A swarm of pegmatite dykes generally strike NW, NE, and nearly N–S (Fig. 2), with a dipping angle of 10°–85°, which formed sharp contacts with the surrounding wall-rocks.The rare-metal pegmatites belong to the beryl-type (e.g., beryl–columbite subtype) and complex-type (e.g., spodumene subtype and lepidolite subtype; Zhou et al., 2019) …
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Tantalite and columbite ores have been reported as containing associated primordial radionuclides, such as uranium and thorium. Ethiopia is one of the world suppliers of tantalite ore through exploitation of Kenticha mine and tantalite production by a large number of artisanal miners. For the purpose of implementing the international standards …
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0.63% of all Tin deposits have Coltan (Columbite-Tantalite). 15.38% of all Coltan (Columbite-Tantalite) deposits have Tin. Mineral specimens: 7: 692: 1.01% of all Mineral specimens deposits have Coltan (Columbite-Tantalite). 13.46% of all Coltan (Columbite-Tantalite) deposits have Mineral specimens. Feldspar: 6: 1,497: 0.40% of all Feldspar ...
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The Herbb Number 2 mine near Flat Rock was open for a short period beginning in 1944. Samples of tantalite and cassiterite obtained in 1991 were reported to contain 33 percent tantalum. Columbite mineral samples from the White Peak Number 2 Prospect (approximately 2 miles southwest of the Herbb No. 2 mine) contain 16.29 percent tantalum.
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Coltan 139 and these three columbite-tantalite samples with variable compositions yielded internally consistent LA-ICP-MS U-Pb ages when using each other for calibration and the weighted mean 206 Pb/ 238 U ages are comparable to respective ID-TIMS ages. Composition-dependent U-Pb fractionation seems to be insignificant under the LA-ICP …
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Columbite has the same composition and crystal symmetry (orthorhombic) as tantalite. In fact, the two are often grouped together as a semi-singular mineral series called columbite-tantalite or coltan in many mineral guides. However, tantalite has a much greater specific gravity than columbite, more than 8.0 compared to columbite's 5.2.
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1 "Conflict minerals", as defined by Securities and Exchange Commission (SEC) rules, is a broad term which means columbite-tantalite (coltan), cassiterite, gold, wolframite, or their derivatives which are limited to tantalum, tin or tungsten, regardless of whether these minerals finance conflict
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In this study, the columbite-tantalite group minerals (CGMs) from a typical Li-rich pegmatite dike were analyzed for major element contents using an EMPA (electron microprobe analyzer), for trace …
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Another strategic mineral mined in the DRC is coltan – a name derived from "columbite-tantalite". In 2021, the DRC's coltan production amounted to an estimated 700 tonnes, ...
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Researchers have studied columbite-tantalite flotation using collectors such as benzyl arsenic acid, sodium oleate, sodium alkyl sulphonate, benzohydroxamic acid, …
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5.5 x 2.1 x 0.9 cm. Columbite-Tantalite is a combination term that is used generically for the specimens in the columbite/tantalite families. Under normal circumstances, they are very difficult to tell apart. This sharp, curved single crystal is actually quite a good example of this family, with good, blackish color and excellent, pearly luster
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(Photo by Al Falster.) Columbite-tantalite refers to a group of minerals having varying amounts of iron, manganese, niobium, and tantalum. They are found as platey black grains in complex granitic pegmatites. …
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as columbite-tantalite, cassiterite and tungsten exist as coar se crystals o r aggregates (Ahmad, 1995). Other . nonsilicates found in the hea vy mineral co ncentrates are rutile, il menite and ...
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General Tantalite-(Fe) Information : Chemical Formula: Fe++Ta2O6 : Composition: Molecular Weight = 513.74 gm Tantalum 70.44 % Ta 86.02 % Ta 2 O 5 ... Tantalite - Columbite Series : 08.03.02.01 Tantalite-(Fe) FeTa2O6 Pcan 2/m 2/m 2/m : 08.03.02.02 Columbite-(Fe) ...
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The columbite group is a solid solution with varying proportions of Nb or Ta in its composition. According to the International Mineralogical Association (IMA), 'tantalite' or 'coltan' are not scientific names, yet they are widely used. Many specimens commonly named tantalite are actually minerals of the columbite or tapiolite group ...
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Introduction. Niobium and tantalum are critical metals that have been used increasingly in advanced technologies (e.g. information technology, energy, aerospace, national defence and military, Linnen et al., Reference Linnen, Van Lichtervelde and Černý 2012).Members of the columbite–tantalite solid-solution series are a major mineral …
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A novel approach for Ta and Nb extraction consisting of the pre-treatment of a coltan-bearing ore with an ammonium bifluoride sub-molten salt and subsequent acid leaching has been studied. The effects …
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The mining of columbite/tantalite (COLTAN) has a negative effect on the different spheres of the environment notably; hydrosphere, lithosphere, and the atmosphere (Eisler 2004). Just like gold mining, COLTAN extraction involves the breaking of crystallographic bond in the mineral ore to get the products in the pure form.
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In this study, we examine the Ta-Nb oxide minerals from the granites, greisens and especially from related granitic pegmatites of the Bugarura–Kuluti …
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A generic name for minerals of the Columbite/Tantalite families which are difficult to distinguish without sophisticated tests. Mindat relies on your donations to survive …
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Columbite-(Fe) is a post-magmatic accessory mineral occurring within syenogranites and greisens from the Desemborque Pluton. The petrographic (SEM) and geochemical (EPMA and LA-ICPMS) examination of this mineral shows two distinct textural types within both the rocks, named columbite-1 and columbite-2. The columbite-1 type …
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From ferrous iron content and the Greek mythological Tantalus, for the difficulty of dissolving the mineral. The original material with Fe>Mn was called Tantalite, subsequent name changes recognized the compositional variability of the series. Type Locality: ⓘ Upper Bear Gulch, Tinton Pegmatite Mining District, Lawrence Co., South Dakota, USA.
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Dissolution textures resulting from the corrosion of columbite and tantalite rims, in particular, are common. The Mn/(Mn + Fe) ratio varies between 0.33 and 0.97 and the Ta/(Ta + Nb) ratio between 0.07 and 0.93. Wodginite and microlite formed as late replacements of CGM and occur associated with tantalite and cassiterite.
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Wolfram is a typomorfic impurity in columbite–tantalite of the Kester Deposit, WO 3 is 1.77%, on average (apfu is 0.03). In tantalite- (Mn), WO 3 is 0.70%, while in columbite- (Fe), WO 3 is 2.67%, reaching 7.12%. The wolfram impurity is more typical for columbite, whereas the tin impurity is typomorphic for tantalite: the average content of ...
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Columbite-Tantalite : Ferrocolumbite - Renamed to Columbite-(Fe) by Mineralogical Record, v39 (2008), p 131 : Niobite : Columbite-(Fe) Image: Images: Columbite-(Fe) Microcline. Comments: Blocky, dark brown ferrocolumbite on …
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columbite, hard, black (often iridescent), heavy oxide mineral of iron, manganese, and niobium, (Fe, Mn)Nb 2 O 6. Tantalum atoms replace niobium atoms in the crystal structure to form the mineral tantalite, which is similar but much more dense. These minerals are the most abundant and widespread of the naturally occurring niobates and ...
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used in capacitors as platinum substitute. Columbite, tantalite, columbite-tantalite (Coltan), pyrochlore, and euxenite constitute the major primary sources for niobium and tantalum and are located in Canada, Brazil, Nigeria, Zaire and Russia [5, 6]. These interesting elements are chemically similar and are associated with each other in nature.
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The processing of tantalite-columbite ore is complex due to its low content and sophisticated composition. Usually, the enrichment flow sheet of tantalite-columbite covers rough concentration and fine selection. And …
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Columbite-tantalite, cassiterite, and wolframite are the mineral ores from which tantalum, tin, and tungsten, respectively, are processed. 3. The act required State, in consultation with the U.S. Agency for International Development, to submit a conflict minerals strategy to the appropriate congressional
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The increased demand of metals such as tantalum (Ta) and niobium (Nb) reflect the on-going development in modern science, engineering and technology. The extraction of these two metals from columbite-tantalite ore is based on generic extractive metallurgy. However, the upstream purification of ore and downstream extraction of Ta …
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Columbite-tantalite (Coltan) occurs in granitic pegmatites, pockets where the deep-seated molten rocks undertook late crystallisation to form Me (II)(Nb, Ta) 2 O 6 more stable than other compounds of the type Me(II) (Nb,Ta)O 2 O 7 and Me(IV)(Nb,Ta)O 2 O 9, which are probably thermodynamically unstable at elevated temperatures, and will ...
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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.
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Columbite-tantalite group minerals (CGMs) are an important source for strategic elements, Nb and Ta, in highly evolved granites and granitic pegmatites [6,7]. These minerals share a general chemical formula AB 2 O 6, in which A is occupied by divalent cations including Fe 2+, Mn 2+, and rarely Mg 2+ and B, by Nb 5+ and Ta 5+ …
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Tantalite is the tantalum-rich member, and Columbite is the niobium-rich member. Tantalite is named after its tantalum content, and, together with Columbite, are the …
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Columbite - tantalite is an important accessory mineral in the Harding granitic pegmatite, a subhorizontal, zoned, complex spodumene-type pegmatite emplaced within the Proterozoic Vadito Group in northern New Mexico. Columbite - tantalite is most abundant in the beryl (wall) zones of the pegmatite, with lesser quantities in the interior units.
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The formation of columbite-group mineral phases in peraluminous granite has not been demonstrated to date. Here, a nanoscale study of the columbite-tantalite mineral in the Zhaojinggou Nb-Ta deposit in North China Craton elucidated its formation mechanism and the role of fluids in Nb-Ta mineralization. Transmission electron …
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