Electrical Contacts - Today I Learned

So they can be coated with silver. And I suspect Tin, though I've not processed my yet to confirm this.

Looking through my random contacts, some did not melt the way I would expect Tin to, or turn into Tin Pest, or even tarnish under heat the way I expected Silver to.

Today I found out why.

Some of the contacts may be electroplated with Palladium!

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In non-arcing electrical contacts, palladium is commonly alloyed with nickel or cobalt. These coatings have higher hardness, lower residual stress, and better ductility than pure palladium.

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https://sc01.alicdn.com/kf/HTB122AVG...Xq6xXFXXX2.jpg
http://www.naeco.net/Contacts-Materi...erview%202.png

Though I kept my crappy thin layer contacts anyway cause I'm a hoarder.
Now it has payed off. They might also be Platinum, or Rhodium too. So if you are selling silver electrical contacts, it would pay to separate these out and get a higher price, also something to keep in mind if you process yourself - you'll want to separate out the heavier Pt & Pd portion of your smelt for future refinement when you have a large enough quantity.

Please do more research on silver contacts. I recall some can be very hazardous if you heat them up to remove them from the base metal. It has to do with the fumes given off during the heating process.

Good point on the potential for higher grade material. 73, Mike

Yep, check out my profile picture :)
Wanna be careful handling them too, be sure to wash your hands - and reduce contact to a minimum.
Cadmium is a pretty cool element, and I plan to extract it (water cooled retort).
Most soldering irons / hot air soldering does not exceed 450 degrees celcius, which is safe. A fire also does not usually get up past this.
Though an enclosed fire running very hot for a long time could could reach 700 degrees required to vapourise Cadmium.
It sublimes: turns from solid to gas - and breathing it in is the greatest danger.

I did notice the Cd and was mildly curious as to which element it represents but did not even google it. So my bad.

Since you seem to be knowledgeable about the hazards involved I would ask you to be one who explains them to others who might want to get involved in removing the electrical contacts.

One thought I has is what happens if I decide to use a cutting torch to heat up contacts that have cadmium in them? I don't have a oxy/acetylene and I use wire cutters to remove the contacts but someone else may want to use a torch. I am not going to process any contacts or other PM's for many reasons, mostly I make more money finding more material.

I do know what a retort is and can appreciate using a water cooled retort to help contain dangerous materials. We don't discuss the refining of PM's do to the dangers and complexity and there is another forum for that. But the removal of electrical contacts that contain silver and other PM's is right up our alley.

I am glad you are a contributing member. 73, Mike

So you have all those contacts with premium metals, have you sold any of it. You know, realized a profit? Profit V time and effort?

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Originally Posted by Ran440

So you have all those contacts with premium metals, have you sold any of it. You know, realized a profit? Profit V time and effort?

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I think I read in the original post that he was a hoarder........Doubt that profit versus time means much to someone who is hoarding metal

When using a torch to remove silver contacts you want a fan of some sort in front of the area as to draw the fumes away from you. Think as the fan as a vacuum sucking the fumes away versus a fan behind you blowing fumes everywhere.

As mentioned above in another post. All metals have a melting point and a vaporizing point. Leading up to the melting point and hitting the metaling point is one thing. Over heating the metal beyond the melting point is when metal lose occurs.

When heating silver contacts off with a torch the solder used to attach the contact to the base metal is a silver cadmium braze.
This is where you will encounter the cadmium metal. Cadmium has a low melting point and the cadmium released is coming from the brazing material holding the contact to the base metal.

The cadmium vaporizes and when it moves through the air and cools is when it converts back to soild. A red colored spider web substances.

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Originally Posted by Ran440

So you have all those contacts with premium metals, have you sold any of it. You know, realized a profit? Profit V time and effort?

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I don't sell my recovery's to scrap yards or other dealers.
My plan is to process all of these things my self.
I'm not a fulltime scrapper, just scrapped a few bits of junk lying around (my grandfather was a hoarder so I have a vast supply).
Once I've refined my techniques, I plan to use many of the elements that I recover for science projects.
Though I have a few ideas about becoming more of a serious scrapper/refiner and buying others scrap recovery (eg tantalum capacitors, etc).

I do sell brass to the scrap yards, as the price is good, and I've no use for it except a few little craft projects. Mostly I do a swap for Alpha brass and German Silver (type of brass) that is the size I need.
Except the copper, copper is quite easy to recover in a rather pure state.
I've a way to process it with zero cost into bars, and if I can get tonnes of it, then I can get $NZ10/kg shipping it to china (99% pure).
(the best local supplier pays $7.80, but many pay about $6ish)

Currently I don't bother with Iron, Stainless, Alumium. As they're just not worth it.
In the future I've a few ideas for the Alumium though which could make it worth my while.

Good info! Thanks guys!