# Hot Ammonium Hydroxide Bath



## LeftyTheBandit (Oct 21, 2008)

This is the step in AP that removes silver.

My question is; is this just a hot ammonia bath? The type you buy in the store (ammonia)?

So close to finishing my 1st batch... I can taste it. 1st filter after SMB looks very very good. I'm hoping my last few rinses will not remove to much mass. Looks like 2 or more grams... bad guess..HooT.


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## Oz (Oct 21, 2008)

Store bought ammonia will remove traces of silver, moderate heat helps. I wouldn’t taste it though :wink:


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## Rag and Bone (Oct 21, 2008)

Be sure to use un-scented ammonia!


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## butcher (Oct 21, 2008)

I have been a little leary of ammonia and silver can form sensitive explosive.


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## Lino1406 (Oct 21, 2008)

As only silver chloride and ammonia
involved


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## Lou (Oct 21, 2008)

I wonder how effective a hot ammonia bath can be, when ammonia's solubility in water decreases greatly as the heat of the solution increases. Remember that ammonium hydroxide doesn't exist, it's really just a solution of gas in water that happens to ionize.

I'd stick with a room temperature or lukewarm bath! As hot ammonia is kind of an impossibility.

Lou


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## LeftyTheBandit (Oct 21, 2008)

Thank you all for the help, its really appreciated!


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## LeftyTheBandit (Oct 22, 2008)

butcher said:


> I have been a little leary of ammonia and silver can form sensitive explosive.



Woh Woh Woh... Silver and ammonia makes an explosive? So, much for that idea, I'm not blowing myself up to remove trace silver. Is there another way to remove the silver?

Regards
Richard


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## butcher (Oct 22, 2008)

Lino say's no danger as long as only Ag chloride & ammonia involved, 

maybe some of the guys can elaborate,

all I know is silver can form fumilate with ammonia, 
so I have tried not to get them together,
have seen here where they recomend it as wash, 
I havent researched it, really dont know about siliver chloride and ammonia, apparantly the chemistry is different,

these guys here are good about not telling us dangerous processes without warning us, 

if Lou the chemist explains it, maybe he can put it in laymans terms were I dont need a dictionary, 
just joking Lou


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## Harold_V (Oct 22, 2008)

I believe the solution is stable, but if it dries, it's very unstable. Perhaps GSP or Lou can elaborate on the subject. 

I used ammonium hydroxide regularly when washing my re-refined gold, with the express purpose of dissolving silver chloride and anything else that may be a contaminant. It's safe to use, assuming you don't allow it to dry out. 

Didn't lazersteve suggested precipitating any silver that may be contained by the addition of HCl to the solution? That would render it harmless. 

Harold


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## butcher (Oct 22, 2008)

Harold you a night owl on watch? how about disposal ect ? can I add to stockpot?


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## Lino1406 (Oct 22, 2008)

No explosive


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## Harold_V (Oct 22, 2008)

butcher said:


> Harold you a night owl on watch? how about disposal ect ? can I add to stockpot?


I am a night person, yes. I'm generally up until about 4:00 AM. Not always on the forum, however. I moderate a machining forum and spend time there, too. 

You could put the ammonium hydroxide in the stock pot, but I'd question the wisdom in doing so. There's generally nothing contained within that would be worthy of recovery. If it was up to me, and I suspected silver, I think I'd opt for recovery with a little HCl, then discard the solution. 

Harold


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## Lino1406 (Oct 22, 2008)

I apologize, ammonium contains (of course) nitrogen.
For explosive we need either -NOx, like in silver nitrate
or conditions for -CNO, -N3 to be produced. All these
do not exist in the meeting of NH4OH and AgCl


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