It’s easy to find, I just reread it.
The approach is quite different and she uses Ammonia and neutral conditions.
Palladium precipitation by formic acid
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The approach is quite different and she uses Ammonia and neutral conditions.
I nutralized the whole solution to a ph 7, filtered it and dissolved every thing again in HCL , i found some silver chloride and got rid of it . Any ways i used sodium carbonate this time to raise the PH and the fluffy precipitate that i showed you in the picture hasnt formed this time . I followed the video of owl tech carefully and reached a PH between 3and4. And a light brown precipitate has formed this time.
Any ways i added 50 ml of formic acid while giving heat to the solution and unluckily nothing happen no color change and no black Pd mirror has formed in an hour of gentle boiling so i am expecting that the formic acid may has a problem.
Hokes page 156-160 is where it is.
Formic acid decomposes so if its old it may have decomposed too much.
Are you sure you have Pd in solution??
Well, about 4 kg of mixed mlccs they should have Pd.
Ill read the pages and get back to you with any news . Thank u
They might not have, have you tested them withe either stannous or DMG?
Well, i tested the powder with a friends xrf device and got a read of 1% palladium , thats about 40 gram in my 4 kilos of mlcc powder
It does not mean that you have managed to get it into solution.
Both stannous and DMG will show that.
Testing your solutions very important...I test at every step. Many things can change during the process and the only way to know where your PM's are is to test.
It takes a lot of sodium carbonate to get the PH up..... that fluffy stuff might be excess sodium carbonate. Sodium hydroxide would have been a better choice...in my opinion. You can use ammonia, but I generally don't keep ammonia in my lab...for safety reasons.
After you adjusted the PH and added formic acid....how long did you boil the solution, it sometimes takes awhile. Last time I used formic acid I had to boil it for 2 hours before it started to clear up.
The solution hasnt darkened and the solution has a brown precipitate even after adding the formic acid and boiling for 1 hour
Test it with either Stannous or DMG.
Make sure your Formic acid is good.
As you saw Owltech pushed the pH up until he had a clear defined "hydroxide" and then added the formic acid and started boiling.
Hokes describes how to use precipitated salts in a near neutral conditions, so obviously there are more ways to skin a cat, even in this realm.
As you see in the pic below i have a clear brown hydroxide precipitate but its bot darkening after adding the formic and boiling
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Since you have no test saying you have Pd in solution it is hard to say what has happened.
Re acidify it and make sure the hydroxides are dissolved again.
Test it with either stannous or DMG.
Then start over.
How old is your Formic acid?
Ok ill do that
Its 1 year and a half old
Might be ok, I have no idea about the decomposition rate.
When i reacidified the solution to minimum ph and added some formic then started adding the caustic soda a black cloud has formed as shown
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EnergeticphenomX
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I had success replicating owltech's version by eventually melting down ~10 grams of pd/pgm. The precipitate was comparable to Owltech as a black flocc rather then a brown precipitate as shown above. I'll add that my remaining solution was blue/green. While trialing, I did notice that the pH conditions 3-4 was needed to remove the precipitate from suspension. I favored increasing pH to avoid using too much filtration. I used quite a bit of Lye as I felt I was combating increasing acidity with my formic acid additions. I'll note the solution was exo heated only, and also was a solution where I extracted gold using MSB.
