Japan bets on deep-sea mud to boost mineral security

Most of my recent newsletters have focused on the U.S. amid the Trump administration’s embrace of deep-sea mining.

But a lot of industry action is happening elsewhere. So today, let’s go elsewhere. Specifically, to Japan.

The country holds a couple ISA contracts to explore the international seabed. More interesting though, is what Japan is doing in its own Exclusive Economic Zone.

The Japanese government this month announced plans to test mine for rare earths. That alone is unique. Most deep-sea mining projects are focused on commodity metals like nickel and cobalt, not rare earths.

I wrote a bit about Japan’s project last year as a way to explain Exclusive Economic Zones. But it’s time to take a closer look now that a test mine appears imminent.

The plan

In January next year, Japan’s earth science agency will send a ship to the waters surrounding remote Minamitorishima, a tiny spit of land marking the country’s easternmost point. The uninhabited island is perhaps best known for being covered in bird poop, but this project could give it a serious rebrand.

The ship will deploy pipes to suck up a few dozen tons of sediment from beneath 3.5 miles of seawater. This is another unique aspect of the project. Deep-sea miners usually target hard substrate like nodules or crusts, not mud.

Japanese scientists will then take the sediment into a lab for chemical analysis. If the trial is successful, Japan will scale up its mining system to harvest ten times the amount of deep-sea mud in 2027.

In a 2018 peer-reviewed study, Japanese scientists estimated the mud around Minamitorishima could help supply Japan’s rare earth needs for decades, if not centuries.

Why rare earths?

Rare-earth elements are a set of 17 metals with silly names like Yttrium and Ytterbium. They’re used in applications ranging from consumer electronics, to fighter jets, to MRI machines, to oil refining.

China mines and refines the vast majority of the world’s rare earths. But in moments of geopolitical tension, China has periodically placed restrictions on their export.

The goal of Japan’s project is "to secure a domestic supply to enhance national security, rather than to enable private companies to profit from selling rare earths," a Japanese official told Reuters.

But one thing about rare earths: They’re not that rare. You don’t need to descend to the darkest ocean depths to find them. Rare-earth deposits are widely distributed around the world.

The problem is, they’re usually found in low concentrations. That means the separation/refining of rare earth ores is what makes production so tricky. And by tricky, I mean expensive and often toxic.

So even if Japan is able to haul up tons of rare earth-laden mud from the bottom of the ocean, it’ll still have to find a suitable way to process that mud without China’s help.

It’s not clear what will come of this project. But since access to rare earths is such a hot-button issue right now, other countries will be watching closely.

Author’s note: The podcast team at Outside/In, from New Hampshire Public Radio, has been doing phenomenal environmental coverage for years. I’ve had the pleasure of producing a couple shows for them, including their latest episode about a bizarre architectural hoax that helped jumpstart the deep-sea mining industry back in the 1970s. Listen here or in any of the podcast apps.