Salt vs. Temperature

November 4, 2014

It’s 15° F and snowing and it feels like the salt you just put down took a vacation.

Salt is the least expensive, most abundant, readily available deicing material on the market. For the result you get, salt’s hard to beat when considered against alternative materials on a cost-benefit analysis. Calcium chloride and magnesium chloride will work very effectively to well below zero, however, they are generally priced 5-8 times the costs of road salt or rock salt.

While salt is inexpensive relative to its competition, it’s not without some limitations. One of them is the practical operating range where salt’s effectiveness drops off exponentially below 25 degrees Fahrenheit.

Here’s a good reference from the Snowfighter’s Handbook published by the Salt Institute showing just how quickly salt’s effectiveness plunges with temperature:

POUNDS OF ICE MELTED PER POUND OF SALT
Temperature Degrees F One Pound of Sodium Chloride (Salt)
30 46.3 lb of ice
20 8.6 lb of ice
15 6.3 lb of ice
10 4.9 lb of ice
5 4.1 lb of ice
0 3.7 lb of ice
-6 3.2 lb of ice

Most experienced snowfighters know that the colder it gets the harder it is to get salt to brine (form a solution from melting snow/ice) but few realize just how dramatically that performance curve drops off.

At 30° F, 1 lb of salt will melt 46 lbs of ice, however, at 15° F that performance will drop by over 86%! Yes it is only 13% as effective at 15 ° as it is at 30°. So what can be done about that?

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The Marquette University Salt Study proved the effectiveness of pre-wetting salt; using a liquid brine to enhance and “jump-start” the brining process with snow at low temperatures. Pre-wetting has many advantages but the costs of liquid application systems to spray the salt on the truck are expensive, require maintenance, and of course you have to have the liquid to fill the saddle tanks on the trucks.

In the 90s a series of boutique additives began to emerge that, for the first time since pre-wetting was employed, were able to allow a stockpile of salt to be treated with a performance liquid that had been modified with an additive that prevented the liquid from activating, and in some cases provided enhanced melting performance.

The first product to the market for this was called IceBan and it was a distillation or brewing waste product. Many will remember the “beer smell” and brown liquids that were promoted in the 90s under the brand. The original IceBan (and Magic) patents for using the brewer’s condensed solubles have now expired and with the explosion of microbreweries, many municipal snowfighters are sourcing some of these liquid additives locally for free or nominal costs and adding them to their liquids and snowfighting arsenal.

Getting back to the temperature performance challenge, if you can envelop or encapsulate the salt particle with a premium chloride liquid such as calcium chloride or magnesium chloride, when that particle hits the pavement, the premium chloride has a lower temperature performance and it will synergize the brining of the salt particle much like putting jumper cables on a dead or weak battery. It gets just enough kick to help the salt to start forming a brine and work.

So how do you get performance at lower temperatures without using all calcium chloride or magnesium chloride? You use our treated or pre-wetted salt, commonly referred to as Magic Salt or treated salt. We encapsulate each particle with a patented mixture of molasses and magnesium chloride which together will provide the advantages of pre-wetting without activating until it is applied to the surface and exposed to snow and ice.

To learn more about our performance products and how to reduce your use of salt and maintain the same level of performance, give us a call at 508-520-3900 or send us a note on our Contact page.