What can stand up to a propane blowtorch?!?!?

Question

I've been trying to make quicklime, and today I was going to try again using a porcelain crucible that I had bought online. I put powdered chalk in the crucible, focused the blowtorch's blue flame on it, and within seconds the lid exploded, sending fragments everywhere. I fixed the lid, but obviously I can't use that container for blowtorching again. I need a container to put the powdered chalk in that will stay in one piece under the temperature of a propane blowtorch. What kind of crucible can I use? Iron? Steel? Any suggestions are much appreciated.

Answer 1

Your crucible shattered because you heated it too fast, not because it can't withstand the heat.  Porcelain crucibles are good up to around 1200 C, a propane flame is at maximum about that same temperature.  Quicklime forms 300 C lower, at around 850 C.  You should be able to do this provided you *slowly* heat your crucible with the torch and don't just slam the hottest part of the torch onto your crucible.  Make sure you move the flame around the crucible, warming the entire thing up before you use the hottest part of the flame.  Patience is a virtue here.

Also, if you are using "chalk" for a chalkboard, that is gypsum, or calcium sulfate, not calcium carbonate.  Heating gypsum won't make quicklime.

Answer 2

Copper.