Road Salts

1
Road Salts
2
Types of Salts We Use

• Sodium Chloride - NaCl, salt, Halite
• Calium Chloride - CaCl2
• Magnesium Chloride - MgCl2
• Potassium Chloride - KCl
• Urea CH4N2O
• Ammonium Nitrate - NH4NO3
• Ammonium Sulfate - (NH4)2SO4
• Calcium Magnesium Acetate CaMg(CH3CO2)4
• Potassium Acetate K(CH3CO2)

3
Home Salt v. Highway Salt

• Home Sodium Chloride
• Highway Sodium, Calcium, Magnesium Chlorides and
  other more expensive salts and chemicals

4
How Salts Work

• Melting/Freezing Equilibrium
• Dissolve and dissociates into ions
• Creates more space between water molecules

http//antoine.frostburg.edu/chem/senese/101/solut
ions/images/fpdepression.swf
5
Road Salt Effects

• Chlorides
• Greatly reduce freezing point
• Damaging to concrete
• Calcium and Magnesium chlorides can be hazardous
  to human health
• Vegetation damage

6
Road Salt Effects

• Potassium Chloride
• Not as effective at very low temperatures
• Safer for vegetation if not used excessively

7
Road Salt Effects

• Urea
• Not corrosive in pure form
• Most urea used for melting ice is agricultural
  grade

8
Road Salt Effects

• Ammonium Sulfate and Nitrate
• Fertilizers
• Attacks concrete and is not recommended

9
Road Salt Effects

• Acetates
• Potassium acetate is biodegradable but corrosive
• Calcium Magnesium acetate is the safest of all
  deicers in regard to vegetation, concrete, and
  water sources
• CMA is biodegradable and non-corrosive
• Very Costly- 30 times the cost of NaCl

10
Environmental Concerns

• Soil and vegetation damage
• Water contamination/pollution
• Concrete and Steel deterioration
• Vehicle corrosion

http//www.billingsgazette.com/krt/winter/hazards/
html/4b.htm
11
Works Cited

• http//antoine.frostburg.edu Why Does Salt
  Melt Ice?
• http//www.riverside.org Low Salt Diets
• http//www.irc.nrc Chemicals for Snow and Ice
  Control Around Building
• http//science/howstuffworks.com/question58
• Baird, Colin. Gloffke, Wendy. Chemistry In Your
  Life. W.H. Freeman and Company. New York, Ny.
  2002
• http//www.geocites.com/desi9646/saltyroad.html
  What is the Best Chemical to Put On an Icy Road?
• http//sciguy.com/experiments/athome/homeexperimen
  t.asp?experiment5 Fish an Ice Cube with String