6 ms·

People cut cables for copper. Imagine what will happen with cables with gold.

nwiswell 3y ago
It would be sub-10%* gold content. We're talking about gold doping, specifically substitution in the Pb(1) site, not an alloy. ETA: I was off by an order of magnitude (originally I said sub-1%) because the doping is extensive, and the mass of the lead/gold is a dominant fraction of the total. The formula given in the paper is (subscripts in brackets): Pb[10−x]Cu[x](PO4)[6]O with 0.9 < x < 1.1. Similarly for Au we would have Pb[10−x]Au[x](PO4)[6]O. Taking the centerpoint x=1, this becomes Pb[9]Au[1](PO4)[6]O. In other words, there would be one gold atom for every 9 lead atoms. The "unit cell weight" is 2647.59 g/mol, and the molar mass of gold is 196.97 g/mol, so in fact the hypothetical gold weight content is about 7.44%, not sub-1%. That said -- presumably superconducting transmission wires would be thinner than the ones we are used to (a function of critical current rather than resistance). So I'm not sure that we'd have a theft problem worse than we already have with copper.
- deleted 3y ago
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- robbintt 3y ago
  FWIW strip mining operations till materials for ~6 PPM gold.
- cperciva 3y ago
  The superconductor itself would be 7.44% gold, but the wire would probably be much less -- superconducting tape isn't particularly strong so it will probably be wrapped up in layers of insulator and support wires.
  - nwiswell 3y ago
    I think that's right. There's no indication that it's mechanically strong, so you'd have it wrapped in layers of rubber/epoxy and steel cables in order to suspend it between power poles or transmission pylons. YBCO tape has a critical current in the 1-10 MA/cm2 range, so if the properties of this RT stuff is anywhere close, the actual superconducting element of the wire could potentially be very thin.
- csteubs 3y ago
  Having to handle lead for a practically unretrievable amount of gold would (I hope) be enough of a deterrent for the vast majority of "citizen scrappers". Worst case, I think a Pb/Au scrap grey-market would look something like the current catalytic converter market, where raw materials are purchased at set rate by an intermediary and then sold for further processing. Most people know there's gold in their computer parts, but still opt for the recycling bin/ziploc bag in a junk drawer.
  - jacquesm 3y ago
    Nah, they'll just drop it in a smelter and sort it using gravity.
  - rajamaka 3y ago
    It might deter those in wealthy countries, everywhere else would be another story.
- araes 3y ago
  7.44% gold? That's ~$75 per oz of material. And you're talking about lead cable. Its kind of heavy, even if its thin. And it seems really easy to melt and separate. Notably, most power lines are actually aluminum, which is probably where people would really want this. Also chosen for its low weight / density, cause if you're gonna hang lines 100's of feet long, you want 2700 kg/m3, not 9000 kg/m3, and definitely not 11000 kg/m3. Although probably also significant applications in mm, um, and nm scale wiring.
  - neltnerb 3y ago
    At the end of their comment it notes that because it's a superconductor it would be thinner. Perhaps assume an aluminum cladding for strength? Depending on how strong of a superconductor it is perhaps it's only 1% superconductor and 99% aluminum on top of the 10% content. So 0.1%? I dunno, all these metals will be valuable in the future. Just saying, there's another large factor in estimating the gold content (conductivity saturation) that we don't know what it might be.
ajuc 3y ago
Computer components already have gold in them, and they are already recycled for gold.
- kbenson 3y ago
  There's a wide space between "can be recycled" and "profitable enough that there's theft for base components that can be resold". That doesn't mean it won't be profitable to harvest the gold (I don't know), but one does not imply the other. For example, paper recycling is profitable when centralized (barely), but even that's with most the pipeline subsidized, and it's not profitable to the degree that people are stealing paper to turn in because it's worth the effort.
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  - kragen 3y ago
    paper recycling is profitable without any subsidies at all, and people do sometimes steal paper to recycle it here in argentina there are tens of thousands of people who make a living by recycling, sorting through whatever trash they can get access to in order to find materials with enough resale value to scrape by. they haul plastic sacks or two-wheeled carts all over the metropolitan area, stacking them high with recyclables: aluminum, copper, car batteries, brass, whatever they can find. a crt tv left out on the curb will have its yoke broken off within an hour or three in order to harvest the copper. neighborhoods sometimes lose phone and internet service for months at a time because someone has recycled the cables. commemorative bronze plaques go missing from cemeteries but the recyclers are not called aluminieros or bronceros or cobreros, taking the name of their profession from aluminum, brass, or copper; they are instead referred to by the most abundant material they recycle they are the cartoneros, because what their carts are usually piled high with is cardboard, cartón (needless to say this activity is not subsidized)
    - cthalupa 3y ago
      I don't understand how your comment implies a lack of subsidy, it only states that the people harvesting the material can make money off of it. Which would be true if it was subsidized, too.
xwdv 3y ago
Gold is everywhere in computing, not a big deal.
- themagician 3y ago
  Not computing, arms manufacturing. Lead, tungsten or uranium projectiles with superconducting jackets fired from railguns.
  - ajuc 3y ago
    You would probably put the superconductor in the barrel and magnets in the ammunition :)
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Teever 3y ago
We'll use them to build spacecraft that retrieve asteroids so rich in gold that it permanently crashes the price of gold? People don't seem to realize how radically society will change if this superconductor thing is legit.
- andrepd 3y ago
  How does room temperature superconductivity lead to the feasibility of asteroid mining? Could you please explain?
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  - deleted 3y ago
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  - ars 3y ago
    Magnetic launch. See: https://en.wikipedia.org/wiki/Mass_driver https://en.wikipedia.org/wiki/Mass_driver
  - Teever 3y ago
    You could also ask "How does room temperature semiconductivity lead to the feasibility of asteroid mining?" the answer to that question is the answer to your question.
    - andrepd 3y ago
      What?
  - cpeterso 3y ago
    Asteroid mining becomes cost effective if the demand increases.
NegativeLatency 3y ago
I don't think the material is very ductile so I'm not sure that you'd be able to easily run a cable like copper/aluminum/steel transmission lines
- nwiswell 3y ago
  That would likely be addressed by vacuum deposition techniques.

It would be sub-10%* gold content. We're talking about gold doping, specifically substitution in the Pb(1) site, not an alloy. ETA: I was off by an order of magnitude (originally I said sub-1%) because the doping is extensive, and the mass of the lead/gold is a dominant fraction of the total. The formula given in the paper is (subscripts in brackets): Pb[10−x]Cu[x](PO4)[6]O with 0.9 < x < 1.1. Similarly for Au we would have Pb[10−x]Au[x](PO4)[6]O. Taking the centerpoint x=1, this becomes Pb[9]Au[1](PO4)[6]O. In other words, there would be one gold atom for every 9 lead atoms. The "unit cell weight" is 2647.59 g/mol, and the molar mass of gold is 196.97 g/mol, so in fact the hypothetical gold weight content is about 7.44%, not sub-1%. That said -- presumably superconducting transmission wires would be thinner than the ones we are used to (a function of critical current rather than resistance). So I'm not sure that we'd have a theft problem worse than we already have with copper.

deleted 3y ago
[deleted]
robbintt 3y ago
FWIW strip mining operations till materials for ~6 PPM gold.
cperciva 3y ago
The superconductor itself would be 7.44% gold, but the wire would probably be much less -- superconducting tape isn't particularly strong so it will probably be wrapped up in layers of insulator and support wires.
- nwiswell 3y ago
  I think that's right. There's no indication that it's mechanically strong, so you'd have it wrapped in layers of rubber/epoxy and steel cables in order to suspend it between power poles or transmission pylons. YBCO tape has a critical current in the 1-10 MA/cm2 range, so if the properties of this RT stuff is anywhere close, the actual superconducting element of the wire could potentially be very thin.
csteubs 3y ago
Having to handle lead for a practically unretrievable amount of gold would (I hope) be enough of a deterrent for the vast majority of "citizen scrappers". Worst case, I think a Pb/Au scrap grey-market would look something like the current catalytic converter market, where raw materials are purchased at set rate by an intermediary and then sold for further processing. Most people know there's gold in their computer parts, but still opt for the recycling bin/ziploc bag in a junk drawer.
- jacquesm 3y ago
  Nah, they'll just drop it in a smelter and sort it using gravity.
- rajamaka 3y ago
  It might deter those in wealthy countries, everywhere else would be another story.
araes 3y ago
7.44% gold? That's ~$75 per oz of material. And you're talking about lead cable. Its kind of heavy, even if its thin. And it seems really easy to melt and separate. Notably, most power lines are actually aluminum, which is probably where people would really want this. Also chosen for its low weight / density, cause if you're gonna hang lines 100's of feet long, you want 2700 kg/m3, not 9000 kg/m3, and definitely not 11000 kg/m3. Although probably also significant applications in mm, um, and nm scale wiring.
- neltnerb 3y ago
  At the end of their comment it notes that because it's a superconductor it would be thinner. Perhaps assume an aluminum cladding for strength? Depending on how strong of a superconductor it is perhaps it's only 1% superconductor and 99% aluminum on top of the 10% content. So 0.1%? I dunno, all these metals will be valuable in the future. Just saying, there's another large factor in estimating the gold content (conductivity saturation) that we don't know what it might be.

ajuc 3y ago

Computer components already have gold in them, and they are already recycled for gold.

kbenson 3y ago
There's a wide space between "can be recycled" and "profitable enough that there's theft for base components that can be resold". That doesn't mean it won't be profitable to harvest the gold (I don't know), but one does not imply the other. For example, paper recycling is profitable when centralized (barely), but even that's with most the pipeline subsidized, and it's not profitable to the degree that people are stealing paper to turn in because it's worth the effort.
- deleted 3y ago
  [deleted]
- kragen 3y ago
  paper recycling is profitable without any subsidies at all, and people do sometimes steal paper to recycle it here in argentina there are tens of thousands of people who make a living by recycling, sorting through whatever trash they can get access to in order to find materials with enough resale value to scrape by. they haul plastic sacks or two-wheeled carts all over the metropolitan area, stacking them high with recyclables: aluminum, copper, car batteries, brass, whatever they can find. a crt tv left out on the curb will have its yoke broken off within an hour or three in order to harvest the copper. neighborhoods sometimes lose phone and internet service for months at a time because someone has recycled the cables. commemorative bronze plaques go missing from cemeteries but the recyclers are not called aluminieros or bronceros or cobreros, taking the name of their profession from aluminum, brass, or copper; they are instead referred to by the most abundant material they recycle they are the cartoneros, because what their carts are usually piled high with is cardboard, cartón (needless to say this activity is not subsidized)
  - cthalupa 3y ago
    I don't understand how your comment implies a lack of subsidy, it only states that the people harvesting the material can make money off of it. Which would be true if it was subsidized, too.

xwdv 3y ago

Gold is everywhere in computing, not a big deal.

themagician 3y ago
Not computing, arms manufacturing. Lead, tungsten or uranium projectiles with superconducting jackets fired from railguns.
- ajuc 3y ago
  You would probably put the superconductor in the barrel and magnets in the ammunition :)

deleted 3y ago

[deleted]

Teever 3y ago

We'll use them to build spacecraft that retrieve asteroids so rich in gold that it permanently crashes the price of gold? People don't seem to realize how radically society will change if this superconductor thing is legit.

andrepd 3y ago
How does room temperature superconductivity lead to the feasibility of asteroid mining? Could you please explain?
- deleted 3y ago
  [deleted]
- deleted 3y ago
  [deleted]
- ars 3y ago
  Magnetic launch. See: https://en.wikipedia.org/wiki/Mass_driver https://en.wikipedia.org/wiki/Mass_driver
- Teever 3y ago
  You could also ask "How does room temperature semiconductivity lead to the feasibility of asteroid mining?" the answer to that question is the answer to your question.
  - andrepd 3y ago
    What?
- cpeterso 3y ago
  Asteroid mining becomes cost effective if the demand increases.

NegativeLatency 3y ago

I don't think the material is very ductile so I'm not sure that you'd be able to easily run a cable like copper/aluminum/steel transmission lines

nwiswell 3y ago
That would likely be addressed by vacuum deposition techniques.