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producing metal in space
What equipment, materials and amount of electricity are needed to
produce steel (in space) from ores found on NEOs? Would there be a need to add carbon (as a reducing agent) during the refining process, or something with characteristics similar to limestone (I believe calcium oxide is the "active ingredient" in limestone)? Would oxygen be needed for a blast furnace? Would water be needed to quench the hot steel? Another question I have is, How would something like a mini-mill be modified to function in zero-G and vacuum? I had thought something like an electric arc furnace would be all that's needed to refine pure iron/steel from NEO ores, but from what I can find, EAFs appear to be used almost exclusivly for refining scrap steel. |
#2
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producing metal in space
On Aug 25, 6:59 pm, byblow wrote:
What equipment, materials and amount of electricity are needed to produce steel (in space) from ores found on NEOs? It depends on the object. Some of them, 1986 DA for example, are thought to be solid nickel-iron. Depending on what you wanted to do with it, the material could be melted using an open ended induction furnace, electromagnetically pumped out and rolled into I beams. If you wanted the nickel, roll the metal into thin strips, and run it though a number of gas lock stages into a 15 Bar (750 psi) long chamber with warm flowing carbon monoxide. The nickle, iron and cobalt carbonals can be sorted out of the gas stream and reduced back to metals. See Mond process. The dust contains the rest of the elements, including platinum group metals, gold and copper. Dr. John Lewis, http://en.wikipedia.org/wiki/John_S._Lewis, has done a lot on this topic. Would there be a need to add carbon (as a reducing agent) during the refining process, or something with characteristics similar to limestone (I believe calcium oxide is the "active ingredient" in limestone)? Would oxygen be needed for a blast furnace? Would water be needed to quench the hot steel? Depends on what you are starting with, but generally no. Another question I have is, How would something like a mini-mill be modified to function in zero-G and vacuum? Vapor deposition is one way to make sheet metal or other fabricated items. Sorting out non metallic inclusions may take some kind of induced g forces. I had thought something like an electric arc furnace would be all that's needed to refine pure iron/steel from NEO ores, but from what I can find, EAFs appear to be used almost exclusivly for refining scrap steel. I think induction is a better way to heat metal in space. Keith Henson |
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producing metal in space
On Aug 26, 8:30 pm, Keith Henson wrote:
On Aug 25, 6:59 pm, byblow wrote: What equipment, materials and amount of electricity are needed to produce steel (in space) from ores found on NEOs? It depends on the object. Some of them, 1986 DA for example, are thought to be solid nickel-iron. Depending on what you wanted to do with it, the material could be melted using an open ended induction furnace, electromagnetically pumped out and rolled into I beams. So the nickel-iron on a metallic NEO (like 1986 DA) is totally pure and doesn't need to be refined? Does it become nickel *steel* after it's melted? Do you happen to know how many kilowatt hours it would take to melt a tonne of nickel-iron using induction heating? How about to melt 100 tonnes? |
#4
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producing metal in space
On Aug 29, 8:07 pm, byblow wrote:
On Aug 26, 8:30 pm, Keith Henson wrote: On Aug 25, 6:59 pm, byblow wrote: What equipment, materials and amount of electricity are needed to produce steel (in space) from ores found on NEOs? It depends on the object. Some of them, 1986 DA for example, are thought to be solid nickel-iron. Depending on what you wanted to do with it, the material could be melted using an open ended induction furnace, electromagnetically pumped out and rolled into I beams. So the nickel-iron on a metallic NEO (like 1986 DA) is totally pure and doesn't need to be refined? It's hardly pure in the sense that it's got lots of different elements in it and we don't yet have samples so we are not certain about what's in it. As for needing to be refined, it depends on what you want to use it for. Construction grade I beams, probably not. Does it become nickel *steel* after it's melted? It's been melted, billions of years ago. As for what you call it, steel is what we call iron reduce from ore and refined to specific composition. Do you happen to know how many kilowatt hours it would take to melt a tonne of nickel-iron using induction heating? How about to melt 100 tonnes? It's easy enough to figure out. Iron is close enough to 56 g/mol. A kg would be 17.8 mols. The specific heat is 25 J/mol/deg K. or 446 J/ kg/deg K. Iron melts at 1800 deg K. so figure heating it 1600 deg. That would take ~714 kJ/kg. The heat of fusion is 13.8 kJ/mol or 246 kJ/kg, around 960 kJ/kg to heat and melt. Given this is rough use 1000 kJ/kg. A kJ is a kW-s, so a 1000 kW (a MW) would heat and melt a kg/s. Over an hour it would melt 3600 kg or 3.6 tons per MW per hour. 100 tons would take 27.8 MWh to melt. This doesn't consider the thermal radiation loss from the induction furnace. In the context of a serious mining project, a kg/s doesn't amount to much. The Morenci mine in Arizona processes a million tons per day or around 11,000 kg/s. A 5 GW power satatellite using 1 GW for the induction furnace would melt 1000 kg/s. The estimated mass is 2 x 10^13 kg so at this rate it would take 2 x 10^10 s to use it up or 634 years. |
#5
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producing metal in space
In sci.space.tech message abcbfb6e-6d12-4cb1-b7a5-2459d2c2d030@l2g2000v
bn.googlegroups.com, Mon, 29 Aug 2011 23:07:23, byblow posted: So the nickel-iron on a metallic NEO (like 1986 DA) is totally pure and doesn't need to be refined? Does it become nickel *steel* after it's melted? Do you happen to know how many kilowatt hours it would take to melt a tonne of nickel-iron using induction heating? The figures necessary for a reasonable estimate are easily found in http://en.wikipedia.org/wiki/Iron. How about to melt 100 tonnes? About a hundred times as much. There ought to be research on what useful can be made just by casting from a melt of metallic or stony asteroid material. For many purposes, ISTM, refining would be an unnecessary refinement. -- (c) John Stockton, nr London, UK. Turnpike v6.05 MIME. Web http://www.merlyn.demon.co.uk/ - FAQqish topics, acronyms and links; Astro stuff via astron-1.htm, gravity0.htm ; quotings.htm, pascal.htm, etc. No Encoding. Quotes before replies. Snip well. Write clearly. Don't Mail News. |
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