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Thread: Is it easy to harvest salt from seawater?

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    Junior Member wildgarden's Avatar
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    Default Is it easy to harvest salt from seawater?

    My family and I were wondering if harvesting salt from seawater was possible by simply collecting seawater and setting it out in shallow pans so the water can evaporate leaving only the salt residue. Sounds so simple, though when looking it up on the internet the information seems more complicated than that. Perhaps that is because the information was geared toward commercial harvesting rather than a survival situation or simply for a hunter gatherer mentality. Anyone know first hand?

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    Administrator Rick's Avatar
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    It depends on where you live and how much you want. If live along a dry coastline then you can probably collect it off of rocks along the shoreline. Crevices, in particular, where water has splashed then dried. If you live along a wet coastline then you might have to boil the sea water.

    There is only about 35 grams of salt in a liter of seawater so we aren't talking about a lot of salt. Just setting out a pan and let water evaporate with yield about +/- 10 grams depending on the size of the pan, of course. If you want a good deal of salt then you will have to boil sea water until you have a concentrated amount of salt then boil the pan dry to collect it.

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    Alaska, The Madness! 1stimestar's Avatar
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    Just boil it (also gets rid of any nasties) until it's almost dried, leave it out till it finishes drying and scrape the salt out. We've done that before and it's kind of fun. I covered the pan with a cut piece of nylon to keep most things out.
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    Senior Member Winter's Avatar
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    Aquire sea water, dilute it, filter it, boil it down, add fresh water, boil it down again, add fresh water, repeat till the salt is white and not green/tan.
    I had a compass, but without a map, it's just a cool toy to show you where oceans and ice are.

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    Senior Member hunter63's Avatar
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    Quote Originally Posted by Winter View Post
    Aquire sea water, dilute it, filter it, boil it down, add fresh water, boil it down again, add fresh water, repeat till the salt is white and not green/tan.
    Ah....White good,.... green/tan, not so much,.......Got it.

    Thanks, as I know what fish do in that water.....and Whales, yeah... white good
    Last edited by hunter63; 12-19-2011 at 01:44 PM. Reason: splin'
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    Senior Member kyratshooter's Avatar
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    Polutants are going to be dependent on where you are. 3/4 of the Earth is water so you are going to have to camp out next to the sewer plant to have a concentration of sea water pollution you should worry about.

    The salt itself is a disinfectant.

    If you boil it why do you have to keep on boiling and adding water and boiling and adding water? If it were from a river you would boil it for 5 minutes and drink it! You can't kill germs twice. Once is dead enough.

    Our commercial salt is white due to bleaching, either in the sun or with chemicals.

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    http://www.cargill.com/sf_bay/index.htm

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    Administrator Rick's Avatar
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    It's not for killing germs. It's to concentrate enough salt to make your effort worthwhile. As I said above, there is only about 35 grams of salt in a liter of water. That's not much when you try to boil the water down. If you keep adding water then you concentrate the salt so you actually have something to scrape out of the pot.

    Salt is naturally white. Or mostly white. Whit...ish. I used the internet so here's a link.

    http://en.wikipedia.org/wiki/Salt

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    Senior Member kyratshooter's Avatar
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    OK Rick, how do you concentrate something by adding water? The articles I read stated that the concentrated water was drained from the pans and stored in sumps with roofs when it rained to protect the concentrated from being diluted.

    Adding water is diluting, removal of water is concentrating.

    In the frontier days they boiled the water from salt springs and continued adding saltwater to the pots just to increase the amount of salt before they stopped to scrape the kettles. It was easier than bringing new kettles of water back to a boil when you were splitting wood by hand.

    We have a salt lick nearby that is a historic site. They boil salt for demonstrations. They do the same at Fort Clatsop where Lewis and Clark camped for the winter in Washington.

    http://www.nps.gov/lewi/planyourvisit/saltworks.htm

    These salt licks were on the maps before any cities were present. The first known place where there is evidence of an organized battle among prehistoric humans is at a place called Esalt, a natural salt spring in the mid-east.
    Last edited by kyratshooter; 12-19-2011 at 07:25 PM.
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    Senior Member gryffynklm's Avatar
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    Quote Originally Posted by kyratshooter View Post
    In the frontier days they boiled the water from salt springs and continued adding saltwater to the pots just to increase the amount of salt before they stopped to scrape the kettles. It was easier than bringing new kettles of water back to a boil when you were splitting wood by hand.
    They also left some salt in the bottom of the kettles because salt crystals form faster on existing crystals then on a clean pot.

    Cool link Kyrat.
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    Administrator Rick's Avatar
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    You add water, boil, when the water gets low you add more water and boil some more. The salt precipitates out and forms on the side of the pot. If you were adding fresh water then yes it would dilute it. But since you are adding salt water and boiling the water away you are concentrating the amount of salt in the kettle, pan, what have you.

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    Senior Member Winter's Avatar
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    If you want green or tan salt, it's just evaporating the water out. Simple evaporation will not kill pesky critters like paralytic shellfish poisoning.

    So, boil it out.

    I like white salt, and if its clean, it's white.

    Only reason I'd dilute it is to mix it back up before the next filtering.

    It's alot more trouble, but I cook the weird critters I eat and I process any plants (other then berries).

    By all means, if you have a potato and no salt, it's emergency time.
    I had a compass, but without a map, it's just a cool toy to show you where oceans and ice are.

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    It might be easier to collect and dry seaweed for seasoning. Other than that, no idea.

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    Senior Member Winter's Avatar
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    Seaweed has a very iron taste. That will make it more savory.

    Great idea Faithnomore. Be really cool if you posted an intro with your experiances and stuff. I'd know better who I was talking to.
    I had a compass, but without a map, it's just a cool toy to show you where oceans and ice are.

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    Would you pour the seawater through a microfilter first, or simply through some sort of cloth...for filtering purposes? I'm very interested in trying this!

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    Quote Originally Posted by Winter View Post
    If you want green or tan salt, it's just evaporating the water out. Simple evaporation will not kill pesky critters like paralytic shellfish poisoning.

    So, boil it out.

    I like white salt, and if its clean, it's white.

    Only reason I'd dilute it is to mix it back up before the next filtering.

    It's alot more trouble, but I cook the weird critters I eat and I process any plants (other then berries).

    By all means, if you have a potato and no salt, it's emergency time.
    Can't say why salt would come out green but pretty sure that "tan colored salt" is the product of a homogenous mixture of sodium chloride (table salt) and magnesium sulfate which is also good for you (in the minute amounts they would be present).

    Quick fact: The sulfate ion is the only thing that can actually reverse the effects of mercury poisoning, which will otherwise stay in your blood till the day you die. What happens in your blood is that the magnesium when dissolved (like any other molecule) splits into its separate ions. Once the sulfate ion comes into contact with the mercury atom a chemical bonding occurs, creating mercury sulfate. Mercury sulfate is a non-soluble molecule, which is easier for your body to process out of your system.

    Another quick fact: Pure Magnesium metal can be obtained through a complicated process straight from the sea!

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    In my experiance, the reason salt has colors is based on minerals in the water. By boiling it till it's white, your also boiling off those minerals. Salt from where I get it is usually pink in color. The reason for me is all because of sodium, potassium, iron, magnesium, calcium, and copper. So if it's green you might got a lot of copper in the water. By the debated "concentration" idea all your doing is adding more sodium/salt while the potassium, iron, magnesium, calcium and copper, is still present, your getting more salt. Since we are talking sea salt rather then the salt I get from my local spring. There is iron, magnesium, calcium, potassium, manganese, zinc and iodine in the salt. Either way these impurites are there all your really doing is adding more salt. For example if I have 70% sodium 4.28% iron, magnesium calcium potassium, magnese, zinc and iodine, and I add more water, The ratios are still the same, but the sodium takes over and it gives it a white color. Least in my mind. The only thing your doing is reducing the amount that's there by weight. If I have 1000 pounds of salt, your going to see more white then anything.

    Really want some fun, build a cold smoker and smoke your sea salt. Sprinkle a little hickory smoked sea salt over your steak mmmm yummy.
    Last edited by grendal; 04-27-2012 at 09:38 PM.

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    Administrator Rick's Avatar
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    You can't boil off minerals. If you could you'd boil off the salt since it is a mineral.

    I'll have to get back to you on the math. I'm still doing my guzintas.

  18. #18

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    Get one of these....

    https://www.coppermasters.com/prod_d...php?iProdId=27

    Fill it with seawater. Have a collection jar on the condenser end to catch the fresh water.
    When the pot gets to about a quarter full refill with fresh sea water as Rick suggested.
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    Senior Member kyratshooter's Avatar
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    You guys are really over-complicating this. It is a survival skill from before there was an official stone age. I am sure pre-humans were along with the other animals that sought out the salt licks to cure their craving for salt in any area they dwelled.

    There are archeological sites in the Ohio Valley where they have recovered the evaporating pans used by the Indians at the salt licks on the Scioto River. They are simple shallow clay bowls the Indians filled with water from the salt licks that feed into the river. They filled them and let the sun do the work.

    One of the most famous salt licks in the world is only 10 miles from my house. It is a place called big Bone Lick, named after the mamoth, Giant Sloth and other megafauna remains scattered about the springs. We kicked a mamoth tooth out of the ground the last time I camped there. It was on the maps being made of North America before Jamestown or Qubec had been founded in 1607.

    Our ancestors boiled salt in simple iron and copper pots until they had enough to do what they needed.

    It is not complicated unless you make it that way. The salt may be brown, gray, green or purple, as long as it cures the meat and gets the minerals into your system that is all that matters.

    You can do it the hard way or you can do it the easy way, or you can worry about it until you get an ulcer. Just make sure you have about 100 pounds per person per year in your long term stores.
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    Excellent post Krayt!
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