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Salt is tough on concrete in winters, so it’s best to use sparingly, but if you are in using salt, instead of going with other products that may contain more additives, consider the type of salt you need to purchase. Salts that are used for ice melting include sodium chloride, potassium chloride, calcium chloride and magnesium chloride. There are four main types of ice melters that are commercially available. They are as follows:
- Rock Salt (25 Degrees Protection) Halite is often used both residentially and municipally for managing ice. Because brine (a solution of water and salt) has a lower freezing point than pure water, putting salt or saltwater on ice that is near 0 °C (32 °F) will cause it to melt. (This effect is called freezing-point depression.) It is common for homeowners in cold climates to spread salt on their walkways and driveways after a snow storm to melt the ice. It is not necessary to use so much salt that the ice is completely melted; rather, a small amount of salt will weaken the ice so that it can be easily removed by other means. Also, many cities will spread a mixture of sand and salt on roads during and after a snowstorm to improve traction.
- Potassium Chloride (15 Degrees Protection) It can be made from salt water by crystallization It can also be seen as a residue from reaction between HCl, Potassium Nitrate and Nitric Acid. Potassium Chloride is used as a table salt substitute. It is also used to make fertilizers.
- Magnesium Chloride (-13 Degrees Protection) “Magnesium chloride is less damaging to concrete, plants and trees.” Magnesium chloride also is more environmentally friendly as it releases less chlorides into the environment than other salts. However, it is important to note that magnesium chloride can cause damage to metal products, such as steel.
- Calcium Chloride (-25 Degrees Protection) By depressing the freezing point of water, calcium chloride is used to prevent ice formation and to deice. This is particularly useful on road surfaces. Calcium chloride dissolution is exothermic, and the compound is relatively harmless to plants and soil; however, recent observations in Washington state suggest it may be particularly harsh on roadside evergreen trees. It is also more effective at lower temperatures than sodium chloride. When distributed for this use, it usually takes the form of small, white balls a few millimeters in diameter, called prills. Solutions of calcium chloride can prevent freezing at temperature as low as −52 °C (−62 °F), making it ideal for filling agricultural implement tires as a liquid ballast, aiding traction in cold climates.
Many suppliers are now offering custom blends of these chemicals to reduce cost, however, these custom blends are less effective than the straight products.
Keep an eye out for and try not to use:
The most damaging of all ice melters contain ammonium nitrate and/or ammonium sulfate. These chemicals attack concrete chemically and can cause great damage, therefore should never be used as ice melters.
Stay safe out there this winter season.
