Thanks for the enlightening links, martyn111. I do understand your intended purpose, by the way.
Early on, I played with some pellets from a Buick cat converter. I could extract values, but didn't find it a very desirable process to deal with. It didn't help that I was becoming busier than I had imagined with my refining exploits, and didn't like wasting my time.
The concept of removing values from these devices is akin to recovering precious metals from the human waste disposal systems in silicon valley. I don't recall the particulars now, but it was well known that the waste from sewage disposal plants in that area contained a generous amount of gold, and, I imagine, other precious metals. However, like extracting gold from the ocean, it may cost more to recover than its value---therefore I'd highly recommend that unless a very efficient system be employed, that attempting to recover values from anything, including the converter, is best left to those who have developed such systems. For sure, I wouldn't encourage anyone to pursue recovering traces in mufflers that had escaped from the converters.
vinod patel,
I am most unusual here. I do not refine, nor do I have any intentions of refining. I am a retired person who used to refine commercially. I no longer have interest in the matter, and am here only to, hopefully, benefit those who have similar objectives to those I used to have. I am not well versed on the catalytic market, nor the types of platinum group metals that may be involved in given types. I am aware of their presence, and that they can be profitably processed. I am not convinced they can be processed efficiently by the amateur refiner, however, and have strong feelings that extraction is most likely not very good. Therefore, I am not a good individual with which to engage in this subject matter. I prefer to leave it for those who have greater experience and knowledge. None of that prevents me from having an opinion, though!
Harold