The Case of Rare Earth Elements: Producers

How Can We Make the Rare Earth Economy More Sustainable?

Adam Schwartz (Director, Ames Laboratory):
You can think about it the same way you think about anything that you don’t have enough of. What do you do? You can either make more or you can use less. Diversifying supply—one aspect of that could mean that you dig more out of the ground. That’s not what our research is involved with. But once you dig it out of the ground or once you identify the location of that material and begin extracting it, the separation process—separating out the rare earth oxides from the ore that it comes from—is a relatively complicated process. It’s time consuming; it’s not particularly economical at this point; and in some cases it’s not the most environmentally friendly. So if research can enable better separation techniques, removing the rare earth oxides from the rock and then separating the rare earth oxides from one another, those separation processes are expensive and time consuming and not particularly environmentally friendly. So research in that area has the potential to further diversify supply to make more rare earths available. For example, from all of the current rare earth mines, you dig the ore, you extract out as best you can the rare earth oxides, and then you have the tailings. You have the leftover. Those leftovers turn out to have a lot of rare earth oxides still in them. If we could have had better separations processes, we would have extracted all the rare earths, but at the time we didn’t. So now current focus is on improving those separation technologies to remove the rare earths from those tailings, from those finds. So that’s one aspect of improving or diversifying supply. 

The other way to make more is to improve reuse and recycling. There is tremendous opportunity, not only in this country but around the world, to reuse or to recycle any material. This country is doing better recycling aluminum, recycling plastics to some extent, but we don’t have a concerted effort to reuse or recycle rare earth materials. For example, there might be tens of millions of hard-disk drives that are discarded every year from the big data centers. Each one of those hard-disk drives has a number of those rare high-performance permanent magnets, the neodymium-iron-boron. If we or the world could figure out a way to pluck out those magnets and reuse them directly, that would have a significant impact on supply. Another area where currently the Critical Materials Institute is doing research is in developing recycling techniques. Same thing. Those hard-disk drives. The Critical Materials Institute team developed an acid-free recycling process—so no hazardous materials—where you could take a shredded hard drive, put that shredded hard drive in this non-acid solution, and extract out those important rare earth ions, leaving all of the copper, all of the aluminum, all the other materials readily available for others to recycle down the road. So those are two aspects of improving supply. Make more: you can either improve separation technologies, you can improve reuse and recycling, and the Critical Materials Institute, academic researchers, other countries are putting lots of effort into the research to make those processes more valuable. 

On the other side of the equation—make more, use less. The way we are addressing use less is to develop substitutes. So developing substitutes could mean either creating material that has exactly the same properties or superior properties but requires no rare earths. We could also develop a substitute that uses less rare earths. For example—I’ll give you two examples. The first one is for fluorescent lighting. Fluorescent tubes use a triphosphor—red, green, blue—and those red, green, blue phosphors currently use some of the more rare rare earths: europium for red, terbium for green. The Critical Materials Institute team working with corporate partners developed a red phosphor that requires no rare earths whatsoever based on aluminum and manganese. That same team also reduced the level of terbium required for green phosphors down to about 10% of the original level. Those phosphors are now in manufacturing trials. So we have a large lighting industry. That lighting industry currently uses significant amounts of the heavy rare earths. Our team is working to reduce the level or eliminate rare earths entirely. The second example is back to the magnets. We talked about neodymium-iron-boron, two neodymium atoms. Research is currently looking into substituting for that neodymium, and currently things are looking promising—not yet finalized but promising—to pluck out one of those neodymium atoms and replace it with lanthanum, or cerium, or a combination of those two. If we are successful in developing the properties that closely match those of the current magnets, we could essentially make twice the magnets using the same amount of neodymium. So a lot of the research these days is looking at ways to improve the separations process, current research is looking at ways to improve the separations processes, improve reuse and recycling, and that has the effect of increasing the supply, while at the same time research is looking at developing substitutes using either no rare earth elements or less rare earth elements to get the same properties. 

Sustainable rare earth economy comes down to more environmentally friendly, very economic separations techniques and mining. Extracting critical materials, extracting hazardous materials from our globe can be done, and it can be done in an environmentally friendly way. The challenge is to balance the cost of that environmental protection versus the cost of extracting out those materials that are so critical. For the rare earths, the environmental challenges, the hazardous aspects are the separations of the rare earth from the ore and the separations of the rare earths from one another, and the forming of metals from those pure rare earth oxides. The United States, the world, needs to continue to pursue clean separations techniques, those techniques that require nonhazardous materials that will not do damage to the environment and that can be contained and mitigated. So fundamental research, applied research, into developing new separations techniques—[current] separation techniques include solvent extraction, ion exchange—a new method may be to use ionic liquids to extract out rare earths in a much cleaner, environmentally friendly, and someday more economical way.

Gwen Bailey (Researcher, KU Leuven): 
It’s something similar to circular economy, so getting the value out of the resource for as long as possible and using it to its full potential. The analogy I always use is like it’s going to the gym. You know, like if you want to lose weight, you have to shed the fat first. That’s the refining process, is cleaning up the refining processes. So that will make the biggest impact on the short term. But in order to keep it, to keep your figure looking good, you have to build muscle. That’s the recycling. And so that’s the thing that you really need to focus on as well to ensure that in the long term you have a circular economy or a resource-efficient economy.
Credits: The Rare Earth Elements Project is made possible by a generous grant from Roy Eddleman, founder of Spectrum LifeSciences.

Illustrations and animations: Claud Li
Music: “Tobaggan” & “No Squirrel Commotion” by Podington Bear
(c) 2020 Science History Institute