Electrochemistry Interesting idea in an old thread- dissolving gold in a Chlor-alkali cell

[haveagojoe]

Depending on the conditions, Gold seem to precipitate between 4.5 to 13 pH.
So this is at least not suited for separation this way.
But since you already are planning a pump, maybe pump it past a Copper system to Cement the Gold in circuit?

Maybe indeed.

There's also the issue of hydrogen production to consider...

 

[Yggdrasil]

Maybe indeed.

There's also the issue of hydrogen production to consider...

The Hydrogen can be vented off the Cathode side and burned for instance.

 

[HarryLee1506]

Ok, here's vague artistic impression of how I think it could work:

View attachment 67538

Your diagram is very detailed... i tried some E-scrap in the anode compartment but the gold did not dissolve into the solution, instead the copper dissolved and plated onto the cathode very quickly... maybe the HCl concentration is still not reasonable to be able to dissolve the gold.

 

[haveagojoe]

Your diagram is very detailed... i tried some E-scrap in the anode compartment but the gold did not dissolve into the solution, instead the copper dissolved and plated onto the cathode very quickly... maybe the HCl concentration is still not reasonable to be able to dissolve the gold.

Yes after thinking about it some more I think my diagram is not correct- I think the electrolysis of NaCl in solution will only produce HOCl and Chlorine at the same time, and only when when the HOCl is completed it will start to break it down to form HCl and at that point the Chlorine production will stop. So I think perhaps he uses fresh HCl in the leaching chamber and the HOCl and Chlorine produced by the cell are sent to it.

What are you using for a membrane?

I can't try anything at the moment, but I would like to experiment with a very basic setup using a terracotta pot for the membrane, sitting in a bucket of NaCl electrolyte and filled with the same electrolyte; with an inverted funnel to collect the Chlorine gas, and bubble it through a second vessel containing HCl and the material to leach. But that would only be using the Chlorine, to use the HOCl as well I think would need a pump of some sort.

Here is a video of making sulfuric acid using a terracotta pot as a membrane in a somewhat similar way, a very simple setup: Video

 

[HarryLee1506]

Yes after thinking about it some more I think my diagram is not correct- I think the electrolysis of NaCl in solution will only produce HOCl and Chlorine at the same time, and only when when the HOCl is completed it will start to break it down to form HCl and at that point the Chlorine production will stop. So I think perhaps he uses fresh HCl in the leaching chamber and the HOCl and Chlorine produced by the cell are sent to it.

What are you using for a membrane?

I can't try anything at the moment, but I would like to experiment with a very basic setup using a terracotta pot for the membrane, sitting in a bucket of NaCl electrolyte and filled with the same electrolyte; with an inverted funnel to collect the Chlorine gas, and bubble it through a second vessel containing HCl and the material to leach. But that would only be using the Chlorine, to use the HOCl as well I think would need a pump of some sort.

Here is a video of making sulfuric acid using a terracotta pot as a membrane in a somewhat similar way, a very simple setup: Video

I used cotton to separate the 2 cells and placed the e-scrap close to the anode where the chlorine is produced, still need to add fresh HCl to the solution but i don't want to use too much because applying it to the ores will cost a lot, the experiment failed and the gold was not dissolved. I look forward to your results...
Your TCCA method is great, I am testing them on ores and trying to lower the HCl concentration as much as possible.