NB

Niobium, symbol Nb and atomic number 41, is a soft, silver-gray transition metal known for a high melting point, excellent corrosion resistance, and strong ductility. It forms stable oxides and is widely used in steel alloys and superconducting technologies.

Discovered in 1801 by Charles Hatchett, niobium was originally named columbium. In 1949 IUPAC adopted the name niobium as the official term to avoid confusion with tantalum, and the symbol Nb reflects that name; the older name remains in some contexts.

Niobium occurs together with tantalum in oxide minerals such as columbite and tantalite (the coltan group) and in pyrochlore. Major producers include Brazil, Canada, Australia, and the Democratic Republic of Congo. Nb is refined from niobium pentoxide (Nb2O5) and then converted to metal for industrial use.

In addition to its metallic properties, niobium's alloys are prized for strength and superconductivity. Pure niobium has a melting point of 2477°C and a density of 8.57 g/cm3. It is highly resistant to corrosion and becomes superconductive below about 9.2 kelvin. It is foundational in superconducting materials such as NbTi and Nb3Sn magnets.

Key applications include strengthening steel to improve creep resistance and toughness at high temperatures, and superconducting magnets for MRI machines and particle accelerators. Nb is also used in specialized equipment for chemical processing and in decorative jewelry due to its ability to take vivid anodized colors.

Safety and environmental: Niobium compounds are considered relatively non-toxic, but mining and refining can pose environmental and occupational hazards, especially in dust form. Proper handling and waste management are standard in Nb mining and processing.