The term “rare earth element” (REE) is somewhat misleading — those 17 squares at the bottom of the periodic table appear fairly plentifully in the earth’s crust. But that doesn’t mean they’re easy to get to. They tend to be widely dispersed and appear in low concentrations, usually in hard-to-separate combinations with other elements.
That factor — the difficulty of collecting and separating significant amounts of the elements — presents a particular challenge to technology-heavy industries. REE are used in everything from cancer treatments to smartphones to nuclear reactor shielding, and the U.S. uses about 20,000 tons of them every year. Of those 20,000 tons, about 19,000 is imported from China. This puts the U.S. at an economic and a national-security disadvantage. Relying on the export policies of a foreign power for the materials needed to build missile guidance systems leaves the country at risk. But the U.S. has the potential to produce twice as much REE as it consumes — if it can separate them from the minerals in which they’re trapped.
Engineers at Southern Research (SR) have been identifying economically viable REE resources and exploring ways to free the REE from those resources. One crucial part of that effort is being able to accurately measure the REE at every phase of the process. Assessing the potential value of a given resource requires knowing how much REE it contains. Developing new technology to recover the REE requires knowing how much elements is present at each step to assess its efficiency. All of it demands accurate measurement of a wide range of REE, in chemically complex resources, in solid, liquid and gas form — which is made even more challenging by the fact that REE have similar chemical properties and are hard to differentiate and measure individually.
Using an industry-leading Agilent 8800 Triple Quad ICP-MS (inductively coupled plasma mass spectrometer), SR is able to measure the tiniest concentrations of these elements. SR modified an existing method for solid sample preparation to efficiently extract REE from more complex samples like coal fly ash. A combination of highly sensitive instrumentation and hard-earned expertise allow engineers to minimize interferences. With the modified sample preparation procedure and our advanced analytical capabilities to remove interferences, SR is able to consistently and accurately measure REE in any number of resources.
Developing a technique to extract and analyze REE from domestic sources could have a major effect on the U.S. economy. It has the potential to change the economic profile of key industries and create a domestic market — and even an export market — for these very valuable elements. “If we can economically extract these rare earth elements, the U.S. wouldn’t have to rely on other countries,” said Nishil Mohammed, Ph.D., a research engineer at SR. “The U.S. could be a source of rare earth elements for the future.”