angelhair
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Shelf life of Hydrated lime
I have an ordinary 20kg bag of hardware store hydrated lime that's been sitting in a damp basement for about 3 years.
Should I assume that some of it would be CaCO3 by now?
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plante1999
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did the bag is at oppen air?
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a_bab
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It takes years and years to turn Ca(OH)2 to calcium carbonate. That's why as the time passes, the walls built with hydrated lime+sand as a liant for
bricks will get stronger and stronger. However, we are talking about tens of years if not hundreds for a full reaction. The reaction is said to be
faster in water though, making the lime an appropiate liant in the past (roman empire bridges for instance).
The easiest way to test your lime is with some acid. The bubbles will give you an idea of how little CaCO3 you've got in there. Simply collecting the
gas will allow you to calculate proportion of "degradation" (although it won't be precise, as lots of it will dissolve in water).
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