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Columbite, hard, black (often iridescent), heavy oxide mineral of iron, manganese, and niobium, (Fe, Mn)Nb2O6. Tantalum atoms replace …
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Members of the columbite–tantalite series are uncommon. They occur in pegmatites with quartz, feldspar, mica, Li-minerals, phosphates, and other typical …
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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 …
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They contain mostly T a-rich columbite-tantalite, including tapiolite and microlite, with spodumene, beryl and some mica and apatite (Krishna and Thirupathi, 1999; Maithani and Singh,
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Numerous granitic pegmatite dikes were emplaced along the northwest-southeast-trending miliolite zones and the secondary faults within the quartz diorites and Dakendaban Group strata (Figures 3, 4A,B) (Pan et al., 2020).These granitic pegmatites are lentoid or banded, are 5–60 m long and 0.2–20 m wide, and include spodumene-bearing …
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Mineral Resources in Nigeria Mineral Resources found in the 36 states of Nigeria and FCT ABUJA Mineral resources in Abuja include: Marble Clay Tantalite Cassiterite Gold (this is partially investigated) Lead /Zinc (Found in traces) Dolomite. ABIA STATE Mineral resources in Abia include: Gold Salt Limestone Lead Zinc Crude Oil …
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New data on rare earth element (REE) concentrations and distribution patterns of columbite-tantalite minerals from Ta-ore provinces worldwide are presented. The REE geochemistry was studied by laser ablation inductively coupled plasma mass spectrometry (LA-ICP-MS). Five major types of chondrite-normalized REE distribution patterns are …
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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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"Conflict Minerals" currently include gold, as well as tin, tantalum and tungsten, the derivatives of cassiterite, columbite-tantalite, and wolframite, respectively. These conflict minerals are referred to as "3TG." The Dodd-Frank Act authorizes the U.S. Secretary of State to designate additional
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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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There is reportedly, a diminishing supply of high-grade Nb and Ta minerals with thus, an increased Table 1 Common properties of columbite and tantalite minerals [7]. demand in certain specific ...
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31 photos of Columbite-Tantalite associated with Muscovite: KAl 2 (AlSi 3 O 10)(OH) 2: 20 photos of Columbite-Tantalite associated with Quartz: SiO 2: 15 photos of Columbite …
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Columbite-tantalite crystals are usually short prisms or tabs, sometimes with heart-shaped twins. Crystal aggregates and masses are common. ... Tapiolite is a polymorph of columbite–tantalite. Other related minerals include microlite, Ca 2 Ta 2 O 6 (O,OH,F); pyrochlore, (Ca,Na) ...
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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 …
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Columbite-tantalite is particularly suitable for U-Pb dating due to its high U and low common Pb contents. In situ isotopic dating of columbite-tantalite by LA-ICP …
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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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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 produce. However, their production of coltan went downhill following environmental regulations and unsuccessful mining company buyouts.
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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) …
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Columbite-tantalite, commonly known as "coltan," is a black metallic ore. When refined, it produces tantalum, which is used to regulate electricity in portable consumer electronics, such as smartphones, laptops, play stations, and digital cameras. The largest share of coltan comes from Africa; other sources include Australia, Brazil, and ...
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Carbochlorination of tantalite-columbite ore. The chlorinated columbite-tantalite ore product contains Fe, Mn, Ti, Sn, Al, Ta, Nb and W chlorides, as well as W and Nb oxychlorides. Oxychloride is converted to pentachloride by passing the chloride and chlorine through a hot bed of carbon.
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Coltan (Columbite Tantalite Ore) Buyers. Many individuals buy and import columbite-tantalite ore and its concentrates in different parts of the world, but a few countries are singled out for the most of importation of this commodity. These countries include: The United States of America, USA. Russia . China . South Korea. Price of Coltan per ...
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The Separation Lake area is host to the most important rare-element pegmatites in Ontario, Canada. They include the Big Whopper and Big Mack petalite pegmatite systems which potentially represent the world's second largest lithium deposit of this type. The pegmatites occur in two distinct clusters adjacent to the Separation Rapids pluton which is thought to …
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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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COLTAN (Columbite-Tantalite) is a dull metallic ore found in major quantities in the eastern areas of Congo. When refined, COLTAN becomes metallic Tantalum, a heat-resistant …
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The REE minerals noted in pegmatites of Idar-Surda-Dhanpura areas of Sabarkantha and Banaskantha districts of Gujarat include allanite, cerianite, xenotime, fergusonite, gadolinite, and yttrotantalite with or without columbite-tantalite and fersmite (Table 7.14). These minerals are hosted mainly in granites and associated pegmatitic veins.
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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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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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Columbite-tantalite is most abundant in the beryl (wall) zones of the pegmatite, with lesser quantities in the interior units. ... Possible factors causing the observed trend in structural state include a decrease in cooling rate by as much as two to three orders of magnitude and the presence of minor elements. The average U content …
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The generalized formula of columbite–tantalite of the deposit is (Mn 0.61 Fe 0.34) 0.95 (Nb 1.37 Ta 0.58 Ti 0.04 W 0.03 Sn 0.01) 2.03 O 6. Columbite–tantalite …
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Table 4 Selected microprobe chemical analyses (oxides in wt.%) and calculated compositional formulae (on the basis of 6 oxygens) of columbite-tantalite oxides in the studied pegmatites, covering the observed range in Mn/(Mn + Fe); FeO T: all Fe as FeO; bdl: below detection limit. Core-rim is indicated for a large and zoned grain; all …
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