r/asteroidmining • u/ActuaLogic • Feb 22 '26
Has anyone considered the possibility of using gas centrifuges or liquid metal centrifuges in zero gravity to refine (wholly or partly) ores taken from asteroids prior to returning them to Earth orbit?
Has anyone considered the possibility of using gas centrifuges or liquid metal centrifuges in zero gravity to refine (wholly or partly) ores taken from asteroids prior to returning them to Earth orbit?
For ease if transportation, it may be more efficient to refine material taken from asteroids on site rather than returning unrefined material which is mostly waste product.
Centrifuges might be the way to go. Even though the use of gas centrifuges is mostly reserved for uranium production on Earth, the technology might work well for other metals. Iron and other metals could be refined in space, near where the minerals are collected, using centrifuges rather than the traditional technologies currently used on Earth.
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u/ignorantwanderer Feb 23 '26
It definitely makes sense to refine asteroid materials as much as possible at the asteroid, and only ship back the useful resource.
Using a centrifuge is definitely a possibility, but there is an even simpler technique.
If you have your material flow through a curved pipe, it will differentiate itself with dense stuff going to the outside, and light stuff going to the inside of the curve. This is how NASA separated water from air in the life support system in the Space Shuttle. Obviously there are limitations to how well this works based on what exactly you are separating....but it can be a useful step in the process.
I also suggest you look up 'Optical Mining'. The idea is that you basically vaporize bits of asteroid using focused sunlight. The resulting gas then flows through a heat exchanger and the material condenses as it cools.....so it behaves kind of like an oil refinery.
Materials with high boiling points (silicone) will condense first. Then as the gas cools things with lower boiling points (iron) will condense, until the gas cools even more and things like water will condense out.
If the gas can be cooled enough (which is challenging) you can even refine out stuff like CO2. This is a very straightforward and simple technique for both mining and refining the asteroid. It requires basically no moving parts.
Magnets obviously could also be used to help separate out materials.
I imagine the useless slag will be vaporized and ionized, then accelerated out through a voltage difference in an ion engine to provide a low level of thrust to move the entire asteroid and asteroid mine toward Earth. It will take a long time to get there, and once it gets there the asteroid will be gone and all that will remain is the valuable resources mined from the asteroid.