4 3 and columbite–tantalite
Columbite–tantalite mineralization is therefore both ... 97 fractionation and typically coupled with increasing concentrations of incompatible elements 98 (Černý and Burt, 1984). However ...
Finger of conflict minerals: columbite …
Concentrations of Y and REE in columbite-tantalite from ore concentrates. (A) Marropino (Mozambique), (B) Buranga (Rwanda), (C) Kokobin (Ghana) and (D) Bikita (Zimbabwe).
Tantalite: The mineral columbite-tantalite information and …
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 …
Mineralogical and physical studies of low-grade
This means that the main mineral with commercial value in the ore-samples is cassiterite associated with particles of columbite-(Fe). The highest concentration of tin oxide 53.44 wt% associated with tantalite-(Mn) (4.59 wt% Ta 2 O 5 and 1.42 wt% MnO) was observed in the concentrate R-KMY Con.
Extractive metallurgy of columbite-tantalite ore: A …
Abstract. 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 …
U-Pb isotopic dating of columbite-tantalite minerals: Development of
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.
Dissolution of columbite and tantalite in acidic fluoride …
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. ...
Columbite–Tantalite of the Kester Deposit (Eastern …
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 …
A review on extractive metallurgy of tantalum and niobium
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 …
Experimental studies of Ta 2 O 5 and columbite-tantalite …
The dependence of columbite-tantalite (Nb 2 O 5 -59 wt. %, Ta 2 O 5 -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).
Extractive metallurgy of columbite-tantalite ore: A detailed …
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 ...
Radionuclides and Radiation Exposure in Tantalite Mining …
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.
(PDF) Columbite-tantalite and cassiterite as indicator …
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 ...
U-Pb isotopic dating of columbite-tantalite minerals: Development of
Most disconcordant dating analyses show extremely high common Pb concentrations (up to ... Columbite-tantalite LA-ICP-MS U-Pb dating is a fast and useful method to determine the age of rare-metal ...
Zoning in columbite-tantalite crystals from the granitic pegmatites …
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 …
Quantitative evaluation of metamictisation of …
Members of the columbite–tantalite solid-solution series are a major mineral resource of Nb and Ta, and have the formula, AB 2 O 6, ... The major–minor-element concentrations and U–Pb isotopic ratios …
Tantalum, niobium, thorium and uranium concentrations (in …
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 ...
Rare earth element geochemistry of columbite-group
New data on rare earth element ( REE) concentrations and distribution patterns of columbite-tantalite minerals from Ta-ore provinces worldwide are presented. …
CAUSTIC FUSION OF COLUMBITE-TANTALITE …
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 …
In situ U–Pb isotopic dating of columbite–tantalite …
U and Th concentrations of sample Coltan139 are the highest among our studied samples, ranging from 1856 to 2364 ppm, and from 69.1 to 99.1 ppm, …
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.
LA-ICP-MS U–Pb zircon, columbite-tantalite and
The Chinese Altai is renowned for its rich rare-element resources. Nine representative rare-element (REL) pegmatites were dated using LA-ICP-MS and 40 Ar– 39 Ar methods. The columbite grains yield a weighted mean 206 Pb/ 238 U age of 239.6±3.8 Ma for the Dakalasu (Be-Nb-Ta) pegmatite and concordia U–Pb ages of 258.1±3.1 Ma and …
A mixed collector system for columbite-tantalite …
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 …
Effects of fluorine on the solubilities of Nb, Ta, Zr and Hf …
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 …
Study on Extraction of Niobium Oxide from …
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,
Columbotantalite (cbt/coltan) | SpringerLink
The generic term columbotantalite, cbt, comprises the different compositional varieties of columbite and tantalite, classically treated (e.g. Ramdohr 1980) as an isomorphic, continuous solid solution series between the members (Fe, Mn)Nb 2 O 6 (niobite, now columbite, cb) and (Fe, Mn)Ta 2 O 6 (tantalite, tan), a series also known …
Processing of columbite-tantalite ores and concentrates …
Columbite and tantalite, either naturally occurring or synthetically produced as concentrates from tinslag, are digested with hydrofluoric acid at elevated …
Dissolution of columbite and tantalite in acidic fluoride media
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 …
Zoning in columbite-tantalite crystals from the granitic pegmatites …
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.
Study on Extraction of Niobium Oxide from Columbite-Tantalite Concentrate
Htwe and Lwin (2008) studied on the extraction of niobium oxide from columbite-tantalite concentrate. With the original Columbitetantalite concentrate containing 19.29% Nb 2 O 5, 9.93% Ta 2 O 5 ...
