40 Fun Facts About Niobium

Which country supplies the vast majority of the world's niobium, mostly from a single mine?

Brazil dominates through a single company, CBMM, which mines and refines the metal at Araxá. That one deposit could meet world demand for at least 200 years.

Superconducting niobium-titanium wire is at the heart of which hospital imaging machines?

MRI scanners are the main commercial use of superconductors, and most of them rely on niobium-titanium coils. Chilled close to absolute zero, the wire carries huge currents with no resistance.

Which particle accelerator holds about 1,200 tonnes of niobium-titanium cable in its superconducting magnets?

Large Hadron Collider magnets are chilled to 1.9 kelvin, barely above absolute zero, so the cable loses all electrical resistance. Only then can it carry the currents that bend the proton beams.

Niobium-titanium magnets ride aboard which country's SCMaglev trains, one of which reached 603 km/h?

Japan developed the SCMaglev, whose onboard niobium-titanium coils lift the train clear of its guideway. A seven-car set reached that speed in April 2015, a record for rail vehicles.

The Merlin Vacuum's huge nozzle, made from a niobium alloy, flies on which company's rockets?

SpaceX fits the nozzle to the upper stage of its Falcon 9. It is cooled only by radiating its heat away, a job suited to niobium, which melts at about 2,470 °C.

Niobium's first commercial use, in the early 1900s, was as the glowing filament inside which household item?

Light bulbs with niobium filaments had a short career. Tungsten, which melts at a far higher temperature, soon pushed niobium out of the job.

Niobium jewellery is sold as a safe choice for people whose skin reacts to which common metal?

Nickel is the usual culprit behind jewellery rashes, and pure niobium needs none of it. Niobium oxidises so slowly in air that it stays inert against the skin.

The discoverer of niobium, a London coachbuilder's son, delivered a coach in 1790 to which Russian ruler?

Catherine the Great took delivery in St Petersburg, and the young chemist used the trip to meet leading scientists. He later gave up chemistry to run the family coach business.

Niobium was first named columbium after Columbia, a poetic name for which country?

The United States earned the tribute because the ore came from Connecticut, sent to London decades earlier by a colonial governor's grandson. Chemists then argued over the name for a century.

Most of the world's niobium is used in tiny amounts, often under 0.1%, to strengthen which material?

Steel made with a pinch of niobium is stronger and tougher, which is why it goes into car bodies and gas pipelines. The effect was discovered in the 1920s and remains the metal's main use.

Most niobium is sold as an alloy that is 60 to 70% niobium and the rest mainly which metal?

Iron makes up most of the rest, and the alloy is called ferroniobium. Producers make it in a fierce thermite-style reaction, ready to be added to a furnace of molten metal.

A niobium alloy formed the big rocket nozzle on the service module of which NASA spacecraft programme?

Apollo's service module engine braked the crew into lunar orbit and later fired to send them home. Its nozzle needed a protective coating, because hot niobium reacts with oxygen and turns brittle.

Niobium makes up about 5% of Inconel 718, a superalloy that keeps its strength in the heat of which machines?

Jet engines run so hot that ordinary alloys would weaken, and niobium forms tiny hardening particles that hold the metal firm. The same superalloys go into rocket parts and gas turbines.

Niobium shrugs off aqua regia, the acid mixture named for its power to dissolve which precious metal?

Gold dissolves in aqua regia, the 'royal water' of the alchemists, yet niobium sits in it unharmed. Chemical plants take advantage by lining their vats with niobium.

Superconducting niobium-tin magnets usually run at 4.2 kelvin, the boiling point of which coolant?

Liquid helium boils just 4.2 degrees above absolute zero. Pure niobium needs that kind of cold too: it turns superconducting at 9.2 kelvin, the highest of any pure element at normal pressure.

Lithium niobate, a compound of niobium, is used extensively inside which everyday devices?

Mobile phones use lithium niobate chips that turn radio signals into tiny sound waves rippling across the crystal, which strips out unwanted frequencies. The same crystal modulates light in optical equipment.

Niobium added to glass raises its refractive index, allowing thinner, lighter versions of which everyday item?

Eyeglass lenses made with niobium bend light more sharply, so a strong prescription needs less glass. The metal is added to the glass in the form of its oxide.

Which two-letter chemical symbol did niobium carry for decades under its older name, columbium?

Cb lingered in chemistry journals into the 1950s, about a century after the rival name niobium was coined. The two names were used side by side for all that time.

Niobium can stand in for its scarcer sister metal tantalum in which tiny components found on most circuit boards?

Capacitors made with niobium compete with tantalum ones because niobium is cheaper and easier to obtain. In both, an ultra-thin oxide layer grown on the metal does the insulating.

Niobium wire carries high voltage aboard which NASA spacecraft, built to fly through the Sun's outer atmosphere?

Parker Solar Probe, launched in 2018, became the first spacecraft to fly into the Sun's corona. Niobium wire feeds the detector that samples the particles streaming past it.

A 'weeping rock' said to be Niobe, the queen behind niobium's name, stands near Manisa in which country?

Turkey is home to the rock, a limestone face that seeps rainwater like tears. In the Greek myth, Niobe wept for her slain children until she was turned to stone.

Which country's mint has issued silver-ringed euro coins with a brightly coloured niobium centre since 2003?

Austria colours each coin without paint or dye: a thin oxide film on the niobium plays tricks with light to produce one vivid shade. Later issues in the series used different colours.

Niobium seals the ceramic arc tubes of high-pressure street lamps whose glow comes from which metal's vapour?

Sodium vapour runs hot inside these lamps, and niobium expands with heat at almost the same rate as the ceramic tube. That match keeps the seal tight every time the lamp warms up.

Which element, best known from imitation diamonds, sits one place before niobium in the periodic table?

Zirconium is element 40, one step before niobium at 41. Its oxide, cubic zirconia, has been the leading stand-in for diamond since the 1970s.

Niobium and tantalum both come from which dull black ore, widely mined in the Democratic Republic of the Congo?

Coltan is short for columbite-tantalite, the two minerals it blends. The columbite half is the one rich in niobium, and it keeps the metal's discarded older name alive.

Niobium jewellery gets its rainbow colours without dye or paint, through which electrical surface treatment?

Anodizing grows a transparent oxide film on the metal, and the film's thickness decides which colour it shows. Titanium and tantalum can be coloured the same way.

The 1949 deal that made niobium's name official also kept 'tungsten' over which rival name, still used in German?

Wolfram lost out in English but lives on in the symbol W. The deal was a trade: one name went the way North American chemists wanted, the other the way Europeans wanted.

The mineral specimen in which niobium was discovered in 1801 sat in the collection of which London institution?

British Museum drawers had held the dark, heavy stone for decades before anyone analysed it. Its discoverer had sold the museum his own collection of 7,000 minerals two years earlier.

Which metal, named after a Norse goddess of beauty, sits directly above niobium in the periodic table?

Vanadium heads group 5, the column that runs down through niobium and tantalum. It honours Vanadís, another name for the goddess Freyja, because its compounds come in so many colours.

Hundreds of tonnes of niobium-tin strands go into the magnets of which fusion reactor in southern France?

ITER uses niobium-tin in its most powerful magnets, and making the strand took nine suppliers seven years. World output of the material had to grow more than sixfold to meet the order.

Which English chemist, the son of a London coachbuilder, discovered niobium in 1801?

Charles Hatchett announced the new element to the Royal Society that November. A yearly prize for niobium research bears his name, with a medal cast in pure niobium.

Christian Wilhelm Blomstrand first prepared niobium metal by heating its chloride in an atmosphere of which gas?

Hydrogen stripped the chlorine away and left the bare metal behind. The Swedish chemist managed it in the 1860s, more than sixty years after the element was first detected.

Which German chemist named niobium in the 1840s after proving that tantalum ores hid a second element?

Heinrich Rose picked the name because Niobe was the daughter of Tantalus, and the two metals were as hard to tell apart as family. Only later was his find accepted as the columbium reported over forty years before.

Which discoverer of palladium and rhodium wrongly ruled in 1809 that niobium and tantalum were one element?

William Hyde Wollaston compared the two oxides and called them identical, even though one was far denser than the other. His verdict stood for more than thirty years.

Most of the world's niobium is mined from which mineral, the ore at all three of the biggest mines?

Pyrochlore takes its name from the Greek for fire and green, because it turns green when heated in a blowpipe flame.

Which synthetic element, named after a Russian research town, sits at the bottom of niobium's group?

Dubnium, element 105, honours Dubna, home of the Joint Institute for Nuclear Research. It has never been found in nature, and even its longest-lived form has a half-life measured in hours.

C-103, the niobium alloy used for rocket nozzles, is one-tenth which metal, named after the Latin for Copenhagen?

Hafnium was sitting unused in one firm's stockpile, a leftover of refining reactor-grade metal, when engineers tried it in niobium. The 103rd recipe they tested gave the best mix of strength and workability.

Which supposed element, named after Niobe's brother by the chemist who named niobium, proved to be a mixture?

Pelopium took its name from Pelops, another child of Tantalus, but it turned out to be niobium and tantalum mixed together. Ilmenium and dianium, two more claimed elements, fell the same way.

Niobium metal slowly takes on a tinge of which colour when left in air at room temperature?

Blue is the faint tinge the grey metal picks up after long exposure. Even so, niobium oxidises very slowly, and it only begins to react readily with air at about 200 °C.

Niobium suits nuclear reactors because it only rarely absorbs which subatomic particles?

Neutrons mostly pass through niobium without being captured, so parts made of it do not starve the chain reaction. The metal also stands up well to heat, corrosion and radiation.