Not a subject I've ever had to talk about in French, but the faithful
Robert & Collins Senior tells me quicklime is, unsurprisingly, "chaux
vive". Slaked lime is "chaux éteinte". Meanwhile, my sympathies.
Personally, I'd park the bag in an odd corner and forget about it for a
year, and pop down to the shop again and get some craie, calcaire, ou
dolomie en poudre (I suppose that's what they call them: they get a few
Google.fr hits), "Mais pas, vous savez, m'sieu, de la chaux vive."
--
Mike.

Thanks for the translation. I'll know what to ask for next time!
I asked for "Chaux pour la jardin" last time, but it never occurred to me
that I'd be given anything other than slaked lime.
David.