From: Monona Rossol <actsnyc**At_Symbol_Here**CS.COM>
Subject: Re: [DCHAS-L] silver recovery units
Date: July 3, 2013 11:21:07 AM EDT
Reply-To: DCHAS-L <DCHAS-L**At_Symbol_Here**MED.CORNELL.EDU>
Message-ID: <8D0461813407939-85C-4F167**At_Symbol_Here**>

Here's something I can't seem to get answered by the companies that put out small silver recovery units for college photography programs.  I know they do a good job of capturing silver ion washed out of the photographic paper, but these people are putting waste from alternative processes through the thing as well.
Those other chemicals include silver nitrate, ferric ferrocyanide, ferric oxalate, potassium and sodium dichromates, a bunch of sulfites, ferrous sulfate, copper toner (not sure what form the copper is in) and thiourea.  It might also be worth noting that the pH of these alternative process wastes can vary from basic to very acidic.
I am assuming the high concentration of silver in the silver nitrate will just wear out the cartridge faster.  And I assume the sulfites and thiourea will just go through.  But the metals I need some information about.  The electron potential table is not enough here.  I need to know.
OH, and there are three basic types of units out there: electrolysis, metallic replacement, and precipitation.  I think this unit is the first of these.  But I also think the people I talked to there don't even really know.
Any ideas?
Monona Rossol
NYC 10012

Previous post   |  Top of Page   |   Next post

The content of this page reflects the personal opinion(s) of the author(s) only, not the American Chemical Society, ILPI, Safety Emporium, or any other party. Use of any information on this page is at the reader's own risk. Unauthorized reproduction of these materials is prohibited. Send questions/comments about the archive to
The maintenance and hosting of the DCHAS-L archive is provided through the generous support of Safety Emporium.