5 ms·
My guess: extracting it from the ocean water requires evaporation, which in turn requires a lot of energy/fuel?
by b3kart 5y ago
My guess: extracting it from the ocean water requires evaporation, which in turn requires a lot of energy/fuel?
- k__ 5y agoDoesn't it evaporate on its own over time?
- Filligree 5y agoThat requires vast quantities of space and a hot/dry climate to be done efficiently. It certainly was done. Looking back at history, the places that could efficiently do so were major salt exporters; which rendered it uneconomical to do elsewhere.
- wikidani 5y agoYes, but I think that maybe in colder regions it's probably not cost effective. Specially in winter. So that would kind of explain why the polish salt mine mentioned earlier was important
- debacle 5y agoDigging the pan, hardening it (so it's relatively impermeable to sea water), and then repeatedly evaporating the water until you have a brine rich enough in salt to precipitate, and then massing that salt slush so it can completely dry, and then smashing it into a usable form. You can look at salt pans on Google Maps. Here is one I have been to: https://goo.gl/maps/uN968Stn6kPHnH6E7 https://goo.gl/maps/uN968Stn6kPHnH6E7 Obviously today this is done with gigantic machines, and the cost/kg is incredibly low to the point that locals do not pay for salt, but back before the advent of Caterpillar, I imagine harvesting salt this way was very labor intensive. There is a documentary on Amazon called My Name is Salt about the salt harvest in India. It is quite good.
- einpoklum 5y agoWell, if you go back long enough when you could use a larger area for a given output of salt, then - once you prepared your pan once, you could just let the water evaporate completely, and then scratch the salt of the surface. If your pan can be made of rocks than that should probably be even easier. Other than needing some decent sunlight and not super-high humidity - what am I getting wrong?
- debacle 5y agoThe massive amount of human labor involved?
- Johnythree 5y agoThe fact that that there is only enough sunlight in tropical areas. And that heavy rain (monsoon, etc) will wipe out all your work.
- einpoklum 5y agoPlenty of sunlight in the Mediterranean basin, most of Asia not including Siberia (not sure about Kazakhstan, Mongolia etc), the middle of the USA and due South from there almost all the way to Southern South-America. Heavy rain would indeed wipe out all your work, which is why you would do it in the drier seasons.
- selimthegrim 5y agoDepends on the source - the Khewra salt mines in Pakistani Punjab's Salt Range are the source of a lot of "Himalayan" salt in America.