Electrolytic Cell Questions / Help Request

[Anonymous]

How long do you leave them in? Have you examined the pins to see if they were completely stripped? Where they touched the plastic? Where they are shielded from the current flow? I would doubt that they are completely stripped, but I may be wrong.

They stop foaming after 1 minute or so, I pull them out and I can tell they have been stripped. I see a nickel layer or copper, etc. After deplating I have looked at a few, bent the pins back and it looks like they all deplate. In some instances on a 48 pin header (ex.) 2 or 3 pins do not deplate. All you have to do is rotate the wire, deplate again and almost always the remaining pins will be deplated.

 

[Anonymous]

Yep I came back into the shop today and there looks to be a fine layer of gold on the bottom. I am going to siphon off the solution and test the powder at the bottom. If it tests for gold I will go ahead and run a big batch in the cell. Thanks everyone for the help so far.

Steve

Keep in mind stannous chloride does not reveal precipitated gold, only gold still in solution.

How did you intend to test this precipitant?

On a very small amount it may not merit redissolving or the rinse steps. Combining it with the next batch of material from the cell may be the most frugal.

How could I verify that the powder at the bottom of the solution is gold? I would like to prove my process before moving on.

 

[goldsilverpro]

From the photo, it looks exactly like gold. Put a little in a test tube, dissolve it in a few drops of AR, and test with stannous chloride.

Break a few pins out of the plastic to check for complete stripping. Dissolve the pins in 50/50 nitric and look for small flakes of gold.