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Sample records for albarrana uranium ores

  1. Processing of Sierra Albarrana uranium ores

    International Nuclear Information System (INIS)

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

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

    Energy Technology Data Exchange (ETDEWEB)

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

    1960-07-01

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

  3. Uranium from phosphate ores

    International Nuclear Information System (INIS)

    Phosphate rock, the major raw material for phosphate fertilizers, contains uranium that can be recovered when the rock is processed. This makes it possible to produce uranium in a country that has no uranium ore deposits. The author briefly describes the way that phosphate fertilizers are made, how uranium is recovered in the phosphate industry, and how to detect uranium recovery operations in a phosphate plant. Uranium recovery from the wet-process phosphoric acid involves three unit operations: (1) pretreatment to prepare the acid; (2) solvent extraction to concentrate the uranium; (3) post treatment to insure that the acid returning to the acid plant will not be harmful downstream. There are 3 extractants that are capable of extracting uranium from phosphoric acid. The pyro or OPPA process uses a pyrophosphoric acid that is prepared on site by reacting an organic alcohol (usually capryl alcohol) with phosphorous pentoxide. The DEPA-TOPO process uses a mixture of di(2-ethylhexyl)phosphoric acid (DEPA) and trioctyl phosphine oxide (TOPO). The components can be bought separately or as a mixture. The OPAP process uses octylphenyl acid phosphate, a commercially available mixture of mono- and dioctylphenyl phosphoric acids. All three extractants are dissolved in kerosene-type diluents for process use

  4. Uranium ore deposits

    International Nuclear Information System (INIS)

    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.)

  5. Uranium ore processing at Lodeve

    International Nuclear Information System (INIS)

    The plant for ore treatment is described. Ore preparation, crushing, alkaline attack, by Na2CO3, washing of solid residues, treatment of uraniferous liquors and effluents are reviewed. Technical and economical information on capacity, personnel, consumptions and investments are given. 881 t of uranium were produced in 1984

  6. Filtration aids in uranium ore processing

    International Nuclear Information System (INIS)

    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

  7. Studies on uranium ore processing

    International Nuclear Information System (INIS)

    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)

  8. Uranium from phosphate ores

    International Nuclear Information System (INIS)

    The following topics are described briefly: the way phosphate fertilizers are made; how uranium is recovered in the phosphate industry; and how to detect covert uranium recovery operations in a phsophate plant

  9. Technological mineralogy study on uranium ores in Yunji ore deposit

    International Nuclear Information System (INIS)

    Based on the study of the types and features of technological mineralogy in Yunji uranium ore deposit, the factors influencing the heap leaching are researched, and uranium occurrence state is found out. The technological mineralogy data are provided for predicting, improving, and controlling the uranium ore heap leaching process. (authors)

  10. Uranium Ore and Concentrate Sampling

    International Nuclear Information System (INIS)

    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 U3O8 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 upon the

  11. Extraction of uranium from its ores

    International Nuclear Information System (INIS)

    The ore is ground and mixed with sulphuric acid to give a moist ore containing a sulphuric acid concentration of less than 4N without forming a continuous liquid phase. The moist ore is cured at from 500 to 1000 while passing an oxidising gas through it. Using this method it is possible to achieve uranium extractions of % or better in 24 hours or less. This invention provides an improved method for acid leaching of uranium from its ores and especially from those ores which contain uranium as a finely-diaseminated refractory material, such as brannerite or uraninite. (LL)

  12. Uranium ore leaching at Bertholene (France)

    International Nuclear Information System (INIS)

    After a brief review of the geology and mineralisation of the uranium deposit ore processing is described. It comprises an acid attack, in immersed boxes of the crushed ore (0-8 mm). Uranium is extracted from the clarified liquor by ion exchange resins, elution and fabrication of magnesium diuranate are realized in another plant

  13. Uranium ore processing minimizing reagent losses

    International Nuclear Information System (INIS)

    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

  14. Geostatistical estimation of uranium ore reserves

    International Nuclear Information System (INIS)

    Since the early 1960s geostatistics have been applied for uranium ore reserves calculation, and, as in the case for other minerals, has been considerably developed. This is because of the ability of geostatistics to quantify clearly the main ore reserve questions, i.e. which are the geological (or in situ) ore reserves; what are the effects of a mining selection (recoverable reserves); and what is the precision of these estimates. These different concepts are presented in this paper as applied to uranium ore deposits. First, the specific problem of uranium is analysed, which is the importance of indirect measurements of grade by radiometry logging, which introduces imprecisions generally higher in the uranium grades and tonnages than those coming from the ore reserve calculation itself. (author)

  15. Securing Uranium Ore Products. Namibian Perspective

    International Nuclear Information System (INIS)

    Namibia has been mining and processing uranium ores since 1970’s and over the past years supplies on average 8% of uranium oxide to the world market. Namibia has several laws governing the security of the ore product and satisfactory control measures at the mine, during transport and at the harbour. Records of incidences of theft proved to be motivated by economic gains but not for terrorist intentions. There is a need to harmonise legislation, regulations and regulatory practices related to the production, storage and transport of ore products among member states. (author)

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

    International Nuclear Information System (INIS)

    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

  17. Radiometric sorting of Rio Algom uranium ore

    International Nuclear Information System (INIS)

    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/in2) but only 7.6 percent of the ore, by weight, was discarded. At 0.8-0.9 counts/cm2 (5-6 counts/in2) 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

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

    International Nuclear Information System (INIS)

    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)

  19. Modelling a uranium ore bioleaching process

    International Nuclear Information System (INIS)

    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

  20. Fractal kinetic model for heap leaching of uranium ore

    International Nuclear Information System (INIS)

    By using fractal dimensions of the full particle size distribution instead of average particle size, the analytical models describing heap leaching of uranium ore which were presented by Mellado et al, were improved. Meanwhile, the relationships between the model parameters of the fractal kinetic model for heap leaching of uranium ore and the fractal dimension of uranium ore were determined by column leaching experiments, and then a fractal kinetic model for heap leaching of uranium ore was established, and was further verified by column leaching experiments. The result shows that the fractal kinetic model can well reflect the law of uranium metal leaching of heap leaching of uranium ore. (authors)

  1. Underground leaching of uranium ores

    International Nuclear Information System (INIS)

    Large amounts of low-grade U ore, not worth processing by conventional methods, are to be found at many sites in mine pillars, walls, and backfilling. Many proven deposits are not being mined because the geological conditions are difficult or the U ore is of relatively low grade. Factors such as radioactive emission, radon emanation, and the formation of radioactive dust give rise to health hazards. When U ores are treated above ground, enormous quantities of solid and liquid radioactive waste and mining spoil accumulate. The underground leaching of U is a fundamentally different kind of process. It is based on the selective dissolving of U at the place where it occurs by a chemical reagent; all that reaches the ground surface is a solution containing U, and after extraction of the U by sorption the reagent is used again. The main difficult and dangerous operations associated with conventional methods (excavation; extraction and crushing of the ore; storage of wastes) are avoided. Before underground leaching the ore formation has to be fractured and large ore bodies broken down into blocks by shrinkage stopping. These operations are carried out by advanced machinery and require the presence underground of only a few workers. If the ore is in seams, the only mining operation is the drilling of boreholes. The chemical reagent is introduced under pressure through one set of boreholes, while the U bearing solution is pumped out from another set. The process is monitored with the help of control boreholes. After extraction of the U by sorption, the reagent is ready to be used again. Very few operations are involved and insignificant amounts of dissolved U escape into the surrounding rock formations. Experience has shown that underground leaching reduces the final cost of the U metal, increases productivity, reduces capital expenditure, and radically improves working conditions

  2. Heap leaching of clay ish uranium ores

    International Nuclear Information System (INIS)

    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)

  3. Economic evaluation of preconcentration of uranium ores

    International Nuclear Information System (INIS)

    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

  4. Uranium valorisation process from an uranium ore containing arsenic

    International Nuclear Information System (INIS)

    The purpose of this process is to remove the arsenic from a uraniferous liquor resulting from the oxidizing sulfuric digestion of an uranium ore. It is characterized in that the arsenic solubilized during the digestion is rendered insoluble as iron arsenate, prior to uranium extraction, by the addition of an alkaline agent to adjust the pH of the solution resulting from the digestion to a figure between 1.5 and 3.5 in the presence of ferric ions, so that the molar ratio (Fe111)/(As) is greater than 1. The iron intervening in this precipitation can come from the ore itself since it is an impurity contained in the uranium ore gang

  5. Lixiviation of uranium ores by capillarity

    International Nuclear Information System (INIS)

    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)

  6. Study on ore stacking after blasting for stope leaching uranium

    International Nuclear Information System (INIS)

    Geology of ore deposits, technical conditions, mining methods and blasting parameters of in-situ leaching uranium after blasting for an outcrop ore body are introduced. Long hole blast is beneficial technique and can bring better economic benefits

  7. Oxidizing roasting enhances extraction of uranium from some refractory ores

    International Nuclear Information System (INIS)

    Roasting in an oxidizing environment improves extraction of uranium from some refractory ores. Roasting of the ore tested also tends to reduce reagent costs and handling problems. Ores that may benefit from roasting include those of low uranium extractability that contain oxidizable organic materials or clay minerals. Roasting improves the porosity of ores by removing carbonaceous material and dehydrating clays, and it may even break down agglomerates of a clay-silica-organic nature. The result is better access of the leaching agent to the uranium-containing fractions of the ore

  8. Static Leaching of Spanish Uranium Ores

    International Nuclear Information System (INIS)

    The paper summarizes the experience acquired in Spain during seven years of investigation on the static leaching of uranium ores. The operations covered minerals showing wide variations with regard to both uranium content (250 and 2000 ppm) and the type of rock and gangue (granites, shales, sandstones, sulphides, carbonates, limonites etc. ). The studies were carried out on quantities of material varying from a few kilograms to several tons. Leaching agents included water, solid reagents (pyrites), alkaline carbonates and sulphuric acid. The systems used consisted of both simple layouts and other, more elaborate schemes including recycling of the liquors. The uranium was recovered from the liquors first by direct precipitation and later by ion-exchange and extraction with amines. (author)

  9. Static leaching of Spanish uranium ores

    International Nuclear Information System (INIS)

    The paper summarizes the experience acquired in Spain during seven years of investigation on the static leaching of uranium ores. The operations covered minerals showing wide variations with regard to both uranium content (250 and 2000 ppm) and the type of rock and gangue (granites, shales, sandstones, sulphides, carbonates, limonites etc.). The studies were carried out on quantities of material varying from a few kilograms to several tons. Leaching agents included water, solid reagents (pyrites), alkaline carbonates and sulphuric acid. The systems used consisted of both simple layouts and other, more elaborate schemes including recycling of the liquors. The uranium was recovered from the liquors first by direct precipitation and later by ion-exchange and extraction with amines. (author)

  10. Alternative leaching processes for uranium ores

    International Nuclear Information System (INIS)

    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

  11. Selection of leaching parameters on uranium ores of a deposit

    International Nuclear Information System (INIS)

    Uranium minerals of a uranium ore in Jiangxi province and its composition were investigated. Baesd on the investigation, the processing method and leaching parameters were selected through experiments. (authors)

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

    International Nuclear Information System (INIS)

    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)

  13. Uranium mobilization from low-grade ore by cyanobacteria

    International Nuclear Information System (INIS)

    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.)

  14. Research on existing state of uranium and uranium ore-formation age at Qianjiadian uranium deposit in Kailu depression

    International Nuclear Information System (INIS)

    The existing state of uranium and the uranium ore-formation process of Qianjiadian uranium deposit have been studied. The uranium existing state in ores of Qianjiadian uranium deposit includes uranium mineral, the adsorbed uranium and U-containing mineral. Of them, the uranium mineral and adsorbed uranium are main forms of uranium existence. The U6+/U4+ ratio ranges from 0.266 to 1.116 with the average value of 0.761. Uranium may be distributed in all grain size fractions, but it is concentrated in the fraction of 0.1-0.25 mm, accounting for 27.89%-76.98% (in average 46.55%) of the total uranium in ore. The U-Pb isochron ages of uranium ore-formation have been obtained at 53±3 Ma and 7±0 Ma. (authors)

  15. Ore-processing technology and the uranium supply outlook

    International Nuclear Information System (INIS)

    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.)

  16. Uranium distribution in uranium ores and source rocks

    International Nuclear Information System (INIS)

    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

  17. The treatment of uranium ores at Bertholene

    International Nuclear Information System (INIS)

    The deposit has modest dimensions and a low grade, as the mineralization is composed of vanadates in the oxidized zone and of predominating coffinite in the reduced zone. The treatment process, specified through laboratory tests, consists of acid leaching, in immersed boxes, of the ore crushed to 0-8 mm. The uranium is extracted from the clarified liquors by a passage over ion exchanger resins. The elution and later the finishing treatment to diuranate of magnesia are effected at Jouac, a plant situated north of the Central Group of Mountains. The plant represents a small investment; it requires little manpower and can be considered as the very type of plant likely to increase the value of small deposits

  18. Dissolution of Uranium Rirang Ore Decomposition Residue

    International Nuclear Information System (INIS)

    Uranium Rirang ore from West Kalimantan origin, contains radioactive elements such as U (0.85%), Th (0.08%), apart from that RE (60.85%) (PO43-) 32.85% and rutile 5.37 %. Ore decomposition using sodium hydroxide (NaOH) in order to separate PO43- has been previously done with result the optimal decomposition conditions are, the ratio : Water : NaOH = 1 : 1.7 : 1.7; temperature 140oC and time 4 hours. In this experiment, totally dissolution of U, Th, and RE with decomposition residue yield has been carried out using concentrated hypochloric acid (HCl) as a solvent, in order to obtain optimally dissolution condition concerring to its parameters such as HCl consumption, temperature and time of dissolution, respectively. The experiment shows that the optimal condition process yielded at the consumption of concentrated HCl is 120 ml/100 gr feed, temperature 80oC, time dissolution 2 hours, yielding the recovery of U = 96.91%, Th = 88.17% and RE = 91.99%, respectively. (author)

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

    International Nuclear Information System (INIS)

    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)

  20. Find that rich uranium some questions for reflection in Taoshan uranium ore field

    International Nuclear Information System (INIS)

    Taoshan uranium ore field is our main field of granite-type uranium deposits, uranium resources is enormous, but short and low grade ore. Articles thoughts that Taoshan ore field looking for high taste ore in the future development of large uranium deposits around the following questions should be started. (1) rock inside and outside the contact zone: Taoshan ore field is located in most major deposits of internal rock, ore a smaller scale, But contacted outside with the rock may be favorable for uranium accumulation. (2) Meeting point geological structure: Taoshan uranium ore field growth of three dikes which orientation NE∼NEE filled. That Dafushang-Wangnitian-Chepankeng vein rock belts, Zhuyuantou-Xiaoyuan vein rock belts, Huangtan-Xiaoyuan vein rock belts. Vein rock band was close to EW. the main lamprophyre dikes, granitic porphyry, fine-grained granite. Whether there have uranium deposits where dikes constructed with the North East to the intersection. It is the good position to looking for high taste ore where Lamprophyre and North East to the intersection of structure. (3) The main structure of the ore potential: on trunk of broken ore whether have uranium is the focus of the next prospecting break; (4) Deep Exploration: to expose the area worthy of deep, deep uranium deposits may be significant. (author)

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

    International Nuclear Information System (INIS)

    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

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

    International Nuclear Information System (INIS)

    Pulmonary function evaluations were conducted on dogs exposed to carnotite uranium ore dust. Significant changes were detected in the slope of the single-breath N2 washout curve, suggesting an uneven distribution of ventilation

  3. Metallogenesis of rich uranium deposits in Xiangshan hydrothermal ore field

    International Nuclear Information System (INIS)

    Xiangshan Uranium Ore field located in Jiangxi Province, south of China, is one of the largest volcanogenic hydrothermal uranium ore fields in China. There are apparent difference in uranium metallogenesis between low-grade deposits and rich uranium ones (U > 0.3%, especially U > 1%) in Xiangshan hydrothermal uranium ore field. The special hydrothermal solution with higher content of P, Ti, K elements is a geochemical controlling factor for rich uranium mineralization. Fluorine is an important transporter for uranium migration in hydrothermal system, however, it plays a limited function of uranium mineralization. In fact, uranium and thorium are migrated and precipitated through some complicated processes including alkali-metasomatism, co-migration, colloid co-precipitation with phosphate minerals and gas reduction etc., which has been proved by field investigation, experiments and a number of analysis. The deeper the orebodies are located, the higher the grade of ore is. The reasonable explanation is as following: (1) the contents of P, Ti, F, K. U and reducing gases in hydrothermal solution increase along with deepness; (2) The temperature and pressure in deep are higher than that on shallower parts. All the factors mentioned above together play active roles in uranium enrichment. Some suggestions for further exploitation and exploration in Xiangshan area have been put forward

  4. Study on groundwater pollution in Xiangshan uranium ore-field

    International Nuclear Information System (INIS)

    The groundwater pollution in uranium deposits in the eastern part of Xiangshan uranium mine of China was theoretically and practically studied by using isotopic and radio-hydrochemical techniques. The linear regression equation of the local meteoric water line was obtained The exploration and mining of the uranium deposits will not lead to the apparent radioactive pollution of groundwater in the uranium ore-field

  5. PROCESS FOR THE CONCENTRATION OF ORES CONTAINING GOLD AND URANIUM

    Science.gov (United States)

    Gaudin, A.M.; Dasher, J.

    1958-06-10

    ABS>A process is described for concentrating certain low grade uranium and gold bearing ores, in which the gangue is mainly quartz. The production of the concentrate is accomplished by subjecting the crushed ore to a froth floatation process using a fatty acid as a collector in conjunction with a potassium amyl xanthate collector. Pine oil is used as the frothing agent.

  6. Present methods for mineralogical analysis of uranium ores

    International Nuclear Information System (INIS)

    Most promising methods of mineralogic analysis of uranium and uranium-containing minerals, ores and rocks are considered. They include X-ray diffraction, electron microscopy and fluorescence spectroscopy methods. Principle physical basis and capabilities of each method are described; examples of its practical application are presented. Comparative characteristic of method for mineralogic analysis of radioactive ores and their reprocessing products is given. Attention is paid to the equipment and various devices for analysis

  7. 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)

  8. Analysis on metallogenic conditions of Xiangshan uranium ore-field

    International Nuclear Information System (INIS)

    Based on the research achievements the authors propose that: the formation of the ore-field not only results from a favourable regional tectonic background, i.e. a giant tectonic intersection of two deep-seated faults expressed as granite and volcanic belts, but also, the more important point is the favourable metallogenic environments, namely: the ore-field is located in a large superimposed collapse-type volcanic basin with simple binary structure; the space superimposition of U-rich basement metamorphic rocks intruded by granite, and extremely thick U-rich volcanic rocks preparing a uranium source 'bank' for the ore-formation; the combination of main faults cutting the basement, the fault structures in the cover and volcanic collapse structures create favourable space for the ore-formation (migration of ore-forming fluid and accumulation of ore-forming material); the geologic trap formed by compression-over thrust is the important ore-preserving condition

  9. Mining and processing of uranium ores in the USSR

    International Nuclear Information System (INIS)

    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)

  10. Large ore-concentrated area of uranium deposits and uranium metellogeny

    International Nuclear Information System (INIS)

    The formation of large ore-concentrated are results from the anomalous concentration of multi-mineral resources and large amount of ore materials during the process of geologic evolution history. Different ore-concentrated areas are characterized by different typical mineral resources and typical ore deposits. By taking uranium deposit as an example, the author recognizes 14 large ore-concentrated areas of uranium deposit in the world, and studies the time-space constraints of large ore-concentrated areas of uranium deposits and their relation with geodynamic evolution, and on the above basis, discusses the unusual concentration of ore elements in large ore-concentrated areas of uranium deposits, as well as proposes the characteristics of 'unusual concentration in certain points and areas' and 'explosion metallogeny in a short period of time' of multiple mineral resources. According to the three basic 'links', i.e. 'source, transportation and precipitation', the author proposes the metallogeny of large ore-concentrated areas of uranium deposits. Of them, the study on the deep-source metallogeny, water-rock intereaction of special alkaline fluid and precipitation environment has made a foundation for the establishment of prospecting model of large uranium ore-concentration areas

  11. Elaboration of uranium ore concentrate by direct precipitation

    International Nuclear Information System (INIS)

    The production of a uranium ore concentrate (yellow cake) is an essential stage in the preparation of fuels used in the nuclear power reactor. In this work, we have studied the elaboration of a uranium ore concentrate from the ore of Tahaggart by testing the direct precipitation process. This choice was justified not only by the physicochemical characteristics of the ore, but also by other important factors such as: capacity of the deposit, geographical situation (desert), availability of water and lowest investment. Samples of uranium ore from Tahaggart, were crushed and leached by percolation with a diluted sulphuric acid solution to solubilize uranium. A rate of 95% was reached. The experiments were carried out with sample extracted from different locations in the deposit. The results indicate that the classical direct precipitation process is still valid only for 5 % of the samples. For the majority of samples treated, we noticed that by precipitation of uranium at very low pH, one precipitation step was sufficient to obtain a concentrate of 65% of U3O8. The concentrate obtained is easily soluble in nitric acid. The chemical characteristics of the ore allow us to produce a concentrate using a process simpler than the classical double precipitation process. (author)

  12. Elaboration of uranium ore concentrate by direct precipitation

    International Nuclear Information System (INIS)

    Full text: The production of a uranium ore concentrate (yellow cake) is an essential stage in the preparation of fuels used in the nuclear power reactor. In this work, we have studied the elaboration of a uranium ore concentrate from the ore of Tahaggart, testing the direct precipitation process. This choice was justified not only by the physicochemical characteristics of the ore, but also by others important factors such as: capacity of the deposit, his geographical situation (desert), the availability of water and the lowest investment. Samples of uranium Ore of Tahaggart, were crushed and leached by percolation with a diluted sulphuric acid solution to solubilise uranium. A rate of 95% was reached.The experiments were conducted with sample extracted at different location in the deposit. The result obtained showed that the classical direct precipitation process worked only with 5% of the sample. For the majority of sample treated, we noticed a precipitation of uranium at very low pH, only one precipitation step was sufficient to obtain a concentrate of 65% of U3O8. The concentrate obtained is easily soluble in nitric acid. The chemical characteristics of the ore allow us to produce a concentrate using a process simpler than the classical double precipitation process. (author)

  13. Estimating activity of uranium ore and solid waste

    International Nuclear Information System (INIS)

    From radioactive equilibrium of natural radioactive decay series and content of several radioactive constituents, the formula for estimating activity of uranium ore and solid waste is derived and a case study on treatment engineering of decommissioning Linchang Uranium Mine is presented

  14. Study on the internal relationship of U(VI) and U in uranium ore and ore with uranium

    International Nuclear Information System (INIS)

    The influence of melt time and melt temperature on U(VI) and U(IV) in uranium ore and uranium measurement were discussed. And the internal relationship between U(VI) and U(IV) in uranium ore with high content (≥100μg/g) and with low content (≥100 μg/g) were investigated respective, by analyzing theory of uranium ore and rule of U(VI) and U(IV). The results indicated that efficiency analysis of U(VI) and U(IV) could be achieved when melted for 3 hour and temperature reached 65 degree C. The content of total uranium equals to the content of U(VI) added U(IV) when the content of U up to high in uranium ore and ore with uranium. But for low U samples, the relationship between U(VI) and U(IV) follows math connection: U(VI)=A560/A583 x Utotal. This math connection used to analyze the low content samples can decrease analysis steps infinitely and also can improve working efficiency. (authors)

  15. Manual on laboratory testing for uranium ore processing

    International Nuclear Information System (INIS)

    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

  16. The effect of humic acid on processing uranium ores

    International Nuclear Information System (INIS)

    The effect of humic acid contained in uranium ores on processing uranium ores is presented. Some characters of humic acid are described. Some harms, such as lowering the percolation rate in heap leaching with sulphuric acid, decreasing the extraction capacity of amine extractants, decreasing the adsorption capacity of resins, raising difficulties in phases separation, promoting emulsification in extraction and stripping, raising cost of organic phase, increasing NaOH consumption and reducing precipitation efficiency of uranium, are explained. The methods of removing humic acid are given

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

    International Nuclear Information System (INIS)

    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

  18. Uranium dissolution rate from ores in carbonate leaching

    International Nuclear Information System (INIS)

    The experiments are performed on the determination of specific dissolution rates for isolated samples of such uranium mineral as pitchblende and its inclusions in ore slurries during autoclave carbonate leaching. The following conclusions are drawn: all types of pitchblende regardless of an oxygen coefficient exhibit close specific dissolution rates; the time of leaching is independent of an uranium content at the initial sample; on ore reducing down to particle size of 0.1 mm practically complete mechanical opening of uranium minerals takes place

  19. Biohydrometallurgy of low-grade, carbonate bearing sandstone uranium ore

    International Nuclear Information System (INIS)

    An alkaline, carbonate bearing, sandstone uranium ore was leached microbiologically. Pure as well as mixed cultures of local isolated of Thiobacillus ferrooxidans were employed. Sandstone uranium ore contained 5% calcite, 2.3% Fe2O3, minor amounts of pyrite and was alkaline in nature. Shake flask studies employing mixed and pure culture of thiobacilli were carried out. Ore was amended with different oxidizable inorganic energy sources such as FeSO4, slag and sulfur etc. The leaching capability of local isolate of T. ferrooxidans was also compared with that of pure ATCC culture number-sign 13661 of this bacteria. It was found that the local isolate leached out uranium more efficiently as compared with exenic culture. Further, slag was found to be economical energy source for these bacteria. Mixed culture studies revealed that the percentage of leached uranium was increasing with increase in the proportion of T. ferrooxidans in the inoculum

  20. Analytic study of organic matters in Lodeve uranium ore

    International Nuclear Information System (INIS)

    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

  1. Processing of low grade uranium ores

    International Nuclear Information System (INIS)

    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

  2. Application of intensified heap leaching technology of uranium ores to Dabu uranium mine

    International Nuclear Information System (INIS)

    In the light of the preliminary design of uranium ore heap leaching for Dabu uranium mine, leaching agent with high concentration of sulfuric acid (about 50 g/L) was used to leach uranium from ores in the initial stage of heap leaching, and then the acidity of leaching agent was gradually reduced according to the concentration of sulfuric acid in leaching solution. Using the leaching agent with low concentration of sulfuric acid to leach uranium in the latter stage leaded to long leaching time, high content of uranium in the leaching residue, and high energy consumption in follow-up producing process. So an intensified heap leaching technology of uranium ores was put forward and adopted to shorten the leaching time and reduce the content of uranium in the leaching residue and the energy consumption. The application of the technology to Dabu uranium mine was introduced, and technical and economic evaluation was carried out. (authors)

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

    OpenAIRE

    Bolat Uralbekov; Mukhambetkaly Burkitbayev; Bagdat Satybaldiev

    2015-01-01

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

  4. Leaching characteristics of a low grade uranium ore

    International Nuclear Information System (INIS)

    Leaching characteristics of a low grade uranium ore in Jiangxi province are studied using agitating leaching and column leaching methods. The results of agitating leaching test show that leaching rate of uranium is above 85% under the conditions of sulphuric acid concentration of 10 g/L and stirring 12 h, and the ore is leachable. The results of column leaching test show that leaching rate of uranium is above 85.7% under the conditions of particle size of-5 mm, sulphuric acid dosage of 4.6% (w/w), and leaching time 40 d, and the permeability of ore heap is good (33 L/m2 h). The obtained leaching parameters can be used as the basis of industrial experiment design and adjusting the leaching parameters in production. (authors)

  5. Aluminum chloride restoration of in-situ leached uranium ores

    Energy Technology Data Exchange (ETDEWEB)

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

    1984-01-01

    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 elements (uranium and selenium) that are mobilized during the leaching process, have also been found in 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 increase in permeability.

  6. Aluminum chloride restoration of in situ leached uranium ores

    International Nuclear Information System (INIS)

    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

  7. Aluminum chloride restoration of in situ leached uranium ores

    Energy Technology Data Exchange (ETDEWEB)

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

    1982-09-01

    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.

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

    International Nuclear Information System (INIS)

    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, H2O2 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% H2O2 (v/v), one to one aqueous to organic ratio, and 40% Tbp in kerosene. The extraction recovery for U, RE, Th, and PO43- 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 HNO3. and the stripping recovery for U, RE, Th, and PO43- are 84%, 80%, 72%, and 83%, respectively

  9. Underground Milling of High-Grade Uranium Ore

    International Nuclear Information System (INIS)

    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. Two stage column leaching of uranium from uraninite ore

    International Nuclear Information System (INIS)

    The leaching process of uraninite ore was divided into the acidification and bacterial leaching stages, and the two stage leaching experiments and the control were conducted with 3 columns, each being charged with 20 kg uraninite ore. The ore contained 0.113% uranium, 1.859% iron and large amounts of silica and alumina. In the acidification stage, high to low concentration sulfuric acid solutions were used to acidify the uranium ore in each column until the pH of the pregnant leach solution from each column was maintained at 2.0. The acidification lasted for 18 d and the uranium recoveries for the three columns reached about 70%. In the bacterial leaching stage, column 1, as the control, continued to be leached with sulfuric acid solution with pH=2.0, column 2, with the bacterial solution based on the indirect leaching mechanism, and column 3, with the bacterial solution based on the direct leaching mechanism. The leaching in this stage was continued until the concentrations of the uranium in the pregnant leach solutions from the three columns amounted to less than 50 mg/L. This stage lasted for 20 d and the final uranium recoveries for columns 1, 2 and 3 reached 73.72%, 78.97% and 75.79%, respectively. (authors)

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

    OpenAIRE

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

    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 ...

  12. Bacteria heap leaching test of a uranium ore

    International Nuclear Information System (INIS)

    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)

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

    International Nuclear Information System (INIS)

    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)

  14. Innovations and trends in uranium ore treatment

    International Nuclear Information System (INIS)

    During the last uranium boom in the nineteen seventies and eighties, some key innovations were introduced into the operations established during that period. Some of these were subsequently carried over into hydrometallurgical copper, gold and nickel-cobalt projects, and others have been added. Many of these are likely to be reflected in the new uranium projects sporned by the current era of increasing uranium demand and high prices

  15. Advantage of uranium contained in low grade dolomite ore

    International Nuclear Information System (INIS)

    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)

  16. Chlorine/chloride based processes for uranium ores

    International Nuclear Information System (INIS)

    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. U3O8/ton ore) and one for a high grade ore (50 lbs U3O8 /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. South African gold and uranium ore mining in 1976

    International Nuclear Information System (INIS)

    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.)

  18. Mining and milling of uranium ore: Indian scenario

    International Nuclear Information System (INIS)

    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)

  19. Variations in the uranium isotopic compositions of uranium ores from different types of uranium deposits

    Science.gov (United States)

    Uvarova, Yulia A.; Kyser, T. Kurt; Geagea, Majdi Lahd; Chipley, Don

    2014-12-01

    Variations in 238U/235U and 234U/238U ratios were measured in uranium minerals from a spectrum of uranium deposit types, as well as diagenetic phosphates in uranium-rich basins and peraluminous rhyolites and associated autunite mineralisation from Macusani Meseta, Peru. Mean δ238U values of uranium minerals relative to NBL CRM 112-A are 0.02‰ for metasomatic deposits, 0.16‰ for intrusive, 0.18‰ for calcrete, 0.18‰ for volcanic, 0.29‰ for quartz-pebble conglomerate, 0.29‰ for sandstone-hosted, 0.44‰ for unconformity-type, and 0.56‰ for vein, with a total range in δ238U values from -0.30‰ to 1.52‰. Uranium mineralisation associated with igneous systems, including low-temperature calcretes that are sourced from U-rich minerals in igneous systems, have low δ238U values of ca. 0.1‰, near those of their igneous sources, whereas uranium minerals in basin-hosted deposits have higher and more variable values. High-grade unconformity-related deposits have δ238U values around 0.2‰, whereas lower grade unconformity-type deposits in the Athabasca, Kombolgie and Otish basins have higher δ238U values. The δ234U values for most samples are around 0‰, in secular equilibrium, but some samples have δ234U values much lower or higher than 0‰ associated with addition or removal of 234U during the past 2.5 Ma. These δ238U and δ234U values suggest that there are at least two different mechanisms responsible for 238U/235U and 234U/238U variations. The 234U/238U disequilibria ratios indicate recent fluid interaction with the uranium minerals and preferential migration of 234U. Fractionation between 235U and 238U is a result of nuclear-field effects with enrichment of 238U in the reduced insoluble species (mostly UO2) and 235U in oxidised mobile species as uranyl ion, UO22+, and its complexes. Therefore, isotopic fractionation effects should be reflected in 238U/235U ratios in uranium ore minerals formed either by reduction of uranium to UO2 or chemical

  20. A review of CANMET's acid chloride leaching of uranium ores

    International Nuclear Information System (INIS)

    Conventional sulphuric acid leach processing of uranium ore is technically and economically viable but presents some environmental concerns because almost all of the radium and the sulphides, especially pyrite (an acid generating mineral), present in the ore report to the tailing disposal sites. In order to obtain leach tailings with a radium (226) content of 20-25 pCi/g solids and essentially free of pyrite, an alternative HCl leach process has been developed. Hydrochloric acid leaching of low-grade pyritic uranium ore (e.g. Elliot Lake U-ore) followed by flotation for pyrite removal from the final leach residue yielded tailings essentially free of pyrite and radionuclides, the radium level in the tailings being in the range of 25-30 pCi g-1 solids. Acid chloride leaching of Midwest Lake uranium ore, under various conditions (e.g., HCl, HCl-CaCl2-O2 pressure, HCL-FeCl3) provided high extraction of U, Ni, As and Ra and tailings with radium levels above 177 pCi g-1 solids. However HCl leaching of the radium preleached Midwest Lake uranium ore provided the best extraction of U(>99%), Ni(88%), As(90%) and Ra (98%) and the tailings with only 108 pCi g-1 solids radium. Of course, out of these 108 pCi/g solids, at least 66 pCi/g solids were tied up with the residual uranium (0.02%) in the tailings, and the remaining radium (42 pCi/g solids) present as sparingly soluble radium salt/salts (e.g., RaS04). The acid chloride leaching process for uranium ore has definite technological and environmental merits but presently compares unfavourably both in capital and operating costs with the conventional sulphuric acid leach process. However, the economics of the HCl leach process could become viable when the costs of removing the radium (226) and the sulphides (i.e., the acid generating minerals) from sulphuric acid leach tailings are taken into consideration

  1. Ore deposit models - 3. Genetic considerations relating to some uranium ore deposits

    International Nuclear Information System (INIS)

    Sandstone ores of major economic importance include classical 'roll fronts', 'tabular bodies' and 'channel-type' ore deposits. In such ores, deposition of uranium occurrs at an oxidation-reduction front. Uranium is reduced and precipitated from solution at an Eh close to that of the Fe2+/Fe3+ boundary, so it is visibly associated with the iron oxidation/reduction front. It is suggested that autogenous enrichment of syngenetic uranium deposits in carbonaceous pelites (mudstones) involves the following stages: first, syngenetic concentration of uranium in the carbonaceous pelites; second, metamorphism and folding at a temperature of about 2500C; third, due to radiogenic heat, development of a thermal anomaly; fourth, (since the solubility of UO2 as a function of temperature goes through a maximum), collection of UO2 by circulating pore water from the fringes of the temperature anomaly, and its precipitation towards the interior of the mineralized zone; lastly, a temperature fall due to cessation of orogeny responsible for metamorphism or to reduction of cover rock thickness by erosion. Cycles of activity may occur. (N.D.H.)

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

    International Nuclear Information System (INIS)

    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

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

    International Nuclear Information System (INIS)

    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

  4. Geological-technological evaluation for in-place crushing-leaching of uranium ores in ore-field NO.322

    International Nuclear Information System (INIS)

    According to the technological demands of the in-place crushing-leaching method, the author discusses the natural geological conditions of uranium ore-field No. 322, such as: geological structure, components of rocks and ores, ore texture, existing state of uranium, physical and mechanical parameters of rocks and ores, the shape, attitude and size of orebodies, as well as hydrogeological conditions of deposits. Meanwhile, a great number of technological parameters have been obtained by both the in-place blasting stacking test and a series of column uranium extracting tests. At last, the conclusion that the in-place cruising-leaching method is suitable for the cataclastic-altered granite type uranium deposits in the ore-field is proposed by a evaluation model for the in-place crushing-leaching method

  5. Uranium extraction from Wadi Belih ore material, eastern desert, Egypt

    International Nuclear Information System (INIS)

    The present work deals with studying the different processes for the extraction of uranium from Wadi Belih ore material. This represents a part of the Front End Cycle required for the preparation of the nuclear fuel. The studied ore is mainly localized in siltstones belonging to the Hammamat sediments situated in the northern part of the Eastern Desert. The uranium minerals in the ore are mainly represented by the silicate mineral uranophane, the vanadate mineral tyuyamunite beside lesser amounts of the sulphate mineral schroeckingerite. Uranium recovery from the acid sulphate leach liquor has been performed with both anion exchange resin and solvent extraction while its recovery from the alkaline leach liquor has been achieved by anion exchange resin. The present work has also studied the conditions necessary for the adsorption of the uranyl divalent disulphate complex by all the resin exchange sites. This has led to increasing the saturation capacity of the resin up to about 170 g U/L. Uranium elution has been carried out using sodium chloride and ammonium carbonate in case of leaching with sulphate or carbonate liquors respectively. Uranium extraction from Wadi Belih sulphate leach liquor has also been studied by solvent extraction using tri-n-octylamine. Study of the required stages for both uranium extraction and its stripping by ammonium carbonate has been undertaken through the corresponding McCabe-Thiele diagram. Thus, using an operating line of slope O/A of 0.65 for extraction and of slope A/O = 0.40 for stripping indicated that only two stages are required for each process

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

    International Nuclear Information System (INIS)

    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)

  7. Geological exploration of uranium ores at Burgos' basin

    International Nuclear Information System (INIS)

    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)

  8. Modelling the leaching behaviour of an uranium ore

    International Nuclear Information System (INIS)

    The leaching behaviour of a uranium ore, with sulfuric acid and sodium chlorate, has been investigated in agitated tanks. Data from conventional leaching studies has been supplemented with mineralogical characterisation and SEM analysis of selected samples. A technique known as block leaching was also used, which allows individual grains of both the ore and gangue minerals to be studied before and after leaching under different conditions. As a result of the experimental investigation a detailed description of the leaching behaviour of the ore has been compiled. The experimental data have been used to prepare a leaching model that describes uranium extraction as a function of residence time, acid strength, temperature and redox potential. In addition, the dissolution behaviour of the key gangue minerals as a function of leaching conditions has been determined. On the basis of ore and gangue mineral dissolution, the consumption of acid has been predicted with good agreement with experimental data. Although the model is largely empirically based, it provides a useful tool for optimising plant operation (author)

  9. Geostatistics applied to estimation of uranium bearing ore reserves

    International Nuclear Information System (INIS)

    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)

  10. Precipitation of uranium by hydrogen peroxide from the liquor of Xiamatang uranium ore

    International Nuclear Information System (INIS)

    A Chemical precipitation process of recovering uranium from the leaching liquor of uranium ore was investigated. The process includes primarily precipitation of iron with lime, preprocessing of the slurry of iron hydroxide and precipitation of uranium with H2O2. The leaching liquor is neutralized by lime milk to pH 3.7 for precipitating iron hydroxide. The precipitated slurry is recycled to leaching process for recovering uranium in it after being flocculated and pre-processed. It can avoid the filter of the slurry of iron bydroxide. H2O2 is used to precipitate uranium in the leaching liquor free of iron, and the pH of process for uranium precipitation is adjusted to 3.5 by adding MgO slurry. It is shown in the results that lime, H2O2 and MgO can be used to obtain the uranium peroxide product containing over 65% uranium without environmental pollution

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

    International Nuclear Information System (INIS)

    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)

  12. Acid chloride leaching of Midwest Lake uranium ore (northern Saskatchewan, Canada)

    International Nuclear Information System (INIS)

    The feasibility of acid chloride leaching (i.e. alternative leaching process) of high-grade complex uranium ore was studied on Midwest Lake uranium ore, one of the main objectives of the work being to produce effluents and tailings almost free from radioisotopes and other toxic materials. Irrespective of leachants, uranium extractions were always high (∼99%). 32 refs.; 5 tabs

  13. Assessment of environmental impact and the contamination effects of uranium ore mining and uranium ore processing operations

    International Nuclear Information System (INIS)

    Studies concerning the contamination of the areas in proximity to the uranium ore exploitations and explorations (Banat, Oriental Carpathians, Apuseni Mountains) with uranium and radium from tailings, as well as the pollution source identification and their delimitation on maps are presented in this paper. The problem of correct understanding and interpretation of the contamination due to the mining activities has to be correlated with element migration from the mineralization by determining radioactive aureoles in water, soil and vegetation. Migration and pollution phenomena in different dispersive media have been studied for uranium, radium and other accompanying elements (Mo, Cu, Zn) from several deposits. Several indirect factors which may influence the pollution degree are studied, such as: water pH, water flow, valley slope and form, climate, altitude and vegetation presence on the dumps. Comparative studies of irradiation and pollution processes from uranium exploration and exploitation mining areas are also presented. (authors)

  14. Model of percolation leaching for non-weathered uranium bearing ores for scale up purpose

    International Nuclear Information System (INIS)

    Uranium bearing sandstone ore in Pa Lua area (Nong Son basin) is a kind of low uranium content ore. Technological method with high potential of application is percolation leaching. This article introduces the setting up a model of percolation leaching for non-weathered uranium bearing ores for scale up purpose. It is possible to calculate efficiency of leaching uranium from ores when changing technological parameters such as acid concentration, height of ore body and effect of differences in distribution of particle size. This tool can help calculation for the design of a system of ore processing to meet certain requirements on the yield to facilitate design and calculation for the pilot of uranium ore processing in the future. (author)

  15. Column leaching of uranium ore with fungal metabolic products and uranium recovery by ion exchange

    International Nuclear Information System (INIS)

    To verifying the feasibility of uranium recovery with fungal metabolic products in large-scale applications, column leaching and ion exchange of uranium was carried out. The uranium recovery reached 81.76 % in 14 days. The ion exchange curve for the leach solution obtained with the metabolic products of Aspergillus niger was in the shape of a wave. The elution curve was similar to that of leaching with H2SO4. The results indicate that leaching with the metabolic products of A. niger is a promising and environmentally friendly method for exploitation of low grade uranium ores in large-scale applications. (author)

  16. Uranium extraction from ores with salicylic acid; II. Uranium extraction from EL-Atshan primary ore, eastern desert, Egypt

    International Nuclear Information System (INIS)

    This work deals with the application of the proposed method for U extraction from the primary ore of El-Atshan locality, Eastern Desert, Egypt. This ore shows the presence of two U mineralization stages. The late stage carry some 85% of the U present in the ore (represented by coffinite and pitchblende). The early U stage is represented by a graphitic Nb - Ti - Zr - U refractory mineral representing some 15% of U in the ore. Study of relevant extraction factors revealed that about 87% as the maximum extraction of U was attained. Failure to attain 100% U extraction could be explained as due to locking of the undissolved amount in the refractory mineral. To recover U from the obtained pregnant leach liquors, the technique followed in the previous study is herein applied. This involved the precipitation of NH4(UO2 SaL3)4 H2O by adjusting the pregnant leach liquor by ammonia to ph 5-6.5 after its concentration by its recycle for uranium extraction from new ore batches. The precipitated ammonium uranyl tri salicylate is calcined at 500 degree for obtaining pure orange-yellow trioxide (UO3) powder

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

    International Nuclear Information System (INIS)

    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

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

    International Nuclear Information System (INIS)

    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.)

  19. Dissolution kinetics of uranium from a low grade uranium ore in acid lixiviant

    International Nuclear Information System (INIS)

    Kinetic studies on uranium dissolution were carried out on an uranium ore sample from Narwapahar, Jharkhand and a pre-concentrate obtained by physical beneficiation of the ore sample. The dissolution was effected by leaching the feed sample with sulphuric acid at a pH of 1.6-1.8 at 50 deg C with pyrolusite (MnO2) as the oxidant. The uranium dissolution was monitored at fixed time intervals by drawing samples and analyzing for the U3O8 content. It was continued up to a cumulative contact time of 12 hours. The experimental data was analyzed using 'shrinking unreacted core' (SUC) model. During the initial stages, the leaching was found to be chemical-reaction controlled and subsequently diffusion controlled. The rate constants for the uranium dissolution under the two different mechanisms have been estimated. (author)

  20. Treatment of Abankor uranium ore by the Eluex process

    International Nuclear Information System (INIS)

    The Eluex process is a possible way of treating the Abankor uranium ore; this work represents a preliminary approach in the development of a process for this ore. However, a cost study would be necessary to enable the appropriate choice of a most adequate flowsheet. The parameters concerning comminution, extraction-purification and concentration for the Eluex process have been obtained. A leaching efficiency of up to 95% was reached with a mean consumption in acid (120 kg of sulfuric acid per metric ton of ore). The concentration-purification of the leach solution was carried out in two successive stages: a strong base ion exchange was used to yield an eluate (5 g U/1) that was then contacted, in a second step with a solvant (D2EHPA + Kerosene) to give an organic solution of 26g U/1. Ammonium uranyl tricarbonate (AUC) was obtained by combining the uranium stripping and cristallization processes in a single operation. A simulation of this last stage was carried out using Aspon plus software

  1. Geophysical testing of low-grade uranium ore technogenic formations

    International Nuclear Information System (INIS)

    Full text: Monitoring of tailing pits of uranium ore conversion products and reserve supplies of low-grade ores stored in dumps is traditionally based on radiation environment on these sites and adjacent territories. The results of gamma-ray spectrometry of solid fractions and radon concentration measurement in liquid and gas phases of technogenic formations are used in radiation hazard evaluation. The monitored sites are known to contain associated elements besides uranium and decay daughter products. Ionic forms of some of them define the migration activity of radioactive nuclides, others possess toxic properties (arsenic, lead, antimony, mercury, selenium, molybdenum, etc.). For instance, the increased content of calcium carbonate and sulphuric acid in natural water solutions promotes active uranium migration whereas ferric iron presence causes high effectiveness of uranium leaching in rocks (dissolution of uranium-containing minerals). Radium tends towards migration in highly saline chloride-bearing solutions. Radiometric testing practice of low-activity field formations in loose and lump masses shows that due to high emanating ability it is necessary to use dual-channel radiometer for ionizing radiation background record and compensation. Thus gamma-radiometry is not the direct method of uranium content determination and alfa- and beta-radiometry can be correctly used only for sample analysis in laboratory environment. Consequently, distant express testing with the help of X-ray radiometric (XRM) instruments (on calcium, iron, manganese, titanium, copper, arsenic, lead, strontium, selenium, molybdenum, uranium, etc.) is recommended for additional introduction in field observations of radio-ecological environment in mining and processing production tailing and dumps of low-grade ore reserve supplies. Thanks to preliminary areal schemes of geochemical zonality as per XRM data XRM application allows to use the sample limit, given for a wide range of laboratory

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

    International Nuclear Information System (INIS)

    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)

  3. Preconcentration of uranium ores by radio-metric sorting

    International Nuclear Information System (INIS)

    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)

  4. Safeguards on uranium ore concentrate? the impact of modern mining and milling process

    International Nuclear Information System (INIS)

    Increased purity in uranium ore concentrate not only raises the question as to whether Safeguards should be applied to the entirety of uranium conversion facilities, but also as to whether some degree of coverage should be moved back to uranium ore concentrate production at uranium mining and milling facilities. This paper looks at uranium ore concentrate production across the globe and explores the extent to which increased purity is evident and the underlying reasons. Potential issues this increase in purity raises for IAEA's strategy on the Starting Point of Safeguards are also discussed

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

    International Nuclear Information System (INIS)

    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)

  6. Analysis of uranium ore concentrates for origin assessment

    International Nuclear Information System (INIS)

    In this study the most important analytical methodologies are presented for the nuclear forensic investigation of uranium ore concentrates (yellow cakes). These methodologies allow to measure characteristic parameters which may be source material or process inherited. By the combination of the various techniques (e.g. infrared spectrometry, impurity content, rare-earth pattern and U, Sr and Pb isotope ratio analysis by mass spectrometry), the possible provenances of the illicit material can be narrowed down to a few options and its declared origin can be verified. The methodologies serve for nuclear forensic investigations as well as for nuclear safeguards, checking the consistency of information. (orig.)

  7. Behavior of uranium migration in epigenetic uranium ore deposits with reference to radioactive waste isolation in geologic media

    International Nuclear Information System (INIS)

    Among the numerous uranium ore deposits and indications which have been discovered in Japan, the important uranium occurrences are found as strata-bound epigenetic ore deposits. This mineralization occurs in basal Neogene sedimentary rocks unconformably overlying granitic basements of the Mesozoic and/or early Cenozoic era. In many of these deposits, the epigenetic uranium mineralization occurs just above the unconformity, and groundwater migration is observed at the unconformity between the Neogene sediments and the granitic basement. This groundwater at the unconformity is thought to be a migrating agent for uranium from source rock to the ore deposit

  8. Discussion on ore-controlling factors and metallogenic model of uranium ore-formation in Xieersu depression, south Songliao Basin

    International Nuclear Information System (INIS)

    Based on the geologic characteristics of Xieersu depression, uranium mineralization in this area is believed to be sandstone type of epigenic of multi times superimposition and the ore-formation is mainly controlled by the factors such as the uranium source, the development of interlayer oxidation zone, the variation of hydrodynamic conditions, etc.. A preliminary metallogenetic model has been set up. (authors)

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

    International Nuclear Information System (INIS)

    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.

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

    International Nuclear Information System (INIS)

    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)

  11. Tailing characterization and management system of Rirang uranium ores processing

    International Nuclear Information System (INIS)

    Tailings generated from Rirang uranium ore processing still contains both radioactive and non radioactive elements. This is due to the incomplete dissolution of such elements in the ore processing the aims of this investigation is to characterize the tailings elemental composition, to evaluate, and to plan a good tailings management system, hence, environmental contamination can be avoided. Several methods of analysis have been utilized; including Atomic Absorption Spectrophotometry (AAS), UV-Vis spectrophotometry, radiometry and gravimetry, to determine elements of interest i.e. silicon, rure earths, uranium, thorium, iron, nickel, zink, phosphor, vanadium, lead, molybdenum and radium. Based on the analytical data evaluation, it is concluded that big scale solid tailings (2,5 ton per day) should with water in a designated place before finally being stored in a 1500 cubic meter pond (pond No.1). Such a washing step is aimed to remove element from the tailings. The over flowing water is then fed into the second pond of 1200. cubic meter capacity. The liquid is then neutralized by adding CraO + NaOH and BaCl2 solution. The eff7uent contains considerably small amount of radioactive and non radioactive elements, hence suitable for direct disposal to the environment (water body)

  12. Current status the bearings of Uranium ores in the Slovak Republic

    International Nuclear Information System (INIS)

    At the mining over many centuries the mineral reserves especially of metallurgical and precious metals in Slovakia have exhausted. Their residues are now only mineralogical significance. The exceptions are bearings of uranium ore, where extensive geological surveys and smaller mining began on the Slovakia until in the year 1948 in the Novoveská Huta. In the last decade last century, the mining in the context attenuation of the mining industry was stopped. The bearings of uranium ore are occur in the arc of the Central Carpathians in the rocks of the Paleozoic - Permian from the Nové Mesto nad Váhom after the South Zemplín ( Rojkovič 1997 ) . About the ore of uranium on the Slovakia they have interested foreign companies and most of the exploration licenses is under the control of the companies from Canada and Australia, which exploring the bearings of Uranium ore since 2005. The expanse of exploration areas is today more than 300 km2 . The exploration of the Uranium bearings met resistance of the local governments and citizens of the concerned areas. They fear that foreign investors do not enter into exploration projects only from the aspect of mapping geological reserves of Uranium ore and do not intend Uranium mine. Aim of this paper is to give a characteristic of selected bearings of Uranium and point out environmental and functional and spatial implications eventual mining of Uranium ore. Key words: Bearings of Uranium Ore, Slovak Republic, exploration of Uranium Ores, Negative Consequences of Mining Uranium Ores on the Environment

  13. Study on uranium distribution in ore samples of Nong Son Basin (Viet Nam)

    International Nuclear Information System (INIS)

    Geological studies show that uranium ore bodies in Nong Son basin (Quang Nam province, Viet Nam) are lens, chain of lenses with uranium content of U3O8 ≥ 0.01%. In one bed of uranium bearing rock, the uranium contents widely vary from 0.001 to 0.675%. Knowledge of the uranium distribution in mined ore is very important for preconcentration processes. The study has conducted classification by radioactivity measurement for each ore grain (size of 25-200 mm) and determine uranium content in respective ore sample. To determine radioactivity, gamma spectrometer (thallium- activated sodium iodide crystals NaI(Tl) 80x80 mm and multi-channel analytical system of model MCA-2003-001,VNEC) were used. Uranium contents were determined by coloriphotometry (Spectronic 20 D+, USA). Based on the results obtained from the study of uranium distribution in ore samples of the above area it was concluded that (1) the uranium distribution levels are not even in the studied ore samples and (2) it is possible to use radiometric sorting to enrich ores from Nong Son basin

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

    International Nuclear Information System (INIS)

    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

  15. Pressure oxidation processing for sulphide-bearing carbonate type uranium ore

    International Nuclear Information System (INIS)

    In this paper the possibility of pressure oxidation processing for the sulphide-bearing carbonate type complex uranium ore is expounded proceeding from the chemical behaviours of pyrite sulphide and carbonate minerals in leaching process and through analysis of orthogonal array test results. The consumption of leaching reagent was decreased and the extraction rate of uranium was increased after pressure oxidation treatment of the complex uranium ore

  16. Research On The Availability Of Palua Uranium Ore Beneficiation In Quang Nam Province Using Gravity Method

    International Nuclear Information System (INIS)

    In this project we have researched and evaluated the separation possibility of uranium ore in Palua area. Although scale and expenses of the project are limited, we have carried out this project during a year and had some reliable results. Uranium ore in Palua area which has concentrate of 440 ppm was separated into two main ingredients containing uranium concentrate more than 550 ppm and less than 190 ppm. (author)

  17. Blind River uranium deposits: the ores and their setting

    International Nuclear Information System (INIS)

    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 U3O8/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

  18. 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)

    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 (UO3). 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 I,b-uranium recovery from pregnant lemon juice liquors obtained by attacking phosphate ores and suggested flowsheet

    International Nuclear Information System (INIS)

    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 o3). On the basis of one ton ore treatment, a flowsheet for uranium recovery from the two ore materials has been suggested

  20. Analysis on uranium ore-formation conditions and prospecting direction of Wulanchabu depression in Erlian basin

    International Nuclear Information System (INIS)

    Through the analysis of uranium source conditions, deposition-tectonic evolution and the characteristics of uranium ore forming in Wulanchabu depression, conclusions are drawn as follows: Wulanchabu depression has favorable ore-forming geology conditions; sandstone-type uranium deposit should be searched in the valley of Saihan formation 'Zhurihe-Qiharigetu-Saihangaobi' in the east of Wulanchabu depression; syndeposition-epigenic alteration type uranium deposits can be exploited in Erlian formation of Erenzuoer north of the depression, and syndepositional type uranium deposit may lies in Naomugen formation of Chagan-Naomugen-Wulanhuxiu zone in the northwest of the depression. (authors)

  1. Beneficiation studies of an uranium siliceous - phosphate ore

    International Nuclear Information System (INIS)

    The consolidation of the beneficiation studies of a low-grade uranium siliceous - phosphate ore (11% P2O5) 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 P2O5 and 71% the U3O8, for a 33% P2O5 phosphate concentrate. (Author)

  2. Comprehension of synergistic mechanisms for uranium extraction from phosphate ores

    International Nuclear Information System (INIS)

    Uranium VI is commonly extracted from phosphoric ores by a well-known process exploiting the synergistic mixture of two extractant molecules: HDEHP and TOPO. In the field of liquid-liquid extraction, synergistic combinations are common but the mechanisms at the origin of the synergy are not well understood. A multi-scale approach has been used to describe these mechanisms, combining two different descriptions: the molecular scale focuses on the ion point of view, while the supramolecular scale focuses on extractants' aggregation. These two approaches have been rationalized by molecular dynamics computations. The results allow describing the synergy through the structure of the complexes and aggregates. With the same approach, some bifunctional compounds, combining the two extracting sites in one molecule, have been studied and compared to the HDEHP/TOPO system in order to identify the origin of their increased capacities in extraction and selectivity. (author)

  3. Bioleaching - an alternate uranium ore processing technology for India

    International Nuclear Information System (INIS)

    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% U3O8) 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)

  4. Attribution of uranium ore concentrates using elemental and anionic data

    International Nuclear Information System (INIS)

    The capability to correctly identify the geological or geographical source of unknown uranium ore concentrates (UOCs) has obvious nuclear security benefits. This paper reports on a scoping study where the trace elemental and anionic compositions of 24 UOC samples, sourced mainly from mines in Australia and Canada, were examined for their ability to allow attribution of the sample to a particular geological U deposit type or to a particular geographical source. Results of statistical analysis using canonical analysis of principal coordinates (CAP) showed that samples originating from certain U ore deposit types, especially phosphorite and quartz-pebble conglomerate, contained a distinct impurity composition. Samples grouped according to their geographical region of origin appeared to contain distinctive impurities in certain cases (Elliot Lake and Bancroft, Ontario). The key impurities responsible for differentiating groups of samples from a particular geological deposit type were identified and the use of certain impurities as signatures of processing history is discussed. The methodology described in this scoping study provides a promising approach for more comprehensive databases.

  5. Oxydizing attack process of an uranium ore by a carbonated liquor

    International Nuclear Information System (INIS)

    Continuous process of oxydizing attack of an uranium ore with a recycled aqueous solution of alkaline carbonates and bicarbonates containing uranium compounds at a concentration near the solubility limit at the attack temperature and recovery of the precipitated uranium in the solid phase remaining after the attack

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

    International Nuclear Information System (INIS)

    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

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

    International Nuclear Information System (INIS)

    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 SO4= ions, containing in solution the sole carbonates and/or bicarbonates involved, towards the digestion of the ore

  8. Uranium leaching and recovery from sandstone ores of Nong Son Basin (Viet Nam)

    International Nuclear Information System (INIS)

    Sandstone ores containing uranium in Nong Son area were treated to recover uranium in the form of MDU. These ores are classified into 3 categories depending on the weathering degree, giving different chemical composition as shown. The amount of calcium carbonate (g CaCO3/100g of ore) reacted with HCI under different conditions of temperature and time shows that stirring method requires high acid consumption. The results obtained from static leaching of the 3 ore categories shows that leaching efficiency largely depends on the weathering degree and particle size of ore. The lowest leaching efficiency was observed for non-weathered ore. In order to increase uranium extraction this ore was ground to the size of max. 2.5mm, and then incubated by 40% H2SO4 for 48 hours with the addition of KCIO3 (3 kg/tone of ore) as oxidant. The results of acid pugging showed that uranium extraction efficiency reached min. 92%. The proposed flow-sheet for obtaining yellowcake is presented. The leaching experiments were carried out under the following conditions: Particle size of ore: Weathered: max. 30mm, Semi-weathered: max. 10mm, Non-weathered: max. 2.5mm (incubated by 40% H2SO4); Temperature 25-30 deg. C; Redox potential; pH1, acid consumption: 40-50 kg/ore tone. Leaching efficiency reached 90%. Uranium concentration in the solution after 8-stage counter-current leaching was min. 4 g/L, uranium content in solid waste 0.01%. Leaching solution was filtered and directly neutralized through two stages to precipitate yellowcake. Experimental data showed that the uranium recovery reached 90%. Yellowcake product met the relevant specifications and had U3O8 content of minimum 76%

  9. Mineralogical characterization of uranium ore to evaluate in-situ leaching prospects

    International Nuclear Information System (INIS)

    Mineralogical studies of ore samples from Mobil uranium properties in the Grants Mineral Belt revealed a correlation between certain mineralogical characteristics of the ore and its leaching behavior in the laboratory. Mild alkaline carbonate solutions containing dissolved oxygen gas or hydrogen peroxide were used to leach ore samples. Leaching effects of the uranium minerals and reactive gangue material were investigated by comparing the mineralogical characteristics between pre- and post-leach samples. In one ore trend where uraninite was the principal uranium mineral, studies showed that the majority of uranium minerals was readily accessible to the leachate on a microscopic scale, the predominant, 1 /sigma phi/m-sized uraninite crystals were rapidly dissolved during leaching, the minor, but locally abundant uranium vanadate species was insoluble in mild alkaline carbonate leachate, and pyrite crystals, with dimensions 10 times greater than the uraninite crystallites, showed some surface etchings. These results indicate that the solubility and microscopic occurrence of uraninite are favorable for high and rapid uranium recovery, while the fraction of uranium contained in the insoluble uranium vanadate phase can not be recovered under mild leaching conditions. Mineralogical studies of the pre- and post-leach ore samples correlate well with the laboratory leach tests which showed 80-90% uranium recovery as well as low vanadium and sulfate levels in the effluents

  10. Uranium extraction from ores with lemon juice I,a- uranium extraction from phosphate ore materials

    International Nuclear Information System (INIS)

    Lemon juice has been tested to extract U from Phosphate ore materials (of Safaga) and phosphatic sandstone (of Qatrani). A series of extraction experiments under variable conditions of lemon juice concentration, time of agitation and temperature were carried out. Increasing input amount of lemon juice reveal however that, although complete U extraction could be achieved, phosphate mineral dissolution is limited in spite of the relatively higher residual acidity reported in solution. On comparing the obtained results with those of similar conditions obtained by leaching Qatrani uraniferous phosphatic sandstone with citric acid, it could be realized that lemon juice amount of comparable citric acid concentration bring more U (and less P2 O5) into solution. The relatively higher U extraction in case of lemon juice study is due to the fact that the latter in addition to citric contains appreciable amounts of other organic acids which increased its ability to complex more U. On the other hand, the lower yield of P2 O5 could be explained as due to the presence of natural organic colloids in lemon juice that tend to inhibit the attack by adsorption. Increasing extraction volumes while fixing the input amounts (decreasing the solid/liquid ratios) led to a sharp decrease in concentration of the inherent acidity. The latter although shifts the strength towards lower levels, an improvement of U extraction efficiency in association with dilution was observed. Although dilution is improving factor in case of using citric acid, it is more pronounced in the present study. This could be attributed to the fact that, dilution eliminates the inhibition effect of the natural organic colloids present in lemon juice. About 50% of the extracted constituents have been obtained within 15 minutes, after which they steadily increased at a slower rate. The expected improvement due to elevating temperature was on the contrary not so high

  11. Leaching technology of uranium in some ore containing several kinds of metallic mineral

    International Nuclear Information System (INIS)

    The mineral components and chemical components of the metal mine containing uranium and other kinds of metallic elements are complicated with mineralogy research. The main zinc mineral is Calamine. The main lead mineral is cesarolite. The main manganese minerals are cesarolite and heterolite. The main iron minerals are limonite and hematite. And the main uranium mineral is PbUO4. The leaching technology tests of uranium of the ore are taken. Research shows that the leaching rate of uranium up to 90% with acidic agitation leaching, while it only about 10% with alkaline agitation leaching. And the leaching rate of uranium up to 91.5%, with acidic column leaching to the -5 mm ore sample. While the leaching rate up to 88.4% with the -10 mm ore sample. Therefore, uranium can be used with acid heap leaching technology in the mine. (authors)

  12. Uranium exploration and uranium ore reserves in Uzbekistan (history, conditions of development, problems)

    International Nuclear Information System (INIS)

    Uranium ore exploration and mining in the Republic of Uzbekistan were a part of a united national economy of the former USSR and were carried out by 'Pervy Glavk' (present name is concern 'Geologorazvedka') together with branch and academician scientific-research institutes. Discovery of a new type deposit - stratiform bed-infiltration (the Uchkuduk type) - was the beginning of creating an uranium ore stock in Uzbekistan, stimulated the survey and development of a new hydratogenous approach in ore formation studying and in common and special metallogenesis. Besides geological survey State Geological Enterprise 'Kiziltepageologiya' is engaged in the elaboration of deep-hole prospecting of zones of bed oxidation and of the procedure for underground leaching of these areas. Under new economic conditions, when the reserves and perspectives for its development are important for the most efficient use and export to a world market. Analysis of the available data showed that the Republic of Uzbekistan has large poly-elemental resources and good prospects for their increasing. (author). 13 refs.; 5 figs

  13. Radiation protection problems connected with uranium ore mining at Kvanefjeld and uranium processing

    International Nuclear Information System (INIS)

    The average content of uranium at Kvanefjeld is 340 gram per metric ton of ore, equivalent to 4200 Bq kb-1 in SI radioactivity units. The corresponding number of thorium are 850 gram per metric ton of ore and 3500 Bq kg-1. The assessment of the radiation dose from external γ-radiation is based partly on the measured radiation levels in the Kvanefjeld plateau area and in the 1980-adit, and partly on measurements, with personal dosemeters, of the doses received by the work force in the adit. The contribution to the annual effective dose equivalent from extenal γ-radiation in an open pit - mine is, on this premise, estimate to be 2.5-3.7 mSv. Planning of a uranium mining and milling enterprise involves conccern about working conditions, but the sum of the calculated dose contributions from external γ-radiation, inhaled radon/thoron-daughter products and inhaled ore dust gives roughly estimated annual effective dose equivalent for work in the open pit-mine about 3.1-16.5 mSv (compared with the annual dose limit of 50 mSv recommended by the ICRP for occupatonally employed persons). (EG)

  14. U-Pb ages of uranium ores in the Church Rock uranium district, New Mexico

    International Nuclear Information System (INIS)

    Examines samples from the largest US uranium-producing region in order to determine ages of mineralization of different orebodies. Uranium from this area has come mainly from arkosic and subarkosic sandstones of the Upper Jurassic Morrison Formation. Several lines of evidence suggest that ages range from Late Jurassic or Early Cretaceous to at least as young as Tertiary. Geologic observations indicate that the oldest (primary) orebodies are tabular in shape and rich in amorphous organic material, whereas the youngest orebodies tend to be poor in amorphous organic material, display roll-front geometry, and are commonly spatially associated with Laramide or younger faults. Both types of ore were formed by relatively lowtemperature, dilute fluids that were essentially ground water in nature. Concludes that the 0- to 1-m.y. U-Pb apparent ages of the United Nuclear Corporation Church Rock Mine relate to redistribution, by roll-front processes, of earlier-formed ores by oxidizing Pleistocene ground waters, perhaps those that resulted in the present-day limonitic zone of the Westwater Canyon Member. Suggests that the 10-m.y. apparent age of sample KM-17-1 may represent an earlier phase of redistributed ore formation, perhaps related to the Tertiary oxidation front that resulted in the present-day hematitic zone of the Westwater Canyon Member

  15. The vertical distribution of uranium ore mineralization in the vein and metasomatic deposits

    International Nuclear Information System (INIS)

    The vertical distribution of the uranium resources (VDR) 43 vein and metasomatic hydrothermal deposits is observed. The common features and the reasons of this distribution are discussed. From the surface to the lowest levels of prospecting works the VDR is defined by the concrete lithological-structural situation (the presence of ''traps'') and does not depend on the distance from the earth's surface. The vertical range of uranium ore mineralization is determined on the basis of VDR data, taking into account the size of post-ore erosional shear, the zonality of ore-enclosed cataclasites and the notions about the uranium transportation and deposition. The maximum range of uranium ore mineralization is equal apparently to 4-4.5 km. The evaluation of the deposit's deep levels should be based on the tendencies of changing of those geological conditions which were discovered by the geological interpretation of VDR diagrams. (author). 10 refs, 2 figs

  16. Case-control study communities with uranium ores deposit/examining versus communities without uranium, or other ores

    International Nuclear Information System (INIS)

    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)

  17. Study on near-fault ore formation ar stratum-infiltration uranium deposits

    International Nuclear Information System (INIS)

    Ore formation of near-fault uranium ores taken as a separate type at deposits of stratum limonitization zones is studied. Mathematical and physical simulations are the investigation means. The developed ore-formation model is based on the equations of convective and dispersive substance transport to the interaction region, thermodynamic calculations and takes account of chemical reaction kinetics. The model calculation and experimental check are carried out, as well as quantitative comparison of the results of mathematical and physical simulation

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

    International Nuclear Information System (INIS)

    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.)

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

    Science.gov (United States)

    Judge, Elizabeth J.; Barefield, James E., II; Berg, John M.; Clegg, Samuel M.; Havrilla, George J.; Montoya, Velma M.; Le, Loan A.; Lopez, Leon N.

    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.

  20. Production of high purity natural uranium oxides by hydrometallurgical processing of uranium ores

    International Nuclear Information System (INIS)

    A research program has been carried out on the production of high purity natural uranium oxides, according to the commercial plant operating standards of uranium isotope separation from ores. The washing process of (NH4)4[UO2(CO3)3] crystals with NH4HCO4 have been studied. The results showed that during washing at: NH4HCO4 concentration of 70-80 kg/m3; solid / liquid ratio of 1:2; refining steps of 2-3; and duration of each washing step of 600 seconds; Molybdenum and nitrogen contents in natural uranium oxide, after calcination of(NH4)4[UO2(CO)3] were reduced to 0.0008 % and 0.011 %, respectively. The process of refining of (NH4)4[UO2(CO)3] and Na2U2O7 crystals with (C4H9O)3PO solution in hydrocarbon thinner has also been studied. It was determined that the primary minerals dissolving in nitric acid, uranium dissolution, uranium counter current extraction with carbonate solutions, (NH4)4 [UO2(CO3)3] crystals precipitation and calcination to U3O8, allows to reduce impurities contents for molybdenum (0.0003 to 0.005 %); nitrogen (0.001 to 0.003 %0) and sulfate ion (0.006 to 0.009 %) to desired levels. (author)

  1. Rirang uranium ore processing using base method with purification of uranium hydroxide from rare earths

    International Nuclear Information System (INIS)

    The experiment has been conducted to Rirang ore uranium extraction to produce ADU with composition of U = 71.29 %, Th = 0.004 % and RE2O3 = 4 %. Experiment to purify uranium hydroxide from rare earth with solvent extraction TBP/ kerosine has been done. Hydroxide solid state precipitated on pH 6.3 contains U, Th and RE, its dissolved by nitric acid, and than uranium nitrate was extracted, stripped and precipitated. The experiment parameters are HNO3; ratio A/O (v); amount of TBP/K; temperature and time. The experiment result is optimally uranium extraction condition at HNO3 = 5N; ratio A/O = 1 : 1 ; TBP/K =30 %; temperature = 25oC; Time = 5 minute and recovery U = 95.99 %; Th = 19.90 % and RE2O3 = 0.06 %. It result were optimally uranium stripping condition at HNO3 = 1 N; ratio O/A = 1:2; temperature = 25oC, time = 5 minute and recovery U = 78.21 %; Th = 40 % and RE2O3 = not detected. Optimum U precipitation condition with NH4OH reagent at pH 7.0 and time 1 hour to recover U = 98.75 % with yellow cake (ADU) which contents U 67.55 % and RE2O3 = not detected. The result is good if compared to its had been done before because rare earth not detected. (author)

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

    International Nuclear Information System (INIS)

    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 234U/238U 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. The present situation and prospects of Ganzhou mining and milling of uranium ore

    International Nuclear Information System (INIS)

    According to the characteristics of natural uranium resources, occurrence of the condition of Ganzhou uranium mining process are used in the production levels of dry-fill method, in- situ blasting method, shallow hole Shrinkage Method. milling process using surface heap leaching, bacteria leaching, heap built underground in situ leaching of uranium ore mining and milling methods of enhanced leaching technology features. The hard rock uranium mining and milling process has been Ganzhou uranium research, elaborate of mining and milling technology used in uranium Ganzhou analysis of the status of various mining and milling technology to evaluate the prospects and development, analysis mining and milling technology in production applications. (author)

  4. Safe disposal and transportation of mining process waste (uranium ore) in Romania

    International Nuclear Information System (INIS)

    The Romanian Nuclear National Plan (PNN) provides that radioactive materials (RAM), e.g. natural radioactive waste, is a subject of investigation for a safe and dedicated disposal as well as for a safe transport of the uranium ore and its concentrations taking into consideration its potential risks to human beings and the environment and possible radiological consequences due to this activity. The paper presents the main sources of natural radioactive wastes in Romania, the transportation routes of natural uranium ore from different subsidiaries to the CNU-Subsidiary Feldioara for processing. The on-site storage of the sterile at the uranium mine (at CNU-Crucea, Suceava Subsidiary) as well as the disposal in the conventional landfill sites (at CNU-Feldioara Subsidiary) of the very low-level waste resulting from handling, transformation and processing of the naturally occurring radioactive material, uranium ore, is presented. Specific problems related to the identification and evaluation of potential environmental risks and impacts as well as possible radiological consequences associated with the disposal of sterile and the very low-level radioactive waste resulting from processing of the uranium ore at Feldioara, Brasov are also approached. Also presented are possible risks associated with the uranium ore and uranium concentrates transportation in Romania both for routine and accident transport situations. (author)

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

    International Nuclear Information System (INIS)

    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.)

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

    International Nuclear Information System (INIS)

    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 H2SO4 per tonne of ore, and oxidant 4 kg of MnO2 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)

  7. Isotope geochemistry of ore fluids for the Dongsheng sandstone-type uranium deposit,China

    Institute of Scientific and Technical Information of China (English)

    2007-01-01

    The Dongsheng sandstone-type uranium deposit is one of the large-sized sandstone-type uranium deposits discovered in the northern part of the Ordos Basin of China in recent years. Geochemical characteristics of the Dongsheng uranium deposit are significantly different from those of the typical interlayered oxidized sandstone-type uranium ore deposits in the region of Middle Asia. Fluid inclusion studies of the uranium deposit showed that the uranium ore-forming temperatures are within the range of 150-160℃. Their 3He/4He ratios are within the range of 0.02-1.00 R/Ra, about 5-40 times those of the crust. Their 40Ar/36Ar ratios vary from 584 to 1243, much higher than the values of atmospheric argon. The δ18OH2O and δD values of fluid inclusions from the uranium deposit are -3.0‰- -8.75‰ and -55.8‰- -71.3‰, respectively, reflecting the characteristics of mixed fluid of meteoric water and magmatic water. The δ18OH2O and δD values of kaolinite layer at the bottom of the uranium ore deposit are 6.1‰ and -77‰, respectively, showing the characteristics of magmatic water. The δ13CV-PDB and δ18OH2O values of calcite veins in uranium ores are -8.0‰ and 5.76‰, respectively, showing the characteristics of mantle source. Geochemical characteristics of fluid inclusions indicated that the ore-formation fluid for the Dongsheng uranium deposit was a mixed fluid of meteoric water and deep-source fluid from the crust. It was proposed that the Jurassic-Cretaceous U-rich metamorphic rocks and granites widespread in the northern uplift area of the Ordos Basin had been weathered and denudated and the ore-forming elements, mainly uranium, were transported by meteoric waters to the Dongsheng region, where uranium ores were formed. Tectonothermal events and magmatic activities in the Ordos Basin during the Mesozoic made fluids in the deep interior and oil/gas at shallow levels upwarp along the fault zone and activated fractures, filling into U-bearing clastic

  8. Application of agglomerated acid heap leaching of clay-bearing uranium ore in China

    International Nuclear Information System (INIS)

    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 present a significant difficulty to acidic heap leaching. The Research Institute of Uranium Mining has engaged over years of studies on the cementing agents of acidic agglomeration, agglomeration method, as well as the curing measures of pelletted balls. On the basis of these studies, several types of clay-bearing ores have been tested with good results. The technique of agglomerated acid heap leaching has been successfully applied in a uranium mine. Since agglomeration has effectively increased the permeability of ore mass, its leaching period is decreased from 200 days to 60 days, the leaching efficiency from less than 40% up to 96%, comparing with direct heap leaching programme. (author)

  9. Uranium ore rolls in Westwater Canyon sandstone, San Juan Basin, New Mexico

    International Nuclear Information System (INIS)

    Recent relatively deep uranium-exploration drilling in the Nose Rock area, San Juan Basin, McKinley County, New Mexico, has resulted in the discovery of previously unrecognized uranium ore rolls in gray, unoxidized Westwater Canyon Sandstone of the Morrison Formation. Both the Nose Rock ores and the primary Ambrosia Lake uranium ores were emplaced during the Late Jurassic-Early Cretaceous erosional interval under the same geologic conditions by the same geochemical-cell process. The red, altered interior ground resulting from the geochemical-cell process has been re-reduced by the subsequent entry of reductants into the formation. The original roll form of the Ambrosia Lake orebodies has been obscured and modified by redistribution related to the present-day active redox interface interweaving with the Ambrosia Lake ores

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

    International Nuclear Information System (INIS)

    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 H2 S O4 and Fe3+ was a result of the bacterial activity on both ore samples containing pyrite (Fe S2). 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)

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

    International Nuclear Information System (INIS)

    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

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

    International Nuclear Information System (INIS)

    The aim of present study is recovery of uranium from such ore leach solution containing 2O7 at pH ∼12.5. The average particle size of the MgU2O7 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

  13. A possible metallogenic model and analysis of potential resources of Xiangshan uranium ore field

    International Nuclear Information System (INIS)

    Based on analysis of metallogenic dynamics process, geological characteristics and geochemistry of Xiangshan uranium ore field, uranium metallogenic model is discussed to guide uranium metallogenic prognosis and analysis of re- sources potential. REE geochemical characteristics, diagenetic and mineralization ages indicate that volcanic rock series in Xiangshan derived from melt of crust materials and are products of pulsating events of the same magma chamber. Di- agenesis of granitic porphyry and metallogenesis are consecutive geological events. On basis of research of fluids of wall rock alteration, REE geochemical feature and regional distribution characteristics of uranium abundance, regional uranium bearing strata are considered as the primary source for metallogenic substances, Xiangshan volcanic basin became uranium accumulative area with the help of volcanism and magmatism. Hydrothermal solution in post magmatism is rich in uranium. Interaction between fluid and rock promotes evolution of hydrothermal solution in post magmatism into metallogenic fluid, further produces process of uranium metallogenesis, eventually forms two-later spatial structure of 'volcanic lava and granitic porphyry' of uranium metallogenesis. There are greater exploration space and resources potential in the north and west parts of the ore field. Caldera, volcanic neck and volcanic pipe, and their peripheries are worth exploration. Total uranium resources of Xiangshan ore field are optimistically predicted to super-large size. (authors)

  14. 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)

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

    International Nuclear Information System (INIS)

    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 NH4HCO3 and from about 0.1 to 3g/l of peroxide (preferably aqueous H2O2), and sufficient NH3 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

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

    International Nuclear Information System (INIS)

    Direct extraction of uranium from different samples viz. sintered UO2, soil and ores was carried out by modifier free supercritical fluid using tri-n-butyl phosphate-nitric acid (TBP-HNO3) adduct as extractant. These studies showed that pre-equilibration with more concentrated nitric acid helps in better dissolution and extraction of uranium from sintered UO2 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)

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

    Energy Technology Data Exchange (ETDEWEB)

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

    1981-06-02

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

    International Nuclear Information System (INIS)

    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

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

    International Nuclear Information System (INIS)

    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)

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

    International Nuclear Information System (INIS)

    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)

  1. Mineralogical characterization of uranium ore to evaluate in-situ leaching prospects

    International Nuclear Information System (INIS)

    Mineralogical studies of ore samples from Mobil uranium properties in Grants mineral belt (NM) revealed a correlation between certain mineralogical characteristics of the ore and its leaching behavior in the laboratory. Mild alkaline carbonate solutions containing dissolved oxygen gas or hydrogen peroxide were used to leach ore samples. Leaching effects of the uranium minerals and reactive gangue material were investigated by comparing the mineralogical characteristics between pre- and postleach samples. Analyses were made by using the X-ray diffraction method, petrographic microscopic, and scanning electron microscopic (SEM) examinations. In one ore trend where uraninite was the principal uranium mineral, studies showed that (1) the majority of uranium minerals was readily accessible to the leachate on a microscopic scale, (2) the predominant, 1-micron (1-μm) size uraninite crystals were dissolved rapidly during leaching, (3) the minor but locally abundant uranium vandate species was insoluble in mild alkaline carbonate leachate, and (4) pyrite crystals, with dimensions 10 times greater than the uraninite crystallites, showed some surface etchings. These results indicate that the solubility and microscopic occurrence of uraninite are favorable for high and rapid uranium recovery, while the fraction of uranium contained in the insoluble uranium vanadate phase cannot be recovered under mild leaching conditions. The uraninite apparently dissolved at a much faster rate than pyrite, indicating a favorable initial selectivity of leachate for uranium. Mineralogical studies of the preand postleach ore samples correlate well with the laboratory leach tests, which showed 80 to 90% uranium recovery as well as low vanadium and sulfate levels in the effluents

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

    International Nuclear Information System (INIS)

    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

  3. The Alligator Rivers Analogue Project - Radionuclide migration around uranium ore bodies

    International Nuclear Information System (INIS)

    Uranium ore bodies in the Alligator Rivers Uranium Province in Australia have been studied since 1981 as analogues of radioactive waste repositories. The main objectives were to understand the processes governing the migration of radionuclides, particularly uranium- and thorium- series radionuclides, under groundwater flow, to develop and test models to describe this migration, and to demonstrate the applicability of the results to the safety analysis of radioactive waste repositories

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

    Energy Technology Data Exchange (ETDEWEB)

    Taki, Tomohiro [Japan Nuclear Cycle Development Inst., Kamisaibara, Okayama (Japan). Ningyo Toge Environmental Engineering Center

    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.)

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

    International Nuclear Information System (INIS)

    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.)

  6. Re-evaluation of Eko-Remaja uranium ore body, Kalan, west Kalimantan

    International Nuclear Information System (INIS)

    Uranium ore body which has been discovered at Eko-Remaja Hill belongs to the vein type system, but later on, after mining test study the oer body might not be as ideal as the vein from; at the southern part they show deviation from the original direction or even discontinue. From the view of the mining work these veins seem to from another type of ore body, which is called a stock work. The stock work consists of groups of closed vein, and the stock work at Eko is assumed to have 6 groups corning from 16 vein system. The stock work ore body seems to fit and to be supported also by the uranium geology condition at Eko hill. According to this assumption, the quality and the quantity of the uranium ore body will change, and the result of the evaluation will have a total of 4.32 million ton of ore, containing 531,56 ton uranium and it can be recovered at as much 0.18 Kg U3O8/ton ore. The mining system for these stock works vein system at Eko Hill is underground bulk mine, which is characterised by higher production capacities compared to underground shrinkage stopping mine

  7. 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)

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

    International Nuclear Information System (INIS)

    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

  9. The mineral composition and the ore types of the uranium-vanadium deposit Srednaya Padma (Onega region, Russian Federation)

    International Nuclear Information System (INIS)

    The deposit Srednaya Padma is the largest and best prospected of the uranium-vanadium deposits of the Onega region. There are abnormally high concentrations of gold, palladium, platinum, copper and molybdenum in the ores. The ore mineralization is located in the albite-mica-carbonate metasomatites upon the proterozoic aleorolites and schists. The ores are generally composed of albite, dolomite and micas. The main vanadium mineral is vanadian flogopite, the main uranium mineral is pitchblende. The proportions of the ore and ore-forming minerals are determined. The noble metal mineralization (which associates with selenides of lead, silver and bismuth) and the copper-molybdenum mineralization (represented by chalcopyrite and molybdenite) are spread extremely irregularly in the orebodies. The ores can be classified as carbonaceous by their compositions. Four mineral ore types, with regard to the mineralization composition of the ore, are determined: pitchblende-flogopite, noble metal-pitchblende-flogopite, sulphide-flogopite and hypergene. The ores are classified in three technological ore types (uranium-vanadium; uranium-vanadium with Au, Pd, Pt; vanadium with Cu, Mo) and two technological ore sorts (by the acid inventory in processing). The correlation between the composition of the ore and the technological processing parameters are determined. The specifics of the various ore types distribution in the orebodies are discovered. A comparison with the other U-V deposits of the Onega region is made. (author). 4 refs, 3 figs, 2 tabs

  10. 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)

    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.

  11. Mini-pilot-scale hydrochloric acid leaching of an Elliot Lake uranium ore

    International Nuclear Information System (INIS)

    An hydrochloric acid leaching process has been found to provide high uranium recoveries and low residual radium content in the tailings. Several uranium extraction process flowsheets have been developed based on hydrochloric acid leaching of uranium ores, of pyrite-free tails from pyrite flotation minerals and of magnetic concentrates from high intensity magnetic separation of radioactive minerals. Two-stage hydrochloric acid leaching of an Elliot Lake uranium ore with 4-hr. retention in each stage provided 98% overall recovery of uranium and tailings containing 30 pCi g-1 Ra. However, the economics of the acid chloride process compares unfavourably both in capital and in operating costs with the conventional sulphuric acid process, unless such a process provides significant savings in environmental costs. (orig.)

  12. Uranium mineralization characteristics and ore-control factors in Shazaoquan area of Badanjilin basin

    International Nuclear Information System (INIS)

    Based on the integration of previous research achievement, this paper discussed the Lower Cretaceous Xinminpu Group and uranium mineralization in Shazaoquan area of Badanjilin basin with results of field geological investigation as well as borehole verification. After analyzing the ore-control factors, the uranium mineralization was believed to be controlled by sequence stratigraphic boundary, lithofacies, epigenetic oxidation. The favorite mineralization area should have relative stable structure and proper structural lift condition in the centre depression of the basin. The boundary of sequence Ⅳ/Ⅲ of Xinminpu Group with the change in structural and depositional system and geochemical condition is the most important ore-control factor. The foreside of alluvial fan and midland also afford favourite lithology combination and space for uranium mineralization. Uranous granite afford the very beneficial uranium mineralizing condition for the sandstone-type uranium deposits. In general, Badanjilin basin have a good prospective. (authors)

  13. 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)

    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 520C (500C) 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

  14. Optimization of technological processes at uranium ore mining and milling in Ukraine

    International Nuclear Information System (INIS)

    Uranium industry of Ukraine is 60 years old. It partly satisfies needs of Ukrainian NPPs; however, the raw materials base of the uranium industry in Ukraine allows covering the requirements of the NPPs fully. The raw materials base has special features comparatively with other countries of the world. The industrial uranium resources of Ukraine are large-scale but the ores, as a whole, are related to low-grade ones by uranium content. The main industrial type of uranium deposits in Ukraine is metasomatite and the ores occur as hard rocks. Monometallic nature of the ores stipulates possibility of high-quality uranium concentrate output with very low content of detrimental impurities. Mining and processing technologies are different from the foreign ones. The Ukrainian government approved a number of programs aimed at increasing uranium production up to the level, which can satisfy the requirements of the nuclear power plants, modernization of technology (heap leaching, in situ leaching, in-place leaching) and also liquidation of negative environmental consequences of uranium mining and processing activities. (author)

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

    International Nuclear Information System (INIS)

    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

  16. Application of integrated logging data for the uranium-beryllium exploration in Baiyanghe ore-district

    International Nuclear Information System (INIS)

    This paper summarized the geophysical parameter characteristics of main rocks in Baiyanghe ore-district, Xuemisitan volcanic belt in Xinjiang, China. According to geological characteristics that the contact zone between granite porphyry and strata is the major store place of orebody, the rock types and the contact zone were identified with integrated logging data, which can play an important role for beryllium-uranium prospection in Baiyanghe ore-district. (authors)

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

    International Nuclear Information System (INIS)

    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.)

  18. The laboratory study on a sandstone uranium ore in-situ leaching

    International Nuclear Information System (INIS)

    Uranium mineral of a sandstone uranium ore and its composition were investigated, Based on the investigated , the leaching technology and parameters were selected through experiments, the U leaching rate to 92.81% use 15 g/L H2SO4, the U leaching rate to 84.24% use 10 g/LNa2CO3 + 5 g/LNaHCO3. Column leaching test using five test column, leaching rate respectively: 95.58%, 98.11%, 59.39%, 46.14%, 59.39%. After approximately 12 void volume laundering, the water quality in ore at or near background values of ore-bearing aquifer. The results from agitation leaching and column leaching experiments show that the sandstone uranium suitable for ISL mining methods. (authors)

  19. Mineralogical and geochemical features of ore-forming conditions of endogenous uranium deposits in the Eastern Europe and CIS

    International Nuclear Information System (INIS)

    Results of long-lasting integrated studies from main uranium ore provinces in a large region are presented. Compositions of ore minerals and their relationship to ore-forming processes are discussed and a mineralogical and geochemical classification of the deposits is given. Patterns of fluid-system evolution are revealed and the possible fluid sources are discussed. (author)

  20. Geological characteristics and analysis on ore-controlling factors of Shihongtan uranium deposit, Turpan-Hami basin

    International Nuclear Information System (INIS)

    On the basis of a brief introduction of regional geology of Turpan-Hami basin, geology and sand bodies characteristics for target stratum of Shihongtan uranium district, the author mainly expounds distributive law, zonation and relation between fronts and u-mineralization of interlayer oxidation zone for deposit district. The author states space arrangement, shape, size, material components of ores, exiting states of uranium as well as comparative study for north-ore belt and south-ore belt of Shihongtan uranium deposit. In final, the author points out ore-controlling factors are interlayer oxidation zone, nose uplift and faulted structure by systematic analysis

  1. Advances in uranium ore processing and recovery from non-conventional resources

    International Nuclear Information System (INIS)

    The main topics covered by the technical sessions were: in situ and heap leaching, improvements in conventional acid and alkaline uranium ore processing, recovery of uranium from wet-process phosphoric acid and recovery of uranium from coal and from natural waters. The technical sessions concluded with three panel discussions dealing with pre-concentration and benefication, in situ and heap leaching, and recovery of uranium from wet-process phosphoric acid. The present volume includes 18 of the 27 presented papers. A separate abstract was prepared for each of these papers

  2. Mineralogy and uranium leaching of ores from Triassic Peribaltic sandstones

    OpenAIRE

    Gajda, Dorota; Kiegiel, Katarzyna; Zakrzewska-Koltuniewicz, Grazyna; Chajduk, Ewelina; Bartosiewicz, Iwona; Wolkowicz, Stanislaw

    2014-01-01

    The recovery of uranium and other valuable metals from Polish Peribaltic sandstones were examined. The solid–liquid extraction is the first stage of the technology of uranium production and it is crucial for the next stages of processing. In the laboratory experiments uranium was leached with efficiencies 71–100 % by acidic lixiviants. Satisfactory results were obtained for the alkaline leaching process. Almost 100 % of uranium was leached with alkaline carbonate solution. In post leaching so...

  3. Theoretical study on law of radon seepage exhalation from blasted uranium ore heap in shrinkage stope

    International Nuclear Information System (INIS)

    One dimensional differential equation for radon migration in the blasted uranium ore heap was established using radon seepage-diffusion migration theory, the formula for calculating the surface radon exhalation rate at the seepage exit in the blasted uranium ore heap was derived, and the methods for determining the relevant physical parameters were proposed. For a specific shrinkage stope, the influences of the air volume for ventilation, ore heap height and ore heap permeability on the radon exhalation rate were studied. The radon exhalation rate of the ore heap increases with the air volume for ventilation and gradually approaches its maximal value, but the growth rate decreases gradually with the increase of the air volume for ventilation. When the air volume for ventilation is small but is kept the same, the higher the ore heap is, the smaller the radon exhalation rate is. With the increase of the air volume for ventilation, the radon exhalation rate of the higher ore heap exceeds successively that of the lower ore heap, and the difference becomes larger and larger, and the higher the ore heap is, the larger the air volume for ventilation is for the radon exhalation rate to amount to its maximal value. The smaller the permeability of the ore heap is, the lower the radon exhalation rate of the heap is, the smaller the growth rate of the radon exhalation rate relative to the air volume is, and the larger the air volume for ventilation is for the radon exhalation rate to come to its maximal value. (authors)

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

    International Nuclear Information System (INIS)

    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

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

    International Nuclear Information System (INIS)

    A reliable routine procedure for determining 226Ra 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 226Ra 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 223Ra, 224Ra and 226Ra between the leach products, (residue and leach liquor), is discussed. (author)

  6. Analysis of uranium ores by energy dispersive X-ray fluorescence

    International Nuclear Information System (INIS)

    The determination of uranium in ores by energy-dispersive X-ray fluorescence (XFA) is demonstrated for uranium ore samples of known content. For calibration silica gel standards are used. Matrix effects are corrected by measuring the Compton scattering peaks. The radionuclide 109Cd as well as a X-ray tube in combination with Mo or Sn as secondary targets are suited as X-ray sources. The mean relative deviation of the values found from the given values is 5%. (orig.)

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

    International Nuclear Information System (INIS)

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

    International Nuclear Information System (INIS)

    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% U3O8) under economical conditions, such as 20 to 40 kg of H2SO4 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 U3O8 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 U3O8 per litre) was then precipitated as a yellow cake with 65 to 75% U3O8 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 H2SO4 per tonne of ore, particle size -1 cm, 250C, 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 400C temperature have been applied to decrease the uranium loss in the raffinate. (iii) Carbonate type: Even if alkaline leaching at 650C, or leaching with 400 kg of H2SO4 per tonne of ore, was carried out on -200 mesh ore samples, no acceptable uranium recoveries were obtained

  9. Restoration of in situ leached uranium ores: A laboratory study of restoration reagents

    International Nuclear Information System (INIS)

    Ammonium bicarbonate has been used as the primary lixiviant in many in situ uranium mining operations. During the leaching operation, ammonium ions exchange with the cations of the ores clay fraction and, after mining is complete, may desorb into the ground water along with other elements. Laboratory column tests were used to evaluate the effect of various restoration reagents on the leakage levels of ammonium, uranium, and selenium ions. Aluminium chloride significantly reduced leakage levels and also increased ore bed permeability. (author). 3 refs, 7 figs, 4 tabs

  10. The primary discussion of the neutral network method application in prospecting uranium ore of radioactive geophysics

    International Nuclear Information System (INIS)

    On the basis of collecting a large number of radioactive geophysical data, the neural network method was introduced into the data-processing work of prospecting the uranium ore through radioactive geophysical method. After adequately analyze the characteristics of the measurement data, the BP model was established and the model calculating results were explained and compared by combining with the geological and geophysical information. The results showed that it was feasible to use the neural network method in forecasting the perspective region of prospecting uranium ore in radioactive geophysics. (authors)

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

    International Nuclear Information System (INIS)

    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 UO22+ ions. The microbial leaching degree was comprised between 40-90%, depending on the used alga and experimental conditions. (author)

  12. Mineralogy and uranium leaching of ores from Triassic Peribaltic sandstones

    International Nuclear Information System (INIS)

    The recovery of uranium and other valuable metals from Polish Peribaltic sandstones were examined. The solid-liquid extraction is the first stage of the technology of uranium production and it is crucial for the next stages of processing. In the laboratory experiments uranium was leached with efficiencies 71-100 % by acidic lixiviants. Satisfactory results were obtained for the alkaline leaching process. Almost 100 % of uranium was leached with alkaline carbonate solution. In post leaching solutions only uranium and small amounts of vanadium were present. (author)

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

    International Nuclear Information System (INIS)

    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

  14. Scientific background, technology and equipment for hydrometallurgical processing of uranium and complex ores

    International Nuclear Information System (INIS)

    Major results of research performed by All-Russian Research Institute of Chemical Technology in the period from 1953 to 2001, which was aimed at the development of scientific fundamentals, technology and equipment for hydrometallurgical processing of uranium and complex ores, are presented. Special attention was paid to leaching as one of the main operations in uranium hydrometallurgy dictating the degree of uranium extraction along with other valuable components. Study of uranium oxidation kinetics during leaching of ores permitted development and putting into service of highly efficient processes of carbonate and acid leaching in pulp agitators under atmospheric pressure, as well as in autoclaves with horizontal mechanical agitators and vertical pneumatically operated mixing of the pulp

  15. Application of gravimetric and aeromagnetic data to the study of uranium ore-formation of granite-type uranium deposits

    International Nuclear Information System (INIS)

    The emplacement status and dynamic field of magma of some granitic massifs in the south of China are analyzed by using gravimetric and aeromagnetic data in this paper, and granitic massifs are classified according to their intensity of dynamic field. Based on the inverse calculation of gravimetric data of Miaoershan-Yuechengling, Zhuguangshan and Guidong granitic massifs, the deep distribution form of these massifs is discussed, then three movement ways of magma flow are proposed, and finally, the emplacement sites of rich-large uranium deposits and area of uranium ore concentration, are pointed out, and the close relation between aeromagnetic anomalies and rich-large uranium deposits are pointed out as well

  16. Mineralogical, radiographic and uranium leaching studies on the uranium ore from Kvanefjeld, Ilimaussaq Complex, South Greenland

    International Nuclear Information System (INIS)

    102 samples of low-grade uranium ore from 70 drill holes at Kvanefjeld, Ilimaussaq alkaline intrusion, South Greenland were studied by means of autoradiography, fission-track investigations, microscopy, microprobe analyses and uraniumleaching experiments. The principal U-Th bearing mineral, steenstrupine, and several less common uranium minerals are disseminated in lujavrite (nepheline syenite) and altered volcanic rocks. Steenstrupine has average composition Nasub(6.7)Hsub(x)Casub(1.0) (REE+Y)sub(5.8)(Th,U)sub(0.5)(Mnsub(1.6)Fesub(1.8)Zrsub(0.3)Tisub(0.1)Alsub(o.2))Sisub(12)Osub(36)(Psub(4.3)Sisub(1.7))Osub(24)(F,OH) x nHsub(2)O; n and x are variable. It either is of magnetic origin (type A) or connected with metasomatic processes (type B), or occurs in late veins (type C). Preponderance of grains are metamict (usually 2000-5000 ppm U3O8) or altered (usually above 5000 ppm U3O8), sometimes zoned with both components present. Occasionally they are extremely altered with U content falling to 500-5000 ppm U3O8 and local accumulations of high-U minerals formed. Replacement by crystalline monazite (+- metamict uranothorite and other components) is locally important. Uranium recovery by carbonate leaching (NaHCO3+Na2CO3+O20) depends both on alteration of steenstrupine and on hydration of parent rocks. Yield is between 98 and 50%, the average U concentration in the examined rock around 350 ppm U. (author)

  17. Non-neoplastic pulmonary disease from inhaled radon daughters with uranium ore dust in beagle dogs

    International Nuclear Information System (INIS)

    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

  18. Alpha spectrometry of thick sources. II. Application to the study of radioactive equilibria in uranium ores

    International Nuclear Information System (INIS)

    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 219Rn and daughters. This phenomenon must be taken in consideration when computing spectra line intensities. (author)

  19. Experimental study on bio-leaching of high sulphuric acid consumption uranium ore by adding sulphide

    International Nuclear Information System (INIS)

    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)

  20. Order of 13 December 1985 on the transfer to ENRESA of the Radioactive Waste Management Facility at Sierra Albarrana

    International Nuclear Information System (INIS)

    This Order provides for the transfer of the Radioactive Waste Management Facility at Sierra Albarrana from the Junta de Energia Nuclear to ENRESA, the National Enterprise for Radioactive Waste; it also organises all stages of the transfer. (NEA)

  1. Uranium ores and depleted uranium in the environment, with a reference to uranium in the biosphere from the Erzgebirge/Sachsen, Germany

    International Nuclear Information System (INIS)

    The Erzgebirge ('Ore Mountains') area in the eastern part of Germany was a major source of uranium for Soviet nuclear programs between 1945 and 1989. During this time, the former German Democratic Republic became the third largest uranium producer in the world. The high abundance of uranium in the geological formations of the Erzgebirge are mirrored in the discovery of uranium by M. Klaproth close to Freiberg City in 1789 and the description of the so-called 'Schneeberg' disease, lung cancer caused in miners by the accumulation of the uranium decay product, radon, in the subsurfaces of shafts. Since 1991, remediation and mitigation of uranium at production facilities, rock piles and mill tailings has taken place. In parallel, efforts were initiated to assess the likely adverse effects of uranium mining to humans. The costs of these activities amount to about 6.5 109 Euro. A comparison with concentrations of depleted uranium at certain sites is given

  2. 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)

  3. Calculation of U, Ra, Th and K contents in uranium ore by multiple linear regression method

    International Nuclear Information System (INIS)

    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

  4. Study on pressure alkaline leaching and its application to uranium ores

    International Nuclear Information System (INIS)

    The chemical processes and mechanism of pressure leaching of uranium ore and the factors affecting leaching rates are discussed in this paper. The results of bench scale experiments, the data from pilot plant operations and the data from industrial productions in a mill are also presented

  5. Leaching behavior of uranium and vanadium using strong sulfuric acid from Korean black shale ore

    International Nuclear Information System (INIS)

    The present scientific study focused on leaching behavior of uranium and vanadium from Korean domestic ore. The leaching process experimental conditions optimized for uranium and vanadium metals recovery from Korean domestic ore and developed the basic experimental procedures such as time, particle size, acid influence, temperature effect and pulp density (PD) behavior. Acid influence on leaching process was tested and noted that 2.0 M sulfuric acid concentration is the optimized conditions for present study. The time influence on leaching process was observed and its optimized 2 h for complete leaching process. The temperature influence tested and optimized the 80 deg C for complete leaching process and PD is 50 % (wt%). The bench scale experiments developed in a laboratory and tested in pilot level each batch 100 kg of ore sample. (author)

  6. New understanding of ore-formation of in-situ leachable sandstone-type uranium deposit in Erlian basin

    International Nuclear Information System (INIS)

    Starting with the ore-controlling role of tectonic evolution of Erlian basin, i.e. the basement evolution stage, the formation state of ore-hosting formation, and the ore-formation stage of epigenetic reworking, authors come to a conclusion, that Erlian basin was a sedimentary basin composed of tens of little separate depressions with their own tectonic and sedimentary evolutionary features, and multiple and near source area at the stage of the ore-hosting formation. Combining above-mentioned factors with the other ore-controlling factors related to sandstone-type uranium deposits, authors suggest that the size of sandstone-type uranium deposits to be found in Erlian basin might be mostly small or medium in size. Bu it is possible that the smaller medium-sized uranium deposits would occur in groups. The dominant subtype of the sandstone-type uranium deposits may be phreatic-interlayered oxidized zone

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

    International Nuclear Information System (INIS)

    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 1000 to 1100C, (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, HNO3 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

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

    Science.gov (United States)

    Landa, E.R.

    1984-01-01

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

  9. Rio Algom investigations into preconcentration of uranium ore

    International Nuclear Information System (INIS)

    Rio Algom Mines Ltd. owns eight U mines and mills in the Elliot Lake district of Ontario, seven of which were producing before 1960. At present only one mine is operating and meeting current contract requirements. Under present economic conditions, it is not feasible to mine ore of less than 2.0 lb/ton U3O8, although there are very large reserves below this grade. Rio Algom is interested in preconcentration for three possible applications: to extend ore reserves by permitting use of lower grade ore, to reduce costs on processing of present grade ore, and to reduce capital investment in expanding production to meet future production goals. Rio Algom has been investigating various applicable preconcentration processes since the early 1950s to date on laboratory and pilot-plant scale. Methods investigated include gravity concentration by sink-float, high-intensity wet magnetic separation, flotation of U, flotation of acid consumers, and a number of electronic sorting methods including radiometric, photometric, and conductimetric. No method tested has yet been satisfactory under Rio Algom's criteria of U recovery and cost, principally because U loss has been too high for a useful weight rejection. Metallurgical results of the preconcentration test work and the economic assessment therefrom are reviewed. (U.S.)

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

    International Nuclear Information System (INIS)

    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)

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

    International Nuclear Information System (INIS)

    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 UO22+ 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 UO22+ ions, in the presence of living plants. (author)

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

    International Nuclear Information System (INIS)

    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 (MnO240%) 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

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

    International Nuclear Information System (INIS)

    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

  14. 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.

  15. Impact Of Low Grade Uranium Ores On The Echo System and the Workers of Phosphate Industry

    International Nuclear Information System (INIS)

    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

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

    International Nuclear Information System (INIS)

    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, CO2, F, et al), tracks of intersection of NWW-across with NNE-trending faults and lithology of diabase. (authors)

  17. Chapter 3. Classical method of uranium leaching from ores and reasons for incomplete recovery at dumps of State Enterprise 'VOSTOKREDMET'. 3.2. Uranium extraction from the ore and classification of its losses

    International Nuclear Information System (INIS)

    Present article is devoted to uranium extraction from the ore and classification of its losses. It was found that uranium commodity balance that has decisive importance during the actual assessment of an enterprise's activity is formed on the basis of chemical sampling and weight accounting for the head grade delivered to the plant, together with the ore and produced finished product. Process balance reflects the actual process nature of uranium extraction from ore into the finished product, the basis of which is the chemical analysis of ore and hydrometallurgical redistribution products on basic operations of the manufacturing process. Technological balance enables, through an analytical approach, to identify uranium extraction by technological redistribution and, in whole, the percentage and weight outcome, uranium concentration degree and extent of process loss. Process extraction does not take into account mechanical losses and therefore, as a rule, exceeds the commodity to an extent of those losses. It was defined that sorption redistribution losses of plant's process flow diagram are uranium losses with hydrates, with slurry solution and with granule resin. Sum of these losses in ratio to uranium amount delivered for sorption defines the process extraction value of sorption redistribution. Total uranium technological extraction to finished product is defined by uranium comparing in residues released to tailings with its content in ore with a glance of increased solid volume.

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

    International Nuclear Information System (INIS)

    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)

  19. Study On The Selection Of Leaching System For The Treatment Of Thanh My, Quang Nam Uranium Ore

    International Nuclear Information System (INIS)

    In this study, the theoretical and practical basis to select leaching systems for the treatment of uranium ore have been analysed. The treatment of Thanh My low grade uranium ore was investigated using leaching methods including agitation leaching, strong acid pugging and curing, and heap leaching with different technological conditions. Based on data obtained from previous techno-scientific researches in the Institute for Technology of Radioactive and Rare elements, and comparison of experimental results obtained from leaching methods, we have selected the heap leaching method as suitable method for treatment of Thanh My low grade uranium ore. (author)

  20. Kinetics of Leaching Process of Sella Uranium Ore Material, South Eastern Desert, Egypt

    International Nuclear Information System (INIS)

    The leaching of uranium from Sella uranium ore using hydrochloric acid solution has been studied. The effect of different parameters such as leaching time, hydrochloric acid concentration, liquid/ solid mass ion temperature, mechanical stirring speed are investigated in order to optimize various process for maximizing the recovery of uranium. The maximum percentage uranium leaching of 96 % 1 after 15 min of contact time leaching using 3.0 M hydrochloric acid and 4/1 liquid/ solid mass ratio at 26 °C with 400 rpm mechanical stirring speed. The experimental data are well interpreted with a shrinking core model with diffusion control through a porous product layer. By using the Arrhenius expression, the apparent activation energy for the uranium action is evaluated

  1. Assessment of environmental impact of mining and processing of uranium ore at Jaduguda, India

    International Nuclear Information System (INIS)

    Uranium ore from three underground mines located within a distance of 12 km is mined and processed by the Uranium Corporation of India Ltd (UCIL) in the mill at Jaduguda in eastern India. Management of mine water, mill tailings and the effluents from the tailings pond is given due importance during the mining and ore processing operations. Radon released from the mines exhausts and emanating from the tailings pile and liquid effluents released from the effluent treatment plant have a potential for environmental impact. Environmental surveillance has, therefore, been an integral part of the uranium mining and ore processing operations since their inception. The radiation exposure rate, atmospheric radon and radioactivity in surface and ground waters, as well as in soil, are monitored to assess the environmental impact of these operations. This paper gives a brief account of the mining, ore processing and waste management operations. The environmental monitoring results of the last few years are summarized in this paper. They indicate the radiological impact of these operations on the environment is only marginal and well within the regulatory limits. (author)

  2. A comparison of pixe and neutron activation techniques for thorium and uranium ore analysis

    International Nuclear Information System (INIS)

    Proton induced X-ray emission (PIXE) and neutron activation analysis (NAA) techniques are used to estimate the concentrations of trace quantitites of thorium and uranium in powdered rock or ore samples. The accuracy of the two methods is compared in both a carbon matrix and a variety of ore matrices over the concentration range 1 to 10000 microgram per gram. Under the test conditions the PIXE and NAA concentration estimates for any individual sample in this range are found to be the same within a 3 sigma standard error of 9 per cent

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

    Science.gov (United States)

    Landa, E.R.

    1982-01-01

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

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

    International Nuclear Information System (INIS)

    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

  5. Behaviour of organic matters in uranium ore processing

    International Nuclear Information System (INIS)

    The oxidation-reduction behaviour of organic matters in the course of oxidation roasting, acid leaching and alkali leaching, the regeneration of humic acid and the consumption of reagents are described. The mineralogical characteristics of the organic matter samples were studied. The results show that its organic matter rich in volatile carbon and with the shorter evolutionary process and lower association is easily oxidized with higher consumption of oxidant during its acid leaching; it is easily oxidized with forming humic acid during alkali leaching; and pretreating it by oxidation roasting is beneficial to the oxidation of uranium. On the contrary, the organic matter rich in fixed carbon, and with longer evolutionary process and higher association is difficultly oxidized with lower consumption of oxidant during its acid leaching; it is difficult to regenerate humic acid for it during alkali leaching; and the uranium can be easily reduced and the leaching performance of uranium can be lowered

  6. The Blind River uranium deposits: the ores and their setting

    International Nuclear Information System (INIS)

    The Matinenda Formation (basal Huronian) comprises northward-derived arkose, quartzite, and pyritic, uraniferous oligomictic conglomerate that contains 75 percent of Canada's uranium reserves. The conglomerate beds occur in southeasterly striking zones controlled by basement topography down-sedimentation from radioactive Archean granite. The mineralization is syngenetic, probably placer. Drab-coloured rocks, uranium and sulphide mineralization, and a post-Archean regolith formed under reducing conditions, suggest a reducing environment. Sedimentary features indicate deposition in fast-flowing shallow water, and possibly a cold climate. (author)

  7. The pretreatment of uranium ores by physical processing

    International Nuclear Information System (INIS)

    After giving an outline of the classical means of physical processing - granulometry, gravimetry, flotation, magnetism, electrostatics, the authors study the methods peculiar to radioactive ores: pretreatment in batches (counting cylinders) or stone by stone (electronic sorting belt). The three factors to be considered in any treatment operation are studied (cost of the operation, metal recovery, ratio of concentration), as well as their bearing on the cost and the productivity of the following operations. Making use of radioactivity in order to find out instantaneously the approximate grade of the obtained product makes it possible to reduce costs and improve results by setting up total automation. (author)

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

    International Nuclear Information System (INIS)

    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 290X109 kWh, i. e. eight times the present requirement, and in the year 2000 it would be 820X109 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 150X109 kWh and hence the difference of about 140X109 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 from the ore deposits at

  9. Link between ore bodies and biosphere concentrations of uranium

    International Nuclear Information System (INIS)

    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 km2 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

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

    International Nuclear Information System (INIS)

    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)

  11. Uranium mineralization environment and prospecting potential of Dawan ore field in Nanling metallogenic belt

    International Nuclear Information System (INIS)

    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)

  12. An approach to the mathematical modelling of the uranium series redistribution within ore bodies

    International Nuclear Information System (INIS)

    The distributions of the uranium series isotopes in the Koongarra ore body were predicted by a simple one-dimensional model of isotopic migration parameters. Controlling the predictions were the retardation factors and the groundwater flow rates. The conditions modelled were a groundwater flow rate of 1 meter per year, retardation factors of 1 x 104 for 238U and of 1.2 x 104 for 234U, and 230Th is immobile. For this set of conditions, an exceptionally good agreement was observed between field-measured isotope ratios and ''predicted'' isotope ratios. A multiphase model adequately describes the redistribution of uranium and daughter radionuclides in the weathered zone of the ore bodies. It redistributes U, Th and Ra isotopes among an aqueous phase, an amorphous iron phase, a crystalline phase and a phase of clay and quartz. 28 refs., 26 figs., 8 tabs

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

    International Nuclear Information System (INIS)

    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/cm3

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

    International Nuclear Information System (INIS)

    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 α1 spectral line is calculated and related to corresponding strontium-Kα spectral line, both detected with a Scintillation Counter. (Author) 31 refs

  15. Improvement to treatment processes of alkaline leaching liquors of uranium ores

    International Nuclear Information System (INIS)

    Process for treating alkaline leaching liquors of uranium ores, the characteristics of which include: - an operation to neutralize at least a fraction of these liquors by an acid in conditions leading to the decarbonation of the said fraction, - where required, joining the neutralized and non neutralized fractions, - adding lime to the mixture of the two fractions in an amount and under conditions giving rise to the precipitation of virtually all the uranium in solution, - separating the precipitate formed constituting a calcic pre-concentrate of the surface floating solution

  16. Simultaneous determination of hafnium and zirconium in low grade uranium ores using INAA

    International Nuclear Information System (INIS)

    A non-destructive neutron activation analysis technique was developed for the determination of hafnium and zirconium in low grade uranium ores. In order to calculate the fission contribution of sup(235)U, thermal neutron absorption cross-section for sup(94)Zr was determined. The study shows that 1 g of uranium produces the same activity as 10.03 g of zirconium. Based on this fact, the degree of interferences was calculated for each sample and the necessary corrections were applied. The values were compared with the reported IAEA and NBS values. (author)

  17. 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.

  18. New knowledge and direction of ore searching about Guizhou 504 uranium, hydrargyrum and molybdenum orebody

    International Nuclear Information System (INIS)

    504 mineral deposit locates in the Jura type Folds zone of mid Guizhou province. The hydrothermal activities of mineral zone is obvious, and the altered minerals is intensity. The proved up orebody of uranium, hydragyrum and molybdenum occurs in interlaminar up and down fracture zone of middle Gaotai Fm shale in cambrian system. The inter laminar glide tectonics exists in deep Qingxudong Fm, Jindingshan Fm, Niutitang Fm, Dengying Fm, and Doushantuo Fm. Perhaps there are orebody of uranium, hydragyrum and molybdenum. And this is main directions of the deeper ascertainment and blindness searching in ore district. (authors)

  19. In-situ leaching of south Texas uranium ores--part 1: laboratory studies of ore composition and leaching performance

    International Nuclear Information System (INIS)

    This paper presents data on mineralogy and laboratory chemical-leaching tests for ore samples from several areas of the south Texas tertiary Catahoula formation. Optical microscope, electron microprobe, spectroscopic, X-ray diffraction (XRD), and various chemical analyses were performed. Batch screening tests gave qualitative estimates of leach rate and potential recovery. Packed column tests using hydrogen peroxide or pressurized oxygen gave more quantitative recovery estimates. The frequently friable sandstones contained highly variable amounts of quartz, feldspar, calcite, and clay, and in some cases, zeolite or mica. Clays were mainly mixed layer illite/smectite type. High cation exchange capacities (CEC's) correlated with clay (and zeolite) content, while high reducing capacities were often associated with pyrite level. Coffinite, in various environments, was the main uranium mineral. With batch tests using pseudo-first-order rate constants, ore leach rates were generally characterized as ''fast'' on a scale of fast, intermediate, and slow. However, there was variability in leach rates, both in samples from different areas and in samples taken at different depths in the same well. Fast rates and recoveries greater than 80% were observed in most column pack tests, but there was variation with leachate composition and sample source. The chemistry and kinetics of leaching are also discussed

  20. In-situ leaching of south Texas uranium ores--Part 1: Laboratory studies of ore composition and leaching performance

    International Nuclear Information System (INIS)

    This paper presents data on mineralogy and laboratory chemical-leaching tests for ore samples from several areas of the south Texas tertiary Catahoula formation. Optical microscope, electron microprobe, spectroscopic, X-ray diffraction (XRD), and various chemical analyses were performed. Batch screening tests gave qualitative estimates of leach rate and potential recovery. Packed column tests using hydrogen peroxide or pressurized oxygen gave more quantitative recovery estimates. The frequently friable sandstones contained highly variable amounts of quartz, feldspar, calcite, and clay, and in some cases, zeolite or mica. Clays were mainly mixed layer illite/smectite type. High cation exchange capacities (CEC's) correlated with clay (and zeolite) content, while high reducing capacities were often associated with pyrite level. Coffinite, in various environments, was the main uranium mineral. With batch tests using pseudo-first-order rate constants, ore leach rates were generally characterized as ''fast'' on a scale of fast, intermediate, and slow. However, there was variability in leach rates, both in samples from different areas and in samples taken at different depths in the same well. Fast rates and recoveries greater than 80% were observed in most column pack tests, but there was variation with leachate composition and sample source. The chemistry and kinetics of leaching are also discussed

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

    International Nuclear Information System (INIS)

    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% U3 O8. Only trace amount of Ca, Fe, Po4, 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

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

    Institute of Scientific and Technical Information of China (English)

    2000-01-01

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

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

    International Nuclear Information System (INIS)

    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 K2O-Al2O3SiO2-H2O and Na2O3-Al2O3SiO2-H2O. Uranium ore containing 0.15 percent U3O8 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

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

    International Nuclear Information System (INIS)

    The supercritical fluid extraction (SFE) method using CO2 as a medium with an extractant of HNO3-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 CO2. It was thus demonstrated that the SFE method using CO2 is useful as a pretreatment method for the analysis of uranium in ores. (author)

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

    International Nuclear Information System (INIS)

    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

  6. REE characteristics of Shannan deposit district in Xiangshan uranium ore field and its geological significance

    International Nuclear Information System (INIS)

    REE geochemical characteristics of rock and ore are studied in Shannan deposit district of Xiangshan Uranium orefield. The mean values of Σ REE of both basement schist and volcanic rock are approximately equal. Σ REE gradually increases from rock, common ore to bonanza. REE distribution patterns of rocks are right declined type to light REE. REE distribution patterns of volcanic rock series are parallel and concordant, the volcanic rock series are homologous, and products of pulsating events of same magma chamber. Eu depletes remarkably in volcanic rock series and ores. On its way to surface, magma underwent high fractionation and crystallization, based on feature of REE component ratio, triangle diagram of light medium and heavy REE, and diagram of LREE/HREE-(Eu/ΣREE) × 100. U and REE enriched in hydrothermal solution of post-magmatism to provide substances for uranium metallogenesis. Both diagenesis of volcanic rock series and uranium metallogenesis in the mining district are constrained by volcano-magmatism. Metallogenic fluid is rich in volatiles, such as F, Cl, CO2 etc. Metallogenic substances are unloaded in reduction environment. Metallogenic temperature is probably less than 250℃. Genesis of bonanza is more complicated and likely superimposed by multi-metallogenesis. (authors)

  7. Bacterial community structure from the perspective of the uranium ore deposits of Domiasiat in India

    International Nuclear Information System (INIS)

    Domiasiat (25°30'N 91°30'E) located in the west Khasi hill district of Meghalaya in northeast India is one of the largest sandstone-type uranium (U) ore deposit in India containing 9.22 million tonnes of ore reserves with an average ore grade of around 0.1 % U3O8. This geographically distinct U deposit of Domiasiat is un-mined and harbours diverse group of bacteria surviving the stressful environmental conditions prevalent in the ore deposit. Studies show that the diverse bacteria belonged to 10 different bacterial groups with occurrence of some previously uncharacterized bacteria. The cultured identified bacteria have been reported to tolerate substantial concentration of U and other metals and showed potent capacity for uptake and precipitation of U. Studying the bacterial community associated with such pre-mined U ore deposit are advantageous as it not only generates the baseline information on microbial community structure as resourceful indicator to estimate the impact of mining to be undertaken in future but also identifies the bacteria which can be explored for their potential as bioremediation agents for radionuclide/multi-metal waste sites. (author)

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

    International Nuclear Information System (INIS)

    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

  9. On the deep origin of the ore-forming solutions in the uranium deposits in platform sequences of depressions (with the Shu-Sarysu Province as an example)

    International Nuclear Information System (INIS)

    Author concepts on the endogenous source of the ore substance and ore -forming solutions at the hydrogenous uranium deposits formation in the Cretaceous and Paleocene horizons in depressions of Kazakstan are outlined. (author)

  10. Photoneutron logging system for direct uranium ore-grade determination

    International Nuclear Information System (INIS)

    A prototype photoneutron probe for direct uranium assay in exploratory boreholes has been built and field tested. An approx. 10-Ci 124Sb gamma-ray source together with a beryllium converter is used to produce neutrons that diffuse into the surrounding formation and cause fissions in any 235U present. The fission neutrons that return to the probe are energy analyzed and counted by a high-pressure helium detector, thus indicating the concentration of uranium. The response of the probe was measured in concrete models at the US Department of Energy (Grand Junction, Colorado) calibration facility and found to be approx. 35 counts/s for an 1% U3O8 concentration in an 11.4-cm-diam water-filled borehole (4.5 in.). The response is linear up to a concentration of at least 0.25% by weight U3O8. Effects resulting from changes in formation density, porosity, and neutron absorber content were also quantified, as well as the tool response as a function of borehole diameter and fluid. A logging vehicle was outfitted, and the photoneutron-based logging system was field tested at an exploration site near Canon City, Colorado. Logging data obtained in several open holes at this site are presented and compared to core chemical analyses and results obtained in the same holes using other logging methods. In about 1 month of field testing, the photoneutron-based uranium exploration system has proved to be simple to use and very reliable. 22 figures, 12 tables

  11. The radioprotection in the french uranium mines and ore factories

    International Nuclear Information System (INIS)

    A regulation concerning workers' radiation protection in mines has been recently introduced in the french Code Minier; it takes into account the ICPR recommendations of Publication 26 and the European directives of 1980 and 1984. This new regulation is being implemented with success in France since 1983. For workers' monitoring in uranium underground mines, an individual dosimeter measuring the three monthly dose equivalents (gamma, potential alpha energy, long-lived alpha emitters) is compulsory. The aim of the ambient monitoring is the early prevention of every defects in the primary and auxiliary ventilation, which is the basis of prevention

  12. Technology of mine water treatment in uranium ore mining

    International Nuclear Information System (INIS)

    The most commonly used method of radioactive water treatment is the sedimentation method based on the adsorption mechanism. Iron, aluminium and calcium hydroxides are used for removal of uranium. Thorium, polonium and lead 210 are removed using the said hydroxides and also barium chloride and sodium phosphate. The mining solutions are mixed with chemicals and cleaning proceses take place including sedimentation, decantation and filtration. The treated water is partially returned into technological operations, partially discharged. Hygiene regulations have so far been missing governing other uses. (M.D.). 3 refs

  13. Regularities of spatial association of major endogenous uranium deposits and kimberlitic dykes in the uranium ore regions of the Ukrainian Shield

    Science.gov (United States)

    Kalashnyk, Anna

    2015-04-01

    During exploration works we discovered the spatial association and proximity time formation of kimberlite dykes (ages are 1,815 and 1,900 Ga for phlogopite) and major industrial uranium deposits in carbonate-sodium metasomatites (age of the main uranium ore of an albititic formation is 1,85-1,70 Ga according to U-Pb method) in Kirovogradsky, Krivorozhsky and Alekseevsko-Lysogorskiy uranium ore regions of the Ukrainian Shield (UkrSh) [1]. In kimberlites of Kirovogradsky ore region uranium content reaches 18-20 g/t. Carbon dioxide is a major component in the formation of hydrothermal uranium deposits and the formation of the sodium in the process of generating the spectrum of alkaline ultrabasic magmas in the range from picritic to kimberlite and this is the connection between these disparate geochemical processes. For industrial uranium deposits in carbonate-sodium metasomatitics of the Kirovogradsky and Krivorozhsky uranium ore regions are characteristic of uranyl carbonate introduction of uranium, which causes correlation between CO2 content and U in range of "poor - ordinary - rich" uranium ore. In productive areas of uranium-ore fields of the Kirovogradsky ore region for phlogopite-carbonate veinlets of uranium ore albitites deep δ13C values (from -7.9 to -6.9o/oo) are characteristic. Isotope-geochemical investigation of albitites from Novokonstantynovskoe, Dokuchaevskoe, Partyzanskoe uranium deposits allowed obtaining direct evidence of the involvement of mantle material during formation of uranium albitites in Kirovogradsky ore region [2]. Petrological characteristics of kimberlites from uranium ore regions of the UkrSh (presence of nodules of dunite and harzburgite garnet in kimberlites, diamonds of peridotite paragenesis, chemical composition of indicator minerals of kimberlite, in particular Gruzskoy areas pyropes (Cr2O3 = 6,1-7,1%, MgO = 19,33-20,01%, CaO = 4,14-4,38 %, the content of knorringite component of most grains > 50mol%), chromites (Cr2O3 = 45

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

    International Nuclear Information System (INIS)

    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 (μmax) and doubling time (td) were obtained 0.08 h-1 and 8.66 h, respectively. Parameters such as Fe2+ 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 d80 = 100 μm. The optimum concentration of supplementary Fe2+ was dependent to the PD. This value was 0 and 10 g of FeSO4·7H2O/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)

  15. Thermal analyse - correlation with chemical analyse and performance of the uranium ores leaching process

    International Nuclear Information System (INIS)

    This paper present the results of the research concerning the existence of some correlations between the results of thermal analyze, chemical analyse and the performances and parameters of the alkaline leaching process for the romanian uranium ores. With a view to putting in the evidence of these corelations they are taking into consideration the thermal effect and gravimetric aspects resulted by heating of the sample, the contents of total uranium, the mobile uranium, U(VI), S-2, CO2, dbc and as technological indicator, the leaching output of uranium for some constant technical parameters: the rapport S/L=1/2, temperature =120 C, pressure=12 atm, and the leaching time-12 hours. The results show very clear difference between the samples as a function of theirs analysed contents. So, the used technological method not diminish the uranium content in the leachings barrem gangue at the level of difference between the total and mobil uranium content of ore sample; the ratio U(VI)/U(VI), generally, has been subunitary, the U(VI) weight of over 50% require stronger condition for oxidation; the sulfides and carbonates content have a direct influence about the natrium carbonate and oxygen consumption; it has been demonstrated the connection between the presence of combustible component part, visible in the thermo-differential curve, in association with some affects on the gravimetric curve and the uranium mobil content but especially the U(IV), content. A large content of the organic matter (coal of bitumen nature) show a large content of U(VI). (orig.)

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

    International Nuclear Information System (INIS)

    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

  17. Uranium-radiu relation concerning there migration from ore and waste dumps

    Energy Technology Data Exchange (ETDEWEB)

    Popescu, M.; Georgescu, D.P.; Sporea, A.; Petrescu, S.; Popescu, C.; Georgescu, A. [Research and Design Inst. for Rare and Radioactive Metals, Bucharest (Romania)

    1998-12-31

    The study refers to uranium-radium migration from the dumps affected by alteration as well as recycling process due to the geochemical barriers in different dispersive media. The problem of correct understanding and interpretation of the contamination due to the mining activities (ore and waste dumps) is a difficult one. It has to be correlated with elements migration from the mineralization determining radioactive aureole in water, soil and vegetation (which are, in fact the means to locate some deposits). Migration and pollution phenomena in different dispersive media have been studied for uranium, radium and other accompanying elements from several deposits. Data obtained from the geochemical studies of the mineralization show a large variety of accompanying elements: Mo, Pb, Bi, Co, Cu, Ag, Tl, As and Li. In order to study the pollution processes, rock, soil, sediments, water and plants samples have been drown and analyzed for uranium, radium, and other twenty elements, determination using fluorimetry atomic absorption spectrometry and emission spectrography. Environmental pollution may be influenced by:mine waters draining in the hydrographic ne and hypergenetic levigation processes of uranium and radium from rocks and ores on the dumps and their transport into the rivers and sediments. (orig.)

  18. Guidebook on the development of projects for uranium mining and ore processing

    International Nuclear Information System (INIS)

    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

  19. On the composition of ore-forming fluids at the vein-type uranium deposits of the Saxonian Erzgebirge (Germany)

    International Nuclear Information System (INIS)

    The fluid inclusions in gangue minerals of pitchblende parageneses from two uranium-bearing formations of the unique Schlema-Alberoda and middle-scale Tellerhauser deposits were studied in detail. The P-T-X conditions of uranium ore formation were determined. The data obtained indicate that U may be transported in chloride complexes with a subordinate role of carbonate complexes. (author)

  20. The flotation of gold, uranium, and pyrite from Witwatersrand ores

    International Nuclear Information System (INIS)

    The Witwatersrand reefs contain gold, uranium, and pyrite in the following average concentrations: 0,001 per cent, 0,02 per cent, and 1,7 per cent respectively. The paper discusses the flotation of pyrite to produce a sulphide concentrate, reviews work done on the production of gold concentrates, discusses attempts to produce maximum concentrates, and closes with a review of processes for the simultaneous flotation of these three species. It is concluded that high recoveries of all three species can be achieved only if a rougher concentrate of perhaps 20 per cent of the feed (by mass) is produced, and it is suggested that reverse leaching (leaching before cyanidation) of this concentrate, followed by a cleaning flotation step for the recovery of the pyrite, would be more efficient than the routes employed at present

  1. Formation of neogenic ores on the dump-heaps of old uranium mines and on the mine-head of mines under exploitation

    International Nuclear Information System (INIS)

    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)

  2. A process for the simultaneous recovery of gold and uranium from South African ores

    International Nuclear Information System (INIS)

    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. The determination of trace elements in uranium ores by x-ray fluorescence spectrometry

    International Nuclear Information System (INIS)

    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

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

    International Nuclear Information System (INIS)

    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)

  5. Lithofacies characteristics of ore-hosting horizon and its relationship to uranium mineralization in Qianjiadian uranium deposit, Songliao basin

    International Nuclear Information System (INIS)

    The host rocks of Qianjiadian uranium deposit in Songliao basin is composed of thick bed sand- bodies, which are formed by braided stream sediment in Yaojia formation. The thick bed sandbody has favorable upper and lower waterproof layer, and has lenticular mudstone interlayer in some parts. On plane, the flood plain face locates around the braided stream face, which is mainly composed of sediments of argillaceous rock. In the middle of braided stream, distributes interchannel sediments, which has thicker mudstone interlayer and thinner sand bodies, and the sand body of these place is more heterogeous than others. Based on the analysis on oxidation zone and uranium mineralization, it is found that the distribution and configuration of oxidation zone and ore bodies are obviously controlled by the lithofaties characteristics and sandbody heterogeneity of Yaojia formation. The reason is that the movement of uranium-bearing oxidizing ground water can be obstructed by interchannel sediments and pelitic interbeds of host sandstones. As a result, the redox interface will be developed and uranium can be concentrated in neighbouring sandstones. The sandbodies with greater homogeneity are favorable for the formation of oxidation zone, and sandbodies with greater heterogeneity are favorable for the uranium mineralization. (authors)

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

    International Nuclear Information System (INIS)

    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 P2O5) leaching efficiency were studied

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

    International Nuclear Information System (INIS)

    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

  8. Thorium-uranium processing with gravity, magnetic and electrical separation in zarigan ore deposit

    International Nuclear Information System (INIS)

    Because of low grade of thorium and uranium in the Zarigan mineral deposit, the pre-concentration operation prior to leaching is necessary. From X-ray diffraction analysis results, it was clear that this ore has large amount of other minerals such as Feldespat, Quartz, Hematite, Titanomagnetite, and rare earths. In this paper the thorium enhancement grade in Zarigan deposit by using gravity, magnetic and electrical separations methods is reported. The output of a Jaw crusher was ground to 85 micron by using ball mill. Then about 95% of SiO2 was separated by using shaking table separation. The heavy concentrate of shaking table was processed by a high intensity magnetic separator and then the magnetic concentrate separated by a low intensity magnetic separator. Finally, the non magnetic concentrate of low magnetic separator was processed with the electrical separation. The grades of thorium and uranium in the non magnetic concentrate of low magnetic separator were increased to 4000 and 5000 ppm, respectively where only 15% of the initial feed (ore) was transferred to this concentrate. Therefore, this resulted in a decrease of acid consumption in the leaching processes and the efficiency enhancement of the process. The pre-treatment circuit of this ore was designed as Jaw crusher/ball mill/shaking table/high-magnetic separator/low-magnetic separator/electrical separator, respectively.

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

    International Nuclear Information System (INIS)

    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

  10. Bois-Noirs ore. Recovery of uranium of solutions from acid treatment. Results of industrial tests at the Gueugnon plant

    International Nuclear Information System (INIS)

    Industrial-scale tests are reported of the efficiency of two recovery processes for the separation of uranium from sulfuric acid pickling solutions used on ore from Bois-Noirs, at the Gueugnon works. The final stage of each process is sodium uranate. The earlier part of the report deals with tests of the separation of uranium from foreign metals by fractional precipitation. The second part deals with the separation of uranium from these metals by carbonation of the solutions. (author)

  11. Physiolgical and ecological studies of the vegetation on ore deposits, 3; Radioecological symptoms of plants over uranium ore deposits in Koisan, Korea

    International Nuclear Information System (INIS)

    From 1975 to 1981, the survey was carried out to find out radioecological effects of uranium ore deposits on natural vegetation in Koisan, Korea. The symptoms of spotty and mosaic chlorosis, and necrosis were observed in flowering plants in the areas of uranium ore deposits at Deok-Peung-Ri A, B, and C in Koisan. Although 13 species were found to be chlorosis and necrosis, foliages observed are small and very rare. The features of these symptoms closely resemble those occured by the effects of heavy metals. The amount of transparent radiation throughout the depth of soils from uranium radiation sources decreases exponentially. The mean contents in leaves of spotty and mosaik chlorotic plants, and soils were 1.36∼1.53 and 5.3∼7.4ppm, respectively

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

    International Nuclear Information System (INIS)

    Full text: The greater part of our activities is connected with the problem of extracting uranium from low-grade ores. In this paper, a brief review of the most important recent developments will be presented. In this connection, it may be useful to determine the definition of low-grade ores. This term can be applied to ore from which the uranium content cannot be extracted under normal economic conditions. Thus this term can be applied to uranium-bearing material with a uranium content of no more than 0. 05%. But, in general, it could be said that there is a very large range of uranium content where uranium extraction may not be economic for such different reasons as; (a) the size or other facts in connection with the orebodies themselves; (b) refractory ore; or (c) other local conditions. During research on the treatment of low-grade ore from the deposit at Gabrovnica (Stara Planina, Yugoslavia) it became apparent that an alkaline leaching process would have to be carried out. The treatment of this granitic type of ore causes no particular difficulties. The required temperature is about 90oC. The retention time in the leaching stage is from 4 to 12 hours. Sodium carbonate consumption is not higher than 15 kg/t of ore. Pachuca-type leaching shows satisfactory maintenance and processing costs. At Kalna uranium precipitation by means of hydrogen pressure reduction has been developed, and is being developed and investigated in full-scale operation. Details of the process were published in Geneva in 1963. On the basis of the experience gained from full-scale operation, many refinements and cost-saving changes have been made. A normal steel wire screen used as a catalyst carrier shows a very good improvement over free-moving UO2 as catalyst. In large-scale operation (200 t/d), after the precipitation of uranium the barren solution content is about 1 g U/m3. The content of the pregnant solution is of the order of 300-600 g/m3. Recycling the barren solution has resulted

  13. Technical characteristics and optimum application conditions of in-situ leaching of uranium ore body

    International Nuclear Information System (INIS)

    Based on theoretical studies and field tests of in-situ leaching of uranium ore body, it is found that the method has very important technical characteristics that the height of heap is extraordinarily high, the shape of heap is irregular, the heap site is enclosed and hidden beneath the surface, the ore can only be fragmented for one time, the fragment size and composition are very important, and the measures to prevent underground pollution have to be taken necessarily. These technical characteristics have to be taken into account and comprehensive quantitative studies have to be conducted in accordance with the criteria of whether the application conditions are very favourable, favourable or unfavourable before the decision is made to adopt the in-situ leaching method

  14. Experience in leaching, separation and purification of uranium from Romanian uraniferous mineral ores

    International Nuclear Information System (INIS)

    Nuclear fuel technology is determined by the type of nuclear reactor to be used and by the chemico-mineralogical characteristics of the raw material, the production units in Romania manufacturing nuclear fuel under the form of sinterable UO2 for a nuclear reactor, PHWR-Candu type, which operates with natural uranium and heavy water moderator. The raw material from which uranium is extracted at industrial level is an ore with silica gangue and a content of over 10% alkaline carbonates. The paper presents the way of development and application of the nuclear fuel technology which is based on carbonate leaching of the uranium ore, technical concentrate purification by TBP-extraction, calcination of ADU to U3O8, reduction to UO2 and nitrogen inert treatment of the pure nuclear dioxide. The original contribution of the Romanian specialists in the research, design and industrial processing fields for the developed technology has a significant importance. The flowsheets for the extraction, purification and pure nuclear UO2 production are also presented

  15. In-situ leaching of crownpoint, New Mexico, uranium ore: part 1--mineralogical frame of reference

    International Nuclear Information System (INIS)

    Before assessing potential for in-situ leaching, it is advantageous to identify the nature of probable reactants in the ore horizon, including both the uranium species and those in the gangue material. We report mineralogical data on a broad suite of samples from the Westwater Canyon member of the Jurassic Morrison formation in the Crownpoint area of the Grants mineral belt. Optical microscope, electron microprobe, X-ray diffraction, and spectroscopic and wet chemical analyses were conducted. In these samples, the uranium occurs predominantly as either coffinite or uraninite. The host rock is arkosic sandstone comprising mainly detrital quartz and feldspar. Kaolinite and chlorite are present in claystone clasts, and calcite occurs as a cement. Major trace elements include molybdenum, vanadium, iron, selenium and sulfur. There is carbonaceous organic material in the ore, and it is intimately associated with the uranium mineral when it is coffinite. Geochemical, pyrolytic and 13C nuclear magnetic resonance (NMR) analyses indicate that the organic material is probably a very mature, coaly kerogen derived from plant components

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

    International Nuclear Information System (INIS)

    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 MnO2 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

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

    Science.gov (United States)

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

    2015-12-01

    Minor element composition and rare earth element (REE) concentrations in nuclear materials are important as they are used within the field of nuclear forensics as an indicator of sample origin. However recent studies into uranium ores and uranium ore concentrates (UOCs) have shown significant elemental and isotopic heterogeneity from a single mine site such that some sites have shown higher variation within the mine site than that seen between multiple sites. The elemental composition of both uranium and gangue minerals within ore samples taken along a single mineral vein in South West England have been measured and reported here. The analysis of the samples was undertaken to determine the extent of the localised variation in key elements. Energy Dispersive X-ray spectroscopy (EDS) was used to analyse the gangue mineralogy and measure major element composition. Minor element composition and rare earth element (REE) concentrations were measured by Electron Probe Microanalysis (EPMA). The results confirm that a number of key elements, REE concentrations and patterns used for origin location do show significant variation within mine. Furthermore significant variation is also visible on a meter scale. In addition three separate uranium phases were identified within the vein which indicates multiple uranium mineralisation events. In light of these localised elemental variations it is recommended that representative sampling for an area is undertaken prior to establishing the REE pattern that may be used to identify the originating mine for an unknown ore sample and prior to investigating impact of ore processing on any arising REE patterns. PMID:26301831

  18. Seismicity induced by mining operations in the surrounding of the uranium ore mine Schlema-Alberoda

    International Nuclear Information System (INIS)

    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 km2 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).

  19. Sedimentary environment analysis of Yaojia formation--the ore-hosting stratum of Qianjiadian uranium deposit

    International Nuclear Information System (INIS)

    Qianjiadian uranium deposit is the first uranium deposit discovered in Songliao basin. In this paper, the sedimentary environment of Yaojia formation, the ore-hosting stratum of Qianjiadian uranium deposit and its relationship with uranium mineralization are studied from several aspects such as lithological combination, sedimentary structures, logging curves, thickness ratio of sandstone layer to mudstone layer, sedimentary petrology and petrological geochemistry. The sedimentary features are characterized by the average value 5.0 between thickness ratio of sandstone layer to mudstone layer of Yaojia formation, and typical tabular cross bedding and trough cross bedding. The lithology of Yaojia formation is mostly composed of intermediate to fine-grained sandstone and mudstone with less conglomerate, and the debris grains have moderate sorting and roundness. These indicate that the source area is far, and that the sediments underwent long-distance transportation before deposition. The large scale and stable extension sand body of the Yaojia formation demonstrated the sedimentary features ora large sedimentary basins. Therefore, the sedimentary environment of Yaojia formation in the study area should be far-sourced sandy braided stream in the united great Songliao basin. The uranium mineralization of Qianjiadian deposit is mainly controlled by the sand bodies of channel-bar and point-bar subfacies, and the scale of the mineralization is closely related to that of the sand bodies. (authors)

  20. Age of uranium ores at Ranger and Jabiluka unconformity vein deposits, Northern Territory, Australia

    International Nuclear Information System (INIS)

    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)

  1. Nuclear wastes: Limousin: alert to pollution coming from old uranium ores

    International Nuclear Information System (INIS)

    At the middle of the debate is the pollution produced by the uranium ores of the Cogema deserted after more than fifty years of exploitation, failing cost effectiveness and often used as radioactive waste storage site. A pollution denounced for about ten years by Sources and Rivers of Limousin (S.R.L.) In 1999, this organization makes complaint with the county court for water pollution, neglected radioactive wastes and to endanger somebody s life. An other organization F.N.E. sues for damages someone being tried in a criminal court in this affair that it considers (F.N.E.) token of French nuclear channel drift. (N.C.)

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

    International Nuclear Information System (INIS)

    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)

  3. 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.

  4. Research on defining the composition of materials in the uranium ore at PaLua mine and its influences on technological process

    International Nuclear Information System (INIS)

    The uranium ore of the Pa Lua mine is a class of the sandstone ore with the ore bodies distributed unevenly and complicatedly. It is mostly existed in the two forms of unweathered ore and weathered one. In the unweathered ore, the specific existing minerals include nasturan, coffinit, pyrites, marcasite, galena, sphalerite, siderite containing manganese, calcite and organic substances. In weathered ore, the existing minerals are products of the oxygenation process altering the pre-existed minerals, that including major minerals such as uranofan, metauranoxiaxit, soddyit, basetit, hematite, hydrogotit, piroluzit, ramsdelit, different clay minerals, etc. The average content of U3O8 of the studied ore sample is 0.077%. Uranium minerals are unevenly distributed and mainly in cement is soft hole structure. Minerals containing iron are the impurity component that receives the most attention and its distributive rule is closely related to uranium minerals. Commonly, the content of iron is high when that of uranium is high and vice versa. The results of the study and exploration show that the uranium ore of the Pa Lua mine is possible separated and selected with traditional methods, in which the radioactive method and floating one are promising. The enrichment coefficient can be obtained at 1.5- 2.5. Due to the fact that the extent of weathering, the hardness and the component of uranium minerals (the ratio of deoxidized form over the oxygenized form) of UW ore and W ore are greatly different, the absorbing speed of the agent dissolved and separated inside the ore particle and its back-to-surface absorbing speed are also different. The absorbing experiment is carried out for the four ore samples in accordance with the Darcy absorbing model. So as to acquire equal uranium dissolution and separation performances under the same conditions, the size of unweathered ore must be a quarter of semi-weathered ore's size. (author)

  5. Occupational diseases in uranium and ore miners, related to the radiation exposure in Czech Republic, in 2003-2013

    International Nuclear Information System (INIS)

    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)

  6. Experience with restoration of ore-bearing aquifers after in situ leach uranium mining

    International Nuclear Information System (INIS)

    In many cases the most important environmental issue for in situ leach uranium mining technology is the impact on groundwater. Usually the greatest issue is the chemical condition of the ore bearing aquifer following the completion of leaching. Based on experience gained during post leach monitoring, it has been found that in properly selected sites the impact following leaching is greatly reduced because of the process of self restoration, otherwise known as natural attenuation. This paper provides ground water monitoring data from 1985 to 1997 following completion of leaching at the Irkol uranium deposit, Kazakhstan. It shows the evolution of the pH, and other chemical parameters over this period. The monitoring results demonstrate that at this site the process of natural attenuation appears to have effectively reduced the impact on groundwater at the site, as well as to keep contaminated leaching fluids from moving more than a few hundreds of metres from the wellfield. (author)

  7. Soil bacterial metagenomic analysis from uranium ore deposit of Domiasiat in Northeast India

    International Nuclear Information System (INIS)

    Total bacterial community analyses were performed for uranium ore deposit soil samples of Domiasiat utilizing cultivation-independent approach. Screening based on amplified ribosomal DNA restriction analysis (ARDRA) using MspI and HaeIII was performed to analyse 150 clones which generated 59 distinct ribo-types from the clone library. Representative 96 clone partial 16S rRNA gene were phylogenetically related to 10 different bacterial groups. Proteobacteria and Acidobacteria were the most abundant bacterial group while 7% of the clones represented novel bacterial lineages. The bacterial diversity obtained by the culture-independent approach presented a larger diversity of bacteria as compared to the conditioned cultivation method. The study also provides baseline me-tagenomic information to assess subsequent impact of environment perturbation consequent to uranium mining at the studied site. (author)

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

    International Nuclear Information System (INIS)

    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

  9. Assessment of gamma radiation exposure to drivers (contractual) engaged with transporting of uranium ore in uranium mines at Narwapahar Mines, India

    International Nuclear Information System (INIS)

    Due to radioactive nature of uranium ore and tailings sand, it is essential to assess the exposure of drivers and helpers, those are continuously engaged with transporting of it. The external exposure is due to gamma radiation, emitted by uranium progeny and its magnitude is therefore directly related to the ore grade. The major gamma emitters in the series are 214Pb and 214Bi. After uranium recovery in ore processing areas the waste generated in mill contains same magnitude of gamma emitters. Tailings sand is the waste generated from mill area, which is used for back filling in underground mine. This paper presents the results of estimation of external gamma radiation levels during transport and assesses the radiation dose to drivers and helpers

  10. Characterization of the Kintyre uranium ore and optimization of the leaching process

    International Nuclear Information System (INIS)

    Cameco's Kintyre uranium project, located in the Eastern Pilbara region of Western Australia, is currently in the final stages of the prefeasibility study. This study is being led from Cameco Australia's Perth office, with assistance from the Cameco Technology and Innovation (CTI) and Major Projects groups. Cameco teams have supported the development of this project on all activities including geology, mineral resource classification, mining, metallurgy, geo-environmental, and design engineering. This paper focuses on the ore properties of this deposit, and how it has influenced the process flow sheet option selection. The Kintyre deposit mineralisation is defined as basement hosted vein type uraninite/coffinite, which is primarily comprised of dolomite, magnesite and calcite. The carbonate content of the ore is high relative to the uranium content (U/CO3 < 5%, and as such, poses challenges with regards to conventional acid leaching, as demonstrated by test work performed by the Cameco Technology and Innovation - Research Centre (CTI - RC) in Port Hope, Canada. Extensive test work has been completed by the CTI - RC and others in efforts to pre-concentrate uranium and to simultaneously reduce carbonate content by means of gravimetric, flotation and radiometric sorting methods. It has become apparent from these metallurgical campaigns that the uranium and carbonate mineralisation's are closely interlinked, and that carbonate is only effectively removed on a mass basis. As a result, acid consumption across all Kintyre zones remains very high, such that it has a significant economic impact on the project. For this reason, the alkali leach path has been investigated as a viable alternative by the Cameco project team. This paper will present the outcomes of this trade-off study in terms of technical, operability and relative economic standpoints. (author)

  11. Data from a uranium ore body on release of dissolved species: comparison with a near field release model

    International Nuclear Information System (INIS)

    In the Swedish repository for spent fuel the canisters containing the uranium oxide fuel are surrounded by compacted bentonite clay which has a low hydraulic conductivity. The transport through the clay will be dominated by diffusion. The water flow in the fractured rock is very small and it is likely that the dissolution rate of the fuel will be solubility limited. Release and transport models based on this assumption have long been used in performance assessments including that used for the Swedish KBS-3 type repository design. In the uranium ore body at Cigar Lake there is a striking similarity between the ore body and a repository. The ore is uranium oxide and it is surrounded on the top side by a dense clay which has a much lower hydraulic conductivity than the surrounding rock. We have used the same principles as for the near field release models for the repository to calculate the dissolution rate of uranium and other species at Cigar lake. At this location a large number of measurements on the water composition in and around the ore body have been made. At one location in the ore body itself the first water samples contained a very high concentration of helium, hydrogen and sulphate. This decreased with continued sampling. (authors). 25 refs., 3 figs., 5 tabs

  12. Radioactive environmental geology of ore-bearing artesian basin and in-situ leach mining of uranium deposit

    International Nuclear Information System (INIS)

    The recent hydrogeological environments of interlayer-infiltration type uranium deposits exert different influence in protecting the environment pollution during in-situ leach mining process. According to the hydrogeologic characteristics, especially the hydrodynamic parameters, uranium deposits may be divided into 3 groups: favorable, unfavorable and extremely unfavorable. Favorable uranium deposits are those in which ground water diagonally flows from oxidation zone and unaltered rock zone to the ore zone interacting along the trending of the ore zone. Under such hydrogeologic conditions leaching solution is not able to flow beyond the ore zone, protecting the environment from pollution. Completely unfavorable hydrogeologic condition are those under which ground water perpendicularly passes through the ore zone flowing from the oxidation zone towards the zone of grey rocks. In this case ground water may carry poisonous elements and heavy metals out of the ore zone to neighbouring areas. Uranium deposits of unfavorable hydrogeologic conditions are those in which the above two situations coexist. Practice demonstrates that the pollution caused by in-situ leach mining is lower than that of the natural radioactive pollution when hydrogeologic conditions are favorable for in-situ leach mining

  13. Recovery of Uranium from Uranium Mine Waters and Copper Ore Leaching Solutions

    International Nuclear Information System (INIS)

    Waters pumped from uranium mines in New Mexico are processed by ion exchange to recover uranium. Production is approximately 200 lb U3O8/d from waters containing 5 to 15 ppm U3O8. Recoveries range from 80 to 90%. Processing plants are described. Uranium has been found in the solutions resulting from the leaching of copper-bearing waste rock at most of the major copper mines in western United States. These solutions, which are processed on a very large scale for recovery of copper, contain 2 to 12 ppm U3O8. Currently, uranium is not being recovered, but a potential production of up to 6000 lb U3O8/d is indicated. Ion exchange and solvent extraction research studies are described. (author)

  14. Recovery of uranium from uranium mine waters and copper ore leaching solutions

    International Nuclear Information System (INIS)

    Waters pumped from uranium mines in New Mexico are processed by ion exchange to recover uranium. Production is approximately 200 lb U3O8/d from waters containing 5 to 15 ppm U3O8. Recoveries range from 80 to 90%. Processing plants are described. Uranium has been found in the solutions resulting from the leaching of copper-bearing waste rock at most of the major copper mines in western United States. These solutions, which are processed on a very large scale for recovery of copper, contain 2 to 12 ppm U3O8. Currently, uranium is not being recovered, but a potential production of up to 6000 lb U3O8/d is indicated. Ion exchange and solvent extraction research studies are described. (author)

  15. Preliminary discussion on tectonic-magmatic evolution with respect to metallogenesis of rich uranium deposits in Xiazhuang ore-field

    International Nuclear Information System (INIS)

    The regional tectonic setting and main geologic features are described. It is suggested that Xiazhuang ore-field is characterized by shallow thermo-upwelling extensional tectonics, and the occurrence and the distribution of rich-large uranium deposits are controlled by the specific tectonic-magmatic evolution under shallow thermo-upwelling extensional tectonics, and those of late-stage rich-large uranium deposits are constrained by the tectonic-magmatic evolution of taphrogenic extensional tectonics. On the above basis, a metallogenic model for rich-large uranium deposit has been set up, and four metallogenically prospective area for rich-large uranium deposits have been predicted

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

    International Nuclear Information System (INIS)

    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)

  17. 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)

    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 NH4OH. 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)

  18. Production of ferric sulphate from pyrite by thiobacillus ferrooxidans. Application to uranium ore leaching

    International Nuclear Information System (INIS)

    A process for uranium extraction by oxidizing solutions of ferric sulphate produced by T. ferrooxidans from pyrite is developed. A new counting method specific of T. ferrooxidans is designed. An uranium resistant wild strain, with oxidizing properties as high as the strain ATCC 19859, is isolated. Optimal conditions for ferric sulphate production from pyrite are defined (pH 1.8, density of the medium 1.2%, pyrite granulometry < 60 micrometers). The comparison of oxidation of 2 pyrites evidences the effect of composition and crystal type on bacterial activity. Latency period is reduced by preliminary adaptation of bacteria to pyrite, a relatively important inoculum and association of T. ferrooxidans to T. thiooxidans. Free bacteria, but not adsorbed bacteria, play an important part in pyrite oxidation, indirectly by regeneration of ferric iron and by maintaining a high redox potential. Leaching of an uranium ore column by an acidic solution of ferric iron increase not only uranium extraction yield but also to decrease acid consumption in respect to acid leaching only

  19. An evaluation of the dissolution process of natural uranium ore as an analogue of nuclear fuel

    International Nuclear Information System (INIS)

    The assumption of congruent dissolution of uraninite as a mechanism for the dissolution behaviour of spent fuel was critically examined with regard to the fate of toxic radionuclides. The fission and daughter products of uranium are typically present in spent unreprocessed fuel rods in trace abundances. The principles of trace element geochemistry were applied in assessing the behaviour of these radionuclides during fluid/solid interactions. It is shown that the behaviour of radionuclides in trace abundances that reside in the crystal structure can be better predicted from the ionic properties of these nuclides rather than from assuming that they are controlled by the dissolution of uraninite. Geochemical evidence from natural uranium ore deposits (Athabasca Basin, Northern Territories of Australia, Oklo) suggests that in most cases the toxic radionuclides are released from uraninite in amounts that are independent of the solution behaviour of uranium oxide. Only those elements that have ionic and thus chemical properties similar to U4+, such as plutonium, americium, cadmium, neptunium and thorium can be satisfactorily modelled by the solution properties of uranium dioxide and then only if the environment is reducing. (84 refs., 7 tabs.)

  20. 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)

    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/m2.h, sandstone is mixed or incubated with acid before the percolation. About 23 kg filter cake per m3 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% U3O8. The water recycle was successfully tested. That results in minimization of water addition to only 0.3m3/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)

  1. DEVELOPMENT OF X-RAY FLUORESCENCE TECHNIQUE FOR THE URANIUM DETERMINATION IN MONGOLIAN COAL, COAL ASH, AND PHOSPHATE ORE

    OpenAIRE

    Cherkashina, Tat`iana Yur`evna; Bolortuya, Damdinsuren; Revenko, Anatolii Grigor`evich; Zuzaan, Purev

    2014-01-01

    The results of the determination of uranium in Mongolian brown coal, coal ash, phosphate rock, and technological samples by X-ray fluorescence (XRF) spectrometry are presented. Technological samples were produced from phosphates by chemical treatment. Powder geological samples and Certified Reference Materials (CRMs) were pressed as tablets. For chosen conditions of the sample preparation procedure analytical figures of merit were carefully studied, as exemplified by the rock and uranium ore ...

  2. 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)

  3. Uranium,Radium and Iron Absorption from Liquid Waste Uranium Ore Processing by Zeolite

    International Nuclear Information System (INIS)

    The aim of this work is to determine zeolites sorption capacity and the distribution coefficient of uranium, radium, and iron in zeolite-liquid waste system. Mineralogical composition of zeolite used in the experiment has been determine by examining the thin sections of zeolite grains under a microscope. Zeolite has ben activated by the dilute sulfuric acid or sodium hydroxide solution. The results show that the use of 0.25 N sodium hydroxide solution could be optimizing the zeolite for uranium and iron ions sorption and that of 0.1 N sulfuric acid solution is for radium sorption. The re-activation process has been carried out in three hours. Under such a condition, the sorption efficiency of zeolite to those ions have been known to be 45.85% for uranium, 96.63 % for iron and 87.80 % for radium. The distribution coefficients of uranium, radium and iron ion in zeolite-liquid waste system have been calculated 0.85, 7.02, and 28.65 ml/g respectively

  4. Regulatory view of the close-out of the uranium ore mine Zirovski Vrh

    International Nuclear Information System (INIS)

    The production of the uranium mine Zirovski Vrh ceased in 1990. The main remaining problem of the remadiation are mine and mill tailings. The uranium mine Zirovski Vrh has one mill tailings site Borst and one waste pile Jazbec. According to the Act on protection against ionising radiation and nuclear safety which was adopted by the Parliament in 2002, they are classified as radiation facilities. Slovenian Nuclear Safety Administration (SNSA) is authorised for issuing a mandatory consent to mining work. The SNSA prepared the initial proposal of content of the safety report for the mine waste pile Jazbec. In 2005, according to the detailed content of this document, the public company Zirovski Vrh Ltd prepared the safety report which was examined by an authorised expert for radiation and nuclear safety. After a careful revision of the safety evaluation report, the consensus for mining work shall be issued by the SNSA. After finishing the mining works the SNSA shall also issue a licence for the closure of waste pile Jazbec. The main goal of this article is to present the Slovenian regulations which cover also mining work in the field of close-out of the uranium ore mine. (author)

  5. Uranium deposits of the Sierra Pena Blanca: Three examples of mechanisms of ore deposit formation in a volcanic environment

    International Nuclear Information System (INIS)

    The Nopal and Escuadra Formations (welded vitroclastic tuffs) contain the uranium deposits of Sierra Pena Blanca (Chihuahua, Mexico). These Tertiary formations (between 44 and 38 million years) overlie Cretaceous limestones. With mineralogical, petrographical, geochemical and fluid inclusion studies of the non-altered rocks of the uraniferous mineralization and the associated alteration three genetic types of ore deposits have been identified. Hydrothermal ore deposits (Nopal I). These ore deposits are linked to faults or a breccia pipe. They are mainly located in the Nopal Formation. Their history is complex and begins soon after the deposition of tuff. They are considered hydrothermal, even if some supergene alteration occurs during late stages. Oxidized mineralization (uranophane) succeeds reduced ore (uranium oxides-ilmenite and pitchblende-pyrite associations). The associated kaolinite has a high temperature habitus. The montmorillonite-zeolite association is local and occurs after kaolinization. Supergene ore deposit (Puerto III). Puerto III is a stratiform-shaped deposit. The only oxidized mineralization lies in the upper part of the Nopal Formation and is located under a silicified bed interpreted as a palaeosoil. Mixed ore deposit (Las Margaritas). This uranium-molybdenum deposit is located in the Escuadra Formation. The alteration products are kaolinite with a middle temperature habitus and alunite. The intensity of this alteration is lower than in the first hydrothermal type, but the volume of altered rock is greater. Uranium mineralizations (silicates, phosphates, vanadates) are associated with molybdenum minerals (sulphides and molybdates). This deposit is considered to be the result of an interaction, in a tectonic valley, between hydrothermal volcanic fluids and underground waters. (author)

  6. Recent Pilot Plant Experience on Alkaline Leaching of Low Grade Uranium Ore in India

    International Nuclear Information System (INIS)

    Uranium deposits in India are low grade and are relatively smaller in extent as compared to present worldwide commercial practice. So far, the vein type deposits of Singhbhum Thrust Belt (STB) are being exploited for meeting the Indian requirements of uranium. The deposits are currently processed by acid leaching in the mills located at Jaduguda and Turamdih near Jamshedpur in Jharkhand State of India. The deposits at Jaduguda and Narwapahar are being mined by underground mining and are processed in Jaduguda mill using airagitated Pachucas. The deposits at Banduhurang and Turamdih are being mined by open cast and underground mining respectively and are processed at Turamdih by acid leaching in mechanically agitated reactors. The occurrences of uranium in North East and Northern part of Kadapa basin are relatively moderate in size and are expected to be processed in the near future by acid leaching. Uranium is also found to occur near Tummalapalle in granitic and limestone host rocks in Southern part of Kadapa basin (Andhra Pradesh) and in Gogi in Bhima basin (Karnataka). The deposit in Tummalapalle is relatively lower in grade (≈ 0.042% U3O8) but is a reasonably large reserve, whereas that in Gogi is rich in uranium content (≈0.18% U3O8) but is relatively small reserve. Laboratory tests based on alkaline leaching have been carried out on both types of deposits. Studies for Tummalapalle deposits have been extended to pilot plant level and a complete flow sheet has been established with the regeneration and recirculation of lixiviants and recovery of sodium sulphate as a by-product. The process involves alkaline leaching under oxygen pressure in batch type and/or continuous leach reactor using sodium carbonate/bicarbonate as a leaching media and uranium is recovered as sodium diuranate. Based on the techno-economic evaluation of the process, an industrial scale mill (3 000 tonnes ore/day) is being set up at Tummalapalle in Andhra Pradesh by Uranium Corporation of

  7. Licensing process for a uranium ore mining and milling facilities located in the state of Bahia, Brazil

    International Nuclear Information System (INIS)

    The Uranium Concentrate Plant – URA – is a plant engaged in uranium ore research, mining and milling activities. The plant aims at producing natural uranium concentrate in the form of ammonium diuranate – ADU, used as raw material for fuel production for nuclear plants. This paper discusses the aspects related to nuclear installation licensing, featuring all steps of the process and emphasizing the requirements of control agencies. It also approaches the epidemiological study required by IBAMA during the process of environment licensing, in order to define possible influences of URA's activities on the neighboring population’s health. (author)

  8. Applicability of Raman spectroscopy as a tool in nuclear forensics for analysis of uranium ore concentrates

    Energy Technology Data Exchange (ETDEWEB)

    Ho Mer Lin, D. [European Commission, Joint Research Centre, Karlsruhe (Germany). Inst. for Transuranium Elements; DSO National Laboratories, Singapore (Singapore); Manara, D.; Varga, Z.; Mayer, K. [European Commission, Joint Research Centre, Karlsruhe (Germany). Inst. for Transuranium Elements; Berlizov, A. [International Atomic Energy Agency (IAEA), Vienna (Austria). Vienna International Centre; Fanghaenel, T. [European Commission, Joint Research Centre, Karlsruhe (Germany). Inst. for Transuranium Elements; Heidelberg Univ. (Germany). Physikalisch-Chemisches Inst.

    2013-07-01

    In the present study, the suitability of Raman spectroscopy for nuclear forensics is proven by a systematic investigation of laboratory-prepared synthetic and industrial uranium ore concentrate (UOC) samples, of different origin and with wide range of impurity content. Besides the identification of the compound type, the identification of process-related impurities observed in these samples is reported for the first time. Both handheld and laboratory Raman spectrometers were used in the measurements. The ability to measure different UOCs and the sufficient sensitivity of the handheld device demonstrate its usefulness in nuclear safeguards and nuclear security applications. Even more importantly in such a context, the likely identity of process-related impurities could be verified by Raman Spectroscopy in the present work, allowing to draw conclusions on the process history of the sample. (orig.)

  9. Processing of Low-Grade Uranium Ores. Proceedings of a Panel

    International Nuclear Information System (INIS)

    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. The development of an ore reserve methodology for the Olympic Dam copper-uranium-gold deposit

    International Nuclear Information System (INIS)

    At the Olympic Dam copper-uranium-gold deposit in South Australia, evolution in the understanding of the controls on mineralisation coupled with the changing demands of the project have led to changes in the approach to reserve estimation. The project has moved into a phase where detailed stope mining reserves are now required as distinct from global ore reserves. To enable the selective manipulation of geological and assay information and its characterisation, a relational database has been developed. For reserve calculations themselves, initial computations were based on a system derived from that used for the Kambalda nickel orebodies. The Olympic Dam system differed mainly in the use of statistical analyses in the estimation of grade instead of the previous polygonal area of influence weighting method. Three dimensional weighting techniques are now being used for local reserve estimates

  11. Design for radiation protection in the mining of high grade uranium ore

    International Nuclear Information System (INIS)

    The estimation of external radiation exposures is an important aid in developing radiation protection plans at the design stage of a uranium mine/mill facility, particularly when high grade ore is involved. The principle factors which should be evaluated in the calculation of external exposures are the dose rates at contact with various types of sources, the distances between the source(s) and the work stations, the affect of any proposed shielding and the selection of exposure times workers spend at the various work stations. The last factor is a particularly important consideration for workers who may be exposed to gamma fields from unshielded high grade sources, such as geologists and surveyors, and mill staff who carry out cleanup or maintenance operations

  12. Treatment of tailings water from uranium ore processing by reverse osmosis

    International Nuclear Information System (INIS)

    Mining and metallurgical waste waters are considered to be the major sources of heavy metal contamination. The need of economic and effective methods for metals removal have resulted in the development of new separation technologies. Precipitation, ion exchange, electrochemical processes, filtration and flotation are commonly applied for industrial effluents treatment. Occasionally, the application of such processes is limited because of technical or economical constraints. The search for new technologies regarding the recovery and removal of toxic metals from waste waters has directed attention to membrane processes. These processes are developed in the recent years due to the availability of many new types of membranes. This paper presents the laboratory test results for liquid radioactive effluent treatment from alkaline uranium ore processing by reverse osmosis. (author)

  13. Hydrogeochemistry of uranium, daughter products and associated elements (lanthanides), application to ore prospection

    International Nuclear Information System (INIS)

    The behavior in ground water of uranium, daughter products with long half life (U234, Th230, Ra226) and stable (radiogenic lead) and lanthanides is studied by two complementary methods: 1) In situ multielement tracing in fracturated granitic rocks and porous sedimentary rocks of low permeability allowing to understand interactions between hydrodynamics and geochemistry. 2) Study of the properties of U234 and Pb236 which are mineralization tracers and are relatively independent of redox conditions, on the contrary U 238 has a low solubility in reducing medium. Three areas are studied: Bazois and Lodeve basin (France) and Cigar Lake (Canada). Radioactive disequilibriums are thoroughly studied when required by ore/rock interaction. Adsorption-desorption phenomena are of great importance in proposed prospection models. If prospection models based on alpha activity ratio U234/U238 and lead isotope ratio in ground water can be applied, an integrated prospection model requires more in situ and laboratory experiments

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

    International Nuclear Information System (INIS)

    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

  15. Combined effects of employment in uranium ore mines, silicosis, and tobacco smoking on the lung cancer risk in men

    International Nuclear Information System (INIS)

    The county Aue belongs since more than forty years to the main regions of the Saxonian uranium ore mining. In the male population of this county an elevated incidence of lung cancers was observable in comparison to the average of the East German countries. For this reason an orientying case-control study was performed in order to find risk factors which might be contributing to this elevated incidence. Our results show that enployment in the uranium mining company 'WISMUT AG', a preexisting silicosis by miners, and tobacco smoking are significant risk factors for the development of lung cancers in this population. These three factors modify the lung cancer risk in an overadditive sense. The elevated lung cancer incidence in the male population of this county is explainable by the influence of occupational factors in uranium ore mining. (orig.)

  16. Some evidence of radiolysis in a uranium ore body -- Quantification and interpretation

    International Nuclear Information System (INIS)

    Locally oxidizing conditions in the near-field of the Cigar Lake uranium deposit was observed. Ongoing processes of water radiolysis has also been predicted previously by the mass transport model. In the ore there was an enhanced concentration of helium, hydrogen and sulfate. Sulfate is the only oxidizing species of substantial amount in the groundwater samples, and is possibly indirectly produced by water radiolysis and oxidation of sulfides. The ongoing oxidant production rate has been calculated by the mass transport model. In this paper, the issue of water radiolysis is addressed from a more fundamental angle of approach. The maximum oxidant production rate is calculated based on the assumptions of geometric dispersion of the ore constituents, the estimate of the total radiation energy, the fraction of energy deposited into the pore water, and the G-values of water. The results show that only a few percent of the total radiation energy is deposited into the pore water to cause water radiolysis. If the recombination factor projected by other researchers are accounted for, the oxidant production rate thus calculated agrees with the present-day ongoing oxidant production rate predicted by the mass transport model

  17. Occupational diseases in uranium and ore miners in connection with radiation exposure in the Czech Republic

    International Nuclear Information System (INIS)

    Dozens cases of diseases are submitted to judgement 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 a 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, which are proposed as occupational disease, are malignant tumors of the lungs. Total majority of judged cases are lung cancers from radioactive agents. In 2002, a total of 33 cases of lung cancer in former uranium or ore miners have been acknowledged as occupational diseases. The decision about occupational disease is derived from probabilistic approach based on estimation of probability of causation of irradiation on disease origin (methodical guideline No. 15 of Ministry of Health Bulletin, part 9, 1998). The presented paper gives a general information about all judged causes of occupational diseases in former uranium and ore miners in the Czech Republic in 2002. A total of 72 cases were submitted to judgement of conditions of disease origin to the National Radiation Protection Institute in 2002. 67 cases were lung cancers, 1 case was chronic myeloid leukemia, acute myeloid leukemia, basaliom, cancer of larynx and cancer of nasal septum. The probability of causation was assessed as prevailing in 32 cases of lung cancer, borderline in 5 cases and low in other 30 cases of lung cancer. The probability of causation was prevailing in both cases of myeloid leukemia. (author)

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

    International Nuclear Information System (INIS)

    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

  19. In-Situ leaching of Crownpoint, New Mexico, Uranium Ore: Part 2--laboratory study of a mild leaching system

    International Nuclear Information System (INIS)

    This paper describes laboratory leaching studies involving Crownpoint uranium ore samples and a mild leaching system. Batch leach tests with sodium bicarbonate solution and either high-pressure oxygen or low-pressure hydrogen peroxide gave qualitative data used to estimate leach rate and potential recovery. Using pseudo-firstorder rate constants derived from the batch test data, ore leachability was characterized as fast, intermediate, or slow. It was observed that leach rates varied by a factor of 50 for samples taken from different areas at Crownpoint; samples from the same ore trend often varied by a factor of 10. Packed-column and core-leach tests with oxygen at pressures up to 800 psig (5520 kPa) provided more quantitative estimates of leach rate and uranium recovery. Batch test results were correlatable with leach rates and uranium recoveries in packed-column or core tests. In ore samples where uraninite was the predominant uranium mineral, leach rates and recoveries were high. In samples containing coffinite, leach rates were generally lower than those with uraninite. Very low leach rates and recoveries were encountered where coffinite was intimately associated with carbonaceous material. However, the slow leaching rates are not caused by differences in reactivity of coffinite and uraninite. Mineralogical studies before and after leaching using electron microprobe analyses indicated that exposed coffinite crystals are dissolved easily, but finely disseminated coffinite crystallites persist after leaching if they are encapsulated in the carbonaceous matrix. Slow-leaching ores that did not respond to the mild oxidant system are called ''refractory.''

  20. Engineering evaluation of the decommissioning of former uranium ore processing facilities

    International Nuclear Information System (INIS)

    The United States Department of Energy has sponsored engineering services relating to the decommissioning and reclamation of former uranium ore milling and processing facilities. The engineering services are divided into two stages: Title I and Title II. The Title I services include: an engineering assessment of existing conditions, estimations of types, areas and volumes of radioactive materials, assessment of building decontamination or demolition efforts, the estimation of potential environmental impacts and the determination of various decommissioning and reclamation alternatives, including cost. The Title II services include the preparation of detailed plans and specifications for implementing the selected reclamation alternatives. Reports have been issued for the Title I effort on 22 inactive uranium milling sites in eight western states. The amount of tailings and contaminated material estimated at the sites ranges from 40,000 to 2,470,000 t. In some cases, the environmental and health impacts dictate that the tailings and contaminated materials be removed from their current location to alternative long-term storage sites. Alternate sites were located based upon remoteness from populated areas, satisfactory hydrological conditions, availability of cover material, and present and future use of the land. Where on-site storage is considered practical and at alternate storage locations, the tailings and contaminated materials will be covered with physical stabilization materials such as clay, soil, and gravel or riprap to reduce gamma radiation to background rates, to reduce radon exhalation, and to eliminate the further spread of contaminated materials. (author)

  1. Study on the structure characteristic of the low permeable sandstone uranium ore rock

    International Nuclear Information System (INIS)

    In order to study the structure characteristic of the low permeable sandstone ore rock as well as the influence of the structure on the penetration ratio, this paper based on the mercury intrusion experiment to analyze the fractal characteristics of the pore and pore specific surface distribution in the low permeable sandstone uranium rock, and study the relation between the structure characteristic and porosity. The study indicates that there are double-fractal characteristics of the structure in the low permeable sandstone uranium rock, it mainly shows the fractal dimension value of the pore distribution and pore specific surface distribution is different with the pore of small and large aperture. The fractal dimension of the pore distribution with the large aperture ranges from 3.687 to 4.255, while that with the small aperture ranges from 3.101 to 3.208. And, the fractal dimension of the pore specific surface distribution with the big particle mass ranges from 2.910 to 3.151, and that with the small aperture ranges from 2.466 to 2.342, and that the relation between the porosity and the fractal dimension of the large aperture is positive correlation, but is negative correlation between the porosity and the fractal dimension of the pore specific surface distribution in the large aperture. (authors)

  2. Mineralogical zoning of ore fields with various types of uranium mineralization (on the example of North Kazakhstan ore province)

    International Nuclear Information System (INIS)

    Mineralogical mapping has allowed to devise spatial substantial models of most ore fields in North Kazakhstan. The early productive associations are situated in the root parts of the ore fields. The younger ones are located generally at their flanks, at the sites of greater structural 'openness'. The comparison of the ore field models, with the account of their position in various structural horizons, and the erosion depth (i.e., the formation depth) implies that they are fragments of extended vertical zonal columns of two types. Each of them is characterized by its own individual series of successively formed productive mineral associations. The analysis of minerals features, the structure and texture of mineral assemblages as well as the geological-structural conditions of their localization lead to the conclusion that the distinctions of mineral association series were conditioned by the degree of 'structural openness'. (author)

  3. Schneeberg lung disease and uranium mining in the Saxon Ore Mountains (Erzgebirge).

    Science.gov (United States)

    Schüttmann, W

    1993-02-01

    The so-called Schneeberg lung disease is a form of bronchial or alveolar carcinoma caused by the effects of the radioactive gas radon and of its radioactive short half-life daughter products. This type of radiation-induced occupational cancer is the most common and the most important radiation injury among workers occupationally exposed to ionizing radiation. There have been many deaths from lung cancer, especially in the Soviet uranium mines in the Erzgebirge of Saxony in the former German Democratic Republic. The history of disease in these miners extends over five centuries; the first observations of their health hazard start in the Middle Ages. The discovery of the lung cancer component was made toward the end of the nineteenth century, and the suspicion that a connection might exist between this cancer type and exposure to ionizing radiation was voiced at the beginning of the twentieth century. In the first half of this century, further research was carried out on this disease in the Schneeberg area of the Erzgebirge. Before the end of World War II, guidelines were set up to define the acceptable limits of radon exposure in the ore mines of Saxony. After World War II, the American uranium mines in the Colorado Plateau used the German research results as a basis for working out their own radiation protection standard. The uranium mines under Soviet occupation in the former GDR, on the contrary, paid no attention to these research findings. For many years, no precautions were taken for the miners' working conditions. The consequence of this serious omission was an estimated 9,000 fatal cases of lung cancer among these underground miners. High concentrations of radon are to be found in indoor air of homes in some districts of the Erzgebirge, suggesting an increasing lung cancer risk for the local inhabitants. The significance of this finding is evaluated. PMID:8427263

  4. 252Cf-based borehole logging system for in-situ assaying of uranium ore

    International Nuclear Information System (INIS)

    A 252Cf based borehole logging system for in-situ assaying of uranium ore has been designed and constructed, and preliminary tests of system operation have been performed. The system employs a delayed neutron activation analysis (DNAA) technique for which the downhole feasibility was demonstrated by Kerr--McGee. DNAA measures uranium directly, thereby circumventing the disequilibrium problems which are inherent to natural gamma ray logging. An improved DNAA technique has been implemented which utilizes a smaller 252Cf source and is more sensitive than the Kerr--McGee system. In particular, the size of the 252Cf source has been reduced by more than a factor of 10 with respect to the source employed by Kerr--McGee. Shielding for the 252Cf source has been designed for ease of operation while meeting occupational radiological safety requirements. The present system is vehicle mounted and includes the downhole sonde, logging winch with 1,000 meters of 4HO cable, data handling electronics, data recording and display equipment, and source shielding. The design of the system includes the following features: logging speeds from stationary to 8 meters/min with the capacity for determining 0.01% U3O8 concentration at 1.5 meters/min; uranium concentration readout independent of source intensity; auxiliary neutron measurement for accurate correlation of DNAA signal to actual U3O8 present; natural gamma ray detector for gauging disequilibrium; and short normal resistivity for lithology. The present system is a fully operational prototype. An extensive field calibration and evaluation program will begin shortly to uncover design problems and to allow simplification of the system for production logging. Commercially available units will reflect the operational experience gained from the testing program

  5. Experience gained from the former uranium ore processing and the remediation of the site in Hungary

    International Nuclear Information System (INIS)

    Full text: Uranium ore processing started in Hungary in 1962 and was terminated in 1997 on economical reasons. The remediation of the site has started immediately and has been practically finished this year. In the poster a brief overview of the used processes, including the heap leaching will be presented including the overall remediation of the former processing site. The lessons learned both from the processing practice and the remediatation will be discussed, aiming at giving supporting tools for the development of new uranium production facilities. Main lessons are: - for the decreasing of the volume of waste rocks to be remediated the radiometric sorting should be placed in underground if possible, - for the heap leaching reusable pads are recommended instead of permanently expanding heaps. - the high contamination of groundwater around the tailings ponds is the consequence of the inadequate neutralization of the barren pulp - uranium contamination on the heap leaching site is the result of the leakage from the pipes rather than the seepage through the liner. Results of the six years' groundwater restoration practice on tailings ponds site will be also discussed together with the estimation of the decreasing of the concentrations of the principal pollutants in the groundwater in long-term. The presentation will highlight the applicability of the geoelectrical multielectrode measurements for monitoring of the contamination (with MgSO4, NaCl, CaCl2 etc.) of the groundwater around tailings piles. The method has proved to be excellent tool for screening large areas aiming at determining the extent of the polluted area. For the determination of the inhomogenity of the water content in the tailings piles neutron probing method was developed. Results are important for the physical stability analyses of the tailings piles. Results of the run of the experimental permeable reactive barrier (built in the frame of EU-sponsored PEREBAR project) also will be presented

  6. Analysis on metallogenic conditions of leaching sandstone-type uranium ore and prospect forecast in Gaolihan depression

    International Nuclear Information System (INIS)

    The Gaolihan depression is one of components of the Erlian basin Wunite down-warping,. Which which is comprised by dispersing small basin lake (remittance fee basin) with growth history and having similarity structure. Its structures are complicated, the characteristics of strong divison property, many of depression slot with multi-sedimentation center, big rock nature change are displayed in this paper. The characteristics of the Gaolihan depression, as structure characteristic, structure characteristic, deposition characteristic, rock sex develop becoming conditional of ore, are analysed. And obtained that Gaolihan depression has the fine uranium mine looking for a prospect an ore. Thus the conculsion that looking for direction of ore area is put forward in the paper that has certain reference significance. (authors)

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

    International Nuclear Information System (INIS)

    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

  8. Solvent extraction studies on uranium using amine based extractants and recovery from low grade ore leach liquors

    International Nuclear Information System (INIS)

    In this study, amine based extractants (Alamine 336, Alamine 308, Alamine 304 and Aliquat 336) diluted in kerosene were used as promising extractants for uranium extraction and separation from other associated elements. Alamine 336 was the best extractant for uranium extraction process from sulfate solutions when compared with other amine based extractants, Alamine 308, Alamine 304 and Aliquat 336. Synergistic extraction behavior was studied with amines as extractants as well as synergist and organophosphorus reagents used as synergist mixed with amines. Synergistic extraction studies with amines were not suitable with each other for better extraction efficiency. However, amines mixed with organophosphorus extractants gave positive synergetic behavior with the highest synergistic coefficient 0.567 calculated from results obtained. The developed methodology was applied to uranium low grade ore processing and 99.83% of uranium was recovered without the interferences of other metals. (author)

  9. Potentialities of in-situ leaching of uranium and copper ore material in west central Sinai, Egypt

    International Nuclear Information System (INIS)

    A low grade uranium-copper ore material is recently recorded in the Paleozoic sedimentary sequence in west central Sinai, Egypt. The host rocks composed mainly of siltstone, clay, sand and gravel. A number of secondary uranium and copper minerals have been reported including mainly uranophane, carnotite, meta-tyuyamunite and meta-autunite beside atacamite, para-atacamite and langite. Series of lab percolation leaching experiments in both vertical and horizontal columns have been performed using acid and alkaline leaching reagents. Due to the fact that the ore material is situated above the water table, the in-situ leaching technique is doubtful. However, other natural leaching methods especially heap and in place leaching could be proposed. (author). 23 refs, 12 figs, 4 tabs

  10. Enumeration and characterization of microorganisms associated with the uranium ore deposit at Cigar Lake, Canada. Informal report

    International Nuclear Information System (INIS)

    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

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

    International Nuclear Information System (INIS)

    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)

  12. Radium-226 in certified uranium reference ores DL-1a, BL-4a, DH-1a and BL-5

    International Nuclear Information System (INIS)

    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

  13. Process for the hot oxidized attack on a uraniferous ore by a concentrated alkaline liquor with simultaneous uranium precipitation

    International Nuclear Information System (INIS)

    The present invention concerns a continuous process for the oxidizing attack of a uraniferous ore by means of an aqueous recycling liquor which contains in a dissolved state alkaline carbonate and bicarbonate and uranium at a concentration close to the limit of solubility thereof at the temperature of the attack operation. The uranium which is precipitated in the course of the attack operation is collected within the solid phase which remains after attack. By redissolution in a suitable aqueous liquor and separation from the sterile materials, a uraniferous liquor is obtained

  14. The development of a model for the simulation of the radiometric sorting of gold and uranium ores

    International Nuclear Information System (INIS)

    The development of a model to simulate the radiometric sorting of gold- and uranium-bearing ores is outlined. The developed program indicates the optimum mass, reject percentage, and expected reject gold and uranium grades for a radiometric sorter. It achieves this by statistical analysis of the data gathered from a large sample of rocks in the required size range for a particular mine. The program can be used in the optimization of existing sorters, as a design tool for new radiometric sorters, and in feasibility studies on radiometric sorting. 10 figs., 2 tabs

  15. Exploring implicit dimensions underlying risk perception of waste from mining and milling of uranium ores in France

    International Nuclear Information System (INIS)

    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)

  16. Application of visible/near-infrared reflectance spectroscopy to uranium ore concentrates for nuclear forensic analysis and attribution.

    Science.gov (United States)

    Klunder, Gregory L; Plaue, Jonathan W; Spackman, Paul E; Grant, Patrick M; Lindvall, Rachel E; Hutcheon, Ian D

    2013-09-01

    Uranium ore concentrates (UOCs) are produced at mining facilities from the various types of uranium-bearing ores using several processes that can include different reagents, separation procedures, and drying conditions. The final UOC products can consist of different uranium species, which are important to identify to trace interdicted samples back to their origins. Color has been used as a simple indicator; however, visual determination is subjective and no chemical information is provided. In this work, we report the application of near-infrared (NIR) spectroscopy as a non-contact, non-destructive method to rapidly analyze UOC materials for species and/or process information. Diffuse reflectance spectra from 350 to 2500 nm were measured from a number UOC samples that were also characterized by X-ray diffraction. Combination and overtone bands were used to identify the amine and hydroxyl-containing species, such as ammonium uranates or ammonium uranyl carbonate, while other uranium oxide species (e.g., uranium trioxide [UO3] and triuranium octoxide [U3O8]) exhibit absorption bands arising from crystal field effects and electronic transitions. Principal component analysis was used to classify the different UOC materials. PMID:24067636

  17. Late stage of weathering of uranium ores as a waste rock after historical silver mining, Joachimsthal, Czech Republic

    International Nuclear Information System (INIS)

    A 450-year old dump after mining of silver ores with significant contents of radionuclides was studied as an analog of modern waste rock dumps after mining of uranium. Migration of radionuclides in the dump and underwards and radioactive disequilibrium were measured using laboratory gamma spectroscopy. The localization and bond of radionuclides were studied by means of alpha-autoradiography. Weathering of selected grains of uranyl phosphates was described. (author)

  18. Removal of hazardous radionuclides from uranium ore and/or mill tailings. Progress report, October 1, 1978-September 30, 1979

    Energy Technology Data Exchange (ETDEWEB)

    Scheitlin, F.M.; Bond, W.D.

    1980-01-01

    The leaching of uranium ore and mill tailings to remove radium was studied. A few scouting tests were performed to obtain data on the recovery of radium, thorium, and uranium from leach liquors and on the recycle of leaching agents. Nitric acid, hydrochloric acid, ethylenediaminetetraacetic acid (EDTA), and diethylenetriaminepentaacetic acid (DTPA) were evaluated as leachants using one sample of a western US ore and two samples of tailings obtained from different uranium mills that employ the sulfuric acid leach process. Leached solids with radium contents approaching 10 pCi/g (98% radium removal) were obtained after six stages of batch, crosscurrent leaching with 3 M HNO/sub 3/ at 33% concentration of solids and a temperature of 60/sup 0/C. On the basis of two-stage tests on mill tailings, 0.5 M EDTA solutions at pH values of 8.2 to 11.6 were found to be more effective, while hydrochloric acid in two- or three-stage tests was less effective than nitric acid. Solutions of 0.3 M EDTA and 0.05 M DTPA were ineffective. No important differences were observed in the leaching behavior of ore and of mill tailings derived from the same ore. The residue remaining after six stages of nitric acid leaching was relatively intractable to radium leaching with water or additional nitric acid leaching. Tests indicated that the recycle of nitric acid is chemically feasible by evaporating the leach liquors to recover unused acid and then thermally decomposing the metal salts to recover consumed acid. Radium recoveries of 99+% by carrying on barium sulfate were shown to be chemically feasible in a series of experiments with leach liquors, but processing applications would probably require methods for barium recycle and barium-radium separation. Recovery of /sup 230/Th and uranium from nitrate leach liquors by tri-n-butyl phosphate extraction appears promising in initial tests.

  19. Occupational diseases in uranium and ore miners related to radiation exposure in the Czech Republic in 2002 - 2007

    International Nuclear Information System (INIS)

    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. Occupational diseases in uranium and ore miners related to radiation exposure in the Czech Republic in 2002 - 2007

    International Nuclear Information System (INIS)

    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)

  1. Size distribution of aerosol particles produced during mining and processing uranium ore.

    Science.gov (United States)

    Mala, Helena; Tomasek, Ladislav; Rulik, Petr; Beckova, Vera; Hulka, Jiri

    2016-06-01

    The aerosol particle size distributions of uranium and its daughter products were studied and determined in the area of the Rožná mine, which is the last active uranium mine in the Czech Republic. A total of 13 samples were collected using cascade impactors from three sites that had the highest expected levels of dust, namely, the forefield, the end of the ore chute and an area close to workers at the crushing plant. The characteristics of most size distributions were very similar; they were moderately bimodal, with a boundary approximately 0.5 μm between the modes. The activity median aerodynamic diameter (AMAD) and geometric standard deviation (GSD) were obtained from the distributions beyond 0.39 μm, whereas the sizes of particles below 0.39 μm were not differentiated. Most AMAD and GSD values in the samples ranged between 3.5 and 10.5 μm and between 2.8 and 5.0, respectively. The geometric means of the AMADs and GSDs from all of the underground sampling sites were 4.2 μm and 4.4, respectively, and the geometric means of the AMADs and GSDs for the crushing plant samplings were 9.8 μm and 3.3, respectively. The weighted arithmetic mean of the AMADs was 4.9 μm, with a standard error of 0.7 μm, according to the numbers of workers at the workplaces. The activity proportion of the radon progeny to (226)Ra in the aerosol was 0.61. PMID:27032340

  2. Histopathologic, morphometric, and physiologic investigation of lungs of dogs exposed to uranium-ore dust

    International Nuclear Information System (INIS)

    The most consistent pulmonary-function change attributed to carnotite uranium-ore-dust exposure (at 15 mg/m3, for 4 h/day, 5 days/week) is an increased slope of the single-breath N2 washout curve, suggesting an uneven distribution of ventilation. This change was observed in dogs exposed for less than 1 year and continued through 4 years of exposure. Measurements of pulmonary resistance, after 27, 40 and 47 months exposure, showed slight age-related changes and increasing differences between control and exposed animals with duration of exposure. These two changes are suggestive of a bronchitic response, similar to the industrial bronchitis of mine workers. The most notable pulmonary lesions observed in dogs exposed for up to 4 years are: vesicular emphysema, peribronchiolitis and focal pneumoconiosis. Lesions of the major airways and upper respiratory tract, when present, were minimal in severity. Pulmonary vesicular emphysema was present in all but one of the examined dogs. The emphysema was dose-related, in that it was present only to a slight degree in dogs exposed for less than 3 years and, thereafter, increased in severity. Morphometric measurement data confirmed the value of the histopathologic grading system for the degree of emphysema. These data correlated best with the dynamic pulmonary compliance measurements

  3. Study of the Treatment of the Liquid Radioactive Waste Nong Son Uranium Ore Processing

    International Nuclear Information System (INIS)

    Liquid waste from Nong Son uranium ore processing is treated with concentrated acid, agglomerated, leached, run through ion exchange and then treated with H2O2 to precipitate yellowcake. The liquid radioactive waste has a pH of 1.86 and a high content of radioactive elements, such as: [U] 143.898 ppm and [Th] = 7.967 ppm. In addition, this waste contains many polluted chemical elements with high content, such as arsenic, mercury, aluminum, iron, zinc, magnesium, manganese and nickel. The application of the general method as one stage precipitation or precipitation in coordination with BaCl2 is not effective. These methods generated a large amount of sludge with poor settling characteristics. The volume of final treated waste was large. This paper introduces the investigation of the treatment of this liquid radioactive waste by the method of two stage of precipitation in association with polyaluminicloride (PAC) and polymer. The impact of factors: pH, neutralizing agents, quantity of PAC and polymer to effect precipitation and improve the settling characteristics during processing was studied. The results showed that the processing of liquid radioactive waste treatment through two stages: first stage at pH = 3 and the second stage at pH = 8.0 with limited PAC and polymer (A 101) resulted in significant reduced volume of the treated waste. The discharged liquid satisfied the requirement of the National Technical Regulation on Industrial Waste Water (QCVN 24:2009). (author)

  4. 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)

    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

  5. In-situ leaching mining for 'tails' of roll-type ore bodies at No 512 deposit of Yining uranium mine

    International Nuclear Information System (INIS)

    In view of the present situation of in-situ leaching at No 512 deposit of Yining Uranium Mine, the author analyses the present problem, the geological and hydrogeological character of the deposit, and gives some suggestions on the in-situ leaching mining of 'tails' of roll-type ore bodies at friable sandstone uranium deposits

  6. 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)

    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

  7. Uranium

    International Nuclear Information System (INIS)

    With the worldwide revival of nuclear energy comes the question of uranium reserves. For more than 20 years, nuclear energy has been neglected and uranium prospecting has been practically abandoned. Therefore, present day production covers only 70% of needs and stocks are decreasing. Production is to double by 2030 which represents a huge industrial challenge. The FBR-type reactors technology, which allows to consume the whole uranium content of the fuel, is developing in several countries and will ensure the long-term development of nuclear fission. However, the implementation of these reactors (the generation 4) will be progressive during the second half of the 21. century. For this reason an active search for uranium ores will be necessary during the whole 21. century to ensure the fueling of light water reactors which are huge uranium consumers. This dossier covers all the aspects of natural uranium production: mineralogy, geochemistry, types of deposits, world distribution of deposits with a particular attention given to French deposits, the exploitation of which is abandoned today. Finally, exploitation, ore processing and the economical aspects are presented. Contents: 1 - the uranium element and its minerals: from uranium discovery to its industrial utilization, the main uranium minerals (minerals with tetravalent uranium, minerals with hexavalent uranium); 2 - uranium in the Earth's crust and its geochemical properties: distribution (in sedimentary rocks, in magmatic rocks, in metamorphic rocks, in soils and vegetation), geochemistry (uranium solubility and valence in magmas, uranium speciation in aqueous solution, solubility of the main uranium minerals in aqueous solution, uranium mobilization and precipitation); 3 - geology of the main types of uranium deposits: economical criteria for a deposit, structural diversity of deposits, classification, world distribution of deposits, distribution of deposits with time, superficial deposits, uranium

  8. Radiation legacy of the USSR enterprises for mining, milling and processing of uranium ores: Conservation, decommissioning and environmental rehabilitation

    International Nuclear Information System (INIS)

    The long-term operation of USSR uranium mining and milling enterprises produced a great volume of low level radioactive waste in the form of rock spoil heaps (181 million m3), hydro-metallurgical plants tailings dumps (340 million m3) and basins of mine waters (200 million m3) with total activity of 25.1·1015 Bq (670 kCi). The total area occupied by the dumps is about 180 km2. The paper presents brief characteristics of the activities of uranium ore mining enterprises located at the CIS countries' territories, their wastes' status and describes measures for rehabilitation and restoration of territories of the Soviet uranium mining and metallurgical complex. (author)

  9. Models to optimize the evaluation and extraction of uranium from sedimentary ore deposits with applications to in-situ leaching

    International Nuclear Information System (INIS)

    With increasing demands for nuclear power supplies, more efficient means of evaluation and extraction of sedimentary uranium ore deposits, which form 96% of the US reserves, are required. Fixation of uranium in the sediments seemed to be controlled by sorption and/or reduction by organic matter, H2S, clays, zeolites, and carbonates. The basic strategies of the carbonate and acid leach systems are discussed. By monitoring effluent uranium and Rn-222 and cumulative uranium and Rn-222 extracted, it is shown that predictions can be made concerning mining efficiency, degree of secular equilibrium, future profitability, and mining duration. Dissolution Eh-pH diagrams constructed by assuming an infinite source of uraninite in water with various complexing agents are shown to agree more accurately with kinetic data of uraninite dissolution than conventional stability Eh-pH diagrams. It is proposed that carbonate leach systems be operated at pH values between 9.0 and 10.0 and sulfate acid leach systems may be operated at pH as high as 3.0. Utilizing evidence that uraninite dissolution is not diffusion limited and that in-situ leach solutions are quite undersaturated with respect to uranium, it is shown that uraninite dissolution is independent of hydrological parameters with the exception of the flow rate which regulates oxidant introduction to the ore body. The optimum well spacing in an in-situ leach system is found to be a complex function of flow rate, the mobilization inhibiting factor (MIF), the rate of total oxidation of the acquifer, and the ability of the well system and the aquifer to confine the system. The results of the research are used to generate models to optimize parameters in the in-situ leach. The models are found to predict values in good agreement with literature values for uranium in-situ leach operations

  10. 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.

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

    International Nuclear Information System (INIS)

    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.

  12. Metabolism of uranium in the rat after inhalation of two industrial forms of ore concentrate: the implications for occupational exposure

    International Nuclear Information System (INIS)

    Aerosols produced from two commercially available ore concentrates in which the uranium was present essentially in the one as ammonium diuranate (ADU) and in the other as uranium octoxide (U3O8) were administered to rats. Uranium in the ADU bearing material was cleared rapidly from the lungs, the retention kinetics being similar to a class D (highly transportable) compound. Uranium in the U3O8 bearing material was removed from the lungs principally by mechanical processes, the retention kinetics being similar to a class Y (poorly transportable) compound. For both materials the distribution of uranium amongst body tissues and the fraction of the systemic content excreted in urine were similar to those obtained after the injection of soluble hexavalent compounds. For workers potentially exposed to both these materials, urine monitoring and lung radioactivity counting measurements should be used in addition to air sampling procedures for assessing the intake of uranium. Intakes of the ADU bearing material should be restricted to those permitted for short-term exposures on the basis of chemical toxicity, whereas those for the U3O8 bearing material should be governed by radiation dose. (author)

  13. The relationship between uranium content of U3O8 type uranium ore concentrate and the volume returned rate of distilled ammonium solution and decreasing yield of HNO3 consumption

    International Nuclear Information System (INIS)

    The effect of uranium content of U3O8 type uranium ore concentrate on the volume returned rate of distilled ammonium solution is slight. The volume returned rate of crystall mother solution is 30.6% while uranium content equals 75.0%. There are no effects of uranium content on the returned rate of NH4NO3 and decreasing yield of HNO3 consumption. When uranium concentration in feed solution equals 250 g/L, the critical returned rate of NH4NO3 is 45.8% and decreasing yield of HNO3 consumption is 162 kg per ton uranium. (authors)

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

    International Nuclear Information System (INIS)

    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

  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)

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

    Science.gov (United States)

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

    2015-12-01

    Extensive measurements of (222)Rn in the town of Xanthi in N Greece show that the part of the town overlying granite deposits and the outcrop of a uranium ore has exceptionally high indoor radon levels, with monthly means up to 1500 Bq m(-3). A large number of houses (40%) in this part of the town exhibit radon levels above 200 Bq m(-3) while 11% of the houses had radon levels above 400 Bq m(-3). Substantial interannual variability as well as the highest in Europe winter/summer ratios (up to 12) were observed in this part of the town, which consist of traditional stone masonry buildings of the late 19th-early 20th century. Measurements of (238)U and (232)Th content of building materials from these houses as well as radionuclide measurements in different floors show that the high levels of indoor radon measured in these buildings are not due to high radon emanation rates from the building materials themselves but rather due to high radon flux from the soil because of the underlying geology, high radon penetration rates into the buildings from underground due to the lack of solid concrete foundations in these buildings, or a combination thereof. From the meteorological variables studied, highest correlation with indoor (222)Rn was found with temperature (r(2) = 0.65). An indoor radon prognostic regression model using temperature, pressure and precipitation as input was developed, that reproduced indoor radon with r(2) = 0.69. Hence, meteorology is the main driving factor of indoor radon, with temperature being the most important determinant. Preliminary flux measurements indicate that the soil-atmosphere (222)Rn flux should be in the range 150-250 Bq m(-2) h(-1), which is in the upper 10% of flux values for Europe. PMID:26372739

  17. Closedown programme for the uranium ore and processing plant at Eleshnitsa, Bulgaria

    International Nuclear Information System (INIS)

    The tailings pond of the uranium ore and resin processing plant at Eleshnitsa, Bulgaria has been subject to a rehabilitation programme under a phare contract. The tailings cover 34 ha behind a 70 m high dam. The volume of waste is 12 million m3. Furhermore, there are considerable areas with contaminated soils within the industrial area. In order to be able to prepare detailed design and full tender documents for the actual contractual works a number of additional studies has been performed. The studies include geophysical, geodetical and geotechnical surveys, piezometer installations, a sub-regional sampling survey of surface and groundwater and a laboratory scale water treatment test. From these studies final design data and parameters have been obtained with respect to long term dam-stability, composition of cover and shape of contouring of the tailings pond area, structures for diversion of upstream surface waters and size and type of waste water treatment plant. Based on this information are contract Dossiers prepared The main part of this paper deals with the rehabilitation concept to be used for the contractual works. A description of present-day conditions, starting point for the rehabilitation concept, is also presented. Specific emphasis is put on the long-term stability of the dam and covering of the tailings by a soil membrane, on the design of the waste water treatment plant and on the monitoring programmes to be put into place. Besides above mentioned more technical and environmental aspects of the closedown programme a preliminary planning as well as cost-estimates for the different contractual works are presented. (orig.)

  18. Control of technological processes of working off of uranium-ore objects by underground leaching with help of carotage of decay neutrons

    International Nuclear Information System (INIS)

    Full text: In the report it is considered questions of repeated involving in operation of uranium-ore objects. One of the basic problems thus is the estimation of residual efficiency of ore. Its decision with use of gamma-carotage (GC) of chinks is unpromising, since it gives distribution on a trunk of a chink of radioactive daughter products of disintegration of uranium-radium chain. The uranium contents with help GC are not determined. Carrying out kern approbations of chinks essentially increases expenses for exploitation-prospecting drilling. Thus not always it is possible to receive a conditional core (an output not less than 80 %) on ore-containing mines. Therefore for more than 10 years at enterprises NMMC as the alternative way of approbation, direct definition of uranium in ore sections with the help of pulse carotage on instant decay neutrons (CND-M) is successfully applied. In the report, by the example of deposit Ketmenchi the data are showed to an opportunity of a method by definition of a degree of working off of ore intervals leaching and to detection of residual ores

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

    International Nuclear Information System (INIS)

    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

  20. Use of sodium sulfide to restore aquifers subjected to in-situ leaching of uranium ore deposits

    International Nuclear Information System (INIS)

    Commonly used restoration techniques include ground water sweeping and recirculation of fresh water through the leached ore zone; however, such techniques introduce oxidizing waters into the ore zone. Consequently, redox-sensitive elements, such as uranium, arsenic, selenium, and molybdenum, may be difficult to restore to background levels because they continue to dissolve when these restoration techniques are used. To immobilize the redox-sensitive elements and restore tthe sediment. sediments as well as the ground water, it has been suggested that a reducing agent be circulated through the leached ore zone during restoration. We have conducted laboratory batch and flow-through column experiments to test the ability of sodium sulfide to enhance the restoration of sediment and solution typical of that found in a leached ore zone. Sodium sulfide effectively lowered the redox potential of the solution to the point that relatively insoluble minerals that contain the redox-sensitive elements should be stable. For some batch experiments, the uranium concentration of the solution decreased by more than three orders of magnitude, from 44 to 0.04 ppM. Although arsenic, selenium, and molybdenum were not present at contaminant levels in these solutions, we expect that, under the chemical conditions imposed by the sulfide, these three elements would also be immobilized because of the formation of insoluble sulfides or other sparingly soluble minerals. In the column experiments, we observed the formation and movement of a redox-interface, starting at the influent end of our columns. By the time ten pore volumes of the sulifide solution had flowed through the columns, the majority of the column had been altered from light gray in color to dark black, suggesting that sulfide minerals were forming throughout the sediment

  1. Determination of uranium in the red blood cells of the workers in the chemical processing of uranium ore

    International Nuclear Information System (INIS)

    Neutron activation analysis was used in determining uranium in the venous blood erythrocytes of controls and of workers exposed to occupational hazards in a uranium chemical treatment plant. While 4.1 +- 2.6 ppb of uranium was found in dry matter of the erythrocytes in controls, 6.5 +- 2.1 ppb of uranium was ascertained in dry matter of the erythrocytes in occupationally exposed workers of a wet preparation plant, and 37.2 +- 20.2 ppb of uranium in the erythrocytes in workers of a dry cleaning plant. (author)

  2. Isolation of thiobacillus ferrooxidans and thiobacillus thiooxidans from West Kalimantan and North Sumatera Uranium ore specimens

    International Nuclear Information System (INIS)

    Isolation of thiobacillus ferrooxidans (T. ferrooxidans) and thiobacillus thiooxidans (T. thiooxidans) from West Kalimantan and North Sumatera U ore specimens have been carried out. T. thiooxidans have the ability to oxidize sulfur to sulfate, and T. ferrooxidans oxidizes ferro iron to ferric iron. Silverman medium (9 K medium) was used as growth medium for T. ferrooxidans. Starkey medium was used as growth medium for T. thiooxidans. For fungi contamination test the medium of malt extract agar was used. Meat pepton was used for the heterotrophic microorganisms contamination test. Results of the experiment showed that isolates of T. ferrooxidans have been obtained from 3 West Kalimantan U ore specimens from 2 North Sumatera U ore specimens. T. thiooxidans have been isolated from 2 West Kalimantan U ore specimens, but none has been isolated from North Sumatera U ore specimens. T. ferrooxidans isolated from West Kalimantan and North Sumatera have been tested in different growth conditions to determine the rate of growth. (author)

  3. Main ways and suitable technologies of improving economic benefits for uranium ore heap leaching in China (to be continued)

    International Nuclear Information System (INIS)

    Combining with practice of China's uranium ore heap leaching, the author proposes main ways and suitable technologies in the fields of emphasizing feasibility research, adopting strengthened technologies, improving equipment level, optimizing control technological factors and developing application range and so on, which include adopting acid-curry and ferric sulphate-trickle leaching process, bacteria heap leaching, countercurrent heap leaching, selecting advanced material of heap bottom, developing large mechanized heap construction equipment and methods, popularizing drip irrigation distributing solution, optimizing heap leaching process parameters, as well as developing recovery equipment suited to heap leaching, etc, in order to increase leaching rate, reduce heap leaching period and achieve more economic benefits

  4. 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)

    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 seawaterin uranium extraction from salted, compared with the normal or sweat waterhas 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

  5. Tectonic and hydrogeological evolution and its relation to sandstone-type uranium ore-formation in Xihulitu basin, Inner Mongolia

    International Nuclear Information System (INIS)

    The Xihulitu basin is an Early Cretaceous down-faulted basin. It was disintegrated into three sub-basins (blocks) by the post-depositional fault displacement. Owing to the connection resulting from the fault structure, a complete groundwater recharge-run off-discharge system was developed leading to the formation of apparent hydrogeologic zonation and different geochemical environments, and creating favourable conditions for the uranium migration, concentration and ore-formation. The tectonic-hydrogeologic evolution of the basin includes the following three stages: (1) the open cycle of down-faulted basin formation; (2) the close cycle sedimentation and diagenesis, and (3) the run-off cycle of epigenetic reworking. Of them, the paleohydrogeologic evolution of epigenetic reworking run-off stage is the main period for the formation of sandstone-type uranium deposit. (authors)

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

    International Nuclear Information System (INIS)

    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

  7. Weathering of mine wastes after historical silver mining in the Jachymov ore district (Czech Republic) and migration of uranium

    International Nuclear Information System (INIS)

    Weathering of 450 years old mine wastes after silver mining at Geister vein in the Jachymov ore district (Czech Republic) and migration of uranium were studied. Specific gamma-ray activity of 226Ra, measured by field gamma-ray spectrometry, varies from 38 Bq/kg (3 ppm eU) to 3816 Bq/kg (309 ppm eU) in the observed area. The most active material forms the top layer of the dump. The gamma-ray activity of the top layer is caused mainly by 226Ra. Uranium is leached from upper layer and accumulated in fossil soils beneath. U-micas were studied using X-ray powder diffraction and EDA. The following succession of supergene alteration was found: autunite → meta-autunite → bassetite →- oxidized bassetite. (author)

  8. Uranium mining and ore processing in Ukraine and its radioecological effects on the Dnieper River water ecosystem and human health

    International Nuclear Information System (INIS)

    Full text: The potential contamination of surface and underground waters in the basin of the Dnieper river is due to uranium mining and ore processing in the Ukraine. From the early 1950s to the early 1990s, the processing of uranium ores was carried out in Dneprodzerzhinsk town located in the upper part of Zaporozhie reservoirs. During that period a number of uranium tailings were created at the Industrial site and in the vicinity of Dnieprodzerzhinsk and Zheltie Wody towns. The main part of tailing is located at the drainage basins of the Dnieper River and its influence due to seepage waters spreads to the Dnieper's reservoirs forming their secondary contamination and present radioecological status. Uranium mining and milling have a number of potential impacts on human health and the environment. They include: - contamination of mine water with uranium and other radionuclides; - release of mill waste waters to surface waters (usually after treatment); - run-off of water from contaminated areas of the mine or mill; - radon release from mines, waste rock dumps and mill tailings piles; - leaching of radionuclides from tailings and their subsequent transport in water; - erosion of tailings storage systems leading to dispersal of tailings by wind and water; - contamination of underground and surface waters by toxic non-radioactive substances such as heavy metals and chemicals used in the processing. The most important waste from the milling of uranium is the finely divided solid residue, known as tailings. It typically contains 70% of the radioactivity in the original ore including the long- lived radionuclides, 230Th (half-life = 80,000 years) and 226Ra (half-life 1,600 years). Radium is a continual source of 222Rn (half-life = 3.8 days) which, being a gas, is readily dispersed. Radon daughters are a source of radiation exposure and a known cause of lung cancer in uranium miners. The town Zheltie Wody in Dniepropetrovsk region is the Industrial Center of Uranium

  9. The efforts of sulfide minerals employing at BM-179 uranium ore Kalan-Kalbar to produce H2SO4 using contact process

    International Nuclear Information System (INIS)

    Eko Remaja BM-179 uranium ore processing conducted by BATAN to obtain U3O8 seems to be inefficient because at leaching state, it consumpts H2SO4 125 kg per ton ore. There is no information about the efforts of mineral sulfide employing at BM-179 ore to support uranium processing. The purpose of the study was the efforts to employ of mineral sulfide at ore's low uranium to produce H2SO4 using contact process, which it would be, used at leaching state of Eko Remaja BM-179 uranium ore processing Kalan-Kalbar. Magnetic separator, flotation, knelson concentrator and shake table could conduct the enrichment of sulfide minerals. The study reveals that magnetic separator method and flotation methods increased sulfur content significantly. Magnetic separator succeed to increase sulfur content to 9.58 times from sulfur's initial and produce 28.44 % H2SO4, while the flotation method increased sulfur's content to 4.71 times from sulfur's initial and produce 22.19 % H2SO4

  10. Rapid and direct determination of uranium concentration in leached residue and beneficiated products using wavelength dispersive X-ray fluorescence spectrometry: a case study on Narwapahar uranium ore

    International Nuclear Information System (INIS)

    A pressed pellet XRF methodology is developed for rapid analysis of uranium in leach residues and beneficiated products, which is otherwise usually carried out by pellet, laser fluorimetry and spectrophotometry after separation and depending on its concentration. Most of the wet chemical methods require separation of uranium from accompanying interfering elements prior to its determination. Decomposition with HF-HNO3 followed by extraction of uranium into ethyl acetate to separate it from the matrix, not only makes the analysis costly and time consuming but also produces hazardous waste, which requires specific procedure for its disposal. In comparison with the conventional wet chemical method, Wavelength Dispersive X-Ray Fluorescence Spectrometry (WDXRFS) technique has been recognised as a powerful analytical tool which is rapid, cost effective and non destructive with minimum sample handling. An attempt has been made to determine uranium concentration in leached residue and beneficiated products obtained from Narwapahar uranium ore, Jharkhand, using WDXRFS technique. Due to non-availability of certified reference materials with matching matrix, which is mandatory for WDXRFS, synthetic standards were prepared by blending the correct proportion of feed with residue and concentrate with tailing of the same ore. A set of two calibration curves were established using the chemically analysed synthetic standards with the concentration ranges of 50-220 ppm U for residues (n=8) and 50-3120 ppm U for beneficiated products (n=10). The reproducibility and accuracy of analysis were evaluated and found to be less than 1% with lower limit of determination was 10 ppm and the time taken for analysing each sample is 140 seconds. The measured values of uranium concentration in residue and beneficiated products were found to be within 4% with the fluorimetric measurements. The present method will be useful for fast routine measurement of uranium concentration in solids samples such

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

    Energy Technology Data Exchange (ETDEWEB)

    Mingarro Martin, E.; Marin Benavente, C.

    1969-07-01

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

  12. Experience in radiation safety assessments for uranium ore mining and processing

    International Nuclear Information System (INIS)

    Based on the experience gained during the expert assessments of the radiation safety activities at uranium facilities, it has been show that it is needed to develop detailed requirements for the structure and content of design documentation for the justification of radiation safety, enhance radiation monitoring at and around uranium facilities, revise existing regulations, develop guidance to assess the impact of uranium facilities on workers, the public and the environment , and ensure radiation monitoring and radiation safety in exploration work at uranium deposits

  13. The regional distribution regularities of ore-hosting horizon, deposit type and mineralization age of China's sandstone-hosted uranium deposits

    International Nuclear Information System (INIS)

    The sandstone-hosted uranium deposits widespread in China's Meso-Cenozoic sedimentary basins are obviously different from each other in ore-hosting horizon, deposit type (ore-forming process) and in the spatial distribution of mineralization ages. All the above changes are originated from the specific characteristics of the tectonic evolution of each tectonic domain where the deposits occur, obeying the affect resulting from the collision of Indian plate and the subduction of Pacific plate respectively. Basins and sandstone-hosted uranium deposits in the Central domain are effected of both Indian and Pacific plates, and are of characteristics of the two metallogenic systems. (authors)

  14. Determination of Optimum Process Conditions for Sulfuric Acid Dissolution of Zarigan Thorium-Uranium Ore Using Taguchi Method

    International Nuclear Information System (INIS)

    This paper deals with the study of digestion and leaching process effectiveness in thorium minerals processing, and determining the optimum process conditions for acidic leaching of thorium- uranium ores in Zarigan region to dissolve thorium. To do this, some samples from Zarigan region were studied mineralogically in laboratory. The sample containing minerals such as Anorthite, Quartz, Sanidine, Vermiculite, Albite, Gypsum, Muscovite, Anatase and Magnetite were ground in specified dimensions and then mixed with concentrated sulfuric acid. Then the mixture was heated to a high temperature. After diluting the mixture with water, it was dissolved by means of agitation leaching. The effects of different parameters such as particle size, temperature and time of digestion, concentration of sulfuric acid, and acid to ore ratio, with the aim of determining their optimum value, were studied which resulted in the following optimum values for the above-mentioned parameters: particle size of 250 μm, temperature of 180degreeC, time of 5h, concentration of sulfuric acid of 10.8 mol/lit, and acid to ore ratio of 3. Under these conditions, maximum recovery of thorium was 92%. Nitric acid (oxidant) concentration effect on the recovery of thorium in the optimum conditions was studied, and for the 2M of nitric acid concentration, thorium recovery of 97% was obtained.

  15. Radionuclide migration around uranium ore bodies - progress report on the Alligator rivers analogue project and proposals for future work

    International Nuclear Information System (INIS)

    The Australian Atomic Energy Commission has extensively evaluated uranium ore bodies in the Alligator Rivers Province of the Northern Territory of Australia as analogues of radioactive waste repositories. The objective has been to assist in the long-term prediction of the rate of transport of radionuclides through the geosphere. The research work was carried out by the AAEC in its laboratories at Lucas Heights and with extensive field trips in the Alligator Rivers Province, particularly at the uranium deposits at Ranger, Jabiluka, Nabarlek, and Koongarra. The results of the work over the last five years are briefly reviewed in this paper with emphasis on those obtained since the last review presented to the Natural Analogue Working Group in 1985. The results, their preliminary interpretation and their significance to the modelling and prediction of radionuclide transport, are discussed under the five main headings: Distribution of Uranium and Thorium Series Nuclides in Selected Uranium Deposits; The Role of Groundwater Colloids in the Transport of Radionuclides; The Study of Selected Fission Products; The Study of Transuranium Nuclides; and Application and Verification of Modelling Codes for the Transport of Radionuclides

  16. Guide lines for control and supervision of dump leaching. Application to the inframarginal uranium ore of the Cellier mine

    International Nuclear Information System (INIS)

    The Cellier mine processes inframarginal uranium ores by a slow dump leaching. Fragmentary information concerning the evolution of the chemical properties of the solutions (inflow-outflow) as a function of the time has been the object of an analysis of data. The latter, which was both descriptive and predictive, made it possible on the one hand to identify facts which have intervened at the time of leaching and on the other hand to pinpoint the influence of the time factor and of the associations of chemical elements (aluminium, phosphorus, etc.) on the passing into solution of the uranium. As this treatment gives only a global view of the problem, it was completed by a mineralogical analysis. The fine mineralogical analysis of the fractions, made soluble by sulphuric attack in a heap, shows that sulphated concretions isolate the uranium from the leaching liquor. A screen of sulphate is composed of a macroscopic web of gypsum (calcium sulphate) in which a microscopic web of hydrated magnesium sulphate is inserted. In the gypsum web are trapped phosphorus minerals and in the magnesium sulphate web manganese and aluminium minerals. As regards the uranium, it is either distributed in the form of fine inclusions of uranyl hydroxide, or associated to chlorinated forms, derived from the treatment aids

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

    International Nuclear Information System (INIS)

    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

  18. Recovery of uranium low grade ores by froth flotation: study of the texture and synergetic effects of flotation reagents

    International Nuclear Information System (INIS)

    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 (K2(UO2)2 [VO4]2.3H2O). 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 or anionic

  19. Research on the possibility of concentrating low-grade uranium ores by bacterial leaching. Part of a coordinated programme on the bacterial leaching of uranium ores

    International Nuclear Information System (INIS)

    Effect of extraction reagents with solvents on the bacteria and the influence of eluants on the bacteria development was studied. To establish the effects of various solvents and eluants on the development of bacteria, on oxidizing capacity of Fe2+ to Fe3+, and to study their influence on bacteria morphology, bacteria strains were contacted with Alamine 336, trioctylamine, LIX and nitric eluant. Bacteria development and the oxidizing ability of Fe2+ to Fe3+ were significantly inhibited and morphological changes of individuals in the bacteria population were found. The bacteria populations resulted from ores had a more decreased resistance as the bacteria culture was better selected by repeated inoculations and incubations. In case of the bacterial leaching in heap or in situ a periodical extraction with solvents is required in order to allow the bacteria population between successive extraction stage be remade

  20. Geological characteristics and metallogenetic model of Zhuguang uranium ore concentrated area

    International Nuclear Information System (INIS)

    The authors mainly discuss the geological background and metallogenic mechanism of large and high-grade uranium deposits in Zhuguang region. New progresses have been made in regional metallogenic regularities and metallogenic theories and a series of new outcoming have been achieved: (1) The pre-Sinian uranium-rich crystalline basement aged at 1.9-2.2 Ga has been determined in the region for the first time. The discovery contributes greatly to the uranium metallogenic potential in Zhuguang area. (2) For the first time, authors propose that uranium and material sources in Zhuguang region were mainly derived from the uranium-rich thermal fluid chambers of crust-mantle mixed-melting origin, rather than from the wall rocks of uranium deposits, as considered by traditional views. (3) The stage and sequence of magmatic activity, and genetic type of magmatic rocks in Zhuguang region have been redetermined. (4) Four NE-trending tectonic belts, i. e. Nanxiong, Baishun, Changjiang and Jilong have been determined as Mesozoic extensional taphrogeny zones, which are the regional crust-cutting tectonic belts controlling the basins, magmatic activities and uranium mineralization. (5) For the first time, uranium deposits in Zhuguang region are divided into two types: the pneumatolytic-hydrothermal fracturing alteration-micro vein dissemination type uranium deposits and the vein-filled type uranium deposits. And a deep-sourced metallogenic model of uranium deposits in the region has been set up

  1. Radiological safety in mining of low grade uranium ores: Four decades of monitoring and control in Indian mines

    International Nuclear Information System (INIS)

    Full text: Mining of low grade uranium ore involves deployment of large man power in many stopes simultaneously to achieve the production target. The first uranium mine in India commenced commercial operation in 1968 with production from shallower haulage levels. The mine is now operating up to a vertical depth of about 905 meters. Radiation exposure of workers is mainly from external gamma radiation and inhalation of radon progeny. The long lived alpha emitters in the airborne ore dust are relatively small in such mines. While gamma radiation is not amenable to control the radon and its progeny can be effectively reduced by adequate ventilation and a judicious distribution of ventilating air to the working zones and sealing of worked out areas. Workplace monitoring for radiological parameters in the mines commenced right from the beginning of the operations. Initially the effective dose to the workers was evaluated from the area monitoring and occupancy period of workers in different zones. Subsequently, SSNTD and TLD based personal dosimeters were developed and deployed in a phased manner. Average dose to the workers in the early stages was around 10 mSv/y. Ventilation was progressively improved by widening of air passages and increasing the fan capacity. The system itself was modified from the series to a parallel system of ventilation to supply fresh air to each operating haulage level and allow the used air to join the return air stream. The modifications had positive impact and the average doses have shown a downward trend are now around 5 mSv/y. Progressive mechanization of mining operations over the years has resulted in reduction of manpower and consequently in a reduction of the collective dose. Subsequently, three additional underground uranium mines have been opened with low grade uranium ores. Increasing ventilation has resulted in reduction of radon concentration to an average of around 0.3 KBq/m3 EER in Jaduguda mine. The internal and external

  2. 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)

    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)

  3. Method for determining microamounts of uranium in solutions from copper ores, by liquid-liquid extraction and spectrophotometry with arsenazo III

    International Nuclear Information System (INIS)

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

  4. 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)

    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)

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

    Science.gov (United States)

    Lowson, Richard T

    2013-04-01

    The Koongarra ore body is an early Proterozoic U ore body in the Alligator Rivers U province, Northern Territory, Australia. It has surface expression with a redox front located ∼30 m below the surface. The (234)U/(238)U activity ratios (AR) for the ground water and the amorphous phase of the solid have been analysed for the ore zone and dispersion halo as a function of depth. The results display a (234)U/(238)U AR signature with depth which may be common to all U ore bodies. The (234)U/(238)U AR is depressed below secular equilibrium in the weathered material above the redox front; rises significantly above secular equilibrium in the vicinity of the redox front; and is followed by a gradual decrease with depth below the redox front. The amplitude of the profile is a function of local conditions. A model is proposed for the signature in which oxidising waters preferentially leach the (234)U sites at the redox front due to preconditioning of the (234)U sites by α recoil during the decay of (23)(8)U to (23)(4)U. Mass balance requires the solid material left behind the redox front to have a (234)U/(238)U AR reduced below 1. Local second order effects may be superimposed on the signature. The signature may have application to calibrating scenarios for nuclear waste repositories, assisting in understanding historical climates, economic evaluation of U ore bodies and U exploration. PMID:23142336

  6. Regional geologic characteristics of uranium ores and assessment of metallogenetic potentials in the central part of Eastern Liaoning Province

    International Nuclear Information System (INIS)

    Regional geologic characteristics, metallogenetic conditions and prospects of uranium ores in the central part of the Eastern Liaoning Province of North China is studied systematically. It demonstrates that the Archaean basement of the study area consists of a special type of granite-greenstone belts in China. It is called the granite-greenstone belts of the Liaoning-model, in which the granitic rocks are mainly migmatitic granite and granite-gneiss of migmatitic genesis. The greenstone belts in this area have undergone strong metamorphism. Large amounts of Precambrian geochronological studies have been made with U-Pb isotopic method on zircon; and a new Precambrian geologic time scale has been established. It is also proved that multistage activation of the Early Precambrian basement and the proto-platform took place in Early Proterozoic. Emphases are laid on uranium and thorium abundances and their variations as well as primary uranium contents of rocks in the granite-greenstone terrain and those of the Lower Proterozoic. At the same time, uraninite as accessory mineral in granitic rocks is found to exist more or less. Early Precambrian strata and many kinds of mineral deposits occurring in the strata are in origin chiefly of syngenetic hot brine sedimentation and of submarine extrusive gas-hydrothermal sedimentation superimposed by metamorphism. Metallogenetic features and models of various types of uranium deposits are studied emphatically and compared with similar large deposits abroad. In addition, overall synthetical appraisals are made for this area; and on this basis, prospecting directions and favourable sections of uranium metallization are suggested. (4 refs., 4 tabs.)

  7. 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)

    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)

  8. Radioelemental equilibrium-disequilibrium studies on uranium ore of Chitrial Area, Nalgonda District, Andhra Pradesh, India

    International Nuclear Information System (INIS)

    This paper discusses the nature of radioactive occurrence in Chitrial Main Block in terms of distribution of uranium and radium with special emphasis on uranium and its disequilibrium behaviour based on the large number of higher order radioactive borehole core samples. The sample data is from eastern and western parts of the main block of Chitrial, which are close to the unconformity depth. The analytical results show that the radioelemental data of Chitrial area essentially belong to the same population and that there is a continuous influx of uranium into the system with strong disequilibrium in favour of parent uranium. (author)

  9. Use of a uranium ore for the overall calibration of gamma spectrometers

    International Nuclear Information System (INIS)

    In analytical laboratories using gamma spectrometry, the need for a range of standards has led to the study of sources made up of a mineral ore with a view to its exclusive use for the overall calibration of the measurement equipment, The qualities of such a source, stable under certain conditions and giving a spectrum made up of a large number of well distributed peaks, show the advantages it presents practically; because of the varieties of ore however, it can only provide a secondary calibration. The ore used has a relatively low specific activity, thus avoiding large self-absorption corrections at low energies. The analysis is carried out using a junction of average characteristics. (author)

  10. 234U/238U signatures associated with uranium ore bodies: part 2 Manyingee

    International Nuclear Information System (INIS)

    The Manyingee ore body is a roll-front U ore body located at depth in the Cretaceous sandstone sediments of a Proterozoic palaeo valley. It is located in a confined aquifer. The aquifer is recharged 4 km upstream by the Ashburton River. Groundwater samples were collected at and up to 4.7 km downstream of the ore body. The ground water 234U/238U activity ratios (AR) were elevated to 1.86 in the vicinity of the ore body and then declined to 1.06 over the 4.7 km transect. The elevated 234U/238U ARs are attributed to selective leaching of 234U sites by oxidising waters, with α recoil as a necessary precursor to produce activated 234U sites. Direct ejection into another phase following α recoil is considered to be a minor contributor to 234U –238U disequilibrium in this environment. The profile is considered to be typical of the 234U/238U AR profile at and down gradient of the redox front of a U ore body. -- Highlights: ► The 234U/238U AR of the ground water of a roll-front U deposit was determined. ► The ground water was sampled at and beyond the redox front. ► The 234U/238U AR was elevated to 1.8 at the redox front. ► The 234U/238U AR was decreased down gradient of the redox front. ► A generic 234U/238U AR signature is proposed for U ore bodies

  11. 234U/238U signatures associated with uranium ore bodies: part 3 Koongarra

    International Nuclear Information System (INIS)

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

  12. Analyzing relationship between late-reformation and sandstone-type uranium ore-formation on Ordos Basin

    International Nuclear Information System (INIS)

    The Late-reformation stages, types, distribution features in Ordos Basin are researched based on contact relation, sedimentary formation, tectonic deformation, main tectonic disturbance and isotopic age determination. Late-reformation of Ordos Basin occurs after Middle-Late Jurassic Epoch,and are divided into 5 phase, such as Late Jurassic, early Cretaceous, early Cretaceous end-paleocene epoch, Eocene epoch -miocene epoch, Miocene epoch-now. the main Late-reformation types are uplifting and weathering, thrust fold, fault depression ,deep burial with superimposition, and thermodynamic reforming. their space distributions are uniformity. Relationship between the Late-reformation and Sandstone-Type Uranium deposits are analyzed to think that Multi-uplifting and weathering after Middle-Late Jurassic Epoch controlle the formation of Sandstone-Type Uranium deposits, specially, uplifting tilting area confroled the space distribution of sandstone-type Uranium deposits, but thrust fold, fault depression, deep burial with superimositon is unfavorable to metallogenetic of sandstone-type Uramium, because the later change the form, depth of bearing-ore layers local groundwater discharge. (authors)

  13. 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)

    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

  14. Radon measurements by IPSN during rehabilitation of the storage site for wastes from the treatment of uranium ores at Bouchet, in the Paris region

    International Nuclear Information System (INIS)

    The French Atomic energy Commission (CEA) has operated between 1949 and 1971 a processing facility for uranium ores at Bouchet, 40 km from Paris. After the dismantling of the facility in seventies, measures have been taken for site rehabilitation and specific methods for radon measurement have been used to assess the efficiency of these measures. 2 refs, 3 figs, 1 tab

  15. Jachymov uranium ore and research into radioactivity at the end of the 19th century and beginning of the 20th century

    International Nuclear Information System (INIS)

    The publication describes uranium ore deposits and mining at Jachymov in the Czech Republic (then Austria-Hungary) in relation especially to the discovery of new elements. The treatment is divided into the periods of 1898-1903, 1904-1906, and 1907-1910 (trends). (P.A.)

  16. Utilization of low grade and waste uranium ores by means of biological processes. Part of a coordinated programme on bacterial leaching of uranium ores

    International Nuclear Information System (INIS)

    Investigation of the possible affect of bacteria in leaching uranium using alkaline carbonate medium has been investigated. Eleven strains of bacteria were isolated from the alkaline percolation solutions. Most belonged to the genus Thiobacillus. Each strain was characterized by growth under aerobic conditions in Levinthal - bouillon medium and under vaseline (semi-anaerobic in Hetehens medium. Growth of the bacteria was optimum at pH range 7 to 8 but a significant population was found to exist in alkaline leaching solutions of about pH 9 to 9.5 in heap leaching experiments. It was concluded that microbiological processes can play a role in alkaline heap leaching although the quantitative measure is yet uncertain

  17. The actual status of uranium ore resources at Eko Remaja Sector: the need of verification of resources computation and geometrical form of mineralization zone by mining test

    International Nuclear Information System (INIS)

    Uranium ore resources calculation was done after ending all of geological work step. Estimation process of ore resources was started from evaluation drilling, continued with borehole logging. From logging, the result has presented in anomaly graphs, then was processed to determine thickness and grade value of ore. Those mineralization points were correlated one another to form mineralization zones which have direction of N 270 degree to N 285 degree with 70 degree dip to North. From Grouping the mineralization distribution, 19 mineralization planes was constructed which contain 553 ton of U3O8 measured. It is suggested that before expanding measured ore deposit area, mining test should be done first at certain mineralization planes to prove the method applied to calculate the reserve. Results form mining test could be very useful to reevaluate all the work-step done. (author); 4 refs; 2 tabs; 8 figs

  18. Atmospheric dispersion of radon gas from a shallow, extended uranium ore body

    International Nuclear Information System (INIS)

    The effects of meteorological variables on the dispersal of radon and its daughters, under the simplifying condition that the radon is produced from a reasonably uniform, extended plane surface, have been investigated. The Yeelirrie ore body in Western Australia is situated in a semi-desert area, where temperature inversions occur frequently

  19. Substrate-enzyme characteristics after derangements of biological combustion processes. Estimations of organism's long term exposure to uranium ore dust

    International Nuclear Information System (INIS)

    Under uranium-mining and processing conditions industrial dust of uranium ore (IDO) is key anthropogenic factor of effect on organism. Industrial dust of uranium ore contains trace of 238uranium oxide making effects of low and ultralow radiation doses along with silicon derivatives, salts of heavy metals and other contaminants. In recent years epidemiological studies showed that along with commonly encountered radiation- induced pathology in zones with radiation problems general somatic morbidity with symptoms of chronic disease with protracted course essentially increased. Above-mentioned facts indicate the exigency of systematized study the nature of systemic effect of ionizing radiation on organism at low doses. Structural and functional irregularities, metabolic imbalances and dyscrasia induced by irradiation can become indicators in this direction. Biological combustion processes performing complex of reductive and oxidative conversions directed to energy-rich compound synthesis occupy a special place among highly sensitive and informative homeostasis systems. In order to reveal the nature of ionizing radiation effect on organism at low doses and search for a relation 'Dose - Effect' we carried out series experiments with different doses of industrial dust of uranium ore from Stepnogorsk mining and chemical complex. Dose load calculation was carried out with a glance for threshold limit value (TLV) of dust control in work zone. Three dose loads satisfied to 5, 10, and 50 times to TLV were studied. Total time on inhalation primer makes up 120 days at doses equal to 5 and 10 times TLV and 60 days at dose 50 times TLV Value of total accumulated dose in the first two series varies within 11 and 22 micro Sv per 120 days of inhalation and is 55 micro Sv per 60 days in the third series. Substrate - enzyme relationships of three energy systems: terminal stages of glycolysis, intermediates and enzymes from Krebs cycle, as well as certain products from lipid

  20. The relationship between depositional system and ore-formation of sandstone-type uranium deposits in Dongsheng area, Ordos basin

    International Nuclear Information System (INIS)

    The analysis on depositional system plays a very important role in studying sandstone-type uranium deposits. Based on depositional system analysis and sequence stratigraphy, and through the study of depositional system characteristics and the spatial distribution of sedimentary facies, the evolution of sedimentary environments as well as the sequence stratigraphy of Zhiluo Formation in Dongsheng area, Ordos basin, authors have come to the following conclusions, (1) the spatial distribution of sand bodies is controlled by the planar distribution of sedimentary facies, which, in turn, affects the spatial distribution of ore-hosting sand bodies; (2) the evolution of sedimentary facies and sedimentary environments creates good lithofacies and lithological conditions favorable for interlayer oxidation; (3) the spatial lithologic combination of 'three layer structure' is controlled by sedimentary sequence. (authors)

  1. Geochemical characteristics and the provenance of cretaceous basic dikes in Zhongdong area of Xiazhuang uranium ore field

    International Nuclear Information System (INIS)

    The NWW-extending Cretaceous amphibolic diabase dikes are developed in Xiazhuang uranium ore field, Northern Guangdong province. Geochemical characteristics and the provenance of Cretaceous amphibolic diabases from Xiazhuang area have been studied from the aspects of major and trace elemental geochemistry. It can be concluded that the amphibolic diabases formed at internal plate tectonic setting with less crustal rocks assimilation during their intrusion and evolution, which mostly represent the primary magma from the mantle. The rocks are enriched in LREE, LILE, incompatible elements (K, Rb, Ba, Th,Ta, Ce, et al), have no Nb, Ta, Zr and Hf anomalies and Eu depletion compared with that of OIB basalts. Trace elements ratios and discrimination diagrams indicate that the amphibolic diabases came from the enriched mantle (EMI and EMII) and related to activities of Cretaceous hotspots (mantle plume) in Xiazhuang district. (authors)

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

    Science.gov (United States)

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

    2013-12-01

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

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

    Energy Technology Data Exchange (ETDEWEB)

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

    1958-07-01

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

  4. Oxidizing attack process of a uranium ore by a carbonated solution

    International Nuclear Information System (INIS)

    The process of this invention consists in uranium solubilization and precipitation separated with the steriles in a solid phase and then separated from the steriles by dissolution in an appropriate aqueous solution

  5. Himalayan tectonic evolution and uranium ore formation, south of Songliao basin

    International Nuclear Information System (INIS)

    Based on the analysis of stress field and geomorphic environment of Songliao Basin during Himalayan Movement, it is presented that Himalayan Movement supplied favorite structural and geomorphic conditions with Eocene and Pliocene being metallogenic epoch for sandstone-type uranium in Songliao Basin. Degradation inliers at the southern margin of Songliao Basin, where structure and mineralization developed well, are the target area for in-situ sandstone type uranium. (authors)

  6. Excess helium-4 in Teggau Lake: possibilities for a uranium ore body

    International Nuclear Information System (INIS)

    Excess 4He (more than five times the solubility) has been measured in Teggau Lake in northwestern Ontario. A model suggests that an adjacent mass of greater than 104 kilograms of uranium is responsible for the observed 4He excess. The area is favorable for pegmatitic uranium deposits, and the release of trapped 4He from uraninite dikes larger than 30 cubic meters (1% U3O8) provides the best explanation for the excess 4He in the lake

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

    Institute of Scientific and Technical Information of China (English)

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

    2003-01-01

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

  8. Rirang Uranium Ore Processing System Design: Designing A Quencher Unit: A Continuous Quencher Has Been Designed

    International Nuclear Information System (INIS)

    The objective of the design is to make a laboratory scale quencher model that is used to facilitate the dissolution and sudden cooling of the digestion product of the Rirang ore. The designed quencher was based on the previous batch quenching data, feed capacity of 325 g/minute, and residence time of one and two hours for quenching tank and thickener, respectively. The cylindrical quenching tank has dimension of 30 cm diameter and 30 cm high. It has three 2,5 cm baffles and is equipped with a blade-impeller agitator. The bottom-pitched cylindrical thickener has the diameter of 56 cm. The thickener is divided into four zones including clarification, feed; critical, and compression with 5, 3, 3, and 4 cm zones height, respectively. In addition, the bottom pitch has 12,5 cm height. The quencher model is further used to conduct performance test against Rirang ore digestion product

  9. A rapid method for the determination of uranium in ores and carbonaceous materials by x-ray-fluorescence spectrometry

    International Nuclear Information System (INIS)

    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 U3O8. It was found that the suitable dilution of resins with river sand and fine grinding makes it possible for up to 6 per cent U3O8 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 U3O8 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 U3O8 concentrations, and instructions for the calculation of the error in the determination are given in the appendices

  10. Ore reserve calculations of a sedimentary uranium deposit in Figueira, PR-Brazil

    International Nuclear Information System (INIS)

    The are reserve calculations of a sedimentary uranium deposit in Figueira-PR-Brazil are presented. The evalution of reserves was based on chemical and/or radiometric analisys from boreholes. Geoestatistical methods were used to study the spacial correlation between radiometric and'in situ' uranium content and to calculate the equivalent uranium content without the need for chemical analysis. To this end, a new method was developed based on the regression between accumulated chemical and radiometric grades as determined by increasing thicknesses defined from the maximum peak of the γ-ray logs. Thus, the effect of non-focalization of the probe and of the continuous logging was eliminated. The system of evalution used was two-dimensional using classical Kriging to calculate thicknesses and accumulations determined using distinct cut-off grades. (Author)

  11. Separation of 230Th (ionium) from uranium ores sulfuric acid and in nitric acid solutions

    International Nuclear Information System (INIS)

    230Th (ionium) is of interest for production of 231Pa, the Pa isotope with the longest half life, and for production of 232U which can be used in radionuclide batteries. Two procedures are presented which have been worked out for separation of 230Th from sulfuric acid and from nitric acid solutions. In the first case the effluents from the anion exchange resins are the starting material for recorvery of 230Th, in the second case the cation exchange resins which are for purification of U. The procedures selected are simple, economic and can be performed in any uranium mill or uranium purification plant without additional investments. (orig.)

  12. Research within the coordinated progamme on bacterial leaching of uranium ores

    International Nuclear Information System (INIS)

    Effect of magnetic field on the growth rate of Thiobacillus ferrooxidans bacteria was studied at intensities of 30, 100, 2400, and 4000 Oe. Low intensity magnetic field was found to stimulate the bacteria growth rate and the rate of ferrosulphate oxidation with optimum values at 30 to 300 Oe (maximum at 300 Oe). Magnetic field of high intensity (2400, 3200, 4000 Oe) inhibits the growth of bacteria and processes of bacterial oxidation. The possibility was also studied of using biocides for inhibiting bacterial processes in uranium-bearing waste dumps. The use of biocides resulted in a decrease of uranium-bearing waste dump autochthonous microflora density

  13. Discussion on the ore-forming geological features and genesis of Ma'andu uranium deposit

    International Nuclear Information System (INIS)

    Ma'andu uranium deposit is a typical carbonaceous -siliceous -pelitic one among those have been discovered in the southeastern Guangxi. The deposit occurs in the Devonian limestone in the external contact of granite pluton and controlled by Linshan-Tengxian regional faults. The paper first expounds the geological features and the metallogenic material sources of the deposit, and then discusses its genesis the mineralization is mainly caused by the superimposition of hydrothermal alteration and epigenetic leaching which are affected by structural activities and favorite storage space. Finally the paper has pointed out the prospecting indicators for the uranium exploration in southeastern Guangxi. (authors)

  14. γ-ray spectrometry investigation of radioactive equilibrium in ancient uranium ores of Ukraine

    International Nuclear Information System (INIS)

    The nuclear-physics technique of determining the radioactive equilibrium. The degree of deviations from the radioactive equilibrium strongly correlates with the mineral content of ores. The possible models of loss/import of radioactive nuclides are investigated. As the more probable the complex model with the loss of 231Pa, 234U and 230Th and further secondary precipitation of 234U is examined. The geologically young ages of the losses of radionuclides were estimated to be equal to the times of the water level lifting for the periods of interglacial temperature optimums

  15. Geostatistical ore reserve estimation for a roll-front type uranium deposit (practitioner's guide)

    International Nuclear Information System (INIS)

    This report comprises two parts. Part I contains illustrative examples of each phase of a geostatistical study using a roll-front type uranium deposit. Part II contains five computer programs and comprehensive users' manuals for these programs which are necessary to make a practical geostatistical study

  16. Bacteriological lixiviation of low-grade uranium ores at low temperatures, by phiobacillus ferrooxidaus

    International Nuclear Information System (INIS)

    Laboratory experiments are described that, using selective and mutagenic agents, allowed the isolation of a strain of thiobacillus ferrooxidams capable of developing at 80C, and keeping its oxidesing characteristics tests showed that the isoled sample is capable of solubilizing 95% of the uranium content in samples with U3O8 content below 1000ppm

  17. Exploration and development of the high-grade uranium ore mine 'McArthur River'

    International Nuclear Information System (INIS)

    The McArthur River deposit is one of the biggest uranium finds of the past years and will make Cameco one of the top producers for decades to come. Analyses have shown that it can be worked without miners entering the mining cavern

  18. Affect of uranium ore dust on separate indexes of nitrous exchange of rat liver using lacryc radices root extract

    International Nuclear Information System (INIS)

    Goal of the research - to reveal peculiarities of metabolic break of nitrous exchange of rat liver tissue at long-term inhalation affect of uranium dust in different terms, and to evaluate effectiveness of corrective effect of lacryc radices root extract. Experiments are executed on white not pedigree male rats with mass of 120-150g. Inhalation of uranium ore dust (UOD) is conducted with using of AID-1 apparatus of inhalation destroy. There are 3 (three) serial of researches are conducted. In blood serum and liver tissue we identified content of general albumen by unify method and activity of aminotransphcrase and gammaglutamiltranspeptidase (GGTP), using biochemical analyzer, content of urea is identified by enzymatic method, and albumen - by method of electrophoresis on paper. Corrective effect of water extract of lacryc radices root is examined. The abstract is devoted to one of the actual problem of modern radiobiology - study of system affects of low doses of ionized radiation on condition of nitrous exchange of rat liver tissue at long-term inhalation affect of uranium dust. In work we got new following results. For the first time by examination of dynamics of simple and complex albumen, separate indexes of nitrous exchange we studied system affect of low doses of ionized radiation, revealed dose-time differences of compensatory-adaptive and cytolysis response of liver tissue for long-term inhalation affects of an industrial dust of uranium ore in different doses. It is determined, that at inhalation of uranium dust in doses, equivalent to 5 maximum-allowed concentration (MAC), during 120 days process of albumen synthesis is activated in liver, that is confirmed by regular increase of albumen concentration in blood serum for 2 times to the end of observation in term of its fixed content in liver tissue. Pointed changes coincide with depression of processes of urea-formation almost in 2 times, consequent depression of aspartataminotraspherase (AsAT) and

  19. Discussion on age and paleo geographical environment of ore bearing strata for sandstone-type uranium deposits in Bayanwula area, Erlian basin

    International Nuclear Information System (INIS)

    The sandstone-type uranium ore-bearing strata of Erlian basin is a suit of coarse crumb rocks that are mainly of river and marsh sedimentary faces, age of ore-bearing strata in this area is in dispute. By studying the palynology of ore-bearing strata in Bayanwula area, particularly the distribution of the spore and the pollen in the stratum and the comparison of domestic and the international palynology as- semblage, its age of the strata was identified belong to aptian-albian stages of the Later Early Cretaceous (Aptian-Albian) under substropic warm humid climate with the tendency to semihumid and semi-dryhot. The paleo geography was of the low-fiat and undulating topography, a few middling and high mountains distributing around the basin. (authors)

  20. Rehabilitation of storage sites for low radioactive uranium ore treatment residues. The example of the Ecarpiere Cogema's site (Loire-Atlantique, France)

    International Nuclear Information System (INIS)

    The rehabilitation of storage sites for residues of ore treatment represents the ultimate phase of this industrial activity and belongs to the ore processing cycle. In order to respect the enforced regulation, the objectives consist in ensuring the durable stability of the site and keeping all the residual environmental impacts as low as reasonably achievable. This paper presents the example of the rehabilitation of the Ecarpiere Cogema's site (Loire-Atlantique, France) where 7500000 t of uranium ore residues are stored. The preliminary studies (petrography and mineralogy of residues, hydrogeology, geotechnical study, cover definition, embankments stability), the works (plant dismantling, basins filling, embankments re-profiling, draining and revegetation), and the site surveillance (geotechnical and radiometric) are described. (J.S.)

  1. 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)

    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)

  2. Process for the separation of uranium in an alkaline solution, particularly extracted from an uraniferous ore

    International Nuclear Information System (INIS)

    Process for the treatment of an alkaline uraniferous liquor containing solubilised uranium, particularly sodium uranyl-tricarbonate, characterised in that this liquor is placed into contact with a cationic ion exchange resin, previously put into ammonium form and, in that after the ion exchange has taken place a solution is collected in which the previous sodium salts and complexes have been mainly transformed in ammonium salts and complexes

  3. Determination of 230Th (Ionium) in uranium ores and wastes from uranium reprocessing. IV. Calculation of ionium separation yield

    International Nuclear Information System (INIS)

    For determining ionium (230Th) in minerals and uranium processing wastes by precipitation with fluorhidric acid, using lanthanum as carrier, and selective extraction with tenoytrifluoroacetone (TTA) followed by radiometric determination of the isolated nuclide, it is necessary the use of a tracer since the chemical yield of the separation ranges between wide limits. In this paper, the use of the beta-emitter 234Th as the most convenient tracer is discussed. Equations are derived for correcting for counting errors introduced by other thorium isotopes which are present either in the sample or in the tracer, as well as for calculating the chemical yield of the separation. These equations have been experimentally checked by ionium determinations carried out with different types of samples. (Author) 18 refs

  4. Quantitative separation of Uranium and Thorium in ores by fusion with mixture of bifluorides of potassium and ammonia; Separacao quantitativa de uranio e torio em minerios atraves de fusao com mistura de bifluoretos de potassio e amonia

    Energy Technology Data Exchange (ETDEWEB)

    Taam, Isabel; Mantovano, J.L.; Vianna, Claudio A. [Instituto de Engenharia Nuclear (IEN), Rio de Janeiro, RJ (Brazil)]. E-mail: taam@ien.gov.br; mantovan@ien.gov.br; cavianna@yahoo.com.br; Dutra, P. Bechara; Vaitsman, Delmo S. [Universidade Federal, Rio de Janeiro, RJ (Brazil). Inst. de Quimica]. E-mail: pbechara@iq.ufrj.br; vaitsman@iq.ufrj.br

    2005-07-01

    The analytical methodologies of quantification for Uranium and Thorium are very restricted when the material of the analysis is a ore. Diverse ores possess in its natural composition Uranium and Thorium as secondary elements in amounts and ratio that varies a lot in the same type of ore, for this reason, becomes impracticable the job of methods to direct determination, without the previous separation of the interest element, a time that stops annulling the generated effect of interference between it would be necessary the use of an ideal matrix of calibration for each case. In the analytical methods that Uranium and Thorium quantification are made after the separation between itselves, it meets difficulty of the long delay in the precipitation processes and filtration of Thorium, normally precipitated by the ion oxalate. The work presented here also demonstrates to the efficiency and the versatility of the use of the fusing with mixture of bifluorides of potassium and ammonia as method of opening for ores that contain Uranium and Thorium, mainly when is desirable the separation and quantitative determination of both. The method was applied in diverse ores that Thorium and Uranium concentrations presented in well varied values and ratio. The analyses for spectrometry of X ray had demonstrated the total separation between Uranium and Thorium in all studied ores. (author)

  5. First aid to fight hazards at the uranium ore processing plant at Seelingstaedt/Thuringia. Sofortgefahrenabwehr im Bereich der Uranerzaufbereitungsanlage Seelingstaedt/Thueringen

    Energy Technology Data Exchange (ETDEWEB)

    Gellermann, R.; Molitor, N.; Ripper, P. (Trischler und Partner GmbH, Darmstadt (Germany))

    Mining for uranium ore in Saxonia and Thuringen under the ownership of the German-Soviet group SDAG Wismut has severely affected the environment in the concerned regions over the last 45 years. By means of a special project, the article gives an overview of hazard potentials, acute hazards and envisaged first aid, as well as on additional measures to restore and revegetate the landscape. The state of knowledge on which the article is based is as at June 1991. (orig./HP).

  6. Age and origin of uraninite in the Elliot Lake, Ontario uranium ores

    International Nuclear Information System (INIS)

    There is a strong, positive linear correlation between the 204Pb/206Pb and 207Pb/206Pb ratios and between the 208Pb/206Pb and 207Pb/206Pb ratios in the galenas. The linear relation is interpreted to be the result of ''mixing'' of isotopically distinct Pb produced during two uraninite Pb loss episodes. A complete mixing of crustal Pb and radiogenic Pb released from the associated uraninite at a time T1 formed one end member of the observed trends. The other end member consists of radiogenic Pb released from the uraninite at a later time T2. The galena Pb isotope data indicate that T0, the inital age of the uraninite in the Elliot Lake ores, is 2200-3300 Ma, T1 is less than 2200 Ma, and T2 is less than 1350 Ma. Upper concordia intercepts for most uraninite grains range from 2210 +/- 430 Ma to 2575 +/- 180 Ma; lower concordia intercepts range from 1200 +/- 120 Ma to 1705 +/- 30 Ma. During the first Pb loss episode, at time T1, the centers of most uraninite grains released 45-90% of the accumulated Pb and the outer 5 μm region of the grains released 95-100% of the accumulated Pb. During the second Pb loss episode, at time T2, the grain exteriors released 2-6 times more Pb than the grain centers. A few highly fractured grains appear to have been ''reset'' at T1. The uraninite U-Pb data indicate that T0 greater than or equal to 1700 Ma. Together, the galena Pb isotope and uraninite U-Pb data require that T0 = 2560 +/- 50 Ma, T1, = 1700 +/- 50 Ma, and T2 = 500 +/- 180 Ma, if the 2350 +/- 100 Ma estimated age of deposition of the Huronian rocks (Roscoe, 1973) is correct, the 2560 +/- Ma obtained for the uraninite requires that the uraninite in the Elliot Lake ores is of detrital derivation

  7. Production of Commercial Uranium Concentrate From El-Sela Shear Zone Mineralized Ore Material, South Eastern Desert - Egypt, At Inshas Pilot Plant Unit

    International Nuclear Information System (INIS)

    This paper is concerned with studying the different processes leading to the production of commercial uranium concentrate (yellow cake) from the mineralized ore material of El-Sela Shear zone, South Eastern Desert, Egypt. Uranium concentrate is produced by the treatment of about 25 tons from the study ore material that assaying about 580 ppmU at Inshas Pilot Plant Unit. In the present work, the studied lab-scale leaching and extraction conditions of the ore material under consideration are shifted to the pilot plant scale. From the latter, an average leaching efficiency exceeding 82% has been achieved. On the other hand, some difficulties being arised during pilot operations such as filtration, settling, washing and huge dilute volumes of the sulfate leach slurry, are overcome through the flocculent addition and reputed concentrations. The pH of prepared pregnant sulfate leach liquor is then adjusted at 1.75 and then shifted to the fixed bed ion exchange resin unit for the extraction of uranium to obtain highly pure concentrate UO4. 2H2O. The latter would be subjected to further purification processes to prepare nuclear fuel.

  8. A study of the volatilization-excitation phenomena affecting to the efficiency of spectrochemical buffers applied to uranium ore analysis

    International Nuclear Information System (INIS)

    A direct-current arc emission spectroscopy method allowing the determination of Alm Ca, Fe, Mg, Mn, Na, P, Si and Ti in uranium ores and geological materials has been developed by studying the efficiency of Ag2O, BaCO3, Bi2O3, CuF2, CuO, Ga2O3, GeO2, graphite, K2CO3, Li2B4O7, Li2CO3, Ni, PbS, Sb2O4, SrCO3, Tl2O3 and ZnO as spectrochemical buffers. Volatilization-excitation mechanisms of Li2CO3: graphite, GeO2: graphite and SrCO3: graphite buffer mixtures have been specially considered. Procedures to investigate phenomena taking place in the electrode, anodic load and arc plasma have been selected. Intensity-time curves; voltage variation between electrodes; vapour diffussion through the electrode walls; load depletion; reaction products formation and temperature, electron pressure and ionization degree in the arc plasma have been studied. Measurements of plasma parameters are performed by introducing thermometric and manometric species in both the anode and the cathode electrodes. The effects of different alkalin matrices on transportation phenomena are also considered. Emission efficiency of some analytical lines has been investigated by the application of a mathematical model enclosing fundamental parameters of the arc plasma. Efficiency of scattered primary X-rays of various wavelengths has been studied as a correction of matrix effects in the uranium determination. Results illustrate that the incoherently-scattered MoKβsub(1,3) radiation is the optimum reference line. (author)

  9. Study of oxygen mass transfer coefficient and oxygen uptake rate in a stirred tank reactor for uranium ore bioleaching

    International Nuclear Information System (INIS)

    Highlights: ► Mass transfer coefficient does not depend on biomass concentration. ► The pulp density has a negative effect on mass transfer coefficient. ► The pulp density is the unique factor that affects maximum OUR. ► In this work, Neale’s correlation is corrected for prediction of mass transfer coefficient. ► Biochemical reaction is a limiting factor in the uranium bioleaching process. - Abstract: In this work, the volumetric oxygen mass transfer coefficient and the oxygen uptake rate (OUR) were studied for uranium ore bioleaching process by Acidthiobacillus ferrooxidans in a stirred tank reactor. The Box-Bohnken design method was used to study the effect of operating parameters on the oxygen mass transfer coefficient. The investigated factors were agitation speed (rpm), aeration rate (vvm) and pulp density (% weight/volume) of the stirred tank reactor. Analysis of experimental results showed that the oxygen mass transfer coefficient had low dependence on biomass concentration but had higher dependence on the agitation speed, aeration rate and pulp density. The obtained biological enhancement factors were equal to ones in experiments. On the other hand, the obtained values for Damkohler number (Da < 0.468) indicated that the process was limited by the biochemical reaction rate. Experimental results obtained for oxygen mass transfer coefficient were correlated with the empirical relations proposed by Garcia-Ochoa and Gomez (2009) and Neale and Pinches (1994). Due to the high relative error in the correlation of Neale and Pinches, that correlation was corrected and the coefficient of determination was calculated to be 89%. The modified correlation has been obtained based on a wide range of operating conditions, which can be used to determine the mass transfer coefficient in a bioreactor

  10. Polyphase coffinite-like U-Si gel and its role in uranium redistribution in the Mo-U deposits of the Streltsovsky Ore Field (Transbaikalia, Russia)

    International Nuclear Information System (INIS)

    The Streltsovsky uranium ore field is located within the Mongol-Okhotsky Proterosoic-Paleozoic fold belt of Central Asia which divides the Siberian and Chinese platforms. It is a unique ore field related to areas of continental volcanism with total uranium reserves exceeding 250,000 tons. Nineteen Mo-U deposits are located in the Streltsovsky caldera which covers an area of about 140 km2. It is filled by Late Jurassic - Early Cretaceous sedimentary-volcanogenic strata consisting of basalt-dacite-liparite series with a total thickness reaching 1000 m. The caldera basement is composed of Precambrian - Early Paleozoic amphibolites, schists, marbles and granitic gneisses and Late Paleozoic granites. Several stages of hydrothermal mineralization developed after Mesozoic volcanism have been recognized. The earliest process consists in extensive illitization of basement rocks and caldera filling, which ended with formation of cryptocrystalline quartz veins with sulfides. Physical and chemical characteristics of the U-Si phases are reported and results discussed as follows. The nature of the U-Si phases is supposed to represent primary gels of variable U-Si composition formed by the post-ore hydrothermal fluids from primary uranium mineralization, through its partial replacement and simultaneous uranium redeposition. The numerous features of a former gel state of the U-Si phases can hardly be explained as resulting from metamictization of coffinite because primary structures of deposition of the polyphase U-Si aggregates on faces of fluorite cubes, in open space of pores, and along fissures represent evidences against a decomposition of initially crystalline coffinite. Moreover, no 'protocoffinite' crystals were found. Presence of coffinite nuclei in gel-like U-Si matter apparently might be explained as the beginning of gel crystallization similarly to opal crystallization when extremely small nuclei of cristobalite and α-quartz form in a silica gel. Extensive formation

  11. Age and origin of uraninite in the Elliot Lake, Ontario uranium ores

    Energy Technology Data Exchange (ETDEWEB)

    Meddaugh, W.S.

    1983-01-01

    There is a strong, positive linear correlation between the /sup 204/Pb//sup 206/Pb and /sup 207/Pb//sup 206/Pb ratios and between the /sup 208/Pb//sup 206/Pb and /sup 207/Pb//sup 206/Pb ratios in the galenas. The linear relation is interpreted to be the result of ''mixing'' of isotopically distinct Pb produced during two uraninite Pb loss episodes. A complete mixing of crustal Pb and radiogenic Pb released from the associated uraninite at a time T/sub 1/ formed one end member of the observed trends. The other end member consists of radiogenic Pb released from the uraninite at a later time T/sub 2/. The galena Pb isotope data indicate that T/sub 0/, the inital age of the uraninite in the Elliot Lake ores, is 2200-3300 Ma, T/sub 1/ is less than 2200 Ma, and T/sub 2/ is less than 1350 Ma. Upper concordia intercepts for most uraninite grains range from 2210 +/- 430 Ma to 2575 +/- 180 Ma; lower concordia intercepts range from 1200 +/- 120 Ma to 1705 +/- 30 Ma. During the first Pb loss episode, at time T/sub 1/, the centers of most uraninite grains released 45-90% of the accumulated Pb and the outer 5 ..mu..m region of the grains released 95-100% of the accumulated Pb. During the second Pb loss episode, at time T/sub 2/, the grain exteriors released 2-6 times more Pb than the grain centers. A few highly fractured grains appear to have been ''reset'' at T/sub 1/. The uraninite U-Pb data indicate that T/sub 0/ greater than or equal to 1700 Ma. Together, the galena Pb isotope and uraninite U-Pb data require that T/sub 0/ = 2560 +/- 50 Ma, T/sub 1/, = 1700 +/- 50 Ma, and T/sub 2/ = 500 +/- 180 Ma, if the 2350 +/- 100 Ma estimated age of deposition of the Huronian rocks (Roscoe, 1973) is correct, the 2560 +/- Ma obtained for the uraninite requires that the uraninite in the Elliot Lake ores is of detrital derivation.

  12. Historical assessment of uranium release by the ore treatment unit - at Caldas, Minas Gerais, Brazil from 1999 to 2011

    Energy Technology Data Exchange (ETDEWEB)

    Pereira, W.S.; Carmo, R.F.; Py Junior, D.A., E-mail: pereiraws@gmail.com [Industrias Nucleares do Brasil (INB), Pocos de Caldas, MG (Brazil). Unidade de Tratamento de Minerio. Grupo Multidisciplinar de Radioprotecao; Kelecom, A., E-mail: akelecom@id.uff.br [Universidade Federal Fluminense (LARARA-PLS/GETA/UFF), Niteroi, RJ (Brazil). Laboratorio de Radiobiologia e Radiometria Pedro Lopes dos Santos. Grupo de Estudos em Temas Ambientais; Pereira, J.R.S., E-mail: pereirarsj@gmail.com [Universidade Federal de Alfenas, Pocos de Caldas, MG (Brazil)

    2013-07-01

    The Ore Treatment Unit (OTU) is located at the source of three rivers: Ribeirao das Antas, Ribeirao do Soberbo and Corrego da Consulta. Each interface of installation with the environment, at the tree rivers, has been monitored for the release of radionuclides. At Ribeirao das Antas a weekly sample collection was made at point 014. At Ribeirao Soberbo there was a weekly sample collection at point 025, and at Corrego da Consulta a monthly collection was carried out at point 076. This work analyses the average annual releases of uranium from the historical series started in 1999 and ended in 2011. Points 014 and 025 showed average release of 0.12 Bq L{sup -1}. Point 076 showed somewhat higher average release, 1.27 Bq L{sup -1}. An Analysis Of Variance test (ANOVA) has been carried out to verify the existence of different means between these collecting points. The averages were considered statistically different. As a complementary analysis, the Student's t test was performed between the averages at considered points. Between points 014 and 025, the averages were considered identical. Between points 014 and 076, the average release at point 076 was considered higher than that at point 014. The same behavior was observed between points 025 and 076. The releases at point 076 were considered higher than those at point 025. Thus it can be concluded that releases at points 014 and 025 are identical and both are lower than releases at point 076. (author)

  13. Exposure of critical group of population to water radionuclides in area affected by uranium ore mining

    International Nuclear Information System (INIS)

    Waste waters from the uranium industry are decontaminated and then discharged into water courses. Inhabitants of the nearest village on the river form the critical group with regard to radiation burden. The critical radionuclides are Usub(nat), Ra 226, Pb 210 and Po 210 whose concentrations were determined in drinking water, in the water course and in plants watered with water from the river. From obtained data on the consumption of foods of own production and of water for drinking and cooking, a weighted sum was made of the intake of critical radionuclides per year on the conservative assumption that ingestion is the sole form of intake (permissible ingestion under Notice 59/72, Coll. of Laws). Under the said criteria the intake of radionuclides from water and foods of own production is for the critical population group 27 times less than the permissible intake for the population. Decontaminated waste waters from the operation of uranium industries contribute to the radiation burden of the population only negligibly. Radionuclides from the investigated sources represent a minute fraction of permissible intake. (author)

  14. Studies on radioactivity distribution and radioactive mineral identification in uranium ores from Espinharas (PB), Brazil

    International Nuclear Information System (INIS)

    Studies about the identification of radioactive minerals in uranium bearing rocks from Espinharas (PB), Brazil are presented. Autoradiography with α-sensitive nuclear emulsions was utilized for determining radioctivity distributions and for localizing radioactive minerals, in combination with microscopy, X-ray diffractometry, PIXE and eletron microprobe analysis for its identification. Mineralized gneisse and feldspatic rock, the two principal samples studied, show distinct differences in radioactive distribution patterns, however the main carriers for U and Th seem to be the same. Microanalysis shows that elements are associated with Si, Ca, Fe and Al an some trace elements like Y, Zr, Ti, etc. U and Th are distributed uniformly in feldspatic rock and inhomogeneously in mineralized gneisse, indicating that the zonary structure of the radioactive cristals, frequently observed in gneisse, could be due to variable U:Th ratios. Chemical analysis, X-ray diffraction datas and microscopic studies indicates that the principal carrier for radioactivity in the rocks of Espinharas is a silicate mineral of U and Th, probably situaded in the series of transition: Coffinite -> uraninite, thorogummite -> thorianite. Some additional experiments about leachability of uranium with diluted sulfuric acid are reported, which confirm the different nature of radioactivity distribution in feldspatic and gneissic rocks. (author)

  15. Determination of U, Fe, V in uranium ore and gross alpha beta through the exploitation, processing and handling of radioactive ore on the portable XRF Si-PIN detector and device of alpha beta MPC-2000

    International Nuclear Information System (INIS)

    The concentration of some elements such as U, Fe, and V in uranium ore was determined by using Si-PIN detector fluorescence spectrometry. The technical parameters of Si-PIN spectrometry were investigated. The fundamental parameters in QXAS software were used for calculating analytical results. The gross alpha beta from the liquid radioactive liquid was also determined by MPC-2000 instrument based on the dependence of the signal received ability of detector on thickness of analysis samples. The precision and accuracy of quantitative analysis were tested by references material standard and comparative analysis with different analytical methods. (author)

  16. The influence of feed dilution on Uranium extraction from Rirang ore

    International Nuclear Information System (INIS)

    Dilution of feed as product of sulfuric acid digestion of Rirang has been done by using of water. The objective of experiment is to find out the optimum condition of feed extraction on uranium extraction with 5 % Alamine 336 (v/v) and 5 % Isodecanol solution (v/v). The extraction was carried out by A/O ratio of 2.5 minutes of extraction time and temperature of 40 oC by variation of feed dilution of 1 : 10; 1 : 11; 1 : 12; 1 : 13; 1 : 14; and 1: 15, respectively. The results shown that the dilution of feed was optimum by ratio feed to water of 1 : 11 or 0.99 of pH. Such condition gave the recovery of extraction was 99.98 % U. The others of extracted elements were 17.18 % of Th, 1.83 % RE2O3, and 3.21 % PO4, respectively

  17. A study of the efficiency of different spectrochemical buffers applied to the uranium ore analysis

    International Nuclear Information System (INIS)

    A direct-reading emission spectroscopy method allowing the determination of Al, Ca, Fe, Mg, Mn, Na, P, Si and Ti in geological materials, that are of interest for the prospecting and recovery of uranium, is proposed. Direct-current are between graphite electrodes Is used as the excitation source. Efficiency of Ag2O, BaCO3, Bi2O3, CuF2, CuO, Ga203, Ge02, graphite, K2CO3, H2B4O7, Li2CO3, Ni, PbS, Sb2o4 , SrC03, Ti2O3 and ZnO as spectrochemical buffers has been studied. It has been inferred that through a sample dilution with Li2CO3, SrC03 and graphite powder in the rations 1:10:10:20, respectively, the highest reduction of the matrix effects is achieved. Phosphorus determination Is better performed with PbS as spectrochemical buffer Instead of the indicated above. The action of the selected compounds Is completed by using Co, In, Li and Sr as internal standards, and, as a whole, satisfactory accuracy and reproducibility are attained. (Author) 7 refs

  18. Significance of special blasting modes for anti shock struggle at hydrothermal Pribram uranium ore deposit

    International Nuclear Information System (INIS)

    Situations are presented which occur in connection with blasting jobs. Special blasting operations are described. In the Pribram uranium deposit two types of special blasting operations were tested. Conditions are described under which softening blasting was carried out. This type of work did not prove satisfactory in operation and is therefore not performed at the Pribram deposit. A theoretical analysis is made of shock distrubance blasting and the procedure of designing such projects, the placement of explosives and the determination of their size. Such blasting jobs have been tested in shock zones of vein node. The total weight of the explosive was 100 to 200 kg of Px V 19. In most cases a mine shock was initiated (in some cases with a delay of up to several dozen hours). The said method increases the technical safety of operation. At the Pribram deposit it is only used in cases of utmost necessity because its use increases costs and delays the procedure of mining work. (E.S.). 9 figs., 1 tab., 6 refs

  19. Liquid wastes from mining and milling of uranium ores - a laboratory study of treatment methods

    International Nuclear Information System (INIS)

    Methods of reducing the concentration of contaminants in mine water and in the acidic raffinate from uranium milling operations have been studied. Lime, limestone, caustic soda and lime-soda ash mixtures were compared as reagents for neutralising raffinates and for removing amines and heavy metals including radium from solution. All methods of neutralisation reduced contaminant levels significantly. Two-stage neutralisation using limestone in the first stage to pH 4, followed by second stage lime treatment appears to be an economically attractive approach. This method usually gave the lowest residual radium concentration provided the solids from the first stage were not removed before adding lime. Radium can be further removed from neutralised raffinates or from mine water conditioned with sulphate by the addition of barium chloride to co-precipitate the sulphates of barium and radium. The concentration of radium was readily reduced to less than 3 pCi l-1 by adding 10 mg Ba l-1 raffinate. For mine waters conditioned to 0.01 M in sulphate, barium additions of 20 mg l-1 were required to attain the same radium concentrations. Adsorption on barytes was also effective in removing radium from conditioned mine water and neutralised raffinates. (author)

  20. Flotation in column-recovery of fine uranium phosphate ore from Itataia, in Brazil

    International Nuclear Information System (INIS)

    A systematic study of main variables of the flotation column and, the study of different pillot circuits integrated by flotation cells in colunm and mechanic cells, aiming at reduction the loss of the sludges for processing uranium phosphate from Itataia, in Brazil, are presented. A recovery of 49% of P2O5 for a content of 24% of P2O5 and 0,185% of U3O8 in the concentrate, using a circuit with two columns, a rougher and scavenger, was obtained. For a content of 33.4% of P2O5 and 0.240% of U3O8, a recovery of 38% of P2O5 was obtained, using a circuit composed by a mechanical cell as scavenger and two columns as rougher and cleaner. The circuit used to obtain these parameters operated with 7,6 Kg/h solid flow in the grain size range of 10μm and 3μm and the flotation column with 5 cm of diameter and 6m of high. (M.C.K.)

  1. A study of the efficiency of different spectrochemical buffers applied to the uranium ore analysis

    International Nuclear Information System (INIS)

    A direct-reading emission spectroscopy method allowing the determination of Al, Ca, Fe, Mg, Mn, Na, P, Si and Ti in geological materials, that are of interest for the prospecting and recovery of uranium, is proposed. Direct-current arc between graphite electrodes is used as the excitation source. Efficiency of Ag2O, BaCO3, Bi2O3, CuF2, CuO, Ga2O3, GeO2, graphite, K2CO3, Li2B4O7, Li2CO3, Ni, PbS, Sb2O4, SrCO3, Ti2O2 and ZnO as spectrochemical buffers has been studied. It has been infered that through a sample dilution with Li2CO3, SrCO3 and graphite powder in the rations 1:10:10:20, respectively, the highest reduction of the matrix effects is achieved. Phosphorus determination is better performed with PbS as spectrochemical buffer instead of the indicated above. The action of the selected compounds is completed by using Co, In and Sr as internal standards and, as a whole, satisfactory accuracy and reproducibility are attained. (auth.)

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

    Energy Technology Data Exchange (ETDEWEB)

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

    2014-06-30

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

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

    International Nuclear Information System (INIS)

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

  4. Phosphoric ore treatment by roasting it with sodium carbonate and leaching it with ammonium citrate for the recovery of soluble phosphate and uranium

    International Nuclear Information System (INIS)

    By thermal treatment of phosphoric ore, with low phosphorus contents and iron, aluminum, and silicon impurities, basic fertilizers with P2O5 soluble in citric acid or ammonium citrate, can be produced. The phosphoric ore lightly grinded with alkaline salts like CO3Na2 y SiO2 is roasted between 800 to 1 000°C in rotary kilns. The roasted material contains from 25–30% of alkaline phosphates soluble in citrates. Phosphoric ore from the province of Napo-Ecuador with 24% of P2O5, 40% CaO in form of apatite, 20% of SiO2 and 7 g/ton U is tested by thermic differential analysis, roasting at 800°C for 2 hours with 50% w/w of sodium carbonate and 2% w/w of SiO2 by using a Nichols pilot furnace with 15 L of capacity which uses gas (propane-butane) as fuel, and agitated leaching with ammonium citrate (5% w/w). The initial ore and products are characterized by using atomic absorption spectrophotometry (Perkin Elmer AA400) and x-ray diffraction (Bruker D8 Advance). In the best conditions, 32% of phosphorus soluble in water is obtained as well as 40% of phosphorus and 56% uranium soluble in ammonium citrate. (author)

  5. Paradigmatic shifts in exploration process: The role of industry-academia collaborative research and development in discovering the next generation of uranium ore deposits

    International Nuclear Information System (INIS)

    Full text: Uranium exploration increased over the past decade in a sympathetic response to a rapid increase in the price of uranium, inspired by fuel supply-demand, and stock market dynamics. Exploration activity likely peaked during this cycle in 2008, with in excess of 850 companies, engaged in the global exploration of a portfolio of over 3000 projects. Global uranium exploration expenditures for the period 2004-2008 are estimated at US$3.2 billion -from US$130 million in 2004, to an estimated peak of US$1.2 billion in 2008. A major focus of the exploration effort has been on brown-fields exploration in historical uranium districts. Less effort has been devoted to exploration at green-field frontiers. An anticipated significant reduction in global exploration expenditures in 2009, and beyond, is anticipated concurrent with the global recession. There is not much evidence to indicate that significant brand-new, large, and higher grade, uranium deposits have been discovered during this uranium exploration cycle. It is likely that future uranium explorers will need to be more efficient, and effective in their efforts, and to adopt new, and innovative business strategies for their survival, and success. This paper addresses some of the fundamental reasons why major economic discoveries of uranium ore bodies have been elusive over the past two decades, through a cyclical model know as the 'learning curve', using the prolific Athabasca Basin, Saskatchewan, as an exemplar. This model incorporates elements relating exploration expenditure, quantities of discovered uranium, and the sequence of uranium deposit discoveries, to reveal that discovery cycles are epochal in nature, and that they are also intimately related to the development, and deployment of new exploration technologies. The history of uranium exploration is parsed into the early 'prospector' exploration phase (1960- 1980), and the current model driven phase (1981-present). The future of successful uranium

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

    International Nuclear Information System (INIS)

    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

  7. The rapid analysis of 230Th in uranium ores by CaC2O4 precipitation, P204 extraction and α inner-scintillation

    International Nuclear Information System (INIS)

    The uranium ore was melted and decomposed with Na2O2, then it was leached by water and the residue was dissolved in the acid. The thorium was preconcentrated and separated from the other impurities by CaC2O4 precipitation. The precipitate was dissolved in 3 mol/L HNO3, then was extracted by P204-toluene solution and stripped by 5% H2C2O4. The solution was precipitated by CaC2O4 again and then mixed with ZnS(Ag). The α-activity of this sample could be measured by an inner-scintillation method. The detection limit is 3 x 10-3 Bq, and the analytic cycle is 6 samples (ores)/8 hours

  8. Paradigmatic Shifts in Exploration Process: The Role of Industry-Academia Collaborative Research and Development in Discovering the Next Generation of Uranium Ore Deposits

    International Nuclear Information System (INIS)

    Uranium exploration increased over the past decade in a sympathetic response to a rapid increase in the price of uranium, inspired by fuel supply-demand and stock market dynamics. Exploration activity likely peaked during this cycle in 2008 with in excess of 900 companies engaged in the global exploration of a portfolio of over 3000 projects. Global uranium exploration expenditures for the period 2004–2008 are estimated at US$3.2 billion — from US$130 million in 2004 to an estimated peak of US$1.2 billion in 2008. A major focus of the exploration effort has been on brown-fields exploration in historical uranium districts. Less effort has been devoted to exploration at green-field frontiers. A significant reduction in global exploration expenditures in 2009 and beyond is anticipated concurrent with the global recession. There is not much evidence to indicate that brand-new, large, and higher grade, uranium deposits have been discovered during this uranium exploration cycle. It is likely that future uranium explorers will need to be more efficient and effective in their efforts and to adopt new and innovative business strategies for their survival and success. This paper addresses some of the fundamental reasons why major economic discoveries of uranium ore bodies have been elusive over the past two decades, through a cyclical model know as the ‘learning curve’, using the prolific Athabasca Basin, Saskatchewan, as an exemplar. This model relates exploration expenditure, quantities of discovered uranium, and the sequence of uranium deposit discoveries, to reveal that discovery cycles are epochal in nature and that they are also intimately related to the development and deployment of new exploration technologies. The history of uranium exploration is parsed into the early ‘prospector’ exploration phase (1960–1980) and the current ‘model driven’ phase (1981–present). The future of successful uranium exploration is envisaged as

  9. Evaluation of the Cerro Solo nuclear ore, province of Chubut. The Cerro Solo project within the frame of uranium exploration in Argentina. Pt. 1

    International Nuclear Information System (INIS)

    The Cerro Solo ore deposit was selected by the CNEA to invest in an assessment project because of their promising grade and amount of known and potential resources, significant to Argentina's uranium requirements. The deposit, which is located in the central region of the Chubut Province, belongs to the sandstone type and is hosted by the cretaceous Chubut Group. Technical studies carried out forecast an important growth of nuclear capacity to meet Argentina's energy requirements in the first two decades of of the the next century. To be in position to confront the challenge presented by increasing uranium resources to fuel the nuclear powers plants it is very important, as a first step, to improve the geological knowledge of uranium favorability in the country. The preliminary results of the Cerro Solo project indicate that the eastern slope of the Pichinan hills is a promising area for development of uranium resources, increasing the favorability of the San Jorge Basin in order to allow contributing to meet future uranium requirements. The Cerro Solo Project was planned in a sequential manner, as a multidisciplinary effort which includes studies on: geologic setting of mineralization, resource estimates, costs of mining and milling methods, economic analysis and environmental impact research. Among the mining methods, studies include the alternative of the in-situ leaching technology, which is becoming a low producing cost interesting possibility. (Author)

  10. Study on uranium loss during 'Iron-Gypsum Cake' precipitation from acid leach liquor of Jaduguda ore using factorially designed experiments

    International Nuclear Information System (INIS)

    Acid leaching process for uranium recovery from ore often generates considerable amounts of impurities into the solution. It is a challenge to separate the non-valuable impurities as manageable and stable waste products for final disposal, without losing the valuable constituents. The main impurities that come with the leach liquor are iron and sulfate. Their removal is essential for meeting the iron requirement in leaching circuit and also for making the effluent suitable for recycle. Factorial design analysis was applied to study of process variables for precipitation of iron and sulphate from leach liquor with composition using CaO as precipitation reagent

  11. Selective arsenical purification of substances during an alkaline treatment process of an uranium and/or molybdenum bearing ore by means of a magnesium compound

    International Nuclear Information System (INIS)

    The ores is digested by means of an aqueous liquor of sodium or potassium carbonate and/or bicarbonate, the digestion being carried out under conditions of concentrations, temperatures and pressures bringing about the solubilization of the uranium and/or molybdenum and the arsenic present in the core. A solid phase suspension is lifted from a liquid phase and the phases are separated. The arsenic solubilized during the digestion is extracted as magnesium arsenate by treatment of the medium containing the arsenic by means of a magnesium compound

  12. Determination of uranium, iron, copper, and nickel from ore samples by MEKC using N,N'-ethylene bis(salicylaldimine) as complexing reagent.

    Science.gov (United States)

    Mirza, Muhammed Aslam; Khuhawar, Muhammad Yar; Arain, Rafee

    2008-02-01

    An analytical procedure has been developed for the separation of dioxouranium(VI), iron(III), copper(II), nickel(II), cobalt(II), cobalt(III), palladium(II), and thorium(IV) by MEKC using N,N'-ethylene bis(salicylaldimine) (H(2)SA(2)en) as a complexing reagent with total runtime uranium ore samples indicating its presence within 103-1789 microg/g with RSD within 0.79-1.87%. Likewise copper, nickel, and iron in their combined matrix were also simultaneously determined with RSD 0.4-1.6% (n = 6). PMID:18186535

  13. A study and practice of heap construction by long hole blasting for in-place leaching of Jiaoping No. 1 ore body in No. 745 uranium mine

    International Nuclear Information System (INIS)

    In No. 745 Mine, there are a great number of residual low grade uranium orebodies and separate orebodies which can not be economically exploited by using conventional methods. In order to recover these uranium ore bodies, an experimental study on the in-place leaching was conducted on a 10 000 t scale at the open-pit bottom. In this test, the heap was constructed by the long hole blasting. On the basis of the practical conditions the suitable stope bottom structure was selected to achieve multi-point solution collection and leach solution leakage prevention. In order to control the heap shape and generate suitable relief space, special consideration was given to undercut slot layout and construction method. Intensive attention was paid to parameters of long hole blasting and the fragmentation size. (authors)

  14. X-ray energy dispersive spectroscopy of uranium ore using a TES microcalorimeter mounted on a field-emission scanning electron microscope

    Energy Technology Data Exchange (ETDEWEB)

    Maehata, Keisuke, E-mail: maehata@nucl.kyushu-u.ac.jp [Department of Applied Quantum Physics and Nuclear Engineering, Kyushu University, 744 Motooka, Nishi-ku, Fukuoka-shi 819-0395 (Japan); Idemitsu, Kazuya [Department of Applied Quantum Physics and Nuclear Engineering, Kyushu University, 744 Motooka, Nishi-ku, Fukuoka-shi 819-0395 (Japan); Tanaka, Keiichi [SII NanoTechnology Inc., 36-1 Takenoshita, Oyama, Sunto, Shizuoka 410-1393 (Japan)

    2011-08-21

    Energy dispersive spectroscopic measurements of uranium ore were conducted using a superconducting phase transition-edge-thermosensor (TES) microcalorimeter mounted on a field-emission scanning electron microscope (SEM) to demonstrate its potential for high-precision microanalysis. The effective solid angle for X-ray detection is found to be larger than 2 msr by precise adjustments in the X-ray polycapillary alignment. The observed detection signal pulses with decay time constant of 50{mu}s enable maximum count rates larger than 300 counts per second. The energy resolution was determined to be 14.6 eV FWHM at Al K{sub {alpha}} X-ray energies of 1487 eV. Distinct peaks appear in the resulting X-ray energy spectrum associated with U-M{sub {alpha}}, U-M{sub {beta}} and U-M{sub {gamma}} X-rays emitted by the uranium ore specimens. This spectrum includes weaker peaks corresponding to C-K{sub {alpha}}, Fe-L{sub {alpha}}, Cu-L and Sr L {sub {alpha}1} X rays.

  15. Research on uranium leaching of some uraniferous ploymetallic ore in Xinjiang%新疆某含铀多金属矿浸铀工艺研究

    Institute of Scientific and Technical Information of China (English)

    赵春; 张霖; 李清海; 郑元泽; 王清良; 胡鄂明; 王国全

    2012-01-01

    采用新疆某含铀多金属矿石,进行了矿石粒度、酸浓度、氧化剂种类及浓度、液固比对铀浸出效果的影响的搅拌浸出试验和柱浸试验,结果表明,该矿石适合酸法浸出,浸出性能好,属易浸矿石;矿石中CaO含量高导致酸耗较高,达到9%以上;酸法浸铀过程中BeO浸出很少,可考虑对浸铀渣进行Be()的提取利用;矿石粒度对浸出效果有较大影响,小粒级矿石浸出率高,浸出周期短,液固比小,但酸耗较高;氧化剂的加入对铀浸出率影响很小;矿层高度对浸出效果有一定影响,矿层高度越大,酸耗较低,液固比越小.为了提高堆浸技术经济指标,生产实际中可考虑增加堆高或串堆浸出,并在浸出中后期采取淋、停交替作业以及翻堆等措施.%The ploymetallic uranium ore from Xinjiang was processed and the influences of particle size, sulphuric acid concentration, types and concentration of oxidants, and the ratio of liquid to solid on uranium leaching were investigated and discussed by agitation leaching test and cylinder leaching test. The result shows that the ore, with a good leaching effect, is suitable for acid leaching and belongs to easy-leaching ore; the ore, with high content of CaO, leads to high acid consumption, reaching more than 9%; in the process of acid leaching of uranium, BeO leaches rarely, which may be considered for extracting and using of BeO; the particle size index affects greatly the leaching effect-small grade ore has a high leaching rate and short leaching cycle, but high consumption of acid; the addition of oxidant has little effect on uranium leaching rate; the seam height has effects on uranium leaching, the greater the height, the lower the acid consumption and the smaller ratio of liquid to solid. In order to improve the technological and economic indexes of heap leaching, in the actual production, it may be considered to increase the usage of high stack or heap leaching and

  16. 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)

  17. Environmental restoration plans and activities in the zones of uranium ore extraction and milling in Romania: 1995-1996 progress report

    International Nuclear Information System (INIS)

    The objective of this paper is to present the ecological impact on environment as a consequence of more than 30 years of activity in the field of uranium exploration, mining and ore processing in Romania and a brief description of the measures taken for limiting the effects of contamination on the affected zones including the proposed restructuring and rehabilitation programmes. The Autonomous Regie for Rare Metals (RAMR), the coordinator of the activities in the uranium field is responsible to implement the provisions of the IAEA Technical Cooperation Project on Environmental Restoration in Central and Eastern Europe joined by Romania in 1993. The characterization of radioactively contaminated areas is dealt with broadly under two categories, one pertaining to sites where the mining and milling activities have already ceased and the other where the units are still operational but are going to be closed down in the near future and will be placed under surveillance. Generally speaking, the activity in the uranium field is developed by observing the national Norms of Nuclear Safety for the Activity of Geological Investigation, Mining and Milling of Nuclear Raw Material. This report includes an evaluation of the necessary investments for the first stage of the programme dealing with the environmental restoration and the necessary research activities. This will be followed by studies for closing down and surveillance of the mines with special problems taking into account their depth and complex hydrology

  18. Field measurements of mixed exposure of operators to radioactive aerosol, gas and quartz in confinement of mining equipment cabs during open-pit mining of high-grade uranium ores

    International Nuclear Information System (INIS)

    A series of field measurements of miners mixed exposure to radon and daughters, uranium ore dust and respirable quartz, was conducted in an open-pit mine in Northern Saskatchewan during 1980-81. Control of radon gas levels in the mining equipment cabs is required. Dust may be reduced by minimizing the resuspension of dust from contaminated surfaces within the cabs

  19. Determination of niobium, tantalum, and uranium in tantalite-columbite ores by X-ray fluorescence spectrometry

    International Nuclear Information System (INIS)

    A simple and quick procedure is carried out to determine niobium, tantalum and uranium employing the internal standard technique; zinc as internal standard for tantalum and molybdenum for niobium and uranium were selected. Some inter element effects were studied and the ratios. (Author)

  20. Uranium conversion

    International Nuclear Information System (INIS)

    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 UF6 and UF4 are present require equipment that is made of corrosion resistant material

  1. Study on the in-situ leaching of sandstone uranium ore by Alkali reagent with dissolved oxygen under pressure

    International Nuclear Information System (INIS)

    It is indicated by experiment that under dissolved oxygen, the technique of in-situ leaching uranium from sandstone with alkali method is reliable. When oxygen pressure is 10kg/cm2 (0.98MPa, dissolved oxygen concentration is about 300ppm), leaching reagent NaHCO3 concentration is 5g/L, average flow rate is 0.34m/d, leaching 16 days with total liquid/solid ratio 4.08, uranium leaching rate is 86% and uranium content in the leached sludge is 0.011%. When leaching reagent NaHCO3 concentration is 1g/L, average flow rate is 0.13m/d, leaching 96 days with total liquid/solid ratio 9.42, uranium leaching rate is 76% and uranium content in the leached sludge is 0.019%

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

    Energy Technology Data Exchange (ETDEWEB)

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

    1978-09-01

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

  3. Synergistic extraction of uranium from Korean black shale ore leach liquors using amine with phosphorous based extractant systems

    International Nuclear Information System (INIS)

    Synergistic extraction of uranium using amine combined with phosphorous based extractant systems was described. The present study focused on the continuous extraction processing of uranium to form precipitation under higher pH conditions and higher aqueous phase ratios. To address this, synergistic extraction studies were carried out with P-based extractants as synergists and investigations were done with better pairs with an amine-based extractant system. Finally, all of the developed synergistic extraction methodologies were compared with each other. This showed that Alamine 336 and D2EHPA was the best pair for uranium extraction, offering as much separation as possible from other associated metals. (author)

  4. Possibility of applying the gamma-gamma method to the in situ determination of uranium-ore densities

    International Nuclear Information System (INIS)

    The principles of the gamma-gamma method are reviewed. It is shown in particular that, under certain conditions, the method makes it possible to obtain a representative measurement of the electronic density. Chemical analyses have been carried out on samples obtained from uranium deposits. The results show that an exact correlation exists between the massive and electronic densities. It is possible to consider the possibility of measuring the density of uranium-containing rocks by the gamma-gamma method. (authors)

  5. Uranium

    International Nuclear Information System (INIS)

    The article includes a historical preface about uranium, discovery of portability of sequential fission of uranium, uranium existence, basic raw materials, secondary raw materials, uranium's physical and chemical properties, uranium extraction, nuclear fuel cycle, logistics and estimation of the amount of uranium reserves, producing countries of concentrated uranium oxides and percentage of the world's total production, civilian and military uses of uranium. The use of depleted uranium in the Gulf War, the Balkans and Iraq has caused political and environmental effects which are complex, raising problems and questions about the effects that nuclear compounds left on human health and environment.

  6. Investigation of trace uranium content in rock phosphate ore samples from Kurun-Uro area, Nuba Mountains, Sudan

    International Nuclear Information System (INIS)

    This investigation was carried out mainly to test the trace uranium level content in rock phosphate, which was used as a low cost fertilizer. Two types of rock phosphate were examined, namely, Kurun and Uro rocks from Nuba Mountains in the Southern Kurdufan province, Sudan.This area has a high background natural radioactivity. Moreover, it contains a rock phosphate zone lying between J. Kurun and Uro. The work included analytical methods carried out for thr rock phosphate samples using spectrophotometric and X-ray fluorescence techniques. The results obtained were compared with the data from literature and they showed a good agreement.The data was statistically analyzed to compare the results by the two techniques. The results of uranium content determined by the two analytical methods were significantly similar.The instrumental analysis revealed that different. Uranium content in the rocks phosphate samples of Uro type was found to be 1.6 times higher than Kurun type. (Author)

  7. 2.5 Mio. m3 decontaminated waste water - successful operation of the treatment plant for waste water from uranium ore mines

    International Nuclear Information System (INIS)

    During the period from 1950 to 1989, approx. 70 million t of uranium ore from the former WISMUT company was processed under Soviet management in the Crossen treatment plant in the former GDR. While the mined uranium was mainly used in nuclear technology in the Soviet Union, the storage of the solid residues contaminated with residual uranium, radium and arsenic at the WISMUT site led to considerable environmental damage over this long period. One of the main aims of WISMUT GmbH, which was newly founded in 1991, is therefore to remediate and recultivate the adsettling plants. Due to the extent of this problem, the processes used must not only prove themselves by showing a high degree of innovation with regard to process engineering, but also by being highly economic. The waste water treatment plant in Helmsdorf, which was planned and erected by Preussag Noell Wassertechnik GmbH, made a major contribution to achieving this objective. Apart from the central plant for degrading the surplus water, which is to be treated to meet the required limits before being discharged into the Zwickauer Mulde, the treatment plant also includes the construction of a plant to immobilize the associated residues. This guarantees that they are deposited in an environmentally acceptable manner. Since starting operation in May 1995, more than 2.5 mio. m3 of waste water had been treated up to the end of 1996. Using the experience gained from more than one year of operation, the throughput, which was planned to be 250 m3/h max., has now been raised by about 10% to 280 m3/h. (orig.)

  8. Hydrochloric acid leaching of uranium, thorium, radium and rare-earth elements, from an Elliot lake radioactive ore

    International Nuclear Information System (INIS)

    Extraction of uranium by commercial methods using sulphuric acid developed a lot of environmental problems. To avoid such problems, other uranium extraction techniques have been adopted including fluorination, chlorination, chlorine assisted leaching, hydrochloric acid leaching, etc. This work is oriented towards the study of the factors controlling the hydrochloric acid leaching. The target of the study is to extract the total amount of U, Th, Ra-226 and rare earth elements. By using a suitable combination of the leaching factors, it was possible to achieve the designed target

  9. Nuclear metallurgy lectures. Chapter 6, Reduction of uranium

    Energy Technology Data Exchange (ETDEWEB)

    Kattner, W.T.

    1955-05-26

    This report consists of Chapter Six of the Nuclear Metallurgy Lectures. Chapter six discusses the reduction of uranium, chemical composition of uranium ores, extraction process for uranium ores, bomb reduction, green salt, and dingots.

  10. Removal of 226Ra from waste waters resulted from mining and processing of uranium ores with natural zeolites

    International Nuclear Information System (INIS)

    The zeolites were of clinoptilolyte type and the used waste waters were: mine drainage waters, waste waters from radiometric sorting and tailings pond waters from a uranium processing plant. On the basis of experimental results, the parameters of the procedure have been established, which enables one to obtain a radium removal efficiency higher than 95 % at the passage of over 2,000 BEV waste water. (author)

  11. Geological prospecting experience resulting in discovery of workable uranium deposits of various genetic types in North Kazakhstan ore province

    International Nuclear Information System (INIS)

    The mineral resources of the North Kazakhstan region are represented by uranium deposits of two major types. These are endogenic, occurring in the basement rocks, and epigenetic. Discovery of the Vostok deposit (1964) of endogenic origin, and the hydrogenous Semizbay (1973) are of particular commercial interest. Guidelines for the prognostication, feasibility study and recommended mining methods successfully conducted in North Kazakhstan are presented in this report. Implementation of these methods may prove useful in conducting exploration under similar conditions. (author). 4 figs

  12. The prospection of uranium and thorium ores in desert country and in equatorial forest regions of the Union Francaise

    International Nuclear Information System (INIS)

    Since it was founded, the D.R.E.M. has carried out important prospection work in the overseas territories which now make up the Communaute Francaise. This work, now involving almost a million km2, represents an experiment scarcely equalled throughout the world. Research in these territories presents both general and technical difficulties, which are especially severe in countries with extreme climates: deserts or dense equatorial forests. The adaptation of various methods of radioactive ore prospection to these regions is described, and also the results obtained. Three particular examples are given in detail: - general exploration in the Hoggar, and reconnoitring of particular indications; - general exploration in the equatorial forest of French Guyana; - detailed study of a sign of uraniferous occurrences and its surroundings in the equatorial zone (Mounana deposit near Franceville (Gabon)). (author)

  13. Uranium recovery from phosphate rocks concentrated

    International Nuclear Information System (INIS)

    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)

  14. Analysis of the tectonic stress field in the Xiangshan uranium ore field,Linchuan area,Jiangxi China%江西临川地区相山铀矿田构造应力场分析

    Institute of Scientific and Technical Information of China (English)

    陈正乐; 喻建发; 杨农; 王平安; 宫红良; 韩凤彬; 周永贵; 邵飞; 唐湘生; 徐金山

    2011-01-01

    相山铀矿田是中国最大的、与火成岩有关的中低温热液型矿床,断裂构造控矿特征明显.目前该矿床的后备资源出现危机,因此开展矿田构造研究,为深部及其外围找矿提供科学指导迫在眉睫.在野外观测分析和节理、擦痕实地测量的基础上,利用构造解析法、共轭剪节理分析法、断层擦痕反演模拟法及X光岩组法等,通过吴氏网投图分析和计算机的反演计算,确定了相山铀矿田多期次构造活动的变形特征及其主应力方向;并根据构造变形叠加关系及其成岩时代的确定,推断了应力作用的期次和时代.为此,将相山铀矿田的构造应力场划分为3期6个阶段,包括:成矿前的基底变形和早期火山活动阶段,早期矿化蚀变和第一、第二主成矿阶段,及其成矿期后阶段,矿体局部被错断;并深入分析了不同阶段构造活动及其铀成矿特征,探讨了区域构造应力场的演变与铀成矿作用关系,认为两者具有一致性特征,进而指出了区域富大矿体产出的有利构造部住.%The Xiangshan uranium ore-field is the largest volcanic-related meso-epithermal deposit in China and the uranium-mineralization is tightly controlled by fault activities. As exploited and doveloped for many years, the ore-reserve resource of the deposit is in current crisis, although the potential reservoir is probably great. Therefore, the study in ore-field structures is imminent to provide scientific guidance for ore-prospecting in the deep and surrounding areas. This paper mainly presents field measurement results ofjoints and fault scratches to identify features of tectonic activities and the principal stress direction, using traditional and modern methods in tectonic stress field research. Stages and times of the tectonic stress field are also determined based on successively superimposed deformation relations and diagenesis ages of volcanic rocks. The result showed that the tectonic

  15. Chemical characterization of the quality of water in a dam under the influence of uranium mining, ore treatment unit, Caldas, Minas Gerais, Brazil

    International Nuclear Information System (INIS)

    The Brazilian Nuclear Industries Ore Treatment Unit (UTM/INB), located in the plateau region of Pocos de Caldas - MG, is the first uranium extraction mine to have its deposits explored in Brazil. The Represa das Antas (RA) receives treated acidic effluents from waste rock dumps, originated from acid mine drainage from UTM/INB. At RA's downstream, the Represa Bortolan (RB) - focus of this study - can be located. The dam is characterized by the receiving of domestic and industrial residue discharges, in addition to the RA waters. Within this context, the purpose of the study is to evaluate if the release of the effluents treated by UTM/INB has influence over the chemical quality of the water at RB. Water samplings were carried out at RB in three different periods of the day (9am, 12pm and 4pm), during three consecutive days, on the surface, through and in the bottom of the water column. The evaluated chemical variables were: zinc (Zn), manganese (Mn), fluoride (F-), molybdenum (Mo), sulfate (SO42-), uranium (U), thorium (Th), pH, dissolved oxygen, total phosphorus and total nitrogen. The results indicated that elevated Mn concentrations - above limits established by current legislation in Brazil - can be related to the treated effluent released by UTM/INB, since the metal Mn is one of the chemical components of the effluent in natura. Regarding the other chemical components (F-, Zn, Mo, SO42-, U and Th), related to the acidic effluent's composition as well, their recorded values were found to be within the limits established by current legislation. (author)

  16. Chemical characterization of the quality of water in a dam under the influence of uranium mining, ore treatment unit, Caldas, Minas Gerais, Brazil

    Energy Technology Data Exchange (ETDEWEB)

    Silva, Thiago A. Vilas Boas; Azevedo, Heliana de; Ferrari, Carla R., E-mail: hazevedo@cnen.gov.br [Comissao Nacional de Energia Nuclear (LAPOC/CNEN), Pocos de Caldas, MG (Brazil). Lab. de Pocos de Caldas

    2011-07-01

    The Brazilian Nuclear Industries Ore Treatment Unit (UTM/INB), located in the plateau region of Pocos de Caldas - MG, is the first uranium extraction mine to have its deposits explored in Brazil. The Represa das Antas (RA) receives treated acidic effluents from waste rock dumps, originated from acid mine drainage from UTM/INB. At RA's downstream, the Represa Bortolan (RB) - focus of this study - can be located. The dam is characterized by the receiving of domestic and industrial residue discharges, in addition to the RA waters. Within this context, the purpose of the study is to evaluate if the release of the effluents treated by UTM/INB has influence over the chemical quality of the water at RB. Water samplings were carried out at RB in three different periods of the day (9am, 12pm and 4pm), during three consecutive days, on the surface, through and in the bottom of the water column. The evaluated chemical variables were: zinc (Zn), manganese (Mn), fluoride (F{sup -}), molybdenum (Mo), sulfate (SO{sub 4}{sup 2-}), uranium (U), thorium (Th), pH, dissolved oxygen, total phosphorus and total nitrogen. The results indicated that elevated Mn concentrations - above limits established by current legislation in Brazil - can be related to the treated effluent released by UTM/INB, since the metal Mn is one of the chemical components of the effluent in natura. Regarding the other chemical components (F{sup -}, Zn, Mo, SO{sub 4}{sup 2-}, U and Th), related to the acidic effluent's composition as well, their recorded values were found to be within the limits established by current legislation. (author)

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

    International Nuclear Information System (INIS)

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

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

    International Nuclear Information System (INIS)

    Full text: The industrial basin of Decazeville (Riou-Mort watershed, South-West France) is well known for its heavy metal pollution and its subsequent environmental effects on the Lot-Garonne River system. The source of this pollution is the Riou-Mort River, which drains smelting waste areas. A first survey after remediation works has revealed elevated dissolved uranium (UD) concentrations in the outlet of the Riou-Mort River. The objective of this research is to identify the origin of UD in the Riou-Mort watershed and to evaluate the impact of industrial activities on this element. Uranium was measured at 10 sites, located upstream and downstream the industrial basin, and in smelting waste deposits. Uranium concentrations in the smelting waste deposits reach up to 14.4 mg kg-1 and (234U/238U) activity ratios (AR) are near unit. Dissolved U concentrations in the Riou-Mort River and its main tributaries ranges over an order of magnitude from nearly 0 to 6.1 μg L-1. The highest levels were measured in a non-polluted site, upstream from the industrial area. This observation suggests that UD is mainly linked to weathering: the elevated UD concentrations originate from the naturally occurring radioactive materials (NORM) located in the Permian bedrock and no significant U pollution exists, at present, in the Riou-Mort watershed. This work demonstrates, that long time-series is an essential prerequisite to assess spatio-temporal variations of UD or of other dissolved species, prior pollution diagnostic in small watershed. (author)

  19. Investigation and remediation of houses affected by radon phenomena connected with earlier exploration of silver and uranium ore

    International Nuclear Information System (INIS)

    The sources of gamma radiation inside buildings affected by earlier silver and uranium mining activities are discussed. Possibilities how to reduce gamma dose rates from building materials were studied on several houses located in the old mining town Jachymov. Results of the efficiency analysis are presented. Experience obtained up to now indicates that it is almost impossible to reduce the gamma dose rates in such buildings to the level corresponding with the natural background, because some of the gamma radiation sources cannot be completely removed from the building structures. (authors)

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

    Science.gov (United States)

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

    2016-05-15

    The identification of interdicted nuclear or radioactive materials requires the application of dedicated techniques. In this work, a new approach for characterizing powder of uranium ore concentrates (UOCs) is presented. It is based on image texture analysis and multivariate data modelling. 26 different UOCs samples were evaluated applying the Angle Measure Technique (AMT) algorithm to extract textural features on samples images acquired at 250× and 1000× magnification by Scanning Electron Microscope (SEM). At both magnifications, this method proved effective to classify the different types of UOC powder based on the surface characteristics that depend on particle size, homogeneity, and graininess and are related to the composition and processes used in the production facilities. Using the outcome data from the application of the AMT algorithm, the total explained variance was higher than 90% with Principal Component Analysis (PCA), while partial least square discriminant analysis (PLS-DA) applied only on the 14 black colour UOCs powder samples, allowed their classification only on the basis of their surface texture features (sensitivity>0.6; specificity>0.6). This preliminary study shows that this method was able to distinguish samples with similar composition, but obtained from different facilities. The mean angle spectral data obtained by the image texture analysis using the AMT algorithm can be considered as a specific fingerprint or signature of UOCs and could be used for nuclear forensic investigation. PMID:26992543

  1. Recover of some rare earth elements from leach liquor of the Saghand uranium ore using combined precipitation and cation exchange methods

    International Nuclear Information System (INIS)

    In this research work, the recovery and separation of La(III), Ce(III), Sm(III), Dy(III) and Nd(III) from Saghand uranium ore have been studied by precipitation and ion-exchange chromatography methods using Dowex 50 W-X 8 cation exchanger. At first, some preliminary and preconcentration experiments such as comminution, sieve analysis, gravity table and electrostatic in preconcentration of lanthanides were performed. Then, acidic digesting and leaching procedure were used. The results of experiments showed that rare earth elements, along with interfering ions such as Al(III), Fe(III), Mg(II) and Mn(II) present in the leach liquor solution. The investigation of separation process by precipitation method revealed that precipitation and then fast separation using centrifugal technique had the best results in the elimination of interference elements. In order to separate the lanthanides and to obtain their elution curves, the chromatographic column containing Dowex 50 W-X 8 resin was employed. For efficient separation of lanthanides from interference elements the hydrochloric acid with concentration of two and six molar was used respectively. Recovery of lanthanides from the leach liquor solution was achieved more than 85%

  2. An investigation into the effects of various flotation parameters on the flotation behaviour of pyrite, gold and uranium contained in Witwatersrand type ores, and their practical exploitation

    International Nuclear Information System (INIS)

    The importance of copper sulphate, pH, conditioning time, grind, the intensity of agitation during conditioning, and the correct type of conditioning on the alkaline flotation of gold, uranium and pyrite from Witwatersrand type ores is shown. The peculiar 'run-away float' condition experienced at high pH with air agitated conditioning is presented. The best laboratory flotation results were obtained after 20 minutes of vigorous mechanical conditioning of the pulp at a pH of 11,8 with copper sulphate 100 g/t Aero promoter 3477 20 g/t, xanthate 80 g/t, frother 5 g/t, grind 68% in - 75 μm and pulp specific gravity of 1,280 (dry solids sp. gr. = 2,70). The practical implementation of the laboratory findings on the Hartebeestfontein No. 7 Shaft flotation plant resulted in an increase in gold recovery from about 76% to about 86%, and an increase in pyrite recovery from about 86% to about 92%

  3. Working and benefit project by the in-situ leaching of the copper-uranium ore of the deposit named Luz del Cobre, in the municipality of Soyopa, state of Sonora, Mexico

    International Nuclear Information System (INIS)

    This research was carried out with the object to recover the existing uranium in the copper-uranium deposit of Luz del Cobre located at 1300 Kms. approximately of the NW of Mexico City in the state of Sonora this deposit is geologically formed by a partially mineralized chimney which contains 572,732 tons of uranium ore with an average of 362.26g. of U3O8 per ton, which represents 207,374 tons of U3O8 in situ. To recover the uranium from this deposit, the only technical and economical possibility which presents a real interest is the system of leaching in situ. This operation will consist in the selective dissolution of the copper and uranium through leaching solution with a pH varying from 2.2 to 2.5, leaving the gangue on the ground and collecting the enriched solutions at the lower level of the mine, precipitating the copper subsequently through scrap iron and recovering the uranium from the tails of the copper precipitation plant through an ionic interchange process in counter current and its subsequent elution solvent extraction, reextraction and precipitation. This system makes possible to recover an uranium concentrate up to 98% of U3O8 and practically free from impurities. The production cost would cost exceeding $300.00 Mexican currency per Kg of U3O8. (author)

  4. Uranium

    International Nuclear Information System (INIS)

    The author discusses the contribution made by various energy sources in the production of electricity. Estimates are made of the future nuclear contribution, the future demand for uranium and future sales of Australian uranium. Nuclear power growth in the United States, Japan and Western Europe is discussed. The present status of the six major Australian uranium deposits (Ranger, Jabiluka, Nabarlek, Koongarra, Yeelerrie and Beverley) is given. Australian legislation relevant to the uranium mining industry is also outlined

  5. Uranium

    International Nuclear Information System (INIS)

    The development, prospecting, research, processing and marketing of South Africa's uranium industry and the national policies surrounding this industry form the headlines of this work. The geology of South Africa's uranium occurences and their positions, the processes used in the extraction of South Africa's uranium and the utilisation of uranium for power production as represented by the Koeberg nuclear power station near Cape Town are included in this publication

  6. Electro-optical detection of uranium-238 decay products in the atmosphere: LIDAR remote sensing techniques are stuied to determine effectiveness in detecting uranium ore

    International Nuclear Information System (INIS)

    This study was conducted in two phases. The first phase dealt with theoretical calculations of expected detection sensitivities using LIDAR remote sensing techniques to measure airborne daughter products of 238U. The most promising species for this technique were found to be 214Bi and 210Pb, with effective photon scattering cross sections of 3.5 x 10-17 cm2 and 8 x 10-15 cm2 respectively. The theoretical calculations regarding system sensitivity were based on approximate calculations of the appropriate transition probabilities and estimates of the effects of atmospheric fluorescent quenching. Phase two consisted of experimental measurements of the total effective photon scattering cross sections and the effects of quenching by various atmospheric gases. Results of these measurements indicated that the calculated transition probabilities and effective scattering cross sections, exclusive of quenching, were in reasonable agreement with measured values. However, results of the quenching measurements showed that the original theoretical estimates had underestimated the effects of quenching by more than an order of magnitude. Calculations of expected LIDAR system performance based on the experimentally measured quantities showed that, although the system would be very sensitive by normal standards (1 part in 1018 at a range of 180 m), it would still be inadequate to the needs of an aerial survey search for 238U ore deposits

  7. Uranium

    International Nuclear Information System (INIS)

    A discussion is given of uranium as an energy source in The Australian economy. Figures and predictions are presented on the world supply-demand position and also figures are given on the added value that can be achieved by the processing of uranium. Conclusions are drawn about Australia's future policy with regard to uranium (R.L.)

  8. Uranium

    International Nuclear Information System (INIS)

    The geological setting of uranium resources in the world can be divided in two basic categories of resources and are defined as reasonably assured resources, estimated additional resources and speculative resources. Tables are given to illustrate these definitions. The increasing world production of uranium despite the cutback in the nuclear industry and the uranium requirements of the future concluded these lecture notes

  9. Processing of lateritic ores

    International Nuclear Information System (INIS)

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

  10. The radon 222 transport in soils. The case of the storage of residues coming from uranium ores processing

    International Nuclear Information System (INIS)

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

  11. Comparative study of leaching behaviour of various leachants in ISL test on Qubul Khel uranium ore body

    International Nuclear Information System (INIS)

    This paper presents detailed information on laboratory conventional leaching and column pack leach tests using various leachants. A comparative study of uranium leaching behaviour was also made by using various alkaline lixiviants employing conventional five spot pattern. The main objective of this study was to investigate the suitable leachant and its concentration through field test which does not foul the surface lines, submersible pumps and strata. Laboratory leaching tests confirmed that U3O8 could be leached efficiently with a recovery of about 95%, 83% and 84% respectively by using (NH4)2 CO3, Na2CO3 + HCO3 and H2SO4 as lixiviants. In alkaline system ammonium carbonate, sodium carbonate-bicarbonate mixture and sodium bicarbonate solutions were found to be the most effective lixiviants. The column pack leaching tests revealed that 95%, 90% and 73% U3O8 recovery could be achieved with 25 g/l (NH4)2 CO3, 10.0 g/l Na2CO3 + 5 g/l NaHCO3 and 10 g/l NaHCO3 solutions respectively in 96, 120 and 216 hrs. leaching time. 8 refs, 17 figs, 13 tabs

  12. Ore metals through geologic history.

    Science.gov (United States)

    Meyer, C

    1985-03-22

    The ores of chromite, nickel, copper, and zinc show a wide distribution over geologic time, but those of iron, titanium, lead, uranium, gold, silver, molybdenum, tungsten, and tin are more restricted. Many of the limitations to specific time intervals are probably imposed by the evolving tectonic history of Earth interacting with the effects of the biomass on the evolution of the earth's s surface chemistry. Photosynthetic generation of free oxygen and "carbon" contributes significantlly to the diversity of redox potentials in both sedimentary and igneous-related processes of ore formation, influencing the selection of metals at the source, during transport, and at the site of ore deposition. PMID:17777763

  13. 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.

  14. Determination of natural isotopes of thorium in uranium ore and soils by spectrophotometry-α counting method

    International Nuclear Information System (INIS)

    After impurities are separated by CaC2C4 precipitation-P204 extraction, 222Th can be determined by spectrophotometry using 15 mL chromogen solution of arsenazo III. The detecting limit is 0.06 μg. The used color solution is re-precipitated by CaC2C4 then mixed evenly with ZnS(Ag). The α-activity can be measured by α-inner scintillation. The 4 π detecting efficiency is (95 +- 1)%. The background of measurement is (1.5 +-0.3) x 10-3 Bq (including blank test value, the sample area is 12 cm2). The total α-activity of Th that is important to investigate the environmental pollution can be calculated by measuring the sample once. If the sum of the α-activities of 232Th and 228Th is far less than that of 230Th, the data can be obtained by simple correction. They could be used in quick analysis of uranium processing samples. If the sum of α-activities of 232Th and 228Th can not be neglected, the α-activity of the sample will be measured again after a period of time. The content of 228Th can be calculated from the change between two measurements, then the content of 230Th can also be obtained by further calculation. Using this method the data of three major isotopes of Th can be obtained by both chemical and physical method through only one sample. All elementary analytical laboratories have the capability to use this method, and it can save at least half of the time in α-spectrometry and γ-spectrometry

  15. Assessment of alternatives for long-term management of uranium ore residues and contaminated soils located at DOE's Niagara Falls Storage Site

    Energy Technology Data Exchange (ETDEWEB)

    Merry-Libby, P.

    1984-11-05

    About 11,000 m/sup 3/ of uranium ore residues and 180,000 m/sup 3/ of wastes (mostly slightly contaminated soils) are consolidated within a diked containment area at the Niagara Falls Storage Site (NFSS) located about 30 km north of Buffalo, NY. The residues account for less than 6% of the total volume of contaminated materials but almost 99% of the radioactivty. The average /sup 226/Ra concentration in the residues is 67,000 pCi/g. Several alternatives for long-term management of the wastes and residues are being considered, including: improvement of the containment at NFSS, modification of the form of the residues, management of the residues separately from the wastes, management of the wastes and residues at another humid site (Oak Ridge, TN) or arid site (Hanford, WA), and dispersal of the wastes in the ocean. Potential radiological risks are expected to be smaller than the nonradiological risks of occupational and transportation-related injuries and deaths. Dispersal of the slightly contaminated wastes in the ocean is not expected to result in any significant impacts on the ocean environment or pose any significant radiological risk to humans. It will be necessary to take perpetual care of the near-surface burial sites because the residues and wastes will remain hazardous for thousands of years. If controls cease, the radioactive materials will eventually be dispersed in the environment. Predicted loss of the earthen covers over the buried materials ranges from several hundred to more than two million years, depending primarily on the use of the land surface. Groundwater will eventually be contaminated in all alternatives; however, the groundwater pathway is relatively insignificant with respect to radiological risks to the general population. A person intruding into the residues would incur an extremely high radiation dose.

  16. Assessment of alternatives for long-term management of uranium ore residues and contaminated soils located at DOE's Niagara Falls Storage Site

    International Nuclear Information System (INIS)

    About 11,000 m3 of uranium ore residues and 180,000 m3 of wastes (mostly slightly contaminated soils) are consolidated within a diked containment area at the Niagara Falls Storage Site (NFSS) located about 30 km north of Buffalo, NY. The residues account for less than 6% of the total volume of contaminated materials but almost 99% of the radioactivty. The average 226Ra concentration in the residues is 67,000 pCi/g. Several alternatives for long-term management of the wastes and residues are being considered, including: improvement of the containment at NFSS, modification of the form of the residues, management of the residues separately from the wastes, management of the wastes and residues at another humid site (Oak Ridge, TN) or arid site (Hanford, WA), and dispersal of the wastes in the ocean. Potential radiological risks are expected to be smaller than the nonradiological risks of occupational and transportation-related injuries and deaths. Dispersal of the slightly contaminated wastes in the ocean is not expected to result in any significant impacts on the ocean environment or pose any significant radiological risk to humans. It will be necessary to take perpetual care of the near-surface burial sites because the residues and wastes will remain hazardous for thousands of years. If controls cease, the radioactive materials will eventually be dispersed in the environment. Predicted loss of the earthen covers over the buried materials ranges from several hundred to more than two million years, depending primarily on the use of the land surface. Groundwater will eventually be contaminated in all alternatives; however, the groundwater pathway is relatively insignificant with respect to radiological risks to the general population. A person intruding into the residues would incur an extremely high radiation dose

  17. Temporal variability of radon in a remediated tailing of uranium ore processing – the case of Urgeiriça (central Portugal)

    International Nuclear Information System (INIS)

    Radon monitoring at different levels of the cover of the Urgeiriça tailings shows that the sealing is effective and performing as desired in terms of containing the strongly radioactive waste resulting from uranium ore processing. However, the analysis of the time series of radon concentration shows a very complex temporal structure, particularly at depth, including very large and fast variations from a few tens of kBq m−3 to more than a million kBq m−3 in less than one day. The diurnal variability is strongly asymmetric, peaking at 18 h/19 h and decreasing very fast around 21 h/22 h. The analysis is performed for summer and for a period with no rain in order to avoid the potential influence of precipitation and related environmental conditions on the radon variability. Analysis of ancillary measurements of temperature, relative humidity, wind speed and wind direction, as well as atmospheric pressure reanalysis data shows that the daily averaged radon concentration in the taillings material is anti-correlated with the atmospheric pressure and that the diurnal amplitude is associated with the magnitude of atmospheric pressure daily oscillations. - Highlights: • The temporal variability of radon at the Urgeiriça tailing is examined. • The cover of the tailing is effective in containing the strongly radioactive waste. • Radon concentration varies with depth and exhibits very large sub-daily variations. • The daily variability is strongly asymmetric and non-stationary. • Apparent influence of atmospheric pressure on radon concentration patterns

  18. Radioactivity and the French uranium bearing minerals

    International Nuclear Information System (INIS)

    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.)

  19. Sedimentary rocks Uranium in Cerro Largo Province

    International Nuclear Information System (INIS)

    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

  20. 氧化还原障在热液铀矿成矿中的作用%The Role of Oxidizing Reducing Barrier in Mineralization of Hydrothermal Uranium Ore

    Institute of Scientific and Technical Information of China (English)

    李延河; 段超; 赵悦; 裴浩翔; 任顺利

    2016-01-01

    铀是变价元素,氧化还原条件控制铀的迁移和沉淀。铀在氧化环境中呈 U6+形式存在,在还原条件下则以 U4+形式存在。氧化态六价铀主要以可溶的碳酸铀酰/氟化铀酰络合物形式在水溶液中迁移,还原态四价铀主要以沥青铀矿和铀石等形式富集沉淀成矿。热液铀矿的形成需要一对空间上密切共生的氧化障/氧化剂和还原障/还原剂,二者缺一不可。首先,氧化障中氧化剂将富铀岩石中的铀大量氧化形成 U6+,溶解进入水溶液迁移;第二,高氧化性富铀溶液遇到还原障,U6+还原成 U4+沉淀下来,富集形成铀矿。前人虽然对铀的地球化学性质及氧化还原反应在铀成矿中作用已比较了解,但如何在实际铀矿成矿系统中准确识别氧化还原障,有效利用氧化还原障的控矿机理指导找矿,还存在一些模糊认识,制约了铀成矿理论的发展和找矿方法的提升。本文以我国最重要的砂岩型铀矿、火山岩型铀矿、花岗岩型铀矿和变质型铀矿为例,总结了与铀矿化有关的氧化还原障的主要类型,探讨了红层等蒸发盐地层(氧化障),有机质、煌斑岩等中基性岩脉(还原障)与铀矿之间的关系及控矿机制,揭示了成矿盆地中铀-煤、铀-气(油)共生的机制,阐明了翁泉沟硼、铁、铀矿共生原因,建立了不同类型铀矿成矿模型。%Uranium is a volatile element,and the redox conditions control the migration and precipitation of uranium.In the oxidation environment,uranium is in the form of U6 + ,and in the form of U4+ in reduction condition.The oxidation state of six valence uranium is mainly in soluble uranyl carbonate / uranyl fluoride complexes form,in aqueous solution migration,and the reductive tetravalent uranium is mainly enriched and precipitated in the form of pitchblende and coffinite in the ore-forming.The formation of