# My silver is not dessolving in nitric



## jacko (Nov 17, 2011)

I has 68 % nitric it is fresh and i put the nitric in a pyrex then put my silver in . It turned a little green but no red fumes and not much of a reaction. Thanks for the help in advance.Oh and everything was marked and tested .


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## jacko (Nov 17, 2011)

I put it on a hot plate and it still is not reacting .


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## publius (Nov 17, 2011)

did you corn-flake it first?


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## jacko (Nov 17, 2011)

I just threw it in but it was all small pieces.


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## publius (Nov 17, 2011)

did you "incinerate" is before introducing it to the acid?


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## goldsilverpro (Nov 17, 2011)

Dilute the nitric with an equal volume of distilled water.


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## nickvc (Nov 17, 2011)

goldsilverpro said:


> Dilute the nitric with an equal volume of distilled water.




Yep that should do it...
Red fumes will ensue very rapidly I hope your extraction is good :shock:


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## jacko (Nov 17, 2011)

now it is starting to work i got in a hurry.


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## publius (Nov 17, 2011)

Hmmm... I was thinking that is was the lack of surface area or a coating that was inhibiting the reaction. Should have paid more attention to the concentration. Good catch Guys (gender neutral term)!


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## jacko (Nov 17, 2011)

Alright it ate up all my silver now the acid is green with crystals on the bottom . Should i filter before i add the copper to it to get cement.


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## Palladium (Nov 17, 2011)

Crystals? Try adding some more water and see if they dissapear before you filter. Those could be silver nitrate and will redissolve if they are.


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## Palladium (Nov 17, 2011)

Yes filter before you cement.


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## jacko (Nov 17, 2011)

You think copper or salt i have heard of people cementing with both .


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## publius (Nov 17, 2011)

copper will net you metallic silver. Salt (NaCl) will net you silver chloride and require additional processes to gain metallic silver.


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## jacko (Nov 17, 2011)

I hope i added enough water to my nitric because it is raining silver but it sure is eating the copper up .I may go out their and add more water.


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## metatp (Nov 17, 2011)

jacko said:


> I hope i added enough water to my nitric because it is raining silver but it sure is eating the copper up .I may go out their and add more water.


You probably have excess nitric acid for the amount of silver you dissolved. The copper is using up the excess nitric acid.


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## jacko (Nov 17, 2011)

Thanks for the help it turned out great the cement looks great for my first batch. I do think i put to much nitric in it are they any measurments for that.


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## goldsilverpro (Nov 17, 2011)

jacko said:


> Thanks for the help it turned out great the cement looks great for my first batch. I do think i put to much nitric in it are they any measurments for that.



I've probably posted this 100 times. 1.22 ml of 67% nitric will dissolve 1 g of silver. 4.15 ml dissolves 1 g of copper. 1.51 ml will dissolve 1 g of sterling silver.


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## kadriver (Nov 18, 2011)

jacko:

Here is the process I have used and achieved excellent results:

First, I ensure that the metal I have is actually 925 or sterling silver. Some items are marked 925, but they are not silver. I encounter about 2% to 4% (estimated) that are marked, but not silver. I use silver test solution (which I just recently started to use). The acid don't lie and the test seems very reliable.

I then clean the metal by hand. I remove all stones and other non-metal using pliers and cutters. It is tedious, but there is less junk to filter when I am done. 

I also snip open each of the clasps on all the chains and remove the little steel springs located inside each one.

If there is alot of dirt inside of the rings, I cut the ring so I can open it flat and use a toothbrush size steel wire brush to lightly remove caked on dirt and grime.

Once this is complete I weight the metal and calculate the amount of nitric acid I will need. I use 1 ml nitric acid for every 1 gram of 925 and sterling silver that I am going to dissolve.

The reason I use this lesser amount than is recommended here on the forum is this: When using the amount of nitric acid recommended, I was getting alot of unused nitric acid left over in my final batch of silver nitrate solution.

This excess nitric acid in the silver nitrate solution caused the copper I was using to be eaten away much faster - wasting my copper - and I was getting brown fumes and heat coming from the container while I was cementing the silver out.

I initially solved the problem by SLOWLY adding a table spoon or so of urea while constantly stirring. Adding urea to the silver nitrate kills the excess nitric acid.

Adding urea too fast will cause the acid to bubble up and could cause a boil over. I always place my cementing vessel inside a pyrex baking dish to catch any over flow from boil overs.

The addition of a small amount of urea worked. The brown fumes stopped and the silver cemented out perfectly. Adding too much urea will kill the acid to the point where the silver won't cement. Some nitric acid is needed for cementing to take place.

Since I was getting this excess nitric acid in the final solution of silver nitrate, I concluded that using a little less nitric acid than recommended might prove beneficial - it did.

I now start by adding only 1ml nitric acid for every 1 gram of 925 or sterling silver that I want to digest. There is seldom excess nitric in my final silver nitrate solution, and I don't have to add urea anymore. Plus, My copper lasts longer, and the nitric acid I save can be used for the next batch of silver that I process.

Once the amount of acid is determined, I add an equal amount of distilled water to my pyrex coffe pot with lid. I use a 1970s style heavy pyress glass coffee pot that I got off ebay for about $35. It has a lid. I have two of them. I would not recommened a thin mr. coffee type coffee pot, but some do use them - no acid yet.

Then, using a propane of MAP torch, I heat each piece of cleaned silver to redness.

This is called annealing. It cleans the metal of external impurities. It can also help to detect non-silver metals. Silver heats up a certain way, and if you get lead or tin or pewter, the metal reacts differently to heating. This lets you know that it might not be silver. This is also the reason why I heat each piece individually using a pair of pliers to hold the metal in the flame while I examine how it looks as heated.

Once all the pieces have been annealed, I put the silver into the coffee pot with the distilled water. I then place the coffe pot inside a corningware casserole dish set on top of a cold hotplate - heat turned off and no acid yet.

I then measure the amount of nitric acid that I will be using, as calculated earlier, into a beaker with a watch glass on top (I use a glass sauce I got at the thrift store as a watch glass)

I slowly and incrementally add the acid to the coffee pot containing the distilled water and the annealed silver pieces. Brown poisonous fumes will eminate from the container almost immediately - don't breath even a little.

The reaction intensifies with each acid addition, then calms down after a few minutes. Once it has calmed down, another increment of acid can be added.

It is important to add the acid in increments. Adding it all at once may cause it to boil over. Boil overs do happen, and this is the reason for the corningware casserole dish - I have about 6 of them that I have collected over time at the local thrift stores. I always place a corningware casserole dish between my coffee pot and the hot plate.

Any time we do reactions it is advisable to put the reaction vessel inside a dish to catch any liquid that may boil over. 

Once all the acid is in the coffee pot with the silver, I can then start adding some heat. I also add the heat in increments also as adding too much heat all at once can cause a boil over.

I keep adding heat until it is all the way up to the high setting.

I continue to heat on high until the brown fumes cease. When the fumes have ceased, I carefully inspect the contents of the coffee pot. There is usually some silver left in the bottom that has not dissolved. But just as often, the silver will have completely digested using only 1ml nitric acid to 1 gram sterling or 925. 

If the amount of silver left is very little, then I just proceded to cooling and filtering and save the few pieces of undissolved silver for my next batch.

If there is more that a little, then I can still just proceded to cooling and filtering, and process the rest of the silver later. Or I can add some more nitric acid to continue to digest the rest of the silver in the coffee pot.

Adding nitric acid to a hot rection vessel with hot pieces of undigested silver is very dangerous. It must be done VERY SLOWLY, and in small increments. if the acid is added too quickly then it will boil over, or even erupt and shoot hot acid and silver nitrate all over your face! Protective clothing and face shield are a must. The vessel should be taken off the heat or the heat reduced before adding additional nitric acid.

To filter, I usually add about 300 or 400 ml cold distilled water and then run the silver nitrate through a vacuum assist filter into a 2 liter filter flask.

I did a batch last night using this exact process described above. Upon filtering the filter paper quickly glogs up and the filtering slows to drips coming from the filter funnel.

I don't see how this liquid can be filtered without vacuum assist. It took nearly 2 1/2 hours to filter just 1 liter of silver nitrate with the vacuum at the highest level it would go.

Another method instead of filtering is to allow the coffee pot to settle overnight. In the morning, the clear liquid can be poured off (decanted) or siphoned out.

I have used both methods with good results.

This description is posted to show how I process my silver. I am not saying that this is how you should process your silver.

Hope this is helpful.

As usual, any inputs or critique would be welcomed - thank you.

kadriver


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## niteliteone (Nov 18, 2011)

Very nice post kadriver,  

I'm going to print out this process and use it when I proces my scrap silver.

Thank you,
Tom C.


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## jacko (Nov 20, 2011)

Yea very nice at firt everything was confusing but now after my 4 batch i think im ready to go for the gold is it more complicated?


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