What's wrong with rock salt?

[Cienja]

Ok, you can buy one of many brands of "snow and ice melter" products. What's wrong with buying a good 'ol bag of rock salt? Damage to the cement?

I use salt, btw...

 

[sjwaste]

It's usually calcium chloride. Probably cheaper? I dunno.

EDIT: Snow melt is usually calcium chloride, not table salt.

 

[Cienja]

I should have said Ice, not snow...

 

[jagec]

Well, it rusts out anything metal (this is why cars don't last long in the Midwest), and when it washed onto the soil or into the river it tends to kill things. Plus you gotta keep putting more down.

 

[ch33zw1z]

Originally posted by: Cienja
I should have said Ice, not snow...

use the edit button

 

[Jeff7]

Some of those things have other compounds in them that are supposed to be better at melting ice. (Ice, snow, whatever - they're both frozen water.) Good old rock salt will still do the trick just fine, I guess it's just not quite as quick. And maybe the other "melter" products will work at even lower temperatures. Even salt water has a freezing point.

 

[Cienja]

heh, ty!

 

[DrPizza]

Majority of people around here use rock salt. It's much cheaper than the other stuff and does just as good of a job.

 

[cKGunslinger]

Originally posted by: DrPizza
Majority of people around here use rock salt. It's much cheaper than the other stuff and does just as good of a job.

At not killing female assassins?

 

[BigJ]

Rock salt is a bad choice to use on anything concrete. You can really wind up pitting and busting it up.

 

[DrPizza]

Originally posted by: BigJ
Rock salt is a bad choice to use on anything concrete. You can really wind up pitting and busting it up.

I think the same is true of calcium chloride or almost any other salt that melts snow/ice. Everyone also seems to realize that sodium chloride is bad (slightly) for the environment. "Therefore, I should use calcium chloride" without even considering if it's also just as bad.

As far as which works better: Calcium choride is CaCl2, while sodium chloride is NaCl. Notice that there are going to be three ions present for calcium chloride vs. only 2 for sodium chloride. Then again, calcium is a much heavier ion than sodium.
28 grams of sodium chloride = 1 mole
54 grams of calcium chloride = 1 mole
So, on a pound for pound basis, (assuming my knowledge of molar freezing point depression hasn't failed me in the 25 years since I learned it) you're going to be able to melt more ice with a pound of sodium chloride than with a pound of calcium chloride. Regardless, the calcium chloride is acknowledged to work more quickly. Also, if I recall correctly, calcium chloride has a higher solubility than sodium chloride, therefore it can melt snow at even lower temperatures. (Rock salt doesn't melt snow too well once you get get below -20 degrees F. )


Better solution (imho): coal cinders. People don't like coal cinders because they make it look dirtier. I like them because people don't track salt stains into the house. They mop up a lot easier too. And, they're more environmentally friendly. Just sweep them off the sidewalk in the spring. They provide far better traction than rock salt. (Plus, being black, they absorb more sunlight and help the ice/snow melt that way.) I'm just kicking myself this year though, because we have a path of 12 inch pavers set in a bed of white marble chips. That's one place where I shouldn't have covered the ice with cinders. Oh well, the hose & pressure washer will probably be able to blow them away in the spring.

 

[FoBoT]

you can
if you want to

 

[Eli]

Coal cinders? Do they keep burning on top of the ice or something?

 

[Analog]

Some people use pelletized lawn fertilizer

 

[SampSon]

Everyone in my area, including the government, uses rock salt in the winter.

There are thoes snow melting pellets, but they are way too expensive.

Some municipalities use heated sand or coal cinders (as DrPizza said, he should know from living in the sticks).