Harold posted this on another thread, seems a better fit here, ::::::::: You guys are missing the boat where it comes to dealing with this material by furnace. Instead of melting, you should be thinking about dissolving. That's the way silicon is dealt with. It melts at about the same temperature as platinum, yet it is put in solution at much lower temps, regularly, by dissolving instead of melting. Fluorspar is an excellent solvent, but keep in mind, it's just as hard on furnace lining as it is the charge. That's the problem with dealing with ceramics.
One other thing that appears to be escaping common logic here is that even if you melt the materials in question, in spite of the weight of these metals, they rarely will agglomerate and collect in the bottom. That would be particularly true of something that is as finely divided as it is in catalytic converters. A collector of some nature may well be required to effectively recover the values if you resort to melting as the method of operation. That will require an operation to sort the values from the collector. Has anyone addressed this issue?
Frankly, I'm of the opinion that most of you guys would be far better served to put your energy into recovering gold, even if it was only from electronic scrap. The investment you'll have to make to recover the platinum group is likely to be far more than you're prepared to pay, and its going to get harder and harder to procure the old cats unless the market does a serious turn-around.