Extractive metallurgy of columbite-tantalite ore: A detailed review
Commercial and innovative pyrometallurgical (direct reduction), hydrometallurgical (pure leaching) and pyro-hydrometallurgical (NH4HF2 or alkali fusion followed by leaching) …
(PDF) A niobian rutile
lumbite-tantalite and tapiolite as documented, for example, by Foord (1976) and Clark & Fejer (1978). The columbites show only limited. variation in Ti. in contrast to the much more.
Compositional and Structural Systematics of the Columbite Group
lumbite-tantalite, substitution of Ta for Nb results in a. slight expansion of both a and b. Consequently, the val-ues of a and b used in the regression analysis were mod-ified to reflect the ...
Alternative beneficiation of tantalite and removal of …
als [1–2]. Columbo–tantalite, which is the major source for these rare metals, occurs mainly in pegmatites associated with granites. The common name for the mineral is tantalite when tantalum predominates over columbium (Nb) and co-lumbite/niobite when columbium is dominant [1,3]. The world resources available today may not meet future de-
(PDF) Two generations of zoned crystals of columbite group …
and have a sharp co ntact betwee n a tantalite-(Mn) core and a co lumbite-(Mn) rim. T he rim ha s a h igher Ti content and lower Sn content and T a/(Ta+Nb) ratio than the co re and a gap occurs ...
Geochemical Exploration Guide for Tantalum Pegmatites
lumbite-tantalite group such as microlite, stibiotan- talite, and wodginite are the most important Ta ore minerals (Parker and Fleischer, 1968; Hatcher and
Experimental studies of Ta2O5 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 …
Fingerprinting of conflict minerals: columbite-tantalite ("coltan") ores
lumbite-tantalite from Africa mostly yields . reliable, concordant to slightly discordant . ages (Fig. 8). In the concentrates analyzed . so far from Africa, four age populations are .
Compositional andstructural systematics …
lumbite-tantalite, substitution ofTaforNbresults ina slightexpansion ofbothaandb.Consequently, theval-uesofaandbusedintheregression analysis weremod-ifiedtoreflecttheeffectoftheNb "" Tasubstitution shown bysynthetic columbite-tantalite, aNb=aH-0.007(5)Ta/(Ta +Nb) (1) bNb=bH- 0.0024(4)Ta/(Ta +Nb) (2) …
U-Pb isotopic dating of columbite-tantalite minerals: Development of
We characterize columbite-tantalite minerals covering a significant range of compositional variation known for columbite-tantalite minerals and having ages between 198.3 ± 1.4 Ma to 2053.2 ± 1.3 Ma. The various minerals are chemically homogenous, and several among them may serve as reference materials for in situ U-Pb dating. ...
(PDF) Geochemistry of granitic aplite-pegmatite dykes and sills …
Some sec- lumbite-tantalite were distinguished (Neiva et al., 2015). Some sec- ondary muscovite replaces plagioclase. Subhedral chlorite occurs. In ondary muscovite replaces plagioclase. more evolved beryl-columbite aplite-pegmatites, crystals of beryl are Metasomatic rocks resembling episyenite occur in the area. subhedral, white, green, blue ...
Mineralogical and physical studies of low-grade
The ICP-OES analysis of the ore-samples revealed the presence of Ta, Nb, Mn, Fe, Sn, Mg, Ti, U, Th, O among others. These elements are mainly dominated by Fe and Nb followed …
Tantalum | Geoscience Australia
Tantalum shares many of its properties with niobium (Nb), with which it is commonly found. This close association has led to use of the 'coltan' terminology, short for columbite-tantalites, reflecting the niobium-dominant (columbite) 2 and tantalum-dominant (tantalite) end-members of this oxide mineral series (see text box below). Tantalite is ...
(PDF) Geochemistry of granitic aplite-pegmatite veins and sills …
correspond to the beryl-co lumbite-pho sphate subtype of. beryl ... This study presents the first characterisation of columbite-tantalite minerals from the Portuguese Gaia-Maçainhas Sn-Ti-Ta ...
[PDF] Study on Extraction of Niobium Oxide from Columbite–Tantalite
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, …
Compositional andstructural systematics ofthecolumbitegroup
lumbite-tantalite, substitution ofTaforNbresults ina slightexpansion ofbothaandb.Consequently, theval-uesofaandbusedintheregression analysis weremod-ifiedtoreflecttheeffectoftheNb "" Tasubstitution shown bysynthetic columbite-tantalite, aNb=aH-0.007(5)Ta/(Ta +Nb) (1) bNb=bH- 0.0024(4)Ta/(Ta +Nb) (2) …
Compositional and structural systematics of the columbite group
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Extractive metallurgy of columbite-tantalite ore: A detailed review
Size reduction with gravity and magnetic separation followed by dissolution of raw columbite-tantalite are common in industrial practices for increasing the concentration …
A geological, geochemical and textural study of an LCT pegmatite
A geological, geochemical and textural study of an LCT pegmatite: implications for the magmatic versus metasomatic origin of Nb-Ta mineralization in the Moose II pegmatite, Northwest Territories, Canada
Pegmatitic Nb-Ta oxide minerals in alluvial placers from Limbach
The most fractionated granitic pegmatites of the BGM contain accessory beryl and co- lumbite-tantalite group minerals (Uher et al. 1994) and they could be classified as belonging to the LCT family, beryl-columbite subgroup of the rare-element class of granitic pegmatites (sensu Černý and Ercit 2005).
Extractive metallurgy of columbite-tantalite ore: A detailed review
Size reduction with gravity and magnetic separation followed by dissolution of raw columbite-tantalite are common in industrial practices for increasing the concentration of Ta and Nb in ore ( Nete et al. 2014a, ( Nete et al., 2014b ); Nete and Purcell, 2016, …
Original paper Pegmatitic Nb-Ta oxide minerals in
Journal of Geosciences, 52 (2007), 133–141 DOI: 10.3190/jgeosci.007 Original paper Pegmatitic Nb-Ta oxide minerals in alluvial placers from Limbach,
(PDF) Mineralogical factors affecting the separation
The mineral composition of gravity separation products 3.3.2. The grain size of columbite-tantalite in gravity separation products Fig. 5 shows that the -38 μm particles mainly enter the tailings ...
Concentrations of Y and REE in columbite-tantalite from ore
The German Federal Geological Survey BGR developed a fingerprinting method to trace the conflict mineral columbite-tantalite ("coltan") back to mining localities, thus contributing to ...
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 …
Radionuclides and Radiation Exposure in Tantalite Mining
Tantalite and columbite ores have been reported as containing associated primordial radionuclides, such as uranium and thorium. Ethiopia is one of the world suppliers of …
TIMS data for columbite-tantalite from Ghana and Rwanda
The results of TIMS and LA ICP-MS analyses in three different la- boratories are consistent and prove that co- lumbite-tantalite from Africa mostly yields reliable, concordant to slightly ...
Mineralogy and chemistry of columbite-tantalite from Bugarura …
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 …
(PDF) Secondary Recovery of Columbite from Tailing Dump in …
Columbite contains oxide of niobium (Nb2O5) and oxide of tantalum (Ta2O5) in different proportions. When the niobium oxide is much more than the tantalum oxide, the mineral is called columbite {(Fe, Mn)Nb2O6}, while it is called tantalite {(Fe, Mn)Ta2O6}, when the tantalum oxide content is much higher.
Experimental studies of Ta 2 O 5 and columbite-tantalite solubility …
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 …