#Lunar Quicklime
10 messages in this thread
Hello All.
Can anyone suggest someone to e-mail to for help in finding processes by which
quicklime might be extracted from minerals which are not generally considered
commercial sources, such as calcic plagioclase feldspars, calcic pyroxenes, or
even basalt? I'm looking for a means of extracting quicklime from lunar rock on
a large scale.
(Water requirements of the process itself can be considered not a problem, but
the types of calcic rock I would be interested in would lack water in their
chemical makeup)
Sincerely,
Darkfyre
74562,245
If possible, can you kindly leave us a message (or just reply to this one),
with your full name, as requested in the opening bulletin … for our records.
Thanks/Rick Needham/SYSOP
Hi–
Welcome to the forum/section!
I do not know if it is a practical process, but silicate rocks are weathered by
rainwater bearing dissolved carbon dioxide (thus mild carbonic acid); this
dissolves out various metal ions, including calcium, later to be deposited as
caliche (mostly calcium carbonate) or 'desert varnish' when the water
evaporates.
On the Moon, treat pulverized high-calcium rocks thusly, and pass the water
through a solar furnace, vaporizing the water for reuse in dissolving calcium,
and further driving the CO2 out of the CaCO3 to get CaO. But you might have to
circulate a huge quantity of water for quite a long time… I hope you were
not looking for high purity.
The folks in the chemistry section of this forum may have a more practical
notion – many of them may not look into this geology section often, and they
should have more experience with _practical_ processes.
–Doug
Hello Doug.
Thank you for your two suggestions. Unfortunately, I can only use one of them.
In the chemistry of lunar rocks, not only water but carbon (and thus CO3) is
depleted. Thus, there is no CaCO3 on the moon. While there may be minerals
there which react similarly, my knowledge of chemical geology is too limited
for me to guess at which ones, since I have little data from Apollo and probe
samples.
However, I fully intend to take your suggestion on e-mail contacts.
Thank you,
Darkfyre
74562,245
The natural process that Doug mentions takes place over geologic time, even in
a solar furnace it may take more time than humans have. Considering how few
useful results we have in trying to get "common" industrial materials and even
metals from silicates, it probably isn't practical, unless the cost and amount
of energy needed is totally unimportant.
Lanny
Hello Lanny.
True enough. However, that natural process Doug described is only useful (or
similar to non-volcanic geologic processes) over a relatively small range of
temperatures.
As for solar funraces, I discussed this problem with a friend, who recommended
using a solar furnace (under lunar conditions, of course) for fractional
distillation of the lunar rock, and he was not kidding in the slightest. It
appears that Anorthite can be separated from less calcium-rich rock in this
fashion.
Of course, the original question would remain. How does one get CaO from
anorthite?
Yours Truly,
C. Michael Edwards
While everyone else asks about solar furnaces, I'll ask about your plans for
the quicklime. What are you going to do with it?
Hello John.
While not as readily reactive as LiOH, the Ca(OH)2 formed by the addition of
CaO to water should make a useful agent for removing CO2 from a lunar habitat's
atmosphere, treating habitat sewage, and other purposes. The actual chemical
uses I'm interested in are for Ca(OH)2. However, I'm told that
production/extraction of CaO (which, as I implied, can be used to make Ca(OH)2
by simply adding water at room temperature) is the necessary first step in the
process, although someone has recommended creating Ca(OH)2 from the mixture of
water and pure Ca metal (which can be extracted by electrolytic methods).
Sincerely,
C. Michael Edwards
AKA,
Darkfyre
74562,245
I imagine you considered using plants to eat the CO2?
Hello John.
Naturally, the use of plants for removal of CO2 was the first scheme
considered. However, even in this scheme, CaO is a useful material to have for
other uses besides CO2 removal.
Someone has asked me to consider the fact that plants can get a large portion
of their needed nutrients (including Ca) from lunar regolith. The proficiency
of plants at this might even be used as an extractive technique.
Sincerely,
C. Michael Edwards AKA Darkfyre