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You can get a very similar effect by throwing a snowball into a pot of molten metal. The steam explosion can empty the pot

I do Lots of work at a few steel mills in this area , I can atest to Aluminum poping with moisture , and I have see some one throw a full can of WD40 in to a slag trough ,
big boom !!!
But the All time best I have see was a LARGE slag pot dumped in the winter at nite , oh did I for get to mention that the operators had put a full gallon jug of water in the hole where the moltent slag was dumped , follow me here , cold ground , moltent slag and a jug of water , the slag covers the water that super heats and the steam has no where to go untill the slag gives way from the pressure , I was about 1/2 mile away and had to duck flying stuff , HELL of a lite show and a BIG BOOM !!!