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Sample records for basinal ore fluids

  1. Metallogeny of the Great Basin: crustal evolution, fluid flow, and ore deposits

    Science.gov (United States)

    Hofstra, Albert H.; Wallace, Alan R.

    2006-01-01

    The Great Basin physiographic province in the Western United States contains a diverse assortment of world-class ore deposits. It currently (2006) is the world's second leading producer of gold, contains large silver and base metal (Cu, Zn, Pb, Mo, W) deposits, a variety of other important metallic (Fe, Ni, Be, REE's, Hg, PGE) and industrial mineral (diatomite, barite, perlite, kaolinite, gallium) resources, as well as petroleum and geothermal energy resources. Ore deposits are most numerous and largest in size in linear mineral belts with complex geology. U.S. Geological Survey (USGS) scientists are in the final year of a research project initiated in the fall of 2001 to increase understanding of relations between crustal evolution, fluid flow, and ore deposits in the Great Basin. Because of its substantial past and current mineral production, this region has been the focus of numerous investigations over the past century and is the site of ongoing research by industry, academia, and state agencies. A variety of geoinformatic tools was used to organize, reinterpret, and display, in space and time, the large amounts of geologic, geophysical, geochemical, and hydrologic information deemed pertinent to this problem. This information, in combination with concentrated research on (1) critical aspects of the geologic history, (2) an area in northern Nevada that encompasses the major mineral belts, and (3) important mining districts and deposits, is producing new insights about the interplay between key tectonic events, hydrothermal fluid flow, and ore genesis in mineral belts. The results suggest that the Archean to Holocene history of the Great Basin was punctuated by several tectonic events that caused fluids of different origins (sea water, basinal brine, meteoric water, metamorphic water, magmatic water) to move through the crust. Basement faults reactivated during these events localized deformation, sedimentation, magmatism, and hydrothermal fluid flow in overlying

  2. Coupled heat and fluid flow modeling of the Carboniferous Kuna Basin, Alaska: Implications for the genesis of the Red Dog Pb-Zn-Ag-Ba ore district

    Science.gov (United States)

    Garven, G.; Raffensperger, J.P.; Dumoulin, J.A.; Bradley, D.A.; Young, L.E.; Kelley, K.D.; Leach, D.L.

    2003-01-01

    The Red Dog deposit is a giant 175 Mton (16% Zn, 5% Pb), shale-hosted Pb-Zn-Ag-Ba ore district situated in the Carboniferous Kuna Basin, Western Brooks Range, Alaska. These SEDEX-type ores are thought to have formed in calcareous turbidites and black mudstone at elevated sub-seafloor temperatures (120-150??C) within a hydrogeologic framework of submarine convection that was structurally organized by large normal faults. The theory for modeling brine migration and heat transport in the Kuna Basin is discussed with application to evaluating flow patterns and heat transport in faulted rift basins and the effects of buoyancy-driven free convection on reactive flow and ore genesis. Finite element simulations show that hydrothermal fluid was discharged into the Red Dog subbasin during a period of basin-wide crustal heat flow of 150-160 mW/m2. Basinal brines circulated to depths as great as 1-3 km along multiple normal faults flowed laterally through thick clastic aquifers acquiring metals and heat, and then rapidly ascended a single discharge fault zone at rates ??? 5 m/year to mix with seafloor sulfur and precipitate massive sulfide ores. ?? 2003 Elsevier Science B.V. All rights reserved.

  3. Stable isotope characteristics and origin of ore-forming fluids in copper-gold-polymetallic deposits within strike-slip pull-apart basin of Weishan-Yongping continental collision orogenic belt, Yunnan Province, China

    Institute of Scientific and Technical Information of China (English)

    WANG Yong; HOU Zengqian; MO Xuanxue; DONG Fangliu; BI Xianmei; ZENG Pusheng

    2007-01-01

    More than 140 middle-small sized deposits or minerals are present in the Weishan-Yongping ore concentra-tion area which is located in the southern part of a typical Lanping strike-slip and pull-apart basin. It has plenty of mineral resources derived from the collision between the Indian and Asian plates. The ore-forming fluid system in the Weishan-Yongping ore concentration area can be divided into two subsystems, namely, the Zijinshan subsystem and Gonglang arc subsystem. The ore-forming fluids of Cu, Co deposits in the Gonglang arc fluid subsystem have δD values between -83.8‰ and -69%0, δ18O values between 4.17‰ and 10.45‰, and δ13C values between -13.6‰ and 3.7‰,suggesting that the ore-forming fluids of Cu, Co deposits were derived mainly from magmatic water and partly from formation water. The ore-forming fluids of Au, Pb, Zn, Fe deposits in the Zijinshan subsystem have δD values between-117.4‰ and-76‰, δ18O values between 5.32‰ and 9.56‰,and δ13C values between -10.07‰ and -1.5‰. The ore-forming fluids of Sb deposits have 6D values between -95%0 and -78‰, δ18O values between 4.5‰ and 32.3‰, and δ13 Cvalues between -26.4‰ and -1.9‰. Hence, the ore-forming fluids of the Zijinshan subsystem must have been derived mainly from formation water and partly from magmatic water.Affected by the collision between the Indian and Asian plates,ore-forming fluids in Weishan-Yongping basin migrated con-siderably from southwest to northeast. At first, the Gonglang arc subsystem with high temperature and high salinity was formed. With the development of the ore-forming fluids, the Zijinshan subsystem with lower temperature and lower salinity was subsequently formed.

  4. Transport of Pb and Zn by carboxylate complexes in basinal ore fluids and related petroleum-field brines at 100°C: the influence of pH and oxygen fugacity

    Directory of Open Access Journals (Sweden)

    Giordano Thomas H

    2002-09-01

    Full Text Available It is well established through field observations, experiments, and chemical models that oxidation (redox state and pH exert a strong influence on the speciation of dissolved components and the solubility of minerals in hydrothermal fluids. log –pH diagrams were used to depict the influence of oxygen fugacity and pH on monocarboxylate- and dicarboxylate-transport of Pb and Zn in low-temperature (100°C hydrothermal ore fluids that are related to diagenetic processes in deep sedimentary basins, and allow a first-order comparison of Pb and Zn transport among proposed model fluids for Mississippi Valley-type (MVT and red-bed related base metal (RBRBM deposits in terms of their approximate pH and conditions. To construct these diagrams, total Pb and Zn concentrations and Pb and Zn speciation were calculated as a function of log and pH for a composite ore-brine with concentrations of major elements, total sulfur, and total carbonate that approximate the composition of MVT and RBRBM model ore fluids and modern basinal brines. In addition to acetate and malonate complexation, complexes involving the ligands Cl-, HS-, H2S, and OH- were included in the model of calculated total metal concentration and metal speciation. Also, in the model, Zn and Pb are competing with the common-rock forming metals Ca, Mg, Na, Fe, and Al for the same ligands. Calculated total Pb concentration and calculated total Zn concentration are constrained by galena and sphalerite solubility, respectively. Isopleths, in log –pH space, of the concentration of Pb and concentration of Zn in carboxylate (acetate + malonate complexes illustrate that the oxidized model fluids of T. H. Giordano (in Organic Acids in Geological Processes, ed. E. D. Pittman and M. D. Lewan, Springer-Verlag, New York, 1994, pp. 319–354 and G. M. Anderson (Econ. Geol., 1975, 70, 937–942 are capable of transporting sufficient amounts of Pb (up to 10 ppm and Zn (up to 100 ppm in the form of carboxylate

  5. By lithology Zbruch deposits (Lower Sarmatian Nikopol manganese ore Basin

    Directory of Open Access Journals (Sweden)

    Bogdanovich V.V.

    2010-06-01

    Full Text Available Based on lithologic-paleogeographic study Zbruch layers of Nikopol manganese ore Basin sediments described lithological and genetic types of rocks and facies conditions of formation of deposits.

  6. Geothermal and fluid flowing simulation of ore-forming antimony deposits in Xikuangshan

    Institute of Scientific and Technical Information of China (English)

    YANG Ruiyan; MA Dongsheng; BAO Zhengyu; PAN Jiayong; CAO Shuanglin; XIA Fei

    2006-01-01

    The Xikuangshan Antimony Deposit located in the Mid-Hunan Basin, China, is the largest antimony deposit in the world. Based on the hydrogeological and geochemical data collected from four sections, Xikuangshan-Dajienao (AO), Xikuangshan-Dashengshan (BO), Xikuangshan-Longshan (CO) and Dafengshan (DO) in the Basin, an advanced metallogenic model related to deep-cyclic meteoric water of Xikuangshan Antimony Deposit is put forward in this paper using a model of heat-gravity-driving fluid flow transportation. The simulation results show that the ore-forming fluid of the deposit mainly comes from the Dashengshan and Longshan areas where BO and CO sections are located if the overall basin keeps a constant atmospheric precipitation and infiltration rate during mineralization, and that the average transportation speed of the ore-forming fluids is about 0.2-0.4 m/a.

  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. Isotope geochemistry of the Huize Zn-Pb ore field, Yunnan province, Southwestern China. Implication for the sources of ore fluid and metals

    International Nuclear Information System (INIS)

    The Huize ore field, which is the most famous high-grade Zn-Pb ore field in China, comprises the Kuangshanchang and Qilinchang deposits. The Zn and Pb reserves of these two deposits are more than 5 Mt with ore grades ranging from 25% to 35% in weight. Lead, sulfur, carbon oxygen, hydrogen and strontium isotope geochemistry is reported to help understand the sources of the ore fluid and metals. The 206Pb/204Pb, 207Pb/204Pb and 208Pb/204Pb values of the ores range from 18.251-18.530, 15.663-15.855 and 38.487-39.433, respectively. These values are similar to those of the wall rocks. The pyrites disseminated in the wall rocks have indistinguishable Pb isotope composition with the ores. These data indicate that the wall rocks provided metals to the ore fluid. Most δ34S values of the ores range from 13 to 17 per mil. The sulfur of the ores originated by in situ reduction sulfate. Three kinds of gangue calcite from the ores have similar isotope compositions, which have δ13C values in the range of -2.1 to -3.5 per mil with respect to PDB and δ18O values in the range of 16.8 to 18.6 per mil with respect to SMOW. The δDFI values of fluid inclusions in the three kinds of gangue calcites have a narrow range of -50 to -60 per mil and the δ18OH2O values calculated from δ18O values of calcite range from 7.0 to 8.8 per mil at 200degC. These data suggest that the ore fluid was a basinal brine that passed through shale, clastic rocks and mudstone underlying the host rock. Initial 87Sr/86Sr values of the pyrite, sphalerite and calcite from the ores range from 0.714 to 0.717. The initial 87Sr/86Sr values of unaltered host rock (0.7083-0.7093) are lower than that of the altered host rock (0.7106). It suggests that the ore fluids have higher initial 87Sr/86Sr values than the wall rocks. These high initial 87Sr/86Sr values may be due to the reaction between the ore fluid and the shale, clastic rocks and mudstone underlying the host rock or the fluid might have originated from these

  9. Basin Fluid Mineralization during Multistage Evolution of the Lanping Sedimentary Basin, Southwestern China

    Institute of Scientific and Technical Information of China (English)

    2007-01-01

    The Lanping sedimentary basin has experienced a five-stage evolution since the late Paleozoic: ocean-continent transformation (late Paleozoic to early mid-Triassic); intracontinental rift basin (late mid-Triassic to early Jurassic); down-warped basin (middle to late Jurassic); foreland basin (Cretaceous); and strike-slip basin (Cenozoic). Three major genetic types of Ag-Cu polymetailic ore deposits, including the reworked hydrothermal sedimentary, sedimentary-hydrothermally reworked and hydrothermal vein types, are considered to be the products of basin fluid activity at specific sedimentary-tectonic evolutionary stages. Tectonic differences of the different evolutionary stages resulted in considerable discrepancy in the mechanisms of formation-transportation, migration direction and emplacement processes of the basin fluids, thus causing differences in mineralization styles as well as in genetic types of ore deposit.

  10. Mineralogical and geochemical characteristics of the Noamundi-Koira basin iron ore deposits (India)

    Science.gov (United States)

    Mirza, Azimuddin; Alvi, Shabbar Habib; Ilbeyli, Nurdane

    2015-04-01

    India is one of the richest sources of iron ore deposits in the world; and one of them is located in the Noamundi-Koira basin, Singhbhum-Orissa craton. The geological comparative studies of banded iron formation (BIF) and associated iron ores of Noamundi-Koira iron ore deposits, belonging to the iron ore group in eastern India, focus on the study of mineralogy and major elemental compositions along with the geological evaluation of different iron ores. The basement of the Singhbhum-Orissa craton is metasedimentary rocks which can be traced in a broadly elliptical pattern of granitoids, surrounded by metasediments and metavolcanics of Greenstone Belt association. The Singhbhum granitoid is intrusive into these old rocks and to younger, mid Archaean metasediments, including iron formations, schists and metaquartzites and siliciclastics of the Precambrian Iron Ore Group (Saha et al., 1994; Sharma, 1994). The iron ore of Noamundi-Koira can be divided into seven categories (Van Schalkwyk and Beukes 1986). They are massive, hard laminated, soft laminated, martite-goethite, powdery blue dust and lateritic ore. Although it is more or less accepted that the parent rock of iron ore is banded hematite jasper (BHJ), the presence of disseminated martite in BHJ suggests that the magnetite of protore was converted to martite. In the study area, possible genesis of high-grade hematite ore could have occurred in two steps. In the first stage, shallow, meteoric fluids affect primary, unaltered BIF by simultaneously oxidizing magnetite to martite and replacing quartz with hydrous iron oxides. In the second stage of supergene processes, deep burial upgrades the hydrous iron oxides to microplaty hematite. Removal of silica from BIF and successive precipitation of iron resulted in the formation of martite- goethite ore. Soft laminated ores were formed where precipitation of iron was partial or absent. The leached out space remains with time and the interstitial space is generally filled

  11. Fluid inclusion, rare earth element geochemistry, and isotopic characteristics of the eastern ore zone of the Baiyangping polymetallic Ore district, northwestern Yunnan Province, China

    Science.gov (United States)

    Feng, Caixia; Bi, Xianwu; Liu, Shen; Hu, Ruizhong

    2014-05-01

    The Baiyangping Cu-Ag polymetallic ore district is located in the northern part of the Lanping-Simao foreland fold belt, which lies between the Jinshajiang-Ailaoshan and Lancangjiang faults in western Yunnan Province, China. The source of ore-forming fluids and materials within the eastern ore zone were investigated using fluid inclusion, rare earth element (REE), and isotopic (C, O, and S) analyses undertaken on sulfides, gangue minerals, wall rocks, and ores formed during the hydrothermal stage of mineralization. These analyses indicate: (1) The presence of five types of fluid inclusion, which contain various combinations of liquid (l) and vapor (v) phases at room temperature: (a) H2O (l), (b) H2O (l) + H2O (v), (c) H2O (v), (d) CmHn (v), and (e) H2O (l) + CO2 (l), sometimes with CO2 (v). These inclusions have salinities of 1.4-19.9 wt.% NaCl equivalents, with two modes at approximately 5-10 and 16-21 wt.% NaCl equivalent, and homogenization temperatures between 101 °C and 295 °C. Five components were identified in fluid inclusions using Raman microspectrometry: H2O, dolomite, calcite, CH4, and N2. (2) Calcite, dolomitized limestone, and dolomite contain total REE concentrations of 3.10-38.93 ppm, whereas wall rocks and ores contain REE concentrations of 1.21-196 ppm. Dolomitized limestone, dolomite, wall rock, and ore samples have similar chondrite-normalized REE patterns, with ores in the Huachangshan, Xiaquwu, and Dongzhiyan ore blocks having large negative δCe and δEu anomalies, which may be indicative of a change in redox conditions during fluid ascent, migration, and/or cooling. (3) δ34S values for sphalerite, galena, pyrite, and tetrahedrite sulfide samples range from -7.3‰ to 2.1‰, a wide range that indicates multiple sulfur sources. The basin contains numerous sources of S, and deriving S from a mixture of these sources could have yielded these near-zero values, either by mixing of S from different sources, or by changes in the geological

  12. 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)

  13. 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)

  14. Characteristics and origin of ore-forming fluids of Jinchangqing gold (copper) ore deposit (s) in Xiangyun, Yunnan Province

    Institute of Scientific and Technical Information of China (English)

    HE Mingqin; SONG Huanbin; LIU Jiajun; LI Chaoyang

    2005-01-01

    On the basis of results of the studies of primary fluid inclusions, and the hydrogen and oxygen isotope data, the authors concluded that the early-stage ore-forming fluid from the Jinchangqing gold (copper) ore deposit is a kind of sulfate type hot brine characterized by medium temperature and salinity, genetically related to the late-stage ore-forming fluid derived from an acidic and more reductive environment. However, the late-stage ore-forming fluid is a sort of low temperature and low salinity chloride-type hot brine which originated from a lower pressure, acidic and more oxidative environment. In general, the ore fluids were derived from the late-stage, or largely from the early-stage groundwater-derived meteoric water, which has a 12‰-17‰ heavier oxygen isotopic composition than the original rain water (δ 18 O= -15.3‰ ), and were formed during gold mineralization as a product of oxygen isotope exchange during the reaction between ore-forming fluid and wall rocks under a lower water/rock ratio condition.

  15. Complexity and Geodynamics of Ore-accumulating Basins in the Qinling Orogenic Belt, China

    Institute of Scientific and Technical Information of China (English)

    2000-01-01

    Researches were made of different continental-margin and intraplate basin systems in the Qinling microplate in terms of hydrothermal deposition, geodynamics of basin formation, hydrothermal sedimentary rock facies, syntectonics in the basins, and the styles of ore accumulation in the basins.

  16. Ore-Forming Fluid Characteristics of the Naoyangping-Damogou zinc-fluorite ore deposit, Pingli County, Shaanxi Province, China

    Directory of Open Access Journals (Sweden)

    Moussounda Kounga Claude1

    2013-01-01

    Full Text Available The Naoyangping-Damogou zinc-fluorite ore deposit is located in the North Dabashan Caledonian fold belt, in the east wing Pingli Anticlinorium, which is one of the most important zinc-fluorite-hosting faults in Shaanxi Province of China. Metallogenesis is controlled by F7 fault structure and other relevant fault structure systems and closely related to the trachyte side. Fluid inclusion (FI petrography and microthermometry, and analysis of oxygen and hydrogen isotopes for fluid inclusions were conducted to determine the characteristics of the ore-forming fluids and the processes of zinc and fluorite mineralizations. Microthermometry data of FI indicated that ore-forming fluids are characterized by low salinity and low density. The data obtained from geothermometric studies of Sphalerite and fluorite associated with zinc-lead mineralization at the Naoyangping-Damogou mine are compatible with a structurally controlled, Sedimentaryhydrothermal origin. Homogenization and last ice melting temperature of primary fluid inclusion indicate that mineralization taken place over a temperature range 295-335°C and salinities of inclusion fluids range 0.53 to 1.33 wt.% TDS. Ore-forming fluids were dominated by magmatic components in the early mineralization period. In the present paper we report our preliminary research results of the data obtained from geothermometric studies of Sphalerite and fluorite at the Naoyangping-Damogou ore deposit. The present study builds on the existing geological, petrographic and geochemical information of Naoyangping-Damogou

  17. Structure and fluid evolution of Yili basin and their relation to sandstone type uranium mineralization

    International Nuclear Information System (INIS)

    Based on the summary of strata and structure distribution of Yili basin, the relation of structure and fluid evolution to sandstone type ur alum mineraliation are analyzed. It is found that uranium mineralization in Yili basin experienced ore hosting space forming, pre-alteration of hosting space, hosting space alteration and uranium formation stages. (authors)

  18. Organic Gases in Fluid Inclusions of Ore Minerals and Their Constraints on Ore Genesis: A Case Study of the Changkeng Au-Ag Deposit, Guangdong, China

    Institute of Scientific and Technical Information of China (English)

    2003-01-01

    The newly discovered Changkeng Au-Ag deposit is a new type of sediment-hosted precious metal deposit. Most of the previous researchers believed that the deposit was formed by meteoric water convection. By using a high vacuum quadrupole gas mass spectrometric system, nine light hydrocarbons have been recognized in the fluid inclusions in ore minerals collected from the Changkeng deposit. The hydrocarbons are composed mainly of saturated alkanes C1-4 and unsaturated alkenes C2-4 and aromatic hydrocarbons, in which the alkanes are predominant, while the contents of alkenes and aromatic hydrocarbons are very low. The Σalka/Σalke ratio of most samples is higher than 100, suggesting that those hydrocarbons are mainly generated by pyrolysis of kerogens in sedimentary rocks caused by water-rock interactions at medium-low temperatures, and the metallogenic processes might have not been affected by magmatic activity. A thermodynamic calculation shows that the light hydrocarbons have reached chemical equilibrium at temperatures higher than 200?C, and they may have been generated in the deep part of sedimentary basins (e.g., the Sanzhou basin) and then be transported by ore-forming fluids to a shallow position of the basin via a long distance. Most of the organic gases are generated by pyrolysis of the type II kerogens (kukersite) in sedimentary host rocks, only a few by microorganism activity. The compositions and various parameters of light hydrocarbons in gold ores are quite similar to those in silver ores, suggesting that the gold and silver ores may have similar metallogenic processes. Based on the compositions of organic gases in fluid inclusions, the authors infer that the Changkeng deposit may be of a tectonic setting of continental rift. The results of this study support from one aspect the authors' opinion that the Changkeng deposit is not formed by meteoric water convection, and that its genesis has a close relationship with the evolution of the Sanzhou basin, so

  19. A Study on the Ore-forming Effect of Mantle-derived Fluid

    Institute of Scientific and Technical Information of China (English)

    Meng Qingqiang; Wu Jianfeng; Zhang Liuping

    2007-01-01

    Based on summarizing of the effect of mantle-derived fluid on the formation of ores, especially on gold ore,and with the latest investigations, such as the formation of ore from the action of shallow-deep fluid, the transportation effect of the thermal energy by mantle-derived fluid, this paper mainly aims at the effect of mantle-derived fluid on the generation of hydrocarbons. With the proof from geochemistry and fluid inclusion, it was suggested that the mantle-derived fluid not only supplied source materials for hydrocarbons, but also supplied essential energy and matter necessary for the generation of hydrocarbons. The mantle-derived fluid had a good effect, but at the same time it had an adverse effect under specific conditions, on the formation of reservoirs. This paper also discusses the future direction and significance of studying mantle-derived fluid.

  20. 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

  1. 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

  2. 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

  3. 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)

  4. Messinian Salinity Crisis and basin fluid flow

    Science.gov (United States)

    Bertoni, Claudia; Cartwight, Joe

    2014-05-01

    Syn- and post-depositional movement of fluids through sediments is one of the least understood aspects in the evolution of a basin. The conventional hydrostratigraphic view on marine sedimentary basins assumes that compactional and meteoric groundwater fluid circulation drives fluid movement and defines its timing. However, in the past few years, several examples of instantaneous and catastrophic release of fluids have been observed even through low-permeability sediments. A particularly complex case-study involves the presence of giant salt bodies in the depocentres of marine basins. Evaporites dramatically change the hydrostratigraphy and fluid-dynamics of the basin, and influence the P/T regimes, e.g. through changes in the geothermal gradient and in the compaction of underlying sediments. Our paper reviews the impact of the Messinian Salinity Crisis (MSC) and evaporites on fluid flow in the Mediterranean sub-basins. The analysis of geological and geophysical sub-surface data provides examples from this basin, and the comparison with analogues in other well-known evaporitic provinces. During the MSC, massive sea-level changes occurred in a relatively limited time interval, and affected the balance of fluid dynamics, e.g. with sudden release or unusual trapping of fluids. Fluid expulsion events are here analysed and classified in relation to the long and short-term effects of the MSC. Our main aim is to build a framework for the correct identification of the fluid flow-related events, and their genetic mechanisms. On basin margins, where evaporites are thin or absent, the sea-level changes associated with the MSC force a rapid basinward shift of the mixing zone of meteoric/gravity flow and saline/compactional flow, 100s-km away from its pre-MSC position. This phenomenon changes the geometry of converging flows, creates hydraulic traps for fluids, and triggers specific diagenetic reactions in pre-MSC deep marine sediments. In basin-centre settings, unloading and

  5. 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)

  6. Clay minerals in uraniferous deposit of Imouraren (Tim Mersoi basin, Niger): implications on genesis of deposit and on ore treatment process

    International Nuclear Information System (INIS)

    Nigerian uraniferous deposits are located in carboniferous and Jurassic formations of Tim Mersoi basin. AREVA is shareholder of 3 mine sites in this area: SOMAIR and COMINAK, both in exploitation since 1960's and IMOURAREN, 80 km further South, whose exploitation is planned for 2015. Mineralization of Imouraren deposit is included in the fluvial formation of Tchirezrine 2 (Jurassic), composed of channels and flood plains. Facies of channel in-fillings range from coarse sandstones to siltstones, while overflow facies are composed of analcimolites. Secondary mineralogy was acquired during 2 stages: 1- diagenesis, with formation of clay minerals, analcime, secondary quartz and albites, and 2- stage of fluids circulations, which induced alteration of detrital and diagenetic minerals, formation of new phases and uranium deposition. A mineralogical zoning, at the scale of deposit resulted from this alteration. The heterogeneity of Tchirezrine 2, at the level of both facies and mineralogy, is also evidenced during ore treatment, as ore reacts differently depending on its source, with sometimes problems of U recovery. Ore treatment tests showed that analcimes and chlorites were both penalizing minerals, because of 1- the sequestration of U-bearing minerals into analcimes, 2- their dissolution which trends to move away from U solubilization conditions (pH and Eh) and to form numerous sulfates, and 3- problems of percolation. A detection method of analcime-rich ores, based on infrared spectroscopy, was developed in order to optimize ore blending and so to reduce negative effects during ore treatment process. (author)

  7. Fluid-solid interaction model for hydraulic reciprocating O-ring seals

    Science.gov (United States)

    Liao, Chuanjun; Huang, Weifeng; Wang, Yuming; Suo, Shuangfu; Liu, Ying

    2013-01-01

    Elastohydrodynamic lubrication characteristics of hydraulic reciprocating seals have significant effects on sealing and tribology performances of hydraulic actuators, especially in high parameter hydraulic systems. Only elastic deformations of hydraulic reciprocating seals were discussed, and hydrodynamic effects were neglected in many studies. The physical process of the fluid-solid interaction effect did not be clearly presented in the existing fluid-solid interaction models for hydraulic reciprocating O-ring seals, and few of these models had been simultaneously validated through experiments. By exploring the physical process of the fluid-solid interaction effect of the hydraulic reciprocating O-ring seal, a numerical fluid-solid interaction model consisting of fluid lubrication, contact mechanics, asperity contact and elastic deformation analyses is constructed with an iterative procedure. With the SRV friction and wear tester, the experiments are performed to investigate the elastohydrodynamic lubrication characteristics of the O-ring seal. The regularity of the friction coefficient varying with the speed of reciprocating motion is obtained in the mixed lubrication condition. The experimental result is used to validate the fluid-solid interaction model. Based on the model, The elastohydrodynamic lubrication characteristics of the hydraulic reciprocating O-ring seal are presented respectively in the dry friction, mixed lubrication and full film lubrication conditions, including of the contact pressure, film thickness, friction coefficient, liquid film pressure and viscous shear stress in the sealing zone. The proposed numerical fluid-solid interaction model can be effectively used to analyze the operation characteristics of the hydraulic reciprocating O-ring seal, and can also be widely used to study other hydraulic reciprocating seals.

  8. Characteristics of the ore forming fluid from the zinc poly-metallic deposit in the Mopan mine area, Guangxi Nandan

    Institute of Scientific and Technical Information of China (English)

    Ou Zheng; Wei Chongtao; Luo Jun; Bao Yuan; Santigie Kekuda Sesay

    2012-01-01

    Fluid inclusions from samples from the layered and veined mineralized belt in the Mopan mine area were studied using microscopic temperature measurements and laser Raman spectroscopy.Further studies were conducted on the nature and source of the ore forming fluid and on the mechanism of deposit formation.The results show that there are three types of inclusions that occur in both the layered and veined ore body.These are liquid inclusions,CO2 inclusions with a liquid phase,and NaCl-H2O multiphase inclusions.The fluid inclusions in both the layered and veined ore bodies have similar characteristics.The ore forming fluid is strongly reducing,was exposed to low to medium temperatures,salinity,and pressures.The source of this ore forming fluid was a mix of submarine volcanic spring (blow-piping),magmatic hydrothermal jet,and underground water.

  9. Territorial pattern and classification of soils of Kryvyi Rih Iron-Ore Basin

    OpenAIRE

    О. О. Dolina; О. М. Smetana

    2014-01-01

    The authors developed the classification of soils and adapted it to the conditions of Krivyi Rih industrial region. It became the basis for determining the degree of soil cover transformation in the iron-ore basin under technogenesis. The classification represents the system of hierarchical objects of different taxonomic levels. It allows determination of relationships between objects and their properties. Researched patterns of soil cover structures’ distribution were the basis for the relev...

  10. 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

  11. Modeling Fluid Flow in Faulted Basins

    Directory of Open Access Journals (Sweden)

    Faille I.

    2014-07-01

    Full Text Available This paper presents a basin simulator designed to better take faults into account, either as conduits or as barriers to fluid flow. It computes hydrocarbon generation, fluid flow and heat transfer on the 4D (space and time geometry obtained by 3D volume restoration. Contrary to classical basin simulators, this calculator does not require a structured mesh based on vertical pillars nor a multi-block structure associated to the fault network. The mesh follows the sediments during the evolution of the basin. It deforms continuously with respect to time to account for sedimentation, erosion, compaction and kinematic displacements. The simulation domain is structured in layers, in order to handle properly the corresponding heterogeneities and to follow the sedimentation processes (thickening of the layers. In each layer, the mesh is unstructured: it may include several types of cells such as tetrahedra, hexahedra, pyramid, prism, etc. However, a mesh composed mainly of hexahedra is preferred as they are well suited to the layered structure of the basin. Faults are handled as internal boundaries across which the mesh is non-matching. Different models are proposed for fault behavior such as impervious fault, flow across fault or conductive fault. The calculator is based on a cell centered Finite Volume discretisation, which ensures conservation of physical quantities (mass of fluid, heat at a discrete level and which accounts properly for heterogeneities. The numerical scheme handles the non matching meshes and guaranties appropriate connection of cells across faults. Results on a synthetic basin demonstrate the capabilities of this new simulator.

  12. Modeling fluid flow in faulted basins

    International Nuclear Information System (INIS)

    This paper presents a basin simulator designed to better take faults into account, either as conduits or as barriers to fluid flow. It computes hydrocarbon generation, fluid flow and heat transfer on the 4D (space and time) geometry obtained by 3D volume restoration. Contrary to classical basin simulators, this calculator does not require a structured mesh based on vertical pillars nor a multi-block structure associated to the fault network. The mesh follows the sediments during the evolution of the basin. It deforms continuously with respect to time to account for sedimentation, erosion, compaction and kinematic displacements. The simulation domain is structured in layers, in order to handle properly the corresponding heterogeneities and to follow the sedimentation processes (thickening of the layers). In each layer, the mesh is unstructured: it may include several types of cells such as tetrahedra, hexahedra, pyramid, prism, etc. However, a mesh composed mainly of hexahedra is preferred as they are well suited to the layered structure of the basin. Faults are handled as internal boundaries across which the mesh is non-matching. Different models are proposed for fault behavior such as impervious fault, flow across fault or conductive fault. The calculator is based on a cell centered Finite Volume discretization, which ensures conservation of physical quantities (mass of fluid, heat) at a discrete level and which accounts properly for heterogeneities. The numerical scheme handles the non matching meshes and guaranties appropriate connection of cells across faults. Results on a synthetic basin demonstrate the capabilities of this new simulator. (authors)

  13. Geothermal fluid genesis in the Great Basin

    Energy Technology Data Exchange (ETDEWEB)

    Flynn, T.; Buchanan, P.K.

    1990-01-01

    Early theories concerning geothermal recharge in the Great Basin implied recharge was by recent precipitation. Physical, chemical, and isotopic differences between thermal and non-thermal fluids and global paleoclimatic indicators suggest that recharge occurred during the late Pleistocene. Polar region isotopic studies demonstrate that a depletion in stable light-isotopes of precipitation existed during the late Pleistocene due to the colder, wetter climate. Isotopic analysis of calcite veins and packrat midden megafossils confirm the depletion event occurred in the Great Basin. Isotopic analysis of non-thermal springs is utilized as a proxy for local recent precipitation. Contoured plots of deuterium concentrations from non-thermal and thermal water show a regional, systematic variation. Subtracting contoured plots of non-thermal water from plots of thermal water reveals that thermal waters on a regional scale are generally isotopically more depleted. Isolated areas where thermal water is more enriched than non-thermal water correspond to locations of pluvial Lakes Lahontan and Bonneville, suggesting isotopically enriched lake water contributed to fluid recharge. These anomalous waters also contain high concentrations of sodium chloride, boron, and other dissolved species suggestive of evaporative enrichment. Carbon-age date and isotopic data from Great Basin thermal waters correlate with the polar paleoclimate studies. Recharge occurred along range bounding faults. 151 refs., 62 figs., 15 tabs.

  14. Territorial pattern and classification of soils of Kryvyi Rih Iron-Ore Basin

    Directory of Open Access Journals (Sweden)

    О. О. Dolina

    2014-10-01

    Full Text Available The authors developed the classification of soils and adapted it to the conditions of Krivyi Rih industrial region. It became the basis for determining the degree of soil cover transformation in the iron-ore basin under technogenesis. The classification represents the system of hierarchical objects of different taxonomic levels. It allows determination of relationships between objects and their properties. Researched patterns of soil cover structures’ distribution were the basis for the relevant mapping and classification of soils. The classification is adapted to highly-influential industrial conditions of soils formation in the region. The adaptation measures were specific classification levels and units, which provided more detailed differentiation of soils. The authors proposed to separate the soils by the degree of soil formation potential realization for super-divisions. The potential determination allowed predicting the outcome of soil formation and identification of transformation degree of soil cover structures in the region. The results indicated that the main type of soil structures in the industrial region was represented by primitive soils (indicated as a separate type. These soils were determined as dynamic elements in the structure of industrial region soil cover. The article indicated that presence of soil cover structures with the domination of technogenic soils, particularly post-technogenic soils, was the marker of the soil cover in Krivyi Rih Iron-Ore Basin

  15. Sources of ore-forming fluids and metallic materials in the Jinwozi lode gold deposit, eastern Tianshan Mountains of China

    Institute of Scientific and Technical Information of China (English)

    LIU; Wei(刘伟); LI; Xinjun(李新俊); DENG; Jun(邓军)

    2003-01-01

    This paper presents gas compositions and H-, O-isotope compositions of sulfide- and quartz-hosted fluid inclusions, and S-, Pb-isotope compositions of sulfide separates collected from the principal Stage 2 ores in Veins 3 and 210 of the Jinwozi lode gold deposit, eastern Tianshan Mountains of China. Fluid inclusions trapped in quartz and sphalerite are dominantly primary. H- and O-isotopic compositions of pyrite-hosted fluid inclusions indicate two major contributions to the ore-forming fluid that include the degassed magma and the meteoric-derived but rock 18O-buffered groundwater. However, H- and O-isotopic compositions of quartz-hosted fluid inclusions essentially suggest the presence of groundwater. Sulfide-hosted fluid inclusions show considerably higher abundances of gaseous species CO2, N2, H2S, etc. Than quartz-hosted ones. The linear trends among inclusion gaseous species reflect the mixing tendency between the gas-rich magmatic fluid and the groundwater. The relative enrichment of gaseous species in sulfide-hosted fluid inclusions, coupled with the banded ore structure indicating alternate precipitation of quartz with sulfide minerals, suggests that the magmatic fluid has been inputted to the ore-forming fluid in pulsation. Sulfur and lead isotope compositions of pyrite and galena separates indicate an essential magma derivation for sulfur but the multiple sources for metallic materials from the mantle to the bulk crust.

  16. Cenozoic evolution of tectono-fluid and metallogenic process in Lanping Basin,western Yunnan Province, Southwest China: Constraints from apatite fission track data

    Institute of Scientific and Technical Information of China (English)

    LI Xiaoming; SONG Yougui

    2006-01-01

    Since the Mesozoic, abundant metal and salt deposits have been formed in the Lanping Basin, western Yunnan Province, Southwest China, constituting a well-known hydrothermal ore belt in China. Most of the deposits are meso-epithermal hydrothermal deposits. This paper preliminarily deals with the mineralization ages of hydrothermal deposits in the Lanping Basin by using the apatite fission track method, and integrates the spatial distribution of the deposits and their regional geological backgrounds, to give the preliminary viewpoints as follows: (1) the apatite fission track ages acquired range from 19.9 Ma to 52.8 Ma, much younger than those of their host strata, so they may be considered to be mineralization ages, which represent the late mineralization period; (2) the apatite fission track ages tend to become younger from the west to the middle of the basin, indicating that the latest evolution of tectono-fluid and/or metallogenic processes of the middle basin ended later than that in the west; (3) in the Paleogene, most of the Cu deposits were formed in the western part of the basin; (4) the major metallogenic processes occur between the Paleogene and the Neogene, because the eastern and western edges of the basin were subducted into and collided with its bilateral continental blocks, respectively, and the central fault was strongly activated, which led to the processes of large-scale ore-forming fluids, and their differentiation and transport because of the variation of their physical and chemical properties. Having been squeezed and uplifted, the Lanping Basin became an intermontane basin that contains many kinds of fluid traps resulting in the formation of different types of ore deposits (for example, Pb-Zn, Cu, Ag) of different scales in the middle of the basin. Simultaneously, the fluids with volatile elements such as Hg, Sb and As were transported upwards along the central fault system and diffused into its subordinate fractures, thus leading to the

  17. 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)

  18. Ore-forming fluid constraints on illite crystallinity (IC) at Dexing porphyry copper deposit, Jiangxi Province

    Institute of Scientific and Technical Information of China (English)

    2001-01-01

    Illite, a distinctive kind of clay minerals of potassiumalteration within the hydrothermal alteration zone, frequently occurs at the Tongchang porphyry copper deposit ore field. The illite crystallinity (IC) value and expandability are mainly affected by water/rock ratio or fluid flux. It was formed by illitization of plagioclase and micas during hydrothermal fluid-rock interaction within the porphyry body and near the contact zone with wall rocks. Moreover, the negative correlation between illite index (IC) and copper grade indicates that within the alteration zone, the smaller the illite crystallinity value, the higher the alteration degree, and the higher the copper grade due to higher water/rock ratio. At lower levels of the porphyry body, however, the illite crystallinity (IC) values are mainly controlled by temperature and time duration.

  19. Ore formation at the Kupol epithermal gold-silver deposit in northeastern Russia deduced from fluid inclusion study

    Science.gov (United States)

    Volkov, A. V.; Prokof'ev, V. Yu.; Savva, N. E.; Sidorov, A. A.; Bayankin, M. A.; Uyutnov, K. V.; Kolova, E. E.

    2012-07-01

    The Kupol epithermal gold-silver deposit-the largest of this type of mineralization in northeastern Russia-is situated in the outer zone of the Okhotsk-Chukotka volcanic belt. The results of thermobarogeochemical study of fluid inclusions in quartz from ore veins at the Kupol deposit are compared with the data on the Dvoinoi and Arykvaam deposits. The study of aqueous extracts from fluid inclusions revealed that the chemical compositions of ore-forming fluids at the Dvoinoi and Kupol deposits are similar in most elements. The only substantial difference is that fluids from the Kupol deposit are considerably enriched in sulfate, as is characteristic of the alunite-subtype of epithermal high-sulfidation mineralization. The salinity of aqueous solutions filling inclusions in amethyst and quartz from ore veins at the Kupol and Dvoinoi deposits is two-three times higher than the salinity of fluid inclusions from the barren veins at the Arykvaam occurrence. The data obtained support the hypothesis put forward earlier that fumaroles and solfataras played a part in ore deposition at the Kupol deposit.

  20. 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)

  1. Fluid inclusions and biomarkers in the Upper Mississippi Valley zinc-lead district; implications for the fluid-flow and thermal history of the Illinois Basin

    Science.gov (United States)

    Rowan, E. Lanier; Goldhaber, Martin B.

    1996-01-01

    The Upper Mississippi Valley zinc-lead district is hosted by Ordovician carbonate rocks at the northern margin of the Illinois Basin. Fluid inclusion temperature measurements on Early Permian sphalerite ore from the district are predominantly between 90?C and I50?C. These temperatures are greater than can be explained by their reconstructed burial depth, which was a maximum of approximately 1 km at the time of mineralization. In contrast to the temperatures of mineral formation derived from fluid inclusions, biomarker maturities in the Upper Mississippi Valley district give an estimate of total thermal exposure integrated over time. Temperatures from fluid inclusions trapped during ore genesis with biomarker maturities were combined to construct an estimate of the district's overall thermal history and, by inference, the late Paleozoic thermal and hydrologic history of the Illinois Basin. Circulation of groundwater through regional aquifers, given sufficient flow rates, can redistribute heat from deep in a sedimentary basin to its shallower margins. Evidence for regional-scale circulation of fluids is provided by paleomagnetic studies, regionally correlated zoned dolomite, fluid inclusions, and thermal maturity of organic matter. Evidence for igneous acti vity contemporaneous with mineralization in the vicinity of the Upper Mississippi Valley district is absent. Regional fluid and heat circulation is the most likely explanation for the elevated fluid inclusion temperatures (relative to maximum estimated burial depth) in the Upper Mississippi Valley district. One plausible driving mechanism and flow path for the ore-forming fluids is groundwater recharge in the late Paleozoic Appalachian-Ouachita mountain belt and northward flow through the Reelfoot rift and the proto- Illinois Basin to the Upper Mississippi Valley district. Warm fluid flowing laterally through Cambrian and Ordovician aquifers would then move vertically upward through the fractures that control

  2. Hydrothermal zebra dolomite in the Great Basin, Nevada--attributes and relation to Paleozoic stratigraphy, tectonics, and ore deposits

    Science.gov (United States)

    Diehl, S.F.; Hofstra, A.H.; Koenig, A.E.; Emsbo, P.; Christiansen, W.; Johnson, Chad

    2010-01-01

    In other parts of the world, previous workers have shown that sparry dolomite in carbonate rocks may be produced by the generation and movement of hot basinal brines in response to arid paleoclimates and tectonism, and that some of these brines served as the transport medium for metals fixed in Mississippi Valley-type (MVT) and sedimentary exhalative (Sedex) deposits of Zn, Pb, Ag, Au, or barite. Numerous occurrences of hydrothermal zebra dolomite (HZD), comprised of alternating layers of dark replacement and light void-filling sparry or saddle dolomite, are present in Paleozoic platform and slope carbonate rocks on the eastern side of the Great Basin physiographic province. Locally, it is associated with mineral deposits of barite, Ag-Pb-Zn, and Au. In this paper the spatial distribution of HZD occurrences, their stratigraphic position, morphological characteristics, textures and zoning, and chemical and stable isotopic compositions were determined to improve understanding of their age, origin, and relation to dolostone, ore deposits, and the tectonic evolution of the Great Basin. In northern and central Nevada, HZD is coeval and cogenetic with Late Devonian and Early Mississippian Sedex Au, Zn, and barite deposits and may be related to Late Ordovician Sedex barite deposits. In southern Nevada and southwest California, it is cogenetic with small MVT Ag-Pb-Zn deposits in rocks as young as Early Mississippian. Over Paleozoic time, the Great Basin was at equatorial paleolatitudes with episodes of arid paleoclimates. Several occurrences of HZD are crosscut by Mesozoic or Cenozoic intrusions, and some host younger pluton-related polymetallic replacement and Carlin-type gold deposits. The distribution of HZD in space (carbonate platform, margin, and slope) and stratigraphy (Late Neoproterozoic Ediacaran-Mississippian) roughly parallels that of dolostone and both are prevalent in Devonian strata. Stratabound HZD is best developed in Ediacaran and Cambrian units, whereas

  3. 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)

  4. Advanced Workflows for Fluid Transfer in Faulted Basins.

    OpenAIRE

    Thibaut Muriel; Jardin Anne; Faille Isabelle; Willien Françoise; Guichet Xavier

    2014-01-01

    The traditional 3D basin modeling workflow is made of the following steps: construction of present day basin architecture, reconstruction of the structural evolution through time, together with fluid flow simulation and heat transfers. In this case, the forward simulation is limited to basin architecture, mainly controlled by erosion, sedimentation and vertical compaction. The tectonic deformation is limited to vertical slip along faults. Fault properties are modeled as vertical shear zones a...

  5. Helium and argon isotope trace in ore-forming fluid of Sawuer gold belt in Xinjiang, China

    Institute of Scientific and Technical Information of China (English)

    SHEN Ping; SHEN Yuanchao; ZENG Qingdong; LIU Tiebing; LI Guangming

    2004-01-01

    The helium and argon isotope compositions of fluid inclusions hosted in pyrite have been measured from Kuoerzhenkuola and Buerkesidai gold deposits in Sawuer gold belt, northern Xinjiang. The results show that fluidinclusion 3He/4He ratios are 0.64 Ra-4.25 Ra and 1.16 Ra 9.48 Ra, 40Ar/36Ar ratios are 282-359 and 312-525 for Kuoerzhenkuola and Buerkesidai gold deposits respectively.The ore-forming fluids of two deposits possessed the same source and derived mainly from mantle beneath the island arc (including oceanic crust and oceanic sediments by subduction of oceanic plate). They were diluted by incorporating meteoric water to form a mixture of mantle- and partial meteoric water-derived fluid. The ore-forming fluids of two deposits are of the same evolutionary histories. From the early to the late mineralization stages, the ratios of meteoric water/mantle- derived fluid in ore-forming fluid increased gradually. Based on these results and detailed geological and geochemical studies on the two deposits, it is proposed that the geneses of the two gold deposits are the same, being volcanogenic late-stage hydrothermal gold deposits occurring in the same volcanic apparatus.

  6. Fluid inclusions of the Horní Slavkov Sn-W ore deposit, Bohemian Massif, Czech Republic: evidence for non-magmatic source of greisenizing fluids?

    Czech Academy of Sciences Publication Activity Database

    Dolníček, Z.; René, Miloš; Prochaska, W.

    2011-01-01

    Roč. 87, - (2011), s. 68-69. ISSN 1017-8880. [Ecrofi XXI. 09.08.2011-11.08.2011, Leoben] R&D Projects: GA ČR GA205/09/0540 Institutional research plan: CEZ:AV0Z30460519 Keywords : fluid inclusion * greisen * tin ore Subject RIV: DB - Geology ; Mineralogy

  7. 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)

  8. Advanced Workflows for Fluid Transfer in Faulted Basins

    Directory of Open Access Journals (Sweden)

    Thibaut Muriel

    2014-07-01

    Full Text Available The traditional 3D basin modeling workflow is made of the following steps: construction of present day basin architecture, reconstruction of the structural evolution through time, together with fluid flow simulation and heat transfers. In this case, the forward simulation is limited to basin architecture, mainly controlled by erosion, sedimentation and vertical compaction. The tectonic deformation is limited to vertical slip along faults. Fault properties are modeled as vertical shear zones along which rock permeability is adjusted to enhance fluid flow or prevent flow to escape. For basins having experienced a more complex tectonic history, this approach is over-simplified. It fails in understanding and representing fluid flow paths due to structural evolution of the basin. This impacts overpressure build-up, and petroleum resources location. Over the past years, a new 3D basin forward code has been developed in IFP Energies nouvelles that is based on a cell centered finite volume discretization which preserves mass on an unstructured grid and describes the various changes in geometry and topology of a basin through time. At the same time, 3D restoration tools based on geomechanical principles of strain minimization were made available that offer a structural scenario at a discrete number of deformation stages of the basin. In this paper, we present workflows integrating these different innovative tools on complex faulted basin architectures where complex means moderate lateral as well as vertical deformation coupled with dynamic fault property modeling. Two synthetic case studies inspired by real basins have been used to illustrate how to apply the workflow, where the difficulties in the workflows are, and what the added value is compared with previous basin modeling approaches.

  9. 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

  10. 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%

  11. Characteristics and evolution of ore-forming fluids of the Chongjiang copper deposit in the Gangdise porphyry copper belt, Tibet

    Institute of Scientific and Technical Information of China (English)

    Yuling Xie; Jiuhua Xu; Guangming Li; Zhiming Yang; Longsheng Yi

    2007-01-01

    Petrography, microthermometry, and scanning electron microscope/energy dispersive spectrometer (SEM/EDS) studies were performed on the fluid inclusions in the ore-bearing quartz veins and quartz phenocrysts in the porphyry of the Chongjiang porphyry copper deposit. The analyses of the fluid inclusions indicate that the ore-forming fluids were exsolved from magma. They are near-saturated, supercritical, rich in volatile constituents, and have the capture temperature of 362-389°C and salinities of 17.7wt%-18.9wt% NaCl eq. With the decreasing of temperature and pressure, the supercritical fluids were separated into a low salinity vapor phase and a high salinity liquid phase. During quartz-sericitization, the high salinity fluid boiled and separated into a low salinity vapor phase and a high salinity liquid phase. The high salinity inclusions that formed in the boiling process had daughter mineral melting temperatures higher than the homogenization temperatures of the vapor and liquid phases. The late fluids that are responsible for argillization are of lower temperature and salinity.

  12. Fluid mixing as the mechanism of formation of the Dajing Cu-Sn-Ag-Pb-Zn ore deposit, Inner Mongolia--Fluid inclusion and stable isotope evidence

    Institute of Scientific and Technical Information of China (English)

    LIU; Wei(刘伟); LI; Xinjun(李新俊); TAN; Jun(谭骏)

    2003-01-01

    Dajing Cu-Sn-Ag-Pb-Zn ore deposit, in the Inner Mongolia Autonomous Region of China, is a fissure-filling hydrothermal ore deposit. The δD values of quartz-hosted inclusion water are centered at -100‰ - -130‰. Theδ34S values of sulfide ore minerals andδ13C values of carbonate gangue minerals vary from -0.3‰ to 2.6‰ and from -2.9‰ to -7.0‰, respectively. Integrated isotopic data point to two major contributions to the mineralizing fluid that include a dominant meteoric-derived groundwater, and sulfur and carbon species from hypogene magma. Linear trends are exhibited on the gaseous H2O versus CO2 plot, and plots of CO, N2, CH4, and C2H6. It is shown by quantitative simulation that magma degassing cannot explain the linear trends. Hence, these linear trends are interpreted in terms of mixing of CO2-rich magmatic fluid with meteoric-derived groundwater. The groundwater circulated in Paleozoic sedimentary rocks and absorbed CO, N2, CH4, C2H6 and radiogenic Ar from organic matter. Cooling effects resulting from mixing have caused the precipitation of ore minerals.

  13. Sedimentary basin geochemistry and fluid/rock interactions workshop

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    1991-12-31

    Fundamental research related to organic geochemistry, fluid-rock interactions, and the processes by which fluids migrate through basins has long been a part of the U.S. Department of Energy Geosciences program. Objectives of this program were to emphasize those principles and processes which would be applicable to a wide range of problems associated with petroleum discovery, occurrence and extraction, waste disposal of all kinds, and environmental management. To gain a better understanding of the progress being made in understanding basinal fluids, their geochemistry and movement, and related research, and to enhance communication and interaction between principal investigators and DOE and other Federal program managers interested in this topic, this workshop was organized by the School of Geology and Geophysics and held in Norman, Oklahoma in November, 1991.

  14. 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)

  15. 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)

  16. Constraints on the composition of ore fluids and implications for mineralising events at the Cleo gold deposit, Eastern Goldfields Province, Western Australia

    International Nuclear Information System (INIS)

    The Cleo gold deposit, 55 km south of Laverton in the Eastern Goldfields Province of Western Australia, is characterised by banded iron-formation (BIF)-hosted ore zones in the gently dipping Sunrise Shear Zone and high-grade vein-hosted ore in the Western Lodes. There is evidence that gold mineralisation in the Western Lodes (which occurred at ca 2655 Ma) post-dates the majority of displacement along the Sunrise Shear Zone, but it remains uncertain if the ore in both structures formed simultaneously or separately. Overall, the Pb, Nd, Sr, C, O and S isotopic compositions of ore-related minerals from both the Western Lodes and ore zones in the Sunrise Shear Zone are similar. Early low-salinity aqueous-carbonic fluids and late high-salinity fluids with similar characteristics are trapped in inclusions in quartz veins from both the Sunrise Shear Zone and the Western Lodes. The early CO2, CO2-H2O, and H2O-dominant inclusions are interpreted as being related to ore formation, and to have formed from a single low-salinity aqueous-carbonic fluid as a result of intermittent fluid immiscibility. Homogenisation temperatures indicate that these inclusions were trapped at approximately 280 deg C and at approximately 4 km depth, in the deeper epizonal range. Differences between the ore zones are detected in the trace-element composition of gold samples, with gold from the Sunrise Shear Zone enriched in Ni, Pb, Sn, Te and Zn, and depleted in As, Bi, Cd, Cu and Sb, relative to gold from the Western Lodes Although there are differences in gold composition between the Sunrise Shear Zone and Western Lodes, and hence the metal content of ore fluids may have varied slightly between the different ore zones, no other systematic fluid or solute differences are detected between the ore zones. Given the fact that the ore fluids in each zone have very similar bulk properties, the considerable differences in gold grade, sulfide mineral abundance, and ore textures between the two ore zones

  17. Multi-stage Ag-Bi-Co-Ni-U and Cu-Bi vein mineralization at Wittichen, Schwarzwald, SW Germany: geological setting, ore mineralogy, and fluid evolution

    Science.gov (United States)

    Staude, Sebastian; Werner, Wolfgang; Mordhorst, Teresa; Wemmer, Klaus; Jacob, Dorrit E.; Markl, Gregor

    2012-03-01

    The Wittichen Co-Ag-Bi-U mining area (Schwarzwald ore district, SW Germany) hosts several unconformity-related vein-type mineralizations within Variscan leucogranite and Permian to Triassic redbeds. The multistage mineralization formed at the intersection of two fault systems in the last 250 Ma. A Permo-Triassic ore stage I with minor U-Bi-quartz-fluorite mineralization is followed by a Jurassic to Cretaceous ore stage II with the main Ag and Co mineralization consisting of several generations of gangue minerals that host the sub-stages of U-Bi, Bi-Ag, Ni-As-Bi and Co-As-Bi. Important ore minerals are native elements, Co and Ni arsenides, and pitchblende; sulphides are absent. The Miocene ore stage III comprises barite with the Cu-Bi sulfosalts emplectite, wittichenite and aikinite, and the sulphides anilite and djurleite besides native Bi, chalcopyrite, sphalerite, galena and tennantite. The mineral-forming fluid system changed from low salinity (<5 wt.% NaCl) at high temperature (around 300°C) in Permian to highly saline (around 25 wt.% NaCl + CaCl2) at lower temperatures (50-150°C) in Triassic to Cretaceous times. Thermodynamic calculations and comparison with similar mineralizations worldwide show that the Mesozoic ore-forming fluid was alkaline with redox conditions above the hematite-magnetite buffer. We suggest that the precipitation mechanism for native elements, pitchblende and arsenides is a decrease in pH during fluid mixing processes. REE patterns in fluorite and the occurrence of Bi in all stages suggest a granitic source of some ore-forming elements, whereas, e.g. Ag, Co and Ni probably have been leached from the redbeds. The greater importance of Cu and isotope data indicates that the Miocene ore stage III is more influenced by fluids from the overlying redbeds and limestones than the earlier mineralization stages.

  18. 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)

  19. 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)

  20. Origin and evolution of ore-forming fluids in the Hemushan magnetite-apatite deposit, Anhui Province, Eastern China, and their metallogenic significance

    Science.gov (United States)

    Luo, Gan; Zhang, Zhiyu; Du, Yangsong; Pang, Zhenshan; Zhang, Yanwen; Jiang, Yongwei

    2015-12-01

    The Middle-Lower Yangtze River Metallogenic Belt in the northern Yangtze Block is one of the most important economic mineral districts in China. The Hemushan deposit is a medium-class Fe deposit located in the southern part of the Ningwu iron ore district of the Middle-Lower Yangtze River Metallogenic Belt. The Fe-orebodies are mainly hosted in the contact zone between diorite and Triassic marble. The actinolite-phlogopite-apatite-magnetite ore shows metasomatic/filling textures and disseminated/mesh-vein structures. Based on evidences and petrographic observations, the ore-forming process can be divided into three distinct periods-the early metallogenic period (albite-diopside stage), the middle metallogenic period (magnetite stage and hematite stage), and the late metallogenic period (quartz-pyrite stage and carbonate stage). Fluid inclusion studies show four types of inclusions: type I daughter mineral-bearing three-phase inclusions (L + V + S), type II vapor-rich two-phase inclusions (L + V), type III liquid-rich two phase inclusions (L + V), and minor type IV liquid-phase inclusions (L). Apatites from the magnetite stage contain type I, type II and type III inclusions; anhydrites from the hematite stage mainly contain abundant type II inclusions and relatively less type I inclusions; quartz and calcite from the late metallogenic stage are mainly characterized by type III inclusions. Laser Raman spectroscopy and microthermometry of fluid inclusions show that the ore-forming fluids broadly correspond to unsaturated NaCl-H2O system. From the magnetite stage to the carbonate stage, the ore-forming fluids evolved from moderate-high temperature (average 414 °C), moderate salinity (average 25.01 wt.% NaCl equiv.) conditions to low temperature (average 168 °C), low salinity (average 6.18 wt.% NaCl equiv.) conditions. Hydrogen and oxygen isotopic studies indicate that the ore-forming fluid during the early stage of middle metallogenic period was mainly of magmatic

  1. 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)

  2. Ore Characteristics and Fluid Inclusion of the Base Metal Vein Deposit in Moncong Bincanai Area, Gowa, South Sulawesi, Indonesia

    Directory of Open Access Journals (Sweden)

    Asmariyadi Asmariyadi

    2014-07-01

    Full Text Available DOI: 10.17014/ijog.v7i4.146This paper is dealing with ore characteristics and fluid inclusion of the Moncong Bincanai, Biringbulu Subregency of Gowa Regency, South Sulawesi Province, Indonesia. The mineralization is a vein type, with the orientation of N170oE /65oSW, hosted in open-space filling within basalt. The mineralization consists of galena, sphalerite, chalcopyrite, and pyrite. Vein thickness ranges from 5 - 17 cm, showing a crustiform banding texture, with a sequence from outer to centre: quartz, carbonate (siderite, sulphide. The quartz displays primary growth textures such as comb, crystalline, saccharoidal, and colloform. Analytical methods applied include AAS and fluid inclusion microthermometry. Chemical composition of the vein indicates an average of Pb = 47.92%, Cu = 1.27%, Zn = 1.02%, and Fe = 9.46%, which shows a significant concentration of Pb. Fluid inclusion microthermometry results indicate a range of formation temperature of 240 - 250C and salinity of the responsible hydrothermal fluid of 2.1 - 2.5 wt.% NaCl eq. The deposit is categorized into low-sulfidation epithermal deposits, which was formed within a range of 410 - 440 m below paleosurface.

  3. D- 18O enriched waters of the Coast Range Mountains, northern California: Connate and ore-forming fluids

    Science.gov (United States)

    Peters, E. Kirsten

    1993-03-01

    D and 18O enriched waters of several weight percent salinity issue from hot and cold springs in Franciscan Complex and Great Valley Sequence rocks in the northern Coast Range Mountains of California. Although these waters have been described separately in the past and called "metamorphic," "connate," and "serpentinizing fluids," this study shows that the hot and cold springs are all fed by one source of water—trapped Cretaceous seawater modified by a variety of reactions. The district is an example of the complexities of subsurface waters and their importance for our understanding of metamorphic fluid sources, oil-field waters, and ore transport problems. The subsurface waters have a range of δ 34S values, including some near marine sulfate values (+20%.), and δ 13C near marine calcite values (0%.). Strontium isotopic signatures in the spring waters are derived from the Great Valley Sequence ( 87Sr /86Sr values near 0.705). The most saline spring pool is lined with serpentine phases found together as a fine white precipitate and has a pH of 11. One portion of the subsurface water is heated and reduced; it transports Au, Ag, Sb, As, and Hg to the surface (gold grades of the hot spring precipitates range from less than 1 ppm to over 10 ppm). These heated waters are chemically and isotopically similar to the fluids which formed Au mineralization at the nearby McLaughlin gold mine. The hot springs precipitate pyrite and native sulfur and are supersaturated with respect to calcite. Other springs are less saline and are oxidized, cooler, and diluted versions of the hot spring fluid. They do not carry ore metals but they are supersaturated with respect to silica and calcite. 3He /4He ratios of the springs gases are all above atmospheric values and indicate a possible magmatic component, consistent with the presence of Quaternary Clear Lake Volcanics. 129I data yield a minimum age of 60-80 Ma for the source of the iodide in the waters, consistent with the connate

  4. 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

  5. Positive feedback between strain localization and fluid flow at the ductile-brittle transition leading to Pb-Zn-Fe-Cu-Ag ore deposits in Lavrion (Greece)

    Science.gov (United States)

    Scheffer, Christophe; Tarantola, Alexandre; Vanderhaeghe, Olivier

    2016-04-01

    At the crustal scale, the ductile-brittle transition (DBT) might correspond to a physical barrier that separates a deep reservoir of metamorphic and magmatic fluids from a shallow reservoir of surficial fluids. Rock rheology, and thus the location of the DBT, is mainly governed by lithology, temperature and the presence/absence of fluids. Accordingly, the position of the DBT potentially evolves during orogenic evolution owing to thermal evolution and fluid circulation. In turn rocks are transferred across it during burial and exhumation. These processes induce connections between fluid reservoirs which might play a role on ore deposition. In this contribution, we discuss the impact of lithological heterogeneities on deformation, fluid flow and ore deposition based on the example of the Lavrion low-angle top-to-the-SSW detachment accommodating gravitational collapse of the Hellenides orogenic belt in Greece. The Lavrion peninsula, localized along the western boundary of the Attic-Cycladic Metamorphic Core Complex, is characterized by Pb-Zn-Fe-Cu-Ag ore mineralization mainly concentrated along a lithological contact (marble/schists) below and within a detachment shear zone. The mylonitic marble below the detachment shear zone is composed of white layers of pure marble alternating with blue layers containing impurities (SiO2, Al2O3, organic matter…). Development of the mylonitic fabric in competent impure blue marble is associated with its preferred dolomitization related to focused fluid infiltration. This mylonitic marble is cross-cut by several cataclastic horizons preferentially developed within the more competent impure blue marble and newly-crystallized dolomitic horizon. These cataclasites are invaded by fluorite and calcite gangue minerals showing locally Mn, Pb, Zn, Fe oxides and/or hydroxides, sphalerite, Ag-galena, Ag-sulfur and native Ag. Oxygen and carbon stable isotopes performed on marble sections point out decarbonation with magmatic contribution and

  6. Chemical and stable isotopic geochemical characteristics of ore-forming fluid of the Shizishan copper and gold ore-field, Tongling, China%铜陵狮子山铜金矿田成矿流体成分及稳定同位素地球化学

    Institute of Scientific and Technical Information of China (English)

    陆三明; 徐晓春; 谢巧勤; 楼金伟; 储国正; 熊亚平

    2007-01-01

    Shizishan ore-field is a nonferrous and noble metal ore-field which is most rich in copper and gold. There are many types of fluid inclusions in minerals of the deposits. The homogeneous temperatures and the salinities of the fluid inclusions in main mineralization stages have wide ranges, while the different types of the fluid inclusions existed together and their homogeneous temperatures are almost identical in the same mineralization stage, which indicates that the ore-forming process has great relation with the fluid boiling. The gas and liquid chemical compositions and the carbon, hydrogen and oxygen isotopic compositions of the fluid inclusions show that the ore-forming fluids of copper-gold deposits have the same characteristics and evolution tendency, which reflects that the ore-forming material mainly came from the magmatism. The stratigraphic component and the meteoric water may mix in oreforming fluids in the later mineralization stages. Furthermore, with the fall of the ore-forming temperature the ratios of water and rock decreased. The characteristics of chemical composition and carbon isotopic composition of fluid inclusions indicate that CH4 may play an important role for separating copper and gold in the ore-forming process.

  7. First Principles Simulations fo the Supercritical Behavior of Ore Forming Fluids

    Energy Technology Data Exchange (ETDEWEB)

    Weare, John H

    2013-04-19

    Abstract of Selected Research Progress: I. First-principles simulation of solvation structure and deprotonation reactions of ore forming metal ions in very nonideal solutions: Advances in algorithms and computational performance achieved in this grant period have allowed the atomic level dynamical simulation of complex nanoscale materials using interparticle forces calculated directly from an accurate density functional solution to the electronic Schrödinger equation (ab-initio molecular dynamics, AIMD). Focus of this program was on the prediction and analysis of the properties of environmentally important ions in aqueous solutions. AIMD methods have provided chemical interpretations of these very complex systems with an unprecedented level of accuracy and detail. The structure of the solvation region neighboring a highly charged metal ion (e.g., 3+) in an aqueous solution is very different from that of bulk water. The many-body behaviors (polarization, charge transfer, etc.) of the ion-water and water-water interactions in this region are difficult to capture with conventional empirical potentials. However, a large numbers of waters (up to 128 waters) are required to fully describe chemical events in the extended hydrations shells and long simulation times are needed to reliably sample the system. Taken together this makes simulation at the 1st principles level a very large computational problem. Our AIMD simulation results using these methods agree with the measured octahedral structure of the 1st solvation shell of Al3+ at the 1st shell boundary and a calculated radius of 1.937Å (exp. 1.9Å). Our calculated average 2nd shell radius agrees remarkably well with the measured radius, 4.093 Å calculated vs. the measured

  8. Geologic and geochemical features of the volatile-rich ore fluid and its tracing and dating in the Xuebaoding Beryl-Scheelite Vein Deposit,China

    Institute of Scientific and Technical Information of China (English)

    2002-01-01

    Laser Raman spectrochemical analysis on single inclusion reveals that multi-phase fluid inclusions exist in the Xuebaoding Beryl-Scheelite Vein Deposit.Besides the solid daughter mineral,there are vapor CO2,liquid CO2,water-deficient CO2 and salt water solution from its center to the border.A close study on the fluid inclusion components and carbon,oxygen,helium and argon isotope tracing and dating suggests that the volatile-rich ore fluid might derive from postmagmatic fluid and rare element enrichment is the result of the mixture of the plutonic alkali granite with crustal material.

  9. Geologic and geochemical features of the volatile-rich ore fluid and its tracing and dating in the Xuebaoding Beryl-Scheelite Vein Deposit, China

    Institute of Scientific and Technical Information of China (English)

    曹志敏; 任建国; 郑建斌; 徐仕进; 李佑国; 王汝成; T.SHOJ; H.KANEDA; S.KABAYASHI

    2002-01-01

    Laser Raman spectrochemical analysis on single inclusion reveals that multi-phase fluid inclusions exist in the Xuebaoding Beryl- Scheelite Vein Deposit. Besides the solid daughter mineral, there are vapor CO2, liquid CO2, water-deficient CO2 and salt water solution from its center to the border. A close study on the fluid inclusion components and carbon, oxygen, helium and argon isotope tracing and dating suggests that the volatile-rich ore fluid might derive from postmagmatic fluid and rare element enrichment is the result of the mixture of the plutonic alkali granite with crustal material.

  10. Laser ablation-ICP-AES for the determination of metals in fluid inclusions: An application to the study of magmatic ore fluids

    Science.gov (United States)

    Wilkinson, J. J.; Rankin, A. H.; Mulshaw, S. C.; Nolan, J.; Ramsey, M. H.

    1994-02-01

    The laser ablation-ICP-AES (L-ICP-AES) technique is an effective method for the multielement analysis of individual fluid inclusions. Recent tests on synthetic fluid inclusions and improvements in data processing suggest that the method is valid for the analysis of a range of alkali-, alkali-earth, and transition metals in single, large inclusions (> 30 μm) of moderate to high salinity (>20 wt% NaCl equiv.). The system, involving a small, perspex ablation chamber, a 1 J ruby laser focussed through an optical microscope, and a conventional ICP-AES instrument is discussed and applied to natural fluid inclusions in quartz from two contrasting types of magmatic-hydrothermal mineralization. Samples were selected from the San Pedro Cu-Au porphyry system, New Mexico, USA, and the Sn-W-Cu-mineralized Dartmoor granite of southwest England. Variable salinity, high temperature fluid inclusions in hydrothermal quartz from both environments display similarly high concentrations and ratios of Na, K, Ca, and Fe. The ore metals Cu, Zn, and Mn (but not Sn, Mo, W) were detected in inclusions from both environments. The estimated combined concentrations of up to 3 wt% show that these three elements are major components of these fluids. A method has been devised to estimate the confidence intervals of the measured concentration ratios. The confidence intervals obtained show that the analytical uncertainty for an inclusion is much less than the natural geochemical variation between inclusions so that geologically useful information can be obtained. A trend of increasing salinity with decreasing Na and K and increasing Ca and Fe contents is observed in inclusions from San Pedro, consistent with the continuous evolution of a magmatic aqueous phase exsolved from a low pressure melt during crystallization. In contrast, the combined compositional and microthermometric data for samples from Lee Moor, Dartmoor, suggest that a magmatic aqueous phase evolved from Fe-K-rich to Na

  11. Triassic fluid mobilization and epigenetic lead-zinc sulphide mineralization in the Transdanubian Shear Zone (Pannonian Basin, Hungary

    Directory of Open Access Journals (Sweden)

    Benkó Zsolt

    2014-06-01

    Full Text Available A combined fluid inclusion, fluid inclusion plane, lead isotope and K/Ar radiometric age dating work has been carried out on two lead-zinc mineralizations situated along the Periadriatic-Balaton Lineament in the central part of the Pannonian Basin, in order to reveal their age and genetics as well as temporal-spatial relationships to other lead-zincfluorite mineralization in the Alp-Carpathian region. According to fluid inclusion studies, the formation of the quartzfluorite- galena-sphalerite veins in the Velence Mts is the result of mixing of low (0-12 NaCl equiv. wt. % and high salinity (10-26 CaCl2 equiv. wt. % brines. Well-crystallized (R3-type illite associated with the mineralized hydrothermal veins indicates that the maximum temperature of the hydrothermal fluids could have been around 250 °C. K/Ar radiometric ages of illite, separated from the hydrothermal veins provided ages of 209-232 Ma, supporting the Mid- to Late-Triassic age of the hydrothermal fluid flow. Fluid inclusion plane studies have revealed that hydrothermal circulation was regional in the granite, but more intensive around the mineralized zones. Lead isotope signatures of hydrothermal veins in the Velence Mts (206Pb/204Pb = 18.278-18.363, 207Pb/204Pb = 15.622-15.690 and 208Pb/204Pb = 38.439-38.587 and in Szabadbattyán (206Pb/204Pb = 18.286-18.348, 207Pb/204Pb = 15.667-15.736 and 208Pb/204Pb = 38.552-38.781 form a tight cluster indicating similar, upper crustal source of the lead in the two mineralizations. The nature of mineralizing fluids, age of the fluid flow, as well as lead isotopic signatures of ore minerals point towards a genetic link between epigenetic carbonate-hosted stratiform-stratabound Alpine-type lead-zinc-fluorite deposits in the Southern and Eastern Alps and the studied deposits in the Velence Mts and at Szabadbattyán. In spite of the differences in host rocks and the depth of the ore precipitation, it is suggested that the studied deposits along the

  12. 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)

  13. A simulating experiment on the geochemical variation trend at the initial period of meteoric waters converting to underground waters and ore fluids

    Institute of Scientific and Technical Information of China (English)

    ZHU Xiaoqing; HUANG Yan; ZHANG Qian; HE Yuliang; ZHU Chaohui

    2005-01-01

    Experimental studies were undertaken on leaching of sedimentary rocks (dolomite and sandstone) and Hg, Sb ores by distilled water under the condition of a completely open system (room temperature and room pressure). The aim is to find whether the halogen elements or metal elements first enter the solution at the early stage of meteoric waters converting to groundwaters and ore fluids, and, at the same time, to understand how and when they enter distilled water solutions from the rocks. The experimental results have shown that F and Cl began to enter the fluids in the initial period of thirty days. With increasing leaching duration, the amounts of the elements that entered the fluids increased steadily. During the period from 120 days to 150 days the amounts increased more drastically, followed a slow increase. It is found that the capability of Cl entering the solutions is much greater than that of F. Hg and Sb were found not to have entered the solutions till 120 days later. During this period of time the pH value of the solutions began to drop. As for Hg and Sb ores, Hg and Sb began to enter the solutions on the 60th or 90th day, greatly ahead of schedule, but the two metallic elements in the rock samples began to enter the solutions 150 days later. Relatively speaking, Hg is more easily leached out than Sb from the rocks. In some rock samples, Sb could be detected in the solutions at the end of the experiment. However, Cu, Pb and Zn had not been detected in the leaching solutions from the beginning to the end of the experiment. In the whole leaching process the pH value of the solutions tend to decrease slowly from 7.1 at the beginning to 6.5 at the end. That is to say, in the interaction between pure water and rock the halogen elements in the rocks were preferentially leached out and then entered the fluids. With increasing water/rock reaction duration and amount of halogen-group elements in the solution and with decreasing pH value of the solution, some active

  14. Geological, fluid inclusion and isotopic studies of the Yinshan Cu-Au-Pb-Zn-Ag deposit, South China: Implications for ore genesis and exploration

    Science.gov (United States)

    Wang, Guo-Guang; Ni, Pei; Wang, Ru-Cheng; Zhao, Kui-Dong; Chen, Hui; Ding, Jun-Ying; Zhao, Chao; Cai, Yi-Tao

    2013-09-01

    The Yinshan Cu-Au-Pb-Zn-Ag deposit is located in Dexing, South China. Ore bodies are primarily hosted in low-grade phyllite of the Neoproterozoic Shuangqiaoshan Group along EW- and NNW-striking fault zones. Pb-Zn-Ag mineralization is dictated by Jurassic rhyolitic quartz porphyries (ca. 172 Ma), whereas Cu-Au mineralization is associated with Jurassic dacite porphyries (ca. 170 Ma). The main ore minerals are pyrite, chalcopyrite, galena, sphalerite, tetrahedrite-tennatite, gold, silver, and silver sulphosalt, and the principal gangue minerals are quartz, sericite, calcite, and chlorite. Two-phase liquid-rich (type I), two-phase vapor-rich (type II), and halite-bearing (type III) fluid inclusions can be observed in the hydrothermal quartz-sulfides veins. Type I inclusions are widespread and have homogenization temperatures of 187-303 °C and salinities of 4.2-9.5 wt.% NaCl equivalent in the Pb-Zn-Ag mineralization, and homogenization temperatures of 196-362 °C and salinities of 3.5-9.9 wt.% NaCl equivalent in the Cu-Au mineralization. The pervasive occurrence of type I fluid inclusions with low-moderate temperatures and salinities implies that the mineralizing fluids formed in epithermal environments. The type II and coexisting type III inclusions, from deeper levels below the Cu-Au ore bodies, share similar homogenization temperatures of 317-448 °C and contrasting salinities of 0.2-4.2 and 30.9-36.8 wt.% NaCl equivalent, respectively, which indicates that boiling processes occurred. The sulfur isotopic compositions of sulfides (δ34S = -1.7‰ to +3.2‰) suggest a homogeneous magmatic sulfur source. The lead isotopes of sulfides (206Pb/204Pb = 18.01-18.07; 207Pb/204Pb = 15.55-15.57; and 208Pb/204Pb = 38.03-38.12) are consistent with those of volcanic-subvolcanic rocks (206Pb/204Pb = 18.03-18.10; 207Pb/204Pb = 15.56-15.57; and 208Pb/204Pb = 38.02-38.21), indicating a magmatic origin for lead in the ore. The oxygen and hydrogen isotope compositions (δ18O = +7.8

  15. Radioelemental equilibrium-disequilibrium and trace elemental studies of quartz pebble conglomerates from the western margin of Koira-Noamundi iron ore basin, Orissa, India

    International Nuclear Information System (INIS)

    The Late Achaean-Early Proterozoic fluvial pyritiferous gold and uranium bearing quartz pebble conglomerate (QPC) deposited over cratonised granite-greenstone basement is well known across the globe. The QPC represents the earliest sediments (>2200 Ma age) developed largely under an anoxic atmospheric condition. In eastern India, uraniferous QPC bearing occurrences at the base of Iron Ore Group (IOG) basins and Dhanjori Basin are situated in Orissa and Jharkhand states. They occur as peri-cratonic basins around Singhbhum Granitic batholiths, viz. Badampahar-Garumahisani basin, to the east of Singhbhum Granite, Daitari basin, to the south and Koira basin, located east of Bonai granite (Singhbhum Granite equivalent). This paper discusses the nature of radioactive QPC occurrences at Taladih, Sarlanga, and Soyamba areas situated along the western margin of Koira Basin in terms of their physical characteristics, radioelemental distribution and their disequilibrium behaviour vis-à-vis the trace elemental distribution. Strong correlation of thorium with Y, La, Zr etc. suggests its association in the resitate detrital mineral phases in the QPC matrix

  16. Evaluation of the Cerro Solo nuclear ore, province of Chubut. Geological characteristics of the deposit and of the basin. Pt. 2

    International Nuclear Information System (INIS)

    The Cerro Solo uranium ore deposit, is located 420 km west from Trelew city, Chubut province, in the extra-andean. The geologic environment belongs to the northwest edge portion of the intracratonic San Jorge Gulf Basin. The uraniferous district is named Pichinanes Ridge district. The mineralization lies 25 to 130 m depth, and is hosted by Los Adobes formation aged Aptian-Albian, made up by conglomerates, sandstones, coarse-sandstones and less abundant siltstones and claystones. The Cerro Solo ore deposit that belongs to the sandstone type-uranium occurrences are lenticular or tabular shaped, associated with organic material and pyrite, generally roughly parallel to the bedding (Trend-Type). The uranium minerals are uraninite and coffinite associated with organic material and pyrite, and frequently hematite, goethite, calcite, siderite and barite are observed. (Author)

  17. Regional Fluid Flow and Basin Modeling in Northern Alaska

    Science.gov (United States)

    Kelley, Karen D., (Edited By)

    2007-01-01

    INTRODUCTION The foothills of the Brooks Range contain an enormous accumulation of zinc (Zn) in the form of zinc sulfide and barium (Ba) in the form of barite in Carboniferous shale, chert, and mudstone. Most of the resources and reserves of Zn occur in the Red Dog deposit and others in the Red Dog district; these resources and reserves surpass those of most deposits worldwide in terms of size and grade. In addition to zinc and lead sulfides (which contain silver, Ag) and barite, correlative strata host phosphate deposits. Furthermore, prolific hydrocarbon source rocks of Carboniferous and Triassic to Early Jurassic age generated considerable amounts of petroleum that may have contributed to the world-class petroleum resources of the North Slope. Deposits of Zn-Pb-Ag or barite as large as those in the Brooks Range are very rare on a global basis and, accordingly, multiple coincident favorable factors must be invoked to explain their origins. To improve our understanding of these factors and to contribute to more effective assessments of resources in sedimentary basins of northern Alaska and throughout the world, the Mineral Resources Program and the Energy Resources Program of the U.S. Geological Survey (USGS) initiated a project that was aimed at understanding the petroleum maturation and mineralization history of parts of the Brooks Range that were previously poorly characterized. The project, titled ?Regional Fluid Flow and Basin Modeling in Northern Alaska,? was undertaken in collaboration with industry, academia, and other government agencies. This Circular contains papers that describe the results of the recently completed project. The studies that are highlighted in these papers have led to a better understanding of the following: *The complex sedimentary facies relationships and depositional settings and the geochemistry of the sedimentary rocks that host the deposits (sections 2 and 3). *The factors responsible for formation of the barite and zinc deposits

  18. Source of ore-forming fluids of the Tianbaoshan Pb-Zn deposit, Southwest China: constrains from C-O, S, and He-Ar isotopes

    Science.gov (United States)

    Wang, Jian; Zhang, Jun; Zhong, Wenbin

    2016-04-01

    The Sichuan-Yunnan-Guizhou (SYG) metallogenic province is one of the most important areas for Pb-Zn resources in China. The metallogenic sources of these Pb-Zn deposits have long been debated. In this study, we provide integrated C-O-S-He-Ar isotopic data of the typical Tianbaoshan Pb-Zn deposit, with an aim to constrain the sources of ore-forming fluids. The Tianbaoshan deposit a large-sized Pb-Zn deposit in SYG metallogenic province, Southwest China. The proven resources include 2.6 Mt metals of Zn+Pb with average grades of 10.09% Zn and 1.50% Pb. The orebodies are hosted within the carbonates of the Ediacaran Dengying Formation. Ore minerals consist mainly of sphalerite, galena, chalcopyrite, and pyrite. Gangue minerals are dominated by calcite and dolomite. The calcite samples from the Tianbaoshan deposit yield homogeneous δ13CV ‑PDBvalues of -1.70‰ to -1.60‰ (average -1.63), with δ18OV ‑SMOW values ranging from 12.9‰ to 15.2‰ (average 14.4). The C-O isotopic data suggest the hydrothermal fluids may be originated from a mixed source involving both mantle and carbonate wall rocks. The δ34S values of the sphalerite, galena and chalcopyrite samples vary from 3.32‰ to 5.71‰ -0.36‰ to 1.31‰ and 4.5‰ to 4.7‰ respectively, indicating a magmatic source for sulfur. The 3He/4He ratios of chalcopyrite samples range from 0.01 to 0.32 Ra which is slightly higher than the crustal ratios (0.05 Ra), but obviously lower than that of mantle fluids (6 to 9 Ra). The 40Ar/36Ar ratios range from 345.0 to 669.1, which are slightly higher than that of air (298.5). The He-Ar isotopic compositions suggest that the ore-forming fluids are dominantly derived from the crust, with litter contamination from mantle-derived fluids. In combination with the C-O, S, and He-Ar isotopic data, we propose the ore-forming fluids of the Tianbaoshan deposit were derived by mixing of crustal and mantle fluids. And the metallogenic process may be genetically related to the

  19. The connection between iron ore formations and "mud-shrimp" colonizations around sunken wood debris and hydrothermal sediments in a Lower Cretaceous continental rift basin, Mecsek Mts., Hungary

    Science.gov (United States)

    Jáger, Viktor; Molnár, Ferenc; Buchs, David; Koděra, Peter

    2012-09-01

    300 m (above sea level); from these volcanoes further terrestrial plant debris got into the basin. Hydrothermal vents, which periodically occurred around basaltic bodies until the Hauterivian, could have contributed to the creation of favourable temperature or nutritional conditions for some decapoda crustaceans - e.g the recently described new callianassid (Nihonotrypaea thermophila), which is known only from hydrothermally infuenced habitats. Around the intrusive pillow basalts, hydrothermal circulation of oxygenated seawater occured and thick seladonitic and goethitic fills formed along the cracks and cavities of pillowed basalts. When oxidized, sulfate-rich fluids passed into the crustacean coprolite-rich, reductive and anaerobic interpillow sediments, these fluids underwent an intensive sulfate reduction. This was primarily due to termophil sulfate reducers which as proved by the negative sulfur isotope values (- 35.9‰ and - 28.0‰ δ 34S) of sulfidic hydrothermal chimneys which contain framboidal pyrite and which were formed between the pillow basalts. The largest chimney structure reached a height of 1 m, with a mass of about 150 kg. The sulfide phase is characterized by Mo enrichments up to 511 ppm. The fluid inclusion measurements from the calcitic precipitations of the sulfide chimneys indicate low temperature (~ 129 °C) hydrothermal activity, and the salinity of the primary fluid inclusions proves the seawater origin of the hydrothermal fluids. In some thalassinid crustacean coprolite rich interpillow sediments and in the cracks of some hydrothermal calcite, there is the presence of black, lustrous bitumine (gilsonite) which is the distillation product of hydrothermal petroleum formed mainly by the coprolites. Hydrothermal circulations of oxygenated seawater caused subsequent oxidation of the sulfidic, interpillow sediments and chimneys; these were altered to form goethite. Due to the short-period of the hydrothermal activity among the intrusive

  20. 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

  1. Thermicity and fluid flow related to the evolution of the South Pyrenean Foreland Basin (SPFB)

    Science.gov (United States)

    Crognier, Nemo; Hoareau, Guilhem; Lacroix, Brice; Aubourg, Charles; Dubois, Michel; Lahfid, Abdeltif; Labaume, Pierre; Suarez-Ruiz, Isabel

    2015-04-01

    The East-West trending South Pyrenean Foreland Basin (SPFB), formed during the upper Cretaceous and the early Miocene due to the collision between Iberian and European plates, is filled by marine to continental deposits affected by a set of successive southvergent thrusts. In the western part of the SPFB (Jaca basin, Spain), from the North to the South the basin is subdivided into four parts: the internal Sierras, the turbiditic basin, the molassic basin and the external Sierras. In order to better constrain the fluid flow dynamic and the thermal regime of the basin during its tectonic evolution, we propose to estimate the temperatures and the O and C isotopic signatures of fluids, as well as the maximum temperatures recorded by pre- to syn-tectonic sediments of the Jaca basin. The C and O isotopic composition has been measured on ~100 veins and host sediment samples. The peak temperatures have also been estimated on 80 bulk rocks and calcite/quartz veins using a combination of several techniques, including Raman Spectroscopy of Carbonaceous Material, vitrinite reflectance, fluid inclusion microthermometry and mass-47 clumped isotopes. We show that in most tectonic fractures, primary fluid inclusions are characterized by moderate salinities (~2.5 wt%) compatible with connate or evolved meteoric waters, with increasing meteoric signature in the south of the basin. As suggested by temperature determinations and stable isotopes, involved fluids were generally in thermal and isotopic equilibrium with the host sediments, suggesting a low fluid-rock ratio (i.e., no significant fluid flow). These results support previous speculations of moderate fluid-flow through thrust faults and the hydrological compartmentalization of the Jaca basin during deformation (Lacroix et al., 2014). In addition we demonstrate that measured peak temperatures rapidly decrease southward, from ~240°C±30°C in Cretaceous to Eocene sediments located in the North of the basin close to the axial

  2. Lead isotope study of Zn-Pb ore deposits associated with the Basque-Cantabrian basin and Paleozoic basement, Northern Spain

    Science.gov (United States)

    Velasco, F.; Pesquera, A.; Herrero, J. M.

    1996-01-01

    A total of forty-three galena samples from syngenetic and epigenetic Pb-Zn mineralizations emplaced in the Lower Cretaceous Basque-Cantabrian basin and Paleozoic basement of the Cinco Villas massif in the western Pyrenees, have been analyzed for Pb-isotopic composition. Galena from sedex mineralizations hosted in Carboniferous clastic rocks in the Cinco Villas massif display an homogeneous lead isotopic signature (206Pb/2044Pb ≈ 18.43, 207Pb/204Pb ≈ 15.66, 208Pb/ 204Pb ≈ 38.69) suggesting a single lead reservoir. These values are slightly more radiogenic than lead from other European Hercynian deposits, possibly reflecting the influence of a more evolved upper crustal source. Underlying Paleozoic sediments are proposed as lead source for the Cinco Villas massif ores. Analyses from twenty-six galena samples from the four strata-bound ore districts hosted in Mesozoic rocks reveal the existence of two populations regarding their lead isotopic composition. Galena from the western Santander districts (e.g., Reocin) is characterized by more radiogenic isotope values (206Pb/204Pb ≈ 18.74, 207Pb/204Pb ≈ 15.67, 208Pb/ 204Pb ≈ 38.73) than those from the central and eastern districts (Troya-Legorreta, Central and Western Vizcaya, 206Pb/204Pb ≈ 18.59, 207Pb/204Pb ≈ 15.66, 208Pb/ 204Pb ≈ 38.73). In all districts, the most likely source for these mineralizations was the thick sequence of Lower Cretaceous clastic sediments. The existence of two separate lead isotopic populations could be the result of regional difference in the composition of the basement rocks and the clastic sediments derived of it or different evolution histories. In both sub-basins, isotopic ratios indicate an increase in crustal influence as the age of the ores decreases.

  3. 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

  4. Lateral fluid flow in a compacting sand-shale sequence: South Caspian basin.

    Science.gov (United States)

    Bredehoeft, J.D.; Djevanshir, R.D.; Belitz, K.R.

    1988-01-01

    The South Caspian basin contains both sands and shales that have pore-fluid pressures substantially in excess of hydrostatic fluid pressure. Pore-pressure data from the South Caspian basin demonstrate that large differences in excess hydraulic head exist between sand and shale. The data indicate that sands are acting as drains for overlying and underlying compacting shales and that fluid flows laterally through the sand on a regional scale from the basin interior northward to points of discharge. The major driving force for the fluid movement is shale compaction. We present a first- order mathematical analysis in an effort to test if the permeability of the sands required to support a regional flow system is reasonable. The results of the analysis suggest regional sand permeabilities ranging from 1 to 30 md; a range that seems reasonable. This result supports the thesis that lateral fluid flow is occurring on a regional scale within the South Caspian basin. If vertical conduits for flow exist within the basin, they are sufficiently impermeable and do not provide a major outlet for the regional flow system. The lateral fluid flow within the sands implies that the stratigraphic sequence is divided into horizontal units that are hydraulically isolated from one another, a conclusion that has important implications for oil and gas migration.-Authors

  5. Genesis of the zinc-lead-barite deposits in the northern Iraq: ore mineralogy, geochemistry, fluid inclusions, lead isotopes and sulfur isotopes implications

    International Nuclear Information System (INIS)

    Zinc - leaed - barite deposits hosted by carbonate rocks are studied mineralogically, geochemically and genetically. These deposits (Lefan, lower Banik, Menin and Upper Banik) locate at the Nortgeren Thrust Zone, Northern Iraq. They consistt of sulfides as sphalerite, galena and pyrite, and sulfates as barite. Fluid inclusions observed in barite contain heavy oil associated with aqueous chloride-rich fluids (13% -15.5% wt equv. NaC1). The temperature of formation of barite is suggested to be 50-60 degree. The sulfur isotope composition (δ34S) of early generated galena is 0.36 per mil. This value is close to the hydrothermal magmatic sulfur origin. The δ34S of late generated galena is 6.41 per mil. This value indicates that the hydrothermal magmatic fluids were partially mixeed with oilfield brine connate waters. The δ34S of barite ranges from 16.64 to 24.23 per mil. These values indicate high isotopeic fractionation that caused by descending meteoric waters which diluted the ascending ore-bearing fluids. The lead isotope compostion (204pb, 206pb, 207pb and 208pb) of galeana has revealed that lead was derived from the crust reservoir. Ore metals (Zn, Pb, Fe, and Ba) may have been originated from oilfield brine waters that may have partially been mixed with the hydrothermal fluids of magmatic origin that supplied sulfur. These fluides have migrated upward as chloride and sulfide complexes along fractures and faults possibly after crustal extension and rifting during Alpine orogeny in the Paleocene. Zinc - lead - barite deposits could be classified as epithermal, eigenetic strata-bound of Mississippi Vally type (MVT) deposits, lithologically and structurally controlled within Cretaceous carbonates. (authors).

  6. Percolation of diagenetic fluids in the Archaean basement of the Franceville basin

    Science.gov (United States)

    Mouélé, Idalina Moubiya; Dudoignon, Patrick; Albani, Abderrazak El; Cuney, Michel; Boiron, Marie-Christine; Gauthier-Lafaye, François

    2014-01-01

    The Palaeoproterozoic Franceville basin, Gabon, is mainly known for its high-grade uranium deposits, which are the only ones known to act as natural nuclear fission reactors. Previous work in the Kiéné region investigated the nature of the fluids responsible for these natural nuclear reactors. The present work focuses on the top of the Archaean granitic basement, specifically, to identify and date the successive alteration events that affected this basement just below the unconformity separating it from the Palaeoproterozoic basin. Core from four drill holes crosscutting the basin-basement unconformity have been studied. Dating is based on U-Pb isotopic analyses performed on monazite. The origin of fluids is discussed from the study of fluid inclusion planes (FIP) in quartz from basement granitoids. From the deepest part of the drill holes to the unconformable boundary with the basin, propylitic alteration assemblages are progressively replaced by illite and locally by a phengite + Fe chlorite ± Fe oxide assemblage. Illitic alteration is particularly strong along the sediment-granitoid contact and is associated with quartz dissolution. It was followed by calcite and anhydrite precipitation as fracture fillings. U-Pb isotopic dating outlines three successive events: a 3.0-2.9-Ga primary magmatic event, a 2.6-Ga propylitic alteration and a late 1.9-Ga diagenetic event. Fluid inclusion microthermometry suggests the circulation of three types of fluids: (1) a Na-Ca-rich diagenetic brine, (2) a moderately saline (diagenetic + meteoric) fluid, and (3) a low-salinity fluid of probable meteoric origin. These fluids are similar to those previously identified within the overlying sedimentary rocks of the Franceville basin. Overall, the data collected in this study show that the Proterozoic-Archaean unconformity has operated as a major flow corridor for fluids circulation, around 1.9 Ga. highly saline diagenetic brines; hydrocarbon-rich fluids derived from organic matter

  7. Application of Fluid Inclusions in the Study of Natural Gas Geology in Ordos Basin

    Institute of Scientific and Technical Information of China (English)

    FAN Ai-ping; YANG Ren-chao; FENG Qiao; LIU Yi-qun; HAN Zuo-zhen

    2006-01-01

    The new recently demonstrated reserves of oil and gas in the Ordos basin are found at the top of petroliferous basins in China. Gas pools discovered in recent years in the Permian system have become the main natural gas resource in the basin. Therefore, synthetic research on fluid inclusions should be done in order to ascertain the pool-forming stage, the maturity of organic matters and the properties of Paleo-fluids. The main types of fluid inclusions in the Permian system in the basin include brine inclusions, carbon dioxide inclusions and organic inclusions. Homogenization temperatures (HT) of brine inclusions can be divided into four intervals: 66-83 ℃, 86-108 ℃, 112-138 ℃ and 142-153 ℃. The fluid inclusions in the interval of 112-138 ℃ are much more than that of other intervals, indicating that the second stage of hydrocarbon migration associated with the third temperature interval is the most important stage of gas pool formations. The fluid inclusion has extensive applications in the study of gas geology, not only in ascertaining the formation stage of gas pools, but also in estimating the maturity of organic matter and restoring Paleo-fluids. The result of testing the HT of brine inclusions shows that there are two stages of gas pool formations in the Permian system occurring ±150 Ma and ±100 Ma. The maturity of organic matter is moderate to high, a conclusion based on the color of fluid inclusions (radiated by fluorescence). The high salinity of Paleo-fluids of the NaCl-H2O and CaCl2-H2O systems shows good preservation conditions of the Paleo-fluids. Two stages of reservoir filling, high maturity of organic matter and good preservation conditions are factors favorable for the formation and preservation of large-scale gas pools in the Permian system in the Ordos basin.

  8. Effects of Overpressured Fluid Flow on Petroleum Accumulation in the Yinggehai Basin

    Institute of Scientific and Technical Information of China (English)

    HAO Fang; DONG Weiliang; ZOU Huayao; JIANG Jianqun

    2004-01-01

    The Yinggehai Basin is a strongly overpressured Cenozoic basin developed in the northern continental sheff of the South China Sea. The flow of overpressured fluids in this basin has given rise to strong effects on petroleum accumulation. (1) The overpressured fluid flow has enhanced the maturation of shallow-buried source rocks, which has caused the source rocks that would have remained immature under the conduction background to be mature for hydrocarbon generation. As a result, the overpressured fluid flow has increased the volume and interval of mature source rocks. (2) The overpressured fluid flow has strong extraction effects on the immature or low-mature source rocks in the shallow parts. This has increased, to some extent, the expulsion efficiency of the source rocks. More importantly, the extraction effects have strongly limited the effectiveness of biomarker parameters from oil and condensate in reflecting the source and maturity of the oil and gas. (3) The flow has caused the sandstones in the shallow parts to get into the late diagenesis stage, and significantly reduced the porosity and penneability of the sandstones. This study confirms that even in sedimentary basins in which no topography-driven groundwater flow systems have ever developed, the cross-formation migration of overpressured fluids and the resultant energy conduction and material exchange can significantly affect the thermal regime, source rock maturation and sandstone diagenesis. As a result, the effects of overpressured fluid flow must be taken into account in analyzing the mechanism of petroleum accumulation.

  9. The Vein-type Zn-(Pb, Cu, As, Hg) mineralization at Fedj Hassene ore field, North-Western Tunisia: Mineralogy, Trace Elements, Sulfur Isotopes and Fluid Inclusions

    International Nuclear Information System (INIS)

    The Fedj Hassene district is localized at the edge of the Tuniso-Algerian border 10 km of Ghardimaou area. It consists of a Zn-Pb vein type with minor amounts of Cu-As-Hg. The total Zn reserves are about 370.000t. The mineralization occurs within sub parallel fractures to the Ain El Kohla ESE-WNW fault. Host rocks consist of limestones and marly limestones of the Middle Turonian. In the principal lode of Fedj Hassene, the mineralization occurs as vein filling of massive and brecciated brown sphalerite and minor galena ore with gangue. Other trace minerals are pyrite, chalcopyrite, orpiment, realgar, smithsonite and cerussite. LA-ICP-MS analyses in sphalerites show mean contents of 0,84 wt% Fe, 0,14 wt% Cd and 0,02 wt% Mn Ore. Fluid inclusions study in calcite and sphalerite reveals one mineralizing fluid characterized by an average salinity 23% wt NaCl with decreasing homogenisation temperature. In fact the temperature shows decrease from sphalerite to calcite. The fluid density that corresponds to trapping pressure ranges between 1.00 g/cm3 and 1.11 g/cm3 and pressure close to 200 bars. Micro thermometric data in fluid inclusion hosted by gangue mineral presented by calcite show an average temperature of formation around 194 degree centigrade. These inclusions homogenized to the liquid phase between 156 degree centigrade and 210 degree centigrade and salinities values ranging from 22 to 28 wt% NaCl and an average around 23% wt NaCl. The δ34S (VCDT) values of sphalerite are in the range of + 4,6% to 6,4% (average=5,6%). Thermochemical reduction of Triassic sulfate by reaction with hydro-carbons is the most probable source for the heavy and the narrow range of the dδ34S values. Mineralogical, geochemical of trace elements, fluid inclusions and sulfur isotopes studies allow to include the vein-type ore field of Fedj Hassene in the polymetallic (Pb-Zn-As-Hg) vein mineralization of the nappe zone in northern Tunisia and north eastern Algeria. (Author) 29 refs.

  10. REE Geochemistry of Fluorite from the Maoniuping REE Deposit, Sichuan Province, China: Implications for the Source of Ore-forming Fluids

    Institute of Scientific and Technical Information of China (English)

    2007-01-01

    Fluorite is one of the main gangue minerals in the Maoniuping REE deposit, Sichuan Province, China. Fluorite with different colors occurs not only within various orebodies, but also in wallrocks of the orefield. Based on REE geochemistry, fluorite in the orefieid can be classified as the LREE-rich, LREE-flat and LREE-depleted types. The three types of fluorite formed at different stages from the same hydrothermal fluid source, with the LREE-rich fluorite forming at the relatively early stage, the LREE-flat fluorite in the middle, and the LREE-depleted fluorite at the latest stage. Various lines of evidence demonstrate that the variation of the REE contents of fluorite shows no relation to the color. The mineralization of the Maoniuping REE deposit is associated spatially and temporally with carbonatite-syenite magmatism and the ore-forming fluids are mainly derived from carbonatite and syenite melts.

  11. Geochemical constraints on the origin of the Kicking Horse and Monarch Mississippi Valley-type lead-zinc ore deposits, southeast British Columbia, Canada

    Science.gov (United States)

    Vandeginste, Veerle; Swennen, Rudy; Gleeson, Sarah A.; Ellam, Rob M.; Osadetz, Kirk; Roure, François

    2007-11-01

    Two Mississippi Valley-type (MVT) ore deposits, Kicking Horse and Monarch, have been studied with the aim of comparing the ores at the two localities and to characterize the origin of the mineralizing fluids and the ore formation process(es). Both deposits are hosted by the Middle Cambrian Cathedral Formation carbonate host rocks, Kicking Horse on the north and Monarch on the south flank of the Kicking Horse valley near Field (SE British Columbia). The ore bodies are situated at the transition of (western) basinal to (eastern) shallow-water strata of the paleo-Pacific passive margin succession in the Cordilleran Foreland Province of the Western Canada Sedimentary Basin. Both deposits are related spatially to normal faults. In both localities, the ore minerals are dominated by pyrite, sphalerite, and galena. Dolomite, minor quartz, and calcite are also present in close association with the ores. The salinity (21-30 wt% NaCl eq.) and homogenization temperatures (63-182°C) measured in fluid inclusions in carbonate, quartz, and sphalerite lie within the typical range of MVT fluid conditions. The good stoichiometry (50-53 mol% CaCO3), low δ18O values (-21 to -14‰ Vienna Peedee belemnite) and relatively high homogenization temperatures (>95°C) of the dolomite suggest the dolomites were formed under burial diagenesis. The ore-forming fluids probably interacted with siliciclastic units, based on elevated Li contents and 87Sr/86Sr ratios, which are highest in the dolomite type after the main ore stage. We propose that the ores formed from the mixing of a downward-infiltrating, sulfur-bearing halite-dissolution fluid with an upward-migrating, metal-rich evaporated seawater fluid, which had already undergone minor mixing with a dilute fluid.

  12. Clay swelling of Quaternary and Paleogene deposits in the south-eastern flanks of West Siberian iron ore basin

    Science.gov (United States)

    Kramarenko, V. V.; El-Shinawi, A.; Matveenko, I. A.; Shramok, A. A.

    2016-03-01

    Revealing soil swelling and estimation of swelling rate are of great importance at the initial survey stages as well as the bases for further determination of more accurate factors used for selection of recovery methods and facility design. The paper states briefly the most conventional prediction express-methods and determination of swelling indicators, the results of laboratory research in clay composition and properties, free swell index of Quaternary and Paleogene clays in the south-east of West Siberian iron-ore, gives the estimates of the swelling rate. The results have been statistically analyzed, revealing the relationship of properties, on the basis of which the correlation dependencies are suggested to predict the free swell index as well as to apply it for frost heave prediction.

  13. Fluid dynamics, particulate segregation, chemical processes, and natural ore analog discussions that relate to the potential for criticality in Hanford tanks

    Energy Technology Data Exchange (ETDEWEB)

    Barney, G.S.

    1996-09-27

    This report presents an in-depth review of the potential for nuclear criticality to occur in Hanford defense waste tanks during past, current and future safe storage and maintenance operations. The report also briefly discusses the potential impacts of proposed retrieval activities, although retrieval was not a main focus of scope. After thorough review of fluid dynamic aspects that focus on particle segregation, chemical aspects that focus on solubility and adsorption processes that might concentrate plutonium and/or separate plutonium from the neutron absorbers in the tank waste, and ore-body formation and mining operations, the interdisciplinary team has come to the conclusion that there is negligible risk of nuclear critically under existing storage conditions in Hanford site underground waste storage tanks. Further, for the accident scenarios considered an accidental criticality is incredible.

  14. Pumping test and fluid sampling report - Sawyer No. 1 well, Palo Duro Basin, Texas: unanalyzed data

    International Nuclear Information System (INIS)

    This report describes pumping test and fluid sampling activities performed at the Sawyer No. 1 well, Donley County, Texas. Sawyer No. 1 well is located along the eastern margin of the Palo Duro Basin in an area of active dissolution within the Permian salt section. These data were collected by Stone and Webster Engineering Corporation working in conjunction with the Texas Bureau of Economic Geology as part of a nationwide program to identify potential locations for a nuclear waste repository. These data support studies to determine the hydrologic characteristics of deep water-bearing formations. Formation fluid studies samples were analyzed in order to evaluate fluid migration and age relationships in the Permian Basin. These data were collected from June until October, 1981. Zone isolation for pump testing was accomplished in November, 1981. These data are preliminary. They have been neither analyzed nor evaluated

  15. Genesis of sediment-hosted disseminated-gold deposits by fluid mixing and sulfidization: chemical-reaction-path modeling of ore- depositional processes documented in the Jerritt Canyon district, Nevada

    Science.gov (United States)

    Hofstra, A.H.

    1991-01-01

    Integrated geologic, geochemical, fluid-inclusion, and stable-isotope studies of the gold deposits in the Jerritt Canyon district, Nevada, provide evidence that gold deposition was a consequence of both fluid mixing and sulfidization of host-rock iron. Chemical-reaction-path models of these ore-depositional processes confirm that the combination of fluid mixing, including simultaneous cooling, dilution, and oxidation of the ore fluid, and wall-rock reaction, with sulfidization of reactive iron in the host rock, explains the disseminated nature and small size of the gold and the alteration zonation, mineralogy, and geochemistry observed at Jerritt Canyon and at many other sediment-hosted disseminated gold deposits. -Authors

  16. Enrichment of copper in ore-forming fluid of copper-tungsten mineralization of the Yamaguchi skarn deposit, Iwate, Japan

    International Nuclear Information System (INIS)

    Chemical composition of the fluids in the fluid inclusions of quartz from the pegmatite veins of the Yamaguchi W-Cu skarn deposit was measured by a combination of the crush-leach method in deionized water and chemical analysis using PIXE. Chemical composition of the fluids is characterized by a low molar ratio of Na/K and a high Cu concentration. The molar ratio of Cu/(Cu+Fe+Zn) of the fluid inclusions is higher than that of massive sulfide deposits on the seafloor. The molar ratio of Cu/(Cu+Fe+Zn) of the fluid inclusions is similar to the ratios of the vapor-rich fluid inclusions from the quartz-cassiterite veins hosted within the Mole Granite in New South Wales, Australia. The high Cu concentration in fluid inclusions of quartz associated with the pegmatite veins from the Yamaguchi deposit suggests that the fluid emanating from the Miyako granitic melt at the later stage of crystallization had a high Cu content. (author)

  17. 白云鄂博矿床碳酸岩墙/脉和赋矿白云岩中流体包裹体研究%Fluid inclusion study of carbonatite dykes/veins and ore-hosted dolostone at the Bayan Obo ore deposit

    Institute of Scientific and Technical Information of China (English)

    秦朝建; 裘愉卓; 周国富; 王中刚; 张台荣; 肖国望

    2007-01-01

    Fluid inclusion study has been carried out for the carbonatite dykes/veins and the ore-hosted dolostone of the Bayan Obo superlarge REE-Fe-Nb deposit in order to provide the evidence and constraint for their origin. Based on the detailed geological observation and mineralogical investigation, the heating and cooling stage and laser Raman spectroscopy were mainly used for the laboratory work of this study. Following results have been obtained: (1) The discovery of melt and melt-fluid inclusions from carbonatite dykes/veins in the Dulahara and Jianshan Mountains, combined with the fine-grained (aplitic) texture of rocks, as well as the types and features of fluid inclusions such as CO2 enrichment, higher homogenization temperature, provides a direct evidence for the magmatic origin of these dykes/veins. (2) The carbonatite dykes/veins distributed in two regions, nearby the axis of the Kuangou anticline and in the east to Bayan Obo town, mainly show coarse-grained texture. No melt inclusion was found, and the fluid inclusions possess features of less CO2, lower homogenization temperature and higher salinity. They are tentatively identified as veins formed by some carbonate-rich hydrothermal solution. (3) Bedding carbonate layers/lens within the hanging wall and foot wall of ore-hosted dolostone, previously recognized as of magmatic origin, mainly composed by dolomite. The existence of single phase pure aqueous inclusions with very low homogenization temperature indicates their sedimentary origin. (4) The ore-hosted dolostone possesses apparent bedding and laminated structures. No melt inclusion was found, but, both single phase pure aqueous inclusions and CO2bearing multi-phase fluid inclusions coexisted in dolostones. In the direction towards ore-bodies, the homogenization temperature and CO2 contents of fluid inclusion show an increasing tendency. It indicates the sedimentary origin of dolostone superimposed by late fluid metasomatism.

  18. Mechanism of diapirism and episodic fluid injections in the Yinggehai Basin

    Institute of Scientific and Technical Information of China (English)

    HAO; Fang

    2002-01-01

    [1]Jackson, M. P. A., Vendeville, B. C., Regional extension as a geologic trigger for diapirism, Geological Society of Ameri-ca Bulletin, 1994, 106(1): 57-73.[2]Pérez-Belzuz, F., Alonso, B., Ercilla, G., History of mud diapirism and trigger mechanisms in the Western Alboran Sea, Tectonophysics, 1996, 282(2): 399-422.[3]Hunt, J. M., Petroleum Geology and Geochemistry, 2nd ed., San Francisco: Freeman and Company, 1996, 743.[4]Gong Zaisheng, Li Sitian, Continental Margin Basin Analysis and Hydrocarbon Accumulation of the Northern South Chi-na Sea (in Chinese), Beijing: Science Press, 1997, 510.[5]Price, L. C., Basin richness and source rock disruption: A fundamental relationship? Journal of Petroleum Geology, 1994, 17(1): 5-38.[6]Roberts, S. J., Nunn, J. A., Episodic fluid expulsion from geopressured sediments, Marine and Petroleum Geology, 1995, 12(2): 195-204.[7]Dewers, T., Ortoleva, P., Nonlinear dynamical aspects of deep basin hydrology: Fluid compartment formation and episodic fluid release, American Journal of Science, 1994, 294(5): 713-755.[8]Dai, J. X., Song, Y., Dai, C. S. et al., Geochemistry and accumulation of carbon dioxide gases in China, AAPG Bulletin, 1996, 80(9): 1615-1626.[9]Hao Fang, Li Sitian, Sun Yongchuan et al., Organic maturation and petroleum generation model in the Yinggehai and Qiongdongnan Basins, Science in China, 1996, 39(6): 650-658.[10]Hao Fang, Li Sitian, Dong Weiliang et al., Abnormal organic matter maturation in the Yinggehai Basin, offshore South China Sea: Implications for hydrocarbon expulsion and fluid migration from overpressured systems, Journal of Petroleum Geology, 1998, 21(4): 427-444.[11]Pollastro, R. M., Considerations and applications of the illite/smectite geothermometer in hydrocarbon-bearing rocks of Miocene to Mississippian age, Clays and Clay Minerals, 1993, 41(2): 119-133.[12]Ko, J., Hesse, R., Illite/smectite diagenesis in the Beaufort-Mackenzie Basin, Arctic Canada

  19. Effects of hydrocarbon generation on fluid flow in the Ordos basin and relationship with uranium mineralization

    International Nuclear Information System (INIS)

    The Ordos Basin is not only an important uranium mineralization province but also a major producer of oil. gas and coal in China. The genetic relationship between uranium mineralization and hydrocarbons has been recognized by a number of previous studies, but it has not been well understood in terms of hydrodynamics of basin fluid flow. In a previous study we have demonstrated that the preferential localization of uranium mineralization in the upper part of the Jurassic strata may have been related to the interface of an upward flowing, reducing fluid and a downward flowing, oxidizing fluid, and that this interface may have been controlled by the interplay between fluid overpressure, which was related to disequilibrium sediment compaction and drove the upward flow, and topographic relief which drove the down- ward flow. In the present study, we carried out numerical modeling for the contribution of oil and gas generation to the development of fluid overpressure, in addition to sediment compaction and heating. Our results indicate that when hydrocarbon generation was taken into account, fluid overpressure during the Cretaceous was more than doubled in comparison with the simulation when hydrocarbon generation was not considered. Furthermore, fluid overpressure dissipation after ceasing of sedimentation slowed down relative to the no-hydrocarbon generation case. These results suggest that hydrocarbon generation may have played an important role in uranium mineralization, not only in providing reducing agents required for the mineralization, but also in contributing to the driving force to maintain the upward flow against the pushing of topography driven. downward flow, thus helping stabilize the interface between the two fluid system and localization of uranium mineralization. (authors)

  20. Vein mineralizations - record of paleo-fluid systems in the Thuringian basin (Germany)

    Science.gov (United States)

    Lepetit, Petra; Viereck, Lothar; Abratis, Michael; Fritsch, Stefanie

    2014-05-01

    Vein-related mineralizations within the Mesozoic sediments of the Thuringian basin (Germany) are investigated in analytical detail (petrography, XRD, XRF, EPMA, LA-ICP-MS, and isotope studies: O, C, S, Sr) in order to characterize paleo-fluid systems that intruded the basin and circulated within it millions of years ago. Samples from 55 outcrops, 34 quarries and 21 drill cores comprise mainly carbonates (calcite, dolomite, siderite, ankerite), additional sulfates (gypsum, celestine, barite,), and rarely sulfides. The mineralizations are almost exclusively restricted to WNW-ESE trending fault systems. First δ13C and δ18O isotope analyses of calcite mineralizations reveal differences between veins within Triassic sediments (Lower Muschelkalk: δ13C: 1.8 to 2.9 o, mean 2.3 o, δ18O: -7.3 to -10.4 o, mean -8.2 o) and Jurassic sediments (δ13C: -0.7 to -2.1 o, mean -1.4 o, δ18O: -9.3 to -10.6 o, mean -9.9 o), indicating intra-formational and extra-formational paleo-fluid transport. Also first δ34S and δ18O isotope analyses of gypsum mineralizations display differences between veins within Triassic and Permian sediments, respectively. These initial data are comparable with isotope analyses of vein-related host rocks and hydrochemical signatures of recent well waters in the Thuringian basin indicating intra-formational in addition to extra-formational paleo-fluid transport. Further isotope studies are in progress including high resolution in situ-Sr- isotope analysis. The present study is part of INFLUINS, a BMBF-funded project bundle, which is dedicated to the comprehensive description and understanding of the fluid systems within the Thuringian basin in time and space.

  1. Environment of ore deposition in the creede mining district, San Juan Mountains, Colorado: Part V. Epithermal mineralization from fluid mixing in the OH vein

    Science.gov (United States)

    Hayba, D.O.

    1997-01-01

    Detailed fluid inclusion studies on coarse-grained sphalerite from the OH vein, Creede, Colorado, have shown that the abrupt color changes between growth zones correspond to abrupt changes in the nature of the ore fluids. Within each growth zone, however, the composition of the fluids remained constant. The base of a distinctive orange-brown growth zone marks a sharp increase in both temperature and salinity relative to the preceding yellow-white zone. The orange-brown growth zone can be correlated along much of the vein and is believed to represent a time-stratigraphic interval. Along the vein, temperatures and salinities of fluid inclusions within this interval show a systematic decrease from about 285??C and 11.5 wt percent NaCl equiv near the base of the vein to about 250??C and 8 wt percent NaCl equiv, respectively, near the top of the vein. The iron concentration of this sphalerite growth zone shows a similar pattern, decreasing from about 2.8 to 1.2 mole percent FeS. When plotted on an enthalpy-salinity diagram, the fluid inclusion data define a spatial trend indicating the progressive mixing of deeply circulating hydrothermal brines with overlying, dilute ground waters. The hydrothermal brines entered the OH vein from below at a temperature, salinity, and density of approximately 285??C, 11.5 wt percent NaCl equiv, and 860 kg/m3, respectively, whereas the overlying ground waters appear to have been preheated to roughly 150??C and had an assumed salinity of 0 wt percent and a density of 920 kg/m3. The greater density of the heated ground water promoted mixing with the hydrothermal brine within the open fractures, causing sphalerite deposition. Although there were also episodes of boiling during vein mineralization, boiling appears unimportant for this sphalerite. Isotopic evidence and geochemical modeling studies also indicate that mixing was the depositional mechanism for sphalerite. An important aspect of the mixing hydrology of the Creede system involves

  2. Numerical modeling of fracking fluid migration through fault zones and fractures in the North German Basin

    Science.gov (United States)

    Pfunt, Helena; Houben, Georg; Himmelsbach, Thomas

    2016-04-01

    Gas production from shale formations by hydraulic fracturing has raised concerns about the effects on the quality of fresh groundwater. The migration of injected fracking fluids towards the surface was investigated in the North German Basin, based on the known standard lithology. This included cases with natural preferential pathways such as permeable fault zones and fracture networks. Conservative assumptions were applied in the simulation of flow and mass transport triggered by a high pressure boundary of up to 50 MPa excess pressure. The results show no significant fluid migration for a case with undisturbed cap rocks and a maximum of 41 m vertical transport within a permeable fault zone during the pressurization. Open fractures, if present, strongly control the flow field and migration; here vertical transport of fracking fluids reaches up to 200 m during hydraulic fracturing simulation. Long-term transport of the injected water was simulated for 300 years. The fracking fluid rises vertically within the fault zone up to 485 m due to buoyancy. Progressively, it is transported horizontally into sandstone layers, following the natural groundwater flow direction. In the long-term, the injected fluids are diluted to minor concentrations. Despite the presence of permeable pathways, the injected fracking fluids in the reported model did not reach near-surface aquifers, either during the hydraulic fracturing or in the long term. Therefore, the probability of impacts on shallow groundwater by the rise of fracking fluids from a deep shale-gas formation through the geological underground to the surface is small.

  3. Regional fluid flow as a factor in the thermal history of the Illinois basin: Constraints from fluid inclusions and the maturity of Pennsylvanian coals

    Science.gov (United States)

    Rowan, E.L.; Goldhaber, M.B.; Hatch, J.R.

    2002-01-01

    Vitrinite reflectance measurements on Pennsylvanian coals in the Illinois basin indicate significantly higher thermal maturity than can be explained by present-day burial depths. An interval of additional sedimentary section, now removed by erosion, has been suggested to account for the discrepancy. Although burial could indeed account for the observed maturity levels of organic matter, fluid-inclusion temperatures provide a stringent additional constraint. In this article, we combine measurements of coal maturity with fluid-inclusion temperatures from three sites to constrain the basin's thermal and burial history: the Fluorspar district at the Illinois basin's southern margin, the Upper Mississippi Valley zinc district at the basin's northern margin, and a north-central location. Two-dimensional numerical modeling of a north-south cross section through the basin tests scenarios both with and without regional fluid flow. Vitrinite reflectance values can be matched assuming burial by 1.8-2.8 km of southward-thickening additional, post-Pennsylvanian sedimentary section. In the central and northern Illinois basin, however, these burial depths and temperatures are not sufficient to account for the fluid-inclusion data. To account for both parameters with burial alone does not appear feasible. In contrast, our best hypothesis assumes a wedge of post-Pennsylvanian sediment-thickening southward to about 1.2 km and a brief period of magmatism in the Fluorspar district. Significant advective heat redistribution by northward regional fluid flow accounts for fluid-inclusion temperatures and coal maturities throughout the basin. The modeling results demonstrate the potential contribution of advective heat transport to the thermal history of the Illinois basin.

  4. Well successfully drilled with high performance water-based fluid: Santos Basins, offshore Brazil

    Energy Technology Data Exchange (ETDEWEB)

    Fornasier, Frank C.; Luzardo, Juan P. [Halliburton Company, Houston, TX (United States); Bishnoi, M.L. [Oil and Natural Gas Corporation Ltda. (ONGC), Dehradun (India)

    2012-07-01

    Santos Basin is a 352,260 square kilometers (136,010 sq mi) offshore pre-salt basin. It is located in the South Atlantic Ocean, some 300 kilometers (190 mi) South East of Sao Paulo, Brazil. One of the largest Brazilian sedimentary basins, it is the site of several recent significant oil fields, including Tupi and Jupiter. The criteria for drilling fluid selection is based upon the following factors: maximum cost efficiency, environmental friendliness, optimum borehole stability, and ease of use. The recommended drilling fluid formulation takes into consideration the experience gained during the drilling of wells in the Santos Basin area. The operator wanted to use a high-performance water-based fluid (HPWBF) that could provide shale inhibition, wellbore stability, lubricity and improved rate of penetration (ROP) as an alternative to synthetic-based drilling fluids to present value in terms of economics and environmental friendliness. The HPWBF consists of three synergistic products: a hydration suppressant, a dispersion suppressant, and an accretion suppressant. The system is formulated based on customized solutions for managing the clay reactivity. High logistics costs require drilling fluids that can be prepared with sea water and discharged to the sea without environmental impact. The HPWBF is a clay-free system designed for maximum shale inhibition in highly reactive formations. The system can provide wellbore stability, high rates of penetration, and acceptable rheological properties over a wide range of temperatures, with the added benefit of allowing cuttings discharge based upon water base environmental restrictions. Since no oil is used in the formulation, the HPWBF eliminates the need for cuttings processing and monitoring equipment, and exceeds the environmental requirements by achieving an LC50 value of 345,478.22 ppm in comparison with the minimum requirement (LC50 > 30,000 ppm in 96 hr), permitting use and discharge to the sea. The HPWBF selected

  5. Pumping test and fluid sampling report - Mansfield No. 1 (PD-4) well, Palo Duro Basin, Texas: unanalyzed data

    International Nuclear Information System (INIS)

    This report contains pumping test and fluid sampling data collected at Mansfield No. 1 well, located in Oldham County, in the Permian Basin of Texas. These data were collected by Stone and Webster Engineering Corporation to support studies of fluid migration and age relationships in the Permian Basin. The testing and sampling took place between October 1981 and October 1982. These data are preliminary. They have been neither analyzed nor evaluated. 4 references, 8 figures, 2 tables

  6. Pumping test and fluid sampling report, Mansfield No. 1 well, Palo Duro Basin: Report of the Geologic Project Manager, Permian Basin

    International Nuclear Information System (INIS)

    This report describes pumping test and fluid sampling activities performed at the Mansfield No. 1 well in Oldham County about 10 miles north of Vega, Texas. The well site was selected by TBEG and is located along the northern margin of the Palo Duro Basin in an area of active dissolution with the Permian salt sections. The objectives of the pumping test and fluid sampling program were to collect data to determine the hydrologic characteristics (formation pressure and permeability) of deep water bearing formations, and to obtain formation fluid samples for analyses (gas and fluid chemistry) in order to evaluate fluid migration and age relationships in the Permian Basin. 4 refs., 8 figs., 2 tabs

  7. Kellad orelis

    Index Scriptorium Estoniae

    2000-01-01

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

  8. Heat transfer and fluid flow modelling in supra-detachment basins: a case study of the Devonian basins of western Norway

    Science.gov (United States)

    Souche, A.; Dabrowski, M.; Andersen, T. B.; Medvedev, S.

    2012-04-01

    The Devonian basins of western Norway are supra-detachment basins located above a large crustal-scale detachment system, so-called the Nordfjord Sogn Detachment Zone. These basins are characterised by a thick succession (>10km) of siliciclastic sediments ranging in size from coarse conglomerates to fine grain sandstones and organized into narrow half-graben systems. Their architecture and geometry is closely controlled by the development of the coeval (i.e. Early to Middle Devonian) detachment acting as a normal fault/shear zone beneath the basins. The exhumation of rocks within the footwall of the detachment was subsequently followed by an increase of the geothermal gradient at the base of the sedimentary successions. Shear heating resulting from the intense rock deformation within the shear zone also played a role in increasing the temperature at the base of the basins. These two significant processes might have in turn contributed to the fluid mobility in the basins. In this study, we explore the feasibility of porous convection to occur spontaneously in sedimentary basins due to a regional increase of the geothermal gradient. Such process can be approximated by Darcy flow through porous media where the fluid density in the system might introduce a buoyancy-driven instability between lighter hot fluids at the base and denser cold fluids at the top of the basin. In geological systems porous flow might be inhibited by the closing of pores with depth, which leads to a reduced permeability and a limited amount of heat carrying fluids. Also, geological heterogeneities inherited from the layered structure of the sedimentary strata introduce large variations in the rock transport properties. We address these problems numerically by modelling heat and mass transport in porous media assuming quasi-incompressible Darcy flow. The fluid (water) density, viscosity, and specific heat are computed from the pore fluid pressure and the temperature. We investigate the onset of

  9. Natural gas leakage of Mizhi gas reservoir in Ordos Basin, recorded by natural gas fluid inclusion

    Institute of Scientific and Technical Information of China (English)

    2007-01-01

    Abundant natural gas inclusions were found in calcite veins filled in fractures of Central Fault Belt across the centre of Ordos Basin. Time of the calcite veins and characteristics of natural gas fluid inclusion were investigated by means of dating of thermolum luminescence (TL) and analyzing stable isotope of fluid inclusion. Results show that natural gas inclusion formed at 130―140℃ with salinity of 5.5 wt%―6.0 wt% NaCl. It indicates that natural gas inclusion is a kind of thermal hydrocarbon fluid formed within the basin. Method of opening inclusion by heating was used to analyze composition of fluid inclusion online, of which the maximal hydrocarbon gas content of fluid inclusion contained in veins is 2.4219 m3/t rock and the maximal C1/Σci ratio is 91%. Laser Raman spectroscopy (LRS) was used to analyze chemistry of individual fluid inclusion in which the maximal hydrocarbon gas content is 91.6% compared with little inorganic composition. Isotope analysis results of calcite veins show that they were deposited in fresh water, in which the δ13CPDB of calcite veins is from -5.75‰ to 15.23‰ andδ18OSMOW of calcite veins is from 21.33‰ to 21.67‰. Isotope results show thatδ13C1 PDB of natural gas fluid inclusion is from -21.36‰ to -29.06‰ and δDSMOW of that is from -70.89‰ to -111.03‰. It indicates that the gas of fluid inclusion formed from coal source rocks and it is the same as that of natural gas of Mizhi gas reservoir. Results of TL dating show that time of calcite vein is (32.4±3.42)×104 a, which is thought to be formation time of gas inclusion. It indicated that natural gas inclusion contained in calcite veins recorded natural gas leakage from Mizhi gas reservoir through the Central Fault Belt due to Himalayan tectonic movement.

  10. Generation and evolution of hydrothermal fluids at Yellowstone: Insights from the Heart Lake Geyser Basin

    Science.gov (United States)

    Lowenstern, J. B.; Bergfeld, D.; Evans, William C.; Hurwitz, S.

    2012-01-01

    We sampled fumaroles and hot springs from the Heart Lake Geyser Basin (HLGB), measured water and gas discharge, and estimated heat and mass flux from this geothermal area in 2009. The combined data set reveals that diverse fluids share an origin by mixing of deep solute-rich parent water with dilute heated meteoric water, accompanied by subsequent boiling. A variety of chemical and isotopic geothermometers are consistent with a parent water that equilibrates with rocks at 205°C ± 10°C and then undergoes 21% ± 2% adiabatic boiling. Measured diffuse CO2 flux and fumarole compositions are consistent with an initial dissolved CO2 concentration of 21 ± 7 mmol upon arrival at the caldera boundary and prior to southeast flow, boiling, and discharge along the Witch Creek drainage. The calculated advective flow from the basin is 78 ± 16 L s−1 of parent thermal water, corresponding to 68 ± 14 MW, or –1% of the estimated thermal flux from Yellowstone. Helium and carbon isotopes reveal minor addition of locally derived crustal, biogenic, and meteoric gases as this fluid boils and degasses, reducing the He isotope ratio (Rc/Ra) from 2.91 to 1.09. The HLGB is one of the few thermal areas at Yellowstone that approaches a closed system, where a series of progressively boiled waters can be sampled along with related steam and noncondensable gas. At other Yellowstone locations, steam and gas are found without associated neutral Cl waters (e.g., Hot Spring Basin) or Cl-rich waters emerge without significant associated steam and gas (Upper Geyser Basin).

  11. Fluid and gasmigration in the southwestern part of the Lower Saxony basin

    Energy Technology Data Exchange (ETDEWEB)

    Lueders, V.; Plessen, B.; Sippel, J. [GeoForschungsZentrum Potsdam (Germany)

    2008-10-23

    Lower Carboniferous and Upper Jurassic sedimentary rocks from wells of the southwestern part of the Lower Saxony Basin (LSB) show locally anomalous maturity reaching 4.5% VRr. The reason for this high maturity is discussed controversy. It may either be related to the intrusions of supposed Late Cretaceous igneous plutons in the area of Bramsche and Vlotho or is explained by models involving deep burial during Early Cretaceous times and uplift during Late Cretaceous/Tertiary times. A fault-slip analysis covering outcrops within the LSB and along the Osning Lineament (OL) has been performed and showed that the area was affected by a stress state with a horizontal N-S- to NE-SW-directed maximum compression ({sigma}1) and a low stress ratio (R=({sigma}2-{sigma}3)/({sigma}1-{sigma}3)) which induced reverse and strike-slip faulting. The regional paleostress field can be related to the Late Cretaceous-Cenozoic intraplate compressional deformation that affected the Alpine foreland as a result of the Alpine orogeny Other stress fields estimated in the study area are much less prevalent. Tectonic activity induced the migration of fluids and let to precipitation of quartz and calcite on veins, fissures and slickensides. Calcite mostly precipitated from local formation waters that were in close equilibrium with the host rocks rather than being derived from a large scale circulating hydrothermal system. Fluid inclusions studies in hydrothermal minerals from wells and outcrops in the study area yield migration of differently composed fluids and gases during stages of burial and uplift. In the vicinity of supposed intrusions the migration of hot fluids (>200 C) is recorded in quartz mineralization that is hosted by Upper Carboniferous to Cretaceous sediments. The salinity of the studied fluid inclusions is highly variable suggesting that different fluid reservoirs were drained. However, fluid entrapment often occurred along with the entrapment of gas mixtures with variable

  12. Environment of ore deposition in the Creede mining district, San Juan Mountains, Colorado; Part IV, source of fluids, from oxygen, hydrogen, and carbon isotope studies

    Science.gov (United States)

    Bethke, P.M.; Rye, R.O.

    1979-01-01

    also oxygen shifted meteoric waters but were some 40 per mil lower in deuterium content than the sphalerite and illite/chlorite waters.We propose that the quartz fluids entered the vein system from reservoirs beneath the mountainous areas to the north in the vicinity of the present Continental Divide, but that the sphalerite and illite/chlorite fluids entered the vein system from a topographically low area to the south along the structural moat of the Creede caldera. The difference in delta D between the two meteoric waters may reflect differences in altitude of the recharge areas for the two reservoirs or may be clue to isotopic evolution of the closed-basin lake and interstitial waters in the moat surrounding the Creede caldera.

  13. Deformation and fluid flow in the Huab Basin and Etendeka Plateau, NW Namibia

    Science.gov (United States)

    Salomon, Eric; Koehn, Daniel; Passchier, Cees; Chung, Peter; Häger, Tobias; Salvona, Aron; Davis, Jennifer

    2016-07-01

    The Lower Cretaceous Twyfelfontein sandstone formation in the Huab Basin in NW Namibia shows the effects of volcanic activity on a potential reservoir rock. The formation was covered by the Paraná-Etendeka Large Igneous Province shortly before or during the onset of South-Atlantic rifting. Deformation bands found in the sandstone trend mostly parallel to the continental passive margin and must have formed during the extrusion of the overlying volcanic rocks, indicating that their formation is related to South-Atlantic rifting. 2D-image porosity analysis of deformation bands reveals significant porosity reduction from host rock to band of up to 70%. Cementation of the sandstone, linked to advective hydrothermal flow during volcanic activity, contributes an equal amount to porosity reduction from host rock to band when compared to initial grain crushing. Veins within the basaltic cover provide evidence for hot fluid percolation, indicated by spallation of wall rock and colloform quartz growth, and for a later low-temperature fluid circulation at low pressures indicated by stilbite growth sealing cavities. Sandstone samples and veins in the overlying volcanic rocks show that diagenesis of the Twyfelfontein sandstone is linked to Atlantic rifting and was affected by both hydrothermal and low-thermal fluid circulation.

  14. Veins and related past fluid flow through the Mesozoic sedimentary cover in the Swiss Molasse Basin

    International Nuclear Information System (INIS)

    Document available in extended abstract form only. The study is based on core samples from the recently drilled, 719 m deep borehole at Oftringen (near Olten), located in the northwestern Molasse basin, 1.5 km from the frontal thrust of the Folded Jura. Veins of calcite (± celestite, pyrite) occur in the whole Malm sequence (up to 8 veins/m), including the more clay-rich Effingen Member (marl and argillaceous limestone). Such an intensity of veining in the Effingen Member has never been found to date in other deep boreholes located in the Molasse basin. Most of the veins are related to tectonic activity, but clay-filled karst structures are recognized in the overlying Geissberg Member limestone, and a few structures probably related to diagenetic processes are documented in the Effingen Member. Fluid inclusions show average salinities between 3.3 and 4.4 wt% eq. NaCl in vein celestite and 2.7 wt% eq. NaCl in vein calcite. Average homogenization temperatures in calcite fluctuate between 56 and 68 deg. C, with a broad increase with depth and no correlation with salinity. Malm whole-rock carbonates have δ18O values fluctuating within a narrow range, probably determined by equilibrium with seawater. Their 87Sr/86Sr ratios follow a well-defined depth profile with minimum values in the middle part of the Effingen Member, fitting with Oxfordian seawater. No correlation is observed between 87Sr/86Sr and clay content, and values higher than contemporary seawater might be related to the incorporation of radiogenic detrital carbonate. The δ18O values of vein calcite are systematically lower than the corresponding whole rock carbonate, consistent with precipitation from seawater at 50-70 deg. C (homogenization temperatures of fluid inclusions). The δ34S and δ18O values of vein celestite follow a bacterial reduction trend pointing to Miocene seawater sulfate. Two vein pyrites gave negative δ34S values consistent with bacterial sulfate reduction. Calcite and celestite of

  15. Intermediate sulfidation epithermal mineralization of No. 4 anomaly of Golojeh deposit (N. Zanjan based on mineralography, alteration and ore fluid geochemistry features

    Directory of Open Access Journals (Sweden)

    Behzad Mehrab

    2014-04-01

    contents of galena, sphalerite and minor chalcopyrite and tennantite, low to moderate temperature and salinity of ore-bearing fluid, low depth of mineralization and Fe–bearing sphalerite features at the No. 4 anomaly of Golojeh deposit, are similar to those of intermediate sulfidation (IS epithermal base and precious metals vein–type deposit that probably might be related to Cu–Au porphyry system in depth.

  16. Fluid transport by solitary waves along growing faults. A field example from the South Eugene Island Basin, Gulf of Mexico

    Science.gov (United States)

    Revil, A.; Cathles, L. M.

    2002-09-01

    The Red Fault system is one of the main growth faults found in the South Eugene Island Basin, a salt withdrawal minibasin located offshore Louisiana, in the Gulf of Mexico. This fault system corresponds to a lateral boundary between fluid overpressured compartments. In addition, there is a set of observations indicating that the Red Fault system exhibits rapid episodic migration of fluids. This fault represents an example of preferential pathway for the upward episodic migration of overpressured hydrocarbons from deep, heavily pressured, compartments on time scales of years. The migrations of fluids into active growing faults could take the form of propagating surges (solitary waves) that propagate upward along the fault planes in a wave-like manner at km/yr. Solitary waves represent a very efficient mechanism for the upward transport of fluids along growth faults in sedimentary basins generating its own permeability. In addition, this mechanism is compatible with the fact that the fault plane is observed to sustain a static pore fluid pressure difference between its two sides. The propagation of solitary waves in active growth faults appears as a fundamental mechanism to understand the nature of upward fast migration of fluids along active growth faults in compartimentalized sedimentary basins.

  17. Characters of fluid inclusions in quartz veins in pyroclastic rock of Budate Group, Hailar Basin

    Institute of Scientific and Technical Information of China (English)

    ZHANG Xin-tao; LIU Li; GAO Yu-qiao; SHAO Hong-mei; SHEN Guang-zheng

    2004-01-01

    It was adopted that the fluorescence microscope, Gas-Flow Heating/Freezing System, Laser-Raman Spectroscopy, etc. are the multimedia techniques for analysing fluid inclusions of quartz veins in Budate Group, Hailar Basin.The results show that fluid inclusions in quartz veins are small (1 ~5 μm) monophase, two-phase (liquid+vapour)aqueous inclusions; the two-phase aqueous inclusions homogeniese to the liquid phase between 120 ~ 180℃, two Laser-Raman Spectroscopy show that both gas phase are enriched in CH4 (94.50% ~99.25% ) and C6H6 (0.75% ~2.70%), under these conditions, inclusions may have come from juvenile fliud followingly the quartz veins formation.While the quartz veins exhibiting different striking luminescence has been proved by cathodoluminescence, it would be belong to secondary hydrocarbon inclusions. The oil inclusions of this stage represent mainly the large scale of oil accumulation, located within the quartz microfracture.

  18. Origin of fluid inclusion water in bedded salt deposits, Palo Duro Basin, Texas

    International Nuclear Information System (INIS)

    Salt horizons in the Palo Duro Basin being considered for repository sites contain fluid inclusions which may represent connate water retained in the salt from the time of original salt deposition and/or external waters which have somehow penetrated the salt. The exact origin of this water is important to the question of whether or not internal portions of the salt deposit have been, and are likely to be, isolated from the hydrosphere for long periods of time. The 18O/16O and D/H ratios measured for water extracted from solid salt samples show the inclusions to be dissimilar in isotopic composition to meteoric waters and to formation waters above and below the salt. The fluid inclusions cannot be purely external waters which have migrated into the salt. The isotope data are readily explained in terms of mixed meteoric-marine connate evaporite waters which date back to the time of deposition and early diagenesis of the salt (>250 million years). Any later penetration of the salt by meteoric waters has been insufficient to flush out the connate brines

  19. Study on Fluid Inclusions of Copper and Nickel Ore Deposit in East Hebei Province%冀东孤山子铜镍矿床流体包裹体

    Institute of Scientific and Technical Information of China (English)

    李昌存; 何佳; 杨东鹏; 何凤广

    2014-01-01

    孤山子超镁铁质岩体是冀东地区重要的磁铁矿源之一,同时也拥有较好的铜镍矿床的成矿条件。流体包裹体的研究表明,该铜镍矿床的流体包裹体主要有3种类型:气液两相包裹体(个别为纯液相包裹体)、富CO2三相包裹体和纯气相包裹体。孤山子铜镍矿床的成矿流体属于中低温、中盐度和中低密度的酸性流体,形成深度约为85.~98.km,成矿流体压力约为106~138 M Pa。%Gushanzi ultrabasic rock mass is one of the important source of magnet in Hebei eastern ,w hich has good metallogenic conditions of copper -nickel .Studies on fluid inclusion show that there are three major types of fluid inclusion :gas-liquid inclusions (individual pure liquid inclusions ) ,rich CO2 three-phase inclusions and pure gas inclusions .Gushanzi copper -nickel deposit ore-forming fluid belongs to a-cidic fluid of mid -low temperature ,middle salinity and mid -low density ,w hich formed under the depth of about 8 5. ~ 9 8. km ,and the pressure of ore -forming fluid was between 106 and 138 Mpa .

  20. Evidence for episodic expulsion of hot fluids along faults near diapiric structures of the Yinggehai Basin, South China Sea

    Energy Technology Data Exchange (ETDEWEB)

    Xinong Xie; Sitian Li [China University of Geosciences, Wuhan (China). College of Earth Resources; Weiliang Dong; Zhongliang Hu [China Offshore Oil Nanhai West Corp., Zhanjiang (China)

    2001-06-01

    Diapiric structures are well developed and occur in most of the central part of the Yinggehai Basin, on the western side of the South China margin. A strong thermal anomaly due to hot fluid flows occurs in the diapiric zone, as evidenced from vitrinite reflectance (R{sub o}), clay mineral transformation, and fluid inclusion homogenization temperatures. This anomaly results from hydrothermal fluid flow along vertical faults from overpressured compartments into the overlying Late Miocene and Quaternary sand-rich layers. The magnitude of thermal anomaly is related not only to the distance to which the vertical fault is hydraulically open, but the permeability of rocks interconnected with the faults. Intense heat transfer for convection of fluids occurs in the sand-rich intervals adjacent to vertical faults. Abnormal organic-matter maturation, together with rapid transformation of clay minerals, which occurs at certain intervals within the present-day normally pressured system and normal conductive temperatures in a diapir, can be used to identify palaeo high pressure zones. Abnormal high temperatures measured from a drill-stem test in a diapir can be inferred to be the results of recent expulsion of hydrothermal fluid flow. The results of this study suggest that thermal fluid expulsion along faults plays an important role in the modification of thermal regimes, the enhancement of organic-matter maturation, and rapid transformation of clay minerals, as well as the accumulation of hydrocarbons in diapiric structures of the Yinggehai Basin, South China Sea. (author)

  1. Assessment of the impact of moving fluids on the regional thermal field for the area of Brandenburg (North German Basin)

    Science.gov (United States)

    Noack, V.; Scheck-Wenderoth, M.; Cacace, M.; Lewerenz, B.

    2012-04-01

    We present results from numerical simulations of the 3D thermal field for the area of Brandenburg in the North German Basin. The study area encompasses a part of the basin centre in the north, whereas to the south the basin margin is enclosed. Starting with Permocarboniferous volcanic rocks the basin fill is represented by Permian to Cenozoic sediments. A thick layer of mobilized salt (Zechstein, Upper Permian) generated elevated structures such as salt pillows and diapirs. Especially where diapirs pierce their overburden, the overlying deposits are strongly influenced in their thickness and distribution. This special configuration of the Zechstein salt is relevant for the thermal calculations due to the fact that salt has a distinctly higher thermal conductivity than the surrounding sediments and is impermeable to fluid flow. Therefore, the Zechstein salt acts as a conductive chimney for heat and a hydraulic decoupling horizon between the Pre-Permian and the Mesozoic-Cenozoic strata. The latter are characterized by two further quasi-impervious sediment complexes, the Rupelian-clay and the Muschelkalk. These two divide the Post-Permian strata in three main aquifer systems: the Buntsandstein, Keuper to Pre-Rupelian and the Post-Rupelian complex. Based on results from purely conductive modelling we additionally analyse the influence of moving fluids on the shallow temperature field above the Zechstein salt. Therefore coupled fluid flow and heat transfer numerical simulations are carried out to investigate the hydrothermal field. The 3D simulations for the heat transport processes are based on the finite element method. The results indicate that the distribution of thermal conductivities in the basin fill controls the short-wavelength pattern of the temperature distribution whereas the long wavelength pattern results from interaction between the highly conductive crust and low conductive sediments. Furthermore, the results reveal that the shallow temperature field

  2. Fluid evolution and mineralogy of Mn-Fe-barite-fluorite mineralizations at the contact of the Thuringian Basin, Thüringer Wald and Thüringer Schiefergebirge in Germany

    Directory of Open Access Journals (Sweden)

    Majzlan Juraj

    2016-02-01

    Full Text Available Numerous small deposits and occurrences of Mn-Fe-fluorite-barite mineralization have developed at the contact of the Thuringian Basin, Thüringer Wald and Thüringer Schiefergebirge in central Germany. The studied mineralizations comprise the assemblages siderite+ankerite-calcite-fluorite-barite and hematite-Mn oxides-calcite-barite, with the precipitation sequence in that order within each assemblage. A structural geological analysis places the origin of the barite veins between the Middle Jurassic and Early Cretaceous. Primary fluid inclusions contain water vapour and an aqueous phase with NaCl and CaCl2 as the main solutes, with salinities mostly between 24–27 mass. % CaCl2 eq. Th measurements range between 85 °C and 160 °C in barite, between 139 °C and 163 °C in siderite, and between 80 °C and 130 °C in fluorite and calcite. Stable isotopes (S, O point to the evaporitic source of sulphur in the observed mineralizations. The S,C,O isotopic compositions suggest that barite and calcite could not have precipitated from the same fluid. The isotopic composition of the fluid that precipitated barite is close to the sea water in the entire Permo–Mesozoic time span whereas calcite is isotopically distinctly heavier, as if the fluids were affected by evaporation. The fluid evolution in the siliciclastic/volcanic Rotliegend sediments (as determined by a number of earlier petrological and geochemical studies can be correlated with the deposition sequence of the ore minerals. In particular, the bleaching of the sediments by reduced Rotliegend fluids (basinal brines could be the event that mobilized Fe and Mn. These elements were deposited as siderite+ankerite within the Zechstein carbonate rocks and as hematite+Mn oxides within the oxidizing environment of the Permian volcanic and volcanoclastic rocks. A Middle-Jurassic illitization event delivered Ca, Na, Ba, and Pb from the feldspars into the basinal brines. Of these elements, Ba was

  3. On the role of buoyancy force in the ore genesis of SEDEX deposits: Example from Northern Australia

    Institute of Scientific and Technical Information of China (English)

    2009-01-01

    Finite element modeling on a highly conceptualized 2-D model of fluid flow and heat transport is un-dertaken to simulate the paleo-hydrological system as if the Mount Isa deposits were being formed in the Mount Isa basin, Northern Australia, and to evaluate the potential of buoyancy force in driving ba-sin-scale fluid flow for the formation of sedimentary-exhalative (SEDEX) deposits. Our numerical case studies indicate that buoyancy-driven fluid flow is controlled mainly by the fault penetration depth and its spatial relation with the aquifer. Marine water recharges the basin via one fault and flows through the aquifer where it is heated from below. The heated metalliferous fluid discharges to the basin floor via the other fault. The venting fluid temperatures are computed to be in the range of 115 to 160℃, with fluid velocities of 2.6 to 4.1 m/year over a period of 1 Ma. These conditions are suitable for the formation of a Mount Isa-sized zinc deposit, provided a suitable chemical trap environment is present. Buoyancy force is therefore a viable driving mechanism for basin-scale ore-forming hydrothermal fluid migration, and it is strong enough to lead to the genesis of supergiant SEDEX deposits like the Mount Isa deposit, Northern Australia.

  4. On the role of buoyancy force in the ore genesis of SEDEX deposits: Example from Northern Australia

    Institute of Scientific and Technical Information of China (English)

    YANG JianWen; FENG ZuoHai; LUO XianRong; CHEN YuanRong

    2009-01-01

    Finite element modeling on a highly conceptualized 2-D model of fluid flow and heat transport is un-dertaken to simulate the paleo-hydrological system as if the Mount Ise deposits were being formed in the Mount Isa basin, Northern Australia, and to evaluate the potential of buoyancy force in driving ba-sin-scale fluid flow for the formation of sedimentary-exhalative (SEDEX) deposits. Our numerical case studies indicate that buoyancy-driven fluid flow is controlled mainly by the fault penetration depth and its spatial relation with the aquifer. Marine water recharges the basin via one fault and flows through the aquifer where it is heated from below. The heated metalliferous fluid discharges to the basin floor via the other fault. The venting fluid temperatures are computed to be in the range of 115 to 160℃, with fluid velocities of 2.6 to 4.1 m/year over a period of 1 Ma. These conditions are suitable for the formation of a Mount Isa-sized zinc deposit, provided a suitable chemical trap environment is present. Buoyancy force is therefore a viable driving mechanism for basin-scale ore-forming hydrothermal fluid migration, and it is strong enough to lead to the genesis of supergiant SEDEX deposits like the Mount Isa deposit, Northern Australia.

  5. 青海东昆仑阿斯哈金矿Ⅰ号脉成矿流体地球化学特征和矿床成因%Geochemical Features of Ore-Forming Fluids and Metallogenesis of Vein Ⅰ in Asiha Gold Ore Deposit,Eastern Kunlun,Qinghai Province

    Institute of Scientific and Technical Information of China (English)

    李碧乐; 沈鑫; 陈广俊; 杨延乾; 李永胜

    2012-01-01

    The Asiha gold ore deposit is located in the east part of the middle uplifted basement and granitic belt which is one important gold and ferro-polymetallic metallogenic belt in eastern Kunlun. The Early Indosinian diorite and biotite granite are the main ore-hosting rocks, while the NNE and NW-trending faults are major ore-bearing structures in the mine area. Vein I is one of the major auriferous veins, and is closely related to the minette spatially. Fluid inclusions in quartz crystals can be classified into aqueous two-phase and CO2-rich three-phase inclusion. Salinities of fluid inclusions contents of NaCl range from 1. 83% to 8. 13%, densities range from 0. 69 to 0. 87 g/cm3, and homogenization temperatures range from 155. 3 'C to 425. 6 °C, In mineralization stage I , fluid inclusions are characterized by low salinity, high-temperature, and CO2-rich. In mineralization stage Ⅱ , CO2-rich fluid inclusions and gas-liquid two-phase inclusions coexist, which show the immiscibility or boiling characterized by CO2 escaping, and resulted in salinity increasing of the residual fluid. Fluid inclusions in mineralized stage Ⅲ are the gas-liquid two-phase inclusions. Charteristics of fluid inclusions, accompanied with H, O, S isotopic compositions, indicates that the ore-forming fluid is mainly mantle-derived and additional meteoric water in the late stage. By analyzing of Laser Raman spectrum, the gas-phase in fluid inclusions chiefly make up of CO2 ,CH4 and N2. According to the diagram of isochore, the ore-forming pressure can be calculated to almost 98 - 132 MPa,the ore-forming depth ranges from 8. 16 -9.58 km. By contrast to other typical orogenic gold deposits, A conclusion can be safely darwn that Asiha gold deposit belongs to the mesozonal orogenic gold deposit, and the gold mineralization occured in the transition period from compression to extension tectonic environment during intro-continental orogenic movement in Early Indosinian.%阿斯哈金矿位于东

  6. 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)

  7. Drilling the centre of the Thuringian Basin, Germany, to decipher potential interrelation between shallow and deep fluid systems

    Science.gov (United States)

    Kukowski, Nina; Totsche, Kai Uwe; Abratis, Michael; Habisreuther, Annett; Ward, Timothy; Influins Drilling-Team

    2014-05-01

    To shed light on the coupled dynamics of near surface and deep fluids in a sedimentary basin on various scales, ranging from the pore scale to the extent of an entire basin, is of paramount importance to understand the functioning of sedimentary basins fluid systems and therefore e.g. drinking water supply. It is also the fundamental goal of INFLUINS (INtegrated FLuid dynamics IN Sedimentary basins), a research initiative of several groups from Friedrich-Schiller University of Jena and their partners. This research association is focusing on the nearby Thuringian basin, a well confined, small intra-continental sedimentary basin in Germany, as a natural geo laboratory. In a multidisciplinary approach, embracing different fields of geophysics like seismic reflection profiling or airborne geomagnetics, structural geology, sedimentology, hydrogeology, hydrochemistry and hydrology, remote sensing, microbiology and mineralogy, among others, and including both, field-based, laboratory-based and computer-based research, an integral INFLUINS topic is the potential interaction of aquifers within the basin and at its rims. The Thuringian basin, which is composed of sedimentary rocks from the latest Paleozoic and mainly Triassic, is particularly suited to undertake such research as it is of relative small size, about 50 to 100 km, easily accessible, and quite well known from previous studies, and therefore also a perfect candidate for deep drilling. After the acquisition of 76 km seismic reflection data in spring 2011, to get as much relevant data as possible from a deep drilling at the cross point between two seismic profiles with a limited financial budget, an optimated core sampling and measuring strategy including partial coring, borehole geophysics and pump tests as well as a drill hole design, which enables for later continuation of drilling down to the basement, had been developed. Drilling Triassic rocks from Keuper to lower Buntsandstein was successfully realised down

  8. Source of ore-forming components at the Peak mine, Cobar, NSW - evidence from isotope studies

    International Nuclear Information System (INIS)

    -lead was initially concentrated within basement granites, then remobilised by hydrothermal fluids into the Cobar Basin sequences. The source of ore fluids at Peak also have been traced by their hydrogen and oxygen isotope compositions. Inclusion fluids within sulphide minerals, including chalcopyrite, sphalerite and galena from paragenetic stages 2 and 4 have been extracted for hydrogen and oxygen isotope analyses. Inclusion fluids from various stages of vein quartz were also analysed for hydrogen isotope compositions. Stage-2 major Cu-Au mineralisation appears to be related to fluids of significantly low δ18O and δD values, ranging from -6.3 to 3.4 per mil and -115 to -96 per mil, respectively. Fluids responsible for the stage-4 major Pb-Zn-Ag mineralisation at Peak are also characterised by low δ18O and δD values between -4.6 and 1.6 per mil, and 110 and -68 per mil, respectively. In contrast, fluids corresponding to formations of the vein quartz have remarkably large δ18O and δD values (-0.5 to 9.9 per mil and -71 to -41 per mil, respectively. It is inferred that depleted δ18O and δD values of inclusion fluids within sulphide minerals from the two stages of ore mineralisation at Peak favour a model of deeply circulated meteoric fluid involvement, not metamorphic fluids. S, Cl and F would be the most important anions involved with complexing and transport of ore-forming elements. Hydrothermal, syngenetic and metamorphic sulphide minerals in the ore and metasedimentary rocks have been analysed for sulphur isotope analysis. The δ34S values for all sulphide minerals from various ore bodies define a relatively narrow range between 5.4 and 8.9 per mil. However, the δ34S distributions for both syngenetic and metamorphic pyrite and pyrrhotite from the country rocks are significantly different from the values obtained for ore sulphides. δ34S values for syngenetic pyrite and pyrrhotite exhibit large positive values ranging from 16.3 to 17.2 per mil. In contrast, δ34S

  9. Mantle fluid metallogeny of granite-type uranium deposits in northern Guangdong

    International Nuclear Information System (INIS)

    Both Guidong and Zhuguang composites in northern Guangdong Province consist of Indosinian and Yanshanian granite bodies. The two most well-known granite-type uranium ore fields in China, Xiazhuang and Changjiang, are located in the eastern parts of the the two composites, respectively. Studies on H, O, C, Pb, Sr, and Nd isotopes of uranium deposits Xiwang, Shituling and Xianshi within the Xiazhuang ore field and deposit Mianhuakeng within the Changjiang ore field showed that ore-forming fluid had DH2O of -97∼-4.1% and δ18OH2O of 8.1∼0.06%; post-ore fluid had δDH2O of -71∼-5% and δDH2O of 2.0∼-0.94%. After being compared with various fluids, these data suggested the ore-forming fluids were mainly composed of mantle fluid, whereas in the post-mineralization fluids, addition of fluids with meteoric water origin became evident or even dominant. Calcites from ore veins had δ13C of -9.2∼-0.31%, indicating mantle origin of ΣCO2. Studies of Pb, Sr and Nd isotopes revealed that ore-forming materials were a mixture of metal elements coming from granites, mafic dikes and basement metamorphic rocks. Mantle fluid metallogeny of these uranium deposits was compatible with the following geological facts. The deposits in Xiazhuang and Changjiang ore fields fell into super large ones. Within the ore fields, there were many mafic dikes of various groups and strike directions. Fault-depression basins were developed outside the granite composites. The timing and space of ore formation were closely related to the extension tectonic event (or emplacement of mafic dikes. The ore components were characterized by multiple origins. Both permissively and zoned distributions of alkaline alterations were strong and the mineralization fluids were originated from the mantle. The mineralization model could be described as follows: Fluids from Dehydration and degassing of subducting slabs in the late Mesozoic altered the mantle in the mantle wedge by metasomatism to form mantle

  10. Sedimentary exhalative nickel-molybdenum ores in south China

    Science.gov (United States)

    Lott, D.A.; Coveney, R.M., Jr.; Murowchick, J.B.; Grauch, R.I.

    1999-01-01

    Unique bedded Ni-Mo ores hosted by black shales were discovered in localized paleobasins along the Yangzte platform of southern China in 1971. Textural evidence and radiometric dates imply ore formation during sedimentation of black shales that grade into readily combustible beds, termed stone coals, which contain 10 to 15 percent organic carbon. Studies of 427 fluid inclusions indicate extreme variation in hydrothermal brine salinities that were contained by Proterozoic dolostones underlying the ore zone in Hunan and Guizhou. Variations of fluid inclusion salinities, which range from 0.1 to 21.6 wt percent NaCl equiv, are attributed to differences in the compositions of brines in strata underlying the ore bed, complicated by the presence of seawater and dilute fluids that represent condensates of vapors generated by boiling of mineralizing fluids or Cambrian meteoric water. The complex processes of ore deposition led to scattered homogenization temperatures ranging from 100??to 187??C within the Hunan ore zone and from 65??to 183??C within the Guizhou ore zone. While living organisms probably did not directly accumulate metals in situ in sufficient amounts to explain the unusually high grades of the deposits, sulfur isotope ratios indicate that bacteria, now preserved as abundant microfossils, provided sufficient sulfide for the ores by reduction of seawater sulfate. Such microbiota may have depended on vent fluids and transported organic matter for key nutrients and are consistent with a sedex origin for the ores. Vent fluids interacted with organic remains, including rounded fragments of microbial mats that were likely transported to the site of ore deposition by the action of waves and bottom currents prior to replacement by ore minerals.

  11. Geology of eastern Smith Lake ore trend, Grants mineral belt

    International Nuclear Information System (INIS)

    The sandstones in the Brushy Basin Member of the Morrison Formation (Jurassic) are the ore-bearing horizons of the eastern Smith Lake area. The Brushy Basin Member in this district consists of three sandstones with interbedded mudstones. Only the lower two sandstones contain ore. The sandstones are fine to coarse grained, well rounded, and arkosic, representing continental stream sediments. The lower sandstone contains rollfront ore. The redox interface is laterally extensive and well defined, extending at least 7 mi (11 km) west of the Bluewater fault zone. The ore generally occurs at the redox boundary but occasionally will be up to 1500 ft (450 m) updip. Limonitic alteration, where present, is downdip from the hematitic zone and is 100-1,500 ft (30 to 450 m) wide. The middle sandstone contains both trend ore and roll-front ore. The trend ore occurs downdip from the redox front in unoxidized ground. The redox front in the middle sand is also laterally extensive but displays a wedge shape, rather than a C shape. The clay assemblages of the two types of ore are different: the trend ore occurs in sands with the pore spaces filled with kaolinite; the roll-front ore is associated with altered illite-montmorillonite as grain coatings. Hematitic alteration is asociated with the latter. A second stage of kaolinite coats the illite-montmorillonite. Two periods of mineralization are suggested, but no absolute dates are known. The trend ore is the oldest (Jurassic) and is similar to the ore found in unoxidized ground elsewhere in the Grants region. The rollfront ore could be Laramide or post-Laramide because of its association with local Laramide structures

  12. 吉林荒沟山金矿床成矿流体特征%Geochemical Characteristics of Ore-Forming Fluid in Huanggoushan Gold Deposit,Jilin Province

    Institute of Scientific and Technical Information of China (English)

    周向斌; 李剑锋; 王可勇; 梁一鸿; 张淼; 韦烈民; 王志高

    2016-01-01

    荒沟山金矿床为吉南老岭金-多金属成矿带内较具代表性矿床之一,产于元古宇老岭群珍珠门组地层之中,受韧性剪切带构造控制。按地质特征、矿物组合及矿脉之间的穿切关系,将荒沟山金矿床热液成矿作用划分为Ⅰ黄铁矿-毒砂-石英阶段和Ⅱ晚期辉锑矿-乳白色石英两个阶段。系统的流体包裹体岩相学及显微测温研究表明:Ⅰ阶段石英中发育含 CO 2三相、碳质及气液两相3种类型的原生流体包裹体,成矿流体属不混溶的中低温、低盐度 NaCl-H 2 O-CO 2体系热液,在成矿过程中发生过不混溶作用而导致金等有用元素沉淀富集;Ⅱ阶段石英颗粒中主要发育气液两相包裹体,成矿流体属均匀的 NaCl-H 2 O 体系热液。碳、氢、氧同位素研究表明,Ⅰ阶段成矿流体主要来源于岩浆热液,Ⅱ阶段流体除继承早阶段的热液外,还有大气降水的混入;δD 和δ13 CV-PDB 值分析结果证明两个成矿阶段流体均与地层发生过较强的水岩反应。矿床成因属于中温岩浆热液矿床。%Occurred in Zhenzhumen Formation of Laoling Group of Proterozoic Era and controlled by ductile shear belt,the Huanggoushan gold deposit is one of the most representative deposits in Laoling gold-polymetallic metallogenic belt in southern Jilin Province.Based on the geological characteristics,mineral assemblage and the crosscutting relationship between different kinds of veins,the hydrothermal mineralization processes can be divided into two main stages,namely,stageⅠpyrite arseno-pyrite quartz and stageⅡ later stibnite-milky quartz.Systematic study on petrography and microthermometry of fluid inclusions shows that quartz of Stage Ⅰcontains three types of primary fluid inclusions,which are CO 2 bearing three phases,carbonic and aqueous two phases inclusions respectively,and the ore forming fluid is of medium to low temperature and low salinity NaCl-H 2 O-CO 2 kind of

  13. Ore-forming and Exploration Models of the Baguamiao Gold Deposit, Shaanxi Province

    Institute of Scientific and Technical Information of China (English)

    2000-01-01

    The Baguamiao superlarge gold deposit in Shaanxi Province is one of the typical cases in China that are hosted by sedimentary rocks. Explorers and researchers have discussed the gold mineralization enrichment conditions by studying sulphur, oxygen, carbon, silicon stable isotopes and mineralizing fluid features of the Baguamiao gold deposit and proposed a hydrothermal sedimentation-magmatic reconstructing gold mineralization model featuring multi-sources of ore-forming materials and multistage mineralizations. In addition, prospecting for "Baguamiao-type"gold deposits was started in the Fengtai Basin and a great number of important prospecting targets such as Tonglinggou, Simaoling, Guoansi and Dachaigou were discovered.

  14. Subsurface plumbing and fluid expulsion from sedimentary basins: evidence from the sedimentary record offshore West Africa (Invited)

    Science.gov (United States)

    Huuse, M.

    2010-12-01

    Many petroliferous basins around the world show evidence for fluid expulsion and seepage on the land surface or seafloor. However, not all fluid expulsion features are evidence of a working hydrocarbon systems and one needs to carefully evaluate fluid expulsion features and their associated geology and in particular their plumbing systems before inferring the nature of the expelled fluids. Geochemical fingerprinting of the migrating fluids may be sampled directly or via carbonate cements secreted in association with focus fluid conduits and may help determine the nature of the expelled fluids including their stratigraphic origin. When such evidence is unavailable, one may have to rely on remote sensing, including 3D seismic characterization in order to assess the nature of expelled fluids and links with hydrocarbon migration and/or ‘normal’ diagenetic fluid expulsion. This paper presents 3D seismic case studies of pockmarks, fluid flow pipes and polygonal fault systems which show evidence of both deep and shallow sources of expelled fluids and discuss the different controls on their occurrence and significance. Importantly, there is evidence of both conducting and sealing behaviours of polygonal fault sytems. Bottom-Simulating Reflections from interfaces between free gas and overlying gas hydrate occur in a variety of manifestations and may be linked with both deep and shallow sources of methane. Their depth of occurrence relative to seafloor depth may be used to infer local geothermal gradients and it is shown that underlying salt causes BSRs to shallow, indicative of a doubling of the geothermal gradient above salt structures compared to the adjacent salt mini basins. It is further suggested that salt structures on the middle slope serve a dual purpose as trap and leak-forming features, with traps focused on the down-dip side of overhanging diapirs and leaks located on the updip side and flanks. Associated leakage phenomena include gas and gas hydrate

  15. Tectonic evolution and its control over ore-formation of interlayer oxidized zone sandstone-type uranium deposit at southern margin of Turpan-Hami basin

    International Nuclear Information System (INIS)

    The tectonic evolution is divided into four stages at the southern margin of Turpan-Hami basin: (1) the development of Xinjiang oldland; (2) the sedimentation of passive-continental margin in the south of Junggar (Turpan-Hami) plate; (3) the accretion nappes of the force-arc margin and the development of foreland-like basin in the island (C2-T); (4) the development of sub-orogenic belt and the slope zone (J-Q). The third stage provided favourable material source and the emplacement space for interlayer oxidized zone-type uranium deposit. The fourth stage of the tectonic evolution was the time for the formation of intramountain basin and controlled the occurrence of the interlayer oxidized zone and sandstone-type uranium deposit

  16. 新疆阿尔泰托莫尔特铁(锰)矿床成矿流体研究%A study of ore-forming fluids of Tuomoerte Fe-(Mn) deposit in Altay, Xinjiang

    Institute of Scientific and Technical Information of China (English)

    张志欣; 杨富全; 黄承科; 刘锋; 柴凤梅; 耿新霞

    2012-01-01

    托莫尔特铁(锰)矿床赋存于上志留统一下泥盆统康布铁堡组上亚组变质火山-沉积岩系中.矿床的形成经历了火山沉积期、岩浆热液叠加改造期和区域变质期,火山沉积期为铁和锰主要成矿期.火山沉积期石英中流体包裹体类型以气液两相包裹体为主,均一温度集中于170~300℃,峰值为190℃,流体的ω(NaClq)为3.23%~22.71%,密度为0.62~ 1.09 g/cm3,气相和液相成分表明成矿流体富含Na+、Cl和H2O,为中-低温、中-低盐度、中-低密度的H2O-NaCl体系.区域变质期石英中以发育含液体CO2包裹体为特征,完全均一温度介于210~523℃,w(NaCleq)为4.80%~11.33%,密度为0.85~1.05 g/cm3,气相和液相成分表明流体富含Na+、Cl、SO2-4、CO2、CH4、C2H6和N2,显示成矿流体为中-高温、中-低盐度、中-低密度的H2O-CO2-CH4-N2-NaCl体系.氢和氧同位素特征表明,火山沉积期成矿流体为海水和岩浆水的混合,区域变质期成矿流体主要为变质水混合深循环的大气降水.%The Tuomoerte Fe-(Mn) deposit occurs in metavolcanic-sedimentary sequence within the upper subforma-tion of Upper Silurian-Lower Devonian Kangbutiebao Formation. Field evidence and petrographic observation indicate three periods of metallogenesis, i. e. , volcano-sedimentation, magmatic-hydrothermal activity and regional metamorphism. The majority of the Fe-Mn metallogenic activity occurred during the volcano-sedimentation period. The homogenization temperatures of the liquid inclusions in quartz of the volcano-sedimentation period are concentrated between 170℃ and 300℃, with a peak temperature of 190℃, the salinities range from 3.23 % to 22.71 % , and the densities range from 0.62 to 1.09 g/cm3. The vapor and liquid composition of fluid inclusions in this period show that the ore-forming fluid was rich in Na+ , Cl and H2O, indicating that the ore-forming fluid was of moderate-low temperature, moderate-low salinity and

  17. Structural and fluid-density controls on the flow system in the Paleozoic arches and basins of the Midwest

    Energy Technology Data Exchange (ETDEWEB)

    Gupta, N.; Bair, E.S. (Ohio State Univ., Columbus, OH (United States). Dept. of Geological Sciences)

    1992-01-01

    Although many conceptual, theoretical, and field studies document the effects of topographic driving forces and the effects of variations in hydraulic conductivity on regional flow patterns, few studies document the effects of fluid-density-related driving forces on regional flow patterns. These few studies indicate that variations in the density of formation fluids in large sedimentary basins are common and can have a pronounced effect on the interpretation of flow directions and flow velocities. The authors goal is to develop an understanding of the influence of fluid-density variations on regional groundwater flow patterns in the Cambrian Mt. Simon Sandstone in the midwestern United States. This was accomplished using data contained in various geologic and hydrologic reports, results of drill-stem tests and core analyses, and information in petitions submitted by waste-injection operators as part of the federal LANDBAN program. These data were incorporated into a regional, three-dimensional, steady-state, finite-difference flow model used to simulate flow of variable-density fluids in the Mt. Simon Sandstone and in 10 overlying hydrostratigraphic units. The model covers an area of approximately 275,000 square miles, including all or parts of 8 states. Simulations were performed using equivalent-freshwater heads and using variable-fluid densities in a 12-layer model representing the entire stratigraphic sequence from the basal Cambrian Sandstone through the Pennsylvanian System and Pleistocene deposits. The results indicate that structural features such as the Cincinnati Arch and surrounding basins control the locations of ground-water divides and flow velocities. In areas of high fluid densities, flow directions and velocities show significant differences compared with flow directions and velocities based on freshwater heads.

  18. Geology and geochemistry of the Macheng Algoma-type banded iron-formation, North China Craton: Constraints on mineralization events and genesis of high-grade iron ores

    Science.gov (United States)

    Wu, Huaying; Niu, Xianglong; Zhang, Lianchang; Pirajno, Franco; Luo, Huabao; Qin, Feng; Cui, Minli; Wang, Changle; Qi, Min

    2015-12-01

    The Macheng iron deposit is located in the eastern Hebei province of the North China Craton (NCC). It is hosted in Neoarchean metamorphic rocks of Baimiaozi formation in the Dantazi Group, consisting of biotite-leptynite, plagioclase-gneiss, plagioclase-amphibolite, migmatite, migmatitic granite and quartz schist. Geochemical analyses of the host biotite leptynite and plagioclase amphibolites show that their protoliths are both volcanics, inferred to be trachytic basalt and basaltic andesite, respectively. Based on the geochemical signature of the host rocks, together with geology of the iron deposit, it is inferred that the Macheng BIF is an Algoma-type iron exhalative formation, formed in an arc-related basin in the Neoarchean. Post-Archean Australian Shale (PAAS)-normalized rare earth elements (REEs) plus yttrium (Y) concentrations of different BIF ores with gneissic, striated and banded structure in the Macheng deposit, show similar patterns with depletions in light rare earth elements (LREEs) and middle rare earth elements (MREEs) relative to heavy rare earth elements (HREEs) and with apparently positive La, Y and Eu anomalies. Y/Ho ratios of the gneissic, striated and banded BIF ores vary from 37 to 56. These geochemical features of the BIF ores reveal their affinity with the sea water and the presence of a high-temperature hydrothermal component, indicating that both the seawater and high temperature hydrothermal fluids derived from alteration of oceanic basalts and komatiites may contribute to formation of the Macheng BIF. Geological, mineralogical and geochemical studies of the Macheng deposit recognized two kinds of high-grade iron ores. One is massive oxidized high-grade ore (Fe2O3T = 74.37-86.20 wt.%), mainly consisting of hematite with some magnetite, which shows geochemical characteristics of the gneissic, striated and banded BIF ores. The other type is magnetite high-grade ore, also massive and consisting of magnetite, with distinct characteristics

  19. The Ancient Ore-forming Fluids Study of Neglasari Mine in West Java, Indonesia%印度尼西亚西爪哇内格拉萨金矿区古成矿流体研究

    Institute of Scientific and Technical Information of China (English)

    徐晓璐; 高建国; 张利军

    2012-01-01

    通过对比研究各种类型矿石的化学组分、矿物共生组合、围岩蚀变特征,以及包体测温数据,初步认为金在古成矿流体在中低温、低氧逸度、pH值接近中性的物理化学环境中,以硫氢络合物(Au(HS))的形式迁移.流体物理化学环境的骤变是引起矿质元素沉淀的内因;而诱发物理化学环境改变的主要外界因素是流体的沸腾作用和硫化作用.基于研究区的大地构造背景、区域成矿带及矿区地质特征,提出“本区矿床属于火山-次火山杂岩成矿体系,相应的热液系统为与火山-次火山杂岩有关的岩浆-大气降水热液系统”的假设,并利用该假设解释本区矿床的成因.%In terms of the chemical composition, symbiotic mineral complexes of various ores, the characteris tics of wall-rock alteration, and homogenization temperature data of fluid inclusions, it is preliminarily concluded that gold in ancient ore-forming fluids migrated as ( Au ( HS) 2 ) under the condition which is low temperature, hy-poxia fugacity and pH close to neutral. The sudden change of physical chemistry condition is the essential cause that leaded gold in hydrothermal fluids to precipitation. And the outer inducement factors that caused physical chemistry environment change are primary fluids boiling and sulfuration. Based on the tectonic setting , regional metallogenic belt and geological characteristics of the mining area, one hypothesis deposit in mining area a part of a volcano-subvolcano complex metallogenic system. And the corresponding hydrothermal system is volcanic-subvocan-ic magma-ground water hydrothermal system is committed. It is easy to interpreter the genesis of this deposit in this mining area with this hypothesis.

  20. Fluid flow in the northern Broad Fourteens Basin during Late Cretaceous inversion

    NARCIS (Netherlands)

    Oude Essink, Gualbert

    2003-01-01

    A basin-scale hydrogeological study of the inverted northern Broad Fourteens Basin, Netherlands offshore, has resulted in a reconstruction of geological evolution, an estimate of Late Cretaceous topography and model scenarios of syn-inversion meteoric water infiltration. This study was performed in

  1. Modeling fluid flow and heat transfer at Basin and Range faults: preliminary results for Leach hot springs, Nevada

    Science.gov (United States)

    López, Dina L.; Smith, Leslie; Storey, Michael L.

    1994-01-01

    The hydrothermal systems of the Basin and Range Province are often located at or near major range bounding normal faults. The flow of fluid and energy at these faults is affected by the advective transfer of heat and fluid from an to the adjacent mountain ranges and valleys, This paper addresses the effect of the exchange of fluid and energy between the country rock, the valley fill sediments, and the fault zone, on the fluid and heat flow regimes at the fault plane. For comparative purposes, the conditions simulated are patterned on Leach Hot Springs in southern Grass Valley, Nevada. Our simulations indicated that convection can exist at the fault plane even when the fault is exchanging significant heat and fluid with the surrounding country rock and valley fill sediments. The temperature at the base of the fault decreased with increasing permeability of the country rock. Higher groundwater discharge from the fault and lower temperatures at the base of the fault are favored by high country rock permabilities and fault transmissivities. Preliminary results suggest that basal temperatures and flow rates for Leach Hot Springs can not be simulated with a fault 3 km deep and an average regional heat flow of 150 mW/m2 because the basal temperature and mass discharge rates are too low. A fault permeable to greater depths or a higher regional heat flow may be indicated for these springs.

  2. Sequential extraction and compositional analysis of oil-bearing fluid inclusions in reservoir rocks from Kuche Depression, Tarim Basin

    Institute of Scientific and Technical Information of China (English)

    2000-01-01

    The free oils, adsorbed oils and oil-bearing fluid inclusions have been extracted separately and analyzed by GC and GC-MS in reservoir rock samples collected from the Kuche Depression. The results demonstrate that the molecular compositions of oil-bearing fluid inclusions are significantly different from those of the free oils (the current oils). Compared with the current oil, the oil-bearing fluid inclusions are characterized by relatively high values of parameters Pr/nC17and Ph/nC18, low values of Pr/Ph, hopanes/steranes, C30-diahopane/C30-hopane and Ts/Tm, low content of C29Ts terpane and high maturities as indicated by C29 steranes 20S/(20R+20S). In addition, the oil-bearing fluid inclusions correlate very well with the oils in northern and central Tarim Basin, which were derived from Cambrian-Ordovician marine source rocks. The adsorbedoils appear to be an intermediate type between free oils and oil-bearing fluid inclusions. The above analytical data indicate that there are at least two oil-charging episodes for these reservoir rock samples. The early charging oils were derived from Cambrian-Ordovician marine source rocks, and the later charging oils, from Triassic-Jurassic terrestrial source rocks. The primary marine oils were overwhelmingly diluted by the following terrestrial oils.

  3. Oil shales, evaporites and ore deposits

    Science.gov (United States)

    Eugster, Hans P.

    1985-03-01

    elevated temperatures and with carbonates as principal host rocks. The Pine Point deposits are cited for their close association with evaporites. Alkaline, metal-rich brines are postulated for the HYC deposit of McArthur River, Australia. Such brines are known from the Green River Formation and deposits formed from such brines constitute the GRT class. They can be recognized by the presence of Magadi-type cherts and zeolite-analcime-K-spar tuffs. The Cu-Co ore bodies of Outokumpu, Finland, might also belong to this type. A new classification of sedimentary ore deposits is proposed, based on their geochemical environment. KST and MVT are formed from acid ore fluids, while GRT and CT (Creede type) are derived from basic ore fluids. pH of the fluids is best evaluated not from the ores themselves, but from their effect on the host-rocks.

  4. 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)

  5. Methane-rich fluid inclusions and their hosting volcanic reservoir rocks of the Songliao Basin, NE China

    Institute of Scientific and Technical Information of China (English)

    WANG Pu-Jun; HOU Qi-jun; CHENG Ri-hui; LI Quan-lin; GUO Zhen-hua; HUANG Yu-long

    2004-01-01

    Methane-rich fluids were recognized to be hosted in the reservoir volcanic rocks as primary inclusions.Samples were collected from core-drillings of volcanic gas reservoirs with reversed δ12C of alkane in the Xujiaweizi depression of the Songliao Basin. The volcanic rocks are rhyolite dominant being enriched in the more incompatible elements like Cs, Rb, Ba, Th, U and Th with relative high LREE, depleted HREE and negative anomalies of Ti and Nb,suggesting a melt involving both in mantle source and crustal assimilation. Primary fluids hosted in the volcanic rocks should have the same provenance with the magma. The authors concluded that the enclosed CH4 in the volcanics are mantle/magma-derived alkane and the reversed δ13C of alkane in the corresponding gas reservoirs is partly resulted from mixture between biogenic and abiogenic gases.

  6. Diagenesis and Fluid Flow History in Sandstones of the Upper Permian Black Jack Formation, Gunnedah Basin, Eastern Australia

    Institute of Scientific and Technical Information of China (English)

    BAI Guoping; John B. KEENE

    2007-01-01

    The fluid flow history during diagenesis of sandstones in the Upper Permian Black Jack Formation of the Gunnedah Basin has been investigated through integrated petrographic observations, fluid inclusion investigations and stable isotope analyses. The early precipitation of mixed-layer illite/smectite, siderite, calcite, ankerite and kaolin proceeded at the presence of Late Permian connate meteoric waters at temperatures of up to 60℃. These evolved connate pore waters were also parental to quartz, which formed at temperatures of up to 87℃. The phase of maximum burial was characterized by development of filamentous illite and late calcite at temperatures of up to ~90℃. Subsequent uplifting and cooling led to deep meteoric influx from surface, which in turn resulted in dissolution of labile grains and carbonate cements, and formation of second generation of kaolin. Dawsonite was the last diagenetic mineral precipitated and its formation is genetically related to deep-seated mamagtic sourced CO2.

  7. Ores and Climate Change - Primary Shareholders

    Science.gov (United States)

    Stein, Holly J.; Hannah, Judith L.

    2015-04-01

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

  8. Coincidence or not? Interconnected gas/fluid migration and ocean-atmosphere oscillations in the Levant Basin

    Science.gov (United States)

    Lazar, Michael; Lang, Guy; Schattner, Uri

    2016-08-01

    A growing number of studies on shallow marine gas/fluid systems from across the globe indicate their abundance throughout geological epochs. However, these episodic events have not been fully integrated into the fundamental concepts of continental margin development, which are thought to be dictated by three elements: tectonics, sedimentation and eustasy. The current study focuses on the passive sector of the Levant Basin on the eastern Mediterranean continental margin where these elements are well constrained, in order to isolate the contribution of gas/fluid systems. Single-channel, multichannel and 3D seismic reflection data are interpreted in terms of variance, chaos, envelope and sweetness attributes. Correlation with the Romi-1 borehole and sequence boundaries constrains interpretation of seismic stratigraphy. Results show a variety of fluid- or gas-related features such as seafloor and subsurface pockmarks, volumes of acoustic blanking, bright spots, conic pinnacle mounds, gas chimneys and high sweetness zones that represent possible secondary reservoirs. It is suggested that gas/fluid migrate upwards along lithological conduits such as falling-stage systems tracts and sequence boundaries during both highstands and lowstands. In all, 13 mid-late Pleistocene sequence boundaries are accompanied by independent evidence of 13 eustatic sea-level drops. Whether this connection is coincidental or not requires further research. These findings fill gaps between previously reported sporadic appearances throughout the Levant Basin and margin and throughout geological time from the Messinian until the present day, and create a unified framework for understanding the system as a whole. Repetitive appearance of these features suggests that their role in the morphodynamics of continental margins is more important than previously thought and thus may constitute one of the key elements of continental margin development.

  9. Coincidence or not? Interconnected gas/fluid migration and ocean-atmosphere oscillations in the Levant Basin

    Science.gov (United States)

    Lazar, Michael; Lang, Guy; Schattner, Uri

    2016-03-01

    A growing number of studies on shallow marine gas/fluid systems from across the globe indicate their abundance throughout geological epochs. However, these episodic events have not been fully integrated into the fundamental concepts of continental margin development, which are thought to be dictated by three elements: tectonics, sedimentation and eustasy. The current study focuses on the passive sector of the Levant Basin on the eastern Mediterranean continental margin where these elements are well constrained, in order to isolate the contribution of gas/fluid systems. Single-channel, multichannel and 3D seismic reflection data are interpreted in terms of variance, chaos, envelope and sweetness attributes. Correlation with the Romi-1 borehole and sequence boundaries constrains interpretation of seismic stratigraphy. Results show a variety of fluid- or gas-related features such as seafloor and subsurface pockmarks, volumes of acoustic blanking, bright spots, conic pinnacle mounds, gas chimneys and high sweetness zones that represent possible secondary reservoirs. It is suggested that gas/fluid migrate upwards along lithological conduits such as falling-stage systems tracts and sequence boundaries during both highstands and lowstands. In all, 13 mid-late Pleistocene sequence boundaries are accompanied by independent evidence of 13 eustatic sea-level drops. Whether this connection is coincidental or not requires further research. These findings fill gaps between previously reported sporadic appearances throughout the Levant Basin and margin and throughout geological time from the Messinian until the present day, and create a unified framework for understanding the system as a whole. Repetitive appearance of these features suggests that their role in the morphodynamics of continental margins is more important than previously thought and thus may constitute one of the key elements of continental margin development.

  10. The Vein-type Zn-(Pb, Cu, As, Hg) mineralization at Fedj Hassene ore field, North-Western Tunisia: Mineralogy, Trace Elements, Sulfur Isotopes and Fluid Inclusions; Le champ filonien a Zn-(Pb, Cu, As, Hg) du district minier de Fedj Hassene (Nord Ouest de la Tunisie): Mineralogie, Elements en traces, Isotopes du Soufre et Inclusions Fluides

    Energy Technology Data Exchange (ETDEWEB)

    Bejaouil, J.; Bouhlel, S.; Barca, D.; Braham, A.

    2011-07-01

    The Fedj Hassene district is localized at the edge of the Tuniso-Algerian border 10 km of Ghardimaou area. It consists of a Zn-Pb vein type with minor amounts of Cu-As-Hg. The total Zn reserves are about 370.000t. The mineralization occurs within sub parallel fractures to the Ain El Kohla ESE-WNW fault. Host rocks consist of limestones and marly limestones of the Middle Turonian. In the principal lode of Fedj Hassene, the mineralization occurs as vein filling of massive and brecciated brown sphalerite and minor galena ore with gangue. Other trace minerals are pyrite, chalcopyrite, orpiment, realgar, smithsonite and cerussite. LA-ICP-MS analyses in sphalerites show mean contents of 0,84 wt% Fe, 0,14 wt% Cd and 0,02 wt% Mn Ore. Fluid inclusions study in calcite and sphalerite reveals one mineralizing fluid characterized by an average salinity 23% wt NaCl with decreasing homogenisation temperature. In fact the temperature shows decrease from sphalerite to calcite. The fluid density that corresponds to trapping pressure ranges between 1.00 g/cm{sup 3} and 1.11 g/cm{sup 3} and pressure close to 200 bars. Micro thermometric data in fluid inclusion hosted by gangue mineral presented by calcite show an average temperature of formation around 194 degree centigrade. These inclusions homogenized to the liquid phase between 156 degree centigrade and 210 degree centigrade and salinities values ranging from 22 to 28 wt% NaCl and an average around 23% wt NaCl. The {delta}{sup 3}4S (VCDT) values of sphalerite are in the range of + 4,6% to 6,4% (average=5,6%). Thermochemical reduction of Triassic sulfate by reaction with hydro-carbons is the most probable source for the heavy and the narrow range of the d{delta}{sup 3}4S values. Mineralogical, geochemical of trace elements, fluid inclusions and sulfur isotopes studies allow to include the vein-type ore field of Fedj Hassene in the polymetallic (Pb-Zn-As-Hg) vein mineralization of the nappe zone in northern Tunisia and north eastern

  11. Isotopic evidence (B, C, O) of deep fluid processes in fault rocks from the active Woodlark Basin detachment zone

    Science.gov (United States)

    Kopf, Achim; Behrmann, Jan H.; Deyhle, Annette; Roller, Sybille; Erlenkeuser, Helmut

    2003-03-01

    We report results from boron, carbon and oxygen stable isotope analyses of faulted and veined rocks recovered by scientific ocean drilling during ODP Leg 180 in the western Woodlark Basin, off Papua New Guinea. In this area of active continental extension, crustal break-up and incipient seafloor spreading, a shallow-dipping, seismically active detachment fault accommodates strain, defining a zone of mylonites and cataclasites, vein formation and fluid infiltration. Syntectonic microstructures and vein-fill mineralogy suggest frictional heating during slip during extension and exhumation of Moresby Seamount. Low carbon and oxygen isotope ratios of calcite veins indicate precipitation from hydrothermal fluids (δ 13C PDB down to -17‰; δ 18O PDB down to -22‰) formed by both dehydration and decarbonation. Boron contents are low (parent solutions to calcite vein fills) are low when compared to deep-seated waters in other tectonic environments, likely reflecting preferential loss of 11B during low-grade metamorphism at depth. Pervasive devolatilization and flux of CO 2-rich fluids are evident from similar vein cement geochemistry in the detachment fault zone and splays further updip. Multiple rupture-and-healing history of the veins suggests that precipitation may be an important player in fluid pressure evolution and, hence, seismogenic fault movement.

  12. Variability in the microbial communities and hydrothermal fluid chemistry at the newly discovered Mariner hydrothermal field, southern Lau Basin

    Science.gov (United States)

    Takai, Ken; Nunoura, Takuro; Ishibashi, Jun-Ichiro; Lupton, John; Suzuki, Ryohei; Hamasaki, Hiroshi; Ueno, Yuichiro; Kawagucci, Shinsuke; Gamo, Toshitaka; Suzuki, Yohey; Hirayama, Hisako; Horikoshi, Koki

    2008-06-01

    A newly discovered hydrothermal field called the Mariner field on the Valu Fa Ridge in the southern Lau Basin was explored and characterized with geochemical and microbiological analyses. The hydrothermal fluid discharging from the most vigorous vent (Snow Chimney, maximum discharge temperature 365°C) was boiling at the seafloor at a depth of 1908 m, and two distinct end-member hydrothermal fluids were identified. The fluid chemistry of the typical Cl-enriched and Cl-depleted hydrothermal fluids was analyzed, as was the mineralogy of the host chimney structures. The variability in the fluid chemistry was potentially controlled by the subseafloor phase-separation (vapor loss process) and the microbial community activities. Microbial community structures in three chimney structures were investigated using culture-dependent and -independent techniques. The small subunit (SSU) rRNA gene clone analysis revealed that both bacterial and archaeal rRNA gene communities on the chimney surfaces differed among three chimneys. Cultivation analysis demonstrated significant variation in the culturability of various microbial components among the chimneys, particularly of thermophilic H2-oxidizing (and S-oxidizing) chemolithoautotrophs such as the genera Aquifex and Persephonella. The physical and chemical environments of chimney surface habitats are still unresolved and do not directly extrapolate the environments of possible subseafloor habitats. However, the variability in microbial community found in the chimneys also provides an insight into the different biogeochemical interactions potentially affected by the phase separation of the hydrothermal fluids in the subseafloor hydrothermal habitats. In addition, comparison with other deep-sea hydrothermal systems revealed that the Mariner field microbial communities have unusual characteristics.

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

    Institute of Scientific and Technical Information of China (English)

    王宝德; 牛树银; 孙爱群; 李红阳

    2003-01-01

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

  14. Gold ore sorting

    International Nuclear Information System (INIS)

    Apparatus for sorting lumps of gold-bearing ore according to their gold content is described. It includes means for irradiating the lumps of ore with neutrons, e.g. a neutron tube adapted to produce at least 1010 neutrons per second with an energy of less than 4.5 MeV. The resulting intensity of 297 keV gamma rays arising from the nuclear reaction 197Au(n,n'#betta#) 197Au is measured. The measured gamma ray intensity from a given lump of ore is used to sort that lump of ore from other lumps. The apparatus includes various cylinders and a vibrator for presenting the lumps of ore to the neutrons in a geometrical configuration such as to enable the lumps to be irradiated uniformly. (author)

  15. Inclusiones fluidas e isotopos estables en la ganga de los yacimientos de manganeso del norte de la provincia de Córdoba Fluid inclusions and stable isotopes in non-ore minerals of the manganese ore deposits in the north of the Córdoba province

    Directory of Open Access Journals (Sweden)

    P.R. Leal

    2002-09-01

    Full Text Available En este trabajo se analizan las características físico-químicas asociadas a la precipitación de la ganga de yacimientos epitermales de manganeso. Estos minerales fueron formados principalmente durante la etapa póstuma del sistema, el cual es posible dividir espacialmente en tres sectores en función del mineral más abundante. En esta oportunidad se estudia el sector austral donde el mineral más común es la calcita. El análisis microtermométrico de las inclusiones fluidas sobre muestras de calcita, baritina y fluorita, hizo posible obtener salinidades del fluido de 2,7 y 4% eq. en peso NaCl y temperaturas inferiores a 100°C. Los estudios de isótopos de 13C, 18O y 34S en calcita y baritina permitieron determinar la fuente meteórica de los fluidos asociados a su precipitación. Al mismo tiempo los valores de d13C en calcita se consideran el resultado de un fluido en equilibrio con CO2 atmosférico y cantidades menores de carbono producto de la disolución de compuestos orgánicos. Por otro lado, los valores de d34S de la baritina pueden ser explicados por un fluido con H2S que resulta de la disolución de sulfuros de las rocas de caja. Finalmente, se postula la presencia de dos fluidos. Un fluido ascendente fue el responsable de la precipitación de la baritina en la zona donde el H2S se oxida a SO4=; al mismo tiempo, éste pudo también formar fluorita y variedades de sílice conforme su temperatura desciende. La existencia de un fluido descendente permite explicar la generación de calcita por calentamiento del mismo.In this paper the non-ore minerals of the southern sector of this deposit are studied. Microthermometric analysis on calcite, barite and fluorite show fluid salinities of 2.7 and 4% wt eq. NaCl, and temperatures below 100°C. Isotopes of 13C, 18O and 34S allow to determine a meteoric source for the fluids associated to their precipitation. The d13C values obtained in calcite are considered the result of a fluid in

  16. Metal transport by deep fluids from evaporite source in the Oxfordian marls of the SE Basin of France. Contribution from PIXE microanalysis

    International Nuclear Information System (INIS)

    Deep-seated fluids uplifted with Triassic diapirs in the SE basin, and minerals precipitated from evolved evaporite fluids in the Oxfordian marls, have been characterized by Proton Induced X-ray Emission (PIXE) microanalysis. Trace amounts of Fe, Cu, ± Zn, ±Ti, ± As, ± Br have been measured in both cases, emphasizing the metallogenic potential of the diapiric fluids, and their influence during early diagenesis of the Oxfordian marls. The low Sr-content of evaporite fluids (<20 ppm) contrasts with the Sr-rich minerals deposited below the sea-floor surface. (authors). 21 refs., 1 fig., 1 tab

  17. Natural gas generation model and its response in accumulated fluids in the Yinggehai basin

    Institute of Scientific and Technical Information of China (English)

    HAO; Fang; (郝; 芳); ZOU; Huayao; (邹华耀); HUANG; Baojia; (黄保家)

    2003-01-01

    The natural gases found in the Yinggehai basin have nitrogen gas content ranging from 3.5% to 35%, and carbon dioxide content ranging from 0.1% to 93%. The nitrogen and CO2 contents show a wide variation even in the same gas field. The natural gas generation and evolution model has been established based on the relationship among the contents of nitrogen, carbon dioxide and hydrocarbon gases in the discovered gas fields, and the results of simulation experiments. The thickness of the Tertiary and Quaternary in the Yinggehai basin is over 17 km, and gas generation stages from diagenesis (microbial methane) to metamorphism have been developed. Nitrogen in this basin is organic in origin, and has been generated mainly in the catagenetic stage, roughly synchronous with hydrocarbon gases. Carbon dioxide is mainly inorganic in origin, and has been generated from high-temperature decomposition of carbonates in the metamorphic stage. The Dongfang gas field shows strong inter-reservoir compositional heterogeneities, and different gas reservoirs have recorded the products of gas generation at different stages. It has been confirmed that the complexity in natural gas composition in the Yinggehai basin is the combined results of multi-stage natural gas generation and multi-stage gas injection and accumulation.

  18. Fluid Flow History in Lower Triassic Bulgo Sandstone, Central Sydney Basin, Australia

    Institute of Scientific and Technical Information of China (English)

    2000-01-01

    The fluid flow history during diagenesis of the Lower Triassic Bulgo sandstone has been investigated through integrated analyses of petrography, stable isotope and fluid inclusion. Combined application of these techniques was intended to constrain the temperature, timing, chemistry and source of pore fluids during diagenetic cementation events in the Lower Triassic Bulgo sandstone. The dlagenesis proceeded in two different flow regimes: early dynamic fluid flow regime and late slow static fluid flow regime. The former was characterized by a slight increase of δ(18O) of pore waters form estimated -15 × 10-3 to -14 × 10-3 with the temperature increasing from ~ 10 ℃ to ~ 75 ℃. During early diagenesis, early clays and pore filling carbonates precipitated from the pore waters. The late slow flow/static fluid regime was characterized by a rapid 18O-enrichment process. δ(18O) of pore waters increased from -14× 10-3 to -5× 10-3 with the temperature increasing from 75 ℃ to 110 ℃. During the late diagenesis, kaolin (generation Ⅲ ), quartz and illite crystallized. Oil migrated to the sandstones of the Bulgo sandstone during quartz cementation.

  19. Fluids preserved in variably altered graphitic pelitic schists in the Dufferin Lake Zone, south-central Athabasca Basin, Canada: implications for graphite loss and uranium deposition

    Science.gov (United States)

    Pascal, Marjolaine; Boiron, Marie-Christine; Ansdell, Kevin; Annesley, Irvine R.; Kotzer, Tom; Jiricka, Dan; Cuney, Michel

    2016-06-01

    The Athabasca Basin (Canada) contains the highest grade unconformity-type uranium deposits in the world. Underlying the Athabasca Group sedimentary rocks of the Dufferin Lake Zone are variably graphitic, pelitic schists (VGPS), altered to chlorite and hematite (Red/Green Zone: RGZ). They were locally bleached near the unconformity during paleoweathering and/or later fluid interaction. Overall, graphite was lost from the RGZ and the bleached zone relative to the original VGPS. Fluid inclusions were examined in different generations of quartz veins, using microthermometry and Raman spectroscopy, to characterize and compare the different fluids that interacted with the RGZ and the VGPS. In the VGPS, CH4-, and N2-rich fluid inclusions, which homogenize into the vapor phase between -100 and -74 °C, and -152 and -125 °C, respectively, and CO2-rich fluid inclusions, homogenizing either into vapor or liquid between 20 and 28 °C, are present. Carbonic fluids could be the result of the breakdown of graphite to CH4 + CO2, whereas N2-rich fluid is interpreted to be the result of breakdown of feldspars/micas to NH4 ++N2. In the RGZ, the presence of fluid inclusions with low ice melting temperature (-38 to -16 °C) reflect the presence of CaCl2, and fluid inclusions with halite daughter minerals that dissolve between 190 and 240 °C indicate the presence of highly saline fluids. These fluids are interpreted to be derived from the Athabasca Basin. The circulation of carbonic fluids and brines occurred during two different events related to different P-T conditions of trapping. The carbonic fluids interacted with basement rocks during retrograde metamorphism of the basement rocks before deposition of the Athabasca Basin, whereas the brines circulated after the deposition of the Athabasca Basin. These latter fluids are similar to brines related to uranium mineralization at McArthur River and thus, in addition to possibly being related to graphite depletion in the RGZ, they could

  20. Determination of paleo-pressure for a natural gas pool formation based on PVT characteristics of fluid inclusions in reservoir rocks--A case study of Upper-Paleozoic deep basin gas trap of the Ordos Basin

    Institute of Scientific and Technical Information of China (English)

    MI; Jingkui; XIAO; Xianming; LIU; Dehan; SHEN; Jiagui

    2004-01-01

    It has been proved to be a difficult problem to determine directly trapping pressure of fluid inclusions. Recently, PVT simulation softwares have been applied to simulating the trapping pressure of petroleum inclusions in reservoir rocks, but the reported methods have many limitations in practice. In this paper, a method is suggested to calculating the trapping pressure and temperature of fluid inclusions by combining the isochore equations of a gas-bearing aqueous inclusion with its coeval petroleum inclusions. A case study was conducted by this method for fluid inclusions occurring in the Upper-Paleozoic Shanxi Formation reservoir sandstones from the Ordos Basin. The results show that the trapping pressure of these inclusions ranges from 21 to 32 MPa, which is 6-7 MPa higher than their minimum trapping pressure although the trapping temperature is only 2-3℃ higher than the homogenization temperature. The trapping pressure and temperature of the fluid inclusions decrease from southern area to northern area of the basin.The trapping pressure is obviously lower than the state water pressures when the inclusions formed. These data are consistent with the regional geological and geochemical conditions of the basin when the deep basin gas trap formed.

  1. 云南毛坪铅锌(银、锗)矿床流体包裹体特征及成矿流体来源%Features of fluid inclusions and sources of ore-forming fluid in the Maoping carbonate-hosted Zn-Pb-( Ag-Ge) deposit, Yunnan, China

    Institute of Scientific and Technical Information of China (English)

    韩润生; 邹海俊; 胡彬; 胡熠昭; 薛传东

    2007-01-01

    The Maoping Zn-Pb-(Ag-Ge) deposit is an important representative of the medium-to large-sized carbonate-hosted Zn-Pb-(Ag) deposits in northeast Yunnan, occurring in the Sichuan-Yunnan-Guizhou Zn-Pb Ore-forming Zone. The spatial distribution of ore bodies were controlled by the NE-extending interstratified fault belts and inverted Maomaoshan fold. Generally, fluid inclusions within the major gangue minerals, as ferro-calcite, calcite and dolomite are dominated by two kinds of small inclusions (3~15 μm) including pure-liquid and liquid. The inclusions exist in concentrated groups along the crystal planes of the gangue minerals. The ore-forming fluids belong to the Na+ -K+ -Ca2+ -Cl- -F - type, are characterized by temperatures of 180 ~ 218 ℃, medium salinity in 4. 1 wt% ~ 9.5wt% NaCl, and medium pressure at 406×105~570×105 Pa. The ratios of Na+/K+ (1.54~4.53 ) and Cl-/F- (0.72 ~ 156.33 ) in the fluid inclusions of gangue minerals are relatively high, while those of Na+/K+ (0. 32 ~ 8.36 ) and Cl-/F- (1.06 ~ 16.77) in the inclusions of barite are relatively low. The waters of fluid inclusions have δD values from -23‰ to -64‰. The δ18OV.SMOWvalues of the ore-forming fluids range from 0. 3‰ to 6.2‰ for galena, -9.0‰ to 3.4‰ for sphalerite, and -6.8‰ to -12.7‰ for pyrite. δ13CV-PDBvalues range from -1.1 to -3.7 for gangue minerals. These data better demonstrate that the ore-forming fluids were the compositing results of the magma water, metamorphic water and hosted water, and mainly derived from magmatic hot fluid and hosted formation water, in relation to the sedimentation, the metamorphism of the Kunyang Group in the basement and magmatic hydrothermalism. The deposit itself might have resulted from ascending cycles along metallogenic structures of ore-forming fluid, enriched in Pb, Zn and Ag. The deposit is related to carbonate-hosted Zn-Pb sulphides.%云南毛坪铅锌(银、锗)矿床是川滇黔成矿域滇东北地区以碳

  2. Hydrocarbon migration and accumulation in the Upper Cretaceous Qingshankou Formation, Changling Sag, southern Songliao Basin: Insights from integrated analyses of fluid inclusion, oil source correlation and basin modelling

    Science.gov (United States)

    Dong, Tian; He, Sheng; Wang, Dexi; Hou, Yuguang

    2014-08-01

    The Upper Cretaceous Qingshankou Formation acts as both the source and reservoir sequence in the Changling Sag, situated in the southern end of the Songliao Basin, northeast China. An integrated approach involving determination of hydrocarbon charging history, oil source correlation and hydrocarbon generation dynamic modeling was used to investigate hydrocarbon migration processes and further predict the favorable targets of hydrocarbon accumulations in the Qingshankou Formation. The hydrocarbon generation and charge history was investigated using fluid inclusion analysis, in combination with stratigraphic burial and thermal modeling. The source rocks began to generate hydrocarbons at around 82 Ma and the hydrocarbon charge event occurred from approximately 78 Ma to the end of Cretaceous (65.5 Ma) when a large tectonic uplift took place. Correlation of stable carbon isotopes of oils and extracts of source rocks indicates that oil was generated mainly from the first member of Qingshankou Formation (K2qn1), suggesting that hydrocarbon may have migrated vertically. Three dimensional (3D) petroleum system modeling was used to evaluate the processes of secondary hydrocarbon migration in the Qingshankou Formation since the latest Cretaceous. During the Late Cretaceous, hydrocarbon, mainly originated from the Qianan depression, migrated laterally to adjacent structural highs. Subsequent tectonic inversion, defined as the late Yanshan Orogeny, significantly changed hydrocarbon migration patterns, probably causing redistribution of primary hydrocarbon reservoirs. In the Tertiary, the Heidimiao depression was buried much deeper than the Qianan depression and became the main source kitchen. Hydrocarbon migration was primarily controlled by fluid potential and generally migrated from relatively high potential areas to low potential areas. Structural highs and lithologic transitions are potential traps for current oil and gas exploration. Finally, several preferred hydrocarbon

  3. Diagenetic fluids evolution and genetic mechanism of tight sandstone gas reservoirs in Upper Triassic Xujiahe Formation in Sichuan Basin, China

    Institute of Scientific and Technical Information of China (English)

    ZHU RuKai; ZOU CaiNeng; ZHANG Nai; WANG XueSong; CHENG Rong; LIU LiuHong; ZHOU ChuanMin; SONG LiHong

    2008-01-01

    The reservoirs of the Upper Triassic Xujiahe Formation in Sichuan Basin have the characteristics of low compositional maturity, low contents of cements and medium textural maturity.The general physical properties of the reservoirs are poor, with low porosity and low permeability, and there are only a few reservoirs with medium porosity and low permeability in local areas.Based on the diagenetic mineral association, a diagenetic sequence of cements is established: early calcites (or micrite siderites)→ first quartz overgrowth→chlorite coatings→dissolution of feldspars and debris→chlorite linings→ second quartz overgrowth (quartz widen or filled in remain intergranular pores and solution pores→ dissolution→third quartz overgrowth (quartz filled in intergranular and intragranular solution pores)→ intergrowth (ferro) calcites→dolomites→ferro (calcites) dolomites→later dissolution→veins of quartz and calcites formation.Mechanical compaction is the main factor in making the reservoirs tight in the basin, followed by the second and third quartz overgrowth.In a long-term closed system, only feldspars and some lithic fragments are dissolved by diagenetic fluids, while intergranular cements such as quartz and calcit are not dissolved and thus have little influence on the porosity of the Xujiahe Formation.This is the third factor that may have kept the sandstones of Xujiahe Formation tight finally.The hydrocarbon was extensively generated from organic materials after the second quartz overgrowth, and selectively entered favorable reservoirs to form tight sandstone gas reservoirs.

  4. Diagenetic fluids evolution and genetic mechanism of tight sandstone gas reservoirs in Upper Triassic Xujiahe Formation in Sichuan Basin, China

    Institute of Scientific and Technical Information of China (English)

    2008-01-01

    The reservoirs of the Upper Triassic Xujiahe Formation in Sichuan Basin have the characteristics of low compositional maturity, low contents of cements and medium textural maturity. The general physical properties of the reservoirs are poor, with low porosity and low permeability, and there are only a few reservoirs with medium porosity and low permeability in local areas. Based on the diagenetic mineral association, a diagenetic sequence of cements is established: early calcites (or micrite siderites) →first quartz overgrowth→chlorite coatings→dissolution of feldspars and debris→chlorite linings→ second quartz overgrowth (quartz widen or filled in remain intergranular pores and solution pores)→dissolution→third quartz overgrowth (quartz filled in intergranular and intragranular solution pores)→intergrowth (ferro) calcites→dolomites→ferro (calcites) dolomites→later dissolution→veins of quartz and calcites formation. Mechanical compaction is the main factor in making the reservoirs tight in the basin, followed by the second and third quartz overgrowth. In a long-term closed system, only feld-spars and some lithic fragments are dissolved by diagenetic fluids, while intergranular cements such as quartz and calcit are not dissolved and thus have little influence on the porosity of the Xujiahe Formation. This is the third factor that may have kept the sandstones of Xujiahe Formation tight finally. The hydrocarbon was extensively generated from organic materials after the second quartz overgrowth, and selectively entered favorable reservoirs to form tight sandstone gas reservoirs.

  5. MAGnetiC AnoMAly feAtureS of the MAbiAnShAn iron ore DepoSit in the northern pArt of the lu-ZonG volCAniC bASin AnD ore-proSpeCtinG proGnoSiS%庐枞火山岩盆地北部马鞭山铁矿床磁异常特征及找矿预测

    Institute of Scientific and Technical Information of China (English)

    尚世贵

    2014-01-01

    The Mabianshan iron ore deposit lies at northern fringe of the Lu-Zong volcanic basin and is hosted in the Dongmaanshan (T2d) iron-bearing and calcareous muddy siltstone. Aeromagnetic map shows that gradient zone is locally overlapped with anomaly, and the local anomaly is regular in form with its trend generally parallel to the zone. Ground magnetic and aeromagnetic features are well matched, without decomposed anomaly. Ground magnetic profile curve is continuous, complete, with pairs of negative and positive and gentle. Wavelet transformation well separates out mineralized anomaly. Local gentle magnetic anomalies on the west and north sides of the basin are important indicators for seeking this kind of iron ore deposit.%马鞭山铁矿处于庐枞火山岩盆地北部边缘,其赋矿层位为东马鞍山(T2d)含铁质、钙质泥质粉砂岩。航磁为梯度带上叠加局部异常、局部异常形态规则,其走向与梯度带大致平行;地磁与航磁对应较好,异常未分解;地磁异常剖面曲线连续完整且正负伴生、具低缓特征。小波变换较好地分离出了矿致异常。盆地西侧和北侧二条航磁梯度带上局部低缓磁异常系寻找该类铁矿的重要指示信息。

  6. Testing of rubber O-rings for R-5 reactor

    International Nuclear Information System (INIS)

    This paper summarises the results of various experiments and tests conducted for the selection of suitable O-rings to be used in R-5 reactor. O-rings of various elastomeric compositions obtained from different manufacturers were tested for heat aging, fluid aging, radiation stability and specific gravity. They were irradiated to various dose levels at Apsara Reactor. The changes in axial thickness and hardness, after each test, were measured and results were correlated. The tests reveal that O-rings made of ethylene-propylene rubber are the best suited for the use in R-5 reactor. The O-rings made of nitrile rubber are also good. Neoprene rubber O-rings were found unsuitable mainly because of their low radiation resistance. (author)

  7. Application of apatite fission tract analysis to problems of Mississippi Valley-type Pb-Zn ore genesis

    International Nuclear Information System (INIS)

    Epigenetic, carbonate-hosted Pb-Zn mineralization of the Mississippi Valley-Type (MVT) is considered to form from warm basinal brines in the temperature range 50-200 deg.C. A variety of genetic fluid flow models have been proposed to explain MVT mineralization, but all suffer from a lack of constraint concerning the timing of ore formation. Fission tracks in apatite resulting from the spontaneous decay of trace amounts of 238U are thermally unstable over the range of temperatures proposed for MVT ore formation, and may therefore record thermal events related to Pb-Zn mineralization provided sufficient time is allowed for track annealing to occur. Zinc mineralization in Devonian carbonates of the Lennard Shelf, northwest Australia is also considered to be of the Mississippi Valley-type. Mean apatite ages from Precambrian basement and from Devonian carbonates generally average 300Ma. Studies of well sequences indicate a period of uplift for the Lennard Shelf area around the Late Triassic/Early Jurassic. For carbonate outcrop samples, a thermal history is proposed involving burial in the Late Paleozoic/Early Mesozoic followed by uplift and cooling from peak temperatures around 70 deg.C. No difference in apatite annealing effects are observed in the vicinity of zinc mineralization. Coupled with other evidence, this suggests that the mineralizing episode was of short duration given temperatures of ore formation in the range 70-110 deg.C indicated by fluid inclusion homogenization temperatures. 3 refs

  8. Diagenesis and fluid flow in the San Juan Basin, New Mexico - regional zonation in the mineralogy and stable isotope composition of clay minerals in sandstone.

    Science.gov (United States)

    Whitney, G.; Northrop, H.R.

    1987-01-01

    The Westwater Canyon Member of the Upper Jurassic Morrison Formation is a relatively homogeneous, hydrologically continuous 100-m-thick sequence of massive fluvial sandstone, bounded above and below by relatively heterogeneous, hydrologically discontinuous units and has served as a primary conduit for fluids within this stratigraphic interval. Patterns of mineral-fluid reactions suggest a basinwide hydrologic regime in which warm, evolved fluids migrated up-dip from the center of the basin under the influence of a regional hydraulic head. -from Authors

  9. Three-dimensional simulation of pore scale fluid flow in granular ore media with realistic geometry%基于真实模型的矿岩散体三维孔隙流数值模拟

    Institute of Scientific and Technical Information of China (English)

    杨保华; 吴爱祥; 王春来; 牛文鑫; 刘金枝

    2012-01-01

    利用X光CT技术采集矿岩散体图像,结合数字图像处理技术和有限元技术构建了表征介质真实孔隙结构的三维物理模型,利用此模型进行颗粒间孔隙流的三维数值模拟,分析堆浸散体孔隙内溶液流速和压力分布规律,并计算出介质的水力传导系数.模拟结果表明溶液流动行为在很大程度上受到孔隙大小及拓扑结构的制约,介质内同时存在明显的优势流和浸出盲区,最高流速出现在具有高压降的细小孔隙处.根据模拟结果计算出的水力传导系数与室内实验测试结果具有相同数量级,说明了模型的有效性.实现了细观尺度与宏观尺度的结合,所构建的模型能应用于堆浸过程其它规律的计算机模拟.%The images of granular ore media were captured by X-ray CT scanner.Combined with digital image processing and finite element techniques,the three-dimensional geometrical model,which represents the realistic pore structure of the media,was constructed.With this model,three dimensional pore scale fluid flow among particles was simulated.Then the distributions of fluid flow velocity and pressure were analyzed and the hydraulic conductivity was calculated.The simulation results indicate the fluid flow behaviors are mainly dominated by the volume and topological structure of pore space.There exist obvious preferential flow and leaching blind zones simultaneously in the medium.The highest velocities generally occur in those narrow pores with high pressure drops.The hydraulic conductivity obtained by simulation is the same order of magnitude as the laboratory test result,which denotes the validity of the model.The pore-scale and macro-scale are combined and the established geometrical model can be used for the simulations of other phenomena during heap leaching process.

  10. Fluids and stress in fractured rocks: A case study with applications to hydrodynamic modelling (Lodeve Basin, South France)

    International Nuclear Information System (INIS)

    In order to stock nuclear waste safely in fractured rock or optimize the development and exploitation of hydrocarbons in fractured reservoirs the same fracture parameters have to be investigated through field studies. It is essential to define the relationships between tectonics, 3D fracture networks and fluid flow, as well as the effect of past stress states on the network evolution and the effect of the present-day stress state on hydrodynamics. A case study was carried out on a site of the COGEMA Uranium mine with a very high density of wells and galleries in a Permian silicoclastic basin. Fracturation on all scales from individual fractures (with their connectivity and hydraulic behaviour) to fracture network was described. A multidisciplinary approach was necessary to understand the importance of fluids and to upscale metric scale obsessations to the well identified fracture network: 3D organization and evolution of the fracture network under the influence of paleostress was obtained from tectonic analysis and response of the reservoir in terms of fracture dilatancy or closure to present day stress was characterized by in situ stress measurements; water geochemistry and hydrogeology showed the large scale flow pattern characterized by the presence of main drains and barriers; geophysical prospecting and study of gaseous emanations from the soil helped to localize the subsurface fracture pattern, especially dilatant fractures. All this data is used to build a 3D model of the fracture pattern and its flow networks

  11. Basin-scale transport of heat and fluid induced by earthquakes

    Science.gov (United States)

    Wang, C.; Manga, M.; Wang, L.; Chen, C.

    2013-12-01

    Large earthquakes are known to cause widespread changes in groundwater flow at distances thousands of kilometers away from the epicenter, yet their relation to subsurface transport is unknown. Since groundwater flow is effective in transporting subsurface heat, studies of earthquake-induced changes in groundwater temperature may be useful for better understanding earthquake-induced heat transport. Here we report systematic changes in groundwater temperature after the 1999 Mw 7.6 Chi-Chi earthquake in central Taiwan, recorded by a dense network of monitoring wells over a large (1,800 km2) alluvial fan near the epicenter. The data documented a clear trend of increase from negative changes (temperature decrease) near the upper rim of the fan near the ruptured fault to positive changes (temperature increase) near the coast. Analysis of the data reveals a hitherto unknown system of earthquake-triggered basin-wide groundwater flow, which scavenges geothermal heat from depths, changing groundwater temperature across the basin. The newly identified earthquake-triggered groundwater flow may have significant implications on post-seismic groundwater supply and quality, contaminant transport, underground repository safety, and hydrocarbon production.

  12. Types, Evolution and Pool-Controlling Significance of Pool Fluid Sources in Superimposed Basins: A Case Study from Paleozoic and Mesozoic in South China

    Institute of Scientific and Technical Information of China (English)

    Xu Sihuang; Mei Lianfu; Yuan Caiping; Ma Yongsheng; Guo Tonglou

    2007-01-01

    Having multiple tectonic evolution stages, South China belongs to a superimposed basin in nature. Most marine gas pools became secondary pools. The pool fluid sources serve as the principal pool-controlling factors. On the basis of eight typical petroleum pools, the type, evolution in time-space,and the controlling of petroleum distribution of pool fluid sources are comprehensively analyzed. The main types of pool fluid sources include hydrocarbon, generated primarily and secondly from source rocks, gas cracked from crude oil, gas dissolved in water, inorganic gas, and mixed gases. In terms of evolution, the primary hydrocarbon was predominant prior to Indosinian; during Indosinian to Yenshanian the secondary gas includes gas cracked from crude oil, gas generated secondarily, gas dissolved in water, and inorganic gas dominated; during Yenshanian to Himalayan the most fluid sources were mixed gases. Controlled by pool fluid sources, the pools with mixed gas sources distributed mainly in Upper Yangtze block, especially Sichuan (四川) basin; the pools with primary hydrocarbon sources distributed in paleo-uplifts such as Jiangnan (江南), but most of these pools became fossil pools; the pools with secondary hydrocarbon source distributed in the areas covered by Cretaceous and Eogene in Middle-Lower Yangtze blocks, and Chuxiong (楚雄), Shiwandashan (十万大山), and Nanpanjiang (南盘江) basins; the pools with inorganic gas source mainly formed and distributed in tensional structure areas.

  13. 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)

  14. Sill intrusion driven fluid flow and vent formation in volcanic basins: Modeling rates of volatile release and paleoclimate effects

    Science.gov (United States)

    Iyer, Karthik; Schmid, Daniel

    2016-04-01

    Evidence of mass extinction events in conjunction with climate change occur throughout the geological record and may be accompanied by pronounced negative carbon isotope excursions. The processes that trigger such globally destructive changes are still under considerable debate. These include mechanisms such as poisoning from trace metals released during large volcanic eruptions (Vogt, 1972), CO2 released from lava degassing during the formation of Large Igneous Provinces (LIPs) (Courtillot and Renne, 2003) and CH4 release during the destabilization of sub-seafloor methane (Dickens et al., 1995), to name a few. Thermogenic methane derived from contact metamorphism associated with magma emplacement and cooling in sedimentary basins has been recently gaining considerable attention as a potential mechanism that may have triggered global climate events in the past (e.g. Svensen and Jamtveit, 2010). The discovery of hydrothermal vent complexes that are spatially associated with such basins also supports the discharge of greenhouse gases into the atmosphere (e.g. Jamtveit et al., 2004; Planke et al., 2005; Svensen et al., 2006). A previous study that investigated this process using a fluid flow model (Iyer et al., 2013) suggested that although hydrothermal plume formation resulting from sill emplacement may indeed release large quantities of methane at the surface, the rate at which this methane is released into the atmosphere is too slow to trigger, by itself, some of the negative δ13C excursions observed in the fossil record over short time scales observed in the fossil record. Here, we reinvestigate the rates of gas release during sill emplacement in a case study from the Harstad Basin off-shore Norway with a special emphasis on vent formation. The presented study is based on a seismic line that crosses multiple sill structures emplaced around 55 Ma within the Lower Cretaceous sediments. A single well-defined vent complex is interpreted above the termination of the

  15. Fluid Chemistry Dynamics Before and After Fire in the Jemez River Basin Critical Zone Observatory

    Science.gov (United States)

    Chorover, J.; Perdrial, J. N.; Field, J. P.; Pelletier, J. D.; Pohlmann, M. A.; Losleben, M. V.; Lasharr, K.; Amistadi, M.; Brooks, P. D.; McIntosh, J. C.; Meixner, T.; Gallery, R.; Rich, V. I.; Rasmussen, C.; Schaap, M. G.; Breshears, D. D.

    2013-12-01

    The largest wildfire in New Mexico state history (prior to the Whitewater-Baldy fire of 2012) burned the eastern portion of the Jemez River Basin Critical Zone Observatory (JRB CZO) in June-July 2011. This Los Conchas fire burned large stands of ponderosa pine and mixed conifer (MC) forest within the East Fork Jemez River watershed generating massive post-fire erosion. We asked the question: What are the implications of wildfire on pulsed carbon and other bio-active element redistributions in impacted soils and catchments? As soon as possible following the fire, our research group installed sensor and sampler instrumentation in soil profiles in an intensively burned zero order basin (ZOB), enabling the initiation of comparisons to a similarly instrumented, unburned MC ZOB. The signal of biomass combustion was propagated through soil and stream. Post-burn solute fluxes were dominated by highly-aromatic character DOM, as well as elevated DIC, sulfate, chloride and non-hydrolyzing cation (Ca, Mg, K) concentrations deriving from biomass combustion. Supporting an apparent trend of increasing wildfire in western montane forests, the Thompson Ridge wildfire burned MC forest throughout much of the western previously unburned portion of the Valles Caldera National Preserve in June 2013, including the (until then) "unburned" MC ZOB sites comprising CZO sensor and sampler network arrays. Post-burn soil samples were collected for geochemical, physical, and microbial composition characterizations. Solute and gas fluxes were monitored in situ to compare CZ response following this high intensity burn to three years of pre-burn data. Results indicate that the post-fire pulse of water soluble, biomass-derived ions and carbon into underlying and downslope soils is generating landscape-scale element distribution that could affect recolonization by biota in the ensuing secondary succession.

  16. 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)

  17. 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)

  18. Ore-Forming Fluid Geochemical Characteristics and Genesis of Pb-Zn Deposit in Hongling,Inner Mongolia%内蒙古红岭铅锌矿床成矿流体地球化学特征及矿床成因

    Institute of Scientific and Technical Information of China (English)

    李剑锋; 王可勇; 陆继胜; 张雪冰; 权鸿雁; 王承洋; 魏良民

    2015-01-01

    Hongling lead-zinc deposit is one of the representative large deposits in southeastern Inner Mongolia.Presently,there’s very little research on geochemical characteristics and evolution of ore-form fluids,and ore genesis.The fluid inclusions are systemly re-searched in this paper,The results show that there are three types of primary fluid inclusions in garnet of garnet-skarn stage (Ⅰ)inclu-ding halite-bearing three-phase,aqueous two-phase as well as vapor-rich two-phase;there are two types of primary fluid inclusions in quartz of stage (Ⅱ)including aqueous two-phase as well as vapor-rich two-phase.It is found in our microthermometric study that the ore-forming fluid is of high temperature,high salinity and immiscible NaCl-H2 O type solutions and the boiling process plays important role in the precipitation of Pb,Zn,and Cu.Quartz of mineralization stage Ⅲ to Ⅳ of quartz-sulfide epochs contains only aqueous two-phase of fluid inclusions.The homogenization temperature of this type of fluid inclusions is obviously lower than that of skarn epoch, while the salinity does not obviously change.The homogenization temperatures of fluid inclusions show a rising trend with salinities dis-playing a dropping trend of stage Ⅳ,and it may be caused by adding of high temperature,low salinity type fluid.The dropping of homogenization temperatures and salinities of ore-forming fluids from mineralization stages Ⅴ to Ⅵ suggests that meteoric water contin-uously joining into the ore-forming fluid.Overall,the ore-forming fluids of quartz-sulfide epoch is of medium-low temperature and low salinity NaCl-H2 O type solutions.C,H,O isotope study of fluid inclusions shows that the ore-forming fluids of skarn epoch mainly came from magmatic water and that of quartz-sulfide epoch came from mixed magmatic water and meteoric water,whereas at the latest stage of mineralization,the ore-forming fluids mainly came from meteoric water.The study of S,Pb isotopes implies that the ore

  19. Infiltration of late Palaeozoic evaporative brines in the reelfoot rift: A possible salt source for Illinois Basin formation waters and MVT mineralizing fluids

    Science.gov (United States)

    Rowan, E.L.; De Marsily, G.

    2001-01-01

    Salinities and homogenization temperatures of fluid inclusions in Mississippi Valley-type (MVT) deposits provide important insights into the regional hydrology of the Illinois basin/Reelfoot rift system in late Palaeozoic time. Although the thermal regime of this basin system has been plausibly explained, the origin of high salinities in the basin fluids remains enigmatic. Topographically driven flow appears to have been essential in forming these MVT districts, as well as many other districts worldwide. However, this type of flow is recharged by fresh water making it difficult to account for the high salinities of the mineralizing fluids over extended time periods. Results of numerical experiments carried out in this study provide a possible solution to the salinity problem presented by the MVT zinc-lead and fluorite districts at the margins of the basin system. Evaporative concentration of surface water and subsequent infiltration into the subsurface are proposed to account for large volumes of brine that are ultimately responsible for mineralization of these districts. This study demonstrates that under a range of geologically reasonable conditions, brine infiltration into an aquifer in the deep subsurface can coexist with topographically driven flow. Infiltration combined with regional flow and local magmatic heat sources in the Reelfoot rift explain the brine concentrations as well as the temperatures observed in the Southern Illinois and Upper Mississippi Valley districts.

  20. Modelling and simulation of compressible fluid flow in oil reservoir: a case study of the Jubilee Field, Tano Basin (Ghana)

    International Nuclear Information System (INIS)

    Oil extraction represents an important investment and the control of a rational exploitation of a field means mastering various scientific techniques including the understanding of the dynamics of fluids in place. This thesis presents a theoretical investigation of the dynamic behaviour of an oil reservoir during its exploitation. The study investigated the dynamics of fluid flow patterns in a homogeneous oil reservoir using the Radial Diffusivity Equation (RDE) as well as two phase oil-water flow equations. The RDE model was solved analytically and numerically for pressure using the Constant Terminal Rate Solution (CTRS) and the fully implicit Finite Difference Method (FDM) respectively. The mathematical derivations of the models and their solution procedures were presented to allow for easy utilization of the techniques for reservoir and engineering applications. The study predicted that the initial oil reservoir pressure will be able to do the extraction for a very long time before any other recovery method will be used to aid in the extraction process depending on the rate of production. Reservoir simulation describing a one dimensional radial flow of a compressible fluid in porous media may be adequately performed using ordinary laptop computers as revealed by the study. For the simulation of MATLAB, the case of the Jubilee Fields, Tano Basin was studied, an algorithm was developed for the simulation of pressure in the reservoir. It ensues from the analysis of the plots of pressure vrs time and space that the Pressure Transient Analysis (PTA) was duly followed. The approximate solutions of the analytical and numerical solutions to the Radial Diffusivity Equation (RDE) were in excellent agreement, thus the reservoir simulation model developed can be used to describe typical pressure-time relationships that are used in conventional Pressure Transient Analysis (PTA). The study was extended to two phase oil-water flow in reservoirs. The flow of fluids in multi

  1. Subsurface fluid data from Longyearbyen CO2 storage site: Basin history and compartmentalization

    Science.gov (United States)

    Huq, Farhana; Mueller, Kristin; Tore Mørkved, Pål; Johansen, Ingar; Johansen, Harald

    2015-04-01

    The Longyearbyen CO2 storage site, located on the main island of Svalbard at the northwestern margin of the Barents Sea Shelf, is a demonstration project for a "green showcase", which aims to make a full value chain of power generation, CO2 capture and storage by achieving a net zero carbon footprint. The key objective of this study was to assess the local geological conditions for CO2 storage by defining a seal sequence stratigraphy above and within the reservoir from gas and fluid geochemical data. Seven wells were drilled at two sites to collect core material and gas samples at various defined depths. Gas composition (C1-5, CO2) and stable isotope (δ13C) analyses were performed on gas samples obtained from both core material and well heads. In addition, Sr isotope data from residual salts extracted from core material were used to look at compartmentalization. The combined analysis of trends in isotope and gas composition data as a function of depth revealed three major breaks and permitted the identification of three major fluid compartments. These compartments are suggested to be associated with impervious caprock and reservoir barriers. The first break in the data trends occurs at approximately 250-300 m depth, which is interpreted as the depth limit of the meteoric water system. A second hydrologic barrier, most likely produced by reservoir uplift was identified. Finally, a very distinct change in trend around 800 m depth may be associated with an observed significant change in reservoir pressure. Three clear breaks in the geochemical data as a function of depth all point towards an efficient seal sequence and demonstrate the potential for CO2 storage at the Longyearbyen site.

  2. 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)

  3. Iron Ore Spies

    Institute of Scientific and Technical Information of China (English)

    2009-01-01

    China has begun to attack industrial spies to prevent state security from being compromised Four employees of Rio Tinto, including Hu Shitai, former head of Rio’s Shanghai office and Rio’s China iron ore division, were detained in Shanghai on July 5, on charges of espionage. A senior executive of

  4. Temporal evolution of magmatic-hydrothermal systems in the Manus Basin, Papua New Guinea: Insights from vent fluid chemistry and bathymetric observations

    Science.gov (United States)

    Reeves, E. P.; Thal, J.; Schaen, A.; Ono, S.; Seewald, J.; Bach, W.

    2015-12-01

    The temporal evolution of hydrothermal fluids from back-arc systems is poorly constrained, despite growing evidence for dynamic magmatic-hydrothermal activity, and imminent commercial mining. Here we discuss surveys of diverse vent fluids from multiple hydrothermal fields in the Manus back-arc basin, Papua New Guinea, sampled in 2006 and 2011. Effects of host rock composition, and dynamic magmatic volatile inputs on fluid chemistry are evaluated to understand changes in these systems. Highly acidic and SO4-rich moderate temperature fluids (~48-215°C), as well as SO4-poor black smoker fluids (up to 358°C), were collected at the PACMANUS, SuSu Knolls and DESMOS areas in 2006 and 2011. Acidic, milky white SuSu and DESMOS fluids, rich in elemental S and SO4, exit the seafloor with Na, K, Mg, and Ca diluted conservatively up to 30% relative to seawater, implying subsurface mixing of seawater with SO2-rich aqueous fluids exsolved from magma, analogous to subaerial fumarole discharge. SO2 disproportionation during cooling and mixing of magmatic fluids contributes acidity, SO4, H2S and S(0)(s), as well as widespread S outcrops on the seafloor. Nearby black smoker fluids indicate entrainment and reaction of magmatic fluid into convecting fluids at depth, and additional hybrid-type fluids appear to consist of evolved seawater and unreacted magmatic fluid SO2 derivatives. Fluids at DESMOS in 2006 indicate increased magmatic SO2 relative to 1995, despite constant low venting temperatures (~120°C). In contrast, dramatic changes in bathymetry and seafloor morphology point to substantial continuous eruption of volcaniclastic material between 2006 and 2011 at SuSu Knolls, burying fumarolic vents from 2006. Compositions of new 2011 acidic, sulfate-rich fluids there suggest reaction with less altered, fresher rock. At the PACMANUS area, farther from the arc, direct magmatic degassing to the seafloor is not occurring presently, but entrainment and reaction of similar acid

  5. Toward a better understanding of the fluid circulation in the Rhine Graben for a better geothermal exploration of the deep basins.

    OpenAIRE

    Dezayes, Chrystel; Lerouge, Catherine; Sanjuan, Bernard; Ramboz, Claire; Brach, Michel

    2015-01-01

    In the Upper Rhine Graben, geothermal projects are strongly under development, particularly for the exploitation of fluid in the deeper part of the basin.This type of reservoirs constitutes a fractured dominated system. However, the hydraulic behaviour of the fracture network is poorly known and its knowledge constitutes an important way to better target the exploration works. Combining data from structural analysis, mineralogical analysis of fracture filling from outcrops and drilling cores ...

  6. Fault-related CO2 degassing, geothermics, and fluid flow in southern California basins---Physiochemical evidence and modeling

    Energy Technology Data Exchange (ETDEWEB)

    Boles, James R. [Univ. of California, Santa Barbara, CA (United States); Garven, Grant [Tufts Univ., Medford, MA (United States)

    2015-08-04

    Our studies have had an important impact on societal issues. Experimental and field observations show that CO2 degassing, such as might occur from stored CO2 reservoir gas, can result in significant stable isotopic disequilibrium. In the offshore South Ellwood field of the Santa Barbara channel, we show how oil production has reduced natural seep rates in the area, thereby reducing greenhouse gases. Permeability is calculated to be ~20-30 millidarcys for km-scale fault-focused fluid flow, using changes in natural gas seepage rates from well production, and poroelastic changes in formation pore-water pressure. In the Los Angeles (LA) basin, our characterization of formation water chemistry, including stable isotopic studies, allows the distinction between deep and shallow formations waters. Our multiphase computational-based modeling of petroleum migration demonstrates the important role of major faults on geological-scale fluid migration in the LA basin, and show how petroleum was dammed up against the Newport-Inglewood fault zone in a “geologically fast” interval of time (less than 0.5 million years). Furthermore, these fluid studies also will allow evaluation of potential cross-formational mixing of formation fluids. Lastly, our new study of helium isotopes in the LA basin shows a significant leakage of mantle helium along the Newport Inglewood fault zone (NIFZ), at flow rates up to 2 cm/yr. Crustal-scale fault permeability (~60 microdarcys) and advective versus conductive heat transport rates have been estimated using the observed helium isotopic data. The NIFZ is an important deep-seated fault that may crosscut a proposed basin decollement fault in this heavily populated area, and appears to allow seepage of helium from the mantle sources about 30 km beneath Los Angeles. The helium study has been widely cited in recent weeks by the news media, both in radio and on numerous web sites.

  7. Large-scale Migration of Fluids toward Foreland Basins during Collisional Orogeny:Evidence from Triassic Anhydrock Sequences and Regional Alteration in the Middle-Lower Yangtze Area

    Institute of Scientific and Technical Information of China (English)

    HOU Zengqian; YANG Zhusen; LI Yinqing; ZENG Pusheng; MENG Yifeng

    2004-01-01

    The middle-lower Yangtze area underwent a series of complex tectonic evolution, such as Hercynian extensional rifting, Indosinian foreland basining, and Yanshanian transpression-transtension, resulting in a large distinctive Cu-Fe-Au metallogenic belt. In the tectonic evolution, large-scale migration and convergence of fluids toward foreland basins induced during the collisional orogeny of the Yangtze and North China continental blocks were of vital importance for the formation of the metallogenic belt. Through geological surveys of the middle-lower Yangtze area,three lines of evidence of large-scale fluid migration are proposed: (1) The extensive dolomitic and silicic alteration penetrating Cambrian-Triassic strata generally occurs in a region sandwiched between the metallogenic belt along the Yangtze River and the Dabie orogenic belt, and in the alteration domain alternately strong and weak alteration zones extend in a NW direction and are controlled by the fault system of the Dabie orogenic belt; it might record the locus of the activities of long-distance migrating fluids. (2) The textures and structures of very thick Middle-Lower Triassic anhydrock sequences in restricted basins along the river reveal the important contribution of the convergence of regional hot brine in restricted basins and the chemical deposition or their formation. (3) Early-Middle Triassic syndepositional iron carbonate sequences and Fe-Cu-Pb-Zn massive sulfide deposits alternate with anhydrock sequences or are separated from the latter, but all of them occur in the same stratigraphic horizon and are intimately associated with each other,being the product of syndeposition of high-salinity hot brine. According to the geological surveys, combined with previous data, the authors propose a conceptual model of fluid migration-convergence and mineralization during the Dabie collisional orogeny.

  8. Dose calculations for intakes of ore dust

    International Nuclear Information System (INIS)

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

  9. Geochemistry and ore prospecting

    International Nuclear Information System (INIS)

    Applied geochemistry is a new technique which helps the geologist in detecting ore deposits. Some deposits, even when they are covered with rather thick surface structures, form around these zones where the infinitesimal content of some elements of soils or waters is notably different. These 'anomalies' may be contemporaneous to the deposit-structure (primary dispersion) or may have occurred later (secondary dispersion). Various factors rule these anomalies: ore-stability, soil homogeneity, water conditions, topography, vegetation, etc... Applied geochemistry is in fact the study of analysis techniques of metal traces in soils as well as the geological interpretation of observed anomalies. This report gives practical data on sampling methods, yields, costs and also on special problems of uranium geochemistry. (author)

  10. 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)

  11. Fluid-assisted particulate flow of turbidites at very low temperature: A key to tight folding in a submarine Variscan foreland basin of SW Europe

    Science.gov (United States)

    Marques, F. O.; Burg, J.-P.; Lechmann, S. M.; Schmalholz, S. M.

    2010-04-01

    The problem addressed in this article is how sedimentary formations like turbidites in a foreland basin, which include layers with apparently great competence contrast, can be tightly folded in a regular manner under very low temperature and pressure. This raises two major issues: the rheological behavior of the rocks at the time of folding and the role played by fluids. In order to understand very low temperature folding and the structural evolution of a submarine foreland basin, we carried out detailed structural work in turbidites with alternating sandstone and shale, for which estimated peak temperature conditions were top diagenetic to very low grade metamorphism. Folds are tight to isoclinal, with local collapsed hinges, which implies that the incompetent shale was mobile enough to flow away from strongly flattened areas. We did not find evidence for cataclastic flow or crystal plasticity at mesoscopic and microscopic scales. Other structures (mostly boudins, foliations, conjugate brittle faults, and quartz veins) associated with folds denote anisotropic compaction by fluid extraction during regional shortening. This is possible if the folded rocks were unconsolidated, fluid-saturated sediments. The estimated low peak temperature is consistent with the shale being unlithified. Poorly cemented grains are free to slide past one another under shallow burial or high pore pressure conditions. Following this line of thought, we consider independent particulate flow assisted by fluids under very low confining pressure (bean bag analogy) as the rock deformation mechanism active during the described intense folding. Similar deformation is likely occurring (and has occurred) in other submarine accretionary wedges.

  12. Primary migration and secondary alteration of the Upper Paleozoic gas reservoir in Ordos Basin,China―Application of fluid inclusion gases

    Institute of Scientific and Technical Information of China (English)

    2008-01-01

    The composition of fluid inclusions(FI)often represents the initial geochemical characteristics of palaeo-fluid in reservoir rock.Influence on composition and carbon isotopic composition of gas during primary migration,reservoir-forming and subsequent secondary alterations are discussed through comparing fluid inclusion gas with coal-formed gas and natural gas in present gas reservoirs in the Ordos Basin.The results show that primary migration of gas has significant effect on the molecular but not on the carbon isotopic composition of methane.Migration and diffusion fractionation took place during the secondary migration of gas in Upper Paleozoic gas reservoir according to carbon isotopic composition of methane in FIs.Composition and carbon isotopic composition of natural gas were nearly unchanged after the gas reservoir forming through comparing the FI gases with the natural gas in present gas reservoir.

  13. Therm odynamics of Diagenetic Fluid and Fluid/Mineral Reactions in the Eogene Xingouzui Formation,Oil Field T,Jianghan Basin

    Institute of Scientific and Technical Information of China (English)

    倪师军; 罗扬棣; 等

    1994-01-01

    This study focuses on the thermodynamics of diagenetic fluid from the Eogene Xingouzui Forma-tion which represents the most important reservoir in Field Oil T in the Jianghan Basin.The meas-ured homegenizagion temperatures(110-139℃)of fluid inclusions in diagenetic minerals fall within the range of 67-155℃ at the middle diagenetic stage .The pressure of diagenetic fluid is estimated at 10.2-56 Mpa .The activity of ions in the fluid shows a tendency of Ca2+>Mg2+>Na+>K+>Fe3+>Fe2+ for cations, and HCO3->SO22->F->Cl->CO22- for anions. For the gaseous facies, there is a tendency of CO2>CO>H2S>CH4>H2. According to the thermodynamic calculations,the pH and Eh of the fluid are 5.86-6.47 and -0.73-0.64V, respectively. As a result of the interaction between such a diagenetic fluid and minerals in the sedi-ments,feldspars were dissolved or alterated by other minerals. The clay mineral kaolinite was instable and hence was replaced by illite and chloritoid.

  14. Intra-field variability in microbial community associated with phase-separation-controlled hydrothermal fluid chemistry in the Mariner field, the southern Lau Basin

    Science.gov (United States)

    Takai, K.; Ishibashi, J.; Lupton, J.; Ueno, Y.; Nunoura, T.; Hirayama, H.; Horikoshi, K.; Suzuki, R.; Hamasaki, H.; Suzuki, Y.

    2006-12-01

    A newly discovered hydrothermal field called the Mariner field at the northernmost central Valu Fa Ridge (VFR) in the Lau Basin was explored and characterized by geochemical and microbiological surveys. The hydrothermal fluid (max. 365 u^C) emitting from the most vigorous vent site (Snow chimney) was boiling just beneath the seafloor at a water depth of 1908 m and two end-members of hydrothermal fluid were identified. Mineral and fluid chemistry of typical brine-rich (Snow chimney and Monk chimney) and vapor-rich (Crab Restaurant chimney) hydrothermal fluids and the host chimney structures were analyzed. Microbial community structures in three chimney structures were also investigated by culture-dependent and - independent analyses. The 16S rRNA gene clone analysis revealed that both bacterial and archaeal rRNA gene communities at the chimney surface zones were different among three chimneys. The bacterial and archaeal rRNA gene communities of the Snow chimney surface were very similar with those in the dead chimneys, suggesting concurrence of metal sulfide deposition at the inside and weathering at the surface potentially due to its large structure and size. Cultivation analysis demonstrated the significant variation in culturability of various microbial components, particularly of thermophilic H2- and/or S-oxidizing chemolithoautotrophs such as the genera Aquifex and Persephonella, among the chimney sites. The culturability of these chemolithoautotrophs might be associated with the input of gaseous energy and carbon sources like H2S, H2 and CH4 from the hydrothermal fluids, and might be affected by phase-separation- controlled fluid chemistry. In addition, inter-fields comparison of microbial community structures determined by cultivation analysis revealed novel characteristics of the microbial communities in the Mariner field of the Lau Basin among the global deep-sea hydrothermal systems.

  15. Geochemical and visual indicators of hydrothermal fluid flow through a sediment-hosted volcanic ridge in the Central Bransfield Basin (Antarctica.

    Directory of Open Access Journals (Sweden)

    Alfred Aquilina

    Full Text Available In the austral summer of 2011 we undertook an investigation of three volcanic highs in the Central Bransfield Basin, Antarctica, in search of hydrothermal activity and associated fauna to assess changes since previous surveys and to evaluate the extent of hydrothermalism in this basin. At Hook Ridge, a submarine volcanic edifice at the eastern end of the basin, anomalies in water column redox potential (E(h were detected close to the seafloor, unaccompanied by temperature or turbidity anomalies, indicating low-temperature hydrothermal discharge. Seepage was manifested as shimmering water emanating from the sediment and from mineralised structures on the seafloor; recognisable vent endemic fauna were not observed. Pore fluids extracted from Hook Ridge sediment were depleted in chloride, sulfate and magnesium by up to 8% relative to seawater, enriched in lithium, boron and calcium, and had a distinct strontium isotope composition ((87Sr/(86Sr = 0.708776 at core base compared with modern seawater ((87Sr/(86Sr ≈ 0.70918, indicating advection of hydrothermal fluid through sediment at this site. Biogeochemical zonation of redox active species implies significant moderation of the hydrothermal fluid with in situ diagenetic processes. At Middle Sister, the central ridge of the Three Sisters complex located about 100 km southwest of Hook Ridge, small water column E(h anomalies were detected but visual observations of the seafloor and pore fluid profiles provided no evidence of active hydrothermal circulation. At The Axe, located about 50 km southwest of Three Sisters, no water column anomalies in E(h, temperature or turbidity were detected. These observations demonstrate that the temperature anomalies observed in previous surveys are episodic features, and suggest that hydrothermal circulation in the Bransfield Strait is ephemeral in nature and therefore may not support vent biota.

  16. Evolution of ore forming fluid of Daping gold deposit in Ailaoshan tectonic zone, Southeast Tibet%青藏高原东南缘哀牢山大坪金矿成矿流体演化

    Institute of Scientific and Technical Information of China (English)

    朱路华; 戚学祥; 彭松柏; 李志群

    2011-01-01

    Daping gold deposit is a large quartz-vein gold deposit in Ailaoshan tectonic zone, made of north and south fields. Fluid inclusion homogenization temperatures range from 187t to 329t (average is 2811) in north field, and from 168℃ to 338℃ (average is 264℃) in south field, respectively. Corresponding, the δDV-SMOW values range from -70‰to -81‰ and from -71‰to-86‰, and the 518OH2O values rang from 2. 9‰ to 9. 8‰ and from 3. 5‰ to 5. 1‰, respectively. All samples plotted at the field between magmatic water and underground water in the plots of 5D vs. δ18OH2O, and that for north field are near magmatic water area, and for south field are near underground water area. The sulfur isotopic compositions (834 S) for north and south fields are 0. 7‰ ~ 15. 5‰ and 10. 6‰ ~ 15. 8‰, respectively. The vapour compositions in fluid inclusions are H2O, CO2 and N2, with a little of CH4 , C2H2, C2H4, C2H6 and CO. The ion compositions in fluid inclusions are K+ , Na+ , Ca2+ , Cl- and SO42- , with a little of NO3 - , F- , Br- and Mg2-. ESR dating data for quartz in gold-bearing quartz veins from north and south fields are 27. 2 - 29. 1 Ma and 17.3~22. 1Ma, respectively. All above show, that the ore forming fluids are mixing of postmagmatic solution and underground water, from north to south, deep to shallow fields and from earlier to later stage, the contents of the postmagmatic solution and sulfur are decreasing, and that of the underground water is increasing, and the age of minerallization is youngling, gradually.%大坪金矿是青藏高原东南缘哀牢山构造带中的大型石英脉型金矿床,由北矿区和南矿区组成.北矿区和南矿区的成矿流体包裹体均一温度及其氢、氧、硫同位素、气液相成份的测试结果表明其成矿温度为:187~329℃(平均为281℃)和168~338℃(平均为264℃)、氢同位素组成(δDV-SMOW)为:-70‰~-81‰和-71‰~-86‰、氧同位素组成(δ18OH2o)为:2.9‰~9.8

  17. Complexing and hydrothermal ore deposition

    CERN Document Server

    Helgeson, Harold C

    1964-01-01

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

  18. New isotopic evidence bearing on bonanza (Au-Ag) epithermal ore-forming processes

    Science.gov (United States)

    Saunders, James A.; Mathur, Ryan; Kamenov, George D.; Shimizu, Toru; Brueseke, Matthew E.

    2016-01-01

    New Cu, S, and Pb isotope data provide evidence for a magmatic source of metal(loid)s and sulfur in epithermal Au-Ag deposits even though their ore-forming solutions are composed primarily of heated meteoric (ground) waters. The apparent isotopic discrepancy between ore metals and ore-forming solutions, and even between the ore and associated gangue minerals, indicates two different sources of epithermal ore-forming constituents: (1) a shallow geothermal system that not only provides the bulk of water for the ore-forming solutions but also major chemical constituents leached from host rocks (silica, aluminum, potassium, sodium, calcium) to make gangue minerals and (2) metals and metalloids (As, Te, Sb, etc.) and sulfur (±Se) derived from deeper magma bodies. Isotopic data are consistent with either vapor-phase transport of metal(loids) and sulfur and their subsequent absorption by shallow geothermal waters or formation of metallic (Au, Ag, Cu phases) nanoparticles at depth from magmatic fluids prior to encountering the geothermal system. The latter is most consistent with ore textures that indicate physical transport and aggregation of nanoparticles were significant ore-forming processes. The recognition that epithermal Au-Ag ores form in tectonic settings that produce magmas capable of releasing metal-rich fluids necessary to form these deposits can refine exploration strategies that previously often have focused on locating fossil geothermal systems.

  19. Niobium ore OKA-1

    International Nuclear Information System (INIS)

    A 287-kg sample of a niobium ore, OKA-1, from Oka, Quebec, was prepared as a compositional reference material. OKA-1 was ground to minus 74 μm, blended in one lot, tested for homogeneity by X-ray fluorescence and chemical methods and bottled in 200-g units. In a 'free-choice' round-robin analytical program, 22 laboratories contributed results for niobium in each of two bottles of OKA-1. A statistical analysis of the data gave a recommended value of 0.37 +- 0.01% for niobium

  20. 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.)

  1. 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)

  2. Green line fracturing systems fluids in Campos Basin, Brazil; Sistemas de fluidos de fraturamento na Bacia de Campos: evolucao em beneficio do meio ambiente

    Energy Technology Data Exchange (ETDEWEB)

    Melo, Alexandre B. de; Araujo, Cosme J.C. de; Martinho, Flavio M.; Gaspar, Fernando [BJ Services do Brasil, Rio de Janeiro, RJ (Brazil)

    2008-07-01

    The constant demand for Services Companies in Oil and Gas Industry to reduce the environmental impacts has led to a race in search of new cleaner technologies. Fluids with low toxicity are the target of research and development by the companies which are committed to ensure the aspects of quality, health, safety and environment from manufacturing up to the use in the final destination of these products. The replacement of these fluids is happening at a larger speed than in the past on the based in two factors: greater awareness on the part of these companies in relation to the environmental and by new environmental laws. The fluids systems used in fracturing operations are not an exception to this rule. Service companies today are in the process of replacing their formulations with systems less aggressive to the environment so-called 'green' systems. In this context the new technological developments of fracturing fluids are of fundamental importance to assist the new environmental requirements of both operators and government regulatory bodies and also to ensure better effectiveness of these products. This paper reports the research, development and application of new environmentally acceptable fracturing fluids technology, reviews the pioneering case histories in offshore operations and the benefits experienced in the Campos Basin - Brazil. (author)

  3. Preliminary report on fluid inclusions from halites in the Castile and lower Salado formations of the Delaware Basin, southeastern New Mexico

    International Nuclear Information System (INIS)

    A suite of samples composed primarily of halite from the upper Castile and lower Salado Formations of the Permian Basin was selected from Waste Isolation Pilot Plant (WIPP) core for a reconnaissance study of fluid inclusions. Volume percent of these trapped fluids averaged 0.7% to 1%. Freezing-point depressions varied widely and appeared to be unrelated to fluid-inclusion type, to sedimentary facies, or to stratigraphic depth. However, because very low freezing points were usually associated with anhydrite, a relation may exist between freezing-point data and lithology. Dissolved sulfate values were constant through the Castile, then decreased markedly with lesser depth in the lower Salado. This trend correlates very well with observed mineralogy and is consistent with an interpretation of the occurrence of secondary polyhalite as a result of gypsum or anhydrite alteration with simultaneous consumption of dissolved sulfate from the coexisting fluids. Together with the abundance and distribution of fluid inclusions in primary or ''hopper'' crystal structures, this evidence suggests that inclusions seen in these halites did not migrate any significant geographical distance since their formation. 28 refs., 17 figs., 2 tabs

  4. Reservoir quality and diagenetic evolution of Upper Mississippian rocks in the Illinois Basin; influence of a regional hydrothermal fluid-flow event during late diagenesis

    Science.gov (United States)

    Pitman, Janet K.; Henry, Mitchell E.; Seyler, Beverly

    1998-01-01

    Conventional reservoir quality data for more than 300 wells provided by the Illinois and Indiana State Geological Surveys were analyzed to determine the factors governing porosity and permeability in the Upper Mississippian Bethel Sandstone and Cypress Sandstone, two of the principal producing units in the Illinois Basin. In addition, approximately 150 samples of the Bethel Sandstone-Cypress Sandstone interval from about 80 wells in the Illinois Basin were collected for mineralogical and geochemical analysis to reconstruct the burial and diagenetic history and to establish the timing of diagenesis relative to the entrapment of hydrocarbons. One aspect of the study involved linking inorganic and organic diagenesis to late Paleozoic tectonism and hydrothermal fluid-flow events in the region.

  5. 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

  6. Ferride geochemistry of Swedish precambrian iron ores

    Science.gov (United States)

    Loberg, B. E. H.; Horndahl, A.-K.

    1983-10-01

    Chemical analysis for major and trace elements have been performed on 30 Swedish Precambrian iron ores and on some from Iran and Chile. The Swedish ores consist of apatite iron ores, quartz-banded iron ores, skarn and limestone iron ores from the two main ore districts of Sweden, the Bergslagen and the Norrbotten province. Some Swedish titaniferous iron ores were also included in the investigation. The trace element data show that the Swedish ores can be subdivided into two major groups: 1. orthomagmatic and exhalative, 2. sedimentary. Within group 1 the titaniferous iron ores are distinguished by their high Ti-contents. From the ferride contents of the Kiruna apatite iron ores, the ores are considered to be mobilization products of skarn iron ores from the Norbotten province.

  7. Episodic fluid movements in superimposed basin:Combined evidence from outcrop and fluid inclusions of the Majiang ancient oil reservoir,Guizhou Province

    Institute of Scientific and Technical Information of China (English)

    2008-01-01

    Combined evidence from the outcrop and the fluid inclusion assemblage (FIA) analysis indicates that there exist two episodes of fluid flow controlled by the tectonic activity. The first episode was recorded mainly in the reservoir rock of the Honghuayuan Formation,representing the fluid flow of hydrocarbon charging. The second episode occurred mainly along the fault systems,representing the fluid move-ment when the ancient oil reservoir was destroyed. The host mineral morphology,homogeneous tem-perature,and salinity of the FIAs record an episodic fluid movement. Characters of high homogenous temperature,low salinity and a quick temperature variation of the first episode fluid flow may indicate an early-stage fluid eruption,and correspondingly,fine-grained calcite was formed. Temperature of the erupted fluid tended to decrease during its mixing with the upper formation fluid and finally had the same temperature as the upper formation. From then on,the temperature was rather steady and fa-vored the growth of the coarse calcite. Due to this character of the temperature variation of the episodic fluid flow,we can use the homogenous temperature of the FIA of the coarse calcite to date the forma-tion and the destruction time of the Majiang ancient oil reservoir. Episodic fluid flow was known for its inhomogeneous trapping,which resulted in the failure of dating according to the burial history. But taking a close look at its temperature variation,we think that the latest stage of fluid flow,characterized by steady state temperature and grow of the coarser crystals,can be used for dating. It will be of great value if this method is proved to be effective. The formation and the destruction time of the Majiang ancient oil reservoir were dated to be in the Indosinian Period and the late Yanshan-early Hymalayan Period respectively. This conclusion is in great discrepancy with the common accepted idea that the Majiang ancient oil reservoir was formed and destroyed during the

  8. 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

  9. Hunting for Iron Ore Bargains

    Institute of Scientific and Technical Information of China (English)

    2009-01-01

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

  10. 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)

  11. Modelling the coupled fluid and heat transport in a geothermal site: First results from Groß Schönebeck, NE-German Basin

    Science.gov (United States)

    Cherubini, Y.; Cacace, M.; Scheck-Wenderoth, M.; Lewerenz, B.

    2010-05-01

    Predicting the temperature distribution in the subsurface becomes increasingly important in the course of recently intensified exploration for geothermal energy. Numerical models considering both the physical processes controlling heat transfer as well as the structural setting of the subsurface are an important option to assess variations in the temperature distribution. The geothermal in-situ laboratory "Groß Schönebeck" located 40 km north of Berlin is one of the key sites of geothermal exploration studies in the North German Basin. 3D numerical simulations of coupled fluid flow and heat transfer processes are carried out to investigate the geothermal field. The Goal of the study is to quantify the impact of variable rock parameters and geological structures on the resulting thermal distribution. The Zechstein salt as a prominent feature in the North German Basin is of particular interest in this context because it locally modifies the geothermal field. Our first attempts to model coupled fluid flow and heat transfer processes confirm the strong impact of the Upper Permian Zechstein salt. Furthermore, our results indicate that conduction is an important heat transfer mechanism below the Middle Triassic layers. Conversely, the more than 3000 m thick and permeable sediments above the Middle Triassic Muschelkalk unit favour the formation of convection cells. Here, especially high degrees of coupling result in remarkable convective heat transport. We assess the sensitivity of these results, and discuss implications for temperature predictions.

  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. Reconstructing fluid-flow events in Lower-Triassic sandstones of the eastern Paris Basin by elemental tracing and isotopic dating of nanometric illite crystals

    Science.gov (United States)

    Blaise, Thomas; Clauer, Norbert; Cathelineau, Michel; Boiron, Marie-Christine; Techer, Isabelle; Boulvais, Philippe

    2016-03-01

    Lower- to Middle-Triassic sandstones from eastern Paris Basin were buried to a maximum depth of 2500 m at a paleo-temperature of about 100 °C. They contain extensive amounts of authigenic platy and filamentous illite particles similar to those reported in reservoirs generally buried at 3000 to -5000 m and subjected to temperatures of 120 to -150 °C. To evaluate this unexpected occurrence, such sandstones were collected from drill cores between 1825 and 2000 m depth, and nanometric-sized sub-fractions were separated. The illite crystals were identified by XRD, observed by SEM and TEM, analyzed for their major, trace, rare-earth elements and oxygen isotope compositions, and dated by K-Ar and Rb-Sr. Illite particles display varied growth features in the rock pore-space and on authigenic quartz and adularia that they postdate. TEM-EDS crystal-chemical in situ data show that the illite lath/fiber and platelet morphologies correspond at least to two populations with varied interlayer charges: between 0.7 and 0.9 for the former and between 0.8 and 1.0 for the latter, the Fe/Fe + Mg ratio being higher in the platelets. Except for the deeper conglomerate, the PAAS-normalized REE patterns of the illite crystals are bell-shaped, enriched in middle REEs. Ca-carbonates and Ca-phosphates were detected together with illite in the separates. These soluble components yield 87Sr/86Sr ratios that are not strictly in chemical equilibrium with the illite crystals, suggesting successive fluids flows with different chemical compositions. The K-Ar data of finer chemical crystallization conditions induced by fluids flows through the host-rock pore system. These flow events were probably driven by repetitive rifting episodes of the North Atlantic Ocean, although located several hundreds kilometers away from eastern Paris Basin, and/or by fracturing events in the nearby basement of the Vosges Massif. Complex relationships between geodynamical events, thermal anomalies, and advective fluids

  14. Evidence for metasomatic mantle carbonatitic magma extrusion in Mesoproterozoic ore-hosting dolomite rocks in the middle Kunyang rift, central Yunnan, China

    Institute of Scientific and Technical Information of China (English)

    2008-01-01

    The Kunyang rift lying on the western margin of the Yangtze platform is a rare Precambrian Fe-Cu mineralization zone. Wuding- Lufeng basin that is an important part of the zone is located on the west edge in the middle of the rift. The most important ore-hosting rocks are Mesoproterozoic dolomite rocks in the basin controlled by a ring fracture system, which is a fundamental structure of the basin. Plenty of silicate minerals and acicular apatite, feldspar phenocrysts and small vesicular, flown line and flown plane structures, melt inclusion and high temperature fluid inclusion found in most ore-hosting dolomites suggest that this kind of rocks could not be sedimentary dolomite, marble or hydrothermal carbonate rocks. The Zr/Hf and Nb/Ta values of the rocks are identical with those of associated mantle-derived rocks, and vary widely. For the monomineral dolomite, δ18OSMOW‰=+5.99 to +18.4 and δ13CPDB‰=-3.01to+0.94, which fall within the range for all carbonatitic volcanic rocks of the world. As for the accessory minerals, the values of δ18OSMOW‰ of magnetite (=+3.47 to +5.99%0) are close to that of the mantle (<5.7%), and the δ34S‰ values of sulfides (-5.09 to+5.78, averaging+1.50) are close to that of meteorite. For all the ore-bearing dolomite rocks, εNd = +0.19 to +2.27, and the calculated Isr = 0.699143, while for the associated mantle-derived rocks, εNd = +3.18 to +3.72. All the data suggest that the mineral assemblage is not only igneous but also of metasomatic mantle origin. And the presence of acicular apatite indicates that the rocks were formed by magma rapidly cooling. And the phenocryst texture and vesicular, flown and ropy and pyroclastic structures suggest that the igneous rocks were extrusive. Therefore, the ore-bearing dolomite rocks are carbonatitic volcanic rocks. This conclusion implies that most iron and copper ore deposits hosted in the dolomite rocks should be of the carbonatitc type.

  15. 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

  16. Kinetics of cyaniding of gold comprising ores

    International Nuclear Information System (INIS)

    Present article is devoted to kinetics of cyaniding process of gold comprising ores. Thus in laboratory conditions the researches on leaching of gold and silver from ores of various deposits of Tajikistan by means of cyaniding were conducted. The results of laboratory researches on cyaniding of ores of various deposits are presented. The flowsheet of cyaniding of gold comprising ores was elaborated.

  17. Shallow burial dolomitisation of Middle-Upper Permian paleosols in an extensional tectonic context (SE Iberian Basin, Spain): Controls on temperature of precipitation and source of fluids

    Science.gov (United States)

    Benito, M. Isabel; De la Horra, Raúl; López-Gómez, José; Barrenechea, José F.; Luque, Javier; Arche, Alfredo

    2011-06-01

    This work is focused on carbonate paleosols developed in three stratigraphic sections (Landete, Talayuelas and Henarejos) of the Middle-Late Permian Alcotas Formation in the SE Iberian Basin. The Alcotas Formation, of alluvial origin, was deposited in semi-connected half-grabens developed during the early stages of the Permian-Triassic rifting stage that affected the Iberian Basin. The studied sections were located in two of these half-grabens, the Henarejos section being much closer to the basin boundary fault than the other two sections. The mineralogy and texture of the carbonate precursor of paleosols in the three studied sections are not preserved because original carbonate is replaced by coarse crystals of dolomite and/or magnesite. Dolomite crystals are typically euhedral, displaying rhombohedral shapes and reddish luminescence, although in the Henarejos section dolomite displays non-planar boundaries and frequently saddle habit. Micas are deformed and adapted to dolomite crystals, which, in turn, are affected by stylolites, suggesting that dolomite precipitated before mechanical and chemical compaction. Carbon and oxygen isotopic compositions of dolomite from the three sections show different values (δ 13C VPDB mean values = - 6.7‰, - 5.5‰ and - 7.5‰; δ 18O VPDB mean values = - 4.0‰; -5.6‰ and - 8.2‰, at Landete, Talayuelas and Henarejos sections, respectively). The 87Sr/ 86Sr ratios are similar in the three sections yielding values between 0.71391 and 0.72213. The petrographic and geochemical features of dolomite in the three studied sections suggest precipitation from similar fluids and during shallow burial diagenesis. Assuming that the minimum temperature for dolomite precipitation in the Henarejos section was 60 °C (as suggested by the presence of non-planar saddle habit), and that the dolomitizing fluid had similar δ 18O values at the three localities, then dolomite in the Talayuelas and Landete sections precipitated at temperatures

  18. 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

  19. Fluid inclusion and vitrinite-reflectance geothermometry compared to heat-flow models of maximum paleotemperature next to dikes, western onshore Gippsland Basin, Australia

    Science.gov (United States)

    Barker, C.E.; Bone, Y.; Lewan, M.D.

    1999-01-01

    Nine basalt dikes, ranging from 6 cm to 40 m thick, intruding the Upper Jurassic-Lower Cretaceous Strzelecki Group, western onshore Gippsland Basin, were used to study maximum temperatures (Tmax) reached next to dikes. Tmax was estimated from fluid inclusion and vitrinitereflectance geothermometry and compared to temperatures calculated using heat-flow models of contact metamorphism. Thermal history reconstruction suggests that at the time of dike intrusion the host rock was at a temperature of 100-135??C. Fracture-bound fluid inclusions in the host rocks next to thin dikes ( 1.5, using a normalized distance ratio used for comparing measurements between dikes regardless of their thickness. In contrast, the pattern seen next to the thin dikes is a relatively narrow zone of elevated Rv-r. Heat-flow modeling, along with whole rock elemental and isotopic data, suggests that the extended zone of elevated Rv-r is caused by a convection cell with local recharge of the hydrothermal fluids. The narrow zone of elevated Rv-r found next to thin dikes is attributed to the rise of the less dense, heated fluids at the dike contact causing a flow of cooler groundwater towards the dike and thereby limiting its heating effects. The lack of extended heating effects suggests that next to thin dikes an incipient convection system may form in which the heated fluid starts to travel upward along the dike but cooling occurs before a complete convection cell can form. Close to the dike contact at X/D 1.5. ?? 1998 Elsevier Science B.V. All rights reserved.

  20. Liassic U-Pb age of the Rabejac pitchblende. Isotopic arguments for a Permian uraniferous preconcentration in the Lodeve basin (Herault)

    Energy Technology Data Exchange (ETDEWEB)

    Lancelot, J.; Vella, V.

    Located in the basal part of the Saxonian formations of he Lodeve basin, the massive pitchblendes of the Rabejac ore deposit provide an age of 183 +- 4 Ma (Pb-Pb isochron), consistent with a Liassic mobilization of uranium in southern Massif central previously dated in the U ore deposits of Lodeve (Herault), Bertholene (Aveyron) and Pierres-Plantees (Lozere). This mobilization is related to the circulation of rather hot saline fluids (3-14%, 130-250/sup 0/C) induced by the tectonic phase of continental crust thinning (horsts, grabens, tilted blocks) which preceded the opening of the Ligurian-Piemontais ocean. Using Concordias diagrams we discuss the isotopic composition of the initial lead incorporated into the Rabejac pitchblendes during their cristallization which appears to have been radiogenic. This constitutes the first isotopic argument in favour of a primary U concentration during Permian times in the Lodeve basin.

  1. Novel Binders and Methods for Agglomeration of Ore

    Energy Technology Data Exchange (ETDEWEB)

    S. K. Kawatra; T. C. Eisele; K. A. Lewandowski; J. A. Gurtler

    2006-03-31

    Many metal extraction operations, such as leaching of copper, leaching of precious metals, and reduction of metal oxides to metal in high-temperature furnaces, require agglomeration of ore to ensure that reactive liquids or gases are evenly distributed throughout the ore being processed. Agglomeration of ore into coarse, porous masses achieves this even distribution of fluids by preventing fine particles from migrating and clogging the spaces and channels between the larger ore particles. Binders are critically necessary to produce agglomerates that will not break down during processing. However, for many important metal extraction processes there are no binders known that will work satisfactorily at a reasonable cost. A primary example of this is copper heap leaching, where there are no binders currently encountered in this acidic environment process. As a result, operators of many facilities see a large loss of process efficiency due to their inability to take advantage of agglomeration. The large quantities of ore that must be handled in metal extraction processes also means that the binder must be inexpensive and useful at low dosages to be economical. The acid-resistant binders and agglomeration procedures developed in this project will also be adapted for use in improving the energy efficiency and performance of a broad range of mineral agglomeration applications, particularly heap leaching. The active involvement of our industrial partners will help to ensure rapid commercialization of any agglomeration technologies developed by this project.

  2. Novel Binders and Methods for Agglomeration of Ore

    Energy Technology Data Exchange (ETDEWEB)

    S. K. Kawatra; T. C. Eisele; J. A. Gurtler; K. Lewandowski

    2005-09-30

    Many metal extraction operations, such as leaching of copper, leaching of precious metals, and reduction of metal oxides to metal in high-temperature furnaces, require agglomeration of ore to ensure that reactive liquids or gases are evenly distributed throughout the ore being processed. Agglomeration of ore into coarse, porous masses achieves this even distribution of fluids by preventing fine particles from migrating and clogging the spaces and channels between the larger ore particles. Binders are critically necessary to produce agglomerates that will not break down during processing. However, for many important metal extraction processes there are no binders known that will work satisfactorily at a reasonable cost. A primary example of this is copper heap leaching, where there are no binders currently encountered in this acidic environment process. As a result, operators of many facilities see a large loss of process efficiency due to their inability to take advantage of agglomeration. The large quantities of ore that must be handled in metal extraction processes also means that the binder must be inexpensive and useful at low dosages to be economical. The acid-resistant binders and agglomeration procedures developed in this project will also be adapted for use in improving the energy efficiency and performance of a broad range of mineral agglomeration applications, particularly heap leaching. The active involvement of our industrial partners will help to ensure rapid commercialization of any agglomeration technologies developed by this project.

  3. NOVEL BINDERS AND METHODS FOR AGGLOMERATION OF ORE

    Energy Technology Data Exchange (ETDEWEB)

    S.K. Kawatra; T.C. Eisele; J.A. Gurtler; C.A. Hardison; K. Lewandowski

    2004-04-01

    Many metal extraction operations, such as leaching of copper, leaching of precious metals, and reduction of metal oxides to metal in high-temperature furnaces, require agglomeration of ore to ensure that reactive liquids or gases are evenly distributed throughout the ore being processed. Agglomeration of ore into coarse, porous masses achieves this even distribution of fluids by preventing fine particles from migrating and clogging the spaces and channels between the larger ore particles. Binders are critically necessary to produce agglomerates that will not break down during processing. However, for many important metal extraction processes there are no binders known that will work satisfactorily. Primary examples of this are copper heap leaching, where there are no binders that will work in the acidic environment encountered in this process, and advanced ironmaking processes, where binders must function satisfactorily over an extraordinarily large range of temperatures (from room temperature up to over 1200 C). As a result, operators of many facilities see a large loss of process efficiency due to their inability to take advantage of agglomeration. The large quantities of ore that must be handled in metal extraction processes also means that the binder must be inexpensive and useful at low dosages to be economical. The acid-resistant binders and agglomeration procedures developed in this project will also be adapted for use in improving the energy efficiency and performance of a broad range of mineral agglomeration applications, particularly heap leaching and advanced primary ironmaking.

  4. Agribusiness geothermal energy utilization potential of Klamath and Western Snake River Basins, Oregon. Final report

    Energy Technology Data Exchange (ETDEWEB)

    Lienau, P.J.

    1978-03-01

    Resource assessment and methods of direct utilization for existing and prospective food processing plants have been determined in two geothermal resource areas in Oregon. Ore-Ida Foods, Inc. and Amalgamated Sugar Company in the Snake River Basin; Western Polymer Corporation (potato starch extraction) and three prospective industries--vegetable dehydration, alfalfa drying and greenhouses--in the Klamath Basin have been analyzed for direct utilization of geothermal fluids. Existing geologic knowledge has been integrated to indicate locations, depth, quality, and estimated productivity of the geothermal reservoirs. Energy-economic needs and balances, along with cost and energy savings associated with field development, delivery systems, in-plant applications and fluid disposal have been calculated for interested industrial representatives.

  5. Microwave enhanced processing of ores

    OpenAIRE

    Kobusheshe, Joseph

    2010-01-01

    Recent research developments have suggested that microwave assisted comminution could provide a step change in ore processing. This is based on the fact that microwave-absorbent phases within a multi-mineral ore can be selectively heated by microwave energy hence inducing internal stresses that create fracture. A detailed review of existing literature revealed that little or no information is available which relates and examines the influence of hydrated minerals on microwave assisted fr...

  6. 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

  7. On the contact behavior analysis of the o-ring depending on the contact surface profiles

    Energy Technology Data Exchange (ETDEWEB)

    Kim, Chung Kyun [Hongik Univ., Seoul (Korea, Republic of)

    2005-02-01

    In this paper, the contact stress and strain distributions in elastomer O-ring seals have been analyzed using a non-linear finite element method. The stress behavior of PTFE materials is assumed as Odgen model because the sealing clearance between the flange and the surface of the O-ring is not small and the sealing pressure of working fluids covers from the atmospheric pressure to high pressure of 15MPa. The contact normal force and stress in wavy O-rings in which is developed for this analysis are uniformly distributed along the flange and the wall of the rectangular groove. And the normal sealing forces are also kept high compared to other contact sealing models such as the conventional O-ring and X-ring. Thus, the FEM computed results indicate that the sealing characteristic of wavy O-rings is good compared with other contact seals.

  8. Geochemical characteristics of the fluid inclusions in the Gangxi Fault Belt, Huanghua Depression, Bohai Bay Basin, China

    Institute of Scientific and Technical Information of China (English)

    DING Wei-wei; DAI Jin-xing; CHU Feng-you; HAN Xi-qiu

    2007-01-01

    We studied the geochemical characteristics of the fluid inclusions in the Ordovician carbonates and the Oligocene Shahejie Formation sandstones from 15 wells in the Gangxi Fault Belt, Huanghua Depression. The fluid inclusions are all secondary with gas/liquid ratio of 5%~10%. Base on Raman they are mainly composed of H2O, CO2 and CH4. The homogenization temperatures, combined with burial and geothermal history of the host rock, indicate that the fluid flows in the Shahejie Formation and the Ordovician carbonates were trapped in Neocene. Using a VG5400 mass spectrometer, the helium isotopic compositions were analyzed. Interpretation of results suggested a significant amount of mantle-derived helium mainly accumulating in the intersections of the NWW trending Xuzhuangzi and NE trending Gangxi faults. The maturity of hydrocarbon decreases from the intersection to the outside pointing out that the fluid related to the NWW trending Xuzhuangzi and NE trending Gangxi faults.These factors implied the fluid inclusions have a close relationship to the local tectonic setting. Gangxi Fault Belt experienced intensive Neo-tectonic activities in Cenozoic. Widespread faulted-depressions and strong volcanic eruptions manifested its tectonic status of extensional stress field. Mantle uplift caused the movement of magma that carried mantle-derived gases and deep heat flows, the deep-rooted tension faults provided the passages for the gases and heat flows to shallow crust levels.

  9. 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

  10. The distribution and evolution of fluid pressure and its influence on natural gas accumulation in the Upper Paleozoic of Shenmu-Yulin area, Ordos Basin

    Institute of Scientific and Technical Information of China (English)

    WANG; ZhenLiang; CHEN; HeLi

    2007-01-01

    On the basis of measuring the pressure distribution and analyzing its origin in the Carboniferous and Permian of Shenmu-Yulin area, the evolution history of ancient pressure is restored mainly by means of the basin numerical simulation technique, in which the paleo-pressure has been constrained by the compaction restoration and the examination of fluid inclusion temperature and pressure. Then the development and evolution history of abnormal pressure and its effect on gas migration and accumulation are investigated. Studies show that the pressure in southeastern and northwestern parts of studied area is near to hydrostatic pressure, whereas in the remainder vast area the pressure is lower than the hydrostatic pressure, which is caused by difficulty to measure pressure accurately in tight reservoir bed, the calculating error caused by in-coordinate between topography relief and surface of water potential, pressure lessening due to formation arising and erosion. There are geological factors beneficial to forming abnormal high pressure in the Upper Palaeozoic. On the distraction of measured pressure, paleo-pressure data from compaction restoration and fluid inclusion temperature and pressure exa- mining, the evolution history of ancient pressure is restored by the basin numerical simulation technique. It is pointed out that there are at least two high peaks of overpressure in which the highest value of excess pressure could be 5 to 25 MPa. Major gas accumulated in main producing bed of Shanxi Fm (P1s) and lower Shihezi Fm (P2x), because of two-fold control from capillary barrier and overpressure seal in upper Shihezi Fm (P2s). In the middle and southern districts, the two periods of Later Jurassic to the middle of Early Cretaceous, and middle of Later Cretaceous to Palaeocene are main periods of gas migration and accumulation, while they belong to readjustment period of gas reservoirs after middle of Neocene.

  11. Petrophysical analysis of regional-scale thermal properties for improved simulations of geothermal installations and basin-scale heat and fluid flow

    CERN Document Server

    Hartmann, Andreas; Clauser, Christoph

    2008-01-01

    Development of geothermal energy and basin-scale simulations of fluid and heat flow both suffer from uncertain physical rock properties at depth. Therefore, building better prognostic models are required. We analysed hydraulic and thermal properties of the major rock types in the Molasse Basin in Southern Germany. On about 400 samples thermal conductivity, density, porosity, and sonic velocity were measured. Here, we propose a three-step procedure with increasing complexity for analysis of the data set: First, univariate descriptive statistics provides a general understanding of the data structure, possibly still with large uncertainty. Examples show that the remaining uncertainty can be as high as 0.8 W/(m K) or as low as 0.1 W/(m K). This depends on the possibility to subdivide the geologic units into data sets that are also petrophysically similar. Then, based on all measurements, cross-plot and quick-look methods are used to gain more insight into petrophysical relationships and to refine the analysis. Be...

  12. Characteristics of the ore-forming fluid of typical gold deposits in Xiaoshan area of Henan and their enlightenment to further prospecting works%河南省崤山地区典型金矿床的成矿流体特征及其对进一步找矿工作的启示

    Institute of Scientific and Technical Information of China (English)

    徐文超; 王通; 常云真; 周奇明; 贾慧敏; 赵留升

    2016-01-01

    Xiaoshan area is located inside the middle-west part of Xiaoqinling-Xiaoshan-Xiong’ershan-Waifang-shan Au-Ag-Mo polymetallic metallogenic belt in western Henan.However,the measured reserves of gold ores is far less than that of Xiaoqinling area and eastern Xiong’ershan area.Therefore,the prospecting po-tential in Xiaoshan area attracts great attention of related industrial sectors.Combined with previous work, this paper put forth the theory that the gold ores in the area were predominated by fracture zone alteration rock type and quartz vein type.According to the analysis of typical deposits,the paper concluded that the mineralization of gold ores could be divided into four stages from early to late:(1)quartz-pyrite (arsenopy-rite)stage,(2)pyrite-quartz stage,(3)quartz-polymetallic sulfide stage,and (4)quartz-carbonate stage. Among the four stages,stage (2)and (3)are the main stages of mineralization.The author conducted analy-sis on the content,homogenization temperature and S-H-O-Pb isotope composition of the fluid inclusions in the quartz crystals in each ore-forming stage.It indicates that the fluid was CO 2-rich aqueous fluid with nu-merous dissolved Na+ and Ca2 + ions.The homogenization temperature of fluid inclusions ranges from 243℃to 285℃,and it suggests that the gold deposits in Xiaoshan area are mainly intermediate temperate hydro-thermal deposits being short of fluid inclusions of high temperature stage.The δ34 S value of metal sulfide ranges from -0.5‰ to 5.4‰ and it shows the characteristics of deep source sulfur.And its δ1 8 O H2 O value ranges from 0.1‰ to 9.4‰ and δ1 8 D value ranges from - 134.9‰ to 24.3‰,and it shows that the ore-forming fluid occurs mainly as magmatic water with lesser atmospheric precipitation and metamorphic water. Based on the comparison between outcrop area of granitic intrusive rocks in Xiaoshan area and that in Xiao-qinling area,it appears that the unsatisfactory prospecting results in Xiaoshan area

  13. Evidence for participation of microbial mats in the deposition of the siliciclastic ‘ore formation’ in the Copperbelt of Zambia

    Science.gov (United States)

    Porada, H.; Druschel, G.

    2010-10-01

    The Copperbelt of Zambia is the world's largest sediment-hosted stratiform copper province, hosted in siliciclastic sediments of the Roan Group, which forms the basal part of the Neoproterozoic-Paleozoic Katanga Supergroup. Much of the ore deposition occurred between 880 Ma and 780 Ma, on a rimmed platform consisting of a carbonate barrier, a lagoonal basin and tidal flats grading into sabkhas in the hinterland. Various sedimentary structures developed in the ore formation at the Mindola Open Pit mine, are herein considered to be microbially induced and are identified as microbial shrinkage cracks, wrinkle structures, mat deformation structures, petees, concentric microfaults, and microbial mat chips. The occurrence of these structures in all ore formation units at the Mindola Mine suggests microbial mats grew on the paleo-sediment surface throughout deposition of the cupriferous succession. As these structures require cohesive layers, the mats were likely of the cyanobacterial type, that grew in the well aerated intertidal to lower supratidal zones. Cyanobacterial mats typically consist of a surface layer of filamentous cyanobacteria underlain by anaerobic, heterotrophic sulfate reducing bacteria (SRB). A distinct sulfide mineral zonation, developed in all major deposits of the Copperbelt, ranges from barren supratidal (sabkha) sediments, through chalcocite in the lower supratidal zone, to bornite followed by chalcopyrite in the intertidal zone, and pyrite in the subtidal zone and anoxic lagoonal depotcentre. This sequence of minerals can be modelled as a paragenetic sequence of mineralization resulting from the progressive reduction of a source fluid, indicating that geochemical conditions of ore formation, at least, are produced by the activity of SRB.

  14. Novel Binders and Methods for Agglomeration of Ore

    Energy Technology Data Exchange (ETDEWEB)

    S. K. Kawatra; T. C. Eisele; K. A. Lewandowski; J. A. Gurtler

    2006-12-31

    Many metal extraction operations, such as leaching of copper, leaching of precious metals, and reduction of metal oxides to metal in high-temperature furnaces, require agglomeration of ore to ensure that reactive liquids or gases are evenly distributed throughout the ore being processed. Agglomeration of ore into coarse, porous masses achieves this even distribution of fluids by preventing fine particles from migrating and clogging the spaces and channels between the larger ore particles. Binders are critically necessary to produce agglomerates that will not break down during processing. However, for many important metal extraction processes there are no binders known that will work satisfactorily. Primary examples of this are copper heap leaching, where there are no binders that will work in the acidic environment encountered in this process, and advanced ironmaking processes, where binders must function satisfactorily over an extraordinarily large range of temperatures (from room temperature up to over 1200 C). As a result, operators of many facilities see a large loss of process efficiency due to their inability to take advantage of agglomeration. The large quantities of ore that must be handled in metal extraction processes also means that the binder must be inexpensive and useful at low dosages to be economical. The acid-resistant binders and agglomeration procedures developed in this project will also be adapted for use in improving the energy efficiency and performance of a broad range of mineral agglomeration applications, particularly heap leaching and advanced primary ironmaking. This project has identified several acid-resistant binders and agglomeration procedures that can be used for improving the energy efficiency of heap leaching, by preventing the ''ponding'' and ''channeling'' effects that currently cause reduced recovery and extended leaching cycle times. Methods have also been developed for iron ore

  15. Implication for horizontally-elongated fluid flow inferred from heat flow measurements in the Iheya-North hydrothermal field, Okinawa Trough back-arc basin

    Science.gov (United States)

    Masaki, Yuka; Kinoshita, Masataka; Kawada, Yoshifumi

    2010-05-01

    The Okinawa Trough is a back-arc basin located in the southwestern part of Japan. It is considered to be in the initial stage of rifting of continental crust, and the activity generates volcanic edifices in this area, accompanied by hydrothermal circulation. The Iheya-North is one of the most active hydrothermal fields among them. As a proposed drilling site for the Integrated ocean Drilling Program, extensive geophysical surveys have been carried out including single-channel seismic imaging, and precise side-scan sonar imaging by using autonomous underwater vehicle 'Urashima' of Japan Agency for Marine-Science and Technology. In the recent few years, we have measured heat flow in and around the Iheya-North hydrothermal field to understand the spatial of hydrothermal circulation in detail. 78 measurements show that heat flow is higher than 10 W/m2 with in 0.5 km of the hydrothermal vent complex, that it gradually decrease eastward to vs. ~a few hundreds meters vertical). We performed numerical calculations of fluid flow and heat transportation to give constraints on the depth of hydrothermal circulation, the magnitude of darcy velocity, and the permeability at depth. The simulated results will be compared with measured heat flow distribution and will be checked for the larger or smaller circulation scale proposed from heat flow or fluid geochemistry data.

  16. Tectonic ore-controlling in the middle southern segment of Da Hinggan Ling, Northeast China

    Institute of Scientific and Technical Information of China (English)

    2006-01-01

    Studies on geotectonic evolution, regionally geological characteristics and ore-forming and ore-controlling structures have shown that since the Mesozoic the Da Hinggan Ling region has entered the typical intercontinental orogenic stage, which appears to be closely related to mantle plume activities. Da Hinggan Ling is a typical mantle branch structure and possesses obvious magmatic-metamorphic complexes in the core, detachment slip beds in the periphery and overlapped fault depression basins. Moreover, all these are the principal factors leading to ore formation and ore controlling in the region. This paper also further explores the mechanism of mineralization in the middle-southern segment of Da Hinggan Ling,summaries the rules of mineralization, puts forward the models of mineralization and points out the oresearch orientations in the future time.

  17. Geochemical element mobility during the history of a Paleo-proterozoic clastic sedimentary basin, the Athabasca Basin (Saskatchewan, Canada)

    International Nuclear Information System (INIS)

    In order to understand the mechanisms of migration and deposition of ore elements, it is essential to determine the timing, source, and destination of the geochemical element mass transfers and/or transportation on a scale encompassing the great sedimentary basins. The purpose of this study is to trace and to date the element migrations that occurred during the history of a Paleo-proterozoic clastic sedimentary basin, the Athabasca Basin, which hosts the world's largest and richest uranium deposits. As this geological environment was proved to be efficient to preserve high grade ore deposits for over more than one billion years, it provides an opportunity to study some natural analogues of deep geological nuclear waste storage. Five research topics were studied: 3D modelling of the distribution of normative minerals and trace elements on a basin-wide scale; U-Pb and Rb-Sr systematics; average chemical age estimation; thermodynamic modelling of the major mineralogical assemblages; U-Pb geochronology of uranium oxides. Some elements have remained immobile (Zr) since their initial sedimentary deposition, or were transferred from one phase to another (Al, Th). Other elements have been transported during fluid flow events that occurred: (1) on a basin wide scale during diagenesis (REE, Y, Sr, Fe), (2) at the unconformity and in the vicinity of the fault zones that represent preferential fluid flow pathways between the basement and the sandstone cover (U, Ni, As, B, Mg, K, Fe, Sr, REE), (3) during the late fault reactivation events associated with the basin uplift (U, Pb, Ni, S, Sr, REE). The successive tectonic events related to the geodynamical context that lead to the formation of these high-grade U concentrations (1460 Ma, 1335 Ma and 1275 Ma in the McArthur River deposit), did not however systematically occur in the whole basin (1275 Ma only at Shea Creek). The exceptionally high grade and tonnages of some deposits seem to be related to a larger number of U

  18. Morphologies, classification and genesis of pockmarks, mud volcanoes and associated fluid escape features in the northern Zhongjiannan Basin, South China Sea

    Science.gov (United States)

    Chen, Jiangxin; Song, Haibin; Guan, Yongxian; Yang, Shengxiong; Pinheiro, Luis M.; Bai, Yang; Liu, Boran; Geng, Minghui

    2015-12-01

    Based on new high-resolution multi-beam bathymetry and multichannel seismic reflection data, two new groups of numerous pockmarks and mud volcanoes were discovered in the northern Zhongjiannan Basin at water depths between 600 and 1400 m. Individual pockmarks are circular, elliptical, crescent-shaped or elongated, with diameters ranging from several hundreds to thousands of meters and tens or hundreds of meters in depth, and they often form groups or strings. Crescent pockmarks, approximately 500-1500 m wide in cross-section and 50-150 m deep, occur widely in the southern study area, both as individual features and in groups or curvilinear chains, and they are more widespread and unique in this area than anywhere else in the world. Conical mud volcanoes, mostly with kilometer-wide diameters and ca. 100 m high, mainly develop in the northern study area as individual features or in groups. Seismic data show that the observed pockmarks are associated with different kinds of fluid escape structures and conduits, such as gas chimneys, diapirs, zones of acoustic blanking, acoustic turbidity and enhanced reflections, inclined faults, small fractures and polygonal faults. The mapped mud volcanoes appear to be fed from deep diapirs along two main conduit types: the conventional conduits with downward tapering cones and another other conduit type with a narrow conduit in the lower half and emanative leakage passages in the upper half. Various types of pockmarks are found and a comprehensive pockmark classification scheme is proposed, according to: (a) their shape in plan view, which includes circular, elliptical, crescent, comet-shape, elongated and irregular; (b) their magnitude, which includes small, normal, giant and mega-pockmarks; and (c) their composite pattern, which includes composite pockmarks, pockmark strings and pockmark groups. For the genesis of the crescent pockmark (strings), a 5-stage speculative formation model is proposed, implying possible controlling

  19. Microthermometric measurement of fluid inclusions and its constraints on genesis of PGE-polymetallic deposits in Lower Cambrian black rock series, southern China

    Institute of Scientific and Technical Information of China (English)

    WANG Min; SUN Xiaoming; MA Mingyang

    2005-01-01

    Systematic microthermometric measurements of fluid inclusions in the PGE-polymetallic deposits hosted in the Lower Cambrian black rock series in southern China were performed, and the results suggest: (1) there exist two types of fluid inclusions. TypeⅠis of NaCl-H2O system with low-medium salinity, and its homogenization temperatures (Th) and salinities are 106.9- 286.4℃ and ( 0.8- 21.8) wt%NaCl eq. respectively; TypeⅡ is of CaCl2-NaCl-H2O system with medium-high salinities, and its homogenization temperatures and salinities range from 120.1℃ to 269.6℃ and ( 11.4- 31.4) wt%NaCl eq., respectively. The typeⅡ fluid inclusions have been discovered for the first time in this kind of deposits; (2) two generations of ore-forming fluids were recognized. Characteristics of fluid inclusions in the PGE-polymetallic ores and carbonate-quartz stockworks in the underlying phosphorites are almost of no difference, they may represent ore-forming fluids at the main metallogenic stage. The peak value of homogenization temperature of those fluid inclusions is about 170℃, while their salinities possess a remarkable bimodal distribution pattern with two peak values of (27-31) wt%NaCl eq. and (4-6) wt%NaCl eq. On the contrary, fluid inclusions in the carbonate-quartz veins in the hanging wall may represent ore-forming fluids at the post-metallogenetic stage. The homogenization temperatures and the peak values of salinities are mostly 130-170℃ and (12-14) wt%NaCl eq., respectively; (3) nobel gas isotopic composition analyses in combination with the microthermometric measurements of fluid inclusions suggest that the ore-forming fluids at the main metallogenetic stage were probably derived from mixing of basinal hot brines with the CaCl2-NaCl-H2O system and seawater with the NaCl-H2O system; (4) in the Early Cambrian, the basinal hot brines were trapped in the Caledonian basins, which were distributed along the southern margin of the Yangtze Craton, and where giant thick

  20. Research on Magnesite Ore Purification

    Directory of Open Access Journals (Sweden)

    Berisha, K.

    2009-12-01

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

  1. Processing Gold Quarry refractory ores

    Science.gov (United States)

    Hausen, D. M.

    1989-04-01

    The Gold Quarry deposit is the largest sediment-hosted gold deposit yet discovered on the Carlin trend in northern Nevada. However, despite the locale's vast reserves, the gold is difficult to extract from portions of the deposit. Detailed, ongoing mineralogical analyses assure proper treatment of the ore.

  2. 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

  3. 四川省牦牛坪稀土矿床成矿流体与碳酸岩-正长岩杂岩体成因联系评述%Genetic Relation of Ore-Forming Fluids and Carbonatite- Syenite Complex in Maoniuping REE Deposit, Sichuan Province, China:A Review

    Institute of Scientific and Technical Information of China (English)

    许成; 黄智龙; 漆亮

    2004-01-01

    The Maoniuping REE deposit is the second largest primary light REE deposit in China.Fluorite is one of main gangue minerals in the orefield. Carbonatites and syenites are spatially and temporally associated with rare earth mineralization. Based on the previous geochemical studies of fluorite and carbonatite-syenite complex, we review the genetic relation of REE ore-forming fluids and carbonatite-syenite complex. It shows that carbonatites and syenites have similar REE distribution patterns, (87Sr/86Sr)0, (143Nd/144Nd)0, 206Pb/204Pb, 208Pb/204Pb ratios, and plot to the area between the mantle end-member EM1 and EM2. They were formed in orogenic setting. Fluorites associated with REE mineralization display different REE distribution patterns, but their Sr, Nd, Pb isotopic ratios are uniform, and are similar to those of carbonatites and syenites. This suggests that the different REE fluorites were products of the same source, and REE ore-forming fluids were related to carbonatite and syenite magmas.%四川省牦牛坪稀土矿床是中国第二大原生轻稀土矿床,萤石是矿区主要脉石矿物之一,碳酸岩和正长岩在空间和时间上与稀土成矿存在密切联系.在过去萤石和碳酸岩-正长岩杂岩体地球化学研究的基础上,评述了稀土成矿流体与碳酸岩-正长岩杂岩体的成因联系.矿区碳酸岩和正长岩具有相似的REE配分模式、(87Sr/86Sr)0,(143Nd/144Nd)0,206Pb/204Pb,208Pb/204Pb同位素比值,位于地幔端元EM1和EM2之间,它们是造山环境的产物.与稀土矿化共生的萤石显示不同的稀土配分模式,但是它们具有一致的Sr、Nd、Pb同位素比值,与碳酸岩和正长岩相似.这些表明不同稀土特征的萤石来自相同的源区,稀土成矿流体与碳酸岩和正长岩岩浆存在密切联系.

  4. 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)

  5. Method of continuous pressure leaching of ores

    International Nuclear Information System (INIS)

    Ore leaching, especially suspensions of ground ore or fine ore fractions from physical treatment was divided into two operations. The former, i.e., ore mixing with technical grade concentrated sulfuric acid proceeded in a separate mixer. The mixture was then transported into an autoclave where the actual leaching proceeded for 2 to 4 hours. The extracted mixture was discharged through the autoclave bottom. The leaching autoclave used can be without any inner structures. The separation of mixing from the actual leaching allows processing ores with high levels of clay components, increasing operating reliability of the facility, reducing consumption of special structural materials and energy, and increasing process efficiency. (E.S.)

  6. Reactor vessel o-ring spring clip

    International Nuclear Information System (INIS)

    A reactor vessel O-ring spring clip is designed to hold a tubular metallic O-ring in the groove of a reactor vessel head flange, especially during vessel head lifting. The spring clip is designed such that the weight of the O-ring acts to increase the friction force between the spring clip and the, typically, threaded hole into which it is inserted. An end of the clip adapted to be inserted through a slot in the tubular O-ring for securement thereto, has a circular member thereon which prevents the spring clip from becoming disengaged from the O-ring during head lifting. (author)

  7. Numerical models of carbonate hosted gold mineralization, Great Basin Nevada

    Science.gov (United States)

    Person, M.; Hofstra, A.; Gao, Y.; Sweetkind, D.; Banerjee, A.

    2006-12-01

    The Great Basin, Nevada contains many modern hydrothermal system and world class gold deposits hosted within Paleozoic carbonate rocks. Temperature profiles, fluid inclusion studies, and isotopic evidence suggest that modern geothermal and fossil hydrothermal systems associated with gold mineralization share many common features including the absence of a clear magmatic source, flow restricted to fault zones, and remarkably high temperatures at shallow depth. While the plumbing of these systems is not well understood, geochemical and isotopic data suggest that fluid circulation along fault zones is relatively deep (greater than 5 km) and comprised of relatively unexchanged Pleistocene meteoric water with small (less than 2.5 per mill) shifts from the MWL. Many fossil ore-forming systems were also dominated by meteoric water, but are usually exhibit shifts of 5 to 15 per mill from the MWL. Here we present two-dimensional numerical models to reconstruct the plumbing of modern geothermal and Tertiary hydrothermal systems in the Great Basin. Multiple tracers are used in our models, including O- and C-isotopic compositions of fluids/rocks, silica transport/ precipitation, and temperature anomalies, to constrain the plumbing of these systems. Our results suggest that both fossil hydrothermal and modern geothermal systems were probably driven by natural convection cells associated with localized high basal heating. We conclude that the fault controlled flow systems responsible for the genesis of Carlin gold mineralization and modern geothermal systems had to be transient in nature. Permeability changes within the carbonate reservoir was probably associated with extensional tectonic events.

  8. Manganese deposits in northeastern European Russia and the Urals: Isotope geochemistry, genesis, and evolution of ore formation

    Science.gov (United States)

    Kuleshov, V. N.; Brusnitsyn, A. I.; Starikova, E. V.

    2014-09-01

    Based on new data on the lithology, mineralogy, chemistry, and isotopic composition of manganese carbonate ores and rocks at the deposits and occurrences in the Novaya Zemlya Archipelago, the Pai-Khoi, and the Urals, as well as using data from the literature, the main Phanerozoic basins of manganese deposition have been established in the geological history of Laurasia, Pangea, and Siberian paleocontinents. The formation conditions of manganese ore gradually changed from hydrothermal-sedimentary in the Middle Paleozoic to sedimentary-diagenetic in Mesozoic and Cenozoic. The ore was also formed under catagenetic conditions. Carbon of oxidized organic matter plays a substantial role in the formation of manganese carbonates.

  9. Ore-turbidity gamma densimeter GTM-200

    International Nuclear Information System (INIS)

    The device is designed for measuring ore turbidity through the pipe walls, without any contact with the measured fluid. The measuring principle is based on the attenuation of gamma beam intensity across a homogeneous medium. The facility consists of a measuring block, mounted on the pipe carrying the fluid whose density is to be measured and a display block which gives the measured density in g/cm3. The measuring block is made up of an emitter equipped with a Cs 137 radiation source and a receiver. The operational and technical features and components of the system are: - Leaden emitter; - Radioactive source: Cs-137; - Measuring range: 1 - 2.1g/cm3; - Maximum admitted error across measuring range: ±1.5% of real conventional value; - Average response time: 30 seconds; - Power supply: 220 V ac±10%; 50 Hz; - Ambient temperature: - 10 deg. C to + 40 deg. C; - Pipe diameter: 80 mm - 200 mm; - Receiver shielding level: IP 65; - Display-transmitter shielding level: IP 54; - Display-transmitter output signal: 4 - 20 mA for a preset measuring sub-range; - Receiver to display-transmitter wire length: 30 m. (authors)

  10. 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)

  11. 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.)

  12. 滇西北红山铜矿床成矿流体地球化学特征及矿床成因%Geochemical characteristics of ore-forming fluids and genesis of Hongshan copper deposit in northwestern Yunnan Province

    Institute of Scientific and Technical Information of China (English)

    李文昌; 王可勇; 尹光侯; 秦丹鹤; 余海军; 薛顺荣; 万多

    2013-01-01

    The Hongshan copper deposit is a large porphyry-skarn type polymetallic deposit in northwestern Yunnan Province. It occurred in quartz diorite porphyry of Indo-Chinese Period and quartz monzonite porphyry of Yanshanian Period as well as their neighbouring wall rocks. The formation of it experienced superimposition of mutiphases/stages hydrothermal mineralization. Comprehensive study on petrography, microthermometry and carbon-hydrogen-oxygen isotope of fluid inclusions showed that the ore-forming fluids of early metallogenic stages are of medium to high temperature, high salinity NaCl-H2 O type solutions and mainly came from arc magmatism of Indo-Chinese Period, they were responsible for the formation of skarn type mineralization. The ore-forming fluids of later metallogenic stages are of medium to high temperature, high salinity NaCl-CO2 -H2 O type solutions and mainly came from the buried granitic magmatism of post orogenic extension environment, and they played important role in the formation of porphyry type Cu, Mo and relevant Pb, Zn mineralization. So the Hongshan copper deposit is of superimposed poyphyry-skarn type deposit that originated from the metallogenic superimposition of two phases of magmatic hydrothermal fluids.%红山铜矿床为滇西北地区一大型斑岩-矽卡岩型铜多金属矿床,它产于印支期石英闪长玢岩及燕山期石英二长斑岩体内及其周边地层中,其形成经历了多期次热液叠加成矿作用过程.流体包裹体岩相学、显微测温及碳、氢、氧稳定同位素综合研究表明,矿区早期成矿流体为中高温、高盐度NaCl-H2O体系热液,主要来源于印支晚期岛弧型岩浆活动,对区内矽卡岩型矿化形成起了重要作用;晚期成矿流体为中高温、高盐度NaCl-CO2-H2O体系热液,主要来源于隐伏的燕山期后造山伸展型花岗质岩浆侵入体,形成了区内斑岩型Cu、Mo及相关的Pb、Zn多金属矿化.因此,红山铜矿床是

  13. Helium isotopic compositions in fluid inclusions of the Gangxi fault belt in the Huanghua Depression, Bohai Bay Basin

    Institute of Scientific and Technical Information of China (English)

    DING Weiwei; DAI Jinxing; YANG Chiyin; TAO Shizhen; HOU Lu

    2005-01-01

    The authors obtained 30 core samples from 15 wells in Gangxi fault belt, Huanghua Depression. Using a VG5400 mass spectrometer, the helium isotopic compositions in fluid inclusion of these samples were analysed. Interpretation of results suggests a significant amount of mantle-derived helium in the inclusions, which were likely trapped during Neocene. Mantle-derived helium have mostly accumulated in the intersections of the NWW trending Xuzhuangzi and NE trending Gangxi faults, and decreased away from the intersections. This pattern implied a close relationship to the local tectonic setting. Gangxi fault belt experienced intensive neo-tectonic activities in the Cenozoic. Widespread faulted-depressions and strong volcanic eruptions manifested its tectonic status of extensional stress field. Mantle uplift caused the movement of magma that carried mantle-derived gas, and the deep-rooted tension faults provided the passages for the gases to shallow crust levels. High-content abiogenic CO2 pools occurred in the study area, hence, using the helium isotopic compositions is of great significance to the exploration of abiogenic natural gases.

  14. Discovery and Significance of High CH4 Primary Fluid Inclusions in Reservoir Volcanic Rocks of the Songliao Basin, NE China

    Institute of Scientific and Technical Information of China (English)

    WANG Pujun; HOU Qijun; WANG Keyong; CHEN Shumin; CHENG Rihui; LIU Wanzhu; LI Quanlin

    2007-01-01

    Comparing compositions of the fluid inclusions in volcanic rocks to the contents and isotopes of the gases in corresponding volcanic reservoirs using microthermometry, Raman microspectroscopy and mass spectrum analysis, we found that: (1) up to 82 mole% methane exists in the primary inclusions hosted in the reservoir volcanic rocks; (2) high CH4 inclusions recognized in the volcanic rocks correspond to CH4-bearing CO2 reservoirs that are rich in helium and with a high 3He/4He ratio and which show reversed order of δ13C in alkane; (3) in gas reservoirs of such abiotic methane (>80%)and a mix of CH4 and CO2, the enclosed content of CH4 in the volcanic inclusions is usually below 42mole%, and the reversed order of δ13C in alkane is sometimes irregular in the corresponding gas pools;(4) a glassy inclusion with a homogeneous temperature over 900℃ also contains a small portion of CH4although predominantly CO2. This affinity between gas pool and content of inclusion in the same volcanic reservoirs demonstrates that magma-originated gases, both CH4 and CO2, have contributed significantly to the corresponding gas pools and that the assumed hydrocarbon budget of the bulk earth might be much larger than conventionally supposed.

  15. StORe Business Analysis

    OpenAIRE

    Miller, Ken

    2006-01-01

    The StORe project is multidisciplinary in scope, embracing the seven scientific domains of archaeology, astronomy, biochemistry, biosciences, chemistry, physics and the social sciences (originally described in the project plan as social policy and political science). The business analysis will formulate general principles for middleware development to link source and output repositories irrespective of discipline, but also outline domain-specific requirements. Consequent to thi...

  16. Radon risk in ore miners

    International Nuclear Information System (INIS)

    Underground workers are exposed to various clastogenic agents. One of these agents, radon, attracts attention of recent research as it causes lung cancer in the population occupationally exposed to its various concentrations especially in mine air of uranium mines or ore mines. This paper is a pilot study in which the numbers of chromosomal aberrations (CA) in lymphocytes of ore mines (Nizna Slana-iron ore, Hnusta-talc ore) located in east central Slovakia were followed and related to the lifetime underground radon exposure and to lifetime smoking. Seventy miners volunteering after an informed consent served as donors of venous blood. Twenty healthy pro-bands, age matched with the miners, which never worked underground (mostly clerks) served as donors of control blood samples. The exposure to radon and smoking has been estimated according to working-records and personal anamnesis. The findings unequivocally showed a small but statistically significant clastogenic effect of the exposure to underground environment of the mines concerned. This study has shown also a small but significant influence of smoking, which in the subgroup of miners working underground less than 1500 shifts may have acted synergically with the underground exposure. It was concluded tat: (1) Significantly higher counts of chromosomal aberrations in lymphocytes of 70 miners than in an age matched control group of 20 white-collar workers were found; (2) The higher counts of chromosomal aberrations could be ascribed to underground exposure of miners and to smoking; (3) The positive dependence of the number of chromosomal aberrations from the exposure to smoking was loose and it was expressed by significantly higher chromosomal aberrations counts in the group of miners working less than 1500 shifts underground; (4) A dependence of chromosomal aberrations counts from the exposure to radon could not be assessed. At relatively low numbers of pro-bands in subgroups it was not ruled out the confounding

  17. 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

  18. Environmental Aspects of Iron ORE Mining

    OpenAIRE

    B. Chandra Sekhar*; *, Dr. S. Siddi Raju

    2014-01-01

    Iron ore mining activities such as top soil stripping, drilling and blasting extraction of ore, waste rock dumping, loading and unloading of ore, crushing and screening, material transport etc., emit both fugitive and fugitive dusts into the environment. A direct effect of the mining and its activities deteriorate the quality of ambient air, which requires mitigation measures. Blasting causes very high noise and vibration at a very short duration. Surface water pollution occurs d...

  19. Device for geophysical reconnaissance of ore deposits

    International Nuclear Information System (INIS)

    Device for geophysical reconnaissance of ore deposits with the polarization curve method. The graphical relation between the intensity J of the current through the surface of the ore body and the potential quantity phi of the electrochemical reaction occuring if this current flows through the body is called 'polarization curve'. From the polarization curves, the potentials of the electrochemical reactions are evaluated from which the mineralogical composition of ore bodies and the limiting current values of the reactions, serving to calculate the size of the ore body and its other parameters, are determined. (orig.)

  20. Mineralogy and geochemistry of banded iron formation and iron ores from eastern India with implications on their genesis

    Indian Academy of Sciences (India)

    Subrata Roy; A S Venkatesh

    2009-12-01

    The geological complexities of banded iron formation (BIF) and associated iron ores of Jilling–Langalata iron ore deposits, Singhbhum–North Orissa Craton, belonging to Iron Ore Group (IOG) eastern India have been studied in detail along with the geochemical evaluation of different iron ores. The geochemical and mineralogical characterization suggests that the massive, hard laminated, soft laminated ore and blue dust had a genetic lineage from BIFs aided with certain input from hydrothermal activity. The PAAS normalized REE pattern of Jilling BIF striking positive Eu anomaly, resembling those of modern hydrothermal solutions from mid-oceanic ridge (MOR). Major part of the iron could have been added to the bottom sea water by hydrothermal solutions derived from hydrothermally active anoxic marine environments. The ubiquitous presence of intercalated tuffaceous shales indicates the volcanic signature in BIF. Mineralogical studies reveal that magnetite was the principal iron oxide mineral, whose depositional history is preserved in BHJ, where it remains in the form of martite and the platy hematite is mainly the product of martite. The different types of iron ores are intricately related with the BHJ. Removal of silica from BIF and successive precipitation of iron by hydrothermal fluids of possible meteoric origin resulted in the formation of martite-goethite ore. The hard laminated ore has been formed in the second phase of supergene processes, where the deep burial upgrades the hydrous iron oxides to hematite. The massive ore is syngenetic in origin with BHJ. Soft laminated ores and biscuity ores were formed where further precipitation of iron was partial or absent.

  1. BIOREMEDIATION OF LOW GRADE ORES

    OpenAIRE

    Rashmi Mishra*

    2016-01-01

    The research work presented in this paper is on a Bioremediation for the recovery of zinc from mining waste i.e. Low grade ore of Hindustan Zinc Limited. They are waste product for the mines, as the recovery process is expensive compared to the recovery product moreover it causes lots of pollution   Bioleaching Studies were carried out at different pH using mixed culture grown from mine water. Recovery of zinc in control set (without culture) was 8% in 37 days and at the same pH ...

  2. 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)

  3. Temporal and spatial distribution of Au-Ag polymetallic ore deposits and source of ore-forming materials in the Zhangjiakou-Xuanhua mantle-branch metallogenetic zone

    Institute of Scientific and Technical Information of China (English)

    2007-01-01

    The Zhangjiakou-Xuanhua area is a mineral resource-concentrated area for gold-silver polymetallic ore deposits. The temporal and spatial distribution and origin of mineral resources have been argued for a long time. Based on the comprehensive studies of geochronology and sulfur, lead, oxygen, carbon and noble gas isotopes, it is considered that the temporal and spatial distribution of mineral resources in this area is obviously controlled by the Zhangjiakou-Xuanhua mantle branch structure, as is reflected by the occurrence of gold deposits in the inner parts and of Ag-Pb-Zn polymetallic ore deposits in the outer parts. The mineralization took place mainly during the Yanshanian period. Ore-forming materials came largely from the deep interior of the Earth, and hydrothermal fluids were derived predominantly from Yanshanian magmatism.

  4. Dissolved Organic Carbon Distribution in Two Hydrothermal Systems - West Mata, NE Lau Basin during an eruption event and basement fluids from sediment-buried Juan de Fuca Ridge flanks

    Science.gov (United States)

    Lin, H.; Cowen, J. P.; Butterfield, D. A.; Embley, R. W.; Resing, J.

    2009-12-01

    Hydrothermal systems have profound influence in regulating seawater chemistry. However, the extent hydrothermal systems have impact on deep ocean DOC remains unclear. This study will provide data on dissolved organic carbon distribution in two very different hydrothermal systems. The first is hydrothermal fluids produced from a near-arc volcano in Northeast Lau Basin. Samples were collected with the Butterfield fluid sampler during an eruption event at West Mata during May 2009. The eruption event allowed collection of fluids from both new and established vents, high temperature focused and low temperature diffused vents. This unique opportunity should shed light on DOC changes in nascent hydrothermal systems in accordance with early microbiological community succession. The second hydrothermal environment is a 3.5 Myr-sediment-covered basement aquifer located on the east flank of Juan de Fuca Ridge. Basement Fluids were collected from basement ~280 mbsf (~20 m below sediment-basement interface) using 0.25” stainless steal fluid delivery lines of the Circulation Obviating Retrofit Kit (CORK) observatories at Ocean Drilling program borehole 1301A; samples were drawn up the FDL by a new clean pumping system (Mobile Pump Valve Unit or MPVU) and collected in an acid-cleaned 60-L Large Volume Bag Sampler (LVBS). Due to the effective hydraulic barrier of the 260 m thick of sediment over-lying the basement at this site, the basement fluid here does not readily exchange with bottom seawater. In contrast to vent fluid in Lau vent field, the basement fluid has been circulating in the basement, on average, several thousand years. DOC data will be presented from these hydrothermal fluids and discussed with respect to the DOC cycle in the deep ocean.

  5. Enriching of Magnesite Ore Containing Dolomite

    Directory of Open Access Journals (Sweden)

    Shaqiri, M.

    2010-10-01

    Full Text Available Minor mineral phases containing calcium and silica in magnesite ore are the main cause of detrimental properties of magnesia refractory materials prepared thereof. All stages of the production process aim to remove such unwanted mineral phases. While the removal of silica minerals is well documented, it is not so for the calcium containing minerals, especially when it is not possible to do so by mechanical separation processes only. In this work, the influence of duration and temperature of heat treatment and subsequent hydration of magnesia has been studied. The final product obtained is a light component from the settling separation utilizing dense water suspension of ferrosilica. The optimal process conditions were: 4 to 6 h soaking at temperature between 600 and 700 °C with subsequent hydration of partially calcined product by immersion in water and settling separation at heavy fluid density ρ= 2.20 g cm–3. Furthermore, a positive influence of prolonged heat treatment on product quality as well as the optimal density of ferrosilica suspension has been obtained.

  6. Continuous Steelmaking Directly from Ore

    Science.gov (United States)

    Warner, Noel A.

    2014-12-01

    In-line continuous processing of high-grade hematite ore (crushed ore or fines) with a pure hydrogen reductant is assessed. An appraisal is made of the rate controlling mechanisms involved in the reduction of a pure layer of molten wustite being transported by floating on a molten carrier iron carbon-free medium at temperatures just in excess of the iron melting point. Published research clearly indicates that under these conditions the kinetics are principally controlled by molecular gaseous diffusion. Thus, the rate is essentially not influenced by total gas pressure above 1 atmosphere. Accordingly, on safety grounds it is recommended that high pressure should not be used for hydrogen steelmaking in the future, but the operation should be conducted close to atmospheric pressure with low pressure steam encapsulation of the plant items involved. Using hydrogen as the reductant means that sub-surface nucleation of CO bubbles cannot disrupt continuous processing. The operation is then no different to processing a normal liquid phase. The off-gases from the reduction zone of a melt circulation loop are super-clean and only contaminated with iron vapor. Accordingly, the best available technology becomes available for energy conservation without risk of non-fusible solids deposition. The net result is that the energy requirements are expected to be superior to other potential processes.

  7. Biomass for iron ore sintering

    Energy Technology Data Exchange (ETDEWEB)

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

    2010-11-15

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

  8. Estimating gold-ore mineralization potential within Topolninsk ore field (Gorny Altai)

    Science.gov (United States)

    Timkin, T.; Voroshilov, V.; Askanakova, O.; Cherkasova, T.; Chernyshov, A.; Korotchenko, T.

    2015-11-01

    Based on the results of ore and near-ore metasomatite composition analysis, the factors and indicators of gold-ore mineralization potential were proposed. Integration of the obtained data made it possible to outline magmatic, structural, and lithological factors, as well as direct and indirect indicators of gold-ore mineralization. Applying multidimensional analysis inherent to geochemical data, the spatial structure was investigated, as well as the potential mineralization was identified. Based on the developed and newly-identified mineralization, small (up to medium-sized) mineable gold-ore deposits in skarns characterized by complex geological setting was identified.

  9. 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

  10. Iron from Zealandic bog iron ore -

    DEFF Research Database (Denmark)

    Lyngstrøm, Henriette Syrach

    2011-01-01

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

  11. The Luster of Iron Ore Prices

    Institute of Scientific and Technical Information of China (English)

    2009-01-01

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

  12. Ore lead isotopical composition of lower Proterozoic volcanogenic sulfide ores at Garpenberg, south central Sweden

    International Nuclear Information System (INIS)

    The isotopic composition of ore lead in galena from the volcanogenic sulfide ores at Garpenberg district is presented. Compared with the average growth curve of Stacey and Kramers, the ore lead at Garpenberg is slightly enriched in radiogenic lead. The influence of metamorphism on the ore lead composition of galena samples is negligible. The observed trend in the standard diagrams may be explained in terms of a mixing line, where the ore lead was derived from two different crustal sources originally enriched in radiogenic lead (e.g. volcanic and sedimentary rocks). Alternatively, it could represent sulfide ores of slightly different ages derived from a common rock source. The composition of the ore lead in the Garpenberg district displays the typical signature of the volcanogenic sulfide ores in Bergslagen, which at a regional scale is relatively homogeneous and is interpreted as derived form an isotopically well mixed orogen-upper crust reservoir. The results are consistent with a common origin for all the sulfide ore types present in the Garpenberg and Garpenberg Norra deposits. However, at a local scale, minor variations in the ore lead composition can be detected within a particular district or single deposit. These differences may be interpreted as due to the influence of the local lithology on the ore lead or differences in mineralization age. (L.E.)

  13. Ore lead isotopical composition of lower Proterozoic volcanogenic sulfide ores at Garpenberg, south central Sweden

    Energy Technology Data Exchange (ETDEWEB)

    Gebeyehu, M.; Vivallo, W. (Stockholm Univ. (Sweden). Dept. of Geology and Geochemistry)

    1991-01-01

    The isotopic composition of ore lead in galena from the volcanogenic sulfide ores at Garpenberg district is presented. Compared with the average growth curve of Stacey and Kramers, the ore lead at Garpenberg is slightly enriched in radiogenic lead. The influence of metamorphism on the ore lead composition of galena samples is negligible. The observed trend in the standard diagrams may be explained in terms of a mixing line, where the ore lead was derived from two different crustal sources originally enriched in radiogenic lead (e.g. volcanic and sedimentary rocks). Alternatively, it could represent sulfide ores of slightly different ages derived from a common rock source. The composition of the ore lead in the Garpenberg district displays the typical signature of the volcanogenic sulfide ores in Bergslagen, which at a regional scale is relatively homogeneous and is interpreted as derived form an isotopically well mixed orogen-upper crust reservoir. The results are consistent with a common origin for all the sulfide ore types present in the Garpenberg and Garpenberg Norra deposits. However, at a local scale, minor variations in the ore lead composition can be detected within a particular district or single deposit. These differences may be interpreted as due to the influence of the local lithology on the ore lead or differences in mineralization age. (L.E.).

  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. Geochemical Characteristics of Two Types of Ores from Jinshan Shear Zone—hosted Gold Deposit,Jiangxi,with a Discussion on the Mechanism of Two—stage Mineralization

    Institute of Scientific and Technical Information of China (English)

    季峻峰; 刘英俊; 等

    1995-01-01

    Two types of gold ores,siliceous mylonite and quartz vein,formed at the first and second stages of mineralization respectively, can be clearly recognized in the shear zone-hosted gold deposit at Jinshan, Jiangxi.Similarity in REE and trace elements between the siliceous mylonite and the country rocks indicates that the ore metals were supplied by the surrounding strata during the first stage of mineralization.On the other hand, as indicated by fluid inclusion data,the ore-forming fluid at the second stage was of meteoric origin and the precipitation of gold was caused by phase separation.

  16. Alteration and ore distribution in the Proterozoic Mines Series, Tenke-Fungurume Cu-Co district, Democratic Republic of Congo

    Science.gov (United States)

    Fay, I.; Barton, M. D.

    2012-06-01

    Two sediment-hosted stratiform Cu-Co deposits in the Tenke-Fungurume district of the Central African Copperbelt were examined to evaluate the alteration history of the ore-hosting Mines Series and its implications for ore distribution and processing. Core logging and petrography, focused on lithology and timing relationships, outlined a complex alteration sequence whose earliest features include formation of anhydrite nodules and laths, followed by precipitation of dolomite. Later alteration episodes include at least two silica introductions, accompanied by or alternating with two dolomite introductions into the existing gangue assemblages. One introduction of Cu-Co sulfides accompanied the last episode of dolomite alteration, overprinting an earlier generation of ore whose gangue association was unidentifiable. Sulfides and some carbonates were subsequently modified by supergene oxidation, transport, and reprecipitation to 100-200 m depth. Present-day ore distribution resulted from these successive processes. Ore is concentrated in two shale-dominated units on either side of a cavernous silicified dolomite, which is interpreted as the main conduit for the mineralizing fluids. Sulfide ores precipitated at the redox or sulfidation contacts between this dolomite and the shales. Later, supergene fluids dissolved and moved some of the metals, redepositing them as oxides and carbonates. Solubility differences between Cu and Co in supergene conditions caused them to precipitate separately. Thus, modern ore distribution at Tenke-Fungurume results both from original hypogene lithology- and contact-related precipitation and from supergene oxidation, transport, and Cu-Co decoupling. The supergene fluid flow also redistributed gangue minerals such as dolomite, which has an economically important influence on the processing costs of supergene ores.

  17. Iron sulphides in mining ores

    International Nuclear Information System (INIS)

    Full text: Mineral samples were obtained from different stages of a mineral processing circuit used to extract the copper and gold rich mineralogical phases. The aim of this work is to characterise the quality of the samples at different stages of processing. The samples were taken of the initial head grade, tailings, initial cyclone concentration and the final concentrate. Characterisation of the samples was carried out using Cu Kα x-ray powder diffraction and 57Fe Moessbauer spectroscopy. These measurements will be presented and discussed in terms of the enrichment of the ore, showing the removal of magnetite and quartz through the processing, the final concentrate being rich in chalcopyrite, bornite and pyrite

  18. Sr evolution in the Upper Permian and Lower Triassic carbonates, northeast Sichuan basin, China: Constraints from chemistry, isotope and fluid inclusions

    International Nuclear Information System (INIS)

    Petrographic features, C, O and Sr isotopes, rare earth and trace elements were determined, and fluid inclusions were analyzed on various stages of interparticle cements and vug-fillings from the Upper Permian and Lower Triassic sour reservoirs in northeastern Sichuan basin. The aim was to assess the origin and evolution of palaeo-waters in the carbonates. The original water was contemporary seawater, from which marine cements precipitated with slightly high Sr contents (mean 1911 ppm), 87Sr/86Sr ratios from 0.7067 to 0.7082 and nonluminescent CL. The palaeo-seawater was diluted by meteoric water, as indicated by bright cathodoluminescence (CL) and Sr-depletion (0–516 ppm) in low-temperature calcite. When buried to temperatures of about 60–90 °C during Middle to Late Triassic, the palaeo-water was enriched in Sr released from the transformation of precursor aragonite and calcite to dolomite, resulting in precipitation of substantial pre-bitumen Sr-rich minerals (SrSO4 and SrCO3). For un-dolomitized limestone sections, aragonite neomorphism may have contributed Sr to the precipitation of small amounts of Sr-bearing minerals and calcite crystals with elevated homogenization temperatures (HTs, mainly from 90 to 130 °C) and wide Sr contents (from 34 to 3825 ppm), as recorded in stage III calcite. Since the Middle Jurassic, almost all of the early stage celestite and significant amounts of solid CaSO4 have been consumed by reactions with hydrocarbons (i.e., TSR), resulting in water enriched in isotopically light CO2 and HCO3-,Sr2+,Ba2+ and Eu2+, as recorded in calcite with low δ13C values (down to −18.9‰), 87Sr/86Sr ratios from 0.7072 to 0.7076, high HTs (mainly 110–198 °C), positive Eu anomalies and high Sr and Ba contents. Subsequently, the water was uplifted and cooled down to about 115 °C, celestite and strontianite were precipitated with the occurrence of natural elemental S immiscible inclusions. TSR may have produced significant amounts of

  19. Modeling of the fault-controlled hydrothermal ore-forming systems

    International Nuclear Information System (INIS)

    A necessary precondition for the formation of hydrothermal ore deposits is a strong focusing of hydrothermal flow as fluids move from the fluid source to the site of ore deposition. The spatial distribution of hydrothermal deposits favors the concept that such fluid flow focusing is controlled, for the most part, by regional faults which provide a low resistance path for hydrothermal solutions. Results of electric analog simulations, analytical solutions, and computer simulations of the fluid flow, in a fault-controlled single-pass advective system, confirm this concept. The influence of the fluid flow focusing on the heat and mass transfer in a single-pass advective system was investigated for a simplified version of the metamorphic model for the genesis of greenstone-hosted gold deposits. The spatial distribution of ore mineralization, predicted by computer simulation, is in reasonable agreement with geological observations. Computer simulations of the fault-controlled thermoconvective system revealed a complex pattern of mixing hydrothermal solutions in the model, which also simulates the development of the modern hydrothermal systems on the ocean floor. The specific feature of the model considered, is the development under certain conditions of an intra-fault convective cell that operates essentially independently of the large scale circulation. These and other results obtained during the study indicate that modeling of natural fault-controlled hydrothermal systems is instructive for the analysis of transport processes in man-made hydrothermal systems that could develop in geologic high-level nuclear waste repositories

  20. Origin of the Rubian carbonate-hosted magnesite deposit, Galicia, NW Spain: mineralogical, REE, fluid inclusion and isotope evidence

    Science.gov (United States)

    Kilias, Stephanos P.; Pozo, Manuel; Bustillo, Manuel; Stamatakis, Michael G.; Calvo, José P.

    2006-10-01

    The Rubian magnesite deposit (West Asturian—Leonese Zone, Iberian Variscan belt) is hosted by a 100-m-thick folded and metamorphosed Lower Cambrian carbonate/siliciclastic metasedimentary sequence—the Cándana Limestone Formation. It comprises upper (20-m thickness) and lower (17-m thickness) lens-shaped ore bodies separated by 55 m of slates and micaceous schists. The main (lower) magnesite ore body comprises a package of magnesite beds with dolomite-rich intercalations, sandwiched between slates and micaceous schists. In the upper ore body, the magnesite beds are thinner (centimetre scale mainly) and occur between slate beds. Mafic dolerite dykes intrude the mineralisation. The mineralisation passes eastwards into sequence of bedded dolostone (Buxan) and laminated to banded calcitic marble (Mao). These show significant Variscan extensional shearing or fold-related deformation, whereas neither Rubian dolomite nor magnesite show evidence of tectonic disturbance. This suggests that the dolomitisation and magnesite formation postdate the main Variscan deformation. In addition, the morphology of magnesite crystals and primary fluid inclusions indicate that magnesite is a neoformed hydrothermal mineral. Magnesite contains irregularly distributed dolomite inclusions (modified basinal brines that have reacted and equilibrated with intercalated siliciclastic rocks. Magnesite formation is genetically linked to regional hydrothermal dolomitisation associated with lithospheric delamination, late-Variscan high heat flow and extensional tectonics in the NW Iberian Belt. A comparison with genetic models for the Puebla de Lillo talc deposits suggests that the formation of hydrothermal replacive magnesite at Rubian resulted from a metasomatic column with magnesite forming at higher fluid/rock ratios than dolomite. In this study, magnesite generation took place via the local reaction of hydrothermal dolostone with the same hydrothermal fluids in very high permeability zones at

  1. Uranium concentration in hydrothermal solutions according to the data of fluid inclusive study

    International Nuclear Information System (INIS)

    Using laser excitation luminescent technique the preliminary results of determination of uranium concentration in fluid inclusions in uranium vein minerals have been presented. Three groups of quartz and calcite specimems of crustification veins of pitchblende-carbonate formation have been investigated : preore formations, barren veins of ore stage and ore veins. Specimens were prepared using decrepitation technique. It is stated that the highest uranium concentrations in hydrothermal solutions are related to the period and areas of ore-forming system formation. Ip preore as well as ore stage but be ond the boundaries of ore-=- bearing areas uranium content in hydrothermal solution was lower

  2. 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

  3. Iron Ore Talks, A Prolonged Race

    Institute of Scientific and Technical Information of China (English)

    Zang Kejia

    2009-01-01

    @@ At press time,Chinese steel makers and the World's biggest iron ore minersstill did not reach the final agreement upon the iron ore price,past the original deadline June 30.Since Rio Tinto and Japan's Nippon Steel Corp.reached the 33percent price cut,the iron ore negotiation went into the even harder period.The China Iron and Steel Association (CISA)issued the statement several times that they would not accept the 33 percent cut,but adhere to 40 percent,however,with the negotiation approaching to the end,the situation for China becomes more unoptimistic.

  4. 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)

  5. Rare Earth Element Geochemistry on Magmatic Rocks and Gold Deposits in Shizishan Ore-Field of Tongling, China

    Institute of Scientific and Technical Information of China (English)

    2006-01-01

    REE geochemical characteristics of the magmatic rocks and gold deposits in Shizishan ore-field of Tongling were studied. Three types of the magmatic rocks have almost the same chondrite-normalized REE patterns, Eu and Ce anomalous values, and ΣREE, ΣLREE/ΣHREE regular changes, which indicates that their magmas come from the same source and their digenetic mechanism is fractional crystallization. In three gold deposits, the mineral ores and related altered rocks have similar chondrite-normalized REE patterns and sharp Eu positive anomalous values. The REE contents reduced from the magmatic rocks to skarnization or alteration magmatic rocks, skarn type ores, sulphide type ores, wall-rocks limestone or marble. The REE geochemical characteristics of the ores and related rocks show that primary fluids originated from magmatic differentiation in lower pressure of shallow crust, ore-forming hydrothermal solutions gained REE and mineralization elements further from leaching the magmatic rocks, then superimposed and reformed the limestones or marbles and deposited ore-forming material.

  6. Paleomagnetic and mineral magnetic studies of zinc-lead ore deposits in the Metaline (Washington state, USA) and Midlands (Ireland) ore fields

    Science.gov (United States)

    Pannalal, Shanmugam Johari

    Carbonate-hosted Zn-Pb deposits of the Metaline (USA) and Irish Midlands (Ireland) ore fields exhibit features of both MVT and SEDER deposits, and therefore, play an important role in the debate over genetic models for MVT - SEDER deposits, including the structural controls on ore mineralization, syngenetic versus epigenetic models, and the origin and migration pathways for hydrothermal fluids. The genetic controversy arises largely because of the lack of direct dates on mineralization. Paleomagnetic analyses on samples of host rock and ore mineralization from 38 sites (400 specimens) in the Metaline Zn-Pb district, Washington (USA), using the known thermal history and the paleoarc method of paleomagnetic dating, indicate coeval postfolding magnetizations acquired during the Middle Jurassic (166+/-6 Ma), in the waning stages of the Nevadan Orogeny. The thermal (Th) and alternating field (AF) step demagnetization, saturation isothermal anaylses (SIRM), and artificial specimens' tests show that the characteristic remanent magnetizations (ChRM) is carried mostly by pseudosingle (PSD) to single domain (SD) pyrrhotite that records a primary chemical remanent magnetization (CRM) in ore and a secondary ChRM in host specimens. Furthermore, the paleomagnetic Middle Jurassic age suggests an epigenetic origin for ore formation of the Zn-Pb mineralization at the Pend Oreille Mine that coincides with the timing of cooling from the regional Nevadan orogenic heating episode. Paleomagnetic analyses of the least thermally affected (conodont alteration indices (CAI) of epigenetic Variscan model of ore genesis in which the mineralization event occurred during the cooling from the regional Variscan thermal episode.

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

    Institute of Scientific and Technical Information of China (English)

    1999-01-01

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

  8. He isotopes constraints to the origin of hydrothermal fluids: application to the fluorite mineralizations of Asturias (N Spain)

    International Nuclear Information System (INIS)

    Helium isotopes have been measured in fluorite and sulphides in order to obtain conclusive means of assessing the involvement of mantle and crustally derived volatiles in F-Ba deposits from Asturias (N of Spain). Fluorite mineralizations are hosted in Mesozoic (Permotriassic) and Paleozoic age rocks. Mineralization is composed of fluorite, barite, calcite, dolomite, quartz and sulphides, and shares the characteristics of most Mississippi Valley Type (MVT) deposits associated with rifting events related to the opening of the Atlantic Ocean. The 3He/4He values of the Asturias ore fluids (≤ 0,1 Ra) indicate a crustal fluid source and exclude the involvement of a mantle helium component. These values are consistent with the acceptance of the existing basinal model for MVT genesis and sedimentary brines migration, with the lack of igneous activity in the area contemporary with the mineralization, and also consistent with similar helium isotope data recorded in other fluorite deposits in Europe. (Author) 24 refs.

  9. 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

  10. Metallogenetic features and perspective evaluation of sandstone-type uranium mineralization in Hailaer Basin, NE, China

    International Nuclear Information System (INIS)

    Hailaer basin is located at the Mongolia-Erguna microplate between Siberian and North-China plates. The basement of the basin is composed of Precambrian igneous and metamorphic rocks, which experienced multiple granitization, and Late Paleozoic, Mesozoic granites and acidic-intermediate volcanics constituting a uranium-enriched provenance area. The sedimentary cover of the basin consists of continental sedimentary series of Late Jurassic to Tertiary. Of them, Lower Cretaceous (Damouguaihe Formation) clastics of alluvial, fan-delta and fluvial facies rich in organic matter are the main uranium ore-hosting series. Numerous uranium occurrences have been found at the western part of the basin, and uranium mineralization mainly occurs in coarse-grained clastics of the second and third members of Damouguaihe Formation. Uranium ore bodies usually are tabular, a few roll-shaped. The thickness of individual orebody ranges from 0.3m to 5m. Ore grade commonly is 0.0n% with the encountered highest grade of 0.38%. Uranium in ores is in adsorption form, heterogeneously disseminated in the cement of sandstone. No independent uranium mineral has been found. Associated elements in ores include Mo, V, Se, Sc, and Re. Discovered uranium mineralization in the basin approximately occurs at the same elevation intervals (660-680m), suggesting the paleo-phreatic origin. Uranium mineralization is mostly localized in permeable sandstone units of fluvial and fan-delta facies with high content of organic matter. Ore-formation age is supposed to be the period from K2 to N when the ore-hosting sedimentary series outcropped at the surface and was eroded. High content of uranium in provenance area, existence of permeable ore-hosting sandstone units and the oxidation (phreatic and interlayer) alteration of ore-hosting sandstone after its deposition under arid climate environments are key factors determining the perspective potential of uranium ore-formation. (author)

  11. Mineralogical Characterization of Goethite- Lateritic Ore & its Implication on Beneficiation

    OpenAIRE

    Nirlipta P. Nayak

    2014-01-01

    Mineralogical characterization of ore has to get due attention before any attempt for its processing and has become almost inevitable these days because of the increasing demand of the ore. Mineral processing technology is evolved to separate and recover ore minerals from gangue in a commercially viable method and is mainly based upon the process of mineral liberation and the process of mineral separation. A very lean grade iron ore sample was collected from Barsua iron ore deposi...

  12. Biomining: metal recovery from ores with microorganisms.

    Science.gov (United States)

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

    2014-01-01

    Biomining is an increasingly applied biotechnological procedure for processing of ores in the mining industry (biohydrometallurgy). Nowadays the production of copper from low-grade ores is the most important industrial application and a significant part of world copper production already originates from heap or dump/stockpile bioleaching. Conceptual differences exist between the industrial processes of bioleaching and biooxidation. Bioleaching is a conversion of an insoluble valuable metal into a soluble form by means of microorganisms. In biooxidation, on the other hand, gold is predominantly unlocked from refractory ores in large-scale stirred-tank biooxidation arrangements for further processing steps. In addition to copper and gold production, biomining is also used to produce cobalt, nickel, zinc, and uranium. Up to now, biomining has merely been used as a procedure in the processing of sulfide ores and uranium ore, but laboratory and pilot procedures already exist for the processing of silicate and oxide ores (e.g., laterites), for leaching of processing residues or mine waste dumps (mine tailings), as well as for the extraction of metals from industrial residues and waste (recycling). This chapter estimates the world production of copper, gold, and other metals by means of biomining and chemical leaching (bio-/hydrometallurgy) compared with metal production by pyrometallurgical procedures, and describes new developments in biomining. In addition, an overview is given about metal sulfide oxidizing microorganisms, fundamentals of biomining including bioleaching mechanisms and interface processes, as well as anaerobic bioleaching and bioleaching with heterotrophic microorganisms. PMID:23793914

  13. Reactor vessel O-ring spring clip

    International Nuclear Information System (INIS)

    This patent describes in a nuclear reactor pressure vessel including a vessel closure head having a bottom surface adapted to be sealingly engaged with the pressure vessel, the vessel head having an annular groove therein for receiving a tubular O-ring having slots therein, the vessel head also having threaded apertures in the bottom surface concentrically disposed with respect to the annular groove, a reactor vessel O-ring spring clip for securing the O-ring to the vessel head. The spring clip comprising a horizontal leg having one end thereof adapted to be received within one of the slots in the O-ring and an opposite end adapted to frictionally engage one of the threaded apertures, such that the weight of the O-ring increases the friction force between the spring clip and the threaded aperture, wherein the one end of the horizontal leg adapted to engage the O-ring includes; a generally vertical leg extending upward from the one end of the horizontal leg; and a generally circular member depending from the vertical leg such that it lies in a vertical plane parallel with that of the horizontal leg

  14. How Many Ore-Bearing Asteroids?

    CERN Document Server

    Elvis, Martin

    2013-01-01

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

  15. Mechanism of mechanical activation for sulfide ores

    Institute of Scientific and Technical Information of China (English)

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

    2007-01-01

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

  16. Oxygen and carbon isotopes in ore deposits in sedimentary rocks, ch. 7

    International Nuclear Information System (INIS)

    In this chapter some aspects of the distribution and processes controlling the abundance of 18O and 13C in hydrothermal systems are discussed. The term hydrothermal refers to hot, mineralized fluids which, in this specific case, deposited economic amounts of ore minerals in sedimentary rocks. Such ore minerals contain, only in exceptional cases, significant amounts of oxygen and carbon but both are normally very abundant in the associated gangue minerals: carbonates and silicates. Therefore, most stable isotope investigations which use 18O or 13C are based on the distribution of these isotopes in these gangue minerals and it is evident that the paragenetic relationships between gangue and ore must be fully understood if such data are to yield information about the formation of ore minerals and the origin of fluids and metals. A more detailed discussion concentrates on four genetically different deposits: the Providencia mines in Mexico; the Bluebell Mine in British Columbia (Canada), the Pine Point deposits in the Northwest Territories (Canada), and the Eldorado Mines in the Beaverlodge district in Saskatchewan (Canada)

  17. 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)

  18. Geology and D-O-C Isotope Systematics of the Tieluping Silver Deposit,Henan,China:Implications for Ore Genesis

    Institute of Scientific and Technical Information of China (English)

    CHEN Yanjing; Franco PIRAJNO; SUI Yinghui

    2005-01-01

    The Tieluping silver deposit, which is sited along NE-trending faults within the high-grade metamorphic basement of the Xiong'er terrane, is part of an important Mesozoic orogenic-type Ag-Pb and Au belt recently discovered. Ore formation includes three stages: Early (E), Middle (M) and Late (L), which include quartz-pyrite (E),polymetallic sulfides (M) and carbonates (L), respectively. The E-stage fluids are characterized by δD=-90‰,δ13Cco2=2.0‰ and δ18O=9‰ at 373℃, and are deeply sourced; the L-stage fluids, with δD=-70‰,δ13Cco2=-1.3‰ and δ18O=-2‰, are shallow-sourced meteoric water; whereas the M-stage fluids, with δD=-109‰,δ13Cco2=0.1‰ and δ18O=2‰, are a mix of deep-sourced and shallow-sourced fluids. Comparisons of the D-O-C isotopic systematics of the Estage ore-forming fluids with the fluids derived from Mesozoic granites, Archean-Paleoproterozoic metamorphic basement and Paleo-Mesoproterozoic Xiong'er Group, show that these units cannot generate fluids with the measured isotopic composition (high δ18O and δ13C ratios and low δD ratios) characteristic of the ore-forming fluids. This suggests that the E-stage ore-forming fluids originated from metamorphic devolatilization of a carbonate-shale-chert lithological association, locally rich in organic matter, which could correspond to the Meso-Neoproterozoic Guandaokou and Luanchuan Groups, rather than to geologic units in the Xiong'er terrane, the lower crust and the mantle. This supports the view that the rocks of the Guandaokou and Luanchuan Groups south of the Machaoying fault might be the favorable sources. A tectonic model that combines collisional orogeny, metallogeny and hydrothermal fluid flow is proposed to explain the formation of the Tieluping silver deposit. During the Mesozoic collision between the South and North China paleocontinents, a crustal slab containing a lithological association consisting of carbonate-shale-chert, locally rich in organic matter (carbonaceous

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

    Institute of Scientific and Technical Information of China (English)

    2007-01-01

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

  20. Stable isotope systematics and fluid inclusion studies in the Cu-Au Visconde deposit, Carajás Mineral Province, Brazil: implications for fluid source generation

    Science.gov (United States)

    da Costa Silva, Antonia Railine; Villas, Raimundo Netuno Nobre; Lafon, Jean-Michel; Craveiro, Gustavo Souza; Ferreira, Valderez Pinto

    2015-06-01

    The Cu-Au Visconde deposit is located in the Carajás Mineral Province (CMP), northern Brazil, near the contact between the ca. 2.76 Ga metavolcano-sedimentary rocks of the Itacaiunas Supergroup rocks and the ~3.0 Ga granitic-gneissic basement. It is hosted by mylonitized Archean rocks, mainly metadacites, the Serra Dourada granite, and gabbros/diorites, which have been successively altered by sodic, sodic-calcic-magnesian, potassic, and calcic-magnesian hydrothermal processes, producing diverse mineralogical associations (albite-scapolite; albite-actinolite-scapolite-epidote; K-feldspar-biotite; chlorite-actinolite-epidote-calcite, etc.). Chalcopyrite is the dominant ore mineral and occurs principally in breccias and veins/veinlets. The aqueous fluids responsible for the alteration/mineralization were initially hot (>460 °C) and very saline (up to 58 wt.% equivalent (equiv.) NaCl), but as the system evolved, they experienced successive dilution processes. Mineral oxygen and hydrogen isotope data show that 18O-rich ( to +9.4 ‰) fluids prevailed in the earlier alteration (including magnetitites) and reached temperatures as high as 410-355 °C. Metamorphic/formation waters, most likely derived from the Carajás Basin rocks, appear to have contributed a major component to the fluid composition, although some magmatic input cannot be discounted. In turn, the later alterations and the mineralization involved cooler (<230 °C), 18O-depleted ( to +3.7 ‰) and less saline (7-30 wt.% equiv. NaCl) fluids, indicating the influx of meteoric water. Fluid dilution and cooling might have caused abundant precipitation of sulfides, especially as breccia cement. Ore δ 34 S values (+0.5 to +3.4 ‰) suggest a magmatic source for sulfur (from sulfide dissolution in pre-existing igneous rocks). The chalcopyrite Pb-Pb ages (2.73 ± 0.15 and 2.74 ± 0.10 Ga) indicate that the Visconde mineralization is Neoarchean, rather than Paleoproterozoic as previously considered. If so, the

  1. Zn-Pb Ores of Mississippi Valley Type in the Lycksele-Storuman District, Northern Sweden: A Possible Rift-Related Cambrian Mineralisation Event

    Directory of Open Access Journals (Sweden)

    Kjell Billström

    2012-06-01

    Full Text Available The epigenetic Zn-Pb deposits in the Lycksele-Storuman ore district, northern Sweden, are hosted by Paleoproterozoic basement near the margin of the Caledonian mountains. A paleogeographic reconstruction suggests that platform sediments, including Cambrian shales, overlaid the mineralised basement. The mineralisation type, containing sphalerite, galena, calcite and fluorite, is confined to veins and breccias and interpreted to be of Mississippi Valley Type (MVT style. There is no appreciable wall rock alteration. Fluid inclusion work reveals coexisting aqueous and hydrocarbon fluids. Ore deposition is interpreted to have occurred during mixing of two fluids; a cool (

  2. Coupled measurements of δ18O and δD of hydration water and salinity of fluid inclusions in gypsum from the Messinian Yesares Member, Sorbas Basin (SE Spain)

    Science.gov (United States)

    Evans, Nicholas P.; Turchyn, Alexandra V.; Gázquez, Fernando; Bontognali, Tomaso R. R.; Chapman, Hazel J.; Hodell, David A.

    2015-11-01

    We studied one cycle (Cycle 6) of gypsum-marl deposition from the Messinian Yesares Member in Sorbas Basin, Spain. The objective was to reconstruct the changing environment of deposition and its relation to astronomically-forced climate change. The δ18O and δD of gypsum hydration water (CaSO4 • 2H2O) and salinity of fluid inclusions were measured in the same samples to test if they record the composition of the mother fluid from which gypsum was precipitated. Water isotopes are highly correlated with fluid inclusion salinity suggesting the hydration water has not exchanged after formation. The relatively low water isotope values and fluid inclusion salinities indicate a significant influence of meteoric water, whereas δ34S, δ18OSO4 and 87Sr/86Sr support a dominant marine origin for the gypsum deposits. The discrepancy between water and elemental isotope signatures can be reconciled if meteoric water dissolved previously deposited marine sulfates supplying calcium and sulfate ions to the basin which maintained gypsum saturation. This recycling process accounts for the marine δ34S, δ18OSO4 and 87Sr/86Sr signatures, whereas the low δ18O and δD values of gypsum hydration water and fluid inclusion salinities reflect the influence of freshwater. The cyclic deposition of gypsum and marl in the Yesares Member has previously been interpreted to reflect changing climate related to Earth's precession cycle. We demonstrate that the δ18O, δD and salinity of the parent brine increased from low values at the base of the cycle to a maximum in the massive gypsum palisade, and decreased again to lower values in the supercones at the top of the cycle. This pattern, together with changes in mineralogy (calcite-dolomite-gypsum), is consistent with a precession-driven change in climate with wettest conditions (summer insolation maxima) associated with the base of the calcium carbonate marls and driest conditions (summer insolation minima) during formation of the gypsum

  3. Environmental Aspects of Iron ORE Mining

    Directory of Open Access Journals (Sweden)

    B. Chandra Sekhar*

    2014-08-01

    Full Text Available Iron ore mining activities such as top soil stripping, drilling and blasting extraction of ore, waste rock dumping, loading and unloading of ore, crushing and screening, material transport etc., emit both fugitive and fugitive dusts into the environment. A direct effect of the mining and its activities deteriorate the quality of ambient air, which requires mitigation measures. Blasting causes very high noise and vibration at a very short duration. Surface water pollution occurs due to erosion of soil by precipitation in the form of runoff. Noise pollution occurs due to drilling and blasting operations. The impact of mining on socio-economic environment is positive (infrastructure development and employment opportunity. There would be a significant impact on biological environment. A green belt with dust-tolerant trees needs to be developed around the Iron ore digging and material storage yard to an extent of 30% of mine-lease area. An environmental management plan is highly essential to mitigate the adverse environmental impact of iron ore mining.

  4. Precipitation of lead-zinc ores in the Mississippi Valley-type deposit at Treves, Cevennes region of southern France

    Science.gov (United States)

    Leach, D.; Macquar, J.-C.; Lagneau, V.; Leventhal, J.; Emsbo, P.; Premo, W.

    2006-01-01

    The Trèves zinc–lead deposit is one of several Mississippi Valley-type (MVT) deposits in the Cévennes region of southern France. Fluid inclusion studies show that the ore was deposited at temperatures between approximately 80 and 150°C from a brine that derived its salinity mainly from the evaporation of seawater past halite saturation. Lead isotope studies suggest that the metals were extracted from local basement rocks. Sulfur isotope data and studies of organic matter indicate that the reduced sulfur in the ores was derived from the reduction of Mesozoic marine sulfate by thermochemical sulfate reduction or bacterially mediated processes at a different time or place from ore deposition. The large range of δ34S values determined for the minerals in the deposit (12.2–19.2‰ for barite, 3.8–13.8‰ for sphalerite and galena, and 8.7 to −21.2‰ for pyrite), are best explained by the mixing of fluids containing different sources of sulfur. Geochemical reaction path calculations, based on quantitative fluid inclusion data and constrained by field observations, were used to evaluate possible precipitation mechanisms. The most important precipitation mechanism was probably the mixing of fluids containing different metal and reduced sulfur contents. Cooling, dilution, and changes in pH of the ore fluid probably played a minor role in the precipitation of ores. The optimum results that produced the most metal sulfide deposition with the least amount of fluid was the mixing of a fluid containing low amounts of reduced sulfur with a sulfur-rich, metal poor fluid. In this scenario, large amounts of sphalerite and galena are precipitated, together with smaller quantities of pyrite precipitated and dolomite dissolved. The relative amounts of metal precipitated and dolomite dissolved in this scenario agree with field observations that show only minor dolomite dissolution during ore deposition. The modeling results demonstrate the important control of the reduced

  5. Mortality among sulfide ore miners

    International Nuclear Information System (INIS)

    Lung cancer mortality was studied during 1965-1985 in Outokumpu township in North Karelia, where an old copper mine was located. Age-specific lung cancer death rates (1968-1985) were higher among the male population of Outokumpu than among the North Karelian male population of the same age excluding the Outokumpu district (p less than .01). Of all 106 persons who died from lung cancer during 1965-1985 in Outokumpu township, 47 were miners of the old mine, 39 of whom had worked there for at least three years and been heavily exposed to radon daughters and silica dust. The study cohort consisted of 597 miners first employed between 1954 and 1973 by a new copper mine and a zinc mine, and employed there for at least 3 years. The period of follow-up was 1954-1986. The number of person-years was 14,782. The total number of deaths was 102; the expected number was 72.8 based on the general male population and 97.8 based on the mortality of the male population of North Karelia. The excess mortality among miners was due mainly to ischemic heart disease (IHD); 44 were observed, the expected number was 22.1, based on the general male population, and the North Karelian expected number was 31.2 (p less than .05). Of the 44 miners who died from IHD, 20 were drillers or chargers exposed to nitroglycerin in dynamite charges, but also to several simultaneous stress factors including PAHs, noise, vibration, heavy work, accident risk, and working alone. Altogether 16 tumors were observed in the cohort. Ten of these were lung cancers, the expected number being 4.3. Miners who had died from lung cancer were 35-64 years old, and had entered mining work between 1954 and 1960. Five of the ten lung cancer cases came from the zinc mine (1.7 expected). Three of them were conductors of diesel-powered ore trains

  6. Permeability evolution as a result of fluid-rock interaction

    Science.gov (United States)

    Astakhov, Dmitriy Konstantinovich

    2000-10-01

    Fluid-rock interaction plays a critical role in the evolution of rock permeability. Among the most important engineering applications are flow of hydrocarbons in petroleum reservoirs, thermal energy extraction, water supply exploration, and toxic and radioactive waste management. Important natural examples include multiple dikes and sheeted intrusions, natural hydraulic fracturing, water circulation in the oceanic crust, and ore deposits formation. In this thesis, new effects associated with stress and temperature dependent permeability of fractured rock were studied. The conducted asymptotic and numerical analysis supported by field and laboratory observations resulted in better understanding of these phenomena and useful recommendations for science and engineering. In particular, the evolution of permeability as a result of the fluid-rock interaction was considered for hydraulic fracturing, fluid flow through jointed layered rocks, and water circulation in seafloor hydrothermal systems. It was shown that in all three cases fluid-rock interaction plays a critical role and must be taken into account by accurately computing changes of fracture apertures. It was also shown that elastic interaction between the segments significantly affects multisegmented hydraulic fracture dimensions and driving pressure and can alter the permeability of jointed layered rocks by orders of magnitude. Fracture closure due to thermal stresses can dramatically reduce water flow through the oceanic crust changing the regime of heat transfer near mid-oceanic ridges and the temperature of the water discharging from the hydrothermal vents. Fracture closure by internal fluid pressure---an effect never previously reported---was found in the study of parallel, closely located fractures. Asymptotic formula that is simple but accurate for all possible parameter ranges was suggested for the permeability of parallel joint sets. These findings may have a significant impact on hydraulic fracture

  7. 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

  8. 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

  9. Aluminum substitution in goethite in lake ore

    Directory of Open Access Journals (Sweden)

    Carlson, L.

    1995-06-01

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

  10. Quantification of heat and fluid flow through time by 3D modeling : an example from the Jeanne d'Arc basin, offshore eastern Canada

    OpenAIRE

    Baur, Friedemann Ulrich Maximilian

    2010-01-01

    Demand for energy is growing rapidly, causing worldwide concerns on security of supply. Petroleum systems modeling in 4 dimensions (cube + time) predicts generation, migration, and quality/quantity of accumulated hydrocarbons in reservoirs, incorporating temperature and pressure through the entire evolution of the basin. A petroleum systems model thus provides the only means to combine all physical aspects (source, trap, seal, and reservoir) and timing (charge) to reduce exploration risk and ...

  11. 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)

  12. High-grade iron ore deposits of the Mesabi Range, Minnesota-product of a continental-scale proterozoic ground-water flow system

    Science.gov (United States)

    Morey, G.B.

    1999-01-01

    The Mesabi Range along the north edge of the Paleoproterozoic Penokean orogen in northern Minnesota has produced 3.6 billion metric tons of ore since its discovery in 1890. Of that amount, 2.3 billion metric tons were extracted from hematite- or geothite-rich deposits generally referred to as 'high-grade' ores. The high-grade ores formed as the Biwabik Iron-Formation was oxidized, hydrated, and leached by solutions flowing along open faults and fractures. The source of the ore-forming solutions has been debated since it was first proposed that the ores were weathering products formed by descending meteoritic ground-water flowing in late Mesozoic time. Subsequently others believed that the ores were better explained by ascending solutions, possbily hydrothermal solutions of pre-Phanerzoic age. Neither Wolff nor Gruner could reconcile their observations with a reasonable source for the solutions. In this paper, I build on modern mapping of the Mesabi Range and mine-specific geologic observations summarized in the literature to propose a conceptual model in which the high-grade ores formed from ascending solutions that were part of continent-scale topographic or gravity-driven ground-water system. I propose that the ground-water system was active during the later stages of the development of a coupled fold and thrust belt and foreland basin that formed during the Penokean orogen.

  13. Geology and geochemistry of the Reocín zinc-lead deposit, Basque-Cantabrian Basin, Northern Spain

    Science.gov (United States)

    Velasco, Francisco; Herrero, Jose Miguel; Yusta, Inaki; Alonso, Jose Antonio; Seebold, Ignacio; Leach, David

    2003-01-01

    fluids responsible for sulfide deposition and the infilling of karst cavities were broadly contemporaneous, indicating a post-Albian age. Vitrinite reflectance data are consistent with previously measured fluid inclusion temperatures and indicate temperatures of ore deposition that were less than 100??C. Carbon and oxygen isotopic data from samples of regional limestone, host-rock dolostone and ore-stage dolomite suggest an early hydrothermal alteration of limestone to dolostone. This initial dolomitization was followed by a second period of dolomite formation produced by the mixing of basinal metal-rich fluids with local modified seawater. Both dolomitization events occurred under similar conditions from fluids exhibiting characteristics of basinal brines. The ??34S values of sulfides are between -1.8 and +8.5 per mil, which is consistent with thermochemical sulfate reduction involving organic matter as the main source of reduced sulfur. Galena lead isotope compositions are among the most radiogenic values reported for Zn-Pb occurrences in Europe, and they are distinct from values reported for galena from other Basque-Cantabrian deposits. This suggests that a significant part of the lead was scavenged from the local underlying Asturian sediments. The stratigraphic and structural setting, timing of epigenetic mineralization, mineralogy, and isotopic geochemistry of sulfide and gangue minerals of the Reoci??n deposit are consistent with the features of most of Mississippi Valley-type ore deposits.

  14. 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)

  15. 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

  16. The non-destructive analysis of fluid inclusions in minerals using the proton microprobe

    Energy Technology Data Exchange (ETDEWEB)

    Ryan, C.G.; Van Achterbergy, E. [Commonwealth Scientific and Industrial Research Organisation (CSIRO), North Ryde, NSW (Australia). Div. of Exploration Geoscience; Heinrich, C.A. [ETH Zentrum, Zurich, (Switzerland). Department Erdwissenschaften; Mernagh, T.P. [Max-Planck-Institut fuer Chemie (Otto-Hahn-Institut), Mainz (Germany); Zaw, K. [Tasmania Univ., Sandy Bay, TAS (Australia)

    1996-12-31

    The study of ore forming fluids trapped as fluid inclusions in minerals is the key to understanding fluid flow paths at the time of ore formation and to predicting the location of ore bodies within large-scale magmatic hydrothermal systems. The large penetration depths and the predictable nature of MeV proton trajectories and X-ray absorption enables reliable modelling of PIXE yields and the development of standardless quantitative analytical methods. This permits quantitative microanalysis of minerals at ppm levels, and more recently has enabled the development of methods for quantitative trace-element imaging and the quantitative, non-destructive analysis of individual fluid inclusions. This paper reports on recent developments in Proton Microprobe techniques with special emphasis on ore systems and fluid inclusion analysis. 6 refs., 2 figs.

  17. The non-destructive analysis of fluid inclusions in minerals using the proton microprobe

    International Nuclear Information System (INIS)

    The study of ore forming fluids trapped as fluid inclusions in minerals is the key to understanding fluid flow paths at the time of ore formation and to predicting the location of ore bodies within large-scale magmatic hydrothermal systems. The large penetration depths and the predictable nature of MeV proton trajectories and X-ray absorption enables reliable modelling of PIXE yields and the development of standardless quantitative analytical methods. This permits quantitative microanalysis of minerals at ppm levels, and more recently has enabled the development of methods for quantitative trace-element imaging and the quantitative, non-destructive analysis of individual fluid inclusions. This paper reports on recent developments in Proton Microprobe techniques with special emphasis on ore systems and fluid inclusion analysis. 6 refs., 2 figs

  18. Deep electrical structure and geological significance of Tongling ore district

    Science.gov (United States)

    Tang, Jingtian; Zhou, Cong; Wang, Xianying; Xiao Xiao; Lü, Qingtian

    2013-10-01

    The Tongling ore district is one of the most important Cu-polymetal producers in the Lower Yangtze River metallogenic belt of China. To understand deep crust structure beneath the Tongling ore district more comprehensively and objectively and to explore important scientific issues, such as characteristics of lithospheric evolution, the relationship between the crustal structure and metallogenesis, it is necessary to study the variation of crust electrical structure in the study area. For this purpose, six magnetotelluric (MT) sounding profiles have been completed by SinoProbe-03 Project. Based on the imaging results of the six profiles, electrical conductivity structure of the crust has been analyzed. The result shows that the geology beneath the profiles is characterized by layering in vertical direction and block division in horizontal direction. The high-resistivity features are related to the transparent zones detected at the upper crust in reflection seismic surveys. The absence of reflectivity from the depths indicates a homogeneous zone, which could often be related to granitic intrusions. Combining the regional tectonic evolution, MT and other geophysical data, we suggest that the high-resistivity bodies crossing the Tongling uplift reveals the center of magma activity and the layering in vertical direction in the lower crust reveals a normal lower crust model and propose a small-scale underplating model which is different with both the “partial melting of a thickened or delaminated lower continental crust” model and the “oceanic ridge subduction”. The underplating might be related to small-scale lithospheric or lower crust delamination controlled by deep fault during the Early Cretaceous. The result of this MT survey is important for constraining lithospheric evolution and metallogenesis in the Lower Yangtze Metallogenic Belt, such as collision of North China Craton and Yangtze Craton, underplating models, deep structure, mechanisms of NE

  19. Partitioning properties of rare earth ores in China

    Institute of Scientific and Technical Information of China (English)

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

    2005-01-01

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

  20. Sulfuric acid leaching of mechanically activated manganese carbonate ore

    OpenAIRE

    Kenan Yıldız

    2010-01-01

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

  1. Sulfuric acid leaching of mechanically activated manganese carbonate ore

    OpenAIRE

    Yıldız, Kenan

    2000-01-01

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

  2. HANDLING, STORAGE AND IRON ORE QUALITY

    Directory of Open Access Journals (Sweden)

    Fabiana Fonseca Fortes

    2012-06-01

    Full Text Available This paper aims to identify handling and storage impact in iron ore quality, in their physical and chemical characteristics most important for a mining. It is tried to show the interferences in iron ore quality caused by the handling equipment and stockpiling. The research is restricted to Complexo Vargem Grande (Vale. The timeline was demarcated based on the formation of stockpiling. The fieldwork enables data collection and distinction of the routine procedures of casual operations handling. The quantitative analysis is conducted by the statistical method. As a conclusion, handling and storage identified are able to insert changes in physical and chemical characteristics of iron ore. Storage contributes to reduce variability of silica and alumina concentrations, but contributes too particle size deterioration. The handling induces degradation and segregation. However, there is the possibility to decrease handling of the ore and to establish the ideal size of stocks on the system in study, improving the efficiency of the system and consequent in global costs.

  3. 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)

  4. Cationic flotation of some lithium ores

    International Nuclear Information System (INIS)

    The cationic flotation of some lithium ores (spodumene, amblygonite, petalite, lepidolite) is studied by the measure of zeta potential and micro-flotation tests in Hallimond tube. The effect of some modifier agents (corn starch, meta sodium silicate) on the lithium flotation is studied. (M.A.C.)

  5. Quantitative PIXE analysis of single fluid inclusions in quartz vein: Chemical composition of hydrothermal fluids related to granite

    International Nuclear Information System (INIS)

    Compositions of fluids trapped as inclusions during the growth of minerals, or during later healing of fluid-filled cracks, provide information on hydrothermal vein-type ore formation. Trace elements in fluid inclusions from hydrothermal quartz vein related to granite were determined by micro-PIXE. High concentration (wt.%) of Ca and Fe, and tens to thousands ppm Mn, Zn, Cu, Br, Rb, Sr, Pb and Ge, were observed in the inclusions, indicating higher metal contents in hydrothermal fluid released from granite

  6. Ore potential of the Olkiluoto district

    International Nuclear Information System (INIS)

    The criticalness of potential future ore occurrences and ore mining in and around the area of the planned Olkiluoto repository for low- and medium-level radioactive waste was analysed. Judging by the theories of ore formation and the statistics based on the known Finnish ore deposits, the geological conditions of the district are rather sterile. Olkiluoto is situated far from the nearest metallogenic zone, the Pori - Kylmaekoski nickel belt. As compared with the ore potential of whole Finland, that of the Olkiluoto district is small. The interpretation of the systematic field investigations carried out in the district gave no indication of minable ores or industrial minerals or rocks. These investigations consist of airborne geophysical surveys (electromagnetic and magnetic measurements) as well as outcrop mapping and boulder tracing. Tiny greisen dikes have been met with in the eastern part of the Olkiluoto island, but according to the interpretation of a gravimetric survey they do not belong to any major tin mineralization possibly associated with the nearby rapakivi-granite massif of Eurajoki. However, a closer evaluation of the greisen dikes would require geochemical survey and additional geophysical measurements from the surface, especially a denser network of gravimetric measurement. The mutual distance of influence between the waste repository and a possible nearby mine was considered theoretically. The most critical factor affecting the distance is the change of the hydraulic gradient and groundwater movement due to the pumping of water from a deep mine. The distance of influence would be roughly of the order of a kilometre at most, in the beginning of the waste disposal even much less, depending on the construction of the adequate technical barriers of the repository. In summary from the point of view of avoiding future mining operations in the waste repository area, the Olkiluoto district is a suitable choice. Any presently known types of ore deposits

  7. Residues leaching from 'Factory of barren ores'

    International Nuclear Information System (INIS)

    The objective of the present work is safe management of residues from Factory of Barren Ores, their reprocessing, expenditures reduction for remediation of Istiklol city former uranium tailings. For this purpose, some experiences were adopted - Factory of Barren Ores tailing use for filling up the open pit where water with uranium content 3-5 mg/l is located. Factory of Barren Ores waste are passed through heap leaching and have some amount of uranium salts dissolved in water. Thus, we propose to dissolve uranium from Factory of Barren Ores wastes with uranium bearing water flowing out from gallery and filling up the open-pit by radioactive wastes. In so doing, uranium content flowing out from gallery will increase twice, and further, passing them through apricot's shell, as a sorbent, we will clean the water against radionuclides. Residue samples with uranium content 0,015% from Factory of Barren Ores and uranium bearing waters from gallery 1 with uranium content 0,0025 g/l were used for laboratory tests. After which, a slurry was prepared by means of residue mixing with water in ratio of solid and liquid phases (S:L) - 1:2 and 9,7 ml of sulfuric acid (Ρ=1,82) was added which corresponds consumption by H2SO4 176,54 kg/t. For the first test, leaching was carried out during 4 hours at ph=1,6 at room temperature. For the second test, leaching was carried out at 60deg Cand ph=1,6 during 4 hours. Slurry heating and mixing was carried out by means of magnetic mixer. The basic residue leaching indicators are provided in this article.

  8. Probing ore deposits formation: New insights and challenges from synchrotron and neutron studies

    International Nuclear Information System (INIS)

    The understanding of the physico-chemical processes leading to the formation and weathering of ore deposits plays an increasingly important role in mineral exploration. Synchrotron, neutron, and nuclear radiation are contributing to this endeavour in many ways, including (i) support the modelling of ore transport and deposition, by providing molecular-level understanding of solvent-solute interaction and thermodynamic properties for the important metal complexes in brines, vapours, and supercritical fluids over the range of conditions relevant for the formation of ore deposits (i.e., temperature 25-600 deg. C; pressure 1-109 Pa; and fluid compositions varying from hypersaline (e.g., >50 wt% NaCl) to volatile-rich (e.g., CO2, CH4, and H2S)); (ii) track the fluids that travelled through rocks and predict their ore-forming potential by analysing hydrothermal minerals and remnants of those fluids trapped in these minerals as 'fluid inclusions'; (iii) characterize the biochemical controls on metal mobility in soils to predict the geochemical footprint of a buried mineral deposit. X-ray fluorescence (XRF), particle-induced X-ray emission (PIXE), and X-ray absorption spectroscopy (XAS) are the most common techniques used in support of mineral exploration. Analytical challenges are related to (i) the complexity of heterogeneous natural samples, which often contain only low concentrations of the elements of interest; (ii) beam sensitivity, especially for redox-sensitive elements in aqueous fluids or biological samples; (iii) extreme sample environments, e.g., in-situ study of fluids at high pressure and temperature. Thus, critical improvements need to be made on a number of fronts to: (i) develop more efficient detectors, able to map large areas in heterogeneous samples (e.g., 106-108 pixels per map), and also to collect a maximum number of photons to limit sample exposure and beam damage; (ii) integrate techniques (e.g., XRF, XAS, and X-ray diffraction (XRD)) on a single

  9. Probing ore deposits formation: New insights and challenges from synchrotron and neutron studies

    Energy Technology Data Exchange (ETDEWEB)

    Brugger, Joel, E-mail: joel.brugger@adelaide.edu.a [Division of Mineral, South Australian Museum, Adelaide (Australia); School of Earth and Environmental Sciences, University of Adelaide, Adelaide (Australia); Pring, Allan [Division of Mineral, South Australian Museum, Adelaide (Australia); School of Earth and Environmental Sciences, University of Adelaide, Adelaide (Australia); Reith, Frank [School of Earth and Environmental Sciences, University of Adelaide, Adelaide (Australia); Ryan, Chris; Etschmann, Barbara; Liu, Weihua [CSIRO Exploration and Mining, Melbourne (Australia); O' Neill, Brian; Ngothai, Yung [School of Chemical Engineering, University of Adelaide, Adelaide (Australia)

    2010-02-15

    The understanding of the physico-chemical processes leading to the formation and weathering of ore deposits plays an increasingly important role in mineral exploration. Synchrotron, neutron, and nuclear radiation are contributing to this endeavour in many ways, including (i) support the modelling of ore transport and deposition, by providing molecular-level understanding of solvent-solute interaction and thermodynamic properties for the important metal complexes in brines, vapours, and supercritical fluids over the range of conditions relevant for the formation of ore deposits (i.e., temperature 25-600 deg. C; pressure 1-10{sup 9} Pa; and fluid compositions varying from hypersaline (e.g., >50 wt% NaCl) to volatile-rich (e.g., CO{sub 2}, CH{sub 4}, and H{sub 2}S)); (ii) track the fluids that travelled through rocks and predict their ore-forming potential by analysing hydrothermal minerals and remnants of those fluids trapped in these minerals as 'fluid inclusions'; (iii) characterize the biochemical controls on metal mobility in soils to predict the geochemical footprint of a buried mineral deposit. X-ray fluorescence (XRF), particle-induced X-ray emission (PIXE), and X-ray absorption spectroscopy (XAS) are the most common techniques used in support of mineral exploration. Analytical challenges are related to (i) the complexity of heterogeneous natural samples, which often contain only low concentrations of the elements of interest; (ii) beam sensitivity, especially for redox-sensitive elements in aqueous fluids or biological samples; (iii) extreme sample environments, e.g., in-situ study of fluids at high pressure and temperature. Thus, critical improvements need to be made on a number of fronts to: (i) develop more efficient detectors, able to map large areas in heterogeneous samples (e.g., 10{sup 6}-10{sup 8} pixels per map), and also to collect a maximum number of photons to limit sample exposure and beam damage; (ii) integrate techniques (e.g., XRF

  10. 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

  11. 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)

  12. A Study on the Role of Pre-Gelatinized Starch (PGS in the Non Damaging Drilling Fluid (NDDF for the Tipam Sand of Geleki Oilfield of Upper Assam Basin

    Directory of Open Access Journals (Sweden)

    Prasenjit Talukdar

    2015-06-01

    Full Text Available The drilling of the wells from surface to target location with conventional drilling fluids may impair production and ultimate recovery by failing to adequately connect the reservoir with the wellbore by damaging the producing interval. One of the most common ways of damaging a formation is the filtration loss. Non Damaging Drilling Fluid (NDDF is a clay and barite free environmental friendly polymer mud system mostly used in pay zone sections of development wells and specifically in horizontal drilling to avoid formation damage. Starches [(C6H10O5 n] are an environment-friendly drilling mud additive for water-base drilling fluids used to control the filtration loss. This paper reports the effect and optimum composition of Pre-Gelatinized Starch (PGS as a filtration control component in the NDDF. PGS is a high-quality nonionic polysaccharide having the Chemical Formula: C27H48O20 and Molecular Weight: 692.658020 [g/mol] which controls the filtration loss by sealing the walls of the borehole due to its long chains of monosaccharide. Some clay specifically the montmorillonite a member of the smectite group that generally also found in the payzones of Geleki Oilfield of Upper Assam Basin absorb hydrogen ions into their structure when comes in contact with fresh water and causing swelling of the clay resulting in a reduction of the pore volume and possibly plug in the pore throats. Therefore the filtration loss should be as low as possible by forming high quality low permeable mud cake of as thin as possible. In this work, an attempt has been made to study the effect of varying composition of PGS on the different mud properties of laboratory formulated NDDF and to choose its optimum composition based on the required mud parameters of the study area.

  13. Comparison of metallogenic conditions for sandstone-type uranium deposit between Erlian basin of China and sedimentary basins of Mongolia

    International Nuclear Information System (INIS)

    Based on the study of metallogenic background and basic metallogenic characteristics,this paper summarizes the main ore-controlling factors of sandstone-type uranium deposits in Erlian basin of China and basins in southeastern Mongolia with the theory of sandstone-type uranium metallogeny,and systematically analyses similarities and differences between the two areas. The general similarities of tectonic attribute, basin type and scale, uranium source, and tectonic evolution in both areas are proposed in this paper, and also their obvious differences in uranium-hosting strata, late tectonic activity and regional uranium mineralization occurrences, especially in tectonic activity and ore-controlling sedimentary system are proposed. The authors believe that the two areas have approximate uranium-productive potentialities, and propose the importence of prospecting 'Sumin-river model' sandstone-type uranium deposit in Erlian basin in the future. (authors)

  14. Study on the Physical and Chemical Conditions of Ore Formation of Hetai Ductile Shear Zone-Hosted Gold Deposit and Discovery of Melt Inclusions

    Institute of Scientific and Technical Information of China (English)

    李兆麟; 翟伟; 李文; 石贵勇; 文拥军

    2002-01-01

    The Hetai ductile shear zone-hosted gold deposit occurs in the deep-seated fault mylonite zone of the Sinian-Silurian metamorphic rock series. In this study there have been discovered melt inclusions, fluid-melt inclusions and organic inclusions in ore-bearing quartz veins of the ore deposit and mylonite for the first time. The homogenization temperatures of the various types of inclusions are 160℃, 180 - 350℃, 530℃ and 870℃ for organic inclusions, liquid inclusions, two-phase immiscible liquid inclusions and melt inclusions, respectively. Ore fluid is categorized as the neutral to basic K+ -Ca2+ -Mg2+ -Na+ - SO2- 4-HCO3-Cl- system. The contents of trace gases follow a descending order of H2O>CO2>CH4>(or < ) H2>CO>C2H2>C2I-I6>O2>N2.The concentrations of K , Ca2 + ,SO2-4,HCO3-,Cl- H2O and C2H2 in fluid inclusions are related to the contents of gold and the Au/Ag ratios in ores from different levels of the gold deposit. This is significant for deep ore prospecting in the region. Daughter minerals in melt inclusions were analyzed using SEM. Quartz, orthoclase, wollastonite and other silicate minerals were identified. They were formed in different mineral assemblages.This analysis further proves the existence of melt inclusions in ore veins. Sedimentary metamorphic rocks could form silicate melts during metamorphic anatexis and dynamic metamorphism, which possess melt-solution characteristics. Ore formation is related to the multi-stage forming process of silicate melt and fluid.

  15. Mineral types of hydrothermal alteration zones in the Dukat ore field and their relationships to leucogranite and epithermal gold-silver ore, northeastern Russia

    Science.gov (United States)

    Filimonova, L. G.; Trubkin, N. V.; Chugaev, A. V.

    2014-05-01

    The paper considers the localization of potassic and propylitic hydrothermal alteration zones in the domal volcanic-plutonic structure controlling the position of the Dukat ore field with the eponymous unique epithermal Au-Ag deposit. Comprehensive mineralogical and geochemical data on rocks and minerals in hydrothermal alteration zones and associated intrusions have shown that quartz-jarosite-sericite, quartz-pyrite-sericite, and quartz-adularia-chlorite alterations were formed with the participation of fluid flows related to a fingerlike projection of a high-K leucogranite porphyry intrusion with large phenocrysts. These hydrothermal alterations developed in the rifted graben under conditions of divergent plate boundaries, whereas quartz-clinozoisite-calcite, epidote-chlorite, and garnet-calcite-chlorite alterations were linked to K-Na leucogranite intrusive bodies and developed under conditions of convergent plate boundaries reactivated as a result of formation of the marginal Okhotsk-Chukotka volcanic belt. Phase separation and coagulation of specific portions of ascending fluids resulted in the formation and stabilization of small-sized particles of native silver and other ore components, which enabled involvement in flows of secondary geothermal solutions and ore-forming fluids. The Sr, Nd, and Pb isotopic compositions of rocks and minerals from the hydrothermal alteration zones, associated intrusions, and economic orebodies at the Dukat deposit indicate that their components have been derived from the juvenile continental crust, which was altered in pre-Cretaceous periods of endogenic activity. The components of gangue minerals of potassic and propylitic hydrothertmal alterations and associated intrusions have been taken from deep sources differing in 87Sr/86Sr and 143Nd/144Nd at similar U/Pb and Th/Pb ratios. Chalcophile lead in products of hydrothermal activity and melanocratic inclusions in leucogranite has been taken from regions with elevated U/Pb and

  16. Algal—Bacterial Fabrics of Ores and Their Genetic Implications in the Longtang Lead—Zinc Deposit at Yanbian,Sichuan

    Institute of Scientific and Technical Information of China (English)

    帅德权; 张寿庭; 等

    1995-01-01

    The Longtang Pb-Zn deposit occurs in the Upper Sinian Guanyinyan For-mation.The host rocks include sandy shale,cherty limestone and dolomitic limestone.The deposit is a typical one of thallogen origin.The mineral assemblage in the ore is made up of sphalerite, galena, pyrite, enargite, tennantite, seligmannite, asphalt, etc.The ore-forming process is possessed of multi-episode and multi-stage characters. Generally, sphalerites exhibit algal stromatolitic, bac-terial and algal colloidal textures, providing evidence for the direct involvement of alage and bacteria in mineralization of ore-forming elements during sedimentary diagenesis. This is the first transmigration of ore-forming elements.However, pyrite embracing bac-teria and galena replacing/filling trichomes are typical organic textures, which are related to organic carbon and bitumen that can adsorb or reduce ore-forming elements. This is an indirect process of organic mineralization ,ie.,the second transmigration of ore-forming elements.&34S values are all greater than 5%o,indicating the dominance of the heavy sulfur isotopes.The ore-forming temperature deduced from fluid inclusions ranges from 100℃to 150℃±.All this goes to show that the Longtang Pb-Zn deposit is of thallogen origin.

  17. High-rate behaviour of iron ore pellet

    Directory of Open Access Journals (Sweden)

    Gustafsson Gustaf

    2015-01-01

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

  18. Hydraulic Conductivity of Compacted Laterite Treated with Iron Ore Tailings

    Directory of Open Access Journals (Sweden)

    Umar Sa’eed Yusuf

    2016-01-01

    Full Text Available The objective of this study was to investigate the effect of iron ore tailings (IOT on hydraulic conductivity of compacted laterite. The IOT conforms to ASTM C 618-15 Type F designations. In the present study, soil was admixed with 0–20% IOT and compacted at moulding water content ranging from 10 to 25% using four types of compactive efforts. Hydraulic conductivities of the compacted soil-IOT mixtures were determined using deionized water and municipal solid waste leachate as the permeant fluids, respectively. Deionized water was the reference permeant fluid. Results of this study showed that hydraulic conductivity decreased with increase in IOT content as a result of improvement in mechanical properties of the soil. Permeation of the soil-IOT mixtures with leachate caused the hydraulic conductivity to drop to less than 1 × 10−9 m/s especially at higher compactive efforts. Also, bioclogging of the soil pores due to accumulation of biomass from bacteria and yeast present in the leachate tends to significantly reduce the hydraulic conductivity. From an economic point of view, it has been found from the results of this study that soil specimens treated with up to 20% IOT and compacted at the British Standard Light (BSL compactive effort met the maximum regulatory hydraulic conductivity of less than or equal to 1 × 10−9 m/s for hydraulic barrier system.

  19. Genetic Pd, Pt, Au, Ag, and Rh mineralogy in Noril'sk sulfide ores

    Science.gov (United States)

    Spiridonov, E. M.; Kulagov, E. A.; Serova, A. A.; Kulikova, I. M.; Korotaeva, N. N.; Sereda, E. V.; Tushentsova, I. N.; Belyakov, S. N.; Zhukov, N. N.

    2015-09-01

    The undeformed ore-bearing intrusions of the Noril'sk ore field (NOF) cut through volcanic rocks of the Late Permian-Early Triassic trap association folded in brachysynclines. Due to the nonuniform load on the roof of intrusive bodies, most sulfide melts were squeezed, up to the tops of ore-bearing intrusions; readily fusible Ni-Fe-Cu sulfide melts were almost completely squeezed. In our opinion, not only one but two stages of mineralization developed at the Noril'sk deposits: (i) syntrap magmatic and (ii) epigenetic post-trap metamorphic-hydrothermal. All platinum-group minerals (PGM) and minerals of gold are metasomatic in the Noril'sk ores. They replaced sulfide solid solutions and exsolution structures. All types of PGM and Au minerals occur in the ores, varying in composition from pyrrhotite to chalcopyrite, talnakhite, mooihoekite, and rich in galena; they are localized in the inner and outer contact zones and differ only in the quantitative proportions of ore minerals. The aureoles of PGM and Au-Ag minerals are wider than the contours of sulfide bodies and coincide with halos of fluid impact on orebodies and adjacent host rocks. The pneumatolytic PGM and Au-Ag minerals are correlated in abundance with the dimensions of sulfide bodies. Their amounts are maximal in veins of late fusible ore composed of eutectic PbS ss and iss intergrowths, as well as at their contacts. The Pd and Pt contents in eutectic sulfide ores of NOF are the world's highest. In the process of noble-metal mineral formation, the fluids supply Pd, Pt, Au, As, Sb, Sn, Bi, and a part of Te, whereas Fe, Ni, Cu, Pb, Ag, Rh, a part of Te and Pd are leached from the replaced sulfide minerals. The pneumatolytic PGM of the early stage comprises Pd and Pt intermetallic compounds enriched in Au along with Pd-Pt-Fe-Ni-Cu-Sn-Pb(As) and (Pd,Pt,Au)(Sn,Sb,Bi,Te,As) solid solutions. Pneumatolytic PGM and Au minerals of the middle stage are products of solid-phase transformation and recrystallization of

  20. Chapter 3. Sulfuric acid decomposition of borosilicate ores. 3.1. Decomposition of borosilicate ores by sulfuric acid

    International Nuclear Information System (INIS)

    Present article is devoted to decomposition of borosilicate ores by sulfuric acid. The sulfuric acid decomposition of borate ores of Ak-Arkhar Deposit was studied. The possibility of multipurpose utilization of borate ores was shown. The influence of process duration on the rate of oxides (B2O3, Fe2O3 and Al2O3) extraction was studied as well. In order to reach the complete decomposition of oxides from danburite ore the dependence of rate of oxides decomposition on concentration of sulfuric acid was studied. The optimal conditions of sulfuric acid decomposition of danburite ores were proposed.

  1. Lithium isotope traces magmatic fluid in a seafloor hydrothermal system

    Science.gov (United States)

    Yang, Dan; Hou, Zengqian; Zhao, Yue; Hou, Kejun; Yang, Zhiming; Tian, Shihong; Fu, Qiang

    2015-09-01

    Lithium isotopic compositions of fluid inclusions and hosted gangue quartz from a giant volcanogenic massive sulfide deposit in China provide robust evidence for inputting of magmatic fluids into a Triassic submarine hydrothermal system. The δ7Li results vary from +4.5‰ to +13.8‰ for fluid inclusions and from +6.7‰ to +21.0‰ for the hosted gangue quartz(9 gangue quartz samples containing primary fluid inclusions). These data confirm the temperature-dependent Li isotopic fractionation between hydrothermal quartz and fluid (i.e., Δδ7Liquartz-fluid = -8.9382 × (1000/T) + 22.22(R2 = 0.98 175 °C-340 °C)), which suggests that the fluid inclusions are in equilibrium with their hosted quartz, thus allowing to determine the composition of the fluids by using δ7Liquartz data. Accordingly, we estimate that the ore-forming fluids have a δ7Li range from -0.7‰ to +18.4‰ at temperatures of 175-340 °C. This δ7Li range, together with Li-O modeling , suggest that magmatic fluid played a significant role in the ore formation. This study demonstrates that Li isotope can be effectively used to trace magmatic fluids in a seafloor hydrothermal system and has the potential to monitor fluid mixing and ore-forming process.

  2. 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)

  3. The mineralogical zoning and ores types of the Elkon ore field (Saha-Yakut Republic, Russian Federation)

    International Nuclear Information System (INIS)

    The mineralogical zoning and ore types of the Elkon ore field, one of the largest in the world, are described. The brannerite mineralization with finely dispersed brannerite is located in the central zone of the ore field. At the periphery of the central zone, dispersed brannerite is replaced by crystalline brannerite. Zone of uraninite is distributed along the northwest flank of the ore field, and the molybdenite-brannerite zone with nasturan occurs at its southeast flank. Regional distribution of various uranium minerals and various paragenetic associations determine ore types with regards to content of useful components, the form of their occurrence, composition and structural features of ores. Several types of ores have been distinguished according to above characteristics. (author)

  4. Bioleaching of a manganese and silver Ore

    International Nuclear Information System (INIS)

    The bioleaching with a strain of Thiobacillus thiooxidans of the ore of Farallon Negro (Catamarca, Argentina) was studied in order to estimate its application to the solution and recovery of the manganese, and to improve the silver extraction. The State company which works the mine has not yet found an economical process to extract the manganese and has only reached a 30% efficiency in the recovery of silver by cianuration. The effects of pulp density variations and the addition of different quantities of FeS were analysed looking for the best working conditions. 74 μm (mesh Tyler 200) of ore particles were used because that is the size used in this plant for the cianuration process. (Author)

  5. Introduction - Acid decomposition of borosilicate ores

    International Nuclear Information System (INIS)

    The complex processing of mineral raw materials is an effective way for the extraction of valuable components. One of these raw materials are borosilicate ores from which the boric acid, aluminium and iron salts and building materials can be obtained. In the Institute of Chemistry of the Academy of Sciences of the Republic of Tajikistan the flowsheets of the processing of borosilicate raw materials by acid and chloric methods were elaborated. The acid methods of decomposition of borosilicate ores of Ak-Arkhar Deposit were considered in present monograph. The carried out researches on elaboration of physicochemical aspects and technological acid methods allowed to define the optimal ways of extraction of valuable products from borosilicate raw materials of Tajikistan.

  6. Direct reducing method for metal ore

    International Nuclear Information System (INIS)

    In a high temperature steam electrolysis device using solid electrolyte, a hydrogen gas is generated from steams by using nuclear heat at high temperature from a high temperature gas cooling reactor (HTGR) and electric power generated by the nuclear temperature, to directly reduce metal ores by the hydrogen gas. With such procedures, no CO2 is evolved. Further, steams in a gas mixture of the hydrogen gas and the steams generated from the high temperature steam electrolysis device are adsorbed by a pressure swing type (PSA) steam adsorbing device to be separated from the hydrogen gas. Metal ores are directly reduced by the hydrogen gas separated from steams. With such procedures, since the steams are adsorbed and separated from hydrogen gas in the PSA without condensation, it is possible to reutilize separated steams as a heat source, thereby enabling to improve thermal efficiency. (T.M.)

  7. Thirty years of ore processing in Spain

    International Nuclear Information System (INIS)

    Spain's experience with the processing of uranium ores covers pegmatitic ores, vein-type deposits, sandstone ores, enrichments in metamorphic sediments, radioactive coals and nonconventional sources such as phosphoric acid and copper waters. Studies have also been conducted for the treatment of very poor ores, such as palaeozoic quartzites. The recovery of by-products (copper) is included in this experience. The technologies employed range from physical concentration, combustion and calcination to conventional treatment with acids and alkalis and leaching under pressure, static leaching and bacterial leaching. Special attention has been devoted to the recovery of uranium from liquids and the development of equipment for this purpose (especially for solvent extraction and continuous ion-exchange techniques). This activity has not been limited to conventional-size plants of 500-3000t/d. Interest in the development of small or remote mines has led to the creation of transportable and re-usable modular plants. Reducing the environmental impact is another aspect of interest. The purification of uranium concentrates and the manufacture of products of nuclear purity, both by wet (nitric acid - TBP) and by dry processes (fluidized beds), is another field in which Spain has made progress. The experience acquired in these 30 years of research and industrial practice and the innovative projets set up for the future could well serve as a good basis for other medium-sized countries wishing to establish a uranium industry. A description of the Spanish experience, indicating what is worth pursuing and what should be avoided, may help new countries to join the circle of uranium producers. (author)

  8. Tourmaline in the central Swedish ore district

    Science.gov (United States)

    Hellingwerf, R. H.; Gatedal, K.; Gallagher, V.; Baker, J. H.

    1994-06-01

    More than 40 recently discovered tourmaline occurrences have been investigated in the Mid-Proterozoic Bergslagen ore district of central Sweden. Some are spatially associated with ores, others with zones of leaching, remobilization and migmatization. Among the tourmaline-bearing ore deposits are the Dammberg ZnPb-Fe sulphide deposit, the Sala Pb-Zn-Ag deposit, the Dalkarlsberg, Pershyttan and Håksberg Fe oxide deposits, the Leja Cu deposit, and the Zinkgruvan Zn-Pb-Ag deposit. Tourmaline has been recorded a) as tourmalinites and tourmaline-bearing chemical sediments; b) in tourmaline-bearing skarns; c) in tourmaline-quartz veins; d) as disseminations along the foliation in schists; e) in tourmaline pegmatites; f) in tourmalinized haloes in metavolcanites along tourmaline pegmatites; and g) in late joints. Tourmalinites, tourmaline-bearing chemical sediments and tourmaline-bearing skarns are spatially associated with sulphide and oxide mineralizations. The dravite components in these tourmalines are proportional to the size of Zn-Pb sulphide mineralizations. Tourmalines from quartz veins close to and within ore deposits contain high Zr and Cr contents. With increasing distance away from these deposits, the Zr and Cr contents fall significantly. Tourmalines from pegmatites have inherited a number of trace element enrichments through partial melting and assimilation of volcaniclastic sediments into granitic melts. Despite magmatic homogenization, Zn contents in these tourmalines reflect the proximity of Zn-Pb-sulphide deposits, decreasing away from them. Tourmalines from late joints with Zn contents above the 100 ppm level are also indicative for the proximity of Zn-Pb sulphide mineralizations. Thus, some trace elements in these tourmalines may represent suitable exploration tools.

  9. Complex geophysical methods for apatitye ore analysis

    International Nuclear Information System (INIS)

    A number of geophysical testing methods are considered, including X-ray radiometry, gamma-gamma techniques and measurements of magnetic susceptibility. This group of methods provides the accuracy needed for determining the phosphate content of all ore types in the Khibiny deposits and allows quantitative assay of a number of minerals, including apatite, sphene and titanomagnetite. It is shown that most testing work can be satisfactorily carried out by the highly efficient gamma-gamma method. (author)

  10. Enriching of Magnesite Ore Containing Dolomite

    OpenAIRE

    Shaqiri, M.; Berisha, K.; Rashani, S.; Hoda, S

    2010-01-01

    Minor mineral phases containing calcium and silica in magnesite ore are the main cause of detrimental properties of magnesia refractory materials prepared thereof. All stages of the production process aim to remove such unwanted mineral phases. While the removal of silica minerals is well documented, it is not so for the calcium containing minerals, especially when it is not possible to do so by mechanical separation processes only. In this work, the influence of duration and temperature of h...

  11. The giant Bayan Obo REE-Nb-Fe deposit, China:Controversy and ore genesis

    Institute of Scientific and Technical Information of China (English)

    Hong-Rui Fan; Kui-Feng Yang; Fang-Fang Hu; Shang Liu; Kai-Yi Wang

    2016-01-01

    Bayan Obo ore deposit is the largest rare-earth element (REE) resource, and the second largest niobium (Nb) resource in the world. Due to the complicated element/mineral compositions and involving several geological events, the REE enrichment mechanism and genesis of this giant deposit still remains intense debated. The deposit is hosted in the massive dolomite, and nearly one hundred carbonatite dykes occur in the vicinity of the deposit. The carbonatite dykes can be divided into three types from early to late:dolomite, co-existing dolomite-calcite and calcite type, corresponding to different evolutionary stages of carbonatite magmatism based on the REE and trace element data. The latter always has higher REE content. The origin of the ore-hosting dolomite at Bayan Obo has been addressed in various models, ranging from a normal sedimentary carbonate rocks to volcano-sedimentary sequence, and a large carbonatitic intrusion. More geochemical evidences show that the coarse-grained dolomite represents a Mesoproterozoic carbonatite pluton and the fine-grained dolomite resulted from the extensive REE mineralization and modification of the coarse-grained variety. The ore bodies, distributed along an EeW striking belt, occur as large lenses and underwent more intense fluoritization and fenitization. The first episode mineralization is characterized by disseminated mineralization in the dolomite. The second or main-episode is banded and/or massive mineralization, cut by the third episode consisting of aegirine-rich veins. Various dating methods gave different mineralization ages at Bayan Obo, resulting in long and hot debates. Compilation of available data suggests that the mineralization is rather variable with two peaks at w1400 and 440 Ma. The early mineralization peak closes in time to the intrusion of the car-bonatite dykes. A significant thermal event at ca. 440 Ma resulted in the formation of late-stage veins with coarse crystals of REE minerals. Fluids involving in

  12. The production and use of citric acid for the removal of potassium from the iron ore concentrate of the Sishen Iron Ore Mine, South Africa

    OpenAIRE

    Peter J. Williams; Thomas E. Cloete

    2010-01-01

    The depletion of the richer iron ore worldwide has made it necessary to process lower quality iron ore. Certain substances, such as potassium, contained within the lower quality iron ore, have a detrimental effect on the smelting process during steel manufacturing. Therefore, international steel-making companies charge penalties when purchasing iron ore concentrates containing high concentrations of potassium. To date, lower quality iron ore has been blended with high quality iron ore in an a...

  13. Paragenesis and conditions of formation of ore minerals from metalliferous breccia pipes, N. Arizona

    International Nuclear Information System (INIS)

    Ore deposits within N. Arizona breccia pipes are currently being exploited for U, but at various times during the past century Cu, Pb, Zn, and Ag were mined. These pipes formed as solution-collapses within the Mississippian Redwall Ls and stopped upward through overlying strata. The principal ore minerals are: uraninite, chalcopyrite, chalcocite, tennantite-tetrahedrite, galena, sphalerite, millerite, gersdorffite, siegenite, and molybdenite. Common gangue minerals are marcasite, pyrite, barite, dolomite, calcite and quartz. Marcasite and pyrite appear to have formed prior to the ore minerals, followed closely by chalcopyrite. The Ni and Co phases also appear to be early: gersdorffite crystals are rimmed by later galena. Tennantite-tetrahedrite formed later than both galena and sphalerite; uraninite, the latest ore mineral, consisting fills interstices. Primary fluid inclusions in dolomite, quartz, and sphalerite show filling temperatures from 80 to 145 degree C and high salinities, averaging 15 wt% NaCl (eq). Secondary inclusions in sphalerite have consistently higher filling temperatures from 105 to 173 degree C, but similar salinities. Rock-Eval pyrolysis of pyrobitumen yields little or no volatile hydrocarbons (S1=0-0.2 mg/gm), but large amounts of pyrolytic hydrocarbons (S2=105-216 mg/gm). Temperatures of maximum pyrolytic yield are relatively low (424-430 degree C), suggesting temperatures did not exceed 150 degree C following pyrobitumen emplacement. Except for uraninite, the breccia pipes are similar to Mississippi Valley-type (MVT) deposits in mineralogy, fluid-inclusion filling temperatures and salinities, and associated organic material. Because MVT deposits do not host U minerals, a possible two-stage mineralization history of the pipes is suggested, the first by a MVT brine and perhaps a second forming the uraninite

  14. Characteristics of sulfur isotope during the epigenetic alteration of oil-gas and coalbed methane in the southeastern Songliao Basin

    International Nuclear Information System (INIS)

    Through studying the characteristics of pyrite and sulfur isotope in the rock of Upper Cretaceous Quantou Formation, Yaojia Formation and Nenjiang Formation in the southeastern Songliao Basin, occurrence features of pyrite and characteristics of sulfur isotope in gray and grayish-green sandstone produced by epigenetic reducing decoloration of Quantou Formation and Yaojia Formation indicate the characteristics of organic fluid composition in deep-seated oil-gas and coalbed methane. δ34SV-CDT of sulfur isotope in original sedimentary diagenite is positive, δ34SV-CDT of organic fluid in oil-gas and coalbed methane is negative. Reduction of oil-gas and coalbed methane not only makes mottled and purplish-red original oxidized sandstone reduce to grey and grayish-green reducing sandstone, which makes the reducing capacities of rocks increase greatly, but also uranium is superimposed and enriched during the interaction of rocks with organic fluid of oil-gas and coalbed methane and uranium content increases generally, which results in the forming of uranium anomaly and mineralization in some areas. Stockwork damouritization is discovered in the ore-bearing sandstone of Yaojia Formation in Menda area at the first time, which shows the uranium mineralization is characterized by low temperature hydrothermal alteration and is related with low temperature hydrothermal fluid. (authors)

  15. Leaching uraniferous ores with carbonated liquors

    International Nuclear Information System (INIS)

    An alkaline carbonate, and optionally bicarbonate solution containing an oxidising agent is used in the leaching of a uraniferous ore. The process is carried out under concentration, temperature and pressure conditions which cause solubilisation of the uranium present in the ore. Uranium alkaline carbonate and, if present, bicarbonate, are present in solution at a concentration close to the limit of solubility at the attack temperature. The solid and liquid phases resulting from the attack operation are separated, the reactants in the liquid are readjusted, and the liquid is recycled to the ore attack operation. The attack is carried out at a temperature lower than 300 deg. C. and the suspension collected after the attack operation is cooled to a temperature higher than 40 deg. C. The uranium is maintained in a state of saturation and is then precipitated in the attack medium. The solid phase is treated with an aqueous liquor to recover the residual liquor resulting from the attack operation and to redissolve the precipitated uranium compound. The solid and liquid fractions are separated

  16. The noble gas systematics of late-orogenic H 2O-CO 2 fluids, Mt Isa, Australia

    Science.gov (United States)

    Kendrick, M. A.; Honda, M.; Oliver, N. H. S.; Phillips, D.

    2011-03-01

    The noble gases (He, Ne, Ar, Kr and Xe) are powerful geochemical tracers because they have distinctive isotopic compositions in the atmosphere, crust and mantle. This study illustrates how noble gases can be used to trace fluid origins in high-temperature metamorphic and mineralising environments; and at the same time provides new information on the composition of noble gases in deeper parts of the crust than have been sampled previously. We report data for H 2O and CO 2 fluid inclusions trapped at greenschist to amphibolite facies metamorphic conditions associated with three different styles of mineralisation and alteration in the Proterozoic Mt Isa Inlier of Australia. Sulphide fluid inclusions are dominated by crustal 4He. However, co-variations in fluid inclusion 20Ne/ 22Ne, 21Ne/ 22Ne, 40Ar/ 36Ar and 136Xe/ 130Xe indicate noble gases were derived from three or more reservoirs. In most cases, the fluid inclusions elemental noble gas ratios (e.g. Ne/Xe) are close to the ranges expected in sedimentary and crystalline rocks. However, the elemental ratios have been modified in some of the samples providing evidence for independent pulses of CO 2, and interaction of CO 2 with high-salinity aqueous fluids. Compositional variation is attributed to mixing of: (i) magmatic fluids (or deeply sourced metamorphic fluids) characterised by basement-derived noble gases with 20Ne/ 22Ne ˜ 8.4, 21Ne/ 22Ne ˜ 0.4, 40Ar/ 36Ar ˜ 40,000 and 136Xe/ 130Xe ˜ 8; (ii) basinal-metamorphic fluids with a narrow range of compositions including near-atmospheric values and (iii) noble gases derived from the meta-sedimentary host-rocks with 20Ne/ 22Ne ˜ 8-9.8, 21Ne/ 22Ne < 0.1, 40Ar/ 36Ar < 2500 and 136Xe/ 130Xe ˜ 2.2. These data provide the strongest geochemical evidence available for the involvement of fluids from two distinct geochemical reservoirs in Mt Isa's largest ore deposits. In addition the data show how noble gases in fluid inclusions can provide information on fluid origins

  17. Study of fluid inclusion from uranium deposit No.302 in north Guangdong

    International Nuclear Information System (INIS)

    The temperature of fluid inclusions in gangue minerals such as calcite, quartz, fluorite was measured and carbon isotope composition of Calcite was studied for uranium deposit No.302 in north Guangdong in this paper. It shows that the homogeneous temperature and salinity decreased from the early ore-forming period to late ore-forming period, and the early ore-forming period had at least two-staged fluid process with medium-high temperature and salinity. The carbon isotopic composition of δ13CPDB of calcites of different stages are: -0.614%--0.971% which indicates that the carbon maybe came from deep crust. (authors)

  18. Ore reserve calculation methods used by Eldorado Nuclear Limited

    International Nuclear Information System (INIS)

    Uranium-bearing pitchblende deposits of the Beaverlodge area in northern Saskatchewan are highly complex. The ideas and concepts of ore reserve calculation methods employed by Eldorado Nuclear Limited in assessing and planning the mining of these deposits are described. A manual block-system of ore reserve calculation was used before the adoption of the current computerized system. Four classifications are used for ore reserves calculated by the system, which provides two main program jobs for calculating ore reserves and several additional ones that involve calculations and graphical presentation of ore reserve information for use in mine planning. A comparison of production statistics and ore reserve calculations illustrates the accuracy of the method. (author)

  19. Sulfuric acid leaching of mechanically activated manganese carbonate ore

    Directory of Open Access Journals (Sweden)

    Kenan Yıldız

    2010-06-01

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

  20. Recovery of Cu and Zn from Complex Sulphide Ore

    Science.gov (United States)

    Talapaneni, Trinath; Sarkar, S.; Yedla, N.; Reddy, P. L. N., Dr

    2015-02-01

    Complex Sulphide Ores are often found to be a close mutual association with each other and with the nonmetallic gangue. The beneficiation experiments showed that it would be very difficult to recover Cu and Zn from the lean complex Sulphide ores using traditional ore beneficiation methods. In the present work, leaching of complex sulfide ores in sulfuric acid was investigated by the Electro hydrometallurgy process. The lab-scale experiments were conducted to investigate the influences of pulp-density, electrolyte concentration, particle size, current density and time on recovery of Cu and Zn. The leach liquor obtained after electrolysis was subjected to Atomic Absorption Spectroscopy analysis for the recovery of minerals.

  1. Pros and Cons,Iron Ore Price Hikes

    Institute of Scientific and Technical Information of China (English)

    Tang Jingtao

    2008-01-01

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

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

    Science.gov (United States)

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

    2016-04-01

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

  3. Study on the Physical and Chemical Conditions of Ore Formation of Hetai Ductile Shear Zone—Hosted Gold Deposit and Discovery of Melt Inclusions

    Institute of Scientific and Technical Information of China (English)

    李兆麟; 翟伟; 等

    2002-01-01

    The Hetai ductile shear zone-hosted gold deposit occurs in the deep-seated falut mylonite zone of the Sinian-Silurian metamorphic rock series.In this study there have been discovered melt inclusions,fluid-melt inclusions and organic inclusions in ore-bearing ruartz veins of the ore deposit and mylonite for the first time.The homogenization temperatures of the various types of inclusions are 160℃,180-350℃,530℃and 870℃ for organic inclusions,liquid inclsions two-phase immiscible liquid inclusions and melt inclusion,respectively,Ore fluid is categoriezed as the neutral to basic K+-Ca2+-Mg2+-Na+-SO42--HCO3-Cl- system.The contents of trace gases follow a descending order of H2O>CO2>CH4>(orCO>C2H2>C2H6>O2>N2.The concentrations of K+,Ca2+,SO42-,HCO3-,Cl-,H2O and C2H2 in fluid inclusions are related to the contents of gold and the Au/Ag ratios in from different levels of the gold deposit.This is significant for deep ore prospecting in the region.Daughter minerals in melt inclusions were analyzed using SEM.Quartz,orthoclase,wollastonite and other silicate minerals were identified.They were formed in different mineral assemblages.This analysis further proves the existence of melt inclusions in ore veins.Sedimentary metamophic rocks could form silicate melts during metamorphic anatexis and dynamic metamorphism,which possess melt-soulution characteristics.Ore formation is related to the multi-stage forming process of silicate melt and fluid.

  4. Deep ancient fluids in the continental crust and their impact on near-surface economic, environmental and biological systems.

    Science.gov (United States)

    Ballentine, Christopher; Warr, Oliver; Sutcliffe, Chelsea; McDermott, Jill; Fellowes, Jonathan; Holland, Greg; Mabry, Jennifer; Sherwood Lollar, Barbara

    2016-04-01

    With a few exceptions the mobility of water, oil and gas, provides for an ephemeral view of subsurface fluids relative to geological or planetary timescales. Aquifers supplying water for drinking and irrigation have mean residence ages from hundreds to tens of thousands of years; Hydrothermal systems can be active for hundreds of thousands to millions of years forming key mineral reserves; Sedimentary basin formation expels fluids during compaction and generates oil and gas on times scales of millions to hundreds of millions of years. Within these exemplar systems biological activity can play a crucial role by mediating system oxidation state: releasing arsenic into shallow groundwaters; precipitating ore bodies; generating methane; and biodegrading oil. It is becoming increasingly apparent that fluids resident in fractures and porespace in the crystalline basement underlying many of these systems can have a mean residence time that ranges from tens to hundreds of millions of years [1,2] to billions of years [3,4]. These fluids are highly saline and trace element rich; they are abundant in nitrogen, hydrogen, methane and helium and can contain microbes that have uniquely adapted to these isolated environments [5]. We are actively expanding discovery of sites with fluids exhibiting extreme age and have recently shown that these systems contribute to half of the terrestrial hydrogen production; a key component in biosphere energy and carbon cycles [6]. Tectonic or thermal release of these fluids can result in helium deposits; possible ore body generation and the inoculation of near-surface systems with microbial biota protected in the deep surface; the controls and rate of fluid release to shallow systems can fundamentally change the nature of some shallow systems. These deep ancient fluids represent a little tapped scientific resource for understanding how life survives and evolves in such isolation, how life is transported and communicates in extremis together and

  5. Analysis on uranium formation conditions of Buya basin, Xinjiang

    International Nuclear Information System (INIS)

    Buya Basin is a favourable ore-formation zone located on the southern margin of Tarim Basin. Based on the concise analysis on the regional geological background and the known uranium mineralization features, the uranium forming conditions (such as strata, structure, hydrogeology and uranium sources)in this basin are analyzed emphathetically from the macroscopic point of view. Four stages of uranium formation in the area are preliminarily summarized with the structure as the thread, i.e. formation of uranium carrier, initial uranium enrichment, relative stagnance and damage, superposition and enrichment. Unique structural evolution facilitates the formation of uranium mineralization. (authors)

  6. Chapter 1. Complex processing of borosilicate ores. 1.1. Properties of borate ores

    International Nuclear Information System (INIS)

    This article is devoted to properties of borate ores, including borax (mineral), boric acid (H3BO3), ulexite (mineral), kernite (mineral), hydrocarbocyte (mineral) Ca Mg(B3O4(OH)3)2·3H2O, datolite (mineral) Ca[B OH(Si-4)], and danburite.

  7. A mineralogical investigation of refractory gold ores and their beneficiation, with special reference to arsenical ores

    International Nuclear Information System (INIS)

    A mineralogical investigation of the main causes of refractoriness of some metallurgically complex gold ores in South Africa is reported. It is shown that this refractoriness is related to the presence of submicroscopic gold, carbonaceous material, pyrrhotite, and base-metal sulphides. Gold ores can be classified according to their content of these components. Electron-microprobe analysis shows that gold occurs in arsenopyrite and pyrite, the gold contents of which can be up to 2700 g/t. The gold and arsenic contents of these minerals are closely correlated. Futhermore, within zoned arsenopyrite grains, the concentration of gold closely follows that of arsenic. Moessbauer spectroscopy carried out on samples of concentrate from the Baberton area indicates that the submicroscopic gold within the sulphides is a non-metallic form. The mineralogical examination of beneficiation products is important, since it sheds light on some fundamental aspects of the behaviour of the ore and gangue components during milling and flotation. Such basic information will lead ultimately to a better understanding of the problems in the beneficiation of these ores. Investigations have shown that the overmilling of the auriferous arsenopyrite and the disseminated nature of the sulphide mineralization are the main problems during beneficiation. 13 refs., 12 figs., 2 tabs

  8. Bioprocessing of ores: Application to space resources

    Science.gov (United States)

    Johansson, Karl R.

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

  9. Mercury exposure aboard an ore boat.

    OpenAIRE

    Roach, Richard R; Busch, Stephanie

    2004-01-01

    Two maritime academy interns (X and Y) were exposed to mercury vapor after spilling a bottle of mercury on the floor in an enclosed storeroom while doing inventory aboard an ore boat. During a 3-day period, intern Y suffered transient clinical intoxication that resolved after he was removed from the environment and he showered and discarded all clothing. His initial serum mercury level dropped from 4 ng/mL to < 0.05 ng/mL. Intern X had an initial level of 11 ng/mL, which continued to rise to ...

  10. Upgrading of boron ores and colemanite flotation

    International Nuclear Information System (INIS)

    Processes applied for the processing and upgrading of sodium and calcium borates in Turkey are described. Details of froth flotation study where a low grade colemanite ore containing calcite and clays as a gangue minerals are given. It has been found that, at the natural pH of a colemanite-containing pulp (pH=9,2) it is possible to float colemanite selectively using dodecyl benzene sulphonate or its combinations with a non-polar reagent or naphthenic acids. (author)

  11. Chromosomal aberrations in ore miners of Slovakia

    International Nuclear Information System (INIS)

    A pilot study was performed in which the incidence of chromosomal aberrations in lymphocytes of miners in ore mines located in Central Slovakia was monitored and related to lifetime underground radon exposure and to lifetime smoking. The conclusions drawn from the results of the study were as follows: the counts of chromosomal aberrations in lymphocytes of miners were significantly higher than in an age matched control group of white-collar staff; the higher counts of chromosomal aberrations could be ascribed to underground exposure of miners and to smoking; a dependence of chromosomal aberration counts on the exposure to radon could not be assessed. (A.K.)

  12. Fluid-inclusion gases in sphalerite, galena, and dolomite from the Silesian-Cracow Zn-Pb district, Poland

    Science.gov (United States)

    Leach, D.L.; Apodaca, L.E.; Kozlowski, A.; Landis, G.P.; Hofstra, A.H.

    1996-01-01

    The gases in fluid inclusions from samples of sphalerite, galena, and sparry dolomite from ore deposits in the Silesian-Cracow zinc-lead district were determined by mass spectrometry. The results show that CO2 is the major gas in the fluid inclusions with lesser amounts of CH4. Samples of galena and sphalerite also commonly contain H2S and short-chain hydrocarbon gases. Gases in sphalerite and galena appear to contain two end-member compositions, CO2-CH4 and CO2-H2S bearing fluid inclusions. The apparent end member compositions could represent chemically distinct generations of fluid inclusions trapped at different times or at least two distinct fluids present during ore formation. The presence of distinct fluid inclusion gas compositions is consistent with previous fluid inclusion studies that show the presence of multiple fluids during ore deposition. The presence of multiple fluids in the ore-forming environment could lead to ore precipitation through processes of fluid mixing.

  13. 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)

  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. Helium-argon isotopic tracing for the Pb-Zn-Ag polymetallic ore deposits in the central-south segment of the Da Hinggan Ling Range

    Institute of Scientific and Technical Information of China (English)

    WANG Baode; NIU Shuyin; SUN Aiqun; HU Huabin; LIU Yaming; GUO Lijun; WANG Shuo

    2008-01-01

    In recent years big strides have been made in the exploration of ores in the central-south segment of the Da Hinggan Ling Range, though some debates still exist on the metallogenesis and sources of ore-forming materials.Pyrite and other sulfides in direct relation to the Pb-Zn-Ag ore deposits were chosen for the He and Ar isotopic analysis of ore-forming fluids, and the first He and Ar isotope data have been obtained from the study region.3He/4He ratios in 14 samples collected from 7 mining districts are 2.17x10-6-12.52×10-6, averaging 6.86×10-6 and their R/Ra ratios are 1.56-9.01 Ra, averaging 4.37 Ra. By projecting the data points onto the 3He-4He concentrations diagram, all the points fall near the mantle helium area. The calculated mantle-source helium ratios are within the range of 19.58%-76.96%, with an average of 49.52%. Argon isotopic characteristics are close to those of mantle source, indicating that the ore-forming material was transport upwards via the multi-stage evolution of mantle plume and concentrated as ores in the favorable loci of mantle branch structures.

  16. 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.)

  17. Mineral paragenesis, geochemistry and geochronology investigations of the Carlin-type gold deposits at the Goldstrike property, northern Nevada: Implications for ore genesis, igneous petrogenesis and mineral exploration

    Science.gov (United States)

    Almeida, Carolina Michelin De

    The Goldstrike property is located in northern Nevada and contains one of the largest and highest-grade Carlin-type gold deposits. The majority of the Eocene Au mineralization (e.g., Ore I) is hosted in intensely altered Paleozoic lower plate impure carbonate rocks, and is characterized by strong to moderate silicification, higher calculated pyrite and ore-related element concentrations (e.g., As, Cu, Hg, Ni, Tl, Sb, W, and Zn) than Ore II, which is weakly altered. However, both ore types contain similar Au concentration in whole rock and pyrite chemistry analyses. Lithogeochemical and microprobe data suggest that the Paleozoic sedimentary rocks may have been a major source of Cd, Mo, Ni, U, V, and Zn and minor As, Cu, Hg, and Se. The Jurassic lamprophyre dikes might have been a significant source of Ba, Co, and Se, and minor Au, and some of the Jurassic and Eocene intrusive rocks may have provided some Fe. Moreover, the Eocene magmas are interpreted to be the main source of auriferous mineralizing fluids. Trace element abundances and ratios of the Jurassic intrusive rocks suggest that they are shoshonitic and formed from a metasomatized mantle-derived magma, crystal fractionation, and crustal contamination. The Eocene dikes, also shoshonitic, are considerably more evolved and contaminated than the studied Jurassic rocks. Furthermore, Ar-Ar results show that the Jurassic rocks were negligibly affected by the Eocene thermal event, and that temperature of mineralizing fluids were below the closure temperature of biotite (gold deposits at the studied area. In this model, Au and the ore-related elements were exsolved along with volatiles by degassing of a deep and large plutonic complex during its early stage of crystallization. As these magmatic-hydrothermal fluids moved upward along major conduits (e.g., NNW-striking faults), they may have interacted with a Fe-rich fluid, pervasively altering the Paleozoic impure carbonate rocks (e.g., carbonate dissolution

  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. 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.

  20. Excited response of granular ores in vibrating field

    Institute of Scientific and Technical Information of China (English)

    2001-01-01

    The dynamical theory was utilized to probe into the law of the excited response of granular ores generated by the exciting action of exciter and the influence of wave propagation in vibrating field. The exciter with double axes was presented as an example, and the principle of exciter and its mathematical expression of the excitation force were given. The granular ores have viscidity and damping speciality, on the basis of which the motion equation of excited response of ores was established and the approximate expression of mode-displacement by harmonic excitation and the steady effect solution of coordinate response were deduced. Utilizing the step-by-step integration method, the recursion relation matrix of displacement, velocity and acceleration of the excited response of ores were obtained, and the computational flow chart and a computational example were given. The results show that the excited response can change the dynamical character and the flowing characteristic of granular ores.

  1. Mineralogical Characterization of Goethite- Lateritic Ore & its Implication on Beneficiation

    Directory of Open Access Journals (Sweden)

    Nirlipta P. Nayak

    2014-11-01

    Full Text Available Mineralogical characterization of ore has to get due attention before any attempt for its processing and has become almost inevitable these days because of the increasing demand of the ore. Mineral processing technology is evolved to separate and recover ore minerals from gangue in a commercially viable method and is mainly based upon the process of mineral liberation and the process of mineral separation. A very lean grade iron ore sample was collected from Barsua iron ore deposits assaying 38.19% Fe, 9.48%SiO2, 19.97 Al2O3 and 15.01LOI. From characterization studies it is revealed that the sample contains huge quantity of goethite which is partially weathered, interlocked with hematite and gangue minerals like kaolinite, gibbsite at different proportion. Mineralogical studies conclude that the final concentrate product quality depends upon the presence of goethite.

  2. Mineralogy and trace element geochemistry of the Co- and Cu-bearing sulfides from the Shilu Fe-Co-Cu ore district in Hainan Province of South China

    Science.gov (United States)

    Wang, Zhilin; Xu, Deru; Zhang, Zhaochong; Zou, Fenghui; Wang, Li; Yu, Liangliang; Hu, Mingyue

    2015-12-01

    Hosted within the metamorphosed, neritic siliciclastic rocks and sedimentary carbonates of the Proterozoic Shilu Group, the Shilu Fe-Co-Cu ore district in Hainan Province of South China comprises the upper Fe- and the lower Co-Cu ore layers. Combined with the field observation, the mineralogical and geochemical studies of sulfides using electron microprobe and laser ablation ICP-MS analyses recognized three types of Co-Cu ores. Type I is represented by massive ores and mainly comprises the first generation of pyrite (PyI) which occurred either as recrystallized, subhedral to euhedral microcrystal aggregates (PyIa) or as elongated, fine-grained euhedral grains (PyIb) with an orientated alignment parallel to S1 foliation. Type II is banded, disseminated and brecciated ores, and composed of the second generation of pyrite (PyII) which displays internal rhythmic growth zoning, the first generations of chalcopyrite (CcpI) and pyrrhotite (PoI), and associated Co-(Ni)-(As)-sulfide minerals. Type III occurring as veins or veinlets mainly consists of the third generation of pyrite (PyIII) and the second generations of chalcopyrite (CcpII) and pyrrhotite (PoII), of which PyIII appears as subhedral to euhedrall grains or as rims of composite pyrite. The moderate Co and As, and high Ni contents as well as the low Co/Ni ratios (∼2-5) in PyI indicate a sedimentary-metamorphic origin for Type I ores. The higher Co, Ni and As concentrations in PyIb relative to PyIa likely was related to an inhomogeneous deformation-metamorphism. The highest Co (av. 51,195 ppm) in PyII and Ni (av. 3374 ppm) in PoI most likely were linked to the preferred incorporation of Co into pyrite and Ni into pyrrhotite. Combined with the high Ag concentrations in CcpI (av. 266 ppm) and PyII (av. 13.32 ppm), the high Co/Ni ratios in PyII (av. 1241) suggest the derivation of Type II ores from a Co-Cu-Ni-Ag-rich hydrothermal fluid. Further, up to 9 wt.% Co concentrations in PyII show a temperature condition of

  3. Application of low-temperature thermochronology to hydrothermal ore deposits: Formation, preservation and exhumation of epithermal gold systems from the Eastern Rhodopes, Bulgaria

    Science.gov (United States)

    Márton, István; Moritz, Robert; Spikings, Richard

    2010-03-01

    New low-temperature thermochronological data have been used to quantify the protracted, Eocene-Miocene cooling histories of upper and lower plate rocks of the Kesebir-Kardamos extensional dome, Eastern Rhodopes, Bulgaria. 40Ar/ 39Ar and apatite fission-track data reveal that the lower plate has experienced continuous cooling and exhumation, since the Late Eocene. Muscovite 40Ar/ 39Ar plateau ages of 36.90 ± 0.16 Ma and 37.28 ± 0.19 Ma (2 σ) from metamorphic rocks of the footwall reveal the approximate time span during which they cooled below ˜ 350 °C during exhumation caused by detachment faulting. The sedimentary rock-hosted gold mineralization, which represents a thermal event at ˜ 250-220 °C, developed during the early stage of basin formation between 34.71 ± 0.16 Ma and 35.36 ± 0.21 Ma (adularia 40Ar/ 39Ar plateau ages; 2 σ). The termination of hydrothermal mineral deposition at Ada Tepe occurred contemporaneously with the earliest phase of calc-alkaline type magmatism at Iran Tepe (33.97 ± 0.36 Ma to 34.62 ± 0.46 Ma, hornblende and biotite 40Ar/ 39Ar plateau ages, 2 σ). Thermal history modelling of apatite fission-track data shows that the lower plate rocks cooled through ˜ 120 °C at ˜ 18.3 ± 1.9 Ma (1 σ). A time-temperature model obtained from zircon and apatite fission-track data from the upper plate reveals that it was being buried during the late Eocene. At ˜ 33-30 Ma, a dramatic change of the time-temperature path was caused by the initiation of horst-graben structures, resulting in rapid exhumation of the upper plate. Our new thermochronological data reveal many aspects of the mechanisms of formation of sedimentary rock-hosted gold deposits. The heat accumulated during sedimentary burial of the upper plate is a plausible heat source to drive hydrothermal fluid circulation and ore formation. The development of large half-graben basins in the hanging walls of detachment faults, accompanied by a favourable climate, may have created a

  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. 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

  6. 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)

  7. 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)

  8. Mercury exposure aboard an ore boat.

    Science.gov (United States)

    Roach, Richard R; Busch, Stephanie

    2004-06-01

    Two maritime academy interns (X and Y) were exposed to mercury vapor after spilling a bottle of mercury on the floor in an enclosed storeroom while doing inventory aboard an ore boat. During a 3-day period, intern Y suffered transient clinical intoxication that resolved after he was removed from the environment and he showered and discarded all clothing. His initial serum mercury level dropped from 4 ng/mL to footwear earlier than intern Y. Intern X's continued exposure due to mercury in the contaminated boots during the 2 weeks before hospitalization was presumed to be the cause. Removing his footwear led to resolution of his toxic symptoms and correlated with subsequent lowered serum mercury levels. Chelation was initiated as recommended, despite its uncertain benefit for neurologic intoxication. Mercury is used in the merchant marine industry in ballast monitors called king gauges. New engineering is recommended for ballast monitoring to eliminate this hazard. PMID:15175181

  9. TEXTURAL DESCRIPTORS FOR MULTIPHASIC ORE PARTICLES

    Directory of Open Access Journals (Sweden)

    Laura Pérez-Barnuevo

    2012-11-01

    Full Text Available Monitoring of mineral processing circuits by means of particle liberation analysis through quantitative image analysis has become a routine technique within the last decades. Usually, liberation indices are computed as weight proportions, which is not informative enough when complex texture ores are treated by flotation. In these cases, liberation has to be computed as phase surface exposed to reactants, and textural relationships between minerals have to be characterized to determine the possibility of increasing exposure. In this paper, some indices to achieve a complete texture characterization have been developed in terms of 2D phase contact and mineral surfaces exposure. Indices suggested by other authors are also compared. The response of this set of parameters against textural changes has been explored on simple synthetic textures ranging from single to multiple inclusions and single to multiple veins and their ability to discriminate between different textural features is analyzed over real mineral particles with known internal structure.

  10. Rigid Ideals and Radicals of Ore Extensions

    Institute of Scientific and Technical Information of China (English)

    Chan Yong Hong; Tai Keun Kwak; S. Tariq Rizvi

    2005-01-01

    For an endomorphism σ of a ring R, Krempa called σ a rigid endomorphism if aσ(a) = 0 implies a= 0 for a ∈ R. A ring R is called rigid if there exists a rigid endomorphism of R. In this paper, we extend the σ-rigid property of a ring R to an ideal of R. For a σ-ideal Ⅰ of a ring R, we call Ⅰ a σ-rigid ideal if aσ(a) ∈Ⅰ implies a ∈Ⅰ for a ∈ R. We characterize σ-rigid ideals and study related properties. The connections of the prime radical and the upper nil radical of R with the prime radical and the upper nil radical of the Ore extension R[x; σ, δ], respectively, are also investigated.

  11. Monitoring of natural radioactivity in manganese ore

    International Nuclear Information System (INIS)

    The natural radionuclides (238U, 232Th, and 40K) contents of Manganese ore collected by Sinai Manganese Company in Egypt-Cairo have been determined by low background spectroscopy using hyper-pure germanium (HPGe) detector. The mean activities due to the three radionuclides (238U, 232Th, and 40K) were found to be 3543 ± 106, 222 ± 6.6 and 3483 ± 104 Bq/kg, respectively. The absorbed dose rates due to the natural radioactivity in samples under investigation ranged from 1522 ± 45 to 1796 ± 53 nGy/h. The radium equivalent activity varied from 3807 ± 114 to 4446 ± 133 Bq/kg. Also, the representative external hazard index values for the corresponding samples were estimated.

  12. 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

  13. Direct Biohydrometallurgical Extraction of Iron from Ore

    Energy Technology Data Exchange (ETDEWEB)

    T.C. Eisele

    2005-10-01

    A completely novel approach to iron extraction was investigated, based on reductive leaching of iron by anaerobic bacteria. Microorganisms were collected from an anaerobic bog where natural seepage of dissolved iron was observed. This mixed culture was used to reduce insoluble iron in a magnetite ore to the soluble ferrous (Fe{sup +2}) state. While dissolution rates were slow, concentrations of dissolved iron as high as 3487 mg/l could be reached if sufficient time was allowed. A factorial study of the effects of trace nutrients and different forms of organic matter indicated that the best dissolution rates and highest dissolved iron concentrations were achieved using soluble carbohydrate (sucrose) as the bacterial food source, and that nutrients other than nitrogen, phosphorus, potassium, sodium, and acetate were not necessary. A key factor in reaching high levels of dissolved iron was maintaining a high level of carbon dioxide in solution, since the solubility of iron carbonates increases markedly as the quantity of dissolved carbon dioxide increases. Once the iron is dissolved, it has been demonstrated that the ferrous iron can then be electroplated from solution, provided that the concentration of iron is sufficiently high and the hydrogen ion concentration is sufficiently low. However, if the leaching solution is electrolyzed directly, organic matter precipitates at the cathode along with the metallic iron. To prevent this problem, the ferrous iron should be separated from the bulk solution in a more concentrated, purified form. One route to accomplishing this is to take advantage of the change in solubility of ferrous iron as a function of carbon dioxide concentration. By cycling the concentration of carbon dioxide in solution, it is possible to produce an iron-rich concentrate that should be suitable for electrolysis. This represents the first viable hydrometallurgical method for leaching iron directly from ore and producing metallic iron.

  14. 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.)

  15. Fluid structure interaction in piston diaphragm pumps

    OpenAIRE

    Van Rijswick, R.; Van Rhee, C.

    2013-01-01

    Piston diaphragm pumps are used world-wide for the transport of aggressive and/or abrasive fluids in the chemical, mining and mineral processing industries. Figure 1 shows a cross section of a piston diaphragm pump as is used in the mining and mineral processing industries for the transport of mineral ores and tailings in the from of a solid water mixture, called a slurry.

  16. Nitrile/Buna N Material Failure Assessment for an O-Ring used on the Gaseous Hydrogen Flow Control Valve (FCV) of the Space Shuttle Main Engine

    Science.gov (United States)

    Wingard, Doug

    2006-01-01

    curves. Correlations were also made between the DMA modulus (at 22 C) and Shore A hardness for all 9 of the FCV O-rings used among the three Shuttle Orbiters. The radial cracking in the FCV O-rings was determined to be due to ozone attack, as nitrile/Buna N rubber is susceptible to such attack. Nitrile/Buna N material under MIL-P25732C should be used in a hydraulic fluid environment to help protect it from cracking. However, the FCV O-rings were used in an air only environment. The FCV design has as much as a 9-mil gap that allows the O.D. of the O-ring to be directly exposed to ozone, pressurized air and some elevated temperatures, accelerating the weathering process that leads to O-ring cracking. Space Shuttle flights will likely not continue past 2010. Therefore, Shuttle management decided to continue using the nitrile/Buna N material for the FCVs, but have each O-ring replaced after 3 years to minimize any chances for crack initiation.

  17. Evaluation des bassins par modélisation intégrée en deux dimensions des transferts techniques, de l'écoulement des fluides, de la genèse et de la migration des hydrocarbures Basin Evaluation by Integrated Two-Dimensional Modeling of Heat Transfer, Fluid Flow, Hydrocarbon Generation, and Migration

    Directory of Open Access Journals (Sweden)

    Chenet P. Y.

    2006-11-01

    transfer, compaction and water flow, hydrocarbon generation, and two-phase migration of fluids. The model reproduces the influence of conductivity variations and of transient heat transfer on paleotemperatures. Quantitative verification of the paleotemperature reconstruction and of the kinetic model of hydrocarbon generation may be obtained from present temperatures and geochemical data. Compaction-driven flows and overpressures are described by coupling a compaction law with Darcy's law for water flow and a criterion for natural hydraulic fracturing. This formulation allows modeling of overpressures in young deltalic sequences (e. g. , the Mahakam delta, Indonesia as well as in old rift basins (e. g. , the North Sea. An adapted two-phase Darcy's law reproduces primary and secondary migration. In particular, the model helps investigate the role of overpressures and fault behavior on hydrocarbon migration and entrapment. Our results confirm that basin models contribute to the synthesis of geological, geophysical, and geochemical data consistently. By defining parameters for petroleum evaluations, these models increase exploration efficiency.

  18. 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

  19. Bog Manganese Ore: A Resource for High Manganese Steel Making

    Science.gov (United States)

    Pani, Swatirupa; Singh, Saroj K.; Mohapatra, Birendra K.

    2016-05-01

    Bog manganese ore, associated with the banded iron formation of the Iron Ore Group (IOG), occurs in large volume in northern Odisha, India. The ore is powdery, fine-grained and soft in nature with varying specific gravity (2.8-3.9 g/cm3) and high thermo-gravimetric loss, It consists of manganese (δ-MnO2, manganite, cryptomelane/romanechite with minor pyrolusite) and iron (goethite/limonite and hematite) minerals with sub-ordinate kaolinite and quartz. It shows oolitic/pisolitic to globular morphology nucleating small detritus of quartz, pyrolusite/romanechite and hematite. The ore contains around 23% Mn and 28% Fe with around 7% of combined alumina and silica. Such Mn ore has not found any use because of its sub-grade nature and high iron content, and is hence considered as waste. The ore does not respond to any physical beneficiation techniques because of the combined state of the manganese and iron phases. Attempts have been made to recover manganese and iron value from such ore through smelting. A sample along with an appropriate charge mix when processed through a plasma reactor, produced high-manganese steel alloy having 25% Mn within a very short time (<10 min). Minor Mn content from the slag was recovered through acid leaching. The aim of this study has been to recover a value-added product from the waste.

  20. METALLURGIC CHARACTERIZATION OF AN IMPORTANT BRAZILIAN MANGANESE LUMP ORE

    Directory of Open Access Journals (Sweden)

    Geraldo Lúcio de Faria

    2014-03-01

    Full Text Available This work proposes a study about important metallurgic parameters of Urucum manganese lump ore, which are: cold and hot particle disintegration mechanisms, heat decompositions and the pre-reduction behavior. A tone of the studied ore was received and representative samples were collected for characterization procedures. Aiming to study ore heat decompositions, it was proposed a quantitative index named Evolution of Heat Decomposition (EHD. Using this index, the chemical and mineralogical characterization data, it was possible to determine the main reactions of mineral decomposition. Two quantitative parameters were proposed to describe the ore solid state reduction; these indexes were named Pre-reduction Efficiency (PE and Pre-reduction Instantaneous Rate (PIR. Applying these parameters it was possible to conclude that Urucum lump ore has a great pre-reduction behavior. The characterization of particle disintegration was performed using three new indexes for manganese ores, which were: Cold Disintegration Index (CDI, Decrepitation Index (DI and Hot Disintegration Index (HDI. These indexes showed that the studied ore did not presents significant cold particle disintegration, but it is susceptive to decrepitation and hot particle disintegration.

  1. Super-Enrichment of Dispersed Elements and Associated Ore Deposits

    Institute of Scientific and Technical Information of China (English)

    高振敏; 姚林波

    2004-01-01

    Dispersed elements do not always occur as associated elements in the ore deposits of other elements. Instead, they can constitute independent ore deposits. The focus of this paper is placed on the mechanism of super-enrichment of the four dispersed elements TI, Ge, Se, and Te under favorable geological conditions, where their enrichment coefficients are so high that their abundances can reach n×103-n×104, sometimes even up to n×106 times (e. g. Te) those of the crust. As a result, they can form their independent ore deposits. Studies have shown that such independent ore deposits are mostly distributed in the southwestern part of China, most of which belong to low-temperature ore deposits, ranging in age from Yanshanian to Himalayan(Cretaceous to Cenozoic), with a significant time gap with the host strata. Moreover, this paper also deals with the existing forms (as independent minerals, occurring isomorphously and being adsorbed) of the dispersed elements in those independent ore deposits. The discovery of independent ore deposits of dispersed elements is a great breakthrough in the study of dispersed element metallogenesis.

  2. Investigation of friction and wear characteristic of O-ring

    Energy Technology Data Exchange (ETDEWEB)

    Oh, Jun Chul; Kim, Dae Eun; Kim, Hyun Jun [Yonsei University, Seoul (Korea, Republic of); Kim, Mun Hwan; Kim, Chun Il [LG Display Co., Ltd., Seoul (Korea, Republic of)

    2009-07-01

    O-rings are commonly used in machines as a seal. Due to prolonged use the surface of an O-ring can degrade which can lead to leakage as well as contamination. Damage of O-rings used in vacuum applications such as sputter is caused by various mechanisms. Particles detached from the O-ring may cause significant problems on the performance of the system in the vacuum chamber. Therefore, understanding the tribological behavior of O-rings is important to tackle the damage caused by repeated contact. In this work, FKM rubber was used for friction and wear tests conducted to investigate the tribological behavior of O-rings. A reciprocating type of tribo-tester was used for the tests. The friction coefficient between the steel ball and the FKM specimen was quite high. Also, in order to identify the wear behavior, the surface of the FKM specimen was characterized using both optical and scanning electron microscopes. Evidence of wear due to adhesion and extrusion could be found. The results of this work will aid in improving the durability of O-rings.

  3. Investigation of friction and wear characteristic of O-ring

    International Nuclear Information System (INIS)

    O-rings are commonly used in machines as a seal. Due to prolonged use the surface of an O-ring can degrade which can lead to leakage as well as contamination. Damage of O-rings used in vacuum applications such as sputter is caused by various mechanisms. Particles detached from the O-ring may cause significant problems on the performance of the system in the vacuum chamber. Therefore, understanding the tribological behavior of O-rings is important to tackle the damage caused by repeated contact. In this work, FKM rubber was used for friction and wear tests conducted to investigate the tribological behavior of O-rings. A reciprocating type of tribo-tester was used for the tests. The friction coefficient between the steel ball and the FKM specimen was quite high. Also, in order to identify the wear behavior, the surface of the FKM specimen was characterized using both optical and scanning electron microscopes. Evidence of wear due to adhesion and extrusion could be found. The results of this work will aid in improving the durability of O-rings.

  4. Bog Manganese Ore: A Resource for High Manganese Steel Making

    Science.gov (United States)

    Pani, Swatirupa; Singh, Saroj K.; Mohapatra, Birendra K.

    2016-06-01

    Bog manganese ore, associated with the banded iron formation of the Iron Ore Group (IOG), occurs in large volume in northern Odisha, India. The ore is powdery, fine-grained and soft in nature with varying specific gravity (2.8-3.9 g/cm3) and high thermo-gravimetric loss, It consists of manganese (δ-MnO2, manganite, cryptomelane/romanechite with minor pyrolusite) and iron (goethite/limonite and hematite) minerals with sub-ordinate kaolinite and quartz. It shows oolitic/pisolitic to globular morphology nucleating small detritus of quartz, pyrolusite/romanechite and hematite. The ore contains around 23% Mn and 28% Fe with around 7% of combined alumina and silica. Such Mn ore has not found any use because of its sub-grade nature and high iron content, and is hence considered as waste. The ore does not respond to any physical beneficiation techniques because of the combined state of the manganese and iron phases. Attempts have been made to recover manganese and iron value from such ore through smelting. A sample along with an appropriate charge mix when processed through a plasma reactor, produced high-manganese steel alloy having 25% Mn within a very short time (<10 min). Minor Mn content from the slag was recovered through acid leaching. The aim of this study has been to recover a value-added product from the waste.

  5. Geochemical and Nd isotopic constraints on provenance and depositional setting of the Shihuiding Formation in the Shilu Fe-Co-Cu ore district, Hainan Province, South China

    Science.gov (United States)

    Yu, Liangliang; Zou, Shaohao; Cai, Jianxin; Xu, Deru; Zou, Fenghui; Wang, Zhilin; Wu, Chuanjun; Liu, Meng

    2016-04-01

    The Shihuiding Formation, a subordinate succession hosting the Fe-Co-Cu ores, is a suite of Neoproterozoic terrigenous clastic rocks occurring in the Shilu Fe-Co-Cu ore district of the Hainan Island, South China. Integrated petrographical, geochemical, and Nd isotopic analyses have been carried out on 23 sandstone specimens of the Shihuiding Formation in order to understand their provenance and the tectonic setting of their deposition. The samples can be divided into two groups, quartzose sandstones (13 samples) and ferruginous sandstones (10 samples). The ferruginous sandstones have average SiO2 and Fetotal contents of 77.23 wt.% and 18.09 wt.%, respectively, and this contrasts with the higher average SiO2 (94.04 wt.%) and lower Fetotal (2.67 wt.%) contents of the quartzose sandstones. The bivariant Th/Sc and Zr/Sc ratios indicate a predominantly recycled sedimentary provenance, and the low to medium degrees of weathering are commonly indicated by an average chemical index of maturity (CIM) of 81 and an average chemical index of alteration (CIA) of 68. The Shihuiding Formation sandstones have REE contents of 21-249 ppm, with LREE/HREE = 9.18 and δEu = 0.67. The εNd (970 Ma) values of -5.7 to -3.4, and model (TDM) ages of 2099-1773 Ma are compatible with a source mainly from the Paleo- to Mesoproterozoic Baoban Group, a suite of metamorphosed sedimentary rocks intruded by ca. 1450 Ma granites. Quantitative provenance modeling indicates that the Shihuiding Formation sandstones are best modeled with a mixture of 29% plagioclase-amphibole gneiss (29 P), 38% quartz-muscovite schist (38 Q), and 33% granite (33 G) detritus. Mixing the εNd values of the sandstones, calculated at 970 Ma, indicates that the sediment received 22-47% (average 34%) of its detritus from the Baoban Group quartz-muscovite schists. Components from hydrothermal fluids may also have been involved during deposition of the Shihuiding Formation sandstones, as revealed by a bivariant Al/(Al + Fe + Mn

  6. Source of ore-forming materials of the Cangpo carbonate replacement tin deposit in the Dachang tin field: evidence from oxygen, carbon and hydrogen isotopes

    International Nuclear Information System (INIS)

    The Dachang tin field with more than one hundred million tonnes of ore at 1% tin and 3% Zn is one of the largest tin fields in the world. The deposit hosted by middle Devonian limestone, argillaceous limestone and black shale, is genetically related to the Longxianggei granite. The oxygen, hydrogen and carbon isotope data of minerals, rocks and fluids suggest a magnatic fluid which evolved during the crystallization of the Longxianggei granite. Mass balance calculations show that the depletions observed in 180 and 13C values of calcites from the ore bodies to the country rocks were due to continous isotopic exchange reactions between the magmatic fluid and the marine limestones at different W/R ratios and between 300 and 600 deg.C. 7 refs., 4 figs

  7. 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)

  8. 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)

  9. Intelligent Forecasting of Sintered Ore's Chemical Components Based on SVM

    Institute of Scientific and Technical Information of China (English)

    ZHONG Luo; WANG Qingbo; YUAN Jingling

    2011-01-01

    Using object mathematical model of traditional control theory can not solve the forecasting problem of the chemical components of sintered ore. In order to control complicated chemical components in the manufacturing process of sintered ore, some key techniques for intelligent forecasting of the chemical components of sintered ore are studied in this paper. A new intelligent forecasting system based on SVM is proposed and realized. The results show that the accuracy of predictive value of every component is more than 90%. The application of our system in related companies is for more than one year and has shown satisfactory results.

  10. A hybrid decision support system for iron ore supply

    OpenAIRE

    A. Samolejová; J. Feliks; R. Lenort; P. Besta

    2012-01-01

    Many European metallurgical companies are forced to import iron ore from remote destinations. For these companies it is necessary to determine the amount of iron ore that will have to be ordered and to create such a delivery schedule so that the continuous operation of blast-furnace plant is not disrupted and there is no exceedingly large stock of this raw material. The objective of this article is to design the decision support system for iron ore supply which would effi ciently reduce uncer...

  11. 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)

  12. 山东牟平宋家沟金矿床流体包裹体研究%Study on fluid inclusions of Songjiagou Gold Deposit in Muping,Shandong Province

    Institute of Scientific and Technical Information of China (English)

    王铎融; 王力; 陈扬

    2015-01-01

    宋家沟金矿床位于胶莱盆地东北缘,牟平—即墨断裂带内,控矿构造为陡倾断裂和裂隙密集带,赋矿围岩为莱阳群的灰白色砾岩,共出露4个矿体. 对区内主成矿阶段石英中的流体包裹体进行了岩相学、显微测温及单个包裹体成分激光拉曼光谱分析. 研究表明,矿石中的包裹体主要有纯CO2包裹体、气液二相包裹体和含CO2三相包裹体3种类型;矿石中的包裹体普遍富含CO2 ,成矿流体为CO2 -NaCl -H2 O 体系,成矿流体具有低盐度(5.0 %~14.42 %)、低密度(0.64 ~0.96 g/cm3 )的特点. 主成矿温度集中在220~240 ℃,成矿压力范围为40~62 MPa,对应的成矿深度为5 .01~6 .34 km. 结合前人研究的流体包裹体氢氧同位素分析认为,宋家沟金矿床的成矿流体以幔源流体为主,后期有少量的岩浆流体参与. 确定其矿床成因类型为受陡倾断裂和裂隙密集带联合控制的中温热液脉型金矿床.%Songjiagou Gold Deposit is located in in Muping-Jimo faults,northeast of Jiaolai Basin.The ore-con-trolling structure is steeply inclined fracture and fissure-intensive belt,the surrounding rocks are pale conglomerates with 4 outcrop orebodies.Petrographic,microthermometric and laser Raman microspectroscopic studies on fluid inclu-sions in quartz of main mineralization stages of Songjiagou Gold Deposit are carried out .The results show that there are three types of fluid inclusions:pure CO2 single-phase fluid inclusions,aqueous two-phrase fluid inclusions and CO2 -bearing fluid inclusions.CO2 are widespread in the fluid inclusions in ores.The fluids of main mineralization stages should be a CO2 -NaCl-H2 O system; The ore-forming fluids are with low salinity (5.0 % to 14.42 %) and low density(0.64 g/cm3 to 0.96 g/cm3 ); Mineralization temperature ranges between 220 ℃ and 240 ℃,mineralization pressure ranges from 40 MPa to 62 MPa,while mineralization depth ranges from 5.01 km to 6.34 km.The paper, based on hydrogen

  13. 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)

  14. Difference of ore-bearing and non-ore-bearing pegmatite in the Guangshigou area and its research significance

    International Nuclear Information System (INIS)

    Guangshigou uranium deposit is one of the typical granite-pegmatite uranium deposits in China, the ore-body are located in the density zone of the outside contact zone of granite pluton. To distinguish the ore-bearing and Non-ore-bearing pegmatite is one of the most practices and have great significance for the effect of mineral exploration. Based on the field investigation and former research results, contrast research on the characteristics of the pegmatite on petrology, geophysical, geochemistry and stable isotopes have been carried out. It is pointed out that the ore-bearing pegmatite differ from the non-ore-bearing one from macro-and-micro-view in Guangshigou Uranium deposits, the main characteristics are summarized; the macro-and-micro signs are established, the genetic difference between the ore-bearing and non-ore-bearing pegmatite are discussed primarily. The achievements would be helpful for prospecting and researching of this type uranium deposits in China. (authors)

  15. Selenium content of sulfide ores related to ophiolites of Greece.

    Science.gov (United States)

    Economou-Eliopoulos, M; Eliopoulos, D G

    1998-01-01

    Several deposits of sulfide mineralization have been described in the ophiolites of Greece. Based on their mineralogical and chemical composition and the host rocks, two types can be distinguished: (1) the Fe-Cu-Ni-Co type consisting of pyrrhotite, chalcopyrite, Co-pentlandite, pyrite, magnetite + arsenides, +/- chromite, hosted in serpentinites, gabbros or diabases, which have variable geochemical characteristics, and (2) sulfide mineralization of the Cyprus type containing variable proportions of pyrite, chalcopyrite, bornite, and sphalerite. The spatial association with shear zones and fault systems, which is a common feature in both types of mineralization, provided the necessary permeability for the circulation of the responsible mineralized hydrothermal fluids. The selenium (Se) content in representative samples of both types of mineralization from the ophiolites of Pindos (Kondro, Perivoli, and Neropriona), Othrys (Eretria and A. Theodoroi), Veria (Trilofon), and Argolis (Ermioni) shows a wide variation. The highest values of Se (130 to 1900 ppm) were found in massive Fe-Cu sulfide ores from Kondro, in particular the Cu-rich portions (average 1300 ppm Se). The average values of Se for the Othrys sulfides are low (< 40 ppm Se). The Se content in a diabase breccia pipe (50 x 200 m) with disseminated pyrite mineralization (Neropriona) ranges from < 1 to 35 ppm Se. The highest values were noted in strongly altered samples that also exhibited a significant enrichment in platinum (1 ppm Pt). Sulfide mineralization (irregular to lens-like masses and stringers) associated with magnetite, hosted in gabbros exposed in the Perivoli area (Tsouma hill), shows a content ranging from 40 to 350 ppm Se. The distribution of Se in the studied type of the sulfide mineralization may be of genetic significance, indicating that the Se level, which often is much higher than in typical magmatic sulfides related to mafic-ultramafic rocks (average 90-100 ppm Se), may positively affect

  16. 40 CFR 440.110 - Applicability; description of the platinum ore subcategory.

    Science.gov (United States)

    2010-07-01

    ... platinum ore subcategory. 440.110 Section 440.110 Protection of Environment ENVIRONMENTAL PROTECTION AGENCY (CONTINUED) EFFLUENT GUIDELINES AND STANDARDS ORE MINING AND DRESSING POINT SOURCE CATEGORY Platinum Ores Subcategory § 440.110 Applicability; description of the platinum ore subcategory. The provisions of...

  17. 40 CFR 440.40 - Applicability; description of the mercury ore subcategory.

    Science.gov (United States)

    2010-07-01

    ... mercury ore subcategory. 440.40 Section 440.40 Protection of Environment ENVIRONMENTAL PROTECTION AGENCY (CONTINUED) EFFLUENT GUIDELINES AND STANDARDS ORE MINING AND DRESSING POINT SOURCE CATEGORY Mercury Ore Subcategory § 440.40 Applicability; description of the mercury ore subcategory. The provisions of subpart...

  18. Mineralogy and fluid inclusion studies in kalchoye Copper- gold deposit, East of Esfahan

    Directory of Open Access Journals (Sweden)

    Rezvan Mehvary

    2009-09-01

    Full Text Available Kalchoye Copper-gold deposit is located about 110 kilometers east of Esfahan province and within the Eocene volcano sedimentary rocks. Sandy tuff and andesite lava are important members of this complex.The form of mineralization in area is vein and veinlet and quartz as the main gangue phase. The main ore minerals are chalcopyrite, chalcocite, galena and weathered minerals such as goethite, iron oxides, malachite and azurite. Studies in area indicate that ore mineralization Kalchoye is low sulfide, quartz type of hydrothermal ore deposits and results of thermometry studies on quartz minerals low- medium fluid with low potential mineralization is responsible for mineralization in this area.

  19. Studies on Sulfating Roasting Process for Mianning Bastnasite and Baotou Mixed RE Concentrate Ore

    Institute of Scientific and Technical Information of China (English)

    Miao Guangli

    2004-01-01

    Some processes of sulfating roasting and water leaching of crude Mianning RE concentrate ore, of fine Mianning RE concentrate ore, of Baotou RE concentrate ore and of their mixture were investigated.The result shows that the mixture of Mianning and Baotou RE concentrate ore has the optimum leaching rate and rate of recovery when the mixture ratio is 1:4.The recovery rate of the mixture is higher by 14.76% than that of crude Mianning RE concentrate ore, by 5.0 % than that of Mianning fine RE concentrate ore and by 2.4 % than that of Baotou RE concentrate ore.

  20. 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

  1. Ore mineralogy of the Serra Pelada Au-Pd-Pt deposit, Carajás, Brazil and implications for ore-forming processes

    Science.gov (United States)

    Berni, Gabriel V.; Heinrich, Christoph A.; Lobato, Lydia M.; Wall, Vic

    2016-01-01

    Serra Pelada is a world-class hydrothermal Au-Pd-Pt deposit located at the eastern border of the Amazon craton, northern Brazil. The rocks at Serra Pelada have experienced intense tropical weathering for about 70 Ma, but drill core samples preserve the primary mineralogy and hydrothermal alteration features, with extreme grades of Au, Pd and Pt individually reaching hundreds of parts per million (ppm) by weight. Mineralization at Serra Pelada occurs in hydrothermally altered metasiltstones and dolomitic metasandstones at the hinge zone of a recumbent syncline, comprising zones of hematite, chlorite-carbon, argillic, and siliceous alteration. The main hydrothermal gangue minerals are quartz, kaolinite, sericite, amesite, hematite, monazite, florencite and variable amounts of highly reflective carbonaceous matter. Hydrothermal carbon input is evident from precipitated carbon occurring along crenulation planes and veinlets associated with the precious metals. Ore and accessory minerals include a variety of sulphide, selenide, arsenide, sulphate and oxide minerals, including gold with variable metal contents, palladian gold, fischesserite, sudovikovite, sperrylite, selenian braggite, isomertieite, mertieite-II and secondary Au-Pt-Pd alloys. The composition of fischesserite varies from the ideal formula (Ag3AuSe2) towards a more Ag-rich composition, indicating a disordered solid solution form that is stable only above 260 °C, consistent with the high thermal maturity of associated carbonaceous matter approaching graphite. Primary ore and gangue minerals at Serra Pelada comprise a suite of elements that are best transported in oxidising conditions and precipitated upon reduction. This suggests that fluid mixing between a highly oxidised (metal carrier) and a reduced fluid was a key process for high-grade noble metal precipitation at Serra Pelada.

  2. Ore mineralogy of the Serra Pelada Au-Pd-Pt deposit, Carajás, Brazil and implications for ore-forming processes

    Science.gov (United States)

    Berni, Gabriel V.; Heinrich, Christoph A.; Lobato, Lydia M.; Wall, Vic

    2016-08-01

    Serra Pelada is a world-class hydrothermal Au-Pd-Pt deposit located at the eastern border of the Amazon craton, northern Brazil. The rocks at Serra Pelada have experienced intense tropical weathering for about 70 Ma, but drill core samples preserve the primary mineralogy and hydrothermal alteration features, with extreme grades of Au, Pd and Pt individually reaching hundreds of parts per million (ppm) by weight. Mineralization at Serra Pelada occurs in hydrothermally altered metasiltstones and dolomitic metasandstones at the hinge zone of a recumbent syncline, comprising zones of hematite, chlorite-carbon, argillic, and siliceous alteration. The main hydrothermal gangue minerals are quartz, kaolinite, sericite, amesite, hematite, monazite, florencite and variable amounts of highly reflective carbonaceous matter. Hydrothermal carbon input is evident from precipitated carbon occurring along crenulation planes and veinlets associated with the precious metals. Ore and accessory minerals include a variety of sulphide, selenide, arsenide, sulphate and oxide minerals, including gold with variable metal contents, palladian gold, fischesserite, sudovikovite, sperrylite, selenian braggite, isomertieite, mertieite-II and secondary Au-Pt-Pd alloys. The composition of fischesserite varies from the ideal formula (Ag3AuSe2) towards a more Ag-rich composition, indicating a disordered solid solution form that is stable only above 260 °C, consistent with the high thermal maturity of associated carbonaceous matter approaching graphite. Primary ore and gangue minerals at Serra Pelada comprise a suite of elements that are best transported in oxidising conditions and precipitated upon reduction. This suggests that fluid mixing between a highly oxidised (metal carrier) and a reduced fluid was a key process for high-grade noble metal precipitation at Serra Pelada.

  3. Potential for use of methylene blue index testing to enhance geotechnical characterization of oil sands ores and tailings

    Energy Technology Data Exchange (ETDEWEB)

    Boxill, Lois [SRK Consulting (Canada)

    2011-07-01

    At the CONRAD conference held in Edmonton in 2011, clay scientist expressed their concern over the variability of clay structures and its impact both on oil sands ores and on tailings. This paper discusses the potential for using methylene blue index testing to enhance geotechnical understanding of the impact of the cation exchange capacity of clay present in oil sands ores and both solid and fluid components of the tailings stream. A description of the methylene blue index test procedure is provided. This process is most commonly used for characterization in the oil sands industry. The requirements for obtaining consistency in the test results are discussed. The test is often used to enhance geotechnical characterization of clays in other areas. The potential for developing correlations between methylene blue index test results and other geotechnical parameters is also discussed. It can be concluded from the study that geotechnical data on soil indicate the effect of clay minerals on the overall plasticity of the soil.

  4. 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

  5. Radioanalysis of RE enrichment of ion adsorption type RE ores

    CERN Document Server

    Zhao Shu Quan; Hu He Ping; Li Fu Sheng; Chen Ying Min; LiuShiMing

    2002-01-01

    Objective: To analyze the radioactivity in Rare Earth (RE) enrichment of ion adsorption type RE ores. Methods: Using HPGe-gamma spectrometer to analyze the activity ratio of gamma radionuclides in kind of samples, using FJ-2603 low background alpha, beta measurement apparatus to measure their total alpha and total beta activities, and using X-ray fluorescence spectrometer to analyze contents of La sub 2 O sub 3 and Y sub 2 O sub 3 , respectively. Results: HPGe gamma spectroscopy and X-ray fluorescence spectroscopy are simple, convenient and non-destructive methods of analyzing radionuclides and La sub 2 O sub 3 , Y sub 2 O sub 3 in RE enrichment of ion adsorption type RE ores, respectively. Conclusion: The basic data were provided for radiation protection and treatment of gas, liquid and solid waste in RE production of ion adsorption type RE ores; method and experience were provided for studying ion adsorption type RE ores

  6. 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)

  7. Collective sulphide flotation of the polymetallic molybdenic ore

    International Nuclear Information System (INIS)

    Results of investigations on polymetallic molybdenic ore are presented. The useful minerals of this ore are as follows: molybdenite, sphalerite, galena and chalcopyrite whereas quartz, feldspars, chlorite and sericite are barren rocks. The flotation process parameters are established i.e. the consumption of flotation reagents, the flotation time and the most advantageous grain composition of the ore submitted to flotation. Taking into consideration the established parameters, a collective sulphide flotation of ore and a control flotation of wastes were carried out. The obtained concentrate was submitted to a single cleaning flotation whereby a concentrate was obtained containing: 4,65% Mo, 2,51% Cu, 0,9% Zn, 0,69% Pb, and 1,4% Bi. (author)

  8. ITABIRITE IRON ORE CONCENTRATION BY PNEUMATIC FLOTATION CELL

    Directory of Open Access Journals (Sweden)

    Angelo Quintiliano Nunes da Silva

    2015-06-01

    Full Text Available The main iron ore processing plants in Brazil operate through reverse cationic flotation. Many studies have been conducted in order to improve flotation efficiency by optimization process variables. The pneumatic flotation cell stands out due to the simplicity to and to the intense contact particle/bubble promoted by the pulp feeding system. In this study, laboratory scale and pilot were conducted using a sample of itabirite iron ore. The objectives are evaluating the performance of this device using low grade iron ore, and drawing a comparison with laboratory scale tests on conventional flotation cell. The results indicate the potential application of pneumatic flotation cell to the ore tested. Adjustments in the feed particle size and process optimizations can be performed on the concentrate, reaching Fe and SiO2 grades used by the industry

  9. Beneficiation studies of Bajaur manganese ore by different processing techniques

    International Nuclear Information System (INIS)

    The manganese ore of Bajaur Agency of Pakistan was subjected to flotation, heavy medium separation, gravity concentration and magnetic separation techniques for beneficiation. The original composition of the manganese ore was 45.56% Mn , 4% Fe/sub 2/O/sub 3/, 40% SiO/sub 2/. The Mn content was raised to a maximum 48.76 % in the concentrate with the recovery of 67.78 % through flotation technique. Other techniques rendered marginal increase in Mn concentration against the theoretical possibility of substantial enrichment by rejecting the 20 % gangue minerals. The separation of manganese minerals from associated gangue was difficult, due to mineralogical complexity of the ore, extreme fineness of the particle size, texture and minerals intergrowth. High Mn/Fe ratio, phosphorus, and silica contents were within tolerable limits for utilisation of the ore in ferro-manganese production. (author)

  10. Discussion on fleet test method for radioactive ore sample

    International Nuclear Information System (INIS)

    Testing radionuclides in building materials sample with γ-ray spectrometry has become a commonly used laboratory method, in view of the activity of radioactive ore is ten times more than the building materials sample,its fleet test is possible. It discusses the fleet test method for radioactivity ore sample from the 'social production' point of view. Achieving the test quickly and effectively within error permission, so the method can enhance the efficiency of test and reduce the economic cost. (authors)

  11. 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

  12. Treatment of molybdenite ore with laboratory scale solar furnaces

    Energy Technology Data Exchange (ETDEWEB)

    Coutures, J.P.; Benezech, G.; Renard, R.; Skaggs, S.R.

    1979-01-01

    The conventional method of extracting molybdenite concentrate (MoS/sub 2/) from raw ore consumes 145 x 10/sup 6/ Btu/ton of concentrate in fossil fuel equivalent energy. Processing the ore using a solar hear source could save 56% of this energy. Thermodynamic considerations indicate that MoS/sub 2/ is the easiest of the economically valuable ores to extract using a solar heat source. Oxidation of MoS/sub 2/ to molybdic oxide (MoO/sub 3/) is an exothermic process, and it should proceed autogenically if the concentration of MoS/sub 2/ is high enough. Experiments to measure the specific heat of the raw ore were conducted to determine the crossover point for concentration of molybdenite vs sensible heat of the reaction. The reaction temperatures were measured using a calorimeter, and three distinct reaction temperatures were found. These were identified as water and organic vapors, the oxidation of pyrite (FeS/sub 2/) which is present in the raw ore, and oxidation of the molybdenite. The production rate of SO/sub 2/ was measured for 0.5 g samples of three different concentrations of molybdenite: (1) 95% MoS/sub 2/ concentrate, (2) 10% concentrate mixed with the raw ore, and (3) the unadulterated raw ore. A crude mass balance was obtained between the reacted product (oxide) and the unreacted ore (sulfide) in the hearth. The curves of reacted product vs time look very similar to the curves of SO/sub 2/ gas production as a function of time. Both sets of curves show the reaction is more than 90% complete in one minute.

  13. Magnetic Characterization of Sulphide Ores: Examples From Sweden

    OpenAIRE

    Jirestig, J.; Forssberg, E.

    1992-01-01

    Diagrams of accumulativemagnetic susceptibility distribution are used to evaluate the suitability of four sulphide ores for magnetic methods of beneficiation. The investigated materials are Garpenberg, Aitik and Kedtrask. The samples were divided into susceptibility classes each of which was characterized by its mineral content. The results are presented as diagrams showing mineral appearance in the whole susceptibility range of the ore. The obtained accumulative susceptibility diagrams can b...

  14. PER - CONCENTRATION OF IRON ORE SLIME IN MAGNETIC SEPARATOR

    OpenAIRE

    Dr. Nirlipta Nayak

    2015-01-01

    Indian iron ore is generally friable in nature that results in generation of significant quantity of fines (around 35%) during mining and processing in the country. The ratio of lumps to fines produced in the country is 2:3. During washing and sizing of the ore, slimes with less than 0.21 mm size are generated and discarded into the tailing pond. It is estimated that around 10 million tons of slimes are being generated in every year during the proces...

  15. ITABIRITE IRON ORE CONCENTRATION BY PNEUMATIC FLOTATION CELL

    OpenAIRE

    Angelo Quintiliano Nunes da Silva; Luiz Cláudio Monteiro Montenegro; Roberto Galer; Henrique Dias Gatti Turrer; Douglas Batista Mazzinghy; Luiz Carlos de Aquino Junior

    2015-01-01

    The main iron ore processing plants in Brazil operate through reverse cationic flotation. Many studies have been conducted in order to improve flotation efficiency by optimization process variables. The pneumatic flotation cell stands out due to the simplicity to and to the intense contact particle/bubble promoted by the pulp feeding system. In this study, laboratory scale and pilot were conducted using a sample of itabirite iron ore. The objectives are evaluating the performance ...

  16. Understanding microwave induced sorting of porphyry copper ores

    OpenAIRE

    John, R.S.; Batchelor, A.R.; Ivanov, D.; Udoudo, O.B.; Jones, D.A.; Dodds, Chris; Kingman, S. W.

    2015-01-01

    Global demand for minerals and metals is increasing. It has been established that the impact of mining and mineral processing operations must be reduced to sustainably meet the demands of a low grade future. Successful incorporation of ore sorting in flow sheets has the potential to improve energy efficiency by rejecting non-economic material before grinding. Microwave heating combined with infra-red temperature measurement has been shown to distinguish low and high grade ore fragments from e...

  17. Characterization and Beneficiation of an Egyptian Nepheline Syenite Ore

    OpenAIRE

    Abouzeid, Abdel-Zaher M.; Negm, Abdel-Tawab A.

    2014-01-01

    Nepheline syenite ore is an essential constituent in ceramics and glass raw material meals, as a flux and as a source of alumina. The natural nepheline syenite rocks contain some undesired minerals, which are usually eliminated or reduced to the allowable limits by beneficiation. The present paper is concerned with characterization and beneficiation of an Egyptian nepheline syenite rock, at Abu Khruq locality, Eastern Desert, Egypt. The ore is exceptionally hard, with high crushing strength o...

  18. Radiotracer investigations of the flotation process in copper ore processing

    International Nuclear Information System (INIS)

    Optimization of copper ore processing requires in particular the investigation of the flotation process. 64Cu induced in natural ore by activation was used as a tracer. Detailed measurements were performed in an industrial flotation plant consisting of 14 cells. As a result the mean residence time of different grain size fractions of natural copper sulphide was determined for all parts of the flotation plant together with the efficiency of the flotation process. (author)

  19. 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

  20. The action of macrosounds on graphite ore and derived products

    Science.gov (United States)

    Bradeteanu, C.; Dragan, O.

    1974-01-01

    A suspension of graphite ore, floated graphite, and the gangue left over from flotation were subjected to the action of macrosounds under determinant conditions. The following was found: (1) The graphite ore undergoes an efficient settling action. (2) The floated graphite is strongly crushed down to the dimensions of colloidal graphite. (3) The gangue left over from flotation can be further processed to recuperate graphite from its nuclei.

  1. Extraction of lithium Carbonate from Petalite Ore (Momeik District, Myanmar)

    International Nuclear Information System (INIS)

    The methods for preparing high purity lithium carbonate which can be used for pharmaceutical applications, electronic grade crystals of lithium or to prepare battery-grade lithium metal are disclosed. Lithium carbonate as commercially produced from mineral extraction, lithium containing brines or sea water. One method for the production of pure lithium carbonate from mineral source (petalite ore) obtained from Momeik District, Myanmar is disclosed. Method for mineral processing of ore concentrate is also disclosed.

  2. 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.)

  3. Tectonic evolution of chagannuoer basin and its relationship to uranium metallogenetic process

    International Nuclear Information System (INIS)

    Starting from the tectonic evolution of the basin, authors expound the controlling role of the tectonic evolution of the basin upon factors closely associated with uranium metallogenesis in the basing such as the structure of the basin, filling sequence of cover deposit, hydrologic conditions and the mobilization and migration of uranium etc. It is suggested that the basin structure created favorable conditions for uranium ore-formation in Chagannuoer basin, it also controlled the genetic types of uranium mineralization, the distribution area and development intensity of uranium mineralization in the basin. Features of tectonic evolution resulted in the development of two type uranium mineralizations in the basin, i.e. phreatic oxidation and local interlayer oxidation types. (authors)

  4. Development of a process selection method for gold ores using case-based reasoning

    OpenAIRE

    Rintala, Lotta

    2015-01-01

    The ore grade, the geometry of an orebody as well as the mineralogical properties of the ore determine process selection for gold extraction. These factors have an effect on the metallurgical response of an ore to a proposed treatment scheme. The uniqueness of each ore deposit is the main challenge in the extraction process development for any ore. The mineralogical mode of occurrence of gold, gold grain size distribution, host and gangue mineral type, mineral associations and alterations all...

  5. 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)

  6. 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)

  7. 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

  8. 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)

  9. Injection of manganese ore in liquid steel

    International Nuclear Information System (INIS)

    A theoretical and experimental analysis is carried out to estimate the rate of MnO5 reduction when manganese ore is injected into liquid steel with three carbon contents, 0,5, 1.0 and 2.0 mass % at 1600 degree centigrade. It is assumed that there are two reaction zones along the flux injection operation: a transitory reaction between the rising particles and the bulk metal, and the permanent reaction between the metal and the top slag. The experiments were carried out in an open 10 kg induction furnace using Al2O3 refractory. The results show that the transitory reaction plays a more important role in the powder injection process than the permanent reaction. The reduction of MnO with silicon is more important when the basicity of the slag is high; this is because the a SiO2 decreases as the slag basicity is increased. However, when the slag basicity is low and the initial carbon content in steel is high the reduction of MnO with silicon becomes less efficient, although silicon still remains better reducing agent than carbon. (Author) 15 refs

  10. Ferrite grade iron oxides from ore rejects

    Indian Academy of Sciences (India)

    K S Rane; V M S Verenkar; P Y Sawant

    2001-06-01

    Iron oxyhydroxides and hydroxides were synthesized from chemically beneficiated high SiO2/Al2O3 low-grade iron ore (57.49% Fe2O3) rejects and heated to get iron oxides of 96–99.73% purity. The infrared band positions, isothermal weight loss and thermogravimetric and chemical analysis established the chemical formulas of iron-oxyhydroxides as -FeOOH.0.3H2O; -FeOOH.0.2H2O and amorphous FeOOH. The thermal products of all these were -Fe2O3 excepting that of -FeOOH.0.3H2O which gave mainly -Fe2O3 and some admixture of -Fe2O3. The hydrazinated iron hydroxides and oxyhydroxides, on the other hand, decomposed autocatalytically to mainly -Fe2O3. Hydrazine method modifies the thermal decomposition path of the hydroxides. The saturation magnetization, s, values were found to be in the range 60–71 emu g–1 which are close to the reported values for -Fe2O3. Mechanism of the -Fe2O3 formation by hydrazine method is discussed.

  11. Chapter 3. Chloric decomposition of aluminosilicate ores. 3.1. Features of chlorination of aluminium containing ores

    International Nuclear Information System (INIS)

    The features of chlorination of aluminium containing ores are considered in this article. Theoretical aspects of metals, oxides and natural compounds chlorination, specific features of synthesis of various chlorides are considered as well.

  12. 新疆塔里木盆地北缘铀矿勘查中高分辨率遥感分析应用%Application of High Resolution Remote Sensing Technology to Uranium Ore Exploration in North Fringe of Tarim Basin, Xingjiang, China

    Institute of Scientific and Technical Information of China (English)

    叶发旺; 刘德长

    2012-01-01

    高分辨率遥感技术(包括高空间分辨率和高光谱分辨率)是新世纪以来地质勘查领域的重要新技术、新方法.本文以新疆塔里术盆地北缘巴什布拉克铀矿区和柯坪地区为例,研究了 Quickbird高空间分辨率卫星遥感技术和CASI(Compact Airborne Spectrographic Imager)/SASI(Shortwave infrared Airborne Spectrographic Imager)航空高光谱遥感技术在铀矿勘查中的应用.首先,介绍了 Quickbird和CASI/SASI高分辨率遥感数据的特点和处理方法;然后,分析了 Quickbird高空间分辨率遥感技术在新疆塔里木盆地北缘巴什布拉克铀矿区油气还原褪色蚀变识别与空间分布规律分析中的应用,为铀矿油气还原成因研究和外围找矿方向提供重要依据;并研究了Quickbird与CASI/SASI两种高分辨率遥感技术在新疆塔里木盆地北缘柯坪地区铀矿勘查中的应用,发现了萨拉姆布拉克铀矿化带及其铀矿化蚀变空间分布特征,确定了铀矿化蚀变类型,预测了铀矿找矿靶区,为该地区铀矿勘查的新突破提供了重要依据.上述应用表明,高分辨率遥感技术在铀矿地质勘查领域可以取得很好的应用效果,值得广大遥感地质工作者今后进一步深入挖掘其应用潜力.%High resolution remote sensing technology ( including high spatial resolution and hyper-spectral resolution) is an important new technology in field of geological exploration since the new century. In order to present the application of high resolution remote sensing technology in geological field, the Quick-bird high spatial resolution satellite remote sensing technology and CASI (Compact Airborne Spectro-graphic Imager)/SASI (Shortwave infrared Airborne Spectrographic Imager) airborne hyper-spectral remote sensing technology were used to mine the uranium exploration information in north fringe of Tarim Basin, Xingjiang, in this paper. In first part, the feature and processing method of Quickbird and CASI

  13. Fluid Mechanics.

    Science.gov (United States)

    Drazin, Philip

    1987-01-01

    Outlines the contents of Volume II of "Principia" by Sir Isaac Newton. Reviews the contributions of subsequent scientists to the physics of fluid dynamics. Discusses the treatment of fluid mechanics in physics curricula. Highlights a few of the problems of modern research in fluid dynamics. Shows that problems still remain. (CW)

  14. Sulfate Saturated Hydrous Magmas Associated with Hydrothermal Gold Ores

    Science.gov (United States)

    Chambefort, I.; Dilles, J. H.; Kent, A. J.

    2007-12-01

    -ICP-MS. Yanacocha anhydrite, hosted by amphiboles, are enriched in FeO (up to 0.6 wt%) and present positive anomalies in Eu and SrO (up to 8000ppm in anhydrite blebs hosted by high Al amphibole of the sample RC6). Anhydrite hosted by clinopyroxene (CPx) and low Al amphibole present higher Ce2O3 content (up to 2000ppm in CPx). In comparison, hydrothermal anhydrite analyzed from El Salvador, Butte and Ajo ore deposits contain less SrO (~ 2000 ppm) and no FeO. Pinatubo anhydrite phenocrysts and inclusions from the 1991 Pinatubo dacite yield low FeO contents, except anhydrite included in amphibole. These data suggest FeO in anhydrite is a product of subsolidus diffusion from the host. The breakdown of abundant anhydrite crystals "stored" in the magma may source of SO2-rich hydrothermal fluids that produced the sulfur enrichment (>500 M Tonnes) observed the Yanacocha hydrothermal gold deposits. The two populations of amphibole are evidence of magma mixing in the Yanacocha magmatic rocks. A sulfate-saturated oxidized dacitic magma chamber resided at about 4 to 8 km depth and 800°C was periodically underplated or fed by hydrous sulfate-rich oxidized basaltic-andesite magma. The shape of the irregular anhydrite blebs suggest that these inclusions could have been trapped as an immiscible sulfate- phosphate rich melt, despite the fact that anhydrite normally has a liquidus temperature of 1450°C and the host amphiboles crystallized at no more than 1050°C based on experiments on andesites and dacites.

  15. Airblast measurements, project diamond ore, Phase IIB

    International Nuclear Information System (INIS)

    Airblast measurements were made with two gages at each of three separate distances from the 20 cratering shots of Project Diamond Ore, Phase IIB. There were seven unstemmed single- charge shots, three unstemmed row-charge shots with three charges, three stemmed row-charge shots with five charges, two stemmed row-charge shots with three charges, and four shots with charges at or near the ground surface. Weights of individual charges ranged from 80 to 34,000 lbs. The unstemmed single-charge shots varied in depth of burial and permitted the attenuation of airblast parameters to be defined as a function of these depths. No comparison of the stemmed row-charge airblast with that from stemmed single charges was possible because no single charges have been fired in the same medium. No comparison was made for single-and row-charge unstemmed detonations because of differences in explosive, charge size, charge burial depth, and open-hole diameter. Differences in airburst from surface and near-surface bursts resulting from variances in charge position were less than differences caused by meteorological changes on the days the shots were fired. The single-charge data provided a further opportunity to evaluate the usefulness of airburst suppression with charge burial depth and stemming as an analog to suppression of radioactivity from nuclear cratering explosions. Airblast gas-venting impulse fractions out of the ground were in agreement with those obtained on one shot for radioactivity fraction using a radioactivity simulant. Airblast as an indicator of suppression has the advantage of being less dependent on local wind conditions. (U.S.)

  16. Quantitative phase analysis of iron ore concentrates

    Directory of Open Access Journals (Sweden)

    Geraldo Magela da Costa

    2002-10-01

    Full Text Available The quantification of goethite, magnetite, martite and specularite in iron ores was successfully achieved by a combination of wet chemical analysis and x-ray diffraction. It was found that the intensity of the goethite (111 peak is constant for a certain sample provided that the same sample holder is used. Calibration curves with a linear behavior have been derived using the areas of the above mentioned peak and the amounts of goethite obtained by Mössbauer spectroscopy and optical microscopy. In addition, the integral width of the hematite (012 line broadens linearly as the amount of martite increases, thus allowing an estimation of the amounts of martite and specularite.A quantificação de goetita, magnetita, martita e especularita em minérios de ferro foi realizada através de uma combinação de análises químicas e difração de raios X. Observou-se que a intensidade do pico de difração (111 da goetita é constante para uma determinada amostra, se o mesmo porta-amostras é utilizado. Curvas de calibração com um comportamento linear foram obtidas usando-se as áreas do pico (111 e as quantidades de goetita obtidas através da espectroscopia Mössbauer e microscopia ótica. Além disso, a largura integral do pico (012 da hematita aumenta linearmente com o aumento da quantidade de martita, permitindo, assim, uma estimativa dos teores de martita e especularita.

  17. Fluorosilicone and silicone o-ring aging study.

    Energy Technology Data Exchange (ETDEWEB)

    Bernstein, Robert; Gillen, Kenneth T.

    2007-10-01

    Fluorosilicone o-ring aging studies were performed. These studies examined the compressive force loss of fluorosilicone o-rings at accelerated (elevated) temperatures and were then used to make predictions about force loss at room temperature. The results were non-Arrhenius with evidence for a lowering in Arrhenius activation energies as the aging temperature was reduced. The compression set of these fluorosilicone o-rings was found to have a reasonably linear correlation with the force loss. The aging predictions based on using the observed curvature of the Arrhenius aging plots were validated by field aged o-rings that yielded degradation values reasonably close to the predictions. Compression set studies of silicone o-rings from a previous study resulted in good correlation to the force loss predictions for the fluorosilicone o-rings from this study. This resulted in a preliminary conclusion that an approximately linear correlation exists between compression set and force decay values for typical fluorosilicone and silicone materials, and that the two materials age at similar rates at low temperatures. Interestingly, because of the observed curvature of the Arrhenius plots available from longer-term, lower temperature accelerated exposures, both materials had faster force decay curves (and correspondingly faster buildup of compression set) at room temperature than anticipated from typical high-temperature exposures. A brief study on heavily filled conducting silicone o-rings resulted in data that deviated from the linear relationship, implying that a degree of caution must be exercised about any general statement relating force decay and compression set.

  18. 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

  19. Vinna Basin

    Czech Academy of Sciences Publication Activity Database

    Honěk, J.; Franců, J.; Mikuláš, Radek; Pešek, J.; Sýkorová, Ivana; Tomanová-Petrová, P.

    Prague: Czech Geological Survey, 2014, s. 223-241 ISBN 978-80-7075-862-5 R&D Projects: GA ČR GA105/06/0653 Institutional support: RVO:67985891 ; RVO:67985831 Keywords : Tertiary basins * Czech Republic * Cenomanian and Tertiary lignite * geology * stratigraphy Subject RIV: DB - Geology ; Mineralogy

  20. Fluids engineering

    International Nuclear Information System (INIS)

    Fluids engineering has played an important role in many applications, from ancient flood control to the design of high-speed compact turbomachinery. New applications of fluids engineering, such as in high-technology materials processing, biotechnology, and advanced combustion systems, have kept up unwaining interest in the subject. More accurate and sophisticated computational and measurement techniques are also constantly being developed and refined. On a more fundamental level, nonlinear dynamics and chaotic behavior of fluid flow are no longer an intellectual curiosity and fluid engineers are increasingly interested in finding practical applications for these emerging sciences. Applications of fluid technology to new areas, as well as the need to improve the design and to enhance the flexibility and reliability of flow-related machines and devices will continue to spur interest in fluids engineering. The objectives of the present seminar were: to exchange current information on arts, science, and technology of fluids engineering; to promote scientific cooperation between the fluids engineering communities of both nations, and to provide an opportunity for the participants and their colleagues to explore possible joint research programs in topics of high priority and mutual interest to both countries. The Seminar provided an excellent forum for reviewing the current state and future needs of fluids engineering for the two nations. With the Seminar ear-marking the first formal scientific exchange between Korea and the United States in the area of fluids engineering, the scope was deliberately left broad and general

  1. Flotation technology of refractory low-grade molybdenum ore

    Institute of Scientific and Technical Information of China (English)

    Du Shuhua; Luo Zhenfu

    2013-01-01

    Because of the low grade,high oxidation rate and the accumulation of little associated metal sulfide ore in the molybdenum concentrate during flotation,the Qingyang molybdenum ore is difficult to beneflciate.The experimental studies of grinding fineness,the amount of roughing modifier,depressant and collector were completed.In the cleaning process,the contrast experiments of one regrinding.the regrinding and scrubbing,two-stage regrinding was carried.The result shows that the grade of molybdenum ore concentrate is 45.31%,the recovery is 65.98% and the rich ore ratio reaches 20.59% by the regrinding and scrubbing seven cleaning,the regrinding of concentrations from middling of molybdenum-sulfur separation.The regularly-concentrated material from the apparatus was as the middling products.Hence,ideal beneficiation index can be obtained with a rational mineral processing,which offers new beneficiating technology for the refractory low-grade molybdenum ore in China.

  2. Existing State and Partitioning of Rare Earth on Weathered Ores

    Institute of Scientific and Technical Information of China (English)

    2005-01-01

    The existing state and partitioning of rare earth (RE) on weathered ores in Longnan County (LN), Xingfeng County(XF) and Ninghua County(NH) were characterized systematically by standard geological analytical methods. It is found that RE in the weathered rare earth ores exist as four phases: (a) water soluble, (b) ion-exchangeable, (c) colloidal sediment (oxides), (d) minerals, in which mainly as ion exchangeable phase, accounting for nearly 80% of total RE,with about 20% in the form of colloid sediment phase and mineral phase, but very little as aqueous soluble phase. These rare earth partitioning were mainly chosen mid-heavy RE elements, occupying above 60%, but not equal in the four phases. The mid-heavy RE elements were primarily enriched in the ion exchangeable phase up to 40%, while the containment of cerium dioxide is below 2%. The cerium deficiency occurs in the ion exchangeable phase in weathered ore. It results from that the Ce3+ is oxidized into Ce4+ and changes into CeO2. For LN ore, the containment of Y is high in weathered ore because Y-minerals are abundant in original rock.

  3. Microbial Beneficiation of Salem Iron Ore Using Penicillium purpurogenum

    Science.gov (United States)

    Mishra, M.; Pradhan, M.; Sukla, L. B.; Mishra, B. K.

    2011-02-01

    High alumina and silica content in the iron ore affects coke rate, reducibility, and productivity in a blast furnace. Iron ore is being beneficiated all around the world to meet the quality requirement of iron and steel industries. Choosing a beneficiation treatment depends on the nature of the gangue present and its association with the ore structure. The advanced physicochemical methods used for the beneficiation of iron ore are generally unfriendly to the environment. Biobeneficiation is considered to be ecofriendly, promising, and revolutionary solutions to these problems. A characterization study of Salem iron ore indicates that the major iron-bearing minerals are hematite, magnetite, and goethite. Samples on average contains (pct) Fe2O3-84.40, Fe (total)-59.02, Al2O3-7.18, and SiO2-7.53. Penicillium purpurogenum (MTCC 7356) was used for the experiment . It removed 35.22 pct alumina and 39.41 pct silica in 30 days in a shake flask at 10 pct pulp density, 308 K (35 °C), and 150 rpm. In a bioreactor experiment at 2 kg scale using the same organism, it removed 23.33 pct alumina and 30.54 pct silica in 30 days at 300 rpm agitation and 2 to 3 l/min aeration. Alumina and silica dissolution follow the shrinking core model for both shake flask and bioreactor experiments.

  4. 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

  5. Utilisation of iron ore tailings as aggregates in concrete

    Directory of Open Access Journals (Sweden)

    Francis Atta Kuranchie

    2015-12-01

    Full Text Available Sustainable handling of iron ore tailings is of prime concern to all stakeholders who are into iron ore mining. This study seeks to add value to the tailings by utilising them as a replacement for aggregates in concrete. A concrete mix of grade 40 MPa was prepared in the laboratory with water–cement ratio of 0.5. The concrete were cured for 1, 2, 3, 7, 14 and 28 days. The properties of the concrete such as workability, durability, density, compressive strength and indirect tensile strength were tested. A controlled mix of concrete was also prepared in similar way using conventional materials and the results were compared with the tailings concrete. It was found that the iron ore tailings may be utilised for complete replacement for conventional aggregates in concrete. The iron ore tailings aggregates concrete exhibited a good mechanical strength and even in the case of compressive strength, there was an improvement of 11.56% over conventional aggregates concrete. The indirect tensile strength did not improve against the control mix due high content of fines in the tailings aggregates but showed 4.8% improvement compared with the previous study where the conventional fine aggregates was partially replaced by 20% with iron ore tailings.

  6. Deformation and metamorphism of gold-sulphide lodes in the Bhukia–Jagpura gold prospect, Rajasthan: Implications for ore genesis

    Indian Academy of Sciences (India)

    S Deol; A Chattopadhyay; M Deb

    2014-02-01

    The role of polyphase deformation in controlling the emplacement of gold-quartz lodes in dilational regimes is demonstrated from the Proterozoic Bhukia–Jagpura gold prospect in south Rajasthan. Earlier researchers deciphered the gold-sulphide mineralisation event as synchronous to the second phase of deformation (D2) without convincing microstructural or metamorphic evidences. In this contribution, we correlate the deformation and metamorphic imprints in the host rocks with those in the gold-sulphide mineralised zone, and present a new interpretation for the relative timing of gold emplacement vis-á-vis deformation. The ore-forming process first involved layer-parallel influx of ore-bearing hydrothermal fluids along S1 schistosity in the host rocks, synkinematic with respect to the first phase of deformation (D1). This initial ore concentration experienced metamorphism isofacially (∼500° C at 5.3 kb) along with its host rocks during D1, and subsequently underwent extensive remobilisation, giving rise to gold-bearing silicified lodes along the hinges and axial surfaces of F2 folds during D2.

  7. 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

  8. 法国比利牛斯山Trimouns滑石-绿泥石矿床地质与成因%Geology and ore genesis of the Trimouns talc-chlorite ore deposit,Pyrénées,France

    Institute of Scientific and Technical Information of China (English)

    Ph de PARSEVAL; 蒋少涌; F FONTAN; 王汝成; F MARTIN; J FREEET

    2004-01-01

    位于法国比利牛斯山的nimouns矿床是世界上最大的滑石-绿泥石矿床之一.对该矿床形成的条件及滑石和绿泥石矿石的含量已较清楚.它是由不同类型的岩石通过热液交代蚀变而形成的,主要包括白云岩蚀变为滑石为主的矿石和硅铝质岩石(云母片岩和伟晶岩)蚀变为绿泥石为主的矿石.滑石矿石显示片理化结构(滑石片岩)或压实块状结构(块滑石).由伟晶岩蚀变而来的绿泥石矿石为呈绿色的球状矿体,而由云母片岩蚀变而来的绿泥石矿石呈块状或片理状、颜色为灰绿色和深灰色.本文对欧洲这个独一无二的滑石和绿泥石矿床的地质特征和成因进行了总结和讨论.流体包裹体研究表明成矿流体为高盐度(20 to30%eq.wt%NaCl)、中温(320℃)、压为为2.5kbars.磷钇矿和独居石的U-Pb定年结果表明,成矿年代为112~97Ma,成矿作用可能持续了16Ma以上.%The Trimouns deposit, in the French Pyr閚閑s, is one of the largest talc and chlorite exploitation in the world. The conditions of formation and concentration for talc and chlorite ores are now well known. The deposit consists the metasomatic alteration of various rocks, mainly dolostones altered into talc-dominant ore and silico-aluminous rocks (mica schists and pegmatites) into chlorite-dominant ore. The talc ore shows schisteous texture (talc schist) or in compact mass (steatite). The chlorite ore altered from pegmatite show green colors and ball bodies. The chlorite ores altered from mica schists are either massive or schisteous ores with graygreenish and dark gray colors. This paper summarizes the general geology and ore genesis of this exceptional talc and chlorite ore deposit in Europe. Fluid inclusion study shows high salinity of 20 to 30% eq. wt% NaCl, intermediate temperature of 320℃ and pressure of 2.5 kbars for the formation of Trimouns deposit. According to U-Pb dating on xenotime and monazite, the mineralization took

  9. A salt diapir-related Mississippi Valley-type deposit: The Bou Jaber Pb-Zn-Ba-F deposit, Tunisia: Fluid inclusion and isotope study

    Science.gov (United States)

    Bouhlel, Salah; Leach, David; Johnson, Craig A.; Marsh, Erin; Salmi-Laouar, Sihem; Banks, David A.

    2016-01-01

    simply by the evaporation of seawater to halite saturation and requires a dilution of more than two times by meteoric water. The higher K/Na values in fluid inclusions from barite suggest that the brines interacted with K-rich rocks in the basement or siliciclastic sediments in the basin. Carbonate gangue minerals (ankerite and calcite) have δ13C and δ18O values that are close to the carbonate host rock and indicate fluid equilibrium between carbonate host rocks and hydrothermal brines. The δ34S values for sphalerite and galena fall within a narrow range (1 to 10 ‰) with a bulk value of 7.5 ‰, indicating a homogeneous source of sulfur. The δ34S values of barite are also relatively homogeneous (22 ‰), with 6 ‰ higher than the δ34S of local and regional Triassic evaporites (15 ‰). The latter are believed to be the source of sulfate. Temperature of deposition together with sulfur isotope data indicate that the reduced sulfur in sulfides was derived through thermochemical sulfate reduction of Triassic sulfate via hydrocarbons produced probably from Late Cretaceous source rocks. The 87Sr/86Sr ratio in the Bou Jaber barite (0.709821 to 0.711408) together with the lead isotope values of Bou Jaber galena (206Pb/204Pb = 18.699 to 18.737;207Pb/204Pb = 15.635 to 15.708 and 208Pb/204Pb = 38.321 to 38.947) show that metals were extracted from homogeneous crustal source(s). The tectonic setting of the Bou Jaber ore deposit, the carbonate nature of the host rocks, the epigenetic style of the mineralization and the mineral associations, together with sulfur and oxygen isotope data and fluid inclusion data show that the Bou Jaber lead-zinc mineralization has the major characteristics of a salt diapir-related Mississippi Valley-type (MVT) deposit with superimposed events of fluorite and of barite deposition. Field relations are consistent with mineral deposition during the Eocene–Miocene Alpine orogeny from multiple hydrothermal events: (1) Zn

  10. 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)

  11. Metallogeny, exploitation and environmental impact of the Mt. Amiata mercury ore district (Southern Tuscany, Italy)

    Science.gov (United States)

    Rimondi, V.; Chiarantini, L.; Lattanzi, P.; Benvenuti, M.; Beutel, M.; Colica, A.; Costagliola, P.; Di Benedetto, F.; Gabbani, G.; Gray, John E.; Pandeli, E.; Pattelli, G.; Paolieri, M.; Ruggieri, G.

    2015-01-01

    The Mt. Amiata mining district (Southern Tuscany, Italy) is a world class Hg district, with a cumulate production of more than 100,000 tonnes of Hg, mostly occurring between 1870 and 1980. The Hg mineralization at Mt. Amiata is younger than 0.3 Ma, and is directly related to shallow hydrothermal systems similar to present-day geothermal fields of the region. There is likely a continuum of Hg deposition to present day, because Hg emission from geothermal power plants is on-going. In this sense, the Mt. Amiata deposits present some analogies with “hot-spring type” deposits of western USA, although an ore deposit model for the district has not been established. Specifically, the source of Hg remains highly speculative. The mineralizing hydrothermal fluids are of low temperature, and of essentially meteoric origin.

  12. Palaeoproterozoic metavolcanic and metasedimentary succession hosting the Dannemora iron ore deposits, Bergslagen region, Sweden

    Science.gov (United States)

    Dahlin, P.

    2012-04-01

    The Dannemora inlier constitutes some of the best preserved primary structures and textures in the metavolcanic and metasedimentary rocks in the Bergslagen region. The aim for this study was to define and interpret the primary textures and deposition environment to obtain a better understanding of the palaeoenvironment in which the Dannemora iron ore deposit formed. In addition, the region has been subjected to at least two fold episodes therefore the establishment of stratigraphy and younging directions were crucial for structural interpretations. The Bergslagen region, located in the south-central Sweden, represents a back-arc setting active c. 1.9 Ga and consisted of numerous large calderas, that accommodated pyroclastic deposits of great thicknesses. The Dannemora inlier is composed of the supracrustal the Dannemora Formation, which is dominated by of metavolcanic rocks and subordinated by marble. The succession is 700-800 m and is divided into a lower and an upper member. The latter hosts the second largest iron ore deposit in the Bergslagen region. The ore is hosted by manganiferous skarn and dolomitic carbonate (marble) and is situated within uppermost part of the upper member positioned in an isoclinal syncline. From reflection seismic imaging and 3-D processing, the ore has been interpreted to reach depths of c. 2000 m. The presence of an anticline west of the ore bearing syncline is suggested by the geochemical similarities of rock units. Undisturbed layers of ash-siltstone with normal grading and fluid-escape structures, units of pyroclastic density currents and ash-fall in the eastern part of the Dannemora inlier indicate subaqueous deposition below wave base of the upper member. Reworking of the volcaniclastic deposits is evident in e.g. channels and cross-bedding, on the other hand, implies deposition above wave base of the upper member in the central part of Dannemora inlier. The thickness of the marble in the eastern part is c. 80 m and in the

  13. Textured fluids

    OpenAIRE

    Guenther, Gerhard K.

    1995-01-01

    The rheology and development morphology of textured fluids have been investigated. The first fluid considered in this work was a liquid crystalline polymer consisting of isotropic and anisotropic solutions of poly-p-phenyleneterephthalamide (PPT) in sulfuric acid. The second textured fluid considered in this work was an immiscible polymer blend consisting of poly(ethylene terephthalate) (PET) and nylon 6,6. The role played by liquid crystalline order (LCO) and a polydomain ...

  14. The production and use of citric acid for the removal of potassium from the iron ore concentrate of the Sishen Iron Ore Mine, South Africa

    Directory of Open Access Journals (Sweden)

    Peter J. Williams

    2010-04-01

    Full Text Available The depletion of the richer iron ore worldwide has made it necessary to process lower quality iron ore. Certain substances, such as potassium, contained within the lower quality iron ore, have a detrimental effect on the smelting process during steel manufacturing. Therefore, international steel-making companies charge penalties when purchasing iron ore concentrates containing high concentrations of potassium. To date, lower quality iron ore has been blended with high quality iron ore in an attempt to alleviate the potassium concentrations in the export iron ore; however, the ratio of low quality iron ore to high quality iron ore is increasing, thereby becoming an escalating problem within the economic functioning of the Sishen Iron Ore Mine. It has, therefore, become necessary to develop an economically viable and environmentally friendly process to reduce the high potassium concentrations contained in the iron ore concentrate of the Sishen Iron Ore Mine. In this study, we compared solid substrate and submerged fermentation using Aspergillus niger for the production of citric acid, which is used for the chemical leaching of potassium from the iron ore concentrate. It was found that submerged fermentation proved to be more economical and efficient, producing a maximum citric acid concentration of 102.3 g/L in 96 h of fermentation. ‘Heap leaching’ simulation experiments were found to be uneconomical, due to the required addition of fungal growth medium every 5 days as a result of growth factor depletion within this time; however, this process removed 17.65% of the potassium from the iron ore concentrate. By contrast, chemical leaching of potassium from the iron ore concentrate proved to be most efficient when using a 1 mol citric acid leaching solution at 60 ºC, removing 23.53% of the potassium contained within the iron ore concentrate. Therefore, the most economical and efficient process for the removal of potassium from the iron

  15. Inversion structure and its contribution to sandstone uranium metallogenesis in southeast uplifted domain of Songliao basin

    International Nuclear Information System (INIS)

    Many positive inversion structures were developed during the end of Nenjiang period in southeast Songliao basin Main styles of inversion structures are inversion anticline in downfaulted and depression sequence, positive footwall and negative upthrown block in downfaulted sequence, negative footwall and upthrown block in downfaulted sequence, negative footwall and upthrown block in depression sequence. Structure inversions may contribute to sandstone uranium ore-formation because they changed the structure shape, physical properties, circulating way of groundwater, geochemical property of rocks in shallow depression layer of the basin and lead to the ascending migration of oil-gas, CO2. Thus, denudation window areas are favorable for sandstone uranium ore-formation and attention must be paid to denudation window areas in Southeast uplifted domain of Songliao basin. (authors)

  16. Fossil bacteria in Xuanlong iron ore deposits of Hebei Province

    Institute of Scientific and Technical Information of China (English)

    DAI Yongding; SONG Haiming; SHEN Jiying

    2004-01-01

    Discovered in Early Proterozoic Xuanlong iron ore deposits are six genera of fossil iron bacteria, i. e. sphere (coenobium of) rod-shaped (monomer) Naumanniella, ellipsoid elliptical Ochrobium, sphere spherical Siderocapsa and chain spherical Siderococcus, chain rod-shaped Leptothrix and Lieskeella, and six genera of fossil blue bacteria, namely sphere spherical Gloeocapsa, Synechocystis and Globobacter, chain spherical Anabaena and Nostoc, and constrictive septate tubular Nodularia. The biomineralized monomers and coenobia of the two categories of bacteria, together with hematite plates made up the bacteria pelletal, bacteria silky,bacteria fibrous and clasty bacteria pelletal textural lamina. The bacteria pelletal laminae combined with other bacteria laminae to make up oncolite, stromatolite and laminate. The precipitation of iron oxide was accelerated due to iron and blue bacteria cohabiting on microbial film or mat. The Xuanlong iron ore deposits are microbial binding ore deposits of ocean source.

  17. Investigation of chemical suppressants for inactivation of sulfide ores

    Institute of Scientific and Technical Information of China (English)

    2001-01-01

    In order to investigate the effective control method of spontaneous combustion in the mining of sulfide ore deposits, This paper presents the testing results of several selected chemicals (water glass, calcium chloride, calcium oxide, magnesium oxide and their composites) as oxidation suppressants for sulfide ores. A weight increment scaling method was used to measure suppressant performance, and this method proved to be accurate, simple and convenient. Based on a large number of experiments, the test results show that four types of chemical mixtures demonstrate a good performance in reducing the oxidation rate of seven active sulfide ore samples by up to 27% to 100% during an initial 76 d period. The mixtures of water glass mixed with calcium chloride and magnesium oxide mixed with calcium chloride can also act as fire suppressants when used with fire sprinkling systems.

  18. 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

  19. Calcination-Digestion-Desliming of Phosphorus Ore Bearing Rare Earth

    Institute of Scientific and Technical Information of China (English)

    Zhang Qin; Zhang Jie; Wang Jing; Qiu Yue qin

    2004-01-01

    The recoveries of phosphorus and RE of ore from Zhijin in Guizhou were studied.The influences of the calcination temperature, resident time, the digested time and water volume of the calcinating on concentrate yield by desliming were also investigated by orthogonal design.Appropriate calcination temperature is initial condition that makes carbonate mineral decomposition.The recovery of phosphorus is 83.02% and rare earth is 90.56% in phosphorus concentrate when calcined temperature is 900 ℃, other conditions include: calcined time is 30 min, digestion water volume is 300 ml, digestion time is 20 min.The results show that the pre-treatment of the ore is favorable for the separation and enrichment of rare earth from phosphorus ore, and a process of calcination-digestion-desliming was promised.

  20. Spectral Reflectance Features of Rocks and Ores and Their Applications

    Institute of Scientific and Technical Information of China (English)

    杨柏林; 王兴理

    1991-01-01

    The spectral reflectance features of rocks and minerals are correlated with their composition,col-or,grain size and surface state.Different wall rocks,altered rocks and ores have their spectral reflectance features,which are very helpful for the explanation of remote sensing data and searching for mineral deposits by remote sensing.After the treatment of spectrum data and searching for mineral deposits by remote sensing.After the treatment of spectrum data of rocks and ores and physical and chemical parameters in the mathematical statistics,we analyzed the laboratorial spectrum dataand put forward better wave bands(520-590,650-710,730-760,770-860,1560-1760,2200 and 2300-2400nm) for distinguishing rocks and ores.

  1. Environmental Mineralogy of the Kursk Iron Ore Deposit

    Science.gov (United States)

    Posukhova, Tatiana V.; Riakhovskaya, Sofiya K.

    The development of new technologies is one of the most effective ways to solve environmental problems related to ore-dressing. Complex mineralogical investigations are able to help in improving this process. In collaboration with researchers from the IPKON institute, we have developed an electrochemical method to improve the properties of crushed ores prepared for the wet magnetic separation. This article studies the samples before and after application of the electrochemical method. Surfaces of mineral grains investigated by the scanning electron microscopy show differences in flocculation. Measured polarization curves showed unequal electrochemical processes on surfaces of magnetite, hematite, and martite particles. X-ray analysis and Mössbauer data also confirmed the changes in compositions of the ores before and after using the electrochemical method. Magnetic properties of the studied species to be compared before and after the application of method showed relevant increase in parameters such as magnetic viscosity (Svo), breaking saturation field (Hcr), magnetic susceptibility (χ), and specific magnetization (Is).

  2. Decomposition of Niobium Ore by Sodium Hydroxide Fusion Method

    Science.gov (United States)

    Yang, Xiu-Li; Wang, Xiao-Hui; Wei, Chang; Zheng, Shi-Li; Sun, Qing

    2013-02-01

    The decomposition kinetics of niobium ore in the NaOH system was studied experimentally. The results show that the reaction products are sodium metaniobate and sodium niobate formed by the reaction of pyrochlore with sodium hydroxide under roasting. The effects of temperature, particle size, and mass ratio of alkali-to-ore were studied. The conversion rate of niobium exceeded 99 pct after 20 minutes at 923 K (650 °C) with a mass ratio of alkali-to-ore 1.2:1 and with initial particle size 75 to 106 μm. The kinetic study indicates that the shrinking core model is applicable and the process is controlled by a chemical reaction. The activation energy was calculated to be 78.82 kJ mol-1.

  3. 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)

  4. A hybrid decision support system for iron ore supply

    Directory of Open Access Journals (Sweden)

    A. Samolejová

    2012-01-01

    Full Text Available Many European metallurgical companies are forced to import iron ore from remote destinations. For these companies it is necessary to determine the amount of iron ore that will have to be ordered and to create such a delivery schedule so that the continuous operation of blast-furnace plant is not disrupted and there is no exceedingly large stock of this raw material. The objective of this article is to design the decision support system for iron ore supply which would effi ciently reduce uncertainty and risk of that decision-making. The article proposes a hybrid intelligent system which represents a combination of diff erent artifi cial intelligence methods with dynamic simulation technique for that purpose.

  5. 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

  6. Agitation leach experiment of fine ore and high grade concentrate

    International Nuclear Information System (INIS)

    Lab experiment and field pilot test were conducted on a slurry from the ore crushing and classification process prior to heap leaching and on a high grade concentrate through ore separation. 96% of uranium extraction can be reached for the slurry ore applying acid leaching. 99% of uranium can be extracted for the concentrate by acid leaching, with the acid consumption being quite high as considerable carbonate associated with the concentrate. While alkaline leaching was applied to the concentrate, only 70% of uranium extraction was approached though the recovery could be enhanced significantly with the temperature increasing. Liquid/solid separation of the leached slurry is feasible through filtration using filter press, with the treatment capacity up to 155 kg/(m2·d) and the washing efficiency over 99%. (authors)

  7. 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.

  8. 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

  9. 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.

  10. Note: O-ring stack system for electron gun alignment

    International Nuclear Information System (INIS)

    We present a reliable method for aligning an electron gun which consists of an electron source and lenses by controlling a stack of rubber O-rings in a vacuum condition. The beam direction angle is precisely tilted along two axes by adjusting the height difference of a stack of O-rings. In addition, the source position is shifted in each of three orthogonal directions. We show that the tilting angle and linear shift along the x and y axes as obtained from ten stacked O-rings are ±2.55° and ±2 mm, respectively. This study can easily be adapted to charged particle gun alignment and adjustments of the flange position in a vacuum, ensuring that its results can be useful with regard to electrical insulation between flanges with slight modifications

  11. Treatment of coking wastewater by using manganese and magnesium ores

    International Nuclear Information System (INIS)

    This study investigated a wastewater treatment technique based on natural minerals. A two-step process using manganese (Mn) and magnesium (Mg) containing ores were tested to remove typical contaminants from coking wastewater. Under acidic conditions, a reactor packed with Mn ore demonstrated strong oxidizing capability and destroyed volatile phenols, chemical oxygen demand (COD), and sulfide from the coking wastewater. The effluent was further treated by using Mg ore to remove ammonium-nitrogen and phosphate in the form of magnesium ammonium phosphate (struvite) precipitates. When pH of the wastewater was adjusted to 1.2, the removal efficiencies for COD, volatile phenol and sulfide reached 70%, 99% and 100%, respectively. During the second step of precipitation, up to 94% of ammonium was removed from the aqueous phase, and precipitated in the form of struvite with phosphorus. The struvite crystals showed a needle-like structure. X-ray diffraction and transmission electron microscopy were used to characterize the crystallized products.

  12. Phase transformation in suspension roasting of oolitic hematite ore

    Institute of Scientific and Technical Information of China (English)

    李艳军; 王儒; 韩跃新; 魏新超

    2015-01-01

    Suspension roasting followed by magnetic separation is a promising method to upgrade oolitic hematite ore. An oolitic hematite ore was roasted using suspension roasting technology at different temperatures. The phase transformation for iron minerals was investigated by XRD and Mossbauer spectrum, and the characteristics of roasted product were analyzed by VSM and SEM-EDS. Results indicate that the magnetic concentrate is of 58.73% Fe with iron recovery of 83.96% at 650 °C. The hematite is rapidly transformed into magnetite during the roasting with transformation ratio of 92.75% at 650 °C. Roasting temperature has a significant influence on the phase transformation of hematite to magnetite. The transformation ratio increases with increased temperature. After roasting, the magnetic susceptibility is significantly improved, while iron ore microstructure is not altered significantly.

  13. 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.)

  14. Fluid mechanics

    CERN Document Server

    Kundu, Pijush K; Dowling, David R

    2011-01-01

    Fluid mechanics, the study of how fluids behave and interact under various forces and in various applied situations-whether in the liquid or gaseous state or both-is introduced and comprehensively covered in this widely adopted text. Revised and updated by Dr. David Dowling, Fluid Mechanics, 5e is suitable for both a first or second course in fluid mechanics at the graduate or advanced undergraduate level. Along with more than 100 new figures, the text has been reorganized and consolidated to provide a better flow and more cohesion of topics.Changes made to the

  15. 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

  16. 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)

  17. Experimental Study of the Distribution of Au and Cu in Aqueous Vapor Phase at High Temperatures and Its Role on Ore-forming Transportation

    Institute of Scientific and Technical Information of China (English)

    ZHANG Ronghua; HU Shumin; ZHANG Xuetong

    2008-01-01

    This study focuses on experiments of Au and Cu dissolved in vapor phase in hydrothernmlfluids. Experiments prove that Au and Cu can re-distribute in vapor phase and liquid phase duringseparation of Au- and Cu-bearing supercriticai fluids to vapor and liquid phases. These experimentalresults can illustrate some ore geneses, where boiling phenomena of ore fluids were found. Au- and Cu-bearing NaHCO3-HCl solutions were heated up to more than 350℃ in the main vessel, and then passedthrough a phase separator in a temperature range from 250oC to 300℃, separated into vapor andliquid phases. We collected and analyzed the liquid and vapor samples separately, and found that Auand Cu dissolved and distributed in vapor phase. In some cases, the concentrations of Au and Cu invapor are higher than those in liquid phase. Those experiments are used to interpret field observationsof fluid inclusion data of some Au and Cu deposits, and demonstrate that some Au and Cu ore depositsare derived from metals transportation in vapor phase.

  18. Isolation and identification of iron ore-solubilising fungus

    Directory of Open Access Journals (Sweden)

    Damase Khasa

    2010-09-01

    Full Text Available Potential mineral-solubilising fungi were successfully isolated from the surfaces of iron ore minerals. Four isolates were obtained and identified by molecular and phylogenetic methods as close relatives of three different genera, namely Penicillium (for isolate FO, Alternaria (for isolates SFC2 and KFC1 and Epicoccum (for isolate SFC2B. The use of tricalcium phosphate (Ca3(PO42in phosphate-solubilising experiments confirmed isolate FO as the only phosphate solubiliser among the isolated fungi. The bioleaching capabilities of both the fungus and its spent liquid medium were tested and compared using two types of iron ore materials, conglomerate and shale, from the Sishen Iron Ore Mine as sources of potassium (K and phosphorus (P. The spent liquid medium removed more K (a maximum of 32.94% removal, from conglomerate, than the fungus (a maximum of 21.36% removal, from shale. However, the fungus removed more P (a maximum of 58.33% removal, from conglomerate than the spent liquid medium (a maximum of 29.25% removal, from conglomerate. The results also indicated a potential relationship between the removal of K or P and the production of organic acids by the fungus. A high production of gluconic acid could be related to the ability of the fungus to reduce K and P. Acetic, citric and maleic acids were also produced by the fungus, but in lower quantities. In addition, particle size and iron ore type were also shown to have significant effects on the removal of potassium and phosphorus from the iron ore minerals. We therefore conclude that the spent liquid medium from the fungal isolate FO can potentially be used for biobeneficiation of iron ore minerals.

  19. [Assessment of Soil Fluorine Pollution in Jinhua Fluorite Ore Areas].

    Science.gov (United States)

    Ye, Qun-feng; Zhou, Xiao-ling

    2015-07-01

    The contents of. soil total fluorine (TF) and water-soluble fluorine (WF) were measured in fluorite ore areas located in Jinhua City. The single factor index, geoaccumulation index and health risk assessment were used to evaluate fluorine pollution in soil in four fluorite ore areas and one non-ore area, respectively. The results showed that the TF contents in soils were 28. 36-56 052. 39 mg.kg-1 with an arithmetic mean value of 8 325.90 mg.kg-1, a geometric mean of 1 555. 94 mg.kg-1, and a median of 812. 98 mg.kg-1. The variation coefficient of TF was 172. 07% . The soil WF contents ranged from 0. 83 to 74. 63 mg.kg-1 with an arithmetic mean value of 16. 94 mg.kg-1, a geometric mean of 10. 59 mg.kg-1, and a median of 10. 17 mg.kg-1. The variation coefficient of WF was 100. 10%. The soil TF and WF contents were far higher than the national average level of the local fluorine epidemic occurrence area. The fluoride pollution in soil was significantly affected by human factors. Soil fluorine pollution in Yangjia, Lengshuikeng and Huajie fluorite ore areas was the most serious, followed by Daren fluorite ore area, and in non-ore area there was almost no fluorine pollution. Oral ingestion of soils was the main exposure route. Sensitivity analysis of model parameters showed that children's weight exerted the largest influence over hazard quotient. Furthermore, a significant positive correlation was found among the three kinds of evaluation methods. PMID:26489337

  20. Geologic feature and exploration vista of leachable sandstone type uranium deposit in Husiliang area of Erdos basin

    International Nuclear Information System (INIS)

    Based on the elaboration of geologic setting, ore-hosting strata, distribution of sand body, paleo interlayer oxidation zone and uranium mineraliation in Husiliang area of Erdos basin, this paper has summarized the uranium metallization condition and exploration orientation. In the western Nalinggou district the orebody was found mainly the lower part of the roll which may be the westward extention part of Zaohuohao ore belt and its roll front might locate at the south, the orebody is deeply buried and hard to control, however, this district is expected to become a large uranium ore belt. In the eastern Nongsh- engxin district, uranium mineralization occurred in the north banks of braided river channel and was con- trolled by the rudimental sand body of gray colour, the orebody was shallow buried in strata of favourable sediment combinatin, this district is expected to become a new uranium ore belt. (authors)