how do you make a silver recovery tank?

[thelovecollect]

and do i even need one if i just develop film?

i've seen the kodak ones for about $80...
worth it or is it an overpriced paint-bucket?

 

[Glenn2]

The best apparatus I've seen for getting silver out of spent fixer was an electroplating device that deposited the silver on rotating thin stainless steel plates. After enough silver built up the plates were flexed to break off the coating. A buddy had one and made money getting used fixer from a company that x-rayed high pressure pipe. For home use it would be over kill. The Kodax device is filled with steel wool which the used fixer is passed through. Iron is higher in the electromotive series and replaces the silver that is in solution. Don't think that they are very efficient and seperating the silver from any remaining steel wool would require a lot of refining. The idea is that you send the cartridge back to Kodak, and they recover the silver, possibily giving you some $. The electroplating device gave almost pure silver that could be melted and put to use. I used to do silver smithing as a hobby and bought some of the metal that my buddies machine produced.
For a little bit of home use it's probably not worth bothering as silver is only fetching about $12 an once at present.

 

[w3rk5]

I wonder how many gallons of spent fixer is needed to get an ounce of silver? Hmmmm.............

 

[phototone]

Silver reclamation is not economically practical, unless you do hundreds of rolls of film every few days. In other words, you need to be a production lab that runs your equipment 8 or more hours a day developing and printing to have enough silver to reclaim to make it worthwhile.

 

[thelovecollect]

my only concern was the environmental impact of dumping spent fixer..
but if there are none...

 

[venchka]

my only concern was the environmental impact of dumping spent fixer..
but if there are none...

Offer your spent fixer to a commercial lab already set up for recovery?

Find a waste disposal company?

 

[thelovecollect]

good idea, maybe school will take it..
i just have to drag a 5 gallon tank on the subway...😀

 

[phototone]

my only concern was the environmental impact of dumping spent fixer..
but if there are none...

There is always an ecological impact from dumping photo chemistry, well except for possibly dilute stop bath and photoflo.

It you are a hobbiest, then you ecological impact will be minimal. I like the idea of taking your spent fixer to a big lab and donating it.

 

[rxmd]

my only concern was the environmental impact of dumping spent fixer.. but if there are none...

It you are a hobbiest, then you ecological impact will be minimal.

Actually spent fixer is the one photochemical substance (not counting bleach and some toners) where even a hobbyist can have substantial ecological impact, because the silver ions are one of the worst things you can do to the bacteria in your local waste water processing plant. It's a good idea to avoid this, even as a hobbyist.

Things you can do to get the fixer off your ecological conscience:

1. Collect the fixer in a big tank and periodically bring it to either a professional photo lab (that is willing to collect it for you), a printing shop (ask before if they run photolithographic or similar processes that use fixer) or a reprocessing plant. In some countries (such as Germany) there are upper bounds on the amount you're allowed to give to them as a hobbyist, a friend of mine had problems when he collected about twenty gallons over the course of a year and then wanted to pass as a hobbyist.
2. Put some iron wool in a bucket or canister and pour the spent fixer in there. The silver from the fixer will attach to the iron and fall out (I'm not a chemist, so I'm unfamiliar with the English proper terminology). Put the canister in a place with good ventilation outside your apartment. Keep it there for a couple of weeks, pour the remaining liquid into the toilet (harmless) and give the now blackened iron wool ro a reprocessing facility (or throw it away, it's not a good thing to do but it's substantially better than spent fixer in the toilet).
3. Best solution: Put the fixer into a canister and add sodium dithionite, maybe three or four ounces for a gallon jug. Don't close the canister, put it in a well-ventilated location outside your apartment, as it will produce some sulphur dioxide which happens to stink. The silver will fall out to the bottom and some to the wall of the canister. After a week or so at room temperature filter the licquid through a coffee filter. The black stuff that remains in the filter and the canister is silver, the liquid can go into the toilet without any trouble. You can collect the silver and later take it to your next-door dental technician - a liter of spent fixer contains some three to six grams of silver - who then can smelt it down into a ring for your loved one every year or two if you have enough throughput. There is a guy on one of the German forums, an amateur with medium throughput, who does that every year.

Philipp

 

[eddie con]

philipp,
thanks for that input. your options are worth considering (#2 especially) even in a country like ours. i plan to go into developing black and white and the practice of being "green" is a challenge even if i will just be a low user.