Gold Mining on The Moon

[Warren Platts]

The idea that it might be profitable to mine gold on the Moon (price of gold as of this writing is an astonishing $44,868.30 USD/kg!) is motivated by the recent LCROSS results that detected 1.6% by mass of gold in the ejected plume. Since this keeps popping up in other threads, I figured I'd start a new one to collect the discussion in one place.

You should work backwards: 40 tons of gold per year at today's prices would bring in about $4B/year. LCROSS said the gold was an incredible 1% of what was observed, IIRC. Taking that at face value, then 4 000 tons of regolith would have to be processed. (this agrees with what the participants said the value of the ore was.) All the equipment necessary could probably be brought in for 5 to 10 20-ton loads (a typical semitruck-trailer load is about 20 tons). If you could keep keep the overhead of the mine down to $2B/year, you could make some money, potentially.

That seems high to me. For instance, 4,000 tons of regolith a year is a little more than 10 tons per day. It would seem to be high mass of equipment at 100 to 200 tons to process 10 tons per day.

I found some portable plants able to do gold processing using the Merrill-Crowe process after a web search:

Merrill-Crowe Zinc Precipitation Plants
For Recovery Of Gold & Silver From Cyanide Solutions
www.sepor.com/new/MerCrowe.pdf

This method precipitates the gold out after dissolving it in sodium cyanide solution. The two plant sizes available here have shipping weights of 1,200 lbs. and 3,100 lbs. and are able to process 65 tons/day and 300 tons/day of the solution, respectively. The amount of gold is given as usually no more than .10 oz. per ton of solution. So for the 300 tons/day plant it would be perhaps 30 oz. per day for a usual Earth mine. So for the lunar concentrations at perhaps 3,000 to 6,000 times higher than usual Earth mines, it might be 100,000 oz. to 200,000 oz. per day. However, it might not be this high because it might be limited by how much gold can dissolve into the solution at a time.
Another method for separating out the gold is called the electrowinning method, for which there are also lightweight portable plants available:

EW Pilot Plants.
http://www.sxkinetics.com/ewplants.htm

Bob Clark

This is interesting Bob. I didn't realize that a cyanide leaching facility could be so lightweight. On the other hand, the figure I provided above (around 100 to 200 tons total) also includes the other stuff you'll need, like a couple of hab modules, a whole suite of earth moving equipment, rock crushers and conveyers, and massive amounts of solar panels. Keep working on it.

[MikeMcc]

Don't forget that the price of gold is also affected by it's availability. Dumping a lot of it into the market would de-value it.

[NEOWatcher]

Also; looking at some of the descriptions, there are areas that require vacuum, and I'm not sure if others require some kind of atmosphere or pressure. Nor do I know how much gravity comes into play.

I'm pretty sure that the gravitational parts can be overcome by just slowing it down so it takes longer (I'm not sure if that's a linear calculation though).
Vacuum sounds like a no-brainer, but if there are areas that rely on atmospheric exposure or pressure (pumping the solution for example), then the entire apparatus needs to be redesigned to basically work in reverse.

Also; there's the matter of the "aqueous solution". You'll also need to create the water (which is discussed elsewhere), holding facilities and purification plants. Plus; you have the chemicals to use in that solution. I understand that the amount of cyanide is very small, but it's still a factor.

Then there's mention of filters. I wonder how long those last, how big they are, and what it takes to replace and/or clean.

And; for future calculations, note that the end content is only 45%-80% gold. So; any "shipping" costs need to be adjusted.

I think it's just another case of something easy on Earth that you can't just plunk down on the moon and have it work.

[Ronald Brak]

Here's a pretty picture of LCROSS:

http://en.wikipedia.org/wiki/File:LC...stallation.jpg

[Siguy]

What about simply sending a remote operated gold processing facility to the moon, and storing the gold there? Obviously the cost of transporting the gold back to Earth is impractical at the moment, but if you sold gold at say, slightly less than market value on the condition that buyers would have to retrieve it themselves, you could make a reasonable profit. I can see people investing in things like that, because it would basically be fiat currency.

[Warren Platts]

What about simply sending a remote operated gold processing facility to the moon, and storing the gold there? Obviously the cost of transporting the gold back to Earth is impractical at the moment, but if you sold gold at say, slightly less than market value on the condition that buyers would have to retrieve it themselves, you could make a reasonable profit. I can see people investing in things like that, because it would basically be fiat currency.

Hm, how about setting up a "bank" on the Moon itself and simply store it there. People on Earth could then buy it. No need for actual delivery. Hardly anybody who owns gold actually has it delivered...

[Damburger]

The price of gold give in the OP is only one order of magnitude higher than the cost of putting stuff in LEO. Likely, the complication of retrieving it from the Moon would push the price/kg up beyond the price of gold.

[Zach Singer]

Why ship gold back? Yeah it has a large value based on scarcity in the modern market, but it also has enormous utility, one of the most conductive elements, if we intend to colonize other bodies at all a gold mine on the moon would be a good first step to building complicated computer parts in space eliminating the need to launch them into orbit. I think that the reduction in cost of deploying advanced circuitry to orbit might outweigh the potential profit of gold on the earth market.

[Hop_David]

Hm, how about setting up a "bank" on the Moon itself and simply store it there. People on Earth could then buy it. No need for actual delivery. Hardly anybody who owns gold actually has it delivered...

That would be a bank more secure than Fort Knox.

[Hernalt]

Leave the gun, take the cannoli.

"Vanadium: 'The element that could change the world'"
http://www.scienceandtrade.com/en/ch...genews/37.html

LRO-LAMP Observations of the LCROSS Impact Plume, Science 330
Element -//- Soil mass abundance* (%)
V -//- <2.4
Au -//- <1.6

I cannot locate it now, but one paper on lunar ISRU solar panel fabrication had an efficient process using local materials that should only require shipment from earth of - vanadium. IIRC.

[JonClarke]

Wow! One extremely dodgy measurement and people are floating entire industries...

[Trakar]

Wow! One extremely dodgy measurement and people are floating entire industries...

Not that its not been known to happen in the past, ...but the simple reality is that if gold were in actual demand, rather than serving as an economic float point, there is a lot more available in the hills and streams of California, Oregon, Nevada and Arizona, than there is in this estimate of interest on the Moon.

[Damburger]

Leave the gun, take the cannoli.

"Vanadium: 'The element that could change the world'"

Thats not a cautious title. Technological hubris is bookended by the phrases 'X: The wonder material of tomorrow!' and 'Studies show X causes cancer and birth defects'

[RGClark]

In this news release LCROSS scientist Peter Schultz says the amounts of silver liberated wouldn't be enough for mining purposes, though he doesn't mention the gold amounts:

October 21, 2010
NASA-engineered collision spills new Moon secrets.
http://news.brown.edu/pressreleases/2010/10/lcross

Anyone see in any of the LCROSS papers in Science where the silver amounts were quantified?

Bob Clark

[RGClark]

This page discusses methods of recovering the gold other than dissolving in sodium cyanide can be used. It depends on how the gold resides in the surrounding material:

THE BASIC PROCESSES OF GOLD RECOVERY
http://www.denvermineral.com/basicp~1.html

For instance gravity separation, based on the fact that gold is much heavier than the surrounding rock, works well for this particular mine:

African Gold Group, Inc. 92% Gold Recovery Using Gravity Separation Only on Oxide Ore From Kobada, Mali.
Press Release Source: African Gold Group, Inc. On Wednesday September 8, 2010, 9:00 am EDT
"The economic implications of being able to recover approximately 90% of the gold contained within the oxide profile at our Kobada, Mali project based solely on gravity recovery, cannot be overstated. It is well known, within the mining industry, that the cost (capex) of building a gravity plant will be significantly less than the cost of building a comparable cyanide agitation leach plant. In addition, operating costs, for gravity, will be significantly less, on a relative basis, when compared to the cost of operating an equivalent cyanide plant."
http://finance.yahoo.com/news/Africa....html?x=0&.v=1


Bob Clark

[NEOWatcher]

This page discusses methods of recovering the gold other than dissolving in sodium cyanide can be used.

So what? How do any of those methods relate to doing it on the moon in the vacuum of space and temperature ranges?

For instance gravity separation, based on the fact that gold is much heavier than the surrounding rock, works well for this particular mine:

So it works well for that mine. Why does that have any bearing on the moon?

[sarcasm]Panning is gravity too. Why not just use the water found on the moon to create a creek and pan for gold? [/sarcasm]

[kamaz]

I have pointed out in the other thread that since we are interesting in using lunar ice for fuel, a propellant factory located at the LCROSS site would produce significant amounts of "waste" gold -- in roughly 3:1 proportion. In other words, I am not sure I would like to build a business case based on mining lunar gold, but it would make a very nice side business.

Also, I am not sure that "classic" gold mining techniques are directly applicable here -- they usually aim to get only the gold, but here, we would like to get both water AND gold, and possibly some other things as well (vanadium?).

[Zach Singer]

is it possible to extract both the gold and the vanadium from the same deposit? are there conflicts of interest chemically that might cause one or the other kind of reaction not to occur in the presence of the materials used in the other process?

[RGClark]

So what? How do any of those methods relate to doing it on the moon in the vacuum of space and temperature ranges?
So it works well for that mine. Why does that have any bearing on the moon?
[sarcasm]Panning is gravity too. Why not just use the water found on the moon to create a creek and pan for gold? [/sarcasm]

What HAS to be done, like yesterday, is to send lander missions to confirm those startling amounts indicated by the LCROSS mission. As Kamaz noted those gold readings are only upper bounds. It needs to be determined if the actual amounts are really close to that. If so, then this is a real game changer. People have been asking what is the real "killer app" for space travel? IF the LCROSS results are true then you have it right there, lunar mining. Even more, this is in fact a killer app for beyond Earth orbit space travel as well!
But then to do the mining you want to use the simplest method that is also the lightest weight method, which for Earth mining would not be major concern. Then it is important as well to characterize in what form the gold appears to find out which method of extraction can do it most profitably. This should be done at the same time we are doing the ground truth missions.


Bob Clark

[RGClark]

I have pointed out in the other thread that since we are interesting in using lunar ice for fuel, a propellant factory located at the LCROSS site would produce significant amounts of "waste" gold -- in roughly 3:1 proportion. In other words, I am not sure I would like to build a business case based on mining lunar gold, but it would make a very nice side business.
Also, I am not sure that "classic" gold mining techniques are directly applicable here -- they usually aim to get only the gold, but here, we would like to get both water AND gold, and possibly some other things as well (vanadium?).

If it is done using the usual cyanide solution method you would need a lot of water like when you usually dissolve a material in a hydrous solution. I don't know if there would be enough water in proportion to the gold available for this to work. That's another reason it has to be determined if other extraction methods could work.

Bob Clark

[kamaz]

What HAS to be done, like yesterday, is to send lander missions to confirm those startling amounts indicated by the LCROSS mission.

The mission has been proposed already -- hopefully it gets funded: http://www.bautforum.com/showthread....tiles-Explorer

It may have a chance -- you know, gold really appeals to politicians

[RGClark]

The mission has been proposed already -- hopefully it gets funded: http://www.bautforum.com/showthread....tiles-Explorer
It may have a chance -- you know, gold really appeals to politicians

That's nice to be done at some point, but the problem is NASA always wants to do these billion dollar missions. LCROSS was the perfect mission because it returned such profoundly important results and at low cost, only $79 million, like pocket change for planetary missions:

Inside NASA's Plan to Bomb the Moon and Find Water.
http://www.popularmechanics.com/science/space/4277592


Bob Clark

[djellison]

, but the problem is NASA always wants to do these billion dollar missions.

Actually - no it doesn't. The SMEX, Discovery and New Frontiers missions all fall well under such figures and there are many many more missions that fall under that category than under a $1B+ Flagship category.

But at some point, you're presented with a challenge that just can't be put under those caps - and that's when you hit flagship status.

[Garrison]

That's nice to be done at some point, but the problem is NASA always wants to do these billion dollar missions. LCROSS was the perfect mission because it returned such profoundly important results and at low cost, only $79 million, like pocket change for planetary missions:

Inside NASA's Plan to Bomb the Moon and Find Water.
http://www.popularmechanics.com/science/space/4277592


Bob Clark

Never thought this day would come but I have to agree with Bob, $1 BILLION dollars for ONE rover? Which won't be ready for 8 years? Do these guys just work out a budget and then add a zero on the end?

[RGClark]

Actually - no it doesn't. The SMEX, Discovery and New Frontiers missions all fall well under such figures and there are many many more missions that fall under that category than under a $1B+ Flagship category.
But at some point, you're presented with a challenge that just can't be put under those caps - and that's when you hit flagship status.

I once did a search for such low cost NASA missions and they were all to LEO for Earth observations. I didn't see any for planetary observations other than that of the Earth.
If you know of any I would like to see since it could serve as a model to do such low cost lunar exploratory missions.
Take a look at that Popular Mechanics article on the LCROSS mission. Colaprete et. al. deserve major kudos for their ingenuity in getting the mission done at low cost and fast. One key thing they were able to do was that they were able to ride piggy back on a mission already paid for so they didn't have to pay launch costs. That's a great idea to follow for cutting the costs of such precursor missions.


Bob Clark

[djellison]

LCROSS was a very very obscure case.

Define low cost.

And incidentally - costs of planetary missions OUTSIDE of NASA are comparable to this inside it. MEX, VEX, Rosetta - they'll all same ballpark as similar spacecraft for NASA. Akatsuki, Nozomi, Haybusa... also the same.

Missions beyond LEO are expensive because they're damn hard.

[Hop_David]

Never thought this day would come but I have to agree with Bob, $1 BILLION dollars for ONE rover?

Soft landing a rover is substantially harder than crashing the Centaur stage of an orbiter.

[Hop_David]

The mission has been proposed already -- hopefully it gets funded: http://www.bautforum.com/showthread....tiles-Explorer

Reading the pdf it looks like they might go for the battery option due to budget constraints? Which would limit it's lifespan to 4.4 days. That would really suck.

[Warren Platts]

Not that its not been known to happen in the past, ...but the simple reality is that if gold were in actual demand, rather than serving as an economic float point, there is a lot more available in the hills and streams of California, Oregon, Nevada and Arizona, than there is in this estimate of interest on the Moon.

The world's placer deposits of gold are pretty much tapped out. There's still enough that a guy with a dredge can go out and make a little money if he knows what he's doing, but the easy stuff is long gone. The remaining gold is hard to get at. Thus, it's not easy to make a profit, even at $45K/kg. That's the reason reason there's not more supply, rather than there being a psuedo-demand versus an "actual" demand.

[Jens]

Thus, it's not easy to make a profit, even at $45K/kg. That's the reason reason there's not more supply, rather than there being a psuedo-demand versus an "actual" demand.

That's right, and in fact, we end up tossing a lot of gold into municipal waste dumps, in cell phones and other devices, and to some extent it's just a case where the price of gold isn't actually high enough to make it a really profitable endeavor, once you factor in equipment and labor costs and what not. A mining venture on the moon would have to be able to pay the presumably high salaries required for people to go there, or for the development of sophisticated mining robots, not to mention the price of getting the stuff back. If we don't bother to recycle cell phones for their gold, I wonder a bit if there will be enough incentive to go to the moon for it.