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 …

Coltan 139 and these three columbite-tantalite samples with variable compositions yielded internally consistent LA-ICP-MS U-Pb ages when using each other for calibration and the weighted mean 206 Pb/ 238 U ages are comparable to respective ID-TIMS ages. Composition-dependent U-Pb fractionation seems to be insignificant under …

The German Federal Geological Survey BGR developed a finger method to trace the conflict mineral columbite-tantalite ("coltan") back to mining localities, thus contributing to ...

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 …

Pyrochlore and columbite-tantalite as indicator minerals for specialty metal deposits | Geochemistry: Exploration, Environment, Analysis | GeoScienceWorld. …

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 …

The chemical and textural features of columbite-tantalite and cassiterite in the Leinster albite-spodumene pegmatites are seen in similar rare element pegmatites and rare metal granites elsewhere ...

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 ...

The Mesoproterozoic Kibaran Orogenic System of central Africa developed between 1.4 and 0.95 Ga (from rifting to post collisional stage). It hosts one of the world ??s largest and valuable quartz and pegmatite veins mined for cassiterite, tungsten, columbite-tantalite, monazite, ilmenite, gold and REE since the 19s.

The dependence of columbite–tantalite (Nb2O5-59 wt. %, Ta2O5-18 wt. %) solubility as a function of solution composition, T, and P has also been investigated. Tantalum and Nb concentrations have the highest values in HF solutions at reduced conditions (up to 10−3 to 10−2 m Ta in 1 m HF). In 1 m NaF solutions, the concentrations …

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 …

The Mineral tantalite. Tantalite forms a solid solution series with Columbite known as the Columbite-Tantalite series. Tantalite is the tantalum-rich member, and Columbite is …

Columbite, also called niobite, niobite-tantalite and columbate, is a black mineral group that is an ore of niobium and tantalum. It has a submetallic luster and a high density and is a niobate of iron and manganese, containing tantalate of iron. Columbite and tantalite are collectively known as coltan in Africa.

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 ...

Here we present U–Pb dating results for columbite–tantalite (i.e., coltan) and 40 Ar/ 39 Ar dating results for muscovite and lepidolite from Li–(Be) rare-element pegmatite samples in the Chakabeishan area. These data allow us to define the age of the pegmatites and discuss their origin and tectonic setting, which will also guide further ...

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 …

Here, a nanoscale study of the columbite-tantalite mineral in the Zhaojinggou Nb-Ta deposit in North China Craton elucidated its formation mechanism and the role of fluids in Nb-Ta mineralization.

These compositions are compatible with the mineralizations of apatite, beryl, columbite-tantalite, spodumene, lepidolite, tourmaline, monazite, gahnite and phosphate group minerals observed in the ...

[Show full abstract] of columbite-tantalite [(Fe0.8Mn0.2) (Nb, Ta)2O6]. The analytical data obtained by application of this method to tin concentrate samples were compared with those obtained by ...

Kathy Feick. Coltan is short for columbite-tantalite, a dull metallic ore. When refined, coltan becomes a heat resistant powder, metallic tantalum, which has unique properties for storing electrical charge. Coltan occurs in granitic pegmatites, pockets where the deep seated molten rock crystallized last. Pegmatites contain many rare metals, as ...

Commercial and innovative pyrometallurgical (direct reduction), hydrometallurgical (pure leaching) and pyro-hydrometallurgical (NH 4 HF 2 or alkali …

General Tantalite-(Fe) Information : Chemical Formula: Fe++Ta2O6 : Composition: Molecular Weight = 513.74 gm Tantalum 70.44 % Ta 86.02 % Ta 2 O 5 ... Tantalite - Columbite Series : 08.03.02.01 Tantalite-(Fe) FeTa2O6 Pcan 2/m 2/m 2/m : 08.03.02.02 Columbite-(Fe) ...

Abstract. The Zashikhinsky massif is unique tantalum-niobium deposit of alkaline-granite type hosted by the Late Paleozoic rare-metal zone of magmatism in the East Sayan Mountains. Columbite is the mineral concentrating Nb, Ta and Y-group elements. It forms both large (2–5 mm) and small (smaller 0.5 mm) black grains, in …

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).

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 ...

In addition, the solubilities of columbite and tantalite increase with increasing temperature and Li content of the melt (Fiege et al., 2011). This trend culminates with late crystallization of tantalite and usually involves decreasing temperature, Li and F contents, leading to the deposition of Li- and F-bearing minerals (spodumene and ...

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 …

Columbite-tantalite recovery was the highest at 3:1 BHA–SIBX among the tested collector suites. Using the 3:1 mixed BHA–SIBX collector yielded a more negative columbite-tantalite in comparison to that measured with BHA alone. This indicated the improved adsorption of the BHA–SIBX mixture on the columbite-tantalite surface and …

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 …

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 ...

The discrimination diagram for columbite-tantalite series minerals is based on 153 new electron microprobe analyses from British Columbia combined with over 2500 analyses complied from the literature. Combining the two discrimination diagrams presented here enhances their effectiveness to explore for specialty metal deposits.

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 …

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. More ...