Best method for processing 4.5 lbs of pins.

[stihl88]

Well Ive spent a month of Sundays individually snipping these pins from their host...

Ive got hands that could crush Hercules nuts after all the snipping Ive done. In total there are individual 12 pins per connector, i had 4000 connectors.
Each connectors pins were snipped off in 4 snips meaning Ive done 16,000 individual snips...

In total their are 48,000 individual pins in that jar.

I'd sit on the recliner for an hour or two a night and slowly whittle away at these connectors. I'm just glad it's a hobby cos I'd be flat broke working at this rate


What would be the preferred method of processing these pins? They appear to be copper based.
Ive got about 5 liters of nitric acid and Ive also got a sulphuric cell with a copper basket at my disposal which is about the same size cell we typically see here on the forum in the Pyrex dishes.

 

[Harold_V]

Sulfuric cell, assuming you can keep them from leaking from the basket.

Harold

 

[Geo]

the component that you cut the pins from, what is that? is it some sort of relay? have you busted one open? it looks like the gold extends all the way inside. you may have snipped for nothing if these can be crushed and theres more gold inside. if its a relay, there could be silver too.

 

[dtectr]

For the risk harold stated, I would use PoorMan's AR, using INCREMENTAL additions of your nitrate of choice - I use potassium, myself. FWIW

 

[gold4mike]

An alternative method for getting the gold off of them, since there appears to be no tin, is "poormans" nitric.

I'm processing roughly 40 pounds of pins for a percentage of the gold and am using battery acid ($28.00 for five gallons locally) with sodium nitrate. I put about an inch or so (depth) of pins in the beaker and add two or three inches of sulphuric acid, then 2 heaping teaspoons of sodium nitrate.

Cover with a watch glass, wait until no more brown fumes, add another teaspoon, etc. After 4 or five additions of sodium nitrate I dump all the liquid, including the foils, into a bucket with a quart or so of water already in it. I let it cool overnight then pour through a filter.

Add more pins to the partially dissolved mass, add acid, sodium nitrate, etc. I'll continue until all the pins are dissolved and then process the foils and filters.

I found that the water bucket was necessary because, if I left the contents in the beaker, I was left with a solid blue chunk of copper nitrate that slowed my progress. If you have enough water it will stay in solution.

I'm now using an electric griddle as a hotplate, with a half inch or so of sand on it. I can fit four 2 liter beakers on it at a time.

 

[rewalston]

I have a question about pins. Most of the posts I've seen talk about using Poorman's Nitric to rid the base metals. I have some sulfuric acid but cannot get any nitrates. I don't have all the parts yet for the acid cell, still lacking the copper mesh and a charger. So I'm wondering if I could use AP for the pins, I know that it would put a lot of copper into the solution but right now AP is the only process that I have available. Also when you pre-treat the pins in straight HCl to remove the solder, after filtering out any possible silver from the solder. I know you can keep using the HCl until it's saturated with tin but what do you do with said acid. I'm assuming you would not want to put that into your stock pot because of the problems with tin in other reactions. I might be wrong but that's why I'm asking.

Rusty

 

[martyn111]

I have a question about pins. Most of the posts I've seen talk about using Poorman's Nitric to rid the base metals. I have some sulfuric acid but cannot get any nitrates. I don't have all the parts yet for the acid cell, still lacking the copper mesh and a charger. So I'm wondering if I could use AP for the pins, I know that it would put a lot of copper into the solution but right now AP is the only process that I have available.

You could use the 'crock pot' method, warm to hot hydrochloric acid will dissolve away the pins leaving either gold flakes / foils or gold tubes.
This method could also be used to reduce steps if your pins have solder on them.

 

[rewalston]

I have a question about pins. Most of the posts I've seen talk about using Poorman's Nitric to rid the base metals. I have some sulfuric acid but cannot get any nitrates. I don't have all the parts yet for the acid cell, still lacking the copper mesh and a charger. So I'm wondering if I could use AP for the pins, I know that it would put a lot of copper into the solution but right now AP is the only process that I have available.

You could use the 'crock pot' method, warm to hot hydrochloric acid will dissolve away the pins leaving either gold flakes / foils or gold tubes.
This method could also be used to reduce steps if your pins have solder on them.

Once the acid is saturated does everything (after filtering of course) go into the stock pot?

Rusty

 

[martyn111]

I would have thought that once the acid is saturated with copper anything of value would have been pushed out of solution by the copper, as would be the case with values dissolved in AP.
I would hope that someone with a deeper understanding of chemistry will chime in if my assumption is incorrect.

 

[stihl88]

Harold, the mesh is quite fine and wont allow the pins to fall through. (It's from Lazersteves site)

Geo, they are just a plug/connector component, not a relay. Ive investigated the internal part of the pin and they aren't plated inside except for the side walls
so i made the decision to sacrifice that 5% of internal gold and just snip the pins.

I think i will try these two methods.

-I'll run a batch through my sulphuric cell and see how they turn out, pretty straight forward.

-I'll weigh 10 or even 100 grams of pins and then figure out how much Nitric is required to dissolve 10g of copper and go for it.
At this stage I'm hoping the copper will dissolve leaving me with nice little floating foils, actually sinking foils would be better

I'm hoping I'll get at least 10g of gold for all my troubles.
These pins were in individual containers of 100 in each, each container was labeled "ERICSSON" so i assume they were manufactured by Ericsson's.
The pins appear to be quite heavily plated compared to flash plated stuff so I'm hoping Ive got a good rich batch but will find out soon.

Stay tuned for more pictures.

 

[Marcel]

I'm hoping I'll get at least 10g of gold for all my troubles.
.

1% fine gold yieldfor high grade goldplated pins is standard, let´s see if these pins can beat this.....

 

[maynman1751]

I would have thought that once the acid is saturated with copper anything of value would have been pushed out of solution by the copper, as would be the case with values dissolved in AP.
I would hope that someone with a deeper understanding of chemistry will chime in if my assumption is incorrect.

Copper in solution will not cement out values. Only solid metallic copper will do that. I think that is what you're asking!!??

 

[gold4mike]

Rusty,

I get my Sodium Nitrate from Duda Diesel's website. I'm not sure if they ship to Canada but it's worth checking. You should also be able to get it from your local farm supply store.

 

[martyn111]

I would have thought that once the acid is saturated with copper anything of value would have been pushed out of solution by the copper, as would be the case with values dissolved in AP.
I would hope that someone with a deeper understanding of chemistry will chime in if my assumption is incorrect.

Copper in solution will not cement out values. Only solid metallic copper will do that. I think that is what you're asking!!??

Not quite what I was asking, the copper (in solid form) being dissolved by the hydrochloric acid will cement out the values as it is taken into solution was what I was saying.

 

[rewalston]

Rusty,

I get my Sodium Nitrate from Duda Diesel's website. I'm not sure if they ship to Canada but it's worth checking. You should also be able to get it from your local farm supply store.

I've checked the local farm supply and they won't even talk about sodium nitrate.

Rusty

 

[Acid_Bath76]

try SPECTRACIDE. They make a tree stump remover powder that is 98% potassium nitrate. Worst case scenario, you could probably order it online without the hassle of purchasing "labelled Sodium Nitrate".

 

[dtectr]

AP was actually my 1st choice - it's slower but fewer "issues". Make sure to read lazersteve's "CuCl II" document on his website.
"Nitric" = "No-No" until you have more experience with acids and their unique reactions with e-scrap.

 

[stihl88]

AP was actually my 1st choice - it's slower but fewer "issues". Make sure to read lazersteve's "CuCl II" document on his website.
"Nitric" = "No-No" until you have more experience with acids and their unique reactions with e-scrap.

If your going to run AP then it should be made mandatory that the AP user invests in an air bubbler, it works wonders.

 

[goldenchild]

The cell is the easiest and cleanest way to do this period. You'll be done in a half hour or less. If you use any other method there are down falls.

AP - inevitably some gold will go into solution and since there is so much copper it will plate out. So you will not only have to remove and filter the foils from all those tiny pins but also have to be on the lookout for a terribly fine black dust in a very dark solution. Time.

Crockpot - that’s a good amount of copper to try to dissolve with an acid that’s not very good at dissolving copper. You'll probably have to keep adding acid to it also. The pins would also have to be damaged in order for the acid to effectively get at the copper. Incineration comes to mind. Time.

Poor man’s nitric - the waste stream will be quite large for such a small amount of material. You'd also have to contend with the blocks of nitrate and copper sulphate like mentioned by gold4mike. Incineration. Time.

Using the cell would be a breeze compared to these other methods and since you have a cell at your disposal you should use it. Knowing what I know now if I didn’t have a cell available yet I would put the scrap to the side until I got one.

 

[rewalston]

Thanks for the replies guys. As I said I have almost everything for the cell, just lack the funds to finish it. I'm hoping that I can find the rest soon. I'm still pulling things apart anyways.

Rusty