# Cat ceramic substrate breakdown?



## nalexandrov (Jun 12, 2011)

So its seems that this question doesn't have a definite answer, each person seems to do it differently.

My preferred method would be to grind the honeycombs/pellets to around .5mm give or take and boil in a strong solution of naoh or koh. Apparently this works well, to weaken the PMG from the substrate but has the unfortunate side effect of creating soluble hydroxides of the PMG, lowering yield. The patent I got this from (cant find it atm) mentioned that platinum hydroxide could be precipitated and the solution filtered and added to the material which did not dissolve. It did not go into details on how to precipitate it, I believe it might have mentioned electrolytic methods. Does anyone have success with this, preferably lowering the volume of material atleast 80% for further extracting?

HCL boils were mentioned but I believe PGM might go into solution a little bit and also someone mentioned the solution thickens making filtration hard. What do you guys think?

What would you guys recommend for dissolving the majority of the substrate?


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## Oz (Jun 12, 2011)

nalexandrov said:


> What would you guys recommend for dissolving the majority of the substrate?


Answer; Don’t do it.

I have not heard of a good efficient process that approaches catalytic converter processing from the standpoint of dissolving the substrate away from the very finely divided values as a production process. I am open to being taught otherwise however.


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