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EDUCATION - FAQ's
- Why is Salt used? Salt is used
as the principal de-icer because it is has historically been the
most readily available and most cost-effective choice. The primary
type used is Rock Salt that is mined from the earth. Salt is used
to keep snow and ice from bonding to the pavement and to allow snowplows
to remove accumulations quickly and efficiently.
- How Does Salt Work? When salt is
applied to ice and snow, it creates a brine that has a lower freezing
temperature than the surrounding ice or snow. To date, Salt has
been the most commonly used de-icing product because it is: readily
available the least expensive de-icer relatively easy to store and
handle easy to spread relatively harmless to skin and clothing believed
to be harmless to the environment when used and stored properly
The use of salt for winter maintenance is based on the fact that
dissolving one substance in another alters the freezing point of
the second. Salt lowers the freezing point of water. The greater
the concentration of salt, the lower the freezing point, although
there is a limit of temperature below which salt will not melt ice.
This is called the eutectic point (-21degrees C). Melting begins
on contact when salt is spread on ice or snow. This produces water,
dissolving more salt and producing further melting. The rate of
melting will depend on the surrounding air and ground temperatures.
Other influences on melting rate are the particle size of the salt
and the amount of mixing often caused by traffic.
- How De-icers Work? De-icing chemicals
get ice off pavement by lowering the melting point of the ice. The
de-icer and ice form a liquid brine and remain in a liquid form
at temperatures where pure water would freeze. The liquid brine
also seeps between the remaining ice and pavement, breaking the
bond between the ice and pavement for easier plowing. The following
are some de-icing products and techniques in use today: Sodium Chloride,
also known as rock salt, is the cheapest and most commonly used
de-icing product. It is produced in various particle sizes. The
larger of these are used for roadways, then progressively smaller
for parking lots and sidewalks. It will work to -7 degrees F, although
it is most effective around 10-15 degrees F. Calcium Chloride, often
used during very cold weather conditions because it can continue
to work to -60 degrees F, but is often considered most effective
around -25 degrees F. More expensive than rock salt. Calcium magnesium
acetate (CMA), is an alternative de-icer with minimal corrosive
properties. CMA can be quite expensive, often more expensive than
calcium chloride. Blended products are relatively new on the market,
with different compositions offered by various manufacturers. The
advantages to using blended products include reduced use of sodium
chloride, and utilizing the strengths of particular chemicals to
maximize aspects of other de-icing products, such as melting rate
and melting capacity. Back to Top
Important Notice: This information
is provided by Draglam Salt as an educational convenience only without
warranty of any kind. Draglam in no way guarantees the completeness
or precise accuracy at any given time. Please consult your manufacturer
for specific details on a de-icing products and their performance
statistics.
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