Extract rare earths outside of China and... cleanly!
The world production of rare earths is an annual market of 4 billion euros. This market continues to grow as new electronics, engines for aircraft, naval vessels, electric automobiles, magnets, and other essential products are developed that require rare earths to function. The value of products made with rare earths, and mainly neodymium, is estimated at more than 4,000 billion euros per year.
The current challenge is that only one country, China, holds the market for the extraction and purification of this essential resource, while other countries in the world, including the United States, are rich in these metals. The detrimental environmental impact of current acid-based rare earth separation and purification prohibits most companies worldwide from entering the market.
New environmentally friendly technologies promise to be a game changer in this area and allow the United States and other countries to create a more stable and reliable local source. Extraction and purification processes patented by Purdue University, using ligand-assisted chromatography, are shown to remove and purify these metals from coal ash, recycled magnets and raw ore in a way safe, effective and with virtually no harmful impact on the environment.
Environmentally friendly ligand-assisted chromatography method
The graphic illustrates an environmentally friendly method of ligand-assisted chromatography to help produce purified rare-earth metals, including neodymium and samarium-cobalt, from magnetic waste to ensure a strong supply of essential materials for electronics. Credit: Illustration provided by Linda Wang
"This is a supply chain challenge that has broad implications for the U.S. economy and national security. We have a critically needed product and a dominant source for that product. This new patented process promises to enable the independence of the United States from the quasi-monopoly of China," said Dan Hasler, founder of Hasler Ventures. "This technology has been researched and developed at Purdue University for over a decade and has proven to be versatile and robust."
Hasler Ventures has obtained the rights to commercialize the intellectual property of this technology from the Purdue Research Foundation.
The technology - developed and patented in the lab of Nien-Hwa Linda Wang, Maxine Spencer Nichols Professor of Chemical Engineering at Purdue - has been successfully shown to separate rare earth metals without the devastating environmental effects of conventional acid-based methods, with high yield and purity.
Some of this technology was published on March 31, 2020 in the Royal Society of Chemistry publication Green Chemistry. The source of funding for this research includes the Department of Defense.
"About 60% of rare earth metals are used in magnets that are needed in almost everyone's daily life. These metals are used in electronics, airplanes, hybrid cars and even wind turbines," said Mr Wang. "We currently have a dominant foreign source for these metals and if supply were to be limited for any reason it would be devastating to people's lives. It's not that the resource is not available in the United States. , but that we need a better, cleaner way to process these rare earth metals."
According to Wang, after China reduced rare earth metal export quotas in 2010, the cost of rare earth magnets for a wind turbine rose from $80,000 to $500,000. After China eased export restrictions 18 months later, prices returned to lower levels than in 2010.
"Conventional methods of producing high-purity rare earth elements rely on two-phase liquid-liquid extraction methods, which require thousands of mixer-settler units in series or in parallel and generate large amounts of toxic waste," Wang said. "We use a two-zone ligand-assisted displacement chromatography system with a novel zone separation method that produces high purity metals (>99%) in high yields (>99%)."
Wang's ligand-assisted method provides the opportunity to effectively and environmentally purify rare earth metals from all recycling sources, such as used magnets and ore-based sources, and helps transform earth processing rare in a circular and sustainable process.
“We continue to work diligently in the lab to learn how to adapt the ligand-assisted system to the many variations we see in source materials and we look forward to collaborating with potential partners and evaluating their suitability for use the basic materials, be it recycled magnets and batteries, coal ash or ore mined in the country.
Joe Pekny, professor of chemical engineering at Purdue, said Wang's innovation allows the United States to re-enter the rare earth metals market in a meaningful and sustainable way.
"What's exciting is that the United States has the rare earth metals needed to meet the growing demands of the U.S. market and other markets around the world, and it's reducing our dependence on foreign sources," Pekny said. "Linda's method replaces a very inefficient process and replaces it with a safe and earth-friendly extraction process."
Reference: Two-Zone Ligand-Assisted Displacement Chromatography to Produce High Purity Praseodymium, Neodymium, and Dysprosium in High Yield and High Productivity from Raw Mixtures Derived from Magnetic Waste by Yi Ding, David Harvey, and Nien- Hwa Linda Wang, March 31, 2020, Green Chemistry.
Source: Scitechdaily.com