Saturday, November 13, 2010

Is Lanthanum A True Blue Rare Earth Element?

With an atomic structure wholly different from that of the rare earth inner transition series, does lanthanum even belong with the rare earth elements?

By: Ringo Bones

Element 57, lanthanum, symbol La, can be considered a maverick among the rare earth elements. In the strictest sense, it is not actually a member of the rare earth inner transition series since it does not have a 4f-electron. Lanthanum’s differentiating electron – from barium – is found in the 5d-orbital. And yet lanthanum’s chemical properties so resemble those of rare earth metals that analytical chemists for much of the 20th Century had placed lanthanum among the rare earth elements.

Given that the Periodic Table of the Elements is based on the periodic law – which according to the wisdom and insight of Dimitri Ivanovich Mendeleyev – revolves around the law in chemistry where he ordered the elements in the sequence of their increasing atomic numbers that show a periodic – as in chemical property variation – in most of their properties. Because of this, groupings of elements are decided more on their chemical properties rather than their atomic structure.

And lanthanum’s chemical properties does resemble very much like that of its rare earth sister metals as opposed to the first transition metals where it resembles in atomic structure. At present, the International Union of Pure and Applied Chemistry (IUPAC) still places lanthanum snugly within the confines of the rare earth metals group even though its atomic structure is a bit suspect for a true blue rare earth element.

Is Yttrium a Rare Earth Element?

Currently being grouped with titanium and zirconium in the first transition metals, does the element yttrium rightfully belong among the rare earth elements?

By: Ringo Bones

Named after the town of Ytterby, Sweden where it was first discovered in 1794; yttrium is a scaly metal with an iron-gray sheen. Primarily used in making phosphors for color TV screens and Microwave filters, yttrium is also well-known in the medical community in the form of yttrium-90, a radioactive isotope that had gained dramatic medical use in needles that had replaced the surgeon’s knife in killing pain-transmitting nerves in the spinal cord. But with an atomic structure and chemical properties resembling more of the rare earths instead of the first transition metals, does this make yttrium a rare earth metal?

From the analytical chemists’ perspective, yttrium, Y, resembles the rare earths more strongly than it does scandium in spite of the fact that it has no 4f-electrons in common with the rare earths. When a rare earth ore is digested with sulfuric acid or fused with potassium bisulfate and the sulfates fractionally crystallized, yttrium is found with the sulfates of dysprosium, holmium, erbium, thulium, ytterbium and lanthanum – the heavy members of the rare earths – in the most soluble fraction. Separation of the Y (III) ion from the other rare earths is achieved most economically and in the highest purity by either ion-exchange or solvent extraction procedures. The hydroxides and oxides of yttrium are somewhat stronger and more soluble than those of terbium but weaker than those of lanthanum. The compound - in general - resembles those of the rare earths of high atomic number – i.e. at the end of the series like ytterbium and lutetium.

For sometime now, the Union of Pure and Applied Chemistry (IUPAC) has placed yttrium in the Group III B of the Periodic Table of the Elements. Chemically, yttrium does possess some very intriguing chemical properties that make it behave as if it is a rare earth element and yet yttrium has no 4f-electrons in common with the rare earths. Given that Dimitri Mendeleyev constructed the Periodic Table of the Elements primarily to arrange individual elements by chemical properties while their atomic structure is of only secondary importance, shouldn’t yttrium belong to the rare earth group of elements instead of in the first transition metals?

Is Scandium A Rare Earth Element?

Currently being grouped with titanium and zirconium in the First Transition Metals part of the periodic table, does the element scandium rightfully belong in the rare earth metals section of the Periodic Table?

By: Ringo Bones

The last time scandium gained widespread press coverage was back in the mid 1990s when this “space age” first transition metal was used in the manufacture of light weight but strong revolvers and related handguns due to the fact that scandium is as light as aluminum but with a much higher melting point. Progress then for such an under-utilized “space age” metal since chemically pure scandium was only produced in one pound quantities only as recently in 1960. But the question now is, does scandium belong to in the rare earth “leg” of the Periodic Table rather than in the first transition metals group?

Even though the International Union of Pure and Applied Chemistry or IUPAC has since placed scandium in the Group III B of the first transition metals, it does have chemical properties and an atomic structure that eerily mimics that of the lanthanide or rare earth elements. During the “space age” science boom of the 1960s, the element scandium, Sc, is usually associated chemically with the lanthanide or rare earth elements of atomic numbers 57 to 71, although its electron structure does not conform to this long series system. Scandium’s differentiating electron, compared to its predecessor, calcium, is in a (n-1) state rather than a (n-2) level. Scandium is found to be a slight fraction of the total in rare-earth minerals – such as monazite, gadolinite, etc. The most abundant source of scandium is the mineral thortveitite.

To separate the element, the ore is first digested with strong sulfuric acid or fused with potassium hydrogensulfate. Water treatment removes the soluble sulphate salts. Unwanted heavy metals are removed by precipitation as sulfides or by careful adjustment of the hydroxide-ion concentration. All of the rare earths, including scandium, are precipitated by addition of oxalic acid. Finally, scandium is separated from the other elements – all of which form soluble oxalates – by forming a sulfate called scandium sulfate pentahydrate which is more soluble than the rare earth sulfates.

Scandium has also been prepared by the electrolysis of its fused chloride on a zinc cathode. The zinc metal is removed from the deposited scandium metal by volatilizing the former. Scandium differs from the other members of the Group III B elements in forming less-basic oxides, though the oxide is still not amphoteric – i.e. soluble in excess base. The chloride is more volatile and the nitrate more easily decomposed. The complexes are somewhat more stable, and surprisingly is the fact that it will form a normal carbonate in view of the relatively small size and the high charge exhibited by the trivalent ion of scandium.

For sometime now, the Union of Pure and Applied Chemistry (IUPAC) has placed scandium in the Group III B of the Periodic Table of the Elements even though chemically, it does possess some very intriguing chemical properties that make it behave as if it is a rare earth element. Given that Mendeleyev’s “construction” of the Periodic Table of the Elements primarily sorts the individual elements by their chemical properties while atomic structure is only a notch below this in terms of importance, shouldn’t scandium be a rare earth element because it has rare earth chemical properties?

Urban Mining: Unseemly Source of Rare Earth Metals?

As the country hardest hit by Mainland China’s “Rare Earth Export Quota Reduction”, will Japan’s Urban Mining scheme become an unseemly source of rare earths?

By: Ringo Bones

Ever since that notorious incident back in September 7, 2010 where a Mainland Chinese trawler captain rammed his fishing trawler into a Japanese navy patrol ship in a disputed territory claimed by both countries, diplomatic tensions between Japan and the People’s Republic of China has since reached an all time high. Soon thereafter, the Beijing government decided to reduce its rare earth export quotas citing its own high tech industry’s growing need of the precious resource.

Unfortunately, given that the People’s Republic of China has a virtual monopoly – over 90% in fact – of the worlds commercial supply of rare earth metals, the move became a thinly-veiled excuse as an embargo on Beijing’s rare earth ore concentrate exports to Japan. As the country hardest hit by the People’s Republic of China’s “Rare Earth Export Quota Reduction”, will Japan eventually find another way to supply its domestic high tech manufacturing firms with rare earth metals?

For over two months now, not a single kilo of rare earth ore concentrate from the Chinese Mainland had arrived in Japanese shores, says Shigeo Nakamura of Advanced Material Japan Corporation, one of Japan’s main rare earth ore concentrate buyers from the People’s Republic of China. Because of this, Japan had resorted to “Urban Mining”, a scheme of extracting rare earths from e-wastes and other obsolete consumer electronic and computer gear.

According to Daisuke Takahashi of Highbridge Computers, his firm now makes a profit in urban mining rare earths from the tin but powerful magnets found in the read/write heads of obsolete computer hard disc drives. Even the phosphors of cathode ray tube type computer monitors – which are rich in rare earths – are already a prime source of the precious raw material in Japan.

Not only e-wastes are a prime rare earth source for urban mining, old electric typewriters, audiophile grade cassette tape decks and even a late 1990s era Sega Megadrive are now mined for rare earth metals in Japan. Even though urban mining might seem like an environmentally friendly way of extracting rare earth metals through recycling by preventing e-wastes and obsolete consumer electronic gear from winding up in landfills and endangering the local water table when rainwater leaches their poisonous by-products of breakdown, it can’t supply Japan and the rest of the world’s need for rare earths in mobile phone, laptop, hybrid car and wind turbine generator production – and future applications that could provide us with carbon neutral energy sources.

As a way of exploring ways on how Japan can weather the global rare earth shortage due to the People’s Republic of China’s strong-arm tactics in keeping geopolitical dominance through rare earth metals monopoly, Kazuhiko Hono of Japan’s National Institute for Material Science had recently been experimenting with lasers to explore the atomic structure of modern rare earth alloy permanent magnets used in hybrid car motors and wind turbine generators. The aim is to find ways of constructing newfangled permanent magnets that are as strong as their predecessors while using reduced amounts of rare earths. But the true long-term solution will be is to restart and develop the rare earth industries of much friendlier countries that previously supplied rare earth metals in the past that has been since superseded by Mainland China due to economic reasons. Like Canada, India, and (hopefully not a Republican run) the United States.

Monday, November 8, 2010

Monazite: Sole Commercial Source of Rare Earths?

Even though there are other minerals that contain a significant amount of rare earth metals, is monazite the only mineral that is a commercially source of rare earths?

By: Ringo Bones

Ever since the People’s Republic of China’s rare earth metals industry gained widespread press notice back in October 21, 2010, the global commodities markets has since set their eyes on – which just a few weeks ago - the least discussed part of the Periodic Table, namely the rare earth element - not only the elements but their source minerals too. Given that there are a number of minerals that became important sources of rare earth elements since the end of World War II, is monazite truly the only economically viable source of rare earths for use in the consumer electronics industry and other high tech pursuits of the 21st Century?

The mineral monazite is a phosphate of cerium and other metals: like sister rare earth metals lanthanum, dysprosium, praseodymium and others of commercial importance like thorium. Monazite is a yellowish, reddish, or yellowish brown usually formless mineral with a hardness of 5 on the Mohs’ Scale. It occurs as an accessory mineral scattered in small grains through continental granites and granite gneisses and very rarely in larger masses in granite pegmatites.

The only commercial occurrence of this mineral is in rolled placer grains in river and beach sands which have been derived from granite terrains. The principal uses of monazite have been as a source of thorium for making incandescent gas mantles and the thoriated tungsten filaments of vacuum tubes; and also of cerium for pyrophoric cigarette lighter flint / misch metal alloys.

Monazite, as a sole ore of thorium, became of paramount importance in World War II as a raw material for the development of atomic energy. The Travancore Coast of India at the time was the principal source of monazite sand. This mineral has also been mined on the coasts of Brazil and Florida before the People’s Republic of China began developing their own monazite deposits.

The post World War II scientific and academic interest on the chemistry and properties of rare earth metals had made methods of purifying this now indispensible commodity more or less a freely shared scientific knowledge. It is somewhat of a no brainer that Mainland China eventually cornered the rare earth metals market by default since miners there work for slave’s wages and rare earth purification knowledge is already akin to a genie that’s already out of the bottle. In Mainland China, the monazite is as if it is there for the picking – commercially viable picking for rare earths.

Rare Earth Metals Mining and Processing: Like Wringing Blood form Stone?

Given the technical challenges faced by start up rare earth metals miners and producers even since Mainland China lowered the quota they want to sell to the world market, is getting rare earths from the ground really like wringing blood from stone?

By: Ringo Bones

When the People’s Republic of China decided to lower the quota of rare earth metals that it sells to the world market in order to bolster their own strategic reserves back in October 21, 2010 commodities traders’ around the world got slightly panicky that this might affect the consumer electronics, hybrid car and wind turbine generator industry. Such is the usefulness of rare earth metals in our contemporary 21st Century society that the lone commercial producer of rare earth metals now has gained tremendous geopolitical clout. Given the difficulty of new and former rare earth producers to start their own rare earth metal industry, is it really that difficult to extract the valuable commodity from the ground that it is compared to “wringing blood from stone”?

The rare earth elements, though not exactly abundant, are not at all rare; they are in fact widely distributed in nature. In actuality, the term “rare” is more descriptive of these elements’ “unusual” properties than of their relative abundance on our planet. The order of magnitude of abundance ranges from lutetium at 0.7 parts per million of the Earth’s crust to 44 parts per million for cerium. Distribution wise, even our seas contains 1.8 long tons of cerium and 1.4 long tons of lanthanum per cubic mile of seawater. Unfortunately at this concentrations, it is too diluted a form to be extracted in an economically viable manner using present technology.

Commercially viable rare earth minerals like monazite, samarskite and even uranite are widely distributed across the Earth’s surface, but mining and processing rare earth metals in a commercially viable manner into their commercially viable forms for the world’s commodities markets is another thing entirely. Samarskite was used to be extensively mined in the continental United States, but since 1990, it can no longer be done in a commercially viable manner due to wage, miner safety and environmental concerns.

From the Periodic Table’s perspective, the rare earths are conveniently grouped according to the solubility behavior of their sulfates or by the slight differences of their basic strength. Their similarities in electron configuration suggested similarities in chemical behavior. The trivalent ions are especially similar in forming salts of nearly identical solubilities, hydroxide strength, and complexing tendency. The latter property and small differences do provide a method of separation.

Rare earth metal manufacturing could be considered a relatively young branch of metallurgy. Until the middle of the 1940s, chemical separation of one rare earth element from another was achieved only by the most tedious means of fractional crystallization of the double sulfates, oxalates, and nitrates. The very slight differences in salt grain size from one rare earth element to another provides very slight differences in solubilities of such compounds. Literally thousands of individual manual operations were required even for crude separations. The need for and interest in the individual members of the rare earth series of elements led to more efficient means of separation. Separation of rare earth ions from each other is currently achieved most economically and in the highest purity by either ion-exchange or solvent-extraction procedures.

Unlike that of the chemical separation and processing of the platinum group of metals which remained a proprietary industrial / commercial / corporate secret, the post World War II scientific interest in are earth metals had made the laboratory separation of them an open knowledge by virtue of academic freedom and a widely-distributed academic pursuit. The knowledge of efficiently separating rare earth metals from their ores and from each other eventually reached the People’s Republic of China.

Slave wages, very lax mining safety, environmental and miner’s health concerns had eventually made Mainland China the sole commercially viable provider of rare earth metals for the world’s commodities markets. The ridiculously low prices are conveniently passed on to their miners, which doesn’t say much about where the Mainland Chinese rare earth metal industry stands when it comes to corporate social responsibility. Mining rare earth metals and processing their ores is indeed like wringing blood from stone in more ways than one.

Wednesday, November 3, 2010

Rare Earth Metals: The Periodic Table’s Undiscovered Country?

Recently gained press attention when the People’s Republic of China planned to reduce its export quota of rare earths back in October 21, 2010, are rare earth metals the periodic table’s “Undiscovered Country”?

By: Ringo Bones

As the only commercial producer of rare earth metals, the global economy got a bit spooked when the Beijing government decided to reduce its export of the valuable metals for its own domestic high tech use back in October 21, 2010. The hybrid car industry and the consumer electronics industry cannot function without rare earth metals, and yet an overwhelming number of us only had passive acquaintance of this quaint group of elements back in high-school chemistry. Does this mean that the rare earth metals or lanthanide metals truly are the periodic table’s “Undiscovered Country”?

Even though it is currently on the commodities traders hotspot du jour, from the perspective of the International Union of Pure and Applied Chemistry or IUPAC, the group of elements commonly referred to as the “rare earths” are neither rare nor earths. The rare earth family or group of elements are composed of soft, malleable metals – and most of them are not at all in short supply. Cerium, the most abundant, is more plentiful than tin or lead – while thulium, the scarcest, is only slightly rarer than iodine. The rare earth misnomer came about because these elements’ oxides not only have earth-like consistency and texture but where at first mistaken for the elements themselves.

All of the 15 rare earth elements have two outer electrons and eight or nine in the second shell in. They only vary in their electron compliment in the third innermost shell. But among the rare earth’s atomic structure, the third-shell electron difference is very slight indeed thus making the 15 elements a very close-knit family. From a mineralogical standpoint, a typical mineral containing a single rare earth element more often than not contains all of the other members.

The rare earth elements are so nearly identical in their chemical properties that separating them can easily involve thousands of steps. Because of this quirk of chemistry, the individual chemically pure rare earth elements did not became available in commercial quantities until the late 1950s – which only added to the group’s reputation as the “Undiscovered Country” of the periodic table of elements.

Nevertheless, the rare earth family in their less than chemically pure form has been used industrially since the early 1900s in the form of their naturally occurring mineralogical mixture. Later on, much purer and refined forms go into the making of powerful ceramic rare earth magnets like the samarium cobalt magnets used in the electric motors of hybrid cars.

For much of the 20th Century, more than a million pounds of low purity rare earth metals still go annually into the manufacture of an alloy called “misch metal” – German for mixed metal. Combined with iron, misch metal products are used in cigarette-lighter flints. But the main use of low purity rare earth metals is in iron and steel-making where it is used to absorb impurities and improve the steel’s texture and workability.

A mixture of rare earths combined with carbon produces the intense carbon arc lights once used to light up Hollywood before being superseded by more energy efficient light sources. And a large number of rare earth compounds go into the making of high-quality glass for computer monitor use by making the glass completely colorless. Or in other applications, by adding deep color depending on the combination used.

Even though the United States has more or less similar amounts of rare earth metals deposits as that of the People’s Republic of China, it has since closed down its mines and related purification facilities back in 1990 due to the fact that it can no longer produce rare earth metals in a way that’s economically competitive with Mainland China while still adhering to OSHA and EPA guidelines and American mine workers – unlike that of Mainland China – won’t work under slave wage conditions; Thus enabling Mainland China as of late to use its rare earth metals industry as geopolitical leverage.