Threw my old fixer in with steel wool. Now what?

[sdotkling]

I'm trying to be eco-aware with my b&w darkroom. I accept the fact that my developers, like Dektol and Rodinal (or whatever they call it these days), aren't all that bad--down the drain it goes. Stop bath, basically vinegar, so no biggie. But because used fixer is full of silver, I followed "best practices" and filled a 5-gallon plastic bucket with steel wool, and poured in expired fixer. The bucket being almost full, I opened it up and --gak!--it's black nasty liquid with much degraded steel wool floating around in it. I poured off the liquid into another jug, and am left with 10 pounds of soggy black steel wool. Now what do I do with it?
Thanks in advance, mates.

 

[santino]

I wouldn’t worry too much. Steel wool should turn pretty fast into dust due to oxidation.

 

[DownUnder]

Silver-coated steel wool, wow! Ebay, maybe?

There may be a chemical recycling depot in your community. If so, they can probably deal with it.

I suggest you phone your local council/municipal office and ask about it.

Bear in mind it may cost you. One hopes not too much.

 

[titrisol]

I'm trying to be eco-aware with my b&w darkroom. I accept the fact that my developers, like Dektol and Rodinal (or whatever they call it these days), aren't all that bad--down the drain it goes. Stop bath, basically vinegar, so no biggie. But because used fixer is full of silver, I followed "best practices" and filled a 5-gallon plastic bucket with steel wool, and poured in expired fixer. The bucket being almost full, I opened it up and --gak!--it's black nasty liquid with much degraded steel wool floating around in it. I poured off the liquid into another jug, and am left with 10 pounds of soggy black steel wool. Now what do I do with it?
Thanks in advance, mates.

Use fixer oneshot and thus the amount of Ag is minimal

 

[BernardL]

Use fixer oneshot and thus the amount of Ag is minimal

Soooo... For the same amount of photo practice, same amount of silver (white/clear areas of fixed prints) goes down the drain. And larger amount of hypo goes down the drain. 🙄

 

[x-ray]

You have to run a lot of fixer to recover any amount of silver. It’s pretty much only viable for commercial labs running hundreds of gallons a month.

Fifty years ago there was an electrolytic cell that was available that you put in a tank of spent fixer and plugged into the wall. It used carbon electrodes as I recall but may have had a zinc or copper electrode in it. It used low voltage DC current and would remove the silver. Again you had to use a lot of fixer to recover any quantity

 

[Glenn2]

About fifty years ago some friends built a large scale electrolytic recovery unit. It used a stack of thin stainless steel disks that rotated in the fixer as the cathode, they may have used carbon for the anode. When silver built up around the edge of the stainless disks to a thickness of 1/2” the stack would be taken apart and flexed. The silver fell right off. This was on a grand scale, they used an old bathtub for holding the fixer which they got a lot of.
There was a large plant that manufactured high pressure pipes for the oil industry. All the pipes had to be X-rayed to check for flaws so a LOT of fixer. Was told that they got around an ounce per gallon, not too shabby, when you consider the fixer was free. Silver was under three dollars per ounce back then. Later when the price went up they paid the company something. I bought a few pounds and melted it down to use in one of my other hobbies, jewelry making.

Probably not enough silver in home darkroom chemicals to bother worrying about. Don’t think any of us go through much film or paper these days.

 

[drjfly]

I am planning on trying the techniques described in this YouTube and comments section and importantly the bit in the comments section about using an alkaline fixer.

 

[Beemermark]

Once upon a time B&W films had a lot of silver but even that amount was truly minuscule unless you were developing hundreds of roll of film on a daily basis. Even then recovery methods were based on the cost of silver. Today silver content has been greatly decreased to save on the cost of manufacturing B&W film. And then what is the concern with washing undetectable (except with highly accurate lab equipment) amounts of silver in the waste water stream? See https://www3.epa.gov/pesticides/chem_search/reg_actions/reregistration/fs_G-75_1-Jun-93.pdf which states in part "Silver, a naturally-occurring element, is registered for use in water filters to inhibit the growth of bacteria within the filter unit of water filter systems"

I think I'd be more concerned with what chemical was created by mixing steel wool in the fixer.