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I guess major equipment items weighing many tons could be used as ore deposits, but most iron is not that. Your nails/screws/whatever are pretty much unrecovera

I guess major equipment items weighing many tons could be used as ore deposits, but most iron is not that. Your nails/screws/whatever are pretty much unrecoverable once corroded. In other words, humans are not an exception to the global entropy growth.

defrost 3y ago
News today, two killed in Texas when 158 tonnes of steel rolls off the back of four low loaders - a single massive heavy guage pipe segment with in line pressure vessels and bleed off tee pieces likely destined for a oil|gas processing plant. Point being, there are massive metal deposits in industrial ares and mineral | energy processing plants - raw girders, fleets of 100 tonne+ trucks, crushers, screen sections, etc. Of some interest, one of many papers* on adaptive metal work by "stone age" people https://www.asha.org.au/pdf/australasian_historical_archaeology/20_04_Harrison.pdf https://www.asha.org.au/pdf/australasian_historical_archaeol... turning horseshoes into spear points, etc. Might even be the same paper that describes people making their own forges from scratch to work recovered iron. Yes, things corrode, but not all things, some get isolated from oxygen and found again. * Not the one I was thinking of, apologies - there's a good one I'll have to work to find that goes into more detail and range on "outsider" metal working.
- flir 3y ago
  There's use of meteoric iron from pre-iron-age societies, too (most famously https://en.wikipedia.org/wiki/Tutankhamun%27s_meteoric_iron_dagger https://en.wikipedia.org/wiki/Tutankhamun%27s_meteoric_iron_... and see "Bronze Age" on this page https://en.wikipedia.org/wiki/Meteoric_iron https://en.wikipedia.org/wiki/Meteoric_iron)
- kragen 3y ago
  jojobas said, 'in "deep future" where all metals have corroded away', and was talking about aluminum casting. given that we have lead artifacts from level ix of çatal höyük (about 8000 years ago?) and that aluminum seems to be even longer lasting than lead, they are presumably talking about a 'deep future' of tens or hundreds of thousands of years in the future, if not millions to hundreds of millions. the 158 tonnes of steel you're talking about will almost certainly become 226 tonnes of hematite long before that. (the oldest surviving iron artifacts are only 5400 years old, the gerzeh beads, and those are entirely oxidized despite being meteoric iron and preserved in dry egypt¹.) 200 tonnes of hematite is not a massive deposit; the minas rio mine produces about 23000000 tonnes of iron every year from a single deposit, and it's far from the world's largest, so a 'massive' deposit of iron needs to be billions of tonnes, not hundreds your hypothetical rusted pipe is an especially rich deposit, and perhaps an especially accessible one, and maybe (if kept away from oxygen, as you point out, or from water) one that doesn't require smelting, but not a massive one the massive deposits, if human-created rather than things like untouched banded iron formations, will be things like landfills rather than oil pipelines or fleets of 100 tonne+ trucks. the apex regional landfill in las vegas currently contains 50 million tonnes of waste and may be close to a billion before it's full, and larger landfills can be built in the future ______ ¹ rehren et al. say, 'The ToF-ND testing for grain size and crystal lattice structure of any metallic phases present in the beads found no metallic form of iron in any of the three beads. (...) typical for the corrosion products of iron, and the absence of metallic iron above the detectable minimum mass of about 10 mg indicates that the samples are to more than [sic] 99.9% corroded, with virtually no metallic form of iron remaining. The noticeable magnetism of the beads is probably due to the presence of magnetite(...)'
HeyLaughingBoy 3y ago
And that right there explains why needing to "bootstrap manufacturing" at this level is a pure fantasy. There's no conceivable future in which it would be necessary. Every country on the planet has existing machine tools that, no matter their condition, would be easier to restore than building them from scratch by smelting iron, melting aluminum, etc. Even in the case where you can't get old machine tools and fix them, there are people using e.g., old engine blocks and crankshafts as lathe headstocks. There is simply so much technology cast-offs in the world that can be repurposed into usable items that I think the whole "manufacturing bootstrap" concept is misguided. But I'll admit that it's a fun mental exercise on a boring afternoon.
kragen 3y ago
a nail rusted into a lump of hematite is still a lump of very rich ore, and the hazard and labor involved in fishing it out of a pile of rotted wood is not disproportionate to the hazard and labor involved in reducing it back to iron, either by artisanal manual processes or by mass-production processes. artisanal manual processes require tens of person-days per kilogram of iron. see christopher roy's documentary https://www.youtube.com/watch?v=RuCnZClWwpQ https://www.youtube.com/watch?v=RuCnZClWwpQ your point about entropy is confused; it's reminiscent of the creationist argument that evolution is impossible because it produces more ordered structures from less ordered ones. yes, human activities do increase entropy, mostly in the form of slightly increasing the amount of infrared radiation into space from earth, but less so than other biological activities they displace. this is almost completely irrelevant to the question of whether landfills are richer or poorer ore deposits than banded iron formations or karst bauxite deposits, because the contribution of that term to the system's total entropy change is insignificantly small, and can therefore easily be positive or negative

defrost 3y ago

News today, two killed in Texas when 158 tonnes of steel rolls off the back of four low loaders - a single massive heavy guage pipe segment with in line pressure vessels and bleed off tee pieces likely destined for a oil|gas processing plant. Point being, there are massive metal deposits in industrial ares and mineral | energy processing plants - raw girders, fleets of 100 tonne+ trucks, crushers, screen sections, etc. Of some interest, one of many papers* on adaptive metal work by "stone age" people https://www.asha.org.au/pdf/australasian_historical_archaeology/20_04_Harrison.pdf https://www.asha.org.au/pdf/australasian_historical_archaeol... turning horseshoes into spear points, etc. Might even be the same paper that describes people making their own forges from scratch to work recovered iron. Yes, things corrode, but not all things, some get isolated from oxygen and found again. * Not the one I was thinking of, apologies - there's a good one I'll have to work to find that goes into more detail and range on "outsider" metal working.

flir 3y ago
There's use of meteoric iron from pre-iron-age societies, too (most famously https://en.wikipedia.org/wiki/Tutankhamun%27s_meteoric_iron_dagger https://en.wikipedia.org/wiki/Tutankhamun%27s_meteoric_iron_... and see "Bronze Age" on this page https://en.wikipedia.org/wiki/Meteoric_iron https://en.wikipedia.org/wiki/Meteoric_iron)
kragen 3y ago
jojobas said, 'in "deep future" where all metals have corroded away', and was talking about aluminum casting. given that we have lead artifacts from level ix of çatal höyük (about 8000 years ago?) and that aluminum seems to be even longer lasting than lead, they are presumably talking about a 'deep future' of tens or hundreds of thousands of years in the future, if not millions to hundreds of millions. the 158 tonnes of steel you're talking about will almost certainly become 226 tonnes of hematite long before that. (the oldest surviving iron artifacts are only 5400 years old, the gerzeh beads, and those are entirely oxidized despite being meteoric iron and preserved in dry egypt¹.) 200 tonnes of hematite is not a massive deposit; the minas rio mine produces about 23000000 tonnes of iron every year from a single deposit, and it's far from the world's largest, so a 'massive' deposit of iron needs to be billions of tonnes, not hundreds your hypothetical rusted pipe is an especially rich deposit, and perhaps an especially accessible one, and maybe (if kept away from oxygen, as you point out, or from water) one that doesn't require smelting, but not a massive one the massive deposits, if human-created rather than things like untouched banded iron formations, will be things like landfills rather than oil pipelines or fleets of 100 tonne+ trucks. the apex regional landfill in las vegas currently contains 50 million tonnes of waste and may be close to a billion before it's full, and larger landfills can be built in the future ______ ¹ rehren et al. say, 'The ToF-ND testing for grain size and crystal lattice structure of any metallic phases present in the beads found no metallic form of iron in any of the three beads. (...) typical for the corrosion products of iron, and the absence of metallic iron above the detectable minimum mass of about 10 mg indicates that the samples are to more than [sic] 99.9% corroded, with virtually no metallic form of iron remaining. The noticeable magnetism of the beads is probably due to the presence of magnetite(...)'

HeyLaughingBoy 3y ago

And that right there explains why needing to "bootstrap manufacturing" at this level is a pure fantasy. There's no conceivable future in which it would be necessary. Every country on the planet has existing machine tools that, no matter their condition, would be easier to restore than building them from scratch by smelting iron, melting aluminum, etc. Even in the case where you can't get old machine tools and fix them, there are people using e.g., old engine blocks and crankshafts as lathe headstocks. There is simply so much technology cast-offs in the world that can be repurposed into usable items that I think the whole "manufacturing bootstrap" concept is misguided. But I'll admit that it's a fun mental exercise on a boring afternoon.

kragen 3y ago

a nail rusted into a lump of hematite is still a lump of very rich ore, and the hazard and labor involved in fishing it out of a pile of rotted wood is not disproportionate to the hazard and labor involved in reducing it back to iron, either by artisanal manual processes or by mass-production processes. artisanal manual processes require tens of person-days per kilogram of iron. see christopher roy's documentary https://www.youtube.com/watch?v=RuCnZClWwpQ https://www.youtube.com/watch?v=RuCnZClWwpQ your point about entropy is confused; it's reminiscent of the creationist argument that evolution is impossible because it produces more ordered structures from less ordered ones. yes, human activities do increase entropy, mostly in the form of slightly increasing the amount of infrared radiation into space from earth, but less so than other biological activities they displace. this is almost completely irrelevant to the question of whether landfills are richer or poorer ore deposits than banded iron formations or karst bauxite deposits, because the contribution of that term to the system's total entropy change is insignificantly small, and can therefore easily be positive or negative