Rare Earth Elements

Ecology: Rare Earth Elements and Deposits Located Around the Earth

The rare-earth elements, often known as rare-earth metals, rare-earth oxides, or lanthanides, are a group of 17 virtually identical glossy silvery-white soft heavy metals. For example, scandium and yttrium are rare-earth elements because they exist in the same ore deposits as lanthanides and have comparable chemical characteristics but distinct electrical and magnetic properties.

Ytterbium Rare Earth Element
Credit: Wikidata

About Rare Earth Elements

The use of rare earth elements applies to different dimensions like electrical capacity, glass, magnetic products, and industrial processes. Most popular is the sale of powerful neodymium magnets as novelty items.

Despite their name, rare-earth elements exist in Earth’s crust, with the cerium element being the 25th most abundant element at 68 parts every million. It makes it more prevalent than copper. All promethium isotopes are radioactive, and it does not occur naturally in the Earth’s crust. Nevertheless, a trace quantity occurs through uranium 238 decay. They exist in minerals containing thorium and, less frequently, uranium.

Symbol Name Etymology
Yb Ytterbium after the Swedish town of Ytterby
Y Yttrium after the Swedish hamlet of Ytterby, where the first rare earth ore was found
Tm Thulium Thule, the legendary northern country.
Tb Terbium after the Swedish town of Ytterby
Sm Samarium Vasili Samarsky-Bykhovets, a mining official.
Sc Scandium originating in Latin Scandia (Scandinavia).
Pr Praseodymium from the Greek words “prasios” (leek-green) and “didymos” (twin).
Pm Promethium after the Titan Prometheus, who gave mortals fire
Nd Neodymium from the Greek words “neos” (new) and “didymos” (twin).

Rare Earth Elements

Lu Lutetium Lutetia was named after the city that became Paris.
La Lanthanum “lanthanein” is a Greek word that means “to be concealed.”
Ho Holmium after the native city of one of its discoverers, Stockholm (in Latin, “Holmia”).
Gd Gadolinium Johan Gadolin (1760–1852) was named after him to commemorate his research into rare earths.
Eu Europium following the continent of Europe.
Er Erbium after the Swedish town of Ytterby
Dy Dysprosium from the Greek “dysprositos,” which means “hard to get.”
Ce Cerium Ceres, named for the Roman goddess of agriculture, is named after the minor planet Ceres.
Thulium REE
Credit: Newton Desk

Global Rare-Earth Element Distribution

Until 1948, most of the REE across the globe traces from sand deposits across India and Brazil. South Africa was the world’s rare-earth supply until the 1950s, thanks to a monazite-rich reef at the Steenkampskraal mine in Western Cape province. Then, from the 1960s through the 1980s, the Mountain Pass rare earth mine in California established the United States as the largest REE producer globally. Today, the Indian and South African resources generate some rare-earth concentrates, but Chinese production dwarfs their output.

In 2017, China produced a total of 81% of the rare-earth element supply of the world, primarily in Inner Mongolia, while having just 36.7% reserves. Australia was the second and only other large producer, accounting for 15% of global output. All of the world’s heavy rare earth elements (such as dysprosium) mostly come from Chinese rare-earth deposits, like the polymetallic Bayan Obo deposit. The Browns Range mine, located 160 kilometres southeast of Halls Creek in northern Western Australia, is now under construction and is poised to become the world’s first large dysprosium producer outside of China.

Demand for REEs

Increased demand has put pressure on supplies, and there is growing worried that the world could soon run out of REE. Unless new sources crop up, global demand for rare-earth elements will exceed supply by 40,000 tonnes per year for several years, beginning in 2009. Furthermore, there was a prediction in 2013 that demand for REEs would rise owing to the EU’s reliance on these elements, other elements cannot substitute rare earth elements, and REEs have a poor recycling rate. Furthermore, due to rising demand and limited supply, future prices are likely to rise, and nations other than China may establish rare earth element mines.

REEs are in high demand as they come into use to develop new and innovative technologies. These new goods that require the manufacturing of REEs include high-tech items such as smartphones, digital cameras, computer components, and semiconductors. Furthermore, these components are more common in the following industries: renewable energy technology, military equipment, glass manufacturing, and metallurgy.

Country-wise Deposits of Rare Earth Elements

Let us look at the countries with reserves of over 1 million MT of rare earth elements.

China

With reserves of 44 million MT

China, unsurprisingly, has the most deposits of rare earth minerals, at 44 million MT. In addition, the country was by far the world’s leading REE producer 2020, producing 140,000 MT.

Despite its dominant position, China is intent on keeping its reserves at a high level. The Asian country claimed in 2012 that its rare earth stocks were dwindling; in 2016, it announced that it would increase domestic reserves by building commercial and national depots.

It’s worth mentioning that China’s dominance in both REE production and reserves has caused issues in the past. For example, when the government stopped exports in 2010, prices skyrocketed, causing a scramble to secure supplies of minerals abroad. While the problem is in control, the ongoing trade war between the United States and China has raised new concerns about the country’s status.

Vietnam

With reserves of 22 million MT

Vietnam’s rare earth mineral deposits are substantial, totalling 22 million MT. According to reports, the country has multiple rare earth material deposits, with concentrations in its northeastern border with China and its eastern coastline. The bulk of the country’s rare earth elements exist in primary ore deposits, with a minor proportion found in coastal placer deposits.

Vietnam’s rare earth element output in 2020 was tiny at 1,000 MT, but it increased 66% over the previous year’s output of 400 MT. Vietnam is interested in increasing its renewable energy capacity and aims to generate additional REEs.

Brazil

With reserves of 21 million MT

Brazil was not a significant producer of REEs in 2020, with output totalling about 1,000 MT. However, with 21 million MT of reserves, the country ranks third in the world. A rare-earth element mine worth $8.4 billion was discovered in Brazil in 2012, but little has been of its production. However, it’s simple to see why the country’s reserves are so large.

Russia

With reserves of 12 million MT

Russia produced 2,700 MT of rare earth elements in 2020, more than Brazil and Vietnam combined, but its reserves are less at 12 million MT. The Russian government has declared plans to invest US$1.5 billion in the REE industry to compete with China.

India

With reserves of 6.9 million MT

India has 6.9 million MT of rare earth deposits and will generate 3,000 MT of rare earth elements in 2020. There are, nevertheless, grounds to hope that the country’s REE sector holds promise. India totals 35% of beach mineral resources globally. These are some of the crucial sources of rare earth elements.

Australia

With reserves of 4.1 million MT

While Australia was the fourth largest rare earths-mining country in 2020, with 27,000 MT of output, it only possesses its sixth most significant reserves. Its reserves currently stand at 4.1 million MT.

Australia has only extracted REEs since 2007, although extraction is likely to rise in the future. Lynas presently runs the country’s Mount Weld mining and concentration plant and a rare earth elements refining and processing factory in Malaysia. It is the world’s largest non-Chinese supplier of REEs.

The United States and Greenland

With reserves of 1.5 million MT

The United States and Greenland both stand in eighth place in rare earth reserves. Mining for REEs in the United States is now limited to the Mountain Pass mine in California. US President Joe Biden passed an executive order in February 2021 to evaluate flaws in America’s domestic supply chains for rare earth elements, medical gadgets, computer chips, and other vital resources. The US Department of Energy launched the following month a $30 million programme to explore and secure domestic supply chains for rare earth elements and battery metals like cobalt and lithium.

In a storey of two rare earth deposits, Greenland’s newly elected government campaigned on a platform that included the cancellation of the island nation’s sole (and contentious) REE mining project.

Promethium REE
Credit: Blog

Recycling of REEs

Electronic trash and other waste containing significant rare-earth components have lately emerged as a new source of REEs. New improvements in recycling technology have made rare earth extraction from these materials more feasible. Recycling factories are already operational in Japan, where an estimated 300,000 tonnes of REEs occur in abandoned electronics.

The Rhodia company is establishing two plants in France, at La Rochelle and Saint-Fons, to produce 200 tonnes of REEs per year from old fluorescent lights, magnets, and batteries. In addition, coal and coal byproducts are a possible supply of essential elements, including rare earth elements (REE), with estimates ranging from 50 million metric tonnes.

Use of Rare Earth Elements

Rare-earth element usage, applications, and demand have grown throughout time. The majority of REEs come into use in catalysts and magnets across the world. More than half of REEs are utilised in catalysts in the United States, with essential applications in ceramics, glass, and polishing.

Other significant applications for rare-earth elements include manufacturing high-performance magnets, alloys, glasses, and electronics. Ce and La are catalysts that are utilised in petroleum refining and as diesel additives. Nd is significant in the manufacture of magnets in both traditional and low-carbon technologies. REE in this group come into use in hybrid and electric cars, electric motors, wind turbine generators, hard disc drives, portable electronics, microphones, and speakers.

Ce, La, and Nd are significant in the manufacture of alloys and fuel cells and nickel-metal hydride batteries. In addition, Ce, Ga, and Nd are essential in electronics because they come into use in manufacturing LCD and plasma displays, fibre optics, lasers, and medical imaging. Rare-earth elements come into use as tracers in medicinal applications, fertilisers, and water treatment.

Rare Earth Elements
Credit: Mining Blog

Usage of REE across Various Sectors

REEs have been employed in agriculture to boost plant growth, productivity, and stress tolerance, ostensibly with no detrimental consequences on human or animal consumption. REEs also come into use in agriculture through REE-enriched fertilisers, which is a common practice in China. Furthermore, rare earth elements are feed additives for livestock, which has resulted in enhanced output such as giant-sized animals and higher egg and dairy product production.

However, this technique has led to REE bioaccumulation in animals and a reduction in flora and algae growth in certain agricultural regions. Furthermore, though there have not been any adverse effects at low doses, the consequences over the long term and with accumulation over time are unclear, causing some to advocate for additional research into their potential impacts.

Given the scarcity of resources, sectors fight for them directly. For example, the electronics industry competes directly with renewable energy consumption in wind farms, solar panels, and batteries.

Impact of REE Contamination on Vegetation

The mining of REE has contaminated the soil and water near production sites, affecting flora in these places by reducing chlorophyll production, which impairs photosynthesis and limits plant development. The influence of REE pollution on vegetation, on the other hand, is contingent on the plants present in the polluted environment: certain plants retain and absorb REEs, while others do not. Furthermore, the capacity of the flora to absorb REE is reliant on the kind of REE available in the soil.

The primary kind of flora affected by REE pollution is agricultural plants, with apples and beets having a higher probability of absorbing and retaining REEs. Furthermore, REEs may leak into aquatic habitats and be absorbed by aquatic vegetation, which may then bio-accumulate and, after that, enter the food chain of humans if animals or people consume the vegetation.

Impact of REE Contamination on Human Health

Rare earth elements are a diverse category with a wide range of characteristics and quantities in the environment. Because of this and limited studies, determining acceptable amounts of exposure for humans has been challenging. Consequently, several studies have focused on risk assessment based on exposure pathways and divergence from baseline values associated with agriculture, mining, and industry.

Numerous REEs have portrayed hazardous characteristics and are found in the environment or at work. Exposure to chemicals can result in various severe health effects, including cancer, lung problems, tooth loss, and even death. However, because REEs are many and present in various forms and toxicity levels, it is challenging to provide blanket warnings about cancer risk and toxicity because some are innocuous while others represent a concern.

Former REE Mine
Credit: Blog

Toxicity and REE

What toxicity has been demonstrated appears to be at very high levels of exposure by consuming the REE contaminated food and water, by inhaling dust/smoke particles as an occupational hazard, or due to proximity to polluted locations such as mines and cities. As a result, the significant concerns these people will encounter are REE bioaccumulation and the influence on their respiratory system. Still, there may be other probable immediate and long-term health consequences.

The mining and smelting of rare earth elements can induce the production of airborne fluoride, which can combine with total suspended particles (TSP) to produce aerosols that can enter human respiratory systems and cause damage and respiratory illnesses. According to research from Baotou China, the fluoride content in the air around REE mines is greater than the WHO guideline value, impacting the surrounding environment and providing a risk to individuals who live or work there.

Impact of REE Contamination on Animal Health

Experiments in which rats were exposed to several cerium compounds revealed buildup predominantly in the lungs and liver. It leads to diverse poor health consequences related to those organs. REEs have been added to cattle feed to improve body mass and milk output. They are most often employed to enhance pig body mass, and results show that rare earth elements improve the digestibility and nutritional utilisation of the pig digestive tract.

When it comes to toxicity vs beneficial benefits, studies show a dosage response. While tiny amounts from the environment or when administered correctly appear to have no harmful consequences, greater dosages have brought deleterious effects, particularly in the organs they collect. For example, the mining of REEs in China has led to soil and water pollution in some regions, which, if carried into aquatic bodies, might bio-accumulate within aquatic biota. Furthermore, animals living in REE-contaminated regions have organ or system issues in some situations.

REEs are employed in freshwater fish aquaculture because they protect the fish against illness. However, one of the primary reasons they have been widely utilised in animal cattle feeding is that they outperform inorganic livestock feed enhancers.

Conclusion

Rare-earth elements are usually scattered and seldom found concentrated in rare-earth minerals due to their geochemical characteristics. As a result, economically exploitable mineral resources are few. Therefore, studying the rare earth elements is equally exciting and wonderous!

Leave a Reply