Rare Earth Elements: Their Importance, Uses, and Environmental Impacts

Rare earth elements, despite their name, are not actually rare. These seventeen chemically similar elements, including fifteen lanthanides along with scandium and yttrium, are found in abundant quantities within the Earth's crust. However, their moniker 'rare' arises from the difficulty associated with mining these elements, as they rarely occur in concentrations rich enough for economical extraction.

The picture contains seven different rare earth elements

What is Rare Earth?

In the periodic table of chemical elements, rare earth refers to the general term of 17 metal elements including lanthanide elements, scandium and yttrium. The "big family" of rare earths is divided into light rare earths and medium and heavy rare earths. Lanthanum, cerium, praseodymium, neodymium, promethium, samarium, and europium are light rare earth elements, also known as cerium group rare earth elements; scandium, gadolinium, terbium, dysprosium, holmium, Erbium, thulium, ytterbium, lutetium and yttrium are medium-heavy rare earth elements, also known as yttrium group rare earth elements. Rare earth elements are widely distributed in the earth's crust, but very unevenly. Countries with large rare earth reserves include China and India in Asia, the United States and Canada in North America, and Russia, Australia, South Africa, Egypt and other countries.

Importance of Rare Earth Elements

The significance of rare earth elements in modern life cannot be overstated. Their unique magnetic, luminescent, and electrochemical properties make them critical components in many technological applications. From powerful magnets to catalysts, ceramics, glass, metallurgy, nuclear energy, and electronics, rare earth elements are the silent facilitators of the technological revolution.

Rare earth element prices rise

Light rare earths are also called "false rare earths" by industry insiders. Although they have a large stock and wide application, their value is relatively low; while heavy rare earth resources are scarce and can be used in high-tech fields such as aerospace, military, national defense, and new material synthesis, and are expensive. Substitutability is small. In 2018, the price of neodymium oxide was US$107,000/t. By 2025, this price is expected to rise to US$150,000/t. Europium is even more expensive, at around $712,000/t. Part of the reason rare earths are so expensive is that rare earth elements are chemically difficult to separate from each other to obtain the pure substances.

Uses of Rare Earth Elements

Among the myriad applications of these elements, some stand out for their ubiquity and indispensability. Neodymium and praseodymium are integral for producing strong permanent magnets, vital in wind turbines and electric vehicles. Lanthanum and cerium are extensively used in catalytic converters to reduce harmful emissions from vehicles. Europium and terbium are vital components in the manufacturing of fluorescent lamps and television screens. As we advance into a more tech-driven era, the demand for rare earth elements is likely to continue growing.

Rare earth elements play an important role in many high-tech applications due to their unique chemical and physical properties. Here are some major uses of rare earth elements:

• Magnetic materials: Rare earth elements such as neodymium and europium are used to create powerful permanent magnets that are widely used in hard disk drives, electric vehicles, wind turbines, and more.

• Catalysts: Many rare earth elements, such as cerium and lanthanum, are important catalysts used in automotive exhaust systems and petroleum refining processes.

• Fluorescent and phosphorescent materials: Rare earth elements such as europium, terbium, and erbium are used to make fluorescent and phosphorescent materials in television and computer displays.

• Metallurgy: Rare earth elements such as samarium and dysprosium can be used as additives to metal alloys to improve their working properties.

• Nuclear Reactions: Certain rare earth elements, such as dysprosium and neodymium, are used to make control rods in nuclear reactors.

• Electronics: Many rare earth elements, such as yttrium, terbium, and erbium, are used in the manufacture of a variety of electronic devices, including batteries, capacitors, lenses, and more.

Environmental Impact of Rare Earth Mining

However, the extraction and processing of rare earth elements pose significant environmental challenges. Mining activities can lead to soil and water contamination and the generation of radioactive waste. As a result, mining rare earths necessitates stringent environmental regulations and monitoring to mitigate these impacts. As we continue to rely on these elements for our technological progress, it is imperative to balance the benefits they bring against the environmental costs of their extraction.

The world of rare earth elements is a fascinating mix of chemistry, technology, and environmental science. As we deepen our understanding of these elements, their uses, and impacts, we can make more informed decisions about our resource use and the future of our planet.

The Geopolitics of Rare Earth Elements

According to the data of the US Geological Survey, as of 2021, the global rare earth reserves will be 120 million tons of rare earth oxides (REO), and China will be 44 million tons (REO), accounting for about 35% of the world (the proportion of rare earth reserves in various countries is shown in the figure 1).

Figure 1 Rare earth reserves in countries around the world (data source: USGS, 2021)

The global politics around rare earth elements are as complex as their chemistry. China currently dominates the world's production and supply of these elements, contributing to over 80% of the global output. This dominance can lead to supply chain vulnerabilities for other nations, particularly those heavily invested in high-tech industries. To mitigate this, several countries, including the United States and Australia, are looking to diversify their sources of rare earth elements, either through domestic production or by forming alliances with other producing nations.

Sustainability and the Future of Rare Earth Elements

Given the environmental implications and geopolitical complexities associated with rare earth elements, sustainability is a key concern. Efforts are underway to develop more environmentally friendly mining and processing techniques, as well as recycling initiatives for products containing these elements. Meanwhile, researchers are also exploring potential substitutes that could reduce our reliance on rare earths without compromising the performance of the products.

Investment Opportunities in Rare Earth Elements

Despite the challenges, the demand for rare earth elements presents significant investment opportunities. Companies involved in mining, refining, and recycling of these elements stand to gain from the increasing demand. However, potential investors need to consider factors such as environmental regulations, geopolitical risks, and market volatility while making their investment decisions.

Are rare earth elements harmful to health?

Whether rare earth elements have an impact on health The main way for rare earth elements to enter the body is the respiratory tract and skin, and they can also be absorbed through the digestive tract through ingestion. After rare earth elements enter the human body, they mainly accumulate in the liver and bones, with the highest content in the bones. The content of different rare earth elements in different human organs is also different. For example, the content of aviation is the highest in the lungs, followed by the liver, and the lowest in the kidneys; the content is the highest in the liver, followed by muscles and bones, and the lowest in the lungs; It is the lowest among the highest kidneys.

After a large dose of rare earth enters the human body, it can cause acute poisoning. The main symptoms are: vomiting, diarrhea, dyspnea, rapid heartbeat, general convulsions, etc., which may lead to diffuse peritonitis, peritoneum, bloody ascites, liver turbidity and swelling, focal pulmonary Hemorrhage and other pathological phenomena: in severe cases, the heartbeat and breathing stop, and die quickly. Under normal circumstances, low-dose exposure to rare elements will not bring obvious harm to humans. However, long-term low-dose intake may have adverse consequences on human health or internal metabolism, such as affecting brain function, increasing the burden on liver and kidney, damaging heart function, and causing abnormal fertility.

Rare earth elements are not completely harmful. Some rare earth elements are not only harmless to human health but also have certain positive effects. For example, rare earth compounds are a typical anticoagulant, which can be used as an anticoagulant in medicine. Some rare earth elements The compound is also antibacterial and can be used to treat burns. Studies have shown that rare earths also have anti-tumor activity and anti-inflammatory effects; rare earths can also regulate the secretion of insulin cells and promote the weak division activity of liver cells, change the phase of the liver cell cycle, and reduce the apoptosis of normal liver cells .

Conclusion

Rare earth elements are a fascinating area of study, intertwining science, technology, politics, and environmental sustainability. As we move forward into a future increasingly reliant on high-tech solutions, the importance of these elements will only continue to grow. At the same time, it is essential to address the associated environmental and geopolitical challenges to ensure a sustainable and equitable future for all.