Introduction. Niobium and tantalum are critical metals that have been used increasingly in advanced technologies (e.g. information technology, energy, aerospace, national defence and military, Linnen et …

The columbite-tantalite group minerals [(Fe,Mn)(Nb,Ta) 2 O 6 ] are critical ore minerals of niobium and tantalum in rare metal pegmatite deposit.

LCT (lithium–cesium–tantalum) pegmatites from the Kaustinen and Kolmozero regions contain columbite–tantalite mineralization, which has been presented in this study. Crystal structure, Raman microscopy, and optical property analyses of these minerals were performed. As a result of the structural studies and micro-area analyses, it was …

The Mineral tantalite. Tantalite forms a solid solution series with Columbite known as the Columbite-Tantalite series. Tantalite is the tantalum-rich member, and Columbite is …

The first applications of LA-ICP-MS for dating columbite-tantalite used non-matrix matched minerals like zircon or monazite (i.e., Smith et al., 2004; Melleton et al., 2012). During the last years ...

Tantalite is the principal ore of the metal tantalum. This article was most recently revised and updated by Amy Tikkanen. Columbite, hard, black (often iridescent), heavy oxide mineral of iron, manganese, and niobium, (Fe, Mn)Nb2O6. Tantalum atoms replace niobium atoms in the crystal structure to form the mineral tantalite, which is similar but ...

The grain size of columbite-tantalite in the concentrate is the coarsest, followed by that in the middlings, and the finest in the tailings, which are mainly distributed in the range of -150+38 ...

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 (CGM) ore, which represents a major source of Nb and Ta, ... 2012, Yang et al., 2014, Zhang et al., 2017). The Gaoling W–Nb–Ta deposit is hosted in two-mica granite that yields a zircon LA–ICP–MS U–Pb age of 220 ± 2 Ma (Zhang et al., 2015). Sample GL was collected from a CGM- and scheelite-bearing quartz vein.

be exhausted tin–rare-metal ores. The Kester Deposit is an ore-bearing greisen. deposit that is located at a hanging endocontact of a. harpolith of rare-metal granites at its bend, and sub-. m e ...

Columbite forms a solid solution series with Tantalite known as the Columbite-Tantalite series. Columbite is the niobium-rich member, and Tantalite is the tantalum-rich …

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 …

These pegmatites are mostly hosted by gabbros (Lindroos et al., 1996) and their distribution is shown in Figure 5 of Eilu et al. (2012). Feldspar quarrying in Kimito followed previous quartz extraction for glass and iron works, presumably since about 1686. In 1737, the occurrence of tantalite was described from the Skogsböle pegmatite.

What are conflict minerals? "Conflict minerals," as defined by the US legislation, currently include the metals tantalum, tin, tungsten and gold, which are the extracts of the minerals cassiterite, columbite-tantalite and wolframite, respectively. Downstream companies often refer to the extracts of these minerals as 3TG.

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 (Melcher et al., 2015). In the research they correctly noticed a wide compositional range of Ta-Nb oxides with predominance of CGM, however no ...

CGM varies appreciably in composition in the columbite–tantalite quadrilateral diagram (Fig. 10 a), with first subparallel to the Mn# = Mn/(Mn + Fe) axis and then to the Ta# axis, which is commonly encountered in complex lepidolite subtype of REL (rare-element)-Li pegmatite group worldwide (Cerny et al., 2012, Wise et al., 2012).

Columbite-tantalite U-Pb dating by isotope dilution thermal ionization mass-spectrometry has been reported for several ... Petrographic details are given in Zhang et al. (2004) and Wang et al. (2012). A-1 columbite-tantalite was sampled from the same pegmatite field as sample 713–79 of Che et al. (2015) that yielded an age of 218 ± 2 ...

Our study characterizes in detail the mineralogical, textural, and compositional features of Ta-Nb oxides from the Bugarura – Kuluti deposit located in the …

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). In 1 m NaF solutions, the concentrations …

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.

Columbite group minerals (CGM, columbite–tantalite, [Mn,Fe][Ta,Nb] 2 O 6,), which are the main economic host for Ta in rare-element pegmatites (Linnen et al., 2012), are also potentially useful targets for studying melt evolution. These oxides are usually strongly zoned, exhibiting a wide range of chemical compositions.

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, 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 ...

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 ...

The corrosive and volatile nature of chlorinating agents used in the chlorination process of columbite-tantalite complicates the process (Ma, 2012, Poupard …

In addition, the solubilities of columbite and tantalite increase with increasing temperature and Li content of the melt (Fiege et al., 2011). This trend culminates with late crystallization of tantalite and usually involves decreasing temperature, Li and F contents, leading to the deposition of Li- and F-bearing minerals (spodumene and ...

The industrial processes for recovery of niobium and tantalum oxides depend on hydrofluoric acid, which is a highly toxic and corrosive reagent with significant environmental consequences. This study presents a fluoride-free, rapid, and energy-efficient process for niobium and tantalum extraction from columbite using microwave-assisted …

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 ...

The leaching of columbite-tantalite in the HF-H 2 SO 4 media is complex as H 2 SO 4 most probably reacts with Fe and Mn whereas HF brings Ta and Nb in solution by forming niobic and tantalic acids.

Abstract. Columbite–tantalite (Coltan) is the most important niobium (Nb)- and tantalum (Ta)-bearing economic mineral, commonly occurring in rare metal granite …