DIGGING IN: At a mine in Mountain Pass, Calif., plans are under way to resume domestic production of rare earth elements. Today 97 percent of the global supply comes from China.
Image: Plazak via Wikimedia Commons
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There in the mud, just waiting to be scooped up, is a natural resource deposit potentially worth billions and billions of dollars. It contains chemical elements needed by automakers, by manufacturers of consumer electronics and by green technology developers—elements for which China currently holds a global near monopoly.
The catch? The mud, which is enriched in the technologically crucial metals known as the rare earth elements, is beneath thousands of meters of water in the Pacific Ocean. Extracting resources from such depths brings technological, economic and regulatory hurdles, all of which would have to be overcome before deep-sea rare earths become an ingredient in tomorrow's catalytic converters, wind turbines and computer screens. As a result, experts say, it will be many years—if ever—before that seafloor resource is tapped.
The deep-sea rare earths came to light in a study by a group of Japanese researchers, which was published online July 3 in Nature Geoscience. (Scientific American is part of Nature Publishing Group.) The researchers analyzed more than 2,000 samples of Pacific seafloor sediment and found high concentrations of rare earth elements. (The 17 rare earth elements include the lanthanide series—from lanthanum to lutetium on the periodic table—plus yttrium and scandium.) They estimated that there could be more than 100 million metric tons of rare earth compounds in the seafloor mud. And a preliminary estimate showed that one square kilometer of seafloor mud around a sampling location known as site 1222 could provide one fifth of the world's annual supply of rare earths. But the reality is that extracting that mud is not yet feasible for a number of reasons.
"To characterize it as something that's an economic resource might be an overstatement at this point," says Porter Hoagland, a senior research specialist in marine policy at the Woods Hole Oceanographic Institution (WHOI). "There are a host of economic factors that kind of work against a cost-effective recovery offshore."
To access the rare earths at site 1222, for instance, would require pulling up the top 70 meters of seafloor sediment, filtering out the water content, removing the valuable rare earths (which make up less than one part per thousand of the sediment) and returning the rest of the material to the seabed.
Such an undertaking would require new technology, a long permitting process—and, of course, a lot of money. So there would have to be a significant economic incentive to access the seafloor resource. "That's why I'm not sure the rare earth elements are enough in themselves to provide that," says James Hein, a geologist at the U.S. Geological Survey in Menlo Park, Calif. After all, the global rare earth market is relatively small—it currently runs about $2 billion to $3 billion annually, according to a recent report from Ernst & Young, whereas the markets for metals such as copper are dozens of times larger. "I'll be surprised, really, if this gets much attention as a resource potential in the near term," Hein says. "The grades really are just not very high, and the environmental issues will just be so great."
At depths of 4,000 to 5,000 meters, seafloor ecosystems are not well understood, nor are the potential impacts of large-scale dredging on those ecosystems. "Essentially, this would be a strip-mining operation where they would be sucking up lots of sediments from the seafloor over large areas," says Craig Smith, a professor of oceanography at the University of Hawaii at Manoa, "which would of course destroy the communities that reside there." Those ecosystems, to the extent that they have been explored, have low biomass but high biodiversity. And, having taken hold in a stable environment, they are not adapted to large-scale disturbances.
"Four thousand meters in the deep ocean is a long way down, and we don't know how to mitigate against significant environmental impacts or how to restore the ecosystem, if you can even restore the ecosystem," says Cindy Van Dover, an oceanographer at Duke University. "We don't understand a lot about what is going on down there from an ecological standpoint."
Many of the sites sampled by the Japanese researchers are in international waters and would fall under the jurisdiction of the International Seabed Authority, based in Jamaica, which means any mining concern looking to extract seafloor rare earths would likely face a long regulatory process. "Doing things there is a very slow and considered process," Van Dover says. "Things don't happen overnight in international waters."
If it does become economically feasible to extract rare earths from the Pacific seafloor, the needs of ecosystems on the seafloor will have to be balanced with the economic and societal benefits from mining there. Rare earths appear in a number of products in relatively small quantities—as phosphors in plasma screens, for instance. Much larger quantities are needed for some green-technology applications—the batteries in hybrid cars contain several kilograms of rare earths, and the magnets used in wind turbines can require hundreds of kilograms.
"If the human demand for metals continues to be as high as it is, or go up, then there will be continued demand for these metals and rare earth elements," Smith says, adding that involving marine scientists early on can help ensure that exploitation is carried out in a responsible way. "I personally would prefer not to see the deep sea trashed, but I think we have to be realistic," he says.
For the time being, though, the barriers to extracting rare earths from the seafloor loom large. And if the deep-ocean mud is never tapped, it would not be the first time that seafloor resources have been trumpeted without much follow through from industry. "My skepticism comes from years of grandiose claims and then nothing really happening," WHOI's Hoagland says. "That says to me that it's not cost-effective to go get this stuff."
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7 Comments
Add CommentI think you are right when you said that copper would be more profitable and friendlier to the ecosystem; but when did America start caring about ecosystems? What about oil spills, mountain top removal, and natural gas fracking? Don't you think those have destroy more ecosystems than any of the mud sucking could?
Reply | Report Abuse | Link to thisThere must be billions of tons of copper in America right over your head. Convert America over to cell phones, fiber optics, and carbon fiber and start extracting the copper from all those phone land lines and power lines. Surely, there must be enough cell phones manufactured in America now that everyone could have at least two to three cell phones, or more. I have six cell phones in a plastic bag in my desk that I acquired from switching back and forth from cell phone companies to get better deals. And my cell phone does not go dead every time a limb falls on one of those land lines. Tear them down and use that copper for better things. We can install solar panels on our roofs and in our yards to produce enough power for our home, or business, or to charge our electric car. Start converting over to smarter technologies and you will not have to go out and suck mud or tear down another mountain or destroy more ecosystems like the Gulf or destroy more peoples land.
It seems to me they are going to tear up the sea floor and ruin another ecosystem for these rare earths. All in the name of going green! How is this a good idea? But you can be certain as soon as they figure out a way to make money off this they will be all over it saying how good it is for us.
Reply | Report Abuse | Link to thisJames Davis is a little late: the advanced countries have been pulling copper out of the wires, replacing it with steel-cored aluminum, for forty years now.
Reply | Report Abuse | Link to thisThese sudden Japanese press releases about their finds are, imho, likely to be a strategic response to China's recent restrictions on rare earth exports. They at least want to keep the Chinese worried.
In 1972 Kissinger cut off soybean exports to Japan in a hissy-fit about a Japanese vote at the UN or something stupid. It took Mitsubishi Shoji until roughly 1:30 that afternoon to start investing in soybean farms in Brazil, and now, a generation later, Brazil is a major player in soybeans, and the US embargo has long-term only hurt the American farmer.
In the same sense I think the recent Chinese action will have concentrated the minds of a lot of peole in the electronics industry around the world.
Why do we keep relying on exotic materials when it has been shown that algae, bacteria, carbon, hydrogen, oxygen and iron are so plentiful. We have put custom tips on viruses, delivered 2 nobels based on graphene, have created multi-sized diamonds, created nanotubes and shown quantum tunneling characteristics on graphene and Carbon, Hydrogen, Iron and Oxygen love to play together.
Reply | Report Abuse | Link to thisBurning carbon is better exploited as barbeque. We are being sold a rain man story with oil is the only answer for the foreseeable time.
And hate to say it but we need to have government subsidies to create the infrastructure and standards. We can have 20 lanes on the highway but they all have the stripes or lines to identify them what is in them can stay rights respected.
I'm wondering what the actual cost would be, and how that might compare to mining the same materials from the lunar surface. At least on the moon or asteroids we wouldn't need to worry about damaging the seafloor habitat and possible pollution of the oceans. Other pluses are, getting humanity off this rock and helping to insure our survival, also acquiring new technology and capabilities which could help us to prevent a future asteroid strike. The costs may be comparable and the benefits may come down solidly on the lunar side. A comparison might settle the discussion for good.
Reply | Report Abuse | Link to thisIt's pretty pathetic to hear people talking about going to other planets when humans haven't even gone everywhere on this planet yet. There should already be deep sea stations. They should've been studying the seafloor ecosystems for years already.
Reply | Report Abuse | Link to thisIf they could make weapons out of that sea muck, you bet your ass they'd be down there digging it up.
Surely the real alternative is to find new materials which occur in abundance which can be substituted for technologies requiring rare earth elements. I know many will claim this is simply impossible, but aren't new solar cell technologies emerging which will use completely novel substances other than silicon? I'd be interested in hearing any news of developments in, for example, plasma screen production, which might offer such a hope.
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