First time silver recovery/refining, too much nitric!

[Edward Muente]

I haven't done this since college, and I remember why I didn't end up pursuing chemistry as a career. I was bad at it. Here, I mistakenly used an excess amount of nitric acid. By a factor of 10. I used 300 mL of nitric for my one ounce of 90% silver (five pre '64 quarters). And I know people may be aghast at using constitutional silver, but I've got about 20 lbs. of these, five won't kill me. And now my reaction has stalled. Liquid is blue with a slight tint of green, as it should be. Reaction is on a hot plate with a stir bar. I had the brownish gas and bubbling for a while, but now nothing. My quarters are not fully dissolved; what is my best course of action?

 

[Yggdrasil]

I haven't done this since college, and I remember why I didn't end up pursuing chemistry as a career. I was bad at it. Here, I mistakenly used an excess amount of nitric acid. By a factor of 10. I used 300 mL of nitric for my one ounce of 90% silver (five pre '64 quarters). And I know people may be aghast at using constitutional silver, but I've got about 20 lbs. of these, five won't kill me. And now my reaction has stalled. Liquid is blue with a slight tint of green, as it should be. Reaction is on a hot plate with a stir bar. I had the brownish gas and bubbling for a while, but now nothing. My quarters are not fully dissolved; what is my best course of action?

Welcome.
How much Silver was there?

 

[Edward Muente]

Welcome.
How much Silver was there?

Five silver quarters, 90% silver, total weight slightly over 1 oz. Fortunately I started small my first time.

 

[Yggdrasil]

Five silver quarters, 90% silver, total weight slightly over 1 oz. Fortunately I started small my first time.

Well as you said too much Nitric.
Did you dilute the Nitric and/or did you heat it?

 

[Martijn]

I haven't done this since college, and I remember why I didn't end up pursuing chemistry as a career. I was bad at it. Here, I mistakenly used an excess amount of nitric acid. By a factor of 10. I used 300 mL of nitric for my one ounce of 90% silver (five pre '64 quarters). And I know people may be aghast at using constitutional silver, but I've got about 20 lbs. of these, five won't kill me. And now my reaction has stalled. Liquid is blue with a slight tint of green, as it should be. Reaction is on a hot plate with a stir bar. I had the brownish gas and bubbling for a while, but now nothing. My quarters are not fully dissolved; what is my best course of action?

Best action: (If you really want to destroy recognizable silver that has a known value for traders and collectors into something that needs to be tested and is not recognized by most "we buy pm shops"?)

Keep adding silver until nitric is used up.
edited to say:
I just read you have too much nitric, by a factor of 10, but the silver is not dissolving? Is there enough water to allow salts to go in solution?
Then you may have a traffic jam. Silver is waiting in line for some room before it can dissolve. Or the solution is too cold to allow salts to de dissolved.

 

[Edward Muente]

I figured I should just keep adding silver. I DO have the reaction going outside, and even though it's a on a heated plate and I have a heater nearby, it's also -2 outside as I type this.

I know it kills some people inside to see silver coinage melted. But...I run a cash-for-gold business, where just about everything I buy goes to the refinery. Some particularly unusual jewelry pieces get saved and re-sold, or I may even keep a Rolex or a 1 oz Black Hills gold ring for myself. People sell me bags or rolls of silver coins all the time, which I will later scan for key dates, errors, etc. But I'm not a coin shop/dealer. Now, I want to try refining on my own for fun.

 

[Edward Muente]

Well as you said too much Nitric.
Did you dilute the Nitric and/or did you heat it?

Heating it, now I also need to dilute it. I realize I'm gonna have to split this between two different beakers.

 

[Darkthirty]

Heating it, now I also need to dilute it. I realize I'm gonna have to split this between two different beakers.

There's $1.50 ozt premium over spot on junk silver from APMEX. No refining required on 90%. $5.38 @ quarter, plus what you make on the front ...

 

[Edward Muente]

Welcome.
How much Silver was there?

Approximately 28.5 grams total weight, which imputes a value of around 25g silver. I have diluted with deionized water, and it seems like my reaction has restarted, now a dark green color.

 

[Edward Muente]

There's $1.50 ozt premium over spot on junk silver from APMEX. No refining required on 90%. $5.38 @ quarter, plus what you make on the front ...

Not too worried about it, as this is one ounce, just for my own personal enjoyment. I have at least 10 lbs of these quarters, probably more.