Harvest before trashing.

I was about to throw some pc accessory , mobo,various gfx/sound cards.

Here what i managed to extract.





Heatsink
50x50x10








BIG HEAVY COPPER/alu-SINK
60x60x10mm of copper and about 40 thick in total. A 50x50 fan fit.

I like the fans.

2x2032 battery also, i have no idea if they got voltages left. il measure them when i go in garage.

And for those of us dabbling in the e-junk gold recovery processes, you can also retrieve all the PCB connectors, usually golds plated pins, the edge connectors of PCI and ISA cards (carefully trimmed with a dremel tool) and various processors and flatpack ceramic chips which are gold plated.

Using chemical processes (too long to describe in the scope of this thread), you can then dissolve and precipitate the pure gold, melt it down and make some $$$ selling that at near market value. A 5 Gal. pail of carefully sorted out of e-junk can get you many many grams of gold, and at 1K per troy ounce... it's worth it!

Robert

Really??? I have tons of this stuff, how exacty is it done? :evil:

FireMyLaser said:

Really??? I have tons of this stuff, how exacty is it done? :evil:

Click to expand...

Scrap are treated a first time with 50% nitric acid at 70 C, for 1 hour or more. This dissolve other metals.

Then all becomes mechanically mangled in fine powders (chips, pcb, anything).

Floating elements are separated, then the remaining is again treated with 50% nitric acid at 70 C, until the rest of the other metallic tracks are completely dissolved, and all that what remain is gold and non metallic elements (ceramic, resins, glass).

Then at this point, different places uses different systems ..... some old industrial processes, still uses mercury for incorporate gold and reject all the rest, then separate gold from mercury (as the old plants was doing for separate glod from other minerals, in old times) ..... other more modern centers, uses "aqua regia", a mix of nitric and chloridric acids, in various cycles at different temperatures, and this dissolve all the gold, then re-precipitate the gold from the solution with ferrous sulphate.

Other systems, based on electrolytic treatments, are also more complex.

Anyway, all the systems are extremely long, complex, and dangerous ..... i know a company that collect mangled electronics for gold recover, in a city near mine ..... they get approximatively a full TIR of grinded material each pair of weeks (final product, not the pc's to mangle, i mean), and also with all this mass of material, they send all in France, to a more big complex, cause there's no convenience for them to work it in place

There are also some researches about using CuCl2 as dissolving material, for restore it with common oxygen, but they are still in research field, as far as i know, still no working apparates, with this system (but i'm not fully updated, about this system, so may also be in error).

I've been experimenting with the halide leaching process of using elemental iodine dissolved in ethanol. It's a slow process but doesn't require toxic chemicals who give off massive quantities of harmful gases. In effect:
Au + H2O•C2H5OH:I = AuI + H2O•C2H5OH
The auric iodide is then processed with heat to separate the iodine from the gold and the bonus is that you can recuperate both the pure gold and the elemental iodine to start all over again with another batch of e-junk. You can use stuff like Providone if you don't have access to elemental iodine... Some people add very small amounts of HCl to pep-up the process. The bonus is that it only dissolves gold, not iron, copper, nickel and other "comntaminant" metals.

The aqua regia process is lightning fast, but the hazardous fumes produced and the dangerous acids used prevent me from using that process in the highly populated urban area I live in...

it's a lot of work to recuperate gold, but in the end, it pays off handsomely for what many consider unusable junk!

- Robert

HIMNL9 said:

... other more modern centers, uses "aqua regia", a mix of nitric and chloridric acids, in various cycles at different temperatures, and this dissolve all the gold, then re-precipitate the gold from the solution with ferrous sulphate.

Click to expand...

Aqua Regia is 3/4 HCl with 1/4 HNO3 and it is awfully corrosive and dangerous, but it works like a charm. Another alternative to ferrous sulphate is to use urea to neutralize the nitric acid, and then use sodium metabisulfite to precipitate the pure gold.

This results in a brown mud at the bottom of your container, which after being filtered and rinsed, basically, is nearly pure gold! Some people drop the mud in a crucible and heat it with an acetylene torch until all the dust is congealed into a lovely gold drop!

Anyone can recuperate gold, but the processes used are hazardous at best, and deadly dangerous at worst. You have to be very prudent and careful when you play with that stuff, and know in advance what to expect when you mic a chemical with another... so you better know full well what you're doing before attempting anything.

Although it's extremely dangerous, shining a 50 mW laser in your eye is pretty mild compared to be in front of an explosive reaction when mixing hydrochloric and nitric acids!!!!

- Robert

I take it the fans are 50x50x10mm? I have a couple 15x15x10mm's.

Isn't aqua regia one of the strongest acids or acid mixes I guess?

A video tutorial would be awesome.

Tutorial of how to get gold out of computers?

YouTube - HOW GOLD IS RECYCLED FROM COMPUTERS

That was entertaing but not much of a tutorial.

HEHE I used to fix PC's and still have a HUGE box of those things, they come in handy for high power diode lasers, especially bars and HHL packages

roddenberry said:

Aqua Regia is 3/4 HCl with 1/4 HNO3 and it is awfully corrosive and dangerous, but it works like a charm. Another alternative to ferrous sulphate is to use urea to neutralize the nitric acid, and then use sodium metabisulfite to precipitate the pure gold.

This results in a brown mud at the bottom of your container, which after being filtered and rinsed, basically, is nearly pure gold! Some people drop the mud in a crucible and heat it with an acetylene torch until all the dust is congealed into a lovely gold drop!

Anyone can recuperate gold, but the processes used are hazardous at best, and deadly dangerous at worst. You have to be very prudent and careful when you play with that stuff, and know in advance what to expect when you mic a chemical with another... so you better know full well what you're doing before attempting anything.

Although it's extremely dangerous, shining a 50 mW laser in your eye is pretty mild compared to be in front of an explosive reaction when mixing hydrochloric and nitric acids!!!!

- Robert

Click to expand...

I don't disagree with anything you said, except that if anything is exploding when mixing up a batch of aqua regia, then you're doing it wrong. Way wrong. All you should be getting is some fuming and a pretty color.

@roddenberry: unfortunately, here, get pure chemicals is a nightmare ..... some ones are restricted (special registers that requires special authorizations, you don't imagine the turns i have to do for get some of them ), some others are available only in industrial packages, like 100Kg, or 209 liters cans ..... a bit too much, for an hobbyst ..... and the rest, the distribution, well, making them a compliment, can say that they suck (sorry) ..... are years that i cannot get metal iodine, as example, all that is possible to find actually is bisublimate for medical use, in small quantities and at high prices, so i never made experiments with it.

BTW, how much long is the process, with iodine ? ..... try it with aqua regia, is really dangerous, also just as experiment, not speaking about mercury process (i have a pair of Kg of mercury, but i keep it for other uses ) ..... and i also live in a populated area, cannot risk to spread around toxic fumes (not speaking about my own health, ofcourse )


@ZRTMWA: yes, it's a mix of acids, and the more dangerous thing is that it practically dissolve also "nobles" metals, like gold, that is not dissolved from other acids (also if is not the more dangerous acid around ..... )


@ pullbangdead: well, maybe it not explode in the common "explosion" sense, but playing with acids mixing is not the more healty and safe game, especially if concentrated acids are used (i still remember a mistake i made years ago, mixing for error H2SO4 and HCL in the wrong way ..... after a week of air circulation, the room was still smelling of sulphuric acid, and also now at years of distance, my fingers are still blessing the inventor of the "nitrotough" acid-proof gloves )