E47: Rare Earths: Why They Matter and What Comes Next | Professor Adam Powell | Mechanical and Materials Engineering

 Rare earths aren't new, and despite their name, they aren't especially rare. So why are they consistently making headlines in the business, technology, even geopolitical news? These elements, along with other critical materials such as magnesium, are essential to everything from smartphones and electric vehicles to renewable energy systems, advanced manufacturing, and national defense. The challenge isn't simply finding them, it's developing the ability to extract, process, and recover them, and reducing America's dependence on supply chains concentrated in countries such as China. Today on the WPI podcast, we'll break down what rare earths are, why they matter, and whether innovation can continue without them. We'll also explore how WPI researchers are developing cleaner ways to recover critical materials, recycle existing resources, and help build a more secure domestic supply, including Professor Adam Powell's work to develop a new approach to magnesium production. Professor Powell, welcome. Thank you. Introduce yourself, your title, and a little bit about why you're the person for this podcast. My name's Adam Powell. I'm a professor in the mechanical and materials engineering department. I came to WPI in, in 2018. I've done a good amount of work in rare earths and magnesium, both here and also in my former role as CTO and co-founder of Infinium, which was a startup company. Our tagline was, "Clean metal production for clean energy." Thank you. First question, what are rare earths? Rare earths are a group of 17 elements, um, that are considered kind of group three by the chemists. If you look on a periodic table, the bottom row, it's represented having uranium and thorium and, and plutonium, all those radioactive ones. The ones just above that are the rare earths, and they include a bunch of elements that their chemical properties are relatively similar, but they include these things called f orbital electrons, which give them very different optical and magnetic properties from anything else in the periodic table. So are they actually rare, or is that name misleading? They're less common than iron and aluminum, of course, but for example, scandium is more common than lead in the Earth's crust, but it's just so dis- so evenly dispersed and chemically difficult to refine as a, a metal that it's less than 100 tons per year, not 100,000 tons, less than 100 tons per year of its production. Wow. Okay. So in that sense, rare. But there are others. There's one called tellurium, which is one of the rarest. Only the platinum group metals are rarer, and tellurium is used in tens of gigawatts of solar panels around the country, mostly made by an Arizona company. So there are much rarer elements that are produced in very significant products. Mostly notice them in a couple of places, that is, in the magnets in motors. So people think of electric or hybrid vehicles when they think motors, but actually, a, any vehicle today will have dozens of motors from the side mirrors to the starter, the braking, power steering, you name it, and a very large number of those are made of an alloy of neodymium, iron, and boron. The iron is m- m- more than 60% of it. The neodymium is about a third. And these are the strongest magnets that are known to people, and they're relatively cheap also. There are some cheaper alternatives, but neodymium iron boron is just cheap enough and powerful enough so you can make it small and light, make very small motors, so it's ubiquitous. It's everywhere. I was just trying to figure out, were these materials always around? Who was like, "You know what would work here? Scandium," or how did this come about that we need rare earth? Yeah, it's, it's pretty incredible just h- how materials are developed, and yeah, you, you s- you can start with some of the base metals that we think about all the time, i- iron, aluminum, copper, nickel, et cetera. You can make a bunch of things out of them. But how do people start throwing in a bunch of neodymium? And yeah, it's a very good question. Some of this is serendipity, and some of it is targeted strategic research. Some of the magnetic properties of the rare earths have been known for a long time as something called the magnetocaloric effect, where you put material in a magnetic field and it changes temperature, and you take it out, it changes temperature again. But then after discovering that effect, people said, "Gee, I wonder if maybe if we add some more iron and try these other things." Now it's a lanthanum iron silicon alloy that, that was discovered, and people are trying lots of new things. And that's, some of it is just the kind of the physics of the way that crystals come together and the way that electrons form bonds in between different metals. And after a while, people develop intuition, or maybe AI is developing intuition. Who knows? But, and so it's some combination of these different things. We hear a lot about rare earths in the news these days, not just in the science and technology sections of your newspaper or magazines, but front page, and a lot of it points to the, quote-unquote, "rarity" of this. So why do some countries appear to have more rare earth resources than others? The key is the word resource is not how much rare earth is inside the country down to a depth of 20 miles, right? Resource means how much of it is concentrated enough and in a place where it's economical to mine it, basically. And in that regard, China has about one-third of the, the world's resources. So when Deng Xiaoping famously said, "Saudi Arabia has, has oil, China has rare earths," they don't have a monopoly on the, uh, the resources. And in fact, the largest mine and most productive throughout most of the 20th century is in Southern California. It's a company, uh, it's c- called Mountain Pass. It's a, a very large deposit with close to 10% r- rare earth oxide content, which is, again, one of the highest in the world. Today, the most productive rare earth mine has been in China. It's actually an iron ore mine for which the rare earths are a very small byproduct, but they separate the rare earths and produce them, use them for magnets, et cetera. And they're able to do that, which we can't economically do here, though we have s- v- very big sources of rare earths here in this country. So to boil it down, China doesn't have the monopoly on this because of what's in the soil there, and I know I'm being very elementary here. They just have figured out a way, a productive way, an economical way to source that material? That's right, and their regulatory environment makes a big deal as well. In the US in particular, we could get huge amounts of rare earths from phosphogypsum mines, primarily in Florida, o- other places as well. However, because the rare earths and the radioactive elements are so chemically similar, if you concentrate the rare earths, you concentrate the radioactive elements, and then the Nuclear Regulatory Commission gets involved, and nobody wants that. That's why so many potential sources in the US just do not actually make rare earths. So rare earths are part of a larger conversation about critical materials. Magnesium metal is not a rare earth, but about 90%, if I'm right here, of the world's supply is produced in China. So why is magnesium so important? Magnesium is important for many reasons. It is the lowest density structural metal, so it's about a third less dense than aluminum. Holding a bar of magnesium in your hand, it almost feels like a piece of wood, it's so light, and yet it's shiny and metallic. The parts made of magnesium have better stiffness to weight ratio, and that's especially important in some key parts. For example, most steering wheel frames are made of magnesium metal or magnesium alloy. And there are all kinds of other ways to use it in vehicles in particular. The n- number of aerospace parts, for example, the lightest helicopter transmission casings are magnesium alloy. You can replace them with aluminum, but they're much heavier. There are a few parts in jet engines, et cetera. And the US military uses them for flares, and they're in fireworks. Oh, really? Other... Yes. It's, that's the, the high school chemistry. You take the thin magnesium ribbon and, and light it on fire, right? I missed that in high school. I was still trying to memorize the periodic table. Okay. Yeah, so it's very flammable when very thin or finely divided, not so much with thick vehicle parts. It's also a very good heat conductor, so if you put a, a, a torch to one side of it, it can conduct a lot of that heat away very quickly, like aluminum. Your research group is working on magnesium. Yes. So what approach is the team developing, and how could it create a more secure domestic source or supply? The two ways of making magnesium today are the one in China, which is extremely labor-intensive, very energy-intensive, and, you know, basically they've made it economical by putting it right next to a coal mine so the energy is almost free. That's where they react silicon with magnesium from dolomite. The other is some magnesium chloride electrolysis. That was the one in production in the US. Dow really pioneered it in the, the 1920s and '30s and became the dominant producer of the world, uh, until the 1990s when China came on. And US Magnesium, which was the last US producer, they used this chloride electrolysis process. Trouble is, it produces chlorine gas, and the US Magnesium path to production also emits dioxins and furans. It's something called carbochlorination, and you think carbon, chlorine, oxygen, very dioxins, bad stuff. Our approach instead is to take magnesium oxide, usually made from hydroxide from desal- seawater desalination concentrate, and turn it directly into metal using the i- infrastructure already existing in aluminum smelters. The aluminum industry is one of the biggest magnesium consumers. They consume about one-third of the world's magnesium metal just to make aluminum alloys as a minor constituent of aluminum, 'cause aluminum metal is so much bigger than magnesium currently. And they're concerned about magnesium as a critical material because if China cuts it off, then a lot of the aluminum alloy production has to shut down, and vehicle production, a lot of it depends on that as well as on rare earths. So if they can take one of their existing plants and rededicate a part of it to magnesium production, it's good for them. It's not only cheaper because you don't have to build a dedicated magnesium plant, it's also reduces risk because if we dropped their tariffs or if China opened back up, if the economic conditions change, they could switch back to making aluminum, so you wouldn't have a big stranded asset of a magnesium plant on your hand. How far along is your research? Is there one particular project? Is this an array of research initiatives? We are working right now with a startup company I founded, Thalon Materials, T-H-A-L-O-N. It's based on a Greek deity of the ocean. The idea is that this is me- metal coming from the ocean. We're small right now. Our research work is focused here at WPI, but we're raising money to, to grow as quickly as we can. Technology that my startup company worked on was invented by someone named Uday Pal at Boston University, who was also my PhD thesis advisor. So we are working on this now. It works beautifully in the lab, and we're working on scaling it up. So we talk about these production cells in terms of how many amps of current they put through them. At five amps, it's amazing. At 40 amps, it's pretty good. We have an MQP team, a senior capstone project team, working on going to 500 amps. Aluminum plants run at 100,000 amps, so we still have a ways to go, but we have a good path to, to get there. This was originally an idea from the 1940s to make magnesium in this way. Problem is, it re- relies on, uh, the aluminum plant would make a magnesium alloy, and then not a especially useful one. You'd have to separate the magnesium out of that, and that has been very expensive until my startup company invented this way of distilling magnesium out of this alloy. So we actually boil the alloy and condense the, the magnesium out of it, a- and we figured out a way to do it very cheaply. Could we continue to develop these advanced technologies without rare earths or these critical materials, or have they become irreplaceable? Potentially. There are a variety of aluminum alloys, but the ones with magnesium are favorable. The standard automotive sheet metal has a good amount of magnesium. For rare earths, it's really hard to substitute away from the magnets. There is a, a US company called Niron, N-I-R-O-N, making iron nitride magnets, and they are starting to build their first plant. It's a Minnesota company. And they have an order from General Motors, so it's a rare earth-free magnet. However, that magnet has very different properties from the neodymium magnets. It's not as strong. It, it decomposes at 200 Celsius, which temperature that a lot of m- motors often reach, so you have to cool it a lot, a lot more actively, and has lower coercivity, so you basically have to redesign the motor around the magnet, which you can do, but it's a big break. And automotive and especially aerospace, other companies are conservative, but at the same time they want to reduce their exposure to big risks, right? So when RAM chips were suddenly in, in a shortage, huge numbers of cars sitting on parking lots waiting for their chips. They don't want that to happen with magnets, so they, they have a strong incentive to make this happen. How much of the solution could come from recycling old electronics, batteries, magnets, and other products? I know that we do research here at WPI. How critical is that part of the equation? Re- recycling is potentially, in the long term, a, a great source of material. Typically, you have the collection yield, what fraction of the end-of-life material is collected, and then what fraction of that actually makes it into products. So of course, the, the material with the highest collection fraction is lead, because you can't buy a new lead-acid battery without turning in your old one, right? It's, it's required. It's 99%. But the rare earths are, are harder because they're deeply embedded into motors. When a vehicle is recycled, its first step is shredding it. If you look up vehicle shredding on YouTube, you find some amazing videos of just vehicles being rip- ripped apart. Comment underneath, "I, I showed my car this video and it promised it would never stall again." But it's ripped into pieces no bigger than a fist, and that process, the motors typically come out in one piece, output stream often called the meatballs. The meatballs. Very technical. And it's just very difficult to take those apart to get the, uh, magnets out of them. Your larger motors are like the traction motor in a Prius or a Tesla. Those may be worth pulling out, and certainly a wind turbine or an MRI machine will have large enough magnets to take out and recycle. There are a bunch of companies ar- around the country working on magnet recycling. Full disclosure, I'm a participant in one of them called Sol- Solkoa Industries in the Bay Area. They're aiming for 500 tons per year of the rare earth production mid- mid next year. What other promising sources, industrial waste, mine tailings, other materials, red mud, does that come into play here? I mentioned the phosphogypsum mine tailings. Another one, red mud is an aluminum mine tailings. So for every ton of aluminum produced in the world, there's about two tons of this, this red mud, which is a nasty, caustic, toxic sludge that just builds up. There are four billion tons of it all over the world, and it has a good amount of rare earths. Aluminum is a group three element like the rare earths, so they co-occur together, but in, in relatively small concentrations. Particularly, there's a good amount of scandium in red mud. The trouble is, if you take out the rare earths, you have to put the red mud back. And one approach that was pioneered here by Brijendra Misra's group and by now Professor Himanshu Tanwar, I was on his PhD thesis committee, is to figure out how to combine a bunch of different processes to capture six different resources and six different products and use up 90 to 95% of the rare earths so you have almost nothing to put back. So that's a pretty exciting process. There's a company called Fastmetals led by a, um, a WPI alum, and they are working on a similar process, similar technology. It's pretty exciting to see this moving forward. You're dropping a lot of company names. I'm glad you are. That does speak to the point that WPI has cutting-edge research, and the professors, such as yourself, you mentioned Professor Misra, who have been working on this for years and are some of the top leaders in the field. I know that because I've talked to other people on this. Have you seen an increase in the amount of government and other types of funding for this problem to come up with a solution? I feel like in the past five to seven years, I've written so many press releases about the grants that are coming in. So is there an increased push, interest, attention to this problem? Short answer is yes. I think the first people to really pay attention to this outside of the US was a, a group in Japan called the Okabe Group. They basically alerted the Japanese industry to this. Toru Okabe is someone I've known since grad school, wonderful guy. And so the Japanese industry was prepared when China cut them off in 2010. The US was not prepared. In fact, GM and Hitachi invented these magnets at the same time. GM spun off and sold their magnet division to a Chinese company, which shipped all of the equipment to China. So we were asleep at the wheel until 2010, until that shock when China cut it off, and then woke up and said, "Okay, we need to do something about this." But it really wasn't until 2018 or so that enough funding was put into this in order to make it an industrial and commercial reality. You know, there were bits of research, but it was scattered. My former startup, we got one grant, and then we said, "Okay, let's follow this up. We want to scale it up." We actually made a neodymium-praseodymium rare earth alloy that performed a little bit better than Chinese alloy in magnet tests at the Critical Materials Institute. But there weren't further grants forthcoming. And so it's just been since about 10 years ago that the large industrial loan guarantees and grants came forward, and have companies like Ph- Phoenix Tailings based here in Massachusetts, and also MP Materials, which is the new owner of that big mine, the Mountain Pass mine, that have built large plants to produce rare earth metals. Interestingly, the MP Materials people, their director, I forget his current title, he's, he's a VP, came out of our startup company, out of Infinium. So he took what he learned there and helped to build the production capacity at Phoenix Tailings, and they in turn taught a lot to MP Materials. Small world in the rare earth community. Small world. Looking at WPI and the research that you're doing and your colleagues are doing, where does WPI have an opportunity to lead perhaps the country in this type of research? WPI has a few u- unique capabilities here. So one of them is that we are the lead on both a recycling center with about 20 companies in the US and Europe. We work alongside Colorado School of Mines and KU Leuven, so we have a good amount of recycling research, a steady stream of this coming through WPI. We have a, a good working understanding in our research groups of the shredding and physical separations, chemical separations that have to be involved in getting rare earths out of a waste stream. In addition, we have a number of people working on the kind of the oxide or, or other compounds to metals. So my group is, is one of them. I mentioned our magnesium work. We've done a little bit of rare earth work as well, a little bit of rare earth recycling work. We just have a lot of very relevant knowledge here. We have about 10 faculty members focused on metal processing here at WPI. It's PI and Mines. We're the two largest, uh, groups in the country in this area, and, uh, the two leads in recycling as well. But I would say also that we have a multidisciplinary way of doing things that... I was just talking with someone the other day. I've been assigned this year as a new faculty mentor to faculty members in biomechanics and aerospace. Okay. And we have these, uh, symposia every year bringing, bringing people together so someone in civil engineering can talk about concrete and a biologist can say, "We have an enzyme to make your reaction 50 times faster," and a startup company is born. And that's a true story. Yes, absolutely. I've never been anywhere else that has that level of interdisciplinary collaboration across very different engineering and science departments. Yeah. With something like this, you can't be siloed. You have to look- Right, right ... at other solutions- Absolutely ... and applications. So pulling out from WPI back to the world view, or at least- Mm-hmm ... the United States view, what breakthrough would most dramatically change this country's outlook for rare earths and other critical materials? Good question. So I think if Niron succeeds, iron and nitrogen are everywhere, Mm-hmm. Right? So that magnet could be pretty exciting. They say that in the long run, prices fall to not much above the cost of the raw materials, and raw materials are so cheap, it'd be pretty incredible. Also, I think if you talk about recycling, if there were ways of getting those magnets out of the motors, they're embedded in-- It's j- it's just tough to, to pull them out. If there were better ways to do that, then we could get a good fraction of our n- new rare earths out of recycled rare earth magnets. The challenge there is that because rare earth magnet production has ramped up so much in the last 15 years for electric vehicles and wind turbine, hybrid vehicles as well, and those products last for so long- Mm-hmm that now we're getting the scrap out of 10 to 15-year-old vehicles, and in 10 or 20 years we'll get the, the scrap out of 30 and 40-year-old wind turbines. So a fast ramp and a long tail so that a- only a small fraction of our needs can be met from recycling for at least the next 10, 10 to 20 years. In the long term, of course, we, we can reach a steady state where about two-thirds of this country's steel and aluminum come from recycling, so when we get to that, that kind of a state, then we're in good shape. So approaching a circular economy, but it's not there yet. That's right. That's right. Okay. Final question. Should people feel worried about the future supply of these materials, or optimistic about the ability to innovate? In the long term, I think optimistic. The US has some of the best innovation engines in the world, um, uh, our universities, our startup ecosystems, et cetera. In the short term, there's still cause for concern that for rare earths and somewhat more so for magnesium, because we're just not as far along, w- we're one of about five startups in the US magnesium. The first one is looking to break ground on its plant that will s- satisfy about five or 10% of US demand. So we're working to move as fast as we can as well, our, our ability to scale quickly with aluminum infrastructure. But it's gonna be a few years still. It's a tough problem. No easy answers, though a lot of companies are moving as quickly as they can, and the government is moving as quickly as they can to help those companies. Yes. All right. So. I choose to be optimistic- Okay. ... especially after this conversation- Great ... and seeing the type of research being done here and in other labs across the country. I wanna thank you for sharing that expertise, and I hope to hear more about some of these startups as we continue this podcast and you continue your work. Terrific. Thank you. Appreciate the opportunity. This has been another episode of the WPI Podcast. If you would like more information about rare earths, check out WPI's explainer section where we answer some of the most frequently asked questions about these materials. If you want more WPI podcasts, you can also find them on our website under Listen. Another thanks to Adam Powell, and a special thanks to Aster Detweiler, our audio producer, and of course to you for listening. I'm Colleen Wambock.