Planetary Resources

[JasonAW3]

Let's be clear about this;

The majority of the value of ANY resources mined from an Asteroid is the fact that it is not in a large gravity well.

Instead of spending $10,000 a kilo to send materials into space, the materials are already there to be reformed into equipment habitats and, yes, even hard currency for use in space.

Unless the value of a particular element or mineral is well beyond $10,000 a Kilogram, then that material would have no real value back on earth.  The trick is cheap transportation and easily accessible raw materials.  This means that not only will we have to develope the means to extract gaseous and liquid volitiles from asteroids, preferablly via robotics, but we will have to develope tools and equipment to extract raw ore and process it into usable materials.  Again, this ought to be as automated as possible, allowing the materials to build up in a cache until the cost to pick up teh materials was far less than the value of said materials, and these materials would be brought, likely to an Earth Moon Lagrange point, likely L-5, for further pro0cessing into habitats, spacecraft and other equipment and consumables.

Again, the main reason that no one has tried to mine asteroids is that the cost of doing so, under current technologies, has always been higher than the actual value of those materials.  But things are changing as travel becomes cheaper and new technologies put those materials within our grasp.  Once colonies are established on Mars and the Moon, free travelind colonies will likely be built around where an astroid currently isdiverting minor comets and asteroids to provide materials that certain asteroids lack.  Orbits will be changed into more useful orbits, so these colonies can be used as stop over points and areas of commerce.

Once again, it won't necessicerily be the destination that is important, but the journey itself...

[go4mars]

...Unless the value of a particular element or mineral is well beyond $10,000 a Kilogram, then that material would have no real value back on earth.  The trick is cheap transportation and easily accessible raw materials...

The second sentence corrects the first.  If for example a large fresnel lens heated a spinning asteroid within a collecting reprecipitation tarp, catching first various volatiles and propellants, then cooked kerogens then metals, clever ways can be imagined where ISRU shipments at vast scale could drop shipping costs arbitrarily low. 

I still really like Jon Goff's suggestion upthread about hollow metal spheres entering Earth's atmosphere on their own; perhaps targeting a specific lake for easy collection. 

[Robotbeat]

How to actually mine Platinum Group Metals from an asteroid:

1) Find a metal-rich rubble pile (if they exist) with a PGM ore concentration of 100ppm (asteroids of that concentration of PGMs supposedly exist).

2) Pick off big metal chunks magnetically or somesuch.

3) After you have a thousand or so tons of metallic ore, put it in the shade to cool off to deep cryogenic temperatures.

4) Then, crush it in a grinder. Cooling the ore to cryogenic temperatures first should significantly reduce the energy needed to grind the ore to a fine powder, but grinding of ore often takes roughly ~10kWh/ton, so it'd take ~10MWh to grind the batch (or about 2 weeks if you have 30kW), although iron-nickel is pretty tough, which is why I included first cryogenically cooling the ore.

5) Grinding may heat up the ore, so it may take several steps where you grind, then cool, then grind.

6) Once the powder is fine enough, you put it in a vibratory centrifuge to clear off the relatively lightweight rocky bits (the metal will be much denser).

7) Then use a magnet to remove the powdered iron and nickle bits.

8) What you have left will be a MUCH more concentrated ore and a lot less material.

9) You can ship this back to Earth (a couple of tons to a few hundred kilograms... small enough to be returned to Earth, perhaps guided by a very small tug and perhaps with a very inexpensive heatshield) for sale or further processing.

10) Or do some wet-processing of the ore to concentrate it to PGMs (like dissolving the ore in acid... PGMs won't dissolve in most acids while everything else will, so you'll be left with fairly pure PGMs) before shipping back to Earth for sale.

However, acid processing may be too chemically intensive, and you might get by with just dry processing of the ore (although it sounds like Planetary Resources intends to do some wet processing, part of their motivation for focusing initially on extracting water).

At the end of this, you'll have about 100kg of PGMs, with a market price of roughly $15-30 million.

Rinse and repeat.

[llanitedave]

Iron and nickel just aren't valuable enough on Earth to make mining them from asteroids attractive.  In addition, for many purposes, the use of iron and other metals is already made obsolete by substitution of composites and carbon nano-structures.  This would be especially true in space.


The main market for space-sourced resources will be the use of them in space itself.  It's going to take a while to get that kind of market up and running.  In the long term, however, the potential economic benefit is huge.

[Robotbeat]

Iron and nickel just aren't valuable enough on Earth to make mining them from asteroids attractive.  In addition, for many purposes, the use of iron and other metals is already made obsolete by substitution of composites and carbon nano-structures.  This would be especially true in space.


The main market for space-sourced resources will be the use of them in space itself.  It's going to take a while to get that kind of market up and running.  In the long term, however, the potential economic benefit is huge.

Is this a response to me? If so, you didn't actual read what I wrote.

[Impaler]

The paper gives an estimate that for 1 TON of Asteroid material 1 ounce of Platinum group Metal would be obtained from complete refining.

PGM is valued at $1200 an ounce currently but lets be generous and assume prices rise to $2000, this means that 1 kg of raw Asteroid material will yield $1.20 to $2 worth of PGMs. 

But intact Asteroid on Earth sells for $100 a GRAM, meaning the 1 kg raw material is worth upwards of $100,000 almost 5 ORDERS OF MAGNITUDE MORE then its PGM content.

Even if the refining process were completely FREE and resulted in 100% pure platinum, a gram of Platinum sells for ~$40 currently and even the speculative increased price doesn't match the raw asteroid value, so you would still be better off transporting unrefined Asteroid back to Earth instead of refined Platinum.

This is why I've said it is foolish to try to jump directly to commodity metal sales as the first revenue source, their is a much more attractive low-volume high-value market that can be serviced which will allow an Asteroid 'exploiting' company to gain valuable experience in all aspects necessary for future metal mining OTHER then the in-space refining process.  They can do navigation, rendezvous, landing, excavation of material and return of material to Earth.  Tell me that doing ALL of that doesn't retire a huge set of risks.

If they can't close a business case with unprocessed Asteroid their is absolutely ZERO chance that adding a refining step AND dropping the per unit value of returned material is going to close it.

The kind of mission I see being possibly viable for them is a one costing $100 million and which returns a 1 ton Asteroid in some kind of ballistic reentry capsule a meter or two across.  This is a cost and a mass within the realm of the possible, the cost is certainly lower then past government run sample retrieval, yes but we expect 'new-space' to be more efficient, the mass is on par with the ARAM mission option B 'claw' concept.  Carved up and sold at $100 a gram in a range of sizes you could pay for the whole mission and make a profit. 

THEN you can start thinking about a refining process and bringing back a 1 ton ingot of Platinum.

[Robotbeat]

 llanitedave: I do agree with you, of course. Mining platinum group metals is a better prospect since you're moving around less material. I mentioned iron-nickel because that's usually where the richest ores are found.

[Robotbeat]

Impaler: what is the market size of raw asteroid material, though? No doubt it's a couple orders of magnitude smaller than the PGM market, about $10 million for meteorites and slightly less than $10 billion per year for PGMs. And truthfully, the PGM market isn't enormous either (... Smaller than the existing space telecommunications market), but it's still significant and big enough to bootstrap significant space mining endeavors.

[llanitedave]

Iron and nickel just aren't valuable enough on Earth to make mining them from asteroids attractive.  In addition, for many purposes, the use of iron and other metals is already made obsolete by substitution of composites and carbon nano-structures.  This would be especially true in space.


The main market for space-sourced resources will be the use of them in space itself.  It's going to take a while to get that kind of market up and running.  In the long term, however, the potential economic benefit is huge.

Is this a response to me? If so, you didn't actual read what I wrote.

Right there.  Sorry about that.  I see that you're treating the iron and nickel as waste to be removed.  The process you propose, though, is very energy intensive, and with the price of gold right now at only a bit more than $1200/oz and the price of platinum a bit less, I just don't see it as very appealing.  Precious metals are commodity items that fluctuate dramatically in price, but there's no long-term shortage for the time being.  Again, whatever value asteroid-mined resources are going to have will depend on their practicality for conversion into finished products close to the point of acquisition, not the export of the material to Earth.

[Robotbeat]

I-Dave:Actually, did you examine the process? Read it again. Not that energy intensive.

[llanitedave]

I-Dave:Actually, did you examine the process? Read it again. Not that energy intensive.

Yes, and I think you're drastically underestimating the energy requirements involved in grinding.  Grinding ore on Earth is done with large, very heavy rollers, and you have the weight of the rollers and of the ore pile working to crush the matrix.  In space, you're going to have to add some other source of pressure to move the material through the rollers and generate the required pressure.  The material also usually needs to be moistened to reduce wear on the teeth, minimize liberated dust, and provide some cooling.  You'd need another technique to do all that in space.  On earth, ore containing precious metals is normally embedded in a matrix that's often high in clay, usually from hydrothermal alteration of the host limestone, shale, or volcanic material.  That's easier to grind than metallic iron/nickel, even if your starting regolith is somewhat pre-pounded.


The separation of gold from ore on Earth is a process that's highly gravity-dependent, and also requires abundant water.  Reduce either of those components in space, and you're going to have to come up with another method, and the substitute will not use less energy than what it is replacing.


I just don't see any way that you can explore, discover, characterize, extract, process, and return any asteroid-based metals, precious or otherwise, for less than it costs to do the same work on Earth.  Not until gold, silver, platinum, and copper become FAR more scarce and expensive on Earth than they are now.  And that's nowhere near happening.


What's more likely is that inexpensive substitutes will be found, and demand will decline.

[Robotbeat]

Tell me a hard number to use for grinding energy per ton, then. I used the best number I could find online, if you have a better one please let me know. But an actual number.

You could always rotate your facility on a tether, allowing you to use whatever gravity level is convenient. You wouldn't have to invent some new force.

Planetary Resources intends to do water mining before PGM mining, so access to water would not be an enormous obstacle by the time they're doing PGM mining.

As far as more inexpensive alternatives being found... You're making the common mistake of assuming this is being done from the perspective of scarcity instead of abundance. It's not about running out of the resource on Earth, it's about adding to Earth's resources.

[RonM]

How many billions of dollars will it cost to place this ore processing facility in space, let alone at an asteroid?

PMG mining is far future, after water mining provides inexpensive fuel for fuel depots and an industrial infrastructure is available in space. That's very far down the road.

[Robotbeat]

How many billions of dollars will it cost to place this ore processing facility in space, let alone at an asteroid?

PMG mining is far future, after water mining provides inexpensive fuel for fuel depots and an industrial infrastructure is available in space. That's very far down the road.

Planetary Resources seems to be starting with reducing the capital costs necessary to get this started. I mean, the same exact question could've been asked about RLV development. Just because something is hard or requires a large (but minimizable!) capital cost doesn't mean it can't or won't be done.

Anyway, I think people are taking an intellectual shortcut here by just assuming it belongs to scifi fantasyland instead of figuring out how it could be done most cheaply. I did the same thing before deciding to think about it seriously. If you aren't interested in it, fine, but otherwise I'd prefer substantive critiques instead of mere opinion.

And illuminatedave: cryogenic grinding reduces the energy requirements dramatically by making the ore more brittle. You ignored that.

[AdrianW]

$100 a GRAM

From where are you getting that number? Apparently, asteroid specimen typically sell for 1-2 $/gram [1][2], rare types for more [3][4] (with the emphasis on rare – once you bring down a tonne of that stuff, it's price will plummet significantly).
Needless to say, this makes the raw asteroid material market a non-starter.

[1] http://www.meteorites-for-sale.com/gebel-kamil.html
[2] http://www.meteorites-for-sale.com/imilchil-meteorite.html
[3] http://www.aerolite.org/articles/how-much-is-a-meteorite-worth.htm
[4] http://www.meteorites-for-sale.com/dorbigny-meteorite.html

[Robotbeat]

By the way, to give an illustration of the reduction in necessary grinding energy if you cryogenically cool the ore first, see this graph which shows the impact (or tear, I think in this case) energy versus temperature for various alloys.

It's a reduction by an order of magnitude.

[llanitedave]

Tell me a hard number to use for grinding energy per ton, then. I used the best number I could find online, if you have a better one please let me know. But an actual number.

You could always rotate your facility on a tether, allowing you to use whatever gravity level is convenient. You wouldn't have to invent some new force.

Planetary Resources intends to do water mining before PGM mining, so access to water would not be an enormous obstacle by the time they're doing PGM mining.

As far as more inexpensive alternatives being found... You're making the common mistake of assuming this is being done from the perspective of scarcity instead of abundance. It's not about running out of the resource on Earth, it's about adding to Earth's resources.

You mean like pouring a cup of water into the ocean?


I can't give you a hard number for grinding energy, it varies depending on the mineralogy of the ore.  Your best number online may be just fine for Earth -- but you start talking about tethers and rotations, then we're back to the same argument about engineering of rotating space stations and the like.  You're bringing in all kinds of new and uncalculated engineering complications that make the figures that you have little more than imaginary.


If you're going to spend billions on adding material to resources that are already abundant, then I think you're going to have a lot of trouble closing a business case.  These guys need to make a profit, and spending more on obtaining a raw material from an exotic location than the material is worth on Earth doesn't strike me as a profitable endeavor.


Now, if you are heading out to the asteroid belt to live and work, and create some self-sustaining operation, then local resource extraction and processing becomes an absolute necessity.  But you're not going to be economically successful exporting your raw materials to Earth.  Even ON Earth, most nations who are primarily exporters of raw materials are impoverished nations.  The wealthy nations  export skilled, advanced manufacturing and services.  Your asteroid mine is a money loser, as are, incidentally, a pretty fair percentage of terrestrial mines.

[TrevorMonty]

There is process that separate elements by electrostatic charge. Place the ore in between to electrostatically charged plates and they will form layers. Needs zero G to work. Google it find more.

[TrevorMonty]

There is process that separate elements by electrostatic charge. Place the ore in between to electrostatically charged plates and they will form layers. Needs zero G to work. Google it find more.

Here is link. Process is called electrophoresis. Perfect for Asteroid mining.

http://www.permanent.com/space-industry-electrophoresis.html

[ChrisWilson68]

I would be more worried about cleaning and maintenance of the equipment than the energy involved.

We're talking about moving large volumes of material through the system.  It's material that will be a mix of different minerals, and we're grinding it all up.  There's going to be lots of different kinds of dust getting everywhere.  And no people around to clean it up and replace parts that wear or break or jam.

A versatile mostly-autonomous robot that can clean and fix things might be the most important technology to develop to make in-space refining of asteroid material more practical.