High quantities and values have been claimed for the Platinum and other high value metals in Asteroids - prompting (or perhaps in order to prompt) interest in mining them. Is this high value metal distributed within (alloyed with) nickel-iron or does it take other forms? My (admittedly limited) reading suggests the estimates would be based on presence within the nickel-iron in meteorites, as those have the highest platinum content, which (IIRC) can exceed 100ppm.

Making alloys is easy but unmaking them is usually much more difficult. Are there low cost methods for extracting these metals from nickel-iron? If not, other kind of ores, even at lower concentrations, may have greater potential by being easier to process. Whilst not strictly exaggeration, failing to note that these metals may be very difficult and uneconomic to extract - even on Earth without the added difficulties - does seem misleading.

  • $\begingroup$ This seems to be a good source with some detail on the economics of plutonium mining. $\endgroup$
    – Jack
    May 24, 2018 at 9:59
  • $\begingroup$ @Jack - that would be platinum, not plutonium, but thanks for the link; interesting, and it sort of says what I thought - extracting specific metals from alloys is hard. Using space resources in space makes sense, sort of, but raises questions about what drives the economics of the space activities that would made more efficient by using them if exploiting those resources is otherwise not economic. Seems a bit too circular. $\endgroup$
    – Ken Fabian
    May 25, 2018 at 1:00
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    $\begingroup$ I suspect they are tentative about investing because there is no reasonable prospect of extracting saleable resources and making a profit from Asteroid mining. I'm not sure the feedback effect - big lots of platinum depressing the price - is anywhere close to being an issue when it's mostly bound up in an intractable ore that wouldn't be viable even on Earth. $\endgroup$
    – Ken Fabian
    May 25, 2018 at 7:05
  • $\begingroup$ In the next years or even decades, platinum mined from Asteroid will be very, very expensive. No danger of a feedback effect on the market. If space exploration costs will be reduced enormously, the situation may change. But there should be Asteroids with a very high platinum content, much higher than on Earth. $\endgroup$
    – Uwe
    Jul 10, 2018 at 14:14

1 Answer 1


I see no reason that platinum groupe metals would have to be mixed with nickel/cobalt/iron , nickel/cobalt/iron are all very close in density , platinum groupe metals are much denser. Either things are segregated by density in which case they would not be , or ther are segrated by some other way in which case they probly still would not be .

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    $\begingroup$ Answers which are supported by linked references or calculations are more likely to receive upvotes. Otherwise, it's just some person writing something that may or may not be correct. $\endgroup$ Jun 10, 2018 at 14:00
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    $\begingroup$ It would be good to see some sound reason (with link, reference) to expect platinum in other - more readily extractable - forms. Samples in meteorites for example or as a consequence of understanding asteroid formation processes. AFAIK the highest concentrations of PGM's are found within NiFe and more closely associated with nickel - "..meteorites with high nickel content were found to contain much more platinum than those with low nickel content." (up to 119ppm in study by Hawley 1939 ( onlinelibrary.wiley.com/doi/abs/10.1111/… ) $\endgroup$
    – Ken Fabian
    Jun 11, 2018 at 0:01
  • $\begingroup$ I should note that in the Hawley study of platinum content in meteorites he refers to the platinum group metals together as platinum - 119ppm is actually of a mixture of iridium, rhodium and palladium as well as platinum. He did not attempt to separate them due to the difficulties in doing so. Whilst methods to do so will have improved since 1939, I expect it will still be problematic for economic extraction. Separating these from each other is probably going to be even more difficult than extracting the PGM's from nickel-iron. $\endgroup$
    – Ken Fabian
    Dec 10, 2018 at 21:01
  • $\begingroup$ Sodium chloride is more than twice as dense as water but it does not sink out of solution on that accord unless saturated. You need to show that the platinum metals would indeed form a separate phase and then we can talk density. Seismic data on Earth usually are interpreted in terms of just a liquid and a solid phase, both iron-based, in the core. $\endgroup$ Sep 5, 2019 at 14:01

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