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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]
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.
In 1809, English chemist William Hyde Wollaston compared the oxides derived from both columbium—columbite, with a density 5.918 g/cm 3, and tantalum—tantalite, with a density over 8 g/cm 3, and concluded that the two oxides, despite the significant difference in density, were identical; thus he kept the name tantalum. [14]
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 ...
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 ...
Columbite, also called niobite, niobite-tantalite and columbate, with a general chemical formula of (Fe II,Mn II)Nb 2 O 6, is a black mineral group that is an ore of niobium. It has a submetallic luster, a high density, and is a niobate of iron and manganese. Niobite has many applications in areospace, construction and the medical industry.
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 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 ...