how does one go about recovering silver from the fixer??? i read the thread from about a month ago on this same problem, but the problem of getting the silver out of the fix and into the wallet was never finished. thanks for any input!

dave

-- dave s. (dws69880@cmsu2.cmsu.edu), March 09, 2002

Answers

Recovery of silver from fixer is done by electrolysis. This means you need large amounts of used fixer to be economical.

-- Marc Leest (classicphoto@leest.net), March 09, 2002.

are there places that you can go to have silver recovery done, or is there a way to do it yourself? just curious. also, how much is a lot of fixer? a large drum full? or more?

thanks, dave

-- dave s. (dws69880@cmsu2.cmsu.edu), March 09, 2002.

I take my used fixer to the local photo shop. They have a recovery system, and gladly pour my fixer through their system. It keeps the heavy metals out of the waste water. --Sam

-- Sam (sselkind@insightbb.com), March 09, 2002.

i think you need many drums before you have a lot, from a silver recovery perspective. Consider the miniscule amounts of silver present in film and paper, then the rather low price of silver, then the expenseof the recovery unit. My understanding is that the recovery units which are practical in price for a small operation also corrode away and have to be replaced just about when they've broken even. The better ones are more expensive and only practical for large volumes. I was told this by a Kodak support person a couple years ago. I would love to find out it isnt true, but I dont know why he would have lied since I had called because I wanted to buy a recovery unit and he talked me out of it!

-- Wayne (wsteffen@skypoint.com), March 09, 2002.

There are several ways of recovering silver. For smaller amounts of fixer a chemical recovery seems the only way that makes sense. For an amateuer it really does not make sense, since the amounts simply do not justify the costs. In most European countries though all professional users are mandated by law to recover silver before dumping fixer. A chemical product widely used for silver recovery in Europe is Tetenal's Exargent. You will get a black silver rich paste which can be sold for further treatment.

-- Volker Schier (volker.schier@fen-net.de), March 10, 2002.

Another way to precipitate the silver out of the fixer is to toss in a few pieces of loosely crumpled aluminum foil. I keep a plastic tub set aside just for stripping silver fom my fixer before re-using it (the fixer) in less-than-critical fixing jobs.

I read about this a few years ago in the German magazine Photo & Labor (too bad it's defunct, it was an excellent source of B&W information). Based on that article, I submitted a question to Chapman at Darkroom Techniques, who, basically said that re-use of the fixer is possible if you're willing to accept the hardening effect of the aluminum ion in the fixer.

Sooooo..... I add enough aluminum foil to assure a few bits are left after it's had a chance to precipitate all of the silver. It takes a couple of days for the action to settle down enough that I can siphon off the clear fixer. I verify that the silver content is zero, using Kodak silver test papers. I then add acetic acid to bring the Ph to 5.5, or lower, and mix it 50-50 with new fixer. After one or two "rounds", I strip the fixer one last time with the aluminum foil before dumping it.

The bottom of my tub has 2 or 3 inches of black silver sludge, which I haven't gotten around to weighing or cashing in for a trip to Reno. I really don't care about getting rich off of the silver, but it's nice to know that I'm doing my part in controlling pollution, not to mention the savings from re-using the fixer.

-- Reinhold Schable (rschable@quik.com), March 11, 2002.

You have to be running alot of film & paper to make it worth your while...we do it for compliance, but I can tell you that it was a good 5 years or so of running an X-Rite unit weekly before we had any sizable amount of "sludge" scraped off the unit......do it for the environment, because you're not really going to make money off silver recovery.

Besides cobbling something together like mentioned above, or using steel wool or something in a bucket...you can get that "silver magnet" thing for tray use. I've never used anything like these, just seen 'em in catalogs. I have used the Kodak units in the 5 gallon drums, but you need to use those on a regular basis...they're not practical for low volume use.

The best thing I could suggest, would be to look for a graphic arts/press supplier in your area that deals with silver recovery...there's one nearby us that makes a variety of recovery units that are similar to the Kodaks, but smaller. They're made into PVC pipes that can be either fitted inline to the drains of processors (like typesetting machines, or xray processors), or smaller units that you can pour the used fix into and let it drain out afterwards....you test the cartridge's capacity with those fixer test papers from Kodak....when the unit is full, you return it to the company (you have to leave a deposit to begin with) and they give you a cut of it, and a new unit to start over again....I don't think you'd get rich off this though, but it's probably better than dumping it down the drain over the long run.

MY opinions as always, hope this helps...

-- DK Thompson (kthompson@moh.dcr.state.nc.us), March 11, 2002.

How much is enough fixer?? We run about 15-20 gallons a month...we're a low-volume in-house lab....that's spent fixer out of deeptank line and a paper processor, as well as from an E6 machine. It literally took 5 years to even have enough to turn over....Kodak has an Environmental site:

http://www.kodak.com/US/en/corp/environment/kes/waste/index.jhtml

you can find all sorts of stuff on there about waste management, safety and silver recovery....my opinions only, once again..

-- DK Thompson (kthompson@moh.dcr.state.nc.us), March 11, 2002.