Silver Recovery

[AgX]

But still the question of Anfenglin of what to do with the Silverdithionite is unanswered. He wants to use it.

I have to correct myself. The precipitate in that text is metallic silver for the cyanide system. And there will be a sulfite. For a thiosulfate system the precipitate is stated to be similar.
However another (industrial) source states silversulfide to be the precipitate in a thiosulfate system.
Others describe it as black sludge.

 

[mnemosyne]

But we have municipal special-waste collecting offers. There are even special codes for photographic baths to ease collecting and recycling.

Have you ever asked there if the spent fixer is still treated separately for recycling? Until recently I lived in a German city with a population of 300,000. For years (starting ~2014, IRRC) I was told at the municipal hazardous waste collecting facility that used fixer is no longer separated for silver recycling. According to the people working there, the volumes collected had become so low, that it was not practical anymore. So the fixer is simply incinerated together with all the other stuff ... I asked every time I showed up there hoping that the policy had changed and got the same answer every time ... So I stopped taking my spent fixer to the facility and kept collecting it at home. The idea was to maybe find a company that would pick it up for recycling after I had collected a volume that was big enough to make it worthwhile for them.

I live in the countryside now, I actually have moved here with all the gallons of used fixer, and haven't been at the collecting station yet, but I assume the situation is no different here. It is probably the same all over the country except maybe for some very big cities. If I cannot find a company that will recycle the silver I will have to go down the home de-silvering route.

 

[AgX]

That is an interesting point, I have not even thought of yet.

The refinery would have to sent their transporter/tanker to the firm that collects the hazardous wastes, typically from households. For them that only makes sense if such collecting of small amounts is still profitable to them. Otherwise they would have to charge for such. That charge a waste collector would have to compare to the charge for having the baths taken to be incinerated.
Some years ago I wrote to the local firm that does the hazardous waste collecting on order by the county, that I can bring in Fixer and Bleach seperated, designated with the different codings, or whether they would treat them the same, which would safe me from keeping them apart.
I got no reply...

Would you then do desilvering yourself with the idea in mind to make actually money with that?

 

[mnemosyne]

Would you then do desilvering yourself with the idea in mind to make actually money with that?

No, actually I would prefer to be spared the hassles of de-silvering and dealing with the resulting silver sludge. But I just hate the idea that a valuable raw material is dumped when it could be kept in the cycle and put to good use instead ...

 

[removed account4]

you might look into finding a local mini lab and seeing if they can dispose of it for you.

 

[AgX]

But I just hate the idea that a valuable raw material is dumped when it could be kept in the cycle and put to good use instead ...

Yes, I see it so too.

Concerning getting paid the true value of the silver, the costs for checking at the refinery just the silver content of the sludge and the overall handling costs will likely reduce the pay-off significantly.

 

[removed account4]

it depends on the refiner.
=
might be worth it to somehow collect that sludge, silver is currently at $25.xx / troy oz !

 

[eli griggs]

it depends on the refiner.
=
might be worth it to somehow collect that sludge, silver is currently at $25.xx / troy oz !

 

[eli griggs]

If you do no want to try to use the pail and steel wool method, try this instead.

Buy, find a one or two clean 5 gallon carboys, onto which you paint the newest "Worlds blackest black paint, and place then in a sunny southern exposure.

Then, add well stired old fixer and sludge, at least in the begining, to about halfway up the bottle.

Now, the following is a simple tool, found in beer and wine makers shops, so be sure to get one.

What I'm speaking of is a simple clear plastic air lock, which, when partly filled with water (it's a small device) will allow CO2, or on this case warmed water vapor to escape out, with the water chamber of the device keeping out other gases, insects etc.

Now you can process your stored fixer/sludge by allowing the water evaporate l, leaving behind the silver and chemicals that did no travel out of the hot jug.

You then just continue the cycle, and allow the dried remains to build up in the carboy, until you decide its time to empty/process the silver into the silver metal, or start a new silver still and store the past finds.

IMO.

 

[msw]

late to the party ... sorry.

I have begun to set up my at- home darkroom. I am on a septic system (since we're out in the woods) and all i really want to do is not kill the system, and not get the fellow who pumps pout the tank jammed up.

Do i conclude correctly that if i dump the used fixer into a 5 gallon pail and put some steel woll in there, the silver will attach to the steel wool and can be disposed of in the "no questions asked" freebie week at the town dump?

Thanks in advance!

 

[eli griggs]

No, the silver ions will fall out of the solution as the iron from the steel wool replace them, so you can later decant the used solution more safely, into the environment, leaving silver sludge in the plastic or Stainless Steel bucket.

You could also use electrolysis and simply plate the silver onto the sides of a stainless steel bucket.

I and others have made simple old 2 - 3 cell battery powered C or D ell plastic flash lights into electrolysis devices for cleaning gun bores, such as old, military surplus long guns, (you can only allow this to run 10-15 minutes before you start damaging the rifle bore) with a steel or brass rod insulated from the barrel walls, to act as the Cathode and the the barrel as Anode.

These work quite well, with an ammonia and distilled water solution, and should do the same in fixer.

To do it this way, take your battery unit, (see YouTube for directions in making and do no forget to makr the Positive and Negative connections) and connect the Cathode to the Stainless Steel bucket, (it should be Stainless no plain or galvanized) metal) filled with silver bearing fix, and suspend some steel wool in the fixer, dangling on a the Anode and no making direct contact with the bucket, so the metal ion exchanges can take place.

The Bulb in the flashlight will indicate if you've got a good current going.

Each batch should no take long and if you like, particularly with a three cell unit, you can use rechargeable Nihm batteries, or Ni-cads.

How you recharge the batteries, solar, wind or household power, is your business but the batteries, if new stock should last years, if used and recharged properly.

After quite a bit of fixer, trash prints and old silver based film ends and trashed rolls have been run through your unit, you should be able to tap on the outsides of the bucket and pop off pieces of the silver material for further processing or disposal.

Double check the above, especially the electrolysis device and connection set-up and if you're satisfied this is for you, enjoy.

P.S., anyone with such silver sludge or bits of plate are welcome to send it on to me.

Be Well, Be Safe,
Eli

 

[removed account4]

hi. msw:

look for posts by Mr. Bill in this thread regarding set up of an electrolytic system. ( that is the electric plating system described Eli's post. there is a certain cathode distance and voltage that needs to be run in the system, it really isn't as easy as he suggests. what the steel wool does is it is a metallic filter with a large surface area that transfers iron ( reactive metal ) ions for silver ones in an exchange .. some fall out of solution others stick to the metal fibers. you don't need to use any sort of silver recovery if you are bringing your fixer to house hold waste disposal day, you can just bring it as far as I know. usually people have to label what is in the container so they know what they are incinerating .. feel free to drop me an email or a PM if you want to learn more about silver recovery systems I sell, I also test strips so you know what is in your waste before or after you extract silver from it.

have fun!