Spending a weekend playing with part of the H2SO4 cell harvest.

[Martijn]

I'm busy stripping gold plated jewelry material for my first customer.
I couldn't resist taking part of the black sulfuric goo and make a cup of yellow juice to play with.
A hot wash of the still very sulfuric goo cleaned it up and made it all settle out nicely to decant. Followed by a dirty dissolution in AR, chilled filtration, predissolved SMB precipitaion (thanks Göran) of the gold, washes in HCl, distilled water and more HCl still left the powder looking black and tending to stay suspended way too long.

A final wash in dilute boiling nitric did the job. Some nicely dried reddish brown powder.

Ten minutes in the propane fired El Cheapo made it flow into a more recognizable form of our much beloved favorite subject.




Thanks to the members who helped me get here and thanks to the forum!

Having lost of fun here

 

[Martijn]

It took me 9 ml of 50% HNO3 to dissolve this dirty gold by the way. Slowly at 80 C in a big beaker with a loose glas plate as a lid.

 

[Yggdrasil]

I'm busy stripping gold plated jewelry material for my first customer.
I couldn't resist taking part of the black sulfuric goo and make a cup of yellow juice to play with.
A hot wash of the still very sulfuric goo cleaned it up and made it all settle out nicely to decant. Followed by a dirty dissolution in AR, chilled filtration, predissolved SMB precipitaion (thanks Göran) of the gold, washes in HCl, distilled water and more HCl still left the powder looking black and tending to stay suspended way too long.

A final wash in dilute boiling nitric did the job. Some nicely dried reddish brown powder.
View attachment 57762
Ten minutes in the propane fired El Cheapo made it flow into a more recognizable form of our much beloved favorite subject.
View attachment 57763
View attachment 57764


Thanks to the members who helped me get here and thanks to the forum!

Having lost of fun here

Nice color

 

[Shark]

And a very nice looking button, too.

 

[orvi]

Good looking stuff. What is the material it came from ?

 

[Martijn]

Good looking stuff. What is the material it came from ?

Gold plated watches.

 

[Shark]

That had to be a lot of watches.

 

[Martijn]

Yield (not in liberty to disclose here) is a lot better than what sreetips got from his trail run of plated jewelry video, I can tell you that much. He had like 0.014% yield if I remember it right, and he abandoned the whole idea based on that one result. It takes a bit more stirring and making good contact to get it all. And then I still have to redo some of them.
High quality plating (20micron) on part of the items helps a lot too.
For me, it's well worth the time and effort I have to put in.

 

[Martijn]

The workshop

 

[BGDOCK]

Do you use the ice cream to cool the solution before dropping ?

 

[Martijn]

No, I ate ice cream to cool myself. It was 35 degrees in the shed.

But for the chilling I first put the beaker in cold water from the tap (23 degrees was cold that day) and chilled it further with ice cubes.
Wrapped the beaker in alu foil to keep the heat out. Got it to 5 degrees C and then filtered.

 

[Shark]

Makes kind of happy I kept all those plated pieces as well.

 

[orvi]

Yield (not in liberty to disclose here) is a lot better than what sreetips got from his trail run of plated jewelry video, I can tell you that much. He had like 0.014% yield if I remember it right, and he abandoned the whole idea based on that one result. It takes a bit more stirring and making good contact to get it all. And then I still have to redo some of them.
High quality plating (20micron) on part of the items helps a lot too.
For me, it's well worth the time and effort I have to put in.

You probably meant 1,4%, 0,014% would translate to 0,14g/kg of material

 

[Martijn]

That does seem a bit low.
But true.
Here is a screenshot of his video:


I'm sure he missed something along the way.

 

[billgold]

You had the advantage of much thicker gold plating than Sreetip's cheap gold plated jewelry. The plating on that is often around 1 - 2 microns thick, so your yield should be 10 - 20 times what Sreetips obtained - assuming similar recovery percentages.

Can your sulfuric acid electrolyte be dumped in with other waste to cement out any remaining gold using copper?

 

[Yggdrasil]

You had the advantage of much thicker gold plating than Sreetip's cheap gold plated jewelry. The plating on that is often around 1 - 2 microns thick, so your yield should be 10 - 20 times what Sreetips obtained - assuming similar recovery percentages.

Can your sulfuric acid electrolyte be dumped in with other waste to cement out any remaining gold using copper?

Sulphuric don’t dissolve Gold.
This is a phenomenon due to the positive charge of the Gold in the cell.
This creates Persulfuric acid which do dissolve the Gold until it reverts back to Sulfuric acid. So cementing would only dissolve the Copper with no gain.

 

[Martijn]

I'm busy stripping gold plated jewelry material for my first customer.
I couldn't resist taking part of the black sulfuric goo and make a cup of yellow juice to play with.
A hot wash of the still very sulfuric goo cleaned it up and made it all settle out nicely to decant. Followed by a dirty dissolution in AR, chilled filtration, predissolved SMB precipitaion (thanks Göran) of the gold, washes in HCl, distilled water and more HCl still left the powder looking black and tending to stay suspended way too long.

A final wash in dilute boiling nitric did the job. Some nicely dried reddish brown powder.
View attachment 57762
Ten minutes in the propane fired El Cheapo made it flow into a more recognizable form of our much beloved favorite subject.
View attachment 57763
View attachment 57764


Thanks to the members who helped me get here and thanks to the forum!

Having lost of fun here

This little furnace will not hold my new A4 crucible I got for Christmas, so I'm drying my gasbottle furnace and will do some repairs to the fireproof perlite concrete lining.
I want to pour bigger tapered anodes for my copper sulfate cell and to pour some nice bars from the copper cell harvest to stock pile in the metal bank

So i needed this bigger furnace I made some years ago back in working condition. It was made for pyrolising chips in the first place.
Poured the water out and put a hot air gun in the inlet to let it dry.
Made a square hole in the bottom concrete to fit a firebrick to put the crucible on.


Because i don't have crucible tongs to lift it out and one to pour the copper with, i decided to make a forging furnace from the same cheap gypsum blocks. Added fire brick on the bottom to make it last longer.
I thought it was hot enough to share with you all


Now let's see how I'm at forging...

Edited due to premature posting...wasn't ready and accidentally pressed post.
And spelling.

 

[Martijn]

Very pleased with the result! Pouring and loading tongs in one. The ring is for tilting with a hook to pour. Saves on cooling time and I can pour right after picking it up.

The furnace does not like to sit next to the anvil on the bench so i moved it outside after cracking. Stupid me. Oh well, 0.75 euro damage is a cheap lesson.

 

[BGDOCK]

Did you forge those crucible tongs ?

 

[Shark]

Very nice looking setup.