The growth in production of hybrid cars is resulting in shortages of rare earths. Well, I know where we can find some, but it’s not on earth.
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The growth in production of hybrid cars is resulting in shortages of rare earths. Well, I know where we can find some, but it’s not on earth.
Comments are closed.
Rare earths, despite their name, are not rare. World reserves are 88 million metric tons (of RE oxide), and the reserve base is even larger. A shortage of 40K tons/year is no reason to open mines on the moon.
See http://minerals.usgs.gov/minerals/pubs/commodity/rare_earths/mcs-2009-raree.pdf
“Undiscovered resources are thought to be very large relative to expected demand.”
Asteroids have very low concentrations of rare-earths. That because they are largely unprocessed (chondritic) material from the original nebula.
However, the Moon has undergone global melting, which has concentrated REE at levels hundreds to thousands of times chondrites. The high-KREEP (KREEP= potassium (K), rare earth elements (REE) and phosphorus(P)) areas of the Moon cluster on the western near side.
Using that data, asteroids are worth about $1 per kg – not terribly impressive, really. More interesting that about half the value is the magnesium contained, and the rest is essentially in really rare stuff.
I’d really like to see that table include a column comparing it to Earth. I don’t think it would be cost effective to get the Rubidium out, for example, unless we are currently mining lower concentrations.
Of course, the flip side is that you do not mine the average asteroid. You mine the exceptional ones.
If incoming materials (whether from Luna or NEOs) were captured by LEO tethers you could import delta v as well as the materials.
Also, to the extent China has a de facto monopoly on the mining of many rare earths there is a geo-political argument not necessarily tied merely to economics.
Curiously, China appears to lack indigenous PGM and imports well over $1 billion dollars in platinum per year. Perhaps China could be a funding source to help establish lunar or NEO PGM mining — maybe we could reduce our trade deficit by partnering with China on a lunar platinum mine — they send us back some of our dollars and we give them a junior stake in a mining facility.
NEAR saw signs of striations in some asteroids that suggest they were comprised of larger objects that were later smashed into smaller chunks. These may have higher concentrations of heavy metals. While other asteroids like Itokawa more resemble large rubble piles and I would agree likely not contain much dense material. I think though that the rubble pile asteroids could be used to scoop up material into a tug. This could be used to increase their mass to help pull other heavier and more valuable asteroids around.
Rand, I posted a response earlier to this thread, and it’s stuck in a “waiting for moderation” state.
Rand, I find it interesting that you seem relatively pessimistic about space solar power, but relatively optimistic about asteroid mining. (If I’m wrong about your opinions, by all means set me straight.) Surely in any world where we were mining anything from asteroids, 99% of the mass of SPS would be derived from asteroidal materials. And in that situation, I don’t think we’d be talking about SPS costing 21 billion dollars each (at least past a point).
Mr. Combs, I agree with you; a source of mine says about half of a SBSP satellite is the panels (I would guess he meant by mass, not volume), and those may be able to be manufactured in space in the (relatively) near term. The open question is how to build a business with two risky ideas that are interdependent. It’s much easier when one can stand alone and the other comes to exist by making the first cheaper. So, if propellant depots can be profitable alone, lunar bases providing cheaper LOX can be developed and close the business case for SBSP. Or, SBSP is profitable alone, raising the case for lunar construction materials. But, if these cases can’t close without each other, no one will invest in either. What is (so far) common knowledge is that lunar and asteroid mining can’t exist to import material back to Earth.
As for the scarcity of REE (rare earth elements) in asteroids, both Mr. Spudis and David are correct; to my knowledge, most asteroids don’t have REE but the ones that do can contain as much as 5% and the remainder is (I think, without looking it up) nickel, iron, and other useful material.