Chemical Forums
Chemistry Forums for Students => Undergraduate General Chemistry Forum => Topic started by: znem1987 on December 28, 2012, 01:36:12 AM
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I am in the radiology field and recently there became available to me some used X-ray film that was to be discarded. I was wondering if anyone knows the chemicals and process required to remove the silver halide from the paper into a solution, and the how to get the silver out of the solution (I was thinking electrolysis, but I'm pretty rusty when it comes to chemistry). I'd appreciate any help.
Thanks, Zack
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Work out the economics first, thats my advise. Is it worth the trouble and cost? How much film? What amount of Ag can you get?
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There are commercial electrolytic silver reclamation systems for sale. I'd expect they're as efficient as possible, way more than someone who isn't sure of the chemistry and engineering involved. They're really only economical if you process a very large amount of photographic material.
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I work for the Cleveland clinic, I have access to 55 gallon barrels of old film. Are there any recommendations as to which electrolysis machine I should acquire?
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I work for the Cleveland clinic, I have access to 55 gallon barrels of old film. Are there any recommendations as to which electrolysis machine I should acquire?
Ok; I take my warning back. :) There might be decent money in this.
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Here's a link that also provides references: http://www.pneac.org/sheets/all/silver.cfm You can also find adverts in the back of photography magazines. I don't know which are better than others, it appears to be all about engineering the system so as to minimize cost and silver loss. For example: http://www.hallmarkrefining.com/product_category.cfm?cid=5
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So I did the math, the machine cost approx. $7000 and it proportedly generates 1 Troy oz. per load. That's I oz in 4 hours. I would have to have to run the machine continuously for about 39 days strait before I would see any profit.
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Assuming there is a troy oz in your raw material. I don't know how much silver remains in the developed film. I also don't understand how the machine pulls the metal out of the film, and that's just the coludition (sp?) that contains the image -- the bulk of the mass of the exposed film is a tough polyester sheet, and that's just wasted mass for your application. But it appears the machine can handle it.
I tried to play with this when I was a kid, I would try to attack film with acid, and collect what I got. I would strip the "film" off the polyester strip rapidly, but I don't know how much metallic silver was in it. I used HCl, so however much it was, it was insoluble anyway, and I couldn't get nitric acid when I was a kid.
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I did a bit more research, I would have to soak the film in developer to "overdevelop" the rest of the film, making the silver drop into the solution. And then you put the liquid through the electrolysis process.