Ice Melting Rates at− 5 C,− 10 C and− 15 C Using Chloride Solutions: A Physical Explanation

摘要: Deicing chemicals is an important tool to keep roads passable and safe during winter. The most common deicing chemical, sodium chloride, works well at temperatures close to 0 C but its effectiveness decreases at low temperatures. One common belief is that this reduced effectiveness stems from a reduction of the ice melting rates. Previous studies have indicated that the melting rate is connected to the diffusive flux of water in a deicing solution, and the aim of this paper was to study whether this hold true also at low temperatures. An experiment was performed where aqueous solutions of sodium, magnesium and calcium chloride melted ice at three different temperatures.-5 C,-10 C and-15 C (23 F, 14 F and 5 F). Our results confirmed that the diffusive flux of water correlated well with the ice melting rate at all temperatures. The observed decrease in melting rate at low temperatures was explained by a decreased driving force for diffusion. Because of this, the eutectic temperature of a chemical becomes more important the lower the temperature becomes. The diffusive flux in deicer solutions could be a useful property. By calculating the diffusive flux of different deicing chemicals, would hence be a way to range them by their melting rates at different temperatures.