Urea is 46% N. We buy and use it by the truck load on the farm. Some time
when you don't have anything better to do, stop by your local fertilizer
co-op. Take a look at their trucks or ask them to see the equipment that
they spread or haul urea with. If it isn't wood, plastic, stainless steel,
or brand new it will have corrosion, pitting, and rust. If aluminum wasn't
affected by urea, we'd use aluminum tanks, hoppers, mixers, conveyors and
augers rather than stainless, everything would be a LOT lighter. Granted,
urea isn't AS corrosive as phosphates and potassiums, but urea by itself
will corrode aluminum. It will corrode copper. It will corrode steel.
I've got plenty of equipment around here that is specifically used to handle
urea and other nitrogen fertilizers that can testify to that. An airplane
makes a well balanced diet for urea.
Jim

wrote in message
oups.com...
Is urea still applied at some airports?

Urea is used as nitrogen-type fertilizer. We've used it on the
runway at low application rates to get thin skins of ice off it. The
urea will melt or cause evaporation of small patches of ice so that the
sun can warm those little patches of pavement and begin the warming
process that gets rid of the rest of the ice. Ice and/or snow will
reflect the sun's heat back into space.
Some have used soot applied to the snow or ice to absorb light
and start melting. Soot, though, is commonly found in ashes, which can
be corrosive.
Sawdust can be used to gain traction on ice. Only disadvantage
is its being tracked into the hangar, airplane, house, whatever.

Dan