Nitric Acid and Copper

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Apr 26, 2013
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Hi!

So far I have been able to cement silver to .999 purity without a problem. I am using a 50/50 solution of 69% Nitric Acid and distilled water. I am using clean copper to cement/dump the pure silver and so far so good.

Here is my question. Once I have finished cementing/dumping the silver out of the solution how can I reclaim/re-use/strengthen/refine the used solution back to the original 50/50 Nitric Acid/distilled water solution to use again or do I just keep having to buy more and more nitric acid?

Thanks,

J.
 
It is possible and you find the informations by a simple search on making nitric or http://goldrefiningforum.com/~goldrefi/phpBB3/viewtopic.php?f=49&t=5410, but when you need to ask this, I would not advise you to do it. All methods, that come to my mind, are quite dangerous (NO and NO2 - no respirator will filter them!).

Since you need more and more sulfuric instead (depending on method), I don't see any sense in it. Ok, also the sulfates can be used again to make new sulfuric. But it's a whole lot of ugly, dangerous work. In the thread above lazersteve mentions decomposition by heating/dissolving the gas in destilled water or electrolysis.

Making some mL would be like a nice school experiment (not harmless though), making some litres is something I would leave to well equipped (semi-)professionals (full-glass distilling aparatus and fumehood with scrubber!).

A sophisticated discussion about it (read at least butcher's and lazersteve's posts!): http://goldrefiningforum.com/phpBB3/viewtopic.php?f=48&t=16420


I am not sure, if electrolysis is more harmless. I guess this would be a way to go and at least worth to do further search about.
 
some of the nitric was used up in the reaction. the remaining nitric in the form of copper nitrate can be reclaimed (or most anyway) by distilling. evaporate the solution to half its volume before starting. add the solution to 1 ounce of concentrated sulfuric acid slowly in the reaction vessel. start the distillation process and test the distillate with a piece of copper. as soon as you begin seeing a reaction, switch receiving vessels.

of coarse all of this needs to be done in a controlled environment under a fume hood or outside with a good breeze blowing. if mother nature fails, you can make a good breeze by mechanical means with a strong fan.
 
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