Silver extraction from used film

[drathgeb]

Howdy gents,
I was wondering if any of you photo hobbyists have any experience extracting silver from used x-ray film. I was just hoping to get an idea of what is involved and possible expense of getting started. I have several hundred pounds of x-ray film and think even at low percentages that is a whole butt load of silver. Thanks for the help.

 

[Legion]

Normally commercial labs recover the silver from the fixer bath. Ammonium thiosulphate is used to reduce the unexposed silver particles on the film to soluble salts. A silver recovery machine basically uses electrolysis to draw that silver out of the solution and attach itself to plates or a metal drum inside the machine, just like silver plating jewellery, but much thicker.

The silver is then broken off the plates and sold.

I've seen a 50L bucket filled with silver from a motion picture laboratory.

 

[AllenG]

^^^^
The above is the process my Dr. father used in his x-ray lab.
You have to recover it from the fixer rather than the film itself. There may be more silver to be made selling the stock on ebay rather than trying to recover metal from the film however.

 

[Legion]

^^^^
The above is the process my Dr. father used in his x-ray lab.
You have to recover it from the fixer rather than the film itself. There may be more silver to be made selling the stock on ebay rather than trying to recover metal from the film however.

+1 to selling the film stock. Even time expired, some art student will think of a way to put it to use. Several hundred pounds worth of film might be worth the effort, but not owning a lab, buying enough raw chemistry to make that quantity of fixer will be difficult, and mixing it correctly even more so. Then, even if you could rent a siltec or similar machine, plumbing the thing would be a hassle, not to mention you are dealing with heavy metals potentially entering your local waste water, so your local council will have a cow.

It is really not so easy to do at home in the kind of quantity that would make it remotely profitable.

Even smaller labs don't bother. Usually they have a silver recovery machine that is owned by a second company, and that company loans it in return for the silver recovered. Unless you were putting through thousands of feet of film a day, like the place I worked for, it is not worth buying the equipment. And when I mixed fixer I did it in 4000L batches, if that gives you an idea.

 

[Edcculus]

I used to work for a printing company that still made film to expose plates with. We had a film processor, and a company came about every 2 weeks to take our fixer away in large 55 gallon drums. I'm sure something could have been recouped by doing it ourselves, but I don't think it was ever worth the effort.