New technology promises to be game-changer in the extraction of rare earths
Neodymium magnets. (Image by Nevit Dilmen, Wikimedia Commons).
Researchers at Purdue University in the US have developed a new technology that promises to be a game-changer in the extraction of rare earths.
The global market of rare earth metals has been valued at $4 billion per year but 70% of the production is concentrated in China
In a paper published in the journal Green Chemistry, the scientists explain that the patented extraction and purifying processes use ligand-assisted chromatography and are shown to remove and purify rare earth metals from coal ash, recycled magnets and raw ore safely, efficiently and with virtually no detrimental environmental impact.
This is key because, at present, many companies across the world don't even dare to consider extracting REE due to the damages caused to the environment by acid-based separation and purification of these elements.
"About 60% of rare earth metals are used in magnets that are needed in almost everyone's daily lives. These metals are used in electronics, aeroplanes, hybrid cars and even windmills," Nien-Hwa Linda Wang, whose lab developed the technology, said in a media statement. "We currently have one dominant foreign source for these metals and if the supply were to be limited for any reason, it would be devastating to people's lives. It's not that the resource isn't available in the US, but that we need a better, cleaner way to process these rare earth metals."
Environmentally friendly ligand-assisted chromatography method to help produce purified rare earth metals from waste magnets. (Illustration provided by Linda Wang/Purdue University).According to Wang, conventional methods for producing high-purity rare earth elements employ two-phase liquid-liquid extraction mechanisms, which require thousands of mixer-settler units in series or in parallel and generate large amounts of toxic waste. Her method, however, uses a two-zone ligand-assisted displacement chromatography system with a new zone-splitting technique that is producing high-purity (>99%) metals with high yields (>99%).
"We continue to work diligently in the lab to learn how to adapt the ligand-assisted system to many variations we see in source material and are excited to collaborate with and assess the suitability of potential partners source material be it recycled magnets and batteries, coal ash or domestically mined ore," the researcher said.
Hasler Ventures, a Florida LLC founded in partnership with Purdue University and the Purdue Foundry to enable the creation of a US rare earth metals supply chain, has secured rights from the Purdue Research Foundation that grant the company first rights to commercialize the technology's intellectual property.