On 23 Feb 2016 at 18:31, Phil Pugliese (via tml list) wrote:

> As has been mentioned before; it seems to me that the biggest problem would be the purity of the 'ice'.
>
> I'd think that It's bound to be 'dirty' in various ways, contaminated w/ who knows what unstable volatiles...

Comets should be a good model.

Mostly a mix of water, ammonia (NH3) and methane. With small amounts
of more complex hydrocarbons and even smaller amounts of other
things. Plus lots of "dust"

Shouldn't be anything "unstable" as it'll have had *billions* of
years to react as it accumulated into the iceball.

Mining it will be a pain unless the body is big enough to have
significant gravity. Otherwise you have to deal with holding down the
mining gear, and dealing with ice chunks/liquids in microgravity and
vacuum.

John Ringo & Travis Taylor describe what it might be like in chapter
11 of Manxome Foe.

The problems with improvising something to get oxygen from a gas
giant were in the previous book.

Anyway, dealing with the ice mix shouldn't be *that* bad. Keep it in
separate compartment/container and heat it slowly. Methane should
melt first, and then vaporize. Other hydocarbons will have higher
melting and vaporization temps.

Ammonia will come off at higher temps.

There may be some methane clathrate and ammonia water solutions. So
you'll be getting mixes for quite a range. But running the vapor into
another chamber and lowering the temp again, you should be able to
condense out an ammonia/water mix. Leaving methanse and other
hydrocarbons as gasses to be drawn off.

The hydrocarbons can be vented or otherwise dealt with. Heck, you
could burn them with oxygen to get CO2 and water vapor which are
easily seperated.

The ammonia/water mix can just be electrolyzed into hydrogen &
oxygen.

Excess ammonia can be "cracked" into nitrogen & hydrogen in various
ways. I think it can also be burned with oxygen to get nitrogen &
water.

The leftover crap (some organics and "dust") can just get dumped. Not
worth messing with unless you are doing a major mining operation.

So for refueling, just dump the mud.

If you are mining a fair sized body, it's probably worth using some
of the water and ammonia to seperate the dust & organics and deal
with them appropriately.

It'll be pretty low grade ore, but given that you already have to
move it and it's finely divided, most of the hard work is already
done.

Magnetic seperators will get out nickel/iron grains. Other stuff can
be seperated by floatation and other methods. Look up how bauxite is
processed for one example.

How much of what can be easily extracted is anybody's guess.

But water, ammonia and methane are dead sure products. Other
hydrocarbons are going to be lesser products. and there'll be some
yield of more complex organics and maybe nitrogenous compouds as
well.

Ammonia and methane are a starting point for all sorts of stuff. A
not overly large installation can start with water ammoinia and
methane and produce most of the stuff needed for life support systems
other than "trace" elements.

As well as plastics and other things.

Airless worlds and asteroid colonies will always need more carbon,
hydrogen and nitrogen. Oxygen is extractable from rock as a worst
case, but water is good to have for reasons besides it's oxygen
content.

So you can ship off all the water, ammonia and methane you can
produce. Going into chemical synthesis gives you value added
products.

Or you can go "low" tech and feed the methane and ammonia the various
bascteria and algae and use that as the start of a food chain and
work up to running farms to export food.

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