5 ms·

In particular, lead is still extremely common in radiation shielding, possibly because the drop in demand for other applications made it so cheap. Lead-lined dr

by scythe 3y ago

In particular, lead is still extremely common in radiation shielding, possibly because the drop in demand for other applications made it so cheap. Lead-lined drywall is the default approach for setting up a radiography, fluoroscopy or CT suite.

thayne 3y ago
> possibly because the drop in demand for other applications made it so cheap Maybe a little bit. But I think it is more that it is a material with heavy atomic nuclei and high density, and thus effective at blocking radiation. And it is also relatively cheap.
- scythe 3y ago
  Lead is absurdly cheap. One dollar a pound! Cheaper than much more common metals like aluminum or magnesium. So I diagnose a low demand. They used to talk about using barium cement but it just can't compete, price-wise.
  - et2o 3y ago
    I believe that most of the lead used today is a by-product or co-product of mining other more valuable metals like Zinc and silver. Lead is quite abundant in the Earth's crust and found in easy to access deposits. I think >80% of the current industrial use of lead is for batteries. It's probably still in the top ten most mined metals by dollar value and definitely by mass.
    - salty_biscuits 3y ago
      The mineral containing Zinc is called Sphalerite, which is based on a greek etymology for "deciever" because it commonly occurs with Galena (which has Lead and Silver) and looks similar.
  - shirleyquirk 3y ago
    It may not come as a complete surprise that the economics of metals are more complex. Aluminium, was so expensive until the Hall/(that other guy) process was developed, that it was used for jewellery [1]. Even today it's expensive and difficult to reduce Al ore to metal, which is a supply side problem. [1]https://www.bellandbird.com/products/aluminum-bangle https://www.bellandbird.com/products/aluminum-bangle
    - stu255 3y ago
      75% of aluminium supply is from recycling aluminium products. The economy sort of has a "working capital" quantum of aluminium which also grows steadily from aluminium mining. Lots of metals have very different and complex supply structures and thus completely different $$$ / volume curves for their supply. Understanding the $$$ / volume curve of commodities is not something that is commonly considered when people try and predict the future. Mining a billion tonnes of Aluminium from an asteroid for example and safely landing it on Earth can never be profitable because the $$$ / volume curve for Aluminium is $0.00 at billion tonne volume.
      - rob74 3y ago
        Now I'm curious where that recycled aluminium is coming from? My guess would be mostly from airplanes and beverage cans...
        tonyarkles 3y ago
        Engine blocks too. If you go to a scrap yard though you’ll be pretty amazed at all of the stuff they’ve got collected and sorted. Metal recycling (compared to, say, electronics recycling or plastic recycling) has a very clear economic model and financial incentives. If you’re demolishing a building or scrapping old machinery it will cost significantly less to recycle the metal (because you get paid decently by the pound) than to take it to a landfill (where you pay by the pound instead).
        iancmceachern 3y ago
        Cars too
EdwardDiego 3y ago
As a young fella, I carried a lot of that lead-lined drywall, it's (obviously) really heavy, and expensive so you got yelled at a lot if you damaged the edges, couldn't just trim it off like normal drywall.

by scythe 3y ago

thayne 3y ago

> possibly because the drop in demand for other applications made it so cheap Maybe a little bit. But I think it is more that it is a material with heavy atomic nuclei and high density, and thus effective at blocking radiation. And it is also relatively cheap.

scythe 3y ago
Lead is absurdly cheap. One dollar a pound! Cheaper than much more common metals like aluminum or magnesium. So I diagnose a low demand. They used to talk about using barium cement but it just can't compete, price-wise.
- et2o 3y ago
  I believe that most of the lead used today is a by-product or co-product of mining other more valuable metals like Zinc and silver. Lead is quite abundant in the Earth's crust and found in easy to access deposits. I think >80% of the current industrial use of lead is for batteries. It's probably still in the top ten most mined metals by dollar value and definitely by mass.
  - salty_biscuits 3y ago
    The mineral containing Zinc is called Sphalerite, which is based on a greek etymology for "deciever" because it commonly occurs with Galena (which has Lead and Silver) and looks similar.
- shirleyquirk 3y ago
  It may not come as a complete surprise that the economics of metals are more complex. Aluminium, was so expensive until the Hall/(that other guy) process was developed, that it was used for jewellery [1]. Even today it's expensive and difficult to reduce Al ore to metal, which is a supply side problem. [1]https://www.bellandbird.com/products/aluminum-bangle https://www.bellandbird.com/products/aluminum-bangle
  - stu255 3y ago
    75% of aluminium supply is from recycling aluminium products. The economy sort of has a "working capital" quantum of aluminium which also grows steadily from aluminium mining. Lots of metals have very different and complex supply structures and thus completely different $$$ / volume curves for their supply. Understanding the $$$ / volume curve of commodities is not something that is commonly considered when people try and predict the future. Mining a billion tonnes of Aluminium from an asteroid for example and safely landing it on Earth can never be profitable because the $$$ / volume curve for Aluminium is $0.00 at billion tonne volume.
    - rob74 3y ago
      Now I'm curious where that recycled aluminium is coming from? My guess would be mostly from airplanes and beverage cans...
      - tonyarkles 3y ago
        Engine blocks too. If you go to a scrap yard though you’ll be pretty amazed at all of the stuff they’ve got collected and sorted. Metal recycling (compared to, say, electronics recycling or plastic recycling) has a very clear economic model and financial incentives. If you’re demolishing a building or scrapping old machinery it will cost significantly less to recycle the metal (because you get paid decently by the pound) than to take it to a landfill (where you pay by the pound instead).
      - iancmceachern 3y ago
        Cars too

EdwardDiego 3y ago

As a young fella, I carried a lot of that lead-lined drywall, it's (obviously) really heavy, and expensive so you got yelled at a lot if you damaged the edges, couldn't just trim it off like normal drywall.