomic Energy Agency, is a recognised world reference on uranium. It is based on information compiled in 40 countries, including those that are major producers and consumers of uranium. This 23rd edition provides a comprehensive review of world uranium supply and demand as of 1 January 2009, as well as data on global ur...

  3. Cellular localization of uranium in the renal proximal tubules during acute renal uranium toxicity.

    Science.gov (United States)

    Homma-Takeda, Shino; Kitahara, Keisuke; Suzuki, Kyoko; Blyth, Benjamin J; Suya, Noriyoshi; Konishi, Teruaki; Terada, Yasuko; Shimada, Yoshiya

    2015-12-01

    Renal toxicity is a hallmark of uranium exposure, with uranium accumulating specifically in the S3 segment of the proximal tubules causing tubular damage. As the distribution, concentration and dynamics of accumulated uranium at the cellular level is not well understood, here, we report on high-resolution quantitative in situ measurements by high-energy synchrotron radiation X-ray fluorescence analysis in renal sections from a rat model of uranium-induced acute renal toxicity. One day after subcutaneous administration of uranium acetate to male Wistar rats at a dose of 0.5 mg uranium kg(-1) body weight, uranium concentration in the S3 segment of the proximal tubules was 64.9 ± 18.2 µg g(-1) , sevenfold higher than the mean renal uranium concentration (9.7 ± 2.4 µg g(-1) ). Uranium distributed into the epithelium of the S3 segment of the proximal tubules and highly concentrated uranium (50-fold above mean renal concentration) in micro-regions was found near the nuclei. These uranium levels were maintained up to 8 days post-administration, despite more rapid reductions in mean renal concentration. Two weeks after uranium administration, damaged areas were filled with regenerating tubules and morphological signs of tissue recovery, but areas of high uranium concentration (100-fold above mean renal concentration) were still found in the epithelium of regenerating tubules. These data indicate that site-specific accumulation of uranium in micro-regions of the S3 segment of the proximal tubules and retention of uranium in concentrated areas during recovery are characteristics of uranium behavior in the kidney.

  4. Gamma Spectrometric Analysis of Iron Ore Samples of Arak, Iran

    Directory of Open Access Journals (Sweden)

    Reza Pourimani

    2016-09-01

    Full Text Available Introduction Iron ore is one of the most important natural raw materials that is widely used for manufacturing iron and steel. This type of ore contains various amounts of radionuclides; thus, exposing workers handling their extraction, transportation, and processing to radiation. Materials and Methods In this study, 12 ore samples (each mass weighing about 2 kg were collected from the iron ore mining areas of Arak region, Iran. The specific activities of 226Ra, 232Th, and 40K were determined usinggamma-ray spectrometry method employing high-purity germanium (HPGe detector. Results The specific activities of 226Ra, 232Th, and 40K in samples were 9.39-271.70 Bq/kg, -3 Sv/y suggested in International Commission of Radiological Protection (ICRP Publication 82. Conclusion The gamma ray spectrometric analysis showed that the specific activities of natural radionuclides in samples, except for limonite ore, were within the worldwide range. The effective dose received by workers was much lower than the maximum acceptable value (1000 μSv/y; therefore, the level of radiations in this mine had no adverse consequences for public health.

  5. Flotation technology of refractory low-grade molybdenum ore

    Institute of Scientific and Technical Information of China (English)

    Du Shuhua; Luo Zhenfu

    2013-01-01

    Because of the low grade,high oxidation rate and the accumulation of little associated metal sulfide ore in the molybdenum concentrate during flotation,the Qingyang molybdenum ore is difficult to beneflciate.The experimental studies of grinding fineness,the amount of roughing modifier,depressant and collector were completed.In the cleaning process,the contrast experiments of one regrinding.the regrinding and scrubbing,two-stage regrinding was carried.The result shows that the grade of molybdenum ore concentrate is 45.31%,the recovery is 65.98% and the rich ore ratio reaches 20.59% by the regrinding and scrubbing seven cleaning,the regrinding of concentrations from middling of molybdenum-sulfur separation.The regularly-concentrated material from the apparatus was as the middling products.Hence,ideal beneficiation index can be obtained with a rational mineral processing,which offers new beneficiating technology for the refractory low-grade molybdenum ore in China.

  6. On the use of bastnasite ore as a phosphor material

    Energy Technology Data Exchange (ETDEWEB)

    Mohapatra, M., E-mail: manojm@barc.gov.in; Natarajan, V.; Rajeswari, B.; Dhobale, A.R.; Godbole, S.V.

    2014-01-15

    Bastnasite ore obtained from Indian Rare Earth (IRE) was investigated for its possible use as a phosphor material. The material was characterized by X-ray diffraction (XRD), energy dispersive X-ray fluorescence (EDXRF), photoacoustic spectroscopy (PAS), photoluminescence (PL) and electron paramagnetic resonance spectroscopy (EPR) techniques. XRD studies revealed the semi processed ore to be consisting of single phase CeO{sub 2} with no other impurities. EDXRF studies revealed the presence of ‘Th’ and traces of ‘Sm’ along with ‘Ce’ in the sample. PAS studies revealed the presence of strong charge transfer from oxygen to cerium in the system. PL studies confirmed the presence of at least four trivalent rare earths, viz. Sm, Eu, Dy and Tb in the system in trace quantities. The emission spectrum and decay time data were evaluated. It was observed that the rare earth ions are situated at distorted sites in the system surrounded by defect centers. EPR studies confirmed the presence of Ce{sup 3+}in the system along with electron trapped in oxygen ion vacancies. CIE indices for the ore sample were evaluated and it was seen that the overall emission from the system was in the ‘magenta’ region of the visible spectrum. The emission intensities were also compared with that of commercial samples. -- Highlights: • Characterization of bastnasite ore as a phosphor material. • Role of RE impurities in the luminescence • CIE index of the bastnasite ore.

  7. Microbial Beneficiation of Salem Iron Ore Using Penicillium purpurogenum

    Science.gov (United States)

    Mishra, M.; Pradhan, M.; Sukla, L. B.; Mishra, B. K.

    2011-02-01

    High alumina and silica content in the iron ore affects coke rate, reducibility, and productivity in a blast furnace. Iron ore is being beneficiated all around the world to meet the quality requirement of iron and steel industries. Choosing a beneficiation treatment depends on the nature of the gangue present and its association with the ore structure. The advanced physicochemical methods used for the beneficiation of iron ore are generally unfriendly to the environment. Biobeneficiation is considered to be ecofriendly, promising, and revolutionary solutions to these problems. A characterization study of Salem iron ore indicates that the major iron-bearing minerals are hematite, magnetite, and goethite. Samples on average contains (pct) Fe2O3-84.40, Fe (total)-59.02, Al2O3-7.18, and SiO2-7.53. Penicillium purpurogenum (MTCC 7356) was used for the experiment . It removed 35.22 pct alumina and 39.41 pct silica in 30 days in a shake flask at 10 pct pulp density, 308 K (35 °C), and 150 rpm. In a bioreactor experiment at 2 kg scale using the same organism, it removed 23.33 pct alumina and 30.54 pct silica in 30 days at 300 rpm agitation and 2 to 3 l/min aeration. Alumina and silica dissolution follow the shrinking core model for both shake flask and bioreactor experiments.

  8. Existing State and Partitioning of Rare Earth on Weathered Ores

    Institute of Scientific and Technical Information of China (English)

    2005-01-01

    The existing state and partitioning of rare earth (RE) on weathered ores in Longnan County (LN), Xingfeng County(XF) and Ninghua County(NH) were characterized systematically by standard geological analytical methods. It is found that RE in the weathered rare earth ores exist as four phases: (a) water soluble, (b) ion-exchangeable, (c) colloidal sediment (oxides), (d) minerals, in which mainly as ion exchangeable phase, accounting for nearly 80% of total RE,with about 20% in the form of colloid sediment phase and mineral phase, but very little as aqueous soluble phase. These rare earth partitioning were mainly chosen mid-heavy RE elements, occupying above 60%, but not equal in the four phases. The mid-heavy RE elements were primarily enriched in the ion exchangeable phase up to 40%, while the containment of cerium dioxide is below 2%. The cerium deficiency occurs in the ion exchangeable phase in weathered ore. It results from that the Ce3+ is oxidized into Ce4+ and changes into CeO2. For LN ore, the containment of Y is high in weathered ore because Y-minerals are abundant in original rock.

  9. NOVEL BINDERS AND METHODS FOR AGGLOMERATION OF ORE

    Energy Technology Data Exchange (ETDEWEB)

    S.K. Kawatra; T.C. Eisele; J.A. Gurtler; C.A. Hardison; K. Lewandowski

    2004-04-01

    Many metal extraction operations, such as leaching of copper, leaching of precious metals, and reduction of metal oxides to metal in high-temperature furnaces, require agglomeration of ore to ensure that reactive liquids or gases are evenly distributed throughout the ore being processed. Agglomeration of ore into coarse, porous masses achieves this even distribution of fluids by preventing fine particles from migrating and clogging the spaces and channels between the larger ore particles. Binders are critically necessary to produce agglomerates that will not break down during processing. However, for many important metal extraction processes there are no binders known that will work satisfactorily. Primary examples of this are copper heap leaching, where there are no binders that will work in the acidic environment encountered in this process, and advanced ironmaking processes, where binders must function satisfactorily over an extraordinarily large range of temperatures (from room temperature up to over 1200 C). As a result, operators of many facilities see a large loss of process efficiency due to their inability to take advantage of agglomeration. The large quantities of ore that must be handled in metal extraction processes also means that the binder must be inexpensive and useful at low dosages to be economical. The acid-resistant binders and agglomeration procedures developed in this project will also be adapted for use in improving the energy efficiency and performance of a broad range of mineral agglomeration applications, particularly heap leaching and advanced primary ironmaking.

  10. Depleted uranium disposal options evaluation

    Energy Technology Data Exchange (ETDEWEB)

    Hertzler, T.J.; Nishimoto, D.D.; Otis, M.D. [Science Applications International Corp., Idaho Falls, ID (United States). Waste Management Technology Div.

    1994-05-01

    The Department of Energy (DOE), Office of Environmental Restoration and Waste Management, has chartered a study to evaluate alternative management strategies for depleted uranium (DU) currently stored throughout the DOE complex. Historically, DU has been maintained as a strategic resource because of uses for DU metal and potential uses for further enrichment or for uranium oxide as breeder reactor blanket fuel. This study has focused on evaluating the disposal options for DU if it were considered a waste. This report is in no way declaring these DU reserves a ``waste,`` but is intended to provide baseline data for comparison with other management options for use of DU. To PICS considered in this report include: Retrievable disposal; permanent disposal; health hazards; radiation toxicity and chemical toxicity.

  11. Miscellaneous radioactive materials detected during uranium mill tailings surveys

    Energy Technology Data Exchange (ETDEWEB)

    Wilson, M.J.

    1993-10-01

    The Department of Energy`s (DOE) Office of Environmental Restoration and Waste Management directed the Oak Ridge National Laboratory Pollutant Assessments Group in the conduct of radiological surveys on properties in Monticello, Utah, associated with the Mendaciously millsite National Priority List site. During these surveys, various radioactive materials were detected that were unrelated to the Monticello millsite. The existence and descriptions of these materials were recorded in survey reports and are condensed in this report. The radioactive materials detected are either naturally occurring radioactive material, such as rock and mineral collections, uranium ore, and radioactive coal or manmade radioactive material consisting of tailings from other millsites, mining equipment, radium dials, mill building scraps, building materials, such as brick and cinderblock, and other miscellaneous sources. Awareness of the miscellaneous and naturally occurring material is essential to allow DOE to forecast the additional costs and schedule changes associated with remediation activities. Also, material that may pose a health hazard to the public should be revealed to other regulatory agencies for consideration.

  12. ELECTROLYTIC CLADDING OF ZIRCONIUM ON URANIUM

    Science.gov (United States)

    Wick, J.J.

    1959-09-22

    A method is presented for coating uranium with zircoalum by rendering the uranium surface smooth and oxidefree, immersing it in a molten electrolytic bath in NaCI, K/sub 2/ZrF/sub 6/, KF, and ZrO/sub 2/, and before the article reaches temperature equilibrium with the bath, applying an electrolyzing current of 60 amperes per square dectmeter at approximately 3 volts to form a layer of zirconium metal on the uranium.

  13. METHOD OF PRODUCING URANIUM METAL BY ELECTROLYSIS

    Science.gov (United States)

    Piper, R.D.

    1962-09-01

    A process is given for making uranium metal from oxidic material by electrolytic deposition on the cathode. The oxidic material admixed with two moles of carbon per one mole of uranium dioxide forms the anode, and the electrolyte is a mixture of from 40 to 75% of calcium fluoride or barium fluoride, 15 to 45% of uranium tetrafluoride, and from 10 to 20% of lithium fluoride or magnesium fluoride; the temperature of the electrolyte is between 1150 and 1175 deg C. (AEC)

  14. Design of Uranium Solution Critical Experimental Device

    Institute of Scientific and Technical Information of China (English)

    YI; Da-yong; GUO; Zhi-jia; YAO; Cheng-zhi; SHI; Chen-lei

    2012-01-01

    <正>In 2012, Department of reactor engineering design completes the design and mechanical analysis of Uranium solution critical experimental device. According to user’s requirements and nuclear safety regulations, design and analysis mainly involves two sets of core structure, uranium solution loop, water loop and experimental bench, etc. The core which includes a core vessel, reactor core support, safety rods, control rods, and so on, is used for containing uranium solution and fuel element and fulfilling the

  15. In Vivo Nanodetoxication for Acute Uranium Exposure

    Directory of Open Access Journals (Sweden)

    Luis Guzmán

    2015-06-01

    Full Text Available Accidental exposure to uranium is a matter of concern, as U(VI is nephrotoxic in both human and animal models, and its toxicity is associated to chemical toxicity instead of radioactivity. We synthesized different PAMAM G4 and G5 derivatives in order to prove their interaction with uranium and their effect on the viability of red blood cells in vitro. Furthermore, we prove the effectiveness of the selected dendrimers in an animal model of acute uranium intoxication. The dendrimer PAMAM G4-Lys-Fmoc-Cbz demonstrated the ability to chelate the uranyl ion in vivo, improving the biochemical and histopathologic features caused by acute intoxication with uranium.

  16. Mitigating uranium in groundwater: prospects and limitations.

    Science.gov (United States)

    Noubactep, C; Meinrath, G; Dietrich, P; Merkel, B

    2003-09-15

    Removal of uranium(VI) by zerovalent iron has been suggested as a feasible pathway to control uranium contaminations in seepage waters. Available information in the literature however presents discrepant evidence on the process responsible for the mitigation effect. On basis of an EH-pH diagram of uranium and iron, it is outlined that these discrepancies may be explained by the aqueous chemistry of uranium and iron. Additional effects contributing to the complexity of the system are given. Solubilization experiments using scrap iron together with water works sludge, MnO2, and pyrite indicate that U(VI) is immobilized by iron corrosion products after about 50 days.

  17. Colorimetric detection of uranium in water

    Science.gov (United States)

    DeVol, Timothy A [Clemson, SC; Hixon, Amy E [Piedmont, SC; DiPrete, David P [Evans, GA

    2012-03-13

    Disclosed are methods, materials and systems that can be used to determine qualitatively or quantitatively the level of uranium contamination in water samples. Beneficially, disclosed systems are relatively simple and cost-effective. For example, disclosed systems can be utilized by consumers having little or no training in chemical analysis techniques. Methods generally include a concentration step and a complexation step. Uranium concentration can be carried out according to an extraction chromatographic process and complexation can chemically bind uranium with a detectable substance such that the formed substance is visually detectable. Methods can detect uranium contamination down to levels even below the MCL as established by the EPA.

  18. Oxidation and crystal field effects in uranium

    Energy Technology Data Exchange (ETDEWEB)

    Tobin, J. G. [Lawrence Livermore National Lab. (LLNL), Livermore, CA (United States); Booth, C. H. [Lawrence Berkeley National Lab. (LBNL), Berkeley, CA (United States); Shuh, D. K. [Lawrence Berkeley National Lab. (LBNL), Berkeley, CA (United States); van der Laan, G. [Diamond Light Source, Didcot (United Kingdom); Sokaras, D. [Stanford Synchrotron Radiation Lightsource, Stanford, CA (United States); Weng, T. -C. [Stanford Synchrotron Radiation Lightsource, Stanford, CA (United States); Yu, S. W. [Lawrence Livermore National Lab. (LLNL), Livermore, CA (United States); Bagus, P. S. [Univ. of North Texas, Denton, TX (United States); Tyliszczak, T. [Lawrence Berkeley National Lab. (LBNL), Berkeley, CA (United States); Nordlund, D. [Stanford Synchrotron Radiation Lightsource, Stanford, CA (United States)

    2015-07-06

    An extensive investigation of oxidation in uranium has been pursued. This includes the utilization of soft x-ray absorption spectroscopy, hard x-ray absorption near-edge structure, resonant (hard) x-ray emission spectroscopy, cluster calculations, and a branching ratio analysis founded on atomic theory. The samples utilized were uranium dioxide (UO2), uranium trioxide (UO3), and uranium tetrafluoride (UF4). As a result, a discussion of the role of non-spherical perturbations, i.e., crystal or ligand field effects, will be presented.

  19. The Leyden uranium prospect, Jefferson County, Colorado

    Science.gov (United States)

    Gott, Garland B.

    1950-01-01

    The Leyden uranium prospect is in sec. 28, T, 2 S., R. 70 W, Jefferson County, Cplo, Examination of the property was made in February 1950. Uranium was first reported in this locality in 1875 by Captain E. L. Berthoud, who noted uranium minerals associated with the main coal bed. The Old Leyden coal mine workings have long been abandoned and caved, but specimens of the uranium-bearing rock can be seen on the old dump 700 feet to the south. The mineralized coal bed is 10 to 12 feet thick and occurs near the base of the Laramie formation of Upper Cretaceous age. Uranium minerals are present in the form of yellow incrustations and inclusions in fractured and partly silicified coal. Petrographic studies indicate that the silica and uranium minerals were deposited after deposition and carbonization of the coal. Secondary uranium minerals also were found by C. R. Butler along the outcrop of the sandstones in the Laramie formation. No uranium minerals were found in place by the writer, but four samples from the dump contained 0.001, 0,005, 0.17 and 0.69 percent uranium.

  20. Statistical data of the uranium industry

    Energy Technology Data Exchange (ETDEWEB)

    None

    1982-01-01

    Statistical Data of the Uranium Industry is a compendium of information relating to US uranium reserves and potential resources and to exploration, mining, milling, and other activities of the uranium industry through 1981. The statistics are based primarily on data provided voluntarily by the uranium exploration, mining, and milling companies. The compendium has been published annually since 1968 and reflects the basic programs of the Grand Junction Area Office (GJAO) of the US Department of Energy. The production, reserves, and drilling information is reported in a manner which avoids disclosure of proprietary information.

  1. 从低品位、高铁含量铀矿石中提取“111”产品%Extracted from Low Grade and High Iron Content in Uranium Deposit Genesis "111"Products

    Institute of Scientific and Technical Information of China (English)

    王中东

    2014-01-01

    In this paper , with a low grade , high iron content uranium ore genesis , the low efficiency of uranium extraction by conventional acid leaching process , the cost is high , and can't production of qualified products of the ore .Through many times test research, results, solved the technical problems to produce qualified products "111".For our country the devel-opment and utilization of low grade of medium and small uranium deposit , remnant ore recovery , has provided the technical support and successful experience .%对以低品位、高铁含量铀矿石中,用常规酸浸工艺提取铀效率低、成本高,且无法生产合格产品的矿石。经多次试验研究,成功解决了该项技术难题,生产出合格的“111”产品。为我国开发利用低品位的中、小型铀矿床,进行残矿回收,提供了技术保障和成功经验。

  2. Treatment of coking wastewater by using manganese and magnesium ores.

    Science.gov (United States)

    Chen, Tianhu; Huang, Xiaoming; Pan, Min; Jin, Song; Peng, Suchuan; Fallgren, Paul H

    2009-09-15

    This study investigated a wastewater treatment technique based on natural minerals. A two-step process using manganese (Mn) and magnesium (Mg) containing ores were tested to remove typical contaminants from coking wastewater. Under acidic conditions, a reactor packed with Mn ore demonstrated strong oxidizing capability and destroyed volatile phenols, chemical oxygen demand (COD)(,) and sulfide from the coking wastewater. The effluent was further treated by using Mg ore to remove ammonium-nitrogen and phosphate in the form of magnesium ammonium phosphate (struvite) precipitates. When pH of the wastewater was adjusted to 1.2, the removal efficiencies for COD, volatile phenol and sulfide reached 70%, 99% and 100%, respectively. During the second step of precipitation, up to 94% of ammonium was removed from the aqueous phase, and precipitated in the form of struvite with phosphorus. The struvite crystals showed a needle-like structure. X-ray diffraction and transmission electron microscopy were used to characterize the crystallized products.

  3. Investigation of chemical suppressants for inactivation of sulfide ores

    Institute of Scientific and Technical Information of China (English)

    2001-01-01

    In order to investigate the effective control method of spontaneous combustion in the mining of sulfide ore deposits, This paper presents the testing results of several selected chemicals (water glass, calcium chloride, calcium oxide, magnesium oxide and their composites) as oxidation suppressants for sulfide ores. A weight increment scaling method was used to measure suppressant performance, and this method proved to be accurate, simple and convenient. Based on a large number of experiments, the test results show that four types of chemical mixtures demonstrate a good performance in reducing the oxidation rate of seven active sulfide ore samples by up to 27% to 100% during an initial 76 d period. The mixtures of water glass mixed with calcium chloride and magnesium oxide mixed with calcium chloride can also act as fire suppressants when used with fire sprinkling systems.

  4. Beneficiation of the gold bearing ore by gravity and flotation

    Science.gov (United States)

    Gül, Alim; Kangal, Olgaç; Sirkeci, Ayhan A.; Önal, Güven

    2012-02-01

    Gold concentration usually consists of gravity separation, flotation, cyanidation, or the combination of these processes. The choice among these processes depends on the mineralogical characterization and gold content of the ore. Recently, the recovery of gold using gravity methods has gained attention because of low cost and environmentally friendly operations. In this study, gold pre-concentrates were produced by the stepwise gravity separation and flotation techniques. The Knelson concentrator and conventional flotation were employed for the recovery of gold. Gold bearing ore samples were taken from Gümüşhane Region, northern east part of Turkey. As a result of stepwise Knelson concentration experiments, a gold concentrate assaying around 620 g/t is produced with 41.4wt% recovery. On the other hand, a gold concentrate about 82 g/t is obtained with 89.9wt% recovery from a gold ore assaying 6 g/t Au by direct flotation.

  5. Calcination-Digestion-Desliming of Phosphorus Ore Bearing Rare Earth

    Institute of Scientific and Technical Information of China (English)

    Zhang Qin; Zhang Jie; Wang Jing; Qiu Yue qin

    2004-01-01

    The recoveries of phosphorus and RE of ore from Zhijin in Guizhou were studied.The influences of the calcination temperature, resident time, the digested time and water volume of the calcinating on concentrate yield by desliming were also investigated by orthogonal design.Appropriate calcination temperature is initial condition that makes carbonate mineral decomposition.The recovery of phosphorus is 83.02% and rare earth is 90.56% in phosphorus concentrate when calcined temperature is 900 ℃, other conditions include: calcined time is 30 min, digestion water volume is 300 ml, digestion time is 20 min.The results show that the pre-treatment of the ore is favorable for the separation and enrichment of rare earth from phosphorus ore, and a process of calcination-digestion-desliming was promised.

  6. A hybrid decision support system for iron ore supply

    Directory of Open Access Journals (Sweden)

    A. Samolejová

    2012-01-01

    Full Text Available Many European metallurgical companies are forced to import iron ore from remote destinations. For these companies it is necessary to determine the amount of iron ore that will have to be ordered and to create such a delivery schedule so that the continuous operation of blast-furnace plant is not disrupted and there is no exceedingly large stock of this raw material. The objective of this article is to design the decision support system for iron ore supply which would effi ciently reduce uncertainty and risk of that decision-making. The article proposes a hybrid intelligent system which represents a combination of diff erent artifi cial intelligence methods with dynamic simulation technique for that purpose.

  7. Fossil bacteria in Xuanlong iron ore deposits of Hebei Province

    Institute of Scientific and Technical Information of China (English)

    DAI Yongding; SONG Haiming; SHEN Jiying

    2004-01-01

    Discovered in Early Proterozoic Xuanlong iron ore deposits are six genera of fossil iron bacteria, i. e. sphere (coenobium of) rod-shaped (monomer) Naumanniella, ellipsoid elliptical Ochrobium, sphere spherical Siderocapsa and chain spherical Siderococcus, chain rod-shaped Leptothrix and Lieskeella, and six genera of fossil blue bacteria, namely sphere spherical Gloeocapsa, Synechocystis and Globobacter, chain spherical Anabaena and Nostoc, and constrictive septate tubular Nodularia. The biomineralized monomers and coenobia of the two categories of bacteria, together with hematite plates made up the bacteria pelletal, bacteria silky,bacteria fibrous and clasty bacteria pelletal textural lamina. The bacteria pelletal laminae combined with other bacteria laminae to make up oncolite, stromatolite and laminate. The precipitation of iron oxide was accelerated due to iron and blue bacteria cohabiting on microbial film or mat. The Xuanlong iron ore deposits are microbial binding ore deposits of ocean source.

  8. Study on Chemical Speciation of Uranium in Samples from in-situ Leaching Sandstone-type Uranium Deposit in Xinjiang%新疆某地浸砂岩型铀矿中铀赋存形态的研究

    Institute of Scientific and Technical Information of China (English)

    马强; 冯志刚; 孙静; 谢二举; 李小军

    2012-01-01

    This paper presents a method of studying uranium speciation from in-situ leaching sandstone-type uranium deposits by a sequential extraction procedure and demonstrates its application to sandstone uranium exploration. The chemical extraction procedure was modified from Tessier. Uranium in samples was classified into five speciations: exchangeable ions, bound to carbonates, bound to Fe-Mn oxides, bound to sulfide-organic matter and residual speciation. The first four phases consisted of active uranium with the residual uranium being stable uranium. The results show that the uranium distribution characteristics were significantly different whether they were in different samples or in the same sample. The average amounts of residual speciation, carbonates speciation, exchangeable speciation, sulfide-organic matter speciation and Fe-Mn speciation decreased in order as 37. 75% (RSD = 1. 80% ), 20. 56% (RSD = 2. 72%), 15. 51% ( RSD = 1. 85% ), 14. 26% ( RSD = 2. 08% ) and 11.91% ( RSD = 1.75% ) , respectively. According to the present technology of acid dipped processing, the active uranium was teachable and the inert uranium was unleachable. This study indicates that residual speciation is the primary component. The uranium extraction rate for uranium ore with a high proportion of residual uranium ( such as the No.4 sample with 57.17% residual uranium in this paper) is lower and the extraction rale does not increase significantly by improving the dissolve acidity and oxidants.%以新疆某地浸砂岩型铀矿为研究对象,参考Tessier逐级化学提取方法,对10件矿芯试样进行铀赋存形态的研究.将铀赋存形态分为可交换离子态、碳酸盐结合态、铁锰氧化物结合态、硫化物及有机物结合态和残渣态,其中前4种形态铀为活性铀,残渣态铀为惰性铀.研究结果显示,无论是试样间还是同一试样内,铀的形态分布特征都存在明显的差异.各形态铀的含量(平均值)

  9. Isolation and identification of iron ore-solubilising fungus

    Directory of Open Access Journals (Sweden)

    Damase Khasa

    2010-09-01

    Full Text Available Potential mineral-solubilising fungi were successfully isolated from the surfaces of iron ore minerals. Four isolates were obtained and identified by molecular and phylogenetic methods as close relatives of three different genera, namely Penicillium (for isolate FO, Alternaria (for isolates SFC2 and KFC1 and Epicoccum (for isolate SFC2B. The use of tricalcium phosphate (Ca3(PO42in phosphate-solubilising experiments confirmed isolate FO as the only phosphate solubiliser among the isolated fungi. The bioleaching capabilities of both the fungus and its spent liquid medium were tested and compared using two types of iron ore materials, conglomerate and shale, from the Sishen Iron Ore Mine as sources of potassium (K and phosphorus (P. The spent liquid medium removed more K (a maximum of 32.94% removal, from conglomerate, than the fungus (a maximum of 21.36% removal, from shale. However, the fungus removed more P (a maximum of 58.33% removal, from conglomerate than the spent liquid medium (a maximum of 29.25% removal, from conglomerate. The results also indicated a potential relationship between the removal of K or P and the production of organic acids by the fungus. A high production of gluconic acid could be related to the ability of the fungus to reduce K and P. Acetic, citric and maleic acids were also produced by the fungus, but in lower quantities. In addition, particle size and iron ore type were also shown to have significant effects on the removal of potassium and phosphorus from the iron ore minerals. We therefore conclude that the spent liquid medium from the fungal isolate FO can potentially be used for biobeneficiation of iron ore minerals.

  10. Novel Binders and Methods for Agglomeration of Ore

    Energy Technology Data Exchange (ETDEWEB)

    S. K. Kawatra; T. C. Eisele; K. A. Lewandowski; J. A. Gurtler

    2006-12-31

    Many metal extraction operations, such as leaching of copper, leaching of precious metals, and reduction of metal oxides to metal in high-temperature furnaces, require agglomeration of ore to ensure that reactive liquids or gases are evenly distributed throughout the ore being processed. Agglomeration of ore into coarse, porous masses achieves this even distribution of fluids by preventing fine particles from migrating and clogging the spaces and channels between the larger ore particles. Binders are critically necessary to produce agglomerates that will not break down during processing. However, for many important metal extraction processes there are no binders known that will work satisfactorily. Primary examples of this are copper heap leaching, where there are no binders that will work in the acidic environment encountered in this process, and advanced ironmaking processes, where binders must function satisfactorily over an extraordinarily large range of temperatures (from room temperature up to over 1200 C). As a result, operators of many facilities see a large loss of process efficiency due to their inability to take advantage of agglomeration. The large quantities of ore that must be handled in metal extraction processes also means that the binder must be inexpensive and useful at low dosages to be economical. The acid-resistant binders and agglomeration procedures developed in this project will also be adapted for use in improving the energy efficiency and performance of a broad range of mineral agglomeration applications, particularly heap leaching and advanced primary ironmaking. This project has identified several acid-resistant binders and agglomeration procedures that can be used for improving the energy efficiency of heap leaching, by preventing the ''ponding'' and ''channeling'' effects that currently cause reduced recovery and extended leaching cycle times. Methods have also been developed for iron ore

  11. [Assessment of Soil Fluorine Pollution in Jinhua Fluorite Ore Areas].

    Science.gov (United States)

    Ye, Qun-feng; Zhou, Xiao-ling

    2015-07-01

    The contents of. soil total fluorine (TF) and water-soluble fluorine (WF) were measured in fluorite ore areas located in Jinhua City. The single factor index, geoaccumulation index and health risk assessment were used to evaluate fluorine pollution in soil in four fluorite ore areas and one non-ore area, respectively. The results showed that the TF contents in soils were 28. 36-56 052. 39 mg.kg-1 with an arithmetic mean value of 8 325.90 mg.kg-1, a geometric mean of 1 555. 94 mg.kg-1, and a median of 812. 98 mg.kg-1. The variation coefficient of TF was 172. 07% . The soil WF contents ranged from 0. 83 to 74. 63 mg.kg-1 with an arithmetic mean value of 16. 94 mg.kg-1, a geometric mean of 10. 59 mg.kg-1, and a median of 10. 17 mg.kg-1. The variation coefficient of WF was 100. 10%. The soil TF and WF contents were far higher than the national average level of the local fluorine epidemic occurrence area. The fluoride pollution in soil was significantly affected by human factors. Soil fluorine pollution in Yangjia, Lengshuikeng and Huajie fluorite ore areas was the most serious, followed by Daren fluorite ore area, and in non-ore area there was almost no fluorine pollution. Oral ingestion of soils was the main exposure route. Sensitivity analysis of model parameters showed that children's weight exerted the largest influence over hazard quotient. Furthermore, a significant positive correlation was found among the three kinds of evaluation methods.

  12. Challenges facing the North American iron ore industry

    Science.gov (United States)

    Jorgenson, J.D.

    2005-01-01

    During the 20th century, the iron ore mining industries of Canada and the United States passed through several periods of transformation. The beginning of the 21st century has seen yet another period of transformation, with the economic failure of a number of steel companies, the acquisition of their facilities by more viable steelmakers, and the consolidation of control within the North American iron ore industry. Changes in Canadian and United States iron ore production and the market control structure involved are analysed. The consolidation of ownership, formation of foreign joint ventures within Nordi America, planned divestitures of upstream activities by steelmakers, and industry changes made to ensure availability of feedstocks will be reviewed. The ttaditional isolation of the Canadian and United States iron ore operations and their strong linkage to downstream steel production will be discussed in the context of a changing global economy. Management-labour conflicts that have taken place and agreements made during 2000 through 2004 will be discussed in the context of the economic environment leading up to these agreements. Cooperative agreements between competing Canadian and United States companies to resolve client needs in processing and blending will be examined. A joint industry-government project designed to use new technology to produce direct reduced iron nuggets of 96 - 98 per cent iron content using non-coking coals will also be assessed. Changes in iron ore transportation methods, ownership and infrastructure will be reviewed for both rail and inland waterway transport between Canadian and United States companies. A brief analysis of social and environmental issues relating to sustainable development of the Canadian-United States iron ore industry will be included.

  13. Improvements made in the methods of purifying uranium compounds and in the production of uranium metal at the Bouchet plant; Ameliorations apportees aux procedes de purification des composes d'uranium et a la fabrication de l'uranium metal a l'usine du Bouchet

    Energy Technology Data Exchange (ETDEWEB)

    Decrop, J.; Delange, M.; Holder, J.; Huet, H.; Sauteron, J.; Vertes, P. [Commissariat a l' Energie Atomique, Saclay (France). Centre d' Etudes Nucleaires

    1958-07-01

    We intend to chart the development of the techniques used at the Bouchet plant since the First International Conference held in Geneva in 1955. During that Conference, the methods adopted at that time were described by B. GOLDSCHMIDT and P. VERTES. Generally speaking, the development since that time has been governed by the following factors: 1- Conversion to a mass-production scale: The metal output, which amounted to approximately 10 tons in 1952, practically doubled each year, reaching successive figures of 80 tons in 1955, 160 tons in 1956 and 300 tons in 1957. At this very moment the output capacity of the plant is approaching its maximum, set at 500 tons/year, which it will reach at the end of the year. Beyond this output figure, the work will be carried on by the second French uranium production plant, which is now being erected at Narbonne. 2- Gradual abandoning of ore treatment, resulting from the decentralization of the duties performed by the CEA; The Bouchet Plant had, as a matter of fact, the first French treatment facilities, operating on the basis of 10 to 20 tons of ore per day. This ore, first concentrated at the production site proper by means of physical or physico-chemical methods to at least a 2 per cent uranium content, was sufficiently valuable to warrant quite well the cost involved in shipping it. However, the increase in the production schedules led to the treatment of ores of lower and lower grades, and it became more profitable to proceed with the chemicalating of these low-grade ores at the site after more or less thorough grading and, if necessary, preconcentration. As a result, the Bouchet plant scarcely ever receives uranium ores; on the contrary, the mining companies send their chemical concentrates, uranous phosphate and then sodium uranate from the Gueugnon Works in Saone-et-Loire since 1955; magnesium uranate from the Ecarpiere Works in Vendee since the beginning of 1957 and, very soon, products from the works which are now being

  14. Evaluating the effectivene