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Columbite-tantalite (COLTAN) COLTAN (Columbite-Tantalite) is a dull metallic ore found in major quantities in the eastern areas of Congo. When refined, COLTAN becomes …
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Tantalite forms a solid solution series with Columbite known as the Columbite-Tantalite series. Tantalite is the tantalum-rich member, and Columbite is the niobium-rich …
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Columbite is the niobium-rich member, and Tantalite is the tantalum-rich member. Columbite is named after its niobium content, which was previous known as columbium prior to its renaming. Columbite is the most important mineral containing the rare element niobium and is its main ore. The name Columbite has been discredited by the IMA, with …
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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 …
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Three fluxing agents were evaluated: K 2 S 2 O 7, KHSO 4 and an equimolar mixture thereof.. KHSO 4 was found to be the more effective fluxing agent for purifying columbite tantalite ore in this study.. Over 97 %wt. of impurities were removed by using KHSO4 as fluxing agent and 15 runs of HCl leaching.
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Columbite and tantalite solubilities in the granitic liquids increase by a factor of approximately 2 to 3 with the addition of 2 wt percent Li 2 O to haplogranite at 750 degrees to 1,035 degrees C, 2 kbars, and water-saturated conditions. The solubility data were extrapolated to a lower temperature, more reasonable for columbite-tantalite ...
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tantalite ore prices had remained at $193 per kilogram of contained Ta 2 O 5 since november 2014. The increases in price in 2018 were thought to have resulted from a combination of increased demand from downstream consumers, increased royalties on exports of columbite-tantalite ore signed into law by the Government of Congo …
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Coltan, short for columbite-tantalite, is a conflict mineral that is usually mined by hand. It's a grayish, metallic ore that may look like just an ordinary rock to you. But for those with an eye for it, it's a precious soil deposit that makes technological advances run. ... Shifting the focus to its environmental effects, coltan mining has ...
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Ruiz et al. (1997) investigated the effect of ore/carbon ratio, mixing time, temperature, reaction time and particle size on chlorination in the carbochlorination of tantalite-columbite ore. The results showed that higher specific surface area, reaction time and temperature favour chlorination.
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The effect on the columbite-tantalite quadrilateral is to move from the ferrocolumbite field (lower left quadrant) to the manganotantalite field (upper right quadrant) with progressive chemical evolution. Complex zoning patterns occur in columbite-tantalite, which can be seen to good effect using backscattered electron images. Variations in Nb ...
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First Online: 13 July 2023. Abstract. This Chapter describes the important ore Columbotantalite-cbt (abbrv. cbt), as seen with optical, reflected light microscopy. …
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This effect is enhanced at decreasing temperature. The effective Ta solubility in melt is demonstrated to be practically independent of the composition of the dissolving mineral of the columbite-tantalite series. The Ta, Nb, Mn, and Fe diffusion coefficients in granitoid melts are estimated.
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The presence of radioactivity in columbite - tantalite is well established; however, in many examples, this property is due to inclusions or alteration by another phase with a relatively high U or Th content (Heinrich 1962, Lumpkin 1992). Effects of radiation damage on the columbite structure have received very littte
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The different columbite-tantalite minerals are available to the scientific community, depending of the quantity available for each reference material. The U-Pb dating of columbite-tantalite minerals by SIMS demonstrates that there are major matrix effects that mainly depend on the Nb/Ta ratio of the columbite-tantalite minerals.
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Niobium and tantalum are transition metals that are almost always found together in nature because they have very similar physical and chemical properties. Their properties of hardness, conductivity, and resistance to corrosion largely determine their primary uses today. The leading use of niobium (about 75 percent) is in the production of high-strength …
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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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Columbite-tantalite LA-ICP-MS U-Pb dating is a fast and useful method to determine the age of rare-metal deposits and fingerprint the provenance of columbite-tantalite ore concentrates.
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Impurities include magnesium (Mg), calcium oxide (CaO), tantalum oxide (Ta 2 O 5), columbite oxide (NbO s), and tin oxide (SnO 2). Columbite (Fe, Mn (Nb 2) O 6 –Tantalite (Fe, Mn, Ta 2 O 6) Columbite is the most widespread niobium mineral and makes for an important ore of the industrially useful metal. Niobium, Nb, is used in alloys …
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A strong negative effect on columbite–tantalite solubility due to increasing oxygen fugacity was observed. Buffered to Ni–NiO oxygen fugacity, Ta and Nb concentrations are 1.5 to 2 orders of magnitude lower than when buffered to Co–CoO.
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Abstract. Columbite-tantalite LA-ICP-MS U-Pb dating is a fast and useful method to determine the age of rare-metal deposits and fingerprint the provenance of columbite-tantalite ore concentrates ...
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The mineral coltan is one of the resources that is playing an important role in the technological revolution. Coltan ore itself hosts technology minerals tantalum and niobium. Brazil, Canada and ...
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Niobium and tantalum, characterized by high melting point, remarkable corrosion resistance, and good cold workability, are widely used in steel, petrochemical, electronics, and aerospace [1, 2].The main ore sources for the production of tantalum and niobium include pyrochlore, microlite, tantalite, columbite, and columbo-tantalite …
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Effects of columbite/tantalite (COLTAN) mining activities on water quality in Edege-Mbeki mining district of Nasarawa state, North Central Nigeria. Authors: …
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Members of the columbite–tantalite solid-solution series are a major mineral resource of Nb and Ta, and have the formula, AB 2 O 6, where A is occupied by Fe 2+ and Mn 2+ (Mg 2+ in rare cases) and B is dominated by Nb 5+ and Ta 5+ (Černý and Ercit, Reference Černý, Ercit, Möller, Černý and Saupé 1989; Ercit, Reference Ercit 1994 ...
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The major problem is to distinguish between primary magmatic columbite–tantalite and secondary hydrothermal–metasomatic ores ... hydrothermal processes should also be taken into consideration. The effect of these processes is clearly visible in the zoning patterns exhibited by CGM-IV (Fig. 4 i, k). As it was discussed …
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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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The industrial processes for recovery of niobium and tantalum oxides depend on hydrofluoric acid, which is a highly toxic and corrosive reagent with significant environmental consequences. This study presents a fluoride-free, rapid, and energy-efficient process for niobium and tantalum extraction from columbite using microwave-assisted …
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Linnen, 1998, Bartels et al., 2010 also observed an increase of the solubility of Mn-columbite and Mn-tantalite with increasing content of fluxing elements like Li, F, B and P. Linnen (1998) assumed that the effect of F is additive to the one of Li, both leading to increasing solubility of Mn-columbite and Mn-tantalite with increasing content.
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Columbite is the niobium-rich member, and Tantalite is the tantalum-rich member. Columbite is named after its niobium content, which was previous known as columbium …
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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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