HOW CALCIUM CHLORIDE WORKS TO CONTROL DUST
Calcium Chloride is hygroscopic – it attracts moisture from the air and its surroundings. This is how it keeps the surface of a road damp and keeps the dust down. Calcium Chloride also resists evaporation which allows one application to last a long time.
HOW LONG CALCIUM CHLORIDE LASTS
Most customers find that one application of Calcium Chloride for dust control will last them through the year. There are a few things to consider though.
If the application area if considered “high traffic,” it may take two or more applications a year. High traffic areas have more vehicles crushing the road base, thus causing more dust.
Weather is also something to consider on the longevity of a Calcium Chloride application. If the summer is very dry with very little rain, you may start to see the effects of the Calcium Chloride diminishing over time. The occasional rain is great for an application of Calcium Chloride and can help reactivate the solution.
Properly prepping the road can also help the Calcium Chloride application last through the season. Having your road graded can also help bring your Calcium Chloride application back to life and keep the dust down longer.
Road Treatment – Information About Calcium Chloride
Calcium chloride outdistances traditional deicing materials to achieve safer, bare pavement – faster than salt or abrasives alone. Calcium chloride melts up to eight times as much ice as does salt alone – within the first 30 minutes at 20F (-7C) following application. Premixed with salt and abrasives, calcium chloride becomes a cost-effective edge for winter road safety.
PROPERTIES
- Exothermic: calcium chloride releases heat as it melts to speed salt’s melting ability.
- Hygroscopic: calcium chloride attracts moisture and dissolves quickly to activate rock salt’s melting action.
- Fast Acting: calcium chloride begins to dissolve immediately upon application to break the bond between pavement and ice.
- Powerful: calcium chloride brine remains active for prolonged periods of time to prevent ice from bonding to the highway.
- Low Eutectic Point: calcium chloride melts to much lower temperatures than salt; controlled studies prove its effectiveness down to -59F (-51C)
BENEFITS
- Highway Safety: studies show that in 85% of applications, calcium chloride/salt mixtures achieve bare pavement faster than salt alone at temperatures near 30F (-1C) to ease traffic and reduce accidents.
- Savings: calcium chloride increases salt’s effectiveness, therefore reducing the number of applications necessary during storms, saving manpower, equipment and material costs. Plus, it freeze-proofs abrasives to help them embed in ice and snow, so you lose less material to spreader bounce and traffic scattering.
DEICING APPLICATION TIPS
When winter storms hit, correct application of premixed or prewetted materials can make a difference in keeping roads in an easily plowable condition. They save valuable time in treating roads before precipitation begins to bond with the road surface. Application tips from road superintendents who use calcium chloride include:
- Get out early and use adequate amounts of road materials throughout the storm.
- Don’t let ice buildup under snow; keep snow slushy and plow it off.
- Treat hills and intersections first.
CALCIUM CHLORIDE VERSUS COMPETITIVE DEICERS ALONE
Rock Salt (Sodium Chloride)
- Has substantially diminished effectiveness below 25°F (-4°C). The amount of ice melted per pound of rock salt drops 61% from 30°F to 25°F.
- Melts less ice in a given time period
- Has slower melting action.
- Bounces and scatters off road (typically 30%)
- Has environmentally negative impact
Sand and/or Abrasives
- Do not melt ice and snow, just provide some traction
- Bounces and scatters off road
- Requires clean-up
Rock Salt and Sand/Abrasives Combined
- Offer less melting performance over rock salt alone
CALCIUM CHLORIDE GIVES OPTIMUM RESULTS
A road is only as strong and durable as its base … and the stability of the road depends on the proper interlocking of the aggregate. Calcium Chloride:
- penetrates the road aggregate, coating the particles and binding them together. Binding action keeps the road dense and compacted.
- speeds compaction of the base materials.
- maintains moisture in road base to minimize the loss of fines, and maximizes the service level of the wearing course.
- is a cost-effective alternate in recycled asphalt bases.
WETTED SALT WITH LIQUID CALCIUM CHLORIDE
At 25F (-4C), rock salt takes a full 19 minutes to embed in ice and hard-packed snow. But wetted with a 32% calcium chloride solution, rock salt immediately digs in – and holds a close pattern on winter roads as temperatures drop down to 0F (-18C). Wetted salt reduces the need for frequently repeated applications, decreasing material use by as much as 40%.
PREPARING WETTED SALT
Storing 32% calcium chloride solution in bulk tanks allows fast, efficient spraying on rock salt as needed. Except for the equipment and adaptation methods described below, wetted salt application techniques vary only slightly from those for conventional rock salt.
- Spraying in the spreader truck Load rock salt into the spreader truck and drive it beneath a spray bar containing calcium chloride solution. You can then easily spray the amount of
calcium chloride needed onto the salt. - Spraying during application Spreader trucks equipped with calcium chloride tank/feeding systems allow fast and effective application of wetted salt. During application, the salt is
wetted with the calcium chloride solution and spread simultaneously.
HOW CALCIUM CHLORIDE AND ROCK SALT WORK TOGETHER
| Calcium Chloride | Rock Salt |
|---|---|
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ADDITIONAL WINTER USES FOR LIQUID CALCIUM CHLORIDE
- Wetted abrasives:
spray calcium chloride solution on abrasives to help them embed quickly in ice and snow save applications, plus material, manpower and equipment costs. - Freeze-resisting stockpiles: spray 32% calcium chloride solution on coal, sand, abrasives, limestone, wood chips, ores and minerals as they are built into stockpiles to keep them free-flowing in winter. Or spray entire stockpiles after they are built for the same long-lasting protection.
- Thawing frozen stockpiles: restore frozen-solid stockpiles to their original condition by adding calcium chloride solution to the frozen masses.
ROAD STABILIZATION PROCEDURES USING CALCIUM CHLORIDE
Stabilizing a road with calcium chloride consists of 7 steps:
- Scarification of road surface
- Addition of aggregate
- Application of calcium chloride
- Mixing of materials
- Shaping and cross section
- Compaction of surface
- Seal surface with calcium chloride
MARKETS AND USES OF CALCIUM CHLORIDE
- Chemical Manufacture: production of calcium salts
- Construction: cold-weather concrete additive; soil solidification; tractor tire weighting
- Drying Air and Gases: direct drying compound
- Highway Construction: shoulder and base stabilization
- Highway Maintenance: dustlaying; snow and ice control
- Mining: dustproofing and freeze-resisting ore and coal
- Paper Manufacture: increases web strength of corrugating media; improves dye retention
- Petroleum: additive to oil well completion fluids; cementing finished oil wells; drilling mud additive; drying petroleum fractions
Calcium Chloride Manufacturing Process
Step 1. Calcium Chloride & Salt Solution:
Calcium Chloride is formed by the reaction of ammonium chloride and milk of lime
Step 2. Primary Settlers:
Solid impurities are “settled out” and pumped to waste beds
Step 3. Evaporators:
The clarified calcium chloride solution contains sodium chloride, which precipitates at a specific concentration in the evaporators
Step 4. Centrifuge:
Sodium chloride is extracted from the slurry by a centrifuge. Liquid calcium chloride is now available for use
Step 5. Concentrator:
A concentrator removes additional water, producing a 73% calcium chloride solution
Step 6. Drum Flaker:
As the hot, highly concentrated solution of calcium chloride is cooled by a drum flaker, it solidifies into flakes
Step 7. Rotary Dryer:
Rotary dryer leaves only 20% to 23% moisture in the finished product. This yields 77% to 80% flake calcium chloride.
LIQUID CALCIUM CHLORIDE HARD ON ICE, EASY ON CORROSION
The growing need for corrosion-inhibited deicers has prompted manufacturers to explore their production. One example of this is a corrosion-inhibited grade of liquid calcium chloride designed to meet or exceed various states’ deicer standards in all respects. In addition to providing low corrosion versus salt, it has calcium chloride’s operational benefits in that it continues to melt snow and ice at 20°F, the temperature at which salt becomes an inefficient deicer.
The most popular types of ice melt products are Calcium Chloride, Magnesium Chloride, and Brine solutions. Calcium Chloride is a hygroscopic salt that utilizes these properties to absorb moisture from the air and lower the freezing point of water to prevent ice build-up. Magnesium Chloride works in the same way, and these two products differ based on their chemical makeup and chloride concentration. It can be said that Calcium Chloride is typically available in higher chloride concentrations, allowing less product per application and potentially being more cost-effective, however, Magnesium Chloride is slightly more environmentally friendly. Brine solutions are typically a mixture of sodium chloride and water, and come in varying concentrations. The concentration of sodium chloride affects the potential freezing point of water, and thus the effectiveness of the product. Typically, brine solutions are not as concentrated as chlorides and may require more applications and a higher degree of product.
You want your deicer and ice melt products to last for many winter seasons to come, making storage crucial to ensure the effectiveness of these products. You want to be sure that any open products are tightly sealed before storage. Deicers and ice melt should be tightly sealed and protected from moisture and exposure to direct sunlight. The ideal location would be in a climate-controlled warehouse or shed to prevent the products from having a reaction before coming in contact with winter ice. However, mass storage of these products often requires outdoor areas for storage. In that case, it’s vital to cover and seal packaged products for multi-surface protection from moisture and sun. Check out this article to learn even more about the ideal storage conditions for ice melt products to maximize their effectiveness for winter seasons to come.