4 ms·

Smelting using focused solar radiation against a spinning carbon crucible would be cheap, mechanically simple, and effective. I’m not sure why you think you can

Smelting using focused solar radiation against a spinning carbon crucible would be cheap, mechanically simple, and effective. I’m not sure why you think you can’t refine in space.

bartonfink 2y ago
Because right now it's not even research, let alone economical. This isn't Stellaris, this is real life.
- fnordpiglet 2y ago
  I see, so when pursuing future technologies we should stick with what we know? We typically research what’s achievable in the near future, however the mechanics for purifying heavy metals with centrifugal forces isn’t new fwiw. It’s how we made atomic bombs.
  - bartonfink 2y ago
    [flagged]
    - fnordpiglet 2y ago
      Yes. 80 year old technology trying to do something much more complex than separating two very distinct elements. I’d remind you you’re commenting on an article about asteroid mining, which is sci-fi that’s becoming more attainable. What I don’t really get is the nasty hostility.
      - bartonfink 2y ago
        Tone policing is a weak retort. If you'd rather we just sing Kumbayah and talk about science fiction then yeah! We could even staff these centrifuges with autonomous bipedal androids a la Lt. Commander Data. Those are becoming attainable in much the same way as your mechanically simple, cost effective, never been built zero g metal gas centrifuges. Learn something with that big brain of yours.
        fnordpiglet 2y ago
        No, I’d rather people just not be assholes but some are simply incapable of it. I’d note you’re responding in a thread about asteroid mining becoming more attainable, at a time of large language models in the last two years being able to remarkably emulate natural language beyond anything dreamed of three years ago, with low earth orbit lift a commodity orders of magnitude cheaper as we work towards a moon base, in the final stages of preparing an interplanetary starship built by a privately owned company whose owner wants to personally colonize another planet, while humans are only years away from potentially being redundant at driving (and possibly many white collar professions)… and none of that was made possible by people with no ability to imagine a future like yourself. Enjoy your petty and cynical existence of insulting people on the internet while the rest of us make the future you were promised despite you.
adrian_b 2y ago
Smelting is for extracting metals from oxides or sulfides. It can be used on the Moon or on Mars. It does not work for asteroid mining. There you have just pieces of iron with a low content of alloying elements. Among the alloying elements, nickel is the most abundant (17.3 times less than iron), then cobalt (20.9 times less than nickel), then germanium (20.4 times less than cobalt). The precious metals that would justify the mining operation are present as a few grams each for a ton of iron. Melting the alloy will never separate the metals by itself. However perhaps some kind of floating zone melting could enrich the proportion of precious metals in a part of the iron, but it is very unlikely that a high enough enrichment could be achieved by a reasonable number of zone melting passes. On earth the cheaper metals could be dissolved by an acid solution, but on metallic asteroids you have neither water nor acids. The SciFi solution would be to vaporize and ionize the metal alloy and separate the metal ions by their specific charge, like in mass spectrometry. This would need a lot of energy, but at least it does not need reactants and it is the only method that achieves almost perfect separation. However for now, the throughput of such a ionic separator is extremely small, too small for industrial production. Perhaps it will become possible to scale such ionic separators to acceptable productivities.
- fnordpiglet 2y ago
  Yes I was actually thinking of a gaseous centrifuge process. It would require turning the metals into a gas yet not ionizing them and venting the iron gas into space leaving an ever enriched gold. Realistically you don’t need to enrich to total purity.
  - adrian_b 2y ago
    Unfortunately that does not work, because these metals are among those with the highest boiling points, even at very low pressures (which is why the oldest solid objects that have formed in the Solar System, at its very beginning, when it was still very hot, have been refractory grains of platinum-group metals with tungsten and rhenium; their condensation has been followed by that of refractory minerals with high content of oxides of aluminum, calcium, titanium and zirconium; and only after additional cooling by the mainstream condensation of silicates and iron alloy). There are no materials from which you could make a centrifuge for gaseous osmium and iridium. Vaporizing the input metal with an electron beam and ionizing the vapors allows after that contactless interaction with the ions, using electric fields and magnetic fields, guiding them into separate condensation chambers (which need strong cooling). The ionic current of such separators must be increased several orders of magnitude over those currently existing, for this to become a viable separation technology.

Smelting using focused solar radiation against a spinning carbon crucible would be cheap, mechanically simple, and effective. I’m not sure why you think you can’t refine in space.

bartonfink 2y ago

Because right now it's not even research, let alone economical. This isn't Stellaris, this is real life.

fnordpiglet 2y ago
I see, so when pursuing future technologies we should stick with what we know? We typically research what’s achievable in the near future, however the mechanics for purifying heavy metals with centrifugal forces isn’t new fwiw. It’s how we made atomic bombs.
- bartonfink 2y ago
  [flagged]
  - fnordpiglet 2y ago
    Yes. 80 year old technology trying to do something much more complex than separating two very distinct elements. I’d remind you you’re commenting on an article about asteroid mining, which is sci-fi that’s becoming more attainable. What I don’t really get is the nasty hostility.
    - bartonfink 2y ago
      Tone policing is a weak retort. If you'd rather we just sing Kumbayah and talk about science fiction then yeah! We could even staff these centrifuges with autonomous bipedal androids a la Lt. Commander Data. Those are becoming attainable in much the same way as your mechanically simple, cost effective, never been built zero g metal gas centrifuges. Learn something with that big brain of yours.
      - fnordpiglet 2y ago
        No, I’d rather people just not be assholes but some are simply incapable of it. I’d note you’re responding in a thread about asteroid mining becoming more attainable, at a time of large language models in the last two years being able to remarkably emulate natural language beyond anything dreamed of three years ago, with low earth orbit lift a commodity orders of magnitude cheaper as we work towards a moon base, in the final stages of preparing an interplanetary starship built by a privately owned company whose owner wants to personally colonize another planet, while humans are only years away from potentially being redundant at driving (and possibly many white collar professions)… and none of that was made possible by people with no ability to imagine a future like yourself. Enjoy your petty and cynical existence of insulting people on the internet while the rest of us make the future you were promised despite you.

adrian_b 2y ago

Smelting is for extracting metals from oxides or sulfides. It can be used on the Moon or on Mars. It does not work for asteroid mining. There you have just pieces of iron with a low content of alloying elements. Among the alloying elements, nickel is the most abundant (17.3 times less than iron), then cobalt (20.9 times less than nickel), then germanium (20.4 times less than cobalt). The precious metals that would justify the mining operation are present as a few grams each for a ton of iron. Melting the alloy will never separate the metals by itself. However perhaps some kind of floating zone melting could enrich the proportion of precious metals in a part of the iron, but it is very unlikely that a high enough enrichment could be achieved by a reasonable number of zone melting passes. On earth the cheaper metals could be dissolved by an acid solution, but on metallic asteroids you have neither water nor acids. The SciFi solution would be to vaporize and ionize the metal alloy and separate the metal ions by their specific charge, like in mass spectrometry. This would need a lot of energy, but at least it does not need reactants and it is the only method that achieves almost perfect separation. However for now, the throughput of such a ionic separator is extremely small, too small for industrial production. Perhaps it will become possible to scale such ionic separators to acceptable productivities.

fnordpiglet 2y ago
Yes I was actually thinking of a gaseous centrifuge process. It would require turning the metals into a gas yet not ionizing them and venting the iron gas into space leaving an ever enriched gold. Realistically you don’t need to enrich to total purity.
- adrian_b 2y ago
  Unfortunately that does not work, because these metals are among those with the highest boiling points, even at very low pressures (which is why the oldest solid objects that have formed in the Solar System, at its very beginning, when it was still very hot, have been refractory grains of platinum-group metals with tungsten and rhenium; their condensation has been followed by that of refractory minerals with high content of oxides of aluminum, calcium, titanium and zirconium; and only after additional cooling by the mainstream condensation of silicates and iron alloy). There are no materials from which you could make a centrifuge for gaseous osmium and iridium. Vaporizing the input metal with an electron beam and ionizing the vapors allows after that contactless interaction with the ions, using electric fields and magnetic fields, guiding them into separate condensation chambers (which need strong cooling). The ionic current of such separators must be increased several orders of magnitude over those currently existing, for this to become a viable separation technology.