• jak@sopuli.xyz
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      10 months ago

      It’s actually too cold for salt to be reliable. Water fully saturated with salt freezes at ~-21/-6(c/f), so if it’s predictably getting colder than that, it’s a bad idea to use salt.

      Edit: They add beet juice when it’s really cold, but otherwise, it looks like they use salt :(

      • RedAggroBest@lemmy.world
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        10 months ago

        It’s salt but it’s not sodium cloride. It’s usually calcium cloride. That’s usually good to -30/-34 F/C.

        • jak@sopuli.xyz
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          10 months ago

          Interesting, I haven’t found anything to support that (but it’s weirdly difficult to research, so it could just be DDG not understanding what I’m looking for), do you have a source for that?

          I found halite (unrefined sodium chloride) as the primary type of rock salt in the US. Wikipedia lists beer, molasses, and beet juice as possible alternatives for roads or glycol and sugar for airlines.

          The EPA does list CaCl as an option, but notes that it’s both better for the environment and more expensive, so it’s reserved for vulnerable areas. I found this which doesn’t specify which they use, but gives an effective temperature range that sounds like NaCl for North Dakota.

    • Trainguyrom@reddthat.com
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      10 months ago

      Many places have switched to a brine which uses a waste byproduct from cheese production. This greatly reduces how much salt is thrown onto the roads and also makes use of literal waste

      Edit: looks like there’s a few different mixtures but here’s the cheese brine from Wisconsin

    • Tenderloins@lemmy.world
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      10 months ago

      When it gets that cold salt is useless, so thankfully we see much less of it throughout the winter. Sand is used instead. -20C and salt sort of stops working.