As technology progresses the demand for innovative and unique materials will only grow. Due to the properties of rare earth metals, especially when used in high strength magnets and electronic displays, it seems unlikely that we will be able to come up with suitable synthetic materials for the same cost. Thus, meeting the growing demand especially in consumer products will require significant increases in production of a variety of materials including REM’s. There are a couple strategies that seem possible to achieve this goal. In order of decreasing economic viability, increased mining, recycling of rare earth metals and mining asteroids for rare earth metals. The last option in particular is quite speculative since no one has really developed an inexpensive method to get these elements from asteroids and bring them back to Earth.
Increasing mining of rare earth metals seems like the most natural way to meet the growing demand, but it is certainly not the most environmentally friendly. From one of my previous posts we can look at estimates for the current land use of REM mining based on the EIO-LCA tool. We see that currently REM mining takes around 16.3 kilo hectares of land. Certainly compared to the overall amount of proven reserves there is plenty of room to expand production. However, a significant fraction of these reserves are located in countries like China which holds around 37% of proven reserves and has somewhat lax environmental policies creating an ecological impact that would be no doubt quite deleterious.
Recycling is another method by which we can reduce not only the impact of mining for REM’s but also the energy cost with refining the metals from bauxite ore. However this approach requires action by the everyday consumer to recycle their electronics and also requires industry to have an effective process to get the materials out of their highly integrated state within modern technology gadgets. Currently, it is estimated that only one percent of rare earth metals are recycled, while this is a massive opportunity to provide sustainability directing consumers to recycle seems quite difficult in today’s culture of constantly throwing things out and buying new products
Finally, we can speculate as to the possibility of mining asteroids to generate new sources of rare earth metals. Currently it is extremely expensive to even launch a payload into space, in fact just to put a satellite in orbit around Earth costs around $10000 per pound. However companies like SpaceX and Planetary Resources are tackling this problem and according to Rene Fradet at the Jet Propulsion Lab asteroid mining could be economical in 20 to 30 years. If asteroid mining were feasible it could allow for an almost unlimited supply of critical REM’s essentially allowing mining and other environmentally harmful forms of resource extraction to become irrelevant.
From my exploration into rare earth metals I believe there is hope for the future, human ingenuity is unmatched when faced with difficult constraints. Though the demand for these elements will no doubt continue, increased recycling and perhaps even asteroid mining will pave the way for a sustainable energy efficient way to harvest rare earth metals.
In some sense, Rare Earth Metals are not strictly required by humanity. If we are willing to accept a lower standard of living and less scientific advancement, we can certainly survive without REM’s. However, the fact remains that REM’s indirectly or directly contribute to much of the technology that we have grown used to in the modern age. Take for example the MRI machine, every day across just the United States there are over seven thousand MRI machines in place. MRI machines work on the basis of strong magnetic fields, these fields are supplied by magnets that use rare earth metal alloys. Clearly this application is critical to modern healthcare and would have a tremendous impact on human lives if it were not available due to a lack of rare earth metals. In terms of convenience compared to necessity, rare earth metals are primarily used in high tech industrial and commercial goods.
The unique properties of rare earth metals make it difficult to find appropriate substitutes, especially if performance is key. For example Ian Baker a professor at Dartmouth looked into using manganese and aluminum powder as a possible replacement for REM’s in magnets, but these compounds were not as favorable magnetically compared to the rare earth metals. Investigations into graphene and carbon nanotubes may someday lead to possible replacements for things like indium oxide in capacitive touchscreens but might take more energy to produce compared to simply mining REM’s from the earth. Moreover the DOE in their December 2011 Critical Materials Strategy report listed that “Five rare earth elements (REEs)—dysprosium, terbium, europium, neodymium and yttrium—were found to be critical in the short term” These elements are actually integral to making efficient magnets for wind turbines, meaning that REM’s have a critical importance in the clean energy arena.
Since it seems that at least in the near term replacing rare earth metals is nigh impossible, the most likely path forward will be recycling. The difficulty with this approach however is that while recycling REM’s found in industrial equipment is quite possible due to the competitive pressures and clear cost savings, REM’s used in the commercial sector(e.g. touchscreens) are difficult to obtain because of the relative lack of recycling of commercial electronics. Indeed according to an article in the Journal of Cleaner Production noted that up until at least 2011 less than 1% of REM’s were recycled. Changing consumer habits is one of the most difficult things to do since often there is no real incentive on the part of the consumer to do so. Looking at the PAT factors(i.e. Population,Affluence and Technology), the rise of third world economies with large populations like India and China play an important role the future demand for electronics and modern technology, which will only grow. Indeed a World Economic Forum article states that consumer consumption is increasing by around 17% per year in the upper classes of China alone.
Overall it seems like the use and thus impact of REM’s on the environment will only grow,until economic pressures force more sustainable use and recycling of rare earth metals. The increasing worldwide consumption especially from developing nations with large populations like China and India will only make REM’s a more integral part of our daily lives making its use harder to replace.
To understand the energy usage associated we can use the estimated economic activity of the industry and derive the approximate energy requirements using the Economic Input-Output Life Cycle Assessment(EIO-LCA) tool. According to a report authored by the National Center for Policy Analysis, the value of rare earth metals sold in North America was 795 million dollars. Even though the economic impact of REM’s trickles down to many different products, to a first order we can use this figure to generate a relatively conservative estimate for the energy impacts of the industry. Since the EIO-LCA tool does not have a specific category relating solely to rare earth metal production, we can use the mining of gold, silver and other miscellaneous metals as a decent proxy. Running the model with the aforementioned economic value of REM’s yields a total energy usage of 11700 Terra-joules. While this number certainly sounds quite large, it is important to understand the context. At the large industrial scale, we simply do not have a good intuitive idea if 11700 TJ is a large amount of consumed energy or a relatively small amount in the bigger picture that looks at the entire mining sector.
To give a sense of the scale at which these sectors of the economy operate at we can look at another mining industry, namely coal. Based on a recent report by the National Mining Association. The economic contribution of just the mining of coal is around 83.2 billion dollars. Using the EIO-LCA to generate an estimate for the energy required to support this industry puts the energy requirement at 710000 TJ. The energy requirements for coal mining is on the order of 60x more than gold,silver and other metal mining. Of course, this makes sense considering how much larger the coal industry is due to the much greater demand for coal compared to REM’s or precious metals. Nevertheless, it is important to see the larger picture especially when you begin to consider how to look at and reduce the environmental impacts of industrialization. Indeed, one of the most significant impacts of mining is of course the land use, strip mining in particular for metals can use large tracts of land and can pollute the local water supply. Rare Earth Metal mining is particularly relevant here since much of the mining occurs in China where environmental regulation is often put on the backburner as evidenced by a New York Times article describing the environmental impacts of REM mining in south-central China.
To get a quantitative idea of just how large the environmental impacts of rare earth metal mining are we can again using gold, silver and other metal mining as a proxy. Looking at the EIO-LCA report we see that the industry is responsible for around 16.3 kilo hectares(kha) of land use and around 39.5 million kilo gallons. However again it pales in comparison to other large scale mining industries like coal which can use around 323 kha, an order of magnitude difference. Thus overall while the environmental impacts of REM mining are not insignificant it is probably more effective to concentrate on other large industries in the mining sector like coal when considering regulation. Indeed, when looking at the future renewable energy sources could one day drastically reduce the demand for coal, while currently there does not seem to be any feasible replacements for many metals, especially rare earth metals, thus it would be more feasible to affect change.
(If you are looking for the blog post related to the current day use and supply of REM’s please look at “Global Supply and Importance of Rare Earth Metals” I accidentally did the 3rd and 2nd Blog Posts in reverse order)
Rare Earth Metals were discovered in a 150 year period starting from the late 1780’s with the discovery of yttrium all the way to 1945 with the isolation of promethium. Up until the modern age of high performance alloys and and sophisticated electronics the use of REM’s in human activities was fairly restricted. Historically, certain rare earth metals were used as colorants for glass. The chart below summarizes the usage of various rare earth metals from the start of the 20th century to the modern era.
While our reliance on REM’s was limited, starting in the 1960’s the “killer app” for rare earth metals was found, namely high performance magnets. Nowadays these magnets are found everywhere from MRI machines and lasers to particle accelerators and high strength alloys. If we were to remove REM’s from our existence we would find it very hard to replace them in the variety of high tech applications they serve in the Information Age. Their unique chemical, electrical and physical properties make them unmatched for the niches they fill. Essentially we would not be able to realize much of the fundamental technology that makes modern life so convenient, especially fast optical communications which form the backbone of the internet.
The mining and distribution of rare earth metals are complex issues. Most REM’s come from refining the minerals monazite and bastnaesite. China and the US have the largest known supply of these ores but there are also significant amounts of reserves in Brazil and India.
In general while the future supply of rare earth metals is not in question, there is an estimated 130,000,000 tons of global reserves for all REM’s, but the relatively long lead time to discover and viably extract these resources does pose a not insignificant problem in regards to future demand.
Considering the domestic issue alone, the United States imports 91% of its REM’s from China. Indeed China dominates both in mining and in reserve capacity of REM’s with 55,000,000 metric tons of reserves and 97% of overall REM mine production(105,000 metric tons). This can lead to significant disruptions in the supply chain if production is lowered or halted . In fact until as recently as 2015 China had imposed rare-earth export quotas that limited the sale of REM’s to outside countries. Further compounding the problem is the recent bankruptcy of Molycorp the only domestic producer of REM’s in the United States.
The primary demand for REM’s in the US and the world are from catalysts,metal alloys and magnets. Indeed 43% of US demand alone for REM’s comes from catalysts alone(e.g. Cerium Oxide in a car’s catalytic converter). Moreover, the use of REM’s in extremely strong magnets like neodymium iron boron (NdFeB) and samarium cobalt (SmCo), is particularly important for national defense reasons as many precision missiles and aircraft rely on the unique properties of these magnets to function.
Overall given the critical importance of REM’s and their relatively fragile supply chain it is likely that disruptions and shortages could lead to a greater focus on the recycling and reuse of REM’s in the future.
Rare earth metals(REM’s) are a collection of 17 elements in the periodic table, specifically Lanthanum, Cerium, Praseodymium, Neodymium, Promethium, Samarium, Europium Gadolinium, Terbium, Dysprosium, Holmium, Erbium, Thulium, Ytterbium, Lutetium, Scandium, and Yttrium.
Rare earth metals were first discovered in the late 1700’s and late 1800’s. In fact some of the names of the elements are based on the location of their discovery like Yttrium which was first found in Ytterby, Sweden.
Rare earth metals have a variety of highly specific industrial uses that are often invisible to the consumer. Many rare earth metals are used in modern electronic devices that underly the current information age. Things like, lasers, high performance alloys, extremely strong magnets and fiber optic cables are just a few of the many specialized and critically important uses of REM’s. As technology continues to advance the use and importance of REM’s will only continue to grow.
The name Rare Earth Metals suggests that these elements are quite scarce this however is a misnomer since the concentrations of many REM’s is on par with other industrial metals for example Cerium is the 25th most abundant material on earth, with the same concentration as copper. However these elements are not found in many ore deposits which necessitates extensive mining and development, which implies a certain level of environmental impact.