Electrochemistry sulfuric gold cell

[timmyhartsing]

hello fellow refiners, i have been reading posts pretty well every day and thinking about what process to use on these gold plated pieces,a sulfuric gold cell sounds like the best way to go.i read some posts from a couple years ago about this method and learned alot.got a question on this method can i use stainless steel as a anode and cathode and does it matter if its 304 or 316 grade or will it work at all ?the pieces are copper with gold plating and sulfuric cell seems the best way to go because dissolving all that copper with acid would be too costly nitric is hard to get here they wont sell it to just anyone.any advice would be greatly appreciated, thanks

 

[bswartzwelder]

Why not just stick with the tried and proven materials like copper mesh and lead? Lasersteve sells them on his website for a good price, and he ships things out fast. They can also be found on the web if you have time to search.

 

[goldsilverpro]

If the gray colored material around the seal ring, under the lid, and under the circuit is gold-bearing braze, it will contain a large portion of the value. In my experience, this material isn't easily removed by the sulfuric. If it does come off, it could take a very long time.

I would probably never use a lead cathode. I ran a 50 gal sulfuric stripper daily, for years. It was in a mild steel tank which was used as the cathode. I have had some bad experiences with 300 series stainless. When used as the anode, the nickel tended to dissolve and ultimately rendered the solution worthless. No matter what you use, you will have big problems if you use too much current and overheat the solution. I wouldn't exceed 5 amps per gallon of solution, were it me, unless you have a way to keep cool.

 

[timmyhartsing]

If the gray colored material around the seal ring, under the lid, and under the circuit is gold-bearing braze, it will contain a large portion of the value. In my experience, this material isn't easily removed by the sulfuric. If it does come off, it could take a very long time.

I would probably never use a lead cathode. I ran a 50 gal sulfuric stripper daily, for years. It was in a mild steel tank which was used as the cathode. I have had some bad experiences with 300 series stainless. When used as the anode, the nickel tended to dissolve and ultimately rendered the solution worthless. No matter what you use, you will have big problems if you use too much current and overheat the solution. I wouldn't exceed 5 amps per gallon of solution, were it me, unless you have a way to keep cool.

what did you use as a anode?

 

[timmyhartsing]

If the gray colored material around the seal ring, under the lid, and under the circuit is gold-bearing braze, it will contain a large portion of the value. In my experience, this material isn't easily removed by the sulfuric. If it does come off, it could take a very long time.

I would probably never use a lead cathode. I ran a 50 gal sulfuric stripper daily, for years. It was in a mild steel tank which was used as the cathode. I have had some bad experiences with 300 series stainless. When used as the anode, the nickel tended to dissolve and ultimately rendered the solution worthless. No matter what you use, you will have big problems if you use too much current and overheat the solution. I wouldn't exceed 5 amps per gallon of solution, were it me, unless you have a way to keep cool.

what did you use as a anode?

sorry for being stupid, but i should have looked harder i found a post by bswartzwelder on the same subject and noblemetalworks pretty well answered my question. harold v is right read before you ask.

 

[niteliteone]

snip
sorry for being stupid, but i should have looked harder i found a post by bswartzwelder on the same subject and noblemetalworks pretty well answered my question. harold v is right read before you ask.

Thank you for catching this and posting a good response that re-enforces what Harold has been asking of members. 8)

 

[yar]

If the base metal is copper why not just put them in AP ? You could take a pair of tin snips and put a cut on each side to expose the copper to the AP.

 

[grance]

Back when I thought I knew every thing about recovery and refining I was runing 4 20gallon heated ap tanks with bublers. Then I found this fourm and realizes quickly I knew nothing, after reading I biuld a cell and did away with 3 ap tanks. I had good base knowlage and the problum with ap is it takes alot longer then most peopel want to wait but yes that should work but take a long time

 

[goldsilverpro]

If the gray colored material around the seal ring, under the lid, and under the circuit is gold-bearing braze, it will contain a large portion of the value. In my experience, this material isn't easily removed by the sulfuric. If it does come off, it could take a very long time.

I would probably never use a lead cathode. I ran a 50 gal sulfuric stripper daily, for years. It was in a mild steel tank which was used as the cathode. I have had some bad experiences with 300 series stainless. When used as the anode, the nickel tended to dissolve and ultimately rendered the solution worthless. No matter what you use, you will have big problems if you use too much current and overheat the solution. I wouldn't exceed 5 amps per gallon of solution, were it me, unless you have a way to keep cool.

what did you use as a anode?

I used the parts I was stripping as the anode. I ran them in two ways. (1) For large parts such as CPU's, I used ladder shaped racks made of 1/4" square stock brass. On each rack, to hold 200-300 parts, there were 200-300 spring contacts made from steel piano wire. (2) For small looses parts, such as pins or CPU lids, I used a commercial plastic barrel plater with dangler contacts.

I found out early that piling up parts in a copper or stainless mesh basket was an inferior way to go. You gotta tumble the parts or keep them separate, like on a rack.

 

[fitzfish]

If the gray colored material around the seal ring, under the lid, and under the circuit is gold-bearing braze, it will contain a large portion of the value. In my experience, this material isn't easily removed by the sulfuric. If it does come off, it could take a very long time.

I would probably never use a lead cathode. I ran a 50 gal sulfuric stripper daily, for years. It was in a mild steel tank which was used as the cathode. I have had some bad experiences with 300 series stainless. When used as the anode, the nickel tended to dissolve and ultimately rendered the solution worthless. No matter what you use, you will have big problems if you use too much current and overheat the solution. I wouldn't exceed 5 amps per gallon of solution, were it me, unless you have a way to keep cool.

what did you use as a anode?

I used the parts I was stripping as the anode. I ran them in two ways. (1) For large parts such as CPU's, I used ladder shaped racks made of 1/4" square stock brass. On each rack, to hold 200-300 parts, there were 200-300 spring contacts made from steel piano wire. (2) For small looses parts, such as pins or CPU lids, I used a commercial plastic barrel plater with dangler contacts.

I found out early that piling up parts in a copper or stainless mesh basket was an inferior way to go. You gotta tumble the parts or keep them separate, like on a rack.

goldsilverpro

Thank you for the information about variations on the cell. What are the drawbacks to a lead cathode?

Are more details of your steel stripping cell included in your book? I would like more information on how you retrieved the values, pictures of the setup, etc. I don't have any interest in something that big but a larger tank than the pyrex dish for some of the parts I have would be a big help.

A small version of the rack that could be easily lowered and raised would seem to be better than alligator clips. I don't care for the the small amounts of acid that are picked up from the clips if I can help it. I also have a few holes in a shirt above the apron at the neck and upper arm that attest to the need for the full face shield and all of the safety gear if anyone considering a cell doubts it (I dropped a small part from less than an inch above the tank back into it when both clips let go).

A diy version of a tumbler might also be interesting for larger groups of small parts like small IC or CPU lids. I considered a variation of something like this: http://www.nulltime.com/zincplating/shop_setup/plating_barrel/index.html. Might be a mess to clean up. Perhaps a copper basket liner inside for the electrode? Any thoughts or suggestions?

I enjoy this hobby and appreciate any advice.
Thanks,
Dave