Precious Metal Refining & Recovery, Episode 12: Gold From Computer Ash


[music] Alright everyone! Welcome back to Cody’s Lab. So I figured it’s about time I finally get around to processing this material that came from electronic computer parts. See this is what the material looks like after it’s been chopped up in a ball mill I think he had used and this just like computer motherboards and stuff, and then this is what it looks like after it’s been incinerated and sifted. Now I have done a fire assay on this already, I think that was about four or five months ago and I found about 5 milligrams of gold in a 150 gram sample, which means, if my math is correct there’s less than an ounce per ton of gold in this, which means that if you’re gonna try to make money on this, the margins will be incredibly tight. But it should be still possible. Let’s see how much gold I can actually extract from it using some sort of actual process here. A fire assay is gonna be way more efficient than anything I can do on a large scale. If you couldn’t already tell from the gold pan, my plan is to knock down most of the material by panning it out and extracting the heavy materials. As I very much doubt the gold will actually be in the ashes, it should actually be stuck to heavy metallic particles. Let’s add a little bit of dish soap here to knock out any oils. Then I’m gonna pre-wet it, to make it easier to pan. Now that I’ve got some of this sloppy material, I’m just gonna wash off all the light stuff, and hopefully, keep all of the gold. Now of course there’s also gonna be a little bit of silver and possibly palladium and other metals in this as well, but I’m really only going after the gold today because, well, that’s all he asked me to find. But also, in the fire assay there really wasn’t very much of the other metals there, the gold seemed to be dominant. And uh, it takes quite a bit of silver to make it worth your while to extract, so I’m not gonna worry about that too much. I’m just gonna process this down for
the gold, and it appears like this has a lot of copper oxide in it, so it’s not like
black sand but it’s copper, so it’s black cupric oxide. That’s pretty easy to dissolve in
hydrochloric acid, but I think what I might do is just melt it down. And anything that still metallic
would form a nice bead and settle to the bottom of the crucible, and then I can
just slag off all those oxides. Think that’d be the cheapest way to do it, at least industrially. Now that I’m done panting off all the fiberglass I’m left
with primarily pieces of metal and metallic oxides. I can see there’s some
pieces of solder in there, mostly these little copper pieces of wire but I have
seen some little tiny gold wires and those would have actually came out of
these integrated circuit chips such as this. You see they use a very fine gold wire
to connect between these thick external wires here and the actual silicon chip
inside of these integrated circuits. Also I’ve seen some very fine gold
powder, I don’t think I’ll be able to take a
very good picture of it, but I’m suspecting that actually came off of the
gold pins here, where the plating kind of flaked off as the base metal melted and/or oxidized and then the little pieces of gold that flake off of this either melt
down into tiny tiny beads or get mixed in with another metal. Some of the gold
may have actually washed off which is why I’m collecting the wash water here,
and if I do find a significantly lower amount of gold than I’m expecting then I
will rework this, probably using a cyanide bath or something. I’d rather avoid that, but that is an
option. Suppose the next step is to remove as much iron as I can. That’s quite a bit of iron coming out of that
actually. I don’t think the gold will be bonded to the iron so I can safely get
rid of this. So the plan for today is just to melt everything — gold, lead, copper — all together into a single chunk of metal and then I’ll work with that. So what I’ve got to do is I’m going to
add some borax, some sodium carbonate, I’m gonna put it all together into a
crucible and furnace it down. This isn’t a clean crucible but it also
never had any gold in it so it shouldn’t cause any trouble. Into the furnace.
Wish it luck. Considering how much lead was in it I
think that should be just hot enough to have it all fluid. So, let’s pull it out of here and see if I actually caught any metal. Ok Looks like I got a blob of metal in
there, I’m gonna put it back in the furnace. Tell you what, this furnace is
taking way too long to heat up and as you can see there’s a little bit of flux
that has spilled out so I’m actually going to turn this thing off and I’m gonna
take the blob of metal out and try to put it in the other furnace. I think it’s small enough, it might work.
Ok, now that’s got to be hot enough to have that melted, so let’s open this up
and pull it out. Okay, here it is. Let’s pour it out on this on this plate. That’s it! Now rather than using acid or something to dissolve away the base metals leaving the gold I thought I’d try something a little
different and use electrolysis. So I’ve got this little bath set up here,
with the negative electrode being a little copper wire and a piece of metal as the positive electrode, so I’m going to add in a little bit of nitric acid to act as an electrolyte.
That ought to get things going. This is actually how they recover most
of their gold at the Bingham copper mine. They get the copper that they smelted
out of the ore and then they electrorefine it, and all of the other metals settle to
the bottom, which is then processed for the gold. So I just tried to lower that piece of
metal and it ended up falling in, also pieces of the copper here on the other
electrode we are starting to fall off into the solution so I decided I’m going to
stop this, and I think looks pretty neat. Quite a bit of copper that
I processed, you guys get the idea. And I’m just going to finish it off with
some acid just to speed things along because this
video is kinda overdue, I kind of wanted to get this out earlier. As for what this black material is, there
is some gold of course but my guess is it also contains your other metals such
as lead, tin, and possibly even silver, because the copper would be the easiest
thing to transfer across. Once all the copper was gone you might get some lead transferring onto the electrode, but, of course, since copper’s the most
abundant metal here it would have just fallen off to the bottom of this thing.
But now it would be much easier to smelt down and recover the gold. Of course, I’m
going to be adding acid to this so it’ll actually concentrate it even more but you guys get the idea. Okay, so it looks like the piece of metal is completely dissolved and I still have the black powder so presumably there is some gold here. So I filtered out the gold containing powder that is the black and I’ve added a little bit of litharge and flux which is the orange-ish color, that is to help
collect it together you know, standard methods of collecting precious metals. So we’re just gonna pack that into the crucible, and load it
in the furnace. Here’s my lead and gold mixed together. Break off the slag and put it into a
cupel to remove the lead. So looks like that piece of metal actually
puffed up like a piece of popcorn down in the cupel which means it wasn’t
pure lead, it must have had some tin or something in it. The best thing I can do to fix that is
actually add some more pure lead to try to, you know, lower the amount of tin and hopefully get that oxide to dissolve into the cupel. Or, I could get it really really hot, that
might work too. I decided to try the lead thing. So I’m cleaning this spilled slag out of the furnace here, and look at that! It’s like bright blue. I’ve never seen that before. I’m pretty
sure this is like copper carbonate or something but that’s just proof that
there’s some really weird stuff in that electronics. [chuckle] Now that’s more like it. I can see that there’s a bead of gold there. Once this is cools off we’ll go weigh it and see how much we recovered. Let’s say it’s probably almost pure gold,
and there it is it just solidified, ha, and I love watching that. So here’s the bead of gold that we
collected from the two kilograms of material, let’s put it on the scale and see
what it weighs. 40 milligrams. Now I was expecting roughly 50 to 60
milligrams, so I say extracted most of the gold using the method I did.
Excellent. Hope y’all enjoyed, and I’ll see you next time.

100 thoughts on “Precious Metal Refining & Recovery, Episode 12: Gold From Computer Ash

  1. I love extracting coper through electrolysis it’s something about making the copper sulphate and the science of extracting it from a liquid

  2. So my question comes up as…. Was that just one computer or multiple? because if thats just one I wonder how much you could recover from 100 computers.

  3. you know you watched too much of this series when you can exactly guess the weight of a tiny piece of gold in cody's hand just by looking at it

  4. Cody I want you to pan for gold in and around your mine. In all that she'll you dugg up, should be sumthing

  5. I think at industrial scales, they go after the bulk metals. The steel, aluminum, and copper being the bulk of value in scrap, then the copper gets refined and that drops the gold.

  6. When he first put the gold bead on the scale and I saw the scale go into grams I was shocked at the weight of the gold for a second. Then I realized it was his hand 😛

  7. "there's also some silver (ok) and palladium (isnt that like the most valuable metal on earth?) in there, but im really only going after the gold"
    REEEEEEEEEEE

  8. Also, you could have added a decent amount of salt to act as the electrolyte instead of using your nitric acid. You can transfer a decent amount of energy, even with just salt.

  9. So if the gold in the electronics is not the driving motivation for the inflation of price then what is. Pls tell me some one I really want to know?

  10. I'm a little unclear as to what role the dozer has in the refining process… but other than that I liked the video a lot. I just "discovered" your channel two videos ago and I'm hooked, you have a new subscriber, (not that you're lacking any).

  11. also , that silvery color with such brilliance as that is a duh sign of what??? silver and ….
    and….. and….
    love your videos and sharing of knowledge

  12. I had never heard the word "assay" outside of this channel. Googled it, mostly to see how it's spelled. Very interesting

  13. hey cody , i bought two plates from a thrift store that i thought were silver , but after melting them (which failed) i found theyre two different types of metal . and i dont know how to identify what they are . all i know is they dont stick to a magnet and one is heavier than the other . if i sent u a sample of each , could you do some kind of test to work out what they are and make a video showing what you did

  14. What’s was up with the bulldozer scene in the end I didn’t know you had a bulldozer! Thats awesome

  15. If scrapers would put their scrap gold plated items in a vibrating tumbler with glass sandblasting beads it will quicken the time for processing.Then you use aqua regia to disolve the gold from the glass beads..filter and dissapate the gold from solution .You may have to refine once more for purity

  16. the thing is with electronics, if you want to make money – it's much easier just selling the full boards on eBay, integrated circuits often get obsoleted and people end up buying boards to replace something from a broken device.

    but from a refining point of view; these videos are very interesting.

  17. I'm starting to think you might not be so good at extracting gold lol that was such a tiny little bead

  18. I just love the 'Home Video' style of your vids.. No big productions, just some fun information… And easy on the brain 🙂

  19. I’m going to love seeing you in probably several years from now make a video titled “Making uniform ingots from my ton and a half of loose gold”

  20. So roughly about a buck per kg of material. I wonder how efficiently you could process large amounts of this material…

  21. Damn dude if you're going to be waving your hands in front of the camera the least you can do is use soap and water. They look like they've been up your ass.🤣🤣🤣

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