Deicing salt

Although another effective but less corrosive deicing agent is commercially available (calcium magnesium acetate or CMA), its price seems to be too high for wide usage. One ton of CMA costs 300 to 600 as opposed to 20 to 70 for rock salt. The use of CMA has 

The impact of salts on protective coatings is widely recognized. 

Any breach or holiday in the coating will let salts reach the metallic substrate and initiate a very aggressive environment that in turn will force the coating to blister and peel off (Figs. 9.16 and 9.17), sometimes until complete perforation of the metal (Fig. 9.18). 

In another study, it was demonstrated that high corrosion rates could be measured more than 100 m downwind of a major highway in similar winter conditions Fig. 9.20 [12]. The corrosion trends measured 

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Water-soluble crystal modifiers such as yellow pmssiate of soda (YPS) (sodium ferrocyanide decahydrate) or ferric ammonium citrate may also be added to some types of salt as anticaking agents. Both are approved by the U.S. Food and Dmg Administration for use in food-grade salt. YPS and Pmssian Blue (ferric ferrocyanide), are most commonly added to rock salt used for wintertime highway deicing. Concentrations of YPS and Pmssian Blue in deicing salt vary, typically in the range of 20—100 ppm. 

Chlorine. Nearly all chlorine compounds are readily soluble in water. As a result, the major reservoir for this element in Figure 1 is the ocean (5). Chloride, as noted earHer, is naturally present at low levels in rain and snow, especially over and near the oceans. Widespread increases in chloride concentration in mnoff in much of the United States can be attributed to the extensive use of sodium chloride and calcium chloride for deicing of streets and highways. Ref. 19 points out the importance of the increased use of deicing salt as a cause of increased chloride concentrations in streams of the northeastern United States and the role of this factor in the chloride trends in Lake Ontario. Increases in chloride concentration also can occur as a result of disposal of sewage, oil field brines, and various kinds of industrial waste. Thus, chloride concentration trends also can be considered as an index of the alternation of streamwater chemistry by human development in the industrialized sections of the world. Although chlorine is an essential element for animal nutrition, it is of less importance for other life forms. 

When mature concrete is contaminated by chloride, e.g. by contact with deicing salts, the cement chemistry is more complex, and less chloride is taken up by the cement hydrate minerals and a larger proportion is free in the pore solutions and can therefore pose a greater hazard. When embedded steel corrodes, the production of a more voluminous corrosion product pushes the concrete from the steel with resultant cracking and spalling of the concrete. 

Soil Combustion (oil, coal, refuse) Tire wear Concrete cement Salt spray, deicing salt Metal corrosion wear Motor vehicle Weathered paint... 

Automotive General corrosion of the body of cars due mainly to deicing salts car scrapped due to accidents, obsolescence and corrosion, correlation between injuries in accidents and age of the car Improvement in the body of the car and its resistance to corrosion. Rustproofing treatments were developed... 

Corrosion of suspension bridge over Severn River, Pelham bridge in Lincoln, bridges in New York state and other areas containing deicing salts. This is an expensive problem that needs immediate attention... 

The source of chloride is seawater as well as the deicing salts used on roads. The hydrogen chloride is also present in seawater aerosols. The corrosion of copper and its alloys in marine atmospheres has been studied and a corrosion rate of 600-700 pg/cm2 yr averaged over a period of 8 yr has been reported.50... 

R.J. Neville, Automotive Corrosion by Deicing Salt, R. Baboiam (ed.), NACE, Houston, Texas, 1981, pp. 182-218. 

Spalling A surface failure of concrete usually occurring at the joint or at the exposed face. It may be caused by overworking the concrete, by deicing salts and so on. 

Bilodeau, A., Carette, G.G. (1989) Resistance of Condensed Silica Fume Concrete to the Combined Action of Freezing and Thawing Cycling and the Deicing Salts, ACI SP 114-47 Trondheim Conference, pp. 945-970. 

Baboian, R. "Automotive Corrosion by Deicing Salts" National Association of Corrosion Engineers 1981. 

Rowe, L. C. and Chance, R. L. "Fundamentals of Corrosion Testing" in AUTOMOTIVE CORROSION BY DEICING SALTS ... 

Hazardous Chemical Hazardous Chemical Highway Deicing Salts Disposal Well... 

Deicing salts can cause concrete to deteriorate. What could be put in or on the concrete to prevent this How might one polymerize a monomer in the concrete to make it stronger and more durable ... 

The regular use of deicing salts, essentially sodium and calcium chlorides, in winter period, affects the resistance to drought stress of trees and crops, and increases the sensitivity of plants to parasitic diseases. 

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