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Is 23% salt brine really the most efficient

Discussion in 'Ice Management' started by turn54, Dec 17, 2014.

  1. turn54

    turn54 Senior Member
    Messages: 114

    Continued from post #1645 & 1646 on page 83 of "Anything Sprayer Related, likes, dislikes, pics, Questions?" Thread

    I wanted to start a new thread as the discussion had changed courses.



    Most important part of my whole post >>>

    In my opinion, tweaking salt percentage of brine would only be marginally beneficial, if at all. And should only be done to a higher percentage of salt in the brine.

    Customization of mix would make very minimal difference for different climates. Once you get to colder/more extreme climates it is easier adding other chemical's (such as calcium chloride) to "spike" the mix instead of trying to control the precision of salt content percentage post application.

    It would make more sense to adjust for application(ie: pre-treat, anti-ice, melting accumulation vs post plow). Basically the higher the moisture content, the more dilution, the higher the salt percentage should be in the brine.

    The most important question would be is it more cost effective to make a higher salt concentration brine or just apply more of the same product. Only you could crunch the numbers and figure this out. To many variables from cost of materials(internally manufactured or purchased), applicator efficiency including labor, brine storage capacity, and location of jobs to brine supply to name a few. Under general conditions, I would say the increased cost of additional salt & labor(mixing time) for an internally manufactured brine would be considerably cheaper than increased application rates.

    I have never adjusted for temperature except when I tried 180 degree water to see how much it increased production. Most of my brine production has consisted of water measuring between 50 and 62 degrees. This would head minimal difference. By the way 180 degree water didn't increase production in my particular brine maker. It did manage to steam up the entire 50 degree shop.
     
  2. White Gardens

    White Gardens 2000 Club Member
    Messages: 2,665

    Good idea posting this separately. Thumbs Up

    I'd like to see some other opinions on this also.

    Here's something else I'd like to point out also.

    If you are just per-treating salt, and not doing a full liquid application, would you be better off going with say a 17%-18% solution?

    Ultimately you don't want your brine to freeze, but the whole point is to get more moisture on the salt and pavement to start the brine process, especially in the case of dry snow with a 15-1 moisture ratio.


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  3. White Gardens

    White Gardens 2000 Club Member
    Messages: 2,665

    And just to throw some numbers out there for the discussion.

    If my math is correct, as I converted metric measurements, are correct.

    Per 400 gal batches (which seems to be the two tote batch that is common)

    25% solution= 840lbs of nacl

    23% solution= 764lbs of nacl

    21% solution= 696lbs of nacl

    Somebody can double check my math if they want.

    25% solution. 25grams of nacl per 100 grams of water. 3780grams in on gallon of water. Rounded, there is 454grams in a pound.


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  4. turn54

    turn54 Senior Member
    Messages: 114

    Not sure of your math, but I always start with 2.2lbs/gal and have to add a little extra salt after that to get it to 23%. This puts me closer to 900lbs per 400 gal batch. The bulk salt I get is not as clean as pure nacl which results in 1/2 ton of bulk salt per 400 gal in my case to get closer to 24% that I usually shoot for.
     
  5. White Gardens

    White Gardens 2000 Club Member
    Messages: 2,665

    Touche.

    I guess the point of the hard math was to show the difference between the batches and percentages.

    Thus pointing out the minimal cost difference in batches that you eluded to.


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  6. Mark Oomkes

    Mark Oomkes PlowSite Fanatic
    Messages: 10,853

    I can't find the phase diagram I need, but basically if you don't have 23.3% you will create ice under certain conditions instead of melting it.

    It's been a long time, and people far smarter than me have figured it out. Something to do with the higher the percentage and the lower the temp, the chance for icing goes up.
     
  7. White Gardens

    White Gardens 2000 Club Member
    Messages: 2,665

    Is that for spraying bare pavement during pre-treatment? That I can see.


    ..
     
  8. terrapro

    terrapro PlowSite Veteran
    from MI
    Messages: 3,873

    Yep I agree, that was floating around years ago and now has just become a fact to me. I don't remember the exact reason now though about the higher %...maybe the salt falls out of suspension and takes the whole brine down percentage wise to far below the 23.3 or something like that. As MarkO said "people far smarter then I have figured it out."

    Same goes with LCC, but it's above like 33% or something...
     
  9. grnstripes

    grnstripes Senior Member
    Messages: 236

    I have been playing with liquids for a couple years now
    And have gone from buying it to now building a maker
    So I am subscribing to this forum. Hopefully I can learn a little more
    I do remember several years ago the state turned the interstate into a skating rink with brine because the numbers were too high so it dose happen
     
  10. White Gardens

    White Gardens 2000 Club Member
    Messages: 2,665

    I think this needs to be discussed more......



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  11. Digger63

    Digger63 Member
    Messages: 44

    If you look it up you'll find that at around 23% salt brine has it's lowest freeze point. either way on the chart the freeze point moves up. It's something like the ratio of pure radiator fluid to water. Most people who produce brine make it in quanities and store it outside. At this 23 % area the freezing point is about -6 degrees. Adding various amounts of chemicals and or organics can lower this freeze point for storage and use. the ground temperture plays a factor for anti-icing. If the ground temperture is lower than the freeze point of the liquid you will probably create the ice skating rink that you were trying to avoid. Raising the percentage of salt up you are putting more salt per gallon of liquid and actually raising the freeze point. As a prewet solution if you can keep it from freezing, having more salt in the liquid would add to the rock salt that you are applying. Being that you are putting solid salt down anyway I don't see benefit of doing this. Usually you are prewetting for enhancing the salt's freeze point usage and reducing the scatter effect that sanders have
     
  12. SnowMatt13

    SnowMatt13 PlowSite.com Addict
    Messages: 1,532

    Google brine phase diagram and you will find it.
     
  13. White Gardens

    White Gardens 2000 Club Member
    Messages: 2,665

    phasediagram.jpg


    What I find interesting is that Mag Chloride isn't linear.

    ................

    phasediagram.jpg
     
    Last edited: Dec 28, 2014
  14. Lynden-Jeff

    Lynden-Jeff PlowSite.com Addict
    Messages: 1,433

    This is absolutely correct.

    There is zero benefit in tweaking the saturation of a sodium chloride brine. By applying rock salt to the road, we are effectively applying 100% sodium chloride which then uses existing ground moisture to create "brine". By making and applying brine, we are reducing potency by 77% already, while applying it in a "brine" state.

    In essence we are making our jobs HARDER by applying brine instead of rock salt. This comes with benefits however as almost EVERY contractor over applies salt to "ensure liability" is covered etc. How many times have you done an extra loop around the lot just to see it "start melting". With brine this it is much LESS likely to overapply and much more likely to under apply however we can see it start melting immediately. This is not necessarily true with calcium chloride which changes the situation completely. Spray brine requires the use of much larger, heavier trucks as water is extremely heavy. Factor in this:

    - 5 ton of salt spread with an F550 weighs 11,0000 lbs.
    - Applying even half amount of salt in the form of brine weighs 14 ton (based on approx 2500 Gal of brine)

    After applying Tens of thousands of gallons of brine and calcium chloride I can pass on the following to people considering liquids:

    - Brine/calcium chloride is an asset to a de-icing program but does not replace rocksalt completely.
    - Prewetting pavement surfaces is a good liability reduction method and may help in certain circumstances (high traffic lots during daytime storms, melting very light snowfalls etc),
    - Pretreating your salt at the spinner or on the pile directly with a proper %calcium chloride can reduce your salt usage by 30-50% as you will see the salt start to work immediately. This is personally my favorite use of Calcium hands down. Calcium is an amazing catalyst for sodium chloride.

    Hope that helps.