# Question on leaching silver from ash



## Marcel (Apr 2, 2013)

I am trying to find a way to recover silver from my 6.5Kg ashed transistors. So far only minimal Pd and Au is expected. I will not go for that.
Now that I have decided to give the leaching another try, this is what I did:
1. Adding 500ml water and some nitric to form dilute nitric acid. Added 250g of the ash step by step when fumes decreased.Stirred occ.
2. Kept it hot for about 1 hr. No more NOx fumes visible.
3. Filtered the solution. Got mud with a black layer (ash was grey, I suspect the black layer to be silver) and a green-blue solution. Filtered again to remove fine particles.
4. Heated that solution and made the water evaporate down to 1/3.
5. All of a sudden white crystals appear and fill out the whole beaker.
6. Remaining deep green solution is decanted. SC test is negative
7. Water is added to crystals. They imm. dissolve and a nice blue solution appears. (AgNo).

Now the nice twist of this is, that I can seperate coppernitrate and silvernitrate quite easily just by evaporating the water from the solution and creating the AgNO3 crystals.
I found this effect by chance, maybe it is well known among the silver experts but I have not worked with silver a lot.
Could just some silverpro tell me, wheter this is an appropriate/common method(exsp. the crystal forming trough evaporation) , or did I miss here something ?


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## FrugalRefiner (Apr 2, 2013)

Marcel,

Why did you start another thread about the same material you talked about here: http://goldrefiningforum.com/phpBB3/viewtopic.php?f=34&t=17862? It makes it confusing when the discussion gets spread across different threads.

You've made a couple of the same errors here that you mentioned there, as well as new ones.


> 3. Filtered the solution. Got mud with a black layer (ash was grey, I suspect the black layer to be silver) and a green-blue solution. Filtered again to remove fine particles.


Your silver should have dissolved in the nitric acid. Why would you suspect it would be the black layer of sediment?



> 7. Water is added to crystals. They imm. dissolve and a nice blue solution appears. (AgNo).


As I mentioned in the other thread, AgNO3 in solution is clear, not a nice blue. The nice blue is usually Cu(NO3)2. In the interest of accuracy, AgNo would indicate a compound of silver and nobellium. I don't believe it exists.



> Now the nice twist of this is, that I can seperate coppernitrate and silvernitrate quite easily just by evaporating the water from the solution and creating the AgNO3 crystals.


I'm pretty sure it's not that easy. As mentioned above, the blue in your solution indicates that you probably dissolved some copper nitrate crystals, perhaps along with some silver nitrate crystals.

More to learn.

Dave


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## Anonymous (Apr 3, 2013)

Marcel,

For one, you never mention how much nitric Acid you used. 

How much was added to 500 ml of water? 
Was it tap or distilled water used?

I am currently working on silver from ash, and I can tell you with certainty, that if you used at least a 50/50 nitric/water or peroxide, then add some heat to the vessel, your silver will dissolve. 

I believe I read it here recently, that the crystals are forming is because the nitric has been depleted and (or) the solution is too cold. Don't quote me on it, but I think I read it here somewhere. 

You must have enough nitric to dissolve the silver, even if it's in an ash pile. If you saw brown or red smoke, then it was dissolving something.

Here is what you should do at this point. 

*1.* Add a piece of scrap silver to the solution and see if it dissolves. If it does, then you have enough nitric. If it doesn't, then you don't have enough nitric in the solution. If that is the case, then you should add about 10 - 20 ml of Nitric and add some heat. At this point, don't dilute it. Stir every 15 - 20 minutes after the fuming/smoking stops.

*2.* After the nitric has been heated for about an hour or so, take it off the heat and let it cool down. 

*The next step is important* *Pay Attention!*

*3.* Filter the solution with *3 filters together*. After that solution has been filtered, get 3 more clean filters and then filter that filtered solution again. Remember to remove the first 3 filters before adding the next 3 filters.

*4.* After you've filtered your solution, you should have a water clear solution. If it's not, then you have something in the solution, like copper or something else. Either way, once you finish the filtration, double the volume with distilled water and then hang a piece of clean copper in the solution.

If you have silver in there, it should cement out of the solution. If not, then you either don't have any silver or you solution may need some heat applied.

One thing to note: I had the experience of burning keyboard mylars to an ash to recover the silver, and I can tell you this much. Depending on how long you incinerate your material, that ash will be so fine, it'll filter through your filters, and it will look grey, and you will think it's silver powder, when in fact, it's the ash or carbon from the burning process. 

Whatever you do, don't skimp on the filtration method I explained to you or you'll be very unhappy with your results.

Kevin


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