Differences between revisions 13 and 38 (spanning 25 versions)
 ⇤ ← Revision 13 as of 2015-12-14 22:04:48 → Size: 10547 Editor: KeithLofstrom Comment: ← Revision 38 as of 2021-04-18 00:58:37 → ⇥ Size: 16026 Editor: KeithLofstrom Comment: Deletions are marked like this. Additions are marked like this. Line 4: Line 4: [[ Rws | Really Wild Stuff ]] - A Silly Argument About So-Called Resources [[ Rws | Really Wild Stuff ]] - A Silly Argument About So-Called Resources on Earth and in Space Line 6: Line 6: Delivering space materials to earth as manufactured goods does not make much sense. The materials are not beneficiated ores, and manufacturing requires a huge and interconnected network of factories. Let's compare it to something equally silly. Delivering asteroidal materials to Earth as manufactured goods does not make much sense. The materials are not beneficiated ores, and manufacturing requires a huge and interconnected network of factories. Gravel or sand is a few dollars per tonne. The asteroids represented by nickel-iron meteorites - mostly metal - are not uniform alloys, and will need purification and blending to make an industrially useful feedstock. Extracting ppm impurities will be expensive and difficult, and will require large amounts of energy and solvents. We will do this someday, feeding the materials to projects in space, but it is unlikely they will ever be competitive with earth sourced materials. Line 8: Line 8: I have a 0.67 acre ( 2711 m², 0.2711 hectare) suburban lot. I (theoretically) own the mineral rights all the way to the center of the Earth. The earth's surface is 510 million km², or 51 billion hectares - my lot is 5.32e-12 of the surface of the earth, and the same fraction of the total mass of the earth (5.6736e24 kg), so my "share" of that is 3e13 kg. The property is above continental granite, but relatively thin - the Juan de Fuca plate, mostly basalt without beneficiated ore bodies, is subducting down into the mantle only a few kilometers beneath me. There are a few dormant volcanos nearby. Let's compare "abundant space materials" to something equally silly. Line 10: Line 10: But let's assume this volume is "average" for the Earth's composition, and make the same kind of calculations that are made for materials in asteroids. Assuming some magic way to keep the sides from collapsing, how much energy would it cost to cut a hole all the way to a point in the center and lift everything out? How much material is that, and (assuming market prices did not collapse) how much is it worth, purified to commercial grade metals? I have a 0.67 acre ( 2711 m², 0.2711 hectare) suburban lot. I (theoretically) own the mineral rights all the way to the center of the Earth. The earth's surface is 510 million km², or 51 billion hectares - my lot is 5.32e-12 of the surface of the earth, and the same fraction of the total mass of the earth (5.6736e24 kg), so my "share" of that is 3e13 kg. The property is above continental granite, but relatively thin - the Juan de Fuca plate, mostly basalt without beneficiated ore bodies, is subducting down into the mantle perhaps ten kilometers beneath me. There are a few dormant volcanos nearby. The hill that I live on is a long-extinct volcanic cinder cone, topped with glacial till, debris, and silt from the Missoula floods.Assume this volume is "average" for the Earth's composition, and make the same kind of calculations that are made for materials in asteroids. Assuming some magic way to keep the sides from collapsing, how much energy would it cost to cut a hole all the way to a point in the center and lift everything out? How much material is that, and (assuming market prices did not collapse) how much is it worth, purified to commercial grade metals and materials? Line 26: Line 28: || Th || 6 ppm || 8.58e05 kg || Thorium || 8.58e05 kg || $250/kg ||$2.1e08 |||| Hf || 3 ppm || 4.29e05 kg || Hafnium || 4.29e05 kg || $1200/kg ||$5.1e08 || Line 27: Line 31: || As || 1.5 ppm || 2.15e05 kg || Arsenic || 2.15e05 kg || $1.43/kg ||$3.1e05 || Line 29: Line 34: ||<-7> '''Mantle, 67.3%, my share is 2.02e13 kg, 35 to 2900 km'''       || ||<-7> '''Mantle, 67.3%, my share is 2.02e13 kg, 35 to 2900 km depth''' || Line 39: Line 44: ||<-7> '''Core 32.2%, my share is 9.8e12 kg, 2900 to 6370 km'''       || ||<-7> '''Core 32.2%, my share is 9.8e12 kg, 2900 to 6370 km depth''' || Line 43: Line 48: ||<-7> '''Addendum: Estimated platinum group metals in Earth's core: ratioed to iron''' ||||<-7> Iron is 185100 ppm of solar abundance, 8.33e12 kg, hence 4.5e7 kg/ppm ||||<-7> for abundances see ElementalAbundances |||| Ru || 714 || 3.21e10 kg ||<)> $x.xx/kg ||$x.xexx |||| Rh || 134 || 6.03e09 kg ||<)> $x.xx/kg ||$x.xexx |||| Pd || 557 || 2.51e10 kg ||<)> $x.xx/kg ||$x.xexx |||| Os || 669 || 3.01e10 kg ||<)> $x.xx/kg ||$x.xexx |||| Ir || 473 || 2.13e10 kg ||<)> $x.xx/kg ||$x.xexx |||| Pt || 953 || 4.29e10 kg ||<)> $x.xx/kg ||$x.xexx || Line 44: Line 58: That's 50 trillion dollars an acre. The entire earth is worth about 6e24 or six septillion dollars. Or nothing, if we wipe ourselves out trying to do this :-). See: https://en.wikipedia.org/wiki/Abundance_of_the_chemical_elements and https://en.wikipedia.org/wiki/Prices_of_elements_and_their_compounds and related pages.For prices, check the spot markets.That's 50 trillion dollars an acre. The entire earth is worth 6e24 or six septillion dollars. Or nothing, if we wipe ourselves out trying to do this :-) . Line 58: Line 76: The amount of energy to lift the slab form depth $R$ a distance of $d R_y$ is The amount of energy to lift the slab from depth $R$ a distance of $d R_y$ is Line 68: Line 86: $E ~ = ~ \rho ~ g ~ A ( R_e )^2 / 15$ $E_{lift} ~ = ~ \rho ~ g ~ A ( R_e )^2 / 15$ Line 76: Line 94: $E ~ = ~ g ~ M ~ R_e / 5$ $E_{lift} ~ = ~ 0.2 ~ g ~ M ~ R_e$ Line 78: Line 96: If $g$ = 9.8 m/s², $M$ = 3e13 kg, and $R_e$ = 6371 km, the total lift energy $E$ is 3.7e20 J, about 50 minutes of earth solar illumination, or 9 hours of 10% efficient global PV. The energy per kilogram is 12.5 MJ, or about 3.47 kilowatt hours, or a $\delta V$ equivalent of 5000 m/s. Assuming that the heat capacity of earth mantle material is 500 J/kg-K (POMA), a kilogram brought up from the 4000 K lower mantle boundary would add about 2 MJ/kg, a total of 6e19 J, about 8 minutes of total earth surface solar energy. If $g$ = 9.8 m/s², $M$ = 3e13 kg, and $R_e$ = 6371 km, the total lift energy (at 100% efficiency) $E$ is 3.7e20 J, about 50 minutes of earth solar illumination, or 9 hours of 10% efficient global PV. The energy per kilogram is 12.5 MJ, or about 3.47 kilowatt hours, or a $\delta V$ equivalent of 5000 m/s. Assuming that the heat capacity of earth mantle material is 500 J/kg-K (POMA), a kilogram brought up from the 4000 K lower mantle boundary would add about 2 MJ/kg, a total of 6e19 J, about 8 minutes of total earth surface solar energy.BTW, the above result is for lifting a tiny fraction of the Earth's mass to the surface. Launching it to escape velocity requires $E_{launch} ~ = ~ 1.2 ~ g ~ M ~ R_e$. Lift energy is a third of the energy of disassembling the entire earth and spreading it out into space, which is $E_{dissassemble} ~ = ~ 0.6 ~ g ~ M_e ~ R_e$. Line 82: Line 102: If the volume of material was shaped into a spherical asteroid, it would have a radius $R_A ~ = ~ ( A ~ R_e / 4 \pi )^{1/3} ~ = ~ 1.11 km. But since we need reaction mass, let's assume we are tossing the material off a much larger asteroid with a superhigh acceleration launcher. If the volume of material was shaped into a spherical asteroid, it would have a radius$ R_A ~ = ~ ( A ~ R_e / 4 \pi )^{1/3} ~ = ~ 1.11 km $. But since we need reaction mass, let's assume we are tossing the material off a much larger asteroid with a superhigh acceleration launcher. Line 84: Line 104: Moving a chunk of asteroid from the asteroid belt into low earth orbit is difficult - let's assume we will merely change its orbit from a circular 2 AU to an elliptical orbit between 2 AU and 1 AU, and we will use the atmosphere to bring the material down, and that the material somehow remains intact and impacts somewhere safe. We will assume it has the same composition as our hypothetical wedge of earth and is equally valuable. Moving a chunk of asteroid from the asteroid belt into low earth orbit is difficult - let's assume we will merely change its orbit from a circular 2 AU to an elliptical orbit between 2 AU and 1 AU, and we will use the atmosphere to slow the material and lower it gently, and that the material somehow remains intact and impacts somewhere safe. We will assume it has the same composition as our hypothetical wedge of earth and is equally valuable. Line 90: Line 110: Launching mass retrograde from an asteroid will eventually speed it up prograde, increasing the size of the orbit and increasing the delta V necessary for launch ('''needs analysis'''). Keeping the asteroid in the same orbit requires balancing mass launched prograde. If the amounts are equal (wasting half the asteroid, preferably the less useful fractions) the total launch energy is doubled.=== How many integrated circuits? ===MOS FETs will continue to scale and exploit new technologies, but lets assume we stop shrinking at 10 nanometer dimensions, and buildfinfets out of bars of silicon 10 nm x 10 nm x 30 nm, with metal gates and 4nm thick hafnium gate oxides. We will ignore the conductor metal used, for now, we can probably use abundant aluminum and iron and magnesium if necessary. Plenty of oxygen in air, water, and granite.The density of silicon is 2.33, !HfO₂ is 9.68, and the hafnium fraction of that is 8.40. So the mass of a transistor is:|| element || Transistor volume || density || mass || my resources |||| Silicon || 10 x 10 x 30 e-27 m³ || 2330 kg/m³ || 7.0e-21 kg || 8.67e10 kg |||| Hafnium || 3 x 10 x 10 x 4 e-27 m³ || 8400 kg/m³ || 1.0e-20 kg || 4.29e05 kg ||Transistor manufacture is limited by the abundance of Hafnium, not far more abundant silicon, so my share of the crust can produce "only" 4.3e25 transistors, a mere 40,000 times more than all the transistors in the world in 2015. Priced at 1e10 transistors per dollar, that is$4e15, or 4 quadrillion dollars. Hafnium at current prices constitutes 0.13 ppm of the cost of those transistors. The semiconductor industry's use of this rare metal is too small to impact its price.=== How much fission energy? ===Assume a technology like the integral fast reactor, that reprocesses fuel and sends the radioactive fission products back through the reactor for neutron bombardment and de-activation. Assuming 200 MeV per fission, 50 MeV lost to deactivation processes, and 33% thermal efficiency, we can expect 5e7 eV per nucleon plant output, or 4.8e12 J/mole.I don't have numbers for thorium in the mantle, but assume it follows the same 3.33 to 1 ratio to uranium as the crust.|| Crust Uranium || 2.57e5 kg || 0.238 kg/mole || 1.1e6 moles |||| Crust Thorium || 8.58e5 kg || 0.232 kg/mole || 3.7e6 moles |||| Mantle Uranium || 4.44e5 kg || 0.238 kg/mole || 1.9e6 moles |||| Mantle Thorium || 1.41e6 kg || 0.232 kg/mole || 3.3e7 moles || WAG ||||<-4>Total || 4.0e7 moles ||4e7 x 4.8e12 = 1.9e20 J, or 5.3e13 kWh. Half the energy we need for the lift. Of course, if we lift only the crust and mantle, the energy needed will be smaller. OTOH, burying the waste (and everyone elses) at the earth's core might be worth the cost of exposing it. At 4 cents per kilowatt hour, a mere 2 trillion dollars worth of energy. Line 92: Line 142: Overall, the two processes are within an order of magnitude of each other, both delivering gravitationally sorted but otherwise non-beneficiated rock of approximately equal (low) value to the earth's surface. The "core the earth" approach is obviously silly - besides access to a nickel-rich core, there many disadvantages compared to a mine 20 km deep and 67 acres in area, or a mine 200 meters deep and 6700 acres in area, which would require far less energy to remove. The product is the same - uninteresting rock, unless this was done around a concentrated ore body. ''Asteroid mining to provide raw materials to Earth is ridiculous.'' Overall, the two processes are within an order of magnitude of each other, both delivering gravitationally sorted but otherwise non-beneficiated rock of approximately equal (low) value to the earth's surface. The "core the earth" approach is obviously silly ... besides access to a nickel-rich core, there many disadvantages compared to a mine 20 km deep and 67 acres in area, or a mine 200 meters deep and 6700 acres in area, which would require far less energy to remove. The product is the same: uninteresting rock, unless this was done around a concentrated ore body. ''Asteroid mining to provide raw materials to Earth is ridiculous.'' Line 96: Line 146: Terrestrial industrial civilization took thousands of years to develop, with the whole human race participating. Please do not underestimate the effort required to recapitulate the process in a far more challenging extraterrestrial environment. It will '''never''' happen without understanding the realities of terrestrial extraction and production. Terrestrial industrial civilization took thousands of years to develop, with the whole human race participating. Please do not underestimate the effort required to recapitulate the process in a far more challenging extraterrestrial environment. It will '''never''' happen without understanding the realities of terrestrial extraction and production; the only advantage we have over our ancestors is accumulated knowledge, ''if we do not ignore it''.

# Backyard Minerals

Really Wild Stuff - A Silly Argument About So-Called Resources on Earth and in Space

Delivering asteroidal materials to Earth as manufactured goods does not make much sense. The materials are not beneficiated ores, and manufacturing requires a huge and interconnected network of factories. Gravel or sand is a few dollars per tonne. The asteroids represented by nickel-iron meteorites - mostly metal - are not uniform alloys, and will need purification and blending to make an industrially useful feedstock. Extracting ppm impurities will be expensive and difficult, and will require large amounts of energy and solvents. We will do this someday, feeding the materials to projects in space, but it is unlikely they will ever be competitive with earth sourced materials.

Let's compare "abundant space materials" to something equally silly.

I have a 0.67 acre ( 2711 m², 0.2711 hectare) suburban lot. I (theoretically) own the mineral rights all the way to the center of the Earth. The earth's surface is 510 million km², or 51 billion hectares - my lot is 5.32e-12 of the surface of the earth, and the same fraction of the total mass of the earth (5.6736e24 kg), so my "share" of that is 3e13 kg. The property is above continental granite, but relatively thin - the Juan de Fuca plate, mostly basalt without beneficiated ore bodies, is subducting down into the mantle perhaps ten kilometers beneath me. There are a few dormant volcanos nearby. The hill that I live on is a long-extinct volcanic cinder cone, topped with glacial till, debris, and silt from the Missoula floods.

Assume this volume is "average" for the Earth's composition, and make the same kind of calculations that are made for materials in asteroids. Assuming some magic way to keep the sides from collapsing, how much energy would it cost to cut a hole all the way to a point in the center and lift everything out? How much material is that, and (assuming market prices did not collapse) how much is it worth, purified to commercial grade metals and materials?

### How much fission energy?

Assume a technology like the integral fast reactor, that reprocesses fuel and sends the radioactive fission products back through the reactor for neutron bombardment and de-activation. Assuming 200 MeV per fission, 50 MeV lost to deactivation processes, and 33% thermal efficiency, we can expect 5e7 eV per nucleon plant output, or 4.8e12 J/mole.

I don't have numbers for thorium in the mantle, but assume it follows the same 3.33 to 1 ratio to uranium as the crust.

 Crust Uranium 2.57e5 kg 0.238 kg/mole 1.1e6 moles Crust Thorium 8.58e5 kg 0.232 kg/mole 3.7e6 moles Mantle Uranium 4.44e5 kg 0.238 kg/mole 1.9e6 moles Mantle Thorium 1.41e6 kg 0.232 kg/mole 3.3e7 moles WAG Total 4.0e7 moles

4e7 x 4.8e12 = 1.9e20 J, or 5.3e13 kWh. Half the energy we need for the lift. Of course, if we lift only the crust and mantle, the energy needed will be smaller. OTOH, burying the waste (and everyone elses) at the earth's core might be worth the cost of exposing it. At 4 cents per kilowatt hour, a mere 2 trillion dollars worth of energy.

### Conclusion

Overall, the two processes are within an order of magnitude of each other, both delivering gravitationally sorted but otherwise non-beneficiated rock of approximately equal (low) value to the earth's surface. The "core the earth" approach is obviously silly ... besides access to a nickel-rich core, there many disadvantages compared to a mine 20 km deep and 67 acres in area, or a mine 200 meters deep and 6700 acres in area, which would require far less energy to remove. The product is the same: uninteresting rock, unless this was done around a concentrated ore body. Asteroid mining to provide raw materials to Earth is ridiculous.

Asteroid mining to feed raw materials to simple manufacturing processes to produce objects used in the asteroid belt may be less ridiculous - except there is no factory infrastructure there. That infrastructure may grow from nothing to full local capability over hundreds or thousands of years - but please keep in mind that this growth will require new kinds of processes to manufacture new kinds of objects, and that will require a vast accumulation of new knowledge, and a vast infusion of capital to speed it up appreciably (in order to pay for all the mistakes and rapid obsolescence incurred during rapid development). It took 8 trillion dollars to develop the rocket fleet we have - use that to estimate the cost of vastly more ambitious projects.

Terrestrial industrial civilization took thousands of years to develop, with the whole human race participating. Please do not underestimate the effort required to recapitulate the process in a far more challenging extraterrestrial environment. It will never happen without understanding the realities of terrestrial extraction and production; the only advantage we have over our ancestors is accumulated knowledge, if we do not ignore it.

BackyardMinerals (last edited 2021-04-18 00:58:37 by KeithLofstrom)