Dry ice melters melt ice from the top down. The dry material is broadcast on top of the ice, and then the dry ice melter lowers the freezing point of the ice so it melts, which converts it into a brine solution. The remaining solid deicer sinks through the ice to the pavement. The brine then spreads out, breaking up the bonded ice from the pavement and melting it.
The Chemistry of Dry Ice Melt
Dry ice melters are mostly mineral elements like sodium, calcium, magnesium and potassium with a chlorine ion (Cl-) attached. Together they are chloride molecules or salts. These chloride ion molecules easily bond with ice molecules. After the salt contacts the ice, the salt molecules begin bonding with the ice molecules, converting the ice into a salt water solution called “brine”. This solution then runs off the surface or evaporates in the air, leaving a safe dry surface.
The most commonly used salts for melting ice are:
- Sodium Chloride (NaCl)
- Calcium Chloride (CaCl2)
- Magnesium Chloride (MgCl2)
- Potassium Chloride (KCL)
Each of these chlorides has unique ice melting performance. The melting performances of dry deicers can be found by viewing the melt value comparison on this site.