Reduction of Transition-Metal Columbite-Tantalite as a …
We successfully report a liquid–liquid chemical reduction and hydrothermal synthesis of a highly stable columbite-tantalite electrocatalyst with remarkable hydrogen evolution reaction (HER) and oxygen evolution reaction (OER) performance in acidic media. The reduced Fe0.79Mn0.21Nb0.16Ta0.84O6 (CTr) electrocatalyst shows a low overpotential …
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.
Tantalite-(Mn): Mineral information, data and localities.
Columbite Group > Columbite Supergroup. Name: From the manganese content and for the Greek mythical figure Tantalus - for its difficulty in dissolving. Type Locality: ⓘ Utö Mines, Utö, Haninge, Stockholm County, Sweden. Tantalite- (Fe)-Tantalite- (Mn) Series and Columbite- (Mn)-Tantalite- (Mn) Series. Formerly known as manganotantalite.
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 ...
Conflict Minerals Compliance
the minerals cassiterite, columbite-tantalite and wolframite, respectively. Downstream companies often refer to the extracts of these minerals as 3TG. Who is impacted? DRC Countries ls Democratic Republic of the Congo (DRC) Congo Republi c Rwand a Burund Tanzan i ia Zambi a Angol a Ugan da South Sudan Central Africa Republic —
Tantalite | mineral | Britannica
columbite. multiple oxide. tantalite, tantalum-rich variety of the mineral columbite ( q.v.) with the chemical formula (Fe,Mn) (Ta,Nb) 2 O 6. …
Tantalite-(Fe): Mineral information, data and localities.
Tantalite-(Fe) is a specific member of the tantalite series, with iron as the dominant end member. It forms dark brown to black crystals with a submetallic luster. It is often associated with columbite and other pegmatite minerals. Find out more about its crystallography, chemistry and localities at mindat, the ultimate online resource for mineral enthusiasts.
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 …
Tantalite-(Mn): Mineral information, data and localities.
Lustre: Vitreous, Sub-Metallic. Hardness: 6. Specific Gravity: 6.65 - 8. Crystal System: Orthorhombic. Member of: Columbite Group > Columbite Supergroup. Name: From …
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 ...
U-Pb isotopic dating of columbite-tantalite minerals: Development of
The columbite-tantalite group minerals [(Fe,Mn)(Nb,Ta) 2 O 6 ] are critical ore minerals of niobium and tantalum in rare metal pegmatite deposit.
Finger of conflict minerals: columbite …
Combined mineralogical-geochemical-geochronological signatures of columbite-tantalite ores are used to trace the origin of ore concentrates. Location of important ore provinces with Nb-Ta mining ...
Tantalite-(Fe): Mineral information, data and localities.
Lustre: Sub-Adamantine, Greasy, Metallic, Sub-Metallic. Hardness: 6 - 6½. Specific Gravity: 6.65 - 7.95. Crystal System: Orthorhombic. Member of: Columbite Group > Columbite …
Can the provenance of the conflict minerals columbite and tantalite …
The columbite–tantalite samples selected for this pilot study come from three pegmatite locations in North America: (1) the Starrett pegmatite in southern Maine; (2) the BeeBee/PackRat pegmatite in San Diego County, California; and (3) the Moose pegmatite in the east-central Northwest Territories, Canada [6–12].The 14 samples …
(PDF) Ultrastructure of a Columbite-Tantalite Mineral from …
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 ...
A mixed collector system for columbite-tantalite flotation
After columbite-tantalite is activated with 60 mg/L Pb(NO 3) 2, the zeta potential of columbite-tantalite for the entire pH range is positively shifted, and the IEP increases from 3.7 to 5.8. The significant positive shift of zeta potential is attributed to the specific adsorption of positively charged Pb species onto the columbite-tantalite ...
Columbite supergroup of minerals: nomenclature and …
Columbite-group minerals with 1-3 wt.% Sc2O3 are referred to as scandian columbite - tantalite and show degrees of structural order similar to columbite - tantalite lacking Sc. Disordered ...
Columbite–Tantalite of the Kester Deposit (Eastern Yakutia)
be exhausted tin–rare-metal ores. The Kester Deposit is an ore-bearing greisen. deposit that is located at a hanging endocontact of a. harpolith of rare-metal granites at its bend, and sub-. m e ...
Effects of columbite/tantalite (COLTAN) mining activities …
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.
Columbite: The mineral columbite-tantalite information …
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 …
U–Pb geochronology of columbite-group mineral
Abbreviations: Clb = columbite; Ttl = tantalite. Cassiterite is locally intergrown with CGM along porous rim-1, which hosts uranmicrolite ((U,Ca) 2 (Ta,Nb) 2 O 6 (OH); …
Towards sustainable processing of columbite group …
In the context of engineering a novel technique for the extraction of niobium-tantalum oxides from columbite-tantalite minerals, we have reviewed the importance of dielectric properties of these ...
1 Key facts and figures about coltan and tantalum
Coltan is short for columbite–tantalite, a mineral containing the elements tantalum and niobium. Niobium was formerly known as columbium, hence the name columbite …
Columbite Tantalite: a film that fuses Congo's past and …
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 ...
ia Energy
The Herbb Number 2 mine near Flat Rock was open for a short period beginning in 1944. Samples of tantalite and cassiterite obtained in 1991 were reported to contain 33 percent tantalum. Columbite mineral samples from the White Peak Number 2 Prospect (approximately 2 miles southwest of the Herbb No. 2 mine) contain 16.29 percent …
The association of columbite, tantalite and tapiolite in the …
Wang Ru Cheng, Francois Fontan, Xu Shi Jin, Chen Xiao Ming, Pierre Monchoux; The association of columbite, tantalite and tapiolite in the Suzhou Granite, China. The Canadian Mineralogist 1997;; 35 (3): 699–706. doi:
In situ U–Pb isotopic dating of columbite–tantalite by LA–ICP–MS
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 ...
Columbite–Tantalite of the Kester Deposit (Eastern Yakutia)
Wolfram is a typomorfic impurity in columbite–tantalite of the Kester Deposit, WO 3 is 1.77%, on average (apfu is 0.03). In tantalite- (Mn), WO 3 is 0.70%, while in columbite- (Fe), WO 3 is 2.67%, reaching 7.12%. The wolfram impurity is more typical for columbite, whereas the tin impurity is typomorphic for tantalite: the average content of ...
Episodic Nb–Ta mineralisation in South China
23 Columbite-tantalite ages from 14 Nb–Ta deposits in South China were reported. • Five distinct Nb–Ta mineralisation events (424–391, 248–204, 160–150, ∼130, and ∼90 Ma) in South China were revealed.
Columbite-tantalite quadrilateral diagram for the …
Linnen & Keppler (1997) demonstrated that the different solubilities of columbite and tantalite in Figure 6. bdl = below detection limit. Table 2. Abbreviations are as in Figures 3 and ...