HCl and lime mixture?
Asked by
El_Cadejo (
34610
)
September 2nd, 2012
I have a pipe that I carved out of stone. A couple days ago it got dropped and snapped in half by someone who was borrowing it. They gave it to one of their friends who fixed it perfectly. It was actually astounding how smooth and perfect the fix was. I only got a few minutes to talk with him and he said to fix it he just mixed powdered lime and muriatic acid and used that to melt the stone together.
When I got home I tried googling this to find out more but havent really been having much luck. As far as I can tell what happened was that the lime was neutralized by the muriatic acid which I assume caused a lot of heat to be given off in the process.
Could someone explain better what exactly happened during this reaction and how I would go about replicating it(ratios) in the future if I ever needed it to fix something like this again?
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14 Answers
(GQ) I’ve been researching this to no avail (yet). My intuition tells me that the reaction (between the lime and the acid) deposits something that fills up the cracks.
@PhiNotPi yea I was thinking something like that too, its just interesting that whatever that compound is, it has the ability to completely fuse stone. Like really if I wasn’t told this pipe was broken at one point I could honestly never tell, its just that perfect.
What type of stone is it? Granite, limestone, something else?
@PhiNotPi its steatite or soapstone so its a fairly soft stone but still…. I just cant get over being amazing by this repair job lol
Soapstone (made mostly of talc) can dissolve in some acids (according to Wikipedia), so it is possible that the acid was able to fuse the stone together.
@PhiNotPi so if the acid dissolved the rock together, was the lime needed for the fusing process, or was it just to neutralize the process and stop further corrosion of the stone?
He might have used it to neutralize the acid to stop the dissolving process and cause the soapstone to re-deposit, fusing the cracks together, although I am starting to go out on a limb.
The reaction between lime (calcium carbonate, CaCO3) and HCl produces calcium chloride (CaCl2), which is a solid at room temp. I’m no chemist but from what I read I’m not sure that’s useful in fixing broken stone. Also, “lime” might not be just calcium carbonate. For all the chemistry I took in school (6 semesters inorganic, 6 semesters organic) I didn’t learn much of practical value.
@gasman ok so CaCO3 +HCl=CaCl2 so when mixed it would make some sort of pastey like substance im going to assume? Then that is just applied to the stone like a glue?
Well, I really don’t know. Need a real chemist to answer this!
I’m not a real chemist either!
Well you guys are good for fake chemists :)
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Update: went to the chem lab today and asked. I was told basically everything thats already been said here. They told me they would research exactly what was going on and let me know so ill post it here when i find out.
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