New data on rare earth element ( REE) concentrations and distribution patterns of columbite-tantalite minerals from Ta-ore provinces worldwide are presented. …

Columbite-tantalite minerals are potentially useful for dating the emplacement age of economically important rare-element pegmatites. Romer and Wright have shown that columbite-tantalite may accommodate considerable amounts of uranium (circa 500–1000 ppm) and exclude lead almost completely.The U-Pb systematics, …

Concentrations of lead are the highest among all fractions of the Seridó columbite–tantalite (0.5 to 40 ppm), and uranium concentrations range from 250 to 9200 ppm (Table 4). The Trigero 1 pegmatite In the …

Tantalum is a valuable rare element used in electronics manufacturing while columbite is used in forming alloys that are useful in nuclear, aerospace and gas turbine engineering. Rare-metal pegmatites containing economic concentrations of columbite-tantalite ore minerals (coltan) are widespread in the Pan-African (600±150Ma) basement …

The letters refer to analyses 8 A-F. zoning of columbite-tantalite, the concentration and diffusion of Ta and and the growth dynamics of columbite-tantalite crystals are considered to be the most important factors that controlled the chemical oscillations. The concentrations of Fe and Mn were seen to be greater in the pegmatite …

For all the collector suites, the recoveries of columbite-tantalite are sharply increased with increases in initial collector concentrations below 100 mg/L; beyond this …

The dissolution reactions of Nb and Ta from columbite and tantalite in the aqueous solutions of HF, HF-HC1, NH4F-HCI, HF-H2SO4, and NH4F-H2SO4 were kinetically studied in the temperature range of 333 to 353 K. The presence of both H+ and F- in the leachant is necessary for the fast dissolution of columbite and tantalite. The increase …

Hydrothermal origin of columbite-tantalite is observed in greisens, expressed by a higher W concentration and coeval or even younger crystallization compared to the associated cassiterite. Fractionation trend in a crystal scale includes an extreme increase in Ta/(Ta + Nb) ratio with little or no change in Mn/(Mn + Fe), mainly …

When columbite-tantalite was treated with BHA, the concentrations of C1 s and N1 s atomic increased by 2.93 % and 2.07 %, respectively, compared with those of bare columbite-tantalite. Moreover, larger increase by 4.33 % and 6.16 % in the C1 s and N1 s concentration was observed after the Pb 2+ -modified columbite-tantalite surface …

from columbite or tantalite are supposed to behave similarly, although the dissolution of Ta at a low temperature was slightly slower than that of Nb. Therefore, hereafter the ... effect of HF concentration on the dissolution of Nb from columbite at 353 K by changing the concentration of HF from 0.1 to 10 mol dm -3. ...

¶Three texturally and compositionally distinct pairs of ferrotapiolite + tantalite, all spatially related to a cleavelandite unit, were distinguished in the zoned beryl-columbite pegmatite at Moravany nad Váhom, Považsky Inovec Mts., Slovakia. (1) Inclusions of ferrotapiolite I (∼200 μm) in zoned ferrotantalite I exhibit crosscutting tielines of coexisting compositions …

Columbite–tantalite is common as elongate-prismatic subhedral crystals associated with muscovite and microcline as well as within albitite. ... However, it is highest in the core (928 ppm) and lowest along fractures as well as in zone 6 (603 ppm). Concentrations of Ta and to a lesser extend W are elevated in close proximity to LB-A …

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).

The zoning of the columbite-tantalite is related to the complex crystallization history of the pegmatite dikes. The main factors controlling oscillatory zoning are considered to be the growth dynamics of the crystals, the concentration and diffusion of the main elements, and the successive flows of the magma in an intrusion channel.

1 (1 and 2 m) the highest Ta2O5concentrations (10− m) were detected in HF solutions. In KF, NaF, and LiF solutions, the Ta2O5 solubility is also high (10−310−2m). The …

Columbite–tantalite mineralization is therefore both ... 97 fractionation and typically coupled with increasing concentrations of incompatible elements 98 (Černý and Burt, 1984). However ...

The effect of fluorine on the solubilities of Mn-columbite (MnNb 2 O 6), Mn-tantalite (MnTa 2 O 6), zircon (ZrSiO 4) and hafnon (HfSiO 4) were determined in highly fluxed, water-saturated haplogranitic melts at 800 to 1000 °C and 2 kbar. The melt composition corresponds to the intersection of the granite minimum with the …

From core to rim, CGM crystals vary from columbite-(Mn) to tantalite-(Fe), recording magmatic fractionation. The Gaoling quartz vein contains homogenous CGM crystals that yield low Ta concentrations (Figs. 2 and 3 c), likely reflecting the action of a hydrothermal fluid, as Nb has a low solubility and is fluid-mobile (Linnen et al., 2014).

Because the tantalite-columbite deposits at Kenticha have higher tantalum concentrations than niobium (Ta:Nb is up to 3:1), we will refer to this ore as tantalite. The tantalite production is relatively small, but the reserves are large and estimated at 20,000 tonne of T 2 O 5 and Nb 2 O 5.

The elemental mapping results show the segregation of particles in two distinct regions where Ta, Nb, Fe, and Mn are present together, which reflects the presence of columbite and tantalite. In contrast, the second region shows the concentration of Sn in the form of the cassiterite phase.

The principal objective of this study is to be able to extract niobium oxide from columbite-tantalite concentrate of Thayet Kon Area in Nay Phi Taw. It is recovered from columbite-tantalite concentrate which contains 19.29 % Nb2O5.The recovery of niobium oxide from columbite-tantalite concentrate can be divided into three main sections, namely, …

Tantalite concentration (Küster et al., 2009) Tabba Tabba: Pilabara Minerals: Australia: Pegmatite: 0.318: 0.095 (BRGM, 2012) Abu Dabbab: ... In this case, the first stage is designed to leach out iron, manganese, tin, titanium and silicon and produce columbite and tantalite concentrates which are then subjected to Ta and Nb leaching …

Tantalite is the tantalum-rich member, and Columbite is the niobium-rich member. Tantalite is named after its tantalum content, and, together with Columbite, are the most important minerals containing the rare element tantalum. The name Tantalite has been discredited by the IMA, with the more specific designations of Tantalite- (Fe) (also …

Columbite-tantalite, cassiterite and other Ta-Nb-Sn oxides in sediments from catchments that contain known LCT pegmatite occurrences show the same textural and chemical characteristics as these ...

concentrations of common lead are between 0.02 to 0.7 . ppm (Table 4). ... These compositions are compatible with the mineralizations of apatite, beryl, columbite-tantalite, spodumene, lepidolite ...

Effect of Acid Concentration on Digestion Columbite-Tantalite concentrate from Thayetkon Area, Pyinmana Township, contained 19.29 % Nb2O5. Heavy concentrate contained 5 % columbite- tantalite mineral. Columbite-tantalite mineral was separated from other mineral by Frantz Isodymamie Magnetic separator. After separation,

In columbite-tantalite ores, Ta and Nb often occur in association with thorium, uranium, titanium, and rare-earth elements (REEs) (Dampare et al., 2005). Thus, these ores can be regarded as ...

Figure 4c, d show a compositional transverse in a regular oscillatory zoned crystal, where Nb and Ta concentrations mirror each other. ... (Ti source) and aplite–pegmatites (Sn source). Columbite–tantalite and ilmenite correlation is relatively poor because columbite–tantalite is a scarce mineral in the primary source. However, …

The U and Pb concentrations and the U-Pb isotopic ratios of columbite-tantalite were analysed at GFZ German Research Centre for Geosciences (Potsdam), using the analytical procedure described in Romer and Smeds (1996).Samples were crushed and picked under the binocular microscope.

The generalized formula of columbite–tantalite of the deposit is (Mn0.61Fe0.34)0.95(Nb1.37Ta0.58Ti0.04W0.03Sn0.01)2.03O6. Columbite–tantalite …

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 and Nb remain a ...

CAUSTIC FUSION OF COLUMBITE-TANTALITE CONCENTRATES WITH SUBSEQUENT SEPARATION OF NIOBIUM AND TANTALUM. United States: N. p., 1956. Web. doi:10.2172/4319208. Copy to clipboard ... In these high concentrations where the activity coefficient is not constant with concentration, the heat of transport is defined based on …