Researchers Advance Critical Materials Recycling Technologies
INL’s Recycling Research
Since the early 2010s, INL has developed technologies that reduce chemical use, energy consumption and waste, making recycling more sustainable and cost-effective. These innovations improve recovery from sources such as electronic and agricultural waste, mine tailings and industrial wastewater.
“INL has developed a comprehensive portfolio of critical materials recycling technologies,” said Mukhopadhyay. “We have the expertise and proven processes to help make recycling economically competitive, which is essential for building a reliable domestic supply of the materials our nation depends on.”
One area INL has worked in for many years is biohydrometallurgy, which uses biological systems to dissolve and recover metals. INL’s research examines how microbial populations fed agricultural or municipal waste biomass produce organic acids that break down metals in both metallic and mineral forms. These biologically produced acids dissolve the material and release valuable metals such as rare earth elements, cobalt and lithium. The dissolved metals can then be recovered from the liquid using natural biology-based molecules instead of man-made chemicals. INL’s work is improving the efficiency, effectiveness and affordability of biohydrometallurgy and offers a promising, cost-effective alternative to harsh chemical reagents.
Ether-based Aqueous Separation and Extraction (EASE) uses water-soluble, ether-based chemicals that pull specific materials from mixtures to recover critical materials from industrial wastewater, desalination brines, mine runoff and geothermal fluids. This process uses less energy and fewer chemicals than conventional extraction methods and produces less waste.
Another area of innovation is INL’s electrochemistry work. Electrochemistry uses electricity to trigger chemical reactions that separate and recover critical materials from waste.
Electrons are easier and less expensive to generate than the chemicals required for traditional extraction methods. Electrochemistry can reduce the use of chemicals, some of which can be toxic, by 88% to 90%, and the process uses up to 75% less energy.
Electrochemical Leach (EC-Leach)
EC-Leach uses electricity to cause chemical reactions in liquids to extract critical materials like lithium, cobalt, nickel and manganese. The process was originally developed to extract critical materials from used lithium-ion batteries, but INL is adapting it for mining applications.
Pilot systems show EC-Leach can recover more than 95% of these critical materials. INL researchers are working to scale this technology for commercial deployment.
Electrochemical Recycling of Electronic Constituents of Value (E-RECOV)
E-RECOV uses an electrochemical cell to recover critical materials from electronic scrap. Electrochemical cells use chemical reactions to produce electricity used in electrochemistry. E-RECOV operates at room temperature, uses up to 75% fewer chemicals than traditional processes and doesn’t produce toxic emissions.
The technology has received a TechConnect National Innovation Award and was a finalist for an R&D 100 Award. The U.S. Department of Energy’s Critical Materials Innovation Hub supported the development of EC-Leach and E-RECOV.
Free Flowing Electrophoretic System (FFES)
The FFE unit uses an electric field with tailored ligand systems (small molecules that bind to metal ions) to separate critical materials from complex mixtures into distinct, isolated streams. The device can be moved closer to, or into, mines to separate critical materials from metal-rich liquids.
Electrochemical Membrane Reactor
Researchers at INL developed an electrochemical membrane reactor that removes contaminants from spent lithium-ion battery leachates, the mineral-rich liquids produced during recycling. The reactor recovers more than 95% of valuable metals such as nickel and cobalt using only water, air and electricity. It also produces acid that can be reused in the extraction process. The system has the potential to serve as a cost-effective closed-loop solution for recycling critical materials from batteries.
Improving Purity
Most modern applications need critical materials to be at 99.999% purity or higher, but most conventional separation processing can only achieve 85% to 95% purity unless the process is run over weeks or months. INL’s electrochemical work can achieve 99.9999% purity in fewer cycles, dramatically reducing processing time and costs.
Rare Earth Element-Metal (RE-Metal)
RE-Metal is a process that recovers rare earth elements from waste materials using electricity. First, the elements are dissolved using nontoxic solutions. Then an electric current is applied to turn the dissolved materials into solid metal on an electrode.
Other projects include generating hydrogen peroxide from air to help dissolve minerals and separating graphite, copper and arsenic while immobilizing toxic chemicals.
Real-World Impact
“Our goal is to make recycling economically viable,” said Mukhopadhyay. “To do that, we’ve focused on reducing chemical use, energy consumption and waste generation while maximizing recovery rates.”
INL’s technologies offer cost-effective options to secure the domestic critical materials supply chain and meet the nation’s growing demand. By advancing recycling and recovery methods, INL helps ensure the U.S. has the materials it needs to overcome current and future challenges.
Brandon Hallmark is a researcher at Idaho National Laboratory (INL)m writing about and highlighting new technologies developed at the laboratory. The articlewas originally posted to the website of the Idaho national Laboratory (INL).
