Palladium contacts with magnetic solder

[semi-lucid]

I have a bunch of old contacts from telecom equipment. The contacts are small rectangles about 1mm x 2mm x .5mm

They are mounted on little copper strips, but they are fairly easy to knock off of the strips. in all I may have about 1 ounce or so.

I knocked about a hundred or so of them off, and was going to try to clean the pile with a magnet, to get rid of any iron fragments from the scraper that I was using. To my surprise all the contacts jumped onto the magnet. They orient themselves so the bottom of the contact is on the magnet.

They come off of the copper without leaving any solder behind, so I'm guessing the solder is magnetic.

Has anyone seen this before?

Thanks.
John

 

[jimdoc]

http://goldrefiningforum.com/phpBB3/viewtopic.php?f=48&t=1347&p=11446&hilit=palladium+nickel#p11446

 

[semi-lucid]

Nickel has a melting point of 1455 °C. Copper has a melting point of 1084.62 °C.

How can they use nickel as a solder? It would seem the copper would melt first?

GSP wrote:
"The nickel backing was then dissolved in hot full-strength muriatic acid. The result was a very pure Pd - with no loses - sold very close to spot."

Wikipedia says: "Palladium dissolves slowly in sulfuric, nitric and hydrochloric acid."

These two statements seem to be contradictory, but if GSP says hot muriatic, I'll give it a try.

 

[jimdoc]

Its not nickel soldering, its nickel back to the contact itself.
So the contacts may be 50 palladium/50 nickel. That is just a guess, Chris will have to let you know if that percentage is right or wrong. I have not processed any of this type yet, I am still saving them up until I have enough.

Jim

 

[a_bab]

Some pictures with the contacts/tips would help alot as I've seen none yet.

I also have some old telecom contacts but they seem to be silver at the first glance. They are really small.

 

[semi-lucid]

a_bab

I'm not sure if I can get a clear picture that small with my camera but I'll give it a shot.

Are your contacts rectangular, or round?

 

[a_bab]

My contacts are round. They weight about 3 mg each, and are attracted by a strong Nd magnet just like yours. They look grey, like iron.


I'll post some pics in a few hours once I do the nitric acid test (don't have yet DMG at hand).


LATER EDIT: sadly it looks like my contacts are silver only, with a small amount of Ni (or something magnetic at least). No pics since it's not what I hoped for.

To some 5 contact points weightning between 3 to 5 mg some nitric acid drops were added. The nitric acid dissolved them really fast, leaving a slightly green solution. The solution tests positive for silver (with chlorides). Since no brown color specific to Pd salts was observed I'd say there is no Pd in my contacts. They rather seem to be very fine silver, soldered with some magnetic alloy, in which case harversting them won't be rentable at all (projected amount would be some 15-20 grams with alot of work).