# gold transistors?



## Anonymous (Oct 9, 2008)

Hey everyone,

I am a newbie to the site, but I was wondering if gold transistors are worth refining, what to expect to yield, and how much is a good price per pound.

I hope I am not posting a common topic but I am trying to buy some from a guy and I was just wanting to know if I should just pass on it.

Thanks


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## wildbill_hickup (Oct 9, 2008)

You might want to give just a little more information  . You know brand, part number, are they gold color outside or are they supposed to contain gold on the inside? Try Googling "gold transistors", :idea: I did after reading your post and came up with several hits. Judging from the discriptions (some have "nanoparticals of gold" in them) I saw and prices unless this guy is practicaly giving them to you and there are alot of them I'd pass.


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## Anonymous (Oct 9, 2008)

The part number is 8409-SMR415388. They look about half gold with gold leads, but I would imagine they're plated if anything.

I was just wondering what would one pay per pound for something like this.


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## goldsilverpro (Oct 9, 2008)

Photos, please or a link with a photo. Well focused, if possible. Inside and outside would be nice. Can't find the number on the internet.


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## Anonymous (Oct 9, 2008)

I couldn't find anything on them either.
I imagine they're rather old, at least they look it.


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## meng2k7 (Oct 10, 2008)

jason,


i also have those components, if u break those upper steel like metals, you will see some goldwire bonds, save also the dies.


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## butcher (Oct 10, 2008)

I see these on pre 1980 circuit boards and I have collected them for use, did not plan on refining them, and no idea of there yield . probably worth more whole, they are gold plated, and do have a lil bit fine gold wire inside, the metal can will cause a little trouble refining but can be done, I would rather refine other electonic scrap without the ferrous metal.


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## goldsilverpro (Oct 10, 2008)

I have never run those exact parts, but have run many TO5s and TO18s, which are similar. Some of the TO5s ran $35/pound at a $400 gold market. *I'm not saying your parts run that high*, but they look quite good. They are probably Kovar, which is magnetic, and consists of 29 nickel, 17 cobalt, and 54 iron. Maybe Steve can pinpoint the gold value closer than I can.

If I remember right, we ran the high grade TO5s in nitric acid to dissolve everything but the gold. I'm thinking the nitric was either 25% or 40%, by volume. I don't think we had to heat the nitric, but maybe we did. After nitric, we used aqua regia. 

It's possible that one of Steve's alternative methods would work.

How many pounds of these are available?


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## 61 silverman (Jan 22, 2009)

I find 1 of these in every disc drive that I take apart for the pins,, this item is held in the aluminum piece that rides on the two ss rods .. I have deplated just a couple of these just as a after thought when finishing a batch of other plated material.. on one of them that stayed in longer than the other the three tiny wires had come off,, not on the other one though,,Next time I have enough too set up again I'll test too see if these wires solder may be able to be removed in the cell there fore the wires would end up with the black too be treated w/ hcl / cl..


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## Anonymous (Jan 26, 2009)

hey why don't you just melt the whole lot down then use electrolysis
to recover the gold?

melt it then roll it out into a thin sheet...

getting silver would be tricky with all that iron in there though-


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## Harold_V (Jan 27, 2009)

elvis said:


> hey why don't you just melt the whole lot down then use electrolysis to recover the gold?


Unless I'm missing something, one of the best reasons I can offer to not melt and roll the material is it won't work. Once you alloy the constituents, only a trace of gold would be recovered, if that. It would be protected by the other metals.

Do you have something you'd like to share?

Harold


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## goldsilverpro (Jan 27, 2009)

> hey why don't you just melt the whole lot down then use electrolysis to recover the gold?
> 
> melt it then roll it out into a thin sheet...



If they are kovar, the melting point is 2642 F, which is above gas furnace capabilities. 

Also, with 3 metals involved, Fe, Ni, and Co, the electrolysis would work great for about 5 minutes. After that, the cathode deposit would be fluffy, would fall off the cathode, and would short out the electrodes. Big mess! Plating one metal is not easy, plating two metals is very difficult, and plating three metals is damned near impossible. I suppose you could use 10% H2SO4 in a tank with an anodic membrane barrier in it to keep the metal from plating out. Electrolytic 10% H2SO4 would dissolve all 3 metals.

Probably the most impossible part would be rolling it out in a thin sheet.

You could lower the melting point to a gas furnace range with the addition of about 65% copper, but then you'd have 4 metals to contend with.


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## butcher (Jan 28, 2009)

how about an expieriment with a few, smash with hammer, boil in dilute H2SO4,to get base metals.
or try steves cell.
or the salt cell with the porous cup.
maybe clip wires from them first as they should process easier.
or even sell them as they are.


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## Lou (Jan 28, 2009)

Chris, do you mean natural gas furnace capabilities? I know air-propane can easily exceed the 2642 mp for kovar.


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## goldsilverpro (Jan 28, 2009)

Yes, I guess I was automatically thinking natural gas, since I've never been a big fan of propane furnaces, for practical reasons. Unless you have a very large propane tank, they tend to freeze up and shut down and you have to keep messing with them. Also, a 2700+deg furnace gets very uncomfortable to work around and it's more expensive to build. No large refiner that I know of uses propane to prepare refiner bars. If there's too much Fe or Ni, they lower the melting point with scrap Cu.


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