# Conservation of nitric acid



## qst42know (Mar 27, 2009)

I have been experimenting with dissolving a thin dish made of something less than [sterling silver] alloy in poor-mans nitric. I started with a 50/50 mix of home made nitric and water. After some time when the activity ceased I added some more nitric to the existing solution. 

What I noticed was the fresh nitric immediately attacked the precipitate, and only then resumed working on the dish.

My question is this, is the silver dropped out of solution by the remaining copper of the undigested alloy consuming some of the added nitric?

After all activity stops would it be a better to remove only the solid item being dissolved from the first solution and place it in a fresh solution each time until finished, saving the solutions and sediments to be combined after all solids have been dissolved?

Am I correct in thinking the nitric that acts on what has already dropped is lost to further reaction?


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## Anonymous (Mar 27, 2009)

I find poor mans nitric to be poor for silver because the silver sulfate that forms from remaining sulfuric shields the silver in much the same way as the chloride does with HCL, though not to the point of totally stopping the reaction like the chloride can when using HCL.

I would suggest getting some copper nitrate and using electricity to part the silver, it will not be pure on the first run but is a good starting point.

I have not tried the Cold nitric, the poors mans I speak of is battery acid with potassium nitrate added, this works great on stuff that is high in copper or iron and stuff like that, but has really let me down on high silver content electricial contacts.

Jim


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## qst42know (Mar 28, 2009)

So by using poor mans nitric I'm ending up with silver nitrate in solution and silver sulfate as a precipitate.  

Can this be recovered by using copper?

Or would it be better to add HCL to turn it all into silver chloride and cement with iron?


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## qst42know (Mar 29, 2009)

It would appear my choice to try homemade nitric on silver was a poor choice.

As an exit strategy here is my plan. Drop silver nitrate from the solution with copper collecting it with any silver sulfate that was formed. Wash and dry. When I melt this I will use a cupel instead of a melting dish and include a quantity of soda ash and some iron to reduce the silver sulfate. The results will be saved for a silver cell.

Does this sound like a good plan?


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## Anonymous (Mar 29, 2009)

I am working out a plan and parts list for a "pot still" as a way to get good sulfate free nitric from poors mans nitric, I will post.

jim


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## butcher (Mar 29, 2009)

I just distill it,


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## Anonymous (Mar 29, 2009)

Most do distill it, but from what I see around the forum, many are trying to find ways to make nitric without buying a 2 or 3 hundred dollar distillation rig.

I have experience, distilling a more flavorful liquid with stuff that you can find in the kitchen, granted it will be small batches, but...

Jim


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## qst42know (Mar 30, 2009)

Now I'm finding out why you don't use poor mans nitric for dissolving silver. I cut a piece of copper bent it into an "S" shape and stood it vertically in the solution. After a brief bit of activity and standing for 24hr. the silver has ceased to drop from this solution. Apparent the compounds left over from the sulfuric acid are protecting the copper and keeping the silver nitrate in solution.

At this point if I don't receive any better suggestions I'm considering a dose of HCL to form AR and force the silver out as Ag-Cl.


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## Anonymous (Mar 30, 2009)

this weekend or maybe earlier I will post a way to distill nitric without all of the hoopla, be patient grass hopper.

Silver sulfate, regretfully I do not know how to reduce it to silver, I am sure someone else on here does.

I know poor mans nitric caused me issued on 6 large I'm talking silver pads from 1000 amp switch gear, so I do not use it for that any more.

Jim


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## oldtimmer (Mar 31, 2009)

thanks for the posting about poor man’s Nitric acid and silver. 

I have been concentrating on doing gold up until now. I have about 60 oz of silver contacts that I had melted down into ingots several years ago. I was planning to use the poor man’s Nitric, but will wait until I can get some good Nitric Acid.


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## butcher (Apr 3, 2009)

I have distilled nitric many times with common second hand store materials electric hotplate, large aluminum pan for sandbath, teflon lid for pickle gallon jar hole in center for chemical resistant hose, and smaller bottle with teflon cork for water to bubble nitrogen oxide into and as condenser. Have bought a nice $92.00 lab distilling kit, but afraid to break it so I still use my pickle jar for now.


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## qst42know (Apr 5, 2009)

After more than a week in the solution the copper seems to be working. It could be that much of this is temperature dependent. Cold at night and barely warm by day. Some mossy silver crystals are forming while the copper is dissolving. There may well be an ideal temp for this reaction. Still it's a slow processes working with poor mans nitric.


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## Anonymous (Apr 5, 2009)

if you have a fluffy bluish grayish precipated that may contain a lot of silver, and if there was anything with lead content it will precipate as a a sulfate also, once all the sulfate is in the bottom as a precipate then it would work allong the lines of nitric.

I had a problem on the electricial pads because they also contain cadnium which also forms insoluble sulfate.

Jim


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