Cleaner Rare Earth Separation Using Water and Manganese Oxide Channels
A solid-state "atomic channel" for separating rare earth elements
We developed a new method to separate rare earth elements using layered manganese oxide and water, avoiding toxic solvents. By engineering channels that match ion sizes and applying an electric current with magnesium, we achieved high purity levels. This approach offers a sustainable alternative to current industrial processes, potentially reshaping where and how rare earths are processed globally.
This is the first time that people have used electrochemical intercalation and harnessed the structural characteristics to separate similar lanthanides, which are intrinsically very hard to separate.
- Animats
Nice. Here's MP Minerals' plant for doing that, in Alliance, TX.[1]
It's a modest sized plant in an industrial park. It's fed by a huge mine in California, which has an onsite beneficiation plant. Beneficiation is the first step of separation - sorting the good stuff out from the unwanted dirt, with rock crushers, screens, and flotation. This being "rare" earth mining, the amount of good stuff is tiny relative to the unwanted dirt. This new technology works on the separated good stuff.
Although these separation plants aren't big compared to mines, US mines had been sending rare earth ores to China for processing. That's gradually moving back to the US as more separating plants are built.
- rpaddock
"“Rare earths always come mixed together, whether they’re in an ore or in a waste stream..."
What these College level projects never address is real world experience with Thorium. "Mixed together" very often includes Thorium. So as you run your process you either leave be hid a pile of Thorium as you extract what you want, or you end up with a pile of Thorium that you extracted.
While Thorium is useful, as I'd love to have a Thorium powered pebble-bed reactor buried in my backyard to power my house, it will attract government regulators when the pile gets big enough causing no end of expansive paperwork on radiological issues.
This is why places like Coal Mines don't extract the Lithium from the Tailings. They just don't want to deal with the radiological issues.
- JumpCrisscross
> Chong Liu and her colleagues knew that one of the differences between rare earth ions was the size of the water shell surrounding each one when they are dissolved in solution. Lighter rare earths like lanthanum have larger first water shell, while heavier rare earths like dysprosium have a smaller first shell. Taking advantage of that size difference, Chong Liu’s group engineered manganese oxide so that the gaps between its stacked layers were only a few water molecules wide. Then, they squeezed raw mixtures of rare earth elements inside.
Cool! Does this only work with a mixture of mostly rare earths, or can ores be "squeezed...inside"? Also, is the end product metal or intercalated manganese oxide?
- minimaltom
This seems very similar to the ion-exchange membrane rowow et all have been refining on youtube over the last year: https://www.youtube.com/watch?v=luulTI1RKHE&t=114s. Rowow himself has videos on using electrochemistry to extract rare elements from mining waste.
- chasil
It appears to me that the "water envelope" refers to chemical hydrates of water.
So the nanostructures allow a maximum size of hydrates.
How is this flushed after collection? What impels the captured molecules out of their recesses?