# Help converting AgNO3 to Ag



## mojojtp (Nov 12, 2013)

OK...here's the deal...I'm a long-time veteran in the small-quantity chemical disposal industry...that being said, I've been able to collect a decent amount of silver salts, especially silver nitrate (approx. 200oz), which I would prefer to convert to metallic silver prior to any type of final sale...I currently have an outlet for the sale of the "scrap" silver nitrate directly to an established precious metal refiner/dealer, but, after processing and recovery fees, I realize less than 50% of the actual silver value contained in my inventory of AgNO3...

...because of the nature of my business, I have a less restrictive access to chemicals which would otherwise prove more difficult for the general public to obtain...

...bottom line: if you are the first respondent that provides the ACTUAL process I invest in and use for the conversion of silver nitrate (AgNO3)-to-metallic Ag, I will gladly request direct contact with you to provide some type of compensation for your efforts...bear in mind that any compensatory decision is mine and mine alone...

...given the amount of AgNO3 indicated above, the %'age of Ag in AgNO3, the actual %'age of Ag expected to result from the process, the cost of chemicals/equipment to facilitate the process and the final 10% taken by the refiner...straight-up...you'll get a "taste"...I'm just sayin'...thanks for your assistance...


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## Lou (Nov 12, 2013)

What's your goal?

If you want the silver to be highly pure and it's pure ACS silver nitrate, the purity is yours to goof up!

If you're just looking to preserve the purity of the metal, I suggest you follow all of these steps:

1. Accurately weigh up the silver nitrate, wearing suitable PPE because it stains and is especially hazardous to the eyes.
2. Once you have it weighed up, divided the weight in grams by 169.87 grams per mole to get moles of silver. At this point you can multiply grams of silver nitrate that by 107.87/169.87 (or 63.5%) to get how many grams of silver (divide that by 31.1035 to convert grams to troy ounces).
3. For however many moles of silver nitrate you have, you will need half as many moles of sodium hydroxide.
4. Dissolve the silver nitrate in distilled water (200 oz of AgNO3 is about 6 kg, so it'll take about 10 liters of distilled water, or two and half gallons).
5. Add in the calculated amount of sodium hydroxide slowly with good stirring in a 5 gallon bucket. Let settle.
6. Decant/pour off the remaining amount of clarified solution (supernate) and filter the rest (to get the filtrate). 
7. The liquids left over from the process should be treated with sodium chloride. Add enough so that the silver stops precipitating, and then add in about 1.5 times that much to further suppress the solubility below 1 ppm. Let that settle, or use an egg white to clarify the turbid solution. That solution should be metal free (pull a sample and leave a copper wire in there for some days to see if any silver grows upon it).
9. Filter the AgCl mud and treat it with dilute sulfuric acid and iron powder, filter that and add it back to the silver oxide you already isolated.

Add in a few scoops of borax and sodium carbonate and melt it, slowly (need to give time for Ag2O to revert to silver and oxygen). Your silver should be very pure.
If this isn't clear enough, let me know.

Alternatively, I would buy it outright just to top off silver cells if it's still in its bottles and free of debris.


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## butcher (Nov 12, 2013)

I thought I would make a comment here.

Normally it is easier to cement silver from a nitrate solution using copper metal, which then can then be washed and be melted to fairly pure silver.
But that is normally in the case where copper (and or other base metals) are normally in the solution we cement the silver from, like from dissolving sterling silver, or from parting silver from gold or another process where we will have copper and many times other base metals in solution.

Here with this situation there is no copper in the silver nitrate, so the silver should be really pure, by converting it to an silver Oxide, Lou is choosing not to use copper to cement the silver (to keep the silver pure).

Any copper when melted with silver will melt into the silver.
By precipitating the silver with the hydroxide to form silver oxide, he is not introducing a metal into the melt.

And with any silver chloride recovered from the solution , by using the Iron and sulfuric acid for conversion of the AgCl back to silver metal, the Iron and silver do not mix in the melt (any iron will report slag as iron oxides. 

With this in mind Lou's choice of using iron will help to keep the silver pure.
I Like How he thinks.


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