Request PDF | Micas, feldspars and columbite–tantalite minerals from the zoned granitic lepidolite-subtype pegmatite at Namivo, Alto Ligonha, Mozambique | The Namivo granitic lepidolite-subtype ...
Wolfram is a typomorfic impurity in columbite–tantalite of the Kester Deposit, WO 3 is 1.77%, on average (apfu is 0.03). In tantalite- (Mn), WO 3 is 0.70%, while in …
Columbite–tantalite (Coltan) is the most important niobium (Nb)- and tantalum (Ta)-bearing economic mineral, commonly occurring in rare metal granite and pegmatite, alkaline granite, syenite and ...
The major problem is to distinguish between primary magmatic columbite–tantalite and secondary hydrothermal–metasomatic ores (Van Lichtervelde et al., 2007). The Kolmozero pegmatite field in the Kola Peninsula seems a perfect study area to tackle this problem. ... (Chevychelov,, 1998, Linnen and Cuney, 2005). …
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 …
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 …
In columbite, the local environment of Nb consists in a strongly distorted octahedron (Table 4), which is consistent with crystal structure data (Wenger et al., 1991;Tarantino, 2005) (Table 4 ...
New data on rare earth element (REE) concentrations and distribution patterns of columbite-tantalite minerals from Ta-ore provinces worldwide are presented. The REE geochemistry was studied by laser ablation inductively coupled plasma mass spectrometry (LA-ICP-MS). Five major types of chondrite-normalized REE distribution patterns are …
Columbite–tantalite mineralization is therefore both ... 2005). Therefore, mica 90 geochemistry in lithium pegmatites has been studied widely (e.g. Jolliff et al., 1987; Roda-
Columbite–tantalite (Coltan) is the most important niobium (Nb)- and tantalum (Ta)-bearing economic mineral, commonly occurring in rare metal granite and …
The recent work related to columbite-tantalite chemistry from the Kibara Belt was mainly focused on building an African-scale database to identify regional and local differences in Ta-Nb deposits ... (2005), pp. 2005-2026, 10.2113/gscanmin.43.6.2005. View in Scopus Google Scholar. Černý et al., 1998.
Received: 02 Jun 2005. Accepted: 06 Jan 2006. First Online: 09 Mar 2017. Online ISSN: 1499-1276. Print ISSN: 0008-4476 ... Homogeneous bodies of pegmatite are barren, whereas the heterogeneous ones have been mined for columbite–tantalite, beryl, gem tourmaline (elbaite), and kaolin. Electron-microprobe analyses reveal that …
Wolfram is a typomorfic impurity in columbite–tantalite of the Kester Deposit, WO 3 is 1.77%, on average (apfu is 0.03). In tantalite- (Mn), WO 3 is 0.70%, while in columbite- (Fe), WO 3 is 2.67%, reaching 7.12%. The wolfram impurity is more typical for columbite, whereas the tin impurity is typomorphic for tantalite: the average content of ...
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 ...
Minerals from the columbite-tantalite series are the most common Nb-tantalates found in granitic pegmatites, mainly occurring as solid solutions. ... (Dissertação de Mestrado em Geologia). and Romeiro and Pedrosa-Soares (2005) ROMEIRO, J.C.P., PEDROSA-SOARES, A.C. Controle do minério de espodumênio em pegmatitos da Mina da …
The recent work related to columbite-tantalite chemistry from the Kibara Belt was mainly focused on building an African-scale database to identify regional and local …
The increased demand of metals such as tantalum (Ta) and niobium (Nb) reflect the on-going development in modern science, engineering and technology. The …
Columbite-(Fe) in tabular crystal from the Nine Mile pluton near Wausau in Marathon County, Wisconsin. Scanning electron microscope image. (Photo by Al Falster.) Columbite-tantalite refers to a group of minerals having varying amounts of iron, manganese, niobium, and tantalum. They are found as platey black grains in complex granitic pegmatites. …
An increase in columbite-tantalite recovery was observed in the presence of BHA–SIBX mixtures relative to those with BHA alone. The 3:1 BHA–SIBX mixture exhibited the highest columbite-tantalite recovery. ... 2010, Chen et al., 2005, Wang et al., 2017). Among these collectors, BHA has shown potential as a columbite-tantalite …
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 …
Combined mineralogical-geochemical-geochronological signatures of columbite-tantalite ores are used to trace the origin of ore concentrates. Location of important ore provinces with Nb-Ta mining ...
Dissolution textures resulting from the corrosion of columbite and tantalite rims, in particular, are common. The Mn/(Mn + Fe) ratio varies between 0.33 and 0.97 and the …
Compositionally, columbite-tantalite of the Li-albite granites is constrained between MnNb 2 O 6 and MnTa 2 O 6 (the Ta/(Nb+Ta) atom. ratio ranges between 0.10 and 0.80). This low to high ratio and the association of columbite-tantalite with topaz, fluorite and lithian micas (in the series zinnwaldite-white mica) indicate a higher solubility ...
Rajak et al. et al., 2006). Researchers have studied columbite-tantalite flotation using collectors such as benzyl arsenic acid, sodium oleate, sodium alkyl sulphonate, benzohydroxamic acid ...
Compositionally, columbite-tantalite of the Li-albite granites is constrained between MnNb 2 O 6 and MnTa 2 O 6 (the Ta/(Nb+Ta) atom. ratio ranges between 0.10 and 0.80). This …
In this study, the columbite-tantalite group minerals (CGMs) from a typical Li-rich pegmatite dike were analyzed for major element contents using EMPA (electron microprobe analyzer), for trace …
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 columbium prior to its renaming. Columbite is the most important mineral containing the rare element niobium and is its main ore. The name Columbite has been discredited by the IMA, with …
Columbite-tantalite (CGM) ore, which represents a major source of Nb and Ta, can be dated using the U–Pb system (Romer and Lehmann, 1995, Romer and Smeds, 1994, Romer and Wright, 1992, Smith et al., 2004). ... 2005). Magmatism in South China occurred primarily during the Caledonian, Indosinian and Yanshanian orogenies, …
Compositional variation of columbite–tantalite obtained from aplite–pegmatites sills and veins of the region, are similar to columbite–tantalite from Li-rich and Be-rich aplite–pegmatite sills and veins and pegmatite veins that intruded the Pega's granite (Ramos et al. 2006; Neiva et al. 2012).
This study reveals that columbite-tantalite in the pegmatites has an extremely wide range of composition from primitive ferrocolumbite to evolved, almost end-member manganotantalite. Evidence is provided that melt evolution resulted in increased fluorine activity (as seen in microlite compositions) and that in situ fractionation of magma within ...
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 …
Columbite–tantalite mineralization is therefore both magmatic and hydrothermal. Albite associated with stage-III muscovite and CGM was likely precipitated from a hydrothermal fluid when pH changed due to hydrolysis of primary minerals. ... 2005) as empirical data show that mean concentrations of >65–70 ppm Ta and >500 ppm Cs …
New data on rare earth element (REE) concentrations and distribution patterns of columbite-tantalite minerals from Ta-ore provinces worldwide are presented. The …
