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Assessments of Criticality

Two speakers at the workshop described recent efforts to establish levels of criticality for materials and determine where particular elements fall within these levels. Both observed that the supply of and demand for critical materials are constantly changing, which complicates assessments of criticality. But supply and demand can be projected into the future to create scenarios of material availability. Such projections can identify opportunities for the chemical sciences to increase supply (through better extraction or recycling technologies, for example) or decrease demand (through the development of replacement materials and new technologies).

A FRAMEWORK FOR ASSESSING CRITICALITY

Though rare earths have drawn the most attention from the media, the concerns surrounding critical elements are much broader, said Roderick Eggert, one of the three members of the organizing committee. The phrase that some people have used to describe the situation is “the periodic table is under siege.” Just a few decades ago, most of the products used in a household or business relied on 20 to 30 elements. Today, as Steven Duclos, Chief Scientist and Manager for Material Sustainability of General Electric Global Research, has said, GE uses at least 70 of the first 83 elements of the periodic table in its products or in the processes used to make these products (Duclos, 2010). “Mineral-based materials are becoming increasingly complex,” said Eggert.

This growing complexity could lead to an explosion in demand for some elements now used in small quantities. For example, gallium, indium, and tellurium are important in emerging photovoltaic technologies. Other elements from throughout the periodic table are critical for various energy technologies (Figure 2-1).

Elements of Criticality

Criticality in element availability has three dimensions, said Eggert.

The first is importance in use. In some cases, the primary concern is physical availability. Will it be possible to get a small amount of an essential element that provides a critical or desired property to a material? In other cases, cost is the essential factor. With photovoltaic thin films, for example, the cost of the gallium, indium, or tellurium is a substantial part of the total cost of the delivered photovoltaic material. The cost of these elements therefore could determine the extent to which thin films are deployed on a large scale. Finally, importance in use relates to the ease or difficulty of substituting another material that can provide the desired properties of a scarce material.

The second dimension is supply risk. Fragile supply chains raise key questions. Will supplies be able to keep up with demand? Will supplies be secure? What are the implications for input costs to products and processes? The threat, said Eggert, is that mineral availability could constrain the development and diffusion of emerging technologies.

The third dimension is time. What is critical today may not be critical tomorrow, and vice versa, said Eggert. The ability to respond to a perceived shortage or supply restriction depends critically on the time period available for response. Adjustments that are possible in the short term—one to a few years—may be constrained by existing production capacity, the nature of capacity, the location of capacity, and existing technologies on either the supply side or demand side. Over the long term—a decade or more—much more significant adjustments are possible. “But these adjustments require investments—time, effort, money—today, with payoffs in the future,” said Eggert.



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2 Assessments of Criticality Elements of Criticality Two speakers at the workshop described recent efforts to establish levels of criticality for materials and determine where Criticality in element availability has three dimensions, particular elements fall within these levels. Both observed that said Eggert. the supply of and demand for critical materials are constantly The first is importance in use. In some cases, the primary changing, which complicates assessments of criticality. But concern is physical availability. Will it be possible to get a supply and demand can be projected into the future to cre- small amount of an essential element that provides a critical ate scenarios of material availability. Such projections can or desired property to a material? In other cases, cost is the identify opportunities for the chemical sciences to increase essential factor. With photovoltaic thin films, for example, supply (through better extraction or recycling technologies, the cost of the gallium, indium, or tellurium is a substantial for example) or decrease demand (through the development part of the total cost of the delivered photovoltaic material. of replacement materials and new technologies). The cost of these elements therefore could determine the extent to which thin films are deployed on a large scale. Finally, importance in use relates to the ease or difficulty A FRAMEWORK FOR ASSESSING CRITICALITY of substituting another material that can provide the desired Though rare earths have drawn the most attention from the properties of a scarce material. media, the concerns surrounding critical elements are much The second dimension is supply risk. Fragile supply broader, said Roderick Eggert, one of the three members chains raise key questions. Will supplies be able to keep up of the organizing committee. The phrase that some people with demand? Will supplies be secure? What are the implica- have used to describe the situation is “the periodic table is tions for input costs to products and processes? The threat, under siege.” Just a few decades ago, most of the products said Eggert, is that mineral availability could constrain the used in a household or business relied on 20 to 30 elements. development and diffusion of emerging technologies. Today, as Steven Duclos, Chief Scientist and Manager for The third dimension is time. What is critical today may not Material Sustainability of General Electric Global Research, be critical tomorrow, and vice versa, said Eggert. The abil- has said, GE uses at least 70 of the first 83 elements of the ity to respond to a perceived shortage or supply restriction periodic table in its products or in the processes used to make depends critically on the time period available for response. these products (Duclos, 2010). “Mineral-based materials are Adjustments that are possible in the short term—one to a few becoming increasingly complex,” said Eggert. years—may be constrained by existing production capacity, This growing complexity could lead to an explosion in the nature of capacity, the location of capacity, and existing demand for some elements now used in small quantities. technologies on either the supply side or demand side. Over For example, gallium, indium, and tellurium are important the long term—a decade or more—much more significant in emerging photovoltaic technologies. Other elements from adjustments are possible. “But these adjustments require throughout the periodic table are critical for various energy investments—time, effort, money—today, with payoffs in technologies (Figure 2-1). the future,” said Eggert. 5

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9 ASSESSMENTS OF CRITICALITY uncertain, and far in the future, making them difficult for a practices could potentially could be overproducing some of private actor to capture. In such cases, government action is them, while underproducing others. justified because of spillover benefits that go beyond private For example, cerium is somewhat abundant relative to the benefits. other rare earths, whereas dysprosium, which is needed for magnets, may not be as rare as terbium, but it is significantly more rare than neodymium, which is another component of The Role of the Chemical Sciences magnets. This aspect of production is important to consider, Eggert concluded his presentation by discussing the role as mines may not be producing rare earth elements in the of the chemical sciences in critical resources. The chemical proportions that are required for the actual technologies sciences are of course essential for research and innovation, being developed. he said. On the demand side, they can enable element-for- Also, even though more than 95 percent of today’s rare element substitution as well as broader system substitutions. earth supply comes from China, new mines are opening The chemical sciences also can relax supply constraints in other countries, further complicating the supply picture through improvements in extraction and recovery. (DOE, 2010). In terms of manufacturing, the chemical sciences can improve manufacturing efficiency in response to increased Matching Supply to Demand scarcity or availability concerns. For example, when flat- panel displays experienced dramatic growth in production The DOE analysis looked at 2010 production for a variety and drove up indium prices a decade ago, the chemical sci- of elements and considered potential additions to supply by ences improved the incorporation of indium into the indium 2015. Some of the supply additions were from recycling, tin oxides in the displays from approximately 25 to 30 per- while others were from new production. cent to 70 to 80 percent of the indium purchased. It then estimated the demand for critical elements by the Finally, the chemical sciences play important roles in four technologies considered in the study under conditions of recycling, which is essentially another form of extractive high and low market penetration and high and low material metallurgy. intensity. Energy technologies can use critical elements to different extents depending on the specific technology used and supply factors. Nonenergy technologies also create a THE DOE CRITICAL MATERIALS STRATEGY demand for these materials, which needs to be factored into As new energy technologies are developed and widely the analysis. And intellectual property can be a factor, Bauer implemented, the demand for critical elements could soar. To noted, when a company holds a patent on a key technology, prepare for such a future, the Department of Energy (DOE) for example. recently issued its first Critical Materials Strategy (DOE, The result of the analysis was a series of charts projecting 2010). Diana Bauer described the main conclusions of the supply and demand through 2025 (Figure 2-6). The charts analysis and briefly discussed an update of the study under show demand under four different scenarios along with the way at the time of the workshop. current and future supply as new mines begin production. The analysis looked at four clean-energy technologies: “These graphs are not predictions,” Bauer emphasized. “We energy-efficient lighting, wind turbines, electric vehicles, are just trying to show how the different factors interrelate.” and photovoltaics. It examined the full supply chain for For example, if research and development were directed the critical elements used in these technologies, including toward lowering material intensity, how much would demand extraction, processing, manufacturing, and recycling. It have to drop to reach the available supply? Or if a company also looked at materials availability and policies in both were considering opening a new mine, what impact will the materials-producing countries and materials-consuming new production have on global demand and price? countries as well as in countries like China that have char- Using the graphs of supply and demand, the DOE analysts acteristics of both. The supply of critical materials is com- assessed criticality using the same approach developed by the plicated by factors like co-production, where the production NRC committee that looked at critical elements (Figure 2-7). of one element depends on the production of another, the According to this framework, the most critical element was availability of substitutes, and the geographically uneven dysprosium, with neodymium, terbium, yttrium, europium, distribution of ores from which the elements can be economi- and indium also judged as “critical.” cally recovered. The study then looked at the change in criticality over Another complexity in the picture is the abundance of rare the short to medium term, which is defined as 5 to 15 years earths are not uniform and it is often not possible to substitute (Figure 2-8). For example, lithium moved from not critical one rare earth for another. Looking at the various deposits and to near critical as projected demand rose during this period, the various rare earth elements, the different deposits have dif- whereas cerium and lanthanum made the opposite transition ferent relative proportions of all the different elements. Current because of increased supply.

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11 ASSESSMENTS OF CRITICALITY of promising technologies. Examples include alternatives to at least for our lifetimes and probably the lifetimes of our motors and generators that do not include rare earths, and children and grandchildren there are significant opportuni- magnet formulations that have higher performance with less ties to expand the availability of things like rare earths if we rare earth content using nanotechnology approaches. DOE choose to devote effort to those activities.” also has been sponsoring critical materials workshops and He also pointed out that the geographic allocation of a international meetings to help build a global as well as a resource can be very important. For some critical elements, national research community. China plays an important role. At present, China is exercis- At the time of the workshop, DOE was working on an ing its market power, which creates, in effect, a two-tiered integrated research plan to be released by the end of 2011. pricing system, where prices in China to Chinese users of As part of these efforts, the department planned to strengthen these elements are lower than to users in the rest of the world. its information-gathering capacity and analyze additional However, this is less an issue of geology and more a result of technologies, such as the fluid-cracking catalysts used in existing production capacity, according to Eggert. petroleum refining. DOE will continue to work closely with Thiel asked Eggert which elements are most worrisome international partners, interagency colleagues, Congress, and to him in terms of price and availability. “The simple answer public stakeholders to incorporate outside perspectives into is gallium, indium, and tellurium for photovoltaics,” Eggert its planning, Bauer noted. Also, a new interagency working replied. “That may be biased because my institution is right group led by the White House Office of Science and Technol- across the street from the National Renewable Energy Lab, ogy Policy has been formed to address critical and strategic and we’ve had lots of discussions on these issues. But those mineral supply chains, she said. elements are relatively rare in a chemical sense in the Earth’s crust, they don’t tend to be concentrated significantly above average crustal abundance in very many locations, and they DISCUSSION are currently all produced as byproducts.” In response to a question about recycling, Bauer noted In response to a question about the role of prices in that the potential varies by technology. For example, wind changing the availability of critical elements, Eggert agreed turbines from 30 years ago will not contain any neodymium, that price is important but also pointed to other factors. so they cannot serve as a source of that material. But fluores- For example, supplies of the platinum-group elements may cent lights offer more potential because they have a shorter be more constrained than supplies of rare earth elements. lifespan, a collection infrastructure is in place, and they For the past several decades, much of the rare earths used contain heavy rare earth elements that will not be produced worldwide have come from two mines—the Mountain Pass in much greater amounts from the mines slated to come on Mine in California and the Bayan Obo Mine in China. The line. “That is a good niche type of recycling application to dramatically higher prices for rare earths over the past year do first,” she said. may not have an immediate impact but over the longer term Bauer also was asked whether actual shortages of critical could lead to more geographically diversified mines. elements can currently be documented, and she responded Dennis Chamot of NRC pointed to the potential for that price pass-throughs have been documented in some relatively inexpensive materials to replace more expensive industries. “Part of the challenge is that a lot of companies ones. For example, composites are replacing more and more don’t want to share publicly their lack of ability to get mate- steel in automobiles. Similarly, biological systems generally rial because that makes them vulnerable within the market cannot afford to use scarce elements in processes such as to price increases or other disruptions,” she said. photosynthesis, so organic chemistry may suggest ways to Finally, Bauer was asked whether DOE has seen evidence replace exotic elements. of black markets in critical elements, and she noted that the In response to a question about supply constraints, Eggert rare earth situation is special. Because China has export said, “We’re really not in danger of running out of anything. quotas on rare earths, producers in China have incentives Human demand relative to what’s available in the Earth’s to develop black-market channels, “and there is definitely crust is relatively small even for the rare elements, and that evidence that that has happened and is happening.”

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