Saturday, January 29, 2011

Are Rare Earth Elements Precious Metals?

With only a handful of countries in the whole world mining and refining them and Mainland China planning to reduce their export quotas for 2011, will rare earth metals soon become precious metals?

By: Ringo Bones

Though Paris Hilton has yet to brag about her brand-new 22-karat dysprosium bracelet (or will it be a 22-karat holmium bracelet?) rare earth metal prices will surely rise and become much rarer because the People’s Republic of China had already decided back in January 6, 2011 to cut their rare earth metal export quotas by 35% for the whole of 2011. Will this turn of events inadvertently turn rare earth elements into precious metals?

The Beijing government’s decision to reduce their rare earth metal export quotas instantly posed a real concern for Japan’s high-tech manufacturing firms since electric motors of hybrid cars and other high-tech consumer items like video monitors are very dependent on rare earth metals in their construction and manufacture. The Mainland Chinese rare earth export quota cut had even stepped-up Japan’s plans to explore the mining potential of the seabed of their territorial waters for rare earth elements.

As a very important reiteration, the elements commonly referred to as “rare earths” are neither rare nor earths. These soft and malleable metals only became commercially rare due to the People’s Republic of China flexing their newfound geopolitical clout by controlling their own export quotas. Cerium, the most abundant, is slightly more plentiful than tin and lead. While thulium – the scarcest of the rare earth elements – is only slightly rarer than iodine. The “earth” misnomer arose from the fact that the first source of the elements during their discovery is from the oxides of the elements themselves.

As the current textbook definition of precious metals – when pertaining to the “top three” like gold, silver and platinum – primarily revolves around their beauty, their rarity and high demand that makes them pricey are just incidentally brought upon by economics. While platinum’s usefulness as a very important chemical catalyst might make it as one of the “traditional” precious metals that has a kinship with the rare earth metals in terms of industrial use, rare earth metals – appearance-wise – have never been and probably never will be “attractive enough” to have lend themselves for jewelry use. Probably due to their rather "mediocre" gray-silver sheen.

And it does deserve worthy of a mention that three of the rare earth elements – europium, lanthanum and yttrium – will surely never be used as a fashionably drab jewelry because chemically pure europium, lanthanum and yttrium will corrode within a few hours upon exposure to our oxygen-nitrogen atmosphere. Chemically pure specimens of europium, lanthanum and yttrium are often available as a laboratory curiosity as a specimen displayed and sealed in a glass container filled with argon gas. So will rare earth metals ever become precious metals? In price maybe, but don’t count on them winding up as part of Paris Hilton’s bling anytime soon.

Wednesday, January 12, 2011

Dysprosium: The Hard to Get At Rare Earth Element?

Even though this rare earth element and its myriad of uses has yet to become a household name, does dysprosium truly deserve its reputation as the hard to get at rare earth element?

By: Ringo Bones

Given that this rare earth element is never found free in nature, the derivation of its name – dysprositos, Greek for hard to get at – is probably an apt name of its chemical properties that eludes dysprosium’s purification to six-nines level (99.9999% purity) until the advent of modern ion-exchange and solvent-extraction procedures of the mid to late 1950s. Dysprosium, atomic number 66, chemical symbol Dy, is a member of the lanthanide – or rare earth series of elements – which also includes such rare earth metals as cerium, lanthanum and yttrium. Dysprosium has a melting point of about 1,500 degree Celsius and a boiling point of 2,300 degree Celsius.

The discovery of dysprosium was credited to the French chemist Paul Émil Lecoq de Boisbaudran back in 1886. Although Georges Urbain later obtained a reasonably pure sample of the metal in 1906, the free element has never been chemically isolated until the advent of modern ion-exchange and solvent-extraction techniques of the mid to late 1950s.

Dysprosium occurs naturally in minerals usually found in granite or pegmatite veins, such as euxenite, gadolinite, samarskite and xenotime. Dysprosium is also found among the products of nuclear-fission reactions. Dysprosium is separated from other rare earth metals which it occurs via ion-exchange and solvent-extraction methods.

Dysprosium is used primarily in nuclear reactor control rods and its other chief practical use is in nuclear reactors, where it serves as a nuclear “poison” – that is, it is employed as a neutron-eating material to keep the neutron-spawning atomic chain reaction from getting out of hand and also in magnetic alloys.

Dysprosium has a valence of +3 and forms yellow-green colored compounds. Dysprosium is ferromagnetic below – 123 degrees Celsius. Just like pure gallium when chilled with liquid nitrogen, dysprosium will stick to an ordinary bar magnet. And at liquid helium temperatures, dysprosium becomes a superconductor.

Dysprosium’s high magnetic susceptibility makes it useful for data storage devices and as a component of Terfenol-D – a powerful rare earth magnet first used in US Navy sonar systems. Soluble dysprosium salts are mildly toxic while the insoluble salts are considered non-toxic.

Carl Auer von Welsbach: The Rare Earth Kingdom’s Royal Surveyor?

As a well-renowned chemist and a discoverer of a number of rare earth elements, is Carl Auer von Welsbch the Rare Earth Kingdom’s Royal Surveyor?

By: Ringo Bones

Born in Vienna back in September 1, 1858, little did the whole world knew that Carl Auer von Welsbach will in a few years time be almost single-handedly exploring and surveying the then relatively unknown “Rare Earth Kingdom” in Mendeleyev’s Periodic Table for the benefit of not just the world of chemistry, but for all mankind. The exploratory journey started when Welsbach first studied chemistry under Robert W. Bunsen at the University of Heidelberg, where Welsbach made investigations in the chemistry of rare-earth metals. Later, Welsbach attended the University of Vienna.

In his exploration of the Rare Earth Kingdom, Welsbach became the first chemist to isolate the elements neodymium, samarium and praseodymium back in 1885. he is also best known for his invention in 1885 of the Welsbach Mantle – a means for increasing the illumination given off by a gas jet – which soon after found world-wide use. The Welsbach Mantle consisted of a wad of cotton which had been dipped in a salt solution of zirconium or some other suitable element. The mantle was supported over a gas jet, which would burn away the cotton the first time it was lit., leaving a brittle network of filament which becomes incandescent at a much lower temperature – thus making gas jet illumination much more fuel efficient.

During the advent of electric lighting, Welsbach invented the osmium filament for electric lights. And in 1907, Welsbach managed to isolate another rare earth element called lutetium to a reasonable degree of chemical purity back in 1907 before the advent of the post-World War II zeolite ion-exchange techniques. For a number of years, Welsbach was a member of technical societies in Vienna, Stockholm and Berlin. He died in Carinthia on August 4, 1929. Before passing away, Carl Auer von Welsbach managed to map much of the rare earth portion of the periodic table for the ease and convenience of a generation of chemists following his footsteps.