Screwed up 486's batch because of the lids!

[a_bab]

Yes, I know - I should have done the lids separately but I said "what the heck, I'll just dump them in".

I'm talking about a beautiful batch of some 3 kilos of 486 procs ONLY.

Now, what are my options? All the metals are dissolved, the nitric was driven off, I got fed up of facepalming myself and I'm staring at the nasty brown solution. I don't even want to dare thinking how to filter the rusty crap before dropping the gold.

Any advices?

 

[Oz]

Any advices?

Yea, do not do this in the future.

Yes Sir you have a mess. Decant solution into a clean container then wash solids well to remove any attached powders as they are likely your values. Rinse this wash and powder into your first solution and test with stannous chloride. Be sure no oxidizers (nitric, Cl2) are still in solution for test. If test is positive, cement on copper until negative test results. Then process your powders.

 

[glondor]

I have run into the nasty brown powder/sludge before. It took a long time to figure it out. I believe the iron has cemented the copper out of solution. I have found that a little more nitric puts the sludge back into solution then I carry on from there. Wrecker 45 took a wild guess at what was happening and it seems he was right. Thanks Jim.

 

[a_bab]

OK, I eventually figured out the darn issue by myself with a bit of thinking.

Oz, Glondor, you are both right: it's a metal that is suspended. I personally guess it's gold/copper; gold in the first place since it's less active then copper. Basically since the surface of the lids is so large the kovar or whatever these are made of instantly cemented the values/copper to the point it looked like a hopeless mess.

I panicked first, then I realized what actually happened and quickly got back to post it only to see the confirmation.

The fix is really a matter of adding just enough nitric to bring everything back in solution, then get rid of the rest. Some HCl may be needed too (remember hydrochloric can also get spent from AR).

At any rate, I see no reason why iron should not stay in the solution. As someone said before, having a AR solution bloated with base metals poses no problem if you know how to get the gold out, and know it's there.


Thank you all for your kindness; a button pic soon to come.