Apparently high yield e-scrap

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MGH

Well-known member
Joined
Sep 28, 2012
Messages
253
Location
Nebraska, USA
Hi all,

I have both a little bit of data to share, and also a question about yield for this material if anyone else has ever handled it. I have just 150 g of these components (I think they’re transistors?). It’s actually not my material – I’ll probably end up doing a toll refine on it. To keep it short, I’ll just list some details and what I’ve done.

Pieces have a dull, matte gold plating.
I opened up one of each of the two main kinds (one “cap type” and one “post type”). The cap type is mostly empty inside except for two L-shaped posts with two gold bonding wires each. The post type has many layers of plastic circles and a couple black plastic rings – didn’t see any circuitry.
Dissolved base metals of the two pieces in nitric acid.
Collected foils, which to a large degree retained their original shape.
Dissolved foils in AR, filtered, precipitated with SMB.
Melted into a 0.22 g button.

The two pieces originally weighed 10.32 g and the final yield was 0.22 g. A 2.1% yield (though certainly not representative of the whole lot) from electronic scrap seems quite high. Has anyone processed this kind of material before, and gotten similar yields? After collecting the foils, I noticed that the two L-shaped pieces that connect to the bond wires were still solid, they weren’t a shell of plating. I know it’s been said many times that it’s incredibly rare if used anywhere, but I’m wondering if maybe these L-shaped posts are a gold alloy, and that accounts for the high yield?

Like I said, I’ll probably end up doing this small lot as a toll refine, but was just curious if anyone else has had some experience with the same material.
 

Attachments

  • final button.jpg
    final button.jpg
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  • foils.jpg
    foils.jpg
    6.3 MB
  • bond wires.jpg
    bond wires.jpg
    1.3 MB
  • disassembled.jpg
    disassembled.jpg
    4.9 MB
  • all transistors.jpg
    all transistors.jpg
    4.4 MB
Very nice! I have to wonder what the post type devices are? I've never seen anything that looked exactly like those. One would assume based on apparently having only two contacts (the post and the case) that they're maybe some type of diodes or rectifiers? Are the clear discs actually plastic, or could they perhaps be mica?

Macfixer01
 
i am thinking Sept. 1965 date code, and for want of a better word for this power control device, / rectifier, i am going to say power transistor of considerable plating.
The seals are " imo " 80 / 20 of Gold / Tin. for heat control of the die. " the most valuable part " the plating, imo, is 125 micro inches. of 23.7 karat gold.
i would buy these at 1 dollar a gram. " they have more value to collectors than getting the gold into a button.
i have refined many, that netted, 2.5 percent gold. just because of the heavy paste used. back in the 1.2 dollar a gram days.
i value the lot at 150 dollars. and think at a high efficiency of recovery, one could expect 3.6 grams.
to a collector, each small gold part, would be 8 to 10 dollars. / and perhaps more. certainly parts like these are RARE, more so than 8008's
So up to 20 bucks a unit may be had, . nice pictures. i will try and show one of mine, thanks for the post, this stuff is exciting, i have handled it. had good recovery at 300 bucks an ounce, and
wish i could find more. keep on the lookout, as i am a buyer. Cheers.
 
Goldbuyer is right. This lot can bring 2x-3x more when sold to collectors than value of gold recovered.
Try to upload picture here:
http://www.cpu-world.com/forum/viewforum.php?f=18

They will tell you more about what collector may pay for them.
 
Smack said:
A couple tons for Smack please :mrgreen:
I'd share if I had a couple tons 8)

macfixer01 said:
Are the clear discs actually plastic, or could they perhaps be mica?
Could be mica, it’s relatively brittle when dry.

Thanks all. Great info. If these might have collectible value, I will certainly look into that. Just might have to offer the owner a cash price and hang onto them for a bit.

I’d like to see if you guys have input on another type of material that was included in this same mixed lot. There is even less of this material, and I haven’t done anything with it except take pictures. It’s a thin white ceramic board with dull plating covering one side, and gold traces with very few components on the other side. The side with the traces has a thin clear plastic-like coating. What you see in the pictures is about half of all the material. Most of the rest of it is broken in smaller pieces averaging 1 inch by ½ inch.

Any thoughts on yield or collectability? I imagine I'd just have to offer the buyer one price for the whole lot - there were a few gold fingers and other types of pins included as well.
 

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    20150627_140034.jpg
    3.9 MB
  • 20150627_135837.jpg
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macfixer01 said:
Very nice! I have to wonder what the post type devices are? I've never seen anything that looked exactly like those. One would assume based on apparently having only two contacts (the post and the case) that they're maybe some type of diodes or rectifiers? Are the clear discs actually plastic, or could they perhaps be mica?

Macfixer01
They are indeed diodes, aka solid state rectifiers, with a higher current rating than leaded devices can manage. They can be pressed right into a heatsink for maximum thermal dissipation.
I found a bunch of 70A/100V devices similar to these kicking around and built a power supply with enough grunt to start my project car.
 
Excellent scrap. Never seen those before. Before my time. I worked for a huge electronics refinery in 1968, in CA, and they weren't making them then. Definite diodes - 2 wires bonded to a chip.
 

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