Issue 32 – October 2011
Recently there has been an increase in concern about rare earth metals because of their great value in a number of product categories; their rapid increase in raw material cost; the environmental impact of mining the metals; and the fact that mining is occurring primarily in China, where 97% of the rare earths used in the world today originate.
In the 1980s, George C. Hadjipanayis, PhD, was working with neodymium metals, but they kept falling apart. He asked his assistant to add some boron to help hold the neodymium together and accidentally discovered the world's strongest magnetic materials. These neodymium magnets are rated 20 times stronger than a typical refrigerator magnet. They are so strong that a human cannot separate them. They must be sawed apart. The fifteen rare earth metals are cerium (Ce), dysprosium (Dy), erbium (Er), europium (Eu), gadolinium (Gd), holmium (Ho), lanthanum (La), lutetium (Lu), neodymium (Nd), praseodymium (Pr), samarium (Sm), terbium (Tb), thulium (Tm), ytterbium (Yb), and yttrium (Y).
Even though these metals are not rare, they are very difficult to mine and separate. There is also a great deal of environmental concern related to mining activity, and in some cases, radioactive materials must be handled.
Until the 1980s, the US dominated production of rare earth metals, but now China mines 97% of them. Yearly production is about 150,000 tons per year. This production rate is below the growing demand level, and therefore a shortage is occurring, which in turn is causing a rapid rise in prices. Some have increased 400% in less than 1 year.
Applications of rare earths
Generally, rare earths are used as alloys, catalysts, ceramics, glass, magnetics, phosphors, or as nuclear materials. They have many practical applications:
- nickel-metal hydride (NiMH) batteries in hybrid automobiles
- luminescence of erbium and europium
- the vibrating component in virtually all smart phones
- the vivid reds and greens in TV displays
- data storage in computer hard drives.
In transportation, rare earths are found in Li-ion batteries for electric vehicles, while high-strength magnets are found in electric motors and generators. In telecommunications, rare earths are found in optical amplifiers and magneto-optical storage components. And in energy, rare earths help wind turbines through the use of high-performance permanent magnets, and solid-oxide fuel cells with the use of cerium and lanthanum nanoparticle catalysts.
As the world continuously develops and more high-tech components and products are needed, this will gradually drive up the demand for rare earth materials globally.
The US is seeing a resurgence of mining activity in rare earth metals. A new mine with state of the art separation and environmental systems to protect people and the planet is expected to open in 2012. This mining activity will help produce more materials that will be in higher demand. The US will need this mining activity to prevent Chinese companies from having total control of the raw materials that many applications depend upon.
Other activities are occurring to search for replacements for rare earth metals in certain applications, or for techniques to produce the excellent characteristics that come from rare earths, but while using far less rare earth raw material. This is being driven by the use of nanomaterials that have the potential of replacing bulk rare earth materials in a number of applications including nanotexturing of electrodes in batteries, nanocrystals of metals for simulated rare earth magnets, quantum dots of indium gallium arsenide phosphide (InGaAsP) replacing erbium in optical amplifiers, and optimised design of permanent magnets.
Although nanotechnology promises to help, there is still much research to be done to overcome practical problems in all of these applications. Therefore, as the world becomes more and more dependent upon rare earth metals and their unique characteristics in certain application areas, we can expect the price of the raw materials to continue to rise, and we should expect greater shortages in the near term.
Governments and corporations have recognised these issues, and are taking action to try to resolve them with increased mining and with research into potential replacement materials.
Considering the unique characteristics of the rare earth metals, these efforts should be accelerated as much as possible, while keeping the protection of the people and the planet front and centre.
Reproduced from an article by Greg Monty, PhD, Underwriters Laboratories, Corporate Research in The Association of Electrical and Medical Imaging Equipment Manufacturers (NEMA) Electroindustry magazine, September 2011.
Dr Monty is part of Corporate Research at Underwriters Laboratories working on safety science and chairs IEC TC1 13, which is focused on nanotechnology Standards development for electrotechnical products. His research interests include nanotechnology, as well as environmental and sustainability technology including environmental health and safety, solar, other renewable energy sources, greenhouse gasses, smart grids, and hazardous materials.