Best way to process tiny flatpacks?

[NobleMetalWorks]

I have 50lbs of this stuff right now, with an opportunity to purchase a lot more. I have to prove destruction.

I posted pictures below, anyone know what the best process would be to not only recover PM's but insure destruction as well? I cannot incinerate them, too much material and I really don't want to wet ash them. Any other ideas?

Also I have another 10lbs of these to run, it's a type of silicon wafer with fine gold thread all through them, I ground some in a mortar and pestle to test for gold, they test positive. Anyone know of a good way to process this type of material as well?

I was thinking about putting the latter through a ball mill until it's a fine powder, but I'm not sure that wouldn't make recovering the values more difficult, I have never run so much of this type of material before.

Thanks

Scott

 

[Geo]

i would think, just like the large. incinerate and separate with a magnet, grind,wash, grade,grind,wash and dissolve.

 

[NobleMetalWorks]

I would if it was a smaller amount, but I have 50lbs of this stuff just as a test run, they have 100s of lbs they want to dump. There is no way I can incinerate that much, my neighbors would wonder what in the world was going on. And wet ashing would be expensive just in the amount of acid I would have to use.

I think I'm going to end up passing on this one.

Scott

 

[necromancer]

you can sell IC chips for about $5.50 a pound (no smoke)

 

[patnor1011]

Ball mill is your only solution if you cant incinerate or wet ash, problem is that many of bonding wires will get "smeared" on pins and metallic parts inside. You will have to run metallics from inside too as your gold will be on them. I observed that on mainly small non magnetic pins and pins fragments, maybe you can grind them wet and grade material through sieve but some bonding wires will end up on pins no matter what you do if force is used to crush/grind material.

 

[Geo]

you can re-use the sulfuric. its not spent, just contaminated. when its saturated with carbon and totally black and thick, dilute with water to double the volume.the carbon will settle as a black mass and you can decant the clear acid off and evaporate down and re-use.

 

[patnor1011]

I would not incinerate material in first picture. Most of plating will end up in smoke.

 

[kurt]

Maybe this impact mill from Action Mining or build your own

 

[NobleMetalWorks]

Can't use a hammer mill, the flat packs are plastic. I'm going to use Geo's suggestion and wet ash a few lbs and see how bad it really is.

By the way Thanks Geo...

Scott

 

[samuel-a]

Scott

What is the problem with plastic and hammer mill?

If you need a proof of destruction, my best suggestion would be to buy a small hammer mill and set it with an 1/8" grid.
Whan you are done with that, find a refinery and pay (to whom you are getting this stuff from) according to the refinery's assay.

I think this way makes the best of all worlds. Trying to process this kind of material at these amount is nearing the impossible for the home refiner. IMHO.


edit: p.s. this is very very rich material.

 

[lazersteve]

Those parts look thin enough to go into a heavy duty paper shredder that will mince them into small bits. These bits should easily extract by normal chemcial processes (40% nitric then AR).

Here's a thread were I did the same thing and a photo of the results:

Shredding IC Packages

Steve

 

[NobleMetalWorks]

Sam,

I thought about putting it through my ball mill originally, but my fear is that it's not going to break it up, it's going to mash it all together because they are plastic. I figured a hammer mill would be the same problem, except worse because it would be mashing it against the metal on the inside of the mill, plus I don't have a hammer mill, not yet anyway.

I agree, it's not the type of material I would want to run at home. I am looking for a building to move into but making the jump from garage to building not only takes a lot of time, but it's expensive, and I have to comply with California EPA regulations which are pretty bad in themselves. I was hoping I could figure out a reasonable way to process these without using an exotic and dangerous method.

I am really curious about the yield Sam, I think you are right about it being rich. I have handled bags of flatpacks, and they feel like plastic chips. A few of these in your hand have some weight to them. But still, I am being skeptical and waiting until after I process some to figure out what they are going to bear. It's the only reason I asked for a sample, because it looked really good.

Scott

 

[NobleMetalWorks]

Those parts look thin enough to go into a heavy duty paper shredder that will mince them into small bits. These bits should easily extract by normal chemcial processes (40% nitric then AR).

Here's a thread were I did the same thing and a photo of the results:

Shredding IC Packages

Steve

Steve,

That was what I was hoping for, an easier, safer way to process them. Any problem with the paper shredder failing? These are really small packages, but I think your method has merit. I was going to wet ash them, and still might if this doesn't work, but I prefer not ashing at all.

Thank you for the pointers!

Scott

 

[lazersteve]

My shredder is still operating today. I've been using it to shred the parts since the reply in the link above was posted (April 29, 2007).

I've had to reinforce the end plates of the shredder as the heavy duty cutting teeth are mounted directly in the molded plastic housing, but other than that it's a chip eating monster. Mine has forward and reverse shredding capabilities. It also has a large catch bin (about 5 gallons) so you can run a lot of material in one batch. Be sure to buy one designed to shred 12-15 pages of paper at the same time.

Be sure to use proper protective equipment (particle mask, gloves, and safety glasses) when operating the shredder as the dust from the crushed silicon wafers can be hazardous to your health.

Steve

 

[kurt]

I could be wrong but I would think an impact mill like this runing at 3600 RPMs would pulverize chips in short order - I mean if it will pulverize 1/2" to 1" rocks to 400 mesh - chips should not be a problem.

Its a simple design & should be relatively cheap to build (for the thifty scaper) it's on my "to do" list

I gota look into that sheder idea to - thanks Steve

Kurt

 

[NobleMetalWorks]

Steve,

Any issues with the resulting waste solution and dropping out the rest of the metals?

I was thinking about stripping the outside layer of gold, and basing what I would pay on that alone, and then retaining the rest of the flatpack material until such a time I had the equipment to incinerate it properly. But I like the shreder idea... Thanks again.

Scott

 

[Geo]

the problem you run into when running plastics in a mill is heat build up. even though the mill itself does not seem to radiate heat, the charge can heat due to friction just enough to cause plastic to make a mess instead of breaking into pieces. if you want to mill the material anyway, it would be best to incinerate it first. mills work great on material that does not contain polymers.

 

[NobleMetalWorks]

the problem you run into when running plastics in a mill is heat build up. even though the mill itself does not seem to radiate heat, the charge can heat due to friction just enough to cause plastic to make a mess instead of breaking into pieces. if you want to mill the material anyway, it would be best to incinerate it first. mills work great on material that does not contain polymers.

I don't put plastics through my ball mill for the same reason you are stating above, the plastic gets hot and gummy, and then gets smashed onto the steel balls, and on the inside walls of the mill. I have no plans putting plastic in a mill. I did it once, learned me lesson and try not to make the same mistake again. I know how the ball mill turned out, I have no clue on a hammer mill I just assumed it would be the same.

I don't care for dealing with polymers to be honest. Not a huge fan of wet ashing, or incinerating. But I do appreciate all the help, I might still wet ash the leftover material when I move into a building and have a proper incinerator.

Scott

 

[lazersteve]

Steve,

Any issues with the resulting waste solution and dropping out the rest of the metals?

I was thinking about stripping the outside layer of gold, and basing what I would pay on that alone, and then retaining the rest of the flatpack material until such a time I had the equipment to incinerate it properly. But I like the shreder idea... Thanks again.

Scott

If you go with 40% nitric acid first to eliminate the base metals and silver/palladium, you'll be fine using AR on the residues. As for what is in the waste solution, it will be the same stuff you will get if you run normal cpus via nitric or AR and require the same disposal techniques.

Steve

 

[samuel-a]

Scott

The platic in these packages doesn't really behave as other plastics. it breaks.
The epoxy resin is molded and then baked dry encapsulating gold wires and leads and the silicon chip. it is very hard but not so flexible. In that sense, Aluminum is much similar to PP then the epoxy of chips.
Sometimes, a fiber layer is attached to the resin, this fiber layer doesn't really smear, it is torn apart by impact.

Since this epoxy is so hard, a ball mill is a lousy choice (been there done that) as it is only abrading the surface and takes forever.
On the other hand, a shredder or an impact mill will both serve you well for breaking them, with the last being capable of pulverizing to high mesh.


Regardless of the method you choose to break the chips, i would strongly advice against any chemical treatment at this stage (broken chips).
One must remember that gold wires are located within the matrix of the package, so you can count on it, the acid will not get it all.
Even if you would pulverize and reduce to 300-400 mesh and treat with chemicals, seperating the pregnant leach from the sludge is going to be one huge pain in your behind.
I know that as i have been there too, i broke a 1lb batch of N/S bridge tops with a hammer and reduced it to 1/8-1/4", leached it with AR.
If memory serves me well, it yielded about 3 grams fine.
It was then dried and reduced to dust and leached again, it produced another 1.3 (or maybe it was 1.4, sorry i can't remember) of gold.

I stand by what i have suggested earlier, your best bet (in my opinion) will be to break them and ship to a refiner who can incinirate, sample and assay it for you.
Had i to make an educated guess, i'd say about 2% yield by mass. But that all that is, a guess.