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

International Nuclear Information System (INIS)

Ji Zengxian

2006-01-01

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

Genesis of iron-apatite ores in Posht-e-Badam Block (Central Iran) using REE geochemistry

Science.gov (United States)

Mokhtari, Mir Ali Asghar; Zadeh, Ghader Hossein; Emami, Mohamad Hashem

2013-06-01

Rare earth elements in apatites of different ore types show characteristic patterns which are related to different modes of formation of the ores. Most of the apatite-bearing iron ores are associated with alkaline magmas with LREE/HREE fractionation varying from moderate to steep. Iron-apatite deposits in Posht-e-Badam Block (Central Iran) have a high concentration of REE (more than 1000 ppm up to 2.5%), and show a strong LREE/HREE ratio with a pronounced negative Eu anomaly. This REE pattern is typical of magmatic apatite and quiet distinct from sedimentary apatites (phosphorites) which have a low REE contents and Ce negative anomalies. On the other hand, they are comparable to the REE patterns of apatites in Kiruna-type iron ores in different parts of the world. The REE patterns of apatites, iron-apatite ores and iron ores are similar and only have different REE contents. This similarity indicates a genetic relation for these rocks. Most of the iron-apatite deposits in Central Iran have similar REE patterns too, which in turn show a genetic relation for all of these deposits. This similarity indicates a similar origin and processes in their genesis. There are some small intrusions around some of the iron-apatite deposits that are petrographically identified as syenite and gabbro. These intrusions also have REE patterns similar to that of iron-apatite ores. This demonstrates a genetic relation between these intrusions and iron-apatite ores. The REE patterns of apatites in different deposits of Posht-e-Badam Block iron-apatite ores show an affinity to alkaline to sub-alkaline magmas and rifting environment. The alkaline host rocks of Central Iran iron-apatite ores are clearly related to an extensional setting where rifting was important (SSE-NNW fault lines). A probable source for this large scale ore forming processes is relatively low partial melting of mantle rocks. The ores have originated by magmatic differentiation as a late phase in the volcanic cycle

Zeolitization at uranium ore manifestation

International Nuclear Information System (INIS)

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

1981-01-01

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

Nanoscale Study of Clausthalite-Bearing Symplectites in Cu-Au-(U Ores: Implications for Ore Genesis

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Nicholas D. Owen

2018-02-01

Full Text Available Symplectites comprising clausthalite (PbSe and host Cu-(Fe-sulphides (chalcocite, bornite, and chalcopyrite are instructive for constraining the genesis of Cu-Au-(U ores if adequately addressed at the nanoscale. The present study is carried out on samples representative of all three Cu-(Fe-sulphides displaying clausthalite inclusions that vary in size, from a few µm down to the nm-scale (<5 nm, as well as in morphology and inclusion density. A Transmission Electron Microscopy (TEM study was undertaken on foils prepared by Focussed Ion Beam and included atom-scale High-Angle Annular Dark-Field Scanning TEM (HAADF-STEM imaging. Emphasis is placed on phase relationships and their changes in speciation during cooling, as well as on boundaries between inclusions and host sulphide. Three species from the chalcocite group (Cu2–xS are identified as 6a digenite superstructure, monoclinic chalcocite, and djurleite. Bornite is represented by superstructures, of which 2a and 4a are discussed here, placing constraints for ore formation at T > 265 °C. A minimum temperature of 165 °C is considered for clausthalite-bearing symplectites from the relationships with antiphase boundaries in 6a digenite. The results show that alongside rods, blebs, and needle-like grains of clausthalite within the chalcocite that likely formed via exsolution, a second, overprinting set of replacement textures, extending down to the nanoscale, occurs and affects the primary symplectites. In addition, other reactions between pre-existing Se, present in solid solution within the Cu-(Fe-sulphides, and Pb, transported within a fluid phase, account for the formation of composite, commonly pore-attached PbSe and Bi-bearing nanoparticles within the chalcopyrite. The inferred reorganisation of PbSe nanoparticles into larger tetragonal superlattices represents a link between the solid solution and the symplectite formation and represents the first such example in natural materials

Neotethyan rifting-related ore occurrences: study of an accretionary mélange complex (Darnó Unit, NE Hungary

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Kiss Gabriella B.

2016-02-01

Full Text Available The geology of the NE Hungarian Darnó Unit is rather complicated, as it is composed mostly of a Jurassic accretionary mélange complex, according to the most recent investigations. The magmatic and sedimentary rock blocks of the mélange represent products of different evolutionary stages of the Neotethys; including Permian and Triassic sedimentary rocks of marine rifting related origin, Triassic pillow basalt of advanced rifting related origin and Jurassic pillow basalt originated in back-arc-basin environment. This small unit contains a copper-gold occurrence in the Permian marly-clayey limestone, an iron enrichment in the Triassic sedimentary succession, a copper-silver ore occurrence in Triassic pillow basalts and a copper ore indication, occurring both in the Triassic and Jurassic pillow basalts. The present study deals with the Cu(-Ag occurrence in the Triassic basalt and the Fe occurrence in the Triassic sedimentary succession. The former shows significant similarities with the Michigan-type mineralizations, while the latter has typical characteristics of the Fe-SEDEX deposits. All the above localities fit well into the new geological model of the investigated area. The mineralizations represent the different evolutionary stages of the Neotethyan rifting and an epigenetic, Alpine metamorphism-related process and their recent, spatially close position is the result of the accretionary mélange formation. Thus, the Darnó Unit represents a perfect natural laboratory for studying and understanding the characteristic features of several different rifting related ore forming processes.

Dynamics of uranium ore formation in the basement and frame of the Streltsovskaya Caldera

International Nuclear Information System (INIS)

Petrov, V.; Schukin, S.

2014-01-01

The analysis of geological-geophysical, paleo-geodynamics, mineralogical, geochemical, isotope, geochronological, and thermo-baro-geochemical data allow us to offer a model of uranium ore formation dynamics in the basement and frame of the Streltsovskaya Caldera connected to activity of the fluid-conducting fault zones network with the aim to identify prospective areas The most ancient fluid-conducting structures are inter-block NE-SW, NNE-submeridional, NW-SE and, probably, WNW-sub-latitudinal faults. The oldest NE-SW faults and schistosity zones were formed during Proterozoic tectonic cycle (TC) with reactivation in T3-J2 time due to global reorganization of stress field and reactivation of tectonic movements. The NNE-submeridional and NW-SE faults were extended with increased fluid permeability during Caledonian and Variscan TCs. They also were reactivated in the process of Late Mesozoic tectonic and magmatic activation (TMA). Thus already at early stages of geotectonic evolution within the intersection of NE-SW (N-Urulyunguyevskiy fault) and NNE-submeridional (Chindachinskaya zone) faults the areas of increased fluid and magmatic activity were formed. The dynamics of fault formation in the basement and frame of the Streltsovskaya caldera and its volcano-sedimentary cover differs. In the basement and granite framework NE-SW, NNEsubmeridional and NW-SE faults are interblock structures of the I rank. Their intersection formed areas of long-term circulation of hydrothermal solutions and telescopic appearance of multi-age metasomatites that created conditions for localizing of vein-stockwork mineralization. In volcanosedimentary cover the NE-SW and NNE-submeridional faults should be considered as interblock structures of the I rank where intersections provided inflow of ore-bearing solutions and their redistribution within the cover. Here the main ore distributing role belongs to NW-SE shears. They are intrablock II rank structures which were formed due to dextral

Mineralogical-Geochemical Peculiarities of Ores in Pyritaceous Fields of Filizchai Type in the Greater Caucasus

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NOVRUZ A. NOVRUZOV

2010-12-01

Full Text Available Pyritaceous fields of the south slope of the Greater Caucasus confined to the Lower-Middle Jurassic sandy clayey deposits are: polygenic polychrone formations which were formed by a complex of hydrothermal sedimentary, hydrothermal metasomatic and hydrothermal metamorphogenic processes of ore formation. Filizchai pyritaceous polymetallic field is the largest in the region and can be characterized by diversity of texture-mineralogical types of ores, rich mineral composition and with geochemical spectrum. Some of the admixture components (Cd, In, Tl, Ga, Ge, Se, Hg are only in isomorphic forms in ores, others (Te, Bi, Au, Ag, Co, Sn, As along with it characterize in their own minerals. The Co is mainly concentrated in pyrite, pyrrhotine; Ag, Bi and also Te – in galenite and chalcopyrite; Se – in pyrite, pyrrhotine and galenite; in sphalerite (mainly in marmatite and chalcopyrite; Cd, Ga, Ge – in sphalerite, mainly in cleiophane; Au – in pyrite and chalcopyrite; Tl – in galenite and colloform pyrite. In all sulphides selenium prevails over tellurium (excepting the late chalcopyrite and cobalt over nickel. Maximum amount of cobalt is confined to pyrite from pyritaceous polymetallic ores and late generation of pyrrhotine. The nature of the connection between chemical elements in ores coordinates with determined stages of minerals formation. The main productive stage of ore formation bringing the main mass of gold, silver, rare and other precious components of ores are sulphosalt polymetallic stage of sulphur ploymetallic stage. Comparative analysis of absolute content of gold, silver and values of gold-silver relation in pyrite fields ores of region with appropriate values in meteorite standard indirectly indicates the relationship between gold-silver mineralization and assimilation crust source.

Mantle geofluid and uranium ore-formation model

International Nuclear Information System (INIS)

Wu Jianhua; Liu Shuai; Yu Dagan; Zhang Bangtong

2005-01-01

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

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

with kaolinite and gibbsite, which make it low grade. Massive iron ores are devoid of any lamination and usually associated with BHJ and lower shale. The thickness of the massive ore layer varies with the location. The massive iron ore grades in to well-developed bedded BHJ in depth. Blue dust occurs in association with BHJ as pockets and layers. Although blue dust and friable ore are both powdery ores, and subjected to variable degree of deformation, leading to the formation of folding, faulting and joints of complex nature produce favourable channels. Percolating water play an important role in the formation of blue dust and the subterranean solution offers the necessary acidic environment for leaching of quartz from the BHJ. The dissolution of silica and other alkalis are responsible for the formation of blue dust. The friable and powdery ore on the other hand are formed by soft laminated ore. As it is formed from the soft laminated ore, its alumina content remains high similar to soft laminated ore compaired to blue dust. Mineralogy study suggests that magnetite was the principal iron oxide mineral, now a relict phase whose depositional history is preserved in BHJ, where it remains in the form of martite. The platy hematite is mainly the product of martite. The different types of iron ores are intricately related with the BHJ. Hard laminated ores, martite-goethite ore and soft laminated ore are resultant of desilicification process through the action of hydrothermal fluids. Geochemistry of banded iron-formations of the Noamundi-Koira iron ore deposits shows that they are detritus-free chemical precipitates. The mineralogical and geochemical data suggest that the hard laminated, massive, soft laminated ores and blue dust had a genetic lineage from BIF's aided with certain input from hydrothermal activity. The comparative study of major elemental composition of the basin samples and while plotting a binary diagram, it shows a relation between major oxides against

87Sr enrichment of ophiolitic sulphide deposits in Cyprus confirms ore formation by circulating seawater

International Nuclear Information System (INIS)

Chapman, H.J.; Spooner, E.T.C.

1977-01-01

The hypothesis that seawater was the source of the hydrothermal fluid which formed the Upper Cretaceous ophiolitic cupriferous pyrite ore deposits of the Troodos Massif (Cyprus) has been tested by analysing the strontium isotopic composition of thirteen mineralized samples from four mines. Initial 87 Sr/ 86 Sr ratios range from 0.7052+-0.0001 to 0.7075+-0.00002, the latter value being indistinguishable from that of Upper Cretaceous seawater at 0.7076+-0.0006 (2 sigma). Hence, the mineralized metabasalt samples have been contaminated with 87 Sr, relative to initial magmatic strontium isotope ratios of the Troodos ophiolitic complex (0.70338+-0.00010 to 0.70365+-0.00005). Since seawater was the only source of strontium available during formation of the Troodos Complex which was isotopically relatively enriched in 87 Sr, the data confirm that seawater was the source of the hydrothermal oreforming fluid. (Auth.)

Complex mineralization at large ore deposits in the Russian Far East

Science.gov (United States)

Schneider, A. A.; Malyshev, Yu. F.; Goroshko, M. V.; Romanovsky, N. P.

2011-04-01

Genetic and mineralogical features of large deposits with complex Sn, W, and Mo mineralization in the Sikhote-Alin and Amur-Khingan metallogenic provinces are considered, as well as those of raremetal, rare earth, and uranium deposits in the Aldan-Stanovoi province. The spatiotemporal, geological, and mineralogical attributes of large deposits are set forth, and their geodynamic settings are determined. These attributes are exemplified in the large Tigriny Sn-W greisen-type deposit. The variation of regional tectonic settings and their spatial superposition are the main factor controlling formation of large deposits. Such a variation gives rise to multiple reactivation of the ore-magmatic system and long-term, multistage formation of deposits. Pulsatory mineralogical zoning with telescoped mineral assemblages related to different stages results in the formation of complex ores. The highest-grade zones of mass discharge of hydrothermal solutions are formed at the deposits. The promising greisen-type mineralization with complex Sn-W-Mo ore is suggested to be an additional source of tungsten and molybdenum. The Tigriny, Pravourminsky, and Arsen'evsky deposits, as well as deposits of the Komsomol'sk and Khingan-Olonoi ore districts are examples. Large and superlarge U, Ta, Nb, Be, and REE deposits are localized in the southeastern Aldan-Stanovoi Shield. The Ulkan and Arbarastakh ore districts attract special attention. The confirmed prospects of new large deposits with Sn, W, Mo, Ta, Nb, Be, REE, and U mineralization in the south of the Russian Far East assure expediency of further geological exploration in this territory.

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

International Nuclear Information System (INIS)

Zhao Honggang

2005-01-01

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

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

International Nuclear Information System (INIS)

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

1995-01-01

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

Geophysical signature recognition of aquifuge and relatively impermeable interbed in ore-hosting sandstone layer at sandstone-type uranium deposit

International Nuclear Information System (INIS)

Zhao Xigang; Wu Hanning; Bai Guanjun; Zhu Huanqiao; Jia Heng

2006-01-01

Geophysical signature recognition of aquifuge and relatively impermeable interbed in ore-hosting aquifer has been carried out a Shihongtan uranium deposit by using comprehensive logging data. The spatial distribution of above aquifuge and impermeable interbed is discussed, and the relation of these layers to sandstone-type uranium deposit, and their impact to in-situ leach mining technology are discussed. It is suggested that the aquifuge and relatively impermeable interbed bring about significant effect to the formation of interlayer oxidation zone sandstone-type uranium deposit, as well as to in-situ leach mining of the deposit. (authors)

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

Science.gov (United States)

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

2017-09-01

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

Evolution of Xihulitu basin and its control to uranium ore-formation

International Nuclear Information System (INIS)

Guo Qingyin; Li Ziying; Dong Wenming

2003-01-01

There is a close relationship between basin filling succession and evolution of the basin. Characteristics of basin evolution can be studied by analyzing the basin filling succession. Two major periods are recognized according to the filling succession and subsequent alteration of the Xihulitu Basin. Evolutionary characteristics of each stage of the basin formation and alteration have been discussed in details. The types and special distribution of uranium metallization are controlled by the scale, connection degree and distribution of sandstone units and impermeable mudstone beds. The environment of uranium ore-formation became favorable as the faults modified the hydrodynamic condition. The basin had been uplifted for a long time after it was filled. Intergranular pores are not destroyed due to the weak mechanical compaction, which is beneficial to groundwater penetrating. Montmorillonitization and zeolitization in some sandstone units are strong because of the high content of volcanic fragments. The major uranium metallization is the phreatic oxidation type. The northern zone of the second sub-basin in the central section of the basin is regarded as the first perspective target for subsequent exploration. (authors)

The North American iron ore industry: a decade into the 21st century

Science.gov (United States)

Jorgenson, John D.; Perez, A. A

2011-01-01

During the 20th century, the iron ore mining industries of Canada and the United States passed through periods of transformation. The beginning of the 21st century has seen another period of transformation, with the failure of a number of steel companies and with consolidation of control within the North American iron ore industry. Canadian and United States iron ore production and the market control structure involved are changing rapidly. Consolidation of ownership, formation of foreign joint ventures, divestitures of upstream activities by steelmakers, and industry changes to ensure availability of feedstocks all played a role in recent developments in the North American iron ore industry. Canadian and U.S. iron ore operations and their strong linkage to downstream production, although isolated, must also be considered within the context of the changing global economy. Projects using new technology to produce direct reduced iron nuggets of 96-98% iron content and other projects designed to produce steel at minesites may once again change the face of the iron ore industry. Social and environmental issues related to sustainable development have had a significant effect on the North American iron ore industry.

Challenges facing the North American iron ore industry

Science.gov (United States)

Jorgenson, J.D.

2005-01-01

During the 20th century, the iron ore mining industries of Canada and the United States passed through several periods of transformation. The beginning of the 21st century has seen yet another period of transformation, with the economic failure of a number of steel companies, the acquisition of their facilities by more viable steelmakers, and the consolidation of control within the North American iron ore industry. Changes in Canadian and United States iron ore production and the market control structure involved are analysed. The consolidation of ownership, formation of foreign joint ventures within Nordi America, planned divestitures of upstream activities by steelmakers, and industry changes made to ensure availability of feedstocks will be reviewed. The ttaditional isolation of the Canadian and United States iron ore operations and their strong linkage to downstream steel production will be discussed in the context of a changing global economy. Management-labour conflicts that have taken place and agreements made during 2000 through 2004 will be discussed in the context of the economic environment leading up to these agreements. Cooperative agreements between competing Canadian and United States companies to resolve client needs in processing and blending will be examined. A joint industry-government project designed to use new technology to produce direct reduced iron nuggets of 96 - 98 per cent iron content using non-coking coals will also be assessed. Changes in iron ore transportation methods, ownership and infrastructure will be reviewed for both rail and inland waterway transport between Canadian and United States companies. A brief analysis of social and environmental issues relating to sustainable development of the Canadian-United States iron ore industry will be included.

The study of ore minerals parageneses in Ponorogo area, East Java

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Wiwik Dyah Hastuti Endang

2017-01-01

Full Text Available The present study was undertaken in the Southern Mountain Range of East Jawa, Ponorogo District. Tectonically, the region extends along the Magmatic Sunda-Banda Arc, which comprises predominantly volcanic rocks of Mandalika Formation, sedimentary rock units of Arjosari Formation, and intrusive sequences such as dacite, andesite and diorite. Structurally, the region is controlled by faults striking NE-SW, NW-SE and N-S. Mandalika Formation and Arjosari Formation have an interfingering relation and are Oligo-Miocene. Results of the field observation and analyses of petrography and mineragraphy on outcrops reveal that the region has commonly undergone alteration and mineralisation. The principle ore minerals occurring in the Ponorogo area are pyrite and sphalerite with abundant mineral assemblages of chalcopyrite, magnetite, hematite, galena, covelite, bornite, and limonite. Mineralisation occurs in argillic zone and subprophyllitic zone. Based on textures, structures and ore mineral assemblages, mineralisation in the study area can be devided at least into two stages. The earlier stage was present in relation to hypogene processes, and resulted in pyrite–sphalerite–chalcopyrite–magnetite– galena. The subsequent stage took place due to supergene enrichment processes, and yielded pyrite– sphalerite–covelite–bournite–limonite. Such mineral assemblages suggest that they are formed at temperatures of about 100–360° C.

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

Energy Technology Data Exchange (ETDEWEB)

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

1993-03-01

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

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

International Nuclear Information System (INIS)

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

1993-03-01

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

Basic feature of host rock and its relation to the formation of leachable sandstone type uranium deposit in Shihongtan

International Nuclear Information System (INIS)

Quan Zhigao; Zhang Jiamin; Ji Haijun; Sun Yanhuan; Zhang Fa

2012-01-01

Basic feature of sedimentology and petrology and lithogeochemistry of middle Jurassic Xishanyao formation were discussed for Shihongtan uranium deposit in the paper. The relation between host rock and ore formation was analysed. It is indicated that the formation of Shihongtan uranium deposit de-ponds on the following host features in sedimentology, petrology, lithogeochemistry and the intense oxidized epigenetic alteration under hot dry climate condition during the formation of peneplain caused by the slow tilting uplift. (authors)

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

International Nuclear Information System (INIS)

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

2012-01-01

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

The genesis of ores

International Nuclear Information System (INIS)

Brimhall, G.

1991-01-01

Human history and technology have been shaped by metals. How did they become concentrated in minable deposits located so conveniently near the earth's surface? The author explains the mechanisms of fluid transport-by magma, water and even air and wind-responsible for the chemical and physical interactions that created bodies of metallic ores throughout geologic history. From their formation to their modification at the surface of the earth, ore deposits are geologically transitory and reflect dynamic processes within the earth as well as atmospheric and climatic influences on hydrologic systems. As highly reactive supracrustal systems, they then serve as geochemical sensors providing a powerful record and set of tracer elements for deducing the history, transport paths and forces operative in the crust

Sedimentary exhalative nickel-molybdenum ores in south China

Science.gov (United States)

Lott, D.A.; Coveney, R.M.; 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.

A study of the distribution of rare-metals in kuroko-type ore

International Nuclear Information System (INIS)

Murao, S.; Sie, S.H.; Suter, G.F.

1996-01-01

We have performed PIXE analysis of kuroko-type ore from the JADE hydrothermal site of the Okinawa Trough, Japan using the proton microprobe (PIXEPROBE). We analysed five kinds of ores dredged from the sea floor: (I) barite ore with small sulfide dissemination; (2) sphalerite-pyrite chimney; (3) pyrite ore; (4) sulfide veinlets in strongly altered rock; and (5) pyrite megacrystals in strongly altered rock. The analyses revealed that the trace element distribution is regulated by the occurrence mode of the ore, and within each ore, by the crystal structure. The distribution suggests that the hydrothermal system for kuroko ore formation is quite heterogeneous and its chemistry is controlled by local factors such as difference in temperature, and that in-situ PIXE analyses are essential for effective beneficiation strategy for the rare-metals from kuroko-type ore. (authors). 10 refs., 1 tab

A study of the distribution of rare-metals in kuroko-type ore

Energy Technology Data Exchange (ETDEWEB)

Murao, S. [Commonwealth Scientific and Industrial Research Organisation (CSIRO), North Ryde, NSW (Australia). Div. of Exploration Geoscience]|[Geological Survey of Japan, Tsukuba, Ibaraki (Japan); Sie, S.H.; Suter, G.F. [Commonwealth Scientific and Industrial Research Organisation (CSIRO), North Ryde, NSW (Australia). Div. of Exploration Geoscience

1996-12-31

We have performed PIXE analysis of kuroko-type ore from the JADE hydrothermal site of the Okinawa Trough, Japan using the proton microprobe (PIXEPROBE). We analysed five kinds of ores dredged from the sea floor: (I) barite ore with small sulfide dissemination; (2) sphalerite-pyrite chimney; (3) pyrite ore; (4) sulfide veinlets in strongly altered rock; and (5) pyrite megacrystals in strongly altered rock. The analyses revealed that the trace element distribution is regulated by the occurrence mode of the ore, and within each ore, by the crystal structure. The distribution suggests that the hydrothermal system for kuroko ore formation is quite heterogeneous and its chemistry is controlled by local factors such as difference in temperature, and that in-situ PIXE analyses are essential for effective beneficiation strategy for the rare-metals from kuroko-type ore. (authors). 10 refs., 1 tab.

A study of the distribution of rare-metals in kuroko-type ore

Energy Technology Data Exchange (ETDEWEB)

Murao, S [Commonwealth Scientific and Industrial Research Organisation (CSIRO), North Ryde, NSW (Australia). Div. of Exploration Geoscience; [Geological Survey of Japan, Tsukuba, Ibaraki (Japan); Sie, S H; Suter, G F [Commonwealth Scientific and Industrial Research Organisation (CSIRO), North Ryde, NSW (Australia). Div. of Exploration Geoscience

1997-12-31

We have performed PIXE analysis of kuroko-type ore from the JADE hydrothermal site of the Okinawa Trough, Japan using the proton microprobe (PIXEPROBE). We analysed five kinds of ores dredged from the sea floor: (I) barite ore with small sulfide dissemination; (2) sphalerite-pyrite chimney; (3) pyrite ore; (4) sulfide veinlets in strongly altered rock; and (5) pyrite megacrystals in strongly altered rock. The analyses revealed that the trace element distribution is regulated by the occurrence mode of the ore, and within each ore, by the crystal structure. The distribution suggests that the hydrothermal system for kuroko ore formation is quite heterogeneous and its chemistry is controlled by local factors such as difference in temperature, and that in-situ PIXE analyses are essential for effective beneficiation strategy for the rare-metals from kuroko-type ore. (authors). 10 refs., 1 tab.

Silicophosphate Sorbents, Based on Ore-Processing Plants' Waste in Kazakhstan

Science.gov (United States)

Kubekova, Sholpan N.; Kapralova, Viktoria I.; Telkov, Shamil A.

2016-01-01

The problem of ore-processing plants' waste and man-made mineral formations (MMF) disposal is very important for the Republic of Kazakhstan. The research of various ore types (gold, polymetallic, iron-bearing) MMF from a number of Kazakhstan's deposits using a complex physical and chemical methods showed, that the waste's main components are…

The role of magmas in the formation of hydrothermal ore deposits

Science.gov (United States)

Hedenquist, Jeffrey W.; Lowenstern, Jacob B.

1994-01-01

Magmatic fluids, both vapour and hypersaline liquid, are a primary source of many components in hydrothermal ore deposits formed in volcanic arcs. These components, including metals and their ligands, become concentrated in magmas in various ways from various sources, including subducted oceanic crust. Leaching of rocks also contributes components to the hydrothermal fluid—a process enhanced where acid magmatic vapours are absorbed by deeply circulating meteoric waters. Advances in understanding the hydrothermal systems that formed these ore deposits have come from the study of their active equivalents, represented at the surface by hot springs and volcanic fumaroles.

Effective Processing of the Iron Ores

Science.gov (United States)

Kuskov, Vadim; Kuskova, Yana; Udovitsky, Vladimir

2017-11-01

Effective technology for a complex wasteless processing of the iron ores has been designed and includes three main components (plats): comminution plant, briquette plant, pigment plant. The comminution is done per energy effective technology. Using of briquetting for ores clotting enables the costs cut and brings to a higher level of environmental safety of the process. Briquette formation can be done as a regular pressing, as an extrusion. Developed technology allows to produce high quality competitively products for metallurgy industry and red iron oxide pigments. The whole production line impacts the environment in a minimal manner.

Effective Processing of the Iron Ores

Directory of Open Access Journals (Sweden)

Kuskov Vadim

2017-01-01

Full Text Available Effective technology for a complex wasteless processing of the iron ores has been designed and includes three main components (plats: comminution plant, briquette plant, pigment plant. The comminution is done per energy effective technology. Using of briquetting for ores clotting enables the costs cut and brings to a higher level of environmental safety of the process. Briquette formation can be done as a regular pressing, as an extrusion. Developed technology allows to produce high quality competitively products for metallurgy industry and red iron oxide pigments. The whole production line impacts the environment in a minimal manner.

Survey of naturally occurring hazardous materials in deep geologic formations: a perspective on the relative hazard of deep burial of nuclear wastes

International Nuclear Information System (INIS)

Tonnessen, K.A.; Cohen, J.J.

1977-01-01

Hazards associated with deep burial of solidified nuclear waste are considered with reference to toxic elements in naturally occurring ore deposits. This problem is put into perspective by relating the hazard of a radioactive waste repository to that of naturally occurring geologic formations. The basis for comparison derives from a consideration of safe drinking water levels. Calculations for relative toxicity of FBR waste and light water reactor (LWR) waste in an underground repository are compared with the relative toxicity indices obtained for average concentration ore deposits. Results indicate that, over time, nuclear waste toxicity decreases to levels below those of naturally occurring hazardous materials

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

International Nuclear Information System (INIS)

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

1982-01-01

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

Sampling of ore

International Nuclear Information System (INIS)

Boehme, R.C.; Nicholas, B.L.

1987-01-01

This invention relates to a method of an apparatus for ore sampling. The method includes the steps of periodically removing a sample of the output material of a sorting machine, weighing each sample so that each is of the same weight, measuring a characteristic such as the radioactivity, magnetivity or the like of each sample, subjecting at least an equal portion of each sample to chemical analysis to determine the mineral content of the sample and comparing the characteristic measurement with desired mineral content of the chemically analysed portion of the sample to determine the characteristic/mineral ratio of the sample. The apparatus includes an ore sample collector, a deflector for deflecting a sample of ore particles from the output of an ore sorter into the collector and means for moving the deflector from a first position in which it is clear of the particle path from the sorter to a second position in which it is in the particle path at predetermined time intervals and for predetermined time periods to deflect the sample particles into the collector. The apparatus conveniently includes an ore crusher for comminuting the sample particle, a sample hopper means for weighing the hopper, a detector in the hopper for measuring a characteristic such as radioactivity, magnetivity or the like of particles in the hopper, a discharge outlet from the hopper and means for feeding the particles from the collector to the crusher and then to the hopper

Geology of eastern Smith Lake ore trend, Grants mineral belt

International Nuclear Information System (INIS)

Ristorcelli, S.J.

1980-01-01

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

Geochemistry and the origin of the Mamouniyeh iron ore-terra rossa deposit, Markazi Province - Iran

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Marziyeh Mahboubiyan Fard

2017-11-01

Full Text Available Introduction Iron is among the metals whose ore deposits are not confined to a specific geologic period of crustal formation and they have formed in various geologic environments during previous periods (Ghorbani, 2007. About 95% of iron ore deposits have sedimentary origin and have formed due to chemical deposition from ancient sea water. The remaining percent is the result of alteration and magmatic activities (Gutzmer and Beukes, 2009. In sedimentary environments, a large amount of sedimentary iron minerals have formed resulting in different iron facies. Iron oxide facies are of the most important facies (James, 1954. The most important Iranian iron deposits are located in Central Iran, Sanandaj- Sirjan and East Iran zones, and the Kordestan area (Ghorbani, 2007. In the Orumiyeh-Dokhtar Zone, many iron ore deposits have been formed in conjunction with granitic and granodioritic plutons related to Oligocene-Miocene plutonic and volcanic activities (Hoshmandzadeh, 1995. The Mamouniyeh iron ore-terra rossa deposit is located in the Orumiyeh-Dokhtar volcanic zone. Iron mineralization have occurred in trachytic-trachyandesitic lavas and pyroclastic rocks of Pliocene age. Materials and methods A total of 28 rock samples were picked up from ore and host rocks during field observations. Petrographical and mineralogical studies were performed on 15 thin sections of ore and host rocks. XRD studies were performed on 3 ore samples. In order to investigate the geochemistry of the ore, 10 samples were analyzed for major, trace and rare earth elements (REEs using the ICP-MS method. Result Field and mineralogical studies reveal that the ore is composed of hematite along with crypto-crystalline silica as alternating layers of various thickness and color. The existence of alternating layers of hematite and quartz implies that the ore is similar to banded iron formations, but on a smaller scale, related to submarine hydrothermal activities. Silica is found as

Stages of ores formation

International Nuclear Information System (INIS)

Khasanov, A.Kh.

1988-01-01

Deposit formation (especially endogenous) is the complicated, multi-stage and long process. Establishment of deposit formation succession, age-specific correlations of minerals and aggregates have a high importance at solving genetic questions. Studying of minerals correlations and mineral aggregates, succession of their crystallization and other observations let restore the history of deposit formation, pick up in it different on duration and physical and chemical conditions stages

The physical hydrogeology of ore deposits

Science.gov (United States)

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

2012-01-01

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

Thallium-rich pyrite ores from the Apuan Alps, Tuscany, Italy:constraints for their origin and environmental concerns

Science.gov (United States)

D'Orazio, Massimo; Biagioni, Cristian; Dini, Andrea; Vezzoni, Simone

2017-06-01

The southern sector of the Apuan Alps (AA) massif, Tuscany, Italy, is characterized by the occurrence of a series of baryte-pyrite-iron oxide orebodies whose Tl-rich nature was recognized only recently. The geochemistry of the pyrite ore was investigated through inductively coupled plasma mass spectrometry. In addition, lead isotope data for selected pyrite ores from AA were collected. Pyrite ores are characterized by a complex geochemistry, with high concentrations of Tl (up to 1100 μg/g) coupled with high As and Sb contents; the Co/Ni ratio is always <1. Geochemical data of pyrite and marcasite ore samples from other mining districts of Tuscany have been collected in order to compare them with those from the AA. These samples usually have very low Tl content (less than 2 μg/g) and high to very high Co/Ni and As/Sb ratios. Only some samples from the Sb-Hg ore deposits showed very high Tl concentrations (up to 3900 μg/g). Another difference is related to the lead isotope composition, with pyrite ores from AA markedly less radiogenic than those from the other deposits from Tuscany. Geochemical data of pyrite ores from AA give new insights on the genesis of the baryte-pyrite-iron oxide orebodies, relating their formation to low-temperature hydrothermal systems active during early Paleozoic; in addition, these data play a fundamental role in assessing the environmental impact of these deposits.

Petrological and geochemical features of the early Paleozoic granitic gneisses and iron ores in the Tianhu iron deposit, Eastern Tianshan, NW China: Implications for ore genesis

Science.gov (United States)

Zheng, Jiahao; Mao, Jingwen; Yang, Fuquan; Chai, Fengmei; Shen, Ping

2017-08-01

This paper reports whole-rock geochemical, zircon U-Pb and Hf isotopic data for ore-hosted granitic gneisses, mineral compositions of oxides, and sulfur isotopic data for sulfides in iron ores from the Tianhu deposit, central part of the Eastern Tianshan. Our results can provide crucial constraints on the genesis of granitic gneisses and early Paleozoic tectonic setting of the Eastern Tianshan. LA-ICP-MS U-Pb dating on magmatic zircons yielded weighted mean 206Pb/238U ages of 463 to 438 Ma, interpreted as the crystallization ages of the granitic protoliths and the formation ages of the Tianhu Group. Zircon U-Pb age of ore-hosted granitic gneiss (ca. 459 Ma) can provide reliable constrains on upper limit for iron mineralization age in the Tianhu deposit. Geochemical characteristics suggest that the protoliths of the Tianhu granitic gneisses are metaluminous to weakly peraluminous high-K calc-alkaline granitic rocks, exhibiting typical subduction-related features such as strong enrichment in LREE and LILE and depletion in HFSE. Zircon Hf isotopic compositions show a positive trend from 463 to 438 Ma, indicating that 460 Ma magmas came from both ancient and juvenile sources, whereas 438 Ma magmas involved more juvenile material. Some early Paleozoic granitoids were recently identified in the Eastern Tianshan with the ages between ca. 475 and ca. 425 Ma. The formation of these early Paleozoic granitoids was in response to subduction processes, suggesting that subduction of Junggar Ocean probably began in the Early Ordovician and lasted until Late Silurian. Pyrite and pyrrhotite in iron ores have δ34SCDT values from + 4.6 to + 15.7‰, which are consistent with the marine source, but inconsistent with the magmatic source or those involved evaporites in skarn iron deposit. Geological, geochemical, and isotopic data suggest that the Tianhu iron ores were formed by volcano-sedimentary processes in a subduction environment during the early Paleozoic time, and Tianhu is a

Ore bearing system and hydrological characteristics of mineralized sector in Hushiliang area

International Nuclear Information System (INIS)

Zhang Zhaolin; Liu Zhengbang; Miao Aisheng

2010-01-01

Hushiliang area is one of the best uranium ore bearing areas in Erdos basin from the point of fluvial sedimentary system and uranium geochemical environment, So far, three mineralized sector has been found that are Nalingou, Nongshengxin, Baobeigou. By using the first-hand data of uranium regional survey in this area lately and systematically comparing and analyzing of the hydrological structure in the mineralized sector of this area, the thesis ascertain the ore and water bearing fluid reservoir's spatial relationship generally, and argues that the Zhiluo formation ore and water bearing fluid reservoir in this area is a unified underwater ore bearing system, and the orebody's hydrological structure is propitious in the distributary channel and unpropitious in the main channel because of deep ore bearing layer to the ISL. (authors)

High-grade iron ore at Windarling, Yilgarn Craton: a product of syn-orogenic deformation, hypogene hydrothermal alteration and supergene modification in an Archean BIF-basalt lithostratigraphy

Science.gov (United States)

Angerer, Thomas; Hagemann, Steffen G.; Danyushevsky, Leonid

2013-08-01

Banded iron formation (BIF)-hosted iron ore deposits in the Windarling Range are located in the lower greenstone succession of the Marda-Diemals greenstone belt, Southern Cross domain, Yilgarn Craton and constitute a total hematite-martite-goethite ore resource of minimum 52 Mt at 60 wt.% Fe (0.07 P). Banded iron formation is interlayered with high-Mg basalts at Windarling and precipitated during episodes of volcanic quiescence. Trace element content and the rare earth element (REE) ratios Y/Ho (42 to 45), Sm/Yb (1.5), together with positive La and Gd anomalies in `least-altered' hematite-magnetite-metachert-BIF indicate the precipitation from Archean seawater that was fertilised by hydrothermal vent fluids with a basaltic HREE-Y signature. Hypogene iron ore in sub-greenschist facies metamorphosed BIF formed during three distinct stages: ore stage 1 was a syn- to post-metamorphic, syn-D1, Fe-Ca-Mg-Ni-Co-P-REE metasomatism that produced local Ni-REE-rich Fe-dolomite-magnetite alteration in BIF. Hydrothermal alteration was induced by hot fluid flow controlled by brittle-ductile reactivation of BIF-basalt margins and crosscutting D1 faults. The Ni-Co-rich content of dolomite and a shift in REE ratios in carbonate-altered BIF towards Archean mafic rock signature (Y/Ho to 31 to 40, Sm/Yb to 1 to 2 and Gd/Gd* to 1.2 to 1.4) suggest that high-Mg basalts in the Windarling Range were the primary source of introduced metals. During ore stage 2, a syn-deformational and likely acidic and oxidised fluid flow along BIF-basalt margins and within D1 faults leached carbonate and precipitated lepidoblastic and anhedral/granoblastic hematite. High-grade magnetite-hematite ore is formed during this stage. Ore stage 3 hydrothermal specular hematite (spcH)-Fe-dolomite-quartz alteration was controlled by a late-orogenic, brittle, compressional/transpressional stage (D4; the regional-scale shear-zone-related D3 is not preserved in Windarling). This minor event remobilised iron oxides

Distribution of the ore elements in ore bodies of the Zapolyarnoe field (Kola Peninsula

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D. V. Taymasov

2017-12-01

Full Text Available The author conducted studies of the chemical zonality of ore deposits of all types for the sulfide-copper-nickel deposit Zapolyarnoe. Within the deposit of sulfide-copper-nickel ores Zapolyarnoe are the following industrial types of ores: rich interspersed ores, which are interspersed mineralization in peridotites; brecciated ores formed by detrital material; poor interspersed ores characterized by vein-interspersed mineralization; solid ores in a form of massive sulphide emissions. This work is based on operational and detailed exploration data. The author sorted samples according to the types of ores. Using the results, the author derived regression lines and their formulas to rectilinear dependencies. Analysis of the graphs showed that for all types of ores the dependences of copper and cobalt content on nickel content are direct, but at that, in thick-interspersed and brecciated types they are similar, and in scattered-interspersed they differ significantly. It becomes clear that correlation of copper and nickel in ore body depends on the scattered-interspersed ores, whereas the correlation of cobalt and nickel is determined mainly by thick-interspersed and brecciated ores. Dependencies between nickel, copper and cobalt in ores change when concentration of nickel in the ore changes. The graphs also show that the ratio of Ni/Cu in breccias and scattered-interspersed ores, as well as in near-ore metaperidotites, is almost constant at different nickel concentrations, on average 2:1.5 and 1, respectively. Thick- interspersed ores show the tendency towards an increase in the ratio with an increase in nickel content. The Ni/Co ratio increases with an increase of Ni concentration in all types of ores. In rich ores, growth occurs along a stepped curve, and in breccias – rectilinearly. Thus, the analysis of distribution of ore elements in ore bodies indicates a complex heterogeneous composition of sulphide mineralizations in different types of ores

Rock-magnetism and ore microscopy of the magnetite-apatite ore deposit from Cerro de Mercado, Mexico

Science.gov (United States)

Alva-Valdivia, L. M.; Goguitchaichvili, A.; Urrutia-Fucugauchi, J.; Caballero-Miranda, C.; Vivallo, W.

2001-03-01

Rock-magnetic and microscopic studies of the iron ores and associated igneous rocks in the Cerro de Mercado, Mexico, were carried out to determine the magnetic mineralogy and origin of natural remanent magnetization (NRM), related to the thermo-chemical processes due to hydrothermalism. Chemical remanent magnetization (CRM) seems to be present in most of investigated ore and wall rock samples, replacing completely or partially an original thermoremanent magnetization (TRM). Magnetite (or Ti-poor titanomagnetite) and hematite are commonly found in the ores. Although hematite may carry a stable CRM, no secondary components are detected above 580°, which probably attests that oxidation occurred soon enough after the extrusion and cooling of the ore-bearing magma. NRM polarities for most of the studied units are reverse. There is some scatter in the cleaned remanence directions of the ores, which may result from physical movement of the ores during faulting or mining, or from perturbation of the ambient field during remanence acquisition by inhomogeneous internal fields within these strongly magnetic ore deposits. The microscopy study under reflected light shows that the magnetic carriers are mainly titanomagnetite, with significant amounts of ilmenite-hematite minerals, and goethite-limonite resulting from alteration processes. Magmatic titanomagnetites, which are found in igneous rocks, show trellis, sandwich, and composite textures, which are compatible with high temperature (deuteric) oxy-exsolution processes. Hydrothermal alteration in ore deposits is mainly indicated by martitization in oxide minerals. Grain sizes range from a few microns to >100 mm, and possible magnetic state from single to multidomain, in agreement with hysteresis measurements. Thermal spectra, continuous susceptibility measurements, and IRM (isothermal remanent magnetization) acquisition suggest a predominance of spinels as magnetic carriers, most probably titanomagnetites with low

Uranium ores

International Nuclear Information System (INIS)

Poty, B.; Roux, J.

1998-01-01

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

The redox reaction kinetics of Sinai ore for chemical looping combustion applications

International Nuclear Information System (INIS)

Ksepko, Ewelina; Babiński, Piotr; Nalbandian, Lori

2017-01-01

Highlights: • Redox reaction kinetics of Fe-Mn-rich Sinai ore was determined by TGA. • The most suitable model for reduction was D3, while R3 for oxidation. • Activation energies 35.3 and 16.70 kJ/mole were determined for reduction and oxidation. • Repetitive redox reactions favor the formation of spinel phases in Sinai ore. • Multiple redox cycles induce formation of extensive porosity of the particles. - Abstract: The objective of this work was to study the use of Sinai ore, a Fe–Mn-based ore from Egypt, as a low-cost oxygen carrier (OC) in Chemical Looping Combustion (CLC). The Sinai ore was selected because it possesses relatively high amounts of iron and manganese oxides. Furthermore, those oxides have low cost, very favorable environmental and thermodynamic properties for the CLC process. The performance of the Sinai ore as an OC in CLC was compared to that of ilmenite (Norway Tellnes mine), the most extensively studied naturally occurring Fe-based mineral. The kinetics of the reduction and oxidation reactions with the two minerals were studied using a thermogravimetric analyzer (TGA). Experiments were conducted under isothermal conditions, with multiple redox cycles, at temperatures between 750 and 950 °C. For the reduction and oxidation reactions, different concentrations of CH_4 (10–25 vol.%) and O_2 (5–20 vol.%) were applied, respectively. The kinetic parameters, such as the activation energy (E_a), pre-exponential factor (A_0), and reaction order (n), were determined for the redox reactions. Furthermore, models of the redox reactions were selected by means of a model-fitting method. For the Sinai ore, the D3 model (3-dimensional diffusion) was suitable for modeling reduction reaction kinetics. The calculated E_a was 35.3 kJ/mole, and the reaction order was determined to be approximately 0.76. The best fit for the oxidation reaction was obtained for the R3 model (shrinking core). The oxidation (regeneration) reaction E_a was equal to 16

Temporal Evolution of Volcanic and Plutonic Magmas Related to Porphyry Copper Ores Based on Zircon Geochemistry

Science.gov (United States)

Dilles, J. H.; Lee, R. G.; Wooden, J. L.; Koleszar, A. M.

2015-12-01

Porphyry Cu (Mo-Au) and epithermal Au-Ag ores are globally associated with shallow hydrous, strongly oxidized, and sulfur-rich arc intrusions. In many localities, long-lived magmatism includes evolution from early andesitic volcanic (v) and plutonic (p) rocks to later dacitic or rhyolitic compositions dominated by plutons. We compare zircon compositions from three igneous suites with different time spans: Yerington, USA (1 m.y., p>v), El Salvador, Chile (4 m.y., p>v), and Yanacocha, Peru (6 m.y., v>p). At Yerington granite dikes and ores formed in one event, at ES in 2 to 3 events spanning 3 m.y., and at Yanacocha in 6 events spanning 5 m.y. At both ES and Yanacocha, high-Al amphiboles likely crystallized at high temperature in the mid-crust and attest to deep magmas that periodically recharged the shallow chambers. At Yanacocha, these amphiboles contain anhydrite inclusions that require magmas were sulfur-rich and strongly oxidized (~NNO+2). The Ti-in-zircon geothermometer provides estimates of 920º to 620º C for zircon crystallization, and records both core to rim cooling and locally high temperature rim overgrowths. Ore-related silicic porphyries yield near-solidus crystallization temperatures of 750-650°C consistent with low zircon saturation temperatures. The latter zircons have large positive Ce/Ce* and small negative Eu/Eu*≥0.4 anomalies attesting to strongly oxidized conditions (Ballard et al., 2001), which we propose result from crystallization and SO2 loss to the magmatic-hydrothermal ore fluid (Dilles et al., 2015). The Hf, REE, Y, U, and Th contents of zircons are diverse in the magma suites, and Th/U vs Yb/Gd plots suggest a dominant role of crystal fractionation with lesser roles for both crustal contamination and mixing with high temperature deep-sourced mafic magma. Ce/Sm vs Yb/Gd plots suggest that magma REE contents at contamination are most evident in pre-ore magmas, whereas ore-forming intrusions at low temperatures are dominated by crystal

Formation of neogenic ores on the dump-heaps of old uranium mines and on the mine-head of mines under exploitation; Formation de mineraux neogenes sur les haldes d'anciennes mines d'uranium et sur le carreau des mines en exploitation

Energy Technology Data Exchange (ETDEWEB)

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

1960-07-01

The aim of this preliminary study is to assess straight away the major degradations suffered by primary and secondary uranium ores under the weathering action of air and water. The uranium ores concerned in this case are those stored in the open air. The pyritic ores are the most vulnerable: the interactions between the pyrite, or rather its oxidation products, and the uraniferous compounds are liable to lead to the formation of neogenic ores, which are of considerable importance in the natural lixiviation of uranium ore stocks. (author) [French] Cette etude preliminaire a pour but de fixer des a present les degradations majeures que subissent les mineraux d'uranium primaires et secondaires, sous l'action de l'air et des eaux meteoriques. Il s'agit en l'occurence des mineraux d'uranium constituant les minerais entreposes a l'air libre. Les minerais pyriteux sont les plus vulnerables: les interactions entre la pyrite ou plutot de ses produits d'oxydation avec les composes uraniferes sont susceptibles de former des mineraux neogenes dont l'importance est considerable dans la lixiviation naturelle des stocks de minerais d'uranium. (auteur)

Analysis on hydrological condition for uranium ore formation in Wuerhe district, Junggar Basin

International Nuclear Information System (INIS)

Zhang Quanqing; Zhang Xinke; Ren Manchuan

2009-01-01

Wuerhe district is located in the northwestern part of Junggar Basin, Xinjiang. It belongs to a relative quiet area without the obvious tectonic activities and obvious subsequent tectonic activization. Through the regional uranium resources evaluation on this area, the inter-bedded oxidation zone and uranium mineralization are discovered in Cretaceous. The wall rock, the recharge-runoff-discharge mechanism of groundwater, palaeo-hydrological condition, hydrological and hydrogeochemical features of groundwater are introduced briefly, the favorable uranium ore-forming segment is summarized to be located in the fore-mountain area to the west of Ke-Xia fault terrace zone. (authors)

By lithology Zbruch deposits (Lower Sarmatian Nikopol manganese ore Basin

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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.

Sedimentary carbonate-hosted giant Bayan Obo REE-Fe-Nb ore deposit of Inner Mongolia, China; a cornerstone example for giant polymetallic ore deposits of hydrothermal origin

Science.gov (United States)

Chao, E.C.T.; Back, J.M.; Minkin, J.A.; Tatsumoto, M.; Junwen, Wang; Conrad, J.E.; McKee, E.H.; Zonglin, Hou; Qingrun, Meng; Shengguang, Huang

1997-01-01

Detailed, integrative field and laboratory studies of the textures, structures, chemical characteristics, and isotopically determined ages and signatures of mineralization of the Bayan Obo deposit provided evidence for the origin and characteristics favorable for its formation and parameters necessary for defining giant polymetallic deposits of hydrothermal origin. Bayan Obo is an epigenetic, metasomatic, hydrothermal rare earth element (REE)-Fe-Nb ore deposit that is hosted in the metasedimentary H8 dolostone marble of the Middle Proterozoic Bayan Obo Group. The metasedimentary sequence was deposited on the northern continental slope of the North China craton. The mine area is about 100 km south of the suture marking Caledonian subduction of the Mongolian oceanic plate from the north beneath the North China craton. The mineralogy of the deposit is very complex, consisting of more than 120 different minerals, some of which are epigenetic minerals introduced by hydrothermal solutions, and some of which are primary and secondary metamorphic minerals. The major REE minerals are monazite and bastnaesite, whereas magnetite and hematite are the dominant Fe-ore minerals, and columbite is the most abundant Nb mineral. Dolomite, alkali amphibole, fluorite, barite, aegirine augite, apatite, phlogopite, albite, and microcline are the most widespread gangue minerals. Three general types of ores occur at Bayan Obo: disseminated, banded, and massive ores. Broad zoning of these ore types occurs in the Main and East Orebodies. Disseminated ores are in the outermost zone, banded ores are in the intermediate zone, and massive ores are in the cores of the orebodies. On the basis of field relations, host rocks, textures, structures, and mineral assemblages, many varieties of these three types of ores have been recognized and mapped. Isotopic dating of monazite, bastnaesite, aeschynite, and metamorphic and metasomatic alkali amphiboles associated with the deposit provides constraints

Process and equipment for in situ ore leaching

International Nuclear Information System (INIS)

Roussel, J.

1983-01-01

A solution for the leaching of uranium, cobalt, copper, ... ores is injected then extracted in a recovery well after extraction of the metal the solution is pressurized and oxygenated. During injection the pressure is maintained constant for a maximum oxygenation without bubble formation [fr

Hydrogen Plasma Processing of Iron Ore

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Sabat, Kali Charan; Murphy, Anthony B.

2017-06-01

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

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

Geology and ore deposits of the Section 23 Mine, Ambrosia Lake District, New Mexico

Science.gov (United States)

Granger, H.C.; Santos, E.S.

1982-01-01

The section 23 mine is one of about 18 large uranium mines opened in sandstones of the fluvial Westwater Canyon Member of the Jurassic Morrison Formation in the Ambrosia Lake mining district during the early 1960s. The Ambrosia Lake district is one of several mining districts within the Grants mineral belt, an elongate zone containing many uranium deposits along the southern flank of the San Juan basin. Two distinct types of ore occur in the mine. Primary ore occurs as peneconcordant layers of uranium-rich authigenic organic matter that impregnates parts of the reduced sandstone host rocks and which are typically elongate in an east-southeast direction subparallel both to the sedimentary trends and to the present-day regional strike of the strata. These are called prefault or trend ores because of their early genesis and their elongation and alinement. A second type of ore in the mine is referred to as postfault, stacked, or redistributed ore. Its genesis was similar to that of the roll-type deposits in Tertiary rocks of Wyoming and Texas. Oxidation, related to the development of a large tongue of oxidized rock extending from Gallup to Ambrosia Lake, destroyed much of the primary ore and redistributed it as massive accumulations of lower grade ores bordering the redox interface at the edge of the tongue. Host rocks in the southern half of sec. 23 (T. 14 N., R. 10 W.) are oxidized and contain only remnants of the original, tabular, organic-rich ore. Thick bodies of roll-type ore are distributed along the leading edge of the oxidized zone, and pristine primary ore is found only near the north edge of the section. Organic matter in the primary ore was derived from humic acids that precipitated in the pores of the sandstones and fixed uranium as both coffinite and urano-organic compounds. Vanadium, molybdenum, and selenium are also associated with the ore. The secondary or roll-type ores are essentially free of organic carbon and contain uranium both as coffinite and

The Krásná Hora, Milešov, and Příčovy Sb-Au ore deposits, Bohemian Massif: mineralogy, fluid inclusions, and stable isotope constraints on the deposit formation

Science.gov (United States)

Němec, Matěj; Zachariáš, Jiří

2018-02-01

The Krásná Hora-Milešov and Příčovy districts (Czech Republic) are the unique examples of Sb-Au subtype orogenic gold deposits in the Bohemian Massif. They are represented by quartz-stibnite veins and massive stibnite lenses grading into low-grade, disseminated ores in altered host rocks. Gold postdates the stibnite and is often replaced by aurostibite. The ore zones are hosted by hydrothermally altered dikes of lamprophyres (Krásná Hora-Milešov) or are associated with local strike-slip faults (Příčovy). Formation of Sb-Au deposits probably occurred shortly after the main gold-bearing event (348-338 Ma; Au-only deposits) in the central part of the Bohemian Massif. Fluid inclusion analyses suggest that stibnite precipitated at 250 to 130 °C and gold at 200 to 130 °C from low-salinity aqueous fluids. The main quartz gangue hosting the ore precipitated from the same type of fluid at about 300 °C. Early quartz-arsenopyrite veins are not associated with the Sb-Au deposition and formed from low-salinity, aqueous-carbonic fluid at higher pressure and temperature ( 250 MPa, 400 °C). The estimated oxygen isotope composition of the ore-bearing fluid (4 ± 1‰ SMOW; based on post-ore calcite) suggests its metamorphic or mixed magmatic-metamorphic origin and excludes the involvement of meteoric water. Rapid cooling of warm hydrothermal fluids reacting with "cold" host rock was probably the most important factor in the formation of both stibnite and gold.

Discourse characteristics of ore-bearing aquifer of Chaidenghao in Husiliang area

International Nuclear Information System (INIS)

Zhou Bowen

2012-01-01

Call Sri Lanka article focuses primarily on wood board beam region trench features lots of ore-bearing aquifer, located in the ore-bearing aquifer under Zhiluo lower sub-section; A brief introduction to the work area's geology and stratigraphic structure, and a brief description of the main ore purpose of the lower layer Zhiluo under sub-section lithology; Shows aquifer top, bottom and described its characteristics, the two formed a 'watertight-water-impermeable' good hydrogeological structure of the ancient interlayer oxidation zone formation to create a favorable space. Based on the above description and analysis of the location of uranium mineralization in good condition, have a good vision of the mineralization. (author)

Ore mineragraphy of uraniferous polymetallic sulphides at Juba, Chhattisgarh basin, Raipur district, Central India

International Nuclear Information System (INIS)

Jain, S.K.; Sinha, D.K.; Verma, S.C.; Singh, Rajendra

1998-01-01

Polymetallic sulphide mineralization associated with uranium, has been located in the subfeldspathic arenite of Rehatikhol Formation of Chhattisgarh Supergroup near Juba (21 o 20'55 N : 83 o 15'43 E ) and Banjhapali (21 o 20'16 N : 83 o 14'44 E ) villages of Raipur district, Madhya Pradesh. The present paper describes ore mineragraphy and petrographic details of ore and the host rock. Ore microscopic study carried out on 82 rock samples has revealed fracture and intergranular space filled epigenetic mineralisation of uraninite/pitchblende, coffinite (1), pyrite, galena and pyrrhotite with traces of, bornite, luzonite, chalcopyrite, covellite, argentite, sternburgite and argentopyrite, besides diagenetically developed pyrite. Silification (chert), argillitisation and minor propylitisation represent the wall rock alterations. Coffinite (II) has formed due to reaction of uraninite/pitchblende and silica. Textural studies indicate, two stages of epigenetic mineralisation. (a) Introduction of sulphides of Fe-Pb-Cu-As and Ag and related potash metasomatism and (b) infiltration of siliceous material with pyrite, pitchblende, and subsequent coffinite. Coffinite (I) is deposited on porous pyrite is dusted with galena. Supergene processes have also formed minerals like bornite, covellite, galena etc. Thus the ore mineragraphic studies indicate epigenetic hydrothermal type uraniferous polymetallic sulphide mineralisation in the Juba area of Raipur district, Madhya Pradesh. (author)

Sintering-alkaline processing of borosilicate ores of Tajikistan

International Nuclear Information System (INIS)

Nazarov, F.A.

2018-01-01

The aim of the work is to study the processes of decomposition of boron-containing ore by sintering with NaOH, finding the optimal parameters of the decomposition process, studying the kinetics of processes and developing the technological foundations for ore processing. The processes of borosilicate ore processing were studied by sintering with NaOH. Possible mechanisms of chemical reactions of the process of sintering-alkaline decomposition of boron-containing ore are established, the results of which are substantiated by physicochemical methods of analysis. A principal technological scheme for processing of borosilicate ores by a sintering-alkaline method has been developed. In the first chapter, data on alkaline and caking processes for processing boron-containing and aluminium comprising raw materials are available in the literature. Based on this, the directions of our own research are outlined. The second chapter is devoted to the study of the chemical and mineralogical compositions of borosilicate ores and their concentrates with the help of X-ray phase and chemical analysis methods, the stoichiometric calculation of the formation of aluminum, iron, and boron salts has been carried out, and a thermodynamic analysis of the processes of sintering borosilicate ores with alkali has been considered. The third chapter presents the results of a study of sintering-alkaline method of processing of initial borosilicate ore of the Ak-Arkhar Deposit and its concentrate without calcination and after calcination. The kinetics of sintering of borosilicate ores with sodium hydroxide was studied. The optimal conditions of borosilicate ore sintering before and after the preliminary calcination with alkali were determined. Optimal parameters of the sintering process have been found: sintering temperature 800-8500 deg C, duration of the process - 60 minutes, mass ratio of NaOH to raw materials 2: 1. The conditions for sintering of borosilicate concentrate with alkali have been

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

International Nuclear Information System (INIS)

Arne, D.C.; Duddy, I.R.; Green, P.F.; Lambert, I.B.

1987-01-01

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 238 U 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

Structure and texture of uranium ores in exogenous deposits

International Nuclear Information System (INIS)

Danchev, V.I.

1977-01-01

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

Microwave enhanced recovery of nickel-copper ore: communition and floatability aspects.

Science.gov (United States)

Henda, R; Hermas, A; Gedye, R; Islam, M R

2005-01-01

A study describing the effect of microwave radiation, at a frequency of 2450 MHz, on the processes of communication and flotation of a complex sulphide nickel-copper ore is presented. Ore communication has been investigated under standard radiation-free conditions and after ore treatment in a radiated environment as a function of ore size, exposure time to radiation, and microwave power. The findings show that communication is tremendously improved by microwave radiation with values of the relative work index as low as 23% at a microwave power of 1.406 kW and after 10 s of exposure time. Communication is affected by exposure time and microwave power in a nontrivial manner. In terms of ore floatability, the experimental tests have been carried out on a sample of 75 microm in size under different exposure times. The results show that both ore concentrate recoveries and grades of nickel and copper are significantly enhanced after microwave treatment of the ore with relative increases in recovered concentrate, grade of nickel, and grade of copper of 26 wt%, 15 wt%, and 27%, respectively, at a microwave power of 1330 kW and after 30 s of exposure time.

Ore sorting using natural gamma radiation

International Nuclear Information System (INIS)

Clark, G.J.; Dickson, B.L.; Gray, F.E.

1980-01-01

A method of sorting an ore which emits natural gamma radiation is described, comprising the steps of: (a) mining the ore, (b) placing, substantially at the mining location, the sampled or mined ore on to a moving conveyor belt, (c) measuring the natural gamma emission, water content and mass of the ore while the ore is on the conveyor belt, (d) using the gamma, water content and mass measurements to determine the ore grade, and (e) directing the ore to a location characteristic of its grade when it leaves the conveyor belt

Chemical fingerprint of iron oxides related to iron enrichment of banded iron formation from the Cauê Formation - Esperança Deposit, Quadrilátero Ferrífero, Brazil: a laser ablation ICP-MS study

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Lucilia Aparecida Ramos de Oliveira

Full Text Available Chemical signatures of iron oxides from dolomitic itabirite and high-grade iron ore from the Esperança deposit, located in the Quadrilátero Ferrífero, indicate that polycyclic processes involving changing of chemical and redox conditions are responsible for the iron enrichment on Cauê Formation from Minas Supergroup. Variations of Mn, Mg and Sr content in different generations of iron oxides from dolomitic itabirite, high-grade iron ore and syn-mineralization quartz-carbonate-hematite veins denote the close relationship between high-grade iron ore formation and carbonate alteration. This indicates that dolomitic itabirite is the main precursor of the iron ore in that deposit. Long-lasting percolation of hydrothermal fluids and shifts in the redox conditions have contributed to changes in the Y/Ho ratio, light/heavy rare earth elements ratio and Ce anomaly with successive iron oxide generations (martite-granular hematite, as well as lower abundance of trace elements including rare earth elements in the younger specularite generations.

Ore-forming fluid system of bauxite in WZD area of northern Guizhou province, China

Science.gov (United States)

Cui, Tao

2017-12-01

The ore-forming fluid system of bauxite in Wuchuan-Zheng,an-Daozhen (short for WZD) Area of northern Guizhou Province was studied from the perspective of deposit formation mechanism. It was discovered that ore-forming fluids were mainly effective for transporting and leaching during the formation of bauxite. The means of transport mainly included colloidal transport, suspended transport and gravity flow transport. In the course of their leaching, fluids had a range of chemical reactions, as a result of which elements such as silicon and iron migrated downwards. In this process, properties of fluids changed as well.

Work within the coordinated programme on bacterial leaching of uranium ores

International Nuclear Information System (INIS)

Jayaram, K.M.V.

1978-10-01

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

Studies on uranium ore processing

International Nuclear Information System (INIS)

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

1981-01-01

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

Summary of the mineralogy of the Colorado Plateau uranium ores

Science.gov (United States)

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

1956-01-01

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

Composition and origin of Early Cambrian Tiantaishan phosphorite-Mn carbonate ores, Shaanxi Province, China

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Hein, J.R.; Fan, D.; Ye, J.; Liu, T.; Yeh, H.-W.

1999-01-01

The Tiantaishan phosphorite-Mn carbonate ores occur in the Early Cambrian Tananpo Formation in complexly folded and faulted rocks located in southern Shaanxi Province. About 65 x 106 tonnes of 17% P2O5 ore reserves exist and Mn-ore reserves are about 8.3 x 106 tonnes of +18% Mn. The stratigraphic sequence in ascending order consists of black phyllite, black to gray phosphorite ore, black phyllite, rhodochrostone ore, Mn mixed-carbonates, and dolostone. Data are presented from microprobe mineral chemistry, whole-rock chemistry, stable isotopes of carbonates, X-ray mineralogy, petrographic and SEM observations, and statistical analysis of chemical data. The dominant ore-forming minerals are hydroxy- and carbonate fluorapatite and Ca rhodochrosite, with Mg kutnahorite and dolomite comprising the Mn mixed-carbonate section. Pyrite occurs in all rock types and alabandite (MnS) occurs throughout the rhodochrostone section. The mean P2O5 content of phosphorite is 31% and argillaceous phosphorite is 16%, while the mean MnO content of rhodochrostone ore is 37%. Phosphorite ores are massive, spheroidal, laminated, and banded, while rhodochrostone ores have oolitic, spheroidal, and granular fabrics. The most distinguishing characteristics of the ores are high total organic carbon (TOC) contents (mean 8.4%) in the phosphorite and high P2O5 contents (mean 2.7%) in the rhodochrostone ore. The atypically high TOC contents in the Tiantaishan phosphorite probably result from very strong productivity leading to high sedimentation rates accompanied by weak reworking of sediments; poor utilization of the organic matter by bacteria; and/or partial replacement of bacterial or algal mats by the apatite. The depositional setting of the ores was the margin of an epicontinental seaway created as a direct consequence of global processes that included break-up of a supercontinent, formation of narrow seaways, creation of extensive continental shelves, overturn of stagnant, metal-rich deep

Permeability restoration and lowering of uranium leakage from leached ore beds

International Nuclear Information System (INIS)

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

1981-01-01

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

Automated microscopic characterization of metallic ores with image analysis: a key to improve ore processing. II: metallogenetic discriminating criteria

International Nuclear Information System (INIS)

Castroviejo, R.; Berrezueta, E.

2009-01-01

ore microscopy may furnish very important information for geo metallurgists, but todays needs for automation are difficult to meet with the optical microscope unless and adequate methodology is developed. Some limitations of the routine procedure, related to risks of mis identification caused by the spectral similarity of some ores, ask for complementary criteria. Defining ore deposit typologies and the corresponding assemblages guides the choice of species and limits the number. Comparison of the reflectance values of the ores in each mineral association defined shows that their automated identification is possible in most of the common occurrence. The number of species to be actually considered being greatly limited, performance is increased. The system is not intended to substitute for a mineralogist, but to enhance enormously his performance, while offering the industry an economic procedure to procedure a wealth of information which would not be possible with traditional methods, as the point counter. (Author) 33 refs.

The formation of technic soil in a revegetated uranium ore waste rock pile (Limousin, France)

Science.gov (United States)

Boekhout, Flora; Gérard, Martine; Kanzari, Aisha; Calas, Georges; Descostes, Michael

2014-05-01

Mining took place in France between 1945 and 2001 during which time ~210 different sites were exploited and/or explored. A total of 76 Kt of uranium was produced, 52 Mt of ore was extracted, but also 200 Mt of waste rocks was produced, the majority of which, with uranium levels corresponding to the natural environment. So far, the processes of arenisation and technic soil formation in waste rock piles are not well understood but have important implications for understanding the environmental impact and long-term speciation of uranium. Understanding weathering processes in waste rock piles is essential to determine their environmental impact. The main objectives of this work are to assess 1) the micromorphological features and neo-formed U-bearing phases related to weathering and 2) the processes behind arenisation of the rock pile. The site that was chosen is the Vieilles Sagnes waste rock pile in Fanay (Massif Central France) that represents more or less hydrothermally altered granitic rocks that have been exposed to weathering since the construction of the waste rock pile approximately 50 years ago. Two trenches were excavated to investigate the vertical differentiation of the rock pile. This site serves as a key location for studying weathering processes of waste rock piles, as it has not been reworked after initial construction and has therefore preserved information on the original mineralogy of the waste rock pile enabling us to access post emplacement weathering processes. The site is currently overgrown by moss, meter high ferns and small trees. At present day the rock pile material can be described as hydrothermally altered rocks and rock fragments within a fine-grained silty clay matrix exposed to surface conditions and weathering. A sandy "paleo" technic soil underlies the waste rock pile and functions as a natural liner by adsorption of uranium on clay minerals. Post-mining weathering of rock-pile material is superimposed on pre-mining hydrothermal and

Metallogenic hydrothermal solution system of post volcanic magma in Xiangshan ore field

International Nuclear Information System (INIS)

Xu Hengli; Shao Fei; Zou Maoqin

2009-01-01

This paper has systematically described uranium metallogenic characteristics of Xiangshan ore field.Sources of metallogenic materials are discussed in different temporal and spatial scale. Combining with background analysis of metallogenic tectonic-magmatic-geodynamics, formation and evolution of metallogenic hydrothermal solution system in Xiangshan volcanic basin are studied. Metallogenic hydrothermal solution system in Xiangshan ore field is considered as the objective product of systematic evolution of hydrothermal solution in post volcanic magma constrained by regional tectonic environment. In time scale, metallogenic hydrothermal solution system developed for about 50 Ma, but its active spaces varied in different time domains. So temporal and spatial distribution of uranium mineralization is constrained. Further exploration for the ore field is also suggested in this paper. (authors)

Retrogressively in-situ ore body chemical mining system and method

International Nuclear Information System (INIS)

Jacoby, C.H.

1981-01-01

A method is provided for mining a horizontal ore body lying underneath an overburden that precludes the use of other mining methods. Such an overburden may comprise a body of water, an inhabited area, or a geological formation that is difficult to penetrate. A vertical shaft is sunk in a convenient location, and at least two boreholes are drilled in a horizontal direction extending outwards from the shaft. The boreholes ae roughly parallel, but sloped in such a way as to facilitate the flow of a leaching solution along them. The formation lying between the boreholes is fractured to make it permeable to the leaching solution, and the solution is injected through one hole and recovered through the other. Different zones of the ore body may be fractured successively, starting with the most distant. It is desirable to backfill depleted zones with an inert waste material, cement, or other filler

Inhalation of uranium ores

International Nuclear Information System (INIS)

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

1975-01-01

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

Geological exploration of uranium ores at Burgos' basin

International Nuclear Information System (INIS)

Cabrera Valdez, M.E.

1975-01-01

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

Development of the Facility for Transformation of Magnetic Characteristics of Weakly Magnetic Oxidized Iron Ores Related to Improvement of Technologies for Iron Ore Concentrate Production

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Ponomarenko, O.M.

2016-01-01

Full Text Available New facility for continuous registration of iron ore magnetization depending on temperature by heating of iron ores upon reducing conditions was created. Facility allows to register the processes of transformation of weakly magnetic minerals into strongly magnetic ones under the influence of reducing agents and temperature, as well as to determine the Curie temperature of the minerals. Using created facility it was shown, that heating of goethite and hematite in the presence of 4 % of starch in the temperature range of 300—650 °С leads to significant increase of magnetization of the samples. X-Ray diffraction confirmed that under indicated conditions the structure of hematite and goethite is transformed into magnetite structure. Obtained results open up new possibilities for the development of effective technologies for oxidized iron ore beneficiation.

Ore sorting

International Nuclear Information System (INIS)

Hawkins, A.P.; Richards, A.W.

1982-01-01

In an ore sorting apparatus, ore particles are bombarded with neutrons in a chamber and sorted by detecting radiation emitted by isotopes of elements, such as gold, forming or contained in the particles, using detectors and selectively controlling fluid jets. The isotopes can be selectively recognised by their radiation characteristics. In an alternative embodiment, shorter life isotopes are formed by neutron bombardment and detection of radiation takes place immediately adjacent the region of bombardment

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)

Billon, Sophie

2014-01-01

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)

Geochemical Peculiarities of Galena and Sphalerite from Polymetallic Deposits of the Dal'negorskii Ore Region (Primorsky Krai, Russia)

Science.gov (United States)

Rogulina, L. I.; Moiseenko, V. G.; Ponomarchuk, V. A.

2018-04-01

New data on the composition of the major minerals from the skarn and vein polymetallic deposits of the Dal'negorskii ore region are reported. Analysis of galena and sphalerite was carried out by the X-ray fluorescent energy-dispersive method of synchrotron radiation for the first time. It is shown that the minor elements in major minerals of different deposits are typomorphic. Among these elements are Fe, Cu, Ni, Cd, Ag, Sn, and Sb, as well as In in sphalerite and Te in galena. The high concentrations of Ag, Cu, Te, Cd, and In in the extracted minerals indicate the complex character of mineralization. The compositional patterns of ore minerals characterize the sequence of mineral formation from the skarn to vein ores, and the sequence of deposits from the mesothermal to epithermal conditions. This provides geochemical evidence for the stage model of the formation of mineralization in the Dal'negorskii ore region.

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

International Nuclear Information System (INIS)

Vincze, Janos; Somogyi, Janos

1984-01-01

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

Genetic relationships between skarn ore deposits and magmatic activity in the Ahar region, Western Alborz, NW Iran

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Mollai Habib

2014-06-01

Full Text Available Paleocene to Oligocene tectonic processes in northwest Iran resulted in extensive I-type calc-alkaline and alkaline magmatic activity in the Ahar region. Numerous skarn deposits formed in the contact between Upper Cretaceous impure carbonate rocks and Oligocene-Miocene plutonic rocks. This study presents new field observations of skarns in the western Alborz range and is based on geochemistry of igneous rocks, mineralogy of the important skarn deposits, and electron microprobe analyses of skarn minerals. These data are used to interpret the metasomatism during sequential skarn formation and the geotectonic setting of the skarn ore deposit related igneous rocks. The skarns were classified into exoskarn, endoskarn and ore skarn. Andraditic garnet is the main skarn mineral; the pyroxene belongs to the diopside-hedenbergite series. The skarnification started with pluton emplacement and metamorphism of carbonate rocks followed by prograde metasomatism and the formation of anhydrous minerals like garnet and pyroxene. The next stage resulted in retro gradation of anhydrous minerals along with the formation of oxide minerals (magnetite and hematite followed by the formation of hydrosilicate minerals like epidote, actinolite, chlorite, quartz, sericite and sulfide mineralization. In addition to Fe, Si and Mg, substantial amounts of Cu, along with volatile components such as H2S and CO2 were added to the skarn system. Skarn mineralogy and geochemistry of the igneous rocks indicate an island arc or subduction-related origin of the Fe-Cu skarn deposit.

XPS and FTIR spectroscopic study on microwave treated high phosphorus iron ore

International Nuclear Information System (INIS)

Omran, Mamdouh; Fabritius, Timo; Elmahdy, Ahmed M.; Abdel-Khalek, Nagui A.; El-Aref, Mortada; Elmanawi, Abd El-Hamid

2015-01-01

Highlights: • The effect of microwave radiation on structure and chemical state of high phosphorus iron ore was studied. • FTIR analyses showed that after microwave radiation the functional chemical groups of phosphorus bearing minerals (fluorapatite) dissociated. • High resolution XPS analyses of Fe 2p peaks showed that after microwave radiation a portion of Fe(+III) was reduced to Fe(+II). • Microwave radiation had a positive effect on the magnetic properties of iron oxide, through formation of ferromagnetic phases. - Abstract: A growing interest in microwave heating has emerged recently. Several potential microwave applications regarding minerals’ processing have been investigated. This paper investigates the effect of microwave radiation on Egyptian high phosphorus iron ore. Three different iron ore samples have varying Fe 2 O 3 and P 2 O 5 contents and mineralogical textures were studied. A comparative study has been carried out between untreated and microwave treated iron ore. XRD and FTIR analyses showed that after microwave radiation the crystallinity of iron bearing minerals (hematite) increased, while the functional chemical groups of phosphorus bearing minerals (fluorapatite) and other gangues dissociated. High resolution XPS analyses of Fe 2p peaks showed that after microwave radiation a portion of Fe(+III) was reduced to Fe(+II). This means that after microwave radiation iron oxide (hematite, Fe 3+ ) transformed into more magnetic phase. The results indicated that microwave radiation had a positive effect on the magnetic properties of iron oxide, through formation of ferromagnetic phases

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

International Nuclear Information System (INIS)

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

1995-01-01

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

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

International Nuclear Information System (INIS)

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

2014-01-01

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

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

International Nuclear Information System (INIS)

Zhao Honggang; Ou Guangxi

2006-01-01

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)

Isolation and identification of iron ore-solubilising fungus

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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.

Skarn and ore formation at Seriphos, Greece as a consequence of granodiorite intrusion

NARCIS (Netherlands)

Salemink, J.

1985-01-01

On the island of Seriphos, Greece, the shallow intrusion of a granodiorite pluton into a series of previously regionally metamorphosed gneisses, marbles and marble-bearing schists produced a contact metamorphic aureole and extensive deposits of Ca-Fe-Mg skarns and Fe-ores. Structural and

NRC's limit on intake of uranium-ore dust

International Nuclear Information System (INIS)

McGuire, S.A.

1983-04-01

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

Composition and method for solution mining of uranium ores

International Nuclear Information System (INIS)

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

1981-01-01

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

Bacterial leaching of pyritic gold ores

International Nuclear Information System (INIS)

Gagliardi, F.M.; Cashion, J.D.; Brown, J.; Jay, W.H.

1998-01-01

Full text: Pyritic ores (pyrite and arsenopyrite) containing gold concentrations in excess of 50g Au/t can be processed to recover the gold by the removal of the sulphur from the ore. This may be achieved by roasting (producing sulphur dioxide emissions), pressure oxidation (expensive and suitable for large high grade deposits), pressure leaching (still currently being developed) or bacterial oxidation. The bacterial oxidation process is a well known process in nature but has only recently come under investigation as a economically viable and relatively clean method of gold recovery from deep low grade sulphidic ores. Samples were obtained from the Wiluna Gold Mine in Western Australia consisting of the original ore, six successive bacterial reactors and the final products. Moessbauer experiments have been performed at room temperature, liquid nitrogen and liquid helium temperatures, and in applied magnetic fields. The main components of the iron phases which were present during the bacterial treatment were pyrite and arsenopyrite which were readily oxidised by the bacteria. Ferric sulfates and ferric arsenates were identified as by-products of the process with a small amount of the oxyhydroxide goethite. These results are in contrast to the similar study of the Fairview Mine in South Africa where principally Fe(II) species were observed

Processing of low-grade uranium ores

International Nuclear Information System (INIS)

Michel, P.

1975-01-01

Four types of low grade ores are studied. Low grade ores which must be extracted because they are enclosed in a normal grade deposit. Heap leaching is the processing method which is largely used. It allows to obtain solutions or preconcentrates which may be delivered at the nearest plant. Normal grade ores contained in a low amplitude deposit which can be processed using leaching as far as the operation does not need any large expensive equipment. Medium grade ores in medium amplitude deposits to which a simplified conventional process can be applied using fast heap leaching. Low grade ores in large deposits. The processing possibilities leading to use in place leaching are explained. The operating conditions of the method are studied (leaching agent, preparation of the ore deposit to obtain a good tightness with regard to the hydrological system and to have a good contact between ore and reagent) [fr

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

International Nuclear Information System (INIS)

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

2012-01-01

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

Filtration aids in uranium ore processing

International Nuclear Information System (INIS)

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

1975-01-01

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

Hydrogen Reduction of Hematite Ore Fines to Magnetite Ore Fines at Low Temperatures

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Wenguang Du

2017-01-01

Full Text Available Surplus coke oven gases (COGs and low grade hematite ores are abundant in Shanxi, China. Our group proposes a new process that could simultaneously enrich CH4 from COG and produce separated magnetite from low grade hematite. In this work, low-temperature hydrogen reduction of hematite ore fines was performed in a fixed-bed reactor with a stirring apparatus, and a laboratory Davis magnetic tube was used for the magnetic separation of the resulting magnetite ore fines. The properties of the raw hematite ore, reduced products, and magnetic concentrate were analyzed and characterized by a chemical analysis method, X-ray diffraction, optical microscopy, and scanning electron microscopy. The experimental results indicated that, at temperatures lower than 400°C, the rate of reduction of the hematite ore fines was controlled by the interfacial reaction on the core surface. However, at temperatures higher than 450°C, the reaction was controlled by product layer diffusion. With increasing reduction temperature, the average utilization of hydrogen initially increased and tended to a constant value thereafter. The conversion of Fe2O3 in the hematite ore played an important role in the total iron recovery and grade of the concentrate. The grade of the concentrate decreased, whereas the total iron recovery increased with the increasing Fe2O3 conversion.

Technique for in situ leach simulation of uranium ores

International Nuclear Information System (INIS)

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

1985-01-01

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

Geology and Ore Deposits of the Uncompahgre (Ouray) Mining District, Southwestern Colorado

Science.gov (United States)

Burbank, Wilbur Swett; Luedke, Robert G.

2008-01-01

The Uncompahgre mining district, part of the Ouray mining district, includes an area of about 15 square miles (mi2) on the northwestern flank of the San Juan Mountains in southwestern Colorado from which ores of gold, silver, copper, lead, and zinc have had a gross value of $14 to 15 million. Bedrock within the district ranges in age from Proterozoic to Cenozoic. The oldest or basement rocks, the Uncompahgre Formation of Proterozoic age, consist of metamorphic quartzite and slate and are exposed in a small erosional window in the southern part of the district. Overlying those rocks with a profound angular unconformity are Paleozoic marine sedimentary rocks consisting mostly of limestones and dolomites and some shale and sandstone that are assigned to the Elbert Formation and Ouray Limestone, both of Devonian age, and the Leadville Limestone of Mississippian age. These units are, in turn, overlain by rocks of marine transitional to continental origin that are assigned to the Molas and Hermosa Formations of Pennsylvanian age and the Cutler Formation of Permian age; these three formations are composed predominantly of conglomerates, sandstones, and shales that contain interbedded fossiliferous limestones within the lower two-thirds of the sequence. The overlying Mesozoic strata rest also on a pronounced angular unconformity upon the Paleozoic section. This thick Mesozoic section, of which much of the upper part was eroded before the region was covered by rocks of Tertiary age, consists of the Dolores Formation of Triassic age, the Entrada Sandstone, Wanakah Formation, and Morrison Formation all of Jurassic age, and the Dakota Sandstone and Mancos Shale of Cretaceous age. These strata dominantly consist of shales, mudstones, and sandstones and minor limestones, breccias, and conglomerates. In early Tertiary time the region was beveled by erosion and then covered by a thick deposit of volcanic rocks of mid-Tertiary age. These volcanic rocks, assigned to the San Juan

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

International Nuclear Information System (INIS)

Kneuper, G.K.; Clasen, D.

1980-01-01

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

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

International Nuclear Information System (INIS)

Zuo Wenqian; Zhang Zhanshi; Sha Yazhou; Rao Chaojun

2011-01-01

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

Processing of low grade uranium ores

International Nuclear Information System (INIS)

Michel, P.

1978-10-01

Four types of low-grade ores are studied: (1) Low-grade ores that must be extracted because they are enclosed in a normal-grade deposit. Heap leaching is the processing method which is largely used. (2) Normal-grade ores contained in low-amplitude deposits. They can be processed using in-place leaching as far as the operation does not need any large and expensive equipment. (3) Medium-grade ores in medium-amplitude deposits. A simplified conventional process can be applied using fast heap leaching. (4) Low-grade ores in large deposits. The report explains processing possibilities leading in most cases to the use of in-place leaching. The operating conditions of this method are laid out, especially the selection of the leaching agents and the preparation of the ore deposit

High-rate behaviour of iron ore pellet

Science.gov (United States)

Gustafsson, Gustaf; Häggblad, Hans-Åke; Jonsén, Pär; Nishida, Masahiro

2015-09-01

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.

Fluid inclusion study of the Witwatersrand gold-uranium ores

International Nuclear Information System (INIS)

Shepherd, T.J.

1977-01-01

Fluid inclusions, preserved in quartz pebbles of the uraniferous and auriferous Precambrian oligomictic conglomerates of the Witwatersrand Basin, provide a unique insight into the genesis of the ores. Using differences in inclusion characteristics in conjunction with intra- and inter-deformational textures for adjacent pebbles, a distinction is made between pre- and post-depositional inclusions. Excluding those related to subsequent brittle fracture, the former comprise five principal types; two of which are distinguished by the development of liquid carbon dioxide. Collectively they indicate a moderate to high pressure-temperature environment of vein quartz formation. Systematic variation in the relative abundance of these inclusion assemblages for different sections of the orefield demonstrates the importance of well-defined provenance areas or multiple entry points into the basins. A marked sympathetic relationship between uraniferous banket ores and the presence of vein quartz rich in liquid carbon dioxide inclusions, together with a corresponding antipathetic relationship for gold, strongly suggests separate sources for the metals. The temporal and spatial aspects of the association 'U-CO 2 ' also imply a uranium influx into the basin from discrete areas of the hinterland contemporaneous with the sediments. Post-depositional inclusions are subordinate and offer no support for the alternative epigenetic model and show only a later interaction of relatively cool circulating groundwaters. A discussion is given of the probable nature and origin of uranium in the source rocks and its mode of transportation. In conclusion, a proposal is made for the use of applied fluid inclusion research in the evaluation of and exploration for similar deposits. (author)

XPS and FTIR spectroscopic study on microwave treated high phosphorus iron ore

Energy Technology Data Exchange (ETDEWEB)

Omran, Mamdouh, E-mail: mamdouh.omran@oulu.fi [Process Metallurgy Research Group, Faculty of Technology, University of Oulu (Finland); Mineral Processing and Agglomeration Lab, Central Metallurgical Research and Development Institute, Cairo (Egypt); Fabritius, Timo [Process Metallurgy Research Group, Faculty of Technology, University of Oulu (Finland); Elmahdy, Ahmed M.; Abdel-Khalek, Nagui A. [Mineral Processing and Agglomeration Lab, Central Metallurgical Research and Development Institute, Cairo (Egypt); El-Aref, Mortada; Elmanawi, Abd El-Hamid [Geology Department, Faculty of Science, Cairo University, Giza 12613 (Egypt)

2015-08-01

Highlights: • The effect of microwave radiation on structure and chemical state of high phosphorus iron ore was studied. • FTIR analyses showed that after microwave radiation the functional chemical groups of phosphorus bearing minerals (fluorapatite) dissociated. • High resolution XPS analyses of Fe 2p peaks showed that after microwave radiation a portion of Fe(+III) was reduced to Fe(+II). • Microwave radiation had a positive effect on the magnetic properties of iron oxide, through formation of ferromagnetic phases. - Abstract: A growing interest in microwave heating has emerged recently. Several potential microwave applications regarding minerals’ processing have been investigated. This paper investigates the effect of microwave radiation on Egyptian high phosphorus iron ore. Three different iron ore samples have varying Fe{sub 2}O{sub 3} and P{sub 2}O{sub 5} contents and mineralogical textures were studied. A comparative study has been carried out between untreated and microwave treated iron ore. XRD and FTIR analyses showed that after microwave radiation the crystallinity of iron bearing minerals (hematite) increased, while the functional chemical groups of phosphorus bearing minerals (fluorapatite) and other gangues dissociated. High resolution XPS analyses of Fe 2p peaks showed that after microwave radiation a portion of Fe(+III) was reduced to Fe(+II). This means that after microwave radiation iron oxide (hematite, Fe{sup 3+}) transformed into more magnetic phase. The results indicated that microwave radiation had a positive effect on the magnetic properties of iron oxide, through formation of ferromagnetic phases.

MINERALOGICAL AND GEOCHEMICAL EVIDENCE FOR MULTI-STAGE FORMATION OF THE CHERTOVO KORYTO DEPOSIT

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Yu. I. Tarasova

2016-01-01

Full Text Available Introduction. The Lena gold province is one of the largest known gold resources in the world. The history of its exploration is long, but the genesis of gold mineralization hosted in black shales in the Bodaibo synclinorium still remains unclear. The studies face the challenge of discovering sources for the useful component and mechanisms of its redistribution and concentration. This study aims to clarify the time sequence of the ore mineralization in the Chertovo Koryto deposit on the basis of detailed mineralogical and geochemical characteristics of the ore, wallrock metasomatites and the Early Proterozoic host black shales, and to assess the applicability of the Sukhoi Log model for clarifying the Chertovo Koryto origin.Geological setting. The Lena gold province is located in the junction area of the Siberian platform and the Baikal mountain region (Fig. 1. The main element of its geological structure is the Chuya-Tonoda-Nechera anticline. Its axial segment is marked by horsts composed of the Early Proterozoic rocks with abundant granitoid massifs. The Chertovo Koryto deposit is located within the Kevakta ore complex at the Tonoda uplift, the largest tectonically disturbed block between the Kevakta and Amandrak granitoids massifs. The 150 m thick and 1.5 km long ore zone of the Chertovo Koryto deposit is confined to the hanging wall of the fold-fault zone feathering the Amandrak deep fault (Fig. 2.Composition. In the ore zone, rocks of the Mikhailovsk Formation include carbonaceous shales of the feldspar-chlorite-sericite-quartz composition with nest-shaped ore accumulations of the pyrite-quartz composition and quartz veinlets. In our study, we distinguish five mineral associations resulting from heterochronous processes that sequentially replaced each other:- The earliest association related with the quartz-muscovite-sericite metasomatism and the removal of REE and other elements from the rocks and their partial redeposition;- Metamorphic

Contribution of U-Pb geochronology to characterizing the Cadomian magmatism of the southeastern French Massif Central and of the related uranium-ore at Bertholene

International Nuclear Information System (INIS)

Leveque, Marie-Helene

1990-01-01

U-Pb geochronology and whole-rock geochemistry (major, trace and rare earth elements) were applied to various ortho- and paragneiss formations of the southeastern part of the French Massif Central. The Mendic granite and the Les Palanges granite were dated at 603 ± 9 Ma and 540 ± 18 Ma, respectively. Their micaschist host-rocks show a multi-episodic evolution that matches the U-Pb data obtained on metasediments and leucogranites of the Variscan Orogen. An old zircon source was detected at 1.87 Ga in the Les Palanges micaschist, while, seemingly, this heritage was wiped out of the Mendic micaschist during the Cadomian events. In the Decazeville gneiss, where a crustal component of unknown age has been detected, the major event is the Variscan migmatization. At Bertholene, the geochronology of uranium ores associated to the Les Palanges orthogneiss evidenced two periods of emplacement: -the relicts of the first phase, of Liassic age at 173 ± 9 Ma, are restricted to an uranium oxide; -the second phase, related to coffinites, represents the economical ore emplaced from Oligocene until Recent times, generated through remobilization of the Liassic stock. A comparison between the geochronological data from the ore, and of those from its granite host, suggests a genetic relationship between the Cadomian magmatism and the U-concentrations, spatially linked to the unconformity between the Les Palanges basement and its Permo-Carboniferous cover series. Metamictization of the source minerals combined with tectonic processes would be responsible for the release of uranium. Uranium-rich minerals from Bertholene, from Lodeve and from Les Pierres-Plantees have been subjected to trial dating by the isotopic Xe-Xe method, which confirms the evolution admitted for those occurrences. This technique is demonstrably expeditious and faithful. Various phenomena were investigated, at the scale of the crystalline structure, related to the xenon energy states and to the problem of rare

Possible uranium sources of Streltsovsky uranium ore field

International Nuclear Information System (INIS)

Zhang Lisheng

2005-01-01

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

On the problems of Ba, Pb, Zn Ple{e ore deposit (Slovenia

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Ivan Mlakar

2003-12-01

Full Text Available In this paper we present the years ago collected unpublished data on the Ple{e ore deposit which we completed also with some recent ones. They all speak against the offered interpretation of the geologic structure (Dozet, 1999, and especially against the Skythianage of this Ba, Pb and Zn deposit.We showed that the two large concordant barite bodies of syngenegtic origin are associated with an exactly determined horizon within the Carboniferous beds, that they were formed almost certainly in relation with the Asturian orogenic phase, and that theyoccur by chance in the hanging wall contact with the Skythian dolomite along a thrust plane. During Tertiary the epigenetic remobilization brought the ore substance from Paleozoic rocks into the mentioned dolomite. In one of the carefully investigated geochemictraverses the remobilization distance for Pb and Hg is 70 meters, and for Ba greater than 100 meters.For the existence of the PleŠe barite-bearing formation as conceived by Dozet (1999 there are no infallible proofs.

Geochemistry and geochronology of ore-bearing and barren intrusions in the Luanchuan ore fields of East Qinling metallogenic belt, China: Diverse tectonic evolution and implications for mineral exploration

Science.gov (United States)

Xue, Fei; Wang, Gongwen; Santosh, M.; Yang, Fan; Shen, Zhiwei; Kong, Liang; Guo, Nana; Zhang, Xuhuang; Jia, Wenjuan

2018-05-01

The Luanchuan ore fields form part of the East Qinling metallogenic belt in central China. In this study, we compare two ore-bearing intrusions, the Shibaogou granitic pluton (SBG) and the Zhongyuku granitic pluton (ZYK), with the ore-barren Laojunshan intrusion (LJS) from the Luanchuan ore field. Geochemically, all the three intrusions are characterized by high-Si, high-K, and alkalis, together with moderate-ASI, exhibiting I-type granite features. The rocks, especially the ore-related plutons also show enrichment in LREEs. Mineral chemistry of biotite from the intrusions exhibits similar features of high Si and Mg, and low Al and Fe. Zircon grains from the ZYK intrusion yielded a U-Pb age of 149.6 ± 2.4 Ma. The zircon grains show εHf (t) values and two stage model ages (TDM2) in the range of -16.8 to -19.7 and 1998-2156 Ma respectively. The biotite composition and Hf isotopic data indicate that the magma was derived by re-melting of deep crustal material with minor input of mantle components. We evaluate the results to understand the physico-chemical conditions, petrogenesis, and tectonic setting, and their implications for mineral exploration. The ore-bearing plutons show wide ranges of temperature and oxygen fugacity, favoring Mo-W mineralization. In addition, estimates on pressure and depth of emplacement suggest that lower solidification pressure in a decompressional setting contributed to the evolution of magmatic hydrothermal deposits. Our data suggest that the ZYK has the highest potential for Mo-W mineralization. The ore-bearing plutons of ZYK and SBG were formed in a transitional tectonic setting from compression to extension, with the large-scale metallogeny triggered by slab melts at ca. 145 Ma. However, the ore-barren LJS batholith formed in an extension-related geodynamic setting at ∼115 Ma. Our study shows that different tectonic settings and consequent physico-chemical conditions dictated the ore potential of the intrusions in the Luanchuan ore

Effect of moisture content on the flowability of crushed ores

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Cabrejos, Francisco

2017-06-01

In many mining and industrial processes where large quantities of non-degrading bulk materials such as crushed ores are handled, silos, hoppers, stockpiles and chutes are widely used because they are economical and reliable (if properly designed and operated). However, they are not free of trouble and may experience flow problems such as arching, ratholing, erratic flow, limited storage capacity, limited discharge flow rate, caking, segregation and/or flooding. Moisture content and fine particles significantly affect the flowability of most ores, increasing their cohesive strength and turning them more prone to these problems. The purpose of this article is to highlight a proven, scientific method that can be utilized to ensure reliable storage, flow and discharge of bulk solids in these equipment based on Jenike's flow-of-solids theory and laboratory testing. Knowledge of the flow properties of the material handled provides a design basis to ensure mass flow, avoid arching and prevent the formation of "ratholes". The effect of an increase in water content of the ore is discussed with experimental results.

Effect of moisture content on the flowability of crushed ores

Directory of Open Access Journals (Sweden)

Cabrejos Francisco

2017-01-01

Full Text Available In many mining and industrial processes where large quantities of non-degrading bulk materials such as crushed ores are handled, silos, hoppers, stockpiles and chutes are widely used because they are economical and reliable (if properly designed and operated. However, they are not free of trouble and may experience flow problems such as arching, ratholing, erratic flow, limited storage capacity, limited discharge flow rate, caking, segregation and/or flooding. Moisture content and fine particles significantly affect the flowability of most ores, increasing their cohesive strength and turning them more prone to these problems. The purpose of this article is to highlight a proven, scientific method that can be utilized to ensure reliable storage, flow and discharge of bulk solids in these equipment based on Jenike’s flow-of-solids theory and laboratory testing. Knowledge of the flow properties of the material handled provides a design basis to ensure mass flow, avoid arching and prevent the formation of “ratholes”. The effect of an increase in water content of the ore is discussed with experimental results.

Geology and ore deposits of the Section 23 mine, Ambrosia Lake District, New Mexico

International Nuclear Information System (INIS)

Granger, H.C.; Santos, E.S.

1986-01-01

The Section 23 mine is one of about 18 large uranium mines opened in sandstones of the fluvial Westwater Canyon Member of the Jurassic Morrison Formation, in the Ambrosia Lake uranium district, during the early 1960s. Two distinct types of unoxidized ore occur in the mine. One type consists of uranium-rich authigenic organic matter that impregnates parts of the reduced sandstone host rocks. This type of ore occurs as peneconcordant layers which are typically elongate east-southeast, subparallel both to the sedimentary trends and to the regional strike of the host rock. A second type of ore is essentially devoid of organic matter and occurs in thick zones which conform to interfaces that separate oxidized from reduced parts of the host rocks. Genesis of the second type of ore is similar to that of roll-type deposits in Tertiary rocks of Wyoming and Texas. Organic matter in the primary ores was probably introduced into the host rock as humic acids that precipitated in the pores of the sandstone. This material is inferred first to have fixed uranium as urano-organic compounds but with further diagenesis, to have released some of the uranium to form coffinite. Vanadium, molybdenum, and selenium are associated with primary ore and may also have been fixed by the organic matter. The secondary or roll-type ores contain uranium mostly in the form of coffinite and only rarely as uraninite. They also contain vanadium and selenium but are virtually devoid of molybdenum

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

International Nuclear Information System (INIS)

Duan Shuxin; Liu Hu

2014-01-01

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

Rapid photometric determination of phosphorus in iron ores and related materials as phosphomolybdenum-blue.

Science.gov (United States)

Bhargava, O P; Gmitro, M

1984-04-01

A rapid, simple and accurate method for determining phosphorus photometrically in iron ores and related materials, obviating the use of perchloric acid, is described. The sample is fused with sodium peroxide in a zirconium crucible and the melt dissolved in hydrochloric acid. The molybdenum-blue complex is developed by the addition of ammonium molybdate and hydrazine sulphate and the absorbance is measured at 725 nm. The range of the method is from 0.005 to 1.0% P. A batch of 6 samples can be analysed in about 2 hr.

Radon risk in ore miners

International Nuclear Information System (INIS)

Beno, M.

1997-01-01

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

Ore loses and dilution of the ore vein no. 4 in the Zletovo mine, Republic of Macedonia

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Bogatinovski Nikola L.

2017-01-01

Full Text Available Zletovo mines have a tradition of exploration and exploitation of vein lead-zinc ores for almost a century. Ore losses and dilutions have always been imperative in production since traditional old methods of mining and low-productivity mineralization are used. In conditions of classical and sub-level method excavations used, the calculated ore losses in ore vein No. 4 are 13.5%, while at the level of all excavations in the Zletovo mines dilution averages at 10%. Ore dilution is also an important technical parameter and several possible variants were calculated. When analyzing the dilution that occurs during the preparation of the sub-level corridor with parameters such: different drop angle (45-60o, constant thickness of 1.47 m as the average vein thickness in the calculated ore reserves, width of the sub-level corridor of 1.57 m or to the width of the ore vein No. 4 were added 10 cm (left and right to 5 cm as much as is taken in the calculation of the planned dilution and height of 2.5 m as suggested for this mining method, it can be noticed that the planned dilution during this method of mining ranges from 26.3% to 42.3%. In conditions of use of this underground method of excavation, parameters are selected that allow for the indicated lowering of the dilution. Namely, the thickness of the ore wire would be 1.47 m, the mining width would be 1.57 m, only 10 cm (left and right up to 5cm to the thickness of the ore vein will be added, the height difference between the consecutive levels would be 7.5 m, dip angle of 45 to 60°, and with the excavation the whole ore vein would be covered in height. On the basis of these parameters, models were prepared in which the ore vein would have a different dip angle, from which the values for the planned ore dilution ranged from 6.7 to 7.8%, which is significantly lower than the average dilution in the Zletovo Mine.

Analysis on depositional system and discussion on ore-formation conditions of channel sandstone type uranium deposit. Taking Dongsheng area, Ordos meso-cenozoic basin as an example

International Nuclear Information System (INIS)

Wu Rengui; Yu Dagan; Zhu Minqiang; Zhou Wanpeng; Chen Anping

2003-01-01

Applying the theory of depositional system, the depositional facies and depositional systems of the Zhiluo Formation in Dongsheng area are systematically analysed, and the authors proposed that sediments of the Zhiluo Formation are of fluvial facies, and streams of the Zhiluo time experienced three evolution stages, namely: the early braided stream, the middle low sinuosity meandering stream and the late high sinuosity meandering stream. Based on features of paleoclimatic evolution, the Zhiluo Formation is divided into two lithological members. The lower lithological member consists of sediments of braided and low sinuosity meandering streams under humid-ward paleoclimatic conditions forming grey sedimentary formation. The upper member is composed of sediments of meandering streams under arid-hot paleoclimatic conditions representing complex-colored (mainly red) sedimentary formation. It is suggested that uranium mineralization in the study area is of channel sandstone type and controlled by braided channel sediments. Besides, the ore-formation conditions for channel sandstone type uranium deposit are preliminarily discussed

Rare earth mobility in hydrothermal ore-forming systems

International Nuclear Information System (INIS)

Cornell, D.H.; Schade, J.; Scheepers, R.; Watkeys, M.K.

1988-01-01

Rocks and ores which form by magmatic processes display a range of chondrite-normalised rare earth profiles. One REE (rare earth elements) profile feature which seems unrelated to magmatic processes is the birdwing profile, in which both heavy and light rare earths are enriched relative to the middle rare earths. Birdwing rare earth profiles are an easily identified geochemical anomaly. It is proposed that rare earth geochemistry could be applied in geochemical prospecting for ore formed by hydrothermal processes. 5 figs

Textural, compositional, and sulfur isotope variations of sulfide minerals in the Red Dog Zn-Pb-Ag deposits, Brooks Range, Alaska: Implications for Ore Formation

Science.gov (United States)

Kelley, K.D.; Leach, D.L.; Johnson, C.A.; Clark, J.L.; Fayek, M.; Slack, J.F.; Anderson, V.M.; Ayuso, R.A.; Ridley, W.I.

2004-01-01

-column sulfate to form barite, and metals combined with H2S derived from bacterial sulfate reduction to form sulfides. Higher temperatures and salinities and relatively oxidized ore-stage fluids (stages 2 and 3) compared with stage 1 were probably important controls on the abundances and relative amounts of metals in the fluids and the resulting sulfide chemistry. Textural observations and isotopic data show that preexisting barite was reductively dissolved, providing a source of H2S for sulfide mineral formation. In stage 3, the continued flow of hydrothermal fluids caused thermal alteration of organic-rich mudstones and a build-up of methane that led to fluid overpressuring, hydrofracturing, and vein formation. Barite, red-brown sphalerite, and other sulfides were deposited in the veins, and preexisting barite was pervasively replaced by red-brown sphalerite. Hydrothermal activity ceased until Jurassic time when thrusting and large-scale fluid flow related to the Brookian orogeny remobilized and formed late tan sphalerite in tectonic breccias. ?? 2004 by Economic Geology.

Ore horizons, ore facies, mineralogy and geochemistry of volconogenic massive sulfide (VMS deposits of the Varandan Ba-Pb-Cu deposit, southwest of Qamsar - Iran

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Fayeq Hashemi

2017-11-01

Full Text Available Introduction The Varandan Ba-Pb-Cu deposits are located15 km southwest of the town of Qamsar and approximately 7 km south west of the Qazaan village, in the Urumieh- Dokhtar magmatic arc. The Kashan region that is situated in west-central Iran hosts several barite-base metal deposits and occurrences, the biggest ones are the Varandan Ba-Pb-Cu (case considered in this study and the Tapeh-Sorkh (Khalajmaasomi et al., 2010 and Dorreh Ba (Nazari, 1994 deposits. Previous researchers (Izadi, 1996; Farokhpey et al., 2010 have proposed an epithermal model for formation of the Varandan deposit. However, based on some feature of the deposit, it seems that this genetic model may not be correct. Therefore, it is necessary to do more precise research studies on the deposit. The main purpose of this paper is to discuss the genesis of the Varandan deposit based on geological, ore facies, mineralogy, wall rock alterations, and geochemical studies. Materials and methods A field study and sampling was performed during the summer of 2013. To assess the geochemical characteristics of the deposit, about 17 systematic samples from different ore facies of the first, second and third sub-horizon were collected for petrography and mineralogy, and for inductively coupled plasma-atomic emission spectroscopy(ICP-AES, X-ray diffraction (XRD and X-ray fluorescence (XRF geochemical analysis methods. The microscopic studies were done in the optics laboratory of the Shahrood University, and the geochemical analyzes were conducted in laboratories of the Center of Research and Mineral Processing Ore Minerals of Iran, Karaj, Iran. Results The host sequence in the Varandan deposit involves three units, from bottom to top: Unit1: grey, green siliceous tuff, brecciated tuff, crystal tuff and andesite; Unit2: white grey nummulitic limestone, limy tuff and marl: and Unit3: tuff breccia and crystal lithic tuff. Mineralization in the Varandan deposit has occurred as four ore sub

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

Science.gov (United States)

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

2007-10-01

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

Microbial reduction of iron ore

Science.gov (United States)

Hoffmann, M.R.; Arnold, R.G.; Stephanopoulos, G.

1989-11-14

A process is provided for reducing iron ore by treatment with microorganisms which comprises forming an aqueous mixture of iron ore, microorganisms operable for reducing the ferric iron of the iron ore to ferrous iron, and a substrate operable as an energy source for the microbial reduction; and maintaining the aqueous mixture for a period of time and under conditions operable to effect the reduction of the ore. Preferably the microorganism is Pseudomonas sp. 200 and the reduction conducted anaerobically with a domestic wastewater as the substrate. An aqueous solution containing soluble ferrous iron can be separated from the reacted mixture, treated with a base to precipitate ferrous hydroxide which can then be recovered as a concentrated slurry. 11 figs.

Geology and genesis of uranium deposits in sedimentary and metamorphic formation

International Nuclear Information System (INIS)

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

1980-01-01

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

Microbial leaching of low grade copper ores

International Nuclear Information System (INIS)

Rauf, A.; Ashfaq, M.

1991-01-01

Biotechnology is regarded as one of the most promising and revolutionary solution to various problems which are generally faced in the extraction of metals from their ores such as high energy, capital costs and environmental pollution. The paper deals with the study of low grade copper ores for their beneficiation and extraction of copper. The ores used were chalcopyrite and oxidized copper ores. Microorganisms play a vital role in the solubilization of valuable contents from ores such as copper and other metals. Studies have been conducted on the indigenous copper ores by using thiobacillus ferro oxidans and thiobacillus thio oxidans. For comparison purpose some experiments have also been conducted by chemical leaching. The results of bacterial leaching are encouraging. (author)

Chlorine/chloride based processes for uranium ores

International Nuclear Information System (INIS)

1980-11-01

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

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

International Nuclear Information System (INIS)

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

1989-01-01

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

A literature survey of the matallurgical aspects of minerals in Witwatersrand gold ores

International Nuclear Information System (INIS)

De Waal, S.A.

1982-01-01

This survey reviews the information in the literature on the auriferous rock formations in the Witwatersrand-Orange Free State gold-mining area, the gold-bearing horizons, and the mineralogy and petrography of the different ore types. The metallurgical aspects of the gold, silver, uranium, platinum-group elements, cobalt, nickel, copper, and chromite in these ores are examined and, on the strength of this information, a list is given of those problems in metallurgical extraction that are of a mineralogical nature. Finally, a number of research projects, aimed to support current research at the Council for Mineral Technology, are suggested

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

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

International Nuclear Information System (INIS)

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

2012-01-01

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

Geology and ore deposits of Johnny M mine, Ambrosia Lake District

International Nuclear Information System (INIS)

Falkowski, S.K.

1980-01-01

The Johnny M mine is one of very few mines in the Ambrosia Lake district with uranium ore in two members of the Morrison Formation (Jurassic); these members are the Westwater Canyon Sandstone and the Brushy Basin Shale. The Westwater Canyon ore is contained in the two upper sandstone units of the member, and the Brushy Basin ore is contained in the Poison Canyon sandstone (informal usage). The sedimentary features and structures in the Westwater Canyon sandstones indicate that the sediments were deposited by a system of aggrading braided streams, possibly at the distal end of coalescing alluvial fans. The Poison Canyon sandstone was probably the result of deposition in a complex environment of meandering and braided streams. Paleocurrent-direction indicators, such as fossilized-log orientation, foreset azimuths, and the axes of crossbeds and channel scours, suggest that the local palostream flow was to the east and southeast. The uranium mineralization is closely associated with 1) local accumulations of carbonaceous (humate) matter derived from the decay of organic material and 2) paleostream channels preserved in the rocks. The ore elements were derived from the leaching of volcanic air-fall tuffs and ash, which were introduced into the fluvial system during volcanic activity in the western United States. The mobile ore-element ions were reduce and concentrated by humic acids and bacteria present in the fluvial system and ultimately remobilized into the forms present today. The uranium is thus envisioned as forming either essentially on the surface as the sediments were being deposited or at very shallow depth

Radioactivity of Ore Sites of Lead, Zinc and Phosphate in Serbia

International Nuclear Information System (INIS)

Todorovic, D.; Jankovic, M.; Nikolic, J.; Kosutic, D.

2011-01-01

Natural resources such as ores contain radioactive nuclides at various concentrations. Therefore it is important to investigate the radioactivity in these resources as well as in the soil at the locations of ore deposits. For that reason we conducted preliminary measurements in the soil samples taken from the locations of lead and zinc ore deposits (Bosilegrad and Raska) and from the locations of phosphate ore deposits of phosphate (Bosilegrad). The activity concentrations of radionuclides in soil samples were determined by gamma spectrometry (HPGe detector, relative efficiency 23 %). Results showed the presence of natural radionuclides 226Ra, 232Th, 40K, 235U, 238U as well as the produced radionuclide 137Cs (from the Chernobyl accident). Ambient gamma radiation dose rate in ground level air was also measured. (author)

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

International Nuclear Information System (INIS)

1988-12-01

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

Method of continuous pressure leaching of ores

International Nuclear Information System (INIS)

Fiala, P.; Baloun, S.; Polansky, M.

1987-01-01

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.)

The Bairendaba silver polymetallic deposit in Inner Mongolia, China: characteristics of ore-forming fluid and genetic type of ore deposit

Science.gov (United States)

Wang, Ying; Xie, Yuling; Wu, Haoran

2018-02-01

Bairendaba silver-polymetallic deposit is located in the middle south of the Xing Meng orogenic belt, and in the silver-polymetallic metallogenic belt on the west slope of the southern of Great Xing’an Range. Based on studying of the fluid inclusion, we discuss the characteristics of ore-forming fluid and the metallic genesis of the Bairendaba silver-polymetallic deposit. By means of the analysis of the fluid inclusions, homogenization temperature, salinity and composition were studied in quartz and fluorite. The result is as the follows: with homogenization temperatures of fluid inclusions in quartz veins being 196∼312 °C, the average 244.52 °C, and fluid salinity 2.90∼9.08 wt%NaCl; with homogenization temperatures of fluid inclusions in fluorite being 127∼306 °C, the average 196.92 °C, and fluid salinity 2.90∼9.34 wt% NaCl. The ore-forming fluid is mainly composed of water and the gas. The results of laser Raman analysis show that the gas phase is mainly CH4. It shows that the ore-forming fluid is characterized by medium-low temperature and low-salinity system. The temperature of ore-forming fluid is from high to low, and the salinity from high to low, and the meteoric water or metamorphic water is added during deposit. According to the geological characteristics of the mining area, it is considered that the genetic type of the ore deposit should be the fault-controlled and the medium-low temperature hydrothermal deposit related to magmatic hydrothermal activities.

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

International Nuclear Information System (INIS)

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

1980-01-01

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

Control of Rock Mechanics in Underground Ore Mining

Science.gov (United States)

Golik, V. I.; Efremenkov, A. B.

2017-07-01

Performance indicators in underground mining of thick iron fields can be insufficient since geo-mechanic specifics of ore-hosting fields might be considered inadequately, as a consequence, critical deformations and even earth’s surface destruction are possible, lowering the indicators of full subsurface use, this way. The reason for it is the available approach to estimating the performance of mining according to ore excavation costs, without assessing losses of valuable components and damage to the environment. The experimental approach to the problem is based on a combination of methods to justify technical capability and performance of mining technology improvement with regard to geomechanical factors. The main idea of decisions to be taken is turning geo-materials into the condition of triaxial compression via developing the support constructions of blocked up structural rock block. The study was carried out according to an integrated approach based on the analysis of concepts, field observations, and simulation with the photo-elastic materials in conditions of North Caucasus deposits. A database containing information on the deposit can be developed with the help of industrial experiments and performance indicators of the field can be also improved using the ability of ore-hosting fields to develop support constructions, keeping the geo-mechanical stability of the system at lower cost, avoiding ore contamination at the processing stage. The proposed model is a specific one because an adjustment coefficient of natural and anthropogenic stresses is used and can be adopted for local conditions. The relation of natural to anthropogenic factors can make more precise the standards of developed, prepared and ready to excavation ore reserves relying on computational methods. It is possible to minimize critical stresses and corresponding deformations due to dividing the ore field into sectors safe from the standpoint of geo-mechanics, and using less cost

Crosslinking of SAVY-4000 O-rings as a Function of Aging Conditions

Energy Technology Data Exchange (ETDEWEB)

Van Buskirk, Caleb Griffith [Los Alamos National Lab. (LANL), Los Alamos, NM (United States)

2017-09-08

SAVY-4000 containers were developed as a part of DOE M 441.1-1 to protect workers who handle stored nuclear material from exposure due to loss of containment.1 The SAVY-4000 is comprised of three parts: a lid, a container, and a cross-linked fluoropolymer O-ring. Degradation of the O-ring during use could limit the lifetime of the SAVY-4000. In order to quantify the chemical changes of the Oring over time, the molecular weight between crosslinks was determined as a function of aging conditions using a swelling technique. Because the O-ring is a cross-linked polymer, it will absorb solvent into its matrix without dissolving. The relative amount of solvent uptake can be related to the degree of crosslinking using an equation developed by Paul Flory and John Rehner Jr3. This method was used to analyze O-ring samples aged under thermal and ionizing-radiation conditions. It was found that at the harsher thermal gaining conditions in absence of ionizing-radiation the average molecular weight between crosslinks decreased, indicating a rise in crosslinks, which may be attributable to advanced aging with no ionizing radiation present. Inversely, in the presence of ionizing radiation it was found that material has a higher level of cross-linking with age. This information could be used to help predict the lifetime of the O-rings in SAVY-4000 containers under service conditions.

The treatment of uranium ores

International Nuclear Information System (INIS)

Michel, P.

1979-01-01

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

Production of Schwarzmoeller briquets from weakly caking black coal and iron ore

Energy Technology Data Exchange (ETDEWEB)

Naundorf, W.

1986-01-01

Laboratory production is explained of coal and iron ore briquets suitable for metallurgy, using type 33 weakly caking black coal, iron ore concentrates from 3 Soviet mines and sulfite lye as binder. Coal and ore were finely ground to 0.3/0.0 mm grain size, briquetted at high pressure of 150 MPa and at 80 C temperature. The sulfite lye binder content ranged from 4 to 10% in the briquet mixture. Briquets were thermally treated up to 1000 C; the resulting coke lumps (Schwarzmoeller briquets) were analyzed for compression and abrasion strength. Detailed graphs of briquet and coke lump quality parameters are provided. The study shows that high quality metallurgical coke lumps are obtained by briquetting mixtures of black coal and iron ore in a mixture of about 70:30 with 4 to 9% addition of sulfite binder. Compression strength of coke lumps exceeded 35 MPa. The minimum black coal-iron ore mass relation for producing metallurgical coke lumps was 30:70 using 2 types of iron ore concentrates. The influence of adding limestone to the briquetting mixture and of coking conditions resembling the horizontal chamber oven process is also investigated. 5 references.

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

International Nuclear Information System (INIS)

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

2005-01-01

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

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

Energy Technology Data Exchange (ETDEWEB)

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

2005-07-11

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

Mineralogy and geochemistry of banded iron formation and iron ...

Indian Academy of Sciences (India)

The geological complexities of banded iron formation (BIF) and associated iron ores of Jilling–. Langalata iron ore ...... sure to sea water. Uranium in these samples varies ..... Ce oxidation and removal (Elderfield and Greaves. 1982; De Baar et ...

A novel stress distribution analytical model of O-ring seals under different properties of materials

International Nuclear Information System (INIS)

Wu, Di; Wang, Shao Ping; Wang, Xing Jian

2017-01-01

The elastomeric O-ring seals have been widely used as sealing elements in hydraulic systems. The sealing performance of O-ring seals is related to stress distribution. The stresses distribution depends on the squeeze rate and internal pressure, and would vary with properties of O-ring seals materials. Thus, in order to study the sealing performance of O-ring seals, it is necessary to describe the analytic relationship between stress distribution and properties of O-ring seals materials. For this purpose, a novel Stress distribution analytical model (SDAM) is proposed in this paper. The analytical model utilizes two stress complex functions to describe the stress distribution of O-ring seals. The proposed SDAM can express not only the analytical relationship between stress distribution and Young’s modulus, but also the one between stress distribution and Poisson’s ratio. Finally, compared results between finite element analysis and the SDAM validate that the proposed model can effectively reveal the stress distribution under different properties for O-ring materials

A novel stress distribution analytical model of O-ring seals under different properties of materials

Energy Technology Data Exchange (ETDEWEB)

Wu, Di; Wang, Shao Ping; Wang, Xing Jian [School of Automation Science and Electrical Engineering, Beihang University, Beijing (China)

2017-01-15

The elastomeric O-ring seals have been widely used as sealing elements in hydraulic systems. The sealing performance of O-ring seals is related to stress distribution. The stresses distribution depends on the squeeze rate and internal pressure, and would vary with properties of O-ring seals materials. Thus, in order to study the sealing performance of O-ring seals, it is necessary to describe the analytic relationship between stress distribution and properties of O-ring seals materials. For this purpose, a novel Stress distribution analytical model (SDAM) is proposed in this paper. The analytical model utilizes two stress complex functions to describe the stress distribution of O-ring seals. The proposed SDAM can express not only the analytical relationship between stress distribution and Young’s modulus, but also the one between stress distribution and Poisson’s ratio. Finally, compared results between finite element analysis and the SDAM validate that the proposed model can effectively reveal the stress distribution under different properties for O-ring materials.

A procedure for acid leaching of ores of the sandstone type, particularly of uranium ores

International Nuclear Information System (INIS)

Fiala, P.; Baloun, S.; Hinterholzinger, O.

1990-01-01

Ore mixed with the enriched fraction of the leached ore is leached with sulfuric acid at 5 to 220 degC. Bulky particles are sorted out from the mixture and reduced in size, and particles with a higher proportion of the useful component are separated from them. The latter particles constitute the enriched fraction of the leached ore, which is partially or completely returned to the mixture with the entering ore. The sorting should preferably be performed in an aqueous system. The assets of this procedure include a better homogenization of the mixture with the acid, a better stability of the reaction mixture which brings about reduced adhesion and solidification, and the possibility of extending the reaction time and increasing the temperature. The reduction in size makes for a better access of the leaching agent to the useful minerals, and the returning of the leachate to the reaction system spares sulfuric acid. (M.D.)

Evaluation of physical health and its relation with history of work accidents in workers of the Central Iron Ore Company of Iran

Directory of Open Access Journals (Sweden)

Gholam Hossein Halvani

2013-01-01

Full Text Available Aims: This study was conducted to determine the state of physical symptoms of the Iranian Central Iron Ore Company workers and its relation with history of work accidents. Materials and Methods: This cross-sectional descriptive study was performed at the Iranian Central Iron Ore Company and included 388 workers sampled randomly out of 2100 workers. Research tool was a two-part questionnaire that its reliability was determined by some of researchers. Data was analyzed by SPSS (Statistical Package for Social Science software and statistical tests included variance analysis and Pearson′ correlation tests. Results: According to the findings, 80.9% had favorable physical health conditions and there was a significant relationship between physical health condition, history of work accidents, cigarette smoking and type of work. Conclusion: Considering the strong relationship between physical health and history of work accidents, it is proposed that high-level managers of the Central Iron Ore Company of Iran should pay special attention to the improvement of physical health, psychological, social, and welfare levels.

Sources of Matter and Ore-Producing Fluid of the Tamunyer Gold-Sulfide Deposit (Northern Urals): Isotope Results

Science.gov (United States)

Zamyatina, D. A.; Murzin, V. V.

2018-02-01

The Tamunyer deposit is a typical example of gold-sulfide mineralization located in the lower lithologic-stratigraphic unit (S2-D1) of the Auerbach volcanic-plutonic belt. The latter comprises island-arc andesitic volcano-sediments, volcanics, and comagmatic intrusive formations. Carbonates have demonstrated intermediate values of δ13C between marine limestone and mantle. The quartz δ18O is in the range of 15.3-17.2‰. The δ34S of sulfides from the beresitized volcano-sedimentary rocks and ores varies widely from -7.5 to 12‰. The calculated isotope compositions of H2O, CO2, and H2S of the ore-bearing fluid imply two major sources of matter contributing to ore genesis: local rocks and foreign fluid. The ore-bearing fluid was formed by interaction and isotope equilibration between a deep magmatic fluid and marine carbonates (W/R 1), with the contribution of sulfur from the volcano-sedimentary rocks.

Four magnetite generations in the Precambrian Varena Iron Ore deposit, SE Lithuania, as a result of rock-fluid interactions

Science.gov (United States)

Skridlaite, Grazina; Prusinskiene, Sabina; Siliauskas, Laurynas

2017-04-01

Iron ores in Precambrian crystalline basement of the Varena area, SE Lithuania, were discovered during the detail geological-geophysical exploration in 1982-1992. They are covered with 210-500 m thick sediments. The Varena Iron Ore deposit (VIOD) may yield from 71 to 219.6 million tons of iron ore according to different economic evaluations (Marfin, 1996). They were assumed to be of metasomatic and hydrothermal origin, however several other hypotheses explaining the VIOZ origin, e.g. as a layered mafic or carbonatite intrusions were also suggested. Magnetites of the VIOD were thoroughly investigated by the Cameca SX100 microprobe at the Warsaw University and by the Quanta 250 Energy Dispersive Spectroscopy (EDS) at the Nature Research Centre in Vilnius, Lithuania. Four generations of magnetite were distinguished in the studied serpentine-magnetite ores (D8 drilling) and were compared with the earlier studied and reference magnetites. The earliest, spinel inclusion-rich magnetite cores (Mag-1) have the highest trace element contents (in wt%): Si (0.032), Al (0.167-0.248), Mg (0.340-0.405), Ti (0.215-0.254), V (0.090-0.138) etc. They might have formed during an early metamorphism and/or related skarn formation. Voluminous second magnetite (Mag-2) replacing olivine, pyroxenes, spinel and other skarn minerals at c. 540o C (Magnetite-Ilmenite geothermometer) has much lower trace element abundances, probably washed out by hydrothermal fluids. The latest magnetites (Mag-3 and Mag-4) overgrow the earlier ones and occur near or within the sulfide veins (Mag-4). As was observed from microtextures, the Mag-3 and Mag-4 have originated from the late thermal reworking by dissolution-reprecipitation processes. To imply an origin of the studied magnetites, they were compared to the earlier studied magmatic-metamorphic (1058 drilling), presumably skarn (982 drilling) magnetites from the studied area and plotted in the major magnetite ore type fields according to Dupuis and Beaudoin

EXPLANATORY MODEL OF SPOT PRICE OF IRON ORE

Directory of Open Access Journals (Sweden)

Juan Enrique Villalva A.

2015-11-01

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

Exploitation study of the ore-body ''Tigre III''. Open-cut design and study of high-recovery underground mining method for the Tigre III ore-body

International Nuclear Information System (INIS)

Baluszka, J.C.

1980-01-01

The paper first carries out an analysis for the purpose of determining the limiting sterile/ore ratio for open-cut and underground mining in the specific filling case of Tigre III. In this connection it considers a high-recovery method of underground mining (involving the use of cemented hydropneumatic chambers), a general mine plan covering access, transport, ventilation and removal of ore as well as auxiliary services relating to the Tigre III ore body as a whole. The costs of this method of mining are determined for purposes of comparison with the open-cut method. Similarly, the limiting sterile/ore ratio is taken as the basis for an analysis of different types of pit and a design suited to the limiting ratio is adopted. As a final solution the paper favours a method which combines open-cut and underground mining. It proposes the use of the open-cut method up to the limiting ratio (in accordance with the pit design chosen) and of underground method (by the filling chamber method) for the rest of the area. (author)

Introduction to ore geology

International Nuclear Information System (INIS)

Evans, A.M.

1987-01-01

This textbook on ore geology is for second and third year undergraduates and closely parallels the undergraduate course given in this subject at England's University of Leicester. The volume covers three major areas: (1) principles of ore geology, (2) examples of the most important types of ore deposits, and (3) mineralization in space and time. Many chapters have been thoroughly revised for this edition and a chapter on diamonds has been added. Chapters on greisen and pegmatite have also been added, the former in response to the changing situation in tin mining following the recent tin crisis, and the latter in response to suggestions from geologists in a number of overseas countries. Some chapters have been considerably expanded and new sections added, including disseminated gold deposits and unconformity-associated uranium deposits. The author also expands on the importance of viewing mineral deposits from an economic standpoint

Decomposition of aluminosilicate ores of Afghanistan by hydrochloric acid

International Nuclear Information System (INIS)

Mamatov, E.D.; Khomidi, A.K.

2015-01-01

Present article is devoted to decomposition of aluminosilicate ores of Afghanistan by hydrochloric acid. The physicochemical properties of initial aluminosilicate ores were studied by means of X-ray phase, differential-thermal analysis methods. The chemical and mineral composition of aluminosilicate ores was considered. The kinetics of acid decomposition of aluminosilicate ores composed of two stages was studied as well. The flowsheets of complex processing of aluminium comprising ores by means of chloric and acid methods were proposed.

Metalogenic study of the uraniferous ore deposit at La Coma, Municipio of General Bravo, N.L. Mexico

International Nuclear Information System (INIS)

Ferriz D, H.

1977-01-01

The uraniferous ore deposit at la Coma is located in a sandy-clayish sequence of the cold formation (non marine member) of the middle oligocene under peneconcordant lenses within a sandy body, situated on the North flank of a microdelta formed by small streams which ran from West to East. The metalogenic study of this ore deposit, permits us to establish mineralization controls and guides for the optimization of the uranium prospecting in the miogeoclinical of the Gulf of Mexico setting. The study was carried out on the basis of sedimentalogic and metalogenic criteria, and it was found that the mineralization process seems to be related to the formation and filling of a paleochannel which cut the microdelta permeable beds. The uraniferous solutions migrated through the conglomeratic filling of the paleochannel and reached this way the permeable horizons of the microdelta, where they infiltrated adopting a pattern like an apron. In the sites where the solutions reached sandy lenses rich in organic matter, the soluble compounds containing the uranium suffered a decomposition with the consequent absorption of the uranium by the organic matter, due to the decrease of the pH value. In conclusion, the favorableness of the environment for mineralization is defined by the convergence of the described paleo-geomorphologic elements. (author)

Depressurization and boiling of a single magmatic fluid as a mechanism for tin-tungsten deposit formation

OpenAIRE

Maximilian Korges; Philipp Weis; Volker Lüders; Oscar Laurent

2018-01-01

Tin (Sn) and tungsten (W) mineralization are commonly associated with each other in relation to highly evolved granites, but economical ore grades are restricted to rare global occurrences and mineralization styles are highly variable, indicating different mechanisms for ore formation. The Sn-W Zinnwald deposit in the Erzgebirge (Germany and the Czech Republic) in the roof zone of a Variscan Li-F granite hosts two contrasting styles of mineralization: (1) cassiterite (Sn) in greisen bodies, a...

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

China's emergence as the world's leading iron-ore-consuming country

Science.gov (United States)

Kirk, W.S.

2004-01-01

China has become the leading iron ore consuming nation, and, based on recent steel production capacity increases and plans for more, its consumption will almost certainly to continue to grow. China's iron ore industry, however, faces a number of problems. China's iron ore is low-grade, expensive to process, and its mines are being depleted. For many Chinese steelmakers, particularly in the coastal regions, the delivered cost of domestic iron ore, is more than the delivered cost of foreign ore. Thus China's iron ore imports are expected to increase. As China's growth continues, it will almost certainly surpass Japan to become the leading iron ore importing country as well. Without China's increasing appetite for iron ore, the world iron ore market would be flat or declining. China's recent imports largely offset the slump in demand in North America and Europe. China is regarded by the iron ore industry as the growth sector for the next decade. Although Chinese imports are expected to continue their rapid increase and imports in other Asian countries are expected to continue growing, there appears to be enough greenfield and expansion projects to meet future demand for iron ore worldwide. Present suppliers of iron ore, Australia, Brazil, India, and South Africa, will probably be the chief beneficiaries of China's increasing consumption of iron ore. How long China can continue its extraordinary growth is the primary issue for the future of the iron ore industry. Based on the number and size of planned blast furnaces it appears that China's growth could continue for several more years. ?? 2004 Taylor and Francis.

Improved leaching process for metal ores

International Nuclear Information System (INIS)

Kar-Kwan Yung, K.; Barlow, C.B.; Glass, J.R.

1980-01-01

The general overall sequence of process steps in the technique of the invention in set forth. In sequence, the ore is crushed, and solubilizing reagents and moisture are added to the crushed ore in preselected controlled portions. The mixture of ore, reagent, and moisture is then cured followed in the preferred process by conditioning for filtration. The slurry that is produced from conditioning is then subjected to multiple stage washing on a belt filter. The filtrate is further processed for metal value recovery and the solids are transported to tailings disposal

Trace-element and multi-isotope geochemistry of Late-Archean black shales in the Carajas iron-ore district, Brazil

DEFF Research Database (Denmark)

Cabral, A. R.; Creaser, R. A.; Naegler, T.

2013-01-01

The 250-300-m-thick Carajas Formation in the Carajas mineral province, northern Brazil, consists of banded iron formation (including giant high-grade iron-ore deposits) and minor black shale, overlying a thick pile (2-3 km) of about 2.75-Ga-old metabasalt. Carbonaceous shale with pyrite-and local...

Aqueous-chlorine leaching of typical Canadian uranium ores

International Nuclear Information System (INIS)

Haque, K.E.

1982-01-01

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

Mineralogical and paragenetical problems of the Mecsek uranium ore

International Nuclear Information System (INIS)

Vincze, J.; Fazekas, V.

1979-01-01

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

Radiometric enrichment of nonradioactive ores

International Nuclear Information System (INIS)

Mokrousov, V.A.; Lileev, V.A.

1979-01-01

Considered are the methods of mineral enrichment based on the use of the radioation of various types. The physical essence of enrichment processes is presented, their classification is given. Described are the ore properties influencing the efficiency of radiometric enrichment, methods of the properties study and estimation of ore enrichment. New possibilities opened by radiometric enrichment in the technology of primary processing of mineral raw materials are elucidated. A considerable attention is paid to the main and auxiliary equipment for radiometric enrichment. The foundations of the safety engineering are presented in a brief form. Presented are also results of investigations and practical works in the field of enrichment of ores of non-ferrous, ferrous and non-metallic minerals with the help of radiometric methods

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

International Nuclear Information System (INIS)

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

1995-01-01

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

Thermodynamic Analysis of the Selective Reduction of a Nickeliferous Limonitic Laterite Ore by Hydrogen

Science.gov (United States)

Elliott, R.; Pickles, C. A.

2017-09-01

Nickeliferous limonitic laterite ores are becoming increasingly attractive as a source of metallic nickel as the costs associated with recovering nickel from the sulphide ores increase. Unlike the sulphide ores, however, the laterite ores are not amenable to concentration by conventional mineral processing techniques such as froth flotation. One potential concentrating method would be the pyrometallurgical solid state reduction of the nickeliferous limonitic ores at relatively low temperatures, followed by beneficiation via magnetic separation. A number of reductants can be utilized in the reduction step, and in this research, a thermodynamic model has been developed to investigate the reduction of a nickeliferous limonitic laterite by hydrogen. The nickel recovery to the ferronickel phase was predicted to be greater than 95 % at temperatures of 673-873 K. Reductant additions above the stoichiometric requirement resulted in high recoveries over a wider temperature range, but the nickel grade of the ferronickel decreased.

Modeling of the fault-controlled hydrothermal ore-forming systems

International Nuclear Information System (INIS)

Pek, A.A.; Malkovsky, V.I.

1993-07-01

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

Geostatistical Approach to Estimating the Gold Ore Characteristics and Gold Reserves: A Case Study Daksa Area, Quang Nam Province, Viet Nam

Science.gov (United States)

Luan Truong, Xuan; Luong Le, Van; Quang Truong, Xuan

2015-04-01

Daksa gold deposit is the biggest gold deposits in Vietnam. The Daksa geological structure complicated, distributed mainly metamorphosed sedimentary NuiVu formation (PR3-?1nv2). The sulfide gold ore bodies distributed in quartz schist, quartz - biotite related to faut and distribution wing anticline. The gold ore bodies form circuits, network circuits, circuits lenses; fill the cup surface layer of the developing northeast - southwest; is the less than or west longitude north - SE. The results show that, Au and accompanying elements (Ag, Pb and Zn) have correlated pretty closely. All of its consistent with the logarithmic distribution standard, in accordance with the law of distribution of content mineral rare. The structure functions have nugget effect and spherical models with show that Au and accompanying elements special variation are changes. Au contents shown local anisotropy, no clearly anisotropy (K=1,17) and weakly anisotropy (K=1,4). Intensity mineralization of the ore bodies are quite high with demand spherical conversion coefficient ranging from 0.49 to 0.75 and from 0.66 to 0.97 (for other body). With nugget effects, ore bodies shown that it is consistent with mineralization in the ore bodies study, ore erasable, micro vein, infilling fractures in quartz vein. All of variogram presents local anisotropy, indicated gold mineralization at study area has least two-mineralization stages, consistent with the analysis of mineralography samples. By the results of the structure function study, the authors present the system optimization for exploration deposit and used to evaluate gold reserves by Ordinary Kriging. High accuracy of Kriging estimation results are expressed in the minimum Kriging variance, by compare the results calculated by some other methods (such as distance inverse weighting method, ..) and specially compare to the results of a some blocks have been exploited. Key words: Geostat and gold deposits VN. Daksa and gold mineralization. Geostat

A mineralogical investigation of the reduction of Mamatwan manganese ore with carbon

International Nuclear Information System (INIS)

Koursaris, A.; Kleyenstueber, A.S.E.; Finn, C.W.P.

1983-01-01

The paper describes two research programmes: small-scale experiments in which cubes (with sides of 20 mm) were heated with coke, coal, or graphite to temperatures of between 1 200 and 1 500 degrees Celsius for 1, 2 or 3 hours in an argon atmosphere; and large-scale experiments in which 4 kg charges of ore and coal, or of ore and coke, in stoichiometric proportions, were heated to temperatures between 1 300 and 1 600 degrees Celsius for up to four hours. The reacted charges were examined by microscopy, by X-ray diffraction analysis, and by X-ray microanalysis using an energy-dispersive system on a scanning electron microscope. It was found that the early stages of reduction involve complex mineralogical changes including the breakdown of braunite and gangue minerals, the reduction of the higher manganese oxides to manganous oxide and of hematite to metallic iron, and the formation of slag as a result of reaction between gangue and manganous oxides. Further reduction of the ore involves the carburisation of the metallic phase and the reduction of solid manganous oxide, or of manganous oxide dissolved in the slag, by solid carbon or carbon dissolved in the metal

Ore reserve estimation of uranium deposit Zirovski vrh

International Nuclear Information System (INIS)

Lukacs, E.

1979-01-01

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

Modelling a uranium ore bioleaching process

International Nuclear Information System (INIS)

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

1990-01-01

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

Pelletized vs. natural iron ore technology: energy, labor, and capital changes. Final report

Energy Technology Data Exchange (ETDEWEB)

Kakela, P.

1978-09-01

Total energy requirements per ton of iron-in-ore for natural and pelletized ore were calculated by a hybrid energy analysis. Energy requirements for ore preparation were subsequently considered as one energy input (embodied) to blast furnaces. Total energy requirements per ton molten iron were calculated for each year from 1955 through 1975 to identify changes attributable to the shift in iron ore preparation. Four results were found. (1) In practice, the lean ores are energetically superior. Pelletized ore requires more energy at the mine than natural ore, but pellets produce offsetting energy savings in the blast furnace. (2) Labor changes followed a similar pattern: man-hours per ton of molten iron increased at the mine with pelletization, but decreased at the blast furnance. Net labor required per ton of molten iron has decreased with pelletization. (3) Capital investments per ton of molten iron have increased greatly at iron ore mines with pelletization and decreased moderately at blast furnaces. New capital investment per ton of molten iron has increased with pelletization. (4) In the iron and steel industry, relatively low-priced energy held a substantial advantage over high-priced labor between 1950 and 1969. The industry, however, discovered that capital investments in pellet plants could save both labor and energy up to 1963; after 1963 capital and energy weresubstituted for labor. A sharp reversal of substitutional advantage occurred in 1970; energy jumped to the most costly factor. Thus capital presently shows a strong substitutional advantage over high-priced energy and intermediately-priced labor.

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

Directory of Open Access Journals (Sweden)

Hong-Rui Fan

2016-05-01

Full Text Available 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 E–W 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 ∼1400 and 440 Ma. The early mineralization peak closes in time to the intrusion of the carbonatite dykes. A significant thermal event at ca. 440 Ma resulted in the formation of late-stage veins with coarse crystals of REE

Computer finds ore

Science.gov (United States)

Bell, Peter M.

Artificial intelligence techniques are being used for the first time to evaluate geophysical, geochemical, and geologic data and theory in order to locate ore deposits. After several years of development, an intelligent computer code has been formulated and applied to the Mount Tolman area in Washington state. In a project funded by the United States Geological Survey and the National Science Foundation a set of computer programs, under the general title Prospector, was used successfully to locate a previously unknown ore-grade porphyry molybdenum deposit in the vicinity of Mount Tolman (Science, Sept. 3, 1982).The general area of the deposit had been known to contain exposures of porphyry mineralization. Between 1964 and 1978, exploration surveys had been run by the Bear Creek Mining Company, and later exploration was done in the area by the Amax Corporation. Some of the geophysical data and geochemical and other prospecting surveys were incorporated into the programs, and mine exploration specialists contributed to a set of rules for Prospector. The rules were encoded as ‘inference networks’ to form the ‘expert system’ on which the artificial intelligence codes were based. The molybdenum ore deposit discovered by the test is large, located subsurface, and has an areal extent of more than 18 km2.

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

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

International Nuclear Information System (INIS)

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

1982-01-01

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

The Application of Artificial Neural Networks to Ore Reserve Estimation at Choghart Iron Ore Deposit

Directory of Open Access Journals (Sweden)

Seyyed Ali Nezamolhosseini

2017-01-01

Full Text Available Geo-statistical methods for reserve estimation are difficult to use when stationary conditions are not satisfied. Artificial Neural Networks (ANNs provide an alternative to geo-statistical techniques while considerably reducing the processing time required for development and application. In this paper the ANNs was applied to the Choghart iron ore deposit in Yazd province of Iran. Initially, an optimum Multi Layer Perceptron (MLP was constructed to estimate the Fe grade within orebody using the whole ore data of the deposit. Sensitivity analysis was applied for a number of hidden layers and neurons, different types of activation functions and learning rules. Optimal architectures for iron grade estimation were 3-20-10-1. In order to improve the network performance, the deposit was divided into four homogenous zones. Subsequently, all sensitivity analyses were carried out on each zone.  Finally, a different optimum network was trained and Fe was estimated separately for each zone. Comparison of correlation coefficient (R and least mean squared error (MSE showed that the ANNs performed on four homogenous zones were far better than the nets applied to the overall ore body. Therefore, these optimized neural networks were used to estimate the distribution of iron grades and the iron resource in Choghart deposit. As a result of applying ANNs, the tonnage of ore for Choghart deposit is approximately estimated at 135.8 million tones with average grade of Fe at 56.14 percent. Results of reserve estimation using ANNs showed a good agreement with the geo-statistical methods applied to this ore body in another work.

Production of High-purity Magnetite Nanoparticles from a Low-grade Iron Ore via Solvent Extraction

Energy Technology Data Exchange (ETDEWEB)

Suh, Yong Jae; Kil, Dae Sup; Jang, Hee Dong [Korea Institute of Geoscience and Mineral Resources, Daejeon (Korea, Republic of); Do, Thi May [Korea University of Science and Technology, Daejeon (Korea, Republic of); Cho, Kuk [Pusan National University, Busan (Korea, Republic of)

2015-02-15

We produced magnetite nanoparticles (MNPs) and a Mg-rich solution as a nano-adsorbent and a coagulant for water treatment, respectively, using a low-grade iron ore. The ore was leached with aqueous hydrochloric acid and its impurities were removed by solvent extraction of the leachate using tri-n-butyl phosphate as an extractant. The content of Si and Mg, which inhibit the formation of MNPs, was reduced from 10.3 wt% and 15.5 wt% to 28.1 mg/L and < 1.4 mg/L, respectively. Consequently, the Fe content increased from 68.6 wt% to 99.8 wt%. The high-purity Fe{sup 3+} solution recovered was used to prepare 5-15-nm MNPs by coprecipitation. The wastewater produced contained a large amount of Mg{sup 2+} and can be used to precipitate struvite in sewage treatment. This process helps reduce the cost of both sewage and iron-ore-wastewater treatments, as well as in the economic production of the nano-adsorbent.

Analysis of copper-nickel ores by gamma-gamma method in ore enrichment works

International Nuclear Information System (INIS)

Bol'shakov, A.Yu.; Tovstenko, Yu.G.; Chinskij, E.B.; Eliseev, G.I.

1973-01-01

The paper presents experimental data on continuous gamma-gamma assay of copper-nickel ores on conveyor belts and of dry discrete samples of classifier overflow at the enrichment plants of the Pechenganikel' group. The relative errors are given of the results of comparison of two-hour rapid analyses and shift and 24-hour chemical analyses of classifier overflow samples with the figures for gamma-gamma assay. The factors affecting the accuracy of the latter technique are elucidated. Practical recommendations are given on the use of this technique at the above enrichment plants. (author)

Fifth Interim Status Report: Model 9975 PCV O-Ring Fixture Long-Term Leak Performance

International Nuclear Information System (INIS)

Daugherty, W.; Hoffman, E.

2010-01-01

life relative to the leak rate criterion. Failure data at lower temperatures is needed to verify this apparent trend. Insufficient failure data exist currently to perform a similar comparison for GLT-S O-rings. Aging and periodic leak testing will continue for the remaining fixtures.

Types of tectonic structures, sedimentary volcanogenetic formations of a mantle, favourable processes for exogenetic and polygenetic uranium deposits formation

International Nuclear Information System (INIS)

Danchev, V.I.; Komarnitskij, G.M.; Levin, V.N.; Shumlyanskij, V.A.

1985-01-01

Factors, affecting mineralization processes are considered. Characteristic features of uranium-bearing provinces are as follows: the presence of crust of continental type; deep-seated tectonic structures-rises and saggings, roofs, gneiss domes, rift zones and transform fractures; specialization for uranium of sedimentary and magmatic formations; the presence of manifestation regions of deep thermal and gaseous flow, etc. In uranium-bearing provinces territories favourable for the manifestation of different types of uranium mineralization: metamorphogenetic, polygenetic and exogenetic ones, are singled out. Different epochs of uranium ore formation are established. In sedimentary masses tectonic regime and climate are of special importance, and for epigenetic deposits, formed with an aid of underground waters-hydrogeological conditions. In the limits of the main structural elements of the Earth crust and geotectonic structures of higher orders the following types of sedimentary and volcanic formations can be singled out: 1-formations with exogenous uranium mineralization; 2-formations, accumulated in the epochs of epigenous ore formation; 3-formations fav ourable for epigenous uranium deposit formation; 4-formations unfavourable for the formation and localization of uranium mineralization

Correlation study of chemical elements in phosphate ores

International Nuclear Information System (INIS)

Braganca, Maura Julia Camara da Silva

1999-07-01

Geological phenomena, 1) endogenous (volcanism, magmatic flow, metasomatism); 2) metamorphic (resultant of action of high temperature and pressure) and; 3) exogenous (intemperism, contamination) can modify the chemical composition of rocks soils. Thus, chemical elements with little mobility can be used as indicators of the previous geological situation before the occurrence of these phenomena and can sign the chemical composition of the initial formation. The elements with great mobility can already be used as indicators of the characteristic and intensity of the changes, can point out the influence factors and its space and time conditions. In this work the results of the study of phosphated samples ores coming from two alkaline-carbonatitic chimneys (Araxa and Catalao) and from a meta sedimentary rock (Patos de Minas), located phosphate rock deposit, are presented. The results were obtained using the instrumental neutron activation analysis, inductively coupled plasma-mass spectrometry (ICP-MS) and ICP-AES techniques. A comparison of the three types of samples ores, using chemical, crystallographic and statistical methods, shows that the Araxa and Catalao present some geochemical similarities and they are distinguished of Patos de Minas, despite its geographic proximity. (author)

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

International Nuclear Information System (INIS)

Garcia Junior, O.

1989-01-01

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

The impact of bacteria of circulating water on apatite-nepheline ore flotation.

Science.gov (United States)

Evdokimova, G A; Gershenkop, A Sh; Fokina, N V

2012-01-01

A new phenomenon has been identified and studied-the impact of bacteria on the benefication process of non-sulphide ores using circulating water supply-a case study of apatite-nepheline ore. It is shown that bacteria deteriorate the floatability of apatite due to their interaction with active centres of calcium-containing minerals and intense flocculation, resulting in a decrease of the flotation process selectivity thus deteriorating the quality of concentrate. Based on the comparative analysis of primary sequences of 16S rRNA genes, there have been identified dominating bacteria species, recovered from the circulating water used at apatite-nepheline concentrating mills, and their phylogenetic position has been determined. All the bacteria were related to γ-Proteobacteria, including the Acinetobacter species, Pseudomonas alcaliphila, Ps. plecoglossicida, Stenotrophomonas rhizophila. A method of non-sulphide ores flotation has been developed with consideration of the bacterial factor. It consists in use of small concentrations of sodium hypochlorite, which inhibits the development of bacteria in the flotation of apatite-nepheline ores.

Acid pre-treatment method for in situ ore leaching

International Nuclear Information System (INIS)

Mallon, R.G.; Braun, R.L.

1975-01-01

An acid leaching method is described for the recovery of a desired element from a subterranean rubblized body of primary ore containing the element and also having associated therewith a carbonate mineral wherein the rubblized ore body is flooded with an aqueous acidic solution in order to release carbon dioxide from the associated carbonate mineral. After a substantial portion of the available carbon dioxide is released and removed from the ore body, as by venting to the atmosphere, an oxidizing gas is introduced into the flooded, rubblized ore to oxidize the ore and form an acid leach solution effective in the presence of the dissolved oxidizing gas to dissolve the ore and cause the desired element to go into solution. The leach solution is then circulated to the surface where the metal values are recovered therefrom

THE ROLE OF DYNAMOMETAMORPHISM IN THE FORMATION OF THE MUKODEK GOLD FIELD (NORTH PRIBAIKALIE

Directory of Open Access Journals (Sweden)

V. A. Vanin

2017-01-01

Full Text Available The Mukodek gold field is discussed as an example proving that dynamometamorphism is a major factor in the formation of gold deposits in the Abchad fault zone. This deposit belongs to the gold‐silver‐ore zones of mylonitization and schistosity. The ore source is related to the original host rocks with an increased geochemical background concentration of Au. Due to dynamometamorphism processes, gold particles are abundant and mostly enlarged. From the primary rocks, the dynamometamorphites inherit a positive correlation between the number of particles and the concentrations of gold. The dynamometamorphic complex of the ore field developed in two stages, as a minimum. At the early stage (321.0±1.9 Ma, the host rocks were mechanochemically deformed and transformed into the gold‐ bearing mineralized dynamometamorphites containing sericite, chlorite, ankerite, albite, and quartz. In the second stage (280±15 Ma, the albite‐dolomite‐quartz ore veins were formed. Such veins have industrial gold contents.

Vanadium-bearing titaniferous iron ores from the Rooiwater, Usushwana, Mambula, Kaffirskraal, and the Trompsburg igneous complexes

International Nuclear Information System (INIS)

Reynolds, A.M.

1979-01-01

The mineralogy and chemistry of some vanadium-bearing titaniferous iron ores from a number of smaller South African basic intrusions are reported, and an assessment is given of the potential of these ores for use as raw materials in the production of iron, high-titania slag, and vanadium pentoxide. The ores from each complex can be distinguised readily on the basis of their chemical composition and textural relations. The Rooiwater Complex represents the most promising area. It contains two layers of titaniferous magnetite, each approximately 8 m thick, in the eastern part, the lowest seam being chemically similar to the economically important main layer of titaniferous magnetite in the Bushveld Complex. The ores are silicate-poor and consist largely of multi-phase titaniferous-magnetite grains containing modified ilmenite and pleonaste micro-intergrowths. The coarse grain size of these ores favours beneficiation, and they can be partially treated to yield ilmenite concentrates and low-titania magnetite fractions in which the content of vanadium pentoxide is higher than that in the original ores. The Mambula ores are silicate-rich and would require extensive beneficiation. The Kaffirskraal ores consist of multi-phase grains of titaniferous magnetite containing crystallographically oriented ilmenite, ulvospinel, and pleonaste micro-intergrowths. Minor coarser-grained ilmenite is also present. The Usushwana ores are texturaly similar but contain abundant lamellar ilmenite in place of the ulvospinel. The ores from these two complexes cannot be beneficiated by conventional ore-dressing techniques, and would require direct metallurgical treatment for the recovery of iron, titania, and vanadium pentoxide [af

Stable isotope and geochronological study of the Mawchi Sn-W deposit, Myanmar : implications for timing of mineralization and ore genesis.

OpenAIRE

Myint, A.Z.; Yonezu, K.; Boyce, A.; Selby, D.; Scherstén, A.; Tindell, T.; Watanabe, K.; Swe, Y.

2018-01-01

Myanmar is endowed with abundant Sn-W mineralization, pre-eminent amongst which is the world-class Mawchi deposit. In the Mawchi area, N-S trending vertical or steeply dipping quartz veins are hosted by both Eocene granite and Carboniferous to Early Permian metasediments. Three stages of ore formation are recognized; (i) tourmaline-cassiterite stage (ii) main ore stage and (iii) sulfide stage. Tourmaline, cassiterite and pyrite-I are early-formed minerals and are representative of the first s...

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

International Nuclear Information System (INIS)

Li Xigen

2002-01-01

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

Composite correlation filter for O-ring detection in stationary colored noise

Science.gov (United States)

Hassebrook, Laurence G.

2009-04-01

O-rings are regularly replaced in aircraft and if they are not replaced or if they are installed improperly, they can result in catastrophic failure of the aircraft. It is critical that the o-rings be packaged correctly to avoid mistakes made by technicians during routine maintenance. For this reason, fines may be imposed on the o-ring manufacturer if the o-rings are packaged incorrectly. That is, a single o-ring must be packaged and labeled properly. No o-rings or more than one o-ring per package is not acceptable. We present an industrial inspection system based on real-time composite correlation filtering that has successfully solved this problem in spite of opaque paper o-ring packages. We present the system design including the composite filter design.

Ore potential of basic rocks in Finland

International Nuclear Information System (INIS)

Reino, J.; Ekberg, M.; Heinonen, P.; Karppanen, T.; Hakapaeae, A.; Sandberg, E.

1993-02-01

The report is associated with a study programme on basic rocks, which has the aim to complement the preliminary site investigations on repository for TVO's (Teollisuuden Voima Oy) spent nuclear fuel. The report comprises a mining enterprise's view of the ore potential of basic plutonic rocks in Finland. The ores associated with basic plutonic rocks are globally known and constitute a significant share of the global mining industry. The ores comprise chromium, vanadium-titanium-iron, nickel-copper and platinum group element ores. The resources of the metals in question and their mining industry are examined globally. A review of the use of these metals in the industry is presented as well. General factors affecting the mining industry, such as metal prices, political conjunctures, transport facilities, environmental requirements and raw material sources for the Finnish smelters have been observed from the point of view of their future effect on exploration activity and industrial development in Finland. Information on ores and mineralizations associated with Finnish basic rocks have been compiled in the report. The file comprises 4 chromium occurrences, 8 vanadium-titanium-iron occurrences, 13 PGE occurrences and 38 nickel-copper occurrences

Testing of X-ray radiometric enrichnment of polymetallic ores

International Nuclear Information System (INIS)

Eliseev, N.I.; Panova, N.I.; Kirbitova, N.V.; Shramm, E.O.; Efremov, Yu.G.

1987-01-01

Testing of X-ray radiometric method of sorting of polymetallic ores using the developed X-ray radiometric device was conducted. It was shown that introduction of preliminary concentration at the factory made the method of fragment separation to be the perspective one, enabling to elevate the factory production with respect to commercial ore and reduce the cost of ore processing. In the case of preliminary concentration, conducted at the mine, it is advisable to perform ore sorting in the flow formed to monolayer

X-ray fluorescence separation of pure lead-zinc ores

International Nuclear Information System (INIS)

Lapshin, S.A.; Filippov, O.K.; Khachatryan, L.S.; Rudnev, B.P.

1987-01-01

To evaluate the influence of the previous concentration of polymetallic ores by the radiometric separation method on indices of flotation and gravitation enrichments, investigations were carried out using ore sample (1.94%Pb, 1.13% Zn) from a lead-zink ore deposit. It is shown that the results obtained on the enrichment of the ore and products of X-ray radiometric separation are similar. However previous removal (up to 40%) of dead rock permits to reduce sharply grinding and transpot costs

New insight into the origin of manganese oxide ore deposits in the Appalachian Valley and Ridge of northeastern Tennessee and northern Virginia, USA

Science.gov (United States)

Carmichael, Sarah K.; Doctor, Daniel H.; Wilson, Crystal G.; Feierstein, Joshua; McAleer, Ryan J.

2017-01-01

Manganese oxide deposits have long been observed in association with carbonates within the Appalachian Mountains, but their origin has remained enigmatic for well over a century. Ore deposits of Mn oxides from several productive sites located in eastern Tennessee and northern Virginia display morphologies that include botryoidal and branching forms, massive nodules, breccia matrix cements, and fracture fills. The primary ore minerals include hollandite, cryptomelane, and romanèchite. Samples of Mn oxides from multiple localities in these regions were analyzed using electron microscopy, X-ray analysis, Fourier transform infrared spectroscopy, and trace and rare earth element (REE) geochemistry. The samples from eastern Tennessee have biological morphologies, contain residual biopolymers, and exhibit REE signatures that suggest the ore formation was due to supergene enrichment (likely coupled with microbial activity). In contrast, several northern Virginia ores hosted within quartz-sandstone breccias exhibit petrographic relations, mineral morphologies, and REE signatures indicating inorganic precipitation, and a likely hydrothermal origin with supergene overprinting. Nodular accumulations of Mn oxides within weathered alluvial deposits that occur close to breccia-hosted Mn deposits in Virginia show geochemical signatures that are distinct from the breccia matrices and appear to reflect remobilization of earlier-emplaced Mn and concentration within supergene traps. Based on the proximity of all of the productive ore deposits to mapped faults or other zones of deformation, we suggest that the primary source of all of the Mn may have been deep seated, and that Mn oxides with supergene and/or biological characteristics resulted from the local remobilization and concentration of this primary Mn.

Technical and economic benefits of nuclear techniques in ore processing

International Nuclear Information System (INIS)

1989-08-01

This report is the outcome of an Advisory Group Meeting organized by the Agency and hosted by the Institute of Physics and Nuclear Techniques, the Academy of Mining and Metallurgy in Krakow, Poland. The purpose of the meeting was to assess the technical and economic benefits of applying nuclear techniques in ore processing industry. Nucleonic control systems and nuclear on-line analytical techniques as well as radioisotope tracer tests and their applications in metallic ore-processing, coal production, and cement fabrication were discussed. This report contains a summary and the presentations dealing with nuclear techniques for process control made at this meeting. Using a number of case-histories as examples, it illustrates technical and economic benefits obtainable by the installation of nuclear process control instrumentation. It is expected to be useful for everybody dealing with ore and coal production, but especially for administrative personnel and engineers who plan and implement national development programmes related to mineral resources. Refs, figs and tabs

Multi-column bioleaching of a uranium ore

International Nuclear Information System (INIS)

Meng Yunsheng; Zheng Ying; Liu Hui; Cheng Hao

2014-01-01

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

Iron from Zealandic bog iron ore -

DEFF Research Database (Denmark)

Lyngstrøm, Henriette Syrach

2011-01-01

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

Phosphate ore beneficiation via determination of phosphorus-to-silica ratios by Laser Induced Breakdown Spectroscopy

International Nuclear Information System (INIS)

Asimellis, George; Giannoudakos, Aggelos; Kompitsas, Michael

2006-01-01

We report development and application of an in-situ applicable method to determine phosphate ore rock quality based on Laser-Induced Breakdown Spectroscopy (LIBS). This is an economically viable method for real-time evaluation of ore phosphate rocks in order to separate high-silica pebbles prior to deep beneficiation. This is achieved by monitoring relative emission line intensities from key probe elements via single laser ablation shots: the ratio of the phosphorous to silica line intensities (P/Si ratio) provides a simple and reliable indicator of ore rock quality. This is a unique LIBS application where no other current analytical spectroscopic method (ICP or XRF) can be applied. Method development is discussed, and results with actual ore samples are presented

Methods of evaluating ore processing and effluent treatment for Cigar Lake ore at the Rabbit Lake Mill

International Nuclear Information System (INIS)

Edwards, C.R.

2002-01-01

Cigar Lake is the second-largest, high grade uranium orebody in the world. Mineable reserves for Cigar Lake Phase 1 are estimated at 191 million pounds U 3 O 8 with a grade of 25.6% U 3 O 8 . Subject to regulatory approval, Cameco intends to process the majority of ore from Cigar Lake in the Rabbit Lake mill. Cameco initiated a programme to study the processing of Cigar Lake ore and the treatment of the resulting waste streams. Laboratory and follow-up pilot scale ore leaching tests with Cigar Lake ore samples were performed. Tailings and effluents were generated from the products of the pilot scale leach tests. Mill process tailings were blended with ground waste rock. Using these materials, geotechnical and geochemical properties, including long term tailings pore water characteristics, will be evaluated. In addition, proposed changes to the mill waste treatment operations were developed to deal with increased levels of arsenic and radium in the waste streams. This paper describes the methods and techniques Cameco used in this programme. (author)

Experiment on bio-leaching of associated molybdenum and uranium ore

International Nuclear Information System (INIS)

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

2007-01-01

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

Collective sulphide flotation of the polymetallic molybdenic ore

International Nuclear Information System (INIS)

Mazanek, C.; Maselko, J.; Rycerz, L.

1980-01-01

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)

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

International Nuclear Information System (INIS)

Mingarro Martin, E.; Marin Benavente, C.

1969-01-01

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

Bacterial bioleaching of low grade nickel limonite and saprolite ores by mixotrophic bacteria

Directory of Open Access Journals (Sweden)

Chaerun Siti Khodijah

2016-01-01

Full Text Available Utilization of indigenous bacteria should be considered to establish a successful biohydrometallurgical process. In this study, mixrotrophic iron-oxidizing bacterial consortia consisting of Comamonas testosteroni, Alicyclobacillus ferrooxydans and Pantoea septic which were isolated from Indonesian mineral ores were examined to determine their abilities to recover nickel from limonite and saprolite ores in the bioleaching experiments using stirred tank reactors. The nickel bioleaching experiments inoculated with the bacterial consortia were carried out using coarse limonite ores and weathered saprolite ores with pulp density of 10% w/v. Abiotic controls were also carried out replacing the inocula by the sterile medium. The bioleaching processes were monitored by measuring Ni and Fe contents and pH of the leaching solution as well as the total bacterial enzymatic activity measured as FDA hydrolytic activity. The effect of leaching on the mineralogy of laterite ores was investigated by the scanning electron microscope equipped with energy-dispersive spectroscopy (SEM-EDS and X-ray powder diffraction (XRD. After 28 days of incubation, the FDA hydrolytic activity was observed in both bioleaching experiments containing limonite (17.2 μg fluorescein/mL and saprolite ores (16.9 μg fluorescein/mL. The leached Ni and Fe in the bioleaching experiments containing limonite ores (30% Ni and 5.6% Fe was greater than that in abiotic controls (1% Ni and 0.1% Fe with the pH range of 2.5 to 3.5. However, the bacterial consortia were less capable of bioleaching of Ni (2.5% with the similar leached Fe (6% from the saprolite ores. In abiotic controls, the medium pH remained relatively constant (pH 6. It was concluded that these bacterial isolated as the consortium were capable of nickel bioleaching (precious metal more effectively than iron (gangue metal, thus being applicable to the commercial processing of the difficult-to-process low-grade nickel laterite ores

The role of granites for the ore mineralization in South German Variscides

International Nuclear Information System (INIS)

Dill, H.G.

1987-01-01

Granites are of widespred occurrence in the South German Variscides (F.R. of Germany), the Black Forest (=BF), and the NE Bavarian Basement (=NEBB). These areas are crossed by the Saxothuringian-Moldanubian plate boundary and were also affected by crustal subdulction and nappe tectonism, both of which are thought to be responsible for granitisation and enrichment of Sn, W,U,Au, Sb,Pb,Zn,F, and Ba in veins of different kind. Heat produced by gliding of plates above each other, by decay of radioctive elements in granites as well as set free by the granites themselves caused the above-mentioned elements to be released from their protores, which formed during Late Proterozoic and Early Paleozoic rifting. These hypogene ore mineralizations may be crudely subdivided into thrustbound, granite-related and granite-induced ore deposites. During Tertiary-Quaternary these granites were exposed the pervasive weathering under subtropical conditions, so that ''U yellow ores'' and china clay deposits came into existence. The whole ore mineralization in that region may be explained by a simple four-step model: preconcentration, fracturation, activation and peneplaination. (author) [pt

Formation conditions for regenerated uranium blacks in uranium-molybdenum deposits

International Nuclear Information System (INIS)

Skvortsova, K.V.; Sychev, I.V.; Modnikov, I.S.; Zhil'tsova, I.G.

1980-01-01

Formation conditions of regenerated uranium blacks in the zone of incomplete oxidation and cementation of uranium-molybdenum deposit have been studied. Mixed and regenerated blacks were differed from residual ones by the method of determining excess quantity of lead isotope (Pb 206 ) in ores. Determined were the most favourable conditions for formation of regenerated uranium blacks: sheets of brittle and permeable volcanic rocks characterized by heterogeneous structure of a section, by considerable development of gentle interlayer strippings and zones of hydrothermal alteration; predominance of reduction conditions in a media over oxidation ones under limited oxygen access and other oxidating agents; the composition of hypogenic ores characterized by optimum correlations of uranium minerals, sulfides and carbonates affecting violations of pH in oxidating solutions in the range of 5-6; the initial composition of ground water resulting from climatic conditions of the region and the composition of ore-bearing strata and others. Conditions unfavourable for the formation of regenerated uranium blacks are shown

Origin of ores of endogeneous uranium ore deposits

International Nuclear Information System (INIS)

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

1976-01-01

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

Supplying the six. [Supplies of nuclear fuels and ores to the European Community

Energy Technology Data Exchange (ETDEWEB)

Oboussier, F

1975-07-01

Under the Euratom Treaty, the European Community must ensure that all users in the Community receive a regular and equitable supply of ores and nuclear fuels. Supply to users in the Community of ores, source materials, and special fissile materials is based on the principle of equal access of the users to the supply sources. To ensure such equal access, the Treaty prohibits all practices designed to secure a privileged position for certain users. In addition, an agency has been set up with two essential rights--that of an option on all ores, source materials, and special fissile materials produced in the territories of the Member States; and the exclusive right to conclude all contracts relating to the supply of ores, source materials, and special fissile materials coming from inside the Community or from outside. Dealings of the Agency with outside agencies, especially the former US AEC, are described. The uranium market and its economics and the availability of special fissile materials are summarized. (MCW)

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

International Nuclear Information System (INIS)

Mueller, T.

2014-01-01

Dozens cases of disease of former or present uranium and ore miners are submitted to judgment as occupational diseases every year in the Czech Republic. Patients or attending physicians suggest that these cases are caused by occupational ionizing radiation. Only a part of these cases is qualified as occupational disease. The term 'occupational disease' is rather juridical term which underlies the right to financial compensation. The causal association with exposure to ionizing radiation cannot be indisputably verified by expert medical opinion. Most diseases in uranium and ore miners, which are proposed as occupational disease, are malignant tumors. The majority of judged cases are lung cancers from radioactive agents. The lecture gives general information about all judged cases of occupational diseases in former uranium and ore miners in the Czech Republic in the years 2002 - 2013. In the period 2002-13 were 40-80 cases submitted to judgment as potential occupational disease every year. (authors)

Geochemistry and ore prospecting; Geochimie et prospection miniere

Energy Technology Data Exchange (ETDEWEB)

Le Caignec, R. [Commissariat a l' Energie Atomique, Saclay(France). Centre d' Etudes Nucleaires

1954-07-01

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) [French] La geochimie appliquee est une nouvelle technique qui vient aider le geologue dans la detection des gisements de minerais. Certains gisements, meme lorsqu'ils sont recouverts par des formations superficielles relativement epaisses, creent autour d'eux des zones ou la teneur infinitesimale des sols ou des eaux en certains elements varie notablement. Ces ''anomalies'' peuvent etre contemporaines de la formation du gisement (dispersion primaire) ou posterieures a celle-ci (dispersion secondaire). De nombreux facteurs gouvernent ces anomalies: stabilite du minerai, homogeneite du sol, regime des eaux, topographie, vegetation, etc... L'etude des techniques d'analyse des traces de metaux dans les sols et l'interpretation geologique des anomalies obtenues constituent la geochimie appliquee. Ce rapport contient, en outre, des donnees pratiques sur les procedes d'echantillonnage, le rendement, les prix de revient, ainsi que sur quelques problemes particuliers a la geochimie de l'uranium. (auteur)

Geochemistry and ore prospecting; Geochimie et prospection miniere

Energy Technology Data Exchange (ETDEWEB)

Le Caignec, R [Commissariat a l' Energie Atomique, Saclay(France). Centre d' Etudes Nucleaires

1954-07-01

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) [French] La geochimie appliquee est une nouvelle technique qui vient aider le geologue dans la detection des gisements de minerais. Certains gisements, meme lorsqu'ils sont recouverts par des formations superficielles relativement epaisses, creent autour d'eux des zones ou la teneur infinitesimale des sols ou des eaux en certains elements varie notablement. Ces ''anomalies'' peuvent etre contemporaines de la formation du gisement (dispersion primaire) ou posterieures a celle-ci (dispersion secondaire). De nombreux facteurs gouvernent ces anomalies: stabilite du minerai, homogeneite du sol, regime des eaux, topographie, vegetation, etc... L'etude des techniques d'analyse des traces de metaux dans les sols et l'interpretation geologique des anomalies obtenues constituent la geochimie appliquee. Ce rapport contient, en outre, des donnees pratiques sur les procedes d'echantillonnage, le rendement, les prix de revient, ainsi que sur quelques problemes particuliers a la geochimie de l'uranium. (auteur)

Mining of sedimentary-type ore deposits

International Nuclear Information System (INIS)

Bruha, J.; Slovacek, T.; Berka, J.; Sadilek, P.

1992-01-01

A procedure is proposed for mining sedimentary-type ore deposits, particularly uranium deposits, using the stope-pillar technique. The stope having been mined out, the free room is filled with hydro-setting gob from the surface. A precondition for the application of this technique is horizontal ore mineralization in sediments where the total thickness of the mineralized ore layer is at least 3 to 5 m. Mining losses do not exceed 5%. For thicknesses greater than 5 m, the roof is reinforced and the walls are secured with netting. The assets of the technique include higher labor productivity of the driving, lower material demands in reinforcing and filling, lower power consumption, and reduced use of explosives. (Z.S.). 3 figs

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 D...

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

International Nuclear Information System (INIS)

Ludwig, K.R.; Grauch, R.I.; Nutt, C.J.; Frishman, D.; Nash, J.T.; Simmons, K.R.

1985-01-01

The Ranger and Jabiluka uranium deposits are the largest in the Alligator Rivers Uranium Field (ARUF), which contains at least 20% of the world's low-cost uranium reserves. Ore occurs in early Proterozoic metasediments, below an unconformity with sandstones of the 1.65 Ga Kombolgie Formation. This study uses U-Pb isotope data from over 60 whole-rock drill core samples that contained a variety of mineral assemblages and textures. Data for Ranger samples indicate a well-defined age of 1.74 +/-.02 Ga. This 1.74 Ga age is distinctly pre-Kombolgie, so the Ranger deposit cannot have been formed by processes requiring its presence. This Ranger age is consistent, however, with mineralization related to heating associated with either the emplacement of early post-metamorphic granites, or possibly with intrusion of the nearby Oenpelli Dolerite. In contrast, data for the least-altered Jabiluka ores yield a concordia-intercept age of 1.44 +/-.02 Ga--significantly younger than the Ranger age, and also younger than the Komobolgie. This age may correspond to a regional thermal event, as indicated both by mafic dikes of roughly this age and a zircon lower-intercept age from a nearby granite-gneiss. Thus, together with the well-defined ∼900 Ma age of ores at the Nabarlek deposit, there are at least 3 distinct periods of major U-mineralization in the ARUF. Data for both Ranger and Jabiluka indicate the same, profound isotopic disturbance at some time in the interval of 0.4-0.6 Ga. Possibly this time corresponds to the development of basins and associated basalt flows to the W and SW, a suggested by Crick et. al. (1980)

In situ carbonate leaching and recovery of uranium from ore deposits

International Nuclear Information System (INIS)

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

1979-01-01

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

Phase transformations of siderite ore by the thermomagnetic analysis data

Energy Technology Data Exchange (ETDEWEB)

Ponomar, V.P., E-mail: vitaliyponomar.vp@gmail.com; Dudchenko, N.O.; Brik, A.B.

2017-02-01

Thermal decomposition of Bakal siderite ore (that consists of magnesium siderite and ankerite traces) was investigated by thermomagnetic analysis. Thermomagnetic analysis was carried-out using laboratory-built facility that allows automatic registration of sample magnetization with the temperature (heating/cooling rate was 65°/min, maximum temperature 650 °C) at low- and high-oxygen content. Curie temperature gradually decreases with each next cycles of heating/cooling at low-oxygen content. Curie temperature decrease after 2nd cycle of heating/cooling at high-oxygen content and do not change with next cycles. Final Curie temperature for both modes was ~320 °C. Saturation magnetization of obtained samples increases up to 20 Am{sup 2}/kg. The final product of phase transformation at both modes was magnesioferrite. It was shown that intermediate phase of thermal decomposition of Bakal siderite ore was magnesiowustite. - Highlights: • Mg-siderite decomposition was investigated by thermomagnetic analysis. • Magnetization and Curie temperature change with each next cycle of heating/cooling. • Magnesioferrite is the final phase of Mg-siderite thermal decomposition. • Transformation exclude the hematite formation.

New understanding on separation of Mn and Fe from ferruginous manganese ores by the magnetic reduction roasting process

Science.gov (United States)

Liu, Bingbing; Zhang, Yuanbo; Wang, Juan; Wang, Jia; Su, Zijian; Li, Guanghui; Jiang, Tao

2018-06-01

Magnetic reduction roasting followed by magnetic separation process is reported as a simple route to realize separation of Mn and Fe from ferruginous manganese ores (Fe-Mn ores). However, the separation and recovery of Mn and Fe oxides are not very effective. This work clarified the underlying reason for the poor separation and also proposed some suggestions for the magnetic reduction process. In this work, the effect of temperature on the magnetic reduction roasting - magnetic separation of Fe-Mn ore was investigated firstly. Then the reduction behaviors of MnO2-Fe2O3 system and MnO2-Fe2O3-10 wt.%SiO2 system under 10 vol.% CO-90 vol.% CO2 at 600-1000 °C were investigated by XRD, XPS, SEM-EDS, VSM, DSC and thermodynamics analyses. Reduction and separation tests showed that higher reduction temperature was beneficial to the recovery of iron while it's not in favor of the recovery of manganese when the temperature was over 800 °C. The formation of composite oxide MnxFe3-xO4 with strong magnetism between the interface of the MnO2 and Fe2O3 particles leaded to the poor separation of iron and manganese. In addition, the formation mechanism of MnxFe3-xO4 from MnO2 and Fe2O3 as well as the interface reaction reduced under 10 vol.% CO was discussed in this study. Finally, some suggestions were recommended for the magnetic reduction roasting for utilizing the Fe-Mn ores effectively.

Turbulent shear flow downstream of a sphere with and without an o-ring located over a plane boundary

Directory of Open Access Journals (Sweden)

Sahin Besir

2012-04-01

Full Text Available Flow-structure interaction of separated shear flow from the sphere and a flat plate was investigated by using dye visualization and the particle image velocimetry technique. Later, a passive control method was applied with 2mm oring located on the sphere surface at 55° from front stagnation point. The experiments were carried out in open water channel for Reynolds number value of Re=5000. Flow characteristics have been examined in terms of the 2-D instantaneous and time-averaged velocity vectors, patterns of vorticity, streamlines, rms of velocity fluctuations and Reynolds stress variations and discussed from the point of flow physics, vortex formation, lengths of large-scale Karman Vortex Streets and Kelvin-Helmholtz vortices depending on the sphere locations over the flat plate. It is demonstrated that the gap flow occurring between the sphere bottom point and the flat plate surface has very high scouring effect until h/d=0.25 and then unsymmetrical flow structure of the wake region keeps up to h/D=1.0 for smooth sphere. For the sphere with o-ring, the wake flow structure becomes symmetrical at smaller gap ratios and reattachment point on the flat plate surface occurs earlier. Moreover, o-ring on the sphere diminishes peak magnitudes of the flow characteristics and thus it is expected that the flow-induced forces will be lessened both on the sphere and flat plate surface. Vortex formation lengths and maximum value occurring points become closer locations to the rear surface of the sphere with o-ring.

Iron-ore resources of the United States including Alaska and Puerto Rico, 1955

Science.gov (United States)

Carr, Martha S.; Dutton, Carl E.

1959-01-01

minerals are associated with other rock-forming minerals, the iron content of marketable ore has a lower range from 30 to 67 percent.Chemical constituents other than iron also are important in determining the marketability of iron ore. Although some iron ores can be used in the blast furnace as mined, others must first be improved either chemically by reduction of undesirable constituents, or physically by aggregation. Phosphorus and sulfur particularly are common deleterious elements; excessive silica is also undesirable but within certain limits can be controlled by additional flux. Lime and magnesia are beneficial in specified amounts because of their fluxing qualities, and a small amount of alumina improves the fluidity of slag. Manganese is especially desirable as a deoxidizing and desulfurizing agent. Titanium, chromium, and nickel must also be considered in the use of ore containing these elements.The principal iron-ore deposits in the United States have been formed by three processes. Hematite-bearing bedded deposits such as those at Birmingham, Ala., are marine sedimentary rocks which, except for weathering along the outcrop, have remained practically unaltered since deposition. Deposits of the Lake Superior region, also in sedimentary strata, originally had a slightly lower iron content than those at-Birmingham, but ore bodies of hematite and limonite were formed by removal of other constituents in solution after deposition of the beds, with a relative increase of iron content in the material remaining. Limestone adjacent to igneous intrusions has been replaced by magnetite deposits at Cornwall, Pa., and by hematite-magnetite deposits near Cedar City, Utah. Magnetite deposits in New Jersey and in the Adirondack Mountains of New York are generally believed to have been formed by replacement of grains of other minerals in metamorphic rocks. Iron-ore resources are made up of reserves of iron ore, material usable under existing economic and technologic conditions

On the problems of the Litija ore field

Directory of Open Access Journals (Sweden)

Ivan Mlakar

1994-12-01

Full Text Available All available information on the now inaccessible Pb-Zb-Ba deposits Litija, Zavrstnik, Zagorica, Maljek, Hrastarija and Štriglovec was critically evaluated. Data were completed and numerous earlier unsolved questions were answered.In the studied area the existence of a Middle Triassic tectonic-erosional phase was proved, the Old Tertiary overthrust structure analyzed and the relative ages of various neotectonic fault systems established.Special attention was attributed to the Litija, or Sitarjevec, deposit. On the ground of data on position of thick shale intercalations within Carboniferous sandstone the geological structure of the deposit was reconstructed, proofs on the conforming or unconforming position of orebodies collected, and certain relati¬onships between the pre-ore and post-ore tectonics clarified. With geochemical investigations the presence of an extensive dispersion halo was proved, in which the anomalies produced by Pb, Hg and Ba are the best expressed.Also the position of other deposits in space and in stratigraphic column was defined. At the end also the author's views on genesis and age of mineralization are presented. Orebodies are hydrothermal. subvertical, epignetic and predominantly discordant, with poorly expressed vertical zoning.The work is a synthesis of understanding of geological structure and mineralization in the Litija ore field.

Uranium ore deposits: geology and processing implications

International Nuclear Information System (INIS)

Belyk, C.L.

2010-01-01

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

Multi-Criteria selection of technology for processing ore raw materials

Science.gov (United States)

Gorbatova, E. A.; Emelianenko, E. A.; Zaretckii, M. V.

2017-10-01

The development of Computer-Aided Process Planning (CAPP) for the Ore Beneficiation process is considered. The set of parameters to define the quality of the Ore Beneficiation process is identified. The ontological model of CAPP for the Ore Beneficiation process is described. The hybrid choice method of the most appropriate variant of the Ore Beneficiation process based on the Logical Conclusion Rules and the Fuzzy Multi-Criteria Decision Making (MCDM) approach is proposed.

Separation of monazite from Rirang ore by floatation method

International Nuclear Information System (INIS)

Affandi, Kosim; Sjahminan, Mainar

1995-01-01

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

O-Ring sealing arrangements for ultra-high vacuum systems

Science.gov (United States)

Kim, Chang-Kyo; Flaherty, Robert

1981-01-01

An all metal reusable O-ring sealing arrangement for sealing two concentric tubes in an ultra-high vacuum system. An O-ring of a heat recoverable alloy such as Nitinol is concentrically positioned between protruding sealing rings of the concentric tubes. The O-ring is installed between the tubes while in a stressed martensitic state and is made to undergo a thermally induced transformation to an austenitic state. During the transformation the O-ring expands outwardly and contracts inwardly toward a previously sized austenitic configuration, thereby sealing against the protruding sealing rings of the concentric tubes.

THE NEOPROTEROZOIC ISLAND-ARC ASSOCIATION OF THE MUKODEK GOLD-ORE FIELD, NORTHERN BAIKAL AREA

Directory of Open Access Journals (Sweden)

V. A. Vanin

2014-01-01

Full Text Available Metamorphosed volcanic rocks of the Ushmukan suite were studied in the Mukodek gold-ore field located in the Baikal-Muya belt in the Northern Baikal area, Russia. The Ushmukan suite shows interleaving of ortoschists which compositions are widely variable. Basalt-andesite-dacite series of normal alkalinity are the substrate of the studied metavolcanic rocks. Based on the set of geochemical characteristics, it is concluded that the rocks were formed in suprasubduction geodynamic conditions corresponding to a mature island arc. The proximity of the geological locations and the similarity of the geochemical characteristics of the volcanic rocks of the Ushmukan suite and rocks of the Kelyan suite (Neoproterozoic, 823 Ma, which have similar compositions, give grounds to consider these two rock suites as age peers. Specific features of gold distribution through the Mukodek gold-ore field are analyzed. Industrial gold contents are recorded only in berezite-listvenite metasomatic rocks of the gold-quartz-sulfide formation which were formed on metavolcanic rocks of the Ushmukan suite. It is concluded that the volcanic rocks, which are specific of the island-arc setting, could be a source of gold for deposits in the Mukodek gold-ore field. 

Use of the high-resolution satellite images for detection of fractures related to the ore deposits

Science.gov (United States)

Cruz-Mondaca, M.; Soto-Pinto, C. A.; Arellano-Baeza, A. A.

2012-12-01

The Aster and GeoEye satellite high-resolution images were used to detect the structures related to the fracturing of the upper crust in the North of Chile. In particular, lineament analysis has been applied to detect the presence of epithermal fluids of low sulfurization associated with the Paleozoic ore deposits. These results have been compared with the location of the minerals altered by the presence of geothermal fluids detected using the spectral libraries. Later, the presence of fractures has been corroborated during recognition of fractures in situ and the geochemical analysis of samples of minerals altered by the presence of fluids. It was shown that the results obtained are relevant for the gold vein detection.

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

International Nuclear Information System (INIS)

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

1978-01-01

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

The late cretaceous Donlin Creek gold deposit, Southwestern Alaska: Controls on epizonal ore formation

Science.gov (United States)

Goldfarb, R.J.; Ayuso, R.; Miller, M.L.; Ebert, S.W.; Marsh, E.E.; Petsel, S.A.; Miller, L.D.; Bradley, D.; Johnson, Chad; McClelland, W.

2004-01-01

-10 per mil, with the sulfur derived from diagenetic pyrite and organic matter within ihe flysch basin. A smaller group of ??34S measurements, which shows values as depleted as -27 per mil, suggests a different local sulfur reservoir in the basin for the later hydrothermal episode dominated by stibnite. Initial ENd of -8.7 to -3.1 and 87Sr/86Sr measurements of 0.706 to 0.709 for the ore-hosting dikes also indicate a crustal reservoir for some of the Late Cretaceous magmatism. Overlapping lead isotope data for these intrusive rocks and for sulfide minerals suggest a crustal contribution for the lead in both. Copper- and gold-bearing stockwork veinlets in hornfels occur at Dome, a prospect located at the northern end of the Donlin Creek deposit. These stockworks are cut by the younger auriferous gold veins that define the main Donlin Creek gold mineralization. Highly saline, gas-rich, heterogeneously trapped fluids deposited the stockworks at temperatures approximately 100??C hotter than those of the main gold-forming event at Donlin Creek. The genetic relationship of the Dome prospect to the main Donlin Creek gold resource is equivocal. The epizonal Donlin Creek deposit shows affinities to the gold systems interpreted by various workers as orogenic or intrusion related; it shows important differences from typical epithermal and Carlin-like deposits. The ore-forming fluids were derived by either broad-scale metamorphic devolatilization above rising mantle melts or exsolution from a magma that was dominated by a significant flysch melt component. ??2004 by Economic Geology.

Uranium extraction from gold-uranium ores

Energy Technology Data Exchange (ETDEWEB)

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

1981-01-01

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

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

International Nuclear Information System (INIS)

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

1984-01-01

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

Process for recovering tungsten from alkaline leaching solution of tungsten ores

International Nuclear Information System (INIS)

Onozaki, S.; Nemoto, S.; Hazeyama, T.

1976-01-01

This invention relates to a process for recovering tungsten from an alkaline leaching solution of tungsten ores. This invention comprises adjusting the pH of an alkaline leaching solution which is obtained by lixiviating ore containing tungsten with an alkaline solution to 7--8 with acid to oxidize molybdic acid ions in the solution, adding a sulfide donor, then precipitating molybdenum sulfide compounds by adjusting the pH value of the solution to 2--3. Tungstic acid ions are recovered as calcium tungstate by the addition of a calcium ion donor after the molybdenum sulfide compounds are separated

Geology and ore deposits of the Pioche district, Nevada

Science.gov (United States)

Westgate, L.G.; Knopf, Adolph

1932-01-01

LOCATION AND SURFACE FEATURES The Bristol Range, Highland, and Ely Range quadrangles make up the larger part of a. rectangular area 35 miles north and south by 24 miles east and west, which lies 19 miles west of the Nevada-Utah line and about 250 miles southwest of Salt Lake City. The district lies within the Great Basin, a semiarid region of alternating mountain ranges and intermontane plains floored largely by outwash from the mountains. The plain, which slopes away from the ranges, stands between 4,700 and 6,000 feet above the sea. The Bristol and Highland Ranges, which are separated only by a low gap, form an almost continuous north-south range that rises about 2,500 feet above the highest part of the surrounding plain, to general altitudes of 8,000 to 9,000 feet, though the highest point, Highland Peak, reaches 9,395 feet. A lower range, the Ely Range, with a northwesterly trend, lies farther east and nearly in touch with the Bristol-Highland Range. The town of Pioche lies midway on the. eastern foot of the Ely Range. ROOKS OF THE PIOOHB REGION The rocks of the ranges are Paleozoic sediments, Tertiary (?) lavas and intrusive rocks, and Pliocene (?) tuffs. The Paleozoic sediments have a total thickness of nearly 18,000 feet. Over 8,000 feet of the Cambrian has been measured without reaching its base. The lowest Cambrian formation is a quartzite, of which only the upper 1,500 feet is exposed, and this is followed by 1,200 feet of shale, 400 feet of limestone, aoid 150 feet of shale. Above this second shale the upper three-fourths of the Cambrian consists of limestone and dolomitic limestone. It is in the quartzite and in the limestone interbedded in and bounding the shales that the main ore bodies of the district have been found. Above the Cambrian comes 1,795 feet of Ordovician limestone, with some interbedded dolomite and with a 50-foot quartzite a, third of the way down from the top; 75 feet of Silurian dolomite; 3,000 feet of Middle Devonian dolomite with

Breakaway frictions of dynamic O-rings in mechanical seals

Science.gov (United States)

Lai, Tom; Kay, Peter

1993-05-01

Breakaway friction of a dynamic O-ring affects the mechanical seal's response to large axial shaft movement and face wear. However, little data exist to help designers. Therefore, a test rig was developed to measure breakaway friction. The research quantitatively shows the effects of lubrication with silicone grease and a change of surface finish. By using the Taguchi statistical experimental design method, the significance of test parameters was evaluated with a minimum number of tests. It was found that fluid pressure, dwell time, and O-ring percentage squeeze affect O-ring breakaway friction more than the O-ring cross sectional diameter and axial sliding speed within the range of values tested. The authors showed that breakaway friction increased linearly with pressure. However, O-rings made of different materials had significantly different increase rates, even if they had nominally the same durometer hardness. Breakaway friction also increased with logarithm of dwell time. Again, the increase rate depended strongly on the specific O-ring material tested. These observations led the authors to believe that the typical approach of generalizing data based on generic polymer type and durometer was inappropriate.

Flocculation of chromite ore fines suspension using polysaccharide ...

Indian Academy of Sciences (India)

Unknown

liquid separation. Keywords. Flocculation; graft copolymer; mineral industry effluent; chromite ore fines; ... work well as flocculating agent on coal washery effluent, copper and iron ore fines etc (Karmakar et al 1998, 1999;. Tripathy et al 2001).

Fundamentals of fast reduction of ultrafine iron ore at low temperature

Institute of Scientific and Technical Information of China (English)

Pei Zhao; Peimin Guo

2008-01-01

Fundamentals on the fast reduction of ultrafine iron ore at low temperature, including characterization of ultrafine ore, de- oxidation thermodynamics of stored-energy ultrafine ore, kinetics of iron ore deoxidation, and deoxidation mechanism, etc., and a new ironmaking process are presented in this article. Ultrafine ore concentrate with a high amount of stored energy can be produced by mechanical milling, and can be dcoxidated fast below 700℃ by either the coal-based or gas-based process. This novel process has some advantages over others: high productivity, low energy consumption, and environmental friendliness.

Automated microscopic characterization of metallic ores with image analysis: a key to improve ore processing. I: test of the methodology

International Nuclear Information System (INIS)

Berrezueta, E.; Castroviejo, R.

2007-01-01

Ore microscopy has traditionally been an important support to control ore processing, but the volume of present day processes is beyond the reach of human operators. Automation is therefore compulsory, but its development through digital image analysis, DIA, is limited by various problems, such as the similarity in reflectance values of some important ores, their anisotropism, and the performance of instruments and methods. The results presented show that automated identification and quantification by DIA are possible through multiband (RGB) determinations with a research 3CCD video camera on reflected light microscope. These results were obtained by systematic measurement of selected ores accounting for most of the industrial applications. Polarized light is avoided, so the effects of anisotropism can be neglected. Quality control at various stages and statistical analysis are important, as is the application of complementary criteria (e.g. metallogenetic). The sequential methodology is described and shown through practical examples. (Author)

Uranium accompanying recovery from copper ores

International Nuclear Information System (INIS)

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

1981-01-01

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

Research on degradation of vacuum O-rings under gamma radiation

CERN Document Server

Ino, H; Saitô, Y; Kubo, T; Kinsho, M

2003-01-01

The high-intensity proton accelerator being constructed by JAERI and KEK will generates greater beam power than conventional accelerators. The radiation emission due to beam losses will therefore increase. Since vacuum O-rings installed in the accelerator will be degraded badly by the radiation, there is need to find an O-ring that has more resistant to radiation. To find an O-ring that has better radiation resistant than that of the fluororubber used for conventional accelerators in general, some O-rings which are expected to have enough resistant to the radiation were irradiated, and estimated a degradation by measurement of outgassing rate, hardness, permeation time of helium gas, and an outward observation. Most of the O-rings were irradiated in an oxygen free atmosphere and in the air. The irradiations were carried out at room temperature in Co-60 gamma irradiation facility until a dose of 1 MGy was reached. The radiation resistance of PURE-RUBBER O-ring showed somewhat better than that of the fluororubb...

Hydrothermal oxidation in the Biwabik Iron Formation, MN, USA

Science.gov (United States)

Losh, Steven; Rague, Ryan

2018-02-01

Precambrian iron formations throughout the world, notably in Australia, Brazil, and South Africa, show evidence of hypogene (≥ 110 °C, mostly > 250 °C) oxidation, alteration, and silica dissolution as a result of tectonic or magmatic activity. Although hydrothermal oxidation has been proposed for the prototype Lake Superior-type iron formation, the Biwabik Iron Formation in Minnesota (USA), it has not been documented there. By examining oxidized and unoxidized Biwabik Iron Formation in three mines, including material from high-angle faults that are associated with oxidation, we document an early hypogene oxidation event ( 175 °C) involving medium-salinity aqueous fluids (8.4 ± 4.9 wt% NaCl equiv) that infiltrated iron formation along high-angle faults. At the Hibbing Taconite Mine, hydrothermal fluids oxidized iron carbonates and silicates near faults, producing goethite ± quartz. In contrast with much of the oxidized iron ores on the Mesabi Range, silica was not removed but rather recrystallized during this event, perhaps lying in a rock-dominated system at low cumulative fluid flux. During the hydrothermal oxidation event in the Hibbing Taconite deposit, quartz-filled microfractures and irregular inclusions commonly formed in coarse variably oxidized magnetite, currently the ore mineral: these inclusions degrade the ore by introducing excess silica in magnetic concentrate. Hydrothermal oxidation at Hibbing Taconite Mine is overprinted by later, relatively minor supergene oxidation both along faults and near the surface, which locally dissolved quartz. At the Fayal Reserve Mine, widespread silicate and carbonate gangue dissolution and iron oxidation was followed by precipitation of pyrite, Mn-siderite, apatite, and other minerals in void spaces, which prevented post-oxidation compaction and significant volume loss in the sampled rocks. Although definitive temperature data for this assemblage are needed, the weight of evidence indicates that this

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

International Nuclear Information System (INIS)

Berikbolov, B.R.

1999-01-01

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

On a Bayesian estimation procedure for determining the average ore grade of a uranium deposit

International Nuclear Information System (INIS)

Heising, C.D.; Zamora-Reyes, J.A.

1996-01-01

A Bayesian procedure is applied to estimate the average ore grade of a specific uranium deposit (the Morrison formation in New Mexico). Experimental data taken from drilling tests for this formation constitute deposit specific information, E 2 . This information is combined, through a single stage application of Bayes' theorem, with the more extensive and well established information on all similar formations in the region, E 1 . It is assumed that the best estimate for the deposit specific case should include the relevant experimental evidence collected from other like formations giving incomplete information on the specific deposit. This follows traditional methods for resource estimation, which presume that previous collective experience obtained from similar formations in the geological region can be used to infer the geologic characteristics of a less well characterized formation. (Author)

Manual on laboratory testing for uranium ore processing

International Nuclear Information System (INIS)

1990-01-01

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

Uranium abundance in some sudanese phosphate ores

International Nuclear Information System (INIS)

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

2009-01-01

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

Natural resources sustainability: iron ore mining

International Nuclear Information System (INIS)

De La Torre de Palacios, Luis

2011-01-01

In the present article, a new tool to determine environmental sustainability, the energy impact index (EII) was developed to classify different iron mine projects according to two main parameters including energy consumption and CO 2 emissions. The EII considers the characteristics of the mineral (such as the quality, size, hardness, iron ore grade, reducibility, mineral/waste rate, and type of deposit), mining processes (type of exploitation, ore processing, available technology), and transportation (distance to cover).

Determination of gold in gold ores

International Nuclear Information System (INIS)

Keedy, C.R.; Parson, L.; Shen, J.

1989-01-01

The gold content of placer gold flakes and gold bearing ores was determined by instrumental and radiochemical neutron activation analysis, respectively. It was discovered that significant errors result in the instrumental method for gold flakes as small as 10 mg due to sample self-absorption of neutrons during irradiation. Reliable results were obtained for both ore samples and gold flakes by dissolving the samples in aqua regia prior to irradiation. (author) 7 refs.; 3 tabs

PROCESS OF RECOVERING URANIUM FROM ITS ORES

Science.gov (United States)

Galvanek, P. Jr.

1959-02-24

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

40 CFR 440.20 - Applicability; description of the aluminum ore subcategory.

Science.gov (United States)

2010-07-01

... subpart B are applicable to discharges from facilities engaged in the mining of bauxite as an aluminum ore. ... (CONTINUED) EFFLUENT GUIDELINES AND STANDARDS ORE MINING AND DRESSING POINT SOURCE CATEGORY Aluminum Ore...

Radiometric sorting of Rio Algom uranium ore

International Nuclear Information System (INIS)

Cristovici, M.A.

1983-11-01

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

Sandbox experiments on Uraninite Ore: ERT and SP measurments.

Science.gov (United States)

Singh, R. K.

2015-12-01

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

Blind River uranium deposits: the ores and their setting

International Nuclear Information System (INIS)

Robertson, J.A.

1981-01-01

In the Blind River area, Proterozoic clastic sedimentary and minor volcanic rocks (Huronian Supergroup) unconformably overlie and transgress northward over dominantly granitic Archean terrane (2500 million years) and are intruded by Nipissing Diabase (2150 million years). Later deformations and metamorphic events are recognized. The Matinenda Formation (basal Huronian) comprises northward-derived arkose, quartzite, and pyritic, uraniferous oligomictic conglomerates, which contain 75 percent of Canada's uranium reserves. Historic grades approximate 2 pounds U 3 O 8 /ton (1 kilogram/metric ton), but lower grade material can be mined with increasing price. Some thorium and rare earths have been marketed. The conglomerate beds lie in southeasterly striking zones controlled by basement topography down-sedimentation from radioactive Archean granite. Distribution of monazite relative to uraninite and brannerite and the presence of uranium values in overlying polymictic conglomerates, which truncate the ore beds, indicate that the mineralization is syngenetic, probably placer. The role of penecontemporaneous mafic volcanics is problematical, but these could have been a source for sulphur in the pyrite. Drab-coloured rocks, uranium and sulphide mineralization, and a post-Archean regolith formed under reducing conditions all suggest a reducing environment. Sedimentary features indicate deposition in fast-flowing shallow water and possibly a cold climate. In the upper Huronian (Lorrain Formation), a monazite and iron oxide assemblage associated with red beds suggests a change to oxidizing conditions

Geochemistry and ore prospecting

International Nuclear Information System (INIS)

Le Caignec, R.

1954-01-01

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) [fr

Geochemical distribution of major, trace and rare elements in chromite ores of Neyriz ophiolite

International Nuclear Information System (INIS)

Karimi, M.; Hosseini, S. Z.; Khankahdani, K. N.

2016-01-01

The chromite deposits in the Neyriz area have lenticular and sometimes vein-like shape which are replaced in serpentinized dunite and harzburgite. Chromite and serpentinized olivines are major minerals and hematite and magnetite are minor minerals in the chromitic ores. Except chromite, other minerals have secondary origin that are related to serpentinization procceses. Whereas along with chromite, only a few of minerals such as pentlandite have primary origin. Native copper and sulfides such as chalcopyrite and bornite have been formed secondarily in microfracturs of chromite grains filled by serpentine. The results of the geochemical data from chromite ores are indicated by the type of chromite in alpine. Despite being the most abundant element in LREE relative to HREE, only six elements Dy, Eu, La, Lu, Nd, and Y are the most common among other elements. Finally, chromite ore in the area is economic but the frequency of trace elements is minimal and non-economic.

Automated recognition of stratigraphic marker shales from geophysical logs in iron ore deposits

Science.gov (United States)

Silversides, Katherine; Melkumyan, Arman; Wyman, Derek; Hatherly, Peter

2015-04-01

The mining of stratiform ore deposits requires a means of determining the location of stratigraphic boundaries. A variety of geophysical logs may provide the required data but, in the case of banded iron formation hosted iron ore deposits in the Hamersley Ranges of Western Australia, only one geophysical log type (natural gamma) is collected for this purpose. The information from these logs is currently processed by slow manual interpretation. In this paper we present an alternative method of automatically identifying recurring stratigraphic markers in natural gamma logs from multiple drill holes. Our approach is demonstrated using natural gamma geophysical logs that contain features corresponding to the presence of stratigraphically important marker shales. The host stratigraphic sequence is highly consistent throughout the Hamersley and the marker shales can therefore be used to identify the stratigraphic location of the banded iron formation (BIF) or BIF hosted ore. The marker shales are identified using Gaussian Processes (GP) trained by either manual or active learning methods and the results are compared to the existing geological interpretation. The manual method involves the user selecting the signatures for improving the library, whereas the active learning method uses the measure of uncertainty provided by the GP to select specific examples for the user to consider for addition. The results demonstrate that both GP methods can identify a feature, but the active learning approach has several benefits over the manual method. These benefits include greater accuracy in the identified signatures, faster library building, and an objective approach for selecting signatures that includes the full range of signatures across a deposit in the library. When using the active learning method, it was found that the current manual interpretation could be replaced in 78.4% of the holes with an accuracy of 95.7%.

Nature and source of the ore-forming fluids associated with orogenic gold deposits in the Dharwar Craton

Directory of Open Access Journals (Sweden)

Biswajit Mishra

2018-05-01

Full Text Available Neoarchean orogenic gold deposits, associated with the greenstone-granite milieus in the Dharwar Craton include (1 the famous Kolar mine and the world class Hutti deposit; (2 small mines at Hira-Buddini, Uti, Ajjanahalli, and Guddadarangavanahalli; (3 prospects at Jonnagiri; and (4 old mining camps in the Gadag and Ramagiri-Penakacherla belts. The existing diametric views on the source of ore fluid for formation of these deposits include fluids exsolved from granitic melts and extracted by metamorphic devolatilization of the greenstone sequences. Lode gold mineralization occurs in structurally controlled higher order splays in variety of host rocks such as mafic/felsic greenstones, banded iron formations, volcaniclastic rocks and granitoids. Estimated metamorphic conditions of the greenstones vary from lower greenschist facies to mid-amphibolite facies and mineralizations in all the camps are associated with distinct hydrothermal alterations. Fluid inclusion microthermometric and Raman spectroscopic studies document low salinity aqueous-gaseous (H2O + CO2 ± CH4 + NaCl ore fluids, which precipitated gold and altered the host rocks in a narrow P–T window of 0.7–2.5 kbar and 215–320 °C. While the calculated fluid O- and C-isotopic values are ambiguous, S-isotopic compositions of pyrite-precipitating fluid show distinct craton-scale uniformity in terms of its reduced nature and a suggested crustal sulfur source.Available ages on greenstone metamorphism, granitoid plutonism and mineralization in the Hutti Belt are tantamount, making a geochronology-based resolution of the existing debate on the metamorphic vs. magmatic fluid source impossible. In contrast, tourmaline geochemistry suggests involvement of single fluid in formation of gold mineralization, primarily derived by metamorphic devolatilization of mafic greenstones and interlayered sedimentary rocks, with minor magmatic contributions. Similarly, compositions of scheelite

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

Energy Technology Data Exchange (ETDEWEB)

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

1967-06-15

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

Uranium ore processing minimizing reagent losses

International Nuclear Information System (INIS)

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

1989-01-01

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

Manganese Ores from South Sulawesi: Their Potential Uses as Raw Materials for Metallurgical Industry

Directory of Open Access Journals (Sweden)

Sufriadin Sufriadin

2017-03-01

Full Text Available Characterization of manganese ores from Barru and Bone regencies of South Sulawesi has been conducted with the aim at clarification of their mineralogical and chemical composition for their potential uses as the raw materials for metallurgical industry. Mineralogical properties of the ores analyzed by means of optical microscopy and X-ray diffractometry (XRD show that samples from Barru consist mainly of rhodochrosite (MnCO3 with less cryptomelane, groutite, bixbyite, and todorokite. Goethite, calcite and small amount of quartz present as impurities. Manganese ore samples from Bone are predominantly composed of pyrolusite (MnO2 with subordinate ramsdellite and hollandite. Barite, quartz, hematite and clay are present as gangue minerals. Chemical compositions determined by using XRF method revealed that Barru samples contain higher in MnO (average is 40.07 wt% than the Bone samples (average is 34.36 wt%. Similarly, Fe2O3 and CaO are also higher in Barru than those of the Bone samples. In contrast, concentrations of SiO2 and total alkali (K2O + Na2O are lower in the Barru samples. The average P2O5 content of samples in both areas is low (<0.2 wt%. Relatively higher grade of Fe2O3 in the Barru ore implies that it has potential application for ferromanganese production; whereas the elevated SiO2 content of the Bone ore is a good indication for silicomanganese manufacture. However, both ores may not favorable to be directly used as raw materials in metallurgical uses. Prior to be used, the ores should be treated by applying physical beneficiation in order to reduce deleterious elements.

Study on epigenetic alterations of ore-enclosing sedimentary rocks

International Nuclear Information System (INIS)

Kondrat'eva, I.A.; Komarova, G.V.

1985-01-01

Epigenetic alterations of sedimentary rocks under effect of exogenous undeground waters of various types: near-surface, ground, stratum, and deep circulation waters, are considered. Association to postsedimentary tectonic structures, confinement of neogenesis to areas of high permeability (porous or crack one), geochemical contradictions between mineral neogenis and facial outlook of deposits, noncoincidence of variability gradient of authigenous mineral associations with variability of primary facial signs of deposits, regular position of mineral formations and ore concentrations in epigenetic mineralogo-geochemical zonation are referred to epigenetic criteria. The complex of epigenetic alterations accompanying mineralization is frequently used as a search sign of uranium deposit of a certain type

Determination of the oxidizing capacity of manganese ores.

Science.gov (United States)

Prasad, R

1974-09-01

An accurate method is described for determining the amount of active oxygen in manganese ores, based on the oxidation-reduction reaction between the ore and arsenic(III) in presence of ammonium molybdate, followed by the back-titration of excess of arsenic(III) with cerium(IV), using osmium tetroxide as catalyst and Disulphine Blue V as indicator. A survey has been made of the applicability of this method to various pyrolusite ores containing less than 0.2% phosphorus. Aluminium(III), copper(II), iron(III), manganese(II), and molybdenum(VI) do not interfere. Up to 30% phosphorus(V) causes no interference.

A REAL-TIME COAL CONTENT/ORE GRADE (C2OC) SENSOR

Energy Technology Data Exchange (ETDEWEB)

Rand Swanson

2005-04-01

This is the final report of a three year DOE funded project titled ''A real-time coal content/ore grade (C{sub 2}OG) sensor''. The sensor, which is based on hyperspectral imaging technology, was designed to give a machine vision assay of ore or coal. Sensors were designed and built at Resonon, Inc., and then deployed at the Stillwater Mining Company core room in southcentral Montana for analyzing platinum/palladium ore and at the Montana Tech Spectroscopy Lab for analyzing coal and other materials. The Stillwater sensor imaged 91' of core and analyzed this data for surface sulfides which are considered to be pathfinder minerals for platinum/palladium at this mine. Our results indicate that the sensor could deliver a relative ore grade provided tool markings and iron oxidation were kept to a minimum. Coal, talc, and titanium sponge samples were also imaged and analyzed for content and grade with promising results. This research has led directly to a DOE SBIR Phase II award for Resonon to develop a down-hole imaging spectrometer based on the same imaging technology used in the Stillwater core room C{sub 2}OG sensor. The Stillwater Mining Company has estimated that this type of imaging system could lead to a 10% reduction in waste rock from their mine and provide a $650,000 benefit per year. The proposed system may also lead to an additional 10% of ore tonnage, which would provide a total economic benefit of more than $3.1 million per year. If this benefit could be realized on other metal ores for which the proposed technology is suitable, the possible economic benefits to U.S. mines is over $70 million per year. In addition to these currently lost economic benefits, there are also major energy losses from mining waste rock and environmental impacts from mining, processing, and disposing of waste rock.

Features molibdenum ore mineralization of Hannivka in the Kryvyi Ryg - Kremenchutske zone of the Ukrainian Shield

Directory of Open Access Journals (Sweden)

Ivanov V.M.

2011-11-01

Full Text Available The new data about Hannivsky occurrence, ones of molybdenum prospects in Ukraine, are given. The results of researched confirmed a complex, multistage character of ore formation in occurrence, which by availability of some pyrite and magnetite generations, and in the spatial dissociation of molybdenite from others sulfides is expressed. molybdenum , mineralization , Ukrainian , Shield.

Conflict between constitutional norms: monopoly of nuclear ore and the social function of property in Brazil

International Nuclear Information System (INIS)

Costa-de-Moura, Jorge

2014-01-01

This monograph broaches about the conflict existing between the social Constitution of 1988, in relation to what is disposed in the Article 5, XXIII and XXIV, entrenchment clause of immediate application that determines the social function of property in Brazil, and articles 21, XXIII, and 177, V, that stipulate the monopoly of ores containing nuclear elements, i.e., those containing the chemical elements uranium, thorium, and plutonium in economically exploitable amounts. Initially, the work deals with legal definitions for nuclear ore, nuclear policy of some countries, the economical concepts of the social function of property and the negative aspects related to the maintenance of the nuclear ore in the state monopole regime in confrontation with the economic and social interest also expressed in the Constitutional Valance of 1988. Finally, it is presented an actualized compilation of nuclear laws related to the Brazilian nuclear policy and a glossary of terms used in the nuclear policy conducted by the Brazilian Nuclear Regulatory Agency (CNEN). (author)

The potential for ore and industrial minerals in the Forsmark area

Energy Technology Data Exchange (ETDEWEB)

Lindroos, Hardy [MIRAB Mineral Resurser AB, Uppsala (Sweden); Isaksson, Hans; Thunehed, Hans [GeoVista AB, Luleaa (Sweden)

2004-03-01

A survey has been made of existing information concerning the potential for ore and industrial minerals in and near the candidate area for a deep repository in Forsmark. A deep repository for spent nuclear fuel should not be located in a rock type or an area where mineral extraction might be considered in the future, since this would make it impossible to exploit this natural resource. Avoiding such areas reduces the risk that people in the future will come into contact with the deep repository through mineral prospecting or mining activities. The survey has made use of all the geoscientific information that was compiled in the more regional investigations in Oesthammar Municipality in 1996-97. In cooperation with the Geological Survey of Sweden (SGU), a new, more detailed mineral resources map has been prepared. The map shows areas with an ore potential that may be unsuitable or unfavourable for siting of a deep repository. The results of the recently completed geophysical helicopter surveys of the Forsmark area are presented in a special chapter. The judgement of the area's ore potential is in part based on the geophysical evaluation of these measurements. Furthermore, the survey obtained information from ongoing deep drillings from the site investigation in Forsmark. In order to better be able to judge the ore potential, the survey has initiated a geochemical investigation of activated soil samples, plus an ore geology sampling of a section in the deep borehole KFM02A, where a hydrothermally altered zone was detected in 2003.The first results from these samplings are presented in the report, which also discusses prospecting efforts in the area as well as relevant Swedish mining legislation. Some suggestions are made for further ore geology investigations. The mineral resources map shows that there is an elongate northwest-southeast zone south and southwest of the candidate area which has a potential for skarn iron ore, and possibly for copper and zinc

The potential for ore and industrial minerals in the Forsmark area

International Nuclear Information System (INIS)

Lindroos, Hardy; Isaksson, Hans; Thunehed, Hans

2004-03-01

A survey has been made of existing information concerning the potential for ore and industrial minerals in and near the candidate area for a deep repository in Forsmark. A deep repository for spent nuclear fuel should not be located in a rock type or an area where mineral extraction might be considered in the future, since this would make it impossible to exploit this natural resource. Avoiding such areas reduces the risk that people in the future will come into contact with the deep repository through mineral prospecting or mining activities. The survey has made use of all the geoscientific information that was compiled in the more regional investigations in Oesthammar Municipality in 1996-97. In cooperation with the Geological Survey of Sweden (SGU), a new, more detailed mineral resources map has been prepared. The map shows areas with an ore potential that may be unsuitable or unfavourable for siting of a deep repository. The results of the recently completed geophysical helicopter surveys of the Forsmark area are presented in a special chapter. The judgement of the area's ore potential is in part based on the geophysical evaluation of these measurements. Furthermore, the survey obtained information from ongoing deep drillings from the site investigation in Forsmark. In order to better be able to judge the ore potential, the survey has initiated a geochemical investigation of activated soil samples, plus an ore geology sampling of a section in the deep borehole KFM02A, where a hydrothermally altered zone was detected in 2003.The first results from these samplings are presented in the report, which also discusses prospecting efforts in the area as well as relevant Swedish mining legislation. Some suggestions are made for further ore geology investigations. The mineral resources map shows that there is an elongate northwest-southeast zone south and southwest of the candidate area which has a potential for skarn iron ore, and possibly for copper and zinc, although

Economic outlook for radiometric selection of ores

International Nuclear Information System (INIS)

Formery, P.; Ziegler, V.

1958-01-01

The value of an ore can be increased by cutting off it's poor fractions. This selection may be realized at two stages: - part of the ore in situ is unable to cover it's extraction and treatment costs, this defines the 'underground cut-off grade'; - another portion of already extracted ore is unable to cover it's transport and treatment costs; this defines the 'surface cut off grade'. These selections are easily feasible owing to the property of uranium ores of emitting gamma radiations. A diagram makes possible a fast forecast on the effect of this selection upon the weight and metal yields. An attempt is made as well in order to provide the expected effect of the composition of underground cut off and surface cut off. This cut off however, being realized through an appreciation of the radiations, involves an alteration of the weight and metal yields which calls for a correction. A survey of the economic interest of the cut-off is done and an example of valorisation in a given deposit of a section at the limit of operability is proposed. (author) [fr

Prediction of ore fluid metal concentrations from solid solution concentrations in ore-stage calcite: Application to the Illinois-Kentucky and Central Tennessee Mississippi Valley-type districts

Science.gov (United States)

Smith-Schmitz, Sarah E.; Appold, Martin S.

2018-03-01

Knowledge of the concentrations of Zn and Pb in Mississippi Valley-type (MVT) ore fluids is fundamental to understanding MVT deposit origin. Most previous attempts to quantify the concentrations of Zn and Pb in MVT ore fluids have focused on the analysis of fluid inclusions. However, these attempts have yielded ambiguous results due to possible contamination from secondary fluid inclusions, interferences from Zn and Pb in the host mineral matrix, and uncertainties about whether the measured Zn and Pb signals represent aqueous solute or accidental solid inclusions entrained within the fluid inclusions. The purpose of the present study, therefore, was to try to determine Zn and Pb concentrations in MVT ore fluids using an alternate method that avoids these ambiguities by calculating Zn and Pb concentrations in MVT ore fluids theoretically based on their solid solution concentrations in calcite. This method was applied to the Illinois-Kentucky and Central Tennessee districts, which both contain ore-stage calcite. Experimental partition coefficient (D) values from Rimstidt et al. (1998) and Tsusue and Holland (1966), and theoretical thermodynamic distribution coefficient (KD) values were employed in the present study. Ore fluid concentrations of Zn were likely most accurately predicted by Rimstidt et al. (1998) D values, based on their success in predicting known fluid inclusion concentrations of Mg and Mn, and likely also most accurately predicted ore fluid concentrations of Fe. All four of these elements have a divalent ionic radius smaller than that of Ca2+ and form carbonate minerals with the calcite structure. For both the Illinois-Kentucky and the Central Tennessee district, predicted ore fluid Zn and Fe concentrations were on the order of up to 10's of ppm. Ore fluid concentrations of Pb could only be predicted using Rimstidt et al. (1998) D values. However, these concentrations are unlikely to be reliable, as predicted ore fluid concentrations of Sr and Ba

The genesis of Kurišková U-Mo ore deposit

International Nuclear Information System (INIS)

Demko, R.; Biroň, A.; Novotný, L.; Bartalský, B.

2014-01-01

The U-Mo ores of the known uranium deposit Kurišková located in the Huta volcano-sedimentary complex (HVC) of lower Permian age belongs to the Petrova Hora Formation of the North-Gemeric tectonic unit (Western Carpathians). The HVC is built up by volcanic rocks of bimodal basalt-rhyolite association, intercalated with sandstones, mudstones and claystones. Based on the sedimentary facies reconstruction, it is supposed paleoenvironment of seasonally flooded shallow lakes of continental fluvial plain with transition to estuaries and shallow marine facies of continental shelf in the upper part of HVC.

Environmental nuclear-geophysical ore monitoring in mines of Corporation Kazakhmys PLC.

Science.gov (United States)

Yefimenko, Sergei; Yefimenko, Olga; Makarov, Dmitriy

2014-01-01

An environmental monitoring of ore composition in complex deposits of Kazakhstan (the Zhezkazgan, Kusmuryn, Artemjevsk, Kounrad, Taskura and Zhaman-Aibat deposits) is carried out using EDXRF spectrometers RPP-12, RLP-21 and RLP-21T. The monitoring of ore concentrates in Satpaev, Balkhashsk and Zhezkazgan processing plants and in Zhezkazgan copper smelter continues at present time. The monitoring suggests data on new promising elements and environmental pollutants in ores and new trends in distribution of bound elements in ores.

Potential for cobalt recovery from lateritic ores in Europe

Science.gov (United States)

Herrington, R.

2012-04-01

Cobalt is one of the 'critical metals' identified under the EU Raw Materials Initiative. Annually the global mine production of cobalt is around 55,000 tonnes,with Europe's industries consuming around 30% of that figure. Currently Europe produces around 27 tonnes of cobalt from mines in Finland although new capacity is planned. Co-bearing nickel laterite ores being mined in Greece, Macedonia and Kosovo where the cobalt is currently not being recovered (ores have typical analyses of 0.055% Co and >1% Ni,). These ores are currently treated directly in pyrometallurgical plants to recover the contained nickel and this process means there is no separate cobalt product produced. Hydrometallurgical treatment of mineralogically suitable laterite ores can recover the cobalt; for example Cuba recovers 3,500 tonnes of cobalt from its laterite mining operations, which are of a similar scale to the current European operations. Implementation of hydrometallurgical techniques is in its infancy in Europe with one deposit in Turkey planning to use atmospheric heap leaching to recover nickel and copper from oxide-dominated ores. More widespread implementation of these methods to mineralogically suitable ore types could unlock the highly significant undeveloped resources (with metal contents >0.04% Co and >1% Ni), which have been defined throughout the Balkans eastwards into Turkey. At a conservative estimate, this region has the potential to supply up to 30% of the EU cobalt requirements.

Analytical procedure for the radiometric determination of uranium in ores

International Nuclear Information System (INIS)

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

1976-06-01

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

Comparison of oxidants in alkaline leaching of uranium ore

International Nuclear Information System (INIS)

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

2007-01-01

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

The Pobei Cu-Ni and Fe ore deposits in NW China are comagmatic evolution products: evidence from ore microscopy, zircon U-Pb chronology and geochemistry

Energy Technology Data Exchange (ETDEWEB)

Liu, G.I.; Li, W.Y.; Lu, X.B.; Huo, Y.H.; Zhang, B.

2017-11-01

The Pobei mafic-ultramafic complex in northwestern China comprises magmatic Cu-Ni sulfide ore deposits coexisting with Fe-Ti oxide deposits. The Poshi, Poyi, and Podong ultramafic intrusions host the Cu-Ni ore. The ultramafic intrusions experienced four stages during its formation. The intrusion sequence was as follows: dunite, hornblende-peridotite, wehrlite and pyroxenite. The wall rock of the ultramafic intrusions is the gabbro intrusion in the southwestern of the Pobei complex. The Xiaochangshan magmatic deposit outcrops in the magnetitemineralized gabbro in the northeastern part of the Pobei complex. The main emplacement events related to the mineralization in the Pobei complex, are the magnetite-mineralized gabbro related to the Xiaochangshan Fe deposit, the gabbro intrusion associated to the Poyi, Poshi and Podong Cu-Ni deposits, and the ultramafic intrusions that host Cu-Ni deposits (Poyi and Poshi). The U-Pb age of the magnetite-mineralized gabbro is 276±1.7Ma, which is similar to that of the Pobei mafic intrusions. The εHf(t) value of zircon in the magnetite-mineralized gabbro is almost the same as that of the gabbro around the Poyi and Poshi Cu-Ni deposits, indicating that the rocks related to Cu-Ni and magnetite deposits probably originated from the same parental magma. There is a trend of crystallization differentiation evolution in the Harker diagram from the dunite in the Cu-Ni deposit to the magnetite-mineralized gabbro. The monosulfide solid solution fractional crystallization was weak in Pobei; thus, the Pd/Ir values were only influenced by the crystallization of silicate minerals. The more complete the magma evolution is, the greater is the Pd/Ir ratio. The Pd/Ir values of dunite, the lithofacies containing sulfide (including hornblende peridotite, wehrlite, and pyroxenite) in the Poyi Cu-Ni deposit, magnetite-mineralized gabbro, and massive magnetite, are 8.55, 12.18, 12.26, and 18.14, respectively. Thus, the massive magnetite was probably the

The Pobei Cu-Ni and Fe ore deposits in NW China are comagmatic evolution products: evidence from ore microscopy, zircon U-Pb chronology and geochemistry

International Nuclear Information System (INIS)

Liu, G.I.; Li, W.Y.; Lu, X.B.; Huo, Y.H.; Zhang, B.

2017-01-01

The Pobei mafic-ultramafic complex in northwestern China comprises magmatic Cu-Ni sulfide ore deposits coexisting with Fe-Ti oxide deposits. The Poshi, Poyi, and Podong ultramafic intrusions host the Cu-Ni ore. The ultramafic intrusions experienced four stages during its formation. The intrusion sequence was as follows: dunite, hornblende-peridotite, wehrlite and pyroxenite. The wall rock of the ultramafic intrusions is the gabbro intrusion in the southwestern of the Pobei complex. The Xiaochangshan magmatic deposit outcrops in the magnetitemineralized gabbro in the northeastern part of the Pobei complex. The main emplacement events related to the mineralization in the Pobei complex, are the magnetite-mineralized gabbro related to the Xiaochangshan Fe deposit, the gabbro intrusion associated to the Poyi, Poshi and Podong Cu-Ni deposits, and the ultramafic intrusions that host Cu-Ni deposits (Poyi and Poshi). The U-Pb age of the magnetite-mineralized gabbro is 276±1.7Ma, which is similar to that of the Pobei mafic intrusions. The εHf(t) value of zircon in the magnetite-mineralized gabbro is almost the same as that of the gabbro around the Poyi and Poshi Cu-Ni deposits, indicating that the rocks related to Cu-Ni and magnetite deposits probably originated from the same parental magma. There is a trend of crystallization differentiation evolution in the Harker diagram from the dunite in the Cu-Ni deposit to the magnetite-mineralized gabbro. The monosulfide solid solution fractional crystallization was weak in Pobei; thus, the Pd/Ir values were only influenced by the crystallization of silicate minerals. The more complete the magma evolution is, the greater is the Pd/Ir ratio. The Pd/Ir values of dunite, the lithofacies containing sulfide (including hornblende peridotite, wehrlite, and pyroxenite) in the Poyi Cu-Ni deposit, magnetite-mineralized gabbro, and massive magnetite, are 8.55, 12.18, 12.26, and 18.14, respectively. Thus, the massive magnetite was probably the

Water leaching of titanium from ore flotation residue.

Science.gov (United States)

Jaworska, Malgorzata M; Guibal, Eric

2003-01-01

Copper ore tailings were tested for the stability of titanium submitted to water leaching in three different reactor systems (agitated vessel, bioreactor and percolated fixed-bed column). For each of these systems, titanium extraction did not exceed 1% of the available metal. Biomass removed from ore residue adsorbed a small part of the titanium with sorption capacities below 20-30 mg g(-1), but most of this biomass was sequestered in the ore residue. Oxygen and carbon dioxide concentrations were monitored and changes in concentration correlated with bacteria development at the initial stage of the process and to fungal development in the latter stages.

Arsenic bioleaching in medical realgar ore and arsenicbearing ...

African Journals Online (AJOL)

However, the maximum arsenic leaching ratio from realgar in the presence of mixed unadapted strains was only 12.4 %. Besides, maximum arsenic leaching ratios from arsenic-bearing refractory gold ore by mixed adapted strains or unadapted strains were 45.0 and 22.9 %, respectively. Oxidation of these two ores by ...

40 CFR 440.90 - Applicability; description of the antimony ore subcategory.

Science.gov (United States)

2010-07-01

... 40 Protection of Environment 29 2010-07-01 2010-07-01 false Applicability; description of the antimony ore subcategory. 440.90 Section 440.90 Protection of Environment ENVIRONMENTAL PROTECTION AGENCY (CONTINUED) EFFLUENT GUIDELINES AND STANDARDS ORE MINING AND DRESSING POINT SOURCE CATEGORY Antimony Ore Subcategory § 440.90 Applicability;...

Proposal for selecting an ore sample from mining shaft under Kvanefjeld

International Nuclear Information System (INIS)

Lund Clausen, F.

1979-02-01

Uranium ore recovered from the tunnel under Kvanefjeld (Greenland) will be processed in a pilot plant. Selection of a fully representative ore sample for both the whole area and single local sites is discussed. A FORTRAN program for ore distribution is presented, in order to enable correct sampling. (EG)

Measurement and Modelling of Blast Movement to Reduce Ore ...

African Journals Online (AJOL)

user

geologists at Newmont Ahafo Mine have realised the impact of blast movement on ore losses and dilution and have ... Movement to Reduce Ore Losses and Dilution at Ahafo Gold Mine in Ghana”, Ghana Mining Journal, pp. .... classification.

Nuclear techniques for bulk ore analysis and their application to quality control

International Nuclear Information System (INIS)

Holmes, R.J.

1981-01-01

Bulk analysis techniques developed for the mining industry in which analyses are obtained directly from 3-30kg ore samples or from ore on conveyor belts are outlined. They include the determination of iron in iron ores from backscattered gamma radiation, shale in sedimentary iron ores from natural gamma activity, iron from a thermal-neutron capture reaction, and aluminium from the thermal neutron activation reaction

Treatment of bastnaesite ore from Vietnamese Socialist Republic

International Nuclear Information System (INIS)

Formanek, J.; Jerabek, J.; Jancarek, J.

1987-01-01

From the Vietnamese deposit at Nam Nam Xe Czechoslovakia imported several hundred tons of ore. Several methods of ore dressing were used: gravitational, preconcentration in electromagnetic field, magnetic separation, high-intesity electromagnetic separation. Flotation evidently was the best dressing method tried. The results are presented of testing using different flotation agents. (E.S.)

Mineralogical study of zard koh and kulli koh iron ore deposits of pakistan

International Nuclear Information System (INIS)

Khoso, S.A.; Abro, M.I.

2017-01-01

Zard Koh and Kulli Koh are two recently discovered iron ore deposits, existing in the Chagai district, Balochistan, Pakistan. PSM (Pakistan Steel Mill Limited) is interested to utilize these ore deposits at priority. Purpose of the present study was to assess the mineralogy of the Zard Koh and Kulli Koh iron ore deposits, as it plays a vital role in the selection of an appropriate processing method. The mineralogical study of ore deposits was carried out by XRD (X-Ray Diffraction), XRF (X-Ray Fluorescence), SEM (Scanning Electron Microscope) attached with EDS (Energy Dispersive Spectroscope) and SM (Stereomicroscope) techniques. Results indicated that the Zard Koh ore is mainly composed of 60.15% maghemite, 23.57% pyrite, 4.07% chlorite, 10.30% grossular and 1.65% admontite minerals. The chemical analysis revealed that Zard Koh iron ore contains an average of 54.27% Fe, 12.73% S, 8.70% Si, 3.07% Al, 4.07% Ca, and 2.16% Mg. Similarly, the mineralogical study of the Kulli Koh iron ore indicated that, ore is containing 51.16% hematite, 29.24% quartz, 8.89% dravite, and 8.76% kaolinite minerals. Elemental analysis of different samples indicated that Kulli Koh iron ore contains an average composition of 40.23% Fe, 20.67% Si, 3.44% Ca, 3.81% Al and 3.25% Mg. Mineralogical study of the Zard Koh and Kulli Koh iron ore deposits suggested that these ore deposits can be beneficiated costeffectively by using magnetic separation techniques. (author)

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)

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

Organic geochemistry of the Dongsheng sedimentary uranium ore deposits, China

International Nuclear Information System (INIS)

Tuo Jincai; Ma Wanyun; Zhang Mingfeng; Wang Xianbin

2007-01-01

Organic matter (OM) associated with the Dongsheng sedimentary U ore hosting sandstone/siltstone was characterized by Rock-Eval, gas chromatography-mass spectrometry and stable C isotope analysis and compared to other OM in the sandstone/siltstone interbedded organic matter-rich strata. The OM in all of the analyzed samples is Type III with Ro less than 0.6%, indicating that the OM associated with these U ore deposits can be classified as a poor hydrocarbon source potential for oil and gas. n-Alkanes in the organic-rich strata are characterized by a higher relative abundance of high-molecular-weight (HMW) homologues and are dominated by C 25 , C 27 or C 29 with distinct odd-to-even C number predominances from C 23 to C 29 . In contrast, in the sandstone/siltstone samples, the n-alkanes have a higher relative abundance of medium-molecular-weight homologues and are dominated by C 22 with no or only slight odd-to-even C number predominances from C 23 to C 29 . Methyl alkanoates in the sandstone/siltstone extracts range from C 14 to C 30 , maximizing at C 16 , with a strong even C number predominance, but in the organic-rich layers the HMW homologues are higher, maximizing at C 24 , C 26 or C 28 , also with an even predominance above C 22 . n-Alkanes in the sandstone/siltstone sequence are significantly depleted in 13 C relative to n-alkanes in most of the organic-rich strata. Diasterenes, ββ-hopanes and hopenes are present in nearly all the organic-rich sediments but in the sandstone/siltstone samples they occur as the geologically mature isomers. All the results indicate that the OM in the Dongsheng U ore body is derived from different kinds of source materials. The organic compounds in the organic-rich strata are mainly terrestrial, whereas, in the sand/siltstones, they are derived mainly from aquatic biota. Similar distribution patterns and consistent δ 13 C variations between n-alkanes and methyl alkanoates in corresponding samples suggest they are derived from

Decomposition of silica-alumina ores of Afghanistan by sulfuric acid

International Nuclear Information System (INIS)

Khomidi, A.K.; Mamatov, E.D.

2016-01-01

Present article is devoted to decomposition of silica-alumina ores of Afghanistan by sulfuric acid. Physicochemical properties of initial silica-alumina ores were studied by means of X-ray phase, differential thermal and silicate analysis. The influence of temperature, process duration and acid concentration on extraction rate of valuable components was considered. The optimal conditions of decomposition of silica-alumina ores of Afghanistan by sulfuric acid were proposed.

Residues leaching from 'Factory of barren ores'

International Nuclear Information System (INIS)

Rakhmatov, N.; Khakimov, N.; Nazarov, Kh.M.; Barotov, A.M.

2012-01-01

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

Ore microscopy applied to beneficiation

International Nuclear Information System (INIS)

Hagni, R.D.

1978-01-01

Ore microscopy can be an important adjunct to beneficiation, because it can be used not only to predict mill problems of undeveloped ore deposits but to identify the causes for the loss of minerals in the products of operating mines and mills. Mineral distribution among various mill products can be determined by examining polished sections prepared from samples obtained from each step of the beneficiation process. The degree of liberation of each mineral can be quantitatively determined for each mill product by counting locked vs. free particles. For many beneficiation problems, the preparation of a few polished sections of carefully selected mill products can yield useful information, which the mill dressing engineer can effectively use to alleviate those problems

X-ray radiometric separation of low-grade tin ores

Energy Technology Data Exchange (ETDEWEB)

Kotler, N.I.; Neverov, A.D.; Konovalov, V.M.; Mironov, I.I.; Zakharov, S.N.

1984-10-01

The investigations on evaluation of X-ray radiometric separation of off-grade tin ores of one of the deposits are carried out. The experiments have been performed at loboratory and pilot-commerical plants. /sup 241/Am has been used as a radiation source. In the course of facility commercial the ore has been separated by means of a device comprising a separator and gate separatin device. The results of X-ray radiometric separation have shown its high productive efficiency. Concentrates with higher tin content at high extraction from ores are obtained.

X-ray radiometric separation of low-grade tin ores

International Nuclear Information System (INIS)

Kotler, N.I.; Neverov, A.D.; Konovalov, V.M.; Mironov, I.I.; Zakharov, S.N.

1984-01-01

The investigations on evaluation of X-ray radiometric separation of off-grade tin ores of one of the deposits are carried out. The experiments have been performed at loboratory and pilot-commerical plants. 241 Am has been used as a radiation source. In the course of facility commercial the ore has been separated by means of a device comprising a separator and gate separatin device. The results of X-ray radiometric separation have shown its high productive efficiency. Concentrates with higher tin content at high extraction from ores are obtained

Economic evaluation of preconcentration of uranium ores

International Nuclear Information System (INIS)

1981-04-01

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

Dynamics of leaching a uniformly fissured ore body

International Nuclear Information System (INIS)

Ignatov, A.A.; Proskurin, S.A.

1987-01-01

Mathematical simulation was used to study the dynamics of mass transfer during the percolation of a reagent solution through a packing of coarse ore particles. The uniformly fissured ore body was represented by a cubic packing of spherical particles of constant radius, formed from a chemically inert silicate cement with a uniformly distributed soluble mineral component. The rate of percolation of the reagent through the packing was constant. The proposed model can be used to find the conditions for underground hydrodynamic leaching. The rate of non-catalytic solid-liquid reaction was deduced on the basis of both the kinetics of dissolution of the mineral component of the ore and the rate of diffusion of the dissolved substance

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

Science.gov (United States)

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

2014-02-01

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

FY2017 status report: Model 9975 O-ring fixture long-term leak performance

Energy Technology Data Exchange (ETDEWEB)

Daugherty, W. L. [Savannah River Site (SRS), Aiken, SC (United States). Savannah River National Lab. (SRNL)

2017-07-27

A series of experiments to monitor the aging performance of Viton® GLT and GLT-S O-rings used in the Model 9975 shipping package has been ongoing since 2004 at the Savannah River National Laboratory. One approach has been to periodically evaluate the leak performance of O-rings being aged in mock-up 9975 Primary Containment Vessels (PCVs) at elevated temperature. Other methods such as compression-stress relaxation (CSR) tests and field surveillance are also on-going to evaluate O-ring behavior. Seventy tests using PCV mock-ups with GLT O-rings were assembled and heated to temperatures ranging from 200 to 450 ºF. They were leak-tested initially and have been tested periodically to determine if they continue to meet the leak-tightness criterion defined in ANSI standard N14.5-97. Due to material substitution, a smaller test matrix with fourteen additional tests was initiated in 2008 with GLT-S O-rings heated to temperatures ranging from 200 to 400 ºF. Leak test failures have been experienced in all of the GLT O-ring fixtures aging at 350 ºF and higher temperatures, and in 8 fixtures aging at 300 ºF. The 300 °F GLT O-ring fixtures failed after 2.8 to 5.7 years at temperature. The remaining GLT O-ring fixtures aging at 300 ºF were retired from testing following more than 5 years at temperature without failure. No failures have yet been observed in GLT O-ring fixtures aging at 200 ºF for 9 to 10.5 years, or in GLT O-ring fixtures aging at 270 ºF for 5.7 years. These aging temperatures bound O-ring temperatures anticipated during normal storage in K-Area Complex (KAC). Leak test failures have been experienced in all of the GLT-S O-ring fixtures aging at 300 ºF and above. No failures have yet been observed in GLT-S O-ring fixtures aging at 200 and 250 ºF for 6.9 to 7.5 years. Data from the O-ring fixtures are generally consistent with results from compression stress relaxation testing, and provide confidence in the predictive models based on those results

Moessbauer study of the chemical state of gold in gold ores

International Nuclear Information System (INIS)

Wagner, F.E.; Marion, P.H.; Regnard, J.-R.

1986-01-01

Information on the chemical state of gold in gold ores has been obtained by 197 Au Moessbauer spectroscopy in cases where the state of this element cannot be determined by such standard methods as optical or electron microscopy. Ore concentrates consisting mainly of pyrite or arsenopyrite and roasted ore and matte samples were studied. The results yielded directly the respective amounts of metallic and chemically bound gold. Unless the gold is metallic, its chemical state in the ores turns out to be different from that in the minerals studied so far as reference materials. The chemical processes taking place during various treatments of the ores, such as roasting or leaching, can also be followed by Moessbauer spectroscopy. It is hoped that Moessbauer spectroscopy will eventually facilitate the development of more efficient methods of gold extraction

Bacterial leaching of pyritic gold ores

Energy Technology Data Exchange (ETDEWEB)

Gagliardi, F.M.; Cashion, J.D.; Brown, L.J. [Monash Univ., Clayton, VIC (Australia). Dept. of Physics; Jay, W.H. [Monash Univ., Clayton, VIC (Australia). Chemical Engineering Department

1996-12-31

The bacterial oxidation process is well known in nature but has only recently come under investigation as a viable and relatively clean method of gold recovery from ores. However there is currently little information about the process at an atomic scale. It is known that the bacterial attack progresses preferentially along grain boundaries which is precisely where the gold has been deposited from aqueous infiltration. Samples have been obtained from the Wiluna mine in Western Australia consisting of the original ore, 2 pre-treatments, and from six successive bacterial reactors. {sup 57}Fe Moessbauer spectra taken at room temperature show only two quadrupole split doublets which can be ascribed to pyrite, FeS{sub 2}, and arsenopyrite, FeAsS. However, the presence of any superparamagnetic oxide or oxyhydroxide species would be expected to give a spectrum very similar to that of pyrite and would be undetectable in small quantities. At a temperature of 5K, a broad magnetically split sextet is observable with a mean hyperfine field of approximately 50T. This field is characteristic of magnetically ordered ferric iron surrounded by an octahedron of oxygens. The intensity and characteristics of this subspectrum alters through the series and interpretations will be given on the oxidation products of the bacterial leaching

Bacterial leaching of pyritic gold ores

International Nuclear Information System (INIS)

Gagliardi, F.M.; Cashion, J.D.; Brown, L.J.; Jay, W.H.

1996-01-01

The bacterial oxidation process is well known in nature but has only recently come under investigation as a viable and relatively clean method of gold recovery from ores. However there is currently little information about the process at an atomic scale. It is known that the bacterial attack progresses preferentially along grain boundaries which is precisely where the gold has been deposited from aqueous infiltration. Samples have been obtained from the Wiluna mine in Western Australia consisting of the original ore, 2 pre-treatments, and from six successive bacterial reactors. 57 Fe Moessbauer spectra taken at room temperature show only two quadrupole split doublets which can be ascribed to pyrite, FeS 2 , and arsenopyrite, FeAsS. However, the presence of any superparamagnetic oxide or oxyhydroxide species would be expected to give a spectrum very similar to that of pyrite and would be undetectable in small quantities. At a temperature of 5K, a broad magnetically split sextet is observable with a mean hyperfine field of approximately 50T. This field is characteristic of magnetically ordered ferric iron surrounded by an octahedron of oxygens. The intensity and characteristics of this subspectrum alters through the series and interpretations will be given on the oxidation products of the bacterial leaching

Mineralogical Study of Zard Koh and Kulli Koh Iron Ore Deposits of Pakistan

Directory of Open Access Journals (Sweden)

SULTAN AHMED KHOSO

2017-10-01

Full Text Available Zard Koh and Kulli Koh are two recently discovered iron ore deposits, existing in the Chagai district, Balochistan, Pakistan. PSM (Pakistan Steel Mill Limited is interested to utilize these ore deposits at priority. Purpose of the present study was to assess the mineralogy of the Zard Koh and Kulli Koh iron ore deposits, as it plays a vital role in the selection of an appropriate processing method. The mineralogical study of ore deposits was carried out by XRD (X-Ray Diffraction, XRF (X-Ray Fluorescence, SEM (Scanning Electron Microscope attached with EDS (Energy Dispersive Spectroscope and SM (Stereomicroscope techniques. Results indicated that the Zard Koh ore is mainly composed of 60.15% maghemite, 23.57% pyrite, 4.07% chlorite, 10.30% grossular and 1.65% admontite minerals. The chemical analysis revealed that Zard Koh iron ore contains an average of 54.27% Fe, 12.73% S, 8.70% Si, 3.07% Al, 4.07% Ca, and 2.16% Mg. Similarly, the mineralogical study of the Kulli Koh iron ore indicated that, ore is containing 51.16% hematite, 29.24% quartz, 8.89% dravite, and 8.76% kaolinite minerals. Elemental analysis of different samples indicated that Kulli Koh iron ore contains an average composition of 40.23% Fe, 20.67% Si, 3.44% Ca, 3.81% Al and 3.25% Mg. Mineralogical study of the Zard Koh and Kulli Koh iron ore deposits suggested that these ore deposits can be beneficiated costeffectively by using magnetic separation techniques.

APPLICATION OF MAGNETIC SURVEY TO EXPLORE THE IRON ORE DEPOSITS IN THE NUSAWUNGU COASTAL REGENCY OF CILACAP CENTRAL JAVA

Directory of Open Access Journals (Sweden)

S Sehah

2017-12-01

Full Text Available The research aiming to explore the iron ore deposits in the Nusawungu coastal Regency of Cilacap has been conducted using the magnetic survey. The acquisition of magnetic data was conducted in April – Mei 2017, covering the area in the ranges of 109.314° – 109.345°E and 7.691° – 7.709°S. The obtained magnetic field strength data were corrected, reduced, and mapped to obtain the contour map of local magnetic anomaly. The modeling process was carried out along the path extending over the map from the positions of 109.314°E and 7.695°S to 109.335°E and 7.699°S, so that some subsurface anomalous objects are obtained. The lithological interpretation was performed to identify the types of subsurface rocks and their formations based on the magnetic susceptibility value of each anomalous objects and supported by the geological information of the research area. Based on the interpretation results, three rocks deposits of alluvium formations were obtained, which are estimated to contain iron ore. The first deposit has a length of 164.85 m, a depth of 0.57 – 8.43 m, and a magnetic susceptibility value of 0.0097 cgs. The second deposit has a length of 376.28 m, a depth of 2.56 – 19.66 m, and a magnetic susceptibility value of 0.0108 cgs. The third deposit has a length of 1,306.26 m, a depth of 3.70 – 58.69 m, and a magnetic susceptibility value of 0.0235 cgs. Out of the whole rocks deposits, the third rock deposit is interpreted to have the most prospective iron ore. This interpretation based on its high magnetic susceptibility value, which indicates the presence of many magnetic minerals (i.e. iron ores in the rock.

Developments of uranium and gold ores heap leaching technologies

International Nuclear Information System (INIS)

Tian Yuan; Guan Zibin; Gao Renxi

1998-01-01

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

Extraction of metals from ores by bacterial leaching: present status and future prospects

International Nuclear Information System (INIS)

Kelly, D.P.

1977-01-01

The principal organism effecting bacterial leaching of ferrous and sulfide ores is Thiobacillus ferrooxidans, though other thiobacilli and other bacteria may be involved. The process depends on (a) direct solubilization of metal sulfides by bacterial oxidation; (b) dissolution of metal sulfides or oxides by ferric iron produced by bacterial pyrite oxidation. Mining spoil dumps and low grade ores can be leached for copper or uranium by cheap low-level technology. Dump leaching enables maximum recovery of valuable metal from any ore, but makes possible exploitation of very low grade Cu and U ores. Continuous extraction processes are possible where a continuously growing bacterial culture is fed with pyritic ores (or FeSO 4 or other sulfide) and continuous metal solubilization proceeds. Intimate contact between the bacteria and the ore to be leached (especially with uranium oxide ores) is not always necessary: leaching of UO 2 ores probably depends only on ferric iron reaction with the ore. Degradation of pyrite-containing rocks may also be developed as part of future recovery processes for petroleum from oil shales. Two-stage leaching systems present the best prospect for developing a higher-level technology for metal extraction. State 1: bacterial generation of Fe 3+ from pyrite or a Fe 2+ source; Stage 2: chemical leaching of ore by Fe 3+ in acid solution. Two-stage processes can be surface processes using crushed or milled ores or can be applied to underground solution mining, when an ore (e.g. uranium) can be leached by pumping Fe 3+ solutions through shattered underground deposits, metal recovered (e.g. solvent extraction) and Fe 3+ regenerated by bacterial oxidation at the surface. The use of controlled continuous microbial cultures to generate either bacteria or ferric iron is outlined

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.

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.

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.

Effects of Ore dust pollution on the physical and chemical features ...

African Journals Online (AJOL)

Effects of wind-blown iron and manganese ore dust on the upper part of a sandy beach have been investigated. The fine ore dust was found to reduce the porosity and permeability of the sand by clogging the interstices. The presence of ore dust also greatly increased the rate of heating and cooling of beach sand. Further ...

Soil Contamination at the Historical Zn-Pb Ore Mining Sites (Southern Poland

Directory of Open Access Journals (Sweden)

Aleksander-Kwaterczak U.

2013-04-01

Full Text Available Results of metals analyses in soil profiles sampled at two 18/19th century mine shafts of the Trzebinia lead-zinc ore mining region in southern Poland are presented. Waste dump sites located at these shafts exhibit initial pedogenesis with clear differences in zinc and cadmium content between soil horizons which changes in depth across each of the investigated dump. The highest metal concentrations occur in horizons containing excavated ore-bearing Triassic dolomites, soils buried beneath are less polluted whereas, initial A0 soil horizons are virtually unpolluted. Relatively low downward metal migration in profiles to the horizons underlying the dumps is related to alkaline pH of soils. Migration appear to be important in the more acidic soils of outer zones in the two dump sites overgrown either with coniferous and deciduous trees.

Decomposition of pre calcined aluminium silicate ores of Afghanistan by hydrochloric acid

International Nuclear Information System (INIS)

Khomidi, A.K.; Mamatov, E.D.

2015-01-01

Present article is devoted to decomposition of pre calcined aluminium silicate ores of Afghanistan by hydrochloric acid. The physicochemical properties of initial aluminium silicate ores were studied by means of X-ray phase, differential thermal and silicate analysis. The chemical composition of aluminium containing ores was determined. The optimal conditions of interaction of initial and pre calcined siallites with hydrochloric acid were defined. The kinetics of acid decomposition of aluminium silicate ores was studied as well.

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.

Multiple Stage Ore Formation in the Chadormalu Iron Deposit, Bafq Metallogenic Province, Central Iran: Evidence from BSE Imaging and Apatite EPMA and LA-ICP-MS U-Pb Geochronology

Directory of Open Access Journals (Sweden)

Hassan Heidarian

2018-02-01

Full Text Available The Chadormalu magnetite-apatite deposit in Bafq metallogenic province, Central Iran, is hosted in the late Precambrian-lower Cambrian volcano-sedimentary rocks with sodic, calcic, and potassic alterations characteristic of iron oxide copper-gold (IOCG and iron oxide-apatite (IOA ore systems. Apatite occurs as scattered irregular veinlets and disseminated grains, respectively, within and in the marginal parts of the main ore-body, as well as apatite-magnetite veins in altered wall rocks. Textural evidence (SEM-BSE images of these apatites shows primary bright, and secondary dark areas with inclusions of monazite/xenotime. The primary, monazite-free fluorapatite contains higher concentrations of Na, Si, S, and light rare earth elements (LREE. The apatite was altered by hydrothermal events that led to leaching of Na, Si, and REE + Y, and development of the dark apatite. The bright apatite yielded two U-Pb age populations, an older dominant age of 490 ± 21 Ma, similar to other iron deposits in the Bafq district and associated intrusions, and a younger age of 246 ± 17 Ma. The dark apatite yielded a U-Pb age of 437 ± 12 Ma. Our data suggest that hydrothermal magmatic fluids contributed to formation of the primary fluorapatite, and sodic and calcic alterations. The primary apatite reequilibrated with basinal brines in at least two regional extensions and basin developments in Silurian and Triassic in Central Iran.

Flotation of uranium from uranium ores in Canada. Part 1

International Nuclear Information System (INIS)

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

1983-01-01

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

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

Energy Technology Data Exchange (ETDEWEB)

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

2013-05-01

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

Commercial development of a new process of uraniferous ore sintering by pelletizing before dump leaching (wet process) application to a very clayey ore of Nord-Aquitaine

International Nuclear Information System (INIS)

Videau, G.; Roche, M.

1990-01-01

Much of the French uranium ore contains clay of sedimentary origin or derived from the alteration of rocks of the granite type. During a dump leaching operation by a wet process, these clays reduce the percolation rates and sometimes the percolation rates are so low that the very essence of the dump leaching operation can be called in question. This problem arises particularly for the treatment of the ore of Nord-Aquitaine. The results of tests, carried out at the SEPA in Bessines, have shown that after pelletizing clayey ores with sodium silicate in the presence of sulphuric acid for the polymerization of the silicate, the percolation rates were much increased. This new method was successfully applied, from a laboratory column to a pilot dump of 500 tonnes for the very clayey ore of Nord-Aquitaine. This ore of low grade (approx. 1000 ppm of U) seems to be difficult to upgrade by any other method of treatment in the present economic context [fr

Fluid evolution and ore genesis of the Dalingshang deposit, Dahutang W-Cu ore field, northern Jiangxi Province, South China

Science.gov (United States)

Peng, Ning-Jun; Jiang, Shao-Yong; Xiong, Suo-Fei; Pi, Dao-Hui

2018-02-01

The Dalingshang W-Cu deposit is located in the North section of the Dahutang ore field, northern Jiangxi Province, South China. Vein- and breccia-style tungsten-copper mineralization is genetically associated with Mesozoic S-type granitic rocks. Infrared and conventional microthermometric studies of both gangue and ore minerals show that the homogenization temperatures for primary fluid inclusions in wolframite ( 340 °C) are similar to those in scheelite ( 330 °C), but about 40 °C higher than those of apatite ( 300 °C) and generally 70 °C higher than those in coexisting quartz ( 270 °C). Laser Raman analysis identifies CH4 and N2 without CO2 in fluid inclusions in scheelite and coexisting quartz, while fluid inclusions in quartz of the sulfide stage have variable CO2 content. The ore-forming fluids overall are characterized by high- to medium-temperature, low-salinity, CH4, N2, and/or CO2-bearing aqueous fluids. Chalcopyrite, muscovite, and sphalerite are the most abundant solids recognized in fluid inclusions from different ores. The H-O-S-Pb isotope compositions favor a dominantly magmatic origin for ores and fluids, while some depleted δ34S values (- 14.4 to - 0.9‰) of sulfides from the sulfide stage are most likely produced by an increase of oxygen fugacity, possibly caused by inflow of oxidized meteoric waters. The microthermometric data also indicate that a simple cooling process formed early scheelite and wolframite. However, increasing involvement of meteoric waters and fluid mixing may trigger a successive deposition of base metal sulfides. Fluid-rock interaction was critical for scheelite mineralization as indicated by in-situ LA-ICP-MS analysis of trace elements in scheelite.

Analytical fingerprint for tantalum ores from African deposits

Science.gov (United States)

Melcher, F.; Graupner, T.; Sitnikova, M.; Oberthür, T.; Henjes-Kunst, F.; Gäbler, E.; Rantitsch, G.

2009-04-01

Illegal mining of gold, diamonds, copper, cobalt and, in the last decade, "coltan" has fuelled ongoing armed conflicts and civil war in a number of African countries. Following the United Nations initiative to fingerprint the origin of conflict materials and to develop a traceability system, our working group is investigating "coltan" (i.e. columbite-tantalite) mineralization especially in Africa, also within the wider framework of establishing certified trading chains (CTC). Special attention is directed towards samples from the main Ta-Nb-Sn provinces in Africa: DR Congo, Rwanda, Mozambique, Ethiopia, Egypt and Namibia. The following factors are taken into consideration in a methodological approach capable of distinguishing the origin of tantalum ores and concentrates with the utmost probability: (1) Quality and composition of coltan concentrates vary considerably. (2) Mineralogical and chemical compositions of Ta-Nb ores are extremely complex due to the wide range of the columbite-tantalite solid solution series and its ability to incorporate many additional elements. (3) Coltan concentrates may contain a number of other tantalum-bearing minerals besides columbite-tantalite. In our approach, coltan concentrates are analyzed in a step-by-step mode. State-of-the-art analytical tools employed are automated scanning electron microscopy (Mineral Liberation Analysis; MLA), electron microprobe analysis (major and trace elements), laser ablation-ICP-MS (trace elements, isotopes), and TIMS (U-Pb dating). Mineral assemblages in the ore concentrates, major and trace element concentration patterns, and zoning characteristics in the different pegmatites from Africa distinctly differ from each other. Chondrite-normalized REE distribution patterns vary significantly between columbite, tantalite, and microlite, and also relative to major element compositions of columbites. Some locations are characterized by low REE concentrations, others are highly enriched. Samples with

Technological studies on the Manisa-Koprubasi uranium ores of Turkey

International Nuclear Information System (INIS)

Sagdik, U.

1980-01-01

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

The role of the thermal convection of fluids in the formation of unconformity-type uranium deposits: the Athabasca Basin, Canada

Science.gov (United States)

Pek, A. A.; Malkovsky, V. I.

2017-05-01

In the global production of uranium, 18% belong to the unconformity-type Canadian deposits localized in the Athabasca Basin. These deposits, which are unique in terms of their ore quality, were primarily studied by Canadian and French scientists. They have elaborated the diagenetic-hydrothermal hypothesis of ore formation, which suggests that (1) the deposits were formed within a sedimentary basin near an unconformity surface dividing the folded Archean-Proterozoic metamorphic basement and a gently dipping sedimentary cover, which is not affected by metamorphism; (2) the spatial accommodation of the deposits is controlled by the rejuvenated faults in the basement at their exit into the overlying sedimentary sequence; the ore bodies are localized above and below the unconformity surface; (3) the occurrence of graphite-bearing rocks is an important factor in controlling the local structural mineralization; (4) the ore bodies are the products of uranium precipitation on a reducing barrier. The mechanism that drives the circulation of ore-forming hydrothermal solutions has remained one of the main unclear questions in the general genetic concept. The ore was deposited above the surface of the unconformity due to the upflow discharge of the solution from the fault zones into the overlying conglomerate and sandstone. The ore formation below this surface is a result of the downflow migration of the solutions along the fault zones from sandstone into the basement rocks. A thermal convective system with the conjugated convection cells in the basement and sedimentary fill of the basin may be a possible explanation of why the hydrotherms circulate in the opposite directions. The results of our computations in the model setting of the free thermal convection of fluids are consistent with the conceptual reasoning about the conditions of the formation of unique uranium deposits in the Athabasca Basin. The calculated rates of the focused solution circulation through the fault

The applications of microwave energy to improve grindability and extraction of gold ores

Energy Technology Data Exchange (ETDEWEB)

Huang, J.H

2000-10-01

In this study, the applications of microwave energy in gold ore processing were investigated. An investigation of microwave heating characteristics indicated that the heating rate of an ore was not only related to the applied microwave field, but also to the mineralogy of the ore. Heating rate and the difference between the bulk temperature of an ore and the local temperature of high dielectric loss minerals increased with applied microwave power level, the content of high dielectric loss minerals, the particle size of the ore and the disseminated high dielectric loss minerals. The relationship between heating rate and surrounding environment is also discussed in this study. Investigations indicated that the microwave exposure could reduce the grindability of ores. For the Lihir gold ore, a decrease of 11% in the comparative grindability was obtained when it was exposed to 1500W microwave energy for 8 minutes. The decrease in grinding resistance resulted predominantly from the fractures induced by thermal stresses and differential thermal expansion of mineral phases during microwave heating. Experimental results showed that marcasite and pyrite could be decomposed into elemental sulphur and pyrrhotite-like Fe-S phases in an inert atmosphere, or oxidised into a porous hematite (Fe{sub 2}O{sub 3}) in an air atmosphere when they were exposed to microwaves. Microwave power had a significant impact on the decomposition of pyrite and marcasite. Marcasite was more readily decomposed than pyrite at the same exposure conditions. Scanning electron microscope (SEM), optical microscope, and X-ray diffraction results indicated that the alterations during microwave treatment were complex. Some intermediate products (e.g. Fe{sub (1-x)}S) were formed before the sulphides were completely oxidised into hematite (Fe{sub 2}O{sub 3}). Oxidation developed from the surfaces into the cores of the microwaved particles. Metallic particles were also formed during microwave exposure. Lihir

The applications of microwave energy to improve grindability and extraction of gold ores

International Nuclear Information System (INIS)

Huang, J.H.

2000-10-01

In this study, the applications of microwave energy in gold ore processing were investigated. An investigation of microwave heating characteristics indicated that the heating rate of an ore was not only related to the applied microwave field, but also to the mineralogy of the ore. Heating rate and the difference between the bulk temperature of an ore and the local temperature of high dielectric loss minerals increased with applied microwave power level, the content of high dielectric loss minerals, the particle size of the ore and the disseminated high dielectric loss minerals. The relationship between heating rate and surrounding environment is also discussed in this study. Investigations indicated that the microwave exposure could reduce the grindability of ores. For the Lihir gold ore, a decrease of 11% in the comparative grindability was obtained when it was exposed to 1500W microwave energy for 8 minutes. The decrease in grinding resistance resulted predominantly from the fractures induced by thermal stresses and differential thermal expansion of mineral phases during microwave heating. Experimental results showed that marcasite and pyrite could be decomposed into elemental sulphur and pyrrhotite-like Fe-S phases in an inert atmosphere, or oxidised into a porous hematite (Fe 2 O 3 ) in an air atmosphere when they were exposed to microwaves. Microwave power had a significant impact on the decomposition of pyrite and marcasite. Marcasite was more readily decomposed than pyrite at the same exposure conditions. Scanning electron microscope (SEM), optical microscope, and X-ray diffraction results indicated that the alterations during microwave treatment were complex. Some intermediate products (e.g. Fe (1-x) S) were formed before the sulphides were completely oxidised into hematite (Fe 2 O 3 ). Oxidation developed from the surfaces into the cores of the microwaved particles. Metallic particles were also formed during microwave exposure. Lihir gold ore, in which

Converting the Key Lake mill process for McArthur River ore

Energy Technology Data Exchange (ETDEWEB)

Rodgers, C. [McArthur River Operation, Cameco Corporation, Saskatoon, Saskatchewan (Canada)

2000-07-01

The Key Lake mill was commissioned in 1983 to process the two Key Lake ore deposits. With the depletion of these ore bodies in 1999, the plant was converted to mill the exceptionally rich McArthur River deposit located seventy eight kilometers northeast of the Key Lake mine site. This paper describes in detail the Key Lake milling process. The mill consists of a grinding circuit, a leach/counter current decantation circuit, a solvent extraction circuit, a yellowcake precipitation/calciner circuit, an ammonium sulphate crystallization circuit, and a waste treatment circuit. The paper also describes process changes to handle McArthur River ore, including the ore receiving station. (author)

Methods for the estimation of uranium ore reserves

International Nuclear Information System (INIS)

1985-01-01

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

Advances and Opportunities in Ore Mineralogy

Directory of Open Access Journals (Sweden)

Nigel J. Cook

2017-11-01

Full Text Available The study of ore minerals is rapidly transforming due to an explosion of new micro- and nano-analytical technologies. These advanced microbeam techniques can expose the physical and chemical character of ore minerals at ever-better spatial resolution and analytical precision. The insights that can be obtained from ten of today’s most important, or emerging, techniques and methodologies are reviewed: laser-ablation inductively-coupled plasma mass spectrometry; focussed ion beam-scanning electron microscopy; high-angle annular dark field scanning transmission electron microscopy; electron back-scatter diffraction; synchrotron X-ray fluorescence mapping; automated mineral analysis (Quantitative Evaluation of Mineralogy via Scanning Electron Microscopy and Mineral Liberation Analysis; nanoscale secondary ion mass spectrometry; atom probe tomography; radioisotope geochronology using ore minerals; and, non-traditional stable isotopes. Many of these technical advances cut across conceptual boundaries between mineralogy and geochemistry and require an in-depth knowledge of the material that is being analysed. These technological advances are accompanied by changing approaches to ore mineralogy: the increased focus on trace element distributions; the challenges offered by nanoscale characterisation; and the recognition of the critical petrogenetic information in gangue minerals, and, thus the need to for a holistic approach to the characterization of mineral assemblages. Using original examples, with an emphasis on iron oxide-copper-gold deposits, we show how increased analytical capabilities, particularly imaging and chemical mapping at the nanoscale, offer the potential to resolve outstanding questions in ore mineralogy. Broad regional or deposit-scale genetic models can be validated or refuted by careful analysis at the smallest scales of observation. As the volume of information at different scales of observation expands, the level of complexity

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

Magmatic Hydrothermal Fluids: Experimental Constraints on the Role of Magmatic Sulfide Crystallization and Other Early Magmatic Processes in Moderating the Metal Content of Ore-Forming Fluids

Science.gov (United States)

Piccoli, P. M.; Candela, P. A.

2006-05-01

It has been recognized for some time that sulfide phases, although common in intermediate-felsic volcanic rocks, are not as common in their plutonic equivalents. That sulfide crystallization, or the lack thereof, is important in the protracted magmatic history of porphyry Cu and related systems is supported by the work of e.g., Rowins (2000). Candela and Holland (1986) suggested that sulfide crystallization could moderate the ore metal concentrations in porphyry environments. Experiments show clearly that Au and Cu can partition into Cl-bearing vapor and brine. This effect can be enhanced by S (Simon, this session). However, in some instances enhances this effect. That is, the partitioning of Au and Cu into vapor+brine is highly efficient (e.g. Simon et al. 2003; Frank et al 2003). This suggests that if sulfides do not sequester ore metals early during the history of a magma body from the melt, they will partition strongly into the volatile phases. Whether volatile release occurs in the porphyry ore environment, or at deeper levels upon magma rise, is a yet unsolved question. Little is known about deep release of volatiles (during magma transport at lower- to mid-crustal levels). Saturation of melts with a CO2-bearing fluid could happen at levels much deeper than those typical of ore formation. CO2 is released preferentially, so a high CO2 concentration in fluids in the porphyry ore environment argues against deep fluid release. Of course, this depends upon the specific processes of crystallization and fluid release, which may be complex. Our experiments on sulfides have concentrated on pyrrhotite and Iss. Our partitioning data for Po/melt exhibit wide variations from metal to metal: Cu (2600); Co (170); Au (140); Ni (100); Bi, Zn and Mn (2). These results suggest that crystallization of Po can contribute to variable ore metal ratios (e.g. Cu/Au). Other sulfides behave differently. If a melt is Iss (Cpy) saturated, then Cu will be buffered at a high value, and Au

Mining and processing of uranium ores in the USSR

International Nuclear Information System (INIS)

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

1983-01-01

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

Influence of Stockpile Angle in Natural Drying of Laterite Ore

Directory of Open Access Journals (Sweden)

Yoalbys Retirado-Mediaceja

2016-10-01

Full Text Available Natural drying is performed at Cuban nickel plants by depositing bulk ore in the open. The ore is currently being stockpiled without much consideration for the impact of the drying surface angle on the process power behavior. Simulations were carried out in this investigation, which prove that an increased triangular stockpile angle considerably reduces natural drying efficiency. A 45 sexagesimal degree angle to the horizontal plane results in exposure of a large volume of ore to natural drying and guarantees adequate energy performance.

Genesis of iron-apatite ores in Posht-e-Badam Block (Central Iran ...

Indian Academy of Sciences (India)

Central Iran; iron-apatite ore; Kiruna-type; Posht-e-Badam Block; REE geochemistry. J. Earth Syst ... ferent ore genesis models have been proposed for ...... volatile-rich magma systems stress the important .... Laco magnetite flow deposits, northern Chile: An up-to- ... economic report on iron ore prevision of the Esfahan steel.

Juuru Mihkli Kiriku Oreli Fond võttis endale uue ülesande / Tauno Kibur

Index Scriptorium Estoniae

Kibur, Tauno

2009-01-01

Oreli fond on võtnud ülesandeks restaureerida koguduse ajalooline pastoraat. Hoone eskiisi tegi Raivi Juks. Oreli restaureerimist ja tulemust jääb fikseerima Juuru oreli plaat, mille muusikapalad mängis sisse Kristel Aer

Helium and deuterium permeability in O-rings

International Nuclear Information System (INIS)

Lakner, J.F.

1976-01-01

To obtain more information on gas permeation through elastomeric O-rings, studies were performed on Parker Seal Company O-rings, Nos. 2-113, 2-006, 3-904, and 3-906, all made of a nitrile rubber. Also included in the tests was a valve packing (Autoclave Engineers) encased in AE Valve 20A-2142. Permeation experiments were run usually in duplicate to 82.7 MPa (12,000 psi) with helium and deuterium at room temperature. The data are extrapolated to give values for tritium

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.

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

International Nuclear Information System (INIS)

Dheeraj Reddy, J.; Narender Reddy, J.

2004-01-01

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

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

Energy Technology Data Exchange (ETDEWEB)

McGinnis, Brent [Innovative Solutions Unlimited, LLC

2014-04-01

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

Characteristics of Crushing Energy and Fractal of Magnetite Ore under Uniaxial Compression

Science.gov (United States)

Gao, F.; Gan, D. Q.; Zhang, Y. B.

2018-03-01

The crushing mechanism of magnetite ore is a critical theoretical problem on the controlling of energy dissipation and machine crushing quality in ore material processing. Uniaxial crushing tests were carried out to research the deformation mechanism and the laws of the energy evolution, based on which the crushing mechanism of magnetite ore was explored. The compaction stage and plasticity and damage stage are two main compression deformation stages, the main transitional forms from inner damage to fracture are plastic deformation and stick-slip. In the process of crushing, plasticity and damage stage is the key link on energy absorption for that the specimen tends to saturate energy state approaching to the peak stress. The characteristics of specimen deformation and energy dissipation can synthetically reply the state of existed defects inner raw magnetite ore and the damage process during loading period. The fast releasing of elastic energy and the work done by the press machine commonly make raw magnetite ore thoroughly broken after peak stress. Magnetite ore fragments have statistical self-similarity and size threshold of fractal characteristics under uniaxial squeezing crushing. The larger ratio of releasable elastic energy and dissipation energy and the faster energy change rate is the better fractal properties and crushing quality magnetite ore has under uniaxial crushing.

Practice and prospect on bioleaching of uranium ore in China

International Nuclear Information System (INIS)

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

2008-01-01

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

Development of Technology for Enrichment of Silver Containing Ores

Science.gov (United States)

Shekiladze, Asmati; Kavtelashvili, Otari; Bagnashvili, Mamuka

2016-10-01

The progress of Georgian economics is substantially associated with a development of new deposits of mineral resources. Among them is the David-Gareji deposit where at present the intensive searching geological works are performed. The work goal involves the elaboration of the technology for processing of silver-containing quartz-barite ores. Without its development the mining of more valuable gold-polymetallic ores is impossible. Because of ore complexity silver and barite are considered in a common technological aspect. The investigations were carried out on the representative samples of quartz-barite ores containing 78-88 g/ton of silver and 27-29 % of silver is a nugget in the form of the simple sulphides and chlorides. The ore is characterized by fine coalescence of barite and ore-generating minerals. Non-ferrous metals haven't any industrial value because of their very low content. Therefore, for the processing of the ores under study the direct selective scheme of flotation enrichment was chosen and the formula of optimal reagent regime was elaborated. Potassium xanthogenate is used as a collector for flotation of silver minerals and pine oil- as a foaming agent. The effect of the pulp - pH and medium temperature on silver flotation was studied. It was established that the silver is actively floats in neutral medium. For barite flotation the various collectors were tested: sulfidezid cotton oil-soap stock, soaps of fatty acids and alkyl sulphates of C12 - C16 row, among the “Baritol” is the most efficient one. Depression of the barren rock was carried out by liquid glass in alkaline medium. The effect of pulp pH on barite flotation has been investigated. The best results were obtained at pH=8.5. The increase of the pulp alkalinity has no essential effect on the indexes of the barite enrichment. Conditional concentrate of the barite is obtained by two fold purification of the main flotation concentrate by the addition of the liquid glass to the re

Analysis on the geological features and ore-forming conditions at the southern margin of Erdos basin

International Nuclear Information System (INIS)

Ren Zhongxian; Shen Pingxi; Chen Fenling

2014-01-01

At the southern margin of Erdos basin, the paleo-interlayer-oxidation was developed in the medium-coarse-grained sandstone of Middle Jurassic System. High content uranium was enriched which are favorable for sandstone-type uranium deposit. There had been found multiple sandstone-type uranium deposits (ore occurrences) in this area. Uranium mineralization occurs in the sand body of braided fluvial facies in the lower member of Zhiluo Formation of Middle Jurassic System. It was controlled by the paleo-interlayer-oxidation. Uranium mineralization was closely related with the permeability of sandstone and occurs generally in the sandstones where is loose cementation and water permeability better. The stratum of Middle Jurassic System was extensively developed in the work area. Therefore it has great prospecting potential for the sandstone-type uranium deposit. (authors)

Beneficiation studies of Bajaur manganese ore by different processing techniques

International Nuclear Information System (INIS)

Riaz, M.; Khan, F.U.; Yamin, A.; Bilquees, R.; Muhammad, N.

2010-01-01

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)

Assessment of the contrast of rare metal ores

International Nuclear Information System (INIS)

Kuznetsova, O.V.

1987-01-01

The method of rapid assessment of useful component content on the basis of X-ray radiometric method of analysis of non-crushed ore lumps is presented. Using as an example rare metal deposits, linear dependence between logarithms of Nb 2 O 6 contents and the value of fragment separation index during radiometric separation is established. The use of the dependence ensures sufficient accuracy for the characteristic of rare metal ore content

Technology of Polish copper ore beneficiation – perspectives from the past experience

Directory of Open Access Journals (Sweden)

Wieniewski Andrzej

2016-01-01

Full Text Available The paper describes the main types of existing copper deposits in the world and the most common enrichment technologies. The characteristic elements of the current flowsheet of the Polish ore beneficiation were discussed together with the reasons for using them. The paper presents a perspective flowsheet based on more than 50-years of experience in beneficiation of Polish copper ore. The main elements of proposed technology are: leaving in justified cases the division of ore into fractions of increased sandstone and carbonate ores content, flotation in the milling circuit as part of the effective preparation of the ore to rougher flotation, intensive rougher flotation, classic cleaning system, processing of the middlings with grinding system in new type mills, classification and flotation with outlet of final tailings.

Mixing of fluids in hydrothermal ore-forming (Sn,W) systems: stable isotope and rare earth elements data

Science.gov (United States)

Sushchevskaya, T. M.; Popova, J. A.; Velivetskaya, T. A.; Ignatiev, A. V.; Matveeva, S. S.; Limantseva, O. A.

2012-04-01

Experimental and physico-chemical modeling data witness to important role of mixing of different type of fluids during tin and tungsten ore formation in hydrothermal systems. Mixing of magmatogeneous fluids, exsolved from granite melts, with exogenic, initially meteoric waters in hydrothermal ore-forming systems may change chemical composition of ore-forming fluid, causing cassiterite and/or wolframite precipitation (Heinrich, 1990; Sushchevskaya, Ryzhenko, 2002). We studied the process of genetically different fluids mixing for two economic Sn-W deposits, situated in the Iultin ore region (North-East of Russia, Chukotka Penninsula). The Iultin and Svetloe deposits are located in the apical parts of close situated leucogranite stocks, formed at the final stage of the Iultin complex emplacement. Both deposits are composed of a series of quartz veins among the flyschoid rocks (T 1-2), cut by the dikes (K1) of lamprophyre, granodiorite porphyre and alpite. The veins of the deposits are dominated by the productive quartz-wolframite-cassiterite-arsenopyrite-muscovite mineral assemblage. Topaz, beryl, fluorite, and albite occur sporadically. The later sulfide (loellingite-stannite-chalcopyrite) and quartz-fluorite-calcite assemblages show insignificant development. The preore quartz veinlets in host hornfels contain disseminated iron sulfides, chalcopyrite, muscovite. Isotopic (H, O, Ar) study of minerals, supplemented by oxygen isotope data of host granites and metamorphic rocks gave us possibility to conclude, that at the Iultin and the Svetloye deposits fluid mixing was fixed on the early stages of deposit formation and could be regarded as probable cause of metal (W, Sn) precipitation. During postore time the intensive involvement of isotopically light exogenic waters have changed: a) the initial character of oxygen isotope zonality; b) the initial hydrogen isotope composition of muscovites, up to meteoric calculated values for productive fluid (while the δ18O

Radiogeochemical features of hydrothermal metasomatic formations

International Nuclear Information System (INIS)

Plyushchev, E.V.; Ryabova, L.A.; Shatov, V.V.

1978-01-01

Considered are the most general peculiarities of uranium and thorium distributions in hydrothermal-metasomatic formations of three levels of substance formation: 1) in hydrothermal minerals; 2) in natural associations of these minerals (in the altered rocks, metasomatites, ores, etc.); 3) ordened series of zonally and in stage conjugated hydrothermal-metasomatic formations. Statistically stable recurrence of natural combinations of hydrothermal-metasomatic formations points out conjugation of their formation in the directed evolution in the general hydrothermal process. Series of metasomatic formations, the initial members of which are potassium metasomatites, mostly result in accumulation up to industrial concentrations of radioactive elements in final members of these formations. Development of midlow-temperature propylitic alterations in highly radiative rocks causes the same accumulation

Tantalum and niobium carbides obtention by carbothermic reduction of columbotantalite ores

International Nuclear Information System (INIS)

Gordo, E.; Garcia-Carcedo, F.; Torralba, J.M.

1998-01-01

Tantalum and niobium carbides are characterized by its high hardness and chemical corrosion resistance. Both carbides, but mainly TaC, are used in hard metals (sintered carbides), together with their carbides, to manufacture cutting tools and dies in special machining applications involving mechanical shock at high temperature. Its use as reinforcement of wear resistant materials through powder metallurgy techniques are being investigated. However, the use of TaC is usually limited because of its high cost. Therefore tantalum carbide with niobium content, which is cheaper, is used. In this work the obtention of complex tantalum and niobium carbides from a Spanish columbotantalite ore is studied through relatively cheap and simple process as it is carbothermic reduction. Concentration of the ore, its reduction and the characterization of products are described. (Author) 11 refs

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

International Nuclear Information System (INIS)

Mueller, T.

2008-01-01

Dozens cases of disease of former or present uranium and ore miners are submitted to judgment as occupational diseases every year in the Czech Republic. Patients or attending physicians suggest that these cases are caused by occupational ionizing radiation. Only a part of these cases is qualified as occupational disease, nevertheless they can cause many juridical problems. The term 'occupational disease' is rather juridical term which underlies the right to financial compensation. The causal association with exposure to ionizing radiation cannot be indisputably verified by expert medical opinion. Most diseases in uranium and ore miners, which are proposed as occupational disease, are malignant tumors. The majority of judged cases are lung cancers from radioactive agents. The poster gives general information about all judged cases of occupational diseases in former uranium and ore miners in the Czech Republic in the years 2002 -2007. It also provides short information about standards of professional radiation exposure assessment valid in the other countries. Most frequent diseases were lung cancers. Nevertheless the rate of lung cancers acknowledged as occupational disease decreases during the last two decades. Non-melanoma skin cancers are on the second place. The rate of skin cancers increases. We can explain this fact by better diagnostics and by new method which allows more precious assessment of the skin dose. The method is used since 2005. Leukemias are on the third place (1-2 cases in the year). (authors)

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

International Nuclear Information System (INIS)

Mueller, T.

2009-01-01

Dozens cases of disease of former or present uranium and ore miners are submitted to judgment as occupational diseases every year in the Czech Republic. Patients or attending physicians suggest that these cases are caused by occupational ionizing radiation. Only a part of these cases is qualified as occupational disease, nevertheless they can cause many juridical problems. The term 'occupational disease' is rather juridical term which underlies the right to financial compensation. The causal association with exposure to ionizing radiation cannot be indisputably verified by expert medical opinion. Most diseases in uranium and ore miners, which are proposed as occupational disease, are malignant tumors. The majority of judged cases are lung cancers from radioactive agents. The poster gives general information about all judged cases of occupational diseases in former uranium and ore miners in the Czech Republic in the years 2002-2007. It also provides short information about standards of professional radiation exposure assessment valid in the other countries. Most frequent diseases were lung cancers. Nevertheless the rate of lung cancers acknowledged as occupational disease decreases during the last two decades. Non-melanoma skin cancers are on the second place. The rate of skin cancers increases. We can explain this fact by better diagnostics and by new method which allows more precious assessment of the skin dose. The method is used since 2005. Leukemias are on the third place (1-2 cases in the year). (authors)

Iron ore pollution in Mandovi and Zuari estuarine sediments and its fate after mining ban.

Science.gov (United States)

Kessarkar, Pratima M; Suja, S; Sudheesh, V; Srivastava, Shubh; Rao, V Purnachandra

2015-09-01

Iron ore was mined from the banded iron formations of Goa, India, and transported through the Mandovi and Zuari estuaries for six decades until the ban on mining from September 2012. Here we focus on the environmental magnetic properties of sediments from the catchment area, upstream and downstream of these estuaries, and adjacent shelf during peak mining time. Magnetic susceptibility (χ lf) and saturation isothermal remanent magnetization (SIRM) values of sediments were highest in upstream (catchment area and estuaries), decreased gradually towards downstream (catchment area and estuaries), and were lowest on the adjacent shelf. The χ lf values of the Mandovi estuary were two to fourfold higher than those in the Zuari. The sediments of these two estuaries after the mining ban showed enrichment of older magnetite and sharp decrease in the SIRM values. Although the input of ore material has been reduced after mining ban, more flushing of estuarine sediments is required for healthier environment.

Geology and ore fluid geochemistry of the Jinduicheng porphyry molybdenum deposit, East Qinling, China

Science.gov (United States)

Li, Hongying; Ye, Huishou; Wang, Xiaoxia; Yang, Lei; Wang, Xiuyuan

2014-01-01

Jinduicheng deposit is a giant Mesozoic porphyry Mo system deposit in the East Qinling molybdenum belt, Shaanxi Province, China. The mineralization is associated with the I-type Jinduicheng granite porphyry. Both the porphyry stock and country rocks underwent intense hydrothermal alteration. The alteration, with increasing distance from the parent intrusion, changes from silicification, through potassic and phyllic assemblages, carbonation, to propylitic assemblages. Molybdenite, the dominant ore mineral, occurs in veinlets, most of which are hosted by the altered country rocks, with less than 25% of the ore in the porphyry body. The hydrothermal system comprises four stages, including pre-ore quartz and K-feldspar; two ore stages of quartz, K-feldspar, molybdenite, and Pb- And Zn-bearing sulfides; and post-ore quartz and carbonate. Six main types of primary fluid inclusions are present in hydrothermal quartz, including two-phase aqueous, one-phase aqueous, three-phase CO2-bearing, CO2-dominated fluid inclusions, gas inclusions, and melt inclusions. The homogenization temperatures of fluid inclusions range from 210 to 290 °C in the pre-ore stage, 150-310 °C in ore stage I, 150-360 °C in the ore stage II, and 195-325 °C in the post-ore stage quartz. Estimated salinities of the ore-forming fluids range from 6.9 to 13.5, 4.3 to 12.3, 6.2 to 12.4, and 3.4 to 9.9 wt.% NaCl equiv. in stages 1-4, respectively. The δ34S values of pyrite in the two ore stages range from 2.8‰ to 4.3‰, whereas the δ34S values of molybdenite range from 2.9‰ to 6.2‰. The data suggest both magmatic and crustal sources of sulfur. The δD and δ18O values for the hydrothermal fluids are -57.2‰ to -84.4‰ and 8.0‰ to -3.2‰, respectively. The fluid inclusion and stable data indicate that the pre-ore hydrothermal fluids were mostly of magmatic origin, but the fluids responsible for ore deposition were mixed magmatic and meteoric, and eventually meteoric water dominated the system

INAA of Zn and impurity elements in Zn ores and concentrates

International Nuclear Information System (INIS)

Op de Beeck, J.; De Norre, L.; Hoste, J.

1985-01-01

The present work concerns the analysis of zinc ores and concentrates. In the first place a procedure for the routine determination of fluorine in Zinc sulfide ores has been developed, based on activation with the fast neutrons of the isotope source. In the second place a procedure for the routine determination of Cadmium in Zinc ores has been developed and finally the routine determination of Zinc itself is at present being completed

Application of biohydrometallurgy to uranium ore processing

International Nuclear Information System (INIS)

Zhang Jiantang

1989-01-01

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

A precise 232Th-208Pb chronology of fine-grained monazite: Age of the Bayan Obo REE-Fe-Nb ore deposit, China

Science.gov (United States)

Wang, Jingyuan; Tatsumoto, M.; Li, X.; Premo, W.R.; Chao, E.C.T.

1994-01-01

We have obtained precise Th-Pb internal isochron ages on monazite and bastnaesite for the world's largest known rare earth elements (REE)-Fe-Nb ore deposit, the Bayan Obo of Inner Mongolia, China. The monazite samples, collected from the carbonate-hosted ore zone, contain extremely small amounts of uranium (less than 10 ppm) but up to 0.7% ThO2. Previous estimates of the age of mineralization ranged from 1.8 to 0.255 Ga. Magnetic fractions of monazite and bastnaesite samples (<60-??m size) showed large ranges in 232Th 204Pb values (900-400,000) and provided precise Th-Pb internal isochron ages for paragenetic monazite mineralization ranging from 555 to 398 Ma within a few percent error (0.8% for two samples). These results are the first indication that REE mineralization within the giant Bayan Obo ore deposit occurred over a long period of time. The initial lead isotopic compositions (low 206Pb 204Pb and high 208Pb 204Pb) and large negative ??{lunate}Nd values for Bayan Obo ore minerals indicate that the main source(s) for the ores was the lower crust which was depleted in uranium, but enriched in thorium and light rare earth elements for a long period of time. Zircon from a quartz monzonite, located 50 km south of the ore complex and thought to be related to Caledonian subduction, gave an age of 451 Ma, within the range of monazite ages. Textural relations together with the mineral ages favor an epigenetic rather than a syngenetic origin for the orebodies. REE mineralization started around 555 Ma (disseminated monazite in the West, the Main, and south of the East Orebody), but the main mineralization (banded ores) was related to the Caledonian subduction event ca. 474-400 Ma. ?? 1994.

Ore-processing technology and the uranium supply outlook

International Nuclear Information System (INIS)

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

1978-01-01

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

Chapter 1. The characteristics of borosilicate ores of Ak-Arkhar Deposit of Tajikistan

International Nuclear Information System (INIS)

Mirsaidov, U.M.; Kurbonov, A.S.; Mamatov, E.D.

2015-01-01

Present article is devoted to characteristics of borosilicate ores of Ak-Arkhar Deposit of Tajikistan. The chemical composition of danburite ore of Ak-Arkhar Deposit was defined. The chemical composition of danburite ore concentrate of Ak-Arkhar Deposit was defined as well.

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

International Nuclear Information System (INIS)

Hussein, E.M.

1997-01-01

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

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

International Nuclear Information System (INIS)

Riese, A.C.; Popp, C.J.

1979-01-01

The tests described were undertaken to determine the extent to leach solution-rock interactions with uranium-bearing ore obtained from the Mariano Lake mine. Leach solutions of an acidic (H/sub 2/O/sub 4/-sulfuric acid) and basic (NaHCO/sub 3/-sodium bicarbonate) nature were tested, in addition to a leach solution containing potassium chloride and sulfuric acid (KCl/H/sub 2/SO/sub 4/). The latter solution was chosen in an attempt to equilibrate the aqueous phase with the rock-forming silicate minerals and minimize adverse effects such as clay formation, porosity loss, and lixiviant loss. 29 refs

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

International Nuclear Information System (INIS)

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

2012-01-01

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

Chemical mining of primary copper ores by use of nuclear technology

Energy Technology Data Exchange (ETDEWEB)

Lewis, A E [Lawrence Radiation Laboratory, University of California, Livermore, CA (United States)

1970-05-15

Chemical mining of primary copper ores, with nuclear explosives to break the ore and in-situ hydrostatic pressure to accelerate dissolution of primary ore minerals, may be feasible. A contained nuclear explosion well below the water table would be used to provide a mass of broken ore in a flooded 'chimney'. The hydrostatic pressure in the chimney should increase the solubility of oxygen in a water-sulfuric acid system enough to allow primary copper minerals such as chalcopyrite and bornite to be dissolved in an acceptably short time. Circulation and collection would be accomplished through drill holes. This method should be especially applicable to the deep portions of porphyry copper deposits that are not economical to mine by present techniques. (author)

Using apatite to discriminate synchronous ore-associated and barren granitoid rocks: A case study from the Edong metallogenic district, South China

Science.gov (United States)

Duan, Deng-Fei; Jiang, Shao-Yong

2018-06-01

In order to find criteria to discriminate the synchronous ore-associated and barren granitoid rocks, we have determined apatite chemistry associated with ore-associated (Cu-Au) and barren granitoid rocks in the Edong district of the Middle and Lower Yangtze River metallogenic belt, South China. Both rock types give zircon U-Pb ages between 135.0 and 138.7 Ma. Apatite has a higher volatile and Li content (Cl: 0.19-0.57 wt%, average 0.35 wt%, SO3: 0.08-0.71 wt%, average 0.32 wt%, Li: 0.49-7.99 ppm, average 3.23 ppm) in ore-associated rocks than those in barren rocks (Cl: 0.09-0.31 wt%, average 0.16 wt%, SO3: 0.06-0.28 wt%, average 0.16 wt%, Li: 0.15-0.89 ppm, average 0.36 ppm). Apatite (La/Yb)N ratios and Eu/Eu* values are relatively high and show wider variation in ore-associated rocks than those in barren rocks. Apatite (La/Sm)N and (Yb/Sm)N show positive correlation in ore-associated rocks but negative in barren rocks. The higher volatile content occurs in ore-associated magma, favoring Cu-Au transportation and deposition. Furthermore, amphibole fractional crystallization in ore-associated magma further enriched the ore elements in the residual melt. Barren rocks may have undergone fluid exsolution before emplacement, which makes it barren in Cl, S and ore elements (Cu, S). These signatures emphases the significance of volatile and magma evolution in mineralization and indicate that analyses of magmatic apatite can serve to distinguish ore-associated from barren intrusions.

Pelletisation Behavior of Fluxed Iron Ore Pellets of Varying Basicities Made with Waste Fines

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Alok Sarkar

2013-10-01

Full Text Available Normal 0 false false false IN X-NONE X-NONE The present study deals with the utilization of fines generated from comminution process (crushing, grinding and screening of the Run of Mines into value added products i.e. fluxed iron ore pellets. The study comprises to understand the physical and mechanical behavior of five distinguished chemical compositions of green and dried iron ore pellets with respect to a typical Mini Blast furnace (MBF burden data and furnace operating parameter. The maximum basicity of pellets was calculated 2.37 to make slag neutral when blast furnace runs at 100% high ash coke (avg. ash content= 29%. The crushing strength and drop number of various green pellets were measured. Green Crushing Strength was decreased with increasing lime fines. The addition of lime fines as a burnt lime, which has acicular structure creates less plasticity and brittle like fracture occurred. Due to formation of hard CaCO3 layer on the surface, after increasing lime contain crushing strength was increased in the air and oven dry pellets with respect to acid pellet (0% lime fines addition. [How to cite this article: Sarkar, A., Mandal, A.K., and Sinha, O.P. (2013 Pelletisation Behavior of Fluxed Iron Ore Pellets of Varying Basicities Made with Waste Fines. International Journal of Science and Engineering, 5(2,9-14. Doi: 10.12777/ijse.5.2.9-14] 

Iron Ore Industry Emissions as a Potential Ecological Risk Factor for Tropical Coastal Vegetation

Science.gov (United States)

Kuki, Kacilda N.; Oliva, Marco A.; Pereira, Eduardo G.

2008-07-01

In the coastal zone of the Espírito Santo state, Brazil, fragments of restinga, which form a natural ecosystem, share their space with an increasing number of iron ore industries. The iron ore dust and SO2 originating from the industry processing activities can interfere with the vegetation of the adjacent ecosystems at various levels. This study was undertaken in order to evaluate the effects of industry emissions on representative members of the restinga flora, by measuring physiological and phenological parameters. Foliar samples of Ipomoea pes caprae, Canavalia rosea, Sophora tomentosa, and Schinus terebinthifolius were collected at three increasing distances from an ore industry (1.0, 5.0, and 15.0 km), and were assessed for their dust deposition, chlorophyll, and Fe content. Phenological monitoring was focused on the formation of shoots, flowers, and fruits and was also performed throughout the course of a year. The results showed that the edaphic characteristics and the mineral constitutions of the plants were affected by industry emissions. In addition, the chlorophyll content of the four species increased with proximity to the industry. Phenological data revealed that the reproductive effort, as measured by fruit production, was affected by emissions and S. tomentosa was the most affected species. The use of an integrative approach that combines biochemical and ecological data indicates that the restinga flora is under stress due to industry emissions, which on a long-term basis may put the ecosystem at risk.

Method of impact evaluation of storage sites for uranium ore tailings

International Nuclear Information System (INIS)

Servant, A.C.; Cessac, B.

2001-11-01

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

Optimization of flotation variables for the recovery of hematite particles from BHQ ore

Science.gov (United States)

Rath, Swagat S.; Sahoo, Hrushikesh; Das, B.

2013-07-01

The technology for beneficiation of banded iron ores containing low iron value is a challenging task due to increasing demand of quality iron ore in India. A flotation process has been developed to treat one such ore, namely banded hematite quartzite (BHQ) containing 41.8wt% Fe and 41.5wt% SiO2, by using oleic acid, methyl isobutyl carbinol (MIBC), and sodium silicate as the collector, frother, and dispersant, respectively. The relative effects of these variables have been evaluated in half-normal plots and Pareto charts using central composite rotatable design. A quadratic response model has been developed for both Fe grade and recovery and optimized within the experimental range. The optimum reagent dosages are found to be as follows: collector concentration of 243.58 g/t, dispersant concentration of 195.67 g/t, pH 8.69, and conditioning time of 4.8 min to achieve the maximum Fe grade of 64.25% with 67.33% recovery. The predictions of the model with regard to iron grade and recovery are in good agreement with the experimental results.

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

Science.gov (United States)

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

2017-06-01

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

Introduction - Acid decomposition of borosilicate ores

International Nuclear Information System (INIS)

Mirsaidov, U.M.; Kurbonov, A.S.; Mamatov, E.D.

2015-01-01

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.

[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.

Acid curing and baking of bastnasite ore and concentrate

International Nuclear Information System (INIS)

Topkaya, Y.; Akkurt, S.

1998-01-01

Full text: In this study, the hydrometallurgical evaluation of a rare earth ore as well as a concentrate obtained from this was done at laboratory. For the mentioned study, a bastnasite type rare earth ore located in Beylikahir in Turkey was used. The total rare earth oxide (REO) content of the deposit was estimated to be 1 million tons with an average concentration of 3.42%REO. The rare earths were contained in bastnasite mineral. The other constituents of the ore were calcium fluoride (52.5%), barite (25.4%), calcite (2.8%) and minor amounts of thorium, iron, manganese, etc. The bastnasite mineral occurred either as cement material between fluoride and barite particles or as intimately associated with these minerals. The rare earth elements were enriched considerably in sub-sieve sizes. After extensive research about the physical concentration of this ore, two different metallurgical routes were followed for the extraction of REE from the ore itself or the preconcentrate obtained by attrition scrubbing and desliming by cyclones. In order to increase the grade of the concentrate, upgrading of the preconcentrate by multigravity was also tried. The two metallurgical routes tested were: Sulphuric acid curing and water leaching; Sulphuric acid baking and subsequent water leaching. The results of the leaching experiments were found to be quite promising. Leach recoveries up to 90% were easily obtainable. In the case of acid baking, hydrofluoric acid recover as a by-product was also possible

Formation of Si-Al-Mg-Ca-rich zoned magnetite in an end-Permian phreatomagmatic pipe in the Tunguska Basin, East Siberia

Science.gov (United States)

Neumann, Else-Ragnhild; Svensen, Henrik H.; Polozov, Alexander G.; Hammer, Øyvind

2017-12-01

Magma-sediment interactions in the evaporite-rich Tunguska Basin resulted in the formation of numerous phreatomagmatic pipes during emplacement of the Siberian Traps. The pipes contain magnetite-apatite deposits with copper and celestine mineralization. We have performed a detailed petrographic and geochemical study of magnetite from long cores drilled through three pipe breccia structures near Bratsk, East Siberia. The magnetite samples are zoned and rich in Si (≤5.3 wt% SiO2), Ca, Al, and Mg. They exhibit four textural types: (1) massive ore in veins, (2) coating on breccia clasts, (3) replacement ore, and (4) reworked ore at the crater base. The textural types have different chemical characteristics. "Breccia coating" magnetite has relatively low Mg content relative to Si, as compared to the other groups, and appears to have formed at lower oxygen fugacity. Time series analyses of MgO variations in microprobe transects across Si-bearing magnetite in massive ore indicate that oscillatory zoning in the massive ore was controlled by an internal self-organized process. We suggest that hydrothermal Fe-rich brines were supplied from basalt-sediment interaction zones in the evaporite-rich sedimentary basin, leading to magnetite ore deposition in the pipes. Hydrothermal fluid composition appears to be controlled by proximity to dolerite fragments, temperature, and oxygen fugacity. Magnetite from the pipes has attributes of iron oxide-apatite deposits (e.g., textures, oscillatory zoning, association with apatite, and high Si content) but has higher Mg and Ca content and different mineral assemblages. These features are similar to magnetite found in skarn deposits. We conclude that the Siberian Traps-related pipe magnetite deposit gives insight into the metamorphic and hydrothermal effects following magma emplacement in a sedimentary basin.

Contact mechanical analysis of O-ring stresses

Energy Technology Data Exchange (ETDEWEB)

Kim, Hyung Kyu

2007-02-15

The purpose of this project is to develop the approximate solutions of contact traction and internal stress of an O-ring by using a two dimensional elasticity for enhancing the design and failure prediction technology. Investigated were the applicability of Lindley's formulae of contact force prediction and the Hertz theory. Three cases of O-ring installation were considered. The approximate solution of contact tractions and internal stresses of each case were derived. The key results are summarized as follows: 1. It is verified that Lindley's formulae predicts the relationship between the fractional compression and contact force. 2. In the case of Case I, II and III without internal pressure, it is found that a function form of the contact traction is the Hertzian. So it is possible to express the traction with a Hertzian form and correction factors. 3. The internal stresses are derived in the case of the Hertzian traction profile. The stresses at the center of O-ring show a satisfactory result when compared with the finite element result.

Radon and Thoron emanation testwork on Nolans Rare Earths ores

International Nuclear Information System (INIS)

Sonter, Mark; Grose, Jeremy

2016-01-01

This paper reports on a series of experiments performed on two bulk ore samples for Arafura Resources' Nolans Rare Earths project, intended to derive information on radon (Rn222) and thoron (Rn220) emanation rates (fluxes) under various circumstances. This data is needed to enable development of predictions of Rn and Tn releases from exposed mine bench ore, ore stockpiles, and tailings, and thus assist in estimation of airborne concentrations within the areas of the future Mine and Processing plant. In turn these estimates will provide guidance on the quantitative risk and the necessity or otherwise of invoking specific control measures, either in design or in operating procedures. This testwork was carried out during the period 2nd to 15th July, at Arafura's Winnellie facility in Darwin. Conclusions are that for uncrushed ore, Rn flux numbers are around 1.0Bq/m"2/s, Tn numbers appear to cluster around 200-300 Bq/m"2/s. Crushing gave no change in Rn flux, Tn flux was doubled for calc-silicate material. Wetting gave significant reductions for both Rn and Tn for ores sampled, and clay capping reduced Rn flux marginally but Tn was reduced by a factor of 100.

Satellite formation flying relative dynamics, formation design, fuel optimal maneuvers and formation maintenance

CERN Document Server

Wang, Danwei; Poh, Eng Kee

2017-01-01

This book systematically describes the concepts and principles for multi-satellite relative motion, passive and near passive formation designs, trajectory planning and control for fuel optimal formation maneuvers, and formation flying maintenance control design. As such, it provides a sound foundation for researchers and engineers in this field to develop further theories and pursue their implementations. Though satellite formation flying is widely considered to be a major advance in space technology, there are few systematic treatments of the topic in the literature. Addressing that gap, the book offers a valuable resource for academics, researchers, postgraduate students and practitioners in the field of satellite science and engineering.

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

International Nuclear Information System (INIS)

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

1991-01-01

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

Replacement of lumpy chrome ore by agglomerated ore concentrates and lowering of specific power consumption and improvement of Cr-yield by means of improved slag composition in the production of H.C. Ferrochrome

International Nuclear Information System (INIS)

Retelsdorf, H.J.; Fichte, R.; Breuer, F.; Zimmermann, H.

1982-06-01

Work on this project is finished, but further work on the use of Cr-ore briquettes seems necessary. It was the aim of the project to develop improved slag compositions for the FeCr 4-6% C-process resulting in higher Cr-yield and lower specific power consumption. Furthermore, replacement of lumpy ore in the charge by agglomerated Cr-ore-fines or concentrates in the form of pellets and briquettes was to be tested. Experimentals were performed in a 70 kW and a 300 kW arc furnace. Two different slag compositions were tested. The high-MgO slag type proved suitable. The specific power consumption and the Cr-yield depend to a large extent on the type of Cr-ore and on the agglomeration process. Cr-ore pellets can be used up to 65% in the ore charge but briquettes can be used only up to 25% to replace lumpy ores without causing higher Cr-losses in the slag. (orig.) [de

Idea of Identification of Copper Ore with the Use of Process Analyser Technology Sensors

Science.gov (United States)

Jurdziak, Leszek; Kaszuba, Damian; Kawalec, Witold; Król, Robert

2016-10-01

The Polish resources of the copper ore exploited by the KGHM S.A. underground mines are considered as one of the most complex in the world and - consequently - the most difficult to be processed. The ore consists of three lithology forms: dolomites, shales and sandstones but in different proportions which has a significant impact on the effectiveness of the grinding and flotation processes. The lithological composition of the ore is generally recognised in-situ but after being mined it is blended on its long way from various mining fields to the processing plant by the complex transportation system consisting of belt conveyors with numerous switching points, ore bunkers and shafts. Identification of the lithological composition of the ore being supplied to the processing plant should improve the adjustments of the ore processing machinery equipment aiming to decrease the specific processing (mainly grinding) energy consumption as well as increase the metal recovery. The novel idea of Process Analyser Technology (PAT) sensors - information carrying pellets, dropped into the transported or processed bulk material which can be read directly when needed - is investigated for various applications within the DISIRE project (a part of the SPIRE initiative, acting under the Horizon2020 framework program) and here is adopted for implementing the annotation the transported copper ore for the needs of ore processing plants control. The identification of the lithological composition of ore blended on its way to the processing plant can be achieved by an information system consisting of pellets that keep the information about the original location of the portions of conveyed ore, the digital, geological database keeping the data of in-situ lithology and the simulation models of the transportation system, necessary to evaluate the composition of the blended ore. The assumptions of the proposed solution and the plan of necessary in-situ tests (with the special respect to harsh

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 (

Evaluation of models of particulate suspension for a thorium ore stockpile

International Nuclear Information System (INIS)

Smith, W.J.

1983-01-01

Fifteen mathematical models of particle saltation, suspension, and resuspension were reviewed and categorized. Appropriate models were applied to the estimation of particulate releases from a hypothetical thorium ore storage pile. An assumed location (near Lemhi Pass, Montana) was used to permit the development of site specific information on ore characteristics and environmental influences. The available models were characterized in terms of suitability for representing aspects of the ore pile, such as rough surface features, wide particle size range, and site specific climate. Five models were selected for detailed study. A computer code for each of these is given. Site specific data for the assumed ore stockpile location were prepared. These data were manipulated to provide the input values required for each of the five models. Representative values and ranges for model variables are tabulated. The response of each model to input data for selected variables was determined. Each model was evaluated in terms of the physical realism of its response of each model to input data for selected variables was determined. Each model was evaluated in terms of the physical realism of its responses and its overall ability to represent the features of an ore stockpile. The two models providing the best representation were a modified version of the dust suspension subroutine TAILPS from the computer code MILDOS, and the dust suspension formulation from the computer code REDIST. Their responses are physically reasonable, although different from each other for two parameters: ore moisture and surface roughness. With the input values judged most representative of an ore pile near Lemhi Pass, the estimate of the release of suspended particulates is on the order of 1 g/m 2 -yr

Study on the relation between uranium content and total phosphorus in some sudanese phosphate ore samples

International Nuclear Information System (INIS)

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

2003-01-01

In the present work uranium content and total phosphorus were determined in 30 phosphate ore samples collected from Kurun and Uro areas in Nuba Mountains in Sudan. Spectrophotometry technique was used for this purpose. Uranium analysis is based on the use of nitrogen (V) acid for leaching the rock, and treatment with ammonium carbonate solution, whereby uranium (Vi) is kept in solution as its carbonate complex. The ion exchange technique was used for the recovery of uranium. Uranium was eluted from the resin with 1 M hydrochloric acid. In the elute, uranium was determined spectrophotometrically by measurement of absorbance of the yellow uranium (Vi)-8-hydroxyquinolate complex at λ 400 nm. The total phosphorus was measured as (P 2 O 5 %) by treatment of the total liquor with ammonium molybdate solution. The absorbance of the blue complex was measured at λ 880 nm. The results show that a limited relation is existed between uranium content and total phosphorus in phosphate samples from kurun area, which contain 58.8 ppm uranium in average, where there are no relation is existed in phosphate samples from uro area, which contain 200 ppm uranium in average. (Author)

Study on the relation between uranium content and total phosphorus in some sudanese phosphate ore samples

International Nuclear Information System (INIS)

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

2003-01-01

In the present work uranium content and total phosphorous were determined in 30 phosphate ore samples collected from Kurun and Uro areas in Nuba mountains in sudan. Spectrophotometry technique was used for this purpose. Uranium analysis is based on the use of nitrogen (V) acid for leaching the rock, and treatment with ammonium carbonate solution, whereby uranium (VI) is kept in solution as its carbonate complex. The ion-exchange technique was used for the recovery of uranium. Uranium was eluted from the resin with 1 M hydrochloric acid. In the elute, uranium was determined spectrophotometrically by measurement of the absorbance of the yellow uranium (VI) - 8- hydroxyquinolate complex at λ 400 nm. The total phosphorus was measured as (P 2 O 5 %) by treatment of the leach liquor with ammonium molybdate solution. The absorbance of the blue complex was measured at λ 880 nm. The results show that a limited relation is existed between uranium content and total phosphorus in phosphate samples from Kurun area, which contain 58.8 ppm uranium in average, where there are no relation is existed in phosphate samples samples from Uro area, which contain 200 ppm uranium in average

Uranium mobilization from low-grade ore by cyanobacteria

International Nuclear Information System (INIS)

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

1985-01-01

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

Uranium mobilization from low-grade ore by cyanobacteria

Energy Technology Data Exchange (ETDEWEB)

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

1985-04-01

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

Aluminum chloride restoration of in situ leached uranium ores

International Nuclear Information System (INIS)

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

1982-01-01

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

Standard values of quality and ore mining costs in management of multi-plant mining company

Energy Technology Data Exchange (ETDEWEB)

Kudelko, Jan [KGHM CUPRUM Research and Development Center, Wroclaw (Poland); Wirth, Herbert [KGHM Polska Miedz S.A., Lubin (Poland)

2010-03-15

Profitability of copper deposit mining depends on three basic variables, electrolytic copper price, manufacturing and selling costs of copper and company property involved in production process. If the company property is adjusted to its tasks then the mining profiability depends on costs of copper mining and selling, because the price is the external variable defined by the market. We can shape the costs in two (complementary) ways, traditionally, reducing the labor, material and power consumption, and by adjusting the quality of mined ore (copper content) to the level required by the current copper prices. Required quality of copper ore in the whole company we determine according to the accepted profitability criteria and then we determine quality standard for individual mines. Algorithms determining the ore quality standard resulting from current market price of copper are presented in the paper. Calculation models for the mined ore quality standards, unit mining costs per one ton of copper, electrolytic copper production and ore output are given. Standards were established for one variable assuming that the other variables are determined in this calculation. Innovative solution, presented in the paper, is the method of decomposition of the company controllable variables into the tasks for individual mines providing reaching the targets to the whole technological circuit. Using the models, having relatively few data, it will be possible to calculate quickly the values which are interesting for managers such as for example the prognosis of rate of return (economic or operational), required copper content in the mined ore for the whole company and individual mines at given rate of return or boundary level of copper content in comparison with cost and production level. Examples of calculation are provided. (orig.)

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

X-ray radiometric method of ore quality monitoring during mining

International Nuclear Information System (INIS)

Ivanyukovich, G.A.

1979-01-01

The method is basically applied for sampling ore deposits, mainly of nonferrous and rare metals. It can be used for determining one, two or three elements in the deposit. In the USSR, the method has so far been used in Far East tin deposits and in the North Caucasus tungsten-molybdenum deposit. It is used for the analysis of boreholes, shaft walls, mined ore and ore material intended for enriching. The instruments used include single-channel gamma spectrometers using scintillation or proportional counters as detectors. Logging instruments include dual-channel spectrometers featuring automatic gain control and data processing devices. The instruments are designed for separating elements with atomic numbers 19 to 88 from mine wall materials and with atomic numbers 26 to 88 in boreholes at concentrations exceeding 0.1% and 0.01% for tin and silver, respectively. The economic benefit is shown of the introduction of the method using the Sadon lead-zinc plant and Khrustalnensk ore treatment plant as examples. (H.S.)

NUMERICAL EVALUATION OF THE EFFECTS OF SOFT-MELTING PROPERTIES ON THE KINETIC OF (CAFE2 O4 -CA2 FE2 O5 FORMATION IN THE IRON ORE SINTERING PROCESS

Directory of Open Access Journals (Sweden)

José Adilson de Castro

2013-03-01

Full Text Available This paper presents a mathematical model able to predict the influence of soft-melting properties of the blend of raw materials used in the iron ore sintering process in the kinetic formation of calcium ferrite and di-calcium ferrite constituents. The model is based on the simultaneous solution of transport equations of Momentum, energy and chemical species in multiphase multicomponent systems coupled with the chemical reactions kinetics and phase transformations that occur within the sinter bed. The numerical solution is obtained using the finite volume method and the model is validated using monitoring data from an industrial scale sintering plant. After validation, the model was used to predict processing conditions using raw materials with different soft-melting properties. Results indicate that the temperatures of starting soft-melting, shrinkage and melting range are the main parameters to be controlled in order to attain liquid phases formation responsible to confer good mechanical and reducibility properties for the sinter product. In this study was found that raw materials with high soft-melting temperature and wilder temperature of mushy zone could decrease up to 30% the calcium ferrites formation and hence deteriorates the metallurgical properties of the sinter.

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

International Nuclear Information System (INIS)

Feng Jianke

2013-01-01

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

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

International Nuclear Information System (INIS)

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

2012-01-01

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

Use of lead isotopic composition in sulfides for the mineral-formation geochronology

International Nuclear Information System (INIS)

Ordynets, G.E.

1977-01-01

A study of the isotopic composition of lead in pyrites and galenites of a hydrothermal uranium deposit makes it possible to determine the time of ore formation. A few types of lead ores are distinguished. Each type corresponds to a definite period of mineralization and is characterized by a specific isotopic composition. The Cimmerian age of carbonate-sulphide veins has been established, the deposit being formed over a period of 150-200 million years

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

Energy Technology Data Exchange (ETDEWEB)

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

1967-06-15

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

94423-6883 Evaluation of Iron Ore Deposits in Elayiram Pannai

African Journals Online (AJOL)

Michael Horsfall

ABSTRACT: 2D Electrical Resistivity Imaging (ERI) investigation is suitable method to determine the geotechnical problems and it is used to identify the iron ore deposits. 2D. Electrical Resistivity Imaging with Wenner array was conducted within the iron ore deposits area in Elayiram Pannai, Virudhunagar District, ...

Studies of leaching of copper ores and flotation wastes

International Nuclear Information System (INIS)

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

2014-01-01

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

Radiometric sampling of bucked copper-nickel ores for determining chemical composition

International Nuclear Information System (INIS)

Komlev, V.N.; Eliseev, G.I.

1978-01-01

Presented are the results and the technique of experimental-methodical works on radiometric sampling of bucked copper-nickel ores for determining chemical composition with their selection and analysis by the neutron-gamma method and by the gamma-gamma method. The error is estimated according to the chosen conditions of sampling. It is found that the gamma-gamma method being more rapid but less accurate is applied for rapid control of ore current, whereas the neutron-gamma method is applied for quality control of ores extracted

Biosolubilization of uranyl ions in uranium ores by hydrophyte plants

International Nuclear Information System (INIS)

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

2006-01-01

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

The performance of leaching and bio-leaching from sulphide ores usiing SEVOP

OpenAIRE

Krstev, Boris; Krstev, Aleksandar; Golomeov, Blagoj; Golomeova, Mirjana; Sala, Ferat; Gocev, Zivko; Zivanovic, Jordan; Krstev, Dejan

2013-01-01

The refractory or low grade copper chalcopyrite ores or galena/sphalerite domestic ores in Republic of Macedonia are investigated by conventional copper flotation and selective flotation for galena/sphalerite. In the meantime, investigations are directed to the new possibilities of leaching by microorganisms – bioleaching. The paper is result of these technologies and investigations carried out for recovery of in the mentioned ores. Using Simplex EVOP and computer programme. Multisimple...

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

International Nuclear Information System (INIS)

EL-Sayed, M.H.

1992-01-01

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

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

International Nuclear Information System (INIS)

Hussein, E.M.

1997-01-01

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

Spatial evolution of Zn-Fe-Pb isotopes of sphalerite within a single ore body: A case study from the Dongshengmiao ore deposit, Inner Mongolia, China

Science.gov (United States)

Gao, Zhaofu; Zhu, Xiangkun; Sun, Jian; Luo, Zhaohua; Bao, Chuang; Tang, Chao; Ma, Jianxiong

2018-01-01

Analyses of sphalerite minerals from the characteristic brecciated Zn-Pb ores of the main ore body in the giant Dongshengmiao deposit have revealed variations in δ66Zn from 0.17 to 0.40‰ and in δ56Fe from -1.78 to -0.35‰. Further, the investigated pyrrhotite samples have iron that is isotopically similar to that of associated sphalerite minerals. The most distinctive pattern revealed by the zinc and iron isotope data is the lateral trend of increasing δ66Zn and δ56Fe values from southwest to northeast within the main ore body. The lead isotopic homogeneity of ore sulfides from the main ore body suggests that there is only one significant source for metal, thus precluding the mixing of multiple metal sources as the key factor controlling spatial variations of zinc and iron isotopes. The most likely control on spatial variations is Rayleigh fractionation during hydrothermal fluid flow, with lighter Zn and Fe isotopes preferentially incorporated into the earliest sulfides to precipitate from fluids. Precipitations of sphalerite and pyrrhotite have played vital roles in the Zn and Fe isotopic variations, respectively, of the ore-forming system. Accordingly, the larger isotopic variability for Fe than Zn within the same hydrothermal system perhaps resulted from a larger proportion of precipitation for pyrrhotite than for sphalerite. The lateral trend pattern revealed by the zinc and iron isotope data is consistent with the occurrence of a cystic-shaped breccia zone, which is characterized by marked elevation in Cu. The results further confirm that Zn and Fe isotopes can be used as a vectoring tool for mineral prospecting.

The experimental study of bacterial leaching at condition of different ore's diameter

International Nuclear Information System (INIS)

Liu Jinhui; Li Lin; Liu Yajie

2006-01-01

This papper compared the effect of leaching rate of uranium and the adaptability of bacteria with the condition of different ore's diameter (2-5 mm, 5-10 mm), which use the way of inleakage-leaching. The experiment use the way that firstly acid leaching, and then 2 bacterial leaching. As a reasult that the total leaching-rate of minute diameter ore are always high than the big diameter one. But for the quantum of consumed acid its just a opposition. During bacterial leaching the adaptability of bacteria in big diameter ore are high than in the minute one. So this experiment may offer a bases for a latter industry experiment which use big diameter ore's bacterial leaching. (authors)

Childhood Lead Poisoning Associated with Gold Ore Processing: a Village-Level Investigation—Zamfara State, Nigeria, October–November 2010

Science.gov (United States)

Lo, Yi-Chun; Dooyema, Carrie A.; Neri, Antonio; Durant, James; Jefferies, Taran; Medina-Marino, Andrew; de Ravello, Lori; Thoroughman, Douglas; Davis, Lora; Dankoli, Raymond S.; Samson, Matthias Y.; Ibrahim, Luka M.; Okechukwu, Ossai; Umar-Tsafe, Nasir T.; Dama, Alhassan H.

2012-01-01

Background: During May–June 2010, a childhood lead poisoning outbreak related to gold ore processing was confirmed in two villages in Zamfara State, Nigeria. During June–September of that year, villages with suspected or confirmed childhood lead poisoning continued to be identified in Zamfara State. Objectives: We investigated the extent of childhood lead poisoning [≥ 1 child with a blood lead level (BLL) ≥ 10 µg/dL] and lead contamination (≥ 1 soil/dust sample with a lead level > 400 parts per million) among villages in Zamfara State and identified villages that should be prioritized for urgent interventions. Methods: We used chain-referral sampling to identify villages of interest, defined as villages suspected of participation in gold ore processing during the previous 12 months. We interviewed villagers, determined BLLs among children lead. Results: We identified 131 villages of interest and visited 74 (56%) villages in three local government areas. Fifty-four (77%) of 70 villages that completed the survey reported gold ore processing. Ore-processing villages were more likely to have ≥ 1 child lead poisoning (68% vs. 50%, p = 0.17) or death following convulsions (74% vs. 44%, p = 0.02). Soil/dust contamination and BLL ≥ 45 µg/dL were identified in ore-processing villages only [50% (p lead poisoning or lead contamination was 3.5 times as high in ore-processing villages than the other villages (95% confidence interval: 1.1, 11.3). Conclusion: Childhood lead poisoning and lead contamination were widespread in surveyed areas, particularly among villages that had processed ore recently. Urgent interventions are required to reduce lead exposure, morbidity, and mortality in affected communities. PMID:22766030

Complex sulphide-barite ore leaching in ferric chloride solution

Directory of Open Access Journals (Sweden)

Miroslav Sokić

2016-06-01

Full Text Available The results of research on the leaching process of complex sulphide-barite ore were presented in this paper. The leaching process was carried out in a laboratory autoclave by ferric chloride solution. Considering that those minerals are represented in complex structural-textural relationships, it is not possible to extract lead, zinc and copper minerals from ore by flotation methods. The obtained results confirmed possibility of the ore processing directly, by chemical methods. The effect of temperature, time and oxygen partial pressure on the lead, zinc and copper dissolution was studied. The maximal leaching degree was achieved at 100 °C and amount of 91.5 % for Pb, 96.1 % for Zn and 60.7 % for Cu. Leaching at temperatures above 100 °C is impractical.

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

International Nuclear Information System (INIS)

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

1982-05-01

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

Ladinian skonca beds of the Idrija Ore Deposit (W Slovenia

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Jože Čar

2013-12-01

Full Text Available The richly mineralised Skonca beds (der Lagerschiefer were the most important mining level of the Idrija ore deposit. In addition to epigenetic ores, exceptional quantities of various rich syngenetic cinnabar ores could be found in these layers. »Jeklenka« (steel ore, »opekovka« (brick ore, »jetrenka« (liver ore, coral ore, and some other bedded cinnabar ores contained up to as much as 78 % Hg. These ores were excavated more or less intensively from their discovery in 1508 until the cessation of works in the Idrija Mine in 1977. The Skonca beds can be found in all parts of the Idrija ore deposit in the form of large or small, irregular, lenseshaped bodies or layers. In the section of the ore deposit known as šTalnina’, the Skonca beds are on average only 4 m thick, and from 10 to maximally 25 m in other parts of the ore deposit. The greatest thickness of these beds, i.e. around 40 m, can be found in the area of the Karóli tectonic unit, situated in the deepest part of the former Idrija Middle Triassic tectonic fault trough. The rocks in the Skonca beds are grouped in typical sequences, which represent a key for the reconstruction of sedimentary environments. The sequences are designated with the letters A, B, C and D. Sequence C is further divided into subsequences C1 with a carbonate and C2 with a siliceous structure. The lithological units of sequence A usually represent the lowest part of the Skonca beds, and may be the lateral equivalents of rocks of series B and subsequence C1. Sequence A is comprised of dispersed, gravelly varieties of carbonatic lythic sandstone, limestone and dolomite siltstone, as well as intercalations of gravelly silty micritic limestone and micritic limestone. Sequence B consists of typical transitional rocks between sequences A and C1, among which silty limestone with transitions to calcitic marlstone and claystone can be found. Sequence C is formed of šclassic’ Skonca rock beds. Although the bottom

Did the Kiruna iron ores form as a result of a metasomatic or igneous process? New U-Pb and Nd data for the iron oxide apatite ores and their host rocks in the Norrbotten region of northern Sweden

Science.gov (United States)

Westhues, A.; Hanchar, J. M.; Whitehouse, M. J.; Fisher, C. M.

2012-12-01

A number of iron deposits near Kiruna in the Norrbotten region of northern Sweden are of the iron oxide apatite (IOA) type of deposits; also referred to as Kiruna-type deposits. They are commonly considered a subgroup or end-member of iron oxide copper gold (IOCG) deposits, containing no economic grades of copper or gold. Both IOCG and IOA deposits are characterized by abundant low-Ti Fe oxides, an enrichment in REE, and intense sodium and potassium wall-rock alteration adjacent to the ores. Deposits of these types are of a great economic importance, not only for iron, but also for other elements such as rare earth elements (REE) or uranium. Kiruna, the type locality of the IOA type of mineral deposits, is the focus of this study. Despite a century-long mining history and 2500 Mt of iron ore produced in the region to date (with grades of 30 to 70 wt.% Fe), the genesis of these deposits is poorly understood: theories of a magmatic vs. a hydrothermal or metasomatic origin have been debated, and the timing of mineralization of the ores in the Norbotten region has never been directly dated. The results anticipated from this study will provide a better understanding of the nature of the IOA type of mineral deposits and their relation to IOCG deposits such as Olympic Dam in Australia. An array of geochemical methods is used in order to gain insights on the emplacement history of the host rocks, their subsequent alteration, and the ore genesis of these deposits. This includes in situ U/Pb geochronology of zircon, monazite, and titanite to constrain the timing between host rock emplacement, alteration and mineralization. Isotopic data from whole rocks and in situ at mineral scale will provide constraints on the involvement of hydrothermal fluids and their possible sources, as well as on the sources of Fe, U, and the REE. Newly obtained Sm-Nd isotopic data points to distinct source differences between host rocks, ore and alteration related samples. Preliminary in situ U

Influence of the Moisture Content on the Flowability of Fine-Grained Iron Ore Concentrate

OpenAIRE

C. Lanzerstorfer; M. Hinterberger

2017-01-01

The iron content of the ore used is crucial for the productivity and coke consumption rate in blast furnace pig iron production. Therefore, most iron ore deposits are processed in beneficiation plants to increase the iron content and remove impurities. In several comminution stages, the particle size of the ore is reduced to ensure that the iron oxides are physically liberated from the gangue. Subsequently, physical separation processes are applied to concentrate the iron ore. The fine-graine...

Hydrometallurgical Processing Technology of Titanomagnetite Ores

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Victor Ivanovich Sachkov

2017-12-01

Full Text Available In this paper, we study the possibility of obtaining iron and titanium-vanadium concentrates with highest contents of iron and titanium, respectively, through hydrometallurgical processing of the titanomagnetite ores of the Chineisk deposit. We varied two key parameters to determine the efficiency of the process: (a concentration of leaching solution (ammonium fluoride; and (b acidity of solution. Ammonium fluoride concentration was varied from 0.08 mol/L to 4.2 mol/L with the other fixed parameters. It was shown that optimum ammonium fluoride concentration for leaching the ore is 0.42 mol/L; at these concentrations iron and titanium contents are about 62.8 wt % and 3.5 wt % in solid phase, respectively. The acidity of solution was changed by adding of hydrofluoric acid with varied concentration (from 0.86 mol/L to 4.07 mol/L to ammonium fluoride solution with fixed concentration of 0.42 mol/L. The best results (degree of titanium extraction = 63.7% were obtained when using a solution of hydrofluoric acid with concentration 4.07 mol/L. In this case, the addition of acid makes it possible to increase the Fe/Ti ratio by 3.4 times in comparison with the original ore. Thus, we conclude that acidity and the concentration of ammonium fluoride solution significantly influences the selectivity of the hydrometallurgical process.

Chemical separation of Th-230 from uranium ore

International Nuclear Information System (INIS)

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

2001-01-01

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

Reagents and fractions impact on sulphide ore heap bioleaching at Smolnik mine

Science.gov (United States)

Oros, L. M.; Zavada, J.

2017-10-01

Mine Smolnik is one of the oldest sulphide ore mines in Europe and it is also an important part of bioleaching development. This paper follows previous attempts to extract residual metals from nearby heaps via variations in bioleaching reagents with regard to recent findings and needs in the related industry. Furthermore, economic and process relations between reagents and chosen heap fractions were also investigated in this case study.

Determination of cadmium in zinc ores by thermal neutron absorption analysis

International Nuclear Information System (INIS)

De Norre, L.; Op de Beeck, J.; Hoste, J.

1983-01-01

A method has been developed for routine determination of cadmium in zinc ores by thermal neutron absorption analysis, based on the attenuation of a thermal neutron flux passing through a neutron absorbing material. The thermal neutron flux in related to the 52 V activity induced in a vanadium detector, surrounded by pellets pressed from a mixture of powdered material with graphite. Besides cadmium, also the major constituents zinc, iron and sulfur contribute significantly to the total attenuation of the thermal neutron flux. Calibration lines for these elements are worked out. All irradiations are carried out for 200 s in the partially thermalized neutron flux of a 5 Ci 227 Ac-Be isotope neutron source. After a decay of 30 s, the 52 V activity of the vanadium detector is measured for 400 s with a NaI(Tl) scintillation detector. The analysis sequence, including the computation of the results from the counting data, is automated by means of a LSI-11 Microprocessor with 12Kx16 bit memory. Zinc ores, containing 0.02 to 1.45% cadmium, have been analyzed with a precision ranging from 12.6% to 0.54%, resp. As a test for the reliability of the method, two NBS standard reference materials were analyzed in the same way as the zinc ore samples. (author)

Waste monitoring of the uranium ore processing activities in Romania

International Nuclear Information System (INIS)

Nica, L.

2002-01-01

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

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

International Nuclear Information System (INIS)

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

2015-01-01

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

Filtration aids in uranium ore processing

International Nuclear Information System (INIS)

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

1975-01-01

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

Investigating the Utility of Iron Ore Waste in Preparing Non-fired Bricks

Science.gov (United States)

Lamani, Shreekant R.; Mangalpady, Aruna; Vardhan, Harsha

2017-10-01

Iron ore waste is a major problem for mine owners due to the difficulty involved in its storage, handling and other environmental related issues. An alternative solution to this is utilisation of iron ore waste (IOW) as some value added product in construction industry. An attempt has been made in this paper in examining the possibility of making non-fired bricks from iron ore waste with some additives like cement and fly-ash. Each of the additives were mixed with IOW in different ratios and different sets of bricks were prepared. The prepared IOW bricks were cured for 7, 14, 21 and 28 days and their respective compressive strength and percentage of water absorption were determined. The results show that IOW bricks prepared with 9% and above cement and with 28 days of curing are suitable for brick making and meet the IS specifications. It was also observed that the weight of the prepared bricks with 9% cement with 28 days of curing varies between 2.35 and 2.45 kg whereas the weight of compressed fire clay bricks varies from 2.80 to 2.89 kg. Results also show that the cost of bricks prepared with cement ranging from 9 to 20% is comparable to that of commercially available compressed bricks.

Technological pretreatment of the synchysite non-oxidized ore

Science.gov (United States)

Munkhtsetseg, B.; Burmaa, G.

2013-06-01

Mongolia has rich deposits of rare, precious, and poly-metallic ores. Nowadays, it is important to research separation of rare earth elements oxides concentrates from the ores, analyze their unique physical chemical characteristics, and purified it. Our investigation on raw materials focuses on rare earth non-oxidized ores. Main mineral in this rock sample is Synchysite (LnCa(CO3)2F. We did technological and thermal pretreatment: direct sulphurization (H2SO4), sulphurization with subsequent roasting (800°C+H2SO4), sulphurization prior to roasting (H2SO4+650°C). Sulphurization method based on dissolution of rare earth mineral into sulfuric acid (93%) according to the reaction. The amount of rare earth element oxides is almost 10 times greater (29.16%) after direct sulphurization process, almost 8 times greater (21.14%) after sulphurization with subsequent roasting, and almost 20 times greater (44.62%) after sulphurization prior to roasting process. After those technological pretreatment raw material's micro elements Thorium and Uranium contents are reduced as follows: H2SO4>800°C+H2SO4>H2SO4+650°C. These results show that cerium group rare earth elements have very good solubility in water at +2°C temperature and decreasing micro elements content uranium and thorium good pretreatment condition is prior to roasting (H2SO4+650°C) of synchysite non-oxidized ore.

Applicability of attrition of iron ore in floating

International Nuclear Information System (INIS)

Fortes, Fabiana Fonseca

2010-01-01

The aim of this study is to investigate the possibility to increase metal recovery in the flotation of iron ore with the implementation of a stage of scrubbing followed by dispersion. The minerals in question stems from two mines located in the western portion of the Iron Quadrangle and differ mainly with respect to the percentage of hematite and porous and the presence of aggregated masses. These characteristics were compared to those of other minerals that have succeeded with the adoption of this technique. Tests were conducted at bench scale scrubbing, desliming and concentration by flotation with the blend of ore from both mines. Were varied stirring time and pH. The chemical results of desliming and flotation products in the different conditions were compared. The presence of porous hematite is relevant in a mine, mainly due to the occurrence of earthy goethite, alumina carrier of the contaminant. The step desliming is insufficient for the removal of harmful sludge flotation. Laboratory experiments showed that the scrubbing of the pulp of iron ore of Minas de Capitao do Mato and Tamandua, agitated for 10 minutes followed by desliming amid scattered, promotes increased metal recovery by about 17% and increases the selectivity of 40 % compared to the results of the scrubbing and without dispersion. The scrubbing of hematite ore followed by desliming amid scattered can bring gains in improving the quality of pellet feed fine if deployed industrially. (author)

Nonlinear metallogeny and the depths of the earth

Science.gov (United States)

Shcheglov, A. D.; Govorov, I. N.

This book is concerned with the basic relations regarding a new approach in the field of knowledge of metallogenesis, taking into account the complex character of the mutual dependence between ore deposits, the structure of the earth's crust, and depth relations. The principles of nonlinear metallogeny are examined, giving attention to the development of the metallogenic science during the past few years, the formation of the concept 'nonlinear metallogeny', the main aspects of nonlinear metallogeny, the origin of the ore deposits and the characteristics of ore formations in the mantle, the parallel manifestation of ore-forming processes in the crust, sedimentary-hydrothermal ore formations and their place in nonlinear metallogeny, and various types of rock and ore formations. The structure, composition, and metalliferous characteristics found at various depth zones of the tectonosphere are discussed along with the geochemical and metallogenic heterogeneity in the mantle. General questions of nonlinear metallogeny are also investigated.

Chemical and thermal evolution of diagenetic fluids and the genesis of U and Cu ore in and adjacent to the Paradox Basin with emphasis on the Lisbon Valley and Temple Mountain areas, Utah and Colorado

International Nuclear Information System (INIS)

Morrison, S.J.

1986-01-01

Strata-of the central Colorado Plateau of southeastern Utah and southwestern Colorado hot Cu(+/-Ag) ore in salt anticline related faults, and stratiform sandstone-type uranium deposits. The goals of this study were to develop, evaluate, and interpret a geochemical data base from a restricted stratigraphic interval, and to develop models of the chemical and thermal evolution of the interaction of rock framework with pore fluids. Fluid inclusions, mineral chemistry, and C/O stable isotopes in calcite gangue associated with vein-type copper ore at Lisbon Valley suggest mixing of two solutions caused precipitation of the ore. Regularly interstratified chlorite/smectite (corrensite) coats grains in marine and eolian sandstones of the Permian Cutler Formation in the Lisbon Valley area. Local hydrothermal fluids rising along the Lisbon fault apparently permeated the Cutler red-bed section and precipitated the clay minerals. Detailed petrographic studies and fluid inclusion data from calcite cements in the Moss Back Member, support theories of syndiagenetic mobilization of humic compounds, uranium fixation and cementation at Lisbon Valley. The Temple Mountain area hosts uranium ore bodies that are unique among sandstone-type uranium deposits in structural setting, mineralogy, exotic elements, and the occurrence of asphaltite in the ores. This study suggests that warm fluids (70 0 C) have migrated along ring fractures bounding the collapse structure as evidenced by fluid inclusions trapped in authigenic dolomite in the basal Triassic Wingate Sandstone. K/Ar dates using alunite indicate that fluid migration was active as late as 13 my. Modeling suggests that dolomite at the Wingate/Chinle contact precipitated as two fluids mixed

Compositional variation of glauconites in Upper Cretaceous-Paleogene sedimentary iron-ore deposits in South-eastern Western Siberia

Science.gov (United States)

Rudmin, Maxim; Banerjee, Santanu; Mazurov, Aleksey

2017-06-01

Glauconite occurs either as unaltered greenish or as altered brownish variety in Upper Cretaceous-Palaeocene sediments in the southeastern corner of Western Siberia. Studied section within the Bakchar iron-ore deposit includes Ipatovo, Slavgorod, Gan'kino and Lyulinvor formations, which are represented by sandstones, siltstones, claystones and oolitic ironstones of coastal-marine facies. The origin of unaltered glauconite is explained by the ;verdissement theory;. Transgressions during Lower Coniacian, Santonian and Campanian favored the formation of unaltered glauconites in dysoxic to anoxic conditions. Subaerial exposure of glauconite resulted in leaching of potassium, oxidation of iron and formation of iron hydroxides in Upper Coniacian, Maastrichtian and Palaeocene. Glauconite ultimately converts to leptochlorite and hydrogoethite by this alteration. Abundant microscopic gold inclusions, besides sulphides, sulphates, oxides and silicates characterize this glauconite. Mineral inclusions include precious, rare metals and non-ferrous metals. The concentration of gold in glauconite may be as high as 42.9 ppb. Abundant inclusions of various compositions in glauconites indicate enrichment of marine sediments in precious and non-precious metals. While major element composition of glauconites is affected by subaerial exposure, the broadly similar micro-inclusions in both altered and unaltered varieties are possibly related to the comparatively immobile nature of REE and trace elements.

Some aspects of the processing development for uranium ores treatment

International Nuclear Information System (INIS)

Bruno, J.B.

1982-01-01

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

Influence of Copper Ore Comminution in HPGR on Downstream Minerallurgical Processes

Directory of Open Access Journals (Sweden)

Saramak D.

2017-09-01

Full Text Available Crushing processes taking place in high-pressure grinding rolls devices (HPGR are currently one of the most efficient methods of hard ore size reduction in terms of the energy consumption. The HPGR products are characterized by a fine particle size and the micro-cracks formation in individual particles, which appears in downstream grinding processes, decreasing their energy consumption. The purpose of the paper was to analyze the effectiveness of a ball mill grinding process and flotation operations depending on the changeable conditions of run of the HPGR crushing process. The research programme carried out included crushing tests in the laboratory scale HPGR device at various settings of the operating pressure volume and selected qualitative properties of the feed material (i.e. particle size distribution. On the basis of obtained results the models, defining the grinding process effectiveness as a function of changeable conditions of HPGR process run, were determined. Based on these models the optimal grinding time in a ball mill was specified which is, in turn, the basis for optimization of operation the technological comminution circuits for a given material type. The obtained results proved that the application of HPGR devices in given copper ore comminution circuit may improve the effectiveness of downstream grinding process what leads to improvement of the entire circuit work efficiency through decreasing the process energy consumption and enhancing the product size reduction.

Optimum condition determination of Rirang uranium ores grinding using ball mill

International Nuclear Information System (INIS)

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

2002-01-01

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

Regulatory concerns for leakage testing of packagings with three O-ring closure seals

International Nuclear Information System (INIS)

Oras, J.J.; Towell, R.H.; Wangler, M.E.

1997-01-01

The American National Standard for Radioactive Materials--Leakage Tests on Packages for Shipment (ANSI N14.5) provides guidance for leakage rate testing to show that a particular packaging complies with regulatory requirements and also provides guidance in determining appropriate acceptance criteria. Recent radioactive packagings designs have incorporated three O-ring closure seals, the middle O-ring being the containment seal. These designs have the potential for false positive results of leakage rate tests. The volume between the containment O-ring and the inner O-ring is used for the helium gas required for the leakage rate tests to reduce both the amount of helium used and the time required to conduct the tests. A leak detector samples the evacuated volume between the outer O-ring and the containment O-ring. False positive results can be caused in two ways, a large leakage in the containment seal or leakage in the inner seal. This paper will describe the problem together with possible solutions/areas that need to be addressed in a Safety Analysis Report for Packagings before a particular packaging design can be certified for transport

The use of radiometric ore sorting on South African gold mines

International Nuclear Information System (INIS)

Boehme, R.C.; Freer, J.S.

1982-01-01

This paper refers to the radiometric sorting tests reported during the 7th CMMI Congress, and then describes the photometric and radiometric sorter installations in operation and under construction in South Africa at present. As radiometric sorting of gold ores uses the radiation from the uranium content as a tracer, it is essential that the sortability of the ore should be reliably determined before sorting is adopted. The method of obtaining the important ore characteristics is described, with examples. The possible increase in gold production from a hypothetical plant as a result of sorting is shown

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

2006-09-30

Heap leaching is one of the methods being used to recover metal from low grade ore deposits. The main problem faced during heap leaching is the migration of fine grained particles through the heap, forming impermeable beds which result in poor solution flow. The poor solution flow leads to less contact between the leach solution and the ore, resulting in low recovery rates. Agglomeration of ore into coarse, porous masses prevents fine particles from migrating and clogging the spaces and channels between the larger ore particles. Currently, there is one facility in the United States which uses agglomeration. This operation agglomerates their ore using leach solution (raffinate), but is still experiencing undesirable metal recovery from the heaps due to agglomerate breakdown. The use of a binder, in addition to the leach solution, during agglomeration would help to produce stronger agglomerates that did not break down during processing. However, there are no known binders that will work satisfactorily in the acidic environment of a heap, at a reasonable cost. As a result, operators of many facilities see a large loss of process efficiency due to their inability to take advantage of agglomeration. Increasing copper recovery in heap leaching by the use of binders and agglomeration would result in a significant decrease in the amount of energy consumed. Assuming that 70% of all the leaching heaps would convert to using agglomeration technology, as much as 1.64*10{sup 12} BTU per year would be able to be saved if a 25% increase in copper recovery was experienced, which is equivalent to saving approximately 18% of the energy currently being used in leaching heaps. For every week a leach cycle was decreased, a savings of as much as 1.23*10{sup 11} BTU per week would result. This project has identified several acid-resistant binders and agglomeration procedures. These binders and experimental procedures will be able to be used for use in improving the energy efficiency of

Bottle roll leach test for Temrezli uranium ore

International Nuclear Information System (INIS)

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

2014-01-01

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

A study on the method for estimating the life time of O-rings made of NBR used in sealing air operating cylinders

International Nuclear Information System (INIS)

Fujii, Yuzo; Mitsuta, Yasumasa

2003-01-01

At nuclear power plants, a large number of O-rings made of rubber are attached to safety related machines and apparatus for sealing two metallic components. O-rings degrade during the long term exposure in environmental conditions in use, and finally lose the requested functions. Therefore it is important to exchange them in a proper period based on the precise life time estimation. This study aimed at to investigate the method for estimating the life time of O-rings made of NBR (acrylonitrile butadiene rubber) attached to the air cylinders which drive the dampers of ventilation systems in nuclear power plants. It has been conducted as follows: (1) After confirming that the main cause of degradation of O-rings is thermo-oxidation reaction, thermally accelerated aging tests were carried out for O-rings with three different temperatures. (2) It was certified that the elongation values of O-rings obtained by the tests could be fitted by the Arrhenius rule, and then the life time of O-rings was estimated using the Arrhenius rule. (3) In order to validate the reliability of this estimation, we measured the elongation values of the O-rings which had been actually used at nuclear power plants, and compared them to the predicted elongation values obtained by the above estimation. The average and standard deviation of the values which is calculated by the equation {(measured value-predicted value)/ predicted value} are 11% and 8%, respectively and there are small errors between the measured value and the predicted values. As a result we can judge that good estimation of life time of O-rings can be done by the above method. (author)

Evaluation of Social Performance and Related Factors in Iranian Central Iron Ore company workers

Directory of Open Access Journals (Sweden)

Gholamhossein Halvani

2013-01-01

Full Text Available Introduction: Psychological and social health is the main problems of workers population, which can increase productivity at work and physical and mental health and provide or decline in these aspects. Materials and Methods: this study was descriptive and crosses - sectional and has been performed on 388 Iranian central iron ore company workers. The tool of study was standard GHQ-28 question are that has been measured under social performance scale. Results: 49.3 and 49 percent of the people have favorable and average score from the state of the social function condition and 1.8 percent of people have severe social dysfunction and besides the employees have less work experienced that have more social dysfunction and there is a relationship between the P = 0.026. With satisfaction with the status of social dysfunction (P = 0 and with the consent of the income (P = 0 there is significant relationship. Conclusion: In this study, a significant percentage of mineworkers were not in good condition from health, social functioning. It reveals the importance of addressing health issues and vulnerable working class, Intervention studies conducted by employers to improve job satisfaction and increased income and received social support from him, can increase the health indicators related to the body and mind.

Study on the pre-treatment of oxidized zinc ore prior to flotation

Science.gov (United States)

He, Dong-sheng; Chen, Yun; Xiang, Ping; Yu, Zheng-jun; Potgieter, J. H.

2018-02-01

The pre-treatment of zinc oxide bearing ores with high slime content is important to ensure that resources are utilized optimally. This paper reports an improved process using hydrocyclone de-sliming, dispersion reagents, and magnetic removal of iron minerals for the pre-treatment of zinc oxide ore with a high slime and iron content, and the benefits compared to traditional technologies are shown. In addition, this paper investigates the damage related to fine slime and iron during zinc oxide flotation, the necessity of using hydrocyclone de-sliming together with dispersion reagents to alleviate the influence of slime, and interactions among hydrocyclone de-sliming, reagent dispersion, and magnetic iron removal. Results show that under optimized operating conditions the entire beneficiation technology results in a flotation concentrate with a Zn grade of 34.66% and a recovery of 73.41%.

Chromosomal aberrations in ore miners of Slovakia

International Nuclear Information System (INIS)

Beno, M.; Vladar, M.; Nikodemova, D.; Vicanova, M.; Durcik, M.

1998-01-01

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.)

Dolochar as a reductant in the reduction roasting of iron ore slimes

Science.gov (United States)

Rath, Swagat S.; Rao, Danda Srinivas

2017-12-01

The present investigation examines the viability of dolochar, a sponge iron industry waste material, as a reductant in the reduction roasting of iron ore slimes, which are another waste generated by iron ore beneficiation plants. Under statistically determined optimum conditions, which include a temperature of 900°C, a reductant-to-feed mass ratio of 0.35, and a reduction time of 30-45 min, the roasted mass, after being subjected to low-intensity magnetic separation, yielded an iron ore concentrate of approximately 64wt% Fe at a mass recovery of approximately 71% from the feed iron ore slime assaying 56.2wt% Fe. X-ray diffraction analyses indicated that the magnetic products contain magnetite and hematite as the major phases, whereas the nonmagnetic fractions contain quartz and hematite.

Radioactivity of phosphate ores from Karatas-Mazidag phosphate deposit of Turkey

International Nuclear Information System (INIS)

Akyuez, T.; Varinlioglu, A.; Kose, A.; Akyuez, S.

2000-01-01

The specific activities of 238 U, 226 Ra, 232 Th and 40 K in the composite samples of phosphate ores of type I (grey-coloured ore, with high P 2 O 5 (21-35%) and low calcite content) and of type II (grey coloured calcite ore, with low P 2 O 5 content (5-17%)) of Karatas-Mazidag phosphate deposit, Turkey, have been determined by gamma spectrometry together with phosphatic animal feed ingredients. The concentrations of 238 U, 226 Ra, 232 Th and 40 K were found to be up to 557, 625, 26 and 297 Bq x kg -1 , respectively. Radium equivalent activities of samples were calculated and compared with those given in the literature. Uranium concentration of the individual phosphate samples, from which composite samples of ores of type I and II have been prepared, were found to show and increasing trend with increasing P 2 O 5 and F concentrations. (author)

Alunite in the Pascua-Lama high-sulfidation deposit: Constraints on alteration and ore deposition using stable isotope geochemistry

Science.gov (United States)

Deyell, C.L.; Leonardson, R.; Rye, R.O.; Thompson, J.F.H.; Bissig, T.; Cooke, D.R.

2005-01-01

The Pascua-Lama high-sulfidation system, located in the El Indio-Pascua belt of Chile and Argentina, contains over 16 million ounces (Moz) Au and 585 Moz Ag. The deposit is hosted primarily in granite rocks of Triassic age with mineralization occurring in several discrete Miocene-age phreatomagmatic breccias and related fracture networks. The largest of these areas is Brecha Central, which is dominated by a mineralizing assemblage of alunite-pyrite-enargite and precious metals. Several stages of hydrothermal alteration related to mineralization are recognized, including all types of alunite-bearing advanced argillic assemblages (magmatic-hydrothermal, steam-heated, magmatic steam, and supergene). The occurrence of alunite throughout the paragenesis of this epithermal system is unusual and detailed radiometric, mineralogical, and stable isotope studies provide constraints on the timing and nature of alteration and mineralization of the alunite-pyiite-enargite assemblage in the deposit. Early (preore) alteration occurred prior to ca. 9 Ma and consists of intense silicic and advanced argillic assemblages with peripheral argillic and widespread propylitic zones. Alunite of this stage occurs as fine intergrowths of alunite-quartz ?? kaolinite, dickite, and pyrophyllite that selectively replaced feldspars in the host rock. Stable isotope systematics suggest a magmatic-hydrothermal origin with a dominantly magmatic fluid source. Alunite is coeval with the main stage of Au-Ag-Cu mineralization (alunite-pyrite-enargite assemblage ore), which has been dated at approximately 8.8 Ma. Ore-stage alunite has an isotopic signature similar to preore alunite, and ?? 34Salun-py data indicate depositional temperatures of 245?? to 305??C. The ??D and ?? 18O data exclude significant involvement of meteoric water during mineralization and indicate that the assemblage formed from H2S-dominated magmatic fluids. Thick steam-heated alteration zones are preserved at the highest elevations in

Modelling Of Monazite Ore Break-Down By Alkali Process Spectrometry

International Nuclear Information System (INIS)

Visetpotjanakit, Suputtra; Changkrueng, Kalaya; Pichestapong, Pipat

2005-10-01

A computer modelling has been developed for the calculation of mass balance of monazite ore break-down by alkali process at Rare Earth Research and Development Center. The process includes the following units : ore digestion by concentrate NaOH, dissolution of digested ore by HCl, uranium and thorium precipitation and crystallization of Na3PO4 which is by-product from this process. The model named RRDCMBP was prepared in Visual Basic language. The modelling program can be run on personal computer and it is interactive and easy to use. User is able to choose any equipment in each unit process and input data to get output of mass balance results. The model could be helpful in the process analysis for the further process adjustment and development

Geological structure and prospects of noble metal ore mineralization of the Khayrkhan gabbroid massif (Western Mongolia)

Science.gov (United States)

Kurumshieva, K. R.; Gertner, I. F.; Tishin, P. A.

2017-12-01

An analysis of the distribution of noble metals in zones of sulfide mineralization makes it possible to justify the isolation of four ore-bearing horizons with a specific geochemical zonation. A rise in the gold content relative to palladium and platinum is observed from the bottom upwards along the section of the stratified series of gabbroids. The study of the mineral phases of sulphides and the noble minerals itself indicates the evolution of hydrothermal solutions, which determines the different activity and mobility of the fluid (mercury, tellurium, sulfur) and ore (copper, nickel, iron, platinum, gold and silver) components.

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

International Nuclear Information System (INIS)

Berger, Bernard.

1978-01-01

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

Underground Milling of High-Grade Uranium Ore

Energy Technology Data Exchange (ETDEWEB)

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

2014-05-15

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

Bioleaching of a manganese and silver Ore

International Nuclear Information System (INIS)

Porro, S.; Tedesco, P.H.; La Plata

1990-01-01

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)

Prospecting For Magnetite Ore Deposits With A Innovative Sensor's of Unique Fundamentally New Magnetometer.

Science.gov (United States)

Emelianenko, T. I.; Tachaytdinov, R. S.; Sarichev, V. F.; Kotov, B. V.; Susoeva, G. N.

After careful study of principles and abilities of all existing magnetmeters of all three revolutions in magnetic prospecting we have come to the conclusion that they cannot solve local guestions of the magnetic prospecting or determine centre coordinates of magnetite ore body before drilling Electromagnetism lows and achievents magnetprospectings and radioelectronics of all 20th century serve as a theoretical base of the "locator". While creating this cardinally new magnetmeter , we borrowed different things from radio-prospectors, magnetprospectors, wireless operators and combined all of them while creating the "locators''. The "locators' construction is bas ed on the "magnetic intensification" principle ,owing to which this "locators" are characterised by hight sensitiveness and ability to determine centers of even little commercial magnetite ore deposits with relatively weak magnetic anomalies. The main advantage of the "locators" over existing ones is that it can solve local questions determine centre coordinates. A remarkably simple locator construction determine direction of the on-surface measurings towards the ore body centre and gives approximate prognosis resourses before/withour/ drilling. The "locators" were worked out for the first time in history , they have 2 licences. The fundamental design and drawbacks of the existing magnetometers have been inherited from the original magnetometre dating back two or three hundred years. The developers of the existing magnetometres have all gone along the same well- beaten track of replacing the primitive sensor in the form of a piece of ore hung on a string at first by an arrow sensor and later by magnetically oriented protons and quanta, with amplification of the sensors' OUTPUT signal. Furthermore, all the existing magnetometres are imperfect in that they, lacking the directivity of the ground-level magnetic measurements, only record the overall magnetic vector field generated by all the ore bodies around the

Paleomagnetic dating of non-sulfide Zn-Pb ores in SW Sardinia (Italy: a first attempt

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L. Sagnotti

2005-06-01

Full Text Available A first paleomagnetic investigation aimed at constraining the age of the non-sulfide Zn-Pb ore deposits in the Iglesiente district (SW Sardinia, Italy was carried out. In these ores, the oxidation of primary sulfides, hosted in Cambrian carbonate rocks, was related to several paleoweathering episodes spanning from the Mesozoic onward. Paleomagnetic analyses were performed on 43 cores from 4 different localities, containing: a non-oxidized primary sulfides and host rock, b oxidized Fe-rich hydrothermal dolomites and (c supergene oxidation ore («Calamine». Reliable data were obtained from 18 samples; the others show uninterpretable results due to low magnetic intensity or to scattered demagnetization trajectories. Three of them show a scattered Characteristic Remanent Magnetization (ChRM, likely carried by the original (i.e. Paleozoic magnetic iron sulfides. The remaining 15 samples show a well defined and coherent ChRM, carried by high-coercivity minerals, acquired after the last phase of counterclockwise rotation of Sardinia (that is after 16 Myr, in a time interval long enough to span at least one reversal of the geomagnetic field. Hematite is the main magnetic carrier in the limestone, whereas weathered hydrothermal dolomite contains goethite or a mixture of both. The results suggest that paleomagnetism can be used to constrain the timing of oxidation in supergene-enriched ores.

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

International Nuclear Information System (INIS)

Wang Juntang; Wang Chengwei; Feng Shirong

2008-01-01

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)

Evaluation of serpentine ore as a nuclear shielding material using gas chromatographic techniques

International Nuclear Information System (INIS)

Singh, B.N.; Unnikrishnan, E.K.; Kumar, Sangita D.

2007-01-01

Serpentine ore mixed with cement has been recognized as a candidate shielding material for use in nuclear reactors because of its many desirable properties. Therefore the assessment of serpentine ore for release of volatile gases during exposure to elevated temperatures, irradiation and changes in chemical composition, is essential. The present paper deals with the studies on the serpentine ores using gas chromatography and combustion gas chromatographic techniques. (author)

PGAA method for control of the technologically important elements at processing of sulfide ores

International Nuclear Information System (INIS)

Kurbanov, B.I.; Aripov, G.A.; Allamuratova, G.; Umaraliev, M.

2006-01-01

Full text: Many precious elements (Au, Re, Pt, Pd, Ag, Cu, Ni, Co, Mo) in ores mainly exist in the form of sulfide minerals and the flotation method is often used for processing of such kind of ores. To enhance the efficiency of the process it is very important to carry out the operative control of the elements of interest at various stages of ore processing. In this work the results of studies for developing methods for control of technologically important elements at processing and enrichment sulfide ores, which content the gold, copper, nickel, molybdenum in the ore-processing plants of Uzbekistan. The design of transportable experimental PGAA device on the basis of low-power radionuclide neutron source ( 252 Cf) with neutrons of 2x10 7 neutr/sec allowing to determine element content of the above named ores and their processing products is offered. It is shown that the use of the thermal neutron capture gamma-ray spectrometry in real samples and technological products allows prompt determination of such elements as S, Cu, Ti and others, which are important for flotation of sulfide ores. Efficiency control of the flotation processing of sulfide ores is based on quick determination of the content of sulfur and some other important elements at different stages of the process. It was found that to determine elements the following gamma lines are the most suitable - 840.3 keV for sulfur, 609 keV and 7307 keV for copper and 1381.5 keV, 1498.3 keV and 1585.3 keV for titanium. Based on the measurements of original ores, concentrates of various stages of flotation and flotation slime the possibility for prompt determination of S, Cu and Ti content and thus to get necessary information on the efficiency of the flotation process was shown. (author)

Ore-lead isotopes and Grenville plate tectonics

International Nuclear Information System (INIS)

Farquhar, R.M.; Fletcher, I.R.

1980-01-01

Recent advances in the 'whole earth' modelling of evolutionary processes of Pb isotopes shed light upon the origin of the metals found in various types of ore deposits. On the bases of these models and several recently published data sets, we believe that the ore deposits formed in various plate tectonic environments may carry 'isotopic fingerprints' which, when used with other characteristics such as mineral assemblages, may identify the depositional environments of many ore bodies. In the present study Pb-isotopic measurements have been made of a number of Precambrain mineralization types and localities throughout the Central Metasedimentary Belt of the Grenville Province. The data for individual deposits are at best ambiguous, but fall into two groups sufficiently distinctive to allow some degree of 'fingerprint' identification. Comparisons with data from other areas suggest that the major periods of sedimentation within the Central Metasedimentary Belt accompanied plate rifting and/or island arc tectonic activity, with most of the mineralized lead being derived from mantle sources. Detailed comparisons between the Grenville and other regions are uncertain, mainly because there are few detailed high-accuracy data sets from younger, tectonically unambiguous mineral occurrences. We suggest that once these data sets are availble, isotopic fingerprinting may become diagnostic for deposits ranging well back into the Precambrain

Stratigraphy, tectonic and ore potential of pre-cambrian unities from Serro region-MG (Mato Grosso quadrangle)

International Nuclear Information System (INIS)

Assis, L.C. de.

1982-01-01

Geological and stratigraphic elements of the Proterozoic units of the Serro region, Mato Grosso Quadrangle, show the absence of the faciological transition between the Espinhaco Group and the Minas Supergroup. Occurs in this region is a lithostratigraphical sequence of four distinct units: the Crystalline Basement; the Volcano-Sedimentary Sequence of Serro; the Minas Supergroup. The ore potential of the region includes: quartz veins, within the Galho do Miguel Formation; diamond, within the Sopa conglomerates; gold, in alluvial deposits and remobilized in quartz veins of the Sopa-Brumadinho Formation; bauxite, in the metabasics; uranium in the metaconglomerates of Moeda Formation; iron, in Caue Formation; chromium, gold and base metals in the Volcano-Sedimentary Sequence of Serro. Emphasis is given to the characterization of the Volcano-Sedimentary Sequence of Serro and its mineralization that is characterized as a stratiform massif with important volcano-sedimentary contribution, possible, a greenstone belt, with high gold-bearing potential. (author)

Influence of attrition variables on iron ore flotation

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Fabiana Fonseca Fortes

Full Text Available Abstract The presence of slimes is harmful to the flotation process: the performance and consumption of reagents are negatively affected. Traditionally, the desliming stage has been responsible for removing slimes. However, depending on the porosity of the mineral particles, desliming may not be sufficient to maximize the concentration results. An attrition process before the desliming operation can improve the removal of slime, especially when slimes cover the surface and/or are confined to the cavities/pores of the mineral particles. Attrition is present in the flowcharts of the beneficiation process of phosphate and industrial sand (silica sand. Research has been undertaken for its application to produce pre-concentrates of zircon and iron ore. However, there is still little knowledge of the influence of the attrition variables on the beneficiation process of iron ore. This study presents a factorial design and analysis of the effects of these variables on the reverse flotation of iron ore. The standard of the experimental procedures for all tests included the attrition of pulp, under the conditions of dispersion, desliming and flotation. The parameter analysed (variable response was the metallurgical recovery in reverse flotation tests. The planning and analysis of the full factorial experiment indicated that with 95% reliability, the rotation speed of the attrition cell impeller was the main variable in the attrition process of the iron ore. The percentage of solid variables in the pulp and the time of the attrition, as well as their interactions, were not indicated to be significant.

A New Direction for Biomining: Extraction of Metals by Reductive Dissolution of Oxidized Ores

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Kevin B. Hallberg

2013-01-01

Full Text Available Biomining, the biotechnology that uses microorganisms to extract metals from ores and concentrates, is currently used exclusively for processing reduced ores and mine wastes. Metals of economic value also occur extensively in oxidized ores, such as nickel laterites. While these are not amenable to oxidative dissolution, the ferric iron minerals they contain can, in theory, be disrupted by iron reduction, causing associated metals to be released. We have harnessed the ability of the facultatively anaerobic, acidophilic bacterium Acidithiobacillus ferroooxidans to couple the oxidation of elemental sulphur to the reduction of ferric iron in the goethite fraction of a limonitic nickel ore at 30 °C. Nickel and other metals (Co, Cr and Mn were effectively solubilised and maintained in solution due to the low pH (1.8 of the leach liquor. The results highlight the potential for the bioprocessing of oxidized, iron-rich ores using an approach that is energy-saving and environmentally-benign compared with metallurgical processes currently applied to the extraction of Ni from lateritic ores.

Image analyses in bauxitic ores: The case of the Apulian karst bauxites

Science.gov (United States)

Buccione, Roberto; Sinisi, Rosa; Mongelli, Giovanni

2015-04-01

This study concern two different karst bauxite deposits of the Apulia region (southern Italy). These deposits outcrop in the Murge and Salento areas: the Murge bauxite (upper Cretaceous) is a typical canyon-like deposit formed in a karst depression whereas the Salento bauxite (upper Eocene - Oligocene) is the result of the erosion, remobilization and transport of older bauxitic material from a relative distant area. This particular bauxite arrangement gave the name to all the same bauxite deposits which are thus called Salento-type deposits. Bauxite's texture is essentially made of sub-circular concentric aggregates, called ooids, dispersed in a pelitic matrix. The textural properties of the two bauxitic ores, as assessed by SEM-EDX, are different. In the bauxite from the canyon-like deposit the ooids/matrix ratio is higher than in the Salento-type bauxite. Furthermore the ooids in the Salento-like bauxite are usually made by a large core surrounded by a narrow, single, accretion layer, whereas the ooids from the canyon-like deposit have a smaller core surrounded by several alternating layers of Al-hematite and boehmite (Mongelli et al., 2014). In order to explore in more detail the textural features of both bauxite deposits, particle shape analyses were performed. Image analyses and the fractal dimension have been widely used in geological studies including economic geology (e.g. Turcotte, 1986; Meakin, 1991; Deng et al., 2011). The geometric properties evaluated are amounts of ooids, average ooids size, ooids rounding and the fractal dimension D, which depends on the ooids/matrix ratio. D is the slope of a plotting line obtained using a particular counting technique on each sample image. The fractal dimension is slightly lower for the Salento-type bauxites. Since the process which led to the formation of the ooids is related to an aggregation growth involving chemical fractionation (Mongelli, 2002) a correlation among these parameters and the contents of major

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