When refining silver you want to make sure you do this outside where there is plenty of ventilation. Give yourself plenty of room in order to have a quicker dissolving reaction from the silver. Depending on how much silver you have to refine will depend on how many 5 gallon buckets you will need. You can have larger buckets as well just as long as there is enough room for a reaction of bubbling and fuming you will get during this process. You can refine silver using acid only or acid and baking soda.
Put 150 ml of nitric acid for every ounce of silver you have in each bucket. Do not overload the bucket since it could overflow. You will need about two to three times more room than the amount of silver in the bucket. You will see the reaction of bubbling and fuming which can take at least 30 minutes. Once this stops you can move onto the next step.
Take the acid and the dissolved silver and pour it into another bucket. Don't allow solid pieces to be poured with the silver and acid since it will contaminate the silver. From here you will add an ounce of silver precipitant crystals or SAC to every 40 ounces of dissolved silver. This will develop silver that will sink to the bottom of the acid. Give 30 minutes or more. Then pour out the acid. Neutralize and dispose of the acid by filtering it making sure that no particles of silver are lost.
Wash the silver thoroughly. You want to rinse off any acid remaining on the silver. Then add about three or four drops of aqua ammonia which will appear blue if there's traces of acid left. If so, then continue rinsing and reapply the ammonia. Do not add too much ammonia since it could damage the silver. Then dry.
Use baking soda along with karo pancake syrup, salt, water and Red Devil drain cleaner in order to use a different process of refining silver. It is basically the same procedures with the nitric acid but this way may be easier to not lose any silver particles. You will begin by dissolving the silver with acid in the plastic bucket. Add salt to acid until white clumps stop appearing in the acid. Then pour off the acid into another bucket.
Add baking soda to the acid. Add about two tablespoons of baking soda which will neutralize it. Then filter the white precipitants that the salt had formed which is pure silver chloride. Rinse the silver with water. Then add the Red Devil drain cleaner to the silver chloride until it turns black. Rinse with water again. Then add karo syrup until the particles turn silver. This will result in refined silver. Be sure to rinse and make it clean of any extra chemicals left on it.
Things You'll Need
Stir rod made of wood or plastic
At least 5-gallon buckets (3 or more)
Concentrated nitric acid