Developing greener, cheaper magnets
Ames Laboratory scientists have come up with a new process to prepare neodymium-iron-boron (Nd2Fe14B) permanent magnets that has the potential to enable them to be produced economically here in the United States. What’s more, the Ames Laboratory process doesn’t produce the environmentally unfriendly byproducts that result from traditional manufacturing methods.
“Neodymium iron boron magnets represent perhaps one of the most important use of rare earth elements,” says Karl A. Gschneidner, Jr., senior metallurgist at Ames Lab, who co-developed the process along with Rick Schmidt, principal scientist emeritus. “They’re the most powerful magnets in the world.” And they can be found in every computer and every hybrid and electric vehicle that rolls off an assembly line as well as a wide array of consumer, commercial and military products.
Little wonder, permanent magnets make up a $4.1 billion global industry. Over the years, however, production of neodymium-based magnets has shifted to China and other low-cost-producing nations. The hope is that the new technology will help US-based companies compete with these other nations on an economic basis.
The Schmidt-Gschneidner process leveraged know-how that had been amassed at the Ames Laboratory for more than half a century. Early lessons learned from the Lab’s World War II role processing uranium were put to use by scientists researching rare earths. As breakthroughs at the Lab continued over the years, the scientific community began to view the Ames’ facility “as one of the best places to be if you’re researching rare earths,” Gschneidner says. Now, fast forward to the early ’80s, when the discovery of Nd2Fe14B by U.S. and Japanese researchers set off a renewed flurry of related research at the Ames Lab and elsewhere.
Owing to their unique advantages of strength and durability, manufacturers began incorporating Nd2Fe14B magnets into more and more products.
Ames Lab senior metallurgist Karl Gschneidner holding a neodymium-iron-boron magnet produced using a new, greener process.
The unfortunate tradeoff was an increase in the amount of unhealthy waste materials created as ever-larger amounts of neodymium for the magnets was being processed.
Indeed, the conventional refining process starts with the neodymium oxide, but goes through two steps in order to obtain the neodymium metal. Waste products are associated with both these steps, and they must be handled in an environmentally friendly manner.
In 2009, Ames Laboratory researchers began work on a greener process for refining neodymium. Instead of two steps, “It is a one-step process going from the neodymium oxide to the neodymium master alloy,” Gschneidner explains, “and since the end-products are completely utilized, there are no waste materials to dispose of.”
A green process with the potential to bring a greater share of the $4.1 billion permanent magnet industry back to U.S. shores represents a major achievement in itself. But the greatest long-term benefit of the Ames Lab process may be yet to come. Gschneidner believes that “A modification of this process should enable us to prepare a lanthanum [element 57 on the periodic table] master alloy to produce lanthanum nickel metal hydride batteries, which are used in hybrid and electrical vehicles.”
A cheaper, greener battery for the world’s growing fleet of hybrid vehicles could eliminate untold tons of CO2, and it’s just the kind of industry needed to help insure America’s economic health for decades to come.
~ By Mark Ingebretsen