Approaching Materials Strategically
Alex King talks about the management of rare and critical resources.
How are rare earth materials critical in clean energy and manufacturing?
Almost anything that you use contains some materials that are potentially in short supply - we call them critical materials. Some are critical if you make cars or textiles or buildings and some are critical if you make clean energy devices.
Almost every list of critical materials contains several rare earth elements; they're the poster children for critical materials. They provide properties to materials that cannot be provided by anything else.
These rare earths are materials like neodymium and dysprosium, both used in high strength magnets. A problem with this type of magnet is that its strength degrades at higher temperatures, so dysprosium is often added to help the magnet retain its properties as it gets hot, which tends to happen with mechanical devices.
These magnets are used in things like disk drives, microphones, loudspeakers and electric motors where it is important that the motor be lightweight, very efficient or very small. A gasoline-powered car, for example, uses about a pound of neodymium-iron-boron magnets in motors for the fuel pump, windows, mirrors, self-opening doors and so on. If you have a hybrid car with an electric drive motor, there are an extra couple of pounds of magnets just for that motor. To keep an ordinary car down in weight we use these magnets. For a hybrid car you need these magnets just to keep the car moving.
In addition, anything that converts mechanical work into electricity - such as a generator for a wind turbine, for example - tends to demand magnets, and the magnets of choice for this are the lightest available, neodymium-iron-boron.
How is the Critical Materials Institute working to take these new materials from research to commercial product?
The challenge is not bringing materials to market. It's about ensuring that there is enough neodymium and dysprosium to make all the magnets we need today, and the ones we anticipate needing over the next 15 or 20 years. (Magnets using neodymium and dysprosium are probably, in terms of revenue, the dominant magnet in the world today.) Our challenge is making sure the supply of materials keeps up with demand and is not subject to supply chain disruption.
We want to diversify the sources. If there is only one supplier, everyone who uses the material is somewhat at the mercy of that supplier and at the mercy of nature, because nature - earthquakes, tornados - can shut down a supplier very easily. So can trade embargoes. It's always better to have more suppliers, which might mean more mines, or other types of primary sources.
We want to develop tools and technologies that make the mining process less expensive. Because it costs up to a billion dollars and 10 or 15 years to start a new mine and bring it online, the investment community is not enthusiastic about mines in general. Anything we can do to reduce the cost makes it easier for investors.
On the other side, we are working on new materials to substitute for critical materials such as neodymium. That requires a great deal of fundamental scientific research, which in some cases is showing promise.
A third approach, if you can't find any more of a material and can't find a substitute, is being more prudent about what is available. We achieve that in two ways. In every manufacturing process, there is waste, so how can we reduce waste to the minimum that we can achieve? Also, how do we make it financially and economically sensible to provide end-of-life recycling - typically a very expensive way to get materials? We're working on tools to lower these costs.
How are standards important to the use of rare earth materials and any substitutes?
Some of the problems are that there are no standards or only those created by supplier catalogs.
If you want to buy a magnet from Supplier A, you use their product number. If you want an equivalent product from a different supplier, all you have is their catalog information. Say you're building a hard disk drive, and you've qualified one magnet for it; if you have to go to a second supplier you have to do the whole qualification all over again.
Standards would allow multiple suppliers, and this is an area we've been discussing with ASTM Committee F40 [Declarable Substances in Materials].
Standardization would also be extremely helpful with recycling. Right now, we do not really recycle materials. We recycle a computer or a car, and buried inside may be a material that we want. You only know it's there if you have previously disassembled that exact same device or if it's labeled to tell you what's inside. Otherwise, you may not find what you wanted and you've wasted a lot of time and effort in what is actually one of the most expensive parts of the recycling.
One of the things we would like to promote is standards that indicate critical materials content and possibly even their location in devices to facilitate recycling and recovery.
What are your current priorities for the Critical Materials Institute?
One of the things that distinguishes CMI's work is that we are specifically focused on delivering technologies that are actually adopted and used. Technology transfer is without a doubt our highest priority.
Among our wide range of projects, we've had a few successes. We've been working in areas where the normal accepted schedule is 20 years to commercialize a technology. After just two years, we're already close to commercializing a material that will substitute for a rare earth material in fluorescent lighting. Fluorescent lamps use three rare earths, europium, terbium and yttrium, which together make white light, and both europium and terbium are in very short supply. With one manufacturer, we're in final testing of a phosphor that produces green light, and we are making good headway on another that produces red light.
In mining, we're working to improve the process when the rocks are crushed and the powder is separated to get to the ore containing valuable rare earth materials. That's called froth flotation. A more efficient process will allow mines to increase their output.
We're also developing technologies that will be used for water treatment and other effluent treatment in mines that help lower the cost of operation, and we have some mining operations that are showing interest in licensing some of those processes.
Success in recycling is a little further away because the challenges are very large, but we're making headway there as well. For example, in every manufacturing process we end up with some waste - sawdust and filings - called swarf. That is traditionally discarded. Our scientists have developed a new recycling method that reuses the waste as raw material for new magnets. These magnets perform like commercial bonded magnets made from new materials.
Alexander H. King, D.Phil., is director of the Critical Materials Institute in Ames, Iowa. CMI is part of the Ames Laboratory, operated for the U.S, Department of Energy by Iowa State University. King had previously been director of the Ames Lab from 2008 to 2013. His experience also includes faculty roles at Purdue University and the State University of New York at Stony Brook. An ASTM member who joined last year, King is a fellow of the Institute of Materials, Minerals and Mining, ASM International and the Materials Research Society.