PDA

View Full Version : Silver recovery from unprocessed paper



LewisDowney
26-Sep-2012, 15:27
Hello,

Over the years friends gave me a few thousand sheets of 8x10 paper they were not going to use. Most of it is RC, some fiber-based. A few months ago I ran some test prints and found the paper to be too fogged to use - even with added restrainer. Paper-base white was long ago and far away for this stuff.

Other than processing each sheet through fixer and then putting the fixer into some sort of silver recovery process, is there a cost effective way to recover the silver in the paper.

Thanks,

Lewis

Sevo
26-Sep-2012, 15:53
I'd recommend using RA-4 blix - faster and more thorough than black-and-white fixers. Besides, black and white fixer is destroyed in the de-silvering, while there are large scale blix formulations capable of in-process electrolytic de-silvering as well as small scale versions that can be de-silvered with steel wool cartridges.

LewisDowney
26-Sep-2012, 19:56
Many thanks!

Electrolytic de-silvering is more what I had in mind. One ideal case would be to deliver the paper to someone who would de-silver it and keep some percentage (half???) of the proceeds.

On the whole, I'd prefer not to put through thousands of sheets of paper through a tray of fixer or blix or whatever. I'd have to do it by hand; it would probably take a long time, and the recovery process will involve an outlay of money.

Much more desirable would be to take the paper somewhere and receive cash for it.

Any thoughts?

Peter Gomena
26-Sep-2012, 21:38
Find out if there's a medical x-ray recycling/reclamation outfit in your area. They may take the paper off your hands, may pay cash. Or not. Worth a call.

Peter Gomena

jnanian
27-Sep-2012, 12:38
if you fix the paper yourself you can get an inexpensive device like a silver magnet
and send it to the refiner whose address is included with the device.
it will leave about 50parts / million and an ionic transfer method will remove the rest.
steel wool, nails, aluminum &c can be messy because of sludge acquired
a trickle tank is sealed and depending on the size, can handle 1000 gallons of fluid
if used with a silver magnet.

good luck !
john

LewisDowney
28-Sep-2012, 07:18
Progress!

Peter, John,

Thank for you for your helpful insights.

Following up on Peter's suggestion I found a local firm that recycles xray film and gave them a call. For xray film they pay about $0.50/pound. They will buy unprocessed photographic paper but the reclamation process is less efficient. For unprocessed paper they only pay $0.20 pound.

Since I have about 100 pounds of paper, my net would be $20.00. That's a better option than throwing the paper away on a couple of fronts:
• less heavy metal in the landfill
• $20 in my pocket

It might be the best I can do for no effort. It also provides a metric to compare with processing the paper through fixer and reclaiming the silver. I do not particularly want to process the paper through trays but there should be more than $20 worth of silver to be recovered.

Thinking out loud here... If I processed paper in stacks of ten sheets for 3 minutes per stack, I could process 20 stacks per hour -- about 200 sheets. For a couple of thousand sheets of paper, it might take 10 hours of tray processing. A year ago I found an estimate for the amount of silver on a square foot of paper. When I did the math, I recall coming up with $200-ish worth of silver at the price that was current at that time. The cost of enough fixer to process 2000 sheets of paper could be $50 (just a guess). If the silver magnet recommended by John is also $50 (spot checked price) then my material cost is about $100. If I pay myself minimum wage that cost is $72.50. Making the pretend profit about $27.50 using these seat of the pants numbers.

Over the weekend I'll do more careful number crunching.

Your comments are great. Thanks again.

LewisDowney
29-Sep-2012, 10:26
Saturday's findings.

I am using data from this post on APUG http://www.apug.org/forums/forum37/11130-any-hard-data-silver-quantity.html. It quotes a small amount of information from a book called The Theory of the Photographic Process including


Table 4 gives the expected range of silver content. Here are some extracts from the table for unprocessed pictorial film, in g/mē:
...
B&W paper: 0.8 to 1.5

I threw together a quick spreadsheet, shown as a screen shot below. Using the figures above, the amount of silver in the paper is 127 to 219 grams. Using a recent price of $34.50 per Troy Ounce the maximum money that could be generated, if 100% of the silver were recovered is $141 to $243.

The $0.20/pound offer from the local recycling outfit looks more attractive given the amount of time and expense I would incur to recoup I dunno what percentage of the silver in the paper. A big side benefit is that this stack of paper can be gone from my basement workspace in a matter of minutes. The stuff is stored in half-a-dozen cardboard file boxes normally used to archive business papers. I need the space back!

81188