Global Metallogeny of Tantalum Through Geological Time
Abstract The global distribution of tantalum deposits and their resources on the geological time scale is analyzed. The analysis is based on the data for 65 deposits …Web
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Abstract The global distribution of tantalum deposits and their resources on the geological time scale is analyzed. The analysis is based on the data for 65 deposits …Web
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An obsolete group name for minerals with the general formula (Mn,Fe)(Ta,Nb) 2 O 6, equivalent to the Tantalite-(Fe)-Tantalite-(Mn) Series.Generally mangan-dominant members are more abundant in nature. Many specimens called tantalite actually belong to the columbite series or tapiolite series. Visit gemdat for gemological information …Web
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The ore-samples were classified as low-grade and non-radioactive ores as they contained less than 0.1% Ta2O5 and Nb2O5, and the percentage of radioactive oxides were below the critical value of 0.5%.Web
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In tantalite, SnO2 is a typomorphic impurity, which is 1.01%, on average (apfu is 0.03); the maximum value is 3.74% (apfu is 0.21). ... and evolution of the columbite group minerals of the Kester Deposit indicate their belonging to the rare-metal ore-magmatic system, which includes ore-bearing rare-metal granites, albitites, and greisens ...Web
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On Boing Boing Gadgets, this wrenching video in which Eve Ensler explains that Congolese militias use rape to enforce discipline among a slave workforce that mines columbite-tantalite ore, a common raw material for many devices.Boing Boing 2009. Among these riches is coltan - columbite tantalite - a mineral highly prized for its use in a number of …Web
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Commercial and innovative pyrometallurgical (direct reduction), hydrometallurgical (pure leaching) and pyro-hydrometallurgical (NH 4 HF 2 or alkali …Web
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The main minerals of tantalum-niobium ores from which both are extracted are columbite ((Mn,Fe)(Ta,Nb) 2 O 6); hatchettolite (Ca,U,Ce) 2 (Nb,Ti,Ta) 2 O 6 (OH,F); …Web
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Massive tonnes of fibrous residues are produced during the harvesting of the Enset plant for food preparation. ... The decomposition of the Ethiopian Kenticha tantalite ore was studied using the ...Web
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Abstract The global distribution of tantalum deposits and their resources on the geological time scale is analyzed. The analysis is based on the data for 65 deposits of the world with a resource estimate from 2000 t of Ta2O5, which are classified into five types: pegmatitic, granitic, alkaligranitic, foidic, and carbonatitic. Placers and ore-bearing …Web
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This may depend on the rate of the decomposition and leaching of the tantalite ore and/or the solubility of the solute to be extracted (Agulyansky, 2004; Zhu and Cheng, 2011; Nete et al., 2014). ...Web
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Tantalite is as an ore of the rare element s tantalum and niobium. NOTEWORTHY LOCALITIES Localities for Tantalite are pretty much the same as Columbite, and it often is not identified individually but more generally as Columbite-Tantalite.Web
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6 Specific Gravity: 6.65 - 8 Crystal System: Orthorhombic Member of: Columbite Group > Columbite Supergroup Name: From the manganese content and for the Greek mythical …Web
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The columbite-tantalite group minerals [(Fe,Mn)(Nb,Ta) 2 O 6 ] are critical ore minerals of niobium and tantalum in rare metal pegmatite deposit.Web
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The beneficiation methods for Ethiopian Kenticha pegmatite–spodumene ores were assessed through mineralogical and quantitative analyses with X-ray diffraction (XRD) and energy-dispersive X-ray fluorescence (EDXRF). The tantalite in the upper zone of the Kenticha pegmatite–spodumene deposit is 58.7wt% higher than that in the inner …Web
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Tantalum mines are under development in Canada and Egypt. In 2010, U.S. apparent consumption of tantalum materials was …Web
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Sample MD078 was analysed by 12 spots of Mn-tantalite and 3 spots on cassiterite. The upper intercept age is 2642 ± 7 Ma (Fig. 5.1d). Data from further 19 grains of cassiterite from sample MD125 yield an age of 2638 ± 8 Ma. Sample MD 131 with predominant cassiterite (12 spots) and minor Mn-tantalite (2 spots) was dated at 2639 ± …Web
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The ore minerals of albitites are Ta-Nb-bearing cassit-erite, columbite–tantalite, struverite, and uranmicro-lite. Thus, the Kester Deposit includes three types of ore-bearing rocks (according to the order of the for-mation): rare-metal granites → albitites → greisens. The greisen deposit has been explored down to a depthWeb
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h as inadvertent ingestion and inhalation of dust and materials from the sites. The dose levels due to heavy metals in tantalite samples from Oke-Ogun, Oyo State have been estimated. Twelve samples of tantalite ore [(Fe, Mn) Ta2O6], were obtained from the mining sites. 500mg of the pulverized samples were pelletized for their elemental …Web
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Tantalum and niobium are extracted from a variety of minerals and concentrates. The major source of niobium and tantalum is columbite-tantalite, also called coltan, with a general chemical formula (Fe,Mn)(Nb,Ta) 2 O 6.The two elements also exist in more than 150 other minerals and are usually present as complex metal oxides and …Web
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Evolution of the chemical composition of columbite–tantalite in Li–F granites and pegmatites — a comparative study ... the ore bodies are massive (e.g., Greenbushes, Australia; Melcher et al., 2016); (2) visible zoning in the lithofacies and mica contents in rare-metal granites and pegmatites (e.g., the Yashan granite and the Koktokay No ...Web
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Ore pre-treatment. The choice of an appropriate pre-treatment step is often considered as a key factor to establish an economically viable process for extraction. The pre-treatment of colombo-tantalite ores involves common size reduction operations such as crushing and grinding coupled with size classification.Web
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The paper presents new geological, mineralogical, and isotope geochronological data for rare-metal pegmatites in the Kalba granitic batholith (Eastern Kazakhstan). Mineralization is especially abundant in the Central-Kalba ore district, where pegmatite bodies occur at the top of large granite plutons and at intersections of deep …Web
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Tantalite, tantalum-rich variety of the mineral columbite (q.v.) with the chemical formula (Fe,Mn) (Ta,Nb)2O6. Tantalite is the principal ore of …Web
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The Jianfengling granite is an important ore-forming rock unit in the Xianghualing orefield in Nanling region (South China), and its magmatic evolution is vital to understand the regional niobium (Nb)-tantalum (Ta) mineralization. ... The rock has massive structure, with feldspar phenocrysts of about 1–10 mm size. The samples contain mainly ...Web
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Lithium-cesium-tantalum (LCT) pegmatites comprise a compositionally defined subset of granitic pegmatites. The major minerals are quartz, potassium feldspar, albite, and muscovite; typical accessory minerals include biotite, garnet, tourmaline, and apatite. The principal lithium ore minerals are spodumene, petalite, and lepidolite; cesium mostly …Web
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The flow diagram for extraction of niobium and tantalum from a columbite-tantalite ore is shown in Fig. ... special techniques must be used for purification and to convert it to massive form. In general they are similar to niobium. The methods used industrially are sintering, vacuum or inert atmosphere arc melting, and electron beam …Web
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This stone is an ore of tantalum, which is mined for its use in mobile phones and other electronic equipment. ... This mineral crystallizes in the massive form, as short prismatic crystals, thin tabular stone, rectangular prisms and as pyramids. ... Tantalite is a useful stone to assist anyone who may have the symptoms of adrenal exhaustion.Web
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Jere et al. (1961) studied the thermodynamic basis of chlorination of oxides present in columbite-tantalite ore. Standard free energy and standard enthalpy change as a function of temperature was calculated. The results confirmed that Nb 2 O 5 had great tendency for chlorination at about 250 °C.Web
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Abstract The paper presents experimental data on tantalite solubility in water-saturated granitoid melts with various alumina and alkaline elements concentrations at T = 650–850°C and P = 100 MPa. The maximum Ta concentration (effective solubility) in melt is shown to be always higher than the Nb concentration. As the melt composition is …Web
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In the ore minerals from the Madeira granite that encompassed the richest granite intrusion (facies), the main ore minerals are cassiterite (associated with zircon), columbite-tantalite, pyrochlore, and xenotime, whereas the Água Boa granite mainly includes cassiterite, columbite-tantalite, and topaz (Koury and Antonietto, 1988).Web
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Combined mineralogical-geochemical-geochronological signatures of columbite-tantalite ores are used to trace the origin of ore concentrates. Location of important ore provinces with Nb-Ta mining ...Web
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