gary@ke4zv.UUCP (Gary Coffman) (06/13/91)
In article <1991Jun12.073415.12543@sequent.com> szabo@sequent.com writes: > >Back to platinum: we have a total of 55 ppm platinum group, about 5 >times better than the best Earth ore. This still wouldn't be that >good, given the high costs of launching mining equipment, except >that there exists a process which, taking advantage of the large >amounts of solar-thermal power available in space, could make >extracting the platinum economical. Seems the only solar-thermal power you need is enough to boil water (100C). We can get that much solar-thermal on the surface of the Earth. That kind of low level process heat, boiling water temperatures, is available from a multitude of sources here on Earth cheaper than going to space to find it. >First, we should find grains with the above concentrations or better >in a high-metal regolith (a task for space exploration). We >extract the metal grains with a magnetic rake. Next, we process After first crushing the ore. Seriously big crusher. 999,945 parts per million waste. Lots of maintenance and replacement parts. >the metal regolith with the gaseous carbonyl process, as follows: > >First phase: > >Treat the regolith with CO at c. 5 atm pressure, 100 degrees >C. This forms a vapor of gaseous carbonyl compounds. >Nickel and iron are selectively deposited in pure metallic form >by lowering the pressure and/or increasing the temperature. >The CO is released and recycled. The residue has a Pt-group >concentration of 5,000 ppm, and Ga/Ge/As at 15,000 to 20,000 ppm. Very big heavy pressure vessel made of non-reactive material. Lots of CO, tankage, pumps, etc. Heavy maintenance and replacement parts. Makeup CO. >Second phase: > >Treat the residue with moist CO at 100 atm near 100 degrees C. >This deposits out cobalt. What is left is largely Pt group >and Ga/Ge/As, and is worth $20,000 per kg at today's prices. >The water and CO are again recycled. Big super heavy pressure vessel. More CO and water, tanks, pumps, etc. More maintenance and replacement parts. Make up CO and water. Moving masses of matter in and out of the high pressure chamber to vaccum will suffer high CO and water losses. >This technique, called the gaseous carbonyl process, is currently >used at the Sudbury mine in Ontario, primarily to extract the nickel, >and secondarily to extract the c. 5 ppm platinum. By some accounts >the Sudbury ore is actually the remains of an impacted asteroid, >but I won't get into _that_ broohaha. :-) > >If we want to get the pure elements additional processing is >required. > >Which brings us to the billion dollar question: how soon will we have >sufficient knowledge (through exploration) and technology (through >research and prototyping) to be able to undertake this projects for >less than $10 billion? Without dirt cheap heavy lift and regular on-site maintenance and replenishment capability, never. Without a station and it's support systems, never. Without men on-site, never. Gary
webber@world.std.com (Robert D Webber) (06/16/91)
In article <1991Jun12.073415.12543@sequent.com> szabo@sequent.com writes: > >The best data we have come from the asteroid samples fallen to Earth, >meteorites, many of which contain metal or metal grains from core >material. The best platinum-group concentrations have been >found in the metal grains of LL-type chondrites, as follows: > [...numbers in the tens of ppm deleted...] > >As an aside, they also contain 1-15 ppm gallium, 200 ppm germanium, and >1.2 ppm arsenic. Space Industries Inc. is currently working on a >wake shield to produce large volumes of very high vacuum, which can >be used with microgravity to create GaAs and other semiconductors >with much greater purity than in Earthside semiconductor fabs. Back in semiconductor fabrication class they always told us the biggest contamination problem came from the container, and that the high vapour pressure of arsenic led to a need for either As pressurization or some kind of complete encapsulation for the melt. In the absence of a container the composition of the GaAs crystal comes out wrong, so I don't see how the "very high vacuum" will help fabrication operations for the materials used to make devices. >Back to platinum: we have a total of 55 ppm platinum group, about 5 >times better than the best Earth ore. This still wouldn't be that >good, given the high costs of launching mining equipment, except >that there exists a process which, taking advantage of the large >amounts of solar-thermal power available in space, could make >extracting the platinum economical. > >First, we should find grains with the above concentrations or better >in a high-metal regolith (a task for space exploration). We >extract the metal grains with a magnetic rake. Next, we process >the metal regolith with the gaseous carbonyl process, as follows: You will need to break the hunk of rock down in size quite a bit, first. On the ground this is generally accomplished by crushing in rather large, heavy machines, then grinding in a mill where balls or rods are raised from and dropped back onto the material to be ground. Obviously the term "dropped" implies the machine's presence in a gravity field. I suppose that some other accelerating field could be substituted. Anyway, the grinding medium in a conventional process needs to be dense so that the individual grinding elements have a lot of kinetic energy for a small surface area: this allows a lot of K.E. to be transformed into the energy of new surfaces during the grinding process in a short period of time. What are you proposing as an alternative to this very much earthbound, heavyweight technology? You definitely need something to get the mineral particles down to liberation size in the process you describe. > >First phase: > >Treat the regolith with CO at c. 5 atm pressure, 100 degrees >C. This forms a vapor of gaseous carbonyl compounds. [...some details of carbonyl processing deleted...] >The water and CO are again recycled. So how much does it cost to get the carbon monoxide and water up there in the first place? I would guess that you can ship up oxygen and make the monoxide on the spot, once you ship up or build the requisite process equipment, but shipping water around seems like a somewhat bad idea. Incidentally, you will need a fair bit of material for the carbonyl process fixtures as well. The units I saw on a tour of the Inco facilities in Sudbury were pretty massive, though I'll grant you that a space facility can be less concerned about accidental carbonyl releases than an earth-based one. One other point: you get metals back out of the carbonyl state by plating them out on metallic seeds. If your particles are all down to liberation size, I'd be willing to bet real money that a lot of platinide dust will end up blowing around in the carbonyl tank and getting trapped by nickel/ cobalt/iron shell growth on a seed. >This technique, called the gaseous carbonyl process, is currently >used at the Sudbury mine in Ontario, primarily to extract the nickel, >and secondarily to extract the c. 5 ppm platinum. By some accounts >the Sudbury ore is actually the remains of an impacted asteroid, >but I won't get into _that_ broohaha. :-) There are several operators and a number of mines and mills in the Sudbury, Ontario area. The carbonyl plant is located (if my memory of my visit hasn't spoiled since it's been defrosted) at one of Inco's facilities, as noted above. However, precious metals are typically recovered from anode slime which collects at the bottoms of electrolytic cells during electrowinning, having precipitated out of molten sulphide as very fine metallic particles. Further separation of gold and platinides is carried out by additional electrochemical processing. The last I heard, the theory was that the high-grade sulphide ore being mined at Sudbury was formed by an upwelling in crustal cracks after a meteor strike. The actual material involved in the meteor seems unlikely to have produced the millions of tons of material which have been mined in the Sudbury area. >If we want to get the pure elements additional processing is >required. No kidding?! I've often wondered whether any of the people who figure that metallurgical operations in space would be simple have ever visited an earthside metals extraction plant. It ain't simple down here, guys, and the size and cost of even crude equipment is pretty staggering for somebody used to stuff like computers. Our state of knowledge for most extraction processes, and for the systems from which we're extracting values, is pretty poor, too: we've come a long way from Agricola, but not as far as it is to what you want to do, and in nowhere nearly as little time.
webber@world.std.com (Robert D Webber) (06/16/91)
After I posted an article to this group regarding some errors in and difficulties not mentioned in one of Nick Szabo's postings on extracting platinides and other materials from an asteroid, I came across the answer to my own question in another of his postings: the oxygen and water to be used in processing the metals will come from previously gathered ice chunks. To me this makes the scheme seem even less likely, or at least less predictable, since one has to assume that yet another whole range of technical problems have been overcome cheaply.
szabo@sequent.com (06/16/91)
In article <1991Jun16.000359.10311@world.std.com> webber@world.std.com (Robert D Webber) writes: [Excellent article re: asteroid mining] >In the absence of a container the composition of the GaAs crystal comes >out wrong... This is an interesting statement; why does this occur? >>First, we should find grains with the above concentrations or better >>in a high-metal regolith (a task for space exploration). We >>extract the metal grains with a magnetic rake. Next, we process >>the metal regolith with the gaseous carbonyl process, as follows: > >You will need to break the hunk of rock down in size quite a bit, first... I agree that breaking down the solid metal is difficult. I don't propose to do that for the first mining projects. I am looking for metal regolith (dust and flakes) that is ready to melt. This is known to exist in very small percentages scattered on the Lunar surface, and probably exists in much higher concentrations, perhaps up to >90%, on the surface of metallic asteroids. Alternatively, brittle chondrites contain up to 30% metal flakes and this can be crushed and raked with a magnet to get nearly pure metal regolith. Exploration can make the mining operations much simpler by pointing out the most easily processed material. >So how much does it cost to get the carbon monoxide and water up there >in the first place? Good question. The answer is that comets, carbonaceous chondrite asteroids, and possibly comet fragments in meteor showers contain carbon compounds including carbon monoxide, and also contain abundant water. The ice can be captured using solar thermal engines and the ice itself as reaction mass. The ice-mining operation will have to pay for itself in terms of reaction mass, shielding, heat sinks, and fuel manufactured from the ice materials and used in Earth orbit. I call this "ice bootstrapping" since ice as reaction mass can be used to lift more equipment to catch more chunks of ice, etc. until the cost of fuel, heat sinks, and shielding in Earth orbit is very low. As you point out rock and metal processing is quite non-trivial. In comparison, however, ice mining requires little more than a mirror, bag, and simple distillery. After the ice bootstrapping takes place, it will be much easier to lift heavy mining equipment out to the asteroids, or alternatively bring raw asteroid regolith to Earth orbit and process it there. The ice also provides the water and carbon monoxide needed for the carbonyl process. Volatile mining will likely be the first use of extraterrestrial materials, but it cannot occur until we have explored the earth-crossing asteroids and meteor showers sufficiently to find good sources of ice, or, failing that, the highest concentrations of water of hydration and carbon in chondrites. >Incidentally, you will need a fair bit of material for the >carbonyl process fixtures as well. The units I saw on a tour of the >Inco facilities in Sudbury were pretty massive, though I'll grant you >that a space facility can be less concerned about accidental carbonyl >releases than an earth-based one. This is a rather underated aspect of space industry. In the long run, it can replace many Earthside industries that really should not be conducted in the middle of an ecosystem. In the short run, the ability to work outside the ecosystem can make some processes significantly cheaper. I am not sure to what extent the carbonyl process is an example; can any readers shed more light on this? >>If we want to get the pure elements additional processing is >>required. > >No kidding?! :-) At this point the impure mixture of platinum-group elements, gallium, arsenic, and other stuff is already worth $20,000/kg. The rest of the processing can be done on Earth. If we want to use any of these in the pure form in orbit, we need the "additional processing." >I've often wondered whether any of the people who figure that metallurgical >operations in space would be simple have ever visited an earthside >metals extraction plant. I share your impatience. In the space community there is an underestimation of mining engineering across the spectrum of mining operations. Many "Manned Mars Mission" scenarios, for example, propose extracting fuel from extraterrestrial regolith and assume that the mining engineering is going to be trivial without detailed analysis or, for that matter, even bothering to ask a mining engineer. Mining equipment is itself difficult; mining equipment in vacuum and microgravity will take much engineering and trial and error before we get it right. On the other hand, if we use the abundant thermal energy, microgravity, and vacuum to full advantage, some of the processes become much easier. (Some become much harder, so we don't use those). That is my other pet peeve on this subject. Merely transfering Earth mining techniques into space is stupidity. We need to take full advantage of the new environment. Much work has to be done to determine which processes gain the most advantage, what new processes are made possible, and how much can be done with the least mass of equipment. The actual mines will bear very little outward resemblence to their Earthside counterparts. At $3.4 billion/year for just the platinum-group elements, billions more for space-manufactured semiconductors, alloys, and other products, and potentially tens of billions per year for solar power satellites, there is quite a bit of incentive for that work to get done. -- Nick Szabo szabo@sequent.com Embrace Change... Keep the Values... Hold Dear the Laughter... These views are my own, and do not represent any organization.
szabo@sequent.com (06/16/91)
In article <1991Jun16.003812.11369@world.std.com> webber@world.std.com (Robert D Webber) writes: [Use ice as source for water and carbon monoxide for asteroid material processing] >To me this makes the scheme seem even less likely, or at >least less predictable, since one has to assume that yet another whole >range of technical problems have been overcome cheaply. This is why the ice mining industry needs to be self-supporting outside of platinum mining. Indeed, this is a general principle that central planners usually miss out on -- the technology needs to evolve in such a way that each step is self-sufficient. Grand schemes to mine the platinum right now, without having first done the exploration and developed the simpler industries, would likely end in financial disaster. Ice can provide reaction mass, fuel, shielding, and heat sinks for Earth orbiting spacecraft, so that ice mining, if undertaken with sufficiently low costs, can pay for itself with current markets. How soon this will become possible depends on whether or not, and how soon, we discover earth-crossing ice, or as a second choice high concentrations of water of hydration, in good trajectories. It also depends on our ability to reduce the cost of automated missions on the order of complexity of CRAF and Phobos. Currently CRAF is in sad shape, using 70's-era computer chips and having to drop the penetrator. We all know what happened to Phobos. :-( We need to be a generation or two beyond that. -- Nick Szabo szabo@sequent.com Embrace Change... Keep the Values... Hold Dear the Laughter... These views are my own, and do not represent any organization.
carl@sol1.gps.caltech.edu (Carl J Lydick) (06/16/91)
In article <1991Jun16.000359.10311@world.std.com>, webber@world.std.com (Robert D Webber) writes: >Back in semiconductor fabrication class they always told us the biggest >contamination problem came from the container, and that the high vapour >pressure of arsenic led to a need for either As pressurization or some >kind of complete encapsulation for the melt. In the absence of a >container the composition of the GaAs crystal comes out wrong, so I >don't see how the "very high vacuum" will help fabrication operations >for the materials used to make devices. You're assuming that the semiconductors will be doped via a diffusion process, in which case you're right. However, if you want to use ion implantation, high vacuum is useful. >>Back to platinum: we have a total of 55 ppm platinum group, about 5 >>times better than the best Earth ore. This still wouldn't be that >>good, given the high costs of launching mining equipment, except >>that there exists a process which, taking advantage of the large >>amounts of solar-thermal power available in space, could make >>extracting the platinum economical. >> >>First, we should find grains with the above concentrations or better >>in a high-metal regolith (a task for space exploration). We >>extract the metal grains with a magnetic rake. Next, we process >>the metal regolith with the gaseous carbonyl process, as follows: > >You will need to break the hunk of rock down in size quite a bit, first. >On the ground this is generally accomplished by crushing in rather large, >heavy machines, then grinding in a mill where balls or rods are raised >from and dropped back onto the material to be ground. Obviously the >term "dropped" implies the machine's presence in a gravity field. I suppose >that some other accelerating field could be substituted. Anyway, the >grinding medium in a conventional process needs to be dense so that the >individual grinding elements have a lot of kinetic energy for a small >surface area: this allows a lot of K.E. to be transformed into the energy >of new surfaces during the grinding process in a short period of time. >What are you proposing as an alternative to this very much earthbound, >heavyweight technology? You definitely need something to get the mineral >particles down to liberation size in the process you describe. He said they'd be using the regolith. This means it's already quite friable. -------------------------------------------------------------------------------- Carl J Lydick | INTERnet: CARL@SOL1.GPS.CALTECH.EDU | NSI/HEPnet: SOL1::CARL
rockwell@socrates.umd.edu (Raul Rockwell) (06/17/91)
Nick Szabo: ... rock and metal processing is quite non-trivial. In comparison, however, ice mining requires little more than a mirror, bag, and simple distillery. After the ice bootstrapping takes place, it will be much easier to lift heavy mining equipment out to the asteroids, or alternatively bring raw asteroid regolith to Earth orbit and process it there. Why process in Earth orbit? Seems to me that you could do quite a lot, in terms of smelting, or whatever, by processing during the transfer orbit. Sure, it would take a few years, but so what? -- Raul <rockwell@socrates.umd.edu>
sking@nowhere.uucp (Steven King) (06/17/91)
Of course, all of this presumes that even if you were to get
there and the processes were viable, that the asteriod is yours
to mine. International law, as I understand it, is less than clear
on this issue. A few billion in precious metals might buy a lot
of influence, but it would also buy a lot of envy.
--
If it don't stick, stink, or sting
It ain't from Texas.
..!cs.utexas.edu!ut-emx!nowhere!skingszabo@sequent.com (06/17/91)
In article <ROCKWELL.91Jun16134443@socrates.umd.edu> rockwell@socrates.umd.edu (Raul Rockwell) writes: >Why process in Earth orbit? Seems to me that you could do quite a >lot, in terms of smelting, or whatever, by processing during the >transfer orbit. Sure, it would take a few years, but so what? Two problems: lifting the heavy processing equipment out to the asteroid, and the round-trip light time for teleoperation. On the other hand, capturing volatiles and raw regolith into Earth orbit will take fairly little equipment and energy, if Earth gravity assist and/or slow aerobraking are used. See previous postings in sci.space for the safety issues involved (a crude summary is that gravity assist and slow aerobraking of small amounts of regolith and ice are fine; fast aerobraking and large solid pieces can be dangerous). Once we have the volatiles and asteroid materials in Earth orbit, equipment can be built and launched from Earth to process the materials into the final products (fuel, heat sinks, shielding, Pt-group metals, new alloys, semiconductors, solar power satellites, etc.). -- Nick Szabo szabo@sequent.com Embrace Change... Keep the Values... Hold Dear the Laughter... These views are my own, and do not represent any organization.
aws@iti.org (Allen W. Sherzer) (06/17/91)
In article <1991Jun17.021943.6721@sequent.com> szabo@sequent.com writes: >>Why process in Earth orbit? Seems to me that you could do quite a >>lot, in terms of smelting, or whatever, by processing during the >>transfer orbit. Sure, it would take a few years, but so what? >Two problems: lifting the heavy processing equipment out to the >asteroid, That shouldn't be a problem. After all, most of the energy and cost is spent getting to LEO. After you get to LEO you are half way to anywhere. >and the round-trip light time for teleoperation. So we send people. Allen -- +---------------------------------------------------------------------------+ |Allen W. Sherzer | DETROIT: Where the weak are killed and eaten. | | aws@iti.org | | +---------------------------------------------------------------------------+
wreck@fmsrl7.UUCP (Ron Carter) (06/19/91)
In <1991Jun16.234110.7241@nowhere.uucp> sking@nowhere.uucp (Steven King) writes: > Of course, all of this presumes that even if you were to get > there and the processes were viable, that the asteriod is yours > to mine. International law, as I understand it, is less than clear > on this issue. A few billion in precious metals might buy a lot > of influence, but it would also buy a lot of envy. Q: How do spacers pay their taxes? A: In gold and platinum, at terminal velocity. The nice thing about moving ton-sized payloads around space is that you can always arrange to drop one, or a few. (Use slag or iron, that way nobody is going to WANT to be the recipient.) If someone gets too envious, you can at least make them keep their head down. I'd suggest paying taxes to the USA or EEC, which are not going to want to jeapordize their revenue stream and will defend it against other entities.