Energy efficient technologies like wind turbines and electric car engines are much greener choices than their traditional counterparts, but the powerful magnets essential to their operation require rare earth metals that are diminishing in supply. While countries in North America, Australia, and South East Asia hurry to bring more rare earth mines into operations — a process that can take years — General Electric scientists have created a new breed of nanocomposite magnets that would require less rare earths to achieve the same high magnetism as magnets currently on the market.
Currently, China produces 95 percent of the world’s refined rare earth elements, and demand is quickly catching up to supply. The strongest magnets rely on an alloy of the rare-earth metal neodymium that includes iron and boron. Sometimes other rare-earth metals, like dysprosium and terbium, are added to these magnets to improve their properties. Supplies of all three of these are at risk because of increasing demand and the possibility that China will restrict exports.
Working with a grant from the Department of Energy, GE researchers found away to boost magnetism in alloys, resulting in more magnetic power per pound of rare earths. Popular Science explains:
These new nanocomposite magnets work via exchange coupling, a complex physical property that can be harnessed in nanomaterials to increase magnetism. It’s all in the arrangement of the nanoparticles; exchange coupling doesn’t occur in pure magnetic alloys, but given the right mix and arrangement of nanoparticles of the same metals, researchers can get the same amount of magnetism out of less material—suddenly less is more.
The magnets would also require less iron, cobalt and other metals, resulting in a final product that is smaller and lighter than anything we see now. GE hopes to demonstrate the new magnets within the next two years, but that may not be soon enough. The DOE projects that demand for key ingredient neodymium oxide could exceed supply by 2015. But thankfully, GE isn’t the only company working to reduce the need for rare earths. Toyota is currently developing an electric engine that would require less rare earth metals.
WHY THIS MATTERS:
The mining, refining, and recycling of rare earth metals can have serious environmental consequences. Rare earth processing uses toxic chemicals, acids, sulfates, and ammonia, plus the processing plants create polluted air emissions and wastewater that contains acid and radioactive materials. By creating magnets that would need less rare earth elements, GE is helping to eliminate the need to mine, thus reducing the overall environmental impact of products that contain rare earth metals.
Via Popular Science