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Columbite-tantalite-bearing granitoids of the Eastern Desert province of Egypt can be categorized into: (i) metaluminous alkali granites; (ii) peraluminous Li …
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Columbite-(Fe) in tabular crystal from the Nine Mile pluton near Wausau in Marathon County, Wisconsin. Scanning electron microscope image. (Photo by Al Falster.) Columbite-tantalite refers to a group of minerals having …
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The chlorination of columbite-tantalite in the presence of a reducing carbon bed produces a mixture of volatile tantalum, niobium, iron, tin, aluminium and …
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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 most important minerals containing the rare element tantalum. The name Tantalite has been discredited by the IMA, with the more specific designations of Tantalite- (Fe) (also known ...
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In full, coltan's name is columbite-tantalite, after Tantalus, the figure in Greek mythology who was condemned to a horrifying eternal torment, of the things he most desired being just out of his ...
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Columbite forms a solid solution series with Tantalite known as the Columbite-Tantalite series. Columbite is the niobium-rich member, and Tantalite is the tantalum-rich …
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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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As for columbite-tantalite mineralization, the determination of the Ta content in muscovite is strongly indicative. ... According to Garba (2003), although Rb is an indicator of the degree of ...
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Moreover, spot no. 17 on a Type 2 CGMs belongs to tantalite (Mn) rather than columbite (Mn) according its Ta# value. Type 2 CGM no. 17 experienced a different petrogenetic path than the Type 1 CGMs, but one dataset has no apparent statistical significance, and the age of 211.0 ± 4.7 Ma for grain no. 17 (Type 2 CGM) hardly …
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Since 2006, our working group has been investigating columbite-tantalite (coltan) mineralisation, especially in Africa, also within the wider framework of establishing certified trade chains.
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It can be seen from Table 4 that the main tantalum or niobium minerals are tantalite, columbite, and ferrotapiolite. These three minerals, tantalite (6.25–7.90), columbite (5.00), and ferrotapiolite (5.00–7.90), are relatively denser compared to the density of albite (2.62) and quartz (2.65).
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Columbite-tantalite is most abundant in the beryl (wall) zones of the pegmatite, with lesser quantities in the interior units. Average compositions of 25 samples …
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1 Geology. The primary ore of tantalum is the columbite-tantalite group. The columbite group is a solid solution with varying proportions of Nb or Ta in its …
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The dielectric properties of the columbite concentrate and its mixture 1:1 with sodium bicarbonate were characterized using the cavity perturbation method 22 from room temperature to 1000 °C with ...
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Three mineral types of the columbite group have been revealed at the Kester Deposit (Eastern Yakutia), that is, columbite-(Fe), columbite-(Mn) and tantalite-(Mn), …
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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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According to Wills and Finch [22], less than 1% of the total input energy is made available for the actual mineral particle size reduction, ... Columbite/tantalite minerals largely comprise of four salts [Fe(NbO 3) 2, Mn(NbO 3) 2, Fe(TaO 3) 2 and Mn(TaO 3) 2] in isomorphous mixtures. Columbite usually occur together with the …
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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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The columbite-tantalite (Nb-Ta) mineralization system of the Hana-Lobo (H-L) Ge-ological Complex (central-western Côte d'Ivoire) has been the subject of several geolog-ical [24–27], and metallogenic research works [28–30]. These studies revealed that the Nb-Ta placer deposits mineralization system is linked to landscape spatial factors, and
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Natural resources are nature's gift to man. It is an endowment by nature for the benefit of the wellbeing or welfare of the people of the geographical region where the resource is located.
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The Cape Cross–Uis pegmatite belt, Damara Orogen, north-central Namibia hosts multiple Ta–Nb- and Sn-oxide-bearing pegmatites. Columbite-group minerals, tapiolite, cassiterite and minor ixiolite and wodginite occur in abundance within pegmatites and display various compositional and internal structural mineralogical variations.
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The generic term columbotantalite, cbt, comprises the different compositional varieties of columbite and tantalite, classically treated (e.g. Ramdohr 1980) as an isomorphic, continuous solid solution series between the members (Fe, Mn)Nb 2 O 6 (niobite, now columbite, cb) and (Fe, Mn)Ta 2 O 6 (tantalite, tan), a series also known …
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2. What is coltan used for? Niobium and tantalum are often found together, but have very different properties and applications;
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Australia was initially the largest producer of columbite-tantalite in the world, closely followed by Canada and Brazil. In 2006 alone, the three countries had an 80% share of total columbite-tantalite …
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Columbite-tantalite is radioactive due to uranium and thorium. It is rich in yttrium (1.29–2.71% Y 2 O 3) with substantial amount of cerium (Muralikrishna et al. 1995). Columbite-tantalite from pegmatite of Umedpur area is also radioactive due to U and Th, and contains 3.99 wt% Y 2 O 3 and 0.1 wt% Ce 2 O 3 (Maithani and Nagar 1999).
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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 most important minerals containing the rare element tantalum.
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According to the US Geological Survey, Mineral Commodity Summaries, majority of the mined products are exported to China, Netherlands, and the Republic of Korea for final production of oxide and metal. ... The thermal decomposition of columbite and tantalite with KOH results in the formation of K 3 NbO 4 and K 3 TaO 4 as per the …
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According to the . Nigerian Geological Survey Agency, the . ... from the Nigerian and Rwandan columbite-tantalite . concentrates. Minerals Engineering 201, 108201. 19 Oyewo, ...
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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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Tantalum shares many of its properties with niobium (Nb), with which it is commonly found. This close association has led to use of the 'coltan' terminology, short for columbite-tantalites, reflecting the niobium-dominant (columbite) 2 and tantalum-dominant (tantalite) end-members of this oxide mineral series (see text box below). Tantalite is ...
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