Non-Chemical Fiberglass

[Goldmember123]

Hello forum, i just need some simple instructions ! Im not asking for English lessons or safety lessons though if you ever notice anything im doing unsafe...always feel free to speak on it ! Ok my simple question that needs a simple answer is how do i get the fiber glass from the motherboards i processed out of my gold flake solution ?

 

[Goldmember123]

It was a mixture i made from nitric and sulfuric acid and i know its a dangerous mix and not needed ! But the mixture was diluted with Water and the solution been sitting for a month ! I just need to know how to get the fiber glass out

 

[Martijn]

Get the gold out of the fiberglass with AR after rinsing and filtering? Rinse and test the rinse water for gold.
How much do you expect?

 

[Goldmember123]

I dont expect very much at all maybe a tiny button if im lucky and patient !

 

[Yggdrasil]

Why did you put all that fibreglass in there? :?

Back to topic, how did you do this and why?

It is highly unlikely you will get all the potential values.
But washing it repetingly and thoroughly until the wash
water is clear and do not test positive for gold will get most dissolved salts out.
Keeping the wash water and combining it, of course
Then you have created another mess for yourself, some 5-10 ++ liters of diluted liqour in need of evaporation.

Nothing to do about that.

Test it for gold, if positive.
Evaporate down to concentrated by time or heating
(not boiling).
Denox and precipitate.

This is more or less it, but please do not do this again,
unless you like to punish yourself with excessive work.

See, no English lesson or safety lecture :twisted:

Edited for clarity

 

[nickvc]

I believe the AR will dissolve the resin as well as your gold so hopefully you will just be left with the glass to filter off which should also be easier to remove any pregnant solution from, try a small sample before going full on.

 

[Palladium]

Man that's a lot of tin!

 

[Martijn]

Man that's a lot of tin!

In what form? As metastannic acid? I thought that was grey.
That complicates things a bit.
Filter, rinse, incinerate and HCL leach first?
Quite a mess to get the tiny bit of gold from ENIG plating out.
The N stands for nickel... now in solution. Be carefull!

 

[galenrog]

Palladium is 100%. Lots of tin. Gigantic mess. Metastannic acid is indeed grey, by itself. The color in the images is due to being mixed with the greens and whites of circuit boards.

Time for more coffee.

 

[g_axelsson]

I've never mixed sulfuric acid with nitric and then added circuit boards to it, so I'm a bit at loss at what we are looking at.

Have you removed the barren circuit boards so that is only metastannic acid mixed with gold foils, or...
Did the circuit boards dissolve in that mixture so what we see here is a pulp of metastannic, dissolved resin and glass fibers mixed with your gold and green solder mask?

My first action would be to test for any dissolved gold using stannous chloride.
Step two would be to separate solids from liquids, wash thoroughly.

If you have any gold in solution then cement on copper or denox and precipitate it as usual.

For the solids I would incinerate to reduce the amount of material. Maybe you need to crush it after that. Then hydrochloric acid boil to further remove problematic stuff, as tin oxides.
After that aqua regia to dissolve any remaining gold, denox if needed, filter and precipitate.

That is basically the steps I would take to get the gold. If you started with ENIG boards then it will probably cost more than gold value to get it out, but the education is priceless.

Göran

 

[lanfear]

As Said you need to filter out the solids. I would recomend a charmin plug made out of glassfiber, since you have sulfuric acid in the mix. Just google charmin plug.