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The mineral group tantalite [(Fe, Mn)Ta 2 O 6] is the primary source of the chemical element tantalum, a corrosion (heat and acid) resistant metal. It is chemically similar to columbite , and the two are often grouped together as a semi-singular mineral called coltan or "columbite-tantalite" in many mineral guides.
Niobium is often found in the minerals pyrochlore and columbite. Its name comes from Greek mythology: Niobe, daughter of Tantalus, the namesake of tantalum. The name reflects the great similarity between the two elements in their physical and chemical properties, which makes them difficult to distinguish. [9]
Tantalite has the same mineral structure as columbite (Fe, Mn) (Ta, Nb) 2 O 6; when there is more tantalum than niobium it is called tantalite and when there is more niobium than tantalum is it called columbite (or niobite). The high density of tantalite and other tantalum containing minerals makes the use of gravitational separation the best ...
Columbite minerals are mainly composed of magnesium, iron, niobium, and tantalum where trace amounts of tin, titanium, and scandium have been observed. [19] The overall composition of columbite influences the crystalline structure resulting in different formation processes. Currently, there are two prominent theories for the formation of columbite.
Coltan (short for columbite–tantalites and known industrially as tantalite) is a dull black metallic ore from which the elements niobium and tantalum are extracted. The niobium-dominant mineral in coltan is columbite (after niobium's original American name columbium), and the tantalum-dominant mineral is tantalite. [1] Tantalum from coltan is ...
The definition of which elements belong to this group differs. The most common definition includes five elements: two of the fifth period (niobium and molybdenum) and three of the sixth period (tantalum, tungsten, and rhenium). They all share some properties, including a melting point above 2000 °C and high hardness at room temperature. They ...
In 1846, Heinrich Rose discovered that tantalite contained an element similar to tantalum and named it niobium. [7] [8] In the 1860s, it was found that niobium and columbium are the same element and are distinct from tantalum. [9] IUPAC officially adopted niobium in 1950 after 100 years of controversy. [10]
The metals form different oxides: vanadium forms vanadium(II) oxide, vanadium(III) oxide, vanadium(IV) oxide and vanadium(V) oxide, niobium forms niobium(II) oxide, niobium(IV) oxide and niobium(V) oxide, but out of tantalum oxides only tantalum(V) oxide is characterized. Metal(V) oxides are generally nonreactive and act like acids rather than ...