[Intro Music]
Hi Everyone, welcome back to Cody's Lab.
So today i'm going to be refining this gold filled gold jewelry for its gold content
This material is not solid gold, in fact it's gold coated.
and this pile right here is one tenth 10 karat gold
which means one tenth of it's weight is 10 karat gold
and the rest is probably brass or copper, something like that.
This pile right here is one twentieth 12 karat gold.
and this is one tenth 14 karat gold.
So, i've got kind of a mix here.
It's all going to be processed basically the same but this probably will contain a lot more gold per weight than the other ones.
Anyway so i've already removed the gemstones.
I've got them over here in this pile
I managed to recover some pearls, a little piece of tourmaline, a tiny diamond and some onyx.
In fact if you look over here to the gemstones i took out during my last video
These two that i didn't know what were
I've now confirmed that this is onyx and this one i'm currently thinking is aquamarine but i could be wrong
it might just be cut glass.
Another thing people have been asking about is how much i spent on the jewelry
versus how much i recovered.
Well this bead that i recovered in my last video
Is worth right around 650, 640-ish dollars
and i spent 590 dollars on the jewelry so i guess i did make a little bit of a profit.
It's not great though.
This material right here that i'm about to be processing i spent 140 dollars on
I don't expect to recover that but it would be cool if i did.
In one of my previous videos i inserted a teaser clip of me adding jewelry to a blender
and i do intend to do that.
Of course this is a different blender because Canyon didn't want me using her good blender
So i went and got me a cheaper blender to possibly destroy.
But mainly what i'm doing this for is i need to rough up the outer surface of this
Because gold wont dissolve in nitric acid but the base metal will
and i want to get rid of the base metal, so i need to rough up the gold so the acid can actually get to it.
So i'm basically putting it in here to use the blender to basically chop it into little bits
so that the gold, so that the base metal will be exposed.
It's probably not necessary that i actually use a blender but it's something i've always wanted to try!
So i hope you guys enjoy this!
[metal dropping onto metal]
[rustling]
[metal clinking]
This is so going to destroy this blender isn't it?!
[laughter]
Canyon: probably
ohh, alright.
Alright so pulse.
[sharp pulsing metallic sounds]
[laughter]
Oh dear!
[sharp pulsing metallic sounds]
[harsher pulsing destructive noise]
Oh it's breaking the plastic stuff here
[laughter]
This is turning into a [inaudible]
This may not be the best idea!
in fact it might be the worst!
[metal smashing into plastic]
Well [laughter]
What do you mean it's broke?
Nothing a little duct tape can't fix
[Pulsed metal pulverizing noise]
[repeated metal pulverizing noises]
It did work to some extent, i mean i was able to rough up most of the material
so the acid will probably dissolve it now.
But to finish up i will cut most of the pieces with a pair of cutters
just to make sure it's got good access to the acid.
[metal being cut]
I'm going to weigh this material.
Not really to figure out how much gold is in it.
But rather to figure out how much acid i need to dissolve away the base metals
because this is going to be mostly base metal.
hopefully by the time i've got this converted down to a bead of gold
i'll actually have my new scale
because i think it should arrive on friday
So ... i'm looking forward to that.
So i was actually balancing the reaction
In order to dissolve this about 3 moles of copper i'm going to need 8 moles of nitric acid.
Which works out to roughly almost a litre of the 70% nitric acid that i'm going to be using here
that will produce 3 moles of copper nitrate and a bunch of nitrogen monoxide gas and a little water.
Now i was thinking i could actually reduce the amount of nitric i'm going to need by adding some hydrogen peroxide.
That will convert the nitrogen monoxide gas into nitrogen dioxide
which will then react with water
with this reaction to produce more nitric acid and some uh a little bit of nitrogen monoxide
which will then react with the hydroc.. hydrogen peroxide again forming ... you know it will do a little bit of a cycle there
But i figured i would actually be able to reduce the amount of nitric acid down to 6 moles
that's definitely a reduction so that brings it down quite a bit
and i've got a little bit of hydrogen peroxide laying around.
I think i might try this 'cos it will definitely reduce the amount of fumes that are produced anyway.
There's probably better ways to dissolve this much copper than nitric
But i'm just going to do it because i have it.
In later episodes i'll definitely show cheaper ways to dissolve large amounts of copper.
You can see i've got a 35% strength hydrogen peroxide
so it's quite a bit stronger than the medical grade hydrogen peroxide which is only about 3%
You could use this but you'd have to concentrate it or just use a really dilute acid.
As you can see it's producing massive amounts of this reddish brown fumes
so now lets put the hydrogen peroxide in and we'll watch what happens.
Ok so the camera stopped recording there but as you can see the red brown fumes are greatly reduced.
Unfortunately when i add in the peroxide you can see it releases lots of oxygen and stuff so.
yeah this is gonna, it bubbles quite a lot as you can see
So i have to add it rather slowly
So i think the problem was that the silver in the gold alloy is actually catalytically reacting with the peroxide
releasing oxygen gas
So the peroxide wasn't having a chance to actually do it's job properly
It was all bubbling away too quickly
Um, It still worked but perhaps this technique is more suitable for situations where you don't have that silver
This thing has been sitting here all night, i poured off the solution once and i added a bit more nitric to scavenge out any remaining copper
and now you can see that i've got a flask full of little bits of gold foil
How about that
Lets get them out of there and clean them up and weigh them
because as it turns out my scale came today
Came a lot earlier than i thought it would but i'm not going to complain about that. Let's go have a look at it.
[pan sliding into oven]
See electronic precision scale
has a capacity of 300 grams with a 1 milligram precision
Let's put this little piece of gold on here
Remember i measured it was 3.9 grams
Let's see what it actually is
3.46 so i was a little over on my weight
But i would say that was pretty good for using rice and coins yeah?
[laughter]
Alright so let's check this one here
Ok, 16.78 grams
So that's quite a lot of gold actually
Let's see with both of these together that's going to be what 20?
Yeah 20.2
Man that's like 800 dollars in gold just right there
Alright so i've got this material here which came off the jewelry
This is all of the gold that was coating the copper, brass base metals
There it is
Let's zero this piece of paper here.
Let's put this gold onto it and let's give this a weigh
Now this is going to be like 10 and 14 and 12 karat gold so it's about half gold by weight.
Alright here it goes
Set them on there
See 4.4 grams
So uh that's probably about 2.2 grams of pure gold
Thats not very much is it
Thats what 60, it's about
It's almost probably around 90 dollars in gold there
and considering i spent 140 on it i lost money
but lets continue processing it anyway
Since this material is so thin i think i could get away just dissolving it in aqua regia directly
So i'm going to go ahead and just do that
and if it doesn't actually work i can always melt it down and work it from there.
There we go
Lets go add some aqua regia or regia to it and dissolve the gold
and hopefully purify it
Just like in the last video i've got some hydrochloric acid
and to this i'm going to add
a little bit of nitric acid
to start dissolving the gold
as you can see i've put it into a beaker full of warm water
that made it start reacting much faster.
It made short work of that
Now from here you guys probably know the drill
I'm just going to pour off the liquid to separate it from the silver which you can see at the bottom there
evaporate it dry
and then extract the gold from the solution and melt it down
You do not want to heat gold directly like if you're using an oxyacetylene torch or something
because the oxyacetylene torch will first of all blow the gold particles away but also gold will actually burn when it's finely divided like this
Now i know you're saying but Cody gold doesn't oxidise
Well ... this is true that gold oxide is definitely not stable
that's why it's such a noble metal
but ...
at high temperatures oxygen molecules will actually stick to the surface of gold
now if you've only got one surface it's not going to really be much big of a deal
but when you've got and incredibly large surface area like this gold powder that's atomically fine almost
the gold partic, the oxygen molecules sticking to it can release a lot of heat
it can cause this to actually vaporise into a purple smoke
I've seen it before, it's not very fun!
[laughter]
But if you heat indirectly like this it will never reach it's ignition temperature
and it will just melt and be all cooperative for you
The gold should be thoroughly melty by now
let's have a look at it
There we go
Now you can see the gold bead slowly cooling off
very pretty isn't it?
Looks like it's got a pretty interesting texture on the surface of it
but it should be pure 24 karat gold
Here's the other 2 beads that I've gotten from previous episodes
Let's compare them
You can see it is currently the smallest one
But there it is
let's see how much this little guy weighs shall we
Put it on this highly accurate scale
and immediately have it roll off!
There we go
2.27 grams so about 2.3
About what i was expecting
very nice
I definitely lost money
Especially if you factor in the fact that i destroyed a 15 dollar blender and used about
10 dollars in acid
So really the only way i could have made money off of doing this if i got the jewelry for free somehow
or you know i posted it to youtube and made some money off the advertisements
So you know i've got that going for me [laughter]
There's all the gold that i've refined together on the scale, you can see it's 22.5 grams.
I've got a few more videos planned so hopefully we'll increase that even more.
Once such video that i will add to the line up includes getting silver off mirrors.
You see this is actually a dewar flask or a thermos
That i was using to carry liquid nitrogen
and i was actually pouring the liquid nitrogen on to a skillet on the stove and the glass dewar actually because i suddenly heated it up
because i got it too close to the flame.
So you can see the double walled reflected mirrored surface there.
It's actually got quite a lot of silver in it
So let's see if i can actually recover it
That will of course be in another episode
So i hope you guys enjoyed and i'll see you next time.
[electronic dance music plays]