Academic literature on the topic 'Tantale – Minerais'
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Journal articles on the topic "Tantale – Minerais"
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Simandl, George J., Richard O. Burt, David L. Trueman, and Suzanne Paradis. "Economic Geology Models 2. Tantalum and Niobium: Deposits, Resources, Exploration Methods and Market – A Primer for Geoscientists." Geoscience Canada 45, no. 2 (2018): 85–96. http://dx.doi.org/10.12789/geocanj.2018.45.135.
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The world’s main tantalum (Ta) resources are in pegmatites (e.g. Wodgina, Australia), rare element-enriched granites (e.g. Abu Dabbab, Egypt), peralkaline complexes (e.g. Nechalacho, Canada), weathered crusts overlying the previously mentioned deposit types, and in placers. Niobium (Nb) resources with the highest economic potential are in weathered crusts that overlie carbonatite complexes (e.g. Catalão I and II, Brazil). Brazil accounts for 90% of the global Nb mine production with another 9% coming from the Niobec Mine, Canada (a hard-rock underground mine). However, at least 17 undeveloped carbonatite complexes outside of Brazil have NI-43-101 compliant Nb resource estimates (e.g. Aley carbonatite, Canada). Concentrates from most carbonatites are used to produce ferroniobium (Fe–Nb alloy), and Ta is not recovered. The Ta and Nb contents of some carbonatites (e.g. Upper Fir deposit and Crevier dyke, Canada) are of the same order of magnitude as that of pegmatite ores; however, concentrates from carbonatites have a higher Nb/Ta ratio. Historically, 10–12% Ta2O5 in Nb concentrates has not been recovered in ‘western’ smelters because of the hydrofluoric acid cost. Western countries perceive Ta and Nb supplies to be at risk. Tantalum market downturns resulted in several mines in Australia and Canada closing, at least temporarily, and a resultant shortfall has been filled by what is now recognized as ‘conflict-free columbite-tantalite’ from Central Africa. The lack of ore will not be a key factor in future Ta and Nb supply disruption. For example, more than 280 Nb- and 160 Ta-bearing occurrences are known in Canada alone, and more resources will likely to be discovered as geophysical and geochemical exploration methods are optimized.RÉSUMÉLes principales sources mondiales en tantale (Ta) sont les pegmatites (par ex. Wodgina, Australie), les granites enrichis en éléments rares (par ex. Abu Dabbab, Égypte), les complexes hyperalcalins (par ex. Nechalacho, Canada), les croûtes altérées recouvrant les types de gisements déjà mentionnés, et les placers. Les sources en niobium (Nb) ayant le meilleur potentiel économique se trouvent dans les croûtes altérées qui recouvrent les complexes de carbonatite (par ex. Catalão I et II, Brésil). Le Brésil est la source de 90% de la production minière mondiale de Nb, et 9% provient de la mine Niobec, au Canada (une mine souterraine). Cela dit, il existe au moins 17 complexes de carbonatite non développés à l'extérieur du Brésil dont les estimations de ressources en Nb sont conformes à la norme NI-43-101 (par ex. Aley carbonatite, Canada). Les concentrés de la plupart des carbonatites sont utilisés pour produire du ferroniobium (alliage Fe-Nb), et le Ta n'est pas récupéré. Les teneurs en Ta et Nb de certaines carbonatites (par ex. le gisement de Upper Fir et le dyke Crevier, Canada) sont du même ordre de grandeur que celles des minerais depegmatite; cependant, les concentrés de carbonatites ont une proportion Nb/Ta plus élevée. Historiquement, 10 à 12% du Ta2O5 des concentrés de Nb n'ont pas été récupérés dans les fonderies de l'Ouest en raison du coût de l’acide fluorhydrique. Les pays occidentaux estiment que les approvisionnements en Ta et Nb sont à risque. Le fléchissement du marché du tantale a entraîné la fermeture, au moins temporaire, de plusieurs mines en Australie et au Canada, et la pénurie qui en résulte a été comblée par ce qui est maintenant reconnu comme étant du minerai de colombite-tantalite «sans conflit» d'Afrique centrale. Le manque de minerai ne sera pas un facteur clé des perturbations à venir de l'approvisionnement en Ta et Nb. Par exemple, plus de 280 occurrences minérales contenant du Nb et 160 occurrences minérales contenant du Ta sont connues au Canada seulement, et davantage de ressources seront probablement découvertes à mesure que les méthodes d'exploration géophysique et géochimique seront optimisées.
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Hrinchenko, O., S. Bondarenko, and T. Mironchuk. "GRANITOIDS, RARE-METAL PEGMATITES AND Ta-Nb MINERALIZATION OF SHPOLIANO-TASHLYK ORE AREA (INGUL MEGABLOCK, UKRAINIAN SHIELD)." Visnyk of Taras Shevchenko National University of Kyiv. Geology, no. 4 (83) (2018): 24–29. http://dx.doi.org/10.17721/1728-2713.83.03.
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Composition of granites, genetically associated pegmatites and superimposed metasomatites distributed within Shpoliano-Tashlyk ore area (Ingul megablock) is considered. It is established, that on the basis of similarity in their petrographic and petrochemical features granitoids of the area can be related to single complex. Features of ore mineralization are defined by both composition of granitoids (Sgranites) after which rare-metal pegmatites are formed and intensity of superimposed metasomatic alterations. Main minerals-concentrators of Ta and Nb mineralization in granitic pegmatites and metasomatites are represented by minerals of three isomorphic series – columbite-tantalite (Fe,Mn)(Nb,Ta,Ti)2O6, ilmenorutile-struverite (Ti,Nb,Ta)O2 and pyrochlore-microlite (Ca,Na)2Ta2O6(O,B,OH,F). Depending on geological setting such ore minerals as tapiolite, ixiolite, cassiterite, uraninite, nigerite, gahnite are commonly found in association with these minerals. Chemical composion of tantalo-niobates sampled from ore-bearing pegmatites and metasomatites is investigated by microprobe analysis. Most minerals of columbite-tantalite series are characterized by distinct and rhythmic internal zonality and contrasting mosaic structure which are related to considerable heterogeneities of their chemical composition. Within one aggregate mineral phases with wide range of values – from 9,80 to 71,0 % for Ta2O5 and from 10,6 to 70,1 % for Nb2O5 – are established. Among minerals ferruginous varieties which composition relates to Fe-columbite-tantalites (Nb2O5/Ta2O5 = 1–1,2; FeO/MnO = 2,5–6) prevail. Columbite-tantalites are characterised by high contents of admixture elements present (%): TiO2 – to 5,88; WO3 – to 3,70; SnO2 – to 9,20; Sc2O3 – to 5,40. Scandium ores occur as scandium-rich minerals that are mostly confined to the minerals of columbite-tantalite series found in Polohivka ore field. On the Ukrainian Shield high contents of Sc2O3 in tantalo-niobates are established for the first time. Minerals of ilmenorutile-struverite series do not quantitatively yield to minerals of columbite-tantalite series. For minerals of this series Nb2O5/Ta2O5 ratio varies in the range of 0,6-1,4. Among characteristic admixture-elements are prevailed (%): SnO2 – to 3,1, V2O5 – to 5,05; FeO – to 11,51, Cr2O3 – to 1,20. Minerals of pyrochlore-microlite series are of subordinate importance. For the first time by results of U-Pb dating of columbite-tantalites from Mostove ore manifestation (Shpoliano-Tashlyk area) the age of Ta-Nb mineralization is established to be about 1965 ± 25 million years.
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Huber, Miłosz, Daniel Kamiński, and Urszula Maciołek. "Columbite–Tantalite from Northern Scandinavia (Kaustinen, Kolmozero) Pegmatites: An Optical and Spectroscopic Properties." Crystals 13, no. 4 (2023): 612. http://dx.doi.org/10.3390/cryst13040612.
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LCT (lithium–cesium–tantalum) pegmatites from the Kaustinen and Kolmozero regions contain columbite–tantalite mineralization, which has been presented in this study. Crystal structure, Raman microscopy, and optical property analyses of these minerals were performed. As a result of the structural studies and micro-area analyses, it was determined that these minerals in the pegmatites in question constitute a solid solution with numerous Mn-Fe and Nb-Ta substitutions within a single crystal. The ratio between Mn-Fe and Nb-Ta can change from crystal to crystal, which makes it impossible to find precise stechiometry between these ions. The crystallization conditions of these minerals were also determined by studying the associations of other rock-forming minerals and accessory minerals in the discussed rocks.
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Alekseev, Viktor I., and Ivan V. Alekseev. "The Presence of Wodginite in Lithium–Fluorine Granites as an Indicator of Tantalum and Tin Mineralization: A Study of Abu Dabbab and Nuweibi Massifs (Egypt)." Minerals 13, no. 11 (2023): 1447. http://dx.doi.org/10.3390/min13111447.
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This study examines the accessory wodginite and the discovery of titanium-bearing wodginite and Fe and Ti-bearing wodginite in lithium-fluorine granites from the Abu Dabbab and Nuweibi massifs in Eastern Egypt. The wodginite group’s mineral association includes tantalum-bearing cassiterite and tin-bearing tantalum–niobate minerals: tantalite-(Mn), columbite-(Mn), and microlite. Three forms of wodginite crystallization were identified: (1) rims around columbite-(Mn) and tantalite-(Mn) varying from 1.5 to 21.9 μm in thickness, (2) micro-inclusions in cassiterite ranging from 5.4 to 27.0 μm in size, and (3) autonomous crystals measuring 3–124 μm in length. Wodginite in the Nuweibi massif is mainly found in porphyritic granite of late-stage porphyry intrusion. It has a similar composition to the worldwide wodginite of rare-metal granites, but exhibits a lower content of TiO2 (average 0.54%) and is a mineral indicator of rich tantalum ore deposits. In contrast, wodginite in the Abu Dabbab massif is replaced by titanium-bearing wodginite (Ti/(Sn + BTa + Ti + Fe3+) = 0.23) and is associated with Fe and Ti-bearing wodginite. Wodginite and Ti-bearing wodginite are maximally enriched in manganese (Mn/(Mn + Fe2+ +Ca) = 0.95), expressed in all intrusive phases of the massif, and are mineral indicators of tantalum-bearing granites with associated cassiterite-quartz mineralization.
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MATONDO, Idylle Plachini LOUFOUANDI, and Mikhail IVANOV. "Composition and probable ore igneous rocks source of columbite from alluvial deposits of Mayoko district (Republic of the Congo)." Journal of Mining Institute 242 (May 24, 2020): 139. http://dx.doi.org/10.31897/pmi.2020.2.139.
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The article presents the results of optical, electron microscopic and electron microprobe studies of columbite group minerals, collected during heavy mineral concentrate sampling of alluvial deposits in the Mayoko region (Republic of the Congo). The aim of the study is revealing tantalum niobates ore body in this region. We found that these minerals in loose deposits are represented by two grain-size groups: less than 1.6 mm (fine fraction) and 1.6-15 mm (coarse fraction). The grains of both fractions belong mainly to columbite-(Fe), less often to columbite-(Mn), tantalite-(Mn) and tantalite-(Fe), contain impurities of Sc, Ti, and W. The crystals have micro-scaled zoning (zones varies slightly in the Ta/Nb ratio values) and contains a lot of mineral inclusions and veins represented by zircon, pyrochlore supergroup minerals and others. Columbite-(Fe) and columbite-(Mn) are characterized by an increased content of Ta2O5 up to the transition to tantalite-(Fe) and tantalite-(Mn). This allows us to exclude the formation of subalkaline rare-metal granites, their metasomatites (albitites and greisenes) and carbonatites, from the list of possible columbite ore rocks source in the Mayoko district. Thus, beryl type and complex spodumene subtype rare-element pegmatites of the mixed petrogenetic family LCT-NYF (according to P.Černý) should be considered as a probable root source. The results of the research should be taken into account when developing the methodology for prospecting in this area.
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Alekseev, Viktor I., and Ivan V. Alekseev. "Tungsten-Bearing Wodginite from the Kester Deposit, Eastern Siberia, Russia." Minerals 13, no. 2 (2023): 231. http://dx.doi.org/10.3390/min13020231.
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Li-F granites from the Kester deposit (Yana Plateau in Yakutia, Russia) are proved to be connected with a rare-metal complex of accessory minerals: montebrasite, columbite-(Mn), columbite-(Fe), tantalite-(Mn), Ta-bearing cassiterite, U-bearing microlite, W-bearing ixiolite, niobian ferberite, U–Hf-rich zircon, and Ta-bearing rutile. Accessory wodginite was discovered at depths of up to 150 m in association with tantalite-(Mn), columbite-(Mn), and cassiterite. According to the content of WO3 (1.23%–3.33%) and the values of Mn/(Mn + Fet) and Ta/(Ta + Nb), Yakut wodginite is an intermediate mineral between wodginite and a hypothetical mineral of the wodginite group—”wolframowodginite”. The discovery of tungsten-bearing wodginite at the Kester deposit confirms the widespread presence of tungstic and tungsten-bearing accessory minerals in Li-F granites in the Russian Far East. It also serves as an indicator of rare-metal tin-tantalum-bearing granites and pegmatites.
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Kabatesi, Juliette Confiance, Jules Uwizeyimana, Digne Edmond Rwabuhungu Rwatangabo, and Jei-Pil Wang. "Evaluation of Efficiency of Using Mechanized Processing Techniques to Recover Tin and Tantalum in Gatsibo, Eastern Province, Rwanda." Minerals 12, no. 3 (2022): 315. http://dx.doi.org/10.3390/min12030315.
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Rwanda is known to be among the top producers of tin and tantalum, despite having low recovery and grades. This study was carried out to evaluate the efficiency of using mechanized methods to increase the recovery rate and grades of tin and tantalum mined in Gatsibo, Eastern Province, Rwanda, since the general separation techniques used are artisanal. The minerals in those mines include cassiterite (SnO2) and colombite–tantalite ((Fe,Mn)(Ta,Nb)2O5), with impurities such as Al2O3, Fe2O3, MnO, MgO, Cao, Na2O, K2O, TiO2, and P2O5. A combination of gravity separation techniques, including shaking tables and magnetic separation, were used as the mechanized processing techniques. The results were compared to the results obtained by artisanal processing techniques. The proposed mechanized techniques were found to increase the efficiency of tin and tantalum recovery from 60.75% to 81.85% and from 22.9% to 48.57%, respectively, and the grades of the tin and tantalum increased to 63.75% and 35.7%, respectively. Based on these results, the proposed mechanized processing techniques and the recycling of waste from artisanal processing techniques are highly recommended.
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Li, Siyang, Jie Liu, Yuexin Han, and Shumin Zhang. "Review on the Beneficiation of Li, Be, Ta, Nb-Bearing Polymetallic Pegmatite Ores in China." Minerals 13, no. 7 (2023): 865. http://dx.doi.org/10.3390/min13070865.
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Lithium-bearing polymetallic pegmatite ores are an important raw material for lithium extraction. They contain not only lithium but also other associated elements such as beryllium, tantalum, and niobium, with great recovery values. It is therefore often called lithium-bearing polymetallic pegmatite ore (LPPO). The recovery and utilization of Be-bearing minerals in LPPOs have yet to be further studied. This paper briefly expounds the geological aspects of LPPO deposits in China and Chinese experiences on the beneficiation of LPPOs, with special emphasis on the flotation separation of lithium-beryllium minerals. In LPPO, spodumene is the main target mineral for lithium, while beryl is the main Be-bearing mineral in a fine-grained embedded state. If the BeO grade of LPPO is greater than the industrial grade (BeO ≥ 0.04%), it will be processed for recovery. Tantalum and niobium minerals are mainly in the form of tantalite, columbite, or ferrotapiolite, which may be recovered by gravity separation or magnetic separation. Gangue minerals are mainly composed of albite and quartz. Currently, the most commonly used methods for separating the target minerals from gangue are dense medium separation and flotation. The manual sorting method has become obsolete and is expected to be replaced by machine sorting methods such as color sorters and X-ray transmission sorters. Flotation is the main method for the separation of fine-grained beryl and spodumene. The success of flotation depends on the selection of suitable pretreatment methods and appropriate flotation reagents for altering the surface properties of spodumene and beryl and for expanding the floatability differences between spodumene and beryl and between spodumene and gangue.
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Adoze, U. J., F. Abubakar, G. D. Ochu, O. A. Danga, M. L. Adamu, and Y. Baba. "Geological and geochemical analyses of pegmatites in Egbe, Isanlu (sheet 225), Southwestern Nigeria." Scientia Africana 23, no. 2 (2024): 188–206. http://dx.doi.org/10.4314/sa.v23i2.17.
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The hitherto pegmatite of the Egbe area has been known to bear valuable economic minerals. They are associated with other rock types including banded gneiss, schist, amphibolite, and granites. These pegmatites and the host rocks were studied in detail to elucidate their petrochemical and geochemical features and also to assess the mineralization of Tantalum- iobium and other minerals. Geological field mapping was done, thin section-petrographic analysis of ten representative rock samples was performed and nineteen whole-rock samples were analyzed for major and trace elements including REES aided by Inductively Coupled Plasma Mass Spectrometry (ICP-MS), Boron- Fusion-Inductively Coupled Plasma Atomic Emission Spectrometry (ICP-AES), and Ion-Selective Electrode (ISE) for Fluorine at Acme Laboratory, Vancouver, Canada. The general structural trend of the area under study is WNW-ESE and foliations of N-S strike were observed in the banded gneiss and schist which also exhibit asymmetric and isoclinals folding respectively. The tantalite-columbite mineralization is associated with the NE-SW trending pegmatite dykes. The mineralized pegmatites are genetically related to the peraluminous S-type granite. The minerals (i.e., Albite, lepidolite and muscovite) extracted from the pegmatites are well enriched in Li, Rb, Cs, Nb and Ta compared to the host rocks. The rare-metal pegmatites exhibit pronounced negative Ce and Eu anomalies and also show weak negative Yb anomalies while the barren pegmatites have positive Ce and weak negative Eu anomalies and exhibit weak positive Yb anomalies. The pegmatites are moderately evolved compared with other highly mineralized pegmatites. The pegmatites from Igbaruku and one from the Okere area are of the rare-metal pegmatite and they are moderately fractionated while the barren pegmatite from Egbe and one from Okere are unfractionated. The economic mineral within the Egbe area is tantalite, with every possibility that the tantalite-columbite enrichment is ferrotantalite-columbite and manganotantalite columbite.
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Dostal, Jaroslav, and Ochir Gerel. "Occurrences of Niobium and Tantalum Mineralization in Mongolia." Minerals 12, no. 12 (2022): 1529. http://dx.doi.org/10.3390/min12121529.
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Niobium and tantalum are two rare metals that have similar physical and chemical properties and occur together in nature. They are considered to be strategic and critical materials for the economy and national security of many industrial countries. Both elements are on the 2022 List of Critical Minerals of the USA as well as on the European Union’s List of Critical Raw Materials. They rarely substitute for common elements in rock-forming minerals but are essential components in a range of rare minerals, particularly oxides and subordinately silicates. The economically important minerals are oxides. The columbite-tantalite and pyrochlore-microlite groups are the most common Ta- and Nb-bearing minerals. In Mongolia, primary niobium and tantalum mineralization includes two main types. The first type is mineralization associated with alkaline to peralkaline granites, pegmatites and syenites whereas the second type is related to the lithium-fluorine-rich peraluminous granites and related rocks (pegmatites and ongonites). The host rocks of both types of mineralization are the fractionated felsic rocks, which contain the primary magmatic ore assemblages associated with fractionation of magma rich in rare metals. Both assemblages were subsequently overprinted by the late magmatic to hydrothermal fluids, which remobilized and enriched the original mineralization. The newly formed ore mineral assemblages display complex replacement textures. In the case of peralkaline felsic rocks the processes produced the mineralization of Zr, Nb, heavy REE, Y, U, Th and Ta whereas peraluminous Li-F felsic rocks contain mainly mineralization of Sn, W, Ta, Li, and Nb. Mongolia hosts several promising occurrences of both types of Nb-Ta mineralization. However, they have not yet been sufficiently explored. Currently, the most promising is the occurrence in the Devonian Khalzan Buregtei peralkaline granites in northwestern Mongolia, where Nb-Ta is associated with REE and Zr mineralization. Mesozoic carbonatites of southern Mongolia do not host significant Nb and Ta mineralization.
Dissertations / Theses on the topic "Tantale – Minerais"
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Boudriss, Abdelhak. "Valorisation du concentré mixte d'Echassieres : concentration des minéraux porteurs du niobium et du tantale par réduction de la cassitérite et extraction de l'étain." Dijon, 1988. http://www.theses.fr/1988DIJOS016.
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Etude du procédé d'extraction et de production de l'étain par réduction de la cassitérite dans l'hydrogène sec et dissolution du métal formé par HCl concentré. Caractérisation des phases solides par diffraction RX, thermogravimétrie, microscopie électronique 0 balayage
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Ciaravino, Célestine. "Elaboration de céramiques à partir de minerais de tungstène, niobium et tantale, caractérisation et propriétés." Toulon, 2001. http://www.theses.fr/2001TOUL0001.
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Zhu, Ze-Ying. "Étude minéralogique des granites de métaux rares en Chine méridionale : étude de cas du granit de Songshugang et de Huangshan, province de Jiangxi." Electronic Thesis or Diss., Université de Lorraine, 2018. http://www.theses.fr/2018LORR0141.
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Les métaux rares, comme le niobium (Nb), le tantale (Ta), le tungstène (W) et l'étain (Sn), sont définis comme des «ressources stratégiques» ou des «matériaux critiques». Dans cette étude, nous prenons les gisements de Nb de Huangshan et de Ta de Songshugang dans le complexe de Lingshan, province de Jiangxi, en Chine du Sud, comme exemples. Les roches de ce gisement sont classées en deux catégories en fonction de la présence de micas riches en Nb et de la quantité de columbite-tantalites: granites à grain moyen avec des micas riches en Nb et sans columbite-tantalites, et granites à grain fin et pegmatites riches en columbite-tantalites. Ces columbite-tantalites sont riches en Nb et pauvres en Mn, les classant comme columbite. Ces columbites ont des zonations complexes liées à des processus répétitifs. Notre travail indique plutôt que la formation de tels minéraux est liée à des processus de mélanges multiples avec au moins deux types de magmas. Les granites à grain moyen dans la suite Huangshan sont différents des autres granites du complexe de Lingshan par la composition de leurs micas: Li-annite (granite MA) et "protolithionite" (granite MP). Ils sont caractérisés par des teneurs Nb élevées (moyenne de 144 ppm en MP et 158 ppm en MA) et des rapports Nb/Ta très élevés (moyenne 15,3 en MP et 31,2 en MA). Le niobium est principalement hébergé dans les micas, avec une teneur moyenne en Nb de 1347 ppm dans les Li annites, et 884 ppm dans le «protolithionite», concentrations encore jamais mesurées dans les micas d’origine magmatique. Avec un contenu estimé à ~80 kt Nb, les granites de Huangshan représentent un nouveau style potentiel de ressource de Nb. Le granite à albite de Songshugang est localisé dans l'ouest du complexe de Lingshan et est enrichi en Ta. Le granite de Songshugang n’affleure pas et est se trouve sous des couches de granites à feldspath K-topaze, de greisens et de pegmatite. Tous les granites et pegmatites sont fortement peralumineux. Les minéraux de columbite-tantalites, de zircons et de cassitérites sont constants pour chaque type de roches et présentent les mêmes textures bi-phasées. Les caractéristiques pétrographiques indiquent que le stade précoce de columbite et de zircon ont été formés dans un environnement strictement magmatique. Le stade postérieur de ces minéraux a été influencé par des circulations fluides à la transition magmatique-hydrothermale. Les micas montrent également une texture en deux étapes, avec une grande quantité de d’inclusions de columbite-tantalites. L'enrichissement en Rb dans les bordures (Znw-II) est le résultat d’un fractionnement magmatique, comme démontré par la diminution de la teneur en Nb (16,3-108 ppm comparé avec 109-313 ppm pour le coeur). Cependant, les teneurs faibles et invariables du Ta, W et Sn démontrent que le magma résiduel n'a eu aucune influence sur les processus post-magmatiques postérieurs, contrairement aux minéraux de columbite-tantalites. Enfin, les datations U-Pb in-situ sur zircons et columbite-tantalites démontrent que les granites de Huangshan et de Songshugang se sont mis en place vers 130 Ma durant l’épisode tardi-Yanshanien (Crétacé), au même moment que l’ensemble des roches magmatiques formant le complexe de Lingshan. Ce résultat indique que cette période géologique est d’intérêt pour la formation de ressources en Nb-Ta, définissant une nouvelle période géologique prospective pour ces ressources<br>Rare metals, including niobium (Nb), tantalum (Ta), tungsten (W) and tin (Sn), are defined as “strategic resources” or “critical materials”. For this work, we studied the Huangshan Nb deposit and Songshugang Ta deposit, in the Lingshan complex, Jiangxi Province, South China, as examples. The rocks from Huangshan granite are classified in two categories based on the occurrence of Nb-rich mica and the amount of columbite-tantalites minerals: medium-grained granites with Nb-rich mica and devoided of columbite-tantalites and fine-grained granites and pegmatites rich in columbite-tantalite minerals. Columbite-tantalite minerals are classified as columbite-(Fe), and characterized by complex zonings with various “go and back” processes, indicating that their formation is linked to multi-mixing processes of two different magma sources. The medium-grained granites in the Huangshan suite differed from the other granites of the Lingshan complex by their mica compositions: lithian annite (MA granite) and “protolithionite” (MP granite). They are characterized by elevated Nb contents (average 144 ppm in MP and 158 ppm in MA) and very high Nb/Ta ratios (average 15.3 in MP and 31.2 in MA). Niobium is mainly hosted in the micas, with an average Nb content of 1,347 ppm in the lithian annite, and 884 ppm in the “protolithionite”. Such contents are the highest ever reported in magmatic-related micas. With an estimated content of ~80 kt Nb, the Huangshan granites represent a new style of potential Nb resource. The Songshugang albite granite is found in the west of Lingshan complex and is specifically enriched in Ta. The major Songshugang albite granite is buried and covered by layers of K-feldspar granite, greisen and pegmatite. All the granites are strongly peraluminous. The compositions of columbite-tantalite minerals, the zircons and cassiterites are constant and display a similar two-stage texture. Petrographic features indicate that the early-stage columbite and zircon were formed in magmatic environment, whereas the later-stage of rare-element minerals were influenced by fluid fluxes at the magmatic-hydrothermal transitional stage. Micas also show a two-stage texture. The Rb-enrichment in the margin of the zinnwaldite is the result of magmatic fractionation, as also demonstrated by the decrease of Nb contents (16.3-108 ppm compare with core of 109-313 ppm). The invariable low contents of Ta, W and Sn demonstrate that the residual melt has no influence on later post-magmatic stages, contrary to the columbite minerals. Finally, in-situ U-Pb dating of zircon and columbite-tantalite by SIMS and LA-ICP-MS indicates that both Huangshan and Songshugang granites were emplaced at ca. 130 Ma during Later Yanshanian (or Cretaceous) and contemporary with the formation of the Lingshan complex. This result indicates that the Later Yanshanian is a prospective geological period for Nb-Ta deposits, and this result enlarges the time frame of rare-metal mineralization
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Zhu, Ze-Ying. "Étude minéralogique des granites de métaux rares en Chine méridionale : étude de cas du granit de Songshugang et de Huangshan, province de Jiangxi." Thesis, Université de Lorraine, 2018. http://www.theses.fr/2018LORR0141.
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Les métaux rares, comme le niobium (Nb), le tantale (Ta), le tungstène (W) et l'étain (Sn), sont définis comme des «ressources stratégiques» ou des «matériaux critiques». Dans cette étude, nous prenons les gisements de Nb de Huangshan et de Ta de Songshugang dans le complexe de Lingshan, province de Jiangxi, en Chine du Sud, comme exemples. Les roches de ce gisement sont classées en deux catégories en fonction de la présence de micas riches en Nb et de la quantité de columbite-tantalites: granites à grain moyen avec des micas riches en Nb et sans columbite-tantalites, et granites à grain fin et pegmatites riches en columbite-tantalites. Ces columbite-tantalites sont riches en Nb et pauvres en Mn, les classant comme columbite. Ces columbites ont des zonations complexes liées à des processus répétitifs. Notre travail indique plutôt que la formation de tels minéraux est liée à des processus de mélanges multiples avec au moins deux types de magmas. Les granites à grain moyen dans la suite Huangshan sont différents des autres granites du complexe de Lingshan par la composition de leurs micas: Li-annite (granite MA) et "protolithionite" (granite MP). Ils sont caractérisés par des teneurs Nb élevées (moyenne de 144 ppm en MP et 158 ppm en MA) et des rapports Nb/Ta très élevés (moyenne 15,3 en MP et 31,2 en MA). Le niobium est principalement hébergé dans les micas, avec une teneur moyenne en Nb de 1347 ppm dans les Li annites, et 884 ppm dans le «protolithionite», concentrations encore jamais mesurées dans les micas d’origine magmatique. Avec un contenu estimé à ~80 kt Nb, les granites de Huangshan représentent un nouveau style potentiel de ressource de Nb. Le granite à albite de Songshugang est localisé dans l'ouest du complexe de Lingshan et est enrichi en Ta. Le granite de Songshugang n’affleure pas et est se trouve sous des couches de granites à feldspath K-topaze, de greisens et de pegmatite. Tous les granites et pegmatites sont fortement peralumineux. Les minéraux de columbite-tantalites, de zircons et de cassitérites sont constants pour chaque type de roches et présentent les mêmes textures bi-phasées. Les caractéristiques pétrographiques indiquent que le stade précoce de columbite et de zircon ont été formés dans un environnement strictement magmatique. Le stade postérieur de ces minéraux a été influencé par des circulations fluides à la transition magmatique-hydrothermale. Les micas montrent également une texture en deux étapes, avec une grande quantité de d’inclusions de columbite-tantalites. L'enrichissement en Rb dans les bordures (Znw-II) est le résultat d’un fractionnement magmatique, comme démontré par la diminution de la teneur en Nb (16,3-108 ppm comparé avec 109-313 ppm pour le coeur). Cependant, les teneurs faibles et invariables du Ta, W et Sn démontrent que le magma résiduel n'a eu aucune influence sur les processus post-magmatiques postérieurs, contrairement aux minéraux de columbite-tantalites. Enfin, les datations U-Pb in-situ sur zircons et columbite-tantalites démontrent que les granites de Huangshan et de Songshugang se sont mis en place vers 130 Ma durant l’épisode tardi-Yanshanien (Crétacé), au même moment que l’ensemble des roches magmatiques formant le complexe de Lingshan. Ce résultat indique que cette période géologique est d’intérêt pour la formation de ressources en Nb-Ta, définissant une nouvelle période géologique prospective pour ces ressources<br>Rare metals, including niobium (Nb), tantalum (Ta), tungsten (W) and tin (Sn), are defined as “strategic resources” or “critical materials”. For this work, we studied the Huangshan Nb deposit and Songshugang Ta deposit, in the Lingshan complex, Jiangxi Province, South China, as examples. The rocks from Huangshan granite are classified in two categories based on the occurrence of Nb-rich mica and the amount of columbite-tantalites minerals: medium-grained granites with Nb-rich mica and devoided of columbite-tantalites and fine-grained granites and pegmatites rich in columbite-tantalite minerals. Columbite-tantalite minerals are classified as columbite-(Fe), and characterized by complex zonings with various “go and back” processes, indicating that their formation is linked to multi-mixing processes of two different magma sources. The medium-grained granites in the Huangshan suite differed from the other granites of the Lingshan complex by their mica compositions: lithian annite (MA granite) and “protolithionite” (MP granite). They are characterized by elevated Nb contents (average 144 ppm in MP and 158 ppm in MA) and very high Nb/Ta ratios (average 15.3 in MP and 31.2 in MA). Niobium is mainly hosted in the micas, with an average Nb content of 1,347 ppm in the lithian annite, and 884 ppm in the “protolithionite”. Such contents are the highest ever reported in magmatic-related micas. With an estimated content of ~80 kt Nb, the Huangshan granites represent a new style of potential Nb resource. The Songshugang albite granite is found in the west of Lingshan complex and is specifically enriched in Ta. The major Songshugang albite granite is buried and covered by layers of K-feldspar granite, greisen and pegmatite. All the granites are strongly peraluminous. The compositions of columbite-tantalite minerals, the zircons and cassiterites are constant and display a similar two-stage texture. Petrographic features indicate that the early-stage columbite and zircon were formed in magmatic environment, whereas the later-stage of rare-element minerals were influenced by fluid fluxes at the magmatic-hydrothermal transitional stage. Micas also show a two-stage texture. The Rb-enrichment in the margin of the zinnwaldite is the result of magmatic fractionation, as also demonstrated by the decrease of Nb contents (16.3-108 ppm compare with core of 109-313 ppm). The invariable low contents of Ta, W and Sn demonstrate that the residual melt has no influence on later post-magmatic stages, contrary to the columbite minerals. Finally, in-situ U-Pb dating of zircon and columbite-tantalite by SIMS and LA-ICP-MS indicates that both Huangshan and Songshugang granites were emplaced at ca. 130 Ma during Later Yanshanian (or Cretaceous) and contemporary with the formation of the Lingshan complex. This result indicates that the Later Yanshanian is a prospective geological period for Nb-Ta deposits, and this result enlarges the time frame of rare-metal mineralization
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McCreath, Jamie Alan. "Petrology and petrogenesis of the Motzfeldt Ta-mineralisation, Gardar Province, South Greenland." Thesis, St Andrews, 2009. http://hdl.handle.net/10023/845.
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CHAMBOUN, HASSAN. "Nouveaux phosphates de vanadium, molybdene, niobium et tantale a charpentes mixtes formees d'octaedres mo : :(6) et de tetraedres po::(4)." Caen, 1987. http://www.theses.fr/1987CAEN2030.
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L'etude des systemes v-p-o et mo-p-v-o a permis d'isoler les nouvelles phases vpo::(4), p::(3)v::(12)o::(34), p::(2)mo::(2)v::(4)o::(19) et de la caracteriser par diffraction rx, microscopie electronique, spectroscopie ir et uv, analyse thermique differentielle et thermogravimetrie. Etude structurale sur monocristal de b-nbpo::(5). Les phases b-nbpo::(5), b-tapo::(5) et tavo::(5) apparaissent apparentees a la familles des bronzes a tunnels pentagonaux mptbp(po::(2))::(4) (wo::(3))::(2m) dont ils constitument le terme m = z. E-nbpo::(5) et g-tapo::(5) ont ete isoles et leurs temperatures de transition determinees. Mise en evidence du nouveau vanadosilicophosphate v::(3)p::(5)sio::(19). Enfin, structure de k::(2)(vo)::(3) (p::(2) o::(7))::(2)
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Lorenzo-Diaz, José-Emilio. "Etude par diffusion de neutrons des transitions de phase dans les composés quasi-unidimensionnels (TaSe4)2I et (NbSe4)3I." Grenoble 1, 1992. http://www.theses.fr/1992GRE10184.
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On a étudié la dynamique de réseau associée à la transition de phase de Peierls dans le composé quasi unidimensionnel à onde de densité de charge (odc) (tase4)2i, par diffusion de neutrons. Cette étude nous a permis de distinguer ce qui est caractéristique de l'état odc. En particulier, nous proposons d'interpréter la résonance observée en conductivité ac (45 ghz) comme des modes optiquement actives par l'état odc, plutôt que comme des modes caractéristiques de cet état. De même, la nature isotrope des fluctuations critiques ainsi que le caractère transverse acoustique des déplacements atomiques en phase modulée, amènent à placer cette transition de Peierls dans une catégorie à part. Un modèle phénoménologique qui prend en compte les deux aspects ci-dessus a été également proposé
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Moleko, Teboho Banele. "A critical analysis of the role of coltan in the Eastern region of the Democratic Republic of Congo’s second war (1998-2003)." Thesis, Rhodes University, 2015. http://hdl.handle.net/10962/d1017864.
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The role of natural resources in African conflicts has been subject to extensive scholarly analysis. However, much of this analysis has taken a narrow economic reductionist bias. As such, it is imperative that the dominant assumptions and accepted concepts and theories about the role of natural resources in African conflicts be re-examined. The aim of this thesis is to offer a revaluation of the role of coltan during the Democratic Republic of Congo’s (DRC) Second War (1998-2003) through a critical engagement with the resource wars literature. The purpose is to offer a re-reading of the role of coltan in the DRC Second War and the broader regional and global economic context in which this conflict took place. It rejects the commonly cited assumption that the presence of coltan in the DRC means it is an initiator of conflict. Rather, this thesis argues that the central role of coltan in the DRC Second War was as an aggravator of conflict in that its exploitation was used by different parties to fund their military and political ambitions. This thesis also argues that the DRC’s weak state structures and pivotal role within the Great Lakes region, as well as the international trade of coltan and the nature of the DRC coltan mining industry are all key factors in understanding coltan exploitation in the country’s Eastern Region during the Second War.
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Li, Zhigang. "Formation et simulation de l'image en microscopie electronique a haute resolution : application a la structure de composes de type "lamellaire"." Toulouse 3, 1987. http://www.theses.fr/1987TOU30282.
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Cette these etudie trois problemes specifiques de la microscopie electronique a haute resolution : le transfert du contraste des images, leur interpretation au moyen de simulations et l'application de cette technique a la determination des structures locales dans les materiaux cristallins, au niveau atomique. Obtention de resultats originaux en ce qui concerne la microstructure de materiaux de type lamelllaire : dans les composes de type re::(6) se::(8) cl::(2), avant et apres insertion d'hydrazine, dans les composes de type mps::(3) et dans taps::(6)se
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Matyszczak, Witold. "Minerały niobu i tantalu w asocjacjach pegmatytowych NE częśći masywu Karkonoszy." Doctoral thesis, 2014. https://depotuw.ceon.pl/handle/item/645.
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Praca przedstawia opis minerałów Nb-Ta-Ti oraz REE pochodzących
z pegmatytów NE części masywu Karkonoszy. Podano charakterystykę chemiczną
ponad 10 minerałów, wśród których najważniejszymi są minerały grupy euksenitu
i aeschynitu, fergusonit, grupa monacytu, ksenotym, liandratyt oraz nadgrupa
pirochloru. Przedstawiono mechanizmy zmian wtórnych w grupie euksenitu
i aeschynitu oraz w fergusonicie. Wyznaczono temperatury krystalizacji monacytu.
Zaklasyfikowano badane pegmatyty do klasy euksenitowej oraz klasy allanitowomonacytowej
rodziny NYF.
Books on the topic "Tantale – Minerais"
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Warner, J. Dean. Critical and strategic minerals in Alaska: Tin, tantalum, and columbium. U.S. Dept. of the Interior, Bureau of Mines, 1985.
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Fetherston, J. M. Tantalum in Western Australia. Geological Survey of Western Australia, 2004.
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M, Sutphin David, ed. International strategic minerals inventory summary report: Niobium (columbium) and tantalum. U.S. G.P.0., 1993.
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Job Luka Izang M Sc. Tin, Columbite, Tantalite... . Solid Minerals Mining - Resuscitation for Investment: Reviving Tin, Columbite, Tantalite and Associated Solid Minerals Mining in Nigeria and Indeed Plateau State for Improved Igr. Independently Published, 2019.
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Azuaje Pirela, Michelle. Fundamentos de la tributación minera: Un estudio del derecho chileno a la luz del derecho español. Universidad Autónoma de Chile, 2018. http://dx.doi.org/10.32457/20.500.12728/87412020dd1.
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La minería es una de las actividades económicas más antiguas de la humanidad. A grandes rasgos consiste en la exploración y extracción de recursos minerales no renovables presentes en el suelo o el subsuelo en la forma de yacimientos, los cuales al ser transformados pueden emplearse en un extenso campo de aplicaciones de la vida cotidiana (tales como la industria eléctrica, automotriz, química, alimentaria; así como en la construcción, el transporte, la salud y la fabricación de armamento, etc.). Esta actividad suele ir de la mano con el desarrollo tecnológico, y dados sus múltiples campos de aplicación en algunos países es y seguirá siendo una actividad económica importante. En efecto, algunas organizaciones internacionales la han considerado como uno de los indicadores básicos de las posibilidades de desarrollo económico de una localidad, región o país. En efecto, la experiencia de países en los que la minería es una actividad económica importante como es el caso de Australia, Estados Unidos, Canadá y algunos países nórdicos como Finlandia, Suecia y Noruega es una muestra de ello. En Chile la minería ha representado entre el 9% y el 16% de su Producto Interno Bruto (PIB) en la última década. En efecto, gracias a su gran riqueza en recursos naturales, la minería en Chile reviste una innegable importancia. Tanta, que el país es reconocido como potencia minera a nivel mundial, siendo la explotación de la minería del cobre una de sus principales actividades económicas.Al ser la explotación del cobre un importante motor de la economía del país, históricamente ha estado rodeada de demandas sociales, de acuerdo con las cuales la participación de las empresas mineras debería verse suficientemente reflejada en el aspecto fiscal y en otros aspectos de la vida de todos los chilenos, más aún si se considera que la Constitución Política de la República, concretamente en su artículo 19, Nº 24, inciso 6º, consagra el dominio absoluto, exclusivo, inalienable e imprescriptible de todas las minas para el Estado. En virtud de este argumento, muchas han sido las discusiones que han rodeado a la actividad minera; habiéndose instalado por mucho tiempo la percepción de que las empresas mineras privadas no contribuyen tanto como podrían a través del pago de sus tributos. Por esta y otras razones la tributación minera en Chile no ha estado exenta de cuestionamientos, fundamentalmente desde dos perspectivas diferentes.Una que preconiza la existencia de un régimen especial de privilegio o fomento, que pondría en duda si la contribución que por vía fiscal realizan las empresas dedicadas a este sector es realmente adecuada a sus características, ingresos, y al impacto que causan al medio ambiente, entre otros aspectos; con lo cual, no sólo se estarían vulnerando los principios tributarios y los del régimen constitucional del dominio minero, sino que además se estaría restando importancia a otros aspectos vitales para la coexistencia de la minería como actividad económica fundamental de Chile y un medio ambiente sano. En contrapartida, otro punto de vista aduce que es necesario mantener una “discriminación positiva” o bien un régimen especial, pero que incentive la inversión privada, a través del establecimiento de beneficios, tasas de imposición bajas, así como de normas que garanticen la estabilidad jurídica, que comprenda las particularidades de la “propiedad minera” y las fases de la actividad, que cuente con una escasa o nula variación fiscal, que brinde celeridad a la aprobación de los proyectos mineros y resulte atractivo para la inversión extranjera. Todo lo anterior, estaría justificado en los excesivos riesgos, elevada cuantía de las inversiones falta de capital nacional para invertir en el sector, largos plazos de los proyectos, el hecho de que, pese a sus efectos o impactos, la minería es una actividad económica necesaria, y las pocas probabilidades de éxito que rodean a esta actividad. Lo dicho lleva necesariamente a preguntarse desde otro punto de vista, si suponiendo que fuese necesario el mantenimiento o en su caso el diseño o la instauración de un régimen especial que grave a la actividad minera, por sus particularidades ¿Debería ser este más o menos oneroso que los regímenes regulares aplicables al resto de los contribuyentes? ¿Por qué? ¿El marco constitucional actual permite que existan regímenes tributarios especiales? ¿Cuáles son los fundamentos que justifican la existencia de un régimen especial para la minería? en ese sentido: ¿Qué es lo que puede gravarse?
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Eyes of the World: Mining the Digital Age in the Eastern DR Congo. University of Chicago Press, 2021.
Find full textBook chapters on the topic "Tantale – Minerais"
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Crowson, Phillip. "Tantalum." In Minerals Handbook 1992–93. Palgrave Macmillan UK, 1992. http://dx.doi.org/10.1007/978-1-349-12564-7_39.
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Crowson, Phillip. "Tantalum." In Minerals Handbook 1994–95. Palgrave Macmillan UK, 1994. http://dx.doi.org/10.1007/978-1-349-13431-1_41.
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Crowson, Phillip. "Tantalum." In Minerals Handbook 1996–97. Palgrave Macmillan UK, 1996. http://dx.doi.org/10.1007/978-1-349-13793-0_43.
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Knudsen, C. "Pyrochlore Group Minerals from the Qaqarssuk Carbonatite Complex." In Lanthanides, Tantalum and Niobium. Springer Berlin Heidelberg, 1989. http://dx.doi.org/10.1007/978-3-642-87262-4_3.
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Gupta, Akanksha, and Brajendra Mishra. "Tantalum Recovery Technique for Recycling of Tantalum Coated Composite Materials." In The Minerals, Metals & Materials Series. Springer Nature Switzerland, 2023. http://dx.doi.org/10.1007/978-3-031-22761-5_25.
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Sanz, Joaquim, Oriol Tomasa, Abigail Jimenez-Franco, and Nor Sidki-Rius. "Tantalum (Ta) [Z = 73]." In Elements and Mineral Resources. Springer International Publishing, 2022. http://dx.doi.org/10.1007/978-3-030-85889-6_53.
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Möller, P. "Rare Earth Mineral Deposits and Their Industrial Importance." In Lanthanides, Tantalum and Niobium. Springer Berlin Heidelberg, 1989. http://dx.doi.org/10.1007/978-3-642-87262-4_6.
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Hofer, Dominik, Stefan Luidold, Frank Schulenburg, and Tobias Beckmann. "High Temperature Characteristics of Slags Originating from the Production of Synthetic Tantalum Concentrate." In The Minerals, Metals & Materials Series. Springer International Publishing, 2018. http://dx.doi.org/10.1007/978-3-319-95022-8_81.
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Praditwan, J. "Mineralogy of Tin and Niobium-Tantalum-Bearing Minerals in Thailand." In Geology of Tin Deposits in Asia and the Pacific. Springer Berlin Heidelberg, 1988. http://dx.doi.org/10.1007/978-3-642-72765-8_49.
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Sanchez-Segado, Sergio, Ahmad Fahmi Ruzaidi, Yuan Zhang, and Animesh Jha. "Characterization of Physico-Chemical Changes During the Alkali Roasting of Niobium and Tantalum Oxides." In Drying, Roasting, and Calcining of Minerals. John Wiley & Sons, Inc., 2015. http://dx.doi.org/10.1002/9781119093329.ch7.
Full textConference papers on the topic "Tantale – Minerais"
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Tucker Roper, B. E., Tim Eastman, Andrew Deal, P. G. Allison, and L. N. Brewer. "In situ laser heating of Cold Spray Deposited Niobium and Tantalum Materials." In TMS 2022 Annual Meeting & Exhibition The Minerals, Metals & Materials Society 2/27/2022 - 3/3/2022. US DOE, 2022. http://dx.doi.org/10.2172/1846160.
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Ivanova, Valentina. "FLOTATION RECOVERY OF VALUABLE MINERALS FROM GRAVITY CONCENTRATION TAILINGS OF RARE-METAL TANTALUM-NIOBIUM ORE." In 16th International Multidisciplinary Scientific GeoConference SGEM2016. Stef92 Technology, 2016. http://dx.doi.org/10.5593/sgem2016/b12/s04.138.
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Clemente, Daniel Mapa, Ana Rosa Rabelo de Lima, Rüdiger Deike, and Carlos Antônio da Silva. "NEW REQUIREMENTS AND OPPORTUNITIES FOR THE BRAZILIAN TANTALUM AND TIN INDUSTRY - AN APPROACH RELATED TO CONFLICT MINERALS." In 50° Seminário de Aciaria, Fundição e Metalurgia de Não-Ferrosos. Editora Blucher, 2019. http://dx.doi.org/10.5151/2594-5300-33824.
Full textReports on the topic "Tantale – Minerais"
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McClenaghan, M. B., D. M. Brushett, C. E. Beckett-Brown, et al. Indicator mineral studies at the Brazil Lake LCT Pegmatites, southwest Nova Scotia. Natural Resources Canada/CMSS/Information Management, 2023. http://dx.doi.org/10.4095/331686.
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Indicator mineral research is currently being undertaken in partnership with the Nova Scotia Department of Natural Resources and Renewables at the Brazil Lake lithium-cesium-tantalum (LCT) pegmatites in southwest Nova Scotia as part of the Geological Survey of Canada's Targeted Geoscience Initiative(TGI) program. The pegmatites, discovered in 1960, are well known from previous detailed bedrock mapping and surficial studies, and are informally named based on their relative geographic positions as the South and North pegmatites. The South pegmatite naturally outcrops, and both pegmatites are surrounded by spodumene-rich boulders on the surface of the thin-till covered (&amp;lt;4 m) drumlinized glacial landscape. For these reasons, the pegmatites are excellent sites to test indicator mineral exploration methods for Li and associated critical elements (e.g. Ce, Ta). Five pegmatite samples were collected for detailed study and analysis of potential indicator minerals. Close to the pegmatite and up to 13 km down ice (south-southeast), 87 bulk (10-14 kg), till sediment samples were collected for indicator mineral analysis. A total of 105 till samples were collected around the pegmatite and across the region for matrix geochemistry. A preliminary list of indicator minerals includes mid-density (e.g., spodumene, tourmaline, blue apatite) and high-density mineral species (e.g., columbite-tantalite, cassiterite) and this list is expected to expand as the detailed studies progress. Trenches dug in the Fall 2022 to collect till samples on the proximal down ice (south) sides of both pegmatites revealed abundant spodumene pebbles and small cobbles in the till, indicating that the local till should display strong indicator mineral and matrix geochemical signatures derived from the pegmatites.
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Van Rythoven, Adrian. Critical mineral: Tantalum. Montana Bureau of Mines and Geology, 2023. http://dx.doi.org/10.59691/ccxj2700.
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Brushett, D. M., C. E. Beckett-Brown, M. B. McClenaghan, et al. Till geochemical data for the Brazil Lake pegmatite area, southwest Nova Scotia, Canada (NTS 21-A/04, 20-O/16 and 20-P/13): samples collected in 2020, 2021, and 2022. Natural Resources Canada/CMSS/Information Management, 2024. http://dx.doi.org/10.4095/332384.
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This open file reports geochemical data for till samples collected as a part of a till geochemical and surficial mapping project around the Brazil Lake lithium-cesium-tantalum (LCT-type) pegmatite in southwestern Nova Scotia (NTS map sheets 21A/04, 20O/16 and 20P/13). The global rise in lithium demand has motivated the Geological Survey of Canada's (GSC) recent investigations of the Brazil Lake pegmatites to study surficial geochemistry methods that can be used to explore for lithium and associated critical minerals (i.e., Cs, Ta, Be, In, Sn, W). These types of deposits are important sources of lithium, tin, and rubidium and the primary source of tantalum. This research at Brazil Lake is being undertaken as part of the GSC's Targeted Geoscience Initiative Program and has been carried out in partnership with the Nova Scotia Department of Natural Resources and Renewables (NSDNRR). The goals of the research are to increase exploration success in regions covered by glacial sediments by documenting how critical minerals and associated elements are glacially dispersed in till from pegmatites at the Brazil Lake property. Newly available LiDAR data assisted in deciphering ice flow trajectories, which in turn, allowed for targeted till sampling. A total of 184 till samples were collected for till geochemistry in 2020, 2021 and 2022 and the data reported here include widely spaced regional samples collected across southwest Nova Scotia, proximal samples collected up-ice, overlying, and down-ice of the Brazil Lake pegmatites. The widely spaced till samples provide the regional context for the interpretation of the case study samples and assess the potential for additional pegmatites buried by extensive till cover. Data reported in this Open File include sample descriptions, location, site photos, and geochemical analyses of the coarse sand (1.0 - 2.0 mm) and silt + clay (&amp;lt;0.063 mm) fractions. For the 2020 samples only, the &amp;lt;0.002 mm (clay) fraction was also analyzed. Analyses over the 3 years (2020-2021-2022) include various combinations of different digestions or fusions to test and compare their efficacy for the various pathfinder elements for LCT pegmatites: aqua regia (partial) digestion, 2) Na peroxide fusion (total), 3) 4-acid (near total) digestion, 4) Li-meta/tetraborate fusion, 5) loss on ignition, and 6) portable X-ray fluorescence (XRF).
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Jacques, I. J., A. J. Anderson, and S. G. Nielsen. The geochemistry of thallium and its isotopes in rare-element pegmatites. Natural Resources Canada/CMSS/Information Management, 2021. http://dx.doi.org/10.4095/328983.
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The Tl isotopic and trace element composition of K-feldspar, mica, pollucite and pyrite from 13 niobium-yttrium-fluorine (NYF)-type and 14 lithium-cesium-tantalum (LCT)-type rare-element pegmatites was investigated. In general, the epsilon-205Tl values for K-feldspar in NYF- and LCT-type pegmatites increases with increasing magmatic fractionation. Both NYF and LCT pegmatites display a wide range in epsilon-205Tl (-4.25 to 9.41), which complicates attempts to characterize source reservoirs. We suggest 205Tl-enrichment during pegmatite crystallization occurs as Tl partitions between the residual melt and a coexisting aqueous fluid or flux-rich silicate liquid. Preferential association of 205Tl with Cl in the immiscible aqueous fluid may influence the isotopic character of the growing pegmatite minerals. Subsolidus alteration of K-feldspar by aqueous fluids, as indicated by the redistribution of Cs in K-feldspar, resulted in epsilon-205Tl values below the crustal average (-2.0 epsilon-205Tl). Such low epsilon-205Tl values in K-feldspar is attributed to preferential removal and transport of 205Tl by Cl-bearing fluids during dissolution and reprecipitation. The combination of thallium isotope and trace element data may be used to examine late-stage processes related to rare-element mineralization in some pegmatites. High epsilon-205Tl and Ga in late-stage muscovite appears to be a favorable indicator of rare-element enrichment LCT pegmatites and may be a useful exploration vector.