Non-Chemical How to melt palladium

[samuel-a]

P.s. - it is not my video.

P.p.s - just imagime what would have happend if it were melted under H2 :O

 

[Lou]

No, it's Bob's video from RDO and was more proof of concept. He's more than fine to melt Pt that way but Pd can't be melted in that fashion and now that lot is a refining lot due to it picking up O.

And actually Sam, you can melt the Pd under an H2 atmosphere so long as it switches over to Argon or Vacuum later on. A mix of H2/Ar is often used for this (and for sintering refractory metals, like W, Ta, Zr, etc.).

It's interesting that he got the powder to couple in his machine, usually you have to use what's called a "Briquetter" or else add copper and/or starter plug. This has everything to do with the frequency of the machine--higher frequency, less penetration, more skin effect. That's ideal for powders.

 

[samuel-a]

Lou,

What about Hydrogen absorbtion? When you melt Pd under H2 and switch to inert gas, did you notice a change in volume or spitting ?

I have seen on another video by him, of which they melt Pt and took a snap shot of the control panel, frequency was 387KHz... I reckon it is high enough (to say the least) for fine powder.

 

[allenp]

Hi all,
Greetings from Western Australia. We routinely melt Palladium and Platinum in a water cooled copper hearth or in large cupels using a 2500 Watt TIG torch. We can melt up to 10 ounces at a time. The argon flow seems to eliminate the Oxygen and the Palladium is readily workable. If you remove the TIG torch while the Palladium is still molten then it behaves as mentioned.

 

[Dan Dement]

Some poor jeweler is going to buy this and make jewelry out of it and it is going to crack to heck. Ever wonder why most jewelers hate Palladium? This is the answer.
Dan

 

[danieldavies]

hi all.
is it ok to pour liquid palladium into cold water to stop hydrogen and oxygen attacking it? or will it react with the water? thanks

 

[Lou]

I wonder. I do not know.

All of the palladium casting grain I've seen from JM has a slight pink hue to it, indicating that at least some oxidation is occurring when shot into water.

 

[Alentia]

I would strip of engineering degree and put him in prison for life endangerment the person who ever thought making those tongs from pliers using totally opposite laws of physics.

On another hand, if Pd shots are dropped into "acid" water from Water Ionizer, which is I believe mainly HOCl, should reduce absorption of oxygen to minimum.

 

[Autch97]

Hello,

I know this is an older thread, but I thought I should add my observations. I am a metallurgist who works at a company that deals with precious metal alloys. If you melt Pd in air and pour into a mold you will essentially get a metal foam because of all the O2 absorbed from the air and this is dangerous for the melter I have tried the following things:

- Forming Gas Cover: Some spitting at the surface. After casting the metal foams.
- Carbon Monoxide Flame Cover: No spitting. After casting metal foams.
- Natural Gas Cover: Lots of spitting. No foaming after casting. Ingot was melted and poured twice. Before and After the second melt IGA was performed. The carbon, oxygen, and hydrogen levels changed (respectively) from 15ppm , 27ppm, 1ppm to 62ppm, 17ppm, 1ppm. The fact that carbon went up while oxygen went down indicates that the carbon from the natural gas acted as a deoxidizer. The density of the ingot was 99.8%.

I know Pd will precipitate out graphite causing a grayish color if the carbon level gets too high, but this isn't a problem for a 62ppm carbon level because based on the phase diagram the practical solubility limit is roughly a 1000 ppm.

Anyways I'm new to this forum and I wanted to contribute this info.

Autch97

 

[Lou]

Thanks and welcome to the forum! Your expertise and experience is valued here!

 

[samuel-a]

Welcome in Autch97.
Happy to have you with us.

 

[saadat68]

Hi
If I have some cemented palladium or platinum
Can I mix them with some lead metal or lead oxide and melt them to get an alloy and send the alloy for fire assay/cupellation and get a piece of palladium instead of powder and sell it ?! :shock:

 

[anachronism]

How much are we talking about here ?

 

[saadat68]

For example 100 or 200 grams

Edit: They don't add whole of bar to cupel, They add just a small sample. Right?

 

[Joshb08]

I'll buy your palladium. Don't bother melting it. It's easier for me to take a sample of the powder and run ICP-AES on it that way.

If you're trying to melt it, get a high back alumina crucible and preferably go at it with an oxyhydrogen torch. Any oxyfuel torch will easily make enough heat to melt platinum or palladium. It just depends on tip and flow rate. That's why I recommend a high back alumina melting dish so that it's much harder for your powder to blow away.

The reason why, the true reason, that carbon-based fuels like MAPP, acetylene, propane, and natural gas aren't recommended is this:

Palladium oxidizes. Platinum does not. You can usually get away melting platinum with oxyacetylene if you keep it lean at all times. You can't with palladium. Palladium has a problem that's kind of like silver's--it absorbs oxygen and fuel gases when molten and tends to spit if you don't know what you're doing. Remember well that these metals are catalytic--so any gas in a rich flame that hits the palladium is going to be split into hydrogen and carbon on the surface of the palladium. The carbon will migrate into the piece and give it a shiny gray-black look. Palladium has to be cooled below red heat in a reducing flame, and the only flame suitable for that is a hydrogen flame.


Lou

Lou I have a ton of polladium I'm looking to sell, would love to speak to you regarding this.

 

[Yggdrasil]

Lou I have a ton of polladium I'm looking to sell, would love to speak to you regarding this.

The post you reply to is very old so depending on factors only Lou can reply to, it may and may not be valid any more.
I guess the “ton” is a matter if speech, use precise information please.
Is it 1kg -10kg or 1000kg?
Sorry I’m a metric guy and relate best to metric dimensions.

Just a heads up and good luck.

 

[Ultrax]

You likely can't melt by heating the crucible. There's too much heat being lost to the atmosphere. It likely would work in a furnace, however, but achieving that temperature is not easy. Induction is really the way to go for these metals, but it's somewhat out of reach for the hobbyist.

Harold

You can heat closed(!) small cylindrical graphite crucible with MMA welding machine with carbon electrodes. It should be fast enough to avoid boiling of metal (electric arc has 6000 C) so you need to practice, but it is possible to successfully melt Pd

 

[Yggdrasil]

You can heat closed(!) small cylindrical graphite crucible with MMA welding machine with carbon electrodes. It should be fast enough to avoid boiling of metal (electric arc has 6000 C) so you need to practice, but it is possible to successfully melt Pd

Harold do not frequent the forum much these days, he has "retired".

 

[Ultrax]

Ok, I understand. Perhaps my small experience with fast Pd melting will be useful to other members

 

[Yggdrasil]

Ok, I understand. Perhaps my small experience with fast Pd melting will be useful to other members

Of course it may be useful, I merely pointed to this fact so you did not expect an answer from him.
Have you actually tried this?
I thought Pd was like Pt and did get brittle and contaminated by Carbon?
Maybe I'm be wrong though