Tantalum (Ta) [Z = 73]
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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Textural and mineral-chemistry constraints on columbite-group …
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. ... Crystals usually constitute isolated grains but are occasionally associated with quartz, muscovite, plagioclase, cassiterite ...
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Zoning in columbite-tantalite crystals from the granitic …
Electron microprobe analyses of zoned columbite-tantalite crystals from the granitic pegmatites of the Eräjärvi area in Orivesi, ... The zones in oscillatory zoned crystals are usually 1–50 μm in width, exceptions reaching 50–120 μm. The wider zones often consist of a group of very narrow subzones of only slightly different composition.
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Frontiers | Columbite-Tantalite Group Mineral U-Pb …
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 element contents using LA-ICP-MS (laser ablation-inductively coupled plasma mass spectrometry), and for ages using LA-ICP-MS U-Pb …
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Crystals | Free Full-Text | Columbite–Tantalite from Northern
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 …
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(PDF) Compositional, structural and phase relationships in …
Most samples of the orthorhombic phase are defined as titanian columbite - tantalite; they have low to moderate Ti content, moderately to considerably disordered structure, and convert to highly ...
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Mineralogy and chemistry of columbite-tantalite from …
The patchy zoning is the most common texture of CGM in the Bugarura-Kuluti. It is often produced when columbite-tantalite is subjected to an alteration by later fluids (Tindle and Breaks, 2000). Usually, an early columbite generation is replaced (or partially replaced) by a later columbite-tantalite generation richer in Ta (Fig. 8 a–c).
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Quantitative evaluation of metamictisation of columbite …
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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(PDF) Columbite-tantalite mineral chemistry from rare
This alteration led to recrystallization of columbite-tantalite and produced compositions with lower Ta contents, but with little change in Mn content. Discover the world's research 25+ million ...
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Columbite | Niobium, Tantalum, Ore | Britannica
Tantalite is the principal ore of the metal tantalum. This article was most recently revised and updated by Amy Tikkanen. Columbite, hard, black (often iridescent), heavy oxide mineral of iron, manganese, and niobium, (Fe, Mn)Nb2O6. Tantalum atoms replace niobium atoms in the crystal structure to form the mineral tantalite, which is similar but ...
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14.5.1: Tetrahedral and Octahedral Oxides
Columbite-tantalite crystals are usually short prisms or tabs, sometimes with heart-shaped twins. Crystal aggregates and masses are common. Structure and Composition The structure of columbite-tantalite consists of chains of (Fe,Mn)O 6 and (Nb,Ta)O 6 octahedra. Edge sharing joins them together.
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Zoning in columbite-tantalite crystals from the granitic pegmatites …
The zones in oscillatory zoned crystals are usually 1–50 μm in width, exceptions reaching 50–120 μm. The wider zones often consist of a group of very narrow subzones of only slightly different composition. ... (// 010) or rarely columnar (// to c), and predominantly subhedral. Columbite-tantalite is often associated with beryl, triphylite ...
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Niobium and tantalum
Artisanal mining of columbite-tantalite (also called coltan) is practiced in many countries, particularly Burundi, the Democratic Republic of the Congo (Congo [Kinshasa]), Nigeria, Rwanda, and Uganda. Brazil has about 40 percent of the identified tantalum resources; other countries and regions with identified tantalum resources include, in ...
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Mineralogy and chemistry of columbite-tantalite …
The patchy zoning is the most common texture of CGM in the Bugarura-Kuluti. It is often produced when columbite-tantalite is subjected to an alteration by later …
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Zoning in columbite-tantalite crystals from the granitic pegmatites …
The zones in oscillatory zoned crystals are usually 1-50 μm in width, exceptions reaching 50-120 μm. The wider zones often consist of a group of very narrow subzones of only slightly different composition. ... Electron microprobe analyses of zoned columbite-tantalite crystals from the granitic pegmatites of the Eräjärvi area in Orivesi ...
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Extractive metallurgy of columbite-tantalite ore: A detailed …
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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Study on Extraction of Niobium Oxide from Columbite-Tantalite Concentrate
Htwe and Lwin (2008) studied on the extraction of niobium oxide from columbite-tantalite concentrate. With the original Columbitetantalite concentrate containing 19.29% Nb 2 O 5, 9.93% Ta 2 O 5 ...
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Columbite Mineral Resources Information And Its Deposits …
Columbite occurs in Plateau state, Jos Nigeria, mainly in the placers deposits of cassiterite usually found only a few of 10km from the granitic parent rocks. It occurs as an accessory mineral in the northern parts of the country in smaller quantities, but the richest deposits occur on the Plateau. ... Coltan (Columbite Tantalite Ore) Buyers.
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Niobium (Nb) [Z = 41]
Niobium and tantalum are usually related. The columbite group includes minerals of varying proportions in their composition, with varying proportions of Nb or Ta in composition. ... Found in pyrochlore (Fig. 36.1), columbite-tantalite (coltan), and euxenite. Fig. 36.1 (Photo Joaquim Sanz. MGVM) Pyrochlore (sodium and calcium niobate). Oka …
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U-Pb isotopic dating of columbite-tantalite minerals: Development of
Columbite-tantalite minerals commonly have a broad range of U contents that may reach several thousand ppm and may substitute for Fe and Mn into the crystal lattice, but for high U contents may form phases of its own (e.g., uraninite; cf. Romer et al., 1996). Furthermore, columbite-tantalite minerals typically have very low common Pb …
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Extractive metallurgy of columbite-tantalite ore: A detailed …
The grain size of columbite-tantalite in the concentrate is the coarsest, followed by that in the middlings, and the finest in the tailings, which are mainly distributed in the range of -150+38 ...
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Accessory columbite to tantalite, tapiolite and zircon: …
Columbite-tantalite crystals show coarse oscillatory zoning, usually with border parts enriched in Ta. Locally, there is a reversal trend of zoning (decrease of Ta towards the border parts), or irregular convoluted zoning as a result of late-magmatic to subsolidus dissolution-reprecipitation. The composition of columbite-tantalite shows a ...
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(PDF) Mineralogy and chemistry of columbite-tantalite
PDF | On Jul 1, 2023, Jakub Ryznar and others published Mineralogy and chemistry of columbite-tantalite from Bugarura-Kuluti area, Karagwe-Ankole Belt, Rwanda: Indicators of pegmatite and granite ...
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Chemistry of columbite-tantalite minerals in rare metal …
Compositionally, columbite-tantalite of the Li-albite granites is constrained between MnNb 2 O 6 and MnTa 2 O 6 (the Ta/(Nb+Ta) atom. ratio ranges between 0.10 and 0.80). This low to high ratio and the association of columbite-tantalite with topaz, fluorite and lithian micas (in the series zinnwaldite-white mica) indicate a higher solubility ...
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Mineral chemistry of columbite–tantalite from
Columbite-group minerals occur in all main parageneses of the pegmatites and form four generations, reflecting the sequence of pegmatite formation. These …
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Tantalite: The mineral columbite-tantalite information and …
Detailed description, properties, locality information guide about the mineral tantalite (columbite-tantalite).
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COLUMBITE (Iron Manganese Magnesium Niobium …
Tantalite's greatest difference from columbite is its much higher specific gravity, 8.0+ compared to columbite's 5.2. Other properties that vary slightly are color, transparency and streak. Both minerals can be found more or less together in granitic pegmatites rich in lithium and phosphorus minerals with columbite concentrated at the edges of ...
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Columbite-Tantalite – WGNHS – UW–Madison
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. Columbite- (Fe) in …
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In situ U–Pb isotopic dating of columbite–tantalite by …
Abstract. 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.
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Factors and challenges in the recovery of niobium and …
The extraction is usually achieved by adopting and incorporating various rigorous mineral characterization, complex/complicated beneficiation and separation routes; encountering various challenges in the process. ... Columbite, tantalite, coltan and most Nb-Ta bearing mineral ores also possess certain measure or degree of radioactive …
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