Rare Earth Elements Part 2: Recycling for a Sustainable Future

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Recycling rare earth elements has become an increasingly prominent issue as supply continues to decrease and demand soars. Rare earth elements are a group of 17 chemical elements that are essential components for a lot of our modern technologies. Unfortunately, mining and extracting them can pose significant environmental impacts including water pollution and the destruction of ecosystems. Recycling can reduce these negative impacts while also conserving valuable resources. Therefore, recycling has got more and more attention from industries, researchers, and governments who are all working towards the same goal of promoting sustainability and reducing carbon footprint.

Fraunhofer IFAM Dresden, oxides of rare earths relevant for recycling of magnets

Despite their importance in our lives, only 1% of rare earth elements get recycled from end products. In 2021, we mined 32 times as many rare earth elements as in the mid-1950s. By 2040, it’s estimated that demands will reach 7 times of what they are now. The extraction and concentration of rare earths will be energy intensive and potentially damaging to the environment. The toxic chemicals and radioactive waste must be safely deposited, which in turn takes up more resources. Also, China currently has a monopoly over the rare earths market, making it difficult for some countries to get their hands on these precious metals. Due to the growing demands, various suggestions about how to obtain more rare earths to satisfy those demands have emerged.

Recycling seems like an easy way to get our hands on a larger supply of rare earths. It is the way the US and Europe get back 15 to 70 percent of other metals such as iron, copper, aluminum, nickel, and tin. “Copper wiring can be recycled into more copper wiring. Steel can just be recycled into more steel,” said Simon Jowitt, an economic geologist at the University of Nevada, but a lot of rare earth products are “inherently not very recyclable.” Rare earth elements are usually mixed with other metals in end products and they generally show up in small amounts. Traditional rare earth recycling methods use harmful chemicals such as hydrochloric acid and a lot of heat. This process releases substances and furthermore, the cost to recycle ends up greater than the worth of the products formed. This is why scientists attempted to find more efficient ways to recycle and save our supply of rare earth materials.

One such solution involves the use of microbes and bacteria. Some bacterias produce organic acids that can pull rare earths, such as lanthanum and cerium, from the mixed end-products. They are better for the environment than hydrochloric acid or other acids traditionally used for the recycling of rare earth metals. However, this process also has its downsides since it has been proven in an experiment that it can only extract about 50% of the rare earths. On the other hand, environmentally-harmful hydrochloric acid can extract up to 99% of rare earths. Furthermore, feeding the bacteria that produce the acids can be extremely costly as well, taking the majority of the profit away. Another potential source of rare earth recycling comes from magnets. 30% of the neodymium-iron-boron magnets are composed of rare earths, making it one of the largest holders of such metals. 

Flash joule heating and the use of intense electricity can be another method of recycling rare earths. It was devised by a group at Rice University, and they did so by putting the target substances in a tube and using electricity that “flashed” it to around 5400 degrees Fahrenheit. This can separate the rare earth elements from the rest of the gadget containing it, and it needs to be processed after the separation process. The system used is designed to be able to capture the toxic chemical released and prevent them from harming the environment. Unlike the strong nitric acid, a more diluted hydrochloric acid is used. However, more waste will be released when the rare earths get separated. Managing the waste products once again became a major issue. 

The flash Joule heating process was developed at Rice University

Scientists are still trying to find ways to make the rare earth business more sustainable. Recycling can certainly be a solution to the growing issue because of the innovations that make the process better for the environment. Nevertheless, recycling can only do so much. Maybe the solution can come from the products themselves, so let’s keep pushing for innovation and creativity – we might just discover the next thing that revolutionizes the rare earth industry and makes the world a better place!

Further Reading: https://areteem.org/blog/rare-earth-elements-a-story-of-economic-gain-and-environmental-loss/

Works Cited:

  • Guthrie, Mike. “Recycling Rare Earth Magnet Materials.” SM Magnetics, smmagnetics.com/blogs/news/recycling-rare-earth-magnet-materials.
  • Jiao, Yongqin, et al. “Engineered Microbes for Rare-Earth Element Adsorption | Laboratory for Energy Applications for the Future.” Leaf.llnl.gov, leaf.llnl.gov/technology-capabilities/engineered-microbes-rare-earth-element-adsorption. Accessed 18 Apr. 2023.
  • Jowitt, Simon M., et al. “Recycling of the Rare Earth Elements.” Current Opinion in Green and Sustainable Chemistry, vol. 13, Oct. 2018, pp. 1–7, https://doi.org/10.1016/j.cogsc.2018.02.008.
  • Rao, Rahul. “Inside the High-Powered Process That Could Recycle Rare Earth Metals.” Popular Science, 11 Feb. 2022, www.popsci.com/environment/rare-earth-metal-recycling/.
  • “Rare Earth Recycling.” Fraunhofer Institute for Manufacturing Technology and Advanced Materials IFAM, www.ifam.fraunhofer.de/en/Aboutus/Locations/Dresden/HydrogenTechnology/recycling.html. Accessed 19 Apr. 2023. ‌
  • “Rare Earths Statistics and Information | U.S. Geological Survey.” Www.usgs.gov, National Minerals Information Center, www.usgs.gov/centers/national-minerals-information-center/rare-earths-statistics-and-information.
  • “Urban Mining for Metals Flashes Forward.” Space Daily, 5 Oct. 2021, www.spacedaily.com/reports/Urban_mining_for_metals_flashes_forward_999.html. Accessed 19 Apr. 2023.
  • Wayman, Erin. “How Science Could Make Recycling Rare Earth Elements Easier.” Science News, 20 Jan. 2023, www.sciencenews.org/article/recycling-rare-earth-elements-hard-new-methods.

This column was submitted by high school student Iris Wang. Student STEM Columns are submitted by high school or advanced middle school students who wish to share their passion for STEM. Students interested in submitting a column should email us at info@areteem.org.

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