Silver Recovery from Fixer Question

I'd heard that you can recover fixer with steel wool and a small

electric charge.

 

If this is true, does the positive terminal of the source go to the

steel wool or the negative? My memory of high school chemistry class

is so far gone!

 

I have spare steel wool and a few solar cells from playing around at

home, perhaps i can put them to good use.

 

Any help or pointers is appreciated!

that should be recover silver FROM fixer.

 

I just want to dispose of it in a responsible manner.

Silver ions are positively charged, so the negative electrode should go on the steel

wool.

The silver deposits on the wool. One is left with a silver sludge. Kodak makes/used to make? a 5 gallon drum; packed with steel wool. You let the old fixer stay in the drum; say overnight; then the fixer was drained out.. This drum was then returned to Kodak or recyclers; who sent you a check for the assay of the silver removed from the sludge. Saddly this low cost technique has gotten out of vogue; it was simple and dumb and worked well. You can build your own; and save up the sludge; and wait till silver prices go up. The electrical removal system we have worked well for many years; and plates a cake on an electrode. Now it is all corroded up; and I use a simple 5 gallon paint bucket; packed with steel wool.

Hi,

Where I live one of the photo dealers, and develops film, takes my fixer for no charge. They make a little from the silver, and I can dispose of it properly.

 

Jennifer

Does the material the other electrode is made of matter?

 

And are any other materials accumulated as solids or emitted as gases, and if so are they harmless or not?

 

Should I find a chemist among my friends and ask her instead?

<p>I know a little about chemistry...its called a redox reaction. An analysis of reduction potentials for the valid half-reactions yields:

 

<p>Ag+ + e- --> Ag E = 0.80V<br>

Fe3+ + 3e- --> Fe E = -0.04V

 

<p>E = (3*0.80V)-0.04V = 2.36V

 

<p>Without going into discussions regarding concentrations, metal complex formation, solubility of Fe3+ wrt to pH <i>etc</i> this reaction is clearly favoured thermodynamically. (quite strongly in fact) You don't need to supply electrical current because the reaction is spontaneous.

 

<p>Another trick people use to clean silver jewelery and flatware is to place the silver piece into an aluminum pie plate in a solution of baking soda (an electrolyte). The aluminum is a facile reductant for silver and the bonus is that you don't rub any silver off like with polish.

 

<p>Perhaps a silver "seed" would give you cleaner results. The silver would likely deposit there instead of getting all mixed-up in the iron/aluminum. I've done some platinum recovery before from machined turnings with great success. In this case though, I had to setup an electrochemical cell.

If you use steel wool you do not need electricity! Essentially the silver percipitates out as a black sludge. The iron, being more active chemically, replaces the silver in the solution. When you dump the liquid it contains iron rather that silver, and the iron is considered relatively harmless.

<p><a href="http://www.kodak.com/eknec/documents/e4/0900688a803130e4/J200_en.pdf">http://www.kodak.com/eknec/documents/e4/0900688a803130e4/J200_en.pdf</a></p>

<p>check this out it might help.</p>