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.
After columbite-tantalite is activated with 60 mg/L Pb(NO 3) 2, the zeta potential of columbite-tantalite for the entire pH range is positively shifted, and the IEP increases from 3.7 to 5.8. The significant positive shift of zeta potential is attributed to the specific adsorption of positively charged Pb species onto the columbite-tantalite ...
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 .
Acid digestion of concentrated columbite-tantalite in a mixture of HF and other mineral acids are common in industrial scale production of Ta and Nb. Majima et al. (1988) studied the dissolution of columbite and tantalite in acidic fluoride media using different aqueous solutions of HF, HF-HCl, NH 4 F-HCl, HF-H 2 SO 4, and NH 4 F-H 2 …
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 carbonatite. Its high U but low common Pb contents make it an ideal mineral for U–Pb isotopic dating of Nb–Ta mineralization.
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 …
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.
Columbite-tantalite minerals are potentially useful for dating the emplacement age of economically important rare-element pegmatites. Romer and …
Episodic Nb–Ta mineralisation in South China: Constraints from in situ LA–ICP–MS columbite-tantalite U–Pb dating. Author links open overlay panel Xu-Dong Che a, Ru-Cheng Wang a, Fu-Yuan Wu b, Ze-Ying Zhu a, Wen-Lan Zhang a, Huan Hu a, Lei Xie a, Jian-Jun Lu a, Di Zhang b. Show more. Add to Mendeley.
Columbite crystals from niobium-yttrium-fluorine (NYF) pegmatites lacking zircon or containing metamict cyrtolite were analyzed for major and minor elements (Electron Microprobe (EMP)), trace elements (Laser Ablation-Inductively Coupled Plasma-Mass Spectrometry (LA-ICP-MS)), and U-Pb geochronology (Laser AblationMulti …
Columbite-tantalite-bearing granitoids of the Eastern Desert province of Egypt can be categorized into: (i) metaluminous alkali granites; (ii) peraluminous Li-albite granites; and (iii) metasomatized biotite and/or muscovite granite (i.e. apogranites). Columbite of the alkali granite is of FeNb 2 O 6 composition and associated with annite. The ...
Tantalite is usually observed in Li-poor pegmatites but occasionally it also occurs in Li-rich pegmatites, as e.g. the present ones. The colour of tantalite is generally black but when the Ta content is high as in the Ricksburg occurrence, the colour is red-brown and in appearance this tantal-ite is identical to manganotantalite. Tantalite has been
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 ...
The name Tantalite has been discredited by the IMA, with the more specific designations of Tantalite-(Fe) (also known as Ferrotantalite), and Tantalite-(Mn) (also known as Manganotantalite) being used for this mineral's IMA-accepted nomenclature.Ferrotantalite is always dark and opaque; Manganotantalite is usually reddish-brown and may exhibit …
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 ...
Columbite-tantalite group minerals (CGMs) from three pegmatite samples give the U-Pb ages of 1844.2 ± 8.1 Ma, 1831.2 ± 12.2 Ma and 1848.0 ± 18.7 Ma, respectively. The U-Pb ages of CGMs show that the Shaliuquan pegmatite is a rare Paleoproterozoic pegmatite rare-metal deposit in the Tibetan Plateau.
TIMS data for columbite-tantalite from Ghana and Rwanda; BGR laboratory (upper diagrams), and LA ICP-MS data for columbite-tantalite from Namibia and the DRC (lower diagrams). Figures - uploaded ...
The pegmatites intrude the Seridó Group and show no signs of deformation. They were emplaced along a major NE-trending shear zone during a post-Brasiliano extensional event (550–500 Ma). Homogeneous bodies of pegmatite are barren, whereas the heterogeneous ones have been mined for columbite–tantalite, beryl, gem …
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.
Columbite–tantalite forms polymineral individuals with concentric growth zonality (from the core to the rim): columbite-(Fe) → columbite-(Mn) → tantalite-(Mn) + uranmicrolite → columbite-(Mn). In columbite of the Kester Deposit, WO3 is a typomorphic impurity, which is 2.67%, on average (formula coefficent, apfu is 0.04); the maximum ...
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 ... lumbite/niobite when ...
Columbite-tantalite is the only primary niobium tantalum oxide mineral; its composition is dominated by Nb, Ta, Fe, and Mn. Ti is present in minor quantities (≤0.1 atoms per formula unit). In ...
U-Pb columbite-tantalite chronology of rare-element pegmatites using TIMS and laser ablation-multi collector-ICP-MS. Contributions to Mineralogy and Petrology 147, 549 …
Dating columbite-tantalite from mineralogically and geochemically similar peg- matites allows to compare corresponding stages of crustal development on a regional scale as similar types of rare-mineral bearing pegmatites are the result of comparable processes, although not necessarily in corresponding tectonomag- matic environments.
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, …
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 …
lumbite-tantalite group such as microlite, stibiotan- talite, and wodginite are the most important Ta ore minerals (Parker and Fleischer, 1968; Hatcher and
The name Columbite has been discredited by the IMA, with the more specific designations of Columbite-(Fe) (also known as Ferrocolumbite), and Columbite-(Mn) (also known as Manganocolumbite) being used for this mineral's IMA-accepted nomenclature.Most Columbite specimens are of the Ferrocolumbite; Manganocolumbite is far less common. …
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 ...
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 …