No platinum showing up???

[jjohio]

Boiled 2 crushed up cats in crock pot(aqua regia) for 6 hours..siphoned off the remaining liquid in jar...dipped a q-tip in it to do stannous check and it showed nothing...qtip remained green.... What the heck???

 

[samuel-a]

This is common where two thing happens with this kind of scrap.
1/ solution is very dilute
2/ oxidizer presence is too great.

I'd suggest you to digest more cat's with same solution if you have more.
or, filter and cement with Zn/Al and watch for black precipitate (PGM's).


btw, you mentioned green color to the solution... that sounds wrong, like you dissoved base metals some how.

 

[jjohio]

acids were green from the get go...It had to of dissolved some Pl, i would of thought...what should i do next?

 

[jjohio]

actually I think the urea i added turned it green...it was brown...I just wonder why nothing showin on stannous check...could there still be pl in there and it not showin cause i added to much urea or did something else wrong?

 

[eeTHr]

jj---

Just curious...where did you get the instructions to use urea?

 

[skippy]

I've had catalyst with enough nickel that the post cementation barren solution was quite green. Nickel presence confirmed strongly by DMG added to sample basified solution.

 

[jjohio]

jj---

Just curious...where did you get the instructions to use urea?

bunches of post on here with people using urea

 

[nickvc]

jj---

Just curious...where did you get the instructions to use urea?

bunches of post on here with people using urea

Forgive me of I'm wrong but I believe urea should never be used in recovery and refining of PGMs....
I'm far from an expert on the platinum group but I'm fairly sure that urea is the kiss of death to their successful recovery.