# Monolithic capacitors



## JustinNH (Oct 13, 2008)

Hey-

Quick question. When I put ground up monolithic capacitors in AP, it turns the red color i read about here on the forums... after a while, it turns a yellor/green color. If the palladium still in the AP, or did it drop out after other metals are taken in? When I add more H2O2, it turns a deep red again. 

Since I want to keep the volume down, I was just wondering if I need to make sure the AP is the red before i filter it (i.e. add more H2O2) or if its ok to filter as is. I tried looking for this and could not find the answer, so sorry if it has already been asked. 

Thank you,


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## JustinNH (Oct 13, 2008)

its 70 grams of ground capacitors too btw, if that matters. I know not to expect a lot (I think steve said about 1/4 gram per 12 grams of ones that are known to have palladium), but I had them, so why not


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## lazersteve (Oct 13, 2008)

Justin,

Test with stannous to confirm Pd is present. Sounds like it is from your descriptions, but testing is the only way to be sure.

The different oxidation states of Pd may be why you are seeing color differences.

The monolithic caps also contain nickel and tin, and sometimes even silver or gold.

Steve


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## Harold_V (Oct 13, 2008)

An even more sensitive test for palladium is to use DMG (dimethylglyoxime). The slightest trace will produce copious amounts of a canary yellow precipitate. It's a good test if you have palladium in solution with gold and can't distinguish one from the other. Sounds stupid, but it's a common occurrence. Palladium often reacts with very unusual colors with stannous chloride, and can be easily confused with a dilute gold solution, especially if the stannous chloride is borderline failing. 

Another way to distinguish between them is to introduce a crystal of ferrous sulfate to your test drop. The ferrous sulfate will precipitate the gold, leaving behind the palladium in solution. You can see the reaction by observing the gold forming, and the solution changing color. When all of the gold is down, witnessed by remaining ferrous sulfate crystal, you can then test with stannous chloride. 

Hoke talks about these tests, which are very handy to know.

Harold


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## jimdoc (Oct 14, 2008)

Here is a link to some dimethylglyoxime on Ebay;

http://cgi.ebay.com/Dimethylgyoxime-25-g-Chemical-Lab-Chemicals_W0QQitemZ250303307674QQcmdZViewItem?_trksid=p3286.m20.l1116


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## JustinNH (Oct 14, 2008)

I did test with the stannous and based on the pics/descriptions ive seen here it looks like its a go. I'll have to pick up some DMG to be sure since just as you described it may be 'iffy'. The monos are from all sorts of boards, but a lot are from pentium cards that I know I saw were confirmed to have palladium. Thanks for the info and the link everyone. I never throught about the different oxidation states making it do that. Thanks again!

One more quick question... If I cannot get the solution to evap/boil down to a more concentrated amount, should I cement it all out and retry it with a smaller amount of AP? I know PGMs are picky...


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