NEWS & REPORTS Siemens AG | Rolf Froböse Pictures of the Future | Autumn 2011 Munich | Germany
Alternatives in the Making Efficient Use of Resources - Raw Materials
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emand for high-performance materials such as rare-earth metals is on the rise worldwide. But many of these materials are becoming scarce. That’s why Siemens experts are developing technologies designed to improve utilization, recycling, and substitution of key materials. Green products are gaining ground so quickly that materials scientists are sounding the alarm. Permanent magnets for wind turbines are a case in point because they require rare-earth metals, including neodymium, praseodymium, and dysprosium. When these materials are optimally combined, their energy density — the unit of storable magnetic energy — exceeds 400 kilojoules per cubic meter (kJ/m3). That value is so high that magnetic systems, compared to conventional magnetic materials, can be made substantially smaller or significantly more powerful.The designation “rare earth” is actually somewhat misleading, because several of these metals, such as neodymium, aren’t really rare. They are even more common in the Earth’s crust than lead, for example. The problem is that few sizeable deposits have been discovered. Many rare earths can be found in Inner Mongolia, Western Australia, Greenland, Canada, and the U.S. But 97 percent of the worldwide production of rare-earth elements is presently concentrated in China. “So we’re facing a resource problem,” warns Dr. Thomas Scheiter, Head of the global technology field for Material Substitution and Recycling at Siemens Corporate Technology (CT).
Issue 04 | 2011
And such resources are hard to do without. For instance, magnets containing only four percent of the silver-gray heavy metal dysprosium enjoy a level of temperature stability that makes them ideal for use in wind energy systems. But today, dysprosium is found only in low-yield deposits, and alternative deposits probably won’t be developed for another five years or more, making supply bottlenecks almost inevitable. Other rare earth deposits, however, such as those at the Mountain Pass mine in California, may soon become available. More remote is exploitation of the rare-earth deposits that were discovered in mid-2011 under the Pacific Ocean floor, not far from Hawaii and Tahiti.
Hooked on Rare Earths The core of the problem is the fact that rare-earth metals are required for many high-tech products, including electric motors, cell phones, laser devices, and LCD television sets. And the introduction of energy-saving light bulbs, whose fluorescent materials also require rare-earth
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