eagle2,
I've run many tons of palladium point scrap. When the telephone switching offices and large plant facilities went from relays to digital, there were millions of pounds of pure Pd contact relays coming into the scrap market. This stuff is still out there. A few years ago, I discovered about 5000# installed in the attic of a 750,000 Sq ft manufacturing plant.
Palladium points are usually about 1/8 long, and skinny. They are gray/silver and usually are tapered on the edges. The cross section kinda looks like half a hexagon or octagon. They have a nickel backing and this is attached to a copper-base blade or wire.
We once ran a 50,000# batch of this material. This gross weight included the shelving, relays, sockets, wiring, and everything else. It took 2 men, 2 months, in and out the door. We pulled the relays, learned how to disassemble them, and cut close to the points with a small, reciprocating alligator shear. At today's prices, the batch would be worth about $6/gross pound, in palladium. There's also lots of copper.
Instead of dissolving everything in the clipped point and dropping the Pd, I decided to selectively dissolve the nickel and the copper base, leaving the very pure palladium untouched. I found that a very dangerous (maybe, the most dangerous combination of chemicals I have known), hot, very strong solution of chromic acid and sulfuric acid dissolved the copper-base (with great relish and foam!) and nothing else - please don't try this at home - the problem is, what do you put it in, that won't break or be attacked - iron or steel might work. 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. We didn't even melt it. We got top dollar in point form.
If a precious metal, especially when pure, is layered onto base metals, it often pays to dissolve the base metals away from the PM, rather than dissolve everything. In the case of the Pd points, I would wager the Pd would lose purity if you, the reader, were to attempt to refine them. It's already pure - don't mess with it!
Most, but not all, telephone relays are just like other plastic box relays, except they are long and skinny and, instead of short blades, the points are mounted on long, round wires. They are called "wire relays."
More rarely, pure Pd points are used for other applications. In every case that I have seen, however, they all looked the same.
