Now, to solve its rare earth elements woes, the Department of Defense is taking a two-pronged approach: They’re asking the scientific community to come up with innovative ways to mine these scarce materials in the United States, and find alternative materials to make rare earths unnecessary.
“The Department of Defense relies on many products that incorporate materials that are not found or produced in sufficient quantities domestically to meet potential crucial defense needs,” states the Office of the Secretary of Defense in a solicitation for research proposals, published at the end of July.
The geopolitical implications of rare earths are nothing new. In 2009 Congress was already asking the Pentagon to look for alternatives and lessen the U.S. dependency on foreign imports after the Chinese government said it was considering limiting exports of the minerals.
Rare earths are not rare in nature, they’re just very hard to find in heavy concentration, and extracting them is both extremely expensive and environmentally dangerous. For all these reasons, the DoD would like to find ways to produce more rare earth elements here in the States.
The first proposal is to find a way to improve separation. Rare earth elements are often found in minerals along with different elements and need to be separated from the rest, less valuable ones. It’s an elaborate, multi-stage process that it’s really hard to master and needs expensive tools. (In fact, U.S.-based mineral extraction company Molycorp Minerals used to ship rare earths to China for final separation.)The Pentagon wants a more effective separation done with the so-called froth flotation, a chemical process to distill elements using water and air bubbles.
Efficiency is not the only concern. The Pentagon wants new, environmentally “less-aggressive techniques,” to separate rare earth elements from minerals. Finding new ways to do it “would improve the availability, decrease the costs of extraction, and decrease the environmental impact of the extraction,” says the proposal.
Recycling is another solution. For example, the DoD is pushing to improve the recovery of rhenium, a rare earth element that is key to produce the new stealth Joint Strike Fighters for its exceptional heat-resistant properties. If all else fails, the DoD would like to just get rid of rare earth elements and find new, alternative compounds that could have the same properties. The plans is to use computer models to find techniques to “change the elemental composition of a material to obviate the need for expensive, rare or hard to find elements.”