The 6,000-Meter Mirage: Is Japan Extracting Rare Earths or Political Capital?
www.chinausfocus.com
China’s export controls on rare earths have exposed Japan’s persistent dependence, prompting Tokyo to promote deep-sea mining as a path to self-sufficiency. However, the Minamitorishima project appears driven as much by political signaling as by industrial viability, given high costs, technological constraints, and China’s continued dominance in refining.

6km underwater sounds bad (and it is), but the main bottleneck is still separation and refining.

I would have given a Japanese source directly but anything remotely skeptical is hard-paywalled and the archive sites can’t get through. This article from China US Focus heavily cites a paywalled article from Mainichi Shimbun. The tone reads like a hit piece, but after digging around I think the picture is broadly accurate. Japan is many years away from having a commercially viable rare earths supply chain.

More links of interest:

It’s a mud layer off the coast of a small Japanese Pacific island.

Japanese survey estimates 16 million tons of heavy REEs and yttrium

General paper on formation and distribution of sea floor REE deposits

In Minamitorishima mud, REEs are concentrated in “fish bone debris”

Paper looks at REE-rich mud cores (from elsewhere) and plots contents

The environmental cost of deep sea mining could be significant

Just to round out the perspective, these guys think Minamitorishima could be economical, but the paper focuses on the mining and leaching, which are early steps, and not the complex separation and refining infrastructure that China dominates. If even the mining and leaching steps are in question, I think that emphasizes what an uphill battle rare earth self-sufficiency would be for Japan.

https://www.mdpi.com/2075-163X/11/3/310

  • test_ [none/use name]@hexbear.netOPEnglish
    23·
    6 days ago

    The “20x the going rate” estimate appears to be expert commentary by someone speaking to the media (Yoshikiyo Shimamine speaking to Nikkei, behind a paywall), not a published study. It’s so early that there’s probably no reliable number or scaling curve or roadmap that anyone can point to. It seems to be vibes at this point.

    • robot_dog_with_gun [they/them]@hexbear.netEnglish
      23·
      6 days ago

      probably an educated guess padded with a safety factor that would still be a lowball.

      and that’s just money, not the environmental destruction. we’d be better off killing anyone who tries to mine the seabed