# converter refining question



## jeweler1 (Mar 11, 2015)

I am doing a favor for a friend who thinks he want’s to refine catalic converters. So I’m trying to refine about a pound of cat dust (some floor sweepings also). I have refined Platinum from Platinum/silver wire very successfully but this is much different. I did some homework and a lot of reading on this forum about converters coming to the conclusion that it’s not really worth it.
I started by dissolving the powder in Aqua regia 3 times (filtering each time) to insure all the metal was dissolved. Than I simmered the nitrate out and added HCL and refiltered to a nice red solution which tested red with stannous chloride. I than added powdered Zinc to drop out all metal (not really much in it). Next I redisolved it a second time in Aqua regia and slowly simmered out the nitrate. This should have concentrated the solution to a point where the Platinum would drop out with Ammonium Chloride as Ammonium Hexachloroplatinate a nice yellow powder. Nothing happened? . Now either there was no Platinum present or the amount was too small to precipate? I have worked with a lot of Palladium and this didn’t test like that I really don’t know what I have? The stannous test is red not orange and my palladium test blue/yellow any ideas would be greatly appreciated?


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## butcher (Mar 11, 2015)

Testing can be an art in itself. 
A mixture of metals may confuse the results, using a spot plate, you can precipitate one metal from the solution (the precipitant can prove, or disprove,that a metal was in solution), then moving the remaining solution to another well of the spot plate, and retesting the remaining solution you can see if it test positive for that test without the previous metals color influencing the reaction.

Maybe try DMG for Palladium looking for a yellow precipitant, then retest remaining solution for platinum with SNCl2, if Pd precipitates as a yellow powder its color will not interfere with the platinum test, as you have removed the palladium from the solution in the previous test.

You can also do a test for iron (ammonium thiocyanate looking for blood red) you may see your leach may be loaded with iron, before it is dissolving the less reactive metals...


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## Harold_V (Mar 12, 2015)

It is my opinion that what you have is platinum (the color I see is in keeping with the reaction I recall). It is also my opinion that the solution may be too dilute to precipitate with ammonium chloride. You might wish to evaporate until you have a very concentrated solution, although unless you're trying to learn from the experience, that may not be worth the time it takes. I had that experience countless times, and was the primary reason I sent small amounts of platinum and/or palladium solutions to my stock pot, where they were concentrated. 

Harold


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## jeweler1 (Mar 12, 2015)

I do tend to agree that the Platinum is only present in trace quantities. And seeing that this is just an experiment I will continue to condense it as much as I can. There was one change I did notice tonight the test for this mystery metal turned light blue over night just like my palladium test? 
 What is DMG? And how is it used? I now test on filter paper swabbing it with stannous chloride. It works great for gold and Palladium.


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## FrugalRefiner (Mar 12, 2015)

jeweler1 said:


> There was one change I did notice tonight the test for this mystery metal turned light blue over night just like my palladium test?
> What is DMG? And how is it used? I now test on filter paper swabbing it with stannous chloride. It works great for gold and Palladium.


DMG is an acronym for dimethylglyoxime. It is a definitive testing solution for palladium or nickel in solution. Hoke describes it, but there is more information on the forum. A test with DMG will tell you, positively, if there is palladium in your solution.

Dave


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