# recovering silver from negatives for offset printing



## croakersoaker (Jan 23, 2012)

Hi Guys, My wife and I own a small Printing company and have been going thru and cleaning out our negative files for about the last 10 years worth.mostly customers that we dont do printing for anymore.we have about 50 pounds worth of negatives that we use to make metal plates with.is there instructions somewhere that tell you step by step how to recover the silver from them. i have used the search function and not been able to find instructions. i have found references to methods but not any real good directions.it it worth doing or would it be better to sell. we get people call almost everyday wanting to buy this stuff.But im a gold and silver bug and i figured if i can add to my stack and its not to difficult i would do it.any help would be aprreciated.ill try to put a picture of the type of film were working with.


----------



## niteliteone (Jan 23, 2012)

Wouldn't these process the same as medical x-rays.

I jusy finished reading several posts on them. Also found this post.
Try:
http://goldrefiningforum.com/phpBB3/viewtopic.php?f=50&t=11672


----------



## croakersoaker (Jan 23, 2012)

thanks i saw that post to but it didnt really give a method.i saw a reference to using bleach somewhere but now i cant find it


----------



## goldsilverpro (Jan 23, 2012)

CS,

Based on that top sheet, I would estimate what you have to be about C Litho (about 60% black). If the film is .004" thick (most common), I would estimate that there is a total of $200 in silver in the 50 pounds, at a $32 spot. If the thickness is .007", it would be about $115. If you could find a local film buyer, you might get half. To set up to process this, it would cost more than it's worth.


----------



## croakersoaker (Jan 23, 2012)

well the sheet i posted is much more developed than most of it. i would say that the majority of it is 80 to 90 percent black.mostly used for low coverage spot colors .still not worth it? what if i wanted to do it just for fun?


----------



## goldsilverpro (Jan 23, 2012)

$266 - $300 max for 4 mil thick stuff. Still not worth it. Here's the steps:

(1) Cut it into small pieces or run the sheets one at a time.
(2) Strip all the black silver and emulsion off in a large amount of a somewhat noxious chemical which will end up as waste that will have to be disposed of. This will create a sludge that will be intermingled with the plastic film pieces.
(3) Rinse all the black out of the plastic.
(4) Figure out how to collect all the black sludge and try to dewater it as much as possible - much more difficult than it sounds. This stuff is VERY hard to filter. We poured it through a 1 micron filter bag and it went through as fast as we could pour it.
(5) Burn the sludge to ash until no black carbon remains. When this stuff burns, it has a horrible gagging stink and makes lots of smoke.
(6) Flux melt with borax, at least.
(7) Pour into mold.


----------

