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Sample records for uranium ore concentrate

  1. Determination of uranium concentration in an ore sample using laser-induced breakdown spectroscopy

    International Nuclear Information System (INIS)

    Kim, Y.-S.; Han, B.-Y.; Shin, H.S.; Kim, H.D.; Jung, E.C.; Jung, J.H.; Na, S.H.

    2012-01-01

    Laser-induced breakdown spectroscopy (LIBS) has been recognized as a promising technique for analyzing sensitive nuclear materials such as uranium, plutonium, and curium in a high-radiation environment, especially since the implementation of IAEA (International Atomic Energy Agency) safeguards. The uranium spectra of ore samples were quantitatively analyzed prior to analyzing sensitive materials in the nuclear industry. The purpose of this experiment is to extract quantitative information about the uranium in a uranium ore using a standard addition approach. The uranium ore samples containing different concentrations of U were prepared by mixing raw ore powder with natural uranium oxide powders. Calibration sets of 0.2, 0.4, 0.6, 0.8 and 1.0 wt.% uranium concentrations within the uranium ore sample were achieved. A pulsed and Q-switched Nd:YAG laser at a wavelength of 532 nm was used as a light source. An echelle spectrometer that covers a 190–420 nm wavelength range is used to generate a calibration curve and determine the detection limit of uranium in the ore matrix. The neutral atomic-emission peak at a wavelength of 356.659 nm indicated a detection limit of ∼ 158 ppm for uranium, and the uranium concentration was determined in a raw ore sample that has an unknown quantity of uranium. - Highlights: ► The feasibility of LIBS application to monitor uranium element was carried out. ► The detection limit of U in ore was determined by a standard additional approach. ► Quantitative analyses of U concentration in a natural uranium ore were performed.

  2. Uranium ores

    International Nuclear Information System (INIS)

    Poty, B.; Roux, J.

    1998-01-01

    The processing of uranium ores for uranium extraction and concentration is not much different than the processing of other metallic ores. However, thanks to its radioactive property, the prospecting of uranium ores can be performed using geophysical methods. Surface and sub-surface detection methods are a combination of radioactive measurement methods (radium, radon etc..) and classical mining and petroleum prospecting methods. Worldwide uranium prospecting has been more or less active during the last 50 years, but the rise of raw material and energy prices between 1970 and 1980 has incited several countries to develop their nuclear industry in order to diversify their resources and improve their energy independence. The result is a considerable increase of nuclear fuels demand between 1980 and 1990. This paper describes successively: the uranium prospecting methods (direct, indirect and methodology), the uranium deposits (economical definition, uranium ores, and deposits), the exploitation of uranium ores (use of radioactivity, radioprotection, effluents), the worldwide uranium resources (definition of the different categories and present day state of worldwide resources). (J.S.)

  3. New route for uranium concentrate production from Caetite ore, Bahia State, Brazil; dynamic leaching - direct precipitation

    Energy Technology Data Exchange (ETDEWEB)

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

    2007-07-01

    The common uranium concentrate production consists of ore leaching, uranium purification/concentration by solvent extraction and uranium precipitation as ammonium diuranate steps. In the present work, a new route of uranium concentrate production from Caetite, BA-Brazil ore was investigated. The following steps were investigated: dynamic leaching of the ground ore with sulfuric acid; sulfuric liquor pre-neutralization until pH 3.7; uranium peroxide precipitation. The study was carried out in bath and continuous circuits. In the dynamic leaching of ground ore in agitated tanks the uranium content in the leached ore may be as low as 100 {mu}g/g U{sub 3}O{sub 8}, depending on grinding size. In the pre-neutralization step, the iron content in the liquor is decreased in 99 wt.%, dropping from 3.62 g/L to 0.030 g/L. The sulfate content in the liquor reduces from 46 g/L to 22 g/L. A calcinated final product assaying 99.7 wt.% U{sub 3}O{sub 8} was obtained. The full process recovery was over 94%. (author)

  4. Chapter 1. General information about uranium. 1.3. Uranium ores

    International Nuclear Information System (INIS)

    Khakimov, N.; Nazarov, Kh.M.; Mirsaidov, I.U.

    2012-01-01

    The uranium ores were described. It was found that uranium ores and natural mineral formations containing uranium and its compounds, can be found in concentrations that are technically possible for industrial utilization and which are economically profitable. It was defined that oxidation levels of uranium minerals have an impact on their reprocessing technology and behavior in hydrometallurgical re partition. It was found that the chemical composition of ores has a decisive importance during selection of their reprocessing method.

  5. Recovery of uranium mineral from Liaoning Fengcheng ludwigite ore by gravity concentration

    International Nuclear Information System (INIS)

    Zhang Tao; Liang Haijun; Xue Xiangxin

    2009-01-01

    A laboratory research was carried out to recover uranium mineral from Liaoning Fengcheng ludwigite ore. Gravity concentration methods including hydroclone, spiral chute and shaking table were applied in this study. The results show that a concentrate with uranium grade of 0.216% and recovery of 44.24% could be produced from the feed of uranium content 0.006 3%. This research is helpful to comprehensive utilization of the mineral resources. Increasing further uranium mineral liberation degree is the key to improve separation effects. (authors)

  6. A discussion about maximum uranium concentration in digestion solution of U3O8 type uranium ore concentrate

    International Nuclear Information System (INIS)

    Xia Dechang; Liu Chao

    2012-01-01

    On the basis of discussing the influence of single factor on maximum uranium concentration in digestion solution,the influence degree of some factors such as U content, H 2 O content, mass ratio of P and U was compared and analyzed. The results indicate that the relationship between U content and maximum uranium concentration in digestion solution was direct ratio, while the U content increases by 1%, the maximum uranium concentration in digestion solution increases by 4.8%-5.7%. The relationship between H 2 O content and maximum uranium concentration in digestion solution was inverse ratio, the maximum uranium concentration in digestion solution decreases by 46.1-55.2 g/L while H 2 O content increases by 1%. The relationship between mass ratio of P and U and maximum uranium concentration in digestion solution was inverse ratio, the maximum uranium concentration in digestion solution decreases by 116.0-181.0 g/L while the mass ratio of P and U increase 0.1%. When U content equals 62.5% and the influence of mass ratio of P and U is no considered, the maximum uranium concentration in digestion solution equals 1 578 g/L; while mass ratio of P and U equals 0.35%, the maximum uranium concentration decreases to 716 g/L, the decreased rate is 54.6%, so the mass ratio of P and U in U 3 O 8 type uranium ore concentrate is the main controlling factor. (authors)

  7. Management of wastes from the refining and conversion of uranium ore concentrate to uranium hexafluoride

    International Nuclear Information System (INIS)

    1981-01-01

    This report is the outcome of an IAEA Advisory Group Meeting on ''Waste Management Aspects in Relation to the Refining of Uranium Ore Concentrates and their Conversion to Uranium Hexafluoride'', which was held in Vienna from 17 to 21 December 1979. The report summarizes the main topics discussed at the meeting and gives an overview of uranium refining processes, being used in nuclear industry. The meeting was organized by the International Atomic Energy Agency, Radioactive Waste Management Section

  8. Uranium abundance in some sudanese phosphate ores

    International Nuclear Information System (INIS)

    Adam, A.A.; Eltayeb, M.A.H.

    2009-01-01

    This work was carried out mainly to analysis of some Sudanese phosphate ores, for their uranium abundance and total phosphorus content measured as P 2 O 5 %. For this purpose, 30 samples of two types of phosphate ore from Eastern Nuba Mountains, in Sudan namely, Kurun and Uro areas were examined. In addition, the relationship between uranium and major, and trace elements were obtained, also, the natural radioactivity of the phosphate samples was measured, in order to characterize and differentiate between the two types of phosphate ores. The uranium abundance in Uro phosphate with 20.3% P 2 O 5 is five time higher than in Kurun phosphate with 26.7% P 2 O 5 . The average of uranium content was found to be 56.6 and 310 mg/kg for Kurun and Uro phosphate ore, respectively. The main elements in Kurun and Uro phosphate ore are silicon, aluminum, and phosphorus, while the most abundant trace elements in these two ores are titanium, strontium and barium. Pearson correlation coefficient revealed that uranium in Kurun phosphate shows strong positive correlation with P 2 O 5 , and its distribution is essentially controlled by the variations of P2O5 concentration, whereas uranium in Uro phosphate shows strong positive correlation with strontium, and its distribution is controlled by the variations of Sr concentration. Uranium behaves in different ways in Kurun phosphate and in Uro phosphate. Uro phosphate shows higher concentrations of all the estimated radionuclides than Kurun phosphate. According to the obtained results, it can be concluded that Uro phosphate is consider as secondary uranium source, and is more suitable for uranium recovery, because it has high uranium abundance and low P 2 O 5 %, than Kurun phosphate. (authors) [es

  9. Fission track method for uranium ore exploration

    International Nuclear Information System (INIS)

    Guo Shilun; Deng Xinlu; Sun Shengfen; Meng Wu; Zhang Pengfa; Hao Xiuhong

    1986-01-01

    The uranium concentrations in natural water collected in the fields of uranium ore exploration with fission track method have been determined. It shows that the results of fission track method are consistent with that of fluoro-colorimetry and laser fluorometry for the same samples of water with uranium concentration in the region of 10 -4 to 10 -8 g/l. For water samples with lower uranium concentration (≤10 -8 g/l), the fission track method can still give accurate or referential results, but the other two methods failed. The reproducibility of fission track method was checked and discussed by using samples collected in the same fields of uranium ore exploration. The effects of the concentration of the impurities in natural water on determination of uranium concentration were analysed and discussed as well

  10. Influence of acid/ore relation in the uranium-silicate ore treatment

    International Nuclear Information System (INIS)

    Antaki, C.; Cipriani, M.; Bruno, J.B.

    1985-01-01

    The estimation of acid addition effect (Kg of H 2 SO 4 /t of ore) in uranium extraction from an uranium-silicate ore, with a view to the control of silica concentration in leach under 0,6 g/l is presented. The analysis was effected based on bench-scale tests, with different quantities of sulfuric acid addition. (Author) [pt

  11. Chapter 3. Classical method of uranium leaching from ores and reasons for incomplete recovery at dumps of State Enterprise 'VOSTOKREDMET'. 3.3. Basic regularities of uranium ores leaching

    International Nuclear Information System (INIS)

    Khakimov, N.; Nazarov, Kh.M.; Mirsaidov, I.U.

    2012-01-01

    Present article is devoted to basic regularities of uranium ores leaching. It was found that the basic method of uranium ores enrichment and producing of reasonably rich and pure uranium concentrates (usually technical uranium oxide) is a chemical concentration concluded in selective uranium leaching from ore raw materials with further, uranium compounds - so called uranium chemical concentrates. Such reprocessing of uranium ores with the purpose of uranium chemical concentrates production, currently, are produced everywhere by hydrometallurgical methods. This method in comparison with enrichment and thermal reprocessing is a universal one. Hydrometallurgy - the part of chemical technology covering so called moist methods of metals and their compounds (in the current case, uranium) extraction from raw materials, where they are contained. It can be ores or ore concentrates produced by radiometric, gravitational, floatation enrichment, sometimes passed through high-temperature reprocessing or even industry wastes. The basic operation in hydrometallurgy is its important industrial element - metal or metals leaching as one or another compound. Leaching is conversion of one or several components to solution under impact of relevant technical solvents: water, water solutions, acids, alkali or base, solution of some salts and etc. The basic purpose of leaching in uranium technology is to obtain the most full and selective solution of uranium.

  12. Removing ferric ions from concentrated acid leaching solution of an uranium ore by jarosite

    International Nuclear Information System (INIS)

    Song Huanbi; Hu Yezang

    1997-01-01

    The author expounds the fundamental rules of removing ferric ions by jarosite and presents results of removing ferric ions from concentrated acid curing-trickle leaching solution of an uranium ore. It turns out that the method can be applied to uranium hydrometallurgical process effectively

  13. Uranium accompanying recovery from copper ores

    International Nuclear Information System (INIS)

    Golynko, Z.Sh.; Laskorin, B.N.

    1981-01-01

    In the search for new raw material sources for nuclear power engineering a review of the technique of uranium accompaning recovery from copper ores reprocessing products in some countries is presented. In the USA a sorption method of uranium extraction by means of strongly basic ion exchange resins from solutions upon copper case- hardening with subsequent extraction from eluates by solutions of tertiary amines is realized. Elution is realized with sulphuric acid. In South Africa an extraction reprocessing of gravitational concentrate extracted from copper sulphide flotation tailings is organized. In India the uranium extraction from copper ores flotation enrichment tailings is organized on a commerical scale. Presented are data on the scale of uranium recovery, various conditions of its recovery as well as block diagrams of the processes. It is shown that copper ores become an additional source of uranium recovery [ru

  14. NRC's limit on intake of uranium-ore dust

    International Nuclear Information System (INIS)

    McGuire, S.A.

    1983-04-01

    In 1960 the Atomic Energy Commission adopted an interim limit on the intake by inhalation of airborne uranium-ore dust. This report culminates two decades of research aimed at establishing the adequacy of that limit. The report concludes that the AEC underestimated the time that thorium-230, a constituent of uranium-ore dust, would remain in the human lung. The AEC assumed that thorium-230 in ore dust would behave like uranium with a 120-day biological half-life in the lung. This report concludes that the biological half-life is actually on the order of 1 year. Correcting the AEC's underestimate would cause a reduction in the permitted airborne concentration of uranium-ore dust. However, another factor that cancels the need for that reduction was found. The uranium ore dust in uranium mills was found to occur with very large particle sizes (10-micron activity median aerodynamic diameter). The particles are so large that relatively few of them are deposited in the pulmonary region of the lung, where they would be subject to long-term retention. Instead they are trapped in the upper regions of the respiratory tract, subsequently swallowed, and then rapidly excreted from the body through the gastrointestinal tract. The two effects are of about the same magnitude but in opposing directions. Thus the present uranium-ore dust intake limit in NRC regulations should provide a level of protection consistent with that provided for other airborne radioactive materials. The report recalculates the limit on intake of uranium-ore dust using the derived air concentrations (DAC) from the International Commission on Radiological Protection's recent Publication 30. The report concludes that the silica contained in uranium-ore dust is a greater hazard to workers than the radiological hazard

  15. Uranium extraction from gold-uranium ores

    Energy Technology Data Exchange (ETDEWEB)

    Laskorin, B.N.; Golynko, Z.Sh.

    1981-01-01

    The process of uranium extraction from gold-uranium ores in the South Africa is considered. Flowsheets of reprocessing gold-uranium conglomerates, pile processing and uranium extraction from the ores are presented. Continuous counter flow ion-exchange process of uranium extraction using strong-active or weak-active resins is noted to be the most perspective and economical one. The ion-exchange uranium separation with the succeeding extraction is also the perspective one.

  16. Study of the dry processing of uranium ores

    International Nuclear Information System (INIS)

    Guillet, H.

    1959-02-01

    A description is given of direct fluorination of pre-concentrated uranium ores in order to obtain the hexafluoride. After normal sulfuric acid treatment of the ore to eliminate silica, the uranium is precipitated by a load of lime to obtain: either impure calcium uranate of medium grade, or containing around 10% of uranium. This concentrate is dried in an inert atmosphere and then treated with a current of elementary fluorine. The uranium hexafluoride formed is condensed at the outlet of the reaction vessel and may be used either for reduction to tetrafluoride and the subsequent manufacture of uranium metal or as the initial product in a diffusion plant. (author) [fr

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

    International Nuclear Information System (INIS)

    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

    2014-01-01

    In early 2009, a state policing agency raided a clandestine drug laboratory in a suburb of a major city in Australia. While searching the laboratory, they discovered a small glass jar labelled 'Gamma Source' and containing a green powder. The powder was radioactive. This paper documents the detailed nuclear forensic analysis undertaken to characterize 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

  18. Inhalation of uranium ores

    International Nuclear Information System (INIS)

    Stuart, B.O.; Jackson, P.O.

    1975-01-01

    In previous studies the biological dispositions of individual long-lived alpha members of the uranium chain ( 238 U, 234 U and 230 Th) were determined during and following repeated inhalation exposures of rats to pitchblende (26 percent U 3 O 8 ) ore. Although finely dispersed ore in secular equilibrium was inhaled, 230 Th/ 234 U radioactivity ratios in the lungs rose from 1.0 to 2.5 during 8 weeks of exposures and increased to 9.2 by four months after cessation of exposures. Marked non-equilibrium levels were also found in the tracheobronchial lymph nodes, kidneys, liver, and femur. Daily exposures of beagle dogs to high levels of this ore for 8 days resulted in lung 230 Th/ 234 U ratios of >2.0. Daily exposures of dogs to lower levels (0.1 mg/1) for 6 months, with sacrifice 15 months later, resulted in lung and thoracic lymph node 230 Th/ 234 U ratios ranging from 3.6 to 9 and nearly 7, respectively. The lungs of hamsters exposed to carnotite (4 percent U 3 O 8 ) ore in current lifespan studies show 230 Th/ 234 U ratios as high as 2.0 during daily inhalation of this ore in secular equilibrium. Beagle dogs sacrificed after several years of daily inhalations of the same carnotite ore plus radon daughters also showed marked non-equilibrium ratios of 230 Th/ 234 U, ranging from 5.6 to 7.4 in lungs and 6.2 to 9.1 in thoracic lymph nodes. This pattern of higher retention of 230 Th than 234 U in lungs, thoracic lymph nodes, and other tissues is thus consistent for two types of uranium ore among several species and suggests a reevaluation of maximum permissible air concentrations of ore, currently based only on uranium content

  19. Discussion on prospecting potential for rich uranium deposits in Xiazhuang uranium ore-field, northern Guangdong

    International Nuclear Information System (INIS)

    Wu Lieqin; Tan Zhengzhong

    2004-01-01

    Based on analyzing the prospecting potential for uranium deposits in Xiazhuang uranium ore field this paper discusses the prospecting for rich uranium deposits and prospecting potential in the region. Research achievements indicate: that the Xiazhuang ore-field is an ore-concentrated area where uranium has been highly enriched, and possesses good prospecting potential and perspective, becoming one of the most important prospecting areas for locating rich uranium deposits in northern Guangdong; that the 'intersection type', the alkaline metasomatic fractured rock type and the vein-group type uranium deposits are main targets and the prospecting direction for future uranium prospecting in this region

  20. Characterization and classification of uranium ore concentrates (yellow cakes) using infrared spectrometry

    Energy Technology Data Exchange (ETDEWEB)

    Varga, Z.; Oeztuerk, B.; Mayer, K.; Wallenius, M.; Apostolidis, C. [Joint Research Centre, Karlsruhe (Germany). Inst. for Transuranium Elements; Meppen, M. [Carl Friedrich von Weizsaecker-Zentrum fuer Naturwissenschaft und Friedensforschung, Hamburg (Germany)

    2011-07-01

    In this work the applicability of Fourier-transform infrared spectrometry (FTIR) for nuclear forensic studies of uranium ore concentrates (UOC) are investigated. The technique was used for the identification of the type of uranium compound and various process-related impurities, which can give information on the production method of the material. The measured spectra were evaluated also by statistical means, using the soft independent modelling of class analogy (SIMCA) technique to reveal less apparent similarities between the measured UOC samples.

  1. Flotation of uranium from uranium ores in Canada. Part 2

    International Nuclear Information System (INIS)

    Muthuswami, S.V.; Vijayan, S.; Woods, D.R.

    1985-01-01

    Measurements are reported for the equilibrium of cupferron from solutions by uranium oxide, quartz, illite, a mixture of these three, pitchblende, pyrite and brannerite ore. The cupferron concentration ranged from 1 to 6 g/L, and the pH was 7 and 8. Most isotherms followed the Langmuir model, although Freundlich behaviour was observed for illite and pitchblende. Most adsorption was pH independent except for illite and pitchblende. The adsorption isotherms for a mixture of uranium oxide, quartz and illite in the same proportions as in the naturally occurring ore agreed with the adsorption of the pyrite-free ore at pH 8 but not pH 7. We attribute the discrepancy to the use of illite as the model clay. The specific adsorption of cupferron on quartz and illite is lower by a factor of about 50 and 5, respectively, than the adsorption on uranium oxide. Specific adsorption less than 1 mg cupferron per gm of pyrite free ore does not float the mineral. The corresponding equilibrium concentration of cupferron is 0.5 g/L. A qualitative model is given, and the implications of this work for practical operations are presented

  2. Ore-concentrating structures with telescoped uranium mineralization

    International Nuclear Information System (INIS)

    Shchetochkin, V.N.; Dmitriyev, V.I.; Tkachenko, I.I.

    1986-01-01

    Deep faults are the main controlling elements in uranium ore fields, although the immediate geologic environments may be quite varied. Within the fault zones, the uranium fields are usually associated with areas where major transverse and diagonal faults intersect or link, and with points of splitting or change in strike in disjunctive zones. Another distinctive feature of the mineralized structure is their long history, with a combination of tectonic elements differing in age and type, usually associated with retrograde dislocation metamorphism. The specific features of these structures control the uranium mineralization, which is usually localized in foci with telescoped tectonic, magmatic, hydrothermal, metasomatic, and sometimes exogenous processes. The unnamed area (in the Ukraine?) furnishes a good example of how successive stages of a complex geologic history affect the occurrence of such a highly mobile element as uranium. 12 references, 4 figures

  3. Manual on laboratory testing for uranium ore processing

    International Nuclear Information System (INIS)

    1990-01-01

    Laboratory testing of uranium ores is an essential step in the economic evaluation of uranium occurrences and in the development of a project for the production of uranium concentrates. Although these tests represent only a small proportion of the total cost of a project, their proper planning, execution and interpretation are of crucial importance. The main purposes of this manual are to discuss the objectives of metallurgical laboratory ore testing, to show the specific role of these tests in the development of a project, and to provide practical instructions for performing the tests and for interpreting their results. Guidelines on the design of a metallurgical laboratory, on the equipment required to perform the tests and on laboratory safety are also given. This manual is part of a series of Technical Reports on uranium ore processing being prepared by the IAEA's Division of Nuclear Fuel Cycle and Waste Management. A report on the Significance of Mineralogy in the Development of Flowsheets for Processing Uranium Ores (Technical Reports Series No. 196, 1980) and an instruction manual on Methods for the Estimation of Uranium Ore Reserves (No. 255, 1985) have already been published. 17 refs, 40 figs, 17 tabs

  4. Investigation of spectral interference effects on determination of uranium concentration in phosphate ore by inductively coupled plasma optical emission spectroscopy

    Energy Technology Data Exchange (ETDEWEB)

    Bachari, Ayoob H.; Jalali, Fatemeh; Alahyarizadeh, Ghasem [Tehran Univ. (Iran, Islamic Republic of). Engineering Dept.

    2017-04-01

    Effects of spectral interferences on determination of the uranium concentration in phosphate ore were investigated by inductively coupled plasma optical emission spectroscopy (ICP-OES). Eleven high intensity emission lines including four lines recommended by ICP-OES apparatus were chosen to determine the uranium concentration. The ore samples were collected from phosphate acid producing industry in the south of Iran. Three different acid combinations [(HNO{sub 3}:HCl:HF-2:6:2), (H{sub 3}PO{sub 4}:H{sub 2}SO{sub 4}:HF-3:3:3), (HNO{sub 3}:H{sub 2}O{sub 2}:HF-4:2:2)] used in microwave digestion method to explore the spectral interference effects in different solvent environments. The results showed that the trusty uranium concentration, obtained in the 367.007 nm, 386.592 nm, 389.036 nm and 409.014 nm by second acid digestion method which were 0.665 ppm, 0.972 ppm, 0.670 ppm and 0.801 ppm, respectively. Although the line of 409.014 nm was reported as the best line for determining of the uranium concentration in several literatures, the results showed that this line has a significant spectral interference with vanadium in some ores which should be considered in determining of the uranium concentration. Spectral interference effects of some elements which have high concentrations in the phosphate ore including Ca, Fe, Mg, Pb, V, Mn, and Ti on the line intensities were also investigated. Results indicated that the chosen elements affect emission intensities of all of 11 lines. They also indicated that the line of 409.014 nm provides a trusty precision in the determination of the uranium concentration in the ore sample with low vanadium concentration (at least, U/V ratio of 1:5). Results show that the line of 409.014 nm provides acceptable precision with some corrections in comparison with other selected lines. For instance in high concentrations of other elements including Fe and Ti in the ore samples, strong influences on the line intensities of the 367.007 nm (by Fe

  5. Research on geochronology and uranium source of sandstone-hosted uranium ore-formation in major uranium-productive basins, Northern-China

    International Nuclear Information System (INIS)

    Xia Yuliang; Liu Hanbin; Lin Jinrong; Fan Guang; Hou Yanxian

    2004-12-01

    A method is developed for correcting uranium content in uranium ore samples by considering the U-Ra equilibrium coefficient, then a U-Pb isochron is drawn up. By performing the above correction ore-formation ages of sandstone-hosted uranium mineralization which may be more realistic have been obtained. The comparative research on U-Pb isotopic ages of detritic zircon in ore-hosting sandstone and zircon in intermediate-acid igneous rocks in corresponding provenance area indicates that the ore-hosting sandstone is originated from the erosion of intermediate-acid igneous rocks and the latters are the material basis for the formation of the uranium-rich sandstone beds. On the basis of the study on U-Pb isotopic system evolution of the provenance rocks and sandstones from ore-hosting series, it is verified that the uranium sources of the sandstone-hosted uranium deposit are: the intermediate-acid igneous rocks with high content of mobile uranium, and the sandstone bodies pre-concentrated uranium. (authors)

  6. 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)

  7. Evaluation the effect of uranium ore concentrations on the cyc2 gene expression in the mutated Acidithiobacillus sp. FJ2

    Directory of Open Access Journals (Sweden)

    Faezeh Fatemi

    2018-06-01

    Full Text Available Introduction: The uranium bioleaching process is performed using Acidithiobacillus ferrooxidans. This bacterium is capable of iron oxidation by an electron transport chain. One of the most important components of this chain is the cyc2 gene product that involved in the oxidation process of iron. Materials and methods: Evaluation of UV mutated (60, 120 and 180s Acidithiobacillus sp. FJ2 cyc2gene in the presence of uranium ore concentrations, has been implemented in this project. For this purpose, the original and mutated bacteria were cultivated in the presence of uranium ore concentrations (5, 10, 15, 25 and 50%. Uranium extraction, variation of pH and Eh values were measured at 24 h intervals. Then, when the uranium extraction yield reached to 100%, gene expressions of cyc2 original and mutatedAcidithiobacillus sp. FJ2 were analyzed using Real-time PCR method. Results: The results of the experiments showed that, with increasing pulp density, the uranium extraction rate and oxidation activity of bacteria were reduced. In addition, the result of cyc2 gene expression showed that the target gene expression increases in the presence of uranium ore compared to sample with absence of uranium ore, andwith further increase of pulp density, due to the toxicity of uranium, shows a decreasing trend. Discussion and conclusion: The results of this study indicated that the mutation in the bacterium has a positive effect on the uranium bioleaching process, which can play an important role in the process of uranium bioleaching at high concentrations. In addition, with increasing pulp density due to uranium toxicity, there is a decreasing trend in the process of uranium extraction, which indicates the important role of this factor in the uranium bioleaching process.

  8. Optimization of dissolution process parameters for uranium ore concentrate powders

    Energy Technology Data Exchange (ETDEWEB)

    Misra, M.; Reddy, D.M.; Reddy, A.L.V.; Tiwari, S.K.; Venkataswamy, J.; Setty, D.S.; Sheela, S.; Saibaba, N. [Nuclear Fuel Complex, Hyderabad (India)

    2013-07-01

    Nuclear fuel complex processes Uranium Ore Concentrate (UOC) for producing uranium dioxide powder required for the fabrication of fuel assemblies for Pressurized Heavy Water Reactor (PHWR)s in India. UOC is dissolved in nitric acid and further purified by solvent extraction process for producing nuclear grade UO{sub 2} powder. Dissolution of UOC in nitric acid involves complex nitric oxide based reactions, since it is in the form of Uranium octa oxide (U{sub 3}O{sub 8}) or Uranium Dioxide (UO{sub 2}). The process kinetics of UOC dissolution is largely influenced by parameters like concentration and flow rate of nitric acid, temperature and air flow rate and found to have effect on recovery of nitric oxide as nitric acid. The plant scale dissolution of 2 MT batch in a single reactor is studied and observed excellent recovery of oxides of nitrogen (NO{sub x}) as nitric acid. The dissolution process is automated by PLC based Supervisory Control and Data Acquisition (SCADA) system for accurate control of process parameters and successfully dissolved around 200 Metric Tons of UOC. The paper covers complex chemistry involved in UOC dissolution process and also SCADA system. The solid and liquid reactions were studied along with multiple stoichiometry of nitrous oxide generated. (author)

  9. Filtration aids in uranium ore processing

    International Nuclear Information System (INIS)

    Ford, H.L.; Levine, N.M.; Risdon, A.R.

    1975-01-01

    A process of improving the filtration efficiency and separation of uranium ore pulps obtained by carbonate leaching of uranium ore which comprises treating said ore pulps with an aqueous solution of hydroxyalkyl guar selected from the group consisting of hydroxyethyl and hydroxypropyl guar in the amount of 0.1 and 2.0 pounds of hydroxyalkyl guar per ton of uranium ore

  10. Origin assessment of uranium ore concentrates based on their rare-earth elemental impurity pattern

    Energy Technology Data Exchange (ETDEWEB)

    Varga, Z.; Wallenius, M.; Mayer, K. [Commission of the European Communities, Karlsruhe (Germany). European Inst. for Transuranium Elements

    2010-07-01

    The rare-earth element pattern was used as an additional tool for the identification and origin assessment of uranium ore concentrates (yellow cakes) for nuclear forensic purposes. By this means, the source of an unknown material can be straightforwardly verified by comparing the pattern with that of a known or declared sample. In contrast to other indicators used for nuclear forensic studies, the provenance of the material can also be assessed in several cases even if no comparison sample is available due to the characteristic pattern. The milling process was found not to change the pattern and no significant elemental fractionation occurs between the rare-earth elements, thus the pattern in the yellow cakes corresponds to that found in the uranium ore. (orig.)

  11. Studies on uranium ore processing

    International Nuclear Information System (INIS)

    Kim, C.H.; Park, S.W.; Lim, J.K.; Chung, M.K.

    1981-01-01

    Chemical and chemical engineering techniques of the uranium ore processing established by France COGEMA (Compagnie Generale des Matieres Nucleaires) have been comprehensively reviewed in preparation for successful test operation of the pilot plant to be completed by the end of 1981. It was found that the amount of sulfuric acid (75 Kg/t, ore) and sodium chlorate (2.5 Kg/t, ore) recommended by COGEMA should be increased up to 100 Kg/t, ore and 10 Kg/t, ore respectively to obtain satisfactory leach of uranium for some ore samples produced at the different pits of Goesan uranium mine. Conditions of the other processes such as solvent extraction, stripping, and precipitation of yellow cake were generally agreed with the results of intensive studies done by this laboratory

  12. The geological characteristics and forming conditions of granite type uranium-rich ore deposits

    Energy Technology Data Exchange (ETDEWEB)

    Tiangang, Li; Hangshou, Tong; Mingyue, Feng; Yuexiang, Li; Zhan, Xu [Beijing Research Inst. of Uranium Geology (China)

    1993-03-01

    The forming conditions and concentration mechanism of rich ore, criteria of ore prospecting and selection of uranium-rich ore target area are introduced in the article that is based on the studying of geological characteristics and conditions of granite type uranium-rich ore deposits of No 201 and 361 and on the comparisons of rich and poor ore deposits in geological conditions. Some new view points are also presented as the separate deposition of uranium minerals and gangue minerals is the main mechanism to form rich ore, for rich ore formation the ore enrichment by superimposition is not a universal regularity and most uranium-rich ore deposits are formed within one mineralization stage or mainly in one mineralization stage.

  13. The geological characteristics and forming conditions of granite type uranium-rich ore deposits

    International Nuclear Information System (INIS)

    Li Tiangang; Tong Hangshou; Feng Mingyue; Li Yuexiang; Xu Zhan

    1993-03-01

    The forming conditions and concentration mechanism of rich ore, criteria of ore prospecting and selection of uranium-rich ore target area are introduced in the article that is based on the studying of geological characteristics and conditions of granite type uranium-rich ore deposits of No 201 and 361 and on the comparisons of rich and poor ore deposits in geological conditions. Some new view points are also presented as the separate deposition of uranium minerals and gangue minerals is the main mechanism to form rich ore, for rich ore formation the ore enrichment by superimposition is not a universal regularity and most uranium-rich ore deposits are formed within one mineralization stage or mainly in one mineralization stage

  14. Simple, cost effective method for determination of phosphorus in uranium ore concentrate

    International Nuclear Information System (INIS)

    Misra, U.B.; Ramamurty, Vasantha; Dutta, M.; Balaji Rao, Y.; Subba Rao, Y.

    2015-01-01

    In this paper determination of phosphate as phosphorus in uranium ore concentrate has been described. The method used is spectrophotometric determination of phosphorus as phospho-molybdenum blue complex. As uranyl ion do not absorb in 600-900 nm range of visible region in the present medium, the phosphomolybdenum blue complex formation which is having maximum absorbance at 825 nm is exploited for determination of phosphorus. The molar absorptivity coefficient with and without the presence of uranium matrix are 2.6048 x 10 4 and 2.6730 x 10 4 lmol -1 cm -1 . The effect of matrix is not evident from the experiment carried out. (author)

  15. Feasibility study of the dissolution rates of uranium ore dust, uranium concentrates and uranium compounds in simulated lung fluid

    International Nuclear Information System (INIS)

    Robertson, R.

    1986-01-01

    A flow-through apparatus has been devised to study the dissolution in simulated lung fluid of aerosol materials associated with the Canadian uranium industry. The apparatus has been experimentally applied over 16 day extraction periods to approximately 2g samples of < 38um and 53-75um particle-size fractions of both Elliot Lake and Mid-Western uranium ores. The extraction of uranium-238 was in the range 24-60% for these samples. The corresponding range for radium-226 was 8-26%. Thorium-230, lead-210, polonium-210, and thorium-232 were not significantly extracted. It was incidentally found that the elemental composition of the ores studied varies significantly with particle size, the radionuclide-containing minerals and several extractable stable elements being concentrated in the smaller size fraction. Samples of the refined compounds uranium dioxide and uranium trioxide were submitted to similar 16 day extraction experiments. Approximately 0.5% of the uranium was extracted from a 0.258g sample of unsintered (fluid bed) uranium dioxide of particle size < 38um. The corresponding figure for a 0.292g sample of uranium trioxide was 97%. Two aerosol samples on filters were also studied. Of the 88ug uranium initially measured on stage 2 of a cascade impactor sample collected from the yellow cake packing area of an Elliot Lake mill, essentially 100% was extracted over a 16 day period. The corresponding figure for an open face filter sample collected in a fuel fabrication plant and initially measured at 288ug uranium was approximately 3%. Recommendations are made with regard to further work of a research nature which would be useful in this area. Recommendations are also made on sampling methods, analytical methods and extraction conditions for various aerosols of interest which are to be studied in a work of broader scope designed to yield meaningful data in connection with lung dosimetry calculations

  16. Lacustrine-humate model for primary uranium ore deposits, Grants Uranium Region, New Mexico

    International Nuclear Information System (INIS)

    Turner-Peterson, C.E.

    1985-01-01

    Two generations of uranium ore, primary and redistributed, occur in fluvial sandstones of the Upper Jurassic Morrison Formation in the San Juan basin; the two stages of ore formation can be related to the hydrologic history of the basin. Primary ore formed soon after Morrison deposition, in the Late Jurassic to Early Cretaceous, and a model, the lacustrine-humate model, is offered that views primary mineralization as a diagenetic event related to early pore fluid evolution. The basic premise is that the humate, a pore-filling organic material closely associated with primary ore, originated as humic acids dissolved in pore waters of greenish-gray lacustrine mudstones deposited in the mud-flat facies of the Brushy Basin Member and similar K shale beds in the Westwater Canyon Member. During compaction associated with early burial, formation water expelled from lacustrine mudstone units carried these humic acids into adjacent sandstone beds where the organics precipitated, forming the humate deposits that concentrated uranium. During the Tertiary, much later in the hydrologic history of the basin, when Jurassic sediments were largely compacted, oxygenated ground water flowed basinward from uplifted basin margins. This invasion of Morrison sandstone beds by oxidizing ground waters redistributed uranium from primary ores along redox boundaries, forming ore deposits that resemble roll-front-type uranium ores. 11 figures

  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. 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.

  19. Behaviour of the pH adjustment, Ion exchange and concentrate precipitation stages in the acid leaching of uranium phosphate ores

    International Nuclear Information System (INIS)

    Estrada Aguilar, J.; Uriarte Hueda, A.

    1962-01-01

    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

  20. Multi-column bioleaching of a uranium ore

    International Nuclear Information System (INIS)

    Meng Yunsheng; Zheng Ying; Liu Hui; Cheng Hao

    2014-01-01

    The technology of bioleaching uranium ore can increase the uranium leaching rate and shorten the leaching uranium period, save consumption of acid and oxidant, lower production costs. An experiment on multi-column bioleaching of a uranium ore was done using mesophilic bacteria, the average uranium recovery of 90% was achieved in 39 days. Compared with traditional process, leaching period was shortened to 39 d from 59 d, acid consumption and liquid-solid ratio were also reduced. The results showed it is suitable to bioleach the uranium ore. (authors)

  1. Mining and milling of uranium ore: Indian scenario

    International Nuclear Information System (INIS)

    Bhasin, J.L.

    2001-01-01

    The occurrence of uranium minerals in Singhbhum Thrust belt of Eastern India has been known since 1937. In 1950, a team of geologists of the Atomic Minerals Division was assigned to closely examine this 160 km long belt. Since then, several occurrences of uranium have been found and a few of them have sufficient grade and tonnage for commercial exploitation. In 1967, the Government of India formed Uranium Corporation of India Ltd., under the administrative control of the Department of Atomic Energy, with the specific objective of mining and processing of uranium ore and produce uranium concentrates. At present the Corporation operates three underground uranium mines, one ore processing plant with expanded capacity, and two uranium recovery plants. Continuing investigations by the Atomic Mineral Division has discovered several new deposits and favourable areas. The most notable is the large Domiasiat deposit of the sandstone type found in the State of Meghalaya. This deposit is now being considered for commercial exploitation using the in-situ leaching technology. (author)

  2. Thirty years of uranium ore processing in Spain

    International Nuclear Information System (INIS)

    Josa, J.M.

    1982-01-01

    Spanish background in the uranium ore processing includes ores from pegmatitic type deposits, vein deposits, sandstone, enrichments in metamorphic rocks, radioactive coals and non-conventional sources of uranium, such as wet phosphoric acid or copper liquors. Some tests have also done in order to recover uranium from very low grade paleozoic quartzites. We have also been involved in by-products recovery (copper) from uranium ores. The technologies that have been used are: physical concentration, combustion and roasting, conventional alkaline or acid methods, pressure, heap and bacteria leaching. Special attention was paid to recover uranium from the pregnant liquors and to develop suited equipment for it; solvent extraction and continuous ion exchange equipment was carefully studied. We have been involved in commercial size (500-3000 t/d) mills, but we have also developed transportable and reussable modular plants specially designed and suited to recover uranium from small and isolated deposits. In both cases the reduction of the environmental impact was taken in account. Spanish experience also includes nuclear purification aspects in order to get uranium nuclear compounds (ADU, UO 2 , UF 4 and UF 6 ). Wet (nitric-TBP) and dry (Fluid-bed) methods have been used. The best of these 30 years of experience in studies and in industrial practice, together with our new developments towards the future, could become in a good contribution for the medium size countries which are going to develop its own uranium industry. The way for these countries could be easier if they know what is valuable and what must be avoid in the uranium ore processing development. In this aim the whole paper was thought and written. (author)

  3. Uranium and Molybdenum extraction from a Cerro Solo deposit ore

    International Nuclear Information System (INIS)

    Becquart, Elena T.; Arias, Maria J.; Fuente, Juan C. de la; Misischia, Yamila A.; Santa Cruz, Daniel E.; Tomellini, Guido C.

    2009-01-01

    Cerro Solo, located in Chubut, Argentina, is a sandstone type uranium-molybdenum deposit. Good recovery of both elements can be achieved by acid leaching of the ore but the presence of molybdenum in pregnant liquors is an inconvenient to uranium separation and purification. A two steps process is developed. A selective alkaline leaching of the ore with sodium hydroxide allows separating and recovering of molybdenum and after solid-liquid separation, the ore is acid leached to recover uranium. Several samples averaging 0,2% uranium and 0,1% molybdenum with variable U/Mo ratio have been used and in both steps, leaching and oxidant reagents concentration, temperature and residence time in a stirred tank leaching have been studied. In alkaline leaching molybdenum recoveries greater than 96% are achieved, with 1% uranium extraction. In acid leaching up to 93% of the uranium is extracted and Mo/U ratio in solvent extraction feed is between 0,013 and 0,025. (author)

  4. Flotation of uranium from uranium ores in Canada. Part 1

    International Nuclear Information System (INIS)

    Muthuswami, S.V.; Vigayan, S.; Woods, D.R.; Banerjee, S.

    1983-01-01

    About 150 flotation tests were done on Elliot Lake ore with 15 reagents as collectors in order to screen and choose an attractive collector for uranium flotation. Several variables were studied including pH, conditioning time and mode of collector addition. The tests were done in a Denver or Agitair subaeration cell. The particle size of the ore was kept at 85% below -325 mesh. Three reagents (Kelex 00, TOPO, and cupferron) were identified as having the most promise. The best results were obtained with cupferron, where 93-95% of the uranium was recovered in 25-30% of the mass of original ore. Radium in the tails varied between 5 and 30 pCi/g depending on the mass of uranium floated. Radium was recovered in proportion to uranium in the tests done at neutral pH. The preconcentration results obtained by flotation alone were comparable to those obtained using pyrite flotation and wet high-intensity magnetic separation of uranium. The consumption of cupferron was 4 kg/Mg ore for each flotation stage. This was 10-15 times larger than the collector usage in conventional oxide flotation. This scheme did not require other reagents as depressants, activators or modifiers. Reproducibility was good and similar recoveries were obtained with fresh or old ores, and with distilled or mine water. The selectivity of cupferron for uranium in the ore studied was outstanding

  5. The role of post-ore processes in the alteration of infiltrational uranium deposits

    International Nuclear Information System (INIS)

    Kondrat'eva, I.A.; Bobrova, L.L.; Nesterova, M.V.

    1992-01-01

    Ore-bearing rocks and ores of uranium deposits that are associated with gray alluvial deposits and formed through oxidation of sedimentary beds at the end of the Jurassic, have undergone intensive alterations. The impact of hot carbonic acid solutions on infiltrational uranium deposits, along with calcite and hematite, resulted in partial dissolution of and redeposition of uranium. Uranium concentrates with newly formed Fe-bisulfides and hydroxides in the reducing stage of epigenetic alterations within a hydrochemical sulfide-gley medium, leading to changes in ore morphology. 20 refs., 7 figs., 3 tabs

  6. 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.

  7. Uranium ore processing

    International Nuclear Information System (INIS)

    Ritcey, G.M.; Haque, K.E.; Lucas, B.H.; Skeaff, J.M.

    1983-01-01

    The authors have developed a complete method of recovering separately uranium, thorium and radium from impure solids such as ores, concentrates, calcines or tailings containing these metals. The technique involves leaching, in at least one stage. The impure solids in finely divided form with an aqueous leachant containing HCl and/or Cl 2 until acceptable amounts of uranium, thorium and radium are dissolved. Uranium is recovered from the solution by solvent extraction and precipitation. Thorium may also be recovered in the same manner. Radium may be recovered by at least one ion exchange, absorption and precipitation. This amount of iron in the solution must be controlled before the acid solution may be recycled for the leaching process. The calcine leached in the first step is prepared in a two stage roast in the presence of both Cl 2 and a metal sulfide. The first stage is at 350-450 0 and the second at 550-700 0

  8. Uranium R and D directed to low-grade ores

    International Nuclear Information System (INIS)

    Anon.

    1976-01-01

    The treatment of depleted uranium ores by in-situ leaching and by counterflow ion exchange in the USA is described. In-situ leaching is mainly suitable for sandstone deposits. The research was originally focused on leaching with an acid and with carbonates. Phosphoric acid appears to be a promising leaching agent. The equipment for continuous ion exchange may be used for sludge processing but the application depends on the type of equipment and mineralogy of processed ores. The method is advantageous for lower capital costs and for smooth operation. Ion exchange is also used for uranium extraction from mine waters in the USA as well as in Canada. For example, in Grants, New Mexico, a yield exceeding 90% was reached in mine waters only containing 5 to 7 ppm U 3 O 8 . In the future, the treatment of ores with a low uranium content will require more selective extraction methods in view of the more stringent technical conditions of uranium concentrate processing. (J.P.)

  9. Uranium extraction from Uro area phosphate ore, Nuba mountains, Sudan

    International Nuclear Information System (INIS)

    Mohammed, A. A.; Eltayeb, M. A. H.

    2003-01-01

    This study was carried out mainly to extract uranium from Uro area phosphate ore in the eastern part of Nuba mountains near Abu Gibiha town in southern Kurdufan state. For this purpose first, the phosphate ore samples were decomposed with sulphuric acid. the resulting phosphoric acid was filtered off, and pretreated with pyrite and activated charcoal. the chemical analysis of the obtained grain phosphoric acid showed that about 98% of uranium content of the phosphate ore was rendered soluble in the phosphoric acid. The clear green phosphoric acid was introduced to uranium extraction by 25% tributylphosphate (Tbp) in kerosene. The effect of several factors on the extraction and stripping processes namely, interference's effect, the suitable strip solution, the required number of extraction and stripping stages, the optimum phase ratio have been studied in details. A three stage extraction at a phase ratio (aqueous/organic) of 1:2, followed by two stages stripping using 0.5 M sodium carbonate solution at a phase ratio (A/O) of 1:4 were found to be the optimum conditions to report more than 98% of uranium content in green phosphoric acid to the aqueous phase as uranyl tricarbonate complex (UO 2 (CO 3 ) 3 ) 4- . By applying sodica decomposition upon the stripping carbonate solution using 50% sodium hydroxide, about 98% of uranium content was precipitated as sodium diuranate concentrate (Na 2 U 2 O 7 ). The chemical analysis using atomic absorption spectrometry (Aas) showed a good agreement between the specification of the obtained uranium concentrate with the standard commercial specification of sodium diuranate concentrate. Further purification was achieved for the yellow cake by selective precipitation of uranium from the solution as uranium peroxide (UO 4 .2H 2 O) using 30% hydrogen peroxide. Finally the uranium peroxide precipitated was calcined at 450 degree C to obtain the orange powder uranium trioxide (UO 3 ). The chemical analysis of the final uranium trioxide

  10. Uranium ore deposits: geology and processing implications

    International Nuclear Information System (INIS)

    Belyk, C.L.

    2010-01-01

    There are fifteen accepted types of uranium ore deposits and at least forty subtypes readily identified around the world. Each deposit type has a unique set of geological characteristics which may also result in unique processing implications. Primary uranium production in the past decade has predominantly come from only a few of these deposit types including: unconformity, sandstone, calcrete, intrusive, breccia complex and volcanic ones. Processing implications can vary widely between and within the different geological models. Some key characteristics of uranium deposits that may have processing implications include: ore grade, uranium and gangue mineralogy, ore hardness, porosity, uranium mineral morphology and carbon content. Processing difficulties may occur as a result of one or more of these characteristics. In order to meet future uranium demand, it is imperative that innovative processing approaches and new technological advances be developed in order that many of the marginally economic traditional and uneconomic non-traditional uranium ore deposits can be exploited. (author)

  11. Technological studies on the Manisa-Koprubasi uranium ores of Turkey

    International Nuclear Information System (INIS)

    Sagdik, U.

    1980-01-01

    At the end of the laboratory and pilot plant scale technological experiments, three main types of ore have been classified: (i) Kasar type: The ores consist of secondary uranium mineralization (autunite, meta-autunite and torbenite) in loosely consolidated sands, gravels and clays of Neogene Age. Heap leaching has been carried out on 100 and 1000 t ore samples (0.05% U 3 O 8 ) under economical conditions, such as 20 to 40 kg of H 2 SO 4 per tonne of ore at ambient temperature; original size -20 cm, solid/liquid ratio of 10, 20 days, and 90% recovery of uranium has been reached. The uraniferous solutions (1 to 2 g of U 3 O 8 per litre) obtained from the heap leaching operations were purified in a solvent extraction unit with a capacity of 100 ltr/h by using an Alamine 336-kerosene-decanol solution. The uranium in the purified and concentrated solutions (15 g of U 3 O 8 per litre) was then precipitated as a yellow cake with 65 to 75% U 3 O 8 content by means of magnesia milk. (ii) Tasharman type: No specific uranium mineral has been detected in the mineralogical determination, although uranium is disseminated in phosphate minerals as dahllite and apatite. Uranium in the ore has been leached under rather uneconomical conditions; 100 kg of H 2 SO 4 per tonne of ore, particle size -1 cm, 25 0 C, 30 days. In the SX-treatment of pregnant solutions phosphate ions, higher acidity than pH 1, and compounds formed as a chemical precipitation, hindered the SX-recoveries. In such cases, the addition of acid, dilution of pregnant solutions, membrane filtration, or 40 0 C temperature have been applied to decrease the uranium loss in the raffinate. (iii) Carbonate type: Even if alkaline leaching at 65 0 C, or leaching with 400 kg of H 2 SO 4 per tonne of ore, was carried out on -200 mesh ore samples, no acceptable uranium recoveries were obtained

  12. Anion analysis in uranium more concentrates by ion chromatography

    International Nuclear Information System (INIS)

    Badaut, V.

    2009-01-01

    In the present exploratory study, the applicability of anionic impurities or attributing nuclear material to a certain chemical process or origin has been investigated. Anions (e.g., nitrate, sulphate, fluoride, chloride) originate from acids or salt solutions that are used for processing of solutions containing uranium or plutonium. The study focuses on uranium ore concentrates ('yellow cakes') originating from different mines. Uranium is mined from different types of ore body and depending on the type of rock, different chemical processes for leaching, dissolving and precipitating the uranium need to be applied. Consequently, the anionic patterns observed in he products of these processes (the 'ore concentrates') are different. The concentrations of different anionic species were measured by ion chromatography using conductivity detection. The results show clear differences of anion concentrations and patterns between samples from different uranium mines. Besides this, differences between sampling campaigns n a same mine were also observed indicating that the uranium ore is not homogeneous in a mine. These within-mine variations, however, were smaller than the between-mine variations. (author)

  13. Chemical treatment of uranium ores in France

    International Nuclear Information System (INIS)

    Mouret, P.; Sartorius, R.

    1958-01-01

    The various processes of chemical treatment of uranium 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) [fr

  14. Uranium recovery from phosphate rocks concentrated

    International Nuclear Information System (INIS)

    Azevedo, M.F. de.

    1986-01-01

    The reserves, geological data, chemical data and technical flowsheet from COPEBRAS and Goiasfertil ores are described, including the process of mining ore concentration. Samples of Goiasfertil ores are analysed by gravimetric analysis, for phosphate, and spectrofluorimetry for uranium. (author)

  15. Influence of radon-daughter exposure rate and uranium ore dust concentration on occurrence of lung tumors

    International Nuclear Information System (INIS)

    Cross, F.T.; Palmer, R.F.; Busch, R.H.

    1980-01-01

    Groups of male SPF Wistar rats were exposed concurrently to several levels of radon daughters and uranium ore dust to study the effect of these variables on pulmonary disease states. Clinical pathology data at 1 yr postexposure indicate no significant differences among exposed animals when compared with controls. Preliminary histopathologic data suggest a trend toward increasing lung tumor risk as the exposure rate is decreased (constant total dose), but the differences are not statistically significant at the 0.05 level. A similar trend occurs with decrease in ore dust concentration (except for the 2560-WLM exposure group), but these differences are also not significant at the 0.05 level. The tumor risk is significantly (0.05 level) increased as the exposure level increases from approximately 320 and 640 WLM to 2560 WLM at the high ore dust concentration

  16. A study on the upgrading by physical means of low grade uranium ore from Phu Wiang District

    International Nuclear Information System (INIS)

    Wihokratna, W.

    1980-01-01

    The purpose of this thesis is to upgrade the uranium ore at Phu Wiang district. Because of the fine grains and high degree of dissemination of uranium in ores, resulting practically complete envelopment of the uranium minerals by the gangue minerals, the ore must first undergo digestion in order to reveal the uranium minerals. After digestion, sodium hydroxide of 0.05 normal was added to the ore and the mixture was fed into the agitator provided with baffles and two specially designed propellers. Due to the 'Push - Pull' motion of the propellers a zone of specially high turbulence was created between them. Also in this region higher concentration of uranium is revealed and the high concentrated uranium ore was regularly stripped off for further analysis. It was found that by using mineral of grain size of 100 mesh and 0.0187% of uranium content a concentration up to 0.063% uranium content (an upgrading better than by a factor of three times) was achieved with the above method. The uranium content was analyzed with 3'' x 3'' NaI (Tl) detector and 1024 channels MCA

  17. Studies on uranium ore processing

    International Nuclear Information System (INIS)

    Suh, I.S.; Chun, J.K.; Park, S.W.; Choi, S.J.; Lee, C.H.; Chung, M.K.; Lim, J.K.

    1983-01-01

    For the exploitation of domestic uranium ore deposit, comprehensive studies on uranium ore processing of the Geum-San pit ore are carried out. Physical and chemical characteristics of the Geum-San ore are similar to those of Goe-San ore and the physical beneficiation could not be applicable. Optimum operating conditions such as uranium leaching, solid-liquid separation, solvent extraction and precipitation of yellow cake are found out and the results are confirmed by the continous operation of the micro-plant with the capacity of 50Kg, ore/day. In order to improve the process of ore milling pilot plant installed recently, the feasibility of raffinate-recycle and the precipitation methods of yellow cake are intensively examined. It was suggested that the raffinate-recycle in the leaching of filtering stage could be reduced the environmental contamination and the peroxide precipitation technique was applicable to improve the purity of yellow cake. The mechanism and conditions the third phase formation are thoroughly studied and confirmed by chemical analysis of the third phase actually formed during the operation of pilot plant. The major constituents of the third phase are polyanions such as PMosub(12)Osub(40)sup(3-) or SiMosub(12)Osub(40)sup(4-). And the formation of these polyanions could be reduced by the control of redox potential and the addition of modifier. (Author)

  18. 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.

  19. Investigation of the degree of equilibrium of the long-lived uranium-238 decay-chain members in airborne and bulk uranium-ore dusts

    International Nuclear Information System (INIS)

    Jackson, P.O.; Thomas, C.W.

    1982-08-01

    The degree of disequilibrium among 238 U decay chain members in some airborne dusts and typical ores has been established by precise radiochemical analyses. This information is necessary to evaluate the lung dose model currently used for estimating the effect of the inhalation of uranium ore dust. The particle size distributions of airborne decay chain components in dusts at one uranium mill have been investigated. Statistically significant disequilibria were observed for 230 Th, 226 Ra, and 210 Pb in both airborne dusts and composite ore samples. With the exception of ore from one mill in the United States, most of the daughter concentrations in powdered ore composites were within 10% of 238 U. In airborne dusts, the concentration of 226 Ra was typically below 238 U; the minimum 226 Ra concentration observed for airborne ore dusts was 56% of equilibrium. A statistically significant particle size dependence was observed for 226 Ra/ 238 U ratios in several airborne dusts collected at a uranium mill

  20. Oxidizing attack process of uranium ore by a carbonated liquor

    International Nuclear Information System (INIS)

    Maurel, Pierre; Nicolas, Francois.

    1981-01-01

    A continuous process for digesting a uraniferous ore by oxidation with a recycling aqueous liquor containing alkaline carbonates and bicarbonates in solution as well as uranium in a concentration close to its solubility limit at digestion temperature, and of recuperation of the precipitated uranium within the solid phase remaining after digestion. The digestion is carried out by spraying oxygen into the hot reactional medium in order not only to permit oxidation of the uranium and its solubilization but also to ensure that the sulphides of impurities and organic substances present in the ore are oxidized [fr

  1. Discussion on uranium ore-formation age in Xiazhuang ore-field, northern Guangdong

    International Nuclear Information System (INIS)

    Wu Lieqin; Tan Zhengzhong; Liu Ruzhou; Huang Guolong

    2003-01-01

    There exist two genetic types of granite-type uranium deposits, i.e. the early-stage one, and the late-stage one. The early-stage uranium deposits are characterized by ore-formation ages of 122-138 Ma, and are high-grade uranium deposits of postmagmatic hydrothermal origin. The late-stage uranium deposits have ore-formation ages of 54-96 Ma. They mostly are low-grade uranium deposits, and of hydrothermal-regeneration origin with the uranium source derived from the mobilization of consolidated rocks. The early-stage uranium deposits should be the main target of further prospecting for high-grade uranium deposits in the region

  2. Application of isotope techniques to groundwater pollution research for Xiangshan uranium ore field, China

    International Nuclear Information System (INIS)

    Liu Fulin; Liu Peilun; Zhu Chuande; Wu Xiaowei; Zeng Yinsheng

    1998-01-01

    The investigation of groundwater pollution due to uranium deposits focused on the most important uranium metallogenic area-Zhoujiashan district of Xiangshan uranium ore field, China. Groundwater collected from five completed exploration boreholes in the area is regarded as the pollution source and is traced and analysed by using isotope as well as radio-hydrochemical techniques. In addition, the pollution situation of a small uranium ore pile for heap-leaching and a big uranium ore open pit are monitored by the same techniques. It has been experimentally proven that the uranium concentration and the uranium isotope ratio 234 U/ 238 U in natural waters are two sensitive indicators of radioactive pollution in natural waters. It was concluded that under present conditions, exploration of uranium deposits may not cause serious groundwater pollution of radioactive elements (U, Ra, Rn and Th), however, it is difficult to avoid the serious surface water pollution coming from the exploitation of uranium ore by a big open pit. (author)

  3. Concentration of gold, sulphide minerals, and uranium oxide minerals by flotation from ores and metallurgical plant products

    International Nuclear Information System (INIS)

    Weston, D.

    1976-01-01

    A process is described for the concentration by flotation of gold, gold bearing minerals and uranium oxide minerals from ores and metallurgical plant products. A pulp of a ground ore is agitation conditioned in at least two agitation conditioning stages wherein in at least one stage the pH of the pulp is lowered with an acid agent to within the pH range of about 1.5 to 5.0, and wherein in at least one additional agitation conditioning stage the pH of the pulp is raised to within the pH range of about 6.0 to 11.0 and wherein in at least the last stage prior to flotation at least one collector selected from the group of sulfhydryl anionic collectors is present. Subsequently, the at least two stage agitation conditioned pulp is subjected to flotation to produce a flotation concentrate enriched in at least one of the mineral values from the group consisting of gold, gold bearing minerals and uranium minerals

  4. Improvements on heap leaching process for a refractory uranium ore and yellow cake precipitation process

    International Nuclear Information System (INIS)

    Feng Jianke

    2013-01-01

    Some problems such as formed harden matrix, ore heap compaction, poor permeability, and agglomeration of absorption resin occur during extracting uranium from a refractory uranium ore by heap leaching process. After some measures were taken, i.e. spraying a new ore heap by low concentration acid, two or more ore heaps in series leaching, turning ores in ore heap, the permeability was improved, acid consumption was reduced. Through precipitate circulation and aging, the yellow cake slurry in amorphous or microlite form was transformed to crystal precipitate, thus uranium content in yellow cake was improved, and water content in yellow cake was lowered with good economic benefits. (author)

  5. New technology of bio-heap leaching uranium ore and its industrial application in Ganzhou uranium mine

    International Nuclear Information System (INIS)

    Fan Baotuan; Meng Yunsheng; Liu Jian; Meng Jin; Li Weicai; Xiao Jinfeng; Chen Sencai; Du Yuhai; Huang Bin

    2006-10-01

    Bioleaching mechanism of uranium ore is discussed. Incubation and selection of new strain, biomembrane oxidizing tank--a kind of new equipment for bacteria culture and oxidation regeneration of leaching agent are also introduced. The results of industrial experiment and industrial production are summarized. Compared with conventional heap leaching, bioleaching period and acid amount are reduced, oxidant and leaching agent are saved, and uranium concentration in leaching solution is increased. It is the first time to realize industrial production by bio-heap leaching in Chinese uranium mine. New equipment-biomembrane oxidizing tank give the basis of bio-heap leaching industrial application. Bio-heap leaching process is an effective technique to reform technique of uranium mine and extract massive low-content uranium ore in China. (authors)

  6. Uranium ore processing minimizing reagent losses

    International Nuclear Information System (INIS)

    Shaogiang, Chen; Moret, J.; Lyaudet, G.

    1989-01-01

    The uranium ore is treated by sodium carbonates and the solution is divided in two parts: a production solution which is decarbonated by an acid before uranium precipitation with sodium hydroxide and a recycling solution directly treated by sodium hydroxide for precipitation of about 85% of uranium and total transformation of sodium bicarbonate into sodium carbonate, the quantity of sodium hydroxide used on the recycling solution brings sodium ions required for attack of the ore [fr

  7. Bottle roll leach test for Temrezli uranium ore

    International Nuclear Information System (INIS)

    Çetin, K.; Bayrak, M.; Turan, A. İsbir; Üçgül, E.

    2014-01-01

    The bottle roll leach test is one of the dynamic leaching procedure which can meet in-situ mining needs for determining suitable working conditions and helps to simulate one of the important parameter; injection well design. In this test, the most important parameters are pulp density, acidic or basic concentration of leach solution, time and temperature. In recent years, bottle roll test is used not only for uranium but also gold, silver, copper and nickel metals where in situ leach (ISL) mining is going to be applied. For this purpose for gold and silver metal cyanide bottle roll tests and for uranium metal; acidic and basic bottle roll tests could be applied. The new leach test procedure which is held in General Directorate of Mineral Research and Exploration (MTA) of Turkey is mostly suitable for determining metal extraction conditions and recovery values in uranium containing ore bodies. The tests were conducted with samples taken from Temrezli Uranium Ore located in approximately 200 km east of Turkey’s capital, Ankara. Mining rights of Temrezli Ore is controlled 100% by Anatolia Energy Ltd. The resource estimate includes an indicated mineral resource of 10.827 Mlbs U_3O_8 [~4160 t U] at an average grade of 1426 ppm [~1210 ppm U] and an additional inferred resource of 6.587 Mlbs of U_3O_8 [~2530 t U] at an average grade of 904 ppm [~767 ppm U]. In accordance with the demand from Anatolia Energy bottle roll leach tests have been initiated in MTA laboratories to investigate the recovery values of low-grade uranium ore under in-situ leach conditions. Bottle roll leaching tests are performed on pulverized samples with representative lixiviant solution at ambient pressure and provide an initial evaluation of ore leachability with a rough estimate of recovery value. At the end of the tests by using 2 g/L NaHCO_3 and 0.2 g/L H_2O_2 more than 90% of uranium can pass into leach solution in 12 days. (author)

  8. Treatment of waste water from uranium ore preparation

    International Nuclear Information System (INIS)

    Klicka, V.; Mitas, J.; Vacek, J.

    1976-01-01

    An improved closed-loop process is described for treating waste water resulting from chemical extraction of uranium from ore. The water is evaporated to form a concentrated solution and is then subjected to crystallization of the least soluble salt component thereof via further evaporation, or cooling or simultaneous cooling and a partial vacuum. The crystallized component is then separated from the mother liquor, whereupon the latter is fed back after removal of residual uranium therefrom to the extraction installation to replace the acids used therein. Additionally, the pure condensate produced during evaporation of the waste waters is employed as a replacement for the fresh water employed in processing of the ore. 6 claims, 2 figures

  9. Sensibility test for uranium ores from Qianjiadian sandstone type uranium deposit

    International Nuclear Information System (INIS)

    Zhang Mingyu

    2005-01-01

    Sensibility tests for uranium ores from Qianjiadian sandstone type uranium deposit in Songliao Basin which is suitable to in-situ leach are carried out, including water sensibility, velocity sensibility, salt sensibility, acid sensibility and alkaline sensibility. The sensibility critical value of this ore is determined. Some references on mining process and technical parameter are provided for in-situ leaching of uranium. (authors)

  10. Uranium Processing Research in Australia [Processing of Low-Grade Uranium Ores

    Energy Technology Data Exchange (ETDEWEB)

    Stewart, J R [Australian Atomic Energy Commission, Coogee, N.S.W. (Australia)

    1967-06-15

    Uranium processing research in Australia has included studies of flotation, magnetic separation, gravity separation, heavy medium separation, atmospheric leaching, multi-stage leaching, alkali leaching, solar heating of leach pulps, jigged-bed resin-in-pulp and solvent-in-pulp extraction. Brief details of the results obtained are given. In general, it can be said that gravity, magnetic and flotation methods are of limited usefulness in the treatment of Australian uranium ores. Alkali leaching seldom gives satisfactory recoveries and multi-stage leaching is expensive. Jigged-bed resin-in-pulp and packed tower solvent-in-pulp extraction systems both show promise, but plant-scale development work is required. Bacterial leaching may be useful in the case of certain low-grade ores. The main difficulties to be overcome, either singly or in combination, in the case of Australian uranium ores not currently considered economically exploitable, are the extremely finely divided state of the uranium mineral, the refractory nature of the uranium mineral and adverse effects due to the gangue minerals present. With respect to known low-grade ores, it would be possible in only a few cases to achieve satisfactory recovery of uranium at reasonable cost by standard treatment methods. (author)

  11. Bacteria heap leaching test of a uranium ore

    International Nuclear Information System (INIS)

    Liu Hui; Liu Jinhui; Wu Weirong; Han Wei

    2008-01-01

    Column bioleaching test of a uranium ore was carried out. The optimum acidity, spraying intensity, spray-pause time ratio were determined. The potential, Fe and U concentrations in the leaching process were investigated. The effect of bacteria column leaching was compared with that of acid column leaching. The results show that bacteria column leaching can shorten leaching cycle, and the leaching rate of uranium increases by 9.7%. (authors)

  12. The treatment of uranium ores

    International Nuclear Information System (INIS)

    Michel, P.

    1979-01-01

    After having described the main steps in the treatment of uranium ores, the author describes the treament activities for these ores, as they are organized in France and in the African countries having made cooperation agreements with France in this field [fr

  13. Critical evaluation of safety and radiological protection requirements adopted for the transport of uranium and thorium ores and concentrates

    International Nuclear Information System (INIS)

    Mezrahi, Arnaldo; Crispim, Verginia R.

    2009-01-01

    This work evaluates in a critical way the safety and radiological protection recommendations established by the International Atomic Energy Agency - IAEA and adopted national and internationally, for the transport of uranium and thorium ores and concentrates, known according the transport regulations, as being of the Low Specific Activity Material Type-I, LSA-I, basing on more realistic scenarios than the presently existent, aiming at the determination of maximum exposure levels of radiation as well as the maximal contents of those materials in packages and conveyance. A general overview taking into account the scenarios foreseen by the regulations of the IAEA pointed out for a need of a better justification of the requirements edited by the Agency or should be used to support a request of revision of those regulations, national and internationally adopted, in the pertinent aspects to the transport of uranium and thorium ores and concentrates. (author)

  14. Ore-processing technology and the uranium supply outlook

    International Nuclear Information System (INIS)

    James, H.E.; Simonsen, H.A.

    1978-01-01

    The subject is covered in sections, as follows: the resource base (uranium content of rocks, regional distribution of Western World uranium); ore types (distribution of Western World uranium, by ore types, response to ore-processing); constraints on expansion in traditional uranium areas (defined for this paper as the sandstone deposits of the U.S.A. and the quartz-pebble conglomerates of the Witwatersrand and Elliot Bay areas, all other deposits being referred to as new uranium areas). Sections then follow dealing in detail with the processing of deposits in U.S.A., South Africa, Canada, Niger, Australia, South West Africa, Greenland. More general sections follow on: shale, lignite and coal deposits, calcrete deposits. Finally, there are sections on: uranium as a by-product; uranium from very low-grade resources; constraints on expansion rate for production facilities. (U.K.)

  15. Commercial test on uranium ore percolation leaching in Fuzhou uranium mine

    International Nuclear Information System (INIS)

    Cai Chunhui

    2002-01-01

    Commercial test on uranium ore percolation leaching was carried out according to ore characteristics of Fuzhou Uranium Mine and results from small test. Technological and economic indexes, such as leaching rate, acid consumption, leaching cycle, etc. are discussed. The general idea applying the test results to commercial production is presented, too

  16. Species of organic matter and their role in the formation of statiform uranium ores

    International Nuclear Information System (INIS)

    Goleva, P.K.; Uspenskij, V.A.

    1983-01-01

    Results of investigation of organic mather (OM) from stratiform uranium ore manifestation in sedimentary Upper Proterozoic rocks of large trough with caledonian folded base are given. Role of OM in concentration of uranium-ore formations of two ore-bearing horizons, presented by rocks of facies of large lakes (''lacustrine'') and continental deltas (''alluvial'') was clarified. Characteristics of OM of rocks of ''lacustrine'' and ''alliivial'' facies, OM types, chemical composition of OM of ''alluvial'' horizon rocks, om spectrograms and diffractograms are presented. It was established that OM of ''lacustrine'' and ''alluvial'' ore-bearing horizons are presented by different morphological and genetic types, which played different roles in t.he process of uranium ore-formation. Faneiy dispersed OM, related to the category of oxidized lower kerites is present in ''lacustrine'' horizon. Ore uranium-arsenide nuneral association substitutes OM of early generation. The latest OM generation is related to epigenetic thread veinlet of dolomite and barite. In ''alluvial'' horizon OM is present in the form of carbonized vegetative residues+ ciosely assocaating with sulfides of different metals, and is presented by high-moiecular carbocyctnc hydroxy compouds. Uranium of carbonized vegetative residues is in finely dispersed state; the form of its fixation was not established. It is proposed that the major part of uranium was sorbed by OM during sedimentogenesis

  17. Biomineral processing of high apatite containing low-grade indian uranium ore

    International Nuclear Information System (INIS)

    Abhilash; Mehta, K.D.; Pandey, B.D.; Ray, L.; Tamrakar, P.K.

    2010-01-01

    Microbial species isolated from source mine water, primarily an enriched culture of Acidithiobacillus ferrooxidans was employed for bio-leaching of uranium from a low-grade apatite rich uranium ore of Narwapahar Mines, India while varying pH, pulp density (PD), particle size, etc. The ore (0.047% U_3O_8), though of Singhbhum area (richest deposit of uranium ores in India), due to presence of some refractory minerals and high apatite (5%) causes a maximum 78% recovery through conventional processing. Bioleaching experiments were carried out by varying pH at 35"oC using 20%(w/v) PD and <76μm size particles resulting in 83.5% and 78% uranium bio-recovery at 1.7 and 2.0 pH in 40 days as against maximum recovery of 46% and 41% metal in control experiments respectively. Finer size (<45μm) ore fractions exhibited higher uranium dissolution (96%) in 40 days at 10% (w/v) pulp density (PD), 1.7 pH and 35"oC. On increasing the pulp density from 10% to 20% under the same conditions, the biorecovery of uranium fell down from 96% to 82%. The higher uranium dissolution during bioleaching at 1.7 pH with the fine size particles (<45μm) can be correlated with increase in redox potential from 598 mV to 708 mV and the corresponding variation of Fe(III) ion concentration in 40 days. (author)

  18. Biomineral processing of high apatite containing low-grade indian uranium ore

    Energy Technology Data Exchange (ETDEWEB)

    Abhilash; Mehta, K.D.; Pandey, B.D., E-mail: biometnml@gmail.com [National Metallurgical Laboratory (CSIR), Jamshedpur (India); Ray, L. [Jadavpur Univ., FTBE Dept., Kolkata (India); Tamrakar, P.K. [Uranium Corp. of India Limited, CR& D Dept., Jaduguda (India)

    2010-07-01

    Microbial species isolated from source mine water, primarily an enriched culture of Acidithiobacillus ferrooxidans was employed for bio-leaching of uranium from a low-grade apatite rich uranium ore of Narwapahar Mines, India while varying pH, pulp density (PD), particle size, etc. The ore (0.047% U{sub 3}O{sub 8}), though of Singhbhum area (richest deposit of uranium ores in India), due to presence of some refractory minerals and high apatite (5%) causes a maximum 78% recovery through conventional processing. Bioleaching experiments were carried out by varying pH at 35{sup o}C using 20%(w/v) PD and <76μm size particles resulting in 83.5% and 78% uranium bio-recovery at 1.7 and 2.0 pH in 40 days as against maximum recovery of 46% and 41% metal in control experiments respectively. Finer size (<45μm) ore fractions exhibited higher uranium dissolution (96%) in 40 days at 10% (w/v) pulp density (PD), 1.7 pH and 35{sup o}C. On increasing the pulp density from 10% to 20% under the same conditions, the biorecovery of uranium fell down from 96% to 82%. The higher uranium dissolution during bioleaching at 1.7 pH with the fine size particles (<45μm) can be correlated with increase in redox potential from 598 mV to 708 mV and the corresponding variation of Fe(III) ion concentration in 40 days. (author)

  19. Status Report from Czechoslovakia [Processing of Low-Grade Uranium Ores

    Energy Technology Data Exchange (ETDEWEB)

    Civin, V; Belsky, M [Research and Development Laboratory No.3 of the Uranium Industry, Prague, Czechoslovakia (Czech Republic)

    1967-06-15

    The present paper deals with the fundamental problems and the main routes followed in processing low-grade uranium ores in CSSR. In this connection it may be useful to discuss the definition of low-grade ore. In our country this term is applied to uraniferous material with a very low content of uranium (of the order of 0.01%) whose treatment causes no particular difficulty. However, the same term is also used to designate those materials whose processibility lies on the verge of economic profitability. In our view, this classification, of an ore using two independent criteria (i.e. uranium content and processing economy) is useful from the standpoint of technology. The treatment of both such ore types is as a rule carried out by specific technological processes. Consequently, low-grade uranium ores can be divided into two groups: (1) Ores with a low uranium content. To this category belong in our country uraniferous materials which originate as a by-product of technological processes used in processing other materials. This is primarily gangue and tailings of various physical or physico-chemical pretreatment operations to which the ore is subjected at the mining site. Mention should be made in this connection of mine waters, which represent a useful complementary source of uranium despite their low uranium content (of the order of milligrams per litre). (2) Ores whose economical treatment is problematic. To this category belong deposits of conventional ore types with a uranium content on the limit of profitable treatment. Also, those deposits containing atypical materials possessing such properties which impair the economy of their treatment. This includes ores with a considerable amount of components which are difficult to separate and which at the same time consume the leaching agents. Finally, it covers uranium-bearing materials in refractory forms which are difficult to dissolve and also some special materials, such as lignites, uranium-bearing shales, loams

  20. PROCESS OF RECOVERING URANIUM FROM ITS ORES

    Science.gov (United States)

    Galvanek, P. Jr.

    1959-02-24

    A process is presented for recovering uranium from its ores. The crushed ore is mixed with 5 to 10% of sulfuric acid and added water to about 5 to 30% of the weight of the ore. This pugged material is cured for 2 to 3 hours at 100 to 110 deg C and then cooled. The cooled mass is nitrate-conditioned by mixing with a solution equivalent to 35 pounds of ammunium nitrate and 300 pounds of water per ton of ore. The resulting pulp containing 70% or more solids is treated by upflow percolation with a 5% solution of tributyl phosphate in kerosene at a rate equivalent to a residence time of about one hour to extract the solubilized uranium. The uranium is recovered from the pregnant organic liquid by counter-current washing with water. The organic extractant may be recycled. The uranium is removed from the water solution by treating with ammonia to precipitate ammonium diuranate. The filtrate from the last step may be recycled for the nitrate-conditioning treatment.

  1. Comparison of oxidants in alkaline leaching of uranium ore

    International Nuclear Information System (INIS)

    Sreenivas, T.; Rajan, K.C.; Srinivas, K.; Anand Rao, K.; Manmadha Rao, M.; Venkatakrishnan, R.R.; Padmanabhan, N.P.H.

    2007-01-01

    The uranium minerals occurring in various ore deposits consists of predominantly uranous ion (U +4 ), necessitating use of an oxidant and other lixiviants for efficient dissolution during leaching. Unlike acid leaching route, where uranium minerals dissolution could be achieved efficiently with cheaper lixiviants, processing of ores by alkaline leaching route involve expensive lixiviants and drastic leaching conditions. Alkaline leaching of uranium ores becomes economical only upon using cheaper and efficient oxidants and conservation of other reagents by their recycle. The present paper gives efficacy of various oxidants - KMnO 4 , NaOCl, Cu - NH 3 , air and oxygen, in the leaching of uranium from a low-grade dolostone hosted uranium ore of India. A comparison based on technical merits and cost of the oxidant chemicals is discussed. (author)

  2. Growth characteristics of a strain of iron-oxidizing bacterium and its application in bioleaching of uranium ores

    International Nuclear Information System (INIS)

    Zhang Rui; Liu Yajie; Gao Feng; Xu Lingling

    2008-01-01

    05B is a strain of iron-oxidizing bacterium which separated from a uranium ore. The effect of temperature, initial pH, inoculation amount and initial total iron concentration on the strain's growth and activities in bioleaching of uranium ores are studied. The results show that the optimum growth temperature is 40-45 degree C, the optimum inoculation pH value being 1.5-1.7, the optimum initial inoculation amount being 10%-20%, and the initial total iron concentration being not more than 5 g/L. 05B is fit for leaching of low grade uranium ores. (authors)

  3. Radiometric sorting of Rio Algom uranium ore

    International Nuclear Information System (INIS)

    Cristovici, M.A.

    1983-11-01

    An ore sample of about 0.2 percent uranium from Quirke Mine was subjected to radiometric sorting by Ore Sorters Limited. Approximately 60 percent of the sample weight fell within the sortable size range: -150 + 25 mm. Rejects of low uranium content ( 2 (2 counts/in 2 ) but only 7.6 percent of the ore, by weight, was discarded. At 0.8-0.9 counts/cm 2 (5-6 counts/in 2 ) a significant amount of rejects was removed (> 25 percent) but the uranium loss was unacceptably high (7.7 percent). Continuation of the testwork to improve the results is proposed by trying to extend the sortable size range and to reduce the amount of fines during crushing

  4. Study of the dry processing of uranium ores; Etude des traitements de minerais d'uranium par voie seche

    Energy Technology Data Exchange (ETDEWEB)

    Guillet, H

    1959-02-01

    A description is given of direct fluorination of pre-concentrated uranium ores in order to obtain the hexafluoride. After normal sulfuric acid treatment of the ore to eliminate silica, the uranium is precipitated by a load of lime to obtain: either impure calcium uranate of medium grade, or containing around 10% of uranium. This concentrate is dried in an inert atmosphere and then treated with a current of elementary fluorine. The uranium hexafluoride formed is condensed at the outlet of the reaction vessel and may be used either for reduction to tetrafluoride and the subsequent manufacture of uranium metal or as the initial product in a diffusion plant. (author) [French] Il s'agit d'une description de fluoration directe de preconcentres de minerais d'uranium en vue d'obtention d'hexafluorure. Apres attaque sulfurique normale du minerai, afin d' eliminer la silice, l' uranium est precipite par un toit de chaux pour obtenir: ou uranate de chaux impur de titre moyen, ou uranium de la dizaine du pourcentage. Ce concentre seche en atmosphere inerte est soumis a un courant de fluor elementaire. L'hexafluorure d'uranium forme est condense a la sortie du reacteur et peut etre utilise soit apres reduction en tetrafluorure par l'elaboration d'uranium metal, soit comme produit de base dans le cadre d'une usine de diffusion. (auteur)

  5. Methods for the estimation of uranium ore reserves

    International Nuclear Information System (INIS)

    1985-01-01

    The Manual is designed mainly to provide assistance in uranium ore reserve estimation methods to mining engineers and geologists with limited experience in estimating reserves, especially to those working in developing countries. This Manual deals with the general principles of evaluation of metalliferous deposits but also takes into account the radioactivity of uranium ores. The methods presented have been generally accepted in the international uranium industry

  6. Mineralogical and paragenetical problems of the Mecsek uranium ore

    International Nuclear Information System (INIS)

    Vincze, J.; Fazekas, V.

    1979-01-01

    The latest results of the ore-mineralogical examination of the uranium ore of a deposit included in Permian sandstones in the Mecsek Mountains, southern Hungary, are presented. The phases of the minerals belonging to the uranium oxide series and their types of development, the post-coffinite nasturan pseudomorphs and the relationship between nasturan and coffinite are dealt with. Of the sulphide ore minerals associated with uranium ore mineralization the type determinant mineral is pyrite, i.e. the mineral forming their bulk and partly represented by characteristically finely aggregated ''bacteriopyrite'' and/or spherical pyrite and ''framboidal pyrite. The textural pattern of the ore mineralization is of typically matrix type. The matrix of sandstone is constituted by carbonate minerals, ''hydromicas'' and ore minerals. The matrix and, consequently, the ore minerals will corrode and consume the allothigenic detrital rockforming minerals, the feldspar, quartz-porphyry and quartz. (A.L.)

  7. Preconcentration of low-grade uranium ores with environmentally acceptable tailings, part I

    International Nuclear Information System (INIS)

    Raicevic, D.; Raicevic, M.; McCarthy, D.R.

    1979-08-01

    The low-grade ore sample used for this investigation originated from Agnew Lake Mines Limited, Espanola, Ontario. It contained about 1% pyrite and 0.057% uranium, mainly as uranothorite with a small amount of brannerite. Both of these minerals occur in the quartz-sericite matrix of a conglomerate. A preconcentration process has been developed to give a high uranium recovery, reject pyrite, radium and thorium from the ore and produce environmentally acceptable tailings. This process applies flotation in combination with high intensity magnetic separation and gravity concentration

  8. Method of removing uranium and its compounds from mine wastewaters and from aqueous solutions discharged in hydrometallurgical uranium ore treatment

    International Nuclear Information System (INIS)

    Jilek, R.; Prochazka, H.; Kuhr, I.; Fuska, J.; Nemec, P.; Katzer, J.

    1974-01-01

    The separation of uranium and its compounds from mine wastewaters and from water solutions discharged from uranium ore hydrometallurgical treatment, and its eventual simultaneous concentration in the biomass during uranium ore technological processing are described. The solutions are replenished with nutrients necessary for the growth of microorganisms, mainly with nitrogen, carbon and phosphorus and inoculated with fungi. During submersion cultivation, uranium incorporates in the mycelium, or is bound physico-chemically to the mycelium components. Together with these components, uranium is mechanically separated, i.e., by filtration, centrifugation or sedimentation. Organisms of the Fungi imperfecti class, mainly the Aspergillus and Penicillium genera are used for cultivation which may be continuous or semicontinuous. (B.S.)

  9. 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)

  10. 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

  11. Uranium ore mill at Dolni Rozinka: 40 years of operation

    International Nuclear Information System (INIS)

    Toman, F.; Jezova, V.

    2007-01-01

    Uranium ore mined in the Rozna deposit is treated at a chemical treatment plant (a mill) situated in the close vicinity of the Rozna mine. In the mill, uranium is extracted from the crushed and ground-up ore by alkaline leaching. Uranium is then recovered from the solution by sorption on ion exchange resin; the next steps are precipitation and drying. Alkaline leaching is applied at the atmospheric pressure and the temperature of 80 deg C; the recovery factor is moving around 93%. The final product of the milling is uranium concentrate, ammonium diuranate (NH 4 ) 2 U 2 O 7 ), a so-called 'yellow cake' which is treated into a fuel for nuclear power plants in conversion facilities abroad. The milling is carried on under the condition of the closed cycle of technology water. Due to the positive annual precipitation balance, the over balance of technology water in tailings pond has to be purified before discharging into a river. Evaporation and membrane processes (electrodialysis and reverse osmosis) are used to purify the water. The mill at Dolni Rozinka has been in operation since 1968. It has processed 13.2 million tons of uranium ore which is about 14000 tons of uranium and purified more than 6 million m 3 of the over balanced technology water during 40 years. From the organizational point of view, the mine and the chemical treatment plant form the branch plant GEAM, which is a part of the state enterprise DIAMO. (author)

  12. Management of wastes containing radioactivity from mining and milling uranium ores in Northern Australia

    International Nuclear Information System (INIS)

    Costello, J.M.

    1977-01-01

    The procedures and controls to achieve safe management of wastes containing radioactivity during the mining and processing of uranium ores are mainly site-specific depending on the nature, location and distribution of the ore and gangue material. Waste rock and below-ore-grade material containing low levels of radioactivity require disposal at the mine site. In open-cut mining the material is generally stockpiled above ground, with revegetation and collection of run-off water. Some material may be used to backfill open cuts. Management of these wastes requires a thorough investigation of groundwater hydrology and surface soil characteristics to control dissipation of radioactive material. Dust containing radon and radioactive particulate is produced during ore milling, and dusts of ore concentrate are generated during calcination and packaging of the yellowcake product. These dusts are managed by ventilation and filtration systems; working conditions and discharges to atmosphere will be according to the Australian Code of Practice on Radiation Protection during Mining and Milling of Uranium Ores. The chemical waste stream from leaching and processing of the uranium ores contains most of the radioactivity resulting from radium and its decay products. Neutralized effluent is discharged into holding ponds for settling solids. The paper describes the nature of wastes containing radioactivity resulting from the mining and milling of uranium, and illustrates modern engineering practices and monitoring procedures to manage the wastes, as described in the Environmental Impact Statement produced by Ranger Uranium Mines Pty Ltd (RUM) for public hearings. (author)

  13. Experiment on bio-leaching of associated molybdenum and uranium ore

    International Nuclear Information System (INIS)

    Zheng Ying; Fan Baotuan; Liu Jian; Meng Yunsheng; Liu Chao

    2007-01-01

    Column leaching experiment results on associated molybdenum uranium ore by bacteria (T. f) are introduced. The ore are leached for 210 days using bacteria domesticated to tolerate molybdenum, the leaching of uranium is of 98% and leaching of molybdenum is of 41%. Sulphuric acid produced by bio-oxidation of sulfides in ore can meet the demand of ore leaching. (authors)

  14. Code of Practice on radiation protection in the mining and milling of radioactive ores (1980) - Guidelines for storage and packaging of uranium concentrates

    International Nuclear Information System (INIS)

    1986-01-01

    This Guideline is intended to provide assistance in the application of the 1980 Code of Practice on radiation protection in mining and milling of radioactive ores. Its purpose is to give advice relevant to the design, construction and operation of an uranium concentrate storage and packaging facility in which exposure to ionizing radiation from uranium-bearing concentrate will not only conform to the Code, but will also be as low as reasonably achievable. (NEA) [fr

  15. Zeolitization at uranium ore manifestation

    International Nuclear Information System (INIS)

    Petrosyan, R.V.; Buntikova, A.F.

    1981-01-01

    The process of zeolitization at uranium ore manifestation is studied. A specific type of low-temperature wall endogenous alteration of rocks due to the effect of primary acid solution with low content of carbonic acid is established. Leaching of calcium from enclosing rocks and its deposition in ore-accompanying calcium zeolites is a characteristic feature of wall-metasomatosis. Formation of desmin- calcite-laumontite and quartz-fluoroapatite of vein associations, including ore minerals (uranophane and metaotenite), is genetically connected with calcium metasomatosis. On the basis of the connection of ore minerals with endogeneous process of zeolitization a conclusion can be made on endogenous origin of uranophane and metaotenite [ru

  16. Uranium mobilization from low-grade ore by cyanobacteria

    International Nuclear Information System (INIS)

    Lorenz, M.G.; Krumbein, W.E.

    1985-01-01

    Three cyanobacterial isolates (two LPP-B forms and one Anabaena or Nostoc species) from different environments could mobilize uranium from low-grade ores. After 80 days, up to 18% uranium had been extracted from coal and 51% from a carbonate rock by the filamentous cyanobacterium OL3, a LPP-B form. Low growth requirements with regard to light and temperature optima make this strain a possible candidate for leaching neutral and alkaline low-grade uranium ores. (orig.)

  17. Uranium mobilization from low-grade ore by cyanobacteria

    Energy Technology Data Exchange (ETDEWEB)

    Lorenz, M.G.; Krumbein, W.E.

    1985-04-01

    Three cyanobacterial isolates (two LPP-B forms and one Anabaena or Nostoc species) from different environments could mobilize uranium from low-grade ores. After 80 days, up to 18% uranium had been extracted from coal and 51% from a carbonate rock by the filamentous cyanobacterium OL3, a LPP-B form. Low growth requirements with regard to light and temperature optima make this strain a possible candidate for leaching neutral and alkaline low-grade uranium ores.

  18. Possible uranium sources of Streltsovsky uranium ore field

    International Nuclear Information System (INIS)

    Zhang Lisheng

    2005-01-01

    The uranium deposit of the Late Jurassic Streltsovaky caldera in Transbaikalia of Russia is the largest uranium field associated with volcanics in the world, its uranium reserves are 280 000 t U, and it is the largest uranium resources in Russia. About one third of the caldera stratigraphic pile consists of strongly-altered rhyolites. Uranium resources of the Streltsovsky caldera are much larger than any other volcanic-related uranium districts in the world. Besides, the efficiency of hydrothermal alteration, uranium resources appear to result from the juxtaposition of two major uranium sources; highly fractionated peralkaline rhyolites of Jurassic age in the caldera, and U-rich subalkaline granites of Variscan age in the basement in which the major uranium-bearing accessory minerals were metamict at the time of the hydrothermal ore formation. (authors)

  19. Uranium ore processing in Spain

    International Nuclear Information System (INIS)

    Josa, J.M.

    1976-01-01

    The paper presents a review of the Spanish needs of uranium concentrates and uranium ore processing technology and trends in Spain. Spain produces approximately 200t U 3 O 8 /a at two facilities. One plant in the south (Andujar, Jaen) can obtain 70t U 3 O 8 /a and uses a conventional acid leaching process with countercurrent solvent extraction. A second plant, situated in the west (Ciudad Rodrigo, Salamanca) has started in 1975 and has a capacity of 120-130t U 3 O 8 /a, using acid heap leaching and solvent extraction. There is another experimental facility (Don Benito, Badajoz) scheduled to start in 1976 and expected to produce about 25-35t U 3 O 8 /a as a by-product of the research work. For the near future (1978) it is hoped to increase the production with: (a) A new conventional acid leaching/solvent extraction plant in Ciudad Rodrigo; its tentative capacity is fixed at 550t U 3 O 8 /a. (b) A facility in the south, to recover about 130t U 3 O 8 /a from phosphoric acid. (c) Several small mobile plants (30t U 3 O 8 /a per plant); these will be placed near small and isolated mines. The next production increase (1979-1980) will come with the treatment of sandstones (Guadalajara and Cataluna) and lignites(Cataluna); this is being studied. There are also research programmes to study the recovery of uranium from low-grade ores (heap, in-situ and bacterial leaching) and from other industries. (author)

  20. Developments of uranium and gold ores heap leaching technologies

    International Nuclear Information System (INIS)

    Tian Yuan; Guan Zibin; Gao Renxi

    1998-01-01

    The author reviews developments in heap leaching of uranium and gold ores at home and abroad, summarises condition of application. The author also presents problems having to be studied and settled urgently in heap leaching of uranium and gold ores in China

  1. Study of the dry processing of uranium ores; Etude des traitements de minerais d'uranium par voie seche

    Energy Technology Data Exchange (ETDEWEB)

    Guillet, H

    1959-02-01

    A description is given of direct fluorination of pre-concentrated uranium ores in order to obtain the hexafluoride. After normal sulfuric acid treatment of the ore to eliminate silica, the uranium is precipitated by a load of lime to obtain: either impure calcium uranate of medium grade, or containing around 10% of uranium. This concentrate is dried in an inert atmosphere and then treated with a current of elementary fluorine. The uranium hexafluoride formed is condensed at the outlet of the reaction vessel and may be used either for reduction to tetrafluoride and the subsequent manufacture of uranium metal or as the initial product in a diffusion plant. (author) [French] Il s'agit d'une description de fluoration directe de preconcentres de minerais d'uranium en vue d'obtention d'hexafluorure. Apres attaque sulfurique normale du minerai, afin d' eliminer la silice, l' uranium est precipite par un toit de chaux pour obtenir: ou uranate de chaux impur de titre moyen, ou uranium de la dizaine du pourcentage. Ce concentre seche en atmosphere inerte est soumis a un courant de fluor elementaire. L'hexafluorure d'uranium forme est condense a la sortie du reacteur et peut etre utilise soit apres reduction en tetrafluorure par l'elaboration d'uranium metal, soit comme produit de base dans le cadre d'une usine de diffusion. (auteur)

  2. Low grade uranium ores as potential sources of raw material

    International Nuclear Information System (INIS)

    Venzlaff, H.

    1976-01-01

    Reports on the uranium requirement and the uranium reserves show that, even if the demand were to be stretched out slightly, the rate of new discoveries of uranium would have to be doubled or even tripled within a few years in order to ensure supply. Despite some spectacular discoveries of large scale deposits in Australia it must be said that only very few truly new uranium provinces have been discovered over the past twenty years. In this situation more attention is now being devoted to low grade uranium depositis, to findings whose concentration does not exceed 1,000 ppm. These deposits contain quantities of uranium many times larger than the deposits that can now be mined at prices up to 30/lb of U 3 O 8 . Even now low grade uranium ore is being mined as a byproduct, with the actual valuable mineral producing most of the income from mining activities. However, if one strikes a balance in this situation, one finds that only part of the requirement can be met in this way. Hence, all possibilities must be exhausted to mine uranium as a byproduct, new techniques of uranium production from low grade ores must be developed, and also conventional prospection must be intensified, if the continuity of supply of the nuclear power stations in the eighties and nineties is to be guaranteed. (orig.) [de

  3. A new approach for the high-precision determination of the elemental uranium concentration in uranium ore by gamma-ray spectrometry

    International Nuclear Information System (INIS)

    Nagel, W.; Quik, F.

    1993-01-01

    A new approach for the determination of elemental uranium in uranium bearing ore, using high resolution gamma-ray spectrometry, was applied. Using a variant of the enrichment meter technique an agreement of better than 1% has been obtained between gamma-ray measurement results and the certified value obtained by other analytical methods. For the calibration of the gamma-ray spectrometer uranium reference samples have been used which are made available jointly in Europe and the USA as Certified Reference Materials for Gamma-ray Spectrometry (EC NRM 171 and NBS SRM 969, respectively). The measured ore has been put in a special designed container which ensured in all directions seen from the radiation window a uniform degree of infinite thickness of about 95%. The measurement results can be taken as an example for the applicability of gamma-ray spectrometry when high accuracy is required and under conditions where homogeneous distributed elemental uranium is embedded in a larger amount of matrix material. (author). 8 refs., 10 figs., 2 tabs., 2 appendices

  4. Recovery of uranium and molybdenum from a carbonate type uranium-molybdenum ore

    International Nuclear Information System (INIS)

    Zhou Genmao; Zeng Yijun; Tang Baobin; Meng Shu; Xu Guolong

    2014-01-01

    Based on the results of process mineralogical research of a carbonate type uranium-molybdenum ore, leaching behaviors of the uranium-molybdenum ore were studied by alkali agitation leaching, conventional alkali column leaching and alkali curing column leaching processes. The results showed that using the alkali curing column leaching process, the leaching rate of molybdenum increased to more than 90%, and the leaching rate of uranium was about 85%, Compared with the conventional alkali column leaching process, the leaching time of the alkali curing column leaching process decreased by 60 days. (authors)

  5. Certain distribution characteristics of uranium and thorium in apatite-carbonate ores

    Energy Technology Data Exchange (ETDEWEB)

    Kharitonova, R Sh; Faizullin, R N; Kozlov, E N; Berman, I B

    1979-01-01

    A study of the total radioactivity, uranium content, thorium content, U/Th ratio, and the spatial distribution of uranium by the f-radiographic method has demonstrated that the apatite ores of the deposit contain elevated concentrations of radioactive elements that are essentially of thorium origin. The main concentration of uranium and thorium is in the cinnemon-brown apatite. Elevated uranium concentrations are also found in hematite and accessory minerals (monacite, zirconium, titanite). Dolomite, quartz, martite, and second generation apatite were found to be weakly radioactive. The uranium and thorium concentration is correlated to the concentration of phosphorus and other petrogenic elements. An analysis of uranium, thorium, and Th/U distribution indicates that the concentration of radioactive elements is not caused by their primary content in carbonate rock but by the outside introduction of these elements together with phosphorus. The cited analyses confirm the chemogenic-sedimentary origin of the dolomite substrate and the metamorphogenic hydrothermal genesis of apatite mineralization. The data on radioactivity may be used as a reliable exploratory criterion for apatite potential. 3 references, 3 figures.

  6. An unusual feature of uranium ore from Domiasiat, Meghalaya: presence of water soluble uranium

    International Nuclear Information System (INIS)

    Singh, A.K.; Padmanabhan, N.P.H.; Sivaramakrishnan, K.; Krishna Rao, N.

    1993-01-01

    An unusual feature of the recently discovered sandstone-type uranium deposit in Domiasiat is the presence of appreciable amount of water soluble uranium. With normal tap water at its natural pH (7.5-7.8), upto 35% of the uranium in the ore was found to be soluble during agitation in the different samples. Presence of other ions in appreciable quantities particularly SO 4 -2 Cl - and Fe +3 appear to influence the dissolution. Percolation experiments give terminal solubilization of upto 58%, but the instantaneous uranium concentration in the percolating water attains its maximum within the first few minutes of contact. A detailed study on the chemistry of uranium dissolution may throw light on the physico-chemical controls of localization of uranium in the deposit. (author). 7 refs., 3 tabs., 4 tabs

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

    OpenAIRE

    Gongxin Chen; Zhanxue Sun; Yajie Liu

    2016-01-01

    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. Howev...

  8. Concentration factors of uranium mineralization in VII depositional cycle of Shuixigou group, lower-middle Jurassic at Wukurqi uranium deposit, Yili basin

    International Nuclear Information System (INIS)

    Liu Taoyong

    2004-01-01

    Starting with the analysis on uranium mineralization, this paper emphatically discusses factors related to uranium concentration in VII depositional cycle, such as the structure, the paleoclimate, the lithofacies-paleogeography, the lithology, the hydrogeology, the geochemistry, and the content of effective reductant. The author suggests that key factors of uranium migration and concentration at Wukurqi uranium deposit are the existence of ore-hosting formation (sand body), the long-term recharge of oxygen and uranium-bearing groundwater, the existence of effective reductant in ore-hosting formation

  9. IAEA sends out samples of uranium ore

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    1966-06-15

    Full text: Governments and organizations interested in developing uranium resources will be assisted by a new service, now being inaugurated by the Agency's laboratories, for the distribution of reference samples of uranium ores. This is an addition to the service which began at Seibersdorf in January 1962 for the distribution of calibrated radionuclides, and which has met with a steadily increasing demand. * Uranium deposits consisting of ores with a uranium content in the range 0.5 - 0.05 per cent occur in a number of countries, including developing countries and can present considerable analytical difficulties. In 1962 the Agency asked Member States whether they would be interested in receiving reference samples of uranium ores to assist them in checking their methods of chemical analysis. The response encouraged the Agency to proceed. There is a multiplicity of types of uranium ores and, initially, three of the most commonly occurring have been selected - torbernite, uraninite and carnotite. Member States have provided the laboratory with supplies of these three types of ore. In order to determine the uranium content, samples are sent to leading laboratories throughout the world, so as to arrive at the most accurate values possible. This work has proved to be useful to the laboratories themselves ; in searching for reasons for discrepancies between the different collaborating laboratories, they enlarge their own knowledge and improve their methods. The reference samples are sent out in the form of fine powder, and are available to atomic energy commissions, research laboratories or mining companies. The requesting laboratory, having worked out the analytical process best suited to its needs, is then able to check its results by analysing an IAEA reference sample of known uranium content. By the end of 1966, reference samples will be available of the three ores mentioned, and later also of pure uranium oxide and of uranium oxide containing trace impurities, the

  10. Status Report from the United Kingdom [Processing of Low-Grade Uranium Ores

    Energy Technology Data Exchange (ETDEWEB)

    North, A A [Warren Spring Laboratory, Stevenage, Herts. (United Kingdom)

    1967-06-15

    The invitation to present this status report could have been taken literally as a request for information on experience gained in the actual processing of low-grade uranium ores in the United Kingdom, in which case there would have been very little to report; however, the invitation naturally was considered to be a request for a report on the experience gained by the United Kingdom of the processing of uranium ores. Lowgrade uranium ores are not treated in the United Kingdom simply because the country does not possess any known significant deposits of uranium ore. It is of interest to record the fact that during the nineteenth century mesothermal vein deposits associated with Hercynian granite were worked at South Terras, Cornwall, and ore that contained approximately 100 tons of uranium oxide was exported to Germany. Now only some 20 tons of contained uranium oxide remain at South Terras; also in Cornwall there is a small number of other vein deposits that each hold about five tons of uranium. Small lodes of uranium ore have been located in the southern uplands of Scotland; in North Wales lower palaeozoic black shales have only as much as 50 to 80 parts per million of uranium oxide, and a slightly lower grade carbonaceous shale is found near the base of the millstone grit that occurs in the north of England. Thus the experience gained by the United Kingdom has been of the treatment of uranium ores that occur abroad.

  11. Management of wastes containing radioactivity from mining and milling of uranium ores in Northern Australia

    International Nuclear Information System (INIS)

    Costello, J.M.

    1977-01-01

    The procedures and controls to achieve safe management of wastes containing radioactivity during the mining and processing of uranium ores are mainly site specific depending on the nature, location and distribution of the ore and gangue material. Waste rock and below-ore-grade material containing low levels of radioactivity require disposal at the mine site. In open cut mining the material is generally stockpiled above ground, with revegetation and collection of run-off water. Some material may be used to backfill open cuts. Management of these wastes requires a thorough investigation of ground water hydrology and surface soil characteristics to control dissipation of radioactive material. Dust containing radon and radioactive particulate is produced during ore milling, and dusts of ore concentrate are generated during calcination and packaging of the yellowcake product. These dusts are managed by ventilation and filtration systems, working conditions, and discharges to atmosphere will be according to the Australian Code of Practice on Radiation Protection during Mining and Milling of Uranium Ores. The chemical waste stream from leaching and processing of the uranium ores contains the majority of the radioactivity resulting from radium and its decay products. Neutralised effluent is discharged into holding ponds for settling of solids. This paper describes the nature of wastes containing radioactivity resulting from the mining and milling of uranium, and illustrates modern engineering practices and monitoring procedures to manage the wastes, as described in the Environmental Impact statement produced by Ranger Uranium Mines Proprietary Limited for public hearings

  12. Recovery of uranium mineral concentrate from copper tailings

    International Nuclear Information System (INIS)

    Chakravarty, S.; Tewari, U.K.; Beri, K.K.

    1991-01-01

    Based on the studies conducted on the samples of copper tailings from Surda Copper Concentrator plant, wet concentrating table (Diaster Diagonal Deck) was found most suitable for recovering uranium mineral concentrate. Based on this technique, uranium recovery plants were set up at Surda, Rakha and Mosabani. The recoveries obtained from Surda Uranium Recovery Plant and Rakha Uranium Recovery Plant were in the range of 40-50%. But in Mosaboni Uranium Recovery Plant which is treating copper tailings from Mosaboni Copper Concentrator Plant, the biggest concentrator plant processing nearly 2,700 MT/day of copper ore, the recovery by wet concentrating tables was found to be around 22%. Low recovery was mainly due to low concentration of uranium in ore and as well as more percentage of uranium distribution in fines which tables were unable to recover. Studies were done to recover uranium mineral concentrate from the fines with new set of equipment viz. Curved Static Screen/Bartles Mozley Separator/Cross Belt Concentrator. This gave an improvement of 14-16% only. Studies by low acid leaching in chemical process side have shown that an overall recovery of 68% can be achieved. Though the chemical process is best as far as recovery is concerned but there are several constraints. The major constraint is pertaining to environmental and pollution control. Depending on the results of studies to overcome the constraints decision for the process to be adopted will be taken up and executed. The test results and plant performance data have also been included in the paper. (author). 8 figs., 11 tabs., 1 appendix

  13. Separation and recovery of uranium ore by chlorinating, chelate resin and molten salt treatment

    International Nuclear Information System (INIS)

    Taki, Tomohiro

    2000-12-01

    Three fundamental researches of separation and recovery of uranium from uranium ore are reported in this paper. Three methods used the chloride pyrometallurgy, sodium containing molten salts and chelate resin. When uranium ore is mixed with activated carbon and reacted for one hour under the mixed gas of chlorine and oxygen at 950 C, more than 90% uranium volatilized and vaporization of aluminum, silicone and phosphorus were controlled. The best activated carbon was brown coal because it was able to control the large range of oxygen concentration. By blowing oxygen into the molten sodium hydroxide, the elution rate of uranium attained to about 95% and a few percent of uranium was remained in the residue. On the uranium ore of unconformity-related uranium deposits, a separation method of uranium, molybdenum, nickel and phosphorus from the sulfuric acid elusion solution with U, Ni, As, Mo, Fe and Al was developed. Methylene phosphonic acid type chelate resin (RCSP) adsorbed Mo and U, and then 100 % Mo was eluted by sodium acetate solution and about 100% U by sodium carbonate solution. Ni and As in the passing solution were recovered by imino-diacetic acid type chelate resin and iron hydroxide, respectively. (S.Y.)

  14. Uranium ore deposits

    International Nuclear Information System (INIS)

    Angelelli, Victorio.

    1984-01-01

    The main uranium deposits and occurrences in the Argentine Republic are described, considering, in principle, their geologic setting, the kind of 'model' of the mineralization and its possible origin, and describing the ore species present in each case. The main uraniferous accumulations of the country include the models of 'sandstong type', veintype and impregnation type. There are also other kinds of accumulations, as in calcrete, etc. The main uranium production has been registered in the provinces of Mendoza, Salta, La Rioja, Chubut, Cordoba and San Luis. In each case, the minerals present are mentioned, having been recognized 37 different species all over the country (M.E.L.) [es

  15. Recent Developments in the Treatment of Uranium Ores from the Elliot Lake District

    Energy Technology Data Exchange (ETDEWEB)

    Downes, K W [Extraction Metallurgy Division, Department of Mines and Technical Surveys, Ottawa (Canada)

    1967-06-15

    A summary of the results obtained during investigations on the treatment of uranium ores from the Elliot Lake district in the laboratories of the Mines Branch, and of developments in operating procedures introduced in the uranium mills in the Elliot Lake district, is presented. Concentration of Elliot Lake ore on a pilot-plant scale by a combined gravity-flotation procedure yielded a 90% recovery of uranium at a ratio of concentration of 2.4 to 1.0. The mineralogical composition of the ore, the flow sheet used and the reagents employed are described. An approximate cost estimate indicates that, although the capacity of an existing uranium leaching plant would be doubled by introducing the procedure, the production cost per pound of U{sub 3}0{sub 8} would not be affected. Bacterial leaching of Elliot Lake ore on a laboratory scale yielded, under favourable conditions, extractions of 90 per cent in 5 weeks, and of 95 per cent in 15 weeks. The conditions that were found to influence the leaching results are outlined, and the effects of the leaching solutions are discussed. The purification of ion exchange eluates by liquid-liquid extraction, using tri-n-butyl phosphate, dibutyl butylphosphonate and tri-capryl amine in a continuous process, yielded solutions from which refined ammonium diuranate was precipitated using gaseous ammonia. The effectiveness of the three extractants is discussed, and the effects of the procedures employed on the production costs per pound of U{sub 3}O{sub 8} is estimated. Some improvements in operating procedures introduced in the Elliot Lake district uranium mills are briefly described, and their effects on the operations are indicated. Present methods of controlling radiological pollution of drainage waters by uranium mill tailings are outlined. (author)

  16. Composition and method for solution mining of uranium ores

    International Nuclear Information System (INIS)

    Lawes, B.C.; Watts, J.C.

    1981-01-01

    It has been found that, in the solution mining of uranium ores using ammonium carbonate solutions containing hydrogen peroxide or ozone as an oxidant, the tendency of the formation being treated to become less permeable during the leaching process can be overcome by including in the leaching solution a very small concentration of sodium silicate

  17. Practice of the counter-current trickle leaching of uranium ore by refreshed liquor of bacterial oxidation

    International Nuclear Information System (INIS)

    Chen Shian; Huang Xiangfu; Fan Baotuan

    1995-01-01

    The uranium ore of the Mine No. 753 is a high-silicate type primary one, in which the tetravalent uranium accounts for 85%, and the uranium grade is in the range of 0.36% to 0.442%. To reduce the engineering investment and the operating cost a four-stage counter-current trickle leaching pilot-plant test was carried out with the leaching time 50 days and acid consumption 38 kg per ton of ore, and the recovery of more than 95% was obtained. Using the counter-current trickle leaching mode and controlling the limit concentration of the harmful matters in the bacterial leaching liquor, the latter can be effectively oxidized by the synchronical regeneration. A trickle leaching comparative test of 25 ton ore single heap also gave a good result of more than 95% in extraction rate, and 30% acid consumption was saved and the 2.0% pyrolusite (containing MnO 2 40%) was eliminated. This process is feasible in technology and worth-while in economy for treating the uranium ore of Mine No. 753, and provides a new method of uranium ore trickle leaching

  18. Uranium extraction from ores with lemon juice I,b-uranium recovery from pregnant lemon juice liquors obtained by attacking phosphate ores and suggested flowsheet

    International Nuclear Information System (INIS)

    EL-Sayed, M.H.

    1992-01-01

    In order to recover uranium from the pregnant liquors obtained by attacking safaga phosphate and qatrani phosphatic sandstone ore materials with lemon juice, methylation for acidic fraction-salt separation has been carried out. Afterwards, separation of uranium from the associated calcium (mainly present in lemon juice liquors as citrate) has been performed by making-use of the wide difference in their water solubility. The solutions containing the separated uranium were then subjected to evaporation till dryness whereby the precipitated uranyl citrate was calcined at 500 degree C to obtain the yellow orange oxide powder (U o 3 ). On the basis of one ton ore treatment, a flowsheet for uranium recovery from the two ore materials has been suggested

  19. Uranium extraction from ores with lemon juice; II,b. uranium recovery from pregnant lemon juice liquors obtained by attacking phosphate ore and suggested flowsheet

    International Nuclear Information System (INIS)

    Hussein, E.M.

    1997-01-01

    In order to recover uranium from the pregnant liquors obtained by attacking Safaga phosphate and Qatrani phosphatic sandstone ore materials with lemon juice, methylation for acidic fraction-salt separation has been carried out. Afterwards, separation of uranium from the associated calcium (mainly present in lemon juice liquors as citrate) has been performed by making-use of the wide difference in their water solubility. The solutions containing the separated uranium were then subjected to evaporation till dryness whereby the precipitated uranyl citrate was calcined at 500 degree C to obtain the yellow orange oxide powder (UO 3 ). On the basis of one ton ore treatment, a flowsheet for uranium recovery from the two ore materials has been suggested

  20. Biosolubilization of uranyl ions in uranium ores by hydrophyte plants

    International Nuclear Information System (INIS)

    Cecal, Alexandru; Calmoi, Rodica; Melniciuc-Puica, Nicoleta

    2006-01-01

    This paper investigated the bioleaching of uranyl ions from uranium ores, in aqueous medium by hydrophyte plants: Lemna minor, Azolla caroliniana and Elodea canadensis under different experimental conditions. The oxidation of U(IV) to U(VI) species was done by the atomic oxygen generated in the photosynthesis process by the aquatic plants in the solution above uranium ores. Under identical experimental conditions, the capacity of bioleaching of uranium ores decreases according to the following series: Lemna minor > Elodea canadensis > Azolla caroliniana. The results of IR spectra suggest the possible use of Lemna minor and Elodea canadensis as a biological decontaminant of uranium containing wastewaters. (author)

  1. Test operation of the uranium ore processing pilot plant and uranium conversion plant

    International Nuclear Information System (INIS)

    Suh, I.S.; Lee, K.I.; Whang, S.T.; Kang, Y.H.; Lee, C.W.; Chu, J.O.; Lee, I.H.; Park, S.C.

    1983-01-01

    For the guarantee of acid leaching process of the Uranium Ore Processing Pilot Plnat, the KAERI team performed the test operation in coorperation with the COGEMA engineers. The result of the operation was successful achieving the uranium leaching efficiency of 95%. Completing the guarentee test, a continuous test operation was shifted to reconform the reproducibility of the result and check the functions of every units of the pilot plant feeding the low-grade domestic ore, the consistency of the facility was conformed that the uranium can easily be dissolved out form the ore between the temperature range of 60degC-70degC for two hours of leaching with sulfuric acid and could be obtained the leaching efficiency of 92% to 95%. The uranium recovery efficiencies for the processes of extraction and stripping were reached to 99% and 99.6% respectively. As an alternative process for the separation of solid from the ore pulp, four of the Counter Current Decanters were shifted replacing the Belt Filter and those were connected in a series, which were not been tested during the guarantee operation. It was found out that the washing efficiencies of the ore pulp in each tests for the decanters were proportionally increased according to the quantities of the washing water. As a result of the test, it was obtained that washing efficiencies were 95%, 85%, 83% for the water to ore ratio of 3:1, 2:1, 1.5:1 respectively. (Author)

  2. Practice and prospect on bioleaching of uranium ore in China

    International Nuclear Information System (INIS)

    Liu Jian; Fan Baotuan; Meng Yunsheng; Zheng Ying; Liu Chao; Zhou Lei

    2008-01-01

    Developing situation on bioleaching of uranium ore in China is introduced. The selection and domestication of bacteria, development and application of biocntact oxidation tank, and practice on bioleaching of uranium ore in China are retrospeted and prospected. (authors)

  3. The determination of trace quantities of thorium and uranium in thick ore samples by proton-induced x-ray emission

    International Nuclear Information System (INIS)

    Cohen, D.D.; Duerden, P.; Clayton, E.

    1979-07-01

    Proton-induced X-ray emission (PIXE) techniques have been used to estimate the concentrations of trace quantities of thorium and uranium in powdered rock and ore samples. Standards of known concentrations were prepared in a carbon matrix and the yields from these used to determine simultaneously the concentrations of thorium and uranium in the ore samples. The experimental detection limit of the technique was found to be 3 to 4 μg g -1 for a 100 μC irradiation. The appropriate matrix corrections for a carbon and ore matrix have been calculated for thick targets and taken into consideration

  4. 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

  5. Investigation of ore processing to recover uranium concentrate from sandstone of Pa Lua area on scale of 2 tons of ore per batch

    International Nuclear Information System (INIS)

    Cao Hung Thai; Dinh Manh Thang; Tran Van Son; Le Quang Thai; Bui Dang Hanh; Hoang Bich Ngoc; Nguyen Hong Ha; Phung Vu Phong; Nguyen Khac Tuan

    2003-01-01

    Based on the laboratory results, a system for testing on scale of 2 tons uranium ore per batch including following parts was established: equipment for crushing and grinding, equipment for acid leaching, equipment for impurity precipitation and filtration and drying. the results of testing by 2 tons ore per batch scale shown that uranium recovery in the leach circuit were achieved of at least 90% under following conditions: The supplying rate of leach agent 50-701/m 2 .h, sandstone is mixed or incubated with acid before the percolation. About 23 kg filter cake per m 3 solution were disposed as tailings. Flocculants N101, A101 (TOAGOSEL, Japan) were used for improvement of filtration and washing capacity of impurity precipitation. Uranium peroxide was precipitated with addition of hydrogen peroxide. The underflow solids were filtered and calcined. The product contained min. 76% U 3 O 8 . The water recycle was successfully tested. That results in minimization of water addition to only 0.3m 3 /ton of ore. Experimental results on 2 tons scale showed that the proposed processing flow sheet using direct precipitation can meet all environmental and technical objectives. (CHT)

  6. Discussion on the impact of uranium ore heap leaching to environment

    International Nuclear Information System (INIS)

    Qin Guoxiu; Liu Qingcheng; Chen Xin; Deng Shengshui; Yang Qinghua

    2012-01-01

    In this paper, the impact of uranium ore heap leaching on the environment were studied with the case of two long production uranium mines. According to the basic requirements of the radiation environment assessment of the nuclear industry, the surface radon exhalation rate of the mine waste, the concentration of radionuclide of the waste water and the γ radiation level and concentration of radionuclide of the waste were investigated and compared to that of the early conventional hydrometallurgical production of the two uranium mines. The merits and disadvantage of the heap leaching was evaluated, and measures and suggestions were proposed for the improvement of heap leaching techniques. (authors)

  7. Ore-forming environment and ore-forming system of carbonaceous-siliceous-pelitic rock type uranium deposit in China

    International Nuclear Information System (INIS)

    Qi Fucheng; Zhang Zilong; Li Zhixing; He Zhongbo; Wang Wenquan

    2012-01-01

    It is proposed that there are four types of ore-forming systems about carbonaceous-siliceous-pelitic rock type uranium deposit in China based on systematic study on structural environment and distribution regularity of uraniferous construction of marine carbonaceous-siliceous-pelitic rock in China: continental margin rift valley ore-forming systems, continental margin rifting deep fracture zone ore-forming systems, landmass boundary borderland basin ore-forming systems and epicontinental mobile belt downfaulted aulacogen ore-forming systems. It is propounded definitely that it is controlled by margin rift valley ore-forming systems and continental margin rifting deep fracture zone ore-forming systems for large-scale uranium mineralization of carbonaceous-siliceous-pelitic rock type uranium deposit in China, which is also controlled by uraniferous marine carbonaceous-siliceous-pelitic rock construction made up of silicalite, siliceous phosphorite and carbonaceous-siliceous-pelitic rock, which settled down accompany with submarine backwash and sub marine volcanic eruption in margin rift valley and continental margin rifting mineralizing environment. Continental mar gin rift valley and continental margin rifting thermal sedimentation or exhalation sedimentation is the mechanism of forming large-scale uraniferous marine carbonaceous-siliceous-pelitic rock construction Early Palaeozoic Era in China or large-scale uranium-polymetallic mineralization. (authors)

  8. Status Report from Yugoslavia [Processing of Low-Grade Uranium Ores

    Energy Technology Data Exchange (ETDEWEB)

    Bunji, B [Institute for Technology of Nuclear and Other Raw Materials, Belgrade, Yugoslavia (Serbia)

    1967-06-15

    barren solution has resulted in important savings on reagent. The overall economy compared under local conditions with ion-exchange or solvent extraction is in favour of the reduction process. Some research work on heap leaching and leaching in situ is included in our activities. In connection with the conditions at Kalna it was possible to carry out large-scale heap leaching and leaching in situ. The former was carried out on waste rocks with a uranium content below the cut-off grade. To avoid solution losses, the surface area from the heap pile is covered with thin plastic sheets. Good drainage from the bottom is obtained by using perforated 10-in. asbestos-concrete pipes. The technique of construction of the heap pile is as usual, and mostly depends on local conditions. The heap leach pile is about 12 m high. The solution retention time is about 8 days. The barren solution from the reduction plant or mine water with a uranium content in the range of 2 to 6 g/m{sup 3} is used for the heap leaching. The pregnant solution is returned into the processing plant. Because the heap leach pile obtained is practically without any charge, the operating and the construction costs of the heap pile need only be in balance with the value of the recovered uranium. Investigation of bacterial leaching has shown some influence on the leaching rate. The bacteria belonging to the Thiobacillus-Ferrobacillus group were obtained from mine water, selected and cultivated. It seems that the concentration of bacteria has some influence on the extraction time and percentage of extracted uranium, and it can be said that the application of bacteria in heap leaching and leaching in situ will in the future be one of the most effective methods of uranium extraction from ore that is below cut-off grade. (author)

  9. Chlorination of uranium ore for extraction of uranium, thorium and radium and for pyrite removal

    International Nuclear Information System (INIS)

    Skeaf, J.M.

    1979-01-01

    The high-temperature chlorination of uranium ore was investigated. The objective was to develop a process which is both economically viable and environmentally acceptable. Test work was directed toward obtaining high extractions of uranium, thorium and radium-226, as well as iron, sulphur and the rare earths, and consists of chlorinating samples of an Elliot Lake uranium ore at elevated temperatures and repulping the resulting calcine in dilute hydrochloric acid. The effect of temperature and chlorine throughput on the extraction of the various metals was investigated. The best conditions yielded extractions of uranium, iron and sulphur (all as chlorides) greater than 95 percent. Chlorine consumption varied between 6 and 16 percent by weight of the ore charge. (author)

  10. 36Cl production in situ, and groundwater transport in a uranium ore deposit

    International Nuclear Information System (INIS)

    Cornett, R.J.; Andrews, H.R.; Brown, R.M.; Chant, L.A.; Cramer, J.; Davies, W.G.; Greiner, B.F.; Imahori, Y.; Koslowsky, V.T.; McKay, J.W.; Milton, G.M.; Milton, J.D.C.

    1992-01-01

    The authors have used AMS to measure 36 Cl concentrations produced in situ in ore and in groundwater within the 1.3 billion year old Cigar Lake uranium ore deposit. 36 Cl concentrations are up to 300 times higher in the ore zone than in the surrounding aquifer. Based on 36 Cl ingrowth, the authors calculate the residence time of water within the ore zone to be 100,000 to 300,000 years. Since the geologic setting of this deposit is a very close natural analogue to a proposed nuclear fuel waste repository, this analysis demonstrates that natural geological barriers can effectively isolate mobile radionuclides from an open, regional groundwater flow system over millennia

  11. Radiation protection of workers in mining and processing of uranium ore

    International Nuclear Information System (INIS)

    Khan, A.H.; Sahoo, S.K; Puranik, V.D.

    2003-01-01

    Low grade of uranium ore mined from three underground mines is processed in a mill at Jaduguda in eastern India to recover uranium concentrate in the form of yellow cake. Radiation protection of workers is given due importance at all stages of these operations. Dedicated Health Physics Units and Environmental Survey Laboratories established at the site regularly carry out in-plant and environmental surveillance to keep radiation exposure of workers and the members of public within the limits prescribed by the regulatory body. The limits set by the national regulatory body based on the international standards recommended by the ICRP and the IAEA are followed. In the uranium mines, external gamma radiation, radon and airborne activity due to radioactive dust are monitored. Similarly, in the uranium ore processing mill, gamma radiation and airborne radioactivity due to long-lived α-emitters are monitored. Personal dosimeters are also issued to workers. The total radiation exposure of workers from external and internal sources is evaluated from the area and personal monitoring data. It has been observed that the average radiation dose to workers has been below 10 mSvy -1 and all exposures are well below 20 mSvy -1 at all stages of operations. Adequate ventilation is provided during mining and ore processing operations to keep the concentrations of airborne radioactivity well below the derived limits. Workers use personal protective appliances, where necessary, as a supplementary means of control. The monitoring methodologies, results and control measures are presented in the paper. (author)

  12. Recent trends in research and development work on the processing of uranium ore in South Africa

    International Nuclear Information System (INIS)

    James, H.E.

    1976-01-01

    The rapid increases in the price of gold and uranium in recent years have coincided with an unprecedented increase in working costs at South African gold mines. A re-examination of the existing flowsheets for the recovery of uranium, gold and pyrite from Witwatersrand ores, in the light of these economic trends, has resulted in the identification of a number of profitable areas for research and development. The main topics under investigation in South Africa in the processing of uranium ore are the use of physical methods of concentration such as flotation, gravity concentration and wet high-intensity magnetic separation; the wider adoption of the 'reverse leach', in which prior acid leaching for uranium improves the subsequent extraction of gold; the use of higher leaching temperatures and higher concentrations of ferric ion in the leach to increase the percentage of uranium extracted, including the production of ferric ion from recycled solutions; the application of pressure leaching to the recovery of uranium from low-grade ores and concentrates; the development of a continuous ion-exchange contactor capable of handling dilute slurries, so that simpler and cheaper techniques of solid/liquid separation can be used instead of the expensive filtration and clarification steps, and the improvement of instrumentation for the control of additions of sulphuric acid and manganese dioxide to the leach. A brief description is given of the essential features of the new or improved processing techniques under development that hold promise of full-scale application at existing or future uranium plants

  13. Recent trends in research and development work on the processing of uranium ore in South Africa

    International Nuclear Information System (INIS)

    James, H.E.

    1976-07-01

    The rapid increases in the price of gold and uranium in recent years have coincided with an unprecedented increase in working costs at South African gold mines. A re-examination of the existing flowsheets for the recovery of uranium, gold, and pyrite from Witwatersrand ores, in the light of these economic trends, has resulted in the identification of a number of profitable areas for research and development. The main topics under investigation in South Africa in the processing of uranium ore are the use of physical methods of concentration such as flotation, gravity concentration, and wet high-intensity magnetic separation; the wider adoption of the 'reverse leach', in which prior acid leaching for uranium improves the subsequent extraction of gold; the use of higher leaching temperatures and higher concentrations of ferric ion in the leach to increase the percentage of uranium extracted, including the production of ferric ion from recycled solutions; the application of pressure leaching to the recovery of uranium from low-grade ores and concentrates; the development of a continuous ion-exchange contactor capable of handling dilute slurries, so that simpler and cheaper techniques of solid-liquid separation can be used instead of the expensive filtration and clarification steps, and the improvement of instrumentation for the control of additions of sulphuric acid and manganese dioxide to the leach. A brief description is given of the essential features of the new or improved processing techniques under development that hold promise of full-scale application at existing or future uranium plants [af

  14. Application of biohydrometallurgy to uranium ore processing

    International Nuclear Information System (INIS)

    Zhang Jiantang

    1989-01-01

    The development on application of biohydrometallargy to uranium ore processing is briefly introduced. The device designed for oxidizing ferrous ions in solution by using biomembrane, several bacterial leaching methods and the experimental results are given in this paper. The presented biohydrometallurgical process for recovering uranium includes bacterial leaching following by adsorption using tertiary amine resin 351 and oxidation of ferrous ions in the device with biomembranes. This process brings more economical benefits for treating silicate type original ores. The prospects on application of biogydrometallyurgy to solution mining is also discussed

  15. Technique for in situ leach simulation of uranium ores

    International Nuclear Information System (INIS)

    Grant, D.C.; Seidel, D.C.; Nichols, I.L.

    1985-01-01

    In situ uranium mining offers the advantages of minimal environmental disturbance, low capital and operating costs, and reduced mining development time. It is becoming an increasingly attractive mining method for the recovery of uranium from secondary ore deposits. In order to better understand the process, a laboratory technique was developed and used to study and simulate both the chemical and physical phenomena occurring in ore bodies during in situ leaching. The laboratory simulation technique has been used to determine effects of leaching variables on permeability, uranium recovery, and post-leach aquifer restoration. This report describes the simulation system and testing procedure in sufficient detail to allow the construction of the system, and to perform the desired leaching tests. With construction of such a system, in situ leaching of a given ore using various leach conditions can be evaluated relatively rapidly in the laboratory. Not only could optimum leach conditions be selected for existing ore bodies, but also exploitation of new ore bodies could be accelerated. 8 references, 8 figures, 2 tables

  16. Microbial leaching of low grade sandstone uranium ores: column leaching studies

    International Nuclear Information System (INIS)

    Bhatti, T.M.; Malik, K.A.; Khalid, A.M.

    1991-01-01

    Microbial leaching studies on a low-grade sandstone uranium ore from Baghalchur Ore Deposits, D. G. Khan, Pakistan, containing 0.027 % U/sub 3/O/sub 8/ for extraction of uranium, were conducted in columns. Baghalchur sandstone uranium ore which is alkaline in nature, contained 5.0% calcite [CaCo/sub 3/], 2-3 % Fe/sub 2/O/sub 3/ and pyrite [FeS/sub 2/] less than 0.1 %. The ore amended with sulfur and/or sulfur slag as external energy source was found to leach with indigenous microflora mostly belonging to the genus Thiobacillus which are present in the uranium mine water. Column leaching studies revealed that when the ore was amended with elemental sulfur and irrigated with mine water (pH 3.5) 53 % U/sub 3/O/sub 8/ could be solubilized from it. However, when the natural mine water was used as such (pH 7.4) the solubilization of uranium was decreased to 41 % U/sub 3/O/sub 8/ in 90 days under similar conditions of percolation rate and temperature. The addition of (NH/sub 4/)/sub 2/SO/sub 4/ (3.0 g/L) in mine water was found to enhance the uranium leaching to 70 % U/sub 3/O/sub 8/ from the columns containing ore amended with sulfur slag. (author)

  17. Aluminum chloride restoration of in situ leached uranium ores

    International Nuclear Information System (INIS)

    Grant, D.C.; Burgman, M.A.

    1982-01-01

    During in situ uranium mining using ammonium bicarbonate lixiviant, the ammonium exchanges with cations on the ore's clay. After mining is complete, the ammonium may desorb into post-leach ground water. For the particular ore studied, other chemicals (i.e., uranium and selenium) which are mobilized during the leach process, have also been found in the post-leach ground water. Laboratory column tests, used to simulate the leaching process, have shown that aluminum chloride can rapidly remove ammonium from the ore and thus greatly reduce the subsequent ammonium leakage level into ground water. The aluminum chloride has also been found to reduce the leakage levels of uranium and selenium. In addition, the aluminum chloride treatment produces a rapid improvement in permeability

  18. Aqueous-chlorine leaching of typical Canadian uranium ores

    International Nuclear Information System (INIS)

    Haque, K.E.

    1982-01-01

    Laboratory-scale aqueous-chlorine leaches were conducted on quartz-pebble conglomerates, pegmatite and vein-type ores. Optimum leach temperatures, pulp density and retention times were determined. Uranium extraction of 98 per cent was obtained from the Elliot Lake, Madawaska Mines of Bancroft and Rabbit Lake ores, 96 per cent from the Key Lake ore and 86 per cent from the Agnew Lake ore. However, tailings containing 15-20 pCi g -1 of radium-226 were obtained only from the Elliot Lake and Agnew lake quartz-pebble conglomerates and Bancroft pegmatite-type ores by second-stage leaches with HCl. The second-stage leach results indicate that multistage (3 or 4) acid-chloride or salt-chloride leaches might be effective to obtain tailings containing 15-20 pCi 226 Ra g -1 from the high-grade vein-type ores. Comparative reagent-cost estimates show that the sulphuric-acid leach process is far less expensive than aqueous chlorine leaching. Nevertheless, only the aqueous chlorine and acid-chloride leaches in stages are effective in producing tailings containing 15-20 pCi 226 Ra g -1 from the typical Canadian uranium ores. (Auth.)

  19. Organic matter in uranium concentration during ancient bed oxidation of carboniferons sediments

    International Nuclear Information System (INIS)

    Kruglova, V.G.; Uspenskij, V.A.; Dement'ev, P.K.; Kochenov, A.V.

    1984-01-01

    Changes in the organic matter accompanying the process of epigenetic ore formation are studied using the example of a deposit localized in carboniferous molasse strata of the Cretaceous period. Peculiarities of the organic matter as the main mineralization agent are studied by a complex of physical and themical methods. A distinct relationship between the uranium concentration and the degree of organic matter oxigenation is a most characteristic feature of the ore localization, however, there is no direct correlation between the contents of uranium and organic matter in ores. Uranium minerallzation was accumulated during infiltration of acid uraniferous.waters into grey stratum in the process of the bed oxidation zone formation oxidizing. Brown coal matter possessing a maximum adsorbability, as compared to other sedimentary rocks, apprared to be the uranium precipitator. The adsorption was accompanie by the formation of proper uranium minerals (coffinite, pitchblende) due to uranium reduction by oxidizing organic matter. Thus, the oxidative epigenesis was an are-forming process with the uranium concentration on organic matter proportionally to oxidation of the latter

  20. Chlorine-assisted leaching of Key Lake uranium ore

    International Nuclear Information System (INIS)

    Haque, K.E.

    1981-04-01

    Bench-scale chlorine-assisted leach tests were conducted on the Key Lake uranium ore. Leach tests conducted at 80 0 C on a slurry containing 50% solids during 10 hours of agitation gave the maximum extraction of uranium - 96% and radium-226 - 91%. Chlorine was added at 23.0 Kg Cl 2 /tonne of ore to maintain the leach slurry pH in the range of 1.5-1.0. To obtain residue almost free of radionuclides, hydrochloric acid leaches were conducted on the first stage leach residues. The second stage leach residue still was found to contain uranium - 0.0076% and radium-226 - 200 pCi/g of solids

  1. Bioleaching of low-grade uranium ore using Acidithiobacillus ferrooxidans

    International Nuclear Information System (INIS)

    Pal, S.; Das, T.; Sukla, L.B.; Roy Chaudhury, G.; Pradhan, D.

    2010-01-01

    Bioleaching of uranium was carried out with Turamdih ore sample procured from Uranium Corporation of India Limited, Jaduguda. The bacterial strain that was used in the leaching experiments was isolated from the Jaduguda mine water sample. Efficiency of bioleaching was studied by varying parameters like pulp density and initial ferrous concentration as source of energy. It is observed that the efficiency of bioleaching was 49% at 10% pulp density (w/v) and initial pH 2.0. Addition of external has no effect on efficiency of bioleaching showing domination of direct leaching mechanism over indirect. (author)

  2. Uranium extraction from ores with salicylic acid; I - uranium extraction from input phosphate ore of Abu Zaabal phosphate plant, Egypt

    International Nuclear Information System (INIS)

    Hussein, E.M.

    1997-01-01

    Salicylic acid has been tested (for environmental importance) to extract U from input phosphate ore of Abu-Zaabal phosphate plant, Egypt prior to its processing for production of phosphatic fertilizers. Uranyl ion forms with this acid three stable complexes; namely [UO 2 Sal] degree, [U O 2 SaL 2 ] 2- and UO 2 SaL-3] 4- depending on the total uranyl and salicylic acid concentrations and their ratios. Study of relevant extraction factors revealed however that, the extraction process is controlled by the amount of salicylic acid used, alcohol/aqueous ratio, solid/liquid ratio and time of agitation. The obtained results showed that uranium is selectively leached by the application of such a leaching reagent. In order to recover U from the obtained pregnant leach liquor, the latter is adjusted by ammonia to PH 5-6.5, where the crystalline pp t of N H 4 [UO 2 SaL 3 ] 4 H 2 O has formed. This precipitation has been carried out after concentrating the obtained pregnant leach liquor by its recycle for U extraction from new ore batches. The precipitated ammonium uranyl tri salicylate is calcined at 500 degree C for obtaining pure orange yellow trioxide (UO 3 ) powder. On the basis of one ton ore treatment, an economic flowsheet for U recover y from the study ore material has been suggested

  3. RL-1: a certified uranium reference ore

    International Nuclear Information System (INIS)

    Steger, H.F.; Bowman, W.S.

    1985-06-01

    A 145-kg sample of a uranium ore from Rabbit Lake, Saskatchewan, has been prepared as a compositional reference material. RL-1 was ground to minus 74 μm and mixed in one lot. Approximately one half of this ore was bottled in 100-g units, the remainder being stored in bulk. The homogeneity of RL-1 with respect to uranium and nickel was confirmed by neutron activation and X-ray fluorescence analytical techniques. In a 'free choice' analytical program, 13 laboratories contributed results for one or more of uranium, nickel and arsenic in one bottle of RL-1. Based on a statistical analysis of the data, the following recommended values were assigned: U, 0.201%; Ni, 185 μg/g; and As, 19.6 μg/g

  4. Modifier free supercritical fluid extraction of uranium from sintered UO2, soil and ore samples

    International Nuclear Information System (INIS)

    Kanekar, A.S.; Pathak, P.N.; Acharya, R.; Mohapatra, P.K.; Manchanda, V.K.

    2011-01-01

    Direct extraction of uranium from different samples viz. sintered UO 2 , soil and ores was carried out by modifier free supercritical fluid using tri-n-butyl phosphate-nitric acid (TBP-HNO 3 ) adduct as extractant. These studies showed that pre-equilibration with more concentrated nitric acid helps in better dissolution and extraction of uranium from sintered UO 2 samples. Modifier free supercritical fluid extraction appears attractive with respect to minimization of secondary wastes. This method resulted 80-100% extraction of uranium from different soil/ore samples. The results were confirmed by performing neutron activation analysis of original (before extraction) and residue (after extraction) samples. (author)

  5. Chloride pyrometallurgy of uranium ore. 1. Chlorination of phosphate ore using solid or gas chlorinating agent and carbon

    International Nuclear Information System (INIS)

    Taki, Tomihiro; Komoto, Shigetoshi; Otomura, Keiichiro; Takenaka, Toshihide; Sato, Nobuaki; Fujino, Takeo.

    1995-01-01

    A thermodynamical and pyrometallurgical study to recover uranium from the phosphate ores was undertaken using the chloride volatilization method. Iron was chlorinated with solid chlorinating agents such as NaCl and CaCl 2 in combination with activated carbon, which will be used for removing this element from the ore, but uranium was not. On the other hand, the chlorination using Cl 2 gas and activated carbon gave a good result at 1,223 K. Not only uranium but also iron, phosphorus, aluminum and silicon were found to form volatile chlorides which vaporized out of the ore, while calcium remained in the ore as non-volatile CaCl 2 . The chlorination condition was studied as functions of temperature, reaction time and carbon content. The volatilization ratio of uranium around 95% was obtained by heating the mixture of the ore and activated carbon (35 wt%) in a mixed gas flow of Cl 2 (200 ml/min) and N 2 (200 ml/min) at 1,223 K for 120 min. (author)

  6. BL-2a and BL-4a: certified uranium reference ores

    International Nuclear Information System (INIS)

    Steger, H.F.; Bowman, W.S.; Zechanowitsch, G.; Sutarno, R.

    1982-05-01

    Samples of two uranium ores BL-2a and BL-4a from Beaverlodge, Saskatchewan, were prepared as compositional reference materials to replace the similar certified ores, BL-2 and BL-4, of which the stock had been exhausted. Each ore was ground to minus 74 μm, blended in one lot and bottled in 200-g units. The homogeneity of the ores with respect to uranium was confirmed by both a neutron activation and a fluorimetric analytical procedure performed by two commercial laboratories. The recommended value for uranium is based on the results of one determination on each of 25 bottles by the volumetric-umpire method performed at CANMET. A statistical analysis of the data gave a recommended value for uranium of 0.426% for BL-2a and 0.1248% for BL-4a

  7. Economic evaluation of preconcentration of uranium ores

    International Nuclear Information System (INIS)

    1981-04-01

    The economics of two options for the preconcentration of low-grade uranium ores prior to hydrochloric acid leaching were studied. The first option uses flotation followed by wet high-intensity magnetic separation. The second option omits the flotation step. In each case it was assumed that most of the pyrite in the ore would be recovered by froth flotation, dewatered, and roasted to produce sulphuric acid and a calcine suitable for acid leaching. Savings in operating costs from preconcentration are offset by the value of uranium losses. However, a capital saving of approximately 6 million dollars is indicated for each preconcentration option. As a result of the capital saving, preconcentration appears to be economically attractive when combined with hydrochloric acid leaching. There appears to be no economic advantage to preconcentration in combination with sulphuric acid leaching of the ore

  8. Lixiviation of uranium ores by capillarity; Lixiviation par capillarite des minerais d'uranium (1962)

    Energy Technology Data Exchange (ETDEWEB)

    Mouret, P; Pottier, P [Commissariat a l' Energie Atomique, Fontenay-aux-Roses (France). Centre d' Etudes Nucleaires

    1962-07-01

    All chemical concentration plants use at the moment a process of lixiviation by agitation for the treatment of uranium ores. It has become necessary for various reasons to study the application of a more economical system which is that of the lixiviation by capillarity in heaps. After presenting the laboratory tests for recognizing the ability of an ore for this type of lixiviation, the authors give an outline of the two semi-industrial tests which are still in progress. The results are such that it has been possible to plan larger installations which are now under construction. (authors) [French] Les usines de concentration chimique utilisent toutes actuellement la lixiviation par agitation des minerais d'uranium. Il est devenu necessaire pour diverses raisons d'etudier l'application d'un procede plus economique, qui est celui de la lixiviation par capillarite en tas. Apres un expose des tests de laboratoire permettant de connaitre l'aptitude d'un minerai a ce type de lixiviation, est donne un apercu de deux essais semi-industriels non encore acheves a ce jour. Les resultats sont tels, qu'ils ont permis de projeter des installations plus importantes, qui sont actuellement en construction. (auteurs)

  9. In situ production of 36CI in uranium ore: a hydrogeological assessment tool

    International Nuclear Information System (INIS)

    Cornett, R.J.; Cramer, J.; Andrews, H.R.; Chant, L.A.; Davies, W.; Greiner, B.F.; Imahori, Y.; Koslowsky, V.; McKay, J.; Milton, G.M.; Milton, J.C.D.

    1996-01-01

    In situ neutron activation of 35 Cl within the rock and groundwater of geologic deposits that have elevated concentrations of uranium provides a hydrogeological tracer. We determine the production rate and mobility of 36 Cl in the 1.3-billion-year-old Cigar Lake uranium ore deposit. Accelerator mass spectrometry was used to map the Concentrations of 36 Cl in the ore and in the groundwater that were up to 100 times greater than those encountered in unmineralized portions of the host sandstone aquifer. The residence time of this mobile anion in groundwater within the mineralized zone ranged from 14 to 280 kyr. These residence times are consistent with the hydraulic and geochemical data, suggesting significant control of Cl - and groundwater movement by the clay-rich matrix of the mineralized zone. (author)

  10. Wet high-intensity magnetic separation for the concentration of Witwatersrand gold-uranium ores and residues

    International Nuclear Information System (INIS)

    Corrans, I.J.; Levin, J.

    1979-01-01

    Wet high-intensity magnetic separation (WHIMS) for the concentration of gold and uranium was tested on many Witwatersrand cyanidation residues, and on some ores and flotation tailings. The results varied, but many indicated recoveries of over 60 per cent of the gold and uranium. The main source of loss is the inefficiency of WHIMS for material of smaller particle size than 20μm. The recoveries in the continuous tests were lower than those in the batch tests. The continuous tests indicated an operational difficulty that could be experienced in practice, namely the tendency for wood chips and ferromagnetic particles to block the matrix of the separator. It was decided that a solution to the problem lies in the modification of the separator to allow continuous removal of the matrix for cleaning. A system has been developed for this purpose and is being demonstrated on a pilot-plant scale. Promising results were obtained in tests on a process that combines a coarse grind, gravity concentration, and WHIMS. In the gravity-concentration step, considerable recoveries, generally over 50 per cent, of high-grade pyrite were obtained, together with high recoveries of gold and moderate, but possibly important, recoveries of uranium. A simple model describing the operation of the WHIMS machine in terms of the operating parameters is described. This should reduce the amount of empirical testwork required for the optimization of operating conditions and should provide a basis for scale-up calculations. The economics of the WHIMS process is discussed [af

  11. Modelling a uranium ore bioleaching process

    International Nuclear Information System (INIS)

    Chien, D.C.H.; Douglas, P.L.; Herman, D.H.; Marchbank, A.

    1990-01-01

    A dynamic simulation model for the bioleaching of uranium ore in a stope leaching process has been developed. The model incorporates design and operating conditions, reaction kinetics enhanced by Thiobacillus ferroxidans present in the leaching solution and transport properties. Model predictions agree well with experimental data with an average deviation of about ± 3%. The model is sensitive to small errors in the estimates of fragment size and ore grade. Because accurate estimates are difficult to obtain a parameter estimation approach was developed to update the value of fragment size and ore grade using on-line plant information

  12. 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.

  13. Chemical separation of Th-230 from uranium ore

    International Nuclear Information System (INIS)

    Kikunaga, H.; Nakanishi, T.; Mitsugashira, T.; Hara, M.

    2001-01-01

    We are studying the decay processes of low energy nuclear isomer of Th-229. Our approach to produce Th-229m is (γ, n) reaction on Th-230, hence, about 100 μg of Th-230 is necessary as a target. However, our stock of Th-230 has run out during several experiments, thus, we tried to separate Th-230 from uranium ore. In this paper, the detail of a chemical separation procedure for Th-230 from uranium ore and the results are reported. (author)

  14. Waste monitoring of the uranium ore processing activities in Romania

    International Nuclear Information System (INIS)

    Nica, L.

    2002-01-01

    The uranium ore processing activities at the Feldioara site produce a range of liquid and solid waste that are monitored. Liquids are treated through decantation, pH correction and uranium precipitation before their release into the environment. The solid waste is gathered into ore specific area and are covered regularly with clay materials. (author)

  15. DH-1a: a certified uranium-thorium reference ore

    International Nuclear Information System (INIS)

    Steger, H.F.; Bowman, W.S.; Zechanowitsch, G.

    1981-09-01

    A 122-kg sample of uranium-thorium ore, DH-1a, from Elliot Lake, Ontario, was prepared as a compositional reference material to replace the similar certified ore, DH-1. DH-1a was ground to minus 74μm, blended in one lot, and bottled in 200 g units. The homogeneity of DH-1a with respect to uranium was confirmed using the volumetric umpire method. The recommended value for uranium is based on the data from the confirmation of homogeneity. For thorium, twelve laboratories provided results in a free choice analytical program. A statistical analysis of the data gave a recommended value of 0.263 percent for uranium and 0.091 percent for thorium

  16. 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.

  17. Origin of ores of endogeneous uranium ore deposits

    International Nuclear Information System (INIS)

    Kasanskij, V.I.; Laverov, N.P.; Tugarinov, A.I.

    1976-01-01

    The consideration mainly includes those endogenous uranium ore deposits of which more exact data are available, such as precambrian ones in areas of proto-activated old platforms, deposits of palaeozoic fold areas, and mesozoic deposits in areas of tectonic-magnetic activation. Their genesis and typical characters are mentioned and conclusions on the general distribution of the deposits are drawn. (author)

  18. Some aspects of the processing development for uranium ores treatment

    International Nuclear Information System (INIS)

    Bruno, J.B.

    1982-01-01

    It is discussed the methodology adopted by NUCLEBRAS to the processing development for uranium ores treatment. The used methodology has the following steps: exploratories studies, preliminaries stiudies and optimization studies. The studies include physical and chemical contained in the solution. As examples are cited the uranium ores treatment in Lagoa Real and Itataia. (A.B.) [pt

  19. Filtration aids in uranium ore processing

    International Nuclear Information System (INIS)

    Ford, H.L.; Levine, N.M.; Risdon, A.L.

    1975-01-01

    The patent describes a process whereby improved flocculation efficiency and filtration of carbonate leached uranium ore pulps are obtained by treating the filter feed slurry with an aqueous solution of hydroxyalkyl guar. (J.R.)

  20. Titrimetric determination of uranium in low-grade ores by the ferrous ion-phosphoric acid reduction method

    International Nuclear Information System (INIS)

    Hitchen, A.; Zechanowitsch, G.

    1980-01-01

    The modification and extension of the U.S.A.E.C. ferrous ion-phosphoric acid reduction method for the determination of uranium in high-grade or relatively pure material to a method for the determination of uranium with a high accuracy and precision, in ores containing 0.004 to 7% U is described. It is simple, rapid and requires no prior separations from elements that, in other methods, frequently interfere. For sample materials having very high concentrations of interfering elements, a prior concentration step using extraction with tri-n-octylphosphine oxide is described, but it is shown that, for most low-grade ores, this step is unnecessary. (author)

  1. Mining and processing of uranium ores in the USSR

    International Nuclear Information System (INIS)

    Laskorin, B.N.; Mamilov, V.A.; Korejsho, Yu.A.

    1983-01-01

    Experience gained in uranium ore mining by modern methods in combination with underground and heap leaching is summarized. More intensive processing of low-grade ores has been achieved through the use of autoclave leaching, sorptive treatment of thick pulps, extractive separation of pure uranium compounds, automated continuous sorption devices of high efficiency for processing the underground- and heap-leaching liquors, natural and mine water, and recovery of molybdenum, vanadium, scandium, rare earths and phosphate fertilizers from low-grade ores. Production of ion-exchangers and extractants has been developed and processes for concomitant recovery of copper, gold, ionium, tungsten, caesium, zirconium, tantalum, nickel and cobalt have been designed. (author)

  2. The geochemical characteristics of alkali metasomatic ore and its ore-forming significance at Zoujiashan deposit, Xiangshan uranium field

    International Nuclear Information System (INIS)

    Wang Yun; Hu Baoqun; Sun Zhanxue; Li Xueli; Guo Guolin; Rao Minghui

    2012-01-01

    Alkaline metasomatites are widely distributed in Zoujiashan uranium deposit and have close relation with uranium mineralization. Based on the study of field geological survey, petrographic methods, element chemical analysis and EPMA, etc, the alteration in alkaline metasomatic ore was found in the order of sodium metasomatism, potassium metasomatism and silica metasomatism. The alkaline hydrothermal fluid of mineralization is rich in Na at first and then rich in K, and quite similar in other chemical composition, but the K rich one is more favourite for the metallization. Compared with the normal porphyroclastic lava, the alkaline metasomatic ores in lower in SiO 2 , but higher in K 2 O or Na 2 O, Al 2 O 3 , Fe 2 O 3 , MgO, P 2 O 5 , CaO and U, Th, Zr, Hf, Sm, Ti, REE. Compared with potassium metasomatic ore, the sodium metasomatic ore is with high ΣLREE/ΣHREE ratio and lower Rb and REE. Because alkaline metasomatism is beneficial to release uranium from accessory mineral and bring out uranium from rocks, therefore it is very important to the migration and precipitation of uranium. (authors)

  3. Status Report from Canada [Processing of Low-Grade Uranium Ores

    Energy Technology Data Exchange (ETDEWEB)

    Thunaes, A [Eldorado Mining and Refining Ltd., Ottawa (Canada)

    1967-06-15

    The Canadian production of uranium increased in a spectacular manner during the period 1955-1959 from 1000 to 15 500 tons U{sub 3}O{sub 8} per year. Since 1959 the production has declined to the 1966 level of 3900 tons U{sub 3}O{sub 8} per year; stretch-out of contracts and government stockpiling programmes has made the decline gradual, and is maintaining the current rate of production until 1970. Nineteen mills were in operation during the period of peak production but only three are operating today. Ten mills were shut down and dismantled because of exhaustion of ore bodies or because the operation was uneconomical; six mills are maintained in stand-by condition. The total daily capacity of mills in operation or standing by is about 28 000 tons ore, but some of these mills would not be reopened unless an appreciable increase in uranium price occurs. The tide of uranium demand is about ready to turn and prospecting for uranium is very active this year, particularly in the Elliot Lake and Beaverlodge areas. The estimates for uranium demand in 1975-1980 are such that new ore will have to be found and developed, and new treatment plants must be built. The new ore that is found will likely be of lower grade or more expensive to mine than most of the current proven reserves in Canada and the most efficient methods of treatment will be needed to avoid excessive increases in production costs. This seems an opportune time to review Canadian milling of uranium ore, the improvements that have been made and development work towards further improvements.

  4. In situ carbonate leaching and recovery of uranium from ore deposits

    International Nuclear Information System (INIS)

    Hunkin, G.G.; Fife, T.P.; Stano, J.R.

    1979-01-01

    Uranium is leached from redox roll ore deposits by selective in-situ leaching with a solution of pH 7.4 to 9 (preferably 7.5 to 8.5) containing from about 0.5 to 5g/l of NH 4 HCO 3 and from about 0.1 to 3g/l of peroxide (preferably aqueous H 2 O 2 ), and sufficient NH 3 to maintain the desired pH. The leach solution is then withdrawn from the ore deposit and contacted with a strong base anion exchange material to strip the uranium from the leach solution. The uranium is eluted from the anion exchange material by an aqueous eluant, and the uranium is recovered from the eluate by first acidifying it and then treating it with ammonia to produce a precipitate of relatively pure ammonium diuranate. The content of the three components in the stripped leach solution is adjusted, and then the leach solution is recirculated through the ore deposit. After the uranium ore is removed to the extent economically practicable, the leach solution is replaced with an aqueous reducing solution which when passed into the ore deposit precipitates and renders insoluble any uranium and elements such as vanadium, molybdenum, and selenium. This process produces above ground a very low volume of impurities and waste solutions requiring disposal and does not cause material contamination of the underground deposit or any aquifer associated with the deposit

  5. Characteristics of sandstone-type uranium mineralization and ore-controlling factors in Wukurqi ore district at southern margin of Yili basin, Xinjiang

    International Nuclear Information System (INIS)

    Li Xigen

    2002-01-01

    With the theories of hydrogenic uranium deposit in the nineties, Wukurqi ore district as a new area was found by the regional prediction and prospecting. Specially, through uranium ore prospecting of about three years, certain prospective reserves are generally controlled in the area. These reserves are hosted in V cyclothem of Middle-Lower Jurassic series, and some prospective reserves are hosted in II and VII cyclothems. By analyzing and summarizing characteristics of sandstone-type uranium mineralization and its ore-controlling factors in Wukurqi ore district, the author provides a foundation for developing further prospecting in this area

  6. Rirang Uranium Ore Processing System Design: Agitated Digester

    International Nuclear Information System (INIS)

    Erni, R.A.; Susilaningtyas

    1996-01-01

    A closed tank digester equipped with a pitched blades turbine agitator has been designed to facilities Rirang uranium ore dissolution using concentrated sulphuric acid at high temperature. The digester was designed to accommodate the digestion of 6 kg of-65 mesh ore at 200 o C, acid resistant material (SS-3 16). It has the dimension of 33 cm high, 22 cm diameter, and elliptical bottom and height of 4 cm. Moreover, the dimension of the 4 blades agitator is as follows: 8 cm long, 1,6 cm blades width. The distance between the blades and digester required 0, 007 Hp for a 500 rpm agitation speed and + 24. 103 kcal energy equipment for heating. Digestion experiment using the agitated digester yielded data that are in good agreement with laboratory scale experiment

  7. Enhancement of Cu, Ni and Mo recoveries in the bulk concentrate of Jaduguda uranium bearing ore

    International Nuclear Information System (INIS)

    Rao, G.V.; Besra, L.D.

    1998-01-01

    The uranium ore treatment plant at Jaduguda, India, recovers copper, nickel and molybdenum as byproducts before the bulk flotation tailings are subjected to leaching to recover uranium values. The recoveries of these sulfide metals in this 900 TPD plant are reported to be around 60 % Cu, 25% Ni and 55% Mo in the bulk concentrate. In this article, flotation studies carried out, at the instance of M/S UCIL, with various reagents and their combination to improve the over all recoveries are presented. It was observed that material coarser than 100 microns, from the flotation feed, could not be floated even in presence of excessive reagent unless it is ground further. It was established that around 95% Cu, 75% Ni and 74% Mo values could be recovered by using either amyl xanthate or mixture of amyl xanthate and Aero Promoter 194 in place of cresylic acid that is being currently used as collector in the plant. (author)

  8. Semi-continuous on-line uranium ore analyzer

    International Nuclear Information System (INIS)

    Campbell, P.; Gurdy, E.M.; Hatchowski, L.

    1984-01-01

    The efficient process control of a uranium mill and its associated mining operation requires a nearly continuous knowledge of the uranium concentration in the ore. Generally, the approach is to use laboratory assays of grab samples from the mill feed belt. In some cases, elaborate and expensive systems have been used to ensure random sampling, but even with these systems, mass-balance discrepancies still exist. There is a requirement for an on-line instrument that can give a prompt, accurate analysis of a large portion of the feed stock. The authors have recently evaluated a laboratory system that achieves these goals using neutron activation and delayed neutron counting. The development of the on-line uranium ore analyzer is a consequence of previous work done at the Whiteshell Nuclear Research Establishment (WNRE) (Campbell et al., 1978 and 1981), and is based on the emission of delayed neutrons after the neutron irradiation of fissionable materials. The mechanism of delayed neutron emission has been described (Keepin, 1965), but briefly is as follows. The fission fragments resulting from irradiation are in an excited state. Certain of these delayed fission products, precursors, decay to a more stable state by the emission of a delayed neutron. The delayed neutrons can be divided into six groups with effective half-lives ranging from 0.2-55 sec. It is important to note that more than 50% of the delayed neutrons are emitted within the first 6 sec after irradiation; this has an influence on the design of the analysis instrument

  9. Underground Milling of High-Grade Uranium Ore

    Energy Technology Data Exchange (ETDEWEB)

    Edwards, C., E-mail: chuck.edwards@amec.com [AMEC Americas Limited, Saskatoon, Saskatchewan (Canada)

    2014-05-15

    There are many safety and technical issues involved in the mining and progressing of high grade uranium ores such as those exploited in Northern Canada at present. With more of this type of mine due to commence production in the near future, operators have been looking at ways to better manage the situation. The paper describes underground milling of high-grade uranium ore as a means of optimising production costs and managing safety issues. In addition the paper presents some examples of possible process flowsheets and plant layouts that could be applicable to such operations. Finally an assessment of potential benefits from underground milling from a variety of viewpoints is provided. (author)

  10. Preconcentration of a low-grade uranium ore yielding tailings of greatly reduced environmental concerns. Part V

    International Nuclear Information System (INIS)

    Raicevic, D.; Raicevic, M.

    1980-11-01

    The low-grade ore sample used for this investigation contained 0.057 percent uranium with uranothorite as the major uranium-bearing mineral and a small amount of brannerite, occurring in the quartz-sericite matrix of a conglomerate. The preconcentration procedures, consisting of pyrite flotation with or without flotation of radioactive minerals, followed by high intensity wet magnetic treatment of the sized flotation tailings, produced pyrite and radioactive concentrates of acceptable uranium grades ranging from 0.1 to 0.135 percent uranium. The combined concentrates comprised 37 to 49 percent of the ore by weight with the following combined recoveries: 95.6 to 97.9 percent of the uranium; 94.7 to 96.3 percent of the radium; 97.8 to 99.3 percent of the thorium over 98 percent of the pyrite. The preconcentration tailings produced comprised between 51 and 63 percent of the ore by weight and contained from: 0.0022 to 0.0037 percent U; 12 to 17 pCi/g Ra; 0.002 to 0.004 percent Th less than 0.03 percent S. Because these tailings are practically pyrite-free, they should not generate acidic conditions. Due to their low radium content, their radionuclide hazards are greatly reduced. These preconcentration tailings therefore, could be suitable for surface disposal, mine backfill, revegetation or other uses

  11. New interpretation of the dominant ore-controlling factor of the uranium ore field No. 322

    International Nuclear Information System (INIS)

    Liu Xiang; Yang Chongqiu

    1996-01-01

    The NE-trending fault structures in ore field NO. 322 are characterized by compress-shearing, left-Lateral left-slipping, having an obvious control over the Localisation of the ore field No. 322, and are the dominant ore-controlling factor of the ore field NO.322. Resulting from the sinistral displacement of the NE-trending fault, there is a pull-apart basin in the Feng Zhou area. The formation and evolution of the NE-trending fault zone and the Feng Zhou basin control the formation of uranium deposits of ore field No. 322

  12. Uranium deposits of the Asian sector of Pacific ocean ore belt

    International Nuclear Information System (INIS)

    Kazanskij, V.I.

    1995-01-01

    Brief description of three basic types of uranium ore deposits in the Asian sector of the Pacific Ocean ore belt, namely uranium-molybdenum vein deposits in the continental volcanic depressions, proper uranium-molybdenum vein deposits in the mesozoic granites and gold-brannerite deposits of the rejuvenated early-proterosoic fractures is given. Schemes of various deposits are presented, petrological and isotope data (K-Ar method) are considered and petro- and oregenesis are analyzed. refs., 9 figs

  13. Practical aspects of monitoring and dosimetry of long-lived dust in uranium mines and mills - determination of the annual limit on intake for uranium and uranium/thorium ore dust

    International Nuclear Information System (INIS)

    Duport, P.; Horvath, F.

    1989-01-01

    Based on the recommendations of ICRP Publication 26, the dosimetric and metabolic data of ICRP Publication 30, and using available information on the physical and solubility characteristics of uranium and uranium/thorium ore, the ALI values for airborne ore dust were calculated. Four hypothetical types of ore were considered: uranium ore with no radon emanation, uranium ore with 50% radon emanation, uranium/thorium ore with neither 222 Rn nor thoron emanation, and uranium/thorium ore with 50% 22 Rn and 220 Rn emanation. Furthermore, the ALI values were calculated assuming the radionuclides present in the ore were all: (a) solubility class Y: (b) solubility class W; and (c) equal parts of classes Y and W. The ALI values were also calculated for Activity Median Aerodynamic Diameters (AMAD) ranging from 1 to 10 μm. The results of the calculations show that the solubility class of the radionuclides is the single most important factor that governs ALI values. The ALI value for uranium and uranium-thorium ore dust is proportional to (AMAD) 0.5 for class Y materials, (AMAD) 0.2 for a mixture of equal parts of class Y and class W materials, and is independent of the AMAD for class W materials. A series of graphs is given from which it is possible to evaluate the ALI for airborne ore dust when the AMAD of the dust and the solubility characteristics are known approximately. (author)

  14. Non-polluting treatment of uranium effluents from the alkaline digestion of an uranium ore containing sulfur

    International Nuclear Information System (INIS)

    Berger, Bernard.

    1978-01-01

    New non-polluting process for treating uranium effluents from the alkaline digestion of an uranium ore containing sulphur, which makes it possible (a) to extract and obtain relatively pure uranium and (b) to process the digestion liquor freed from the uranium and containing in an aqueous solution a mixture of alkaline carbonate and/or bicarbonate and sodium sulphate, consisting in the selective extraction of the sodium sulphate present and the recycling of the liquor free of SO 4 = ions, containing in solution the sole carbonates and/or bicarbonates involved, towards the digestion of the ore [fr

  15. Uranium reduction by carbon oxide during ore formation

    International Nuclear Information System (INIS)

    Matyash, I.V.; Gavrusevich, I.B.; Pasal'skaya, L.F.; Shcherba, D.I.

    1981-01-01

    Using the method of gas chromatography the gas content in Pre-Cambrian granitoils of various types and in natrometasomatites associted with them is studied. It is established that granites associated with ore-bearing albitites have sharply elevated amounts of CO as compared with granites, which do not include mineralization. Simultaneously in ore samples the absence or sharply low amounts of CO as compared with ore-free samples is observed, that is reverse dependence of CO and ore components. Carbon oxide is the reducing agent of uranium mineralization and alongside with other reducing agents can be a geochemical barrier in the process of ore formation [ru

  16. Chlorine/chloride based processes for uranium ores

    International Nuclear Information System (INIS)

    1980-11-01

    The CE Lummus Minerals Division was commissioned by The Department of Supply and Services to develop order-of-magnitude capital and operating cost estimates for chlorine/chloride-based processes for uranium ores. The processes are designed to remove substantially all radioactive consituents from the ores to render the waste products harmless. Two processes were selected, one for a typical low grade ore (2 lb. U 3 O 8 /ton ore) and one for a high grade ore (50 lbs U 3 O 8 /ton). For the low grade ore a hydrochloric acid leaching process was chosen. For high grade ore, a more complex process, including gaseous chlorination, was selected. Capital cost estimates were compiled from information obtained from vendors for the specified equipment. Building cost estimates and the piping, electrical and instrumentation costs were developed from the plant layout. Utility diagrams and mass balances were used for estimating utilities and consumables. Detailed descriptions of the bases for capital and operating cost estimates are given

  17. A discussion on several problems in determination of uranium ore grade criteria

    International Nuclear Information System (INIS)

    Zhu Zhixiang.

    1991-01-01

    The course of determination of uranium ore grade criteria in China is briefly introduced. The cut-off grade minimum industrial grade and allowable minimum average grade uranium ore bodies used in China are reviewed. The meanings and role of various grade criteria and their economic basis for determination in uranium exploration, mining and sorting are discussed and the author's ideas are given

  18. Status report from India [Processing of Low-Grade Uranium Ores

    Energy Technology Data Exchange (ETDEWEB)

    Fareeduddin, S [Atomic Energy Establishment, Trombay, Bombay (India)

    1967-06-15

    The Energy Survey Committee of India, in its report to the Government, has estimated that the energy requirements in the year 1985/86 would be 290X10{sup 9} kWh, i. e. eight times the present requirement, and in the year 2000 it would be 820X10{sup 9} kWh, which is about 22 times the present requirement. The hydropotential that can be developed during the next 20 years is estimated to be of the order of 150X10{sup 9} kWh and hence the difference of about 140X10{sup 9} kWh will have to be obtained from either fossil or nuclear fuel. This would mean installating a generation capacity of about 26 000 MW in the next 20 years. To conserve the limited fossil fuel reserves, it has been estimated that about 70% of this capacity, i. e. about 18 000 MW, should form the nuclear component. This will be about 25% of the total energy requirements by 1985/86. The uranium requirements to meet this growth will be about 10 000 tonnes by 1985/86 which, from the point of view of our resources, is a substantial quantity. The most important uranium deposits are located in South Bihar in the Singhbhum Thrust belt, which is well known for its copper, apatite magnetite and kyanite deposits. On the basis of their uranium contents, these ores can be classified into two broad categories - one with low copper and high uranium contents and the other with high copper and low uranium contents. Another source of uranium in India is monazite. Some particulars about these deposits are given. Facilities for the recovery of byproduct uranium from monazite already exist in the country. But its production from this source, conditioned as it is by the limited demand for thorium, cannot be very large. Both the categories of the ores from the Singhbhum belt can be considered as low grade. Uranium from the ores in category (B) can be recovered, in the present state of knowledge, only as a byproduct of the copper industry. In the case of ores in the category (A), attempts have been made to recover uranium

  19. Work within the coordinated programme on bacterial leaching of uranium ores

    International Nuclear Information System (INIS)

    Jayaram, K.M.V.

    1978-10-01

    The paper relates geological and lithological aspects of host rocks to the leaching and precipitation of uranium through the agency of microorganisms. For this purpose three different host rocks were studied: a low grade uranium ore analysing 0.045% U 3 O 8 and two high grade ores analysing 0.27% and 1.8% U 3 O 8 respectively. The affect of ore composition, water composition and climatic conditions were studied in relation to the nature of the microflora indigenously developed

  20. Ore controlling oxidized zonation epigenetic uranium-coal deposits and regularities in lignite transformations

    International Nuclear Information System (INIS)

    Uspenskij, V.A.; Kulakova, Ya.M.

    1982-01-01

    Complex of analytical methods was used to study epigenetic transformations in uranium-coal ore manifestation. To clarify the principle scheme of oxidized zonation in coals the materials, related to three similar objects were used. When comparing obtained epigenetic column with columns of similar ore objects the principle scheme of oxidized epigenetic zonation for ancient infiltration uranium-coal deposits was specified; general regularities of eignite transformations and characteristics of profile distribution of uranium and accessory metal zonations were revealed. Infiltration processes, proceeded in coal measureses, formed the steady epigenetic oxidized zonation: O - zone of barren unoxidized coals, 1 - zone of ore-bearing unoxidized coals, 2 - zone of weakly ore-bearing oxidized coals, 3 - zone of oxidized terrigenous rocks with zonules of development of yellow and red iron hydroxides. Capacities of some zones and zonules reflect the intensity and duration of ore-forming processes. Distribution of U and accessory elements obeys completely epigenetic zonation. It is assumed, that ancient infiltration uranium-coal deposits formed due to weakly uranium-bearing oxygen-containing waters

  1. Extraction of uranium from coarse ore and acid-curing and ferric sulphate-trickle leaching process

    International Nuclear Information System (INIS)

    Jin Suoqing

    1994-01-01

    On the basis of analysis of the problems in the technology of the traditional uranium hydrometallurgy and the limitations of thin layer leaching process (TLL), a new leaching system-acid-curing and ferric sulphate-trickle leaching (AFL) process (NGJ in Chinese) has developed for extraction of uranium from the coarse ore. The ferric sulphate solution was used for trickling the acid-cured uranium ore and the residual leaching reaction incomplete in TLL process can be improved in this process. And the AFL process has a wide applicability to China's uranium ores, being in competition with the traditional agitation leaching process for treating coarse ores. The uranium ore processing technology based on the AFL process will become one of the new basic technologies of uranium hydrometallurgy. A series of difficulties will be basically overcome associated with fine grinding because of its elimination in the presented process. Moreover, the situation of the present uranium hydrometallurgy can be also changed owing to without technological effluent discharge

  2. Uranium Rirang ore processing: extraction of uranium from Rirang ore digestion solution with tributyl phosphate

    International Nuclear Information System (INIS)

    Arief, E. R.; Zahardi; Susilaningtyas

    1998-01-01

    Uranium is extracted from Rirang ore acid digestion solution containing rare earths. A mixture of tributyl phosphate solvent and kerosene diluent is employed. Several parameters of solvent extraction have been studied included aqueous to organic phase ratio, H 2 O 2 reductor concentration and Tbp concentration in the solvent mixture, as well as the aqueous to organic phase ratio in the stripping process. The optimum conditions for the extraction step include the use of 25% H 2 O 2 (v/v), one to one aqueous to organic ratio, and 40% Tbp in kerosene. The extraction recovery for U, RE, Th, and PO 4 3 - are 99%, 4%, 70%, and 30%, respectively. The stripping step optimum conditions include the use of one to five organic to aqueous phase ratio 0.24 N HNO 3 . and the stripping recovery for U, RE, Th, and PO 4 3 - are 84%, 80%, 72%, and 83%, respectively

  3. The uranium ore deposits of the pine creek geosyncline in North Territory, Australia

    International Nuclear Information System (INIS)

    Kneuper, G.K.; Clasen, D.

    1980-01-01

    The geological history of the Pine Creek geosyncline is reviewed, and recent research findings and model assumption on the formation of uranium ore deposits are presented. The geological similarities between the Alligator River uranium ore district and the Athabasca Lake district in Saskatchewan, Canada, are pointed out. Present geographic and climatic differences between these two uranium districts and the consequences of these differences for uranium exploration are discussed. The uranium mining activities planned in Australia are illustrated by the example of the Ranger uranium deposit. (orig.) [de

  4. Geochemical study of the insoluble organic material (kerogen) in the Oklo uranium ore and the associated Francevillian schists

    International Nuclear Information System (INIS)

    Vandenbroucke, M.; Rouzaud, J.N.; Oberlin, A.

    1978-01-01

    The purpose of this study was to describe the organic material associated with uranium ore and ore transformations undergone by it, in terms of the following problems: (1) In the natural reactor zones, evolution of the organic material in the core and as a function of the distance away from it; (2) Comparison of organic materials from a rich and a poor ore; (3) Intercomparison of organic materials in the dispersed and concentrated state; (4) Comparison of organic materials in the uranium ore zones and in the adjacent non-mineralized Francevillian. The organic material from the reactor core could not be isolated by the normal techniques of treatment with acid. It is found in other cases that the organic material is oxidized in the uranium-bearing sediments and that the nearer to the reaction zone, the greater the oxidation, irrespective of the state of dispersion of the organic material in the rock. The uranium content does not affect this phenomenon, which is attributed to the action of the water raised to a high temperature in the vicinity of the reaction zones. On the basis of the present distribution of organic material and uranium the authors suggest a pattern for the formation of the deposit that would take into account localization of the ore in the sandstones and the part played by organic material in the accumulation process. (author)

  5. Geochemical features of the ore-bearing medium in uranium deposits in the Khiagda ore field

    Science.gov (United States)

    Kochkin, B. T.; Solodov, I. N.; Ganina, N. I.; Rekun, M. L.; Tarasov, N. N.; Shugina, G. A.; Shulik, L. S.

    2017-09-01

    The Neogene uranium deposits of the Khiagda ore field (KOF) belong to the paleovalley variety of the hydrogene type and differ from other deposits of this genetic type in the geological and geochemical localization conditions. The contemporary hydrogeochemical setting and microbiological composition of ore-bearing medium are discussed. The redox potential of the medium (Eh is as low as-400 mV) is much lower than those established at other hydrogenic deposits, both ancient Late Mesozoic and young Late Alpine, studied with the same methods in Russia, Uzbekistan, and southern Kazakhstan. The pH of subsurface water (6.86-8.13) differs in significant fluctuations both between neighboring deposits and within individual ore lodes. Hydrogen-forming and denitrifying bacteria are predominant in microbiological populations, whereas sulfate-reducing bacteria are low-active. The consideration of these factors allowed us to describe the mechanism of uranium ore conservation as resulting from the development of the cryolithic zone, which isolates ore lodes from the effect of the external medium. Carbonated water supplied from the basement along fault zones also participates in the formation of the present-day hydrogeochemical setting. Based on the features of the ore-bearing medium, we propose a method of borehole in situ acid leaching to increase the efficiency of mining in the Khiagda ore field.

  6. Heap bioleaching of uranium from low-grade granite-type ore by mixed acidophilic microbes

    International Nuclear Information System (INIS)

    Xuegang Wang; Zhongkui Zhou

    2017-01-01

    We evaluated uranium bioleaching from low-grade, granite-type uranium ore using mixed acidophilic microbes from uranium mine leachate. A 4854-ton plant-scale heap bioleaching process achieved sustained leaching with a uranium leaching efficiency of 88.3% using a pH of 1.0-2.0 and an Fe"3"+ dosage of 3.0-5.5 g/L. Acid consumption amounted to 25.8 g H_2SO_4 kg"-"1 ore. Uranium bioleaching follows a diffusion-controlled kinetic model with a correlation coefficient of 0.9136. Almost all uranium was dissolved in aqueous solution, except those encapsulated in quartz particles. Therefore, heap bioleaching by mixed acidophilic microbes enables efficient, economical, large-scale recovery of uranium from low-grade ores. (author)

  7. Precipitation of uranium peroxide from the leach liquor of uranium ores

    International Nuclear Information System (INIS)

    Gao Xizhen; Lin Sirong; Guo Erhua; Lu Shijie

    1995-06-01

    A chemical precipitation process of recovering uranium from the leach liquor of uranium ores was investigated. The process primarily includes the precipitation of iron with lime, the preprocessing of the slurry of iron hydroxides and the precipitation of uranium with H 2 O 2 . The leach liquor is neutralized by lime milk to pH 3.7 to precipitate the iron hydroxides which after flocculation and settle is separated out and preprocessed at 170 degree C in an autoclave. H 2 O 2 is then used to precipitate uranium in the leach liquor free of iron, and the pH of process for uranium precipitation adjusted by adding MgO slurry to 3.5. The barren solution can be used to wash the filter cakes of leach tailing. The precipitated slurry of iron hydroxides after being preprocessed is recycled to leaching processes for recovering uranium in it. This treatment can not only avoid the filtering of the slurry of iron hydroxides, but also prevent the iron precipitate from redissolving and consequently the increase of iron concentration in the leach liquor. The results of the investigation indicate that lime, H 2 O 2 and MgO are the main chemical reagents used to obtain the uranium peroxide product containing over 65% uranium from the leach liquor, and they also do not cause environmental pollution. In accordance with the uranium content in the liquor, the consumption of chemical reagent for H 2 O 2 (30%) and MgO are 0.95 kg/kgU and 0.169 kg/kgU, respectively. (1 fig., 8 tabs., 7 refs.)

  8. Concentrations of heavy metals (lead, manganese, cadmium) in blood and urine of former uranium workers

    International Nuclear Information System (INIS)

    Apostolova, D.; Pavlova, S.; Paskalev, Z.

    1999-01-01

    Uranium ores contain heavy metals and other stable chemical elements as oxides, hydro-carbonates, sulphates, etc. During chemical processing of ore they could be transformed into compounds soluble in biologic liquids. The purpose of this study was to determine the combined intoxication of uranium miners and millers by heavy metals and radiation. Heavy metal (lead, manganese and cadmium) concentrations in blood and urine od 149 former uranium miners and millers were determined by AAS method. Data of significantly increased lead and manganese concentration in blood (p<0.05) of two groups were established in comparison with a control group. There is no statistical significant differences in the cadmium concentrations. The lead and manganese blood levels at the uranium millers were significant higher than those of the uranium miner group (p<0.05). Tendency towards increased blood lead concentrations of uranium millers depending on the length of service was established

  9. The determination of radium-226 in uranium ores and mill products by alpha energy spectrometry

    International Nuclear Information System (INIS)

    Zimmerman, J.B.; Armstrong, V.C.

    1975-12-01

    A reliable routine procedure for determining 226 Ra by alpha energy spectrometry is described. Radium is isolated as sulphate from the sample matrix by co-precipitation with a small mass of barium and analysed using a ruggedized silicon surface barrier detector. The method is capable of providing high accuracy over a large 226 Ra concentration range and is applicable to materials such as uranium ores, uranium mill products and effluent streams. Samples resulting from nitric acid leach experiments with Elliot Lake ores were examined using the procedure. The distribution of 223 Ra, 224 Ra and 226 Ra between the leach products, (residue and leach liquor), is discussed. (author)

  10. Application of solution-mineral equilibrium chemistry to solution mining of uranium ores

    International Nuclear Information System (INIS)

    Riese, A.C.; Propp, C.J.

    1980-01-01

    Modern methods of uranium solution mining are typically accompanied by gains and losses of mass through reagent consumption by rock-forming minerals, with subsequent formation of clay minerals, gypsum, carbonates, and iron oxyhydroxides. A systematic approach to alleviate such problems involves the application of leach solutions that are in equilibrium with the host-rock minerals but in disequilibrium with the ore-forming minerals. This partial equilibrium can be approximated by solution-composition adjustments within the systems K 2 O-Al 2 O 3 SiO 2 -H 2 O and Na 2 O 3 -Al 2 O 3 SiO 2 -H 2 O. Uranium ore containing 0.15 percent U 3 O 8 from the Gulf Mineral Resources Corporation's Mariano Lake mine, the Smith Lake district of the Grants mineral belt, was collected for investigation. Presented are a theoretical evaluation of leachate data and an experimental treatment of the ore, which contained mainly K-feldspar, plagioclase feldspar, and quartz (with lesser amounts of micas, clay minerals, and organic carbonaceous material). Small-scale (less than or equal to 1 kg) column-leaching experiments were conducted to model the results of conventional leaching operations and to provide leachate solutions that could be compared with solutions calculated to be in equilibrium with the matrix minerals. Leach solutions employed include: 1) sulfuric acid, 2) sodium bicarbonate, and 3) sulfuric acid with 1.0 molal potassium chloride. The uranium concentrations in the sodium-bicarbonate leach solution and the acid-leach solution were about a gram per liter at the termination of the tests. However, the permeability of the ore in the acid leach was greatly reduced, owing to the formation of clay minerals. Uranium solubility in the leach column stabilized with the potassium-chloride solution was calculated from leachate compositions to be limited by the solubility of carnotite

  11. Studies on geneses of Lianshanguan granites and Lianshanguan uranium ore deposit

    International Nuclear Information System (INIS)

    Zhang Jiafu; Xu Guoqing; Wang Wenguang

    1994-02-01

    Based on the field work, and through the studies of thin-sections, minerals fluid inclusions, isotope geology, rare-earth elements and U-content in rocks and minerals, it is suggested that Lianshanguan granites are of magmatization genesis with multistage. The genetic model of mineralization of Lianshanguan uranium ore deposit is the magmatization-hydrothermal-filled uranium type. The role of mineralization of uranium ore deposit in that area is discussed. Furthermore, the direction of prospecting and following prospecting criteria for similar deposits in this area are also given

  12. South African gold and uranium ore mining in 1976

    International Nuclear Information System (INIS)

    Hentrich, W.

    1977-01-01

    1976 was a difficult year for the South African gold and uranium ore mining industry, the region of Witwatersrand (Transvaal province) producing some 75% of all the gold mined in the western world besides being an important producer of uranium oxide. Despite the gold production, declining since 1971, not showing a downward tendency anymore as far as the quantity was concerned, the economic result, however, deteriorated as a consequence of continuously falling gold prices, but also on account of the inflationary rise in wages and the prices for energy and materials. Much higher prices for uranium oxide, which some mines produce as interim products from the 'degolded' slurries of their gold ore leaching plants, improved the economic overall result only to a small degree. (orig.) [de

  13. Radiation risk, medical surveillance programme and radiation protection in mining and milling of uranium ores

    International Nuclear Information System (INIS)

    Rakshit, A.K.

    1991-01-01

    Mining and milling of uranium ores comprise multiple operations such as developement, drilling, blasting, handling, crushing, grinding, leaching of the ore and concentration, drying, packaging and storing of the concentrate product. Apart from the hazards of any metal mining and milling operations due to dust, noise, chemicals, accidents etc there are radiation risks also resulting from exposure to airborne radioactivity and external radiation. The inhalation risk is of more concern in underground mines than in open pit mines. The objective of a Medical Surveillance Programme (an occupational Health Programme) is to ensure a healthy work force. It should ultimately lead to health maintenance and improvement, less absenteeism increased productivity and the achievement of worker and corporate goals. The programme includes prevention, acute care, counselling and rehabilitation. Radiological workers require special monitoring for their work-related radiation exposure effect by film monitoring service, whole body counting and bioassay. Radiation protection in the mining and milling of Uranium ores include the use of personal protective equipment, work station protection, personal hygiene and house keeping. (author). 15 refs

  14. Hyperspectral information identification for characterizing metallogenic factors of Taoshan uranium ore-field

    International Nuclear Information System (INIS)

    Zhang Jielin

    2007-01-01

    The application of high resolution remote sensing technology to uranium mineralization is discussed in detail. By utilizing field hyperspectrum measurement method (VIS/NIR-SWIR-FIR) and fusion technology of ETM image and Radarsat data, the spectral characteristic of uranium mineralization factors including rock mass, ore-control fault and hydrothermal alteration are studied in Taoshan granite type uranium deposits. The main ore-control structure has been identified based on remote sensing image feature. Those results and experiences provide the new remote sensing approaches to the prospecting and evaluation of uranium resources. (authors)

  15. Formation and uranium explorating prospect of sub-volcanic granitic complex and rich uranium ore deposit in South China

    International Nuclear Information System (INIS)

    Wang Yusheng

    1997-01-01

    The rich uranium ore deposits are all closely related to tecto-magmatism of late-magmatic cycle whether volcanic types or granitic types in south China. Volcanic type rich uranium deposit has closely relationship with sub-volcanic activity, and granitic type rich uranium deposit is also closely related to mid-fine, unequal particle small massif in late main invasion stage. Based on characteristics of magmatism, we name the rock sub-volcanic granite complex, which is a unique style and closely related to the formation of rich uranium ore deposit

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

    International Nuclear Information System (INIS)

    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 222 Rn emanation from mill tailings, 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 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 226 Ra concentration of waste-water. Leachability of radium from treated tailings was markedly reduced

  17. Permeability restoration and lowering of uranium leakage from leached ore beds

    International Nuclear Information System (INIS)

    Burgman, H.A.; Grant, D.C.

    1981-01-01

    The injection of an ammonium sulfite or bisulfite solution increases the permeability of an uranium ore bed that has suffered permeability losses during the in-situ mining of uranium with an alkaline leach solution containing a peroxide or dissolved oxygen oxidant. Such an injection recovers much of the lost formation permeability, thus decreasing costs and effort required to put needed restoration solutions or further leach solutions through the ore bed. In addition, uranium contamination of the ground water normally occurring after cessation of leaching is significantly lowered by such injection

  18. Rirang uranium ore processing: continuous solvent extraction of uranium from Rirang ore acid digestion solution

    International Nuclear Information System (INIS)

    Riza, F.; Nuri, H. L.; Waluya, S.; Subijanto, A.; Sarono, B.

    1998-01-01

    Separation of uranium from Rirang ore acid digestion solution by means of continuous solvent extraction using mixer-settlers has been studied and a mixture of 0.3 M D2EHPA and 0.075 M TOPO extracting agent and kerosene diluent is employed to recover and separate uranium from Th, RE, phosphate containing solution. The experiments have been conducted batch-wise and several parameters have been studied including the aqueous to organic phase ratio, A/O, the extraction and the stripping times, and the operation temperature. The optimum conditions for extraction have been found to be A/O = 2 ratio, five minute extraction time per stage at room temperature. The uranium recovery of 99.07% has been achieved at those conditions whilst U can be stripped from the organic phase by 85% H 3 PO 4 solution with an O/A = 1 for 5 minutes stripping time per stage, and in a there stage operation at room temperature yielding a 100% uranium recovery from the stripping process

  19. Studies on the recovery of uranium from low-grade ores in India

    International Nuclear Information System (INIS)

    Jayaram, K.M.V.; Dwivedy, K.K.; Deshpande, A.S.; Ramachar, T.M.

    1976-01-01

    Investigations were carried out to utilize the available para-marginal and low-grade ores - chlorite schists, amphibolites, carbonate ores, clays and quartzites - analysing between 0.027 and 0.08% U 3 O 8 . In addition, tests were undertaken on the technical and economic feasibility of recovering uranium as a byproduct from the copper flotation tailings and phosphorites. Heap and bacterial leaching tests were conducted on quartz-chlorite schists from the Singhbhum district, Bihar, analysing about 0.03% U 3 O 8 . Studies also showed that the ores harbour active Ferrobacillus ferrooxidans. Studies on 10-mesh samples of amphibolites from Inderwa, Bihar, (0.08% U 3 O 8 ) showed that only 32.8% recovery could be obtained by wet tabling and 85% by agitation leaching, while static leaching tests yielded 81% recovery in 24 hours of contact time. Similar tests on calcareous phyllites (0.05% U 3 O 8 ) with 30 kg/t Na 2 CO 3 and 8 kg/t NaHCO 3 yielded 86% uranium leachability at ambient temperature. Biogenic uraniferous clay from Udaisagar (0.029% U 3 O 8 ) yielded 43.3% uranium recovery using 1000 l/t of neutral water for 6 h. Percolation leaching tests were conducted with hard quartzites (0.06% U 3 O 8 ), and the results showed that 81% uranium could be recovered in 24 days. Although preliminary ore dressing studies on tailings obtained from the copper flotation (0.013% U 3 O 8 ) at Surda yielded a concentrate analysing 0.063% U 3 O 8 at 66% recovery, recent tests on the tailings from the copper concentrator indicated only 48% recovery at a grade of 0.112% owing to decrease in the feed grade. Studies on the utilization of large-capacity gravity machines and selective mining of uranium-rich copper lodes may render this source economic. Preliminary studies on a phosphorite sample containing 22.0% P 2 O 5 and 0.04% U 3 O 8 from the Mussorie area in Uttar Pradesh on calcination followed by scrubbing yielded a sand enriched in P 2 O 5 values (33.7% P 2 O 5 at 92.5% recovery) but

  20. Agpaitic nepheline syenites from the Ilimaussaq Complex, south Greenland; an important new uranium ore type (v.2)

    International Nuclear Information System (INIS)

    Mair, J.L.; Bunn, S.

    2010-01-01

    The Ilimaussaq Intrusive Complex in south Greenland is a layered alkaline igneous body that is predominantly comprised of agpaitic nepheline syenites. The Complex is now recognized as containing vast resources of uranium in polymetallic ores that are also strongly enriched in rare earth elements (REEs) and zinc. Uranium and REEs are dominantly hosted in phosphate minerals with a minor proportion hosted in zirconium silicate minerals. Equivalent ores are yet to be mined for uranium anywhere in the world; however, studies are well advanced in confirming a process route to economically extract uranium. The Ilimaussaq Complex is considered the world's type-locality for agpaitic rocks. Formation of the complex is attributed to four successive pulses of magma. The first produced an augite syenite, which now forms a marginal shell. This was followed by intrusion of a sheet of peralkaline granite. The third and fourth stages make up the bulk of the intrusion and are peralkaline to hyper-agpaitic in composition. The third batch of magma differentiated to produce pulaskite, foyaite and naujaite. Stage four produced the kakortokites and lujavrites, which are the units of particular economic significance. Kakortokites are strongly enriched in zirconium, niobium and tantalum, whereas the lujavrites are strongly enriched in uranium, rare earth elements, fluorine and zinc. Lujavrites are vertically zoned with arfvedonsite (black) lujavrites grading downward into aegerine (green) lujavrites. The upper most portions of the black lujavrites contain uranium concentrations of greater than 450 ppm, which decreases downward over 200 - 300m toward green lujavrites where uranium concentrations rarely exceeds 200 ppm. Resources defined to date in accordance with the Australian JORC code include 192 million lb. of U_3O_8 at 350 ppm within an overall resource of 282 million lb. of uranium oxide at a grade of 280 ppm. With scope for several other similar sized resources within complex, the

  1. Environmental monitoring data review of a uranium ore processing facility in Argentina

    International Nuclear Information System (INIS)

    Bonetto, J.

    2014-01-01

    An uranium ore processing facility in the province of Mendoza (Argentina) that has produced uranium concentrate from 1954 to 1986 is currently undergoing the last steps of environmental restoration. The operator has been performing post-closure environmental monitoring since 1986, while the Nuclear Regulatory Authority (ARN) has been carrying out its own independent radiological environmental monitoring for verification purposes since its creation, in 1995. A detailed revision of ARN´s monitoring plan for uranium mining and milling facilities has been undergoing since 2013, starting with this particular site. Results obtained from long-time sampling locations (some of them currently unused) have been analyzed and potentially new sampling points have been studied and proposed. In this paper, some statistical analysis and comparison of sampling-points’ datasets are presented (specifically uranium and radium concentration in groundwater, surface water and sediments) with conclusions pertaining to their keeping or discarding as sampling points in future monitoring plans. (author)

  2. Hydrogeochemical radioactive features and prospecting in granopegmatite type uranium ore district in Danfeng area

    International Nuclear Information System (INIS)

    Feng Zhangsheng

    2011-01-01

    Hydrochemical radioactive prospecting plays an important role in the all stages of grano-pegmatite type uranium deposit exploration in Danfeng area dut to its fast, simple, economic and high effective advantage. Radioactive anomalous halo in the shallow underground water has identical distribution scopes with the ore-bearing biotite granite-pegmatite, which can be used to delineate uranium ore-forming prospective area, reconnaissance area and detailed prospecting area. Deep underground water close to the ore is characterized by hydrogeochemical radioactive features with high uranium and radon content. Through prospecting engineering of radioactive hydrogeochemical, the situation of blind ore bodies can be used to guide the layout. (authors)

  3. Link between ore bodies and biosphere concentrations of uranium

    International Nuclear Information System (INIS)

    Gordon, S.

    1992-01-01

    A literature review of uranium exploration studies was carried out to determine the size and concentration of uranium anomalies in the biosphere. Fourteen sites were studied and uranium data were obtained for rocks, water-borne sediments, surface waters, groundwaters, soils and plants. Detailed descriptions of the study areas and of their uranium anomalies are provided. No statistical analyses of the data of anomaly sizes was undertaken because of the variation in the scale of the studies and in the threshold values used and the small number of samples for each medium. The threshold values and the size of the anomaly were found to be dependent on the scale of the study and of the sampling density. Sediments and surface waters were found to have the largest uranium dispersion. Although there was a wide range in the anomaly sizes it was possible to assign typical values for each medium. Based on a typical source of 1 km 2 in the rock it was found that anomalies of similar size as the source are expected in soils and plants, anomalies twice as large are typical for sediments and surface waters and anomalies of smaller areas than the source are possible for groundwater. Some limitations to providing typical groundwater anomaly sizes are outlined. Typical maximum concentrations for the sites studied were greater than 1300 ppm for rock, 10 to 110 ppm for sediment, and 5 ppb for surface waters. No typical values were observed for groundwater, soils and plants. Susceptibility of the host rock to leaching and the presence of discharge zones were assessed for their role in biosphere anomalies

  4. More light on the U clan. [Uranium behaviour in complex ores

    Energy Technology Data Exchange (ETDEWEB)

    De Waal, S.A. (Potchefstroom Univ. for C.H.E. (South Africa). Dept. of Geology)

    1983-07-01

    A thorough knowledge of the geochemistry of uranium is necessary for the exploration and beneficiation of this mineral. At present we lack knowledge of the behaviour of uranium minerals in complex ores. This article deals with the geochemistry of uranium, its group identity, uranium minerals and the extraction mineralogy.

  5. User's guide for the Uranium Ore Reserve Calculation System (URAD)

    International Nuclear Information System (INIS)

    1988-12-01

    The URAD (Uranium Reserves and Data) system consists of four computer programs designed to facilitate the evaluation of uranium ore reserves analysis and the handling of basic uranium assay data. URAD is designed specifically as a training tool for anyone unfamiliar with the methodology, data requirements, and/or general computer applications in the field of uranium ore reserves analysis. However, it can effectively be used in a 'production' environment involving considerable amounts of data. The resulting programs are written in Microsoft FORTRAN (Version 3.1) and may be run on any IBM-compatible microcomputer under DOS 2.1 (or later). Only a basic working knowledge of DOS 2.1 is needed to maintain the system and run the programs. This guide includes the overview of the URAD system, the review of sample data and a complete description of the file structure and sample type formats of the basic sample data files. Program URDAT explains the initial processing of the primary UDAT files to obtain standard output listings and gamma-log interpretations of radiometric data, and to create intermediate UDAT files which are used by the ore reserves programs - RESUV, ORSAC, and SCOR. Figs and tabs

  6. Leaching of U, 230Th and 226Ra from Saskatchewan uranium ore after removing clay

    International Nuclear Information System (INIS)

    Muthuswami, S.V.; Mohd Yunus, M.Z.; Mohamad Nor, M.I.; Kassim, Z.A.; Nirdosh, I.

    1993-01-01

    Distribution of U, 230 Th and 226 Ra in various size fractions in a typical Saskatchewan uranium ore and its resultant mill tailings indicated that less than 4% of these radionuclides were present in the fine ≤ 45 μm) size fraction in the ore whereas their concentration in the similar size fraction in the tailings was > 80%. Removal of clay minerals from the ore by flotation was unsuccessful whereas sedimentation gave nearly complete removal. Leaching of 230 Th from the ore before and after removing clay minerals indicated that dissolution of 230 Th was mproved at higher E h and acidity of the leaching medium and that it was independent of the presence of clay minerals in the ore. (orig.) [de

  7. Aftermath of Uranium Ore Processing on Floodplains: Lasting Effects of Uranium on Soil and Microbes

    Science.gov (United States)

    Tang, H.; Boye, K.; Bargar, J.; Fendorf, S. E.

    2016-12-01

    A former uranium ore processing site located between the Wind River and the Little Wind River near the city of Riverton, Wyoming, has generated a uranium plume in the groundwater within the floodplain. Uranium is toxic and poses a threat to human health. Thus, controlling and containing the spread of uranium will benefit the human population. The primary source of uranium was removed from the processing site, but a uranium plume still exists in the groundwater. Uranium in its reduced form is relatively insoluble in water and therefore is retained in organic rich, anoxic layers in the subsurface. However, with the aid of microbes uranium becomes soluble in water which could expose people and the environment to this toxin, if it enters the groundwater and ultimately the river. In order to better understand the mechanisms controlling uranium behavior in the floodplains, we examined sediments from three sediment cores (soil surface to aquifer). We determined the soil elemental concentrations and measured microbial activity through the use of several instruments (e.g. Elemental Analyzer, X-ray Fluorescence, MicroResp System). Through the data collected, we aim to obtain a better understanding of how the interaction of geochemical factors and microbial metabolism affect uranium mobility. This knowledge will inform models used to predict uranium behavior in response to land use or climate change in floodplain environments.

  8. Trace-element analysis of uranium ores by x-ray fluorescence spectrometry

    International Nuclear Information System (INIS)

    Coetzee, P.P.; De Villiers, W.v Z.

    1985-01-01

    The determination of seventeen trace elements (As, Ba, Co, Cr, Cu, Mo, Nb, Ni, Pb, Sr, Th, U, V, Y, Zn, and Zr) in uranium ores by x-ray fluorescence spectrometry was investigated. For the elements with analyte lines in the vicinity of the U-L lines, large overlap corrections were necessary and only a few completely interference-free background positions were available. Consequently, the Feather and Willis method was used for determining the background intensity at the peak positions as well as mass absorption coefficients. As a result of the presence of the U-L absorption edges, both primary and secondary mass absorption coefficients had to be used for matrix corrections. Furthermore, it was observed that the background intensity in the region of the uranium lines increased with increasing uranium content of the sample, instead of the expected decrease due to the increasing mass absorption coefficient. This was attributed to the scattering of uranium lines in the spectrometer chamber. A method was developed to correct the measured intensities for this effect. The contribution from the scattering of uranium lines to the measured intensity at the various 20 positions was determined on samples with different uranium concentrations and for which the mass absorption coefficients and concentrations of the various elements were known

  9. Selection of mining method for No.3 uranium ore body in the independent mining area at a uranium mine

    International Nuclear Information System (INIS)

    Ding Fulong; Ding Dexin; Ye Yongjun

    2010-01-01

    Mining operation in the existed mining area at a uranium mine is near completion and it is necessary to mine the No.3 uranium ore body in another mining area at the mine. This paper, based on the geological conditions, used analogical method for analyzing the feasible methods and the low cost and high efficiency mining method was suggested for the No.3 ore body in the independent mining area at the uranium mine. (authors)

  10. The relationship between tectonic-thermal evolution and sandstone-type uranium ore-formation in Ordos basin

    International Nuclear Information System (INIS)

    Zhao Honggang

    2005-01-01

    The comprehensive study of the volcanic activities, the geothermal field, the thermal flow field, the paleogeo-thermal activity and the tectonic evolution of the Ordos basin indicates that the tectonic-thermal evolution of the Ordos basin has offered the basis for the fluid-fluid and fluid-rock mutual reactions, and has created favourable conditions for the formation of organic mineral resources and sandstone-type uranium deposits. Especially, the tectonic-thermal event during middle-Late Jurassic to Cretaceous played an important role in providing uranium source material, and assisting the migration, the concentration and precipitation of uranium and uranium ore-formation. (authors)

  11. Lung cancer and inhaled uranium ore dust in rats

    International Nuclear Information System (INIS)

    Mitchel, R.E.J.; Jackson, J.S.

    1997-01-01

    Using a nose only inhalation system, 187 nine week old male Sprague-Dawley rats were exposed to two different concentrations of natural uranium ore dust aerosol (44% U) without significant radon content. Inhalation exposures averaged about 4.2 h/day, 5 days/week for 65 weeks at which point lung uranium burdens in the two groups averaged 0.9 and 1.9 mg/g dry weight. Animals (63) exposed to the air stream without dust served as controls. After inhalation exposure ceased, the rats were allowed to live for their natural lifetime, a maximum of about 900 days after the start of dust inhalation. Lung uranium burdens were measured at the time of death of each animal. Lung burdens were found to decline exponentially after dust inhalation ceased, and the rate of decline was independent of the initial lung burden. All lungs were examined at necropsy and histologically for lung tumors. Lung tumors of lung origin were observed in both exposed groups and in the control group. The frequency of primary malignant lung tumors was 0.016, 0.175 and 0.328 and primary non-malignant lung tumors 0.016, 0.135 and 0.131 in the control low and high aerosol exposed groups respectively. Absorbed dose to the lung was calculated for each animal in the study. The average maximum doses for all the animals exposed to the low or high concentration of dust aerosol were 0.87 Gy and 1.64 Gy respectively. The average risk of malignant lung tumors from inhaled natural uranium ore dust was therefore about 0.20 tumors/animal/Gy. For animals with lung tumors, the average doses were 0.98 and 1.90 in the exposed groups. In both exposed groups, the frequency of primary malignant or non-malignant lung tumors was significantly greater than in the control group (p < 0.02) and the frequency of primary malignant lung tumors in the two exposed group were significantly different from each other (p = 0.05). The frequency of primary lung tumors (malignant and non-malignant) was calculated as a function of dose

  12. Alternative leaching processes for uranium ores

    International Nuclear Information System (INIS)

    Ring, R.J.

    1979-01-01

    Laboratory studies have been carried out to compare the extraction of uranium from Australian ores by conventional leaching in sulphuric acid with that obtained using hydrochloric acid and acidified ferric sulphate solutions. Leaching with hydrochloric acid achieved higher extractions of radium-226 but the extraction of uranium was reduced considerably. The use of acidified ferric sulphate solution reduced acid consumption by 20-40% without any detrimental effect on uranium extraction. The ferric ion, which is reduced during leaching, can be reoxidized and recycled after the addition of acid makeup. Hydrogen peroxide was found to be an effective oxidant in conventional sulphuric acid leaching. It is more expensive than alternative oxidants, but it is non-polluting, lesser quantities are required and acid consumption is reduced

  13. Chemical treatment proceed of poor uranium content ores; Un procede de traitement chimique des minerais pauvres d'uranium

    Energy Technology Data Exchange (ETDEWEB)

    Mouret, P [Commissariat a l' Energie Atomique, Saclay (France). Centre d' Etudes Nucleaires; Pagny, P [Societe Potasse et Engrais Chimiques (France)

    1955-07-01

    The needs in uranium constantly increased inciting to develop new chemical processes for the treatment of uranium ores. we searched processes that permit to get this element from ores poor in uranium, to a reasonable cost price. We used a sulphuric attack and a precipitation of uranium as phosphate uranate or pyrophosphate uranate to separate its from the different impurities. The process permitted to process ores contents of about 0,05% of uranium and to get an end product of sodium carbonate uranate containing 60 to 65% of uranium, with an acceptable cost price and an extraction yield situated between 90 and 95%. (M.B.) [French] Les besoins sans cesse accrus en uranium ont incite de developper de nouveaux procedes chimiques pour le traitement de minerais uranifere. nous avons recherche des procedes qui permettent d'obtenir cet element a partir de minerais pauvres en uranium, a un prix de revient raisonnable. Nous nous sommes orientes vers une attaque sulfurique et une precipitation de l'uranium sous forme de phosphate uraneux ou de pyrophosphate uraneux pour le separer des differentes impuretes. Le procede a permis de descendre a des teneurs en uranium de l'ordre de 0,05 % et d'obtenir un produit final a l'etat d'uranate de soude contenant 60 e 65 % d'uranium, avec un prix de revient acceptable et avec un rendement global d'extraction situe entre 90 et 95 %. (M.B.)

  14. Pilot plant studies on the treatment of El Atshan Uranium Ores, Eastern Desert, Egypt.

    Energy Technology Data Exchange (ETDEWEB)

    Abd Elghany, M S; Mahdy, M A [Nuclear materials authority, El-Maadi, Cairo, (Egypt); Abd El-Monem, A M; El-Hazek, A T [Faculty of engineering, Cairo university, Cairo, (Egypt)

    1995-10-01

    The present work deals with studying the different processes leading to the preparation of commercial uranium concentrate (yellow cake) from El Atshan granitic ore material (0.077%U) after acid leading of the latter, the two common extraction techniques of uranium from the obtained sulphate leach liquor; namely, anion exchange rein and solvent extraction have been studied. The studied leaching and extraction conditions-realized on the lab scale-were applied to inches pilot plant unit (capacity 150 kg ore). An average leaching leaching efficiency exceeding 88% has been achieved. Using anion exchange resin, it has been possible to prepare a uranium peroxide concentrate assaying a uranium content of about 67% U{sub 3} O{sub 8}. Only trace amount of Ca, Fe, Po{sub 4}, Cr and Pb have been detected. On the other hand, sodium uranate, as a uranium precipitate was prepared from the strip solution of the loaded solvent (di-2-ethyl) phosphoric acid concerned with the evaluation of a new optimized technique for the principle of chloramine-T method used for insulin iodination for the modified procedure can be carried out under normal condition of room temperature, employed longer reaction times and omitted the addition of inorganic reducing salts maintaining efficient iodination and avoiding denaturation to obtain labels of exceedingly high specific activity and small quantities of insulin for in vitro usage in the investigation of human erythrocytes 125 I-inulin binding capacity in normal and in some disease status. 9 figs., 2 tabs.

  15. Pilot plant studies on the treatment of El Atshan Uranium Ores, Eastern Desert, Egypt

    International Nuclear Information System (INIS)

    Abd Elghany, M.S.; Mahdy, M.A.; Abd El-Monem, A.M.; El-Hazek, A.T.

    1995-01-01

    The present work deals with studying the different processes leading to the preparation of commercial uranium concentrate (yellow cake) from El Atshan granitic ore material (0.077%U) after acid leading of the latter, the two common extraction techniques of uranium from the obtained sulphate leach liquor; namely, anion exchange rein and solvent extraction have been studied. The studied leaching and extraction conditions-realized on the lab scale-were applied to inches pilot plant unit (capacity 150 kg ore). An average leaching leaching efficiency exceeding 88% has been achieved. Using anion exchange resin, it has been possible to prepare a uranium peroxide concentrate assaying a uranium content of about 67% U 3 O 8 . Only trace amount of Ca, Fe, Po 4 , Cr and Pb have been detected. On the other hand, sodium uranate, as a uranium precipitate was prepared from the strip solution of the loaded solvent (di-2-ethyl phosphoric acid concerned with the evaluation of a new optimized technique for the principle of chloramine-T method used for insulin iodination for the modified procedure can be carried out under normal condition of room temperature, employed longer reaction times and omitted the addition of inorganic reducing salts maintaining efficient iodination and avoiding denaturation to obtain labels of exceedingly high specific activity and small quantities of insulin for in vitro usage in the investigation of human erythrocytes 125 I-inulin binding capacity in normal and in some disease status. 9 figs., 2 tabs

  16. Study of a bacterial leaching program for uranium ores by Thiobacillus ferroxidans

    International Nuclear Information System (INIS)

    Garcia Junior, O.

    1989-01-01

    The development of a bacterial leaching program for uranium ores is studied. Three basic points are presented: isolation and purification of Thiobacillus ferroxidans, as well Thiobacillus thio oxidans; physiological studies of growth and respiratory metabolism of T. ferroxidans; uranium leaching from two types of ore by T. ferroxidans action, on laboratory, semi pilot and pilot scales. The bacterial leaching studies were carried out in shake flasks, percolation columns (laboratory and semi pilot) and in heap leaching (pilot). The potential of the ores studied in relation to bacterial action, was first showed in shake flask experiments. The production of H 2 S O 4 and Fe 3+ was a result of the bacterial activity on both ore samples containing pyrite (Fe S 2 ). These two bacterial products resulted in a high uranium and molybdenum extraction and a lower sulfuric acid consumption compared to the sterilized treatments. Similar results were obtained in percolation column at the same scale (lab). (author)

  17. Ore-forming environment identification and uranium metallogenic features in Manite depression

    International Nuclear Information System (INIS)

    Liu Zhengyi; Liu Wusheng; Jia Licheng; Shi Qingping; Peng Cong; Chen Hua

    2014-01-01

    By using limonitization, the important indicator of uranium ore-forming identification as the product of acid water transportation from the reducing environment to the oxidation environment, based on the specimen examination naked eye, microscopic identification, electron microscopy, electron microprobe were used to study the major elements, trace elements, organic carbon, total sulfur, uranium valence and uranium, thorium isotope "2"3"4U/"2"3"8U, "2"3"0Th/"2"3"2Th ratio, hydrocarbons especially clay mineral species and the total amount, V/(V + Ni) water stratification and bottom hydrodynamic environment and other factors, which can indicate the microphase environment of all types of rocks in Manite depression, and uranium ore-forming factors were identified and evaluation are discussed and some suggestions were submitted. (authors)

  18. The distribution of E-centres concentration in the minerals of the wall-rocks of uranium deposit

    International Nuclear Information System (INIS)

    Kislyakov, Ya.M.; Moiseev, B.M.; Rakov, L.T.; Kulagin, Eh.G.

    1975-01-01

    Electron paramagnetic resonance was used to investigate the distribution of electron-hole centres caused by natural radioactive irradiation in terrigenous arcosic rocks and their principal mineral components (quartz-feldspar concretions, white and smoky quartz, feldspars). The relationship between concentrations of E-centres and the uranium content of the rocks reflects the genetic features of the uranium mineralization. Taking one specific deposit as an example, the author shows the proportional dependence between uranium content and E-centre concentration. The dependence reflects the practically simultraneous formation of the main mass of epigenetic mineralization. The hypothesis that older (syngenetic) ore deposits may have existed was not confirmed. Despite the long interval between sedimentary accumulation end epigenesis, no significant surplus concentrations of E-centres were found in epigenetic-metamorphic rocks. Anomalous concentrations of uranium and E-centres are caused by uranium migration during later epigenetic processes superimposed on the mesozoic ore-controlling zonality. One result of this migration is the formation in limonitized rocks of ''augen'' ores for which low concentrations of paramagnetic centres are typical. For the study of the distribution of E-centres in rocks from uranium deposits, it is possible to use polymineral mixtures. For the proper interpratation of the data obtained, however, account must be taken of the sensitivity to irradiation of the various mineral components, particularly the various forms of quartz, which is the principal natural dosimeter. (E.G.)

  19. Inverse method for determining radon diffusion coefficient and free radon production rate of fragmented uranium ore

    International Nuclear Information System (INIS)

    Ye, Yong-jun; Wang, Li-heng; Ding, De-xin; Zhao, Ya-li; Fan, Nan-bin

    2014-01-01

    The radon diffusion coefficient and the free radon production rate are important parameters for describing radon migration in the fragmented uranium ore. In order to determine the two parameters, the pure diffusion migration equation for radon was firstly established and its analytic solution with the two parameters to be determined was derived. Then, a self manufactured experimental column was used to simulate the pure diffusion of the radon, the improved scintillation cell method was used to measure the pore radon concentrations at different depths of the column loaded with the fragmented uranium ore, and the nonlinear least square algorithm was used to inversely determine the radon diffusion coefficient and the free radon production rate. Finally, the solution with the two inversely determined parameters was used to predict the pore radon concentrations at some depths of the column, and the predicted results were compared with the measured results. The results show that the predicted results are in good agreement with the measured results and the numerical inverse method is applicable to the determination of the radon diffusion coefficient and the free radon production rate for the fragmented uranium ore. - Highlights: • Inverse method for determining two transport parameters of radon is proposed. • A self-made experimental apparatus is used to simulate radon diffusion process. • Sampling volume and position for measuring radon concentration are optimized. • The inverse results of an experimental sample are verified

  20. Mantle geofluid and uranium ore-formation model

    International Nuclear Information System (INIS)

    Wu Jianhua; Liu Shuai; Yu Dagan; Zhang Bangtong

    2005-01-01

    Results of the recent research show that volcanic-type and granite-type uranium deposits have both early and late phases of uranium mineralization, and the early phase uranium mineralization is characterized by metallogenetic features of mantle fluids. This paper discusses the geofluids and related metallogenesis, as well as characteristics of early phase uranium mineralisation, and emphasizes, that the ΣCO 2 , U and H 2 O, that comprise the bulk of the ore-forming hot fluids, are originated from different sources, namely CO 2 comes from mantle fluids, U comes from country rocks the mantle fluids have passed during their ascending way, and H 2 O comes from mantle fluids and country rocks the mantle fluids have passed during their ascending way. (authors)

  1. Uranium mining and production of concentrates in India

    International Nuclear Information System (INIS)

    Bhasin, J.L.

    1997-01-01

    In order to meet the uranium requirements for the atomic power programme of the country, uranium deposits were explored, mined and concentrates were produced indigenously. The geology of the areas, mode of entries and the various extraction methods deployed in different mines with their constraints are described. The various equipments used in mining and processing activities are elaborated. The flow sheets for processing the uranium ore and that of the effluent treatment plant are given in detail. The future plans of the company for undertaking the new projects to meet the demand of uranium requirement for the increasing nuclear power programme are given. (author). 18 figs

  2. Electron microscopy and microanalysis of uranium phases in primary ores, Eocene and Miocene of south Texas

    International Nuclear Information System (INIS)

    Liang, L.C.; Price, J.G.; Bobeck, P.

    1984-01-01

    Two contrasting types of roll-front uranium deposits occur in south Texas. In the barrier-bar sands of the Eocene Jackson Group, organic matter was essential to uranium reduction, whereas in the fluvial sands of the Miocene Oakville Formation, epigenetic pyrite was the reductant. In a sample of reduced Oakville ore, a uranium phase with grains ranging in diameter from < 1 to 20μm was recognized by SEM backscattered-electron imaging and wavelength-dispersive spectrometer (WDS) elemental-dot mapping. Quantitative microprobe analyses indicated that the phase is a uranium-calcium silicate-phosphate with molar Ca/P approximately equal to 1.0, U/P equal to 2.8 +/- 0.4 (n = 27), and U/Si approaching 1.0 in samples uncontaminated with quartz, feldspar, or clay minerals. Highest uranium content is 59%. Oakville ore is typically easy to leach by in-situ methods. Jackson ore contains 2 uranium phases. Sulfur-rich organic matter contains 4.1 +/- 1.6% uranium (n = 27). Although individual grains of a possible uranium mineral within the organic matter are too small to be resolved by electron imaging, a consistent molar U/Fe (0.5 +/- 0.1) suggests a uranium-iron oxide phase. Alternatively, uranium is adsorbed by or otherwise bound to the organic matter. The second phase is a uranium-calcium silicate-phosphate that differs from the Oakville ore. Molar Ca/P equals 0.8 +/- 0.2 (n = 13), and U/P equals 4.7 +/- 0.4. Small grain size (generally less than 1 μm) prevented analysis of samples uncontaminated with quartz and pyrite. The grain with highest uranium content (43%) has U/Si equal to 0.34. Jackson ore is less favorable for in-situ leaching than Oakville ore in part because the organic-associated uranium is difficult to extract

  3. Report on intercomparisons IAEA/S-17, S-18, and S-19 of the determinaton of uranium in uranium phosphate ores

    International Nuclear Information System (INIS)

    Pszonicki, L.; Hanna, A.N.; Suschny, O.

    1984-08-01

    The aim of the reported intercomparisons, organized by the IAEA's Analytical Quality Control Service, was to provide an opportunity to the participating laboratories to check the reliability of their results by comparing them with the results obtained by other laboratories. The participants were requested to determine the concentration of uranium in three samples of Brasilian uranium phosphate ores containing uranium of a low, a medium, and a large concentration. Twenty-four laboratories from 19 countries returned results. The analytical method most frequently used was radiometry of natural isotopes, followed by neutron activation analysis, fluorimetry, X-ray fluorescence and spectrophotometry. In general, the results can be considered as satisfactory. The relative confidence intervals of the medians extend in the range from -3% to +5%. The overall medians of all materials were accepted as reliable for certification

  4. Research on metallogenic conditions of intersection-type uranium ore-deposits in Zhongdong area, Northern Guangdong province

    International Nuclear Information System (INIS)

    Wang Zhengqi; Wu Lieqin; Zhang Guoyu

    2007-12-01

    The methods following as field geological investigation, trace element geo- chemistry and isotope geochemistry were used in this project. Based on geological and geochemical characteristics of Xiaoshui uranium ore deposits in Zhongdong area, Xiazhuang ore-field, Guangdong province, it could be concluded that: (1) The Provenance of Cretaceous mantle is a enriched mantle; (2) Silicified zone-type and intersection-type uranium ore are distinctness in the metallogenic period and mineralization process, and main metallogenic period of Xiaoshui uranium ore-deposit is 73.5 Ma; (3) The sources of uranium mineralization substance derived from enriched mantle; and (4)The intersection-type high grade uranium deposits were controlled by substances derived from mantle (contain with U, CO 2 , F, et al), tracks of intersection of NWW-across with NNE-trending faults and lithology of diabase. (authors)

  5. Research on metallogenic conditions of intersection-type uranium ore-deposits in Zhongdong area, Northern Guangdong province

    Energy Technology Data Exchange (ETDEWEB)

    Zhengqi, Wang [East China Inst. of Technology, Fuzhou (China); [Beijing Research Inst. of Uranium Geology, Beijing (China); Lieqin, Wu [Institute No.290, CNNC, Shaoguan (China); Guoyu, Zhang [East China Inst. of Technology, Fuzhou (China)

    2007-12-15

    The methods following as field geological investigation, trace element geo- chemistry and isotope geochemistry were used in this project. Based on geological and geochemical characteristics of Xiaoshui uranium ore deposits in Zhongdong area, Xiazhuang ore-field, Guangdong province, it could be concluded that: (1) The Provenance of Cretaceous mantle is a enriched mantle; (2) Silicified zone-type and intersection-type uranium ore are distinctness in the metallogenic period and mineralization process, and main metallogenic period of Xiaoshui uranium ore-deposit is 73.5 Ma; (3) The sources of uranium mineralization substance derived from enriched mantle; and (4)The intersection-type high grade uranium deposits were controlled by substances derived from mantle (contain with U, CO{sub 2}, F, et al), tracks of intersection of NWW-across with NNE-trending faults and lithology of diabase. (authors)

  6. Development of the heap leaching of low-grade uranium ores for conditions of OJSC Priargunsky Mining and Chemical plant (PPGKhO)

    International Nuclear Information System (INIS)

    Morozov, A.; Litvinenko, V.

    2014-01-01

    The treatment of low-grade commercial uranium ores by heap leaching has been carried out at the enterprise since 1996. During the initial stage of development, the ore piles were formed of the raw ore having the run-of-mine coarseness with uranium content around 0.08%. Under such conditions, recovery of the metal to the solution is 60-65% in case of a pile treatment lasting 2 years. To intensify the process and to provide a stable concentration of uranium in the productive solutions transferred to sorption, the enterprise developed and implemented a method of percolation leaching of low-grade ores with re-circulation of productive solutions through the re-treated ore bulk (RF patent No. 2226564). The main peculiarity of such leaching is simultaneous moistening of the ore by productive solutions and by barren solutions that are sharpened with sulphuric acid; that gives the possibility to wet far bigger areas of piles under constant volume of productive solutions outputting to the sorption treatment. Such scheme enables to treat successively first the piles at the “re-treatment” (where the metal is mainly extracted), and then the piles at the “active leaching” stage (where the metal is mainly inside the ore bulk). The technical and economic indexes of the heap leaching of low-grade uranium ores were significantly increased in 2006, when the X-ray-radiometric treatment plant was commissioned. The technological scheme of ore treatment at the processing plant includes mould and grating of the raw material with delivery of undersized products enriched with uranium: -5 mm are transferred to the pulp process; fractions (-200+40) mm to the X-ray-radiometric separation; the material of size (-40+5) mm, washed-out from clayey and fine particles, are sent to the uranium heap leaching in piles. Delivery of the ore material having size (-40+5) mm to treatment by the acid leaching method excluded colmatage and creation of zones impermeable for water, and in combination

  7. Uranium ores of Kazakhstan as the most technologic source of a fissionable material

    International Nuclear Information System (INIS)

    Berikbolov, B.R.

    1999-01-01

    Kazakhstan as is known has unique deposits of uranium. Its resources composed a third part of the world resources. The most important part of resources having a practical value, is related with depression in southern regions of the Republic. By now more than 15 deposits are discovered and partially explored. These deposits from three uranium provinces - Shu-Sarysu, Syr-Darya and Ili. The ores occur in friable water-bearing sandy horizons of Cretaceous and Paleogene age between waterproof agrillaceous sediments at depth from 100 up to 600 m. Ore bodies thickness changes from 5 to 10 m at uranian average-grade 0.03-0.1 %. Width of band shaped ore bodies changes from tens meters to the one kilometers and extent changes from one kilometer up to many tens kilometers. The important feature of deposits is their suitability for development by progressive in situ leaching (ISL) method. It was demonstrated, that uranium ores are comprehensive and, that is important, a lot of commercially important elements, containing in ores, gives in to extraction at development by the ISL method. The preliminary calculation of expenditures for the extraction of useful byproducts from ordinary sulphate solution have demonstrated rather high profitableness for rhenium, scandium, selenium, rare earth even at the very low contents in solution. It was pointed out, that whole technological chain applied now at industrial scale is oriented to mono-metallic uranium ores, therefore present technology of leaching and recovery of industrial solution does not allow ti extract all valuable components containing in ores. The development of new improved technological chain. beginning with a composition of leaching out reagent and up to applying of miscellaneous sorbing materials, can create new mineral-raw base of rare and dissipated elements and to lower considerably the price of uranium mining from sandstone deposits

  8. Structure and texture of uranium ores in exogenous deposits

    International Nuclear Information System (INIS)

    Danchev, V.I.

    1977-01-01

    Structure and texture signs of uranium rock exogenous deposits have been systematized for the first time, taking into account the slaging of the ore-formation process, connected with formation and change of containing sedimentary rocks, starting with the sedimentogenesis stage and early sediment diagenesis and their subsequent transformation in katagenesis and metamorphism processes. The main features of uranium geochemistry in the exogenous process are considered. Suggested is the genetic classification of uranium exogenous deposits in rocks of sedimentary cover, made with respect to conjugation and various ore-forming productivity of the litogenesis stage. Described are the main combinations of various rock texture and structure properties, characteristic of deposits of genetic classes and groups of the above classification. Eight most frequently occuring textures (lamellar, concretion, oolitic, coagulate, crack, mixed and impregnated) and their types are described and illustrated. Materials of soviet and foreign authors have been used to compile the atlas

  9. Study On The Choice Of Leaching System For Thanh My, Quang Nam Province Uranium Ores Treatment

    International Nuclear Information System (INIS)

    Than Van Lien; Nguyen Dinh Van; Tran The Dinh

    2011-01-01

    In order to implement the plan of peaceful uses of atomic energy, the Radioactive and Rare Earth Geology Division have been carried out the uranium ores exploitation project in Thanh My area of Quang Nam province since 2010. The treatment uranium ores samples is one of works of this project. In order to preparing for uranium ores samples treatment, the Institute for Technology of Radioactive and Rare Elements have been studied and have chosen the heap leaching method for Thanh My uranium ore treatment. The ore, which contained less than 0.07% U, was crushed to -1 cm before being placed in the heap. The acid consumption for this heap leach operation was approximately ranged 40 kg - 45 kg of H 2 SO 4 per tonne of ore, and oxidant 4 kg of MnO 2 per tonne of ore. The entire treatment cycle required 20-25 days, the recovery exceeded 80%, the leached tails contained less than 0.01% U. The experimental results were comparable with those obtained in the field scale heap leaching in the world. (author)

  10. Preconcentration of a low grade uranium ore in CPDU and laboratory investigation to optimize the dewatering conditions of the preconcentration products

    International Nuclear Information System (INIS)

    Cristovici, M.A.; Berry, T.F.; Raicevic, M.M.; Brady, E.L.; Bredin, E.L.; Leigh, G.W.; Rouleau, J.P.

    1982-04-01

    A process consisting of pyrite flotation and magnetic concentration of radionuclides was developed by CANMET over several years, to preconcentrate low grade uranium ores prior to leaching. When the economics of the preconcentration-leaching technology was compared with the leaching of the entire ore after pyrite flotation (Base Case variant), the preconcentration method appeared to be economically less advantageous than expected, due to the high cost of dewatering the preconcentration products. Further investigations examined in-depth the metallurgy and dewatering of the two variants: preconcentration and base case. A typical low grade uranium ore from Elliot Lake area was used. The metallurgy was compared based on data from continuous operation (CPDU). In the preconcentration variant the amount of ore directed to leaching was reduced to more than one third of that processed in the base case, while the radionuclide concentration became more than three times higher. However, by preconcentration 7% of the uranium was lost before leaching. Systematic laboratory-scale settling and filter tests optimized the dewatering conditions of the preconcentration technology to the extent that rates similar to those of the base case were obtained

  11. Analysis on ore-controlling factors of Zhajistan uranium deposit, Xinjiang

    International Nuclear Information System (INIS)

    A Zhongming

    2000-01-01

    The geologic-structural background where the Zhajistan uranium deposit is located, and sedimentary features of the basin, as well as ore-controlling factors such as the uranium source, the reductant, hydrogeologic conditions and development features of interlayer oxidation zone in Zhajistan, are analysed. Then the author proposes the most favourable sedimentary cycle for uranium metallogenesis and the most favourable prospecting areas

  12. Uranium conversion

    International Nuclear Information System (INIS)

    Oliver, Lena; Peterson, Jenny; Wilhelmsen, Katarina

    2006-03-01

    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 6 and UF 4 are present require equipment that is made of corrosion resistant material

  13. Extraction of uranium low-grade ores from Great Divide Basin, Wyoming. National Uranium Resource Evaluation

    International Nuclear Information System (INIS)

    Judd, J.C.; Nichols, I.L.; Huiatt, J.L.

    1983-04-01

    The US Bureau of Mines is investigating the leachability of carbonaceous uranium ore samples submitted by the DOE under an Interagency Agreement. Studies on eight samples from the Great Divide Basin, Wyoming, are the basis of this report. The uranium content of the eight ore samples ranged from 0.003 to 0.03% U 3 O 8 and contained 0.7 to 45% organic carbon. Experiments were performed to determine the feasibility of extracting uranium using acid leaching, roast-acid leaching and pressure leaching techniques. Acid leaching with 600 lb/ton H 2 SO 4 plus 10 lb/ton NaClO 3 for 18 h at 70 0 C extracted 65 to 83% of the uranium. One sample responded best to a roast-leach treatment. When roasting for 4 h at 500 0 C followed by acid leaching of the calcine using 600 lb/ton H 2 SO 4 , the uranium extraction was 82%. Two of the samples responded best to an oxidative pressure leach for 3 h at 200 0 C under a total pressure of 260 psig; uranium extractions were 78 and 82%

  14. 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.

  15. Technical application of agglomerated acidic heap leaching of clay-bearing uranium ore in China

    International Nuclear Information System (INIS)

    Zeng Yijun; Li Jianhua; Li Tieqiu; Zhong Pingru

    2002-01-01

    The permeability of ore mass has a great influence on the leaching period of heap leaching and the leaching efficiency, hence the uranium ores with high content of clay is difficult to acidic heap leaching. The Research Institute of Uranium Mining has engaged several years studies on the cementing agents of acidic agglomeration, agglomeration conditions, as well as the curing measures of agglomerated balls. On the basis of these studies, several types of clay-bearing ores have been tested with good results. The technique of agglomerated acidic heap leaching has been successfully applied in a uranium mine. Since agglomeration has effectively increased the permeability of ore heap, its leaching period is decreased from 200 days to 60 days, the leaching efficiency is increased to 96% from less than 40% comparing with direct heap leaching program

  16. Study of the sulfuric acid leaching and bacterial leaching of low grade uranium ore by orbital shaker experiment

    International Nuclear Information System (INIS)

    Li Guangyue; Liu Yulong; Wang Yongdong; Ding Dexin

    2009-01-01

    The sulphuric acid leaching and bacteria leaching by orbital shaker experiments were conducted for the low grade uranium ore from a uranium mine in Guangdong Province. The results show that, when the concentration of sulphuric acid and that of slurry were 30 g/L and 25%, respectively, the conditions were most favourable for sulphuric acid leaching and the rate of leaching reached 92.92%, that, when pH value was 1.5, inoculation amount, 10%, concentration of slurry, 10%, the conditions were most favourable for bacteria leaching and the rate of leaching reached 95.93%, that, compared with sulphuric acid leaching, bacteria leaching decreased sulphuric acid consumption by 17.2% and increased the rate of leaching by 3%, and that, under the most favourable conditions for suphuric acid leaching, if 1% natrium chlorate was added, the rate of leaching increased to 96.46%, but 10 kg of natrium chlorate was consumed for 1 ton of uranium ore. (authors)

  17. Research within the coordinated programme on bacterial leaching of uranium ores

    International Nuclear Information System (INIS)

    Marjanovic, D.

    1975-02-01

    The bacteria of some Yugoslav uranium ore deposits were studied to determine the factors controlling the rate of bacteria growth and their activity. The determination of the bacteria was made on the basis of morphological, physiological and cultivating properties of isolated bacteria, bacterial culture activity was determined by the density of bacterial cells using the method of probable numbers and determination of iron oxidation effect. The temperature optimum for the bacterial culture isolated from uranium ore deposits is 28-30degC, while those of bacteria isolated from copper deposits is higher. T.ferrooxidans tolerate high concentrations of heavy metals, including iron and uranium which are toxic for the majority of other bacteria. The optimum air flow is one liter per cubic meter of solution per minute. It appears the highest activity of T.ferrooxidans culture cultivating under optimum conditions is between 3 and 6 days, which term corresponds to the logarithmic stage of bacterial growth, when the culture consists almost exclusively of young cells. The action of a magnetic field of given intensity stimulates the growth and activity of T.ferrooxidans. This phenomenon is observed when the entire/or half of the amount of water for nutritive medium preparation was previously magnetized. Uranium recovered by biomass Scenedesmus is most efficient. In addition to sorption the biomass has capability of regeneration. But some adsorption of T.ferrooxidans by the biomass is observed during the process of uranium sorption. The adsorption of the bacteria results from the affinity between their cellular walls and the sorbent. The highest growth of bacteria is observed when acidic ferrisulphate is present in solutions

  18. Recovery of uranium from low-grade sandstone ores and phosphate rock

    Energy Technology Data Exchange (ETDEWEB)

    Kennedy, R H [United States Atomic Energy Commission, Washington, D. C. (United States)

    1967-06-15

    This paper is concerned principally with commercial-scale experience in the United States in the recovery of uranium from low-grade sources. Most of these operations have been conducted by the operators of uranium mills as an alternative to processing normal-grade ores. The operations have been generally limited, therefore, to the treatment of low-grade materials generated in the course of mining normal-grade ores. In some circumstances such materials can be treated by simplified procedures as an attractive source of additional production. The experience gained in uranium recovery from phosphate rock will be treated in some detail. The land pebble phosphate rock of central Florida generally contains about 0.01 to 0.02% U{sub 3}O{sub 8}. While no uranium is being recovered from this source at the present time, it does represent a significant potential source of by-product uranium production because of the large tonnages being mined. (author)

  19. A procedure for oxidation during the acid leaching of non-ferrous ores, particularly uranium ores

    International Nuclear Information System (INIS)

    Zubcek, L.; Baloun, S.; Martinek, K.; Vebr, Z.; Krepelka, J.; Lasica, S.

    1989-01-01

    It is suggested that dust from the production of ferroalloys of manganese, particularly ferrosilicomanganese and ferromanganese, can be conveniently used for oxidation during the acid leaching of non-ferrous ores, particularly uranium ores. This dust contains 30 to 40% oxides of manganese, about one-half of this is MnO 2 . Iron in the dust is present in the trivalent form, and the dust is pefectly dry. The conventional grinding of oxidants for the ore processing is eliminated, the dust being available in particle size below 0.2 mm. The dust is added in amounts of 5 to 100 kg per ton of the ore, and the suspension is typically heated at 115 degC for 3.5 hr. (P.A.)

  20. Analytic study of organic matters in Lodeve uranium ore

    International Nuclear Information System (INIS)

    Campuzano, E.J.

    1981-01-01

    Exploitation of uranium in the Permian basin of Lodeve is difficult because of simultaneous extraction of organic matters which are found, in small proportion, in ammonium diuranate and a supplementary purification is required. Available information on natural organic matters are briefly reviewed. Natural organic matters contained in the Lodeve uranium ore processing fluid is separated and fractionated. Physicochemical properties of ligands in each fraction are studied. The existence of bonds between these ligands and dissolved uranium is experimentally demonstrated [fr

  1. Geological exploration of uranium ores at Burgos' basin

    International Nuclear Information System (INIS)

    Cabrera Valdez, M.E.

    1975-01-01

    The outcrop sediments of the Burgos river basin cover the complete Cenozoic sequence from the Pallaeocene to recent date, and are arranged in the form of parallel strips with a regional dip towards the east, in which direction the sediments become steadily younger. Generally speaking they correspond to a regressive process the lithology of which is an alternation of shales, sandstones, tuffaceous material and conglomerates. The explorations and evaluations of sedimentary uranium deposits so far carried out in the north-east of Mexico show close relationships between the mineralization and the sedimentary processes of the enclosing rock. Analysis of the sedimentary-type uranium ore bodies in Mexico indicates characteristics very similar to those found in the deposits of the same type which were first studied and described in southern Texas and were used as a standard for the first exploratory studies. The uranium ore in the State of Texas is found in sands belonging mainly to the Jackson group of the Eocene and, to a lesser extent, the Catahoula formation of Miocene-Oligocene age. In the Burgos basin the existence of uranium deposits in the non-marine Frio formation of Oligocene age, with geological characteristics similar to the Texan deposits, has been demonstrated. This comparative analysis suggests very good prospects for uranium exploration in the region; it is recommended that priority be given to intensive study of the sediments of the non-marine member of the Frio formation, and the Jackson and Catahoula formations. (author)

  2. 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.

  3. Continuous tests of Phosphoric Acid - dihydrate process - from phosphatic concentrate of Itataia-CE ore

    International Nuclear Information System (INIS)

    Santos Benedetto, J. dos.

    1984-01-01

    A consolidation of principal studies and continuous tests done with phosphatic concentrated of Itataia ore intending phosphoric acid production by humid-route dihydrate way process is presented. The production of phosphoric acid is applied in uranium extraction process by solvents. (author) [pt

  4. Fast quantification of uranium ores by X-ray fluorescence analysis

    International Nuclear Information System (INIS)

    Morales, E.; De la Roca, W.

    1988-09-01

    A fast and reliable method for batch quantification of uranium in mineral ores is described. It is based on the verification of the homogeneity of the samples through measuring the ratio of coherent and incoherent dispersion. A few samples, 6 or more, are taken from the whole batch and analyzed by fundamental parameters method. A calibration curve using Lancance-Traill or Lucas-Tooth algorithms is constructed in order that the absorption and enhancement effects could be corrected. Simple interpolation of the intensities of the remaining samples gives their concentration. (author)

  5. Flotation-nitric acid leach procedure for increasing uranium recovery from a refractory ore

    International Nuclear Information System (INIS)

    Carnahan, T.G.; Lei, K.P.V.

    1979-01-01

    The Bureau of Mines investigated a flotation-nitric acid leach procedure as part of the goal to maximize minerals and metals recovered from primary and secondary domestic resources. Studies were conducted on an ore that contained carbon-bearing and sulfide mineralization that rendered a portion of the ore refractory (resistant) to conventional leaching technology. The procedure investigated for treating the ore consisted of the following: (1) separation by flotation of the carbonaceous and sulfidic components from the ore, (2) leaching the flotation concentrate with nitric acid at 100 0 to 110 0 C, (3) leaching the flotation tailings with sulfuric acid, and (4) processing the combined leached slurries in a conventional manner to recover yellow cake. In step 2, HNO 3 is converted to gaseous products from which it is regenerated by reacting these products with air and water for further leaching. An overall uranium extraction of 96% was achieved by this procedure

  6. Hydrogeological analysis applied to regional evaluation of sandstone-type uranium ore-formation in sedimentary basins

    International Nuclear Information System (INIS)

    Xu Laisheng

    2005-01-01

    The main purpose of regional evaluation of uranium ore-formation is to preliminarily divide environmental zones and to delineate favourable areas for uranium ore-formation in order to provide basis for further detailed prospecting work. Of the various kinds of prospecting work, the hydrogeologic work should be mainly carried out in following aspects: division of hydrogeological units, the determination of artesian water-bearing system and the identification of prospecting target horizon; the analysis on hydrodynamic regime, the analysis on hydrogeochemical environments, the paleo-hydrogeologic analysis and the delineation of redox front and favourable area for uranium ore-formation. (author)

  7. Bioleaching of UO22+ ions from a Romanian poor uranium ore

    International Nuclear Information System (INIS)

    Cecal, Al.; Popa, K.; Moraru, R.T.; Patachia, S.

    2002-01-01

    An experimental study on the bioleaching of a poor uranium ore by means of hydrophytic plants Lemna minor and Riccia fluitans, under various operating conditions is discussed. The maximum degree of bioleaching (42%) of the reduced uranium species to U(VI) has been attained for the ore-Lemna minor-alkaline carbonate solution system. The UO 2 2+ ions amount accumulated in the plants is negligible as compared to the dissolved quantity, owing to the ionic competition between uranyl ions and the cations necessary to the mineral nutrition. The X-ray diffraction patterns prove that the uranium species in pyrochlore mineral are completely oxidized to U(VI), while thucolite is only partially turned into UO 2 2+ ions, in the presence of living plants. (author)

  8. Beneficiation studies of an uranium siliceous - phosphate ore

    International Nuclear Information System (INIS)

    Bruno, J.B.; Santos, A.T.; Santos Benedetto, J. dos

    1980-01-01

    The consolidation of the beneficiation studies of a low-grade uranium siliceous - phosphate ore (11% P 2 O 5 ) from Itataia region in the Northeast of Brazil, owned by Empresas Nucleares Brasileiras S.A. - NUCLEBRAS, are presented. Laboratory studies using froth flotation technique and applying statistical methods for data evaluation were made. Pilot plant tests in a 120 Kg/h scale were conducted as a consequence of the bench scale tests. The developed process using tall-oil as collector and starch as depressant gave a total yield of 80% for the P 2 O 5 and 71% the U 3 O 8 , for a 33% P 2 O 5 phosphate concentrate. (Author) [pt

  9. Heap leaching of clay ish uranium ores

    International Nuclear Information System (INIS)

    Gonzalez, E.; Sedano, A.

    1973-01-01

    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)

  10. 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.

  11. The progress in the researches for uranium mill tailings cleaning treatment and no-waste uranium ore milling processes

    International Nuclear Information System (INIS)

    Wang Jintang

    1990-01-01

    The production of uranium mill tailings and their risk assessment are described. The moethods of uranium mill tailings disposal and management are criticized and the necessity of the researches for uranium mill tailings cleaning treatment and no-wasle uranium ore milling process are demonstrated. The progress for these researches in China and other countries with uranium production is reviewed, and the corresponding conclusions are reported

  12. Radiation protection of workers in uranium mining, ore processing and fuel fabrication in India

    International Nuclear Information System (INIS)

    Khan, A. H.; Jha, G.; Jha, S.; Srivastava, G. K.; Sadasivan, S.; Raj, Venkat

    2002-01-01

    Low grade of uranium ore mined from three underground mines is processed in a mill at Jaduguda in eastern India to recover uranium concentrate in the form of yellow cake. This concentrate is further processed at the Nuclear Fuel Complex at Hyderabad, in southern India, to produce fuel for use in nuclear power plants. Radiation protection of workers is given due importance at all stages of these operations. Dedicated Health Physics Units and Environmental Survey Laboratories established at each site regularly carry out in-plant and environmental surveillance to keep radiation exposure of workers and the members of public within the limits prescribed by the regulatory body. The limits set by the national regulatory body are based on the international standards suggested by the ICRP and the IAEA. In the uranium mines external gamma radiation, radon and airborne activity due to radioactive dust is monitored. Similarly, in the uranium mill and the fuel fabrication plant gamma radiation and airborne radioactivity due to long-lived α -emitters are monitored. Personal dosimeters are also issued to workers. The total radiation exposure of workers from external and internal sources is evaluated from the personal monitoring and area monitoring data. It has been observed that the total radiation dose to workers has been well below 20 mSv.y 1 at all stages of operations. Adequate ventilation is provided during mining, ore processing and fuel fabrication operations to keep the concentrations of airborne radioactivity well below the derived limits. Workers use personal protective appliances, where necessary, as a supplementary means of control. The monitoring methodologies, results and control measures are presented in the paper

  13. Radiation protection of workers in uranium mining, ore processing and fuel fabrication in India

    International Nuclear Information System (INIS)

    Khan, A.H.; Jha, G.; Jha, S.; Srivastava, G.K.; Sadasivan, S.; Venkat Raj, V.

    2002-01-01

    Full text: Low grade of uranium ore mined from three underground mines is processed in a mill at Jaduguda in eastern India to recover uranium concentrate in the form of yellow cake. This concentrate is further processed at the Nuclear Fuel Complex at Hyderabad, in southern India, to produce fuel for use in nuclear power plants. Radiation protection of workers is given due importance at all stages of these operations. Dedicated Health Physics Units and Environmental Survey Laboratories established at each site regularly carry out in-plant and environmental surveillance to keep radiation exposure of workers and the members of public within the limits prescribed by the regulatory body. The limits set by the national regulatory body are based on the international standards suggested by the ICRP and the IAEA. In the uranium mines external gamma radiation, radon and airborne activity due to radioactive dust is monitored. Similarly, in the uranium mill and the fuel fabrication plant gamma radiation and airborne radioactivity due to long-lived a- emitters are monitored. Personal dosimeters are also issued to workers. The total radiation exposure of workers from external and internal sources is evaluated from the personal monitoring and area monitoring data. It has been observed that the total radiation dose to workers has been well below 20 mSvy -1 at all stages of operations. Adequate ventilation is provided during mining, ore processing and fuel fabrication operations to keep the concentrations of airborne radioactivity well below the derived limits. Workers use personal protective appliances, where necessary, as a supplementary means of control. The monitoring methodologies, results and control measures are presented in the paper

  14. Ore-controlling mechanism of carbonaceous-siliceous-pelitic rock type uranium deposits with down-faulted red basins in the southeast continental margin of Yangtze plate

    International Nuclear Information System (INIS)

    Zhang Zilong; Qi Fucheng; He Zhongbo; Li Zhixing; Wang Wenquan; Yu Jinshui

    2012-01-01

    One of the important ore-concentrated areas of carbonaceous-siliceous-pelitic rock type uranium deposits is the Southeast continental margin of Yangtze plate. Sedimentary-exogenously transformed type and sedimentary- hydrothermal superimposed transformed type uranium deposits are always distributed at or near the edge of down-faulted red ba sins. In this paper, the distributions of the deposits are analyzed with the relation to down-faulted red basins. The connective effect and ore-controlling mechanism are proposed of carbonaceous-siliceous-pelitic rock type uranium deposits with marginal fractures of red basins. (authors)

  15. Radionuclide migration around uranium ore bodies in the Alligator Rivers region of the Northern Territory, Australia - analogue of radioactive waste repositories

    International Nuclear Information System (INIS)

    Airey, P.L.; Roman, D.; Golian, C.; Short, S.; Nightingale, T.; Lowson, R.T.; Davey, B.G.; Gray, D.

    1984-01-01

    Appropriate geochemical analogues may be used to reduce the uncertainties in predicting the long-term transport of actinides, radium and fission products from laboratory adsorption and hydrological data. In this study the migration of uranium series nuclides within, and down-gradient of ore bodies in the Alligator Rivers uranium province of the Northern Territory of Australia is described. A mathematical framework was developed to permit calculation of the rate of leaching or deposition of uranium and radium between defined zones of the ore bodies, and the rate of loss of the nuclides due to groundwater transport and surface erosion. A detailed study was made of the distribution of uranium, thorium and radium isotopes within various minerals comprising the weathered ore assemblage. Uranium and thorium concentrate principally in the iron minerals and radium in the clay-quartz phases. Substantial disequilibria are observed, which are attributed to a combination of α-recoil and chemical effects. Evidence of the relative lability of iron phases is presented. The transport of uranium series nuclides in groundwater intersecting the deposits was investigated. Down-gradient of the Ranger One deposit, the maximum retardation factor of uranium is 250. The role of colloids in groundwater transport is being studied. Uranium is transported principally in solution. There appears to be an equilibrium between solute and articulate uranium

  16. Chlorination separation of uranium, thorium, and radium from low-grade ores

    International Nuclear Information System (INIS)

    Sastri, V.S.; Perumareddi, J.R.

    1995-01-01

    Low-temperature chlorination of low-grade uranium ores containing uranium in the 0.02 to 0.06% range, thorium in the 0.036 to 0.12% range, and radium in the 70 to 200 pci/g range resulted in the extraction of >90% of the constituents. The residue left after chlorination was found to be innocuous and suitable for disposal as a waste acceptable to the environment. Use of sodium chloride in the charge was useful in reducing the chlorination temperature and in the formation of nonvolatile anionic chloro complexes of the metal ions in the ore

  17. Calculation of gamma ray exposure rates from uranium ore bodies

    International Nuclear Information System (INIS)

    Thomson, J.E.; Wilson, O.J.

    1980-02-01

    The planning of operations associated with uranium mines often requires that estimates be made of the exposure rates from various ore bodies. A straight-forward method of calculating the exposure rate from an arbitrarily shaped body is presented. Parameters for the calculation are evaluated under the assumption of secular equilibrium of uranium with its daughters and that the uranium is uniformly distributed throughout an average soil mixture. The spectral distribution of the emitted gamma rays and the effect of air attenuation are discussed. Worked examples are given of typical situations encountered in uranium mines

  18. The uranium ore deposits in Ciudad Rodrigo Phyllites. about the possibility of new deposits

    International Nuclear Information System (INIS)

    Mingarro Martin, E.; Marin Benavente, C.

    1969-01-01

    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)

  19. Contribution to study of effects consecutive to alpha decay of uranium 238 in some uranium compounds and uranium ores

    International Nuclear Information System (INIS)

    Ordonez-Regil, E.

    1985-06-01

    The consequences of alpha decay of 238 U in uranium compounds and in uranium bearing ores have been examined in two ways: leaching of 234 Th and determination of the activity ratio of 234 U and 238 U. The results have been interpreted mainly in terms of the ''hot'' character of the nascent 234 Th atoms [fr

  20. Uranium ore mining in Spain with a focus on the closure and remediation measures in former production facilities

    International Nuclear Information System (INIS)

    Koch, H.; Blunck, S.; Lopez Romero, A.R.

    2004-01-01

    In early 2000, the uranium ore mining activities in Spain ceased. Since the middle of the last century, Spain had pushed ahead its own production of uranium concentrate with the formation of several companies (ENUSA, J.E.N.). In that period, Spain produced around 6000 t of uranium. With the completion of the operations at Andujar, La Haba and Elephante as well as Quercus at Saelices el Chico, the corporate tasks have shifted from building-up of a strategic uranium reserve to remediation and subsequent use of the locations. The operations have reached different remediation phases. While at Saelices el Chico remediation is still proceeding, the Andujar and La Haba locations are undergoing a monitoring phase as agreed for all former operating facilities. The estimated closure and remediation costs for the three operating facilities described amount to approx. 85 mio. Euro. In all three cases dealt with, however, these limited financial resources have been sufficient to successfully implement a closure and remediation concept that minimizes the risks from the facilities of uranium ore mining and processing with regard to the environment. (orig.)

  1. Status report from USSR [Processing of Low-Grade Uranium Ores]; Doklad o sostoyanii voprosa v SSSR

    Energy Technology Data Exchange (ETDEWEB)

    Zefirov, A P [Gosudarstvennyj Komitet Po Ispol' zovaniyu Atomnoj Ehnergii SSSR, Moskva, Union of Soviet Socialist Republics (Russian Federation)

    1967-06-15

    The uranium industry for processing poor uranium ores in the USSR was established in recent years. As a result of research work institutions and enterprises in the development of this industry was provided by rapid technological advances that allowed dramatically increased productivity, reduced consumption of reagents, simplified process flow diagrams, and reduced production costs. At present, the basis for uranium industry, including and poor uranium ore deposits in the USSR are with different content valuable components (uranium, phosphorus, molybdenum, rare earth elements, thorium, iron, .. .)

  2. Optimization of operating parameters and rate of uranium bioleaching from a low-grade ore

    International Nuclear Information System (INIS)

    Rashidi, A.; Roosta-Azad, R.; Safdari, S.J.

    2014-01-01

    In this study the bioleaching of a low-grade uranium ore containing 480 ppm uranium has been reported. The studies involved extraction of uranium using Acidithiobacillus ferrooxidans derived from the uranium mine samples. The maximum specific growth rate (μ max ) and doubling time (t d ) were obtained 0.08 h -1 and 8.66 h, respectively. Parameters such as Fe 2+ concentration, particle size, temperature and pH were optimized. The effect of pulp density (PD) was also studied. Maximum uranium bio-dissolution of 100 ± 5 % was achieved under the conditions of pH 2.0, 5 % PD and 35 deg C in 48 h with the particles of d 80 = 100 μm. The optimum concentration of supplementary Fe 2+ was dependent to the PD. This value was 0 and 10 g of FeSO 4 ·7H 2 O/l at the PD of 5 and 15 %, respectively. The effects of time, pH and PD on the bioleaching process were studied using central composite design. New rate equation was improved for the uranium leaching rate. The rate of leaching is controlled with the concentrations of ferric and ferrous ions in solution. This study shows that uranium bioleaching may be an important process for the Saghand U mine at Yazd (Iran). (author)

  3. Fungi outcompete bacteria under increased uranium concentration in culture media

    International Nuclear Information System (INIS)

    Mumtaz, Saqib; Streten-Joyce, Claire; Parry, David L.; McGuinness, Keith A.; Lu, Ping; Gibb, Karen S.

    2013-01-01

    As a key part of water management at the Ranger Uranium Mine (Northern Territory, Australia), stockpile (ore and waste) runoff water was applied to natural woodland on the mine lease in accordance with regulatory requirements. Consequently, the soil in these Land Application Areas (LAAs) presents a range of uranium concentrations. Soil samples were collected from LAAs with different concentrations of uranium and extracts were plated onto LB media containing no (0 ppm), low (3 ppm), medium (250 ppm), high (600 ppm) and very high (1500 ppm) uranium concentrations. These concentrations were similar to the range of measured uranium concentrations in the LAAs soils. Bacteria grew on all plates except for the very high uranium concentrations, where only fungi were recovered. Identifications based on bacterial 16S rRNA sequence analysis showed that the dominant cultivable bacteria belonged to the genus Bacillus. Members of the genera Paenibacillus, Lysinibacillus, Klebsiella, Microbacterium and Chryseobacterium were also isolated from the LAAs soil samples. Fungi were identified by sequence analysis of the intergenic spacer region, and members of the genera Aspergillus, Cryptococcus, Penicillium and Curvularia were dominant on plates with very high uranium concentrations. Members of the Paecilomyces and Alternaria were also present but in lower numbers. These findings indicate that fungi can tolerate very high concentrations of uranium and are more resistant than bacteria. Bacteria and fungi isolated at the Ranger LAAs from soils with high concentrations of uranium may have uranium binding capability and hence the potential for uranium bioremediation. -- Highlights: ► Fungi outcompete bacteria under increased uranium concentration in culture media. ► Soil microorganisms isolated from the Ranger Land Application Areas (LAAs) were resistant to uranium. ► Bacillus was the most abundant cultivable genus retrieved from the Ranger LAAs soils. ► Uranium in LAAs soils is

  4. Method of gradual acid leaching of uranium ores of silicate and aluminosilicate nature

    International Nuclear Information System (INIS)

    Bosina, B.; Krepelka, J.; Urban, P.; Kropacek, J.; Stransky, J.

    1987-01-01

    Leaching uranium ore pulp is divided into two stages. The first stage takes place without any addition of a leaching agent at elevated pressure and temperature. In the second stage, sulfuric acid is added to the pulp (50 to 1000 kg per tonne of ore) or an oxidation agent. Leaching then proceeds according to routine procedures. The procedure is used to advantage for silicate or aluminosilicate ores which contain uranium minerals which are difficult to leach, pyrite and reducing substances. The two stage leaching allows to use the technology of pressure leaching, reduces consumption of sulfuric acid and oxidation agents and still achieves the required reduction oxidation potential. (E.S.)

  5. Determination of uranium and thorium by X-ray fluorescence analysis in ores and derivatives

    International Nuclear Information System (INIS)

    Sato, I.M.

    1979-01-01

    A method to determinate the elements thorium and uranium by X-rays fluorescence in ores and derivatives is presented. The chosen samples are ores from Morro do Agostinho, Pocos de Caldas, Minas Gerais and monazite concentrated from Nucleomon which has the feature of being complex, and which is a type of material frequently found in nuclear technology. The method of fusion is chosen to prepare the samples, in which they are fused in borax in its natural form thus, proposing analyses of those elements without any previous chemical treatment. In the analyses of uranium, the effect of absorption of iron existing in the distinctive line ULα (n=2) of second order is mathematically corrected, instead of baing eliminated by chemical separation. The determination of thorium is made through the method of double-dilution in which several reasons have shown the advantages of its employment. The precision in function the coefficient of variation in percentage and the accuracy of the method proposed are discussed [pt

  6. Biogenic non-crystalline U(IV) revealed as major component in uranium ore deposits

    Science.gov (United States)

    Bhattacharyya, Amrita; Campbell, Kate M.; Kelly, Shelly D.; Roebbert, Yvonne; Weyer, Stefan; Bernier-Latmani, Rizlan; Borch, Thomas

    2017-06-01

    Historically, it is believed that crystalline uraninite, produced via the abiotic reduction of hexavalent uranium (U(VI)) is the dominant reduced U species formed in low-temperature uranium roll-front ore deposits. Here we show that non-crystalline U(IV) generated through biologically mediated U(VI) reduction is the predominant U(IV) species in an undisturbed U roll-front ore deposit in Wyoming, USA. Characterization of U species revealed that the majority (~58-89%) of U is bound as U(IV) to C-containing organic functional groups or inorganic carbonate, while uraninite and U(VI) represent only minor components. The uranium deposit exhibited mostly 238U-enriched isotope signatures, consistent with largely biotic reduction of U(VI) to U(IV). This finding implies that biogenic processes are more important to uranium ore genesis than previously understood. The predominance of a relatively labile form of U(IV) also provides an opportunity for a more economical and environmentally benign mining process, as well as the design of more effective post-mining restoration strategies and human health-risk assessment.

  7. Method of impact evaluation of storage sites for uranium ore tailings

    International Nuclear Information System (INIS)

    Servant, A.C.; Cessac, B.

    2001-11-01

    Mining and ore processing generate liquid effluents and solid waste ( tailings) in important quantities. On fifty years exploitation, 50 millions tons of tailings have been stored on twenty sites in France. From a radiological point of view, the uranium tailings contain only natural radioisotopes, daughters of 238 U and 235 U families and for a low part daughter's of 232 Th family. Their activity stay low to very low, under the ore activity. It decreases very slowly because of the long period of some radionuclides ( 230 Th, 75 000 years, 226 Ra, 1600 years). generally stored on the exploitation site, these tailings constitute a radiological source term of which it is necessary to evaluate the impact on man and environment. At close-down of an uranium ore exploitation site, the operator is required to give to the prefect of his region a file of rehabilitation with the dispositions to take to limit the radiological impact of the storage. It is in this frame that the direction of pollutions and risks prevention (D.P.P.R.) from the Minister of Territory landscaping and the Institute of protection and nuclear safety (I.R.S.N.) established a convention, reference 56/2000, relative to investigations in matter of radiological impact evaluation of uranium tailings storage sites, in order to supply a document allowing to judge the pertinence of the different files made by Cogema in the frame of tailings storage of uranium ore processing. The present document constitutes the report planned at the 3. article ( 3. paragraph) of the convention. It gives the information necessary to the evaluation of impact studies for the sites in question. (N.C.)

  8. Mining industry and explorations for uranium ore - the situation in Europe

    Energy Technology Data Exchange (ETDEWEB)

    Lange, G

    1976-05-01

    A survey is given of the present state of knowledge on uranium ore reserves, uranium production and uranium consumption. The supply with uranium of the various European countries is explained in brief sections. The results of the exploration efforts so far indicate that in the future, too, the demand can only be met partially by European deposits, and that the dependence on uranium imports cannot be deleted. Secure supply can be fortified by acquiring a share in overseas deposits and by geographic diversification. Activities in this direction have been started already.

  9. Bacterial leaching of uranium ores - a review

    International Nuclear Information System (INIS)

    Lowson, R.T.

    1975-11-01

    The bacterial leaching of uranium ores involves the bacterially catalysed oxidation of associated pyrite to sulphuric acid and Fe 3+ by autotrophic bacteria and the leaching of the uranium by the resulting acidic, oxidising solution. Industrial application has been limited to Thiobacillus thiooxidans and Thiobacillus ferrooxidans at pH 2 to 3, and examples of these are described. The bacterial catalysis can be improved with nutrients or prevented with poisons. The kinetics of leaching are controlled by the bed depth, particle size, percolation rate, mineralogy and temperature. Current work is aimed at quantitatively defining the parameters controlling the kinetics and extending the method to alkaline conditions with other autotrophic bacteria. (author)

  10. Comparative toxicity in rats vs hamsters of inhaled radon daughters with and without uranium ore dust

    International Nuclear Information System (INIS)

    Gaven, J.C.; Palmer, R.F.; McDonald, K.E.; Lund, J.E.; Stuart, B.O.

    1977-01-01

    Simultaneous exposures of rats and hamsters to inhaled radon daughters, with and without uranium ore dust, were performed daily for five months. Pulmonary pathology developing in 6 to 13 mo after cessation of daily exposures included interstitial fibrosis, emphysema, epithelial hyperplasia, squamous metaplasia, and malignant neoplasia. Rats showed a greater variety and more severe response to these uranium mine inhalation exposures than did hamsters. Inhalation of radon daughters with uranium ore dust displayed the site of greatest damage, including squamous carcinoma, from the nasopharynx to the lungs. Sixty percent of the rats exposed to radon daughters with ore dust developed primary pulmonary carcinomas, providing an appropriate short-term experimental animal model for investigation of respiratory tract carcinogenesis in uranium miners

  11. Development of lesions in Syrian golden hamsters following exposure to radon daughters and uranium ore dust

    International Nuclear Information System (INIS)

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

    1981-01-01

    The development of lesions in Syrian Golden hamsters was studied following life-span inhalation exposures to radon, radon daughters and uranium ore dust. Clinical measurements revealed that life-span exposures to radon daughters and uranium ore dust, singly or in combination, caused no significant changes in mortality patterns, body weights or hematological parameters compared with controls. Pulmonary and nonpulmonary lesions are presented. Exposure to uranium ore dust provoked inflammatory and proliferative responses in the lungs consisting of macrophage accumulation, alveolar cell hyperplasia, and adenomatous alteration of alveolar epithelium. The adenomatous lesions did not undergo further morphologic change. Exposure to radon and radon daughters was associated with increased occurrence of bronchiolar epithelial hyperplasia and with metaplastic changes of alveolar epithelium. Squamous carcinoma developed in only a few hamsters and only in those animals receiving radon daughter exposures exceeding 8000 WLM. It is concluded that an animal model other than the hamster would be more appropriate for study of the pulmonary carcinogenic potential of uranium ore alone. (author)

  12. Ore reserve estimation of uranium deposit Zirovski vrh

    International Nuclear Information System (INIS)

    Lukacs, E.

    1979-01-01

    The uranium ore deposit Zirovski vrh is in the Permian sediments of Northwest Yugoslavia. Lenticular bodies occur at several stratiform levels in grey, medium-grained sandstone. The ore deposit will be mined entirely by underground methods. It is possible to define three stages of deposit evaluation requiring different densities of exploration effort: preliminary evaluation of in situ ore reserves; evaluation of mineable ore reserves; evaluation of production capability and mine planning. The drilling density increases markedly with each succeeding stage. The optimal drilling density for all three stages of evaluation should be determined, but there is some concern that too close spaced drilling would considerably increase the exploration costs without a corresponding increase in effectiveness. On the other hand, too sparsely spaced drilling may result in some difficulties in following the ore in mining. The paper treats the problem of the density of drilling for evaluation of mineable ore reserves compared to that required for mine planning and mine production capability. The purpose of investigation of mineral raw materials is to define economic deposits (ore bodies). To evaluate the deposit economically an accurate reserve estimate is required. If it is accordingly established that such an estimate is within the degree of admissible error, the purpose of the exploration is satisfied. However, the problem as to whether the drilling grid is sufficiently dense remains, because the majority of estimates of ore reserves do not provide a measure of the reliability of the estimate. (author)

  13. Exploration on relationship between uranium and organic materials in carbonate-siliceous pelite type uranium ore deposits

    International Nuclear Information System (INIS)

    Dong Yongjie

    1996-01-01

    The author determines the content of uranium and organic carbon of part specimen of surrounding rocks and ores, which sampled from carbonate and black shale type uranium deposits in Xiushui, Jiangxi Province, and Tongcheng, Hubei Province. According to the analytical operation regulations of organic materials, extraction and separation of chloroform pitch is carried out. Internal relationships between uranium and organic derivative is discussed. The conclusion shows that: (1) certain co-relationship between U and organic carbon and chloroform extract is detected; (2) evolutionary processes of organic materials in the exogenetic uranium deposits are not all the same; (3) non-hydrocarbon is closely related to uranium, so it can be regarded as indicator of uranium gathering in exogenetic uranium deposits

  14. Ore petrography of a sedimentary uranium deposit, Live Oak County, Texas

    International Nuclear Information System (INIS)

    Bomber, B.J.; Ledger, E.B.; Tieh, T.T.

    1986-01-01

    Samples from the McLean 5 open-pit uranium mine, a small high-grade deposit located along a normal fault in the Miocene Oakville sandstone of Live Oak County, Texas, have been studied for uranium abundance, distribution, and nature of occurrence on the microscopic level. The host sandstone is composed of quartz, feldspars, and volcanic rock fragments, cemented by sparry calcite. Authigenic minerals include iron disulfide minerals (dominantly pyrite and some marcasite) and small amounts of clays, Ti oxides, and opal. High-grade ore (to 3% U) occurs along the fault, decreasing to less than 1,000 ppm within 10 m from the fault. The ore mineral is amorphous pitchblende and exhibits botryoidal morphology. The microscopic occurrence of uranium, documented by fission-track mapping of petrographic thin sections, is presented in detail. Uranium occurs abundantly as grain coatings and fillings in intergranular spaces in samples with high uranium content, where calcite cement has been partially or totally leached as mineralization proceeded. Lesser amounts are adsorbed onto leucoxene (microcrystalline anatase), mud clasts, and altered igneous rock fragments. Adsorbed uranium is the major code of occurrence in samples, with lower uranium contents farther from the orebody. Textural relations indicate that iron sulfides formed both before and after mineralization. Initial mineralization was by adsorption onto aggregates of fine particles of Ti oxide and clay minerals of various origins. With dissolution of cement and continued uranium influx, uranium precipitated as grain coatings and pore fillings

  15. Uranium Ore and Concentrate Sampling; Echantillonnage des Minerais et des Concentres d'Uranium; Otbor prob uranovoj rudy i kontsentratov; Muestreo de Minerales y Concentrados de Uranio

    Energy Technology Data Exchange (ETDEWEB)

    McGinley, F. E.; Brown, D. L.; Langridge, R. W. [United States Atomic Energy Commission, Grand Junction, CO (United States)

    1966-02-15

    The Grand Junction Office of the United States Atomic Energy Commission has been responsible for procuring large quantities of natural uranium in both ores and concentrates. The techniques used for sampling ores are necessarily different from those used for concentrates. Each step in the overall measurement and sampling systems for both ores and concentrates is discussed, giving particular attention to the accuracy and precision of that step. During the years 1948-1964, a total of 58 million tons of ore was sampled in about 40 different mechanical sampling plants in the western United States. All plants have been required to weigh, sample and analyse ore in accordance with practices satisfactory to the USAEC. The ordinary principles of ore sampling, as used for years in the mining industry, have been followed. However, sufficient check sampling and other tests were performed to ensure that the uranium content of the variety of ores sampled was as accurately determined as economically feasible. Concentrates containing about 129 000 t of U{sub 3}O{sub 8} were purchased from domestic producers during the last 17 years. This uranium was contained in approximately 10 000 lots, each of which was weighed, sampled, and analysed in accordance with carefully controlled procedures. These lots were received at USAEC-owned sampling facilities at Grand Junction or Weldon Spring, Missouri, both of which are contractor operated. The average lot consists of about 50 drums (55-gallon size) and weighs approximately 35 000 lb. Because concentrate varies so much in both physical and chemical characteristics, it is necessary to sample each drum. Through the years, various sampling systems were used, such as pipes, open auger, enclosed augers, and falling stream sampling. Falling stream sampling is the most accurate, provided precautions are taken to prevent changes in weight due to exposure to the atmosphere. Because of the tendency of concentrates to sorb or desorb moisture, depending

  16. Neutron activation probe for measuring the presence of uranium in ore bodies

    International Nuclear Information System (INIS)

    Goldstein, N.P.; Smith, R.C.

    1979-01-01

    A neutron activation proble comprises a pulsed neutron source in series with a plurality of delayed neutron detectors for measuring radioactivity in a well borehole together with a NaI (Tl) counter for measuring the high energy 2.62 MeV gamma line from thorium. The neutron source emits neutrons which produce fission in uranium and thorium in the ore body and the delayed neutron detectors measure the delayed neutrons produced from such fission while the NaI (Tl) counter measures the 2.62 MeV gamma line from the undisturbed thorium in the ore body. The signal from the NaI (Tl) counter is processed and subtracted from the signal from the delayed neutron detectors with the result being indicative of the amount of uranium present in the ore body

  17. Simulation of weathering processes of uranium-nickel ore from Key Lake, Sask., Canada - a contribution of uranium mineralogy to environmental protection

    International Nuclear Information System (INIS)

    Pechmann, E. von; Voultsidis, V.

    1979-01-01

    The impact of frost and rain on stockpiles of uranium-nickel or from the Key Lake deposits has been investigated in simulation tests. Frost splitting causes strong disaggregation of the rock and fragmentation of the mineral grains. The ore is much less affected in the sandstone than in the mylonitized basement. During the tests, the uranium minerals have nearly not been weathered. The nickel minerals are quickly transformed into water soluble secondary minerals (sulphates and arsenate). The weathering effects on stored ore depend on the degree of ore comminution and its exposition to the atmospheric elements. (orig.) [de

  18. Effect of reagent parameters on recovery of South Africa uranium ore

    Energy Technology Data Exchange (ETDEWEB)

    Afolabi, A.S., E-mail: afolaas@unisa.ac.za [Univ. of South Africa, Dept. of Civil and Chemical Engineering, Johannesburg (South Africa); Muzenda, E. [Univ. of Johannesburg, Chemical Engineering Technology Dept., Johannesburg (South Africa); Sigwadi, R. [SGS Lakefield Research Africa (Pty) Ltd., Johannesburg (South Africa)

    2010-07-01

    The effects of leach parameters to determine the variability of reagents consumption on a uranium ore was investigated in this work. The effects of time, temperature sulphates, and acid consumption on the rate of dissolution of the comminuted uranium ore samples were also studied. It was found that 77% dissolution of uranium was achieved after 8 hours while maximum uranium leaching of 92% was achieved at temperature 30{sup o}C for 1 hour. The addition of ferric sulphate at 30{sup o}C showed a decrease in acid consumption from 79.32 kg/t to 32.32 kg/t as well as decrease in the MnO{sub 2} consumption from 21.03 kg/t to 15.06 kg/t. At elevated temperature of 6{sup o}C a higher acid consumption of 100 kg/t was obtained and this is attributed to the fact that other acid consuming minerals were leached at this temperature. Maximum uranium dissolution of 89.37% was achieved after 24 hours and the acid consumption was 31 kg/t with a MnO{sub 2} addition of 24.26 kg/t. (author)

  19. Non-cyanide process for flotation of a uranium-bearing lead-zinc polymetallic sulphide ore

    International Nuclear Information System (INIS)

    Li Qingxin

    1988-01-01

    The characteristics of the minerals of a urnium-bearing lead-zinc ore are described in this paper, And the experimentsl results of non-cyanide flotation process are given. The tests show that the selective flotation process of lead and zinc followed by uranium treatment is feasible in technology and reasonable in economics. When the run-of-mine contains 2.86%Pb, 2.47%Zn and 0,019%U, the lead concentrate containing 65.13%Pb, and 4.51%Zn, the zinc concentrate containing 52.00%Zn and 1.22%Pb, and the uranium concentrate containing 0.028%U can be obtained with the recoveries of 94.87%Pb, 87.61%Zn and 66.13%U respectively. The influence of sodium sulphite on flotaion process, the effect of sodium sulphite and the flotation mechanism of dibutyldithiophosphate ammonium are also discussed

  20. Sedimentary rocks Uranium in Cerro Largo Province

    International Nuclear Information System (INIS)

    Scaron, P.; Garau Tous, M.

    1976-01-01

    With the aim of the uranium minerals exploration has been carried out several studies by UTE technicians in Cerro Largo Province from 1968 to 1969. In uranium concentration has been found pyrite, phosphate, iron oxides and manganese in uranium. Furthermore in La Divisa Ore were studied concentration Uranium enrichment has been studied in La Divisa ore

  1. Spectrophotometric determination of trace uranium in phosphate ore samples from kurum and uro areas, Nuba mountains, Sudan

    International Nuclear Information System (INIS)

    Mohamed, A. A.; Ali, A. H.; Altayeb, M. A. H.

    2004-01-01

    A method was proposed for the spectrophotometric determination of uranium content in phosphate ores. the method is based on the use of nitrogen (v) acid for leaching the rock, and treatment with ammonium carbonate solution, whereby uranium (Vi) is kept in solution as its carbonate complex. The ion-exchange technique was used for the recovery of uranium. Uranium was determined spectrophotometrically by measurement of the absorbance of the yellow uranium (Vi)-8-hydroxyquinolate complex at λ 425 nm. The procedure was used for the determination of trace uranium content in 30 phosphate ore samples collected from Kurun and Uro areas in Nuba mountains in Sudan. X-ray fluorescence technique was employed for the assessment of the method used. The spectrophotometric method results show a high similarity with those obtained by XRF technique. This agreement indicates that the procedure proposed here has been successfully applied for the determination of uranium in phosphate ores. (Author)

  2. Preconcentration of low grade uranium ores by gravity and magnetic methods: a case study with copper tailings from Singhbhum, Bihar, India

    International Nuclear Information System (INIS)

    Natarajan, R.; Sreenivas, T.; Krishna Rao, N.

    1992-01-01

    The physical beneficiation methods applied to uranium ores are gravity and magnetic techniques. Feasibility of application of these two techniques has been industrially demonstrated in the case of Palabora copper-uranium ores and Witwatersrand gold-uranium ores respectively. In India exhaustive studies have been carried out on the application of gravity and magnetic methods for preconcentration of uranium values from tailings of copper plants at Surda, Rakha and Mosabani in Singhbhum. While recovery by shaking tables is poor owing to non-liberation and inefficient recovery in finer particle sizes (-37μm), gravity machines like Bartles Mozely Separator and Bartles Cross Belt Concentrator are able to give improved recovery in sizes down to about 15μm. Application of Wet High Intensity Magnetic Separator (WHIMS) is able to improve the recovery to about 75 to 85% from the three tailings, and the improvement is due to the ability of WHIMS collect the micaceous mineral particles containing composite uranium values, as well as uraninite particles down to about 10μm in size. WHIMS is inefficient in recovering uraninite particles below 5μm. High Gradient Magnetic Separator and Super Conducting High Gradient Magnetic Separator, on the other hand, are able to give enhanced recovery of even < 5μm uraninite particles. With the improved technology of gravity and magnetic methods now available, it should now be techno-economically feasible to employ preconcentration of low tenor uranium ores by physical beneficiation, prior to chemical processing. (author). 25 refs. 8 figs, 5 tabs

  3. Pulmonary function evaluations of dogs exposed to uranium ore dust

    International Nuclear Information System (INIS)

    Loscutoff, S.M.; Buschbom, R.L.; Palmer, R.F.; Cross, F.T.

    1980-01-01

    Pulmonary function evaluations were conducted on dogs exposed to carnotite uranium ore dust. Significant changes were detected in the slope of the single-breath N 2 washout curve, suggesting an uneven distribution of ventilation

  4. Status Report from the United States of America [Processing of Low-Grade Uranium Ores

    Energy Technology Data Exchange (ETDEWEB)

    Kennedy, R H [United States Atomic Energy Commission, Washington, D.C. (United States)

    1967-06-15

    The US uranium production rate has been dropping gradually from a high of 17 760 tons in fiscal year 1961 to a level of about 10 400 tons in fiscal year 1966. As of 1 January 1966, there were 17 uranium mills in operation in the USA compared with a maximum of 26 during 1961, the peak production year. Uranium procurement contracts between the USAEC and companies operating 11 mills have been extended through calendar year 1970. The USAEC contracts for the other six mills are scheduled to expire 31 December 1966. Some of these mills, however, have substantial private orders for production of uranium for nuclear power plants and will continue to operate after completion of deliveries under USAEC contracts. No new uranium mills have been brought into production since 1962. Under these circumstances the emphasis in process development activities in recent years has tended toward improvements that could be incorporated within the general framework of the existing plants. Some major flowsheet changes have been made, however. For example, two of the ore-processing plants have shifted from acid leaching to sodium carbonate leach in order to provide the flexibility to process an increasing proportion of ores of high limestone content in the tributary areas. Several mills employing ion exchange as the primary step for recovery of uranium from solution have added an 'Eluex' solvent extraction step on the ion exchange eluate. This process not only results in a highgrade final product, but also eliminates several metallurgical problems formerly caused by the chloride and nitrate eluants. Such changes together with numerous minor improvements have gradually reduced production cost and increased recoveries. The domestic uranium milling companies have generally had reserves of normal-grade ores well in excess of the amounts required to fulfil the requirements for their contracts with the USAEC. Therefore, there has been little incentive to undertake the processing of lower grade

  5. Preliminary discussion on uranium metallogenic models of China's in-situ leachable sandstone-type uranium deposits

    International Nuclear Information System (INIS)

    Zhang Jindai; Xu Gaozhong; Chen Anping; Wang Cheng

    2005-01-01

    By comprehensively analyzing metallogenic environments and main ore-controlling factors of important uranium metallogenic regions of in-situ leachable sandstone-type uranium deposits at the southern margin of Yili basin, at the south-western margin of Turpan-Hami basin and in the northeastern Ordos basin, the authors of this paper discuss the metallogenic models of China's in-situ leachable sandstone-type uranium deposits, and suggest that the interlayer oxidation zone type uranium deposits in Yili and Turpan-Hami basins are basically controlled by favourable structures, sedimentary formations and interlayer oxidation zone, and are characterized by multistage uranium concentration, namely the uranium pre-concentration of ore-hosting sedimentary formation, the uranium ore-formation in the stage of supergenic epigenetic reworking, and the further superimposition enrichment of post-ore tectonic activity. However, the interlayer oxidation zone type uranium deposit in the northeastern Ordos was formed after the formation of the secondary reduction. So, paleo-interlayer oxidation zone type uranium mineralization has the mineralization size much greater than the former two. (authors)

  6. Prospects for increasing uranium resources in the Khiagda ore field (Russian Federation)

    International Nuclear Information System (INIS)

    Novgorodtcev, A.; Martynenko, V.; Gladyshev, A.

    2014-01-01

    The Khiagda ore field uranium deposits are located in the Republic of Buryatia, on the Amalat Plateau formed by the Neogene basalts. The position of the ore field is defined by a large tectonic structure having a north-eastern strike the Baisykhan Uplift. The slopes of the Baisykhan dividing uplift are incised by short (4 to 16 km) lateral tributaries of the Amalat and Atalanga paleorivers. The paleovalley network is filled with terrigenous-volcanogenic units of the Miocene Dzhilinda Formation (N1dz) buried under a thick cover of plateau basalts. The upheaval of the Baisykhan Uplift in the Neogene caused the penetration of the hydrodynamic flow of oxygenous uranium-bearing water into the sedimentary rock mass and formation of the subsoil/tabular oxidation zone (STOZ) on the boundary of which there formed uranium mineralisation.

  7. Application of anatectic mineralization to prospecting in-situ leachable sandstone type uranium ore in South Songliao Basin

    International Nuclear Information System (INIS)

    Zhao Zhonghua

    2001-01-01

    The deep ore-forming origin is a new theory for prospecting in-situ leachable sandstone type uranium. Tectonics, lithologic and geochemistry are basic forecasting criteria. Previous unconsolidated sand, source area and geochemical barrier are three essential conditions for forming uranium deposit. Metallogenic environment and prospective region are found. Tertiary system is prospective layer for prospecting in-situ leachable sandstone type uranium ore in south Songliao Basin

  8. Two-stage fungal leaching of vanadium from uranium ore residue of the leaching stage using statistical experimental design

    International Nuclear Information System (INIS)

    Gharehbagheri, Hassan; Safdari, Jaber; Roostaazad, Reza; Rashidi, Abbas

    2013-01-01

    Highlights: ► In this work, the percent of vanadium recovery from uranium mine waste was 44.8. ► Unlike autotrophs, Aspergillus niger is a suitable microorganism to deal with such a resource. ► In the first step of the present work, citric acid was produced more than the other acids. ► When sterilization of uranium ore waste is not economic, two-step bioleaching is an appropriate method. - Abstract: In this investigation, bioleaching of vanadium from uranium ore residue of the leaching stage was studied by Aspergillus niger in a two-step process at 30 °C and 150 rpm. The first step was initiated by growth of fungi in the absence of mine waste. Using response surface methodology, three factors were surveyed for fungal growth: initial pH, sucrose concentration and spore population. Also concentrations of oxalic, citric, and gluconic acids were measured as response in this step. During 30 days, maximum productions of these acids were 3265, 11578, and 7988 mg/l, respectively. Initial pH and sucrose concentration were significant factors for oxalic and citric acid production; however, for gluconic acid production sucrose concentration and spore population were significant. Then, the content of each flask was filtered and mine waste was added to liquor with pulp density of 3%. During 3 days, in the second step, vanadium recovered about 44.8% in the liquor

  9. Equilibria determination in uranium ores by alpha spectrometry

    International Nuclear Information System (INIS)

    Tormo Ferrero, M.J.

    1976-01-01

    A method for the measurement of the U-234/U-238 activities is described. The separation of the uranium from the interferring elements is carried out by ionic change with anionic resine, in chlorhydric-metanol-ascorbic acid medium. The method has been applied to different spanish ores in which the equilibrium state has been determined (author)

  10. Uranium distribution in uranium ores and source rocks

    International Nuclear Information System (INIS)

    Kurat, G.

    1981-11-01

    A variety of uranium ore samples from different localities was processed in the usual way: samples were cut and autoradiographed. On the basis of these pictures areas were selected for thin sections. These polished thin sections were investigated microscopically in transmitted and reflected light and the most typical or most important areas were photographically documented. Selected portions have then been routinely analyzed using an ARL-SEMQ electron microprobe under standard conditions (15kV acceleration, 15nA sample current). Most of the analyzed areas have also been documented by secondary electron scanning images and X-ray scans for the most important elements present

  11. The seat of ground water discharge as ore-mabilizing factor in the formatian of hydrogenic uranium deposits

    International Nuclear Information System (INIS)

    Natal'chenko, B.I.; Gol'dshtejn, R.I.

    1982-01-01

    The role of structural-hydrogeological factor in the process of ore-controlling zoning development during hydrogeneous deposit formation is discussed, as reflecting in the most objective way the spreading of stratal oxidation zones and morphology of uranium mineralization as regards discharge seats because there are only they which mobilize stratal waters for active displacement. The types of discharge seats of stratal waters and their effect on formation of ore-controlling zones of stratal oxidation with uranium mineralization are presented. The conclusion is drawn that local and regional discharge seats of stratal waters dictate both the spacing of regional fronts of stratal-oxidized rocks and their ore content degree. The displacement of discharge seats or their growing into local regions of alimentation results in reorganization of the total ore-controlling zoning, which enables to consider the seats of water discharge as ore-mobilizing structures in the formation of hydrogenic uranium deposits

  12. Study on treatment of radioactive liquid waste from uranium ore processing by the use of nano oxide ferromagnetic

    International Nuclear Information System (INIS)

    Vuong Huu Anh; Nguyen Van Chinh; Nguyen Ba Tien; Doan Thi Thu Hien; Luu Cao Nguyen

    2015-01-01

    Nano oxide ferromagnetic Fe_3O_4 KT which was produced by the Military Institute of Science and Technology were used to adsorbed heavy metal elements in liquid waste. In this report, the nano oxide ferromagnetic Fe_3O_4 KT with the particle size of 80-100 nm and the specific surface area of 50-70 m"2/g was applied to study the adsorption of radioactive elements in the liquid waste of uranium ores processing. The effective parameters on adsorption process included temperature, stirring rate, stirring time, the pH value of the solution, the initial concentration of uranium in solution were investigated. The results showed that the maximum adsorption capacity for uranium of the nano Fe_3O_4 KT was 53.5 mgU/g with conditions such as: room temperature, stirring speed 120 rounds/minute, the pH value of solution was 8, stirring time about 2 hours . From the results obtained, nano Fe_3O_4 KT was tested to treatment real liquid waste of uranium ore processing after removing almost heavy metals and a part of radioactive elements by preliminary precipitation at pH 8. The results were analyzed on the ICP-MS and α, β total activity equipment, the solution concentration after treatment suitable for Vietnamese Technical Regulation on industrial wastewater QCVN 40: 2011 (concentrations of heavy metals; total activity of α and β). (author)

  13. Bioleaching of UO22+ ions from poor uranium ores by means of cyanobacteria

    International Nuclear Information System (INIS)

    Cecal, A.; Humelnicu, D.; Popa, K.; Palamaru, I.; Nemtoi, G.; Rudic, V.; Gulea, A.

    2000-01-01

    Uranium (VI) leaching, as uranyl ions, from ores with a poor content in util minerals, using some algae as: Porphyridium cruentum (Smith and Soerly) Naegeli, Spirulina platensis CNM-CB-02 and Nostoc linkia (Roth) Born and Flah was studied. The basic composition of these ores allowed the self-maintenance and self-development of these microorganisms, which have facilitated then the leaching of the uranium (VI) as UO 2 2+ ions. The microbial leaching degree was comprised between 40-90%, depending on the used alga and experimental conditions. (author)

  14. A comment on the metallogenic theory of exogenetic uranium ore deposits

    International Nuclear Information System (INIS)

    Liu Xiaodong; Yu Dagan

    2010-01-01

    The theory of exogenetic sandstone-type uranium followed the form process of construction in the early time, and discussed the uranium metallization by chemical enrichment during the phase of syn-deposition and diagenesis. Later, the epigenetic theory was put forward by emphasizing hydrodynamic influence on mineralization. The idea of uranium mineralization in open systems is a renovated metallogenic theory for uranium, which confirms the role of exogenesis playing in uranium mineralization. For open systems, this paper underlines that, as the most critical factors for uranium mineralization, both uranium sources and reduce agents should be open to form a dual-open system. Uranium ore deposits in the tectonic zone of eastern China formed in dual-open system, where uranium has been associated with coal, petroleum and natural gas in the sandstone sequence. (authors)

  15. Potential health hazard of nuclear fuel waste and uranium ore

    International Nuclear Information System (INIS)

    Mehta, K.; Sherman, G.R.; King, S.G.

    1991-06-01

    The variation of the radioactivity of nuclear fuel waste (used fuel and fuel reprocessing waste) with time, and the potential health hazard (or inherent radiotoxicity) resulting from its ingestion are estimated for CANDU (Canada Deuterium Uranium) natural-uranium reactors. Four groups of radionuclides in the nuclear fuel waste are considered: actinides, fission products, activation products of zircaloy, and activation products of fuel impurities. Contributions from each of these groups to the radioactivity and to the potential health hazard are compared and discussed. The potential health hazard resulting from used fuel is then compared with that of uranium ore, mine tailings and refined uranium (fresh fuel) on the basis of equivalent amounts of uranium. The computer code HAZARD, specifically developed for these computations, is described

  16. Dense medium ore concentrates of Bois-Noirs; Minerais des bois noirs, concentres de milieu dense

    Energy Technology Data Exchange (ETDEWEB)

    Le Bris, J; Leduc, M

    1959-01-20

    The chemical treatment of uranium concentrates of Bois-Noirs ore obtained by heavy medium are discussed. The first part deals with sulfuric acid attack on the concentrate, and the second part with the separation of the solution from residues by filtration. A third part deals with this separation by decantation. The fourth part deals with the carbonation of the pickling solutions obtained. (author) [French] Le present rapport est relatif a l'etude du traitement chimique de concentres uraniferes de minerais des Bois-Noirs obtenus par milieu dense. Une premiere partie est consacree a l'attaque sulfurique des concentres, une deuxieme partie a Ia separation de Ia solution d'attaque des residus par decantation. Une quatrieme partie a la carbonatation des solutions d'attaque obtenues. (auteur)

  17. The impact of new technology on the economics of uranium production from low-grade ores

    International Nuclear Information System (INIS)

    Simonsen, H.A.; Boydell, D.W.; James, H.E.

    1981-01-01

    The subject is discussed under the following headings: influence of a depressed market on uranium supply from low-grade ores; potential areas for a reduction in uranium ore processing costs; in-situ leaching (solution mining; heap leaching; resin-in-pulp; solvent-in-pulp; belt filtration; continuous ion exchange; solvent extraction); preconcentration (upgrading of coarse rock; upgrading in the mill; wet high-intensity magnetic separation; flotation); summary and conclusions. (U.K.)

  18. Exploration on trickle leaching of uranium ore by refreshed liquor of bacterial oxidation

    International Nuclear Information System (INIS)

    Chen Shian; Huang Xiangfu; Fan Baotuan

    1995-01-01

    The paper describes the adaptation of the domesticated thiobacillus ferroxidans to the trickle leaching conditions of uranium ore. When the bacterial leaching liquor through multiple cycles of oxidation and regeneration was used to return to the trickle leaching, the following results were obtained: the extraction rate was more than 95%, the acid consumption was saved by 30%, and the consumed 2.0% pyrolusite (MnO 2 40%) was eliminated. The following problems are discussed: the basic principle, process and some factors influencing the process of the trickle leaching of uranium ore using regenerated liquor of bacterial oxidation, counter-current trickle leaching mode, oxidation and regeneration techniques of bacterial leaching liquor and other technological problems on the process of uranium extraction by thiobacillus ferroxidans

  19. Optimum condition determination of Rirang uranium ores grinding using ball mill

    International Nuclear Information System (INIS)

    Affandi, Kosim; Waluyo, Sugeng; Sarono, Budi; Sujono; Muhammad

    2002-01-01

    The grinding experiment on Rirang Uranium ore has been carried out with the aim is to find out the optimum condition of wet grinding using ball mill to produce particle size -325, -200 and -100 mesh. This will be used for decomposition feed the test was done by examine the parameters comparison of ore's weight against ball's weight and time of grinding. The test shown that the product of particle size -325 meshes was achieved optimum condition at the comparison ore's weight: ball = 1:3, grinding time 150 minutes, % solid 60, speed rotation of ball mill 60 rpm and recovery of grinding was 93.51 % of -325 mesh. The product of particle size -200 mesh was achieved optimum condition at comparison ore's weight: ball = 1:2, time of grinding 60 minutes, the fraction of + 200 mesh was regrind, the recovery of grinding 6.82% at particle size of (-200 + 250) mesh, 5.75 % at (-250 + 325)m mesh and, 47.93 % -325 mesh. The product of particle size -100 mesh was achieved the optimum condition at comparison ore's weight: ball = 1:2, time of grinding at 30 minutes particle size +100 mesh regrinding using mortar grinder, recovery of grinding 30.10% at particle size (-100 + 150) m, 12.28 % at (-150 + 200) mesh, 15.92 % at (-200 + 250) mesh, 12.44 % at (-250 + 325) mesh and 29.26 % -325 mesh. The determination of specific gravity of Rirang uranium ore was between 4.15 - 4.55 g/cm 3

  20. Carcinogenesis of inhaled radio daughters with uranium ore dust in beagle dogs

    International Nuclear Information System (INIS)

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

    1977-01-01

    Daily exposures of adult beagle dogs to inhaled radon daughters and to uranium ore dust for 4-1/2 to 6 yr have produced respiratory tract carcinomas, at similar cumulative working level months (WLM) of exposures to those which induced carcinomas in uranium miners. Biological data from the beagle-dog experiments can therefore be used for prediction of carcinogenic risk under changing exposure conditions in future uranium miners

  1. Brief analysis on relationship between red beds and sandstone-type uranium ore-formation

    International Nuclear Information System (INIS)

    Ji Zengxian

    2006-01-01

    Red beds are sandy gravel beds deposited under the arid and hot climates and correspondent to the oxidation environment of continental basins. As an exogenetic epigenetic uranium deposit, the formation of the sandstone-type uranium deposit needs a large chronologic gap between the diagenesis and the subsequent uranium metallogenesis of the ore-hosting target layer with a sedimentary discontinuity and an alternative humid-arid climate. Red beds are the product of this time. The evolutionary times of red beds are in accordance with the formation of the sandstone-type uranium deposit. Both domestic and abroad researches indicate that each times evolution of a red bed might be associated with uranium ore-formation in one or more sandstone layers in the region. In China, red beds are developed in many geologic periods, but sandstone-type uranium mineralization occurs mostly in Mesozoic-Cenozoic. Taking five known sandstone-type uranium deposits as examples, the author makes a primary analysis on the relationship between red beds and the subsequent sandstone-type uranium mineralization. It is suggested that the deposition of red beds and sandstone-type uranium metallogenesis are of 'cogenesis and coexistence' and that the deposition of red beds and its evolutionary times can be regarded as the prerequisites to judge the potential of sandstone-type uranium mineralization in a Mesozoic-Cenozoic sedimentary basin. (authors)

  2. Studies of leaching of copper ores and flotation wastes

    International Nuclear Information System (INIS)

    Wawszczak, D.; Deptula, A.; Lada, W.; Smolinski, T.; Olczak, T.; Brykala, M.; Wojtowicz, P.; Rogowski, M.; Milkowska, M.; Chmielewski, A.G.

    2014-01-01

    In Poland, there are significant deposits of copper ores. During the copper extraction, large amounts of flotation wastes are produced. In the ores and flotation wastes many other important elements are present. The main goal of this work was analysis of uranium content and to elaborate procedures for recovery of U from these materials. Two types of ores and four types of waste were examined. It has been found that uranium content varies from 4.5 to 25 ppm. The other elements have also been determined in these materials: Cu (4-5 % in ores and 0.3-1.7 % in waste), Ag, Re, Mo, La, Ni, V, etc. For leaching, sulfuric acid and sodium carbonates of various concentrations (temperature, time) were used. The optimum conditions for leaching have been found. The concentration of uranium in the final solution was generally less than 25 μg/mL. The other elements are also present in the leaching solutions. Simultaneous liquid-liquid extraction of uranium with these elements from leaching solution is under study. In our opinion, only such combined procedure for the recovery of uranium together with the accompanying elements could be cost-effective. (author)

  3. Research of geological technologic condition in laboratory about the ore of 501 deposits

    International Nuclear Information System (INIS)

    Ma Guoxiang; Yu Baoli; Gao Yuyou; Li Changhua

    2009-01-01

    501 deposits of uranium ore grade is 0.052%. The radio of U +6 /U 4+ is 1.7-4.6. there is less content of sarbonate, such as sulfide and organic matter which disservice baptist uranium geological process, and the uranium and oxygen with a high level in the water of seam. The content of [HCO 3 ] - is lower. By conducting the static leaching test, the important technical parameters of uranium ore extraction are determined: with 7.91 g/L H 2 SO 4 , to soak uranium ore which the grade is between 0.007% and 0.216% for 48 hours, the uranium extraction rate of 64.69-99.17%, and extract uranium concentration 9.51-427.6 mg/L; the formula of infusion solution is obtained by using percolation leaching test: 6-8 g/L H 2 SO 4 , the rate of uranium extraction is 95.71%-96.33%, an average of leaching solution uranium concentration of 88.33-111.32 mg/L, leaching liquid-solid ratio of 4.46-5.66, ore tons of sulfuric acid consumption to 27.58-29.83 kg/t, extraction of uranium 1 kg of sulfuric acid consumption to 55.17-60.06 kg. That indicate the geological technologic conditions which the leaching of uranium ore deposits is better. (authors)

  4. Commercial experimental on bacteria heap leaching of uranium ore from Caotaobei mining area in Ganzhou uranium mine

    International Nuclear Information System (INIS)

    Fan Baotuan; Meng Yunsheng; Liu Jian; Xiao Jinfeng; Chen Sencai; Cao Jianbo; Wu Yichang; Liu Chengwu

    2002-01-01

    The author presents the result of commercial experiment on bacteria heap leaching of uranium ore from Caotaobei mining area in Ganzhou Uranium Mine and summarizes the heap situation, installation of spraying and sprinkling devices, and operation management of continuous oxidizing tank of bio-membrane. The leaching rate is 92.95% and 91.88% respectively by liquid and residue measurement during 85 d bacterial leaching experiment. The acid consumption is 2.1% and the total liquid-solid ratio is 2.9 m 3 /t. Compared with conventional heap leaching, the time of bacteria heap leaching shorted about 75 d, the acid consumption reduced by 0.35% and the leaching rate improved by 2%. It is an optimize plan to reform the heap leaching technology for Caotaobei ore

  5. Column leaching experiments of a uranium ore by atomizing irrigation technique

    International Nuclear Information System (INIS)

    Zeng Yingying; Lei Zeyong; Chen Haihui

    2007-01-01

    Column leaching experiments ora uranium ore were made by atomizing irrigation technique. The leaching results are compared with the results obtained by spray irrigation and drip irrigation techniques respectively under the same conditions of column leaching experiments. The results show that the atomizing irrigation technique has more uniform solution distribution, higher leaching rate, shorter leaching period, and less ratio of liquid to solid. Consequently, the atomizing irrigation technique is suitable to the ore. (authors)

  6. Extraction of uranium from simulated ore by the supercritical carbon dioxide fluid extraction method with nitric acid-TBP complex

    International Nuclear Information System (INIS)

    Dung, Le Thi Kim; Imai, Tomoki; Tomioka, Osamu; Nakashima, Mikio; Takahashi, Kuniaki; Meguro, Yoshihiro

    2006-01-01

    The supercritical fluid extraction (SFE) method using CO 2 as a medium with an extractant of HNO 3 -tri-n-butyl phosphate (TBP) complex was applied to extract uranium from several uranyl phosphate compounds and simulated uranium ores. An extraction method consisting of a static extraction process and a dynamic one was established, and the effects of the experimental conditions, such as pressure, temperature, and extraction time, on the extraction of uranium were ascertained. It was found that uranium could be efficiently extracted from both the uranyl phosphates and simulated ores by the SFE method using CO 2 . It was thus demonstrated that the SFE method using CO 2 is useful as a pretreatment method for the analysis of uranium in ores. (author)

  7. Studies on the mechanism for in-place leaching of fragmented uranium ore by blasting

    International Nuclear Information System (INIS)

    Wu Hengshan; Wang Changhan

    2001-01-01

    The report is based on the locale test studies at No.745 Mine and Baifang Copper (Uranium) Mine. According to hydrokinetics of porous medium. The character of mining methods of in-place leaching of fragmented uranium are, the best application conditions, in-place leaching theory, the fittest composite of fragments of crashing uranium ore, the lowest velocity of flow in solution liquid, the reasonable parameter of stop structure, the technology of leaching, meaning, the equation of solution liquid, the name of solution mining and its classification are studied. Especially some creation in the theory of leaching in mud ore and the technology of strengthened leaching are given. It would be helpful to the design and production

  8. A Comparative Analysis of Uranium Ore using Laser Fluorimetric and gamma Spectrometry Techniques

    International Nuclear Information System (INIS)

    Madbouly, M.; Nassef, M. H.; El-Mongy, S.A.; Diab, A.M.

    2009-01-01

    A developed chemical separation method was used for the analysis of uranium in a standard U-ore (IAEA-RGU-1) by LASER fluorimetric technique. The non-destructive gamma assay technique was also applied to verify and compare the uranium content analyzed using laser technique. The results of the uranium analysis obtained by laser fluorimetry were found to be in the range of 360 - 420 μg/g with an average value of 390 μg/g. The bias between the measured and the certified value does not exceed 9.9%. For gamma-ray spectrometric analysis, the results of the measured uranium content were found to be in the range of 393.8 - 399.4 μg/g with an average value of 396.3 μg/g. The % difference in the case of γ- assay was 1.6 %. In general, the methods of analysis used in this study are applicable for a precise determination of uranium. It can be concluded that, laser analysis is preferred for assay of uranium ore due to the required small sample weight, the low time of sample preparation and cost of analysis.

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

    International Nuclear Information System (INIS)

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

    2005-01-01

    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

  10. 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.

  11. Safe management of wastes from the mining and milling of uranium and thorium ores

    International Nuclear Information System (INIS)

    1987-01-01

    Wastes from the mining and milling of uranium and thorium ores pose potential environmental and public health problems because of their radioactivity and chemical composition. This document consists of two parts: a Code of Practice (Part I) and a Guide to the Code (Part II). The Code sets forth the requirements for the safe and responsible handling of the wastes resulting from the mining and milling of uranium and thorium ores, while the Guide presents further guidance in the use of the Code together with some discussion of the technology and concepts involved

  12. 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.

  13. Evolution of ore-bearing material sources of endogenous uranium deposits

    International Nuclear Information System (INIS)

    Kazansk, V.I.; Laverov, N.P.; Tugarinov, A.I.

    1976-01-01

    Considered are the regularities of changes in types and conditions of uranium deposit formation in connection with the general development of the earth crust tectonic structures. Out of pre-Kembrian uranium deposits considered are Vitwatersrand conglomerates, hydrothermal deposits in pre-Kembrian iron quartzites in the areas of regional fractures in exocontacts of big multiphase granitoid massifs of Proterozoic age and in the fundament folded structures. The hydrothermal-metamorphogen theory is supported of the origin of uranium-bearing sodium metasomatite of Proterozoic, including uranium deposits in the area of the Atabaska lake. Four genetic classes of Palaeozoic deposits are considered. Four periods are singled out in the development of Palaeozoic uranium provinces. Most of the Palaeozoic deposits are shown to be of polygenous origin. Mesozoic deposits are also polygenous, but the combination of ore substance sources in them is more complex

  14. Status Report from Sweden [Processing of Low-Grade Uranium Ores

    Energy Technology Data Exchange (ETDEWEB)

    Peterson, A [AB Atomenergi, Stockholm (Sweden)

    1967-06-15

    The Ministry of Education was authorized in November 1945 to appoint a commission to study the organization of nuclear energy research. In April 1947 this commission, the Swedish Atomic Energy Commission, proposed the formation of a semi-state-owned company to be a central body for applied research work and development in the nuclear energy field in Sweden. In November 1947 the Atomic Energy Company (AB Atomenergi) had its statutory meeting. The State owns 4/7 of the share capital and the remaining 3/7 is owned by 71 private and municipal share-holders. Except for a part of the stock capital, all investments and running costs of the company have been financed by the Government. The company is in practice answerable to the Department of Commerce which has an advisory body, the Atomic Energy Board. AB Atomenergi is responsible for Government-financed research on the industrial applications of nuclear energy, the milling of uranium ores and refining of uranium. The total number of employees is at present about 1400, 800 of which work at the company's research establishment Studsvik about 120 km south of Stockholm. As early as 1945 the Research Institute of the Swedish National Defence started work in the field of uranium processing. Similar work was also started quite early by the Boliden Mining Company, the Swedish Shale Oil Company and Wargons AB. After the establishment of AB Atomenergi, all work in the uranium processing field was transferred to this company. In fact one of the main reasons for the formation of AB Atomenergi was the need for Swedish uranium production as there was no possibility of importing uranium at that time. As a result of research and development in uranium processing a pilot plant at Kvarntorp near Orebro in central Sweden started milling a low-grade uranium ore (shale) in 1953. The capacity of this plant was 5-10 tons of uranium a year. A uranium mill at Ranstad in south-west Sweden, near Skovde, with a capacity of 120 tons of uranium a

  15. Assessment of the effect of innovation on the costs of a uranium ore concentration plant by means of a technical and economic model. Examples of applications: direct precipitation of the peroxide UO4 xH2O high temperature and high concentration alkaline treatment

    International Nuclear Information System (INIS)

    Boutonnet, G.; Roullier, J.P.

    1983-01-01

    Uranium Pechiney Ugine Kuhlmann has developed an economic model for uranium ore treatment plants. In this model, the basic economic data for a given plant, such as capital expenditures, operating costs, etc. are derived from parameters based partly on the size of the plant and the production progamme considered, and partly on the cost and specifications of the ore to be treated. In addition to numerous macro-economic applications (not considered here), the model can be used for making coherent comparisons of the economy of a plant designed for an innovative production process with that of the same plant designed for a conventional process of acid treatment followed by solvent extraction. The model shows that two new processes are highly competitive with the conventional process. They are: 1. Direct precipitation of the peroxide UO 4 xH 2 O in the pregnant liquor without concentration or purification by solvents or exchangers, and 2. High temperature and high concentration alkaline treatment

  16. Advantage of uranium contained in low grade dolomite ore

    International Nuclear Information System (INIS)

    Carneiro, A.L.M.

    1988-01-01

    The purpose of this work is to investigate a technological route to recover uranium from a lean mineral ore. The experimental work includes studies concerning calcination, carbonate leaching, settling, filtration and resin-ion-exchange. Experimental data confirm the technological feasibility of the proposed process and two different preliminary flowsheets of a pilot plant were suggested. (author) [pt

  17. Uranium ore waste management of the CIPC (Mining Industrial Complex of Pocos de Caldas Plateau, Minas Gerais State, Brazil)

    International Nuclear Information System (INIS)

    Wiikmann, Luiz Oide; Figueiredo, Nestor; Taddei, Jose Fernando Aguiar Carrazedo; Valente, Sergio Mozart Coutinho; Chilelli Junior, Vicente; Souza, Vicente Paulo de

    1995-01-01

    Since 1982, the facilities in CIPC has been producing a uranium concentrate under ammonium diuranate form, from uranium ore. The CIPC,s Waste Management System is responsible for monitoring and controlling the mining and milling effluents, in accordance with norms established by government regulatory agencies. Here we are concerned with this system's efficiency, costs and, with necessary procedures for waste rock piles'stabilization in physical, chemical and biological aspects with aim of environmentally restoring these areas. (author). 2 refs., 6 figs., 5 tabs

  18. Experience Gained from the Former Uranium Ore Processing and the Remediation of the Legacy Site in Hungary

    Energy Technology Data Exchange (ETDEWEB)

    Csövári, M.; Földing, G.; Berta, Zs.; Németh, G., E-mail: csovarimihaly@mecsekoko.hu [MECSEK-ÖKO Zrt, Pécs (Hungary)

    2014-05-15

    Uranium explorations in Hungary started 1953. By 1957 the uranium ore reserves were confirmed and the feasibility of mining in the Mecsek Mountains demonstrated by opening the first shaft. In 1962 the mill was built. The mining and processing of the uranium ore were terminated in 1997 mainly on economical reasons. The remediation of the site has started immediately and had been practically finished in 2008. The paper summarises the remediation work, and some lessons learned from the former mill practice, and from the remediation activity. (author)

  19. The Crouzille (Haute-Vienne, France) uranium ores. Half a century of human and industrial adventure in Limousin

    International Nuclear Information System (INIS)

    Bavoux, B.; Guiollard, P.C.

    1998-01-01

    The 16 uranium deposits of the Crouzille (Haute-Vienne, France) have produced 25000 tons of uranium between 1950 and 1995. The uranium content of the ores ranges from 1 to 10/1000. The main production came from the underground exploitation up to 300 m of depth. This book presents the historical aspects of this industrial and human epopee and describes with details the underground exploitation of the ore, its processing and the rehabilitation of the site after the mines have closed down. (J.S.)

  20. Non-filtration method of processing uranium ores

    International Nuclear Information System (INIS)

    Laskorin, B.N.; Vodolazov, L.I.; Tokarev, N.N.; Vyalkov, V.I.; Goldobina, V.A.; Gosudarstvennyj Komitet po Ispol'zovaniyu Atomnoj Ehnergii SSSR, Moscow)

    1977-01-01

    The development of the non-filtration sorption method has lead to procedures of the sorption leaching and the extraction desorption, which have made it possible to intensify the processing of uranium ores and to improve greatly the technical and economic indexes by eliminating the complex method of multiple filtration and re-pulping of cakes. This method makes it possible to involve more poor uranium raw materials, at the same time extracting valuable components such as molybdenum, vanadium, copper, etc. Considerable industrial experience has been acquired in the sorption of dense pulp with a solid-to-liquid phase ratio of 1:1. This has led to a plant production increase of 1.5-3.0 times, an increase of uranium extraction by 5-10%, a two- to- three-fold increase of labour capacity of the main workers, and to a several-fold decrease of reagents, auxiliary materials, electric energy and vapour. This non-filtration method is a continuous process in all its phases thanks to the use of high-yield and high-power equipment for high-density pulps. (author)

  1. X-Ray Fluorescence Spectrometry. II. Determination of Uranium in ores

    International Nuclear Information System (INIS)

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

    1961-01-01

    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 α 1 spectral line is calculated and related to corresponding strontium-K α spectral line, both detected with a Scintillation Counter. (Author) 31 refs

  2. Microcontroller based, ore grade measuring portable instruments for uranium mining industry

    International Nuclear Information System (INIS)

    Dheeraj Reddy, J.; Narender Reddy, J.

    2004-01-01

    Ore Face Scanning and Bore Hole Logging are important essential activities which are required to be carried out in any Uranium mining industry. Microcontroller based, portable instruments with built-in powerful embedded code for data acquisition (of Radiation counts) and Ore Grade calculations will become a handy measuring tool for miners. Nucleonix Systems has recently developed and made these two portable instruments available to UCIL, which are under use at Jaduguda and Narvapahar mines. Some of the important features of these systems are compact, light weight, portable, hand held, battery powered. Modes of Data Acquisition: CPS, CPM and ORE GRADE. Detector: Sensitive GM Tube. Choice of Adj. TC (Time Constant) in 'ORE GRADE', acquisition mode. Built-in automatic BG (Background) recording and subtraction provided to indicate net CPS, CPM or ore GRADE in PPM. Can store 1000 readings at users choice. Built-in RS232 serial port facilitates data downloading into PC. This paper focuses on design concepts and technical details for the above two products. (author)

  3. Natural uranium concentrations of native plants over a low-grade ore body

    International Nuclear Information System (INIS)

    Sheppard, M.I.; Thibault, D.H.

    1984-01-01

    Plant uranium concentrations generally reflect soil or rock substrate concentrations in upland areas, but they may not in lowland areas where the rhizoids of Sphagnum spp. and rocks of Ledum groenlandicum may be in direct contact either continuously or on a seasonal basis with the groundwater. This study points out the importance of selecting plant species and collection sites where the true substrate can be well defined and sampled. Sphagnum spp. and Ledum groenlandicum best reflect the substrate uranium concentrations in lowland areas, Umbilicaria spp. and Cladonia spp. in rock outcrop, and Picea mariana and Betula papyrifera in upland locations. The study shows the best plant part to sample is the older tissue such as the stems, twigs, and wood. Since no systematic changes in plant tissue concentrations were found throughout the season, sampling can be carried out anytime. Expression of soil concentrations on an ash weight basis gave a considerably different result than those on a dry weight basis, particularly when comparisons were made between litter-enriched mineral soil and true organic soils. The amount of ash varied among plant organs, species, and taxonomic divisions, and a constant value cannot be used to convert plant ash concentrations on a dry weight basis

  4. The geologic character of nappe structure and its relation to uranium mineralization of Xiangshan ore-field in the middle of Jiangxi Province

    International Nuclear Information System (INIS)

    Zhou Yulong; Yang Song

    2012-01-01

    Started with the spatial distribution of nappe structure, the geologic features are discussed and its effect on uranium mineralization in systematically summarized for Xiangshan ore-field in the middle of Jiangxi Province. The nappe structure not only formed a 'cross-over' lithologic combination which creates a network system which can connect, transport, migrate the mineralized matter, but also formed some close or semi-close geologic setting beneath the nappe which can act as the store ore shield space for the mineralized liquid to form uranium deposit. The mineralization is concentrated at the varied place of occurrences or shape of sub-volcanic rocks and the intersection of concealed overthrust and NE strike basic fractures. (authors)

  5. Molybdenum isotope fractionation during acid leaching of a granitic uranium ore

    Science.gov (United States)

    Migeon, Valérie; Bourdon, Bernard; Pili, Eric; Fitoussi, Caroline

    2018-06-01

    As an attempt to prevent illicit trafficking of nuclear materials, it is critical to identify the origin and transformation of uranium materials from the nuclear fuel cycle based on chemical and isotope tracers. The potential of molybdenum (Mo) isotopes as tracers is considered in this study. We focused on leaching, the first industrial process used to release uranium from ores, which is also known to extract Mo depending on chemical conditions. Batch experiments were performed in the laboratory with pH ranging from 0.3 to 5.5 in sulfuric acid. In order to span a large range in uranium and molybdenum yields, oxidizers such as nitric acid, hydrogen peroxide and manganese dioxide were also added. An enrichment in heavy Mo isotopes is produced in the solution during leaching of a granitic uranium ore, when Mo recovery is not quantitative. At least two Mo reservoirs were identified in the ore: ∼40% as Mo oxides soluble in water or sulfuric acid, and ∼40% of Mo hosted in sulfides soluble in nitric acid or hydrogen peroxide. At pH > 1.8, adsorption and/or precipitation processes induce a decrease in Mo yields with time correlated with large Mo isotope fractionations. Quantitative models were used to evaluate the relative importance of the processes involved in Mo isotope fractionation: dissolution, adsorption, desorption, precipitation, polymerization and depolymerization. Model best fits are obtained when combining the effects of dissolution/precipitation, and adsorption/desorption onto secondary minerals. These processes are inferred to produce an equilibrium isotope fractionation, with an enrichment in heavy Mo isotopes in the liquid phase and in light isotopes in the solid phase. Quantification of Mo isotope fractionation resulting from uranium leaching is thus a promising tool to trace the origin and transformation of nuclear materials. Our observations of Mo leaching are also consistent with observations of natural Mo isotope fractionation taking place during

  6. Processing Pa-Lua Uranium ore by Mixing and Curing with Sulfuric Acid on a Scale of 500 kg/Batch to Recover Yellowcake

    International Nuclear Information System (INIS)

    Le Quang Thai; Cao Hung Thai; Le Thi Kim Dung; Phung Vu Phong; Tran Van Son

    2007-01-01

    Uranium ore in Pa-Lua area is sandstone with different levels of weathering. This kind of ore contains calcium and clay that may cause clogs during heap leaching. In this study, a technique of mixing and curing with strong acids is used and followed by washing to recover uranium. This study also focuses on study of ore processing issues such as crushing, regenerating particles in fine ores, mixing, curing and washing. The leach solution is treated by ion-exchange and precipitation of products by NH 4 OH. The experiment results show that regenerating a portion of fine ores, mixing and curing help washing residues in the column more effectively. Flow rate of the input solution can be controllable and stable. Columns do not clog even when washing takes place in the ore column of 5 meters high. Efficiency of uranium recovery can reach to 85-90%. Products of technical uranium are obtained with high quality. (author)

  7. 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.)

  8. Geostatistics applied to estimation of uranium bearing ore reserves

    International Nuclear Information System (INIS)

    Urbina Galan, L.I.

    1982-01-01

    A computer assisted method for assessing uranium-bearing ore deposit reserves is analyzed. Determinations of quality-thickness, namely quality by thickness calculations of mineralization, were obtained by means of a mathematical method known as the theory of rational variables for each drill-hole layer. Geostatistical results were derived based on a Fortrand computer program on a DEC 20/40 system. (author)

  9. Uranium ore from Morro do Agostinho, Pocos de Caldas, Minas Gerais, Brazil

    International Nuclear Information System (INIS)

    Matsuda, H.T.

    1976-01-01

    Three non-destrutive methods for determination of uranium from Morro do Agostinho's ore, Pocos de Caldas, Minas Gerais are presented. Comparative data between chemical analysis (volumetric method) and cited non-destructive methods are shown. Gamma spectrometry, x-rays fluorescense and delayed neutrons counting are the methods discussed. Uranium's and molibdenium's behavior related to anionic sulphuric resin system is also discussed. Comparative studies concerning retention of uranium and molibdenium in strong and weak anionic resins as well as selective elution using appropriate solvents are shown [pt

  10. Heap-leaching of low-grade uranium ore at SOMAIR: from laboratory tests to production of 700 tonnes U per year

    Energy Technology Data Exchange (ETDEWEB)

    Durupt, N.; Blanvillain, J.J., E-mail: nicolas.durupt@areva.com [AREVA NC, Service d' Etudes de Procedes et d' Analyses (SEPA), Bessines sur Gartempe (France)

    2010-07-01

    In 2006, SOMAIR decided to increase the uranium production by 50% using heap leaching for the treatment of low grade ores. These ores, which come from different ores with various properties, have been studied in four steps: Lab tests: to compare the ores (characterization, acid consumptions, recovery); Column tests on an average sample: to define significant parameters for a feasibility study; Column tests on specific samples: to optimize recovery for each ore and identify problems of percolation due to the clays; and, Pilot tests in large boxes (stalls): to validate process parameters. Uranium production by heap leaching started commercially in July 2009. (author)

  11. The acid aging as alternative process for uranium recovery from silicated ores

    International Nuclear Information System (INIS)

    Cipriani, M.; Della Testa, A.

    1984-01-01

    The influence of different variables on the extraction uranium efficiency and on the silicate solubility by means of acid aging is studied. The variables studied in bench scale were: acid/ore, oxidizing/ore and liquid/solid relationships; reaction time; temperature and recovery time. The results are discussed and compared with the ones of continuous operation of a semi-pilot plant. A flowsheet of the industrial process application is presented. (M.A.C.) [pt

  12. Present and future: heap leaching of uranium ore in China

    International Nuclear Information System (INIS)

    Li Jianhua

    2010-01-01

    Based on small and disperse uranium deposits, and low grade ores, heap leaching has been developed as the dominating technique in the uranium production of China. It is indicated that heap leaching technique has such advantages as less capital, low cost, low power consumption and water consumption. At the meanwhile, heap leaching technique presents shortcomings of poor adaptability and low recovery rate. In order to meet the oncoming enormous demand of nuclear power, great effort shall be put on research of new technology, new equipment, new material. (authors)

  13. A case study of shrinkage-in place leaching of low grade uranium ore deposit

    International Nuclear Information System (INIS)

    Ding Dexin; Zhou Guohe

    1998-09-01

    A case study of shrinkage-in place leaching of low grade uranium ore deposit is dealt with. A test block was selected, and the shrinkage mining method was employed to construct the in place heap for leaching. Blast parameters and operations were carefully tried in order to make sure that the fragment size composition was adequate for leaching. A leaching system was planned and the corresponding leaching parameters were tried, too. The results show that the shrinkage method and the parameters for blasting and leaching are all adequate for the in-situ leaching of the blasted ore. This shrinkage-in place leaching system combines the mining and metallurgy processes into one and produces a lot of profits and could be applicable to many low grade uranium ore deposits which are so hard and compact that they have to be fragmented before being leached

  14. Remediation of Canada's historic haul route for radium and uranium ores - the northern transportation route - 59303

    International Nuclear Information System (INIS)

    Geddes, Brian; Wenzel, Chris; Owen, Michael; Gardiner, Mark; Brown, Julie

    2012-01-01

    Established in the 1930's, the Northern Transportation Route (NTR) served to transport pitchblende ore 2,200 km from the Port Radium Mine in Canada's Northwest Territories to Fort McMurray in Alberta. From there, the ore was shipped 3,000 km by rail to the Town of Port Hope, Ontario, where it was refined for its radium content and used for medical purposes. Later, transport and refinement focussed on uranium. The corridor of lakes, rivers, portages and roads that made up the NTR included a number of transfer points, where ore was unloaded and transferred to other barges or trucks. Ore was occasionally spilled during these transfer operations and, in some cases, subsequently distributed over larger areas as properties were re-developed or modified. In addition, relatively small volumes of ore were sometimes transported by air to the south. Since 1991, the Low-Level Radioactive Waste Management Office (LLRWMO), working with communities and its consulting contractors, has conducted surveys to identify and characterize spill sites along the NTR where soils exhibit elevated concentrations of uranium, radium and/or arsenic. In addition to significant areas of impact in Fort McMurray, contamination along the NTR was centered in the Sahtu region near Great Bear Lake and along the southern part of the Slave River. Early radiological investigations found contaminated buildings and soil and occasionally discrete pieces of pitchblende ore at many transfer points and storage areas along the NTR. Where possible, survey work was undertaken in conjunction with property redevelopment activity requiring the relocation of impacted soils (e.g., at Tulita, Fort Smith, Hay River, and Fort McMurray). When feasible to consolidate contaminated material locally, it was placed into Long Term Management Facilities developed to manage and monitor the materials over extended timelines. Radiological activity generated by these engineered facilities are generally below thresholds established by

  15. Application of AMT in detecting deep geological structures in Lejia district of Xiangshan uranium ore field

    International Nuclear Information System (INIS)

    Duan Shuxin; Liu Hu

    2014-01-01

    In recent years, exploration in Xiangshan uranium ore field shows that the intersection of faults and the interface of different rock formation and the basement is an important sign of deep ore- prospecting. In order to evaluate deep uranium resource in Lejia district, audio magnetotelluric method (AMT) was undertaken to carry out profile investigation. With that method, we discerned the interface of different rock formation and the basement successfully, and faults in the deep, which provides a good basis for the prediction of deep uranium resource. Drilling results show that AMT method has an obvious advantage in detecting deep geological structures in Xiangshan. (authors)

  16. Study on treatment of radioactive liquid waste from uranium ore processing by the use of nano Fe_3O_4 KT particles

    International Nuclear Information System (INIS)

    Vuong Huu Anh; Nguyen Ba Tien; Doan Thi Thu Hien; Luu Cao Nguyen; Nguyen Van Chinh

    2015-01-01

    Nano Fe_3O_4 KT was produced from the Military Institute of Science and Technology were used to adsorbed heavy metal elements in liquid waste. In this report, the nano Fe_3O_4 KT particles sized 80-100 nm and specific surface area was 50-70 m"2/g was applied to study the adsorption of radioactive elements in the liquid waste of uranium ores processing. The effective parameters on adsorption process included temperature, stirring rate, stirring time, the pH value of the solution, the initial concentration of uranium in solution. The results showed the maximum adsorption capacity of the nano Fe_3O_4 KT was 53.5 mg/g with conditions such as room temperature, stirring speed 120 rounds/minute, the pH value of solution was 8, stirring time about 2 hours (Uranium/materials). From the results obtained, nano Fe_3O_4 KT tested to treatment liquid waste of uranium ore processing after preliminary precipitation removed almost heavy metals and a part of radioactive elements. The results were analyzed on the ICP-MS and α, β total counting, instrument. The solution concentration after treatment was suitable for Vietnam discharge standards into environment (QCVN 40:2011 on Industrial wastewater). (author)

  17. Design and construction of the multilayer cover for uranium ores landfills in Andujar (Spain) mining

    International Nuclear Information System (INIS)

    Sanchez, M.; Santiago, J.L. de.

    1994-01-01

    This report shows the design and construction of multilayer cover for the landfill of sterile uranium ores in Andujar Mining (Spain). The main chapters are: 1.- Decommissioning project of Uranium Mining in Andujar (Spain) 2.- Elements and design of cover. 3.- Characteristic material

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

    International Nuclear Information System (INIS)

    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

  19. Technologies for processing low-grade uranium ores and their relevance to the Indian situation

    International Nuclear Information System (INIS)

    Murthy, T.K.S.

    1991-01-01

    The technology for uranium ore processing is well established. Various estimates have shown that on a global basis uranium resources are adequate to meet the forseeable demand. The Indian resources are estimated to be about 60,000 t U. The grade of the ores is low and the individual deposits are small. The nature of the deposits, precarious resources position and relatively small capacity of the mines do not permit the country to take advantage of large throughputs in the mill to achieve substantial cost reduction. However by resorting to as high a scale of milling as the mines would permit, by reducing the loss of solubilised uranium after leaching and by undertaking production of nuclear grade final product at the mill site, significant though not a major, economic benefit can be derived. (author). 2 figs., 3 tabs

  20. Natural galvaniv effect when bed-oxidation ore-bearing zone forming

    International Nuclear Information System (INIS)

    Shchetochkin, V.N.; Kislyakov, Ya.M.; Vasil'eva, Eh.G.

    1995-01-01

    Hypothesis of the essential role of natural galvanic process in exogenetic-epigene ore-formation the model of which was elaborated earlier, is grounded. Genetic conjuction of variations near geochemical barrier of redox and acidic-alkaline hydrogeochemical parameters is stated. These variations in total enable to understand the mechanism of formation of infiltration uranium mineralizatiuon, to explain a number of the observed peculiarities of oxidation ore-controlling zoning, and to explain, as well, slightly-expressed concentration of elements-hydrolyzates in uranium ores. 29 refs.; 6 figs.; 3 tabs

  1. Effects of barium chloride treatment of uranium mill tailings and ore on radon emanation and 226Ra levels. Progress report

    International Nuclear Information System (INIS)

    Ibrahim, S.A.; Flot, S.L.

    1983-01-01

    The purpose of this study was to investigate the effect of barium chloride treatments on: reduction of 222 Rn emanation from mill wastes; reduction of 226 Ra levels in wastewater; and decreased leachability of 226 Ra from mill wastes. Baseline 226 Ra concentrations were determined for ore and tailings as well as radon emanation fractions. Uranium ore was treated with soluble barium at concentrations of 10, 25, 50, and 100 mg per litre of slurry. The leach-liquor declined in 226 Ra concentration by as much as 50%. When soluble potassium as well as barium was used in the treatment process at equal concentrations of 10, 25, 50, and 100 mg per litre of slurry, a similar reduction was observed. No significant difference was noted between the two treatment regimes. An accelerated leaching experiment was performed on the ore treated with barium chloride. All treatment groups except that treated with 10 mg of soluble barium per litre of slurry showed significant decreases in leachability. Available 222 Rn (corresponds with radon emanation fraction) was measured in treated and untreated ore. Ore treated with concentrations of Ba ++ up to 1.00 mg per gram of ore did not show a statistically significant reduction in available 222 Rn, however when potassium sulfate was also added, a significant decline was noted. This study suggests that barium chloride treatments reduce radon emanation from mill wastes and reduce 226 Ra levels in wastewater. Leachability of 226 Ra from treated samples decreased markedly. 19 references, 8 figures, 7 tables

  2. Recovery of uranium from alkaline ore (Tummalapalle) leach solution using novel precipitating method

    International Nuclear Information System (INIS)

    Biswas, Sujoy; Rupawate, V.H.; Hareendran, K.N.; Roy, S.B.; Chakravartty, J.K.

    2014-01-01

    The aim of present study is recovery of uranium from such ore leach solution containing 2 O 7 at pH ∼12.5. The average particle size of the MgU 2 O 7 particles was 20 micron and overall uranium recovery was 97%. The composition of final precipitate was characterized using XRD and surface morphology was studied using SEM

  3. Extraction of uranium from anomaly ores no 1,6,8 in salt domes of Bandar Abbas region using column leaching by seawater in sulfuric acid medium

    International Nuclear Information System (INIS)

    Fatemi, K.

    2003-01-01

    Column leaching is one of the experimental methods which is used for identifying the specifications of uranium ores. From the efficiency point of view, the process has some complications and usually it is applied in parallel with the conventional leaching process in order to facilitate of finding an appropriate design and operational method, to be applicable in an large practical scale. In this research work, at the first stage, the existed free chlorine in the samples was washed out using seawater. Then, in a process of acid leaching with seawater and sulfuric acid by the use of the column leaching was applied. The results show that the maximum of 85% of uranium from the ore of Anomali ≠1 is extracted. The extra residual of the used acid dose not react with the uranium and therefore it will increase the free acidity of the leach liquor. In Anomali ≠6, the extraction efficiency of uranium is 75%, while in Anomali ≠8, using 30 periods of leaching, the efficiency is 81%. However, the maximum efficiency achievement has to be avoided by the non-economical circumstances. Based on some comparisons, it is shown that the presence of chlorine in ore will affect the efficiency. The capability of s eawater i n uranium extraction from salted, compared with the n ormal or sweat water h as some advantages. These include: reduction of the operational period, less acid consumption, and reduction in the ore leaching costs. Thus, the heap leaching industry is believed to be a valuable and economical method for uranium extraction, where the needs of utilizing the complicated technical facilities can be reduced. The present work is the first research project on the uranium extraction and concentration in solution containing chlorine. Our experimental results can provide a valuable pattern for the heap leaching of uranium ores design from arches shaped in the region Bandar Abbas

  4. Deactivation and treatment of mine wastewaters and of aqueous solutions discharged in uranium ore treatment and processing

    International Nuclear Information System (INIS)

    Jilek, R.; Prochazka, H.; Fuska, J.; Nemec, P.; Katzer, J.

    1974-01-01

    A description is presented of decontamination and purification of mine wastewaters and water solutions discharged from uranium ore treatment and processing and of the simultaneous removal and concentration of uranium-radium daughters, mainly of 226 Ra and 210 Pb. These elements are incorporated in the mycelium of microorganisms, such as those of the Fungi imperfecti class or are sorbed on the mycelium surface. The mycelia are then mechanically separated from the decontaminated solution, e.g., by filtration, centrifugation or sedimentation. The mycelium may be cultivated in the purified solutions to which nutrients are added, such as carbon, nitrogen and phosphorus in concentrations necessary for the growth of the microorganisms used. The mycelium may be added to the purified solution either in the native or in the dried state. (B.S.)

  5. Uranium recovery from the concentrated phosphoric acid prepared by the hemi-hydrate process

    Energy Technology Data Exchange (ETDEWEB)

    Fouad, E A; Mahdy, M A; Bakr, M Y [Nuclear materials authority, Cairo, (Egypt); Zatout, A A [Faculty of engineering, Alex. university, Alex, (Egypt)

    1995-10-01

    It has been proved that the uranium dissolution from El-sebaiya phosphate ore was possible by using 10 Kg of K Cl O{sub 4}/ ton rock during the preparation of high strength phosphoric acid using the hemi hydrate process. In the present work, effective extraction of uranium (about 90%) from the high strength phosphoric acid using a new synergistic solvent mixture of 0.75 M D 2 EHPA/0.1 M TOHPO had been a success. Stripping of uranium from the organic phase was possible by 10 M phosphoric acid while the direct precipitation of uranium concentrate from the later was feasible by using N H{sub 4} F in presence of acetone. 8 figs.

  6. Uranium recovery from the concentrated phosphoric acid prepared by the hemi-hydrate process

    International Nuclear Information System (INIS)

    Fouad, E.A.; Mahdy, M.A.; Bakr, M.Y.; Zatout, A.A.

    1995-01-01

    It has been proved that the uranium dissolution from El-sebaiya phosphate ore was possible by using 10 Kg of K Cl O 4 / ton rock during the preparation of high strength phosphoric acid using the hemi hydrate process. In the present work, effective extraction of uranium (about 90%) from the high strength phosphoric acid using a new synergistic solvent mixture of 0.75 M D 2 EHPA/0.1 M TOHPO had been a success. Stripping of uranium from the organic phase was possible by 10 M phosphoric acid while the direct precipitation of uranium concentrate from the later was feasible by using N H 4 F in presence of acetone. 8 figs

  7. Treatment of uranium ores by natural leaching in Portugal; Traitement par lixiviation naturelle des minerais uraniferes portugais

    Energy Technology Data Exchange (ETDEWEB)

    Lacerda, J de [Junta de Energia Nuclear, Lisbonne (Portugal)

    1967-06-15

    The technique described for treating uranium ores by natural leaching has been developed as a result of research carried out in Portugal with a view to determining and eliminating the causes of uranium migration in ores stored in the open. With the natural leaching method, which has been successfully applied to primary uranium ores, the ore is piled up on a waterproof surface and sprayed intermittently with mine water. Pyrite and ferrous sulphate are used as solid reagents and are mixed with the ore in amounts averaging 0.4% and 0.2% respectively. Over 70 000 tons of ore with a U{sub 3}O{sub 8} content of between 0.076 and 0.150% have been treated at five natural leaching plants. The average recovery in these operations was between 57.7 and 85.9%. The average cost was US $3.31/lb U{sub 3}O{sub 8}. (author) [French] Le traitement des minerais uraniferes par lixiviation naturelle est le fruit des recherches effectuees au Portugal dans le but de determiner et d'eliminer les causes de la migration de l'uranium contenu dans les minerais emmagasines a ciel ouvert. La methode de lixiviation naturelle, appliquee avec succes aux mineraux primaires d'uranium, consiste essentiellement en l'arrosage intermittent, avec l'eau des mines, du minerai entasse sur des aires impermeabilisees. On utilise comme reactifs solides la pyrite et le sulfate ferreux melanges avec le minerai a raison de 0,4% et 0,2% respectivement en moyenne. Plus de 70 000 t de minerai, dont les teneurs en U{sub 3}O{sub 8} etaient comprises entre 0,076% et 0,150%, ont ete traitees dans cinq installations de lixiviation naturelle ou on a obtenu des recuperations moyennes oscillant entre 57,7% et 85,9%, pour le prix de revient moyen de 3,31 dollars par livre de U{sub 3}O{sub 8}. (author)

  8. Development of uranium industry in Romania

    International Nuclear Information System (INIS)

    Iuhas, Tiberiu

    2000-01-01

    The management of the uranium resources is performed in Romania by the National Uranium Company. The tasks to be done are: 1. management and protection of rare and radioactive metal ores in the exploitation areas; 2. mining, preparation, refining and trading the radioactive ores, as well as reprocessing the uranium stock from the uranium concentrate in the national reserve; 3. performing geologic and technologic studies in the exploitation areas; 4. performing studies and projects concerning the maintenance of the present facilities and unearthing new ores; 5. building industrial facilities; 6. carrying out technological transport; 7. importation-exportation operations; 8. performing micro-production activity in experimental research units; 9. personnel training; 10. medical assistance for the personnel; 11. environment protection. The company is organized as follows: 1.three branches for uranium ore mining, located at Suceava, Bihor and Banat; 2. one branch for geologic survey, located at Magurele; 3. one branch for uranium ore preparation and concentration and for refining uranium concentrates, located at Feldioara; 4. One group for mine conservation, closure and ecology, located at Bucuresti. The final product, sintered powder of UO 2 produced at Feldioara plant, was tested in 1994 by the Canadian partner and met successfully the required standards. The Feldioara plant was certified as supplier of raw material for CANDU nuclear fuel production and as such, Romania is the only authorized producer of CANDU nuclear fuel in Europe and the second in the world, after Canada. Maintaining the uranium production in Romania is justified by the existence of uranium ore resources, the declining of natural gas resources, lower costs per kWh for electric nuclear power as compared to fossil-fuel power production, the possibility for Romania to become an important supplier of CANDU nuclear fuel, the low environmental impact and high costs for total shutdown of activity, high

  9. Preconcentration of uranium ores by radio-metric sorting; Preconcentration des minerais d'uranium par triage radiometrique

    Energy Technology Data Exchange (ETDEWEB)

    Avril, R; Grenier, J [Commissariat a l' Energie Atomique, Fontenay-aux-Roses (France). Centre d' Etudes Nucleaires

    1964-07-01

    The uranium ore chemical treatment plant at Bessines-sur-Gartempe is supplied entirely by the La Crouzille Mining Division of the French Atomic Energy Commission mainly from mining districts of Fanay, Margnac and Le BRUGEAUD in the Limousin province and also, for the remainder, by a certain amount of private production in the 'Massif Central'. The supply mixture, which is very heterogeneous, is enriched before being treated chemically. The pre-concentration operation is carried out in the divisions ore treatment work-shop. It consists in a stone removal operation using radiometric sorting along a continuous belt; this makes it possible to eliminate 50 pour cent of the only fraction which is thus treated - that from 50 to 120 mm; it represents 15 to 20 per cent of the total tonnage supplied to the plant. (authors) [French] L'usine chimique de traitement des minerais d'uranium de Bessines-sur-Gartempe est entierement alimentee par la Division Miniere de La Crouzille, du Commissariat a l'Energie Atomique, principalement a partir des ensembles miniers limousins de Fanay, Margnac et du Brugenud et, pour le complement, par une certaine production privee en provenance du Massif Central. Le melange d'alimentation, tres heterogene, est enrichi avant d'etre livre a la chimie. L'operation de preconcentration est realisee dans l'atelier de preparation des minerais de la division. Il s'agit d'un epierrage par triage radiometrique sur bande, en continu, qui permet d'eliminer 50 pour cent de la seule fraction granulometrique qui le subit - le 50-120 mm - soit encore 15 a 20 pour cent du tonnage global d'alimentation livre a l'usine. (auteurs)

  10. On stages of hydrothermal mineralization of molybdenum-uranium ore manifestation in volcanic edifice

    International Nuclear Information System (INIS)

    Yakovlev, P.D.; Mamotin, S.A.

    1976-01-01

    Volcanogenic-intrusive complex of the ore manifestation region is represented by various facies of liparite and granitoid formation rocks. Numerous dislocations with breaks in continuity and the corresponding feathering fissures relate to 3 stages of hydrothermal mineralization of rocks. Quartz-sericite-kaolin metasomatites were formed at the earlier (volcanic) stage. Tourmalinization was associated with the middle stage which accompanied the granitoid intrusive formation. The later mineralization stage was accompanied by formation of beresites and molibdenum-uranium ores. Identification was controlled by the dislocation, ore bodies had the shape of lens, vein or small nest. 7 stages separated by shores were identified at the ore stage: quartz-sericite pyritic; quartz-pyrite-arsenopyritic; sulfide-pitchblendic; chalcedonic; ankeritic; quartz-calcitic and pyrite-ankeritic

  11. An instrument for rapid delineation of grade boundaries in selective mining of uranium ore

    International Nuclear Information System (INIS)

    Clark, G.J.; Dickson, B.L.; Meakins, R.L.; Kenny, D.; Talaska, A.

    1982-01-01

    A vehicle-mounted radiation detector interfaced to a microprocessor called PRAM (programmable radioactive analyser mobile) has been developed to provide grade control for selective mining of a soft rock uranium ore. The grade of ore over which the vehicle passes is determined and indicated by several coloured lights to a pegman who walks behind the vehicle. Coloured pegs are then laid out to mark the uranium grade ranges on the floor of the mine pit. Comparison between grade ranges determined by the PRAM and by prior drilling and downhole logging at the Yeelirrie deposit, Western Australia indicate good agreement. Use of the PRAM decreases the cost, manpower and time required to grade extensive areas of a mine pit floor

  12. Status report from South Africa [Processing of Low-Grade Uranium Ores

    Energy Technology Data Exchange (ETDEWEB)

    Robinson, R E [Atomic Energy Board, Pretoria (South Africa)

    1967-06-15

    Most of the research work on the processing of uranium ores in South Africa is being conducted by the Extraction Metallurgy Division of the S.A. Atomic Energy Board. Nevertheless, a considerable amount of applied research has been done by the different mining groups concerned with the operation of uranium plants, and also by the Transvaal and Orange Free State Chamber of Mines research laboratories. There is, however, very close collaboration between the various research groups and the Atomic Energy Board and the main research described is conducted on a collaborative basis.

  13. The chemical industry of uranium in France

    International Nuclear Information System (INIS)

    Goldschmidt, B.

    1955-01-01

    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.)

  14. An example of economical evaluation of stratiform uranium ore deposit

    International Nuclear Information System (INIS)

    Miyata, Hatsuho; Tabuchi, Akihiro; Ushijima, Kenichi.

    1992-01-01

    The Power Reactor and Nuclear Fuel Development corp. has carried out the business of uranium resource investigation and exploration in foreign countries aiming at securing uranium resources. If there is the possibility of economically developing the discovered uranium deposit, it is transferred to a Japanese private enterprise. In this paper, among the economical evaluation works that were carried out for the uranium deposits discovered by the Corp., the example of the initial economical evaluation for a stratiform uranium deposit carried out recently is reported. The deposit is located at the depth of 50 m - 70 m, and is a stratiform deposit having the extension of 4000 m x 1000 m. The boring investigation of about 350 holes was carried out for it. The estimation of the amount of uranium was done, and the production plan was made considering the scale of production, the characteristics of the ore, the circumstances of the site and so on. Based on the production plan, the initial expenses and the operation expenses were calculated. The design of the optimal pit which affects most the profitability and the economical evaluation were carried out. (K.I.)

  15. Geology and genesis of uranium deposits in sedimentary and metamorphic formation

    International Nuclear Information System (INIS)

    Danchev, V.I.; Belevtsev, Ya.N.

    1980-01-01

    Main genetic types of uranium deposits in sedimentary cover are described. Their genetic classification is based on the principle of conjugation of ore-forming process with the stages of lithogenesis of ore-enclosing rocks. Examples of poligeneity of uranium mineralization are presented. Texture-structural peculiarities of ores and types of ore-controlling zonality are considered as criteria of definite deposits belonging to various genetic classes. The analysis is given of main regularities of location of exogenous and poligenic uranium deposits. Processes of uranium ore-formation under the conditions of low and high degrees of metamorphism are considered. On the basis of separate types of deposits shown is the possibility of mobilization, transfer and concentration of ore substance, its transformation from primary to secondary forms. Metamorphous and ultrametamorphous deposits are formed as a result of ore element translocation within considerable distances under the effect of endogenous solutions and their concentration in favourable structures. Conclusions on the effect of lithogenesis and metamorphism processes on the ore formation are substantiated by field observations, analyses (including methods of isotopic geochemistry) as well as by experiments

  16. Hydrochemical uranium mining at the Straz ore deposit and its hydrogeological consequences

    International Nuclear Information System (INIS)

    Hanzlik, J.; Moravec, J.; Macak, P.

    1992-01-01

    The uranium ore deposit at Straz is situated in the North Bohemian Cretaceous Massif. Uranium is extracted from the deposit by underground chemical leaching by means of drills from the ground. Relevant to this kind of extraction, from the hydrogeological and environmental aspects, are the hydrogeological location of the deposit, the kind and amounts of the leaching solution and ways of its injection. The following amounts, in thousand tons, have been injected underground throughout the entire period of practicing chemical extraction of uranium (till 1990): sulfuric acid 3700, nitric acid 270, ammonia 100, hydrofluoric acid 25. The overall area of the leaching fields is 630 hectares, which accommodate 9300 technological boreholes. The environmental burden of the Cenomanian rocks and Turonian water reservoir was analyzed, and significantly elevated heavy metal contents from the recirculation of the technological solutions were found. The solutions expand beyond the leaching fields, causing a contamination of underground water within wider surroundings. The volume of contaminated water in the Turonian reservoir is currently estimated at 2 - 20 million m 3 . Uranium extraction by leaching is harmful at this deposit, having far-reaching impacts on the hydrosphere and ecosystem (increased dust, deforestation of slopes of the Ralsko hill, contamination of water and soil, etc.). Abandoning the ore extraction appears to be the sole feasible approach to this problem. (Z.S.). 2 tabs., 3 figs

  17. Direct separation of uranium and thorium from Qatrani phosphatic raw ore by consecutive percolation leaching

    Energy Technology Data Exchange (ETDEWEB)

    Hussein El-Sayed, M

    1984-07-01

    Phosphatic sandstone of Qatrani area contains high concentrations of uranium and thorium (1450 and 870 ppm respectively). These elements were directly separated from a representative sample of the ore by percolation leaching. Separation made was carried out by using two different leaching reagents, citric and nitric acids for obtaining two separate concentrates of U and Th consecutively from the sample. Uranium was leached first by using citric acid where other rock ingredients were left intact. The effects of: (a) increasing acid input amounts and (b) increasing leaching solution volumes (dilution) on U leaching efficiency were studied. The results revealed that citric acid reaction upon phosphate is limited in spite of higher residual acidity reported in the leach liquors. Regarding uranium, its leaching efficiency increased by increasing acid amounts and/or leaching solution volumes while fixing the acid input amounts. The efficiency of U leaching is more pronounced in the second case than in the first. Increasing U leaching while phosphate dissolution is limited could be interpreted as that the relative complexing affinity of citrate anion for hexavalent uranium is by far much greater than with phosphate. Thorium was thereafter leached by using dilute solutions of nitric acid to avoid dissolution of nitric acid to avoid dissolution of impurities. Percolation leaching experiments were thus performed on the uranium-free samples in the columns used previously in uranium leaching. The effects of increasing acid amounts and increasing leach liquor recycles on Th (and P/sub 2/O/sub 5/) leaching efficiency were studied.

  18. Sulphatising roasting of a Greenlandic uranium ore, reactivity of minerals and recovery

    International Nuclear Information System (INIS)

    Gamborg Hansen, J.K.

    1977-03-01

    Uranium in the lujavrite ore from Kvanefjeld, South Greenland, can be solubilised by sulphatising roasting at 700degC. The reactivity of various lujavrite minerals in the roasting process and the mechanism of the reaction were investigated by X-ray diffraction, optical microscopy, electron microprobe, thermal analysis, Moessbauer and infrared spectroscopy. Soluble sulphates are formed on the surface of the grains; an outer zone of the grains is transformed; usually a core remains unchanged. Variations in uranium recovery can be explained by variations in the contents of the uranium-bearing minerals, steenstrupine and uranium-containing pigmentary material (altered Zr containing silicate minerals), and in the degree of alteration os steenstrupine. Characterization of these minerals required many qualitative and a few quantitative electron microprobe analyses. (author)

  19. A new genetic interpretation for the Caotaobei uranium deposit associated with the shoshonitic volcanic rocks in the Hecaokeng ore field, southern Jiangxi, China

    Directory of Open Access Journals (Sweden)

    Dong-Sheng Yang

    2017-03-01

    Full Text Available Combined with in-situ laser ablation-inductively coupled plasma-mass spectrometry (LA-ICP-MS zircon UPb geochronology, published and unpublished literature on the Caotaobei uranium deposit in southern Jiangxi province, China, is re-examined to provide an improved understanding of the origin of the main ore (103 Ma. The Caotaobei deposit lies in the Hecaokeng ore field and is currently one of China's largest, volcanic-related uranium producers. Unlike commonly known volcanogenic uranium deposits throughout the world, it is spatially associated with intermediate lavas with a shoshonitic composition. Uranium mineralization (pitchblende occurs predominantly as veinlets, disseminations, and massive ores, hosted by the cryptoexplosive breccias rimming the Caotaobei crater. Zircons from one latite define four distinct 206Pb/238U age groups at 220–235 Ma (Triassic, 188 Ma (Early Jurassic, 131–137 Ma (Early Cretaceous, and 97–103 Ma (Early-Late Cretaceous transition, hereafter termed mid-Cretaceous. The integrated age (134 ± 2 Ma of Early Cretaceous zircons (group III is interpreted as representing the time of lava emplacement. The age data, together with the re-examination of literature, does not definitively support a volcanogenic origin for the generation of the deposit, which was proposed by the previous workers based mainly on the close spatial relationship and the age similarity between the main ore and volcanic lavas. Drill core and grade-control data reveal that rich concentrations of primary uranium ore are common around the granite porphyry dikes cutting the lavas, and that the cryptoexplosive breccias away from the dikes are barren or unmineralized. These observations indicate that the emplacement of the granite porphyries exerts a fundamental control on ore distribution and thus a genetic link exists between main-stage uranium mineralization and the intrusions of the dikes. Zircon overgrowths of mid-Cretaceous age (99.6

  20. Guidebook on design, construction and operation of pilot plants for uranium ore processing

    International Nuclear Information System (INIS)

    1990-01-01

    The design, construction and operation of a pilot plant are often important stages in the development of a project for the production of uranium concentrates. Since building and operating a pilot plant is very costly and may not always be required, it is important that such a plant be built only after several prerequisites have been met. The main purpose of this guidebook is to discuss the objectives of a pilot plant and its proper role in the overall project. Given the wide range of conditions under which a pilot plant may be designed and operated, it is not possible to provide specific details. Instead, this book discusses the rationale for a pilot plant and provides guidelines with suggested solutions for a variety of problems that may be encountered. This guidebook is part of a series of Technical Reports on uranium ore processing being prepared by the IAEA's Division of Nuclear Fuel Cycle and Waste Management. 42 refs, 7 figs, 3 tabs

  1. The Upper Permian sandstones of Mountains Mecsek: form elements of uranium ore mineralization and facies relations Pt. 2

    International Nuclear Information System (INIS)

    Vincze, Janos; Somogyi, Janos

    1984-01-01

    The ore mineralization in the Upper Permian sandstones of Mountais Mecsek, Hungary, was brought about at the oxidation-reduction front between the grey and red sandstones; the predominant rock colour here is green. The sandstones of different colour are oxidation-reduction species. The formation is a megacycle containing in its core grey sandstones of reduced state with coalified plant remains and in its mantle oxidized red sandstones. Uranium accumulates mainly in the transitional green facies. Uranium content gets enriched to a commercial concentration only if the difference in potential of neighbouring beds is in the range of 400-480 mV. The relationship between organic matter and uranium content in the individual facies is shown. The principles of oxidation-reduction processes in the formation of boundary facies are discussed. (V.N.)

  2. Hydrochloric acid leach of Agnew Lake uranium concentrate

    International Nuclear Information System (INIS)

    Haque, K.E.; Ipekoglue, B.

    1981-10-01

    Hydrochloric acid leaching was conducted on the radioactive mineral concentrate separated from the Agenw Lake uranium ore. Leach tests conducted at the optimum conditions (75 0 C; 36 hours; 66.0 Kg HCl/tonne; solid:liquid -1:1) resulted in the extraction of 87% uranium and 84% radium. The radionuclide level of the residue was U-0.016%, Th-0.24% and Ra-65 pCi/g solids. However to obtain a residue almost free of radium (i.e., Ra level at the detection limit: 4-6 pCi/g solids), the first stage leach residue was further treated with hydrochloric acid. The radium level in the best second stage leach residue was also above the target level. Therefore, multistage (3 or 4) hydrochloric acid and/or neutral chloride leaching is recommended to obtain tailings almost free of radionuclide

  3. Bioleaching of low grade uranium ore containing pyrite using A. ferrooxidans and A. thiooxidans

    International Nuclear Information System (INIS)

    Alexey Borisovich Umanskii; Anton Mihaylovich Klyushnikov

    2013-01-01

    A process of uranium extraction from ore containing 3.1 % pyrite by bacterial leaching was investigated in shaken flasks during 90 days. The highest uranium recovery amounting to 85.1 % was obtained using binary mixture of Acidithiobacillus ferrooxidans and Acidithiobacillus thiooxidans that was exceeding results obtained by traditional acid leaching technique up to 27 %. High uranium recovery was founded to be due to the high degree of pyrite dissolution that can be readily achieved by bacterial leaching (up to 98.0 %). (author)

  4. Separation of monazite from Rirang ore by floatation method

    International Nuclear Information System (INIS)

    Affandi, Kosim; Sjahminan, Mainar

    1995-01-01

    Separation of monazite from Rirang ore has been carried out by means of floatation using oleic acid and pine oil as promoter and frothier reagents, respectively. Several parameters affecting floatation process, i.e. grain size of the ore, pulp pH, and reagents concentration were examnined. The optimal conditions for the process include the use of -100 mesh feed ore, pulp pH 9.0 and 1 kilogram of each oleic acid and pine oil per tonne ore. Based on the conditions, monazite recovery of 90% was achieved with about 20% uranium remain in monazite concentrate. (author). 7 refs, 9tabs, 1 fig

  5. Significance of mineralogy in the development of flowsheets for processing uranium ores

    International Nuclear Information System (INIS)

    1980-01-01

    This report has been prepared from material developed at and subsequent to a consultants' meeting held in Vienna in January 1978. The main purpose of the meeting was to prepare a document in the form of a guide for planning and developing treatment flowsheets for uranium ore processing. It was apparent that ore mineralogy, analysed, described and interpreted in ways most meaningful to the metallurgist, is the most essential information required for forming the basis of such planning. This topic, here termed metallurgical mineralogy, is therefore a major theme of this publication. In preparing the report the Agency has borne in mind the important need to impart the experience and knowledge gained in the more developed countries to those who are in the early stages of exploiting their uranium resources. The contents may be criticized as lacking, in some respects, the requisite depth and detail of treatment. The Agency and the consultants are conscious of the need to expand the information in a number of ways. However, the report is presented in its present form in the belief that, as the first attempt to correlate, on a world-wide basis, ore type with processing, it will be considered as a useful basis for future development of these themes

  6. Thorium content of a mineral ore from Morro do Ferro by fission track technique

    International Nuclear Information System (INIS)

    Oliveira, C.A.N. de.

    1980-10-01

    The feasibility to determine thorium concentrations by fission track technique in samples of mineral ore has been demonstrated. The literature registers only the application of the fission track technique to mineral ore in the case where the fissionable element is uranium. The technique was applied to determine the thorium concentration of an ore sample from Morro do Ferro, taking advantage of the high thorium to uranium ratio in that mineral. The sample analysed presented a thorium concentration of 2467 +- 400 mg Th/Kg ore. The so called wet method was adopted by using the Bayer made Makrofol KG 10μm thick, as the detector foil, immersed in the thorium solution. The technique is also useful to determine thorium concentrations in environmental samples because of the following aspects: high sensitivity; fast chemical separation of interfering elements; low cost; and operational simplicity. (Author) [pt

  7. Determination of U (Ⅵ) content in uranium molybdenum ores

    International Nuclear Information System (INIS)

    Wang Haisheng; Ding Hongfang

    2014-01-01

    Potentionmetric titration is established to determine U (Ⅵ) in uranium molybdenum ores. In the closed condition, U (Ⅵ) is leached by carbonate solution. U (Ⅵ) is reduced to U (Ⅳ) by ferrous sulfate in phosphoric acid. The exess ferrous sulfate is oxidized by sodium nitrite. urea decompose the exess sodium nitrite. U (Ⅳ) is titrated by ammonium metavanadate standard solution with potentionmetric titration. The precision is better than 5%, The recovery rate is 97.2%∼101.9%. (authors)

  8. Analytical procedure for the radiometric determination of uranium in ores

    International Nuclear Information System (INIS)

    Bone, S.J.; Porritt, R.E.J.

    1976-06-01

    Two methods are described for the non-destructive determination of uranium in ores: a beta-gamma measuring method and a gamma-spectrometrical one. The first has the advantage that the analysis is not influenced by a radioactive unbalance in the sample (say by loss of radium as a result of chemical decomposition of the ores) and that it can be carried out with comparitively simple apparative expenditure. It is, however, relatively inaccurate (+-25%) and should only be used as a surveying method. The gamma-spectrometrical analysis (accuracy about +-10%) gives information about an unbalance present between U 238 and Ra 226 and thus enables an appropriate correction to be made. A thorium contribution with its decay products can also be corrected. (RB) [de

  9. Use of low-cost heat sources to improve the efficiency of heap leaching of uranium ores. Part of a coordinated programme on bacterial leaching of uranium ores

    International Nuclear Information System (INIS)

    Ajuria, S.

    1977-12-01

    Basic technical parameters are given of two solar heaters designed for use in heap leaching of uranium ores. Inexpensive and easily available materials such as flat glass panes, glass tubing and corrugated metal sheets were used in the construction of the heaters. Under optimum conditions, the heaters can produce temperature differentials of 52 0 C (50 0 C) at the flow rate of 30ml/min. The dependence of percent recovery on the temperature of solutions in heap leaching of ore from 'El Nopal' was studied. Even though no precise correlation was found, an increase in the temperature of solutions seems to improve the efficiency of heap leaching

  10. Developments of bacteria leaching technologies in uranium and gold ores at home and abroad

    International Nuclear Information System (INIS)

    Gao Renxi; Guan Zibin; Tian Shengjun

    2000-01-01

    The present development, including development of new leaching processes and equipment and soon, in bacteria leaching of uranium and gold ores at home and abroad are described. Opinions and advices are presented

  11. Analysis on hydrological condition for uranium ore formation in Wuerhe district, Junggar Basin

    International Nuclear Information System (INIS)

    Zhang Quanqing; Zhang Xinke; Ren Manchuan

    2009-01-01

    Wuerhe district is located in the northwestern part of Junggar Basin, Xinjiang. It belongs to a relative quiet area without the obvious tectonic activities and obvious subsequent tectonic activization. Through the regional uranium resources evaluation on this area, the inter-bedded oxidation zone and uranium mineralization are discovered in Cretaceous. The wall rock, the recharge-runoff-discharge mechanism of groundwater, palaeo-hydrological condition, hydrological and hydrogeochemical features of groundwater are introduced briefly, the favorable uranium ore-forming segment is summarized to be located in the fore-mountain area to the west of Ke-Xia fault terrace zone. (authors)

  12. Application of dual-wavelength spectrophotometry to the uranium ore analysis

    International Nuclear Information System (INIS)

    Jin Wenlong; Yao Mingxia; Yin Zinan; Guo Hancheng.

    1988-03-01

    In the buffer solution (pH 2.2) with citric acid and sodium hydrogen phosphate, the uranium in ores can be directly determined with arsenazo III by dual-wavelength spectrophotometric method when Triethylenetetraminehexaacetic acid, diethylenetriaminepentaacetic acid and maleic acid are added as masking agents. The measuring wavelength and referential wavelength are 653.0 nm and 607.5 nm respectively. The interference of calcium can be fully eliminated because of its equivalent absorbance at these two wavelengths. The method is simple and rapid. The coefficient of variation (n=5) is less than 5% for 0.06% ∼ 0.5% of uranium in five certified reference materials. The values obtained for U agree with the certified values

  13. Chloride pyrometallurgy of uranium ore. 2. Selective extraction of uranium using the mixed gas of chlorine and oxygen in the presence of activated carbon

    International Nuclear Information System (INIS)

    Taki, Tomihiro; Komoto, Shigetoshi; Otomura, Keiichiro; Takenaka, Toshihide; Sato, Nobuaki; Fujino, Takeo.

    1996-01-01

    Selective extraction of uranium from a phosphate ore was studied by using the mixed gas of Cl 2 and O 2 . On heating the ore and carbon mixture in Cl 2 , the volatilized chloride of uranium is accompanied by iron, aluminum, phosphorus and silicon chlorides. The addition of O 2 gas effectively lowered the volatilization ratios of aluminum, phosphorus and silicon. The ratio decreased with increasing oxygen flow rate up to 50 ml/min at 1,223 K (Cl 2 : 100 ml/min, O 2 +N 2 : 400 ml/min). The volatilization ratio of uranium was almost unchanged at 90% up to 50 ml/min O 2 (carbon amount: 15 wt%). The effect of the other parameters, i.e. Cl 2 flow rate, carbon amount, reaction temperature and time was examined. (author)

  14. Difference of ore-bearing and non-ore-bearing pegmatite in the Guangshigou area and its research significance

    International Nuclear Information System (INIS)

    Zuo Wenqian; Zhang Zhanshi; Sha Yazhou; Rao Chaojun

    2011-01-01

    Guangshigou uranium deposit is one of the typical granite-pegmatite uranium deposits in China, the ore-body are located in the density zone of the outside contact zone of granite pluton. To distinguish the ore-bearing and Non-ore-bearing pegmatite is one of the most practices and have great significance for the effect of mineral exploration. Based on the field investigation and former research results, contrast research on the characteristics of the pegmatite on petrology, geophysical, geochemistry and stable isotopes have been carried out. It is pointed out that the ore-bearing pegmatite differ from the non-ore-bearing one from macro-and-micro-view in Guangshigou Uranium deposits, the main characteristics are summarized; the macro-and-micro signs are established, the genetic difference between the ore-bearing and non-ore-bearing pegmatite are discussed primarily. The achievements would be helpful for prospecting and researching of this type uranium deposits in China. (authors)

  15. Prediction of ore fluid metal concentrations from solid solution concentrations in ore-stage calcite: Application to the Illinois-Kentucky and Central Tennessee Mississippi Valley-type districts

    Science.gov (United States)

    Smith-Schmitz, Sarah E.; Appold, Martin S.

    2018-03-01

    Knowledge of the concentrations of Zn and Pb in Mississippi Valley-type (MVT) ore fluids is fundamental to understanding MVT deposit origin. Most previous attempts to quantify the concentrations of Zn and Pb in MVT ore fluids have focused on the analysis of fluid inclusions. However, these attempts have yielded ambiguous results due to possible contamination from secondary fluid inclusions, interferences from Zn and Pb in the host mineral matrix, and uncertainties about whether the measured Zn and Pb signals represent aqueous solute or accidental solid inclusions entrained within the fluid inclusions. The purpose of the present study, therefore, was to try to determine Zn and Pb concentrations in MVT ore fluids using an alternate method that avoids these ambiguities by calculating Zn and Pb concentrations in MVT ore fluids theoretically based on their solid solution concentrations in calcite. This method was applied to the Illinois-Kentucky and Central Tennessee districts, which both contain ore-stage calcite. Experimental partition coefficient (D) values from Rimstidt et al. (1998) and Tsusue and Holland (1966), and theoretical thermodynamic distribution coefficient (KD) values were employed in the present study. Ore fluid concentrations of Zn were likely most accurately predicted by Rimstidt et al. (1998) D values, based on their success in predicting known fluid inclusion concentrations of Mg and Mn, and likely also most accurately predicted ore fluid concentrations of Fe. All four of these elements have a divalent ionic radius smaller than that of Ca2+ and form carbonate minerals with the calcite structure. For both the Illinois-Kentucky and the Central Tennessee district, predicted ore fluid Zn and Fe concentrations were on the order of up to 10's of ppm. Ore fluid concentrations of Pb could only be predicted using Rimstidt et al. (1998) D values. However, these concentrations are unlikely to be reliable, as predicted ore fluid concentrations of Sr and Ba

  16. Occupational diseases in uranium and ore miners, related to the radiation exposure in Czech Republic, in 2003-2013

    International Nuclear Information System (INIS)

    Mueller, T.

    2014-01-01

    Dozens cases of disease of former or present uranium and ore miners are submitted to judgment as occupational diseases every year in the Czech Republic. Patients or attending physicians suggest that these cases are caused by occupational ionizing radiation. Only a part of these cases is qualified as occupational disease. The term 'occupational disease' is rather juridical term which underlies the right to financial compensation. The causal association with exposure to ionizing radiation cannot be indisputably verified by expert medical opinion. Most diseases in uranium and ore miners, which are proposed as occupational disease, are malignant tumors. The majority of judged cases are lung cancers from radioactive agents. The lecture gives general information about all judged cases of occupational diseases in former uranium and ore miners in the Czech Republic in the years 2002 - 2013. In the period 2002-13 were 40-80 cases submitted to judgment as potential occupational disease every year. (authors)

  17. Current uranium activities in Pakistan

    International Nuclear Information System (INIS)

    Moghal, M.Y.

    2001-01-01

    The rocks of Siwaliks group in Pakistan, extending from Kashmir in the east through Potwar Plateau, Bannu Basin and Sulaiman range up to the Arabian Sea in the west have been extensively explored for uranium. The Dhok Pathan Formation, which is younger member of the middle Siwaliks has been aeroradiometrically surveyed and extensively prospected on foot. A large number of anomalies were encountered in Kashmir, Potwar Plateau, Bannu Basin and Sulaiman range. While exploratory work in Sulaiman range and Bannu Basin yielded a few workable deposits, none of the anomalous areas yielded an ore grade concentration in Potwar Plateau. As conventional exploration activities in Potwar Plateau did not yield any ore grade concentration therefore a resource potential evaluation programme through geological modeling was started under the guidance of an IAEA expert. The volcanic material found in the middle Siwaliks is considered to be the main source of uranium and siliceous cement in the sandstones. These findings have considerably increased uranium potential in Siwaliks. The tectonic deformation during and after the deposition of Siwaliks is considered to be the main reason for mobilization of uranium, while permeability barriers and upward movement of oil products may provide trappings for the mobilized uranium. Through this survey south western part of Potwar Plateau being relatively less deformed is considered to provide conducive environments for concentration of uranium. Low grade uranium concentrations have also been discovered in carbonatites in northern part of Pakistan. Preliminary exploration in Sallai Patti carbonatite through drilling supplemented by trenching, pitting and aditing, subsurface continuation of surface concentrations has been confirmed. The ore contains about 200 ppm of uranium and 3 to 4% phosphate in addition to magnetite, rare metals and rare earths. It has been demonstrated on laboratory/pilot scale that the concentrations of uranium and phosphate

  18. Two cases of physical treatment of uranium ore; Deux cas de traitement physique de minerai d'uranium

    Energy Technology Data Exchange (ETDEWEB)

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

    1955-07-01

    Until now, all uranium deposits exploited in France are vein type and present a very big variety of mineralization and structure. The process of concentration of these ores requires a study for each of them and, in a lot of cases, only the chemical attack can solve the problem. However, the flotation succeeded to results permitting a very interesting enrichment with lower investments expenses and cost prices. Enrichment by flotation would be foreseeable for poor layers and weak tonnage, permitting to absorb facilities on tonnages three times less important than the acidic treatment, or, to equality of cost price, to treat ores having contents of 2,5 to 4 times weaker. (M.B.) [French] Jusqu'ici, tous les gisements uraniferes exploites en France sont du type filonien et presentent une tres grande variete de mineralisation et de structure. Le procede de concentration de ces minerais necessite une etude pour chacun d'eux et, dans bien des cas, seule l'attaque chimique peut resoudre le probleme. Toutefois, la flottation a abouti a des resultats permettant un enrichissement tres interessant avec les depenses d'investissements et des prix de revient beaucoup plus bas. Un enrichissement par flottation serait envisageable pour des gisements pauvres et de faible tonnage, permettant d'amortir les installations sur des tonnages trois fois moins importants que le traitement acide, ou encore, a egalite de prix de revient, de traiter des minerais ayant des teneurs de 2,5 a 4 fois plus faibles. (M.B.)

  19. Mechanism of near-fault ore deposition in stratal infiltration uranium deposits

    International Nuclear Information System (INIS)

    Belova, L.L.; Krichevets, G.N.; Shmariovich, E.M.; Salmin, Yu.P.; Tatarkin, M.A.

    1986-01-01

    The authors have examined the conditions for the formation of uranium ores associated with faults, which constitute a distinct type at various deposits associated with stratal zones of limonitization. Mathematical and experimental models were devised in which uranium-bearing oxidizing fluids and H 2 S-bearing reducing fluids interact in porous media. The algorithm used incorporated the hydrodynamics, the dispersal, and as far as possible also the thermodynamics and kinetics. This combined approach enabled them to examine not only the final result but also the intermediate stages, which are time- and space-dependent. The authors have found that the models reproduce zoning pattern found in natural uranium deposits. The paper describes the algorithm, discusses the results of mathematical modeling, and compares the results of mathematical and physical modeling. 16 references, 3 figures

  20. Radioactive equilibrium of uranium-bearing ores in some problems of applied geology

    International Nuclear Information System (INIS)

    Coulomb, R.; Girard, Ph.; Goldsztein, M.

    1964-01-01

    The state of equilibrium between several nuclides in radioactive relationship is determined with accuracy by the fundamental equations of radioactivity. It can be measured physically and expressed in suitable and internationally adopted units; Equilibrium - disequilibrium of uranium-bearing ores is a fairly complex phenomenon but the problem can be much simplified by well-chosen approximations in various practical field cases. The results of radiometric and radiochemical measurements lead to the interpretation of geochemical anomalies and may be used in the qualitative and quantitative estimation of uranium bearing deposits. (authors) [fr

  1. Problems of developing remedial strategy for the uranium ore processing legacy site Pridneprovsky Chemical Plant site (Dneprodzerginsk, Ukraine)

    International Nuclear Information System (INIS)

    Riazantsev, V.; Bugai, D.; Skalskyy, A.; Tkachenko, E.

    2014-01-01

    In this paper we present results of works and studies carried out in the frame of ongoing national and international projects aimed at developing the remedial strategy for the Soviet era legacy uranium production site Pridneprovsky Chemical Plant, Dneprodzerginsk, Ukraine. The site includes several uranium mill tailings, contaminated buildings, ore storage grounds and other contaminated facilities. Taking into account the necessity to implement provisions of the new IAEA standards (Radiation Protection and Safety of Radiation Sources: International Basic Safety Standards, No. GSR Part 3 (Interim) and others) as well as the provisions of the ICRP 103 publication, the State Nuclear Regulatory Inspectorate Ukraine developed the draft of the new licensing requirements for activities of uranium ores processing.

  2. Analytical method of uranium (IV) and uranium (VI) in uranium ores and uranium-bearing rocks

    International Nuclear Information System (INIS)

    Shen Zhuqin; Zheng Yongfeng; Li Qingzhen; Zhong Miaolan; Gu Dingxiang

    1995-11-01

    The best conditions for keeping the original valences of uranium during the dissolution and separation procedure of geological samples (especially those micro uranium-bearing rock) were studied. With the exist of high concentration protectants, the sample was decomposed with concentration HF at 40 +- 5 degree C. The U(VI) was dissolved completely and formed stable complex UO 2 F 2 , the U(IV) was precipitated rapidly and carried by carrier. Quantitative separation was carried out immediately with suction. The decomposition of sample and separation of solid/liquid phases was completed within two minutes. After separation, the U(IV) and U(VI) were determined quantitatively with laser fluorescence or voltametry respectively according to the uranium content. The limit of detection for this method is 0.7 μg/g, RSD is 10.5%, the determinate range of uranium is 2 x 10 -6 ∼10 -1 g/g. The uranium contents and their valence state ratio were measured for more than one hundred samples of sand stone and granite, the accuracy and precision of these results are satisfactory for uranium geological research. (12 tabs.; 11 refs.)

  3. Role of oxidizing agent in the chemistry of in-situ uranium leaching

    International Nuclear Information System (INIS)

    Carlson, R.H.; Norris, R.D.; Schellinger, R.

    1982-01-01

    Synthetic two-component mixtures (uraninite and iron sulfide) as well as native uranium ores obtained from Texas and Wyoming have been examined. Physical/chemical ore properties are correlated with observed laboratory leach response. Data show a large inherent selectivity of oxidant for uranium in the early stages of a leach period. Uranium head grade was found to increase in a nearly linear fashion with hydrogen peroxide concentration in the leach solution. As uranium in the ore is depleted, uranium response decreases and the oxidant serves mainly to leach iron sulfide gangue material. 6 refs

  4. Underground leaching - A method for the economic extraction of uranium from low-grade ores; Podzemnoe vyshchelachivanie - sposob ehkonomicheskogo izvlecheniya urana iz bednykh rud

    Energy Technology Data Exchange (ETDEWEB)

    Zefirov, A P [Gosudarstvennyj Komitet po Ispol' zovaniyu Atomnoj EHnergii SSSR, Moskva, Union of Soviet Socialist Republics (Russian Federation)

    1967-06-15

    The method of underground leaching of uranium ores has a number of advantages over extraction followed by processing of the ores in factories. It has been studied in two types of deposit, occurring in rock masses and sandy shales. Research techniques were worked out accordingly for the leaching of uranium from large-grained ore (-200 mm) and from layers in natural stratification. Special models were constructed permitting the simulation of underground leaching conditions. The results obtained were checked in field conditions on experimental plots and experimental underground blocks. The investigations demonstrated the practicability of the process of underground leaching of uranium from certain ores and made it possible to work out flow-sheets and routines for an industrial process, information about which is given in the paper. (author)

  5. Sedimentary rocks Uranium in Cerro Largo Province; Uranio en rocas sedimentarias en el departamento de Cerro Largo

    Energy Technology Data Exchange (ETDEWEB)

    Scaron, P; Garau Tous, M

    1976-07-01

    With the aim of the uranium minerals exploration has been carried out several studies by UTE technicians in Cerro Largo Province from 1968 to 1969. In uranium concentration has been found pyrite, phosphate, iron oxides and manganese in uranium. Furthermore in La Divisa Ore were studied concentration Uranium enrichment has been studied in La Divisa ore.

  6. Impact Of Low Grade Uranium Ores On The Echo System and the Workers of Phosphate Industry

    International Nuclear Information System (INIS)

    Anwar, S.M.

    1999-01-01

    The present study aims to investigate the influence of uranium present in phosphate rocks as an environmental factor in the ccho system and on the workers of Abu-Zaabal Phosphate Company subjected to the inhalation of big quantities of rock phosphate dust during the benefication of the ore and the production of the fertilizers. Besides. extra amount of uranium reach the workers also through two path ways.The first is direct through eating contaminated planted grown in the near by area.The second is indirect through eating animals fed with contaminated plants. The uranium content is estimated in the soil samples at different depths, water (irrigation and drainage), air samples and plant samples (shoot and root) in Berseem from the four directions, urine samples from twenty workers in charge of the processing of phosphate compared to twenty volunteers far from the contaminated area.The results showed an elevated values for phosphorus and uranium in the air, water. soil and plant (Berseem) around Abu Zaabal Factory and extending to about 2 km from all directions. Urine may be considered as a biological indicator medium for the uptake of uranium in uranium miners and the workers in charge of ore processing and can represent the major route of excretion for the absorbed metal. Significant differences were shown between the uranium level in the urine of workers group and the control group

  7. Guidebook on the development of projects for uranium mining and ore processing

    International Nuclear Information System (INIS)

    1991-04-01

    Bringing a uranium operation into production involves a sequence of interrelated steps. These are outlined in the simplified diagram of Fig. 1. The challenge is to determine how the various steps of the development sequence should function and whether the costs are sufficiently low to return a positive benefit to the owner. This Guidebook has been prepared to aid in the planning, development and implementation of feasible uranium projects. It is one in a series of publications by the IAEA. This guidebook is essentially the executive summary of the other publications. It is an overview of the systematic approach to project development. It might be viewed as the ''road map'' of a project. A list of other publications in this series is provided in the Bibliography. Each chapter of the Guidebook addresses a critical aspect of project development. Chapters follow a general sequence, but none should be considered in isolation. Each Chapter presents an overview of the requirements for reaching decisions necessary to advance a project. References are provided to more definitive information and to documents which will be required by technical personnel on a project. Such detailed publications include IAEA books such as ''An Instruction Manual on Methods for Estimation of Uranium Ore Reserves'', and the ''Significance of Mineralogy in the Development of Flow Sheets for Processing Uranium Ores''. This Guidebook does not detail how to do project development but rather what must be done to insure that all critical elements of a project are considered. Refs, figs and tabs

  8. Shutdown and cleanup of the East German uranium ore mining industry

    International Nuclear Information System (INIS)

    Runge, W.; Boettcher, J.

    1994-01-01

    In late 1991, the company was changed from SDAG Wismut into a private company (GmbH under German law) with the sole purpose of cleaning up the decommissioned uranium ore mining and dressing plants in such a way that pollutants, contaminated soil, water and air, and other damage to the environment will be removed both from the plant premises and from associated real estate. (orig./HP) [de

  9. Geological-economic analysis on the exploration of backup resources for depleted mines in Lujing uranium ore-field, central-southern China

    International Nuclear Information System (INIS)

    Li Deping; Wang Zhicheng; Fan Shaoyun

    2006-01-01

    With the geological-economic evaluation program for pithead heap-leaching mining uranium deposits developed by the authors and the data of column-leaching tests and the geological reserve, the geological-economic evaluation is made to the residual geological reserves of both Lujing and Huangfengling deposit, and the geological reserves of Yangjiaonao deposit of the depleted mines in Lujing uranium ore-field, central-southern China. The results of static analysis on these reserves show that the residual geological reserves of both Lujing and Huangfengling deposit belong to sub-profitable type, but the ones of Yangjiaonao deposit is profitable with 26.56% tax-before profit. 1 tU profitable type of ore from Yangjiaonao deposit can use 2.40-3.79 tU subprofitable type of ores from Lujing and Huangfengling deposit. In order to solving the problem on scarcity of backup resources of the depleted mines in Lujing uranium ore-field and using the existing sub-profitable type of geological reserves, it is suggested that the high grade of profitable type of deposits should be explored around the exhausting mines so that the production of the mines could be profitable by the pithead heap-leaching mining method with arrangement groups of both sub-profitable and profitable type of ores. (authors)

  10. A new type on line fast analysis instrument of uranium ore grade

    International Nuclear Information System (INIS)

    Guo Maojin.

    1992-01-01

    The instrument is used to analyse the average grade of uranium ore on the belt. Its average analysis speed is about 300 t/h. The physical mechanism of measurement, characteristics, principle of operation and applications in several years are described. The CMOS LSI IC are adopted. The stability, reliability and anti-interference ability are very good

  11. Statistical data of the uranium industry

    International Nuclear Information System (INIS)

    1976-01-01

    Historical facts and figures of the uranium industry through 1975 are compiled. Areas covered are ore and concentrate purchases; uranium resources; distribution of $10, $15, and $30 reserves; drilling statistics; uranium exploration expenditures; land holdings for uranium mining and exploration; employment; commercial U 3 O 8 sales and requirements; and processing mills

  12. Expansion of the ore treatment plant at Ranger Uranium Mines at Jabiru, NT Australia

    International Nuclear Information System (INIS)

    Nice, R.W.; Banaczkowski, M.

    2000-01-01

    The Ranger Uranium Mine commenced processing ore in 1980. The original plant designed by the joint venture between Davy and Wright Engineers had been designed to treat 1.3 Mtpa of ore to produce 3500 tpa of U 3 O 8 concentrates. The plant operated successfully through good and bad years until the 1995 when the owners of Energy Resources of Australia, North Ltd. (70%) decided that there was a market opening to allow expansion of the treatment plant such that it would produce 6000 tpa of concentrate.The desire to produce more concentrates was market driven but the change from the mine Ranger 1 to a new pit Ranger 3 also necessitated the inclusion of the ability to treat more ore. This involved the installation of more grinding and CCD washing capacity. There were some other changes that were to be included into the expansion to overcome operating deficiencies, reduce operating costs and to generally make the operation easier.The Australian engineering company, Kvaerner Davy, was commissioned to provide the EPCM services to the clients, North and the Ranger Operation Group. North Technical Services managed the Project with considerable input from the site operating and maintenance personnel. The site operating personnel commissioned the plant and are successfully operating it at the time of the preparation of this paper. The first part of this paper presents the basic process related activities required to provide the expanded facilities. This includes the flowsheet modifications, equipment changes and new equipment procured. Additionally, a discussion is given regarding the P and ID changes, the piping modifications and the means to install the expanded facilities with a minimum of interruption to the continuing plant operation. A second part of the paper details some of the experiences gained while constructing the expansion and commissioning and operating the expanded plant. (author)

  13. Extraction and analysis of reducing alteration information of oil-gas in Bashibulake uranium ore district based on ASTER remote sensing data

    International Nuclear Information System (INIS)

    Ye Fawang; Liu Dechang; Zhao Yingjun; Yang Xu

    2008-01-01

    Beginning with the analysis of the spectral characteristics of sandstone with reducing alteration of oil-gas in Bashibulake ore district, the extract technology of reducing alteration information based on ASTER data is presented. Several remote sensing anomaly zones of reducing alteration information similar with that in uranium deposit are interpreted in study area. On the basis of above study, these alteration anomaly information are further classified by using the advantage of ASTER data with multi-band in SWIR, the geological significance for alteration anomaly information is respectively discussed. As a result, alteration anomalies good for uranium prospecting are really selected, which provides some important information for uranium exploration in outland of Bashibulake uranium ore area. (authors)

  14. Problems in the separation of radium from uranium ore tailings

    Energy Technology Data Exchange (ETDEWEB)

    Seeley, F.G.

    1976-01-01

    The radium content of a representative sandstone type of uranium ore was found to be distributed uniformly according to particle size before leaching, but in sulfuric acid-leached tailings was found predominantly in the -325 mesh fraction. The radium leaching characteristics from both ore and sulfate-leached tailings were investigated. Several 1 M salt solutions showed poor to moderate RaSO/sub 4/ dissolution from ''slimes solids'' tailings, while 3 M HNO/sub 3/ or HCl solutions dissolved approximately 95% of the radium content of either ore or tailings. Tests are reported in which -325 mesh sand particles were coated with alkaline-earth sulfates by a special technique to simulate slime solids tailings. The dissolution of RaSO/sub 4/ from these coated sands was decreased by the presence of BaSO/sub 4/, but increased by the presence of CaSO/sub 4/. The interrelationships in the dissolution of mixtures of CaSO/sub 5/, SrSO/sub 4/, BaSO/sub 4/, and RaSO/sub 4/ are shown, and a generalized equation for the estimation of the dissolution of a minor component is presented.

  15. Non-neoplastic pulmonary disease from inhaled radon daughters with uranium ore dust in beagle dogs

    International Nuclear Information System (INIS)

    Filipy, R.E.; Palmer, R.F.; Stuart, B.O.

    1977-01-01

    Daily exposures of adult beagle dogs to inhaled radon daughters plus uranium ore dust, with and without concurrent cigarette smoking, for 2 to 5-1/2 yr have produced massive pulmonary fibrosis and severe emphysema. The cumulative exposure doses are similar to those associated with a 5-fold or greater increase in death rate of uranium miners due to chronic respiratory insufficiency, including pneumoconiosis, pulmonary fibrosis, and emphysema

  16. An innovative jet boring mining method available for the high grade uranium ore underground deposits

    International Nuclear Information System (INIS)

    Narcy, J.L.

    1996-01-01

    An innovative mining method, based on the capability of a high pressure water jet to desaggregate rock, has been conceived and tested with success at the highest grade uranium ore deposit in the world, the Cigar Lake deposit in Saskatchewan, Canada. 113 tonnes of ore at 13% U were mined out by a new jet-boring mining method operated on a semi-industrial basis, in 1992 during the test mining program of Cigar Lake Project. (author). 9 figs

  17. Formation of neogenic ores on the dump-heaps of old uranium mines and on the mine-head of mines under exploitation; Formation de mineraux neogenes sur les haldes d'anciennes mines d'uranium et sur le carreau des mines en exploitation

    Energy Technology Data Exchange (ETDEWEB)

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

    1960-07-01

    The aim of this preliminary study is to assess straight away the major degradations suffered by primary and secondary uranium ores under the weathering action of air and water. The uranium ores concerned in this case are those stored in the open air. The pyritic ores are the most vulnerable: the interactions between the pyrite, or rather its oxidation products, and the uraniferous compounds are liable to lead to the formation of neogenic ores, which are of considerable importance in the natural lixiviation of uranium ore stocks. (author) [French] Cette etude preliminaire a pour but de fixer des a present les degradations majeures que subissent les mineraux d'uranium primaires et secondaires, sous l'action de l'air et des eaux meteoriques. Il s'agit en l'occurence des mineraux d'uranium constituant les minerais entreposes a l'air libre. Les minerais pyriteux sont les plus vulnerables: les interactions entre la pyrite ou plutot de ses produits d'oxydation avec les composes uraniferes sont susceptibles de former des mineraux neogenes dont l'importance est considerable dans la lixiviation naturelle des stocks de minerais d'uranium. (auteur)

  18. Uranium Chemical and Radiological Risk Assessment for Freshwater Ecosystems Receiving Ore Mining Releases: Principles, Equations and Parameters

    International Nuclear Information System (INIS)

    Beaugelin-Seiller, K.; Garnier-Laplace, J.; Gilbin, R.; Adam, C.

    2008-01-01

    Uranium is an element that has the solely characteristic to behave as significant hazard both from a chemical and radiological point of view. Exclusively of natural occurrence, its distribution into the environment may be influenced by human activities, such as nuclear fuel cycle, military use of depleted uranium, or coal and phosphate fertilizer use, which finally may impact freshwater ecosystems. Until now, the associated environmental impact and risk assessments were conducted separately. We propose here to apply the same methodology to evaluate the ecological risk due to potential chemotoxicity and radiotoxicity of uranium. This methodology is articulated into the classical four steps (EC, 2003: problem formulation, effect and exposure analysis, risk characterisation). The problem formulation dealt both with uranium viewed as a chemical element and as the three isotopes 234, 235 and 238 of uranium and their main daughters. Then, the exposure analysis of non-human species was led on the basis of a common conceptual model of the fluxes occurring in freshwater ecosystems. No-effect values for the ecosystem were derived using the same effect data treatment in parallel. A Species Sensitivity Distribution was fitted: (1) to the ecotoxicity data sets illustrating uranium chemotoxicity and allowing the estimation of a Predicted-No-Effect-Concentration for uranium in water expressed in μg/L; (2) to radiotoxicity effect data as it was done within the ERICA project, allowing the estimation of a Predicted No-Effect-Dose-Rate (in μGy·h -1 ). Two methods were then applied to characterize the risk to the ecosystem: a screening method using the risk quotient approach, involving for the radiological aspect back calculation of the water limiting concentration from the PNEDR for each isotope taken into account and a probabilistic risk assessment. A former uranium ore mining case-study will help in demonstrating the application of the whole methodology

  19. Study of a proposed method of uranium concentration determination using low-energy γ-ray spectroscopy

    International Nuclear Information System (INIS)

    Rossiter, K.G.; Tang, J.C.N.

    1980-01-01

    The problems associated with in-situ uranium assaying are discussed, especially in relation to the secular disequilibrium between the parent uranium and its radioactive daughters. A detailed study of the gamma-spectra of some natural uranium bearing ore and mineral samples was performed using a high resolution Ge(Li) detector. A method of spectroscopic analysis of the low energy gamma-rays of U-238 and its daughter Th-234, using a proportional counter and a series of Ross filters, was found to be feasible. The application of such a method to uranium assaying in natural ore bodies is discussed

  20. Installation of Radiometric Sorting throughout the Cogema-Simo Mining Complex at Lodeve. [Uranium ores

    Energy Technology Data Exchange (ETDEWEB)

    Grenier, J.; Winter, J.M.; Deville, P.

    1986-06-01

    The ores of Lodeve present no physical characteristics which permit an elimination of the lowest grade fractions, with the exception of the radioactivity and the radium which accompanies the uranium. The mine therefore turned to radiometric pebble-by-pebble sorting on a machine model M 17 of Ore Sorters who have a monopoly of this type of equipment; this permits an operation over a size range from 25 to 160 mm. Sampling of the deposit investigation of pebble samples, construction of the sorting plant and commissioning are described.

  1. Tectonic regime and evolution of exogenous uranium ore formation in sedimentary rocks

    International Nuclear Information System (INIS)

    Danchev, V.I.; Shumlyanskij, V.A.; AN Ukrainskoj SSR, Kiev. Inst. Geokhimii i Fiziki Mineralov)

    1981-01-01

    Regularities of the formation and location of exogenous uranium deposits are studied depending on the tectonics regime. It is shown that the successive alternation of sedimentogenous deposits by diagenetic and, subsequently, catogene ones takes place from early Proterozoic to Cenozoic, i.e. exogenous ore formation in the history of the Earth proceeds from early to late stages of lithogenesis [ru

  2. The basement control on Xiazhuang uranium ore field in south sector of Wuyi tumescence and relevant geological problems

    International Nuclear Information System (INIS)

    Xu Dazhong; Xue Zhenhua

    1994-01-01

    Based on the two rift-trench tectonic framework in Wuyi as well as its adjacent areas proposed previously, this study takes Yingtan-Nancheng-Anyuan-Heyuan tenacity fracture belt as the geological boundary between two types of uranium deposits (granite and volcanic rock). It is noted that the distinct function of Caledonian movement in this area is the formation of the linear migmatization and granitization on the basis of rift and tumescence basement. Simultaneously, according to the new discovery of hypometamorphic rock and large scaled ductile mylonitized zone in Xiazhuang uranium ore field and its adjacent area, it is concluded that the Xiazhuang uranium ore field is the result of multiple tectonism and magmatic activations on the Caledonian hot dome on the basis of ancient basement. Because the uranium mineralization is present in two kinds of rocks (ductile and brittle), it is suggested that the types of mineralization in Xiazhuang can be considered in order to guide the further prospecting

  3. Uranium prospecting; La prospection de l'uranium

    Energy Technology Data Exchange (ETDEWEB)

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

    1955-07-01

    This report is an instruction book for uranium prospecting. It appeals to private prospecting. As prospecting is now a scientific and technical research, it cannot be done without preliminary studies. First of all, general prospecting methods are given with a recall of fundamental geologic data and some general principles which are common with all type of prospecting. The peculiarities of uranium prospecting are also presented and in particular the radioactivity property of uranium as well as the special aspect of uranium ores and the aspect of neighbouring ores. In a third part, a description of the different uranium ores is given and separated in two different categories: primary and secondary ores, according to the place of transformation, deep or near the crust surface respectively. In the first category, the primary ores include pitchblende, thorianite and rare uranium oxides as euxenite and fergusonite for example. In the second category, the secondary ores contain autunite and chalcolite for example. An exhaustive presentation of the geiger-Mueller counter is given with the presentation of its different components, its functioning and utilization and its maintenance. The radioactivity interpretation method is showed as well as the elaboration of a topographic map of the measured radioactivity. A brief presentation of other detection methods than geiger-Mueller counters is given: the measurement of fluorescence and a chemical test using the fluorescence properties of uranium salts. Finally, the main characteristics of uranium deposits are discussed. (M.P.)

  4. Procedure for recovery from an uranium containing concentrate and phosphoric acid, as well as an uranium containing concentrate and phosphoric acid obtained by this procedure

    International Nuclear Information System (INIS)

    1980-01-01

    The phosphate ore is dissolved in sulphuric acid and the formed calcium sulphate is separated from the solution. The uranium is then precipitated by adding ammonium fluoride solution to the remaining phosphoric acid solution. When the phosphate ore is dissolved in sulphuric acid, fluorine gas is liberated and this is then used to produce the ammonium fluoride solution. (Th.P.)

  5. Physico-chemical and radiological characterization of uranium tailings from Tummalapalle uranium mining site

    International Nuclear Information System (INIS)

    Patra, A.C.; Sahoo, S.K.; Lenka, P.; Gupta, Anil; Jha, S.K.; Tripathi, R.M.; Molla, S.; Rana, B.K.

    2018-01-01

    Mining of uranium bearing minerals is essential for the extraction of uranium to meet the power requirements of India. Mining and milling activities produce large quantities of low active tailings, as wastes, which are contained in Tailings Ponds. The nature of tailings depends on the mineralogy of ore and host rock and their quantity depends on the configuration of the ore body and mining methods. The mobility of an element from these tailings depends on elemental concentration, pH, particle size, cation exchange capacity, bulk density and porosity of the tailings etc. This necessitates complete characterisation of the tailings. In this paper we aim to characterize the uranium mill tailings generated from Tummalapalle uranium mining facility in Kadappa district, Andhra Pradesh, India

  6. Detection of uranium mining activities

    International Nuclear Information System (INIS)

    Maiorov, V.; Ryjinski, M.; Bragin, V.

    2001-01-01

    In undisturbed natural uranium ore the 238 U decay chain isotopes appear in secular decay equilibrium with activity ratios equal to one. In the course of ore processing the bulk of the uranium decay products is separated from the uranium product and concentrated in the tails. Therefore the disturbed activity ratios of short-lived daughters to long-lived parents can be indicators of ore processing. Using 234 Th and 238 U activities (the short-lived daughter with T 1/2 =24.1 days and the long- lived parent respectively) one can roughly estimate how much time has elapsed since ore processing occurred. Equilibrium is reached in about three months after processing and the 234 Th and 238 U activity levels are approximately equal (taking into account the error of measurements). Higher or lower 234 Th activity levels, relative to 238 U, indicate the material has been recently processed. Assuming the product is depleted in Th and the tails are enriched, the activity of 234 Th in fresh product should be lower than 238 U and higher in fresh tails. The 234 Th/ 230 Th activity ratio can also be used for age estimations ( 230 Th is a long-lived nuclide). Five samples were taken from the Ranger Uranium Mine and Concentration Plant in Australia, and one sample was taken from the Jabiluka mine (10 km far from the Ranger Mine). The samples included non-processed ore, coarse ore from the stockpile, final crushed ore, fresh and old tails, and fresh product (U 3 O 8 ). All the samples were analyzed by HRGS to measure the activities of gamma emitting nuclides. XRF and IDMS were used to measure uranium content and isotopic composition. The 238 U activity was calculated from these measurement results. The 234 Th activity was measured by HRGS with a planar HPGe detector and a calibrated low activity 241 Am solution as an internal standard. The 234 Th/ 230 Th activity ratio was measured using the 60 keV energy region where both isotopes have gamma lines. Use of gamma lines with close

  7. The design and construction of the bottom working for in-situ leaching of fragmented uranium ore by blasting in No. 745 mine

    International Nuclear Information System (INIS)

    Ding Dexin; Yang Shijiao; Li Ming

    1998-11-01

    Bottom working is a very important structure for in-situ leaching of fragmented uranium ore by blasting. Its design and construction should simultaneously satisfy the requirements for receiving fragmented ore, transporting the ore, providing relief space for blast operation, passage for workers and fresh air for the slope and collecting the pregnant solution from spraying over the fragmented ore. The author deals with the design and construction of the complete water cutoff bottom working for collecting the pregnant solution for in-situ leaching of fragmented uranium ore by long hole blast in No. 745 mine in Guangdong Province. The preparation system for the block, the undercutting, the construction process and method of the bottom working and the measures to guide the solution leaked into the surrounding rock mass to the bottom of the block are described in detail

  8. Fluid inclusion study of the Witwatersrand gold-uranium ores

    International Nuclear Information System (INIS)

    Shepherd, T.J.

    1977-01-01

    Fluid inclusions, preserved in quartz pebbles of the uraniferous and auriferous Precambrian oligomictic conglomerates of the Witwatersrand Basin, provide a unique insight into the genesis of the ores. Using differences in inclusion characteristics in conjunction with intra- and inter-deformational textures for adjacent pebbles, a distinction is made between pre- and post-depositional inclusions. Excluding those related to subsequent brittle fracture, the former comprise five principal types; two of which are distinguished by the development of liquid carbon dioxide. Collectively they indicate a moderate to high pressure-temperature environment of vein quartz formation. Systematic variation in the relative abundance of these inclusion assemblages for different sections of the orefield demonstrates the importance of well-defined provenance areas or multiple entry points into the basins. A marked sympathetic relationship between uraniferous banket ores and the presence of vein quartz rich in liquid carbon dioxide inclusions, together with a corresponding antipathetic relationship for gold, strongly suggests separate sources for the metals. The temporal and spatial aspects of the association 'U-CO 2 ' also imply a uranium influx into the basin from discrete areas of the hinterland contemporaneous with the sediments. Post-depositional inclusions are subordinate and offer no support for the alternative epigenetic model and show only a later interaction of relatively cool circulating groundwaters. A discussion is given of the probable nature and origin of uranium in the source rocks and its mode of transportation. In conclusion, a proposal is made for the use of applied fluid inclusion research in the evaluation of and exploration for similar deposits. (author)

  9. Occurrence of uranium in the itabiritic iron ore of Morro Agudo on the NE border of the iron Quadrangle/Minas Gerais, Brasilien

    International Nuclear Information System (INIS)

    Guba, I.

    1982-01-01

    The precambrian itabirites and hematite ores of the Morro Agudo iron ore mine on the NE border of the Quadrilatero Ferrifero in Minas Gerais/Brazil contain uranium-bearing minerals and rare-earth elements. In association with phosphates they occupy planes of joints, fractures and cleavage in the area of amphibolitic schist which is intercalated in the s 1 -planes of the itabirites and hematite ores. Preliminary analyses of the uranium-bearing minerals were made by energy dispersive X-ray spectrometry and electron microscopy. The results are presented in connection with the lithologic and tectonic features of the Morro Agudo mine. (orig.) [de

  10. Assessment of surface contamination level in an operating uranium ore processing facility of Jaduguda, India

    International Nuclear Information System (INIS)

    Meena, J.S.; Patnaik, R.L.; Jha, V.N.; Sahoo, S.K.; Ravi, P.M.; Tripathi, R.M.

    2014-01-01

    Radiological concern of the occupational workers and the area is given priority over other safety issue in confirmation with the stipulated guideline of national regulatory agency (AERB/FEFCF/SG-2, 2007). The key concern from the radiological hazard evaluation point of view is air activity, external gamma level and surface contamination. Present investigations was carried out to ascertain the surface contamination level of uranium ore processing facility at Jaduguda, Jharkhand. For a low grade uranium ore processing industry surface contamination is a major concern in product precipitation and recovery section. In view of this, the ore processing plant can broadly be classified into three areas i.e. ion exchange area, precipitation and product recovery section and other areas. The monitoring results incorporate the level of surface contamination of the plant during the last five years. The geometric mean activity of surface contamination level was 31.1, 34.5 and 9.8 Bq dm -2 in ion exchange, product precipitation and recovery and other areas with GSD of 2, 2.5 and 1.9. In most of the cases the surface contamination level was well within the recommended limit of 100 Bq dm -2 for M class uranium compound. Occasional cases of surface contamination levels exceeding the recommended limit were addressed and areas were decontaminated. Based on the study, modification in the design feature of the surface of the finished product section was also suggested so that the decontamination procedure can be more effectively implemented

  11. Early Jurassic mafic dykes from the Aigao uranium ore deposit in South China: Geochronology, petrogenesis and relationship with uranium mineralization

    Science.gov (United States)

    Zhang, Di; Zhao, Kui-Dong; Chen, Wei; Jiang, Shao-Yong

    2018-05-01

    Mafic dykes are abundant and widely distributed in many granite-hosted uranium ore deposits in South China. However, their geochronology, petrogenesis and relationship with uranium mineralization were poorly constrained. In this study, apatite U-Pb dating, whole-rock major and trace element and Sr-Nd-Pb isotope analysis were conducted for the dolerite dykes from the Aigao uranium ore deposit. Apatite U-Pb isotopic data indicate that the mafic dykes were emplaced at Early Jurassic (189 ± 4 Ma), which provides new evidence for the rarely identified Early Jurassic magmatism in South China. Pyroxene from the dykes is mainly augite, and plagioclase belongs to albite. The dolerite samples have relatively low SiO2 contents (45.33-46.79 wt%), relatively high total alkali contents (K2O + Na2O = 4.11-4.58 wt%) and Al2O3 contents (13.39-13.80 wt%), and medium MgO contents (4.29-5.16 wt%). They are enriched in Nb, Ta, Ti, rare earth elements and depleted in Rb, K, Sr, Th, showing the typical OIB-like geochemical affinity. All the dolerite samples show homogeneous Sr-Nd-Pb isotopic compositions, with (87Sr/86Sr)i varying from 0.706049 to 0.707137, εNd(t) from +4.6 to +5.2, 206Pb/204Pb from 19.032 to 19.126 and 207Pb/204Pb from 15.641 to 15.653. The mafic dykes in the Aigao deposit should be derived from the partial melting of the asthenospheric mantle and formed in a within-plate extensional environment. The emplacement age of the mafic dykes is older than the uranium mineralization age. Therefore, CO2 in ore-forming fluids couldn't originate from the basaltic magma as suggested by previous studies. The dolerite dykes might only provide a favorable reducing environment to promote the precipitation of uraninite from oxidize hydrothermal fluids.

  12. Laboratory studies on leaching of low grade uranium ores and treatment of low level liquid waste generated by leaching experiments

    International Nuclear Information System (INIS)

    Palabrica, O.T.; Antonino, E.J.; Caluag, L.A.; Villamater, D.

    1980-07-01

    Acid leaching experiments of preconcentrated uranium ore were carried out at a pulp density of 50% solids, using sulfuric acid with sodium chlorate as oxidant. The different leaching parameters considered in this work were temperature, oxidant level and leaching time. In the experimental procedure, the concentration of oxidant and the temperature were varied to determine how they affect the leaching process. Experimental results are illustrated in tabulated form for better interpretation. Uranium analyses were done by fluorimetric and delayed-neutron activation analysis. An anion exchange method using Dowex 1 x 8, 200-400 mesh (Cl - ) was used in treating the low-level liquid waste generated by leaching experiments. The purpose of this treatment was to minimize radioactive contamination in the waste materials and also to recover some of the uranium left in the liquid waste. (author)

  13. Biomembrane oxidizing tank used in the process of bacterial heap leaching of uranium ore

    International Nuclear Information System (INIS)

    Meng Yunsheng; Fan Baotuan; Liu Jian; Zheng Ying; Liu Chao

    2004-01-01

    The construction characteristic of biomembrane oxidizing tank and specialty of packing material used in the process of bacterial heap leaching of uranium ore are introduced in this paper. Method for designing biomembrane oxidizing tank, layout principle of aeration system and measurements on running management are summarized

  14. Report on intercomparisons S-14, S-15, and S-16 of the determination of uranium and thorium in thorium ores

    International Nuclear Information System (INIS)

    Pszonicki, L.; Hanna, A.N.; Suschny, O.

    1983-06-01

    Twenty-nine laboratories from 18 countries took part in this intercomparison, organized by the IAEA's Analytical Quality Control Service, to help laboratories engaged in this task to check the reliability of their results. An additional aim was to establish the concentrations of thorium and uranium in three large batches of thorium ores and certifying them as reference materials. The evaluation was based on 438 individual results (108 laboratory means) for thorium, and on 412 individual results (106 laboratory means) for uranium. The number of laboratory means per element and per sample varied from 34 to 38. The methods most frequently used in the determination of both elements were neutron activation analysis and radiometry. They were followed by spectrophotometry and X-ray fluorescence analysis for thorium and by fluorimetry, X-ray fluorescence analysis and spectrophotometry for uranium determination, respectively. The relative uncertainty of all computed overall medians which were used as the best estimations of true values, does not exceed +-10% and +-5% for the concentration values below and above 0.1%, respectively

  15. High temperature chlorination of uranium and some radionuclides from rich sulphide ores

    International Nuclear Information System (INIS)

    Mahdy, M.A.

    1992-01-01

    This work is concerned with the application of the high temperature chlorination technique upon a sulphide-rich uranium ore from elliot lake, ontario, canada. The purpose is to find a substitute to conventional sulphuric acid leaching which involves both acid drainage and radionuclide dissolution problems. Test work has therefore been directed towards studying some relevant factors of chlorination beside the effect of a number of additives

  16. Uranium from phosphates in the United Arab Republic

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    1959-04-15

    In response to a request from the UAR Government, the IAEA sent a Soviet expert, to make an on-the-spot study of data on the mining and processing of phosphates in the UAR and to examine the possibility of recovering uranium from the phosphate ores. In his report to the IAEA Director General, he has listed the following conclusions: 1.The uranium content of run-of-the-mine phosphoric ores in the United Arab Republic is very low and the recovery of uranium from them is therefore hardly likely to be an economic proposition. 2. It is essential to press on with prospecting work in order to discover richer uranium deposits and regions of phosphoritic ores. 3. It is essential to organize scientific research work on the recovery of uranium from the various types of uranium-bearing phosphoritic ores in the United Arab Republic, using mechanical concentrating methods and chemical processing methods. 4. The Agency could assist in carrying out this work either by sending as many technicians as a required to help in planning and undertaking the research work in the UAR or by getting appropriate Member States to carry out this work on preliminary samples of ore with the participation of representatives of the UAR

  17. Uranium prospecting; La prospection de l'uranium

    Energy Technology Data Exchange (ETDEWEB)

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

    1955-07-01

    This report is an instruction book for uranium prospecting. It appeals to private prospecting. As prospecting is now a scientific and technical research, it cannot be done without preliminary studies. First of all, general prospecting methods are given with a recall of fundamental geologic data and some general principles which are common with all type of prospecting. The peculiarities of uranium prospecting are also presented and in particular the radioactivity property of uranium as well as the special aspect of uranium ores and the aspect of neighbouring ores. In a third part, a description of the different uranium ores is given and separated in two different categories: primary and secondary ores, according to the place of transformation, deep or near the crust surface respectively. In the first category, the primary ores include pitchblende, thorianite and rare uranium oxides as euxenite and fergusonite for example. In the second category, the secondary ores contain autunite and chalcolite for example. An exhaustive presentation of the geiger-Mueller counter is given with the presentation of its different components, its functioning and utilization and its maintenance. The radioactivity interpretation method is showed as well as the elaboration of a topographic map of the measured radioactivity. A brief presentation of other detection methods than geiger-Mueller counters is given: the measurement of fluorescence and a chemical test using the fluorescence properties of uranium salts. Finally, the main characteristics of uranium deposits are discussed. (M.P.)

  18. Research on ore-controlling factors and prospecting targets in Shihongtan uranium deposit area, turpan-hami basin

    International Nuclear Information System (INIS)

    Fu Chengming

    2005-01-01

    Based on analyzing the controlling role of geologic structure, host formation and hydrodynamic environments on interlayer oxidation zone and uranium mineralization, the author suggests that the Aiding structural slope, block-faulting structure, and subsidiary faults and folds are indications of uranium mineralization emplacement, sand bodies of braided stream facies provide favorable space for the development of interlayer oxidation zone and uranium mineralization, and variation sites of interlayer artesian water and geochemical environments are important places for the precipitation of ore material. Based on the above-mentioned a prediction of favorable metallogenic targets is made. (author)

  19. Age of uranium ores at Ranger and Jabiluka unconformity vein deposits, Northern Territory, Australia

    International Nuclear Information System (INIS)

    Ludwig, K.R.; Grauch, R.I.; Nutt, C.J.; Frishman, D.; Nash, J.T.; Simmons, K.R.

    1985-01-01

    The Ranger and Jabiluka uranium deposits are the largest in the Alligator Rivers Uranium Field (ARUF), which contains at least 20% of the world's low-cost uranium reserves. Ore occurs in early Proterozoic metasediments, below an unconformity with sandstones of the 1.65 Ga Kombolgie Formation. This study uses U-Pb isotope data from over 60 whole-rock drill core samples that contained a variety of mineral assemblages and textures. Data for Ranger samples indicate a well-defined age of 1.74 +/-.02 Ga. This 1.74 Ga age is distinctly pre-Kombolgie, so the Ranger deposit cannot have been formed by processes requiring its presence. This Ranger age is consistent, however, with mineralization related to heating associated with either the emplacement of early post-metamorphic granites, or possibly with intrusion of the nearby Oenpelli Dolerite. In contrast, data for the least-altered Jabiluka ores yield a concordia-intercept age of 1.44 +/-.02 Ga--significantly younger than the Ranger age, and also younger than the Komobolgie. This age may correspond to a regional thermal event, as indicated both by mafic dikes of roughly this age and a zircon lower-intercept age from a nearby granite-gneiss. Thus, together with the well-defined ∼900 Ma age of ores at the Nabarlek deposit, there are at least 3 distinct periods of major U-mineralization in the ARUF. Data for both Ranger and Jabiluka indicate the same, profound isotopic disturbance at some time in the interval of 0.4-0.6 Ga. Possibly this time corresponds to the development of basins and associated basalt flows to the W and SW, a suggested by Crick et. al. (1980)

  20. Uranium-series disequilibria as a means to study recent migration of uranium in a sandstone-hosted uranium deposit, NW China

    International Nuclear Information System (INIS)

    Min Maozhong; Peng Xinjian; Wang Jinping; Osmond, J.K.

    2005-01-01

    Uranium concentration and alpha specific activities of uranium decay series nuclides 234 U, 238 U, 230 Th, 232 Th and 226 Ra were measured for 16 oxidized host sandstone samples, 36 oxic-anoxic (mineralized) sandstone samples and three unaltered primary sandstone samples collected from the Shihongtan deposit. The results show that most of the ores and host sandstones have close to secular equilibrium alpha activity ratios for 234 U/ 238 U, 230 Th/ 238 U, 230 Th/ 234 U and 226 Ra/ 230 Th, indicating that intensive groundwater-rock/ore interaction and uranium migration have not taken place in the deposit during the last 1.0 Ma. However, some of the old uranium ore bodies have locally undergone leaching in the oxidizing environment during the past 300 ka to 1.0 Ma or to the present, and a number of new U ore bodies have grown in the oxic-anoxic transition (mineralized) subzone during the past 1.0 Ma. Locally, uranium leaching has taken place during the past 300 ka to 1.0 Ma, and perhaps is still going on now in some sandstones of the oxidizing subzone. However, uranium accumulation has locally occurred in some sandstones of the oxidizing environment during the past 1 ka to 1.0 Ma, which may be attributed to adsorption of U(VI) by clays contained in oxidized sandstones. A recent accumulation of uranium has locally taken place within the unaltered sandstones of the primary subzone close to the oxic-anoxic transition environment during the past 300 ka to 1.0 Ma. Results from the present study also indicate that uranium-series disequilibrium is an important tool to trace recent migration of uranium occurring in sandstone-hosted U deposits during the past 1.0 Ma and to distinguish the oxidation-reduction boundary

  1. Nitric acid leaching of radium and other significant radionuclides from uranium ores and tailings

    International Nuclear Information System (INIS)

    Ryon, A.D.; Hurst, F.J.; Seeley, F.G.

    1977-08-01

    Nitric acid leaching of representative uranium ores and mill tailings from the western U.S. mining districts removes up to 98% of the 226 Ra and 230 Th, yielding a residue containing 17 to 60 pCi of radium per gram. At best, this is an order of magnitude greater than that in surrounding soils, but about the same level as a standard proposed for building materials in the United Kingdom. Data are also presented on the water penetration and leaching of tailings, the solubility of BaSO 4 , and radon emanation coefficients of ores, tailings, and nitric acid-leached residues

  2. A process for the simultaneous recovery of gold and uranium from South African ores

    International Nuclear Information System (INIS)

    Fleming, C.A.

    1986-01-01

    Leaching tests carried out on run-of-mine ore from one of South Africa's gold-and-uranium mines show that gold and uranium dissolve simultaneously in an acidic solution containing ferric sulphate and thiocyanate ions, and that, under appropriate conditions, the recovery of both metals is similar to that achieved in conventional leaching. Moreover, since the gold and uranium are leached as anionic complexes, they can be extracted simultaneously from the leach liquor with an anion-exchange resin. The results presented indicate that it is technically feasible to recover the metals onto a strong-base resin, to strip them selectively from the resin, and to recover them in a marketable form from the strip liquors

  3. Case-control study communities with uranium ores deposit/examining versus communities without uranium, or other ores

    International Nuclear Information System (INIS)

    Letkovicova, M.; Letkovic, M.; Daniel, J.; Licivjansky, J.

    2008-01-01

    That is why the present study has been carried out to show, by means of both classical epidemiological and up-to-date mathematical methods, whether there is a difference in the health status of people living in areas with occurrence of pitchblende and those living in areas without any territorial contact with coal or ore mining or with deposits of any known exploitable minerals. The present study on differences in demography and health of population in municipalities with deposits or even with a history of stopping of uranium in comparison with municipalities without any mining or stopping past has been worked out in cooperation of URANPRES in Spisska Nova Ves and the company ENVIRONMENT in Nitra, Slovakia. The background data were provided by the fund ( database ) of the geological data of Uranpres as well as by the author' s databases of Environment, Inc., and the Statistical Office of the Slovak republic in Bratislava. The methods used for comparison have been either the common epidemiological ones, or the up-to-date mathematical methods. There was no difference between municipalities with and without occurrence of pitchblende within their cadastre. On the contrary, municipalities with a uranium extraction history seem to be balanced in respect of all indicators observed, with a long life expectancy, without any impairment of reproduction, with a lower incidence of cancer, and with a decidedly acceptable index of growth. The inhabitants neither have any health troubles nor do they think so and they do not intend to leave their municipalities. (authors)

  4. Uranium mineralization in the central region of Cuba

    International Nuclear Information System (INIS)

    Valdez, M.G.; Olivera, J.; Fernandez, P.

    1995-01-01

    The present work shows different geological and geophysical index for uranium mineralization found at Loma Alta iron ore deposit, located in the central region of Cuba. In this deposit was carried out pull work of iron ore. The tunnels were radiometrically documented in the wall and the floor observing some anomalies of the gamma ray intensity (up to 1700 c.p.s.) associated with the poor iron ore. In those points were collected solid sample. The obtained results were very important (uranium concentrations values up to 3500 ppm)

  5. The production and use of citric acid for the removal of potassium from the iron ore concentrate of the Sishen Iron Ore Mine, South Africa

    Directory of Open Access Journals (Sweden)

    Peter J. Williams

    2010-04-01

    Full Text Available The depletion of the richer iron ore worldwide has made it necessary to process lower quality iron ore. Certain substances, such as potassium, contained within the lower quality iron ore, have a detrimental effect on the smelting process during steel manufacturing. Therefore, international steel-making companies charge penalties when purchasing iron ore concentrates containing high concentrations of potassium. To date, lower quality iron ore has been blended with high quality iron ore in an attempt to alleviate the potassium concentrations in the export iron ore; however, the ratio of low quality iron ore to high quality iron ore is increasing, thereby becoming an escalating problem within the economic functioning of the Sishen Iron Ore Mine. It has, therefore, become necessary to develop an economically viable and environmentally friendly process to reduce the high potassium concentrations contained in the iron ore concentrate of the Sishen Iron Ore Mine. In this study, we compared solid substrate and submerged fermentation using Aspergillus niger for the production of citric acid, which is used for the chemical leaching of potassium from the iron ore concentrate. It was found that submerged fermentation proved to be more economical and efficient, producing a maximum citric acid concentration of 102.3 g/L in 96 h of fermentation. ‘Heap leaching’ simulation experiments were found to be uneconomical, due to the required addition of fungal growth medium every 5 days as a result of growth factor depletion within this time; however, this process removed 17.65% of the potassium from the iron ore concentrate. By contrast, chemical leaching of potassium from the iron ore concentrate proved to be most efficient when using a 1 mol citric acid leaching solution at 60 ºC, removing 23.53% of the potassium contained within the iron ore concentrate. Therefore, the most economical and efficient process for the removal of potassium from the iron

  6. Acid curing and baking of bastnasite ore and concentrate

    International Nuclear Information System (INIS)

    Topkaya, Y.; Akkurt, S.

    1998-01-01

    Full text: In this study, the hydrometallurgical evaluation of a rare earth ore as well as a concentrate obtained from this was done at laboratory. For the mentioned study, a bastnasite type rare earth ore located in Beylikahir in Turkey was used. The total rare earth oxide (REO) content of the deposit was estimated to be 1 million tons with an average concentration of 3.42%REO. The rare earths were contained in bastnasite mineral. The other constituents of the ore were calcium fluoride (52.5%), barite (25.4%), calcite (2.8%) and minor amounts of thorium, iron, manganese, etc. The bastnasite mineral occurred either as cement material between fluoride and barite particles or as intimately associated with these minerals. The rare earth elements were enriched considerably in sub-sieve sizes. After extensive research about the physical concentration of this ore, two different metallurgical routes were followed for the extraction of REE from the ore itself or the preconcentrate obtained by attrition scrubbing and desliming by cyclones. In order to increase the grade of the concentrate, upgrading of the preconcentrate by multigravity was also tried. The two metallurgical routes tested were: Sulphuric acid curing and water leaching; Sulphuric acid baking and subsequent water leaching. The results of the leaching experiments were found to be quite promising. Leach recoveries up to 90% were easily obtainable. In the case of acid baking, hydrofluoric acid recover as a by-product was also possible

  7. Preliminary discussion on the application of the geological conceptual model method of uranium ore formation

    International Nuclear Information System (INIS)

    Ma Guangzhong; Wei Mingji; Luo Yiyue

    1992-01-01

    The geological conceptual model method of uranium ore formation is established on the basis of geological theory and apriorism. Variables are screened with the application of the method of mathematical geology to find out the variables which are more contributed. In combination with the practical situation in Xikang-Yunnan axis, the variables are compiled and graded so as to determine the optimal ore-controlling factor and to establish the statistical predictive model which is of geological significance. The resources evaluation work has been conducted in the Late Proterozoic geological terrain in Xikang-Yunnan axis

  8. Non-filtration method of processing of uranium ores

    International Nuclear Information System (INIS)

    Laskorin, B.N.; Vodolazov, L.I.; Tokarev, N.N.; Vyalkov, V.I.; Goldobina, V.A.; Gosudarstvennyj Komitet po Ispol'zovaniyu Atomnoj Ehnergii SSSR, Moscow)

    1977-01-01

    The development of the filterless sorption method has lead to working out the sorption leaching process and the process of extraction desorption, which has made possible to intensify the process of uranium ore working and to improve greatly the technical economic indexes by liquidating the complex method of multiple filtration and repulping of cakes. This method makes possible to involve more poor uranium raw materials and at the same time to extract valuable components: molybdenum, vanadium, copper, etc. Great industrial experience has been accumulating in sorption of dense pulp with the ratio of solid phase to liquid one equal to 1:1. This has lead to the increase of productivity of working plants by 1,5-3,0 times, the increase of uranium extraction by 5-10%, the increase of labour capacity of main workers by 2-3 times, and to the decrease of reagents expense, auxiliary materials, electric energy and vapour by several times. In fact the developed technology is continuous in all its steps with complete complex automatization of the process with the help of the most simple and available means of regulation and controlling. The process is equipped with high productivity apparatuses of great power with mechanic and pneumatic mixing for high density pulps, and with the columns KDS, KDZS, KNSPR and PIK for the regeneration of saturated sorbent in the counterflow regime. The exploitation of fine-granular hydrophilic ion-exchange resins in hydrophobized state is foreseen [ru

  9. New techniques for the treatment of uranium ores

    International Nuclear Information System (INIS)

    Renaud, J.; Boutonnet, G.

    1977-01-01

    The growth in nuclear power programmes since 1970 has led to an increasing demand for uranium, and tenders have been invited from all parts of the world for the construction of new treatment plants. What types of plant could be suggested. The diversity of ores and sites, even more stringent safety requirements, greater care for the environment and economic facts called for numerous, if not basic, reviews of the conventional techniques. Two examples illustrate this point. In the case of a plant to treat a refractory ore situated in a desert area with limited water resources, Pechiney Ugine Kuhlmann studied and applied a new technique of leaching by sulphuric acid pulping, which gives a considerable saving of sulphuric acid and water in comparison with conventional leaching techniques. In dealing with a problem which arose at a plant situated in a mountainous region of touristic interest, where a tailings settling tank could not be installed, Pechiney Ugine Kuhlmann studied and developed techniques involving the use of band filters for solid-liquid separation and pulp washing. Apart from lowering investment costs by about 15% in comparison with the techniques used so far, this technique produces the tailings in solid form so that they do not require a settling tank for storage. (author)

  10. Experimental study on bio-leaching of high sulphuric acid consumption uranium ore by adding sulphide

    International Nuclear Information System (INIS)

    Meng Yunsheng; Zheng Ying; Liu Hui; Cheng Hao; Zhou Lei; Liu Chao; Fan Baotuan; Li Jianhua

    2012-01-01

    In order to decrease acid consumption and increase leaching rate, an experiment on bio-leach-ing of low grade uranium ore by adding sulphide was done. Compared with conventional leaching method, the leaching rate of uranium is improved by 3% and the leaching period was reduced to 60 days from 90 days by bio-leaching method of adding sulphide. In order to decrease acid consumption with bio-leaching by adding sulphide obviously, robust bacteria to sulphide should be chosen. (authors)

  11. Processing of low-grade uranium ores

    International Nuclear Information System (INIS)

    Michel, P.

    1975-01-01

    Four types of low grade ores are studied. Low grade ores which must be extracted because they are enclosed in a normal grade deposit. Heap leaching is the processing method which is largely used. It allows to obtain solutions or preconcentrates which may be delivered at the nearest plant. Normal grade ores contained in a low amplitude deposit which can be processed using leaching as far as the operation does not need any large expensive equipment. Medium grade ores in medium amplitude deposits to which a simplified conventional process can be applied using fast heap leaching. Low grade ores in large deposits. The processing possibilities leading to use in place leaching are explained. The operating conditions of the method are studied (leaching agent, preparation of the ore deposit to obtain a good tightness with regard to the hydrological system and to have a good contact between ore and reagent) [fr

  12. Uranium mineralization environment and prospecting potential of Dawan ore field in Nanling metallogenic belt

    International Nuclear Information System (INIS)

    Yang Shanghai

    2011-01-01

    Located in the middle part of Jiuyishan complex pluton, Nanling metallogenic belt, Dawan uranium ore field in Hunan Province is an important uranium-producing and rare metal, nonferrous metal cluster area due to the favourable mineralization environment. The Cambrian is the main uranium source bed and their contact zone to the pluton is the favorable part for mineralization. The uranium deposits which have been explored are all located in the exocontact zone of Jinjiling pluton in the middle part of Jiuyishan complex pluton which is composed of the independent eastern and western magma evolution centers. In the west center, Jinjiling pluton is closely related to uranium mineralization where the trinity geologic setting was formed with magma evolution, hydrothermal fluid action and mineralization. The deep slitted and large faults provide the pathway and thermodynamic source for circulating migration of mineralizing fluid. The uranium mineralization mainly occurred in crustal stress conversion period of Late Cretaceous and related to the tensive NW extending fault and deep originated fluid. The gravity, aero magnetic, airborne gamma-ray spectrometry anomalies and radioactivity hydrochemical anomaly are important criteria for uranium prospecting. Based on the analysis of regional uranium mineralization environment, the prospecting potential is forecasted. (authors)

  13. Alpha spectrometry of thick sources. II. Application to the study of radioactive equilibria in uranium ores

    International Nuclear Information System (INIS)

    Acena Barrenechea, M.L.; Tormo Ferrero, M.J.

    1977-01-01

    A method for determining nuclide activities in 4n + 2 uranium series using alpha spectrometry of thick sources is described. This method has been applied to several uranium ores, showing different states of radioactive equilibria. The spectra from samples prepared by cold compression show some anomalies, due to the evolution and later decay of 219 Rn and daughters. This phenomenon must be taken in consideration when computing spectra line intensities. (author) [es

  14. Study on geochronology and uranium source of sandstone-type uranium deposit in Dongsheng area

    International Nuclear Information System (INIS)

    Liu Haibin; Xia Yuliang; Tian Shifeng

    2007-01-01

    This paper studied the geochronology of sandstone-type uranium deposit in the Dongsheng area of Ordos Basin. In eastern segment, ages of mineralization at the wing of the ore-roll are found to be 120 ± 5 Ma and 80 ± 5 Ma, and at the front of the ore-roll are 20 ± 2 Ma and 8 ± 1 Ma; While in middle segment, ages of mineralization are 124 ± 6 Ma and 80 ± 5 Ma. This means that the main mineralization in Dongsheng area were formed at early Jurassic and late Cretaceous, and correspondent to the time of structure uplift. Mineralization of roll-front (rich ore) which formed in Miocene and Pliocene may related to tectonic-thermal event taken place at that time and reformed the early mineralization in this area. The isochron line age of sample with uranium grade 0 ) in the sandbody is 24.64 x 10 -6 also shows the uranium pre-concentration in the strata. The even value of ΔU of rocks in Zhiluo formation is -70.2%, this shows that non-mineralized rocks have migrated uranium and acted as important metallogenic uranium sources. (authors)

  15. Novel precipitation technique for uranium recovery from carbonate leach solutions

    International Nuclear Information System (INIS)

    Sujoy Biswas; Rupawate, V.H.; Hareendran, K.N.; Roy, S.B.; Chakravartty, J.K.

    2015-01-01

    The recovery of uranium from carbonate ore leach solution was studied using novel precipitation method. The uranium from leach liquor was recovered as magnesium diuranate with NaOH in presence of trace amount of Mg 2+ . Effects of various parameters such as addition of H 2 SO 4 , MgO, MgSO 4 as well as NaOH were investigated for maximum uranium recovery. Overall uranium recovery of the process was 97 % with improved particle size (∼57 µm). Based on the experimental findings, a process flow-sheet was developed for uranium recovery from carbonate ore leach solution with a uranium concentration of <1 g/L. (author)

  16. Development of the Falea polymetallic uranium project

    International Nuclear Information System (INIS)

    Ring, R.; Freeman, P.

    2014-01-01

    The Falea uranium, silver, copper deposit is located in south western Mali, West Africa and is owned by Denison Mines Corp. The current resource estimate is approximately 45 million pounds of U_3O_8 [~17,300 t U] at an average grade of ~ 0.07% U_3O_8. [~0.06% U].The deposit also contains ~37 million Oz Ag and ~70,000 t Cu. The dominant uranium mineral is uraninite, copper is present mainly as chalcopyrite and silver mainly as argentite, and in its native form. Only 5% of the property has been explored to date, and all zones remain open. This paper reports the results of several stages of metallurgical investigations to support ongoing economic studies for the project. The polymetallic nature of the Falea deposit dictates that there are a range of flowsheet options. The ore contains both carbonate and sulphide mineralisations, which have potential impacts on acid and alkaline leaching, respectively. There is also the need to recover both silver and copper. Two primary flowsheet options were considered: 1) Acid leach of ore to recover uranium / flotation of leach residue to recover sulphide concentrate, treatment of concentrate for Cu and Ag recovery; 2) Flotation of ore / alkaline leaching of flotation tails to recover uranium and treatment of flotation concentrate for Cu and Ag recovery. A number of sub-options were considered for each flowsheet. Test work showed that high recoveries of copper and silver to flotation concentrate were obtained for both flotation of ore or acid leach residue. Uranium extraction was also > 90% for both acid and alkaline leaching. The preferred flowsheet was selected after trade-off studies by DRA. This paper presents an overview of the various flowsheet options considered, an outline of the preferred flowsheet, and the results and conclusions of on-going engineering and laboratory/pilot studies to refine the preferred flowsheet. (author)

  17. 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)

  18. Disposal of residue from uranium ore processing in France

    International Nuclear Information System (INIS)

    Crochon, Ph.

    2011-01-01

    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)

  19. Evolution of Xihulitu basin and its control to uranium ore-formation

    International Nuclear Information System (INIS)

    Guo Qingyin; Li Ziying; Dong Wenming

    2003-01-01

    There is a close relationship between basin filling succession and evolution of the basin. Characteristics of basin evolution can be studied by analyzing the basin filling succession. Two major periods are recognized according to the filling succession and subsequent alteration of the Xihulitu Basin. Evolutionary characteristics of each stage of the basin formation and alteration have been discussed in details. The types and special distribution of uranium metallization are controlled by the scale, connection degree and distribution of sandstone units and impermeable mudstone beds. The environment of uranium ore-formation became favorable as the faults modified the hydrodynamic condition. The basin had been uplifted for a long time after it was filled. Intergranular pores are not destroyed due to the weak mechanical compaction, which is beneficial to groundwater penetrating. Montmorillonitization and zeolitization in some sandstone units are strong because of the high content of volcanic fragments. The major uranium metallization is the phreatic oxidation type. The northern zone of the second sub-basin in the central section of the basin is regarded as the first perspective target for subsequent exploration. (authors)

  20. Processing of low grade uranium ores

    International Nuclear Information System (INIS)

    Michel, P.

    1978-10-01

    Four types of low-grade ores are studied: (1) Low-grade ores that must be extracted because they are enclosed in a normal-grade deposit. Heap leaching is the processing method which is largely used. (2) Normal-grade ores contained in low-amplitude deposits. They can be processed using in-place leaching as far as the operation does not need any large and expensive equipment. (3) Medium-grade ores in medium-amplitude deposits. A simplified conventional process can be applied using fast heap leaching. (4) Low-grade ores in large deposits. The report explains processing possibilities leading in most cases to the use of in-place leaching. The operating conditions of this method are laid out, especially the selection of the leaching agents and the preparation of the ore deposit

  1. Enumeration and characterization of microorganisms associated with the uranium ore deposit at Cigar Lake, Canada. Informal report

    International Nuclear Information System (INIS)

    Francis, A.J.; Joshi-Tope, G.; Gillow, J.B.; Dodge, C.J.

    1994-03-01

    The high-grade uranium deposit at Cigar Lake, Canada, is being investigated as a natural analog for the disposal of nuclear fuel waste. Geochemical aspects of the site have been studied in detail, but the microbial ecology has not been fully investigated. Microbial populations in an ore sample and in groundwater samples from the vicinity of the ore zone were examined to determine their effect on uranium mobility. Counts of the total number of bacteria and of respiring bacteria were obtained by direct microscopy, and the viable aerobic and anaerobic bacteria were assessed as colony forming units (CFUs) by the dilution plating technique. In addition, the population distribution of denitrifiers, fermenters, iron- and sulfur-oxidizers, iron- and sulfate-reducers, and methanogens was determined by the most probable number (MPN) technique

  2. Bioleaching - an alternate uranium ore processing technology for India

    International Nuclear Information System (INIS)

    Abilash; Mehta, K.D.; Kumar, V.; Pandey, B.D.; Tamarakar, P.K.

    2010-01-01

    Meeting the feed supply of uranium fuel in the present and planned nuclear reactors calls for huge demand of uranium, which at the current rate of production, shows a mismatch. The processing methods at UCIL (DAE) needs to be modified/changed or re-looked into because of its very suitability in near future for low-index raw materials which are either unmined or stacked around if mined. There is practically no way to process tailings with still some values. Efforts were made to utilize such resources (low-index ore of Turamdih mines, containing 0.03% U 3 O 8 ) by NML in association with UCIL as a national endeavor. In this area, the R and D work showed the successful development of a bioleaching process from bench scale to lab scale columns and then finally to the India's first ever large scale column, from the view point of harnessing such a processing technology as an alternative for the uranium industry and nuclear sector in the country. The efforts culminated into the successful operation of large scale trials at the 2 ton level column uranium bioleaching that was carried out at the site of UCIL, Jaduguda yielding a maximum recovery of 69% in 60 days. This achievement is expected to pave the way for scaling up the activity to a 100T or even more heap bioleaching trials for realization of this technology, which needs to be carried out with the support of the nuclear sector in the country keeping in mind the national interest. (author)

  3. A rapid method for the determination of uranium in ores and carbonaceous materials by x-ray-fluorescence spectrometry

    International Nuclear Information System (INIS)

    Tolmay, R.T.; Jacobs, J.J.

    1980-01-01

    The determination of uranium by a non-fusion method in a wide range of uranium-bearing materials, e.g. ores, coals, and resins, is described. Matrix effects are corrected for by dilution and fine grinding of the sample with coarse river sand and application of a technique for background correction. The linear calibration range is up to 1000 p.p.m. of U 3 O 8 . It was found that the suitable dilution of resins with river sand and fine grinding makes it possible for up to 6 per cent U 3 O 8 to be determined. Ten samples can be analysed in two-and-a-half hours. The precision and accuracy is 5 and 2 per cent at U 3 O 8 concentrations of 500 and 2000 p.p.m. respectively. The laboratory method, a listing of the computer programme required for the calibration and calculation of the U 3 O 8 concentrations, and instructions for the calculation of the error in the determination are given in the appendices [af

  4. Preliminary discussion on deep-sourced uranium metallogenesis and deep prospecting

    International Nuclear Information System (INIS)

    Huang Shijie

    2006-01-01

    Prospecting for hydrothermal type uranium deposits should be aimed at medium-to large-sized deposits, and be guided by mantle-sourced, superimposed, deep-sourced metallogenic theory and the establishment of a multifactor, composite, deep-sourced metallogenic model. The author suggests that hydrothermal uranium deposits may be classified into three genetic types, i.e. hydrothermal circulation concentration, postmagmatic hydrothermal and mantle fluid concentration. These types of uranium deposits are characterized by their own metallogenic features and are concentrated in the same mineralization-concentrated area forming a metallogenic series. Large-sized uranium ore fields and rich-large uranium deposits are usually closely associated with mantle-sourced metallogenesis and the formation of such uranium ore fields and deposits is characterized by specific and unique regional geologic environments. Recognition criteria of mantle-sourced metallogenesis are preliminarily proposed in the paper. It is pointed out that prospecting in the future should follow the metallogenic model proper for the specific genetic type, and the establishment of operable prospecting model to realize the model-guided prospecting. (authors)

  5. Residues leaching from 'Factory of barren ores'

    International Nuclear Information System (INIS)

    Rakhmatov, N.; Khakimov, N.; Nazarov, Kh.M.; Barotov, A.M.

    2012-01-01

    The objective of the present work is safe management of residues from Factory of Barren Ores, their reprocessing, expenditures reduction for remediation of Istiklol city former uranium tailings. For this purpose, some experiences were adopted - Factory of Barren Ores tailing use for filling up the open pit where water with uranium content 3-5 mg/l is located. Factory of Barren Ores waste are passed through heap leaching and have some amount of uranium salts dissolved in water. Thus, we propose to dissolve uranium from Factory of Barren Ores wastes with uranium bearing water flowing out from gallery and filling up the open-pit by radioactive wastes. In so doing, uranium content flowing out from gallery will increase twice, and further, passing them through apricot's shell, as a sorbent, we will clean the water against radionuclides. Residue samples with uranium content 0,015% from Factory of Barren Ores and uranium bearing waters from gallery 1 with uranium content 0,0025 g/l were used for laboratory tests. After which, a slurry was prepared by means of residue mixing with water in ratio of solid and liquid phases (S:L) - 1:2 and 9,7 ml of sulfuric acid (Ρ=1,82) was added which corresponds consumption by H 2 SO 4 176,54 kg/t. For the first test, leaching was carried out during 4 hours at ph=1,6 at room temperature. For the second test, leaching was carried out at 60 d eg C a nd ph=1,6 during 4 hours. Slurry heating and mixing was carried out by means of magnetic mixer. The basic residue leaching indicators are provided in this article.

  6. Uranium metallogenic geological conditions in the south central section of da hinggan mountains

    International Nuclear Information System (INIS)

    Wang Qing; Liu Qing

    2014-01-01

    The south central section of Da Hinggan Mountains, where the Zha Lantun prospecting zones of volcanic type uranium ore, is a high density concentrated distribution area of uranium and polymetallic mineral. This article elaborated uranium metallogenic geological conditions in the south central section of Da Hinggan Mountain, from the tectonic conditions, the source of uranium, the heat source, the space for ore-forming, hydrothermal alteration, the mineralization, and ect. This area has a good prospecting foreground and potentiality. (authors)

  7. Problems occurred in prospecting and mining of a broken thick large uranium ore body and improvement scheme

    International Nuclear Information System (INIS)

    Hu Longfei; Fang Yang; Wang Yishun; Wang Long

    2014-01-01

    In prospecting and mining of a broken thick large uranium ore body, uncertain prospecting and shallow-hole shrinkage mining method resulted in large dilution rate and resource waste problems. Aimed at these problems, improvement schemes of enhancing the strength force of 'drilling prospecting instead of pit prospecting' and employing filling method stoping ore body were applied, and improvement result was analyzed. Experience was accumulated and evidence was provided for late prospecting and stoping work. (authors)

  8. Blind River uranium deposits: the ores and their setting

    International Nuclear Information System (INIS)

    Robertson, J.A.

    1981-01-01

    In the Blind River area, Proterozoic clastic sedimentary and minor volcanic rocks (Huronian Supergroup) unconformably overlie and transgress northward over dominantly granitic Archean terrane (2500 million years) and are intruded by Nipissing Diabase (2150 million years). Later deformations and metamorphic events are recognized. The Matinenda Formation (basal Huronian) comprises northward-derived arkose, quartzite, and pyritic, uraniferous oligomictic conglomerates, which contain 75 percent of Canada's uranium reserves. Historic grades approximate 2 pounds U 3 O 8 /ton (1 kilogram/metric ton), but lower grade material can be mined with increasing price. Some thorium and rare earths have been marketed. The conglomerate beds lie in southeasterly striking zones controlled by basement topography down-sedimentation from radioactive Archean granite. Distribution of monazite relative to uraninite and brannerite and the presence of uranium values in overlying polymictic conglomerates, which truncate the ore beds, indicate that the mineralization is syngenetic, probably placer. The role of penecontemporaneous mafic volcanics is problematical, but these could have been a source for sulphur in the pyrite. Drab-coloured rocks, uranium and sulphide mineralization, and a post-Archean regolith formed under reducing conditions all suggest a reducing environment. Sedimentary features indicate deposition in fast-flowing shallow water and possibly a cold climate. In the upper Huronian (Lorrain Formation), a monazite and iron oxide assemblage associated with red beds suggests a change to oxidizing conditions

  9. Determination of uranium and thorium isotopes by solid phase extraction and alpha spectrometry

    International Nuclear Information System (INIS)

    Kuruc, J.; Kovacova, M.; Strisovska, J.; Galanda, D.

    2013-01-01

    The aim of this work was to test the modified method suitable for the separation of isotopes of uranium and thorium samples of rocks, including gold ore and gold concentrate using of extraction chromatography method, after digestion of the sample, concentrating, separate the isotopes of uranium and thorium isotopes to prepare sources for the measurement of alpha spectra. Samples of rocks, gold ore and gold concentrate were digered in microwave decomposition in the environment of hydrogen peroxide and concentrated nitric acid. For the separation of uranium and thorium the vacuum box with cartridges DGA Resin and Resin(R) UTEVA (Triskem International, France) was used. Both sorbents allow separation of uranium from thorium. The results confirmed that the both sorbents give the same results within expanded uncertainty. The mass activity of monitored uranium and thorium radioisotopes was determined by alpha spectrometry method. The yields of separation were determined using uranium-232 as a tracer radionuclide; the activity of 232 U was 0.1438 Bq. Alpha spectra were measured on the Alpha spectrometer EG and G ORTEC 576A with the software MAESTRO, MCA Emulator and Gamma Vision-32 for Windows, USA. Mass activities of radionuclides were converted to mass concentration of isotopes 238 U, 234 U, 232 Th, 230 Th and 228 Th. The highest concentration of 238 U was sampled in granodiorite (Tunnel S-XIV-2, southwards, mining of Cu ore, not working there since 1990), where m( 238 U) = (0.81 ± 0.09) mg kg -1 (DGA Resin) and m( 238 U) = (0.90 ± 0.09) mg kg -1 (UTEVA(R) Resin), as well as m( 232 Th) = (18.8 ± 1.7) mg kg -1 (DGA Resin) and m( 232 Th) = (17.8 ± 1.5) mg kg -1 (UTEVA(R) Resin). In other samples of rocks, gold ore and gold concentrates have specific masses of isotopes of uranium and thorium two-to ten-folds lower. It can be concluded that the rocks, gold ores and concentrates of gold from the 'Rozalia' mine contain lower concentrations of uranium several times against

  10. Underground bioleaching: extracting from low-grade ore

    International Nuclear Information System (INIS)

    McCready, R.G.L.

    1986-01-01

    In 1984, Denison Mines began a research and demonstration project on the engineering aspects of bacterial leaching of low-grade uranium ore at Elliot Lake. The leaching solution was acidic mine water enriched in bacterial nutrients and innoculated with Thiobacillus ferrooxidans. Leaching of one stope was found to be impeded by fungi of the genus penicillium. Although fungal growth on leaching stopes must be prevented, research is proceeding on the potential use of the fungi to concentrate uranium from bioleaching solutions

  11. Pressure leaching of uranium-bearing Witwatersrand ores

    International Nuclear Information System (INIS)

    Bovey, H.J.; Stewart, L.N.

    1979-01-01

    Since 1955 extensive pressure-leaching testwork has been conducted by Anglo American Research Laboratories (AARL) in laboratory-scale batch autoclaves. In 1958 a small continuous pilot-plant of 45 kg of solids per hour was operated by AARL. In 1974, when high uranium prices were anticipated, Anglo American, encouraged by successful commercial-scale autoclave operations as practised by Outokumpu, Sherritt Gordon, and Impala Platinium, decided to install a continuous pilot plant at Western Deep Levels. At that time the proposed pilot plant was considered to be of prototype size. The project was funded by members of the Nuclear Fuels Corporation (Nufcor). Since its commissioning in February 1977, the pilot plant at Western Deep Levels, which can treat between 10 and 20 tons of dry solids per hour, has been used to test ores from four different mines. The paper compares the uranium extractions and pyrite oxidation obtained in laboratory batch autoclaves with those obtained in the continuous pilot plant. In general, differences in uranium extraction are not great and can be explained; the differences in pyrite oxidation are less well understood. The effect on plant design of the evolution of carbon dioxide during leaching is discussed. Evaluation of the equipment and materials of construction would have been almost impossible in a small-scale batch autoclave. It is doubtful whether such results would have generated the necessary confidence to permit decisions to install a commercial-size plant. The development and performance of the multistage pumps, instrumention, shaft seals and shaft-seal water treatment are discussed. It is concluded that the operation of a large-scale continuous pressure-leaching pilot plant to supplement laboratory batch autoclave tests has been a necessary part of the development of this process [af

  12. Uranium and heavy metals in phosphate fertilizers

    International Nuclear Information System (INIS)

    Khater, A.E.M.

    2008-01-01

    Agricultural applications of chemical fertilizers are a worldwide practice. The specific activity of uranium-238 and heavy metals in phosphate fertilizers depends on the phosphate ore from which the fertilizer produced and on the chemical processing of the ore. Composite phosphate fertilizers samples where collected and the uranium-238 specific activity, in Bq/kg, and As, Cd, Cu, Pb, Se concentration, in ppm, were measured. The annual addition of these elements in soil due to fertilization were calculated and discussed. (author)(tk)

  13. Uranium and heavy metals in phosphate fertilizers

    International Nuclear Information System (INIS)

    Khater, Ashraf E.M.; King Saud University, Riyadh

    2008-01-01

    Full text: Agricultural applications of chemical fertilizers are a worldwide practice. The specific activity of uranium-238 and heavy metals in phosphate fertilizers depends on the phosphate ore from which the fertilizer produced and on the chemical processing of the ore. Composite phosphate fertilizers samples were collected and the uranium-238 specific activity, in Bq/kg, and As, Cd, Cu, Pb, Se concentration were measured. The annual addition of these elements in soil due to soil fertilization were calculated and discussed. (author)

  14. Recovery of uranium in mine waters

    International Nuclear Information System (INIS)

    Sugier, P.

    1967-01-01

    In a brief introductory survey the author indicates the date on which leaching was first observed in the CEA mines and lists the main factors necessary for, or favourable to, the solubilization of uranium in mines. Information is given on the various sources of this type at present identified in France and the methods used to recover uranium in mines situated near ore-concentration plants. An explanation is given for the use of the calcium precipitation technique in connection with waters produced in mines not situated near ore-concentration plants. Data are given on the results of laboratory tests carried out on waters containing uranium, together with a description of an industrial-scale facility built in consequence of these tests. Details are given of the statistical results obtained. The author concludes by outlining the programme which will be implemented in the near future with a view to increasing the tonnage of uranium produced by in situ leaching and indicates that the CEA engineers are very optimistic about the prospects of this new low-cost method of producing uranium. (author) [fr

  15. The basic characteristics of TRPO-GDX-301 resin extraction chromatography and its application in analysis of uranium ore

    International Nuclear Information System (INIS)

    Jin Wenlong; Yao Mingxia.

    1986-01-01

    The basic characteristic, including capacity of column, loading quality of extraction agent, relationship between flow-rate of solution and height of theorical tower plate, leakage of extraction agent, separation behavior of uranium, of TRPO-extraction chromatography for separation of uranium has been inveistigated. The microamount of uranium on column can be eluted with mixed complex solution at pH 5.8-6.2 and determined by 5-Br-PADAP spectrophotometry. The method is simple and easy to operate. It has reasonable precision and accuracy. It is very suitable for determination of 0.002-0.4% uranium in ore

  16. Concentration of gold, sulphide minerals and uranium oxide minerals by flotation from ores and metallurgical plant products

    International Nuclear Information System (INIS)

    Weston, D.

    1974-01-01

    A process for the recovery by froth flotation of gold and mineral values selected from the group consisting of gold bearing minerals, platinum group minerals, silver group minerals, and uranium group minerals, from ores and metallurgical plant products containing at least gold and at least one of the other said minerals comprising: subjecting a suitably prepared pulp of the material to mechanical agitation in at least one agitation conditioning stage wherein the pH of the said pulp has been lowered with an acid agent to an optimum pH point within the pH range of about 1.5 to 5.0 and wherein the agitation conditioning is for a sufficient period of time to bring about heavy activation of at least one of the said mineral values in at least one subsequent mechanical agitation conditioning stage wherein the said pulp is further agitation conditioned for a sufficient period of time and at an optimum pH point in the pH range of about 6.0 to 11.0 in the presence of at least one collector selected from the group of sulfhydryl anionic collectors to produce the said heavy activation of at least gold and at least one of the other said mineral values; and subsequently in the presence of a frother subjecting and said agitation conditioned pulp to flotation to produce a concentrate enriched in gold and at least one of the othersaid mineral values, and a tailings product impoverished in at least gold and at least one of the other said mineral values

  17. Recent technical changes in the treatment plants of Sismo for uranium ores

    International Nuclear Information System (INIS)

    Clappier, L.; Michel, P.

    1983-01-01

    The mills of the Ste. Industrielle des Minerais de l'Ouest (Simo) have undergone various reconstructions, consisting of the replacement of worn equipment, an extension of the capacity (from 600000 to 1100000 tonnes per year) and the introduction of new techniques which are described in the present article: endless belt filters; the grinding operations in a wet medium lead to a pulp which contains 1.11 m 3 of water per tonne of ore; the insulation of one endless-belt filter from the washing sector after leaching has permitted an increase of the solid concentration of the pulps; the recovery of uraniferous solutions includes generally a stage of concentration and of purification of the uranium in solution by ion exchange on a resin or liquid solvent substrate; instead of using them in parallel, the ''Eluex'' process utilizes them in series; the extraction by solvent is achieved with mixers and decanters and more recently with the ''pulsed column'' since 1981; the treatment of scum which hampers the liquid/liquid extraction has been planned in several ways; the latest solution adopted concerns the filtration under pressure; the drying of the concentrate has been effected for several years at ''l'Ecarpiere'' by atomization at the drying space on the belt [fr

  18. Uranium-Series Disequilibria in the Groundwater of the Shihongtan Sandstone-Hosted Uranium Deposit, NW China

    Directory of Open Access Journals (Sweden)

    Xinjian Peng

    2015-12-01

    Full Text Available Uranium (U concentration and the activities of 238U, 234U, and 230Th were determined for groundwaters, spring waters, and lake water collected from the Shihongtan sandstone-hosted U ore district and in the surrounding area, NW China. The results show that the groundwaters from the oxidizing aquifer with high dissolved oxygen concentration (O2 and oxidation-reduction potential (Eh are enriched in U. The high U concentration of groundwaters may be due to the interaction between these oxidizing groundwaters and U ore bodies, which would result in U that is not in secular equilibrium. Uranium is re-precipitated as uraninite on weathered surfaces and organic material, forming localized ore bodies in the sandstone-hosted aquifer. The 234U/238U, 230Th/234U, and 230Th/238U activity ratios (ARs for most water samples show obvious deviations from secular equilibrium (0.27–2.86, indicating the presence of water-rock/ore interactions during the last 1.7 Ma and probably longer. The 234U/238U AR generally increases with decreasing U concentrations in the groundwaters, suggesting that mixing of two water sources may occur in the aquifer. This is consistent with the fact that most of the U ore bodies in the deposit have a tabular shape originati from mixing between a relatively saline fluid and a more rapidly flowing U-bearing meteoric water.

  19. Yellow cake to ceramic uranium dioxide

    International Nuclear Information System (INIS)

    Zawidzki, T.W.; Itzkovitch, I.J.

    1983-01-01

    This overview article first reviews the processes for converting uranium ore concentrates to ceramic uranium dioxide at the Port Hope Refinery of Eldorado Resources Limited. In addition, some of the problems, solutions, thoughts and research direction with respect to the production and properties of ceramic UO 2 are described

  20. Seismicity induced by mining operations in the surrounding of the uranium ore mine Schlema-Alberoda

    International Nuclear Information System (INIS)

    Wallner, Olaf; Hiller, Axel

    2013-01-01

    The uranium mine Schlema-Alberoda of the Wismut GmbH (Chemnitz, Federal Republic of Germany) is situated in the Westerzgebirge between the villages Aue, Schneeberg and Hartenstein. This 22 km 2 large area contains the villages Bad Schlema with the districts Oberschlema, Niederschlema and Wildbach as well as the district Alberode of the village Aue. The most important waters are the Zwickauer Mulde flowing through this territory from the south to the north. This territory can be designated as a densely populated low mountain range landscape being characterized by mining operations for centuries. Subsequently to the year 1945, the former Soviet 'Saxonian mining administration' started the first explorations on uranium ores inter alia in the area around Schneeberg and Schlema. In the year 1946, the intensive exploration and exploitation began in the health resort Oberschlema well-known by the existence of water containing radium. Up to the year 1959, the part deposit Oberschlema was dismantled. The dismantling ranged till to a depth of 750 m. With the expansion of the explorations in north-western direction, in 1948 the first uranium containing corridors of the part deposit Niederschlema-Alberoda was verified. The mining activities began in the year 1949 and culminated in the midst of the 1960ies with an annual production of more than 4,000 tons of uranium. The 1,800 m floor level as the deepest floor level was reached in the year 1986. A total of 49.5 million cubic meters of rocks was dissolved, and a total of 80,500 tons of uranium ores was mined. These were nearly 35% of the total production of the former Soviet-German public limited company Wismut (SDAG Wismut).

  1. Carcinogenic effects of radon daughters, uranium ore dust and cigarette smoke in beagle dogs

    International Nuclear Information System (INIS)

    Cross, F.T.; Palmer, R.F.; Filipy, R.E.; Dagle, G.E.; Stuart, B.O.

    1982-01-01

    The development of pulmonary lesions in beagle dogs was studied following chronic inhalation exposures to radon (at 105 +- 20 nCi/l), radon daughters (at 605 +- 169 WL), uranium ore dust (at 12.9 +- 6.7 mg/m 3 ) and cigarette smoke. Chronic exposures to mixtures of these agents caused significant lifespan shortening compared with controls. Survival times of controls and smoke-exposed dogs were equivalent during the 4 to 5-yr mean survival time of the dogs exposed to radon-daughter and ore-dust mixtures (with or without added cigarette smoke). Animals with tumors of the respiratory tract generally has cumulative radon-daughter exposures exceeding 13,000 WLM; their survival time was longer than that of nontumor-bearing animals. Exposure to cigarette smoke had a mitigating effect on radon daughter-induced tumors. Exposures to smoke from 10 cigarettes/d, 7 d/wk produced no significant respiratory tract lesions. Exposure to 20 cigarettes/d, 7 d/wk resulted in pulmonary emphysema, fibrosis and chronic bronchitis and bronchiolitis. Emphysema and fibrosis were much more prevalent and severe in the dogs exposed to mixtures including radon daughters and uranium/ore dust. These dogs also had adenomatous lesions which progressed to squamous metaplasia of alveolar epithelium, epidermoid carcinoma and bronchioloalveolar carcinoma. Pathologic changes in the airways of these dogs were most prominent in the nasal mucosa, and included a few squamous carcinomas in the nasal cavity. (author)

  2. Method for the recovery of uranium from phosphoric acid, originating from the wet-process of uraniferous phosphate ores

    International Nuclear Information System (INIS)

    Pyrih, R.Z.; Rickard, R.S.; Carrington, O.F.

    1978-01-01

    Improvement in the process for recoverying uranium from wet-process phosphoric acid solution derived from the acidulation of uraniferous phosphate ores by the use of two ion exchange circuits is described. (Auth.)

  3. Methods for the exploration and recovering of uranium

    International Nuclear Information System (INIS)

    Kegel, K.E.

    1982-01-01

    The uranium reserves in the western world occur basically in two types of deposits a) vein type and vein like types b) sedimentary types, with the vein deposits providing only 5 percent of the actual uranium production. 85% of the known uranium reserves in the western world, amounting to about 5 million metric tons U occur in a relatively small number of countries (U.S.A., Canada, Australia, South Africa and Namibia, France, Niger and Gabun). Exploration on uranium deposits is carried out by using geophysical and geochemical methods. Radiometry, i.e. the determination of the radioactivity of the ground in a prospective area, is the main geophysical tool. In the mining of uranium ores, practically all mining methods, applied in other metal mining branches, are being used. The benefication of uranium ore is characterized by a large up-grading factor (i.e. the ratio between the uranium content in the concentrates and the uranium content in the ore) which is higher than in most other metal mining operations. In the field of health and safety in uranium mines, the radiation protection of the workers plays a paramount role. Strict rules exist for maximum values of certain elements in waste air and waste water of uranium mining operations, emitted into the environment. (orig.)

  4. Studies on feasibility of recovering uranium from Dongkeng second class submarginal ore by heap leaching

    International Nuclear Information System (INIS)

    Yang Qingyi

    1994-01-01

    It was proved that it is feasible in economy and in technology to recover uranium from Dongkeng second class submarginal ore by heap leaching, on the basis of analysing the conditions of Mine No. 743 and the tests conducted. Moreover, the social and environmental effects are good. Two valuable suggestions are presented

  5. The determination of trace elements in uranium ores by x-ray fluorescence spectrometry

    International Nuclear Information System (INIS)

    De Villiers, W. van Z.

    1983-11-01

    The determination of 17 trace elements (As, Ba, Co, Cr, Cu, Mo, Nb, Ni, Pb, Rb, Sr, Th, U, V, Y, Zn and Zr) in uranium ores by x-ray fluorescence spectrometry was investigated in this study. The determination of major elements was also necessary for the calculation of mass absorption coefficients. Initially a method was developed for the determination of the elements of interest in unmineralised silicates. Correction for absorption of radiation by the sample were made by means of mass absorption coefficients which were obtained from the relation between the inverse of the mass absorption coefficient and the intensity of the Compton scattering peak. The Feather and Willis method was used for determining the background intensity at the peak positions as well as for mass absorption coefficients. It was observed that the background intensity in the region of the uranium lines increases with increasing uranium content of the sample

  6. Study on extraction of uranium from clayey sandstone with floatation-leaching process

    International Nuclear Information System (INIS)

    Meng Guangshou; Zhao Manchang; Wu Peisheng; Song Wenlan; Li Wenxia.

    1985-01-01

    An improved floatation-leaching process is proposed to extract uranium from some clayey sandstone type of ore. By two-step flotation, the ground feed ore can be divided into three urani-ferous sections, i.e., the sulfidic concentrate carrying organic matter, the carbonate concentrate, and the tailings. The sulfidic concentrate is mixed with the tailings and then treated by acid-leaching with the result that 93% uranium extraction can be attained. The excess free acid of the leached slurry is further neutralized with the carbonate concentrate instead of lime commonly used. As a result, approximately 60% uranium extraction can be attained. As a whole, by the flotation-leaching process the acid consumption can be reduced from 200 kg/t down to < 80 kg/t and the uranium extraction can be raised from 85% to 90% as compared with the conventional acid-leaching process

  7. Glances on uranium. From uranium in the earth to electric power

    International Nuclear Information System (INIS)

    Valsardieu, C.

    1995-01-01

    This book is a technical, scientific and historical analysis of the nuclear fuel cycle from the origin of uranium in the earth and the exploitation of uranium ores to the ultimate storage of radioactive wastes. It comprises 6 chapters dealing with: 1) the different steps of uranium history (discovery, history of uranium chemistry, the radium era, the physicists and the structure of matter, the military uses, the nuclear power, the uranium industry and economics), 2) the uranium in nature (nuclear structure, physical-chemical properties, radioactivity, ores, resources, cycle, deposits), 3) the sidelights on uranium history (mining, prospecting, experience, ore processing, resources, reserves, costs), 4) the uranium in the fuel cycle, energy source and industrial product (fuel cycle, fission, refining, enrichment, fuel processing and reprocessing, nuclear reactors, wastes management), 5) the other energies in competition and the uranium market (other uranium uses, fossil fuels and renewable energies, uranium market), and 6) the future of uranium (forecasting, ecology, economics). (J.S.)

  8. Uranium concentrations in groundwater, northeastern Washington

    Science.gov (United States)

    Kahle, Sue C.; Welch, Wendy B.; Tecca, Alison E.; Eliason, Devin M.

    2018-04-18

    A study of uranium in groundwater in northeastern Washington was conducted to make a preliminary assessment of naturally occurring uranium in groundwater relying on existing information and limited reconnaissance sampling. Naturally occurring uranium is associated with granitic and metasedimentary rocks, as well as younger sedimentary deposits, that occur in this region. The occurrence and distribution of uranium in groundwater is poorly understood. U.S. Environmental Protection Agency (EPA) regulates uranium in Group A community water systems at a maximum contaminant level (MCL) of 30 μg/L in order to reduce uranium exposure, protect from toxic kidney effects of uranium, and reduce the risk of cancer. However, most existing private wells in the study area, generally for single family use, have not been sampled for uranium. This document presents available uranium concentration data from throughout a multi-county region, identifies data gaps, and suggests further study aimed at understanding the occurrence of uranium in groundwater.The study encompasses about 13,000 square miles (mi2) in the northeastern part of Washington with a 2010 population of about 563,000. Other than the City of Spokane, most of the study area is rural with small towns interspersed throughout the region. The study area also includes three Indian Reservations with small towns and scattered population. The area has a history of uranium exploration and mining, with two inactive uranium mines on the Spokane Indian Reservation and one smaller inactive mine on the outskirts of Spokane. Historical (1977–2016) uranium in groundwater concentration data were used to describe and illustrate the general occurrence and distribution of uranium in groundwater, as well as to identify data deficiencies. Uranium concentrations were detected at greater than 1 microgram per liter (μg/L) in 60 percent of the 2,382 historical samples (from wells and springs). Uranium concentrations ranged from less than 1 to

  9. Study on the relation between uranium content and total phosphorus in some sudanese phosphate ore samples

    International Nuclear Information System (INIS)

    Eltayeb, M. A. H.; Mohammed, A. A.

    2003-01-01

    In the present work uranium content and total phosphorus were determined in 30 phosphate ore samples collected from Kurun and Uro areas in Nuba Mountains in Sudan. Spectrophotometry technique was used for this purpose. Uranium analysis is based on the use of nitrogen (V) acid for leaching the rock, and treatment with ammonium carbonate solution, whereby uranium (Vi) is kept in solution as its carbonate complex. The ion exchange technique was used for the recovery of uranium. Uranium was eluted from the resin with 1 M hydrochloric acid. In the elute, uranium was determined spectrophotometrically by measurement of absorbance of the yellow uranium (Vi)-8-hydroxyquinolate complex at λ 400 nm. The total phosphorus was measured as (P 2 O 5 %) by treatment of the total liquor with ammonium molybdate solution. The absorbance of the blue complex was measured at λ 880 nm. The results show that a limited relation is existed between uranium content and total phosphorus in phosphate samples from kurun area, which contain 58.8 ppm uranium in average, where there are no relation is existed in phosphate samples from uro area, which contain 200 ppm uranium in average. (Author)

  10. Study on the relation between uranium content and total phosphorus in some sudanese phosphate ore samples

    International Nuclear Information System (INIS)

    Mohammed, A.A.; Eltayeb, M.A.H.

    2003-01-01

    In the present work uranium content and total phosphorous were determined in 30 phosphate ore samples collected from Kurun and Uro areas in Nuba mountains in sudan. Spectrophotometry technique was used for this purpose. Uranium analysis is based on the use of nitrogen (V) acid for leaching the rock, and treatment with ammonium carbonate solution, whereby uranium (VI) is kept in solution as its carbonate complex. The ion-exchange technique was used for the recovery of uranium. Uranium was eluted from the resin with 1 M hydrochloric acid. In the elute, uranium was determined spectrophotometrically by measurement of the absorbance of the yellow uranium (VI) - 8- hydroxyquinolate complex at λ 400 nm. The total phosphorus was measured as (P 2 O 5 %) by treatment of the leach liquor with ammonium molybdate solution. The absorbance of the blue complex was measured at λ 880 nm. The results show that a limited relation is existed between uranium content and total phosphorus in phosphate samples from Kurun area, which contain 58.8 ppm uranium in average, where there are no relation is existed in phosphate samples samples from Uro area, which contain 200 ppm uranium in average

  11. Uranium deposit of Bauzot (Saone et Loire)

    International Nuclear Information System (INIS)

    Carrat, G.H.

    1956-01-01

    The best known of the uranium ore deposits of the Morvan (a province of France) is in the form of a bundle of quartz-fluor lodes with pitchblende and B.P.G.C. ore. The pitchblende seems to have been deposited at different time in respect to the formation of the gangue minerals, but generally it is ore of the first-formed. The main concentrations of ore are always in the vicinity of dykes of basic crystalline rocks. (author) [fr

  12. Characterization of heavy metals in a uranium ore region of the state of Pernambuco, Brazil.

    Science.gov (United States)

    Bezerra, Jairo Dias; dos Santos Amaral, Romilton; dos Santos Júnior, José Araújo; Genezini, Frederico Antonio; Menezes, Rômulo Simões Cezar; de Oliveira, Iane Andrade

    2014-03-01

    The concentrations of As, Zn, Co, Cr, and Ba were determined in soil samples from an anomalous uranium ore region in the countryside of the state of Pernambuco, Brazil. The main land use system in this region is dairy farming, and there is a need to evaluate the potential risk of milk contamination. Twenty-three soil samples were activated with neutrons and analyzed using a high-resolution gamma-ray spectrometer system. The results, recorded in mg kg(-1), varied from 0.4 to 6.7 for As, from 17.0 to 110.0 for Zn, from 2.8 to 38.4 for Co, from 12.1 to 65.5 for Cr, and from 443.0 to 1,497.0 for Ba. All of the Ba concentrations were higher than the intervention value adopted by the Brazilian National Environmental Board. This finding justifies research in other environmental areas to predict the toxicological risks to the local population.

  13. Analysis of Uranium and Thorium in Waste Water from Rare Earth Research and Development by ICP Spectrometry

    International Nuclear Information System (INIS)

    Pichestapong, Pipat; Injareon, Uthaiwan

    2007-08-01

    Full text: Waste water from Rare Earth Research and Development Center (RRDC) was analyzed to determine uranium and thorium concentration using ICP spectrometry. RRDC processes monazite ore to separate uranium, thorium and rare earth elements from the ore. Water samples from the ditch surrounding the center and from the canal nearby were also analyzed. Matrix spike technique was applied in this analysis. It was found that the highest concentration of uranium and thorium in the waste water samples were 3028±11 and 439±7 ppb, respectively. The concentration of uranium and thorium in the waste water samples were higher than those in water samples from the ditch and canal

  14. Radium-226 in certified uranium reference ores DL-1a, BL-4a, DH-1a and BL-5

    International Nuclear Information System (INIS)

    Smith, C.W.; Steger, H.F.

    1983-05-01

    Radium-226 radioactivity in uranium reference ores BL-4a and BL-5 and uranium-thorium reference ores DL-1a and DH-1a was determined in an interlaboratory program. Twelve of thirteen participants used certified radium solutions from the United States National Bureau of Standards (NBS) for calibration purposes. Recommended values of sup(226)Ra activity and associated parameters were calculated by statistical treatment of the results. In all cases, the recommended values are within 2 percent of activities predicted assuming secular equilibrium in the sup(238)U decay series. The recommended values for radium activity are 1.40, 15.5, 31.5 and 857 Bq/ for DL-1a, BL-4a, DH-1a and BL-5, respectively

  15. Radioactivity and the French uranium bearing minerals

    International Nuclear Information System (INIS)

    Guiollard, P.Ch.; Boisson, J.M.; Leydet, J.C.; Meisser, N.

    1998-01-01

    This special issue of Regne Mineral journal is entirely devoted to the French uranium mining industry. It comprises 4 parts dealing with: the uranium mining industry in France (history, uranium rush, deposits, geologic setting, prosperity and recession, situation in 1998, ore processing); radioactivity and the uranium and its descendants (discovery, first French uranium bearing ores, discovery of radioactivity, radium and other uranium descendants, radium mines, uranium mines, atoms, elements and isotopes, uranium genesis, uranium decay, isotopes in an uranium ore, spontaneous fission, selective migration of radionuclides, radon in mines and houses, radioactivity units, radioprotection standards, new standards and controversies, natural and artificial radioactivity, hazards linked with the handling and collecting of uranium ores, conformability with radioprotection standards, radioactivity of natural uranium minerals); the French uranium bearing minerals (composition, crystal structure, reference, etymology, fluorescence). (J.S.)

  16. Uranium deposit of Bauzot (Saone et Loire); Le gisement d'uranium de Bauzot (Saone et Loire)

    Energy Technology Data Exchange (ETDEWEB)

    Carrat, G H [Commissariat a l' Energie Atomique, Saone et Loire (France). Centre d' Etudes Nucleaires

    1956-07-01

    The best known of the uranium ore deposits of the Morvan (a province of France) is in the form of a bundle of quartz-fluor lodes with pitchblende and B.P.G.C. ore. The pitchblende seems to have been deposited at different time in respect to the formation of the gangue minerals, but generally it is ore of the first-formed. The main concentrations of ore are always in the vicinity of dykes of basic crystalline rocks. (author) [French] Bauzot, le plus connu des gisements d'uranium du Morvan est constitue d'un faisceau de filons quartzofluores, mineralise en pechblende et sulfures B.P.G.S. La pechblende semble s'etre mide en place a des periodes variables par rapport a la gangue mais en general elle constitue un des premiers mineraux deposes. Les principaux amas se situent toujours a proximite de filons de roches lamprophyriques. (auteur)

  17. Biological effects in beagle dogs of inhaled radon daughters, uranium ore dust, and cigarette smoke

    International Nuclear Information System (INIS)

    Palmer, R.F.; Filipy, R.E.; Stuart, B.O.; Hackett, P.; Ragan, H.A.; McDonald, K.E.

    1975-01-01

    After 5 years of daily inhalation exposures to 600 WL radon daughters plus uranium ore dust and/or cigarette smoking, observed pulmonary lesions include macrophage proliferation, septal fibrosis, epithelial hyperplasia, emphysema, endothelial proliferation, and bronchiolar-alveolar epithelial changes involving multiple foci of squamous metaplasia with atypia. Epithelial neoplasms were found in the respiratory tracts of three dogs. (U.S.)

  18. Occupational diseases in uranium and ore miners related to radiation exposure in the Czech Republic in 2002 - 2007

    International Nuclear Information System (INIS)

    Mueller, T.

    2008-01-01

    Dozens cases of disease of former or present uranium and ore miners are submitted to judgment as occupational diseases every year in the Czech Republic. Patients or attending physicians suggest that these cases are caused by occupational ionizing radiation. Only a part of these cases is qualified as occupational disease, nevertheless they can cause many juridical problems. The term 'occupational disease' is rather juridical term which underlies the right to financial compensation. The causal association with exposure to ionizing radiation cannot be indisputably verified by expert medical opinion. Most diseases in uranium and ore miners, which are proposed as occupational disease, are malignant tumors. The majority of judged cases are lung cancers from radioactive agents. The poster gives general information about all judged cases of occupational diseases in former uranium and ore miners in the Czech Republic in the years 2002 -2007. It also provides short information about standards of professional radiation exposure assessment valid in the other countries. Most frequent diseases were lung cancers. Nevertheless the rate of lung cancers acknowledged as occupational disease decreases during the last two decades. Non-melanoma skin cancers are on the second place. The rate of skin cancers increases. We can explain this fact by better diagnostics and by new method which allows more precious assessment of the skin dose. The method is used since 2005. Leukemias are on the third place (1-2 cases in the year). (authors)

  19. Occupational diseases in uranium and ore miners related to radiation exposure in the Czech Republic in 2002 - 2007

    International Nuclear Information System (INIS)

    Mueller, T.

    2009-01-01

    Dozens cases of disease of former or present uranium and ore miners are submitted to judgment as occupational diseases every year in the Czech Republic. Patients or attending physicians suggest that these cases are caused by occupational ionizing radiation. Only a part of these cases is qualified as occupational disease, nevertheless they can cause many juridical problems. The term 'occupational disease' is rather juridical term which underlies the right to financial compensation. The causal association with exposure to ionizing radiation cannot be indisputably verified by expert medical opinion. Most diseases in uranium and ore miners, which are proposed as occupational disease, are malignant tumors. The majority of judged cases are lung cancers from radioactive agents. The poster gives general information about all judged cases of occupational diseases in former uranium and ore miners in the Czech Republic in the years 2002-2007. It also provides short information about standards of professional radiation exposure assessment valid in the other countries. Most frequent diseases were lung cancers. Nevertheless the rate of lung cancers acknowledged as occupational disease decreases during the last two decades. Non-melanoma skin cancers are on the second place. The rate of skin cancers increases. We can explain this fact by better diagnostics and by new method which allows more precious assessment of the skin dose. The method is used since 2005. Leukemias are on the third place (1-2 cases in the year). (authors)

  20. Recovery of uranium low grade ores by froth flotation: study of the texture and synergetic effects of flotation reagents

    International Nuclear Information System (INIS)

    Duverger, Agathe

    2013-01-01

    Due to the energy growing demand, uranium low grade ores may be those exploited in the future. Uranium ores conventional treatment does not often use mineral processing such as concentration methods for reducing leaching reagent consumption. The aim of this work is to develop an upgrading process to improve the operating process (alkaline heap leaching) taking into account the mineralogical and textural variability of the ore. The Trekkopje deposit is composed of calcrete and a gypscrete. The uranium bearing mineral is carnotite (K 2 (UO 2 ) 2 [VO 4 ] 2 .3H 2 O). The gangue minerals are composed by silicates, such as quartz, feldspars, micas and Ca-minerals, calcite and gypsum (XRD and ICP-MS analysis). A SEM image processing was used to study the textural properties and the exposed free surface of mineral inclusions in clay clusters. In calcrete milled to -200 μm, 50 % of all carnotite is associated with clay clusters, which are composed by 98 % of palygorskite, 2 % of illite, montmorillonite, and interbedded clays (XRD and microprobe analysis). The carnotite grain size is 95 % less than 70 μm. Calcite is the main inclusion in clay clusters. Indeed, the calcite inclusions average rate in the clay clusters is 12 % and 5 % for carnotite inclusion. And the free exposed surface percentage of these minerals in clay clusters is 3 % and 6 %, thus indicating that the inclusions should not affect the behavior of mixed clay particles. However, ore flotation essays did not verify this hypothesis. Three minerals separation have been proposed based on the mineral ability to consume leaching reagents: separating Ca-minerals from silicates, palygorskite from gangue minerals and carnotite from gangue minerals. A study of silicates and Ca-minerals electrokinetic properties (electrophoresis) was carried out to select the collectors and the optimum pH range for selective flotation. Basic pH near neutral was proved to be optimal for the separation of gangue minerals with cationic

  1. Cost study on waste management at three model Canadian uranium mines

    International Nuclear Information System (INIS)

    1984-03-01

    A waste management cost study was initiated to determine the capital and operating costs of three different uranium waste management systems which incorporate current technologies being used in Canadian uranium mining operations. Cost estimates were to be done to a thirty percent level of accuracy and were to include all waste management related costs of a uranium ore processing facility. Each model is based on an annual uranium production of 1,923,000 kg U (5,000,000 lbs U 3 O 8 ) with a total operating life of 20 years for the facility. The three models, A, B, and C, are based on three different uranium ore grades, 0.10 percent U 3 O 8 , 0.475 percent U 3 O 8 and 1.5 percent U 3 O 8 respectively. Yellowcake production is assumed to start in January 1984. Model A is based on a conceptual 7,180 tonne per day uranium ore processing facility and waste management system typical of uranium operations in the Elliot Lake area of northern Ontario with an established infrastructure. Model B is a 1.512 tonne per day operation based on a remote uranium operation typical of the Athabasca Basin properties in northern Saskatchewan. Model C is a 466 tonne per day operation processing a high-grade uranium ore containing arsenic and heavy metal concentrations typical of some northern Saskatchewan deposits

  2. Preservation and concentration of uranium mineralization in the crust of weathering

    International Nuclear Information System (INIS)

    Ashikhmin, A.A.; Kuznetsov, S.V.; Shmarovich, E.M.

    1983-01-01

    Inprecision of the concept on indispensable evacuation of U from ores during formation of the crust of weathering of lateritic or kaolinitic profile due to the existence of oxidative situation in the crusts is established. At hydrothermal uranium deposit in Eocambrian sandy-shaly and Paleozoic volcanogenous-sedimentary rocks a high degree of mineralization preservation in lower and medium horizons of Mesozoic-Cenozoic hydro-micaceous-kaolinitic crust of weathering, characterized by reductive situation, presence of carbonaceous substance, pyrite and siderite, is established. Mineralization attained there black composition and was additionally enriched with uranium. A supposition is made that the case is specific for the development of lateritic and kaolinitic crust formation according to ore-bearing rocks, rich in reducing agents-carbonaceous substances, sulfides and minerals of protoxidic iron. The data obtained should be taken into account during prediction and prospecting activities

  3. The Streltsovskoye uranium district

    International Nuclear Information System (INIS)

    Ischukova, L.P.

    1997-01-01

    This paper describes the geology of the Streltsovskoye uranium district located in south-eastern Zabaikalie region, Chita Province, Siberia, Russia. This district hosts Russia's only currently active uranium production centre. The uranium ore was discovered from 1963 to 1967 by drilling below fluorite veins which had minor associated uranium mineralization and radioactive anomalies. The uranium occurs as large scale vein stockwork deposits of hydrothermal origin within a volcano-tectonic caldera formed by continental volcanism of Late Mesozoic age. Rocks occurring in the caldera include basalt and trachydacite, overlain by rhyolite, and with associated interbedded sediments. The ore bodies occur in steeply dipping faults, with the greatest concentrations located where faults along the margins of the caldera intersect steeply dipping, cross cutting, northeasterly and northwesterly striking faults. The Streltsovskoye caldera extends over an area of 150 km 2 and is underlain by a large batholith. The 19 identified uranium deposits occurred in structural features that cut through the caldera sequence and extend into the basement rocks. The caldera has a maximum thickness of 1400 metres. Details of several deposits are given, including descriptions of mineralization and associated alteration. (author). 10 figs

  4. Grade control and the determination of ore reserves at a low-grade uranium mine

    International Nuclear Information System (INIS)

    Reid, J.A.F.; Robertson, B.

    1982-01-01

    In 1966 an intensive exploration programme was conducted by Rio Tinto South Africa Ltd, involving airborne and ground radiometric surveys, percussion and diamond drilling, and pilot-plant tests. This investigation established the presence of a large deposit of low-grade uranium that could be mined on a large scale by open-pitting. Soon after production started in June 1974, it was realized that the original presentation of the ore reserves did not give a true reflection of the orebody. A comparison between the estimates and the ore mined from reserve blocks over the period 1975 to 1977 showed that the reserve grades were over-optimistic. In 1977 Rio Tinto Zinc Consultants were commissioned to re-evaluate the ore reserves from exploration diamond-drill data with the help of The Centre de Geostatistique at Fontainebleau, France. A new global reserve using disjunctive kriging techniques was developed, and is now the long-term reserve used for planning purposes at the Roessing Mine. For short-term planning, ore-reserve data are replaced by information from an intermediate drilling programme and blast-hole assays if these are available. A computerized short-term planning system has been established that reconciles the ore mined against the reserve blocks, as well as a system by which composited blast-hole assays are analysed for grade-control purposes. Owing to the complexity of the orebody, additional monitoring is achieved by the scanning of each truckload of ore with a group of scintillation crystal heads that evaluate the material mined

  5. Exploring implicit dimensions underlying risk perception of waste from mining and milling of uranium ores in France

    International Nuclear Information System (INIS)

    Guillaume, B.; Charron, S.

    2000-01-01

    Understanding public perceptions of risks is increasingly considered to be important in order to make sound policy decisions. For many years, social scientists have been working to understand why the public is so concerned about nuclear energy and radioactive waste. Indeed, risk perception studies have essentially focused on high-level nuclear waste. As a result, there is now a fair understanding of what determines public support or opposition to high-level nuclear waste storage and disposal facilities. However, to date, little research has been conducted into radioactive waste from mining and milling of uranium ores. In France, such waste have a much debated legal status, which illustrates their ambiguous origin (natural versus artificial) and the manner people can perceive them. Therefore, it seems relevant to explore the individual judgements, attitudes and beliefs towards risk associated with uranium mill tailings. The present study provides a structural model based on both the identification and analysis of implicit dimensions underlying risk perception (psychological, cultural, moral...) applied to the case of french uranium mill tailings. One objective of the research has been to develop an interview grid based on this conceptual model in order to elicit social demand beyond public attitudes. Semi-structured interviews have been conducted on site in french uranium bearing areas. The relationships inferred between identified risk characteristics and contextual risk perceptions suggest that five majors thematics (time, space, nature, ethics and trust) build determinants of the public's perceptions of risk related to waste from mining and milling of uranium ores. (author)

  6. Calculation of U, Ra, Th and K contents in uranium ore by multiple linear regression method

    International Nuclear Information System (INIS)

    Lin Chao; Chen Yingqiang; Zhang Qingwen; Tan Fuwen; Peng Guanghui

    1991-01-01

    A multiple linear regression method was used to compute γ spectra of uranium ore samples and to calculate contents of U, Ra, Th, and K. In comparison with the inverse matrix method, its advantage is that no standard samples of pure U, Ra, Th and K are needed for obtaining response coefficients

  7. Radioactivity of phosphate ores from Karatas-Mazidag phosphate deposit of Turkey

    International Nuclear Information System (INIS)

    Akyuez, T.; Varinlioglu, A.; Kose, A.; Akyuez, S.

    2000-01-01

    The specific activities of 238 U, 226 Ra, 232 Th and 40 K in the composite samples of phosphate ores of type I (grey-coloured ore, with high P 2 O 5 (21-35%) and low calcite content) and of type II (grey coloured calcite ore, with low P 2 O 5 content (5-17%)) of Karatas-Mazidag phosphate deposit, Turkey, have been determined by gamma spectrometry together with phosphatic animal feed ingredients. The concentrations of 238 U, 226 Ra, 232 Th and 40 K were found to be up to 557, 625, 26 and 297 Bq x kg -1 , respectively. Radium equivalent activities of samples were calculated and compared with those given in the literature. Uranium concentration of the individual phosphate samples, from which composite samples of ores of type I and II have been prepared, were found to show and increasing trend with increasing P 2 O 5 and F concentrations. (author)

  8. 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. Copyright © 2016 Elsevier Inc. All rights reserved.

  9. Processing of Low-Grade Uranium Ores. Proceedings of a Panel

    International Nuclear Information System (INIS)

    1967-01-01

    The 22 specialists from 15 countries and one international organization who attended the meeting were asked to give an appraisal of the current situation with regard to the processing of low-grade uranium ores and make recommendations for a possible IAEA programme of activities. This publication covers the work of the panel. Contents: Status reports (13 reports); Technical reports (13 reports); Summaries of discussions; Recommendations of the panel. Each report is in its original language (16 English, 4 French, 2 Russian and 4 Spanish) and each technical report is preceded by an abstract in English and one in the original language if this is not English. The summaries of discussions and the panel recommendations are in English. (author)

  10. Processing of Low-Grade Uranium Ores. Proceedings of a Panel

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    1967-06-15

    The 22 specialists from 15 countries and one international organization who attended the meeting were asked to give an appraisal of the current situation with regard to the processing of low-grade uranium ores and make recommendations for a possible IAEA programme of activities. This publication covers the work of the panel. Contents: Status reports (13 reports); Technical reports (13 reports); Summaries of discussions; Recommendations of the panel. Each report is in its original language (16 English, 4 French, 2 Russian and 4 Spanish) and each technical report is preceded by an abstract in English and one in the original language if this is not English. The summaries of discussions and the panel recommendations are in English. (author)

  11. PHWR fuel fabrication with imported uranium - procedures and processes

    International Nuclear Information System (INIS)

    Rao, R.V.R.L.V.; Rameswara Rao, A.; Hemantha Rao, G.V.S.; Jayaraj, R.N.

    2010-01-01

    Following the 123 agreement and subsequent agreements with IAEA & NSG, Government of India has entered into bilateral agreements with different countries for nuclear trade. Department of Atomic Energy (DAE), Government of India, has entered into contract with few countries for supply of uranium material for use in the safeguarded PHWRs. Nuclear Fuel Complex (NFC), an industrial unit of DAE, established in the early seventies, is engaged in the production of Nuclear Fuel and Zircaloy items required for Nuclear Power Reactors operating in the country. NFC has placed one of its fuel fabrication facilities (NFC, Block-A, INE-) under safeguards. DAE has opted to procure uranium material in the form of ore concentrate and fuel pellets. Uranium ore concentrate was procured as per the ASTM specifications. Since no international standards are available for PHWR fuel pellets, Specifications have to be finalized based on the present fabrication and operating experience. The process steps have to be modified and fine tuned for handling the imported uranium material especially for ore concentrate. Different transportation methods are to be employed for transportation of uranium material to the facility. Cost of the uranium material imported and the recoveries at various stages of fuel fabrication have impact on the fuel pricing and in turn the unit energy costs. Similarly the operating procedures have to be modified for safeguards inspections by IAEA. NFC has successfully manufactured and supplied fuel bundles for the three 220 MWe safeguarded PHWRs. The paper describes various issues encountered while manufacturing fuel bundles with different types of nuclear material. (author)

  12. Quantifying multiple trace elements in uranium ore concentrates. An interlaboratory comparison

    International Nuclear Information System (INIS)

    Buerger, S.; Boulyga, S.F.; Penkin, M.V.; Jovanovic, S.; Lindvall, R.; Rasmussen, G.; Riciputi, L.

    2014-01-01

    An intercomparison was organized, with six laboratories tasked to quantify sixty-nine impurities in two uranium materials. The main technique employed for analysis was inductively coupled plasma mass spectrometry in combination with matrix-matched external calibration. The results presented highlight the current state-of-the-practice; lessons learned include previously unaccounted polyatomic interferences, issues related to sample dissolution, blank correction and calibration, and the challenge of estimating measurement uncertainties. The exercise yielded consensus values for the two analysed materials, suitable for use as laboratory standards to partially fill a gap in the availability of uranium reference materials characterized for impurities. (author)

  13. Ore leaching processing for yellow cake production and assay of their uranium content by radiometric analysis

    Energy Technology Data Exchange (ETDEWEB)

    Abdel-Rahman, Mohamed A.E. [Nuclear Engineering Department, Military Technical College, Kobry El-Kobbah, Cairo (Egypt); El-Mongy, Sayed A. [Nuclear and Radiological Regularity Authority (ENRRA), Nasr City, Cairo (Egypt)

    2018-01-17

    In this study, Ore granite samples were collected from Gattar site for leashing of yellow cake. The process involves heap leaching of uranium through four main steps; size reduction, leaching, uranium purification, and finally precipitation and filtration. The separation process has been given in details and as flow chart. Gamma spectrometry based on HpGe detector and energy dispersive X-ray (EDX) were used to assay uranium content and activity before and after separation. The uranium weight percentage value as measured by EDX were found to be 40.5 and 67.5 % before and after purification respectively. The results of the calculations based on gamma measurements show high uranium activity and the uranium activity ratios values are 0.045 ± 4.9, 0.043 ± 4.7, and 0.046 ± 2.3 %, before purification, whereas these values were found to be 0.050 ± 3.3, 0.049 ± 3.3, and 0.050 ± 2.7 %, after purification, respectively. The results are discussed in details in the paper. (copyright 2018 WILEY-VCH Verlag GmbH and Co. KGaA, Weinheim)

  14. REE characteristics and uranium metallogenesis of sandstone-type uranium deposits in northern Sichuan

    International Nuclear Information System (INIS)

    Zhu Xiyang; Wang Yunliang; Wang Zhichang; Zhang Chengjiang

    2004-01-01

    On the basis of the analysis of a large number of samples at sandstone-type uranium deposits in northern Sichuan, this paper analyses the REE composition of country rocks, ores, calcite-veins and uranium minerals, and systematically summarizes their REE geochemical characteristics, and discusses variation regularity of REE during depositional and diagenetic processes. By comparing these characteristics with those of typical hydrothermal volcanics-type and metamorphic rock type uranium deposits both at home and abroad, authors suggest that sandstone-type uranium deposits in northern Sichuan are characterized by REE geochemical features of hydrothermal reworking metallogenesis, the uranium mineralization has experienced two stages: the diagenetic preconcentration and the concentration of hydrothermal reworking

  15. Origin of granite and mineralization of uranium ore field No.6210

    International Nuclear Information System (INIS)

    Xu Guoqing.

    1987-01-01

    Uranium ore field No.6210 is of granitic type. A lot of work about the origin of the granite and mineralization has been done by many geologists over the years, but the conclusion remains disputable. Some authors suggest that the granitic magma was derived from mantle, others maintain that it was resulted from partial melting of crustal materials. There are two main points of view about the genesis of mineralization: magmatic hydrothermal and vadose. Therefore, with the exception of field investigation, strontium, sulfur, oxygen, carbon and lead isotopes were studied. REE distribution pattern, chemical compositions of biotite and whole rocks were explored. In granite the values of δ 34 S scatter in the range from -0.5 to 2.5per mille with a mean value of 0.77per mille, the values of δ 18 O lie in the range from 7.59 to 13.0per mille with an average of 10.55per mille. The ratio of ( 87 Sr/ 86 Sr)i of whole rocks is 0.7197. Biotite index MF 8 pa. In ore deposits, the values of δ 34 S range from -1.2 to 4.6per mille with a mean value of 1.52per mille, the values of δ 18 O fall in the range from -9.88 to 12.02per mille with an average amount of 3.56per mille, the values of δ 13 C are in the narrow range between -7.15 and -9.79per mille with an average of -8.96per mille and the ratios of 206 Pb/ 204 Pb 208 Pb/ 204 Pb < 39.5. Therefore, by the sulfur, carbon and lead isotopes, it is shown that the ore-forming solution in the ore field is magmatic hydrothermal, but by the oxygen isotope, it is implicated that after the fromation of hydrothermal ineralization, the ore deposits were reformed by meteoric water

  16. Solubility classification of airborne products from uranium ores and tailings piles

    International Nuclear Information System (INIS)

    Kalkwarf, D.R.

    1979-01-01

    Airborne products generated at uranium mills were assigned solubility classifications for use in the ICRP Task Group Lung Model. No significant difference was seen between the dissolution behavior of airborne samples and sieved ground samples of the same product. If the product contained radionuclides that dissolved at different rates, composite classifications were assigned to show the solubility class of each component. If the dissolution data indicated that a radionuclide was present in two chemical forms that dissolved at different rates, a mixed classification was assigned to show the percentage of radionuclide in each solubility class. Uranium-ore dust was assigned the composite classification: ( 235 U, 238 U) W; ( 226 Ra) 10% D, 90% Y; ( 230 Th, 210 Pb, 210 Po) Y. Tailings-pile dust was classified: ( 226 Ra) 10% D, 90% Y; ( 230 Th, 210 Pb, 210 Po) Y. Uranium octoxide was classified Y, uranium tetrafluoride was also classified Y, ammonium diuranate was classified D, and yellow-cake dust was classified ( 235 U, 238 U) 60% D, 40% W. The term yellow cake, however, covers a variety of materials which differ significantly in dissolution rate. Solubility classifications based on the dissolution half-times of particular yellow-cake products should, thus, be used when available. The D, W, and Y classifications refer to biological half-times for clearance from the human respiratory tract of 0 to 10 days, 11 to 100 days, and > 100 days, respectively

  17. Report on the progress of work in Portugal [Processing of Low-Grade Uranium Ores]; Rapport sur l'etat d'avancement des travaux au Portugal

    Energy Technology Data Exchange (ETDEWEB)

    Carreira Pich, H [Junta de Energia Nuclear, Laboratorio de Fisica e Engenharia Nucleares, Sacavem (Portugal)

    1967-06-15

    The purpose of the principal studies until now in Portugal were the development of two types of treatment of the uranium minerals: - Traditional leaching by agitation of the ore milled in a finely sulphuric acid solution; - Leaching of the type 'heap leaching' in which the ore is hard crushed, and then sprinkles is crammed with sulphuric acid solution. Leaching tests were performed traditionally with samples of available Portuguese minerals. In most cases, the dissolution of uranium is easy and low consumption of acid. Efforts were oriented in the direction of a leaching type 'heap leaching'.

  18. Pleistocene apparent ages by U-Pb isotope and U-series methods for uranium ore in Dakota Sandstone near Gallup, New Mexico

    International Nuclear Information System (INIS)

    Ludwig, K.R.; Szabo, B.J.; Granger, H.C.

    1977-01-01

    Radiometric dates of a high-grade uranium ore from the Hogback No. 4 mine in Dakota Sandstone near Gallup, N. Mex., indicate a late Pleistocene age of mineralization. The 206 Pb/ 238 U and 207 Pb/ 235 U apparent ages of about 70,000 y and 100,000 y, respectively, are discordant, but are in broad agreement with the discordant 230 Th/ 238 U and 230 Pa/ 235 U apparent ages of 130,000 y and 78,000 y, respectively. Although it is not clear how the analyzed sample relates to the main period of mineralization at this mine, these dates are consistent with previous age limits suggested for Dakota Sandstone uranium ores

  19. Rirang uranium ore processing : separation of rare earth from alkaline digest

    International Nuclear Information System (INIS)

    Erni, R.A.; Pudjianto, R.; Zahardi; Susilaningtyas

    2000-01-01

    Rirang uranium ore contains several economically potential elements, including U (0.52%), RE (63.04 %), PO 4 3- 24.55 % and Th 0.02 %. Separation and purification processes are employed to obtain relatively pure concentrate of the elements. Separation of phosphate by decomposition using NaOH was conducted previously. The present experiment has an objective, e.g. to separate RE from U and Th through a two step process, total dissolution of RE, U, Th and undercomposed of phosphate remain using HCI, by precipitation of U and Th using NH 4 OH. Experimental condition includes dissolution of RE in hydrochloric acid 15 ml/10 gr feed at 80 o C for 1 hr, followed by precipitation of U and Th using 2 N NH 4 OH at pH 6.4 and room temperature. Experimental data show excellent dissolution recovery for Re 94.41 %, U 99.15 %, Th 95.17 %, while precipitation of U and Th produced separation recovery of RE 91.97 %, U 1.01 %, Th 5 % and PO 4 3- not detected. As a conclusion, RE can be separated from U and Th. (author)

  20. The discovery of hornblende-garnet-zoisite hornfels in the metamorphic basement of Xiangshan uranium ore field

    International Nuclear Information System (INIS)

    Jiang Zhenpin; Dong Yongjie; Yu Jianfa; Hu Rongquan; Wu Shuilin

    2007-01-01

    Some vein rocks are found among mica schist in the metamorphic rock area of the Xiangshan uranium ore field. They are petrologically denominated as hornblende-garnet-zoisite hornfels. The primitive rocks are basic vein rocks. The hornfels are formed under thermal metamorphism with the temperature about 640 degree C and belong to low-pressure faces. This is closed to the form condition of EarlyMiddle Proterozoic metamorphic rocks in the area. The metamorphism forming the hornfels means that the Early-Middle Proterozoic metamorphic rocks was superimposed to another thermal metamorphism and produced the second phase metamorphic minerals such as staurolite, almandine and biotite. The lattice of the second phase metamorphic mineral developed continuously with the first phase minerals. The overlapping metamorphism made the first phase metamorphic mineral suffer recrystallization, auto purification and idiomorphism. The discovery of hornfelsed basic rock veins discloses that strong geologic process with the activity of fault, magma and metamorphism were still taken placed in Paleozoic era within the metamorphic basement of the Xiangshan uranium ore field. (authors)