# Refining silver with nitric acid cementing with copper



## Rreyes097 (Oct 3, 2016)

So this is my third refining of silver using nitric acid and cementing with copper. But this time I'm refining not just sterling silver but silver coins from Mexico Canada and even then us I believe. Many of these coins have 80% or as low as 72% silver content. So I put roughly 200 grounds this silver that I explained some of its Sterling most of it coins. Well after getting the distilled water and nitric acid in the hot plate it turned a reddish-brown color instead of the normal green or blue. Please advise.


----------



## Smack (Oct 3, 2016)

Did you check your material with a magnet?


----------



## Rreyes097 (Oct 3, 2016)

No i thought all the coins were silver and copper. Is that the problem? How do I fix it?


----------



## Rreyes097 (Oct 4, 2016)

Yup! I just pulled a rookie move. There is indeed a magnetic coin in there. But how do i fix it now?


----------



## Rreyes097 (Oct 4, 2016)

I put some magnetic coins in with my other silver coins and some sterling silver jewelry. Got a reddish brown solution. Removed coins but what do i do to clean this mess up?


----------



## Rreyes097 (Oct 4, 2016)

I filtered solution this far. Cleaned off silver and still filering solution when i came across this sediment of something i think might be cemented silver? I have to wash it but could it be cemented silver?


----------



## Barren Realms 007 (Oct 4, 2016)

Please try to keep your posts on the same subject in the same thread so they don't get scattered on the forum.


----------



## FrugalRefiner (Oct 4, 2016)

Rreyes097, I've combined your two threads on this problem.

Dave


----------



## Smack (Oct 4, 2016)

Your mistake presents your lack of knowledge as self evident. Stop processing stuff and read, read to gain knowledge. It's provided to you free of monetary expense right here on this forum.


----------



## Rreyes097 (Oct 5, 2016)

Thanks so much!


----------



## upcyclist (Oct 6, 2016)

It sounds (to me, i.e., this village idiot) like this might be an example of the Reactivity Table of Metals, something for you to read up on. The iron in your magnetic coin wants to be in solution more than the copper or silver, so it has pushed your copper out of solution, thus the brown sludge. 

Seniors members, feel free to chide me if I'm talking out my 4th point of contact. I can take it 

As an aside, most coin silver is 90% silver, 10% copper. The increased copper makes it both cheaper and more durable than sterling. 'Most' applies better to European, US, and Canadian coins than it does to those from other parts of the world. After having come back from sorting through my dad's stuff for an estate auction, I found some change from his days in Germany in the 50s. Some of the silver coins are only valued at their intrinsic/melt value, so they may well end up with my inquartation stock.


----------



## Rreyes097 (Oct 6, 2016)

Thanks for your response. I have done my reading although i just made the assumption that the coins that i thought were silver and copper were actually not. So therefore im left with this mess. I was hoping for some advice on how to clean it up. But i think i got it covered. Ill tell you what i did and maybe you can let me know if I missed something. I filtered the solution. Recovered my silver, which i rinsed thoroughly with distilled water. Now i have what looks to me like cemented silver. So i suppose i will rinse that? Or should i rinse it and then disolve in nitric acid and distilled water again? Then my final question is the red sludge. What should i do with it? Dipose of it properly? Orv is there PMs in it do you think?


----------



## kurtak (Oct 7, 2016)

Soak the silver cement (that has the red sludge in it) in some "dilute" HCl (2 - 3 parts D-water 1 part HCl)

that should dissolve the iron oxide without effecting the cemented silver

you can "warm" the dilute HCl soak "a bit" but don't heat it to hot or it may cause some of your silver cement to convert to silver chloride

wash/filter the now clean silver cement GOOD to wash out the HCl

dry & melt

Kurt


----------



## Rreyes097 (Oct 7, 2016)

Thank you for your help. It is greatly appreciated.


----------

