Frequently Asked Questions - Ice Melt
WHAT IS BLENDED ICE MELT?
A blended ice melting product is a composition of numerous de-icing granules which work in conjunction with one another to provide optimum melting performance. Blended product typically contains two or more of the following chlorides or granular products (along with liquid enhancement products and liquid dyes):
• Sodium Chloride (Rock Salt)
• Magnesium Chloride
• Urea (Nitrogen)
• Liquid dyes (for increased visibility, no melting capabilities)
• Calcium Chloride
• Potassium Chloride
• Limestone (for traction)
• Liquid enhancement products (typically sprayed on)
The percentage of each ingredient utilized in any given blend will dictate the quality, consistency, and appearance of the de-icing product. Each ingredient listed above brings with it a set of positive and negative characteristics in regards to performance, price, and de-icing effects.
In formulating a blend, the ingredients most often utilized are three chlorides: sodium, calcium and magnesium. The basis for the majority of blends on the market is sodium chloride as it carries a low cost and is readily available. It also performs down to relatively cold temperatures and can be activated by friction from tires and even heavy foot traffic. Sodium and potassium chloride both work by absorbing heat, they do not generate heat by themselves. The low temperature melting and speedy activation of a blend is normally attributed to the calcium and magnesium chloride in the blend. Both chlorides react faster and to lower temperatures than sodium or potassium as they benefit from hygroscopic characteristics. In other words, calcium and magnesium draw in moisture from the surrounding air to create heat. The higher the percentage of calcium and magnesium in a blend, the faster the product will work. It also means that the blend will work to lower temperatures. With the increased performance comes a higher price tag, calcium and magnesium chloride are expensive raw materials, so the higher the percentage of calcium and magnesium, the higher the cost of the product.
EFFECTS OF ICE MELTERS
This is an example of concrete that would be at risk of damage to increased freeze/thaw cycles. The concrete either has not been given ample amounts of time to dry, or there was too much water added to the concrete mix
CONCRETE DAMAGE
Any and all effective ice melting products have the potential to create a circumstance where concrete damage may occur. De-icing products will not chemically damage high quality concrete. However, damage can occur when a de-icing product works properly and causes water to seep into naturally occurring cracks and air pockets in concrete and other hard surfaces. When the de-icing material dissipates, the water eventually re-freezes. When the water re-freezes, it expands. This expansion of water causes a hydraulic effect on the concrete walls and causes the disruption and weakening of the overall concrete.
To avoid damaging the concrete, applicators should follow the application directions on the back of the bag or container and remove the slush or pooled water that is produced as soon as possible. If the de-icing product is over applied, there will be a greater melting period, allowing for more freeze/thaw cycles. Also, establishing strong, properly air entrained, and properly finished concrete will also increase resistance to the re-freezing of water and reduce the potential for concrete damage.
VEGETATION
The best way to control vegetation damage from ice melting products is to minimize usage and curb runoff as much as possible. Therefore, the best way to reduce the chance of harming vegetation is to apply product at the recommended rates and to control the spread of the product. For this reason, the applicator has the biggest hand in controlling vegetation kill. Each chloride and granular product used in a blended ice melting product has the potential to harm vegetation when over-applied. The key is to use an effective product that allows you to spread less material. Commonly used ice melters like urea and potassium chloride are very gentle to vegetation, but they do not de-ice effectively. Sodium, magnesium, and calcium chloride are much more active de-icers, therefore; applicators can use less of these products and yield the same results as urea and potassium. This will result in faster and more efficient results at a lower cost.
CORROSION
It is a natural characteristic of chlorides to corrode metal to a certain degree; however, when used properly the effect can be contained. Magnesium is the least corrosive of all the chlorides. This reduces the probability of chloride brine coming in contact with metal and causing corrosion. The higher the magnesium content in a blend, the less corrosive the product will be. Sodium, calcium, and potassium chloride are all rather corrosive to metal, so to minimize the risk of corrosion, products with high percentages of these chlorides should not be spread near metal objects or metal framework.
TRACKING
A main area of concern for businesses, institutions, government facilities, and homeowners comes during and after the storm in the form of ice melt residue and tracking. All ice melters have the potential to be tracked indoors. Although it is impossible to avoid tracking altogether, applicators can take steps to dramatically reduce the amount tracked indoors. The degree of tracking is based on three things:
1) MELTING SPEED: Ice Melting products geared for speed track less because they penetrate the ice quickly and dissolve into a liquid brine faster. Once in a liquid form, the slush and brine can be tracked into buildings, where they will dry out and leave a powdery, chalky residue. This residue is easily swept or mopped up and is not a threat to cause long term damage.
2) ICE MELT COMPOSITION: Ice Melting products with high percentages of calcium and magnesium chloride tend to track less than other formulations. This is true because the faster a product breaks down and activates, the less likely it is to be tracked indoors. Calcium and magnesium chloride tend to break down and leave a white, chalky residue, but the advantages of the speed enhancement they provide far outweigh the minimal residue created.
3) OVER-APPLICATION: When an ice melting product is over-applied, the risk of tracking increases as well. By applying too much product, the applicator increases the chance of having inactive material sitting on the surface. Inactive material increases the chance for granules to be tracked in on the soles of pedestrians’ shoes.