Recycling precipitated silver in old fixer?

[Philippe Gauthier]

I've noticed that silver tends to precipitate as flakes in old film fixer left to sit for a couple of weeks. Has anyone here tried to recycle it? I'm not thinking of getting metallic silver, for which I have no use, but to get silver nitrate, which is expensive and used in small quantities in several cool alt processes.

I know that you must dissolve silver in nitric acid to get silver nitrate, but pure nitric acid is nasty stuff; does anyone knows of the lowest concentration that would work? Are the flakes pure enough to be turned in sufficiently high grade silver nitrate? Other safety considerations?

My assumption here that the silver which precipitates spontaneously will be purer than the mixed silver/iodine sludge that you get with the usual "iron sponge" trick to remove the silver from the fixer. Is this a reasonable hypothesis?

[Capocheny]

Hi,

Good question Philippe...

When I worked for a newspaper back in the early 80s they had a silver recovery process in place. However, it's viable only if you're putting through quite a bit of raw materials.

I would contact a local newspaper and ask them if they have such a recovery system in place. Alternatively, you can also contact either Kodak or Ilford and query them about this. I'd be awfully surprised if they didn't.

IMHO, I think it's a good thing to do... much safer for the environment.

Cheers

[Abe Slamowitz]

All labs have to recycle silver. However you do need to run quite a large amount of chemical to get a few drops of silver. you can buy a can and collect your chemicals until you have a large batch and than you must run many more batches to get any amount of silver. It's good for the environment and makes money for the big labs.

[jnantz]

hi philippe:

i'm not sure where you live, but these guys are on the west coast ( usa ) and convert spent photochemicals into fertilizer.

http://www.itronics.com/index.html

[Philippe Gauthier]

Just be clear - the process doesn't have to make much business sense. I can access my own processing and some of my photo club's. Even 10 or 20 grams of silver in a year would be great if I can easily (and relatively cheaply) turn it into useful silver nitrate. I could some milleage on a salted paper recipe that requires only 12 grams of silver nitrate. It would be satisfying to get it from recycled silvr, even if buying such a small amount of silver isn't THAT expensive.

Any hints?

[Rob Tucher]

One thing not many know is that it is highly illegal for anyone to dump untreated fixer down the drain. As rare as it is that anyone is made aware of this and as hard as it is to come across companies that make silver recovery paraphernalia, you can be fined big time if you get caught. These days waste water companies have chemical sniffers that can locate polluters. You can be fined thousands based on your buying and usage history verified by your receipts for chemistry. I know of a small time black and white guy who was fined $15,000 but later had it lowered to $7500 for dumping. It's done by state DEPs but is based in federal law. Not to be an alarmist but this thread kind of indicated to me that not many people know about this.

[Mike Chini]

Considering all of the pollutants we all dump down the drain and in the garbage - on a regular basis and in bulk, (bleach, household cleaners, plastics, paints, cosmetics, rotted food, metals etc.) that seems absurd.

[jnantz]

Iknow what you mean Rob: Where I live people get fined $10,000 / day that they are "non-complient". The authorities test down to 3pts/ million ( lowest amount they can detect before it is deemed "undetectable").

As for the " you dump everything else down the drain " argument, everything else isn't a heavy metal, or illegal

goodlight JAKE

[darter]

Fines for illegal dumping are generally reserved for commercial users, not for those who merely develop their own film. Of course, this varies by local ordinance. I uncovered an article that said that steel wool placed in used fixer will precipitate the silver into a sludge that can be eventually be collected and dumped as solid waste (or hopefully, recovered). This is far less harmful than letting it enter the liquid waste stream. Even the smallest silver recovery systems available are designed for those who use more fixer than the average hobbyist. I've heard that some schools and labs will accept used fixer, so it is worth checking local high schools or colleges.

[Philippe Gauthier]

(sigh)

OK, I'll try one last time. I live in Canada and the american law on toxic waste does not apply to me. I don't want to recuperate silver to make some real money or even just to protect the environment, I just want to recuperate a few grams here and there just for the sake of doing it and making my own silver nitrate - I'd eventually like to get 12 to 15 grams of it just to try the salt paper technique.

I don't think it's an absurd objective even in the context of the home darkroom; now, how can it be done in practice and as safely as possible, that's the question. The rest is, as far as I'm concerned, off topic. BTW, I already have a local supplier for silver nitrate.But I'd like to do it myself, if possible, just for the fun of playing with chemicals. That's why we play with alt techniques, isn't it?