Photographic silver recovery - home darkroom
 

Porters sells this device to collect silver from spent photographic film and paper fixer.

Silver Magnet Silver Recovery Unit

They say that a home darkroom that goes through a gallon of fixer a week can recover from 30 to 50 ounces of silver per year. I rarely consume fixer at that rate, at least not for sustained periods, but I may go through enough fixer to recover 10 ounces of silver a year. It seems a pity to keep throwing my silver-laden fixer down the drain, as I've done for many years.

This is what they say about it:

They sell the unit for $46, and replacement cells for $18. So after the initial investment of 2.5 oz of silver to buy the unit, it'll cost you another ounce per replacement cell. That's not so bad, but I figure I might be able to make my own device for lower cost.

Can someone suggest how to construct a simple homemade electrolytic silver recovery device to extract silver from sodium or ammonium thiosulfate type film and paper fixers?

Re: Photographic silver recovery - home darkroom
 

Found this on another site:

How much current? What would make good electrodes?

Re: Photographic silver recovery - home darkroom
 

Best to go to http://goldrefiningforum.com ; the guys there seem to know it cold.

Re: Photographic silver recovery - home darkroom
 

I'll check that out SJS, thanks. I forgot about that site. I believe I registered there a long while back...

I also found this discussion on photo.net:

Electrolytic silver recovery voltage & current

Re: Photographic silver recovery - home darkroom
 

Hmmmmm what do studios do with their spent photographic film and paper fixer?

Re: Photographic silver recovery - home darkroom
 

The silver deposits on the wool. One is left with a silver sludge. Kodak makes/used to make? a 5 gallon drum; packed with steel wool. You let the old fixer stay in the drum; say overnight; then the fixer was drained out.. This drum was then returned to Kodak or recyclers; who sent you a check for the assay of the silver removed from the sludge. Saddly this low cost technique has gotten out of vogue; it was simple and dumb and worked well. You can build your own; and save up the sludge; and wait till silver prices go up. The electrical removal system we have worked well for many years; and plates a cake on an electrode. Now it is all corroded up; and I use a simple 5 gallon paint bucket; packed with steel wool.

If you use steel wool you do not need electricity! Essentially the silver percipitates out as a black sludge. The iron, being more active chemically, replaces the silver in the solution. When you dump the liquid it contains iron rather that silver, and the iron is considered relatively harmless.
http://photo.net/black-and-white-pho...g-forum/006io9

Re: Photographic silver recovery - home darkroom
 

I considered the steel wool method. Kodak still makes their recovery buckets, or at least, you can still buy them from certain photographic supply vendors (e.g., Calumet). Rotex also makes them - http://www.rotexsilver.com/reloadable_canisters.htm. Also a company called CPAC, and another company called Imagemax. Some of them are fairly expensive, but as your quote from the photo.net thread indicated, you can make your own.

According to Rotex, one pound of steel wool can recover 6 to 9 troy ounces of silver "in normal operation". But therein lies the problem for a home darkroom. Normal operation for a dentist may be a gallon of fixer a day. For a minilab, it could be many times that. But the volumes of spent fixer produced by a home darkroom are so low that the steel wool or iron may degrade (rust) before it has recovered much silver.

Anyway, I'm still looking into it. Electrolytic recovery seems simpler for low and irregular volumes.

Re: Photographic silver recovery - home darkroom
 

Do you have any idea how much the steel wool canister costs? I would specifically be interested in the M-25 (capacity is about 150+ tr oz).

I'll call rotex next week, but thought maybe someone here has purchases this one or one similar and have a ballpark price.
Thanks!:s1:

Re: Photographic silver recovery - home darkroom
 

I haven't checked the price yet. You know you can make your own by packing common steel wool, which you can get at Home Depot or similar, into a bucket, then just slowly pour in spent fixer, or drain it in slowly from your fixer tank.

Do you use a lot of fixer?

Re: Photographic silver recovery - home darkroom
 

I saw the following in the local news and thought of this thread. I admit I know nothing about this topic. Ya learn something new everyday. The place I retired from was pretty tough on people that were caught 'stealing' their recycle materials.

Re: Photographic silver recovery - home darkroom
 

Ran/Owned a "litho' prep shop in the 70's. I had 3 - 30" film processors all equipped with silver recovery units. We also sold any scrap film.

Originally when the price of silver was low I would throw one hell of a Christmas in July party for the employees in the Key's.

When the Hunt's made the run on silver I bailed out at $30 +/- a oz. When it crashed I just kept it here. I still have about 200 lbs of the sledge. If I recall correctly, the purity varries from 70 to 80 %.

It has been a long time and many miles since I sent any to a refiner. Maybe I get the son to dig it up and send it out.