Quote Originally Posted by Ian Grant View Post
In large scale silver recovery silver is plated out of recirculating fixer or bleach fix (blix) using sophisticated plating units that control the ampage precisely, too much current and the fixer is destroyed.

Colour processing:

On a smaller scale usually mixing the bleach fix (prints) with the fixer from films after colour processing and also the rinse/wash water is sufficient before passing the solutions through a device like the Silver Magnet units. This will remove most of the silver however the remainder should be removed by then passing the solutions through a Steel/Wire wool cartridge.

The Silver magnet should reduce the level of Silver to 10-15 ppm (very approx) with the cartridge as well to below 1ppm. With just a Silver Magnet then the spent solutions should be diluted by about 10 -20X to comply with the legal 1ppm discharge limits (most areas UK/EU/US).

thanks for the info. My next big dumb question is does a bleach for black and white reversal processing work like a color bleach when using the silver magnet? I usually mix all my chems together and drop them off at the chemical drop-off site, but I'm wondering if I should keep them in seperate labeled containers...

Lets say I do pour my bleach, which is potassium permanganate and sodium bisulfate, the clear bath (sodium metabisulfite), spent fixer, and wash water in the same container, the silver magnet would be able to retrieve the silver from that, right? Sorry if this sounds like a dumb question, but I think I've gotten myself confused trying to figure out how to get the ph to 3, as Jnanian said his magnet supplier suggested. BTW, I'm finding nothing worth mentioning about silver recovery on the internet. All I'm finding are MSDS sheets on potassium permanganate, patents for silver recovery systems, and some wikipedia entries for potassium permanganate and processing film :/