silver fixer
- Thread starter jjohio
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Doesn't sound very feasible to me. I would think you would just end up with a sludge of silver thiosulfate, sodium thiosulfate, and everything else that was originally in the fixer. You might be able to flux melt this in a crucible furnace, however, but I would bet it would involve using something like rebar to slag out the sulfur. There are better ways of doing this. Search the forum.
Did wherever you heard this explain how to get the silver out of the sludge? If so, what was it?
Did wherever you heard this explain how to get the silver out of the sludge? If so, what was it?
Juan Manuel Arcos Frank
Well-known member
No way...follow GSP´s directives.
Manuel
Manuel
jjohio said:
Then what?
Buy some sodium thiosulfate powder, add water, evaporate water, what's left? Hint: it's a salt.
Just adding water and evaporating water does nothing to reduce the salt, in your case silver thiosulfate. You need to reduce the salt to metal, then separate the two.
time for more reading.
Just adding water and evaporating water does nothing to reduce the salt, in your case silver thiosulfate. You need to reduce the salt to metal, then separate the two.
time for more reading.
jeneje
Well-known member
I just done three gallons of fixer, so learn from my mistakes.... add lye to the fixer ONLY and let set, it will take a day or two but the silver will drop out, filter, wash and then melt. Do not expect a quick drop it does not happen that way, at least not for me.
Kenneth
Kenneth
There are reasons why you are being told not to melt the sludge, but apparently you are not interested. So melt it, just use a hood.
jeneje
Well-known member
4metals said:
4metals, I should'nt but I will. Don't get mad at me... :lol: The first thing is the sludge is not pure silver, second...if you breath the fumes from your one and only melting experince...it might be your last. Silver fumes are toxic follow 4metal advice use a fume hood and stay clear, or better yet follow the advice given here by the experts, they really do know what they are doing.
Good luck with your silver :roll:
Kenneth
jeneje
Well-known member
jjohio said:
Ok...I am going to try to help you here. First take the sludge and wash it with tap water a couple of time and filter. Next rinse the sludge into a beaker or glass container, use a spray bottle to rinse it off the filter into the container. Next add an equal amount of HNO3 ( nitric). Place container in a fume hood or outside away from people and anminals. The solution will digest the silver. Let it set overnight or 24 hr's.
When you have done this take photos and repost here on this thread.
jjohio I strongly suggest you get a copy of hokes book on refining and read the section about silver. The members here only ask that one reads and understand what they are trying to do. Then if you get stuck they are more than happy to help you.
What I have discribed is the way I would handle the sludge. They may be a better way and if I am misleading in anyway the senior members will correct me.
If they chime in - it is in your best interest to listen to what they have to say. They are experts and have done this many years ... most all their adult life.
Repost after you have digested the sludge.
Kenneth
jeneje said:
Confusing thread. Is the sludge from the addition of NaOH or is it from evaporation? In the following, I assume it was evaporated.
The silver thiosulfate in the evaporated sludge is soluble in a sodium thiosulfate solution and the sodium thiosulfate in the sludge is soluble in water. Therefore, rinsing will dissolve some silver thiosulfate.
I think the addition of nitric will create a black stinking mess.
If you have already evaporated this solution, were it me, I think I would attempt to get everything re-dissolved and back to where you started. Maybe, just some warm water would do it, especially if it isn't totally dry. If that didn't work, you might add a little fresh sodium thiosulfate to the water. I would first experiment with this in small quantities. If you can get everything re-dissolved, start from scratch - several methods for reducing the silver from the hypo solution have been given on the forum. Ask Manuel about all this - he has more experience working with these solutions than anybody. The evaporation is really a bad idea, in my humble opinion.
I was just reading and had some questions myself. Silver is not my thing. Does the NaOh method work by just adding NaOh and melting? Number two, where can you buy bulk sodium sulfide and how much does it generally take to drop silver from a solution of sodium thiosulfate? I also heard someone mention copper recovery. If so is that like a cementation process we do with gold? Does it drop metallic silver in metal form?
I know sounds like a newbie. Lol
I know sounds like a newbie. Lol
Palladium said:
As far as adding NaOH is concerned, it seems to be assumed that silver oxide or silver hydroxide is formed. So far, though, there has been a lot of talk and little action. Has anyone been totally successful doing this - by totally, I mean 100% recovery? If so, how do you know you got it all? Has anyone even been partially successful? I have grave doubts about this process. Prove me wrong, guys.
Juan Manuel Arcos Frank
Well-known member
GSP´s directives are right and wise.
Adding NaOH to spent fixer is a process used by many people,in my own experience it did not work,I have added NaOH,cold,warm,with sugar,boiling the solution for a while and I have never got any mud or silver,for all these reasons I gave up using this process.
About Palladium´s questions,first one answer is "YES",but I can not be able to get the mud(GSP is right,that mud should be silver oxide or silver hydroxide),second one answer is:sodium sulphide(Na2S) is wide used in food´s industry,it bleaches some grains,like corn,wheat,barley or oats so you can get sodium sulphide pretty easy,here in Mexico I buy 25 Kg. for $ 24 USD.
Reaction between Na2S and silver thiosulfate complex is an instantaneous one,it forms silver sulphide(Ag2S) which takes some time to settle down,spent fixer is regenerated.
The process for making metallic silver from silver sulphide has been posted in this wonderful Forum.
Cementation techniques(copper or iron wool) for spent fixers work well.
_________________________________________________________________________________________________
Jjohio:
Man,you are in trouble but you have come to this Forum to find answers,so let us try to solve your problem:
First of all,we have to know if you have silver dissolved in your fixer,so dip a piece of clean copper wire for 5 seconds into your fixer and tell us what happens.If there is any silver dissolved we will use zinc/sulphuric acid or sodium sulphide process to recover that silver.
If you have any mud then filter it and dry it,this mud could be many things(silver oxide/silver hydroxide/silver sulphide/insoluble metal sulphides/insoluble metal hydroxides),we need to melt it with potassium nitrate(salpeter) with 1:3 ratio(1 part mud+3 parts of saltpeter) this action will lead us to metallic silver.
Keep us posted.
Kindest regards.
Manuel
Adding NaOH to spent fixer is a process used by many people,in my own experience it did not work,I have added NaOH,cold,warm,with sugar,boiling the solution for a while and I have never got any mud or silver,for all these reasons I gave up using this process.
About Palladium´s questions,first one answer is "YES",but I can not be able to get the mud(GSP is right,that mud should be silver oxide or silver hydroxide),second one answer is:sodium sulphide(Na2S) is wide used in food´s industry,it bleaches some grains,like corn,wheat,barley or oats so you can get sodium sulphide pretty easy,here in Mexico I buy 25 Kg. for $ 24 USD.
Reaction between Na2S and silver thiosulfate complex is an instantaneous one,it forms silver sulphide(Ag2S) which takes some time to settle down,spent fixer is regenerated.
The process for making metallic silver from silver sulphide has been posted in this wonderful Forum.
Cementation techniques(copper or iron wool) for spent fixers work well.
_________________________________________________________________________________________________
Jjohio:
Man,you are in trouble but you have come to this Forum to find answers,so let us try to solve your problem:
First of all,we have to know if you have silver dissolved in your fixer,so dip a piece of clean copper wire for 5 seconds into your fixer and tell us what happens.If there is any silver dissolved we will use zinc/sulphuric acid or sodium sulphide process to recover that silver.
If you have any mud then filter it and dry it,this mud could be many things(silver oxide/silver hydroxide/silver sulphide/insoluble metal sulphides/insoluble metal hydroxides),we need to melt it with potassium nitrate(salpeter) with 1:3 ratio(1 part mud+3 parts of saltpeter) this action will lead us to metallic silver.
Keep us posted.
Kindest regards.
Manuel
