On 8 Dec 2014 at 15:10, Ian Whitchurch wrote:

> Regrettably, if you follow this line of thinking, there is no
> asteroid mining, ever, because it is actually tectonic and biological
> processes.that concentrate minerals to payable quantities and so on.
>
> As asteroid mining is both cool and part of canon, mumble mumble
> science handwave handwave. mumble mumble.

Actually, carbonaceous chodrites are worth mining for the nitrogen
and organics.

Icy asteroids (proto-comets) are worth processing for the water,
ammonia and to a lesser extent, the methane.

Nickel-iron ones are worth mining for the metal, and in the process
of refining it, you can get a lot of valuable stuff as "by-products".

With stony asteroids, you can use them as a cheap source of stuff
like aluminum, magnesium and titanium, but only if you don't have a
handy planet that has better concentrations.

With cheap access to space the biggest reason for mining stony
asteroids goes away. Though "gravel bank" type asteroids may still be
worth processing, just because they are already broken up into easy
to handle chunks.

I suppose that the process of differentiating could result in some
interesting minerals that don't survive in planets.

Murray Leinster had that as a minor plot point in one book. Broken up
"planets" (from collidsions during system formation) were mined for
crystals that formed at the boundary between the mantle and iron
core.

--
Leonard Erickson (aka shadow)
shadow at shadowgard dot com