By Greg Baun
The snow and ice industry has had an 80-year history of using white salt as a stand-alone product to deice roads and other surfaces. Although salt continues to be the workhorse for the industry, a number of advancements over the past 20 years have improved site safety, reduced costs and helped the environment.
The thought of treating white salt with a liquid has been around since the early 1970s. In some municipal yards, you can see the remnants of old spray showers. A plow truck loaded with white salt would pull under a showerhead that dispensed calcium chloride on top of the white salt. This technique had its limits in being able to properly coat the material to achieve the desired benefits. Equipment was also limited, making reliability an issue.
Use of carbohydrates in winter maintenance is linked to 1986 when Hungarian chemist Peter Toth worked in a distillery and was asked to investigate why the tailing pond was not freezing during winter conditions. Initially, the company thought they were losing alcohol, but after further investigation Toth discovered that the effluent from distillation was acting as a freeze point depressant. Toth filed patents in Europe and North America for use of carbohydrates as a liquid road deicer. This would set the stage for further advancements in the deicing industry.
To my knowledge, in 1996, in our lab in Ajax, Ontario, chemist Derek Yan discovered the synergistic effect between magnesium chloride solution and carbohydrates. Yan discovered that by adding magnesium chloride solution and carbohydrates (sugars) in certain ratios, the eutectic point (freeze point) would drop, in some cases below minus -60° C. This significant discovery changed winter maintenance operations forever.
Treating white salt with a magnesium chloride-carbohydrate blend began in western New York in the winter of 1996 with a portable stacker outfitted with a liquid application system where white salt was coated with a blend of magnesium chloride and carbohydrate. It has taken 20-plus years to refine both the liquid treatment and the production process to ensure every grain of treated salt is produced on specification.
The moisture level and gradation of the salt, and concentration, blend and application rate of liquids are vital to a reliable effective end product.
Today, every major salt company in North America offers a magnesium-chloride treated salt. By making treated salt at the mine site or at a large salt depot, it can ensure that both the quantity is available and that the quality of the treated salt meets industry standards. Quality of material is important because millions of tons of treated salt are being dispensed on roadways and parking lots throughout North America.
With today’s environmental concerns and economic landscape, having treated salt in your winter maintenance toolbox makes good business sense.
Treated salt 101
Treated salt, with its many attributes, is a great tool for snow and ice professionals.
- Starts to work immediately
- Reduces effective working temperatures
- Reduces bounce and scatter
- Residual effect that keeps product working longer than untreated salt
- Requires less product to cover same area
- Is less corrosive to vehicles and infrastructure
- Is better for the environment
- Doesn’t require the purchase of specialized application equipment
Questions to consider before you buy:
- What level of service does your client demand?
- Do they need bare pavement 24/7? (e.g., hospital, retirement home, casino, etc.)
- Is your customer willing to pay extra for a premium product that works better than plain rock salt?
- Do you have enough equipment and equipment operators to manage all of the properties that you service?
- Do your operators overapply regular rock salt?
- Does the customer site have any “trouble” areas that warrant using a better product (e.g., low-traffic areas, shaded areas, etc.)?
- Is your equipment calibrated so you know how much material is being used?
- How important are environmental factors to your customer?
Questions to ask a treated salt supplier before you buy:
- What type of liquid is the salt treated with?
- What is the working temperature of the treated salt in comparison to white salt?
- How much longer will it last?
- How much less material can we expect to use?
- How much does treated salt cost compared with regular rock salt?
- Should it only be used in colder temperatures?
- How should it be stored?
- How long is the shelf life?
- Does your salt have issues with leaching?
- Will it clump up in our spreaders?
- Is it made using a pugmill or is it blended with a loader?
- Does it stink or will it stain my customer’s property?
- Is it less corrosive on equipment compared with rock salt?
- What is the best way to conduct a proper trial of rock salt vs. treated salt?
- Do you have any references from customers who have used your product?
Greg Baun owns Innovative Surface Solutions with offices in Ajax, Ontario, and Albany, NY. Learn more at www.innovativecompany.com.