Gold inside chips (black, flatpacks - not CPU)

[patnor1011]

I can remove most of burned carbon from s/n as there is no metal inside so no problem to get rid of nearly all of that. Problem is when concentrating values from IC chips due to large amount of metal pins inside. If you crush too hard, gold will smear on pins, also bonding wires disintegrate to very small particles - which is not happening with wires from s/n.

I just processed 914 grams mixed IC from boards, yield was 1 gram. After second refining.

 

[patnor1011]

Anyone processed this type of older RAM IC? Can you share yields?
I got surprisingly low yield only 0.6g from 2.5 kilograms and that look low to me but no matter what I do, can't squeeze more from them.

 

[g_axelsson]

Sorry, I haven't refined any chips of this kind yet so I have no hard facts to add but I'm not surprised by the low yield. There are only 20 bond wires per chip and a lot of metals and plastics. I have always suspected that old ram sim modules with tin plate actually have a low yield. You only confirms my suspicion.

Göran

 

[patnor1011]

My logic tells me this.
I got about gram from thin IC from newer type of ram.
Thin IC from RAM is about half of weight of this particular type. So to get gram you need 2 kilograms of them - weight/number wise. Then there is another thing, new IC do have about 56 pins - which lead to bonding wires and thick do have less than half of it 24. That makes me think that in order to get similar results you again need to double that amount.
Am I right? Can someone discuss this with me preferably with his own observations or yields?
Summary - I got:
0.5g from 590g thin IC - new type of ram
0.6g from 2520g thick IC older type of ram

 

[patnor1011]

s/n bridge chips you should avoid.

From now on I am separating s/n to 2 types. Computer and video cards do have s/n on which bottom green part is thin, we all know how it look like.
There are different s/n which can be found on boards from TV. Those do have green part which feel considerably thicker, I would estimate double of computer s/n. They also have round shaped metallic heat sink visible on black top part. When incinerated some of them do have big square metal piece, I did not identify what metal it is but it is soft. I recently processed 1.7 kilogram of them which is 3.74 pounds and yield was 2.6 gram of gold. So this is very important message to everyone who purchase s/n always check source or do visual/touch check - green bottom part must be thin for better variety which yield 5g+/kg and if thicker and with visible metallic heat sink part then yield is just 1.5g/kg.
The ones I processed did have Wise View logo.

*edited added pictures

 

[ovidiuanghel]

When incinerated some of them do have big square metal piece, I did not identify what metal it is but it is soft.

*edited added pictures

The metal is copper!

 

[Geo]

The copper heat spreader and then there's an aluminum piece that is shaped somewhat like a star (these differ from each other too). They break into pieces that looks like fluffy white metal that does not react to nitric acid. You can add HCl first until all the fizzing stops and then dry and incinerate the material. The nitric bath will then remove the copper legs with no problems.

 

[patnor1011]

Yeah and the point is that if you have those in batch yield drop significantly. As I said, 1,5g/kg instead of 5.

 

[jays_computers]

Using the forums and videos I've been trying a few different ways to incinerate the chips. After trial and error I found this setup works good for me at my level. And it's cheap and simple. There's nothing new about it but I thought it would help to have some good pictures and explanations for the total noob like myself

Basically I just used firebricks, charcoal briquets, a 22oz/625g dog food can with holes drilled in it and a hair dryer. I also mixed in small amounts of regular coal once it got going. I could fill the dog food can a little more than half way with chips and have them all get glowing red hot for as long as needed, about 10 minutes. I would have to add 3 or 4 charcoal briquets after each batch. The can started melting after 3 or 4 runs.

I'm just doing a practice run using low grade chips. If you see any flaws or something please let me know. Thanks!

 

[FrugalRefiner]

Not a good idea to be operating that inside an enclosed space.

Dave

 

[ericrm]

how do you deal with the fumes?

 

[jays_computers]

Thanks, I did this outside, the table has wheels so I pulled it in a little for some pictures. The garage is more of an open long house. In hind sight perhaps I will retake some photos outside so as to not mislead a novice into thinking they could do this in their garage. As for fumes the wind carries them south. We have no neighbors for at least a quarter mile.

 

[JHS]

I know I will be shot down for this. Would it be possible after incineration is complete to then put
the ashes in a crucible and melt the gold to the bottom?
Then let the crucible cool, dump the ash and remelt the gold and pour to cornflake?
My first thought is you would need to have a large crucible and a lot of ash to make it
worth while.
john

 

[4metals]

The overall percentage of precious metals to other metals will be low, you will likely end up with a high copper alloy.

In the days that I incinerated this material (commercially on a small scale) we ended up with 2 fractions, a pulp which was the burnt powder which was crushed and sifted and shipped off to have any values recovered from a major sweeps refiner. The metallics, which is the part you were inquiring about, were melted with copper and shipped to a copper refiner. Our trays held about 500 pounds and we had enough volume to run 2 to 3 burns a week (that is why I said small scale, in the scheme of things that is relatively small scale)

If I were doing this on a very small home refining scale, I would melt a few lots with copper and have them assayed for PMs. Then, depending on the assay and how much I could get of this type of material, I would set up a small electrolytic copper refinery and collect the values in the slimes.

With copper at $3 a pound and a decent supply it could be cost effective.

 

[Geo]

If you were going to use a collector for the gold, wouldn't silver do just as good a job for small lots (a home refiner)? The silver could be used over and over again.

 

[patnor1011]

Copper is cheaper and besides there will be quite a lot of copper there already in form of pins.

 

[4metals]

The reason I said copper was this is the kind of material that is recovered from electrolytic copper refining in the slimes. If you wanted to make it an electrolytic silver proposal you would have to have upwards of 80% of the entire alloy as silver. Since the copper is at 60%, going the rest of the way up to the high 90's is easier than overcoming all of that copper with silver.

 

[nickvc]

Following 4metals approach would also allow the copper to be re used once the cell was working so the initial outlay of funds would be relatively small if any as copper is usually a large component in e scrap.

 

[zoltan]

Hello all,
I have 1kilo of these BGA chips. They are from set top boxes. Have someone try to process them?

 

[g_axelsson]

Hello all,
I have 1kilo of these BGA chips. They are from set top boxes. Have someone try to process them?

Yes, that's really nice material and should contain approximately 5g of gold. (Less if they have an integrated heat spreader, makes them heavier.)

Try https://www.google.com/search?q=site:goldrefiningforum.com+bga+chips

There is even an eBook about it, Processing s/n bridge BGA chips ebook.

Göran