columbite tantalite samples

Frontiers | Columbite-Tantalite Group Mineral U-Pb ...

Jan 14, 2021· Columbite-tantalite group minerals (CGMs) are important sources of critical elements, i.e., Nb and Ta, in highly evolved granites and granitic pegmatites ... First, the samples were coated with a thin conductive carbon film prior to analysis. The precautions suggested by Zhang and Yang (2016) ...

columbite tantalite, columbite tantalite Suppliers and ...

278 columbite tantalite products are offered for sale by suppliers on Alibaba.com, of which mineral separator accounts for 61%, other ore accounts for 4%. A wide variety of columbite tantalite options are available to you, such as none, egypt, and mexico. You can also choose from manufacturing plant, energy & mining columbite tantalite, as well ...

Columbite-Tantalite: Mineral information, data and localities.

Columbite-(Fe), Columbite-(Mn), Stibiocolumbite, Stibiotantalite, Tantalite-(Fe), Tantalite-(Mn) A generic name for minerals of the Columbite/Tantalite families which are difficult to distinguish without sophisticated tests.

Comparison of Some Physicochemical Characterization of ...

Abstract A detailed physicochemical characterization of columbite and tantalite samples from different locations in Nigeria has been undertaken. Parameters such as moisture content, loss of mass on ignition, pH, and the specific gravity of columbite

Estimation of uranium in columbite-tantalite samples: A ...

Oct 01, 1984· The occlusion found was higher for tantalite samples than for columbite samples. The higher retention of uranyl ion by the hydrated tanta- lum pentoxide can be attributed to the greater cation- exchange behaviour of the latter.5 Similar behaviour was also exhibited in the analysis of the natural columbite-tantalite samples (Table 2).

(PDF) GEOCHEMICAL SIGNATURE OF COLUMBITE-TANTALITE …

Inclusions of uraninite were described in samples of compositions from columbite(Fe) to columbite(Mn) in the garimpo Alto do Trigueiro I [3], a Type IV pegmatite. Unfortunately, there are not many data on thorium contents of coltan in the literature. Columbite and Tantalite are dark brown to black-brown.

Simultaneous determination of tantalum, niobium, thorium ...

Tantalum, niobium, thorium and uranium contents of 21 columbite-tantalite minerals from the Akim Oda District of Ghana have been determined using epithermal instrumental neutron activation analysis (ENAA) with a conventional counting system. As thermal neutron filters, boron carbide was encapsulated in the irradiation vials during irradiation. The samples were irradiated at one of the outer ...

niobium tantalum ore

Tantalite Fe Mn Ta2O6 is the most important mineral for tantalum extraction Tantalite has the same mineral structure as columbite Fe Mn Ta Nb 2O6 when there is more tantalum than niobium it is called tantalite and when there is more niobium than tantalum is it called columbite or niobite The high density of Tantalite Fe Mn Ta2O6 is the most ...

Frontiers | Columbite-Tantalite Group Mineral U-Pb ...

May 05, 2019· On the 10 columbite-tantalite samples with homogeneous BSE, a total of 232 EMPA analyses were performed (Table 1, Appendix A), including transects for each sample. The results are plotted in the reference columbite-tantalite diagram . All samples are chemically homogeneous at the different scales tested (μm to mm).

Coltan - Wikipedia

Coltan (short for columbite–tantalites and known industrially as tantalite) is a dull black metallic ore from which the elements niobium and tantalum are extracted. The niobium-dominant mineral in coltan is columbite (after niobium's original American name columbium), and the tantalum-dominant mineral is the tantalite.. Tantalum from coltan is used to manufacture tantalum capacitors which ...

Moess assessment of cation disorder in columbite ...

Mar 01, 1999· The authors have used X-ray diffraction and Moess spectroscopy to investigate the cationic disorder between crystallographic sites of a columbite-tantalite series of pegmatites. The X-ray results show that the pegmatites have different degrees of crystallographic disorder according to the quarries where the samples come from.

(PDF) Compositional, structural and phase relationships in ...

Columbite-(Fe) phase represents 42% of total Nb-tantalates analyzed samples, tantalite-(Fe) 19%, columbite-(Mn) 3% and ixiolite, 36%. Cassiterite, also observed, shows significant Ta2O5 contents ...

ia Geological Survey - Tantalum

Columbite mineral samples from the Morefield mine have been collected and analyzed several times in the 1980s, and contain approximately 25 percent tantalum. Some of the tantalite crystals are reported to be well formed and weigh as much as half a pound …

Late Neoproterozoic over of the cassiterite and ...

U-Pb ages of columbite-tantalite samples vary between ̃975 Ma and ̃930 Ma. The oldest ages (975 + 8.2/-8.3 Ma and 966 + 8.7/-8.6 Ma) overlap with previous reported Rb-Sr ages of the emplacement of the pegmatites (̃965 Ma) and are interpreted to reflect the crystallisation of the Nb-Ta mineralisation. The youngest ages (951 ± 15 Ma to 936 ± ...

Solvent Extraction Tantalite

However tantalite has a much greater specific gravity than columbite more than 8.0 compared to columbites 5.2. REFINING The extraction and refining of tantalum including the separation from niobium in these various tantalum-containing mineral concentrates is generally accomplished by treating the ores with a mixture of hydrofluoric and .

Dismal Swamp Placer Deposit Elmore County Idaho

Columbite-tantalite and quartz in one sample from drill hole 3 and columbite-tantalite, rutile, anatase, and quartz in a sample from drill hole 9 were identified by X-ray analysis in the U. S. Geological Survey laboratory at Denver, Colo. Analyses of the "weakly magnetic" (see p. 387) fractions from 12

Minerals | Free Full-Text | A Process Mineralogy Approach ...

For all samples, columbite and tantalite are closely associated, which is to be expected given they are end members of the same mineral series and occur as solid solution of (Fe,Mn)(Nb,Ta) 2 O 6 within the same particles. Both minerals also show close association with quartz, particularly in the rough tailings from the Mozley table test (33% ...

Effects of columbite/tantalite (COLTAN) mining activities ...

Columbite/Tantalite (COLTAN) mining site, North Central Nigeria. Results: A total of 15 water samples were collected and analyzed in triplicate. The concentrations of five heavy metals (Ni, Mn, Pb, Cd, and Fe) in surface and groundwater samples were measured using atomic absorption spectrophotometer (AA-6800 Shimadzu).

White Paper Spectroscopy (LIBS) - SEC.gov

Columbite-tantalite samples from North America, South America, Africa, and Asia have been examined by LIBS using laboratory-based and field portable instruments. The data was analyzed using chemometric techniques such as partial least squares discriminant analysis (PLSDA) to

U-Pb isotopic dating of columbite-tantalite minerals ...

Tests of in situ U-Pb dating demonstrate that SIMS can easily be used to date columbite-tantalite minerals with errors and precisions overlapping the reference ID-TIMS age. There are, however, significant matrix effects for non-matching Nb-Ta-Fe-Mn compositions of sample and reference material.

Geochemical Finger of Conflict Minerals using LIBS

Samples from the Pack Rat and Beebe locations were combined for PLSDA statistical analyses since they represent a single locality. Experimental Method Spectral data were collected using Applied Spectra's pre-installed Axiom software package. Spectra of Nb, Ta, Mn, Fe, W, and Ti metal standards and columbite-tantalite ore samples were taken ...

Can the provenance of the conflict minerals columbite and ...

To test this idea for columbite-tantalite, three sample sets were analyzed. Partial least squares discriminant analysis (PLSDA) allows correct sample-level geographic discrimination at a success rate exceeding 90%. PMID: 21537914

Finger of conflict minerals: columbite-tantalite ...

Jan 01, 2008· Combined mineralogical-geochemical-geochronological signatures of columbite-tantalite ores are used to trace the origin of ore concentrates. ... Ti/Sn versus Zr+W plot for …

Economic Geology of Niobium and Tantalum

Note that pure niobite and tantalite are unknown in nature; they are theoretical end members of a solid solution series called columbite group minerals (CGM), or short, columbites. Typically, CGM form the recoverable part of a large number of minor Ta Nb oxides (TNO) in the ore (Melcher et al. 2015). Tantalite is defined by an Nb/Ta atomic ...

Occurrence and Composition of Columbite-(Fe) In the ...

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 is characterized by zoned crystals with two stages of …

Columbite Tantalite: a film that fuses Congo's past and ...

Dec 11, 2013· Columbite Tantalite: a film that fuses Congo's past and present struggles. Chiwetel Ejiofor on his short film, which focuses on how the wealth …

(PDF) Zoning in columbite-tantalite crystals from the ...

The difference in chemical composition between the The branches of the replacing columbite-tantalite have cores and the later columbite-tantalite generation may cores of the early columbite-tantalite, and in the ex- be very small, as in the crystal shown in Fig. 10 (see treme cases, most of the cores have been resorbed and Table 1, anal. 7 A-E).

Columbite-Tantalite - Mindat.org

4.4 x 3.8 x 2.3 cm. A rare and very showy columbite-tantalite combination specimen from Pech. The lustrous, tabular, twinned, black columbite-tantalite crystals, 1.2 cm across, are very deftly framed within a cluster of pearlescent muscovite plates. Lustrous, snow-white cleavelandite blades below the columbites are a very nice accent. Ex. Herb ...

Pyrochlore and columbite-tantalite as indicator minerals ...

A columbite-tantalite series discrimination quadrilateral indicates that minerals from carbonatites and related deposits are Nb-rich, with Mn/(Mn+Fe) and Ta/(Ta+Nb) atomic ratios ≤ 0.25 and ≤ ...

Determination of Th and REE in columbite - tantalite ...

[en] A simple method of decomposition and separation of Th and REE in columbite- tantalite is developed for determination by ICP- OES. The sample is decomposed with hydrofluoric and hydrochloric acid in presence of little sulphuric acid to avoid drying on water bath. Th and rare earths are separated as fluoride together with undecomposed sample.

SCANDIUM SUBSTITUTION IN COLUMBITE-GROUP …

of Sc in columbite-tantalite and ixiolite is presented in this paper. EXPERIMENTAL METHODS Samples of columbite-group minerals and ixiolite used in this study were selected to cover a broad compositional range. Given the extremely rare occur rence of Sc-enriched phases and the ubiquitous

Can the provenance of the conflict minerals columbite and ...

May 03, 2011· 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 analyzed varied in shape, size, and color.

Characterization and alternative dissolution of tantalite ...

the niobate-tantalate mineral columbite-tantalite (coltan), which normally contains mixtures of columbite and tantalite with up to 60% Nb content. Columbite and tantalite are variations of the general formula ... of tantalite mineral samples from Mozambique by M. Nete*, ...

Columbite Ore Mineral Deposits in Nigeria with their ...

Columbite is a black, crystalline mineral group, and the main ore of niobium which is also called columbate, niobite, and niobite-tantalite [ (Fe, Mn)Nb2O6], it is also a niobate of iron and manganese. It is found in granite, pegmatites, and placer deposits together with tantalite, but has less density. Columbite has the same mineral structure ...

Estimation of uranium in columbite-tantalite samples: A ...

A method has been developed for obtaining a clear solution of columbite-tantalite samples in nitric acid medium before the fluorimetric estimation of uranium. Ammonium hydrogen fluoride is used to keep tantalum, niobium and titanium dissolved in the acid medium. The excess of fluoride is …

columbite tantalite samples

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