Dobrescu, Emilian M. (2023), The Importance of the Rare Earths for the World Economy, Cunoașterea Științifică, 2:3, 62-68, https://www.cunoasterea.ro/the-importance-of-the-rare-earths-for-the-world-economy/

 

Abstract

“Rare earth elements” (REE) is a frontier discipline between economics as a generic science and the economy of rare earth elements, which studies the production, the distribution and the circulation of the rare earths. On our planet, over a quarter of the new technologies involved in producing economic goods use REE, also known as critical minerals. In the near future, the competition to control the reserves of REE will get tough. In the 21^st Century, REE are as important as oil was for the previous century and coal for the 19 ^th Century, namely, the engine of a new industrial revolution. Rare earth elements represent a new concept and become an important part of our daily life, given the increased use of smart devices.

Keywords: rare earths, world economy, critical minerals, metals, China, Europe

Importanța pământurilor rare pentru economia mondială

Rezumat

„Elementele pământurilor rare” (REE) este o disciplină de frontieră între economie ca știință generică și economia elementelor pământurilor rare, care studiază producția, distribuția și circulația pământurilor rare. Pe planeta noastră, peste un sfert din noile tehnologii implicate în producerea de bunuri economice utilizează REE, cunoscute și sub numele de minerale critice. În viitorul apropiat, competiția pentru controlul rezervelor de REE va deveni dură. În secolul al XXI-lea, REE sunt la fel de importante precum petrolul în secolul precedent și cărbunele pentru secolul al XIX-lea, și anume, motorul unei noi revoluții industriale. Elementele pământurilor rare reprezintă un concept nou și devine o parte importantă a vieții noastre de zi cu zi, având în vedere utilizarea sporită a dispozitivelor inteligente.

Cuvinte cheie: pământuri rare, economie mondială, minerale critice, metale, China, Europa

 

CUNOAȘTEREA ȘTIINȚIFICĂ, Volumul 2, Numărul 3, Septembrie 2023, pp. 62-68
ISSN 2821 – 8086, ISSN – L 2821 – 8086
URL: https://www.cunoasterea.ro/the-importance-of-the-rare-earths-for-the-world-economy/
© 2023 Emilian M. Dobrescu. Responsabilitatea conținutului, interpretărilor și opiniilor exprimate revine exclusiv autorilor.

 

The Importance of the Rare Earths for the World Economy

Emilian M. Dobrescu[1]

dobrescu@acad.ro

[1] Romanian Academy of Scientists

 

“Rare earth elements” (REE) is a frontier discipline between economics as a generic science and the economy of rare earth elements, which studies the production, the distribution and the circulation of the rare earths.

On our planet, over a quarter of the new technologies involved in producing economic goods use REE, also known as critical minerals. The industries based on these precious elements are valued at $5.000 billion, which represent 5% of the world GDP.

In the near future, the competition to control the reserves of REE will get tough. In the 21^st Century, REE are as important as oil was for the previous century and coal for the 19 ^th Century, namely, the engine of a new industrial revolution. The energy of the future will be generated with equipment made out of steel, concrete, non-ferrous metals, and also rare earth elements. The scale development of the new technologies will boost the demand for these resources. It is worrying that the reserves of REE are scarce in Europe and other developed countries such the US and Japan and abundant in China, which in the past five years became, almost, the only producer. The technology used to produce REE is complex and very polluting.

Rare earth elements represent a new concept and become an important part of our daily life, given the increased use of smart devices. In 1982, the public awareness on REE was almost nonexistent. Only few decision makers from the military and intelligence fields were familiar with it. Civil and military high-tech applications (smart weapons, TVs, computers, smartphones, permanent magnets etc.) make this critical mineral very desirable (see Table 1 in the annexes).

The E.U., the U.S., Japan and an increasing number of emerging countries (BRICS etc.) depend on the availability of REE, which are of paramount importance for their economic and military development.

Discovered in the 18 ^th Century, REE are not that “rare” in the proper sense of the word. They are available in larger quantities then copper, gold, lead or platinum, but mining them is difficult due to low percentage of REE in the carrying minerals. The world production of REE is about 150.000 tons per year, very modest in comparison with the iron production of 2.3 billion tons per year[1]. For electronics and the green industries these minerals are of vital importance.

REE are accounted as the 5^th strategic raw material after water, steel, oil and rubber.

Many strategic battles during the World War II were carried out in order to get the control over oil reserves (Eurasia) or rubber production (south-east Asia).

In the last three or four decades, the regional wars in Afghanistan, Iraq, Iran were waged for the same reasons (oil and REE) as we argue in our book.

In Mendeleev’s periodic table, 15 out of 17 rare earth elements can be found in the lanthanide series which comprises the chemical elements with atomic numbers from 57 to 71, starting with lanthanum and ending with lutetium. The other two are scandium and yttrium, considered as transition metals.

Important metals comprised in the rare earth elements

In nature, it is difficult to find pure REE oxides, in rich concentrations. The enumeration of the chemical elements from the lanthanide series sounds like reciting from Latin language: lanthanum, cerium, praseodymium, neodymium, promethium, samarium, europium, gadolinium, terbium, dysprosium, holmium, erbium, thulium, ytterbium and lutetium.

The REE were discovered in 1787 by a Swedish lieutenant. Most of the rare earth elements are pretty common and more abundant in the earth’s crust than lead or gold.

The deposits of REE can be found mixed with precious metal deposits. This fact was noticed in the State of Carolina in the U.S., during the gold washing process. The slit resulted was very rich in monazites[2].

Most permanent magnets contain neodymium or cobalt-samarium. The advantage of neodymium magnets consists in their low mass, high reliability and excellent magnetic properties. These magnets are very brittle and vulnerable to corrosion. In order to protect them from breaking they are coated or plated.

Samarium-cobalt magnets are recommended to be used for high temperatures applications due to their high stability. This kind of magnets don’t corrode and they are resistant against acidic or basic liquids. These magnets can be produced by means of casting, cold pressing or sinterization. The rare earth-based magnets have the highest magnetic energy known at present. From economic standpoint, REE belong to the group of strategic metals. As we mentioned, they are not as rare as their name suggests, being abundant in the earth’s crust. For example cerium it’s as spread as copper. Thulium is the rarest. In the last decades the demand for rare earths increased due to the development of high-tech technologies and industries (see chapter 4).

The REE have a metallic appearance, they are soft, malleable and ductile. These elements are chemically reactive, especially at high temperature or when they are finely divided.

The name “earth” comes from the fact that REE were discovered in minerals the old French word for oxides.

Given their geochemical properties, they are very unevenly distributed in the earth’s crust, often in concentrations that are not profitable for mining. The Swedish chemist Jons Jacob Berzelius (1779-1848) divided the lanthanides into two subgroups depending on the solubility of their sulfates:

Cerium’s subgroup (cerium, lanthanum, praseodymium, neodymium, promethium, and samarium) with atomic number from 57 to 63;

Yttrium’s subgroup (europium, gadolinium, terbium, dysprosium, holmium, erbium, thulium, ytterbium, lutetium) with atomic numbers from 64 to 71.

The world reserves of REE are estimated at 45 megatons[3]. Among them, lanthanum and neodymium are more abundant than lead and cerium is more spread than tin or zinc. Few experts know that thulium and lutetium are 200 times more abundant in the earth’s crust than gold, according to the satellite prospections of the US Geological Survey.

The REE don’t exist as separate elements in or on the earth’s crust, but only in mixtures of about 150 known minerals, with specific spread for each of it.

Rare earth elements have the same external electronic configuration and therefore similar chemical properties. The lanthanides, also called transition elements, differ only by the structure of an internal electronic layer. This feature explains their association in the group and the fact that they have similar chemical and physical properties.

Their great affinity for oxygen translates into a significant pyrophoricity of the metal as through a great stability of the chemical bond between REE and oxygen.

REE easily combine with anions to make soluble salts (chloride, nitrate) or insoluble salts (sulfites, fluorides, carbonates, oxalates, phosphates); can be also used to make synthetic mineral compounds (borates, molybdates, silicates) and can be bond in two or more distinct layers through organic molecules in order to make very stable compounds.

We must distinguish between rare earth elements and rare metals. These are two distinct categories of substances, even if the first one generates the second one. To avoid the confusion, the experts use the syntagm of “critical metals”. In general, REE can’t be found in pure concentration in nature.

In 2010, a committee of E.U. experts classified the 14 “critical metals”, extracted by means of various technologies from REE, vital for the production of new goods (see chapter 4). Between 2006 and 2012, China exported 97 percent of the “critical metals”. The critical metals are the least recyclable and for now apparently can’t be reused.

Most of the world reserves of REE consists of two minerals: 1) bastnasite which contains cesium, lanthanum, ytterbium, and can be found in China and the U.S.; 2) 4 kinds of monazites (with cesium, lanthanum, neodymium, and praseodymium) which can be found especially in Australia, Brazil, China, India, Malaysia, South Africa, Sri Lanka, Thailand and the U.S.

Other minerals containing REE are:

• apatite Cas(PO4)3(F,Cl,OH);
• cheralite (Ca,Ce)(Th,Ce)(PO4)2,
• eudialyte (Na1sCa6(Fe,Mn)3Zr3SiO(O,OH,H2O)3(Si3O9)2(Si9O272(OH,Cl)2,
• loparite (Ce,Na,Ca)(Ti,Nb)O3,
• phosphorite 3Ca3(PO4)2‘Ca(OH,F,Cl)2,
• clays (extracted through ionic absorption);
• secondary monazite;
• residues of uranium solutions;

In the past there were no separation technologies for the various metals and REE, which had only limited use. Due to the modern technologies, now all rare earth elements can be separated and transformed in economic goods (batteries for electric cars and smartphones etc.) Therefore, the battery factories increased their demand for lithium, a vital raw material for durable, quality products.

The importance of the „critical metals” for the world economy

In the study “Minerals, critical minerals and the U.S. economy[4], the National Research Council recommended the US Government to take the necessary steps to secure the the supply of non-energy minerals, considered critical and strategic to the U.S. economy. The study analyzes all the risks:

• the availability of REE extracted with the current technologies;
• the substitution degree;
• the political risks in the international trade with strategic and critical resources;
• the U.S. defense policy and the strategic importance of some minerals for civil, but mainly for defense technologies.

 

The above-mentioned study was taken as reference by other interested parties. The European Commission is working on a viable strategy regarding the raw materials. In this regard, the Commission will assess every two years the progress made in order to identify the problems occurred and to correct ineffective measures.

When they were discovered, back in the 19^th century, the rare earth elements were considered as some of the most special materials on the planet. As we mentioned the REE are relatively abundant. However, the operational and environmental costs are very high. That’s why only the rich deposits worth being operated. The rare earth elements are, by their nature, malleable and have high electrical conductivity.

Their process of extraction consists in dissolving the mineral in liquids like water and acidic solvents.

As we mentioned, there are 17 rare earth elements, each very important for the production of hi-tech goods such as batteries, smart TVs, smartphones, notebooks, seismic monitoring equipment, nuclear reactors, rockets etc.

Terbium is a natural signal amplifier being used to manufacture optical fiber cables. Also when compressed it generates a change in the electrical circuits and for that feature is used in the production of earthquake detectors.

The REE are combined in alloys to make strong magnets which are used to manufacture wind turbines. The magnets are crucial parts of electric generators, and they help transforming the rotation movement of the propellers into electricity.

Dysprosium, another rare earth element is used to produce advanced electric motors and the battery systems of the hybrid cars, because the magnets comprising this element are much lighter and therefore more efficient. The fact that dysprosium absorbs neutrons makes it valuable in nuclear reactors to control the availability rate of the neutrons. Due to its magnetic properties, dysprosium is also use to mass-produce cd players.

Cerium is used in the fabrication of catalytic converters that reduce the carbon dioxide emissions of the vehicles. Praseodymium gives the yellow color to ceramic alloys.

REE deposits are abundant, but the risk of not having them available for the dependent industries is still high, considering their strategic importance. In order to compensate the decrease in the international supply, due to the Chinese trade policies, it is essential to rapidly make operational the new deposits discovered, especially the ones in Afghanistan (see subchapter 3.2) or to discover new ones. Afghanistan’s infrastructure is very poor and the costs to start operating the deposits will be high. To finance projects in these difficult times will also be a great endeavor.

The economy of such materials and the manufacturing technologies involved, some of them very recent, as we mentioned, make difficult the replacement REE. Permanent magnets made of neodymium have qualities that make them irreplaceable with the classical ones, based on ferrite, with lower performances. The car batteries based on nickel metal hydride (NiMH), comprising lanthanum can be progressively replaced with batteries based on lithium-ion (Li-ion).

Bibliography

• [1] The US Geological Survey, 2011.
• [2] Paul Truchot, Les terres rares: mineralogie, proprietes, analyse, Paris, G. Carre şi C. Naud, 1898, p. 29.
• [3] US Geological Survey, 2011.
• [4] National Research Council. Minerals, Critical Minerals, and the U.S. Economy. Washington, DC: The National Academies Press, 2008.

 

Source: Dobrescu, Emilian M. (2023). The Rare Earths Economy, MultiMedia Publishing, ISBN: 978-606-033-785-0, DOI: 10.58679/TW70453, https://www.telework.ro/en/e-books/the-rare-earths-economy/