Scandium – a „spice metal“

Source: Flickr/Creative Commons (Ehrmann, 2010)

Source: Flickr/Creative Commons (Ehrmann, 2010)

Today’s blog is about scandium. It is one of the most expensive elements, at around 5 million US dollars per tonne, with a very small production volume of an estimated 5-15 tonnes per year (Castilloux, 2015). There is currently no mine operational which is dedicated solely to the production of scandium, i.e. it is mined as a by-product (Scandium International Mining Corp., 2014). Contrary to other rare earths, the market is not dominated by China – its production and use has been driven by the former Soviet Union countries. Russian stockpiles are currently the largest source, with growing supply from China, and interest in the development of new mines from other countries (Scandium International Mining Corp., 2014).

Scandium is used in solid oxide fuel cells. The addition of scandium to zirconia-based electrolytes used in fuel cells results in high ionic conductivity and makes the fuel cell more efficient (Metallica Minerals, 2013; USGS, 2015).

Scandium-aluminium alloys constitute the main application by weight (PR Newswire, 2015). Small amounts of scandium, as little as 0,2-1%, are added to the aluminium alloys, which has a beneficial effect on the microstructure of the alloy material; making the material stronger and more workable – hence the name “spice metal” (Metallica Minerals, 2013). This is beneficial in aerospace applications where compound weight is key. Heavy joints in aluminium alloy structures can be omitted due to the higher strength of the alloy material. This also makes the material potentially interesting for future automotive applications (Castilloux, 2015; Scandium International Mining Corp., 2014). Other applications of scandium include special high-end sports equipment such as baseball bats, bicycle frames, golf clubs and ski poles. 

Besides solid oxide fuel cells and scandium-aluminium alloy applications, scandium iodide is used in mercury vapour high-intensity lights to simulate natural light (USGS, 2015), which can be used for example in television studios.


  • Castilloux, R., 2015. Why Everyone Is Talking About Scandium. Accessed 2 January 2016.
  • Ehrmann, T., 2010. Scandium. Accessed 2 January 2016.
  • Metallica Minerals, 2013. Scandium: A new “spice” metal to enhance industry & life. Accessed 2 January 2016.
  • PR Newswire, 2015. Global Scandium Market – Segmented by Product Type, End-User Industry and Geography – Trends and Forecasts (2015-2020) – Reportlinker Review.—segmented-by-product-type-end-user-industry-and-geography—trends-and-forecasts-2015-2020—reportlinker-review-300145399.html. Accessed 2 January 2016.
  • Scandium International Mining Corp., 2014. Developing the World’s First Primary Scandium Mine, Dec 2014.
  • USGS, 2015. Scandium – Mineral Commodity Summaries 2015. USGS National Minerals Information Center. Accessed 2 January 2016.




E-bikes and rare earths


1.  Types of e bikes / electric two-wheelers

Electric two-wheelers/bikes are powered by a combination of manpower and electric power, or electric power only. They include bicycle-style electric bikes (BSEB), namely pedelecs (pedal assisted bikes), or throttle-controlled e-bikes, where pedaling is not required, and scooter-style electric bikes (SSEB), i.e. electric scooters and electric motorbikes (Fu, 2013))

2.  Current e-bike adoption

The largest market for e-bikes is China (Hoganas, 2010; Statistica, 2015), followed by Europe, Japan and US (INSG, 2014). The electric bicycle boom in China was triggered by local bans of motorcycles motivated by the aim to reduce air pollution and traffic congestion, a well as safety concerns (Yang, 2010). However, legislation discouraging the use of e-bikes was put in place in some cities, including bans of-e-bikes in some cities and the introduction of e-bike licenses (Shaw and Constantinides, 2012), most likely due to safety concerns. A survey conducted in Shanghai revealed that e-bikes are mostly used for commuting, closely followed by shopping trips (An et al., 2013). The main motivation stated in the paper was that e-bikes were “more labour-saving than bike and more convenient and faster than bus” (An et al., 2013). The typical Chinese bicycle looks like a cross between an e-bike and a scooter (Zeit Online, 2013).

The largest European markets for e-bikes are Germany, the Netherlands, France and Italy (Bike Europe, 2014). A study on early adopters in Austria found that users there were mainly aged 60 plus and used e-bikes for leisure trips (Wolf and Seebauer, 2014). With that image in mind, some cyclists may consider e-bikes a lazy option -  see for example the following blogs: London Cyclist (2012); npr (2014). However, according to (2013), at least in Germany, age is becoming a less important factor in the definition of the target group for e-bikes.

3.    Technology, Magnets, RE content

E-bike motors constitute an important application of NdFeB magnets. They were responsible for around 10% of the neodymium use in 2010, with a similar percentage projected for 2030 (Bast et al., 2014). The motors are either mounted on a hub of the bike – the most common type – or between the pedals (so-called mid-drive system). In accordance with the expectance of an expanding e-bike market, the demand for NdFeB magnets for use in e-bikes is expected to grow (Bast et al., 2014; Shaw and Constantinides, 2012). Estimates for the weights of magnets used in e-bikes range from 60 g to 350 g (Shaw and Constantinides, 2012). Zepf (2013) assumes an average of 100 g per magnet used for e-bike applications, Habib and Wenzel (2014) assume 300 g. The rare earth content of the magnets is estimated at 30% Nd and 4% Dy (Binnemans et al., 2013; Zepf, 2013).

However, research aiming at the replacement of magnets relying on rare earths is underway. A US start-up company won a prize for its patented switched reluctance motor intended for use in e-bikes, an alternative to motors based on permanent magnets (Wang, 2012; Yale Global Online, 2012). However, no evidence of those types of e-bikes on the market could be found. Other researchers work on rare-earth free nanocrystalline permanent magnets for e-bikes, with a public demonstration planned for June 2015 (Archer-Boyd, 2015).

4.   Environmental considerations

Environmental considerations regarding e-bikes focus around use-phase impacts and impacts associated with lead batteries rather than rare earth use.

Chinese bikes often contain lead acid batteries, which do not have a long battery life and are not disposed of in an environmentally sound manner (Zeit Online, 2013). The bikes have a lifetime of approximately four years during which the lead acid batteries are replaced five to seven times (Zeit Online, 2013). E-bikes sold on the European market are mainly equipped with lithium ion batteries.

Environmental benefits of e-bike usage depend, amongst other factors, on intensity of usage and the “direction of modal shift” –  see Wolf and Seebauer (2014). i.e., the shift in impact will be different depending on whether conventional bikes, walks, cars, or public transport options are replaced. According to Bike Europe, e-bike sales in Europe have affected sales for conventional bikes (Bike Europe, 2014) – this however, is not directly transferable to shifts in user behavior. In their Austrian study, Wolf and Seebauer (2014) found that carbon-intensive travel modes on commuting trips were barely substituted (Wolf and Seebauer, 2014). According to Zeit Online (2013), traditional bikes are becoming less popular as a transport option in China; cars and e-bikes are on the rise. Results of a survey conducted with e-bike users in Shanghai by An et al. (2013) indicate that the survey participants would mainly shift to bus (55%) or conventional bikes (33%) if an e-bike ban was introduced. Similar findings are reported by Cherry et al. (2009), who found that Chinese e-bike users mainly shifted from, and would mainly shift back to, buses or bikes.

The modal shifts associated with e-bike can differ between cultures, social groups and change over time, since the market is still developing.

5.     References

An, K., Chen, X., Xin, F., Lin, B., Wei, L., 2013. Travel Characteristics of E-bike Users: Survey and Analysis in Shanghai. Procedia – Social and Behavioral Sciences 96, 1828–1838.

Archer-Boyd, A., 2015. Positive solutions to Europe’s magnet problem.

Bast, U., Blank, R., Buchert, M., Elwert, T., Finsterwalder, F., et al. ., 2014. Recycling von Komponenten un strategischen Metallen aus elektrischen Fahrantrieben: Kennwort: MORE (Motor Recycling), pre-release.

Bike Europe, 2014. All Signs Are Green Thanks To E-Bikes. Accessed 13th Jan 2015.

Binnemans, K., Jones, P.T., Blanpain, B., van Gerven, T., Yang, Y., Walton, A., Buchert, M., 2013. Recycling of rare earths: a critical review. Journal of Cleaner Production 51, 1–22.

Cherry, C.R., Weinert, J.X., Xinmiao, Y., 2009. Comparative environmental impacts of electric bikes in China. Transportation Research Part D: Transport and Environment 14 (5), 281–290.

Fu, A., 2013. China electric two-wheelers: Market analysis, trends, issues and perspectives.

Habib, K., Wenzel, H., 2014. Exploring rare earths supply constraints for the emerging clean energy technologies and the role of recycling. Journal of Cleaner Production 84, 348–359.

Hoganas, 2010. The electric bicycle race. Metal Powder Report 65 (5), 14–15.

INSG, 2014. The Global E-Bike Market: INSG Secretariat Briefing Paper, 6 pp. Accessed 27 April 2015.

London Cyclist, 2012. Electric Bikes: It’s not Cheating, it’s Transport. Accessed 13th Jan 2015., 2013. Bericht zur Studie ‘Konsumwelt 2013: E-Bikes’ Valide Marktdaten durch eine strategische Marktanalyse. Accessed 13th January 2015.

npr, 2014. Electric Bikes, On A Roll In Europe, Start To Climb In U.S. Accessed 13th January 2014.

Shaw, S., Constantinides, S., 2012. Permanent Magnets: the Demand for Rare Earths: 8th International Rare Earths Conference, 33 pp. Accessed 27 April 2015.

Statistica, 2015. Projected worldwide sales of electric bicycles in 2018, by region (in million units). Accessed 13th January 2015.

Wang, U., 2012. An electric motor that’s ditched the rare earth materials: Gigaom Blog.

Wolf, A., Seebauer, S., 2014. Technology adoption of electric bicycles: A survey among early adopters. Transportation Research Part A: Policy and Practice 69, 196–211.

Yale Global Online, 2012. No Rare Earths in Next Generation Electric Vehicles.

Yang, C.-J., 2010. Launching strategy for electric vehicles: Lessons from China and Taiwan. Technological Forecasting and Social Change 77 (5), 831–834.

Zeit Online, 2013. Velophil – Das Fahrrad-Blog. Chinas E-Bike-Boom auf Kosten der Umwelt. Accessed 13th Jan 2015.

Zepf, V., 2013. Rare Earth Elements: A New Approach to the Nexus of Supply, Demand and Use: Exemplified along the Use of Neodymium in Permanent Magnets. Doctoral Thesis accepted by the University of Augsburg, Germany. Springer Theses, 162 pp. Accessed 27 April 2015.


Case study: Öko-Institut’s study on permanent magnets used in industry in Baden-Württemberg

Today’s blog is on a study conducted last year by Öko-Institut, dealing with permanent magnets used in industry in Baden-Württemberg – one of the federal states in Germany. The project was funded by the Ministry of the Environment, Climate Protection and the Energy Sector of Baden- Württemberg.


Source: Flickr /Creative Commons

Industrial applications of permanent magnets include motors, generators, and applications related to attractive magnetic forces, i.e. magnetic separators in sorting plants, but also to remove metal contamination e.g. during food production and many other industries, and for lifting. The poor availability of data on these types of magnet applications was the motivation for the study. Baden-Württemberg was chosen for the case study since a relatively high percentage of the German manufacturing industry is based there. Permanent magnet use in motors and generators is most important in terms of volumes. Furthermore, their dysprosium content is higher than that of magnets used for attraction purposes. To be more specific, synchronous servomotors are the most important application of permanent magnets in industry. These motors are more energy efficient than their predecessors (three-phase asynchronous motors). Their use has been accelerated by an EU directive on efficiency standards for new electric motors.

In order to investigate the use of permanent magnets in industry in Baden-Württemberg, a bottom-up analysis was conducted, based on a company survey and supported by industry associations. This approach proved to be difficult due to a general lack of knowledge on permanent magnet use in most of the companies surveyed. This is not overly surprising since the magnets are mainly components part of larger equipment and not purchased as stand-alone items. In absence of relevant or rather, sufficiently detailed production statistics, expert interviews were conducted with producers of magnets and motors using permanent magnets as well as industry association representatives. The interviews provided a good understanding of the use and stock distribution of permanent magnets in industry in Germany. The numbers were then extrapolated for Baden-Württemberg. Furthermore, historic and future production data was collected in these interviews, which also allowed an estimation of the future magnet recycling potential.



Source: Öko-Institut, calculations based on information from expert interviews

As shown in the figure above – data here refers to the whole of Germany and motors from industrial applications expected to reach the end of lives – the projected increase in the use of synchronous servomotors and the subsequent accumulation of permanent magnets in use over time means an increase in recycling potential for permanent magnets from industrial applications. However, the actual recycling potential is compromised by the common exports of industrial machinery for reuse abroad – effectively an extension of in-use lifetimes.

recycling electric motors

Recycling of electric motors in Nanjing, China.

The introduction of a recycling system is complicated by the lack of a collection, sorting and disassembly system, meaning that a reliable feedstock supply is not yet available. In light of the expected increase in recycling potentials, the authors recommend the establishment of those systems by 2030, ideally on a European level in order to enable the collection of sufficiently large quantities. In addition, a mandatory labelling system indicating the presence and types of permanent magnets in industrial machinery is recommended.


Buchert, M., Manhart, A., Sutter, J., 2013. Untersuchung zu Seltenen Erden: Permanentmagnete im industriellen Einsatz in Baden-Württemberg: Öko-Institut e. V., Freiburg, 54 pp. Accessed 16 December 2014.

EU, 2012. Commission Communication in the framework of the implementation of the Commission Regulation (EC) No 640/2009 implementing Directive 2005/32/EC of the European Parliament and of the Council with regard to ecodesign requirements for electric motors, 2 pp. Accessed 24 April 2015.

Kuenl, G., 2013. Deutschland politisch: (map listed under creative commons license).

Stougard. Wikimedia Commons, License: CC-BY-SA-3.0,


Ce in car cats for oxygen storage


Ce is the most common rare earth element and usually seen as non-critical (3), but has also been classed as “near critical” in the short term by the US Department of Energy due to its importance to clean energy technologies in combination with projected supply risks (7) (citing (8)). Its abundance is similar to that of copper (5). However, it is still one of the eight rare earth elements of highest economic interest (alongside lanthanum, neodymium, praseodymium, samarium, dysprosium, europium and terbium) (5) Common applications include lens polishes, petroleum refining, metal alloys and automotive catalysts (6, 7).

Ce used in automotive catalysts

Automotive catalysts convert toxic exhaust fumes into less harmful fumes. Hydrocarbons (CmHn) carbon monoxide (CO) and nitrous oxides  (NOx)are converted into CO2; H2O and N2 via redox reactions (2).

In order for the process to work efficiently, a certain operating temperature, a large surface area and a certain level of oxygen are necessary. In the first few minutes of the engine warm-up phase, the operating temperatures are still too low for the process to work well, which results in most emissions being released in this phase (1). The required surface area is often achieved by a honeycomb structure made from ceramic or stainless steel and coated with aluminum oxide, rare earth oxides and platinum group metals which act as catalysts (2). Three-way catalysts use ceria compounds for oxygen storage (4). The compounds act as a buffer by absorbing and releasing oxygen, thereby helping to generate the required stoichiometric conditions for the redox transformations to work (4). The cerium is oxidized “by default”, but capable of absorbing further oxygen in an oxygen-rich atmosphere, thereby helping to increase the efficiency of the nitrogen oxide reduction process (2). The stored oxygen is released again when needed, which again helps the oxidation of carbon monoxide to work more efficiently (2). The process is supported by sensors which measure the oxygen content and the air-to-fuel ratio is adjusted accordingly (10, 4). It may be interesting to mention that it has been suggested to utilize the oxygen buffer capacity of cerium oxides in medical applications, too. Scientists at Rice University found that the use of cerium oxide as an antioxidant aimed at damaging reactive oxygen species could help treat traumatic brain injuries, cardiac arrest and Alzheimer’s patients and help with radiation-induced side effects suffered by cancer patients (9).

Furthermore, organic cerium compounds added to diesel fuel help promote soot combustion and thereby help avoid the clogging of diesel particulate filters (4).

The conversion efficiency rates of cats (for hydrocarbons, carbon monoxide and nitrogen oxides) lie at around 98% (10). The use of rare earths in automotive catalyst applications has helped to improve their performance greatly and may help further enhance the exhaust fume control and fuel efficiency in future (4).

Cat recycling activities

Monoliths (the previously described honeycomb structures in automotive catalysts) are recycled, which is primarily due to the fact that they contain platinum group metals. BASF, Umicore and Johnson Matthey, for example, refine precious metals from cats (11, 12, 13). Used cats provide a valuable recycling stock at 75-250 $ per piece (2010 figures) (2). Existing commercial-scale recycling processes do not currently recover cerium compounds, which are disposed of with the slag (2). However, proactive research on the recovery of cerium compounds from cats is being undertaken to prepare for potential future cerium supply shortages and/or price increases, and 70% recovery rates have been achieved in small scale experiments (2).


1)    GSF & Flugs (2004): Katalysatoren in Kraftfahrzeugen – Freund oder Feind für Umwelt und Gesundheit?

2)    Bleiwas, D.I., USGS (2013):  Potential for recovery of cerium contained in automotive catalytic converters; Open-File Report 2013–1037; U.S. Department of the Interior, U.S. Geological Survey.

3)    Hatch, G. P. (TMR, LCC) (2011): Critical Rare Earths Global supply & demand projections and the leading contenders for new sources of supply.

4)    Shinjoh, H. (2006): Rare earth metals for automotive exhaust catalysts, Journal of Alloys and Compounds 408–412, 1061–1064

5)    Massari, S.; Ruberti, M. (2013): Rare earth elements as critical raw materials: Focus on international markets and future strategies, Resources Policy 38, 36–43

6)    Hayes-Labruto, L,  Schillebeeck, S.; Workman, M., Shah, N. (2013): Contrasting perspectives on China’s rare earths policies: Reframing the debate through a stakeholder lens, Energy Policy 63, 55–68

7)    Weber, R.J., Reisman, D.J. (2012):  Rare Earth Elements: A Review of Production, Processing, Recycling, and Associated Environmental Issues

8)    US Department of Energy (2011): Critical Materials Strategy – Summary

9) (2013): Scientists create a super antioxidant: Common catalyst cerium oxide opens door to nanochemistry for medicine Oct 15, 2013, accessed 09th April 2014

10) BASF (2014): How Catalytic Converters Work , accessed 09th April 2014

11) BASF (2014): Autocatalyst Recycling, accessed 16th April 2014

12) Johnson Matthey (2014): Refining and Precious Metal Management Services, accessed 23rd April 2014

13) Umicore (2014): Excellence in Recycling; accessed 23rd April 2014

Europium (Eu) used in TVs and lamps

Introduction: Europium
Although Europium is one of the light rare earth elements (USGS definition) which tend to be more abundant than the heavy rare earths, it is one of the most expensive rare earth elements and has been classed as one of the critical rare earths(2). Shortages have been predicted with a high degree of probability (3). Due to the high prices of europium and terbium, lighting and display systems constitute one of the most economically relevant rare earth applications (4).

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