Tuesday, June 11, 2024

Essential rare earth elements pulled from water using eggshells

Neat as the mineral can adsorb the rare earth elements from the brine.  this produces a recoverable mineral holding any of the rare earth after which further processing is then possible.

It certainly gets rid of the brine itself and super concentrates the rare earths.

This is a excellent process, easily implimented and temperature controled.  after enricshment, the second phase eliminates all the calcium and you have purified rare earth mineral complex rerady to work with and both brine and egg shells are gone.

this is practical research at bits best.

Essential rare earth elements pulled from water using eggshells

June 06, 2024


The humble eggshell has been used to recover rare earth elements essential to green energy technologies

Using humble waste eggshells to pull rare earth elements from water, researchers have developed a simple, low-cost and sustainable procedure to provide the essential materials needed for a transition to green energy technologies.

Making the successful transition to green energy is dependent on rare earth elements (REEs), which are needed to make essential components in things like hybrid and electric vehicles and wind turbines. Despite their name, these elements aren't actually rare. The problem is, though, that they’re usually found in low concentrations and are combined, meaning their extraction and separation are expensive, energy- and water-intensive, and generate a lot of waste.

In a new study, researchers from Trinity College at the University of Dublin tested a simple process of REE recovery that relies on a cheap, sustainable resource: the humble eggshell.

“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 valorization,” said Remi Rateau, from the College’s School of Natural Sciences and the study’s lead and corresponding author.

Composite image using high-resolution microscopy and spectroscopy showing the absorption and replacement processes of rare earth elements (REEs) in the eggshell

Trinity College Dublin/University of Dublin

The researchers placed waste hen eggshells in solutions containing REEs and heated them to temperatures ranging from 25 °C (77 °F) up to 205 °C (401 °F) for up to three months. They observed that the REEs diffused – that is, they moved from a region of high concentration to one of low concentration – into the eggshells along the calcium carbonate (calcite) boundaries and the organic matrix, a complex mixture of organic material, including protein, that’s intimately associated with the outer calcite shell.

The REEs formed new minerals at higher temperatures on the eggshell’s surface. At 90 °C (194 °F), kozoite formed on the surface of the dissolving calcite. At 165 °C (329 °F) and 205 °C, the researchers noted that the calcite dissolved completely and was replaced by polycrystalline kozoite. At 205 °C, the kozoite was slowly replaced by bastnäsite, the stable rare earth mineral typically used to extract REEs for technological applications.

The researchers say their simple, low-cost and environmentally friendly process could help meet the increasing demand for REEs as the world embraces more green energy technologies.

“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," said Juan Diego Rodriguez-Blanco, lead researcher on the study.

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