Rare earth elements are useful in developing green energy technologies. But with increasing demands and limited availability, things are not moving faster. Recently, researchers discovered that eggshell waste can recover rare earth materials from water at varied temperatures.

Recently, through collaborative research, it was discovered that eggshell waste has the potential to recover rare earth elements (REEs) from water. This shows a new environmentally friendly method for their extraction. The collaborative team includes researchers from Trinity’s School of Natural Sciences and iCRAG.

What are REEs?

Rare earth elements are important for wind turbines and electric cars’ technologies. Their supply is less than required and extraction methods are also harmful, making them rare materials. Due to this, scientists are finding new ways to sustainably extract them from the environment.


  • Researchers find that calcite (calcium carbonate) in eggshells can effectively absorb and separate these REEs from water.
  • For up to 3 months, eggshells were placed under different temperatures in a solution containing REEs. The temperature varies from 25° C to 205° C.
  • Elements can enter eggshells via diffusion along the calcite boundaries and organic matrix.
  • At higher temperatures, REEs built new minerals on the surface of eggshells.
  • At 90° C, eggshell surface helped in recovering formations of kozoite, a rare earth compound.
  • Eggshells experienced a complete transformation with rising temperatures. Calcite shells start to dissolve and soon polycrystalline kozoite replace it.
  • At the highest temperature of 205° C, kozoite transitions to bastnasite. It is a stable rare earth carbonite mineral that many industries use to extract REEs for technological applications.
eggshell waste can recover rare earth materials
Pic Credits: Trinity College


The research concludes that over time, eggshell waste can recover rare earth materials and effectively trap them within their structure. This research highlights the possibility of repurposing waste eggshells as a low-cost and eco-friendly material to help with the growing demands for REEs.

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Lead author, Remi Rateau states, “This study presents a potential innovative use of waste material that not only offers a sustainable solution to the problem of rare earth element recovery but also aligns with the principles of circular economy and waste valorisation.”

Prof. Juan Diego Rodriguez-Blanco, principal investigator, adds, “By transforming eggshell waste into a valuable resource for rare earth recovery, we address critical environmental concerns associated with traditional extraction methods and contribute to the development of greener technologies.”

Source: A cracking discovery


Elliot is a passionate environmentalist and blogger who has dedicated his life to spreading awareness about conservation, green energy, and renewable energy. With a background in environmental science, he has a deep understanding of the issues facing our planet and is committed to educating others on how they can make a difference.

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