Fertilizer Can Melt Snow and Ice
By Chad Upton | Editor
If you need to boil water while cooking, the recipe may suggest that you add salt to the water. This salt is not for taste, it’s for efficiency. The salt lowers the heat capacity of water, making it boil with less energy (heat) from your stove. It also raises the boiling point of the water slightly, although not significantly. In other words, it helps you get the water hotter and in less time than if you didn’t add salt.
Salt also has an affect on the freezing point of water — it lowers it. This is important to understand during winter, especially if you have a driveway or sidewalk to keep clear. Because salt lowers the heat capacity of water (or snow/ice), it’s takes less energy (heat) to melt. This only happens down to about 15°F (-9°C). Below that, salt is not very effective because it cannot dissolve at those temperatures.
Rock salt (sodium chloride) is the usually the cheapest of all the ice melting products. There are a variety of alternatives that are effective at lower temperatures.
You should be careful when choosing an ice melter. Most ice melting products, including salt, are corrosive and can damage concrete, especially if it’s very new concrete. They can also be harmful to vegetation and grass.
In fact, some of these products are basically just higher concentrations of fertilizers that you might use on your lawn, such as ammonium sulfate and potassium chloride. These would definitely “burn” your lawn if you missed your driveway. If you’re concerned about any of these factors, consult the manufacturer’s directions and warnings before making your purchase.
Salt, and many of these alternatives, also do a good job at preventing the formation of ice, which is why you may see salt trucks on the streets just before a storm, especially if freezing rain is expected.
Photo: Angela (cc)