Hi everyone, welcome back to Cody's lab.
So today we're going to be refining gold of some of these actual computer parts.
These are RAM fingers and some sort of circuit board here.
They're both coated in gold,
and today we're going to be extracting it.
Now i thought about using nitric acid again,
which is certainly doable because this is basically a 22 karat gold coating or something like that, it's very thin.
So it would be fairly easy to do it with acid, just you know use a dilute acid.
and that would dissolve the gold off of it.
But you know I've been dissolving with acid basically this whole time so I thought I'd change it up a little bit
I ended up grabbing some iodine,
from the store, i think i'll try dissolving some of it with iodine.
Maybe off of these RAM fingers here,
and since I'm going to be doing these separate because I want to separate them to see how much gold I get off of each,
perhaps I'll do cyanide on these.
Lets weigh everything.
Well I bought this scale, i may as well.
That will tell you how much mass of those fingers i have.
Of course, most of that mass is fibreglass.
So....
The idea here is that the elemental iodine in solution will form a complex with the gold,
dissolving it and making it water soluble,
and then all I've got to do is extract the gold from the solution.
which will be later in this video.
So for now lets just put in this iodine here.
Which is a mixture of sodium iodide.
elemental iodine and a little bit of alcohol, the alcohol really doesn't do anything here.
But lets add these in.
Let them sit overnight and see if it dissolves the gold.
I'm going to actually cover the iodine with something because the elemental iodine will vapourize out over time.
You'll notice I'm actually doing this indoors,
because the iodine is fairly safe compared to the acid.
Now you can see that I've cut up those circuit boards and put them inside this glass bottle.
I'm going to be leaching the gold off of them using cyanide.
So lets make the leaching solution now.
So to start i'm going to add some potassium hydroxide -
this will keep everything basic, because if it becomes acidic the cyanide will actually turn into hydrogen cyanide.
Which uh,
produces vapours which are toxic.
So,
lets dissolve this with a little bit of distilled water.
There we go.
Now here's the cyanide,
this is sodium cyanide by the way,
it's a very useful chemical because it can do many many things.
I've done a video about making cyanide,
and actually Nerd Rage has just made a video about making sodium cyanide,
so I'll post links to those in the description.
And perhaps I'll do another better video about making cyanide later on.
Alright so that's mostly dissolved.
Now in order to get the cyanide to dissolve the gold,
it needs a source of oxygen.
So, you could use the air
but that's fairly slow especially if you're using a sealed container.
So I'm going to splash in a little bit of hydrogen peroxide.
That will be my source of oxygen.
This reaction actually produces hydrogen peroxide as an intermediate anyway,
so this just speeds up the process.
There's my gold dissolving solution.
Lets add it into this
container and see if it will dissolve it.
[musical interlude]
Okay it looks like all the gold is dissolved.
There's a little bit of a base metal underneath the gold by the looks of it
but it shouldn't cause too much trouble.
Lets just pour it off
and so we can deal with the liquid.
[water pouring]
Hopefully that contains lots and lots of gold.
Probably don't, but I'm sure it's got some.
So now I've got to get rid of the peroxide,
because if I try to drop the gold out now, the cyanide will just dissolve it back in.
So I'm just going to add a little bit of yeast here
and the yeast will catalytically destroy the peroxide.
See the bubbles of oxygen come up as the yeast destroys the peroxide?
I couldn't find any zinc powder because I'm not back at the ranch,
but pieces of aluminium foil ought to do just as well.
So the idea here is that the aluminum will actually replace the gold in solution,
so it will make it
aluminium dissolved in solution, and the gold should fall out as a solid.
So that's the theory anyway.
The little bit of potassium hydroxide in there should actually begin reacting with the aluminum
and I believe it is.
That's not really a problem, that will actually help us out 'cos it will dissolve away the aluminum oxide coating
So it will expose the fresh aluminum to the gold
well this is probably going to take quite a while for that gold to fall out so let's go do something else.
Ok, let's pull this off and see how the iodine's doing.
Yeah, it looks like the material has dissolved away some of the gold,
see there?
But unfortunately the solution appears to have gone clear.
That means the iodine is no longer elemental and in solution,
which means it's probably stopped dissolving the gold, and there might be some gold down in the bottom of that,
as a black powder.
Lets look at this.
Yeah, looks like there's a little bit of gold still on there,
lets actually let this go on for a little bit longer
but in order to do that I've got to convert the iodine back into elemental form, so lets do that now.
Alright, so I'm going to add a little bit of acid to the solution, it's just hydrochloric acid
That alone might actually, yeah.
Needs an oxidiser.
Lets oxidise it with a little bit of hydrogen peroxide here.
There we go, now we've got some iodine in solution.
Ok, so this has actually sit for quite a bit longer since the last cut
notice, the solution's still brown.
As long as it's brown, I should have to gold still dissolved.
Ok, now that I've got these rinsed off
There's not that much iodine on 'em, we should see that, yeah, most of the gold's gone!
You can actually see the fibreglass underneath where the gold used to be.
Very nice.
So it's taken it off.
There is one issue I'm seeing though
This stuff, the sludge left in the bottom of the container?
I don't know if you can tell, but it's actually got some little sparklies, like there's little bits of gold in it.
So I think the iodine must have caused some of the pieces of gold just to flake off of this and then sink to the bottom,
and it hasn't been dissolved.
So either I need to dissolve this up, or just put it into the furnace along with whatever else I get.
Yeah, pretty much the same story here in the filter.
You see these little bits of gold that are in it?
So, it didn't dissolve all the gold unfortunately.
As you can see, I've transferred the iodine solution into this other beaker
and I'm going to add in a little bit of potassium hydroxide solution.
This should convert the iodine back into a salt,
Rather than its elemental form.
Ok, this has got a little bit of a reaction going.
Ooo, you know what I bet it is? I bet it's the peroxide coming out of solution
because the potassium iodide is now decomposing the peroxide.
So this is oxygen.
Interesting.
[chuckles]
There must be my gold, right there.
There's probably a lot of copper as well, you can tell because of the blue colour.
At least it looks like I'm going to be able to filter it out pretty clear
all the stuff's being caught up here.
Ok, so here's the pieces of paper that I used as filters
you'll notice they're brown and crispy.
That's because I just took them out of the oven where I was drying them off.
So now I'm just going to break all the stuff that's on them off
and then I'll put this stuff into a crucible and furnace it down.
And then extract all the gold from it.
Alright, so I'm going to leave the lid open on this, so it'll actually oxidise all that paper and hopefully the copper as well.
That way, we're left with just the noble metals when we're done.
[crucible clangs]
I didn't see any metal, did you?
Hopefully there's some in there at all.
Ok, so it's now cooled off, and I was looking through this,
I didn't really see anything that looked like gold
until I turned this one around.
And look at that!
There's a little bead inside there.
Let's get that out, and see how much it weighs, shall we?
So here's those RAM fingers, and here's the gold that I recovered off of them.
So small you can hardly see it.
There, that's better, now you can see it.
Little tiny bead of gold here.
Yep. It's probably not 100% pure, you'll notice its colour is a little bit off
it's probably got a little bit of copper in there.
But, it's pretty much too small for me to try to refine it on its own, so lets just weigh it and figure that it's mostly gold.
There we go.
Oh, just under a third of a gram.
So point two - actually, that's a quarter of a gram isn't it.
That's certainly not very much.
Alright, lets go work on the other thing.
Ok, here's the cyanide solution
I've been adding aluminium foil to it to help drop the gold out and, uh,
as you can see, the aluminium is completely dissolved.
There's a little bit stuck to the glass right there.
Yep
And you can see there's some material down at the bottom which is probably primarily
from the aluminium.
But, hopefully there's also some gold in there.
Now, as for the intense colour that it has
I'm thinking that's actually not copper, but rather
little, tiny microfine particles of gold giving it that colour
so its basically a little bit of colloidal gold in solution.
I don't think there's a whole lot there so I'm just going to pour this off
into a container here.
Maybe I'll let it settle out over a couple of weeks and see if there's any significant amount of gold in it.
Alright, just like last time, I've got some borax flux in a crucible
And I'm going to add in this cementation slime
that I filtered out of the cyanide solution.
Oops. Let me fix that.
For those of you worried about the leftover cyanide solution
it's nothing a little bit of bleach won't be able to take care of.
Just throw that in there, goodbye cyanide [chuckles].
Alright, here we go.
Ok so, I found gold
it's still stuck inside the crucible.
So, I'm going to take this, and put this stuff back in
and heat it up again,
and give it a little bit more time for the beads to come together.
Alright, let's do this again.
Lets see if we have a bead of gold.
Ooo.
That is mighty warm.
Did it come out this time?
I don't see any in there, so it must've.
Alright, lets let it cool off [taps tongs].
It's still got a little bit of slag on it, but there's that bead of gold!
Yeah, this one's very pretty
although, it's very small.
And, here's the bead that I extracted earlier.
Yeah, so, there it is.
You'll notice the cyanide process produced a much purer product, by the looks of it.
Let's weigh this little guy.
See how much it weighs.
Fortunately, I have a scale that can actually do it.
There it goes.
Not quite a tenth of a gram
and both of them together, lets see what that weighs,
yeah, now we've got about a third of a gram.
So, two days worth of work, and I managed to get a third of a gram of gold!
How about that.
[laughs]
Ahhhhh.
I guess it really isn't worth it, unless you can do tonnes and tonnes of the stuff.
Hope you all enjoyed, and I'll see you next time.
[outro music plays]