Would these chips be worth trying to recover the gold from?

[kurtak]

but uf it was cyanide leached,

There is NO gold exposed in this black epoxy part of the chip - the gold (bond wires) are incased in the epoxy

Therefore there is NO reason to per leach them in cyanide !!!!!

Kurt

 

[kurtak]

They look quite normal to me. 1kg batch should yield a good return.

Incinerate/pyrolyze and treat like any other IC chip.

This is ABSOLUTELY CORRECT !!!!!!

About a 9 grams of gold return !!!!!

The black epoxy part of those chips is the PAY DAY part of the chip !!!!!!

Kurt

 

[kurtak]

there are 500 kg of these in total, the 1 KG was a starter batch.

HOLLY COW !!!!

If that is 500 kg of just the black epoxy part of the chips you have one hell of a PAY DAY coming !!!!!!

500 kg X 2.2 pounds per kg X 4 grams gold per pound = 4,400 grams gold

If it is the whole chip (the black epoxy still on the green fiber) the gold recovery will be right at half that (or 2,200 grams gold)

And I thought the 25 - 30 pound batches of these I have done were a hell of a pay day

Kurt

 

[Martijn]

There is NO gold exposed in this black epoxy part of the chip - the gold (bond wires) are incased in the epoxy

Therefore there is NO reason to per leach them in cyanide !!!!!

Kurt

No reason, I agree, but certainly not impossible.

There is no reason to use excess amounts of concentrated nitric on PCB's full of aluminium, components and lead solder, that does not mean people will never do it. We have a forum full of examples.

What my concern was: you do not know what you got and they are clearly pretreated, unsuccesfully, otherwise you would have not been offered them for another treatment, and there are a lot of stupid people who read something and try it out without thinking. And the next thing, and the next, oh, it doesn't work, lets add some more.

Clean used electronics, okay, but some vague lot of half oxidized and pulled apart chips?

I you don't know for sure, so be sure is my motto.

 

[jord]

No reason, I agree, but certainly not impossible.

There is no reason to use excess amounts of concentrated nitric on PCB's full of aluminium, components and lead solder, that does not mean people will never do it. We have a forum full of examples.

What my concern was: you do not know what you got and they are clearly pretreated, unsuccesfully, otherwise you would have not been offered them for another treatment, and there are a lot of stupid people who read something and try it out without thinking. And the next thing, and the next, oh, it doesn't work, lets add some more.

Clean used electronics, okay, but some vague lot of half oxidized and pulled apart chips?

I you don't know for sure, so be sure is my motto.

There is a lot of comments here so i will just reply to last also a lot of good knowledge/opinions that have been shared. The chips are BGA tops and will be tested beforehand but there is no visual signs like salt deposits etc. If tests run clear the batch will be processed the normal way Incinerate them using the standard method and treat with HCL beforehand. If yield is good or as roughly expected will carry on with the rest.

 

[jord]

This is ABSOLUTELY CORRECT !!!!!!

About a 9 grams of gold return !!!!!

The black epoxy part of those chips is the PAY DAY part of the chip !!!!!!

Kurt

You clearly know a lot about e scrap, I will go through your profile & posts to see what I can dig up.

 

[GoIdman]

There is NO WAY that the gold has been "striped" from these chips yet - the gold bond wires are "incased" in the black epoxy (so acid CAN NOT get to them) - to recover (strip) the gold from them they NEED to be incinerated (turn epoxy to ash) in order to "liberate" the bond wires for processing

Kurt

If you look at the picture, there is a strange relief on the back of the epoxy casing. I have separated some of my BGA`s to see wheter my will look the same as these but the bottom part of the epoxy doesn`t look like anything in this picture. It is flat, no holes, no relief differences. I don`t know if there is a possibility to leach out the gold or not from these BGA`s other than the know processing steps but deffinitely the picture is very strange, that is why i asked a close-up picture.
Other than that, if the chips are genuine...man....will be a hell of a ride...

Pete.

 

[jord]

If you look at the picture, there is a strange relief on the back of the epoxy casing. I have separated some of my BGA`s to see wheter my will look the same as these but the bottom part of the epoxy doesn`t look like anything in this picture. It is flat, no holes, no relief differences. I don`t know if there is a possibility to leach out the gold or not from these BGA`s other than the know processing steps but deffinitely the picture is very strange, that is why i asked a close-up picture.
Other than that, if the chips are genuine...man....will be a hell of a ride...

Pete.

Thank you for taking the time to do so, I believe these are just the tops. Some great issues have been raised here in this thread and all opinions accounted for and noted. I will post the results afterwards.

 

[eaglekeeper]

Hi, I hope all are well. I have been given a job to process these chips, there is 1kg of them and it looks like they have already been stripped. I have included a photo of a small sample, all the chips are the same as ones in the photo. To me it doesnt look like the gold left would be worth the time or expense to recover. Does anybody have an opinion on th

As others have mentioned, the bonding wires are not accessible until they are Incinerate/pyrolyze.

The chips with the metal heat spreaders (circled in yellow) don't yield as much as the ones with out the spreaders.

 

[patnor1011]

If you look at the picture, there is a strange relief on the back of the epoxy casing. I have separated some of my BGA`s to see wheter my will look the same as these but the bottom part of the epoxy doesn`t look like anything in this picture. It is flat, no holes, no relief differences. I don`t know if there is a possibility to leach out the gold or not from these BGA`s other than the know processing steps but deffinitely the picture is very strange, that is why i asked a close-up picture.
Other than that, if the chips are genuine...man....will be a hell of a ride...

Pete.

There are multiple ways how to separate top from bottom. You can use heat and then they come apart more easily and top part looks let us just say better with no or very little traces of wires, solder balls, pieces of fiber bottom part and copper traces which run from bonding wire to solder ball.
If you separate them more crudely like just pulling them apart some times you get the same result but most of the time they will look exactly as they look on a picture with all I mentioned still attached to top epoxy part. Incineration, milling, sieve, water wash and acid wash take care of the crap.

 

[jord]

As others have mentioned, the bonding wires are not accessible until they are Incinerate/pyrolyze.

The chips with the metal heat spreaders (circled in yellow) don't yield as much as the ones with out the spreaders.
View attachment 59767

The majority are without heat spreaders, they will be Incinerated.

 

[jord]

There are multiple ways how to separate top from bottom. You can use heat and then they come apart more easily and top part looks let us just say better with no or very little traces of wires, solder balls, pieces of fiber bottom part and copper traces which run from bonding wire to solder ball.
If you separate them more crudely like just pulling them apart some times you get the same result but most of the time they will look exactly as they look on a picture with all I mentioned still attached to top epoxy part. Incineration, milling, sieve, water wash and acid wash take care of the crap.

I think this is how they where originally parted, i did not seperate the chips they came like this. The process you stated will be the one used, I will post the results.

 

[GoIdman]

There are multiple ways how to separate top from bottom. You can use heat and then they come apart more easily and top part looks let us just say better with no or very little traces of wires, solder balls, pieces of fiber bottom part and copper traces which run from bonding wire to solder ball.
If you separate them more crudely like just pulling them apart some times you get the same result but most of the time they will look exactly as they look on a picture with all I mentioned still attached to top epoxy part. Incineration, milling, sieve, water wash and acid wash take care of the crap.

Yes, I know , since i am collecting these chips as well (i separate them mechanically, ripping the bottoms with pliers), the only thing which was very strange for me on the picture is those reliefs that i have never experienced on either of my "decapitated" chips. Other than that, these are one of the best yielding chips to go after.

Pete.

 

[jord]

For anybody processing these to crush by hand I would highly recommend the grinder from amazon, this was only 20 seconds of it running. Saves huge amount of time when running through screens.

 

[GoIdman]

For anybody processing these to crush by hand I would highly recommend the grinder from amazon, this was only 20 seconds of it running. Saves huge amount of time when running through screens.

Nice grind. Keep us posted with the results.

Pete

 

[patnor1011]

If you are not incinerating them before grinding then your grinder blades wont last long. Even incinerated with big metallic "shield" parts from inside removed there is still some copper and silicon inside involved and blades will suffer gradually over time. I went through several of grinders like that, it all depends on volume that is processed. Proper incineration is what will save you a lot of time and effort since it is all easier from there.

 

[jord]

If you are not incinerating them before grinding then your grinder blades wont last long. Even incinerated with big metallic "shield" parts from inside removed there is still some copper and silicon inside involved and blades will suffer gradually over time. I went through several of grinders like that, it all depends on volume that is processed. Proper incineration is what will save you a lot of time and effort since it is all easier from there.

Yes chips are Incinerated properly before use and metal heat shrinks pulled off

 

[canedane]

Yes chips are Incinerated properly before use and metal heat shrinks pulled off

I am not sure about that. The ash have to be light grey before it is incinerated proberly. If it is done in a thick layer the oxygene wont come to all the carbon.Try again with a thin layer.
Henrik

 

[jord]

7.75 Grams of gold recovered, definitely shocked. Reckon can squeeze a a bit more out too

 

[Golddigger76]

Was that from one kilo of chips ?

If I remember correctly Kurtak said they should contain about 9 grams per kilo, where are you thinking that you can squeeze a little more from, solution, solids ?

Either way the gold that you did get looks great and thank you for sharing about these !!!

Also are you considering refining the rest of the 500 kilos ?