Sciencemadness Discussion Board

Few questions about Gold recovery

Romix - 17-6-2021 at 12:08

Here is gold after washing it with 20 litters of water.

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Romix - 17-6-2021 at 12:09

No matter how much I wash it, solution still dirty. Why ?

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Romix - 17-6-2021 at 12:11

And after dropping the Gold with Sodium Sulfite, I added KOH to the solution that's what precipitated. Any ideas what is it?
Solution still were lightly greenish after filtering it.
I've checked PH, basic.

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[Edited on 17-6-2021 by Romix]

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paulll - 17-6-2021 at 13:17

Any chance there's a bunch of iron in there?

Romix - 17-6-2021 at 13:38

Could be, I dissolved 8 ceramic processors + a lot of other gold containing scrap. Here's just 200ml tester.

Romix - 17-6-2021 at 13:39

That's how pure gold looks like, dropped it from dissolved Alaskan nuggets.


[Edited on 17-6-2021 by Romix]

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draculic acid69 - 17-6-2021 at 17:25

Did U just aqua regia the straight processors without first dissolving tramp metals?
Could you just wash the red goo with nitric acid to remove some of the crap?

paulll - 17-6-2021 at 17:31

Ooh that looks like it'd be satisfying to melt down.

I think you're carrying a lot of Iron and Nickel; I'd decant that off and treat the precipitate with successive HCl washes 'til it comes up clear, and take it from there.

Romix - 17-6-2021 at 17:33

I tried boiling it in 3% nitric first... but after an hour nothing happened.
So chucked in very diluted AR.
Yes, that's what I thought about doing. Just waiting for the wash solutions to settle down. And they still dirty after whole day standing.

paulll - 17-6-2021 at 18:00

Quote: Originally posted by Romix  
I tried boiling it in 3% nitric first... but after an hour nothing happened.
So chucked in very diluted AR.
Yes, that's what I thought about doing. Just waiting for the wash solutions to settle down. And they still dirty after whole day standing.

It'll probably take a few goes-around but I'd put aside the nitric (Actually if I suspected there was any there I'd wash it out like a lipstick stain) and AR, and focus on dissolving everything that *isn't* Gold.

Romix - 17-6-2021 at 22:38

After boiling it in water, solution became clearer!

Romix - 18-6-2021 at 00:56

Added nitric all dissolved!!!!!! No gold left!!!!

[Edited on 18-6-2021 by Romix]

Romix - 18-6-2021 at 01:05

Solution is green.

Romix - 18-6-2021 at 01:10

200ml lost, what to do with the rest of gold containing solution?

Romix - 18-6-2021 at 03:28

It took few seconds for all of it to dissolve, reaction was exothermic.

Romix - 20-6-2021 at 13:55

Google saying that this yellow - orange precipitate is CuOH.


[Edited on 20-6-2021 by Romix]

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Romix - 20-6-2021 at 13:57

Could be, decomposed it to black oxide and flame test is green.


[Edited on 20-6-2021 by Romix]

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Romix - 21-6-2021 at 06:05

Cu(OH)2

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Romix - 23-6-2021 at 04:22

That's camera lenses of the phone's that I've dissolved, even double that because half of them didn't had cameras, were to old.
+ 8 ceramic processors.
Please help, what to drop gold with?


[Edited on 23-6-2021 by Romix]

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Romix - 23-6-2021 at 04:26

Lenses only weigh 15 grams. I reckon 1/100 of the weight gold maybe more.

[Edited on 23-6-2021 by Romix]

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Romix - 23-6-2021 at 04:47

Only neutralized wash waters of copper nitrate solutions. Do you know maybe phone PCB's also contain nickel?
Still have plenty of concentrate.
Found cheap funnel on Ebay 4.5 litters.
Will neutralize all metals with KOH, filter it out, leave evaporate through the summer and then I'll try to crystalize KNO3.
Tried feeding KNO3 from wash solutions to my garden flowers, they died next day after watering.
And then dry dirty Cu(OH)2 on my LED lamp.

[Edited on 23-6-2021 by Romix]

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Romix - 23-6-2021 at 04:58

+ All phones yielded bit over 200 grams of gold plated pins.


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Romix - 23-6-2021 at 05:58

Ceramic lenses from old digital cameras, under 4 megapixels.
Maybe someone have a small device to crash them, interested in buying one.
They'll break average kitchen blender.

[Edited on 23-6-2021 by Romix]

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Romix - 24-6-2021 at 07:08

Tried cementing sample on copper.
Small amount of black mud formed, I can tell by the look of it that it's not metal.
And all mud dissolved in nitric.
There was some metal but all of it stuck to the walls of a beaker.
After few days copper bar passivated with white CuCl and recovery stopped.
And a lot of insoluble salt farmed on a top of the solution, when AR was very very diluted.


[Edited on 24-6-2021 by Romix]

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[Edited on 24-6-2021 by Romix]

Romix - 26-6-2021 at 21:36

Sodium Metabisulfite. After night standing some mirror like dirt appeared on a beaker's walls.
Added a lot of SMB, copper salts not precipitating like it was with NaSO3.

[Edited on 27-6-2021 by Romix]

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Romix - 27-6-2021 at 01:40

This black mud of the walls turning yellow so not gold...

[Edited on 27-6-2021 by Romix]

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Romix - 27-10-2021 at 19:14

Iron(II) sulfate best precipitant from dirty solutions, all gold dropped out in seconds!!


[Edited on 28-10-2021 by Romix]

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Romix - 27-10-2021 at 19:16

Dirty, because I didn't filter Iron(II) sulfate before the precipitation.

Romix - 27-10-2021 at 20:02

ALSO toxic gases not coming off.

Romix - 29-10-2021 at 20:12

Had an accident, lucky 5 liter PET bottle was standing in a bath, and all concentrated slightly basic KNO3 escaped in to the drain.
KNO3 crystalized out nicely out of it. Had a go crystalizing it before I went to bed and situation above happened.
Very very very diluted KOH ate a crack at the button of the PET bottle. Now I'll use HDPE canister instead.
That shows that KOH is a much stronger base then NaOH. Was boiling PET in NaOH for hours and only yielded 1 gram of terephthalic acid at the end.

Romix - 29-10-2021 at 20:26

Also bases like NaOH and KOH eats glass too... Once had a jar standing with galvanized with zinc steel bits...
And it ate a crack in that too and leaked out. It's ok to filter something quickly in a borosilicate, but not boiling it in it.
What for? I think I was recovering zinc with aluminium from basic complex.
Unfortunately not tried melting this zinc because of the accident.
Might melt might not. For example tin recovered from chloride salt not melting.

[Edited on 30-10-2021 by Romix]

Romix - 29-10-2021 at 20:28

Ammonia solution much weaker base, stood in PET bottle with a nickel coin in for years with out any cracks.

Romix - 29-10-2021 at 20:48

What about recovering Tin with electrolysis, is Chlorine coming off? You'll need to make a set up to use it some where else in a different reaction.

Romix - 15-1-2022 at 15:47

Lucky, found two good lenses!! Usually you get short and thin 16 bonding wires on a lenses. Here you get that much only on one side of lens. And there's 3 more sides like that. And wires are longer and thicker.

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