How to Extract Gold from a Circuit Board - Bang Goes the Theory - BBC

Jem Stansfield shows how it is possible to extract pure Gold from some old electronic circuit boards. Incredible clip from acclaimed BBC 1 science series, Bang Goes the Theory.

[skelitalmisfit]

good, the amount of gold you just salvaged will almost cover the cost of the advanced acids and butane from the torches lol

[dermotheaney]

It's the force of gravity on the materials mixed, that's what he's missing. Sorry if this ruins it.

[thereaper]

i have collected a lot of e-waste for the gold content of the gold plated pins and connector strips of ram sticks but at first i never knowing that i couldn't purchase these acids in the uk but since i found this out i am keep to know if there is a company that can process my e-waste gold computer scrap with acids to make a pure gold bar. Any suggestion please leave a reply thanks

[restorator]

I think he blasted most of the gold out of his crucible with that torch at the end. A kiln-style furnace is more like it, and I think you need to add a pinch of borax to get it to form a bead that doesn't need to be chipped off the bottom.

[magifesq]

Seems to me he could have saved a lot of time and expense by putting all those boards into a large crucible and separated the gold using flux from the rest

[RDStewart]

Doesn't seem an overly efficient way to extract gold.

[sujcd]

Stansfield was just giving a laboratory demonstration of gold extraction.  It's much different when done on an industrial scale.
I can't help but wonder, though, how much toxic pollution such processes create.

[janetmendezorta]

I tried that a few times. lost a lot of gold and when I got the hang of it. all I extracted from the dust looked like metal or silver but there was no gold from it. I tried it with pins

[davidqrobinson]

like the one guy said, there's other ways to dissolve the gold, , as well as other ways to extract the gold, , , AND ITS NEVER LOST! if something go's wrong all you have to do is add its volume of water to it, , place the beaker or reaction vessel in a bucket an add aluminum foil until no more foil dissolves, , the black looking mud the foil leaves is your gold, , that gold will have aluminum in it but at least its not lost

[Turboy]

A more profitable and safer alternative is to save up your gold scrap and when you have enough of it, send it off to a well established, reputable commercial gold recovery and refining company, which will recover and refine your gold and buy it from you or take a percentage of it as their fee and send you the rest.  That company will be able to process the stuff economically and safely.   

[edgarsikes]

ok let me share a few tidbits of knowledge here.... using nitric acid to achieve the dissolving process while effective isn't worthwhile monetarily. go to the pool supply store buy a couple gallons of 20 deg/ baume hydrochloric acid 31.5 percent strength. and 2 or three super sized bottles of 3% hydrogen peroxide (1 liter) standard stuff you can get at the pharmacy... a fifty fifty ratio of those in a large clear plastic container does the same thing as the nitric in the beaker. no toxic NO2 gas emitted (which was the brown gas) which comes when dissolving copper no nitric burns, highly corrosive! and expensive, did i mention expensive? hydrochloric is about 7 dollars a gallon where nitric is 50+ a liter bottle. after the process rinse the gold foils with water, and THEN dissolve in the aqua regia... about 200 ml hydrochloric, and add nitric slowly (with a pippette preferably) after the hydrochloric is around 130 degrees F shouldnt take too much more than 10mL of nitric to do the trick at that stage... if it doesnt dissolve after ten.... ad a little more very slowly then follow the rest of the recipe.... urea til it stops foaming. and sodium meta, till it turns dark brown and the gold falls out of suspension. ALWAYS REMEMBER TO TEST THE GOLD LIQUID WITH STANNOUS CHLORIDE TO MAKE SURE YOU GOT ALL THE GOLD!
 

[spiders]

Running this I got a gold/copper amalgam of about 10 carat. This only after 2 washes with HCl and one wash with sulfuric to remove the base metals.  Worry about your lungs not the environment.  Plants and people like nitrogen.  Mercury extraction is long term damage.  Remember to carefully neutralize  acids with a base (NaOH perhaps) before disposal.  This experience was more fun than profitable.. 

[TheStowndPanda]

Instead of disovling the fold and losing all of the yeild in the beginning... Why not out it in water and the gold should fall off you'd be ble to pick up the boards

[JasmineBellato]

"way beyond school chemistry", yea looks like it. lol

[phillipag]

I used to use rust to retrieve the gold

[KillerMeme]

If you have any unwanted gold put in an envelope marked all my gold to cash my gold don't want postmen to think it's a shit load of copper

[MultiDrGh]

how did he come up with this long unexpected-to-work method? a professional chemist ? 
do i really need to take a tough chemistry course to do such thing or i need to do researches and stuff ?

[addjewelry]

This video seems a bit theatrical compared to the one from periodicvideos.

[phillipag]

now if he started off with hydrochloric acid and hydrogen peroxide mixed, that together.That would extract the gold from the circuit boards.Then the aqua regia to dissolved the gold.I would have used urea to neutralized the acid.Then I'd used Sodium Meta Bisulfite to drop the gold from it.I think he lost some of his gold in that.

[vlsr]

Why not just melt it all to begin with not using any chemicals at all?