Switch to English Language Passer en langue française Omschakelen naar Nederlandse Taal Wechseln Sie zu deutschen Sprache Passa alla lingua italiana
Members: 71,829   Posts: 1,582,228   Online: 1038
      
Page 1 of 4 1234 LastLast
Results 1 to 10 of 38
  1. #1

    Join Date
    Jan 2008
    Shooter
    35mm
    Posts
    29

    harvesting silver from over-exposed paper

    Hi, I have a large stack of photo paper that was ruined due to a classmate kicking open the single door to the darkroom... I tested the paper, and it is all ruined. Is it possible to somehow separate the silver from the paper? I saw someone once remove the silver from fixer, and I thought of using some fresh fixer and just running undeveloped paper through it to strip the emulsion. Will this work?
    I also, as a side question, wondered: since the silver in the fixer is removable by redox (I've seen it with steel wool), is it possible, using an electric current, to put it back into a fresh silver chloride emulsion using a current and a saltwater solution?

    edit: also, I have some homemade emulsion that went bad, I thought about reacting it with copper to get silver metal, then using an electrical redox reaction in the same way as above, with a salt solution, to make silver chloride... will this work as well?

  2. #2
    glbeas's Avatar
    Join Date
    Sep 2002
    Location
    Roswell, Ga. USA
    Shooter
    Multi Format
    Posts
    3,307
    Images
    109
    That will work for removing the silver. Don't know about rechlorinating the silver though. It would be easier to sell the silver and buy some fresh photo grade silver nitrate.
    Also if you want to go to the trouble of washing and drying the paper it can be reused for alt processes. Ask Kerik about it.
    Gary Beasley

  3. #3

    Join Date
    Jan 2008
    Shooter
    35mm
    Posts
    29
    I did not know that any alternate processes use completely exposed paper! which ones so, so you have a link? I have a lot of this paper I saved for the purpose of removing the silver that was ruined (the photo head here told me to put it to use, the second that Kodak stopped making photo paper, this guy splurged on it like crazy... he was pi**ed!

  4. #4

    Join Date
    Mar 2004
    Shooter
    8x10 Format
    Posts
    94
    You could toss it out in the sun to really over expose it, develop it, and use it to make an ass kicking hypo-alum toner.

  5. #5

    Join Date
    Jan 2008
    Shooter
    35mm
    Posts
    29
    I just realized, the reaction with salt might make pure sodium metal, which is not good in a water solution (unless it's a lake you make things go boom on B - )
    anyways, I thought about actually reintroducing the emulsion (removed from the paper) into an aqueous solution, causing them to reform when dried... or using copper hydroxide or copper carbonate in the reaction to replace the salt

    or I could dissolve the silver in some nitric or sulfuric acid

    Johnny was a chemist's son, but Johnny is no more,
    what johnny thought was H20 was H2SO4!
    so yes, I know the dangers of doing the above with the acids, before any comments.

  6. #6

    Join Date
    Jun 2004
    Location
    Portland, OR
    Shooter
    4x5 Format
    Posts
    3,268
    Quote Originally Posted by knoxissimpler View Post
    I just realized, the reaction with salt might make pure sodium metal, which is not good in a water solution (unless it's a lake you make things go boom on B - )
    This will not happen - you cannot make sodium metal this way.

  7. #7

    Join Date
    Jan 2008
    Shooter
    35mm
    Posts
    29
    Quote:
    Originally Posted by knoxissimpler View Post
    I just realized, the reaction with salt might make pure sodium metal, which is not good in a water solution (unless it's a lake you make things go boom on B - )
    This will not happen - you cannot make sodium metal this way.
    then where would the sodium go? it would be a single replacement reaction if it happened, would it not?

  8. #8
    donbga's Avatar
    Join Date
    Nov 2003
    Shooter
    Large Format Pan
    Posts
    2,084
    Quote Originally Posted by glbeas View Post
    That will work for removing the silver. Don't know about rechlorinating the silver though. It would be easier to sell the silver and buy some fresh photo grade silver nitrate.
    Also if you want to go to the trouble of washing and drying the paper it can be reused for alt processes.
    One would need an extremely large amount of paper to make silver recovery financially worth the trouble.

    Fixed out B&W fiber based paper can be used for carbon transfers but the paper has to be throughly washed. Also some B&W papers (I don't know which) may not work well for carbon transfers.

    I have a friend here locally who has used the back of fixed out gelatin silver paper to do palladium printing so it may work well for other iron processes. I well say that I didn't care much for the texture of the surface that showed in the prints.
    Don Bryant

  9. #9
    gainer's Avatar
    Join Date
    Sep 2002
    Posts
    3,726
    Images
    2
    When one considers that the major cost of manufacturing paper and film is not the silver, one wonders if the silver recovered is worth the cost of recovering it. At least, this one does. You could weigh several sheets of dry paper, bleach, fix and dry it and weigh it again to see how much difference the silver could have made. You might find out that the cheapest thing you can do with the ruined paper, if you are worried about the effect on the environment of just pitching it, is piitching it at a hazardous waste dump. If it is fiber-based paper, you could remove the emulsion with chlorine bleach and use the paper for other art purposes. I think the paper is worth more than the silver on it. Just a thought.
    Gadget Gainer

  10. #10

    Join Date
    Jun 2004
    Location
    Portland, OR
    Shooter
    4x5 Format
    Posts
    3,268
    Quote Originally Posted by knoxissimpler View Post
    then where would the sodium go? it would be a single replacement reaction if it happened, would it not?
    I kind of have a hard time following what you are proposing, but I think you are saying you want to take the bad paper, remove the silver from the paper with fixer, and then you want to put the silver back into the paper using electrolysis.

    It's that last step that will not happen. I assume you think that electrolysis will create silver metal, which you think will react with the sodium chloride that you've added to the fixer solution - and then the sodium will be left behind as free metal?

    That's not going to happen - remember that the sodium in the sodium chloride is ionic sodium. It's in solution and it will stay in solution. If you drop out the chloride ions from the solution with the silver, you still have the ionic sodiums floating around. I thint what they will probably do is start raising the pH of the solution.

Page 1 of 4 1234 LastLast


 

APUG PARTNERS EQUALLY FUNDING OUR COMMUNITY:



Contact Us  |  Support Us!  |  Advertise  |  Site Terms  |  Archive  —   Search  |  Mobile Device Access  |  RSS  |  Facebook  |  Linkedin