Calcium chloride is an ionic compound composed of one calcium ion and two chloride ions. It is a colorless or white crystalline solid at room temperature that is highly soluble in water. This compound is notably hygroscopic, meaning it readily absorbs moisture from the surrounding air, a property exploited in many of its applications. When dissolved, calcium chloride releases heat in an exothermic reaction, making it effective for melting ice. It is commercially available in several forms, including dry flakes, small spherical pellets, and as a concentrated liquid solution.
Commercial Availability and Typical Pricing
The cost of calcium chloride varies widely based on its intended use, purity level, and the quantity purchased. For large-scale industrial buyers, like municipalities purchasing for de-icing, the price is often quoted by the ton. Industrial-grade flakes used for de-icing and dust control typically range from $90 to $350 per ton in bulk. Higher purity, anhydrous grades, which have very little water, can show greater price volatility than the more common dihydrate forms.
Consumers purchasing smaller quantities, such as 50-pound bags for home use, pay a significantly higher price per pound. This consumer-level pricing can range from about $0.57 to over $2.50 per pound, depending on the retailer and the volume purchased. Food-grade and pharmaceutical-grade calcium chloride command a premium price, often ranging from $250 to $600 per ton in bulk. The product is widely available to the public at hardware stores, big-box retailers, and through specialized agricultural or chemical supply distributors.
Determining Application Rates for De-Icing and Road Treatment
The required quantity of calcium chloride for de-icing and road stabilization is highly dependent on environmental factors and the specific form of the product being used. For de-icing, the compound is particularly effective because it can melt ice at temperatures as low as -25°F, a much lower threshold than common rock salt. A general application guideline for solid de-icing products is 14 to 28 pounds per 1,000 square feet, or roughly 2 to 4 ounces per square yard, when melting a thin layer of ice.
For controlling dust on unpaved roads, known as road stabilization, the application rate is generally measured in gallons or pounds per surface area. Liquid calcium chloride, typically a 38% concentration, is often applied at a rate of about 0.27 gallons per square yard.
When using solid forms for dust control, such as flakes or pellets, the rate is often around 1.3 to 1.5 pounds per square yard. The hygroscopic nature of the chemical draws moisture into the road surface, binding the fine dust particles together. This application rate may need to be adjusted based on the road’s aggregate composition, the local humidity, and whether a second treatment is planned for later in the season.
Concentration Requirements in Food Preservation and Brewing
Food-grade calcium chloride is used in culinary applications where the required quantities are measured with precision, often in parts per million (ppm) or as a small percentage of total volume. It functions as a firming agent in foods like canned vegetables and pickles, where it helps maintain a crisp texture. For these uses, a concentration of 0.1% to 0.3% in the brining or processing liquid is a common range.
In cheesemaking, it is added to milk to restore calcium levels lost during pasteurization, which improves the firmness and yield of the curd. Brewers use the salt to adjust the mineral content of their water, contributing to flavor and optimizing the mash chemistry. A common homebrewing addition is 1 gram per gallon of water, which increases the water’s mineral content. The final, total concentration of salts in brewing water is often targeted between 100 and 1,000 ppm.