##tihuan2##Pure columbite and tantalite are unknown in nature; they are theoretical end members of a solid solution series, the columbite group (see section 2.2.1). Therefore its members are also called Columbite-Group Minerals, symbol CGM [19]. The relation Nb2O5/Ta2O5 represents the columbite-tantalite composition in the following graphs.
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##tihuan2##Columbite, also called niobite, niobite-tantalite, columbate or coltan, in short form, is an ore source of niobium produced globally. The countries listed below are the important players in columbite-tantalite production.
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##tihuan2##Hydrothermal origin of columbite-tantalite is observed in greisens, expressed by a higher W concentration and coeval or even younger crystallization compared to the …
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##tihuan2##Columbite–tantalite (Coltan) is the most important niobium (Nb)- and tantalum (Ta)-bearing economic mineral, commonly occurring in rare metal granite and pegmatite, alkaline granite, syenite and carbonatite. Its high U but low common Pb contents make it an ideal mineral for U–Pb isotopic dating of Nb–Ta mineralization. In order to ...
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##tihuan2##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 tantalates and …
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##tihuan2##tin slags, which will continue to be an important source of tantalum in the future (1). Nb 0 is approximately 1:0.85. Tin slags also contain niobium. The average ratio of TaZ05 : 25 Niobium and tantalum ores as well as tin-slags with a high tantalum content (exceeding 12% Ta 0 ) are directly dressed, in most cases by a wet chemical process.
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##tihuan2##COLTAN (Columbite-Tantalite) is a dull metallic ore found in major quantities in the eastern areas of Congo. When refined, COLTAN becomes metallic …
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##tihuan2##The pegmatites occur in two distinct clusters adjacent to the Separation Rapids pluton which is thought to be the source of the rare-elements. Beryl-type and complex-, petalite-subtype pegmatites are the most common and a few pegmatites have characteristics similar to the lepidolite-subtype. ... Columbite-Tantalite zeigen ein …
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##tihuan2##Coltan is short for columbite-tantalite, a dull metallic ore. When refined, coltan becomes a heat resistant powder, metallic tantalum, which has unique properties for storing electrical charge. Coltan occurs in granitic …
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##tihuan2##Columbite–tantalite minerals are an important source of Nb and Ta. Their presence in LCT pegmatites, together with spodumene and lepidolite, is an interesting occurrence that may be the subject of further exploration in northern Scandinavia. ... 2023. "Columbite–Tantalite from Northern Scandinavia (Kaustinen, Kolmozero) Pegmatites: …
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##tihuan2##Columbite-tantalite is a solid solution whose chemical composition varies by the substitution and coexistence of niobium, tantalum, manganese, and iron, in ore structures between pure columbite ...
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##tihuan2##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 ... source of tantalum, tin, tungsten and gold ...
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##tihuan2##Usually, an early columbite generation is replaced (or partially replaced) by a later columbite-tantalite generation richer in Ta (Fig. 8 a–c). These later domains occur often at the corroded margins of crystals or along fracture surfaces and have been interpreted as the evidence of partial resorption followed by a later crystallization ...
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##tihuan2##This review presents an overview of the currently mined tantalite ores in Ethiopia (in particular Kenticha ores) and potentialities to extract niobium (Nb) and tantalum (Ta) products using green technologies. The foremost source of niobium and tantalum is the columbite-tantalite mineral or "coltan". Since hydrometallurgical methods are
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##tihuan2##The eastern part of the Democratic Republic of Congo (DRC) is extremely rich in Coltan (Columbite-Tantalite), a rare metallic ore used for the production of electronic goods of mass consumption ...
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##tihuan2##Columbite-tantalite, cassiterite and other Ta-Nb-Sn oxides in sediments from catchments that contain known LCT pegmatite occurrences show the same textural and chemical characteristics as these ...
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##tihuan2##The chlorination of columbite-tantalite in the presence of a reducing carbon bed produces a mixture of volatile tantalum, niobium, iron, tin, aluminium and manganese chlorides along with niobium oxychloride. Gaballah et al. (1997) studied the chlorination …
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##tihuan2##Columbite-tantalite (CGM) ore, which represents a major source of Nb and Ta, can be dated using the U–Pb system (Romer and Lehmann, 1995, Romer and Smeds, 1994, Romer and Wright, 1992, Smith et al., 2004).
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##tihuan2##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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##tihuan2##Paragenetic, textural, and chemical characteristics of columbite-tantalite minerals are examined as steps towards identifying the metallogenetic processes of …
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##tihuan2##deposit source named as Rare element pegmatite - LCT family. Figure 2. Figure 2. ... COLTAN (COLUMBITE & TANTALITE), HAND HELD XRF INTO OVERSIGHT OF TRADE 5 Author GÜIZA-GONZÁLEZ, SONIA ...
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##tihuan2##Columbite-tantalite is a solid solution whose chemical composition varies by the substitution and coexistence of niobium, tantalum, manganese, and iron, in ore …
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##tihuan2##The pegmatites occur in two distinct clusters adjacent to the Separation Rapids pluton which is thought to be the source of the rare-elements. ... This study reveals that columbite-tantalite in ...
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##tihuan2##The use of CT oxides with this purpose is supported by different facts: (1) columbite-tantalite group minerals cannot be inherited from the source of a granitic magma, (2) they show high U and low ...
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##tihuan2##The ultrastructure of the columbite-tantalite mineral suggested the columbite-group mineral in the Zhaojinggou Nb-Ta deposit formed during magmatic crystallization rather than from hydrothermal fluids. Furthermore, HR-TEM images provided the first nanoscale observations of the fluid-mediated mineral dissolution and amorphous …
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##tihuan2##The dependence of columbite–tantalite (Nb2O5-59 wt. %, Ta2O5-18 wt. %) solubility as a function of solution composition, T, and P has also been investigated. Tantalum and Nb concentrations have the highest values in HF solutions at reduced conditions (up to 10−3 to 10−2 m Ta in 1 m HF). In 1 m NaF solutions, the …
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##tihuan2##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 composition. ... The main source of tantalum recycling is scrap generated in the manufacture of capacitors, electronic components, tools, and the alloys based on this metal. Further …
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##tihuan2##Study with Quizlet and memorize flashcards containing terms like Why is coltan such a valuable mined resource? - The tantalum in coltan is a precious metal used in jewelry. - Coltan contains columbite. Columbite is required for microprocessors such as the ones in your cell phone. - Coltan is a source of energy that is used to power cell phones. - …
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##tihuan2##Columbite-(Fe)-Tantalite-(Fe) Series and the Columbite-(Fe)-Columbite-(Mn) Series. Formerly known as columbite and ferrocolumbite. ... (2006) - Igneous albitite dikes in orogenic lherzolithes, Western Pyrénées, France: A possible source for corundum and alkali feldspar xenocrysts in basaltic terranes. I. Mineralogical Asssociations. The ...
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