We collected a few aluminum cans, and after lots of FaceTubing, we thought we'd try melting them down into ingots.
First try was with coal in the forge, while we pounded out some metal. We cut the top off an old, used up propane tank. This method was pretty slow but didn't cost anything. It took us ~30 min to melt a can or two and we lost interest.
Our next attempt was with a #10 can and some ceramic paper. The paper was off ebay, and we paid ~$6 for 3 sheets. it took 2 sheets to line the can. This time we punched a hole in the side of the can for the hand-held propane torch.
This method was MUCH faster - we melted ~30 cans in about 30 minutes. Cheap, and fast enough it kept our attention this time.
The flame was concentrated on the one side of the crucible. the heat spread, but not more than half way around.
The cans melted pretty fast, but we were surprised how much garbage was in the metal. About half of the metal was unusable - and we had to do a lot of skinning off the top.
The ingots we poured into a small muffin tin. They turned out really cool! You can see some of the 'garbage' metal, too. Not sure if this is poor-quality aluminum or from all the plastic, etc in the cans.
Great fun, fairly fast, and pretty cheap to do. $6 for the ceramic paper, $1.50 for the propane, and $2 for the muffin tin. Worth a try!