Asteroids vs Planetary Mines

[Varyon]

A tangent in another thread threatened to derail it, so I felt it would make sense to split it off here. The discussion is between the merits of processing asteroids for their raw materials and getting those same materials from mining planet-side deposits.

Originally Posted by Daigoro

There might be a cost-benefit crossover point where it's cheaper to mine out a vein of ore than pulverise and process a whole asteroid to get the same output.

Potentially, yes. From what I understand, however, for a lot of materials a good deal of the cost is strongly related to rarity, and if you can economically mine asteroids, that rarity largely goes away, making the cost simply a function of processing the material and taking it from source to destination.

For planetary uses, mining from the ground is probably cheaper, but has a lot of issues associated with it. First off, I suspect it's easier (particularly at TL10) to locate which asteroids have decent concentrations of the material(s) you want than it is to find a vein of said material on a planet. Also, while you need to have your space mine designed to be vacuum capable (and radiation-shielded), you don't need to worry as much about gravity or the environment. Planetside, you often need to dig carefully to avoid collapses, and likely need to be careful with what you do with excess/waste material so you don't end up with environmentalists coming after you. In space, you can basically just chew your way through the asteroid, keeping what you want and using the rest as reaction mass for mass drivers.

It seems to me that, unless there are materials that can only be found planetside (like various flavors of unobtanium), a colonized planet would be unlikely to contain any mines (because who wants to punch holes in a perfectly-good planet?). The planet the TL10 civilization originated on certainly would, but by the time they've reached TL10, those are likely sufficiently tapped-out as to no longer be economically mine-able.

[Fred Brackin]

Originally Posted by Varyon

A tangent in another thread threatened to derail it, so I felt it would make sense to split it off here. The discussion is between the merits of processing asteroids for their raw materials and getting those same materials from mining planet-side deposits.

You speak of "concentrations" and "deposits" and asteriods probably lack those due to a lack of geological processes. It's probably easy to mine for water ice or similar things but if you're going to grab all those precious metals in those M-type asteroids be prepared to take the whole thing apart atom by atom and then sift those one at a time.

In a certain sort of fiction from the late 70s this was done with a "Santa Claus machine" which was a fusion torch that ionized the asteroid material and then separated the different isotopes in a giant magnetic ring.

A couple of decades alter they started doing it all with magic nanotech but yo don't do it at all with any process comparable to a TL7-8 terrestrial mining operation. Maybe your space setting has Santa Claus machines or magic nanotech but decide that first before people there routinely do asteroid mining for heavy elements.

[malloyd]

Originally Posted by Fred Brackin

You speak of "concentrations" and "deposits" and asteriods probably lack those due to a lack of geological processes.

This is definitely still the major bit of information we don't have but need to decide if asteroid mining is practical at all. We just don't know how differentiated asteroids are, and won't until we have samples from multiple spots on several of them.

If there aren't any high concentration deposits then no, asteroid mining is not competitive - if you can get something out of "average" concentration rocks, we have plenty of them on the ground, not to mention much more concentrated "ores" like sea water. Or landfills.

[AlexanderHowl]

Analysis of metallic meteorites suggest levels of up to 250 ppm of precious metals (a typical rich vein in planetary mines has 5 ppm), so we are talking about undifferentiated objects that are equivalent to the richest veins in the richest mines on Earth. Even 'poor' M-type asteroids likely have 30 ppm of precious metals, making them more than competitive with planetary mines (by comparison, seawater is less than 1 ppb precious metals and mine tailings are usually less than 0.5 ppm). Now, S-type asteroids are likely not that worthwhile to mine because of a lack of differentiation, at least as a primary activity.

[Anthony]

The main virtue of asteroids is that most siderophile elements on Earth are trapped in the core; hence the reason people talk about platinum-group metals (most of the group 4/5 elements are common enough that being relatively rare is still not a huge issue, though palladium might be of interest).

[RyanW]

Originally Posted by Anthony

The main virtue of asteroids is that most siderophile elements on Earth are trapped in the core; hence the reason people talk about platinum-group metals (most of the group 4/5 elements are common enough that being relatively rare is still not a huge issue, though palladium might be of interest).

Having a source of materials (both raw ingredients and building materials for infrastructure) closer to where they are needed is worth a lot. And in space travel terms, the asteroid belt is closer to low Earth orbit than the surface of Earth is. So asteroid mining will be very appealing to space based industry, even if less efficient than terrestrial mining.

[Anaraxes]

Originally Posted by AlexanderHowl

a typical rich vein in planetary mines has 5 ppm),

The World Gold Council defines "high grade" ore as 8+ g/t (ppm), while "low grade" ore is 1-4 g/t. Open pit mines have lower standards (perhaps a tenth as high). 5 g/t wouldn't be considered especially "rich", but merely average. The highest grade underground mine in operation is 44.1 g/t, with a couple of runner-ups over 20 g/t, and the top ten all clocking in at over 11.

[Varyon]

Originally Posted by Fred Brackin

You speak of "concentrations" and "deposits" and asteriods probably lack those due to a lack of geological processes. It's probably easy to mine for water ice or similar things but if you're going to grab all those precious metals in those M-type asteroids be prepared to take the whole thing apart atom by atom and then sift those one at a time.

Yeah, I largely envision asteroid "mining" as consisting of basically having machines that chew up (probably mechanically and thermally, possibly chemically) the asteroid, and then process the resulting slurry to pull out the desirable bits and concentrate them. Geological concentration does a lot of your work for you planetside, but I wonder if the issues I noted associated with planetside mining are enough to offset this advantage.

Originally Posted by johndallman

Possibly no metal mines, but sand and gravel are naturally created and partly sorted by weathering processes. They are used in such vast quantities for construction that bringing them down from orbit is unlikely to be worth the cost.

I failed to consider such materials. Stone of various types - as well as dirt, now that I think of it - would almost certainly be sourced locally. In my defense, I think such places aren't called "mines" per se, but rather "quarries."

Originally Posted by khorboth

Something often forgotten in these anslyses is the human factor.

Given the level of technology I assumed (original thread was about a TL10 setting), mining of either flavor is likely more-or-less fully automated. My thoughts on the human element was more "Nobody wants a mine in their backyard" - and certainly, environmental regulations are one of the things likely to be in favor of asteroid mining.

Originally Posted by Daigoro

Likewise, the political factor has been ignored so far.

I was assuming a situation where the main polity had access to the asteroids. Certainly, planetside mining is going to win out when the alternative is not getting any materials at all (or having to pay through the nose to the Baron Lords of the Belt, or whatever).

Originally Posted by ericthered

The precious metals probably hit the $50/lb of savings, but I don't know if you get those savings on pharmaceutical drugs. At least not most of them, especially because a lot of precursor chemicals will be down on earth.

The high cost of drugs is often more closely related to the cost of developing them (note generics tend to be far cheaper than the originals, even when made to exactly the same standards), not to the actual cost of manufacture. Manufacturing them in space may be cheaper (as you note, the precursors may be more readily-available planetside), but once the costs to bring them down the well are factored in, I'd be surprised if they were truly cheaper (at least without something to make space transport dirt cheap). Even if they aren't, of course, you'll probably still have such manufacturing done, as it's likely cheaper to make the drugs there for use in space than it is to make them planetside and carry them up the well.

[David Johnston2]

Originally Posted by Varyon

Y

Given the level of technology I assumed (original thread was about a TL10 setting), mining of either flavor is likely more-or-less fully automated. My thoughts on the human element was more "Nobody wants a mine in their backyard" - and certainly, environmental regulations are one of the things likely to be in favor of asteroid mining.

Unless you've got environmental regulation on an interplanetary scale, that's mostly going to start being a thing as the population gets denser. It's not something people are going to worry when about the planetary population is numbered in the millions or less. And it's in the earlier periods of development when people are more liable to use more human labour because they don't have a local industrial complex churning out automated machinery.

And if the Federation is imposing environmental regulations created for planets with populations in the billions on start-up colonies, I suspect the colonists are going to be pretty damn disgruntled.

[Varyon]

Originally Posted by David Johnston2

And if the Federation is imposing environmental regulations created for planets with populations in the billions on start-up colonies, I suspect the colonists are going going to be pretty damn disgruntled.

I suppose this was indeed what I was assuming, and you do make a good argument against it.