As a snow and ice management contractor or business owner, you probably spend most of your time chasing contracts, hiring employees, managing equipment, and making sure you have a healthy supply of ice melt products. You may not take time to consider detailed questions about calcium chloride products, so here is a summary of commonly asked questions and answers that will help educate you in your business.
General Calcium Chloride Questions & Answers:
What is the proper method for preparing solutions by combining solid calcium chloride with water?
To create solutions using solid calcium chloride and water, begin by using cool water to mitigate the significant heat generated during the dissolution process. Gradually add the solid calcium chloride into the water while continuously stirring. It’s crucial to avoid letting the solids remain undisturbed in contact with the water, as this can lead to the formation of a dense cake that dissolves slowly.
Keep in mind that the temperature will rise when solid calcium chloride is dissolved, and the extent of the increase depends on the specific conditions of each application. For instance, if you’re dissolving DOWFLAKE™ Xtra 83-87% Calcium Chloride Flakes, anticipate a temperature rise of 2.8°F per percentage increase in concentration. Therefore, when preparing a 30% solution, you can expect the temperature to increase by approximately 84°F (30 x 2.8°F = 84°F).
How can you decrease the concentration of a liquid calcium chloride solution to reach a lower target concentration?
You can achieve dilution through three options: (1) using water for dilution; (2) diluting with a lower concentration calcium chloride solution; or (3) combining both water and a lower concentration calcium chloride solution. Our user-friendly Diluting Solutions Calculator tool accommodates all three scenarios for your convenience.
Is it possible to restore usability to solid calcium chloride that has solidified?
If stored in conditions allowing contact with humid air, calcium chloride may cake. For lightly caked product, tapping the sealed package against a hard surface, similar to breaking up ice, may render it usable. However, if the caking is too severe, forceful hammering is not recommended due to potential hazards. In such cases, follow the disposal guidance on the product label for caked material that cannot be restored to a usable form.
What are the recommended storage practices for solid calcium chloride packages?
Solid calcium chloride is hygroscopic and deliquescent, capable of absorbing moisture from the air, leading to liquid brine formation. To maintain product quality, it should be stored in a dry place, away from excessive moisture exposure. Store packaged calcium chloride in a manner that prevents leakage, and be cautious with certain bag types that may not seal well when standing upright. Reseal opened packages tightly after each use to prevent caking and liquid brine formation due to exposure to humid air.
For palletized products covered by an intact plastic shroud, outdoor storage on a well-drained surface is acceptable. If the shroud is damaged, torn, or removed, store the palletized product indoors or under a waterproof covering. Drums or FIBCs (Super Sacks or Big Bags) typically lack shrouds and should be stored indoors or under a waterproof covering. Solid calcium chloride is temperature-stable under all ambient storage conditions.
What construction materials are recommended for storing liquid calcium chloride solutions?
For large liquid storage tanks, the recommended material is carbon steel with an epoxy-based interior coating and a robust exterior coating. Smaller tanks storing the product at ambient temperature can use non-metallic materials like fiberglass or plastic; however, it’s important to note that these materials are not as durable as carbon steel and may lose strength at elevated temperatures.
What is the average shelf life of calcium chloride packaged products?
When properly stored to protect from moisture contact, the expected shelf life of most calcium chloride packaged products is about 36 months.
Common Calcium Chloride Ice Melting Questions
Is it safe to use calcium chloride near grassy areas and other vegetation?
In standard application conditions, calcium chloride is not harmful to grass or vegetation neighboring a deiced surface. However, similar to fertilizer or any other deicer, there is a risk of damage if the chloride-based deicer is excessively applied or if large quantities are directly placed on the grass or vegetation. Additionally, the potential for roadside damage to conifers exists when exposed to chloride-containing mist generated by high-speed tire action in highway applications of any chloride-based deicer.
Do Calcium Chloride products damage concrete when used for deicing?
Calcium chloride products are recommended for deicing asphalt and concrete surfaces designed and constructed for winter weather conditions and deicer usage. These products will not chemically attack asphalt or concrete. However, it’s essential to note that melting water from the deicing process may penetrate porous concrete and re-freeze, potentially creating pressure within the structure. Concrete resistance to scaling damage is achieved through proper air entrainment, mixing, placement, and curing, following the guidelines of the American Concrete Institute Committee 201.
Is there a risk of damage due to rebar corrosion when using chloride-based deicers on concrete structures like bridges and parking garages?
The permeation of chloride ions from deicing salts into porous concrete poses a potential threat. When chloride, oxygen, and moisture converge on the surface of unprotected steel reinforcement (rebar) embedded in concrete, corrosion occurs. Rust formation on rebar exerts pressure on the concrete, leading to issues such as cracking, spalling, and delamination. The loss of bond between concrete and reinforcing steel, along with the reduction in rebar cross-sectional area, can result in significant structural problems.
Concrete construction technology experts from companies and trade organizations are well-versed in corrosion protection options for new or rehabilitated structures. With guidance from these experts, end users should assess whether the application of chloride-based deicers is suitable for their specific situation.
How does the corrosiveness of calcium chloride compare to that of other deicers?
Assessing corrosion involves complex factors, and simple answers may not universally apply to all real-world scenarios. Generally, common types of bare metal exposed to chloride tend to experience an elevated rate of corrosion. The corrosion performance among chloride-based deicers, including rock salt (sodium chloride), magnesium chloride, and calcium chloride, shows little variation.
While some vendors may reference specific lab tests to claim one chloride-based deicer is “less corrosive” than another, such tests often do not accurately represent real-world conditions. Scientifically, there’s insufficient evidence to distinguish the corrosion performance of one chloride-based deicer over another.
Non-chloride deicers are generally less corrosive, but they exhibit weaker deicing performance. Despite their cost, these products may still be associated with corrosion problems in certain situations.
Have more questions? Contact our experienced team anytime!