Selecting the Best Color for Ice Melts
Talking about winter commuting almost always leads to stories about slipping on ice or packed snow. Car, truck, heels, or work boots – ice covered surfaces are a nuisance at best and dangerous at their worst.
The US, EU, and Canada all have high volumes of traffic in areas that receive more than 13 cm (10 inches) of snow or accumulated ice each year. Deicing is vital to prevent vehicular deaths, auto accidents, slips, and falls during the cold months. Deicing salts can be an expensive proposition, exceeding USD $3 billion per year. But the cost reduction from avoided accidents can save even more than the projected expense.
Worldwide consumption of deicing salts are about 20 – 30 million tons per year. Proper use of deicing salts can include a wetting agent to ensure the crystals don’t bounce off the road surface. Colorants allow for a visual indicator to ensure the spread uniformity during mechanical broadcasting. We’ll look at how ice melts improve surface friction and melt away dangerous ice conditions. Then, we’ll review how to get the most out of your ice melt products by additive agents and colorants.
Using Ice Melt to Improve Surface Friction
Modern ice control methods can create traction on surfaces covered in snow and ice. They improve surface friction and speed ice melting; even when temperatures are below water’s normal melting point of 0⁰C (32⁰F).
The friction of the surface increases by adding sand or other bulk minerals to the ice melt product. Distributed by broadcasting them across the surface, the mineral will bite into the ice and provide extra traction with a shoe’s sole or a vehicle’s tire.
Sands and minerals also have a slight assist in melting the ice. If the material is dark, it will absorb some heat energy from the sun. The material also absorbs friction-generated heat from vehicular traffic.
How Salt Melts Ice and Snow
Salts mix in an ice melt as a large crystal or in a brine solution. Its main job is to melt the ice into water, which allows it to flow off the roadway or sidewalk. Salt also provides some traction for foot traffic. Minerals and sand add in the traction, as salt is soon crushed by traffic.
Ice melts work because salt and water create a eutectic mixture, a unique solution with a depressed melting point. This is what allows the ice to melt and run off the roadways regardless of the freezing temperatures.
Choosing the Right Kind of Salt
Ice control works with many different kinds of ice. The most common is sodium chloride (NaCl). The eutectic mixture of sodium chloride and water can have a depressed freezing point of -21⁰C (-5⁰F). Magnesium chloride and calcium chloride are capable at even lower depressed freezing points, able to melt ice at -40°C (−40°F). Salts with lower corrosion potential – sodium formate, potassium formate, sodium acetate, and potassium acetate – are available and used in critical infrastructure deicing, such as airport runways and taxiways.
Wetting Agents and Colorant Additives to Ice Melts
It’s much more effective when salt remains on the road, rather than bouncing off into the shoulder or ditch. The proper application of rock salt (NaCl) generally includes a wetting agent. In the pre-wetting stage, we see water and sometimes another salt, like calcium chloride, spray applied on rock salt. Pre-wetting helps the salt stick to the road during broadcasting.
Another advancement to ice melt is the addition of a colorant to crystal salts. The colored salt gives an excellent visual indicator of how heavy and how even it’s spread on the ground. Colorants can be either dyes or pigments and shade matched. It’s also possible to create a specific brand color for brand identity retention. Colors are also useful in identifying the application temperature ranges to ensure use of the right salt blend for the conditions.
Colorants can be applied by the salt supplier or added to wetting agents at local warehouses. Some colorants are low-staining, which can reduce the chance of staining carpets and clothing. Nontoxic, eco-friendly, and natural colorants have shown to be commercially viable. There are also fluorescent colors available, which will glow under ultraviolet light (black light) for nighttime applications.
Protecting roads from the dangers of ice becomes a high priority for many states come winter. Doing so in an efficient, regulated manner guarantees you’re providing safety to communities while effectively using resources. Adding dyes or pigments to ice melt products will help protect drivers and pedestrians. You’ll have the ability to choose the right ice melt, or see where it’s been applied. Another unexpected way colorants enhance our lives.
About the Author: Doug Thompson
