nitric turned from blue to brown

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jamiebridges7

Member
Joined
Aug 13, 2018
Messages
7
so i have a larger batch of mixed plated pins i put into my 5l beaker maybe about 2000 grams or so give or take that i covered with distilled water and added maybe 500ml of nitric acid and let the reaction run threw. everything was fine and went per usual until i added more nitric about another 500ml. the solution originally was a nice blue. i went and got some food and when i came back it was brown.
 

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Looks like iron to me. Did you say you have processed these pins this way before? What does the undissolved debris look like?
 
Decant solution
Add some disstiled hot water to residue and try dissolve them
If they don't dissolve, Add hcl
Don't forget test solution with stannous chloride. When you add hcl to nitric you will make some AR
 
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