De-icing salt refers to sodium chloride, calcium chloride, magnesium chloride, potassium chloride, etc., which have a freezing point below zero after being dissolved in water (snow). The freezing point of salt water is lower than that of water, so it is difficult to form ice cubes after the salt is dissolved in the snow water.

Product classification

De-icing agents are mainly divided into two categories. One is an organic de-icing agent with potassium acetate as the main component. Although this type of de-icing agent has a good snow melting effect and no corrosion damage, its price is too high and is generally only suitable for airports and other places. The other type is chloride salt de-icing agent, including sodium chloride, calcium chloride, magnesium chloride, potassium chloride, etc., commonly known as "de-icing salt". Its advantage is that it is cheap, and its price is only equivalent to 1/10 of that of organic de-icing agents, but it is very corrosive to large public infrastructure.

Chloride salt de-icing agents have two functions in snow removal. In addition to the heat absorption of salt dissolution, another function is that the freezing point of salt water is low, so it is difficult to form ice cubes after the salt is dissolved in the snow water, which is conducive to snow removal.

When the snow melter is dissolved in water, the ion concentration in the water increases, causing the liquid vapor pressure of water to decrease, but the solid vapor pressure of ice remains unchanged. In order to achieve a state where the solid and liquid vapor pressures of the ice-water mixture are equal, the ice melts. This principle also explains why salt water is not easy to freeze.