Projekt/Project Sidnr/Page no International collaboration 1 (11) Projektnummer/Project no A95422 FoT-område Kund/Customer Klicka här för att ange text. Handläggare/Our reference Datum/Date Steven J Savage 2014-03-07 FOI Memo 4859 steven.savage@foi.se CNC Materials & Structures Technologies Critical rare earth materials conference - report Abstract Based on this conference a brief analysis of ongoing R&D and commercial activities, expected future developments and the effects these may have on the situation regarding European non-dependence and security of supply of rare earth materials is given. The conference discussed current and future uses of rare earth materials, mainly in magnets although there are many other applications for the earth materials. The need for rare earth magnets in energy generation and in transport is expected to grow significantly in coming years. Sources of rare earth materials, both existing and new were discussed, including the recycling of rare earth materials from redundant equipment. The recycling industry is in this context still very immature. More efficient ways to use rare earth materials are being studied, as are alternative technologies to eliminate their use in some applications.
2014-03-07 2 (11) Sändlista/Distribution: (by e-post only) Lars Bohman (FOI) Jerker Hellström (FOI) Malek Khan (FOI) Göran Kindvall (FOI) Martin Lundmark (FOI) Johannes Malminen (FOI) Steven Savage (FOI) Lars Stenholm (FOI) Stefan Törnqvist (FOI) Anders Berg (FMV) Ola Dickman (FMV) Björn Jonsson (FMV) Evorn Mårtensson (HKV LEDS INRI) Inge Ceuppens (EDA) Patricia Vicente (EDA) Christina Wilén (Fö) Jakob Blomgren (Acreo Swedish ICT AB) Vincent Shaller (Chalmers Industriteknik) FHS FM Contents Abstract... 1 Analysis... 3 Background... 4 Introduction to REMs... 4 Conference overview... 6 Summary... 9 Acknowledgements... 9 Appendix 1 Conference programme... 10 Appendix 2 Conference statistics... 11
2014-03-07 3 (11) Analysis The dramatic price increase in 2011 of some of the rare earth metals, and dysprosium in particular caused concern to users of these materials. Dysprosium is particularly important in the permanent magnets used in motors and generators in expanding markets in the transport sector (conventional, electric and hybrid electric automobiles) and the energy sector (wind power generation). This demonstrated clearly the risk for supply disruption in single source markets (in this case China, which currently supplies >90 % of the world market). Reliable and stable supplies are essential for manufacturers to continue to develop and invest in these technologies. Multiple sources can reduce the risk for supply disruption and in a free economy contribute to price stability through competition. The rare earth elements and their compounds and alloys are essential in society today and cannot be easily replaced. They are used in many portable electronic devices, lighting, oil refining and increasingly in transport and energy. Since 2011 many actors have started operations to increase the number of rare earth material suppliers and to explore new ways to recover rare earth materials from redundant equipment. The recovery, recycling and reuse market is underdeveloped with respect to rare earth materials since they are used in small quantities in a very wide range of small devices. Use of rare earth materials in larger devices (motors and generators) is relatively recent, so while recovery from this type of equipment is easier, there is relatively little currently entering the scrap market. This will change in the future. Attempts are also being made to improve existing magnetic materials to use rare earth materials more efficiently. This is done through design of improved microstructures and alloys, and studies of new motor designs which eliminate the rare earth materials and use alternatives. New processes are being studied to improve the recovery, recycling and reuse of redundant equipment. New processes are being studied to recover rare earth materials from waste or residual materials produced by other processes, e.g. from other mining / mineral operations. Already new (or to be more accurate previously closed) production facilities are coming online. In summary, there are a multiplicity of ongoing activities by a wide range of commercial and research organisations aiming at increasing the number of rare earth suppliers, increasing the quantities of rare earths recovered from scrap and at using rare earth materials more efficiently. While the current situation is unstable, it is reasonable to assume that over the coming decade the overall situation concerning the rare earth materials will stabilise and European security of supply increase significantly. It should be noted that Chinese domestic consumption of rare earth materials is increasing rapidly, and therefore export of these as unprocessed materials is very likely to decrease in the foreseeable future. Future exports are most likely to be in the form of finished products.
2014-03-07 4 (11) Background Critical raw materials and technologies is a topic of international concern and in Europe increasing efforts are being made to ensure security of supply, particularly in technologies related to security & defence. Rare earth materials (REMs) is a case in particular since one source China; currently supplies >90 % of the world s needs. REMs are used in a very wide range of applications in communications, electronics, the transport (automotive) sector, energy generation & storage, aerospace and sensors, many of which are essential in security & defence. The subject conference arranged by the UK Magnetics Society is one step in a complex process to identify critical materials & technologies and to strengthen the supply chain. This conference focused on REMs in applications utilizing their unique magnetic properties, but it is emphasized that REMs find very important applications in other areas where their electrooptical and chemical properties are utilized in for example light emission and in oil refining. To reduce European dependence on non-european sources of REMs various strategies are available including: Opening / re-opening rare earth mines in countries outside China Using alternative technologies which do not use REMs Design improvements to use REMs more efficiently Recycle / re-use of REMs from redundant equipment Introduction to REMs The rare earth metals are a group of elements with chemically very similar properties but with a wide range of unique magnetic properties. Figure 1 below shows their positions in the periodic table of the elements. Note that Scandium (Sc) and Yttrium (Y), while not strictly belonging to the group of REMs are often included because of their chemical similarity. Despite the name the REMs are not particularly rare. They occur widely distributed in the earth s crust, at average concentrations in the range 150 to 220 ppm. Many other commonly mined metals occur in much lower average concentration, such as copper (55 ppm) and zinc (70 ppm). However, the REMs do not occur in concentrated mineral deposits, and are therefore difficult to mine economically. Mining and separating the REMs is complex chemically, and if done improperly will cause significant environmental damage. Although there are 17 REMs, not all of them have economically important uses. The most important applications for REMs in terms of volume demand are permanent magnets in motors and generators, in oil refining where REMs are used to crack oil into lighter fractions such as gasoline, kerosene and diesel and in lighting where REMs are used in a wide range of phosphors. Commercially important REMs include Neodymium (Nd), Dysprosium (Dy), Samarium (Sm) and Gadolinium (Gd). Cerium (Ce) is also important.
2014-03-07 5 (11) Separation of the valuable REMs therefore also produces quantities of the less commercially important metals, for which there is little demand. An important factor in the separation process is that thorium is frequently found in the same minerals as the REMs, so concentration of the REMs also involves concentration of thorium, which is a radioactive element. In the natural concentrations thorium is found everywhere in harmless quantities, but as the concentration increases so does the difficulty of handling the radioactive minerals. Figure 1. Showing the rare earth metals in the periodic table of elements Important current applications for REMs include the following, although some are used in relatively small quantities and are perhaps less important commercially (but nonetheless important technically): High energy density magnets for compact motors and generators (Nd, Pr, Dy, Tb, Sm, Gd, Y) High energy density nickel-metal hydride batteries (La, Ce, Pr, Nd) Catalysts for hydrocarbon fuel (gasoline, diesel, kerosene) production (La, Ce, Pr, Nd) Fibre optics including lasers (Er, Y, Tb, Eu) Magnetic disc storage (Gd, Tb) Magnetostrictive alloys, e.g. for sonar transducers (Tb, Dy) Phosphors in light sources (Eu, Y, Tb, La, Ce) Metal alloys for high strength, impact resistance and high temperature stability (Ce, Er, Sc) Corrosion resistant coatings (Ce, La)
2014-03-07 6 (11) Conference overview The conference programme is attached (appendix 1). The main points covered included: Where the REMs are found in commercially viable quantities Uses of REMs, especially in magnets The supply chain Recycling of REMs from magnets in redundant equipment Rare earth-containing minerals are found throughout the world. Known mineral deposits include North America (USA & Canada), eastern Africa, Australia, China, India, Greenland and Sweden, although current production is localized in China and especially Bayan Obo. China currently dominates the world production, as can be seen from figure 2. Note that the USA was a major producer until about 1998. Figure 2. Production of the rare earth oxides prior to year 2000 The current concern regarding security of supply was triggered by dramatic price increases in 2011, as seen in table 1 and figure 3. Prices have since then relaxed to more normal levels although are still higher than pre-2011, but the action created concern regarding stability of supply and stability of price.
2014-03-07 7 (11) Table 1 showing the change in price of selected REMs between January & September 2011. Source http://www.marketoracle.co.uk/article30924.html (accessed 2014-02-24) Figure 3. Source Brown et al, JoP, 2014 1 There is significant activity around the world to document and study the commercial feasibility of opening new REM production facilities. Deposits of rare earth-containing minerals, mainly monazite, xenotime and bastnasite occur widely, and >800 occurrences were documented in 2002, and today (2014) 57 resources in 16 countries now figure on a list of advanced REM projects. 1 D.N. Brown, Z. Wu, F. He, D.J. Miller & J.W. Herchenroeder, Dysprosium-free melt-spun permanent magnets, J. Phys: Condensed Matter 26 (2014) 064202
2014-03-07 8 (11) Previous REM production in the USA from the Mountain Pass mine in California ceased in 1998 (cf. figure 2), but restarted at the end of 2012. A potential source of REMs often overlooked is waste minerals from which other metals have already been extracted, for example crushed rock from iron ore mining. Since much energy is expended in crushing rock, the recycling of already crushed rock represents a significant energy saving compared to mining virgin minerals, and the waste is often easily accessible in large piles next to existing infrastructure for mineral processing. Rare earth metals cannot be mined individually (as for example copper, tin, iron). All the REMs are extracted, despite only a few being needed in large quantities. The others have little value and are normally stockpiled. This is known as a balance problem, which may be partially alleviated by improved recovery/recycling and re-use, which of course produces those REMs for which there is a demand. This is a non-trivial solution, as for example it is known that as much as 30 % of all platinum used is recycled. An application for REMs which superficially seems unimportant is in phosphors for light emission. While direct lighting is one obvious application, enormous numbers of electronic devices are dependent on displays and screens. A well know application for REMs is in permanent magnet motors and generators. The latter is especially important for the emerging wind turbine market, since alternative solutions are larger and heavier, which has a cascade effect on the size, weight and cost of the turbine pylon. Generator reliability is also improved by using REM-based permanent magnets as stability against demagnetization (e.g. under short-circuit conditions) in increased compared to more conventional techniques. The main REM used is Nd, but smaller amounts of Dy are needed especially in applications where higher operating temperatures occur, such as in electric automobiles. Both these applications are expected to grow dramatically in the near future, resulting in significant increases in the demand for REMs. Recovery, recycling and re-use of REMs is still an immature technology. REMs are used in small or very small amounts (sub-gram quantities) in many devices, from low energy lighting through mobile telephones to large wind turbine generators (100 s of kg). The recycling industry is not yet able to recycle REMs, although attempts are being made to do this from electronic scrap. On example is the voice coils used in computer hard drives, which contain a few grams of Nd. Disassembly is a complex and time-consuming process, made more difficult by the different designs and difficulty in locating and identifying the rare earth magnets. A process using hydrogenation-dehydrogenation is under development to recover sintered magnets, but many rare earth magnets are polymer-bonded and this process is unsuitable. Using smaller quantities of REMs in existing applications appears to be feasible. Examples of this are additions of Dy to NdFeB magnets to improve high temperature stability. Designers may be tempted to over-specify the performance needed from a magnet, to increase the margin of safety. By refining the design or by increasing cooling it may be possible to relax the material specifications without risking failure of the magnet due to overheating. It is also possible to improve the microstructure of existing magnets and retain performance while reducing Dy usage, by selectively alloying Dy at the grain boundaries in the magnet. This seems to be a promising concept, but the technology is immature.
2014-03-07 9 (11) Redesign of electric motors to reduce the use of REMs to zero is also a subject of investigation, and there are claims that this would reduce significantly the total lifecycle greenhouse gas emissions of a motor. This approach entails a complete redesign of the motor, using the principle of magnetic reluctance to induce the necessary magnetic poles on the rotor. The technology for recycling REMs is immature, but as this is improved both efficiency and quantity of REMs from this source should be expected to grow in importance as a domestic source of REMs in the future. This will of course also reflect the greater volumes of redundant equipment reaching the end of life. An important advantage is that that only the desired / most valuable REMs will be recovered (cf. the mixture recovered from mining and refining mined virgin minerals). However, there will be a significant time lag between new equipment entering the market and obsolescent/redundant equipment entering the scrap stream. This is especially the case for motors and generators containing large quantities of REMs. A new wind turbine generator entering service today has an expected lifetime of 120000 hours (ca. 14 years) before replacement. To address the subject of critical raw materials a project financed by the EC within FP7 has been started (in 2012). More details can be found at: http://www.criticalrawmaterials.eu Summary REMs are essential in many applications in energy generation, transport, oil production and information storage (to name but a few). A direct application in defence materiel is in sonar transducers. Over the coming decades, if current trends continue the need for REMs will grow considerably. Alternative, non-chinese sources of REM minerals exist and are being actively developed. However significant investment will be needed and the environmental challenges associated with handing radioactive minerals are not trivial. New mineral deposits are being exploited and existing mines re-opened. Recycling of REMs from redundant equipment is immature. Separation of the often small REM-containing components from the equipment is difficult, as is refining of the recovered REMs. However, a significant advantage is that the most valuable REMs are those which will be recovered. Technologies to use REMs more effectively are being developed, including new processes and alloys, and new electromechanical designs studied. Acknowledgements The author acknowledges with thanks a critical review and valuable comments from Malek Khan.
2014-03-07 10 (11) Appendix 1 Conference programme
2014-03-07 11 (11) Appendix 2 Conference statistics Almost 100 delegates were pre-registered at the start of the conference, representing academia, industrial and government organisations in the main from the UK. About 110 actually attended. A copy of the delegate list is available from the author of this report. Copies of most of the presentations given at the conference are available from the author.