According to the University of Michigan, magnesium chloride can be used in an anti-icing application. Anti-icing involves spraying a brine of the magnesium chloride on a road surface when precipitation is anticipated. The brine lowers the freezing point of the new moisture and prevents it from attaching to the pavement. Snow plows can work more efficiently and do a better job of clearing ice from the road surface if it is not bonded to the road surface. The anti-icing qualities of magnesium chloride are effective to approximately 10 degrees Fahrenheit. One of the drawbacks of magnesium chloride is its effective range of temperatures. It is not effective at melting snow or ice if the air temperature falls below 5 degrees Fahrenheit. This can be a problem in some of the colder portions of snow country.
Magnesium chloride can also be applied after the precipitation has fallen although there are some limitations. Magnesium chloride easily and rapidly absorbs moisture and forms a brine. The quicker the brine forms, the quicker the solution starts to melt the ice and snow.
Cost is another issue with magnesium chloride. Average cost of application is approximately twice as high as salt or sand applications. Magnesium chloride is also corrosive to metal and, because of its high moisture absorbency, attracts water to the road surface, which can keep the road pavement wet longer than would occur if there were no application of magnesium chloride.
Magnesium chloride is considered more environmentally friendly than salt or even sand. It is not known to affect plant life adversely.
Even though it is corrosive to metal, it is considered less corrosive than some other products used for ice and snow removal.
Because of these qualities, magnesium chloride does not need to be cleaned up after a storm has passed. This reduces the total cost of the snow and ice removal project and the amount of road equipment traffic on the highways and can improve traffic flow.
