Non-Chemical Separation by density

[JoeyJoystick]

Hi All. I'm all new here so please bare with me. If I do something wrong, please let me know and I will try to correct it.

Anyways, I have been reading this forum with great interest and I have read several times now that it is difficult to separate Palladium (Pd) and Platinum (Pt).

I was wondering if these can not be separated by there density. In solution there would be Palladium Chloride (PdCl₂) and Platinum Chloride (PtCl₂). And with a Molar Mass of 80 and 112 respectively we have a significant difference in density of roughly 28.5%.

Now Uranium is enriched by means of centrifuges and there is a weight difference of only about 1.3% between Uranium235 and Uranium238.

So here is my question. Would it be feasible to separate the Platinum Chloride (PtCl₂) from the Palladium Chloride (PdCl₂) by means of a centrifuge? Has anyone heard of this being done? Maybe for other harder to separate chemicals? And even if this has not been done that we know of, would is be feasible?

I am not an expert in this field; just like to think out of the box at times. Curious and looking forward to hear what you all think.

Joey

 

[goldandsilver123]

It's possible, like you said, they separate uranium isotopes this way, in practice I think it will never be done, as aquous and pyro methods are cheaper and faster.

 

[JoeyJoystick]

That's a more than fair comment I would say, but what do you think about the quality of separation?

 

[g_axelsson]

Uranium is converted to uranium hexafluoride and centrifuged in the gas phase, if my memory isn't wrong. The centrifuges are connected in series as each centrifuge only raises the concentration a small percentage.

Assuming (big assumption) that platinum and palladium in liquid solution could be separated by centrifuge in the same way, you still need a series of centrifuges to get a decent separation. And you will really struggle to come near the separation you can achieve with common chemical methods.

No, it won't be practical and you would need a huge plant for just for doing what you can easily do in a fume hood with some beakers and a bit of common salts.

Göran

 

[JoeyJoystick]

Hi Göran,

I agree with you. I guess I was hoping that the rather large difference in density would make it easier. Just checked a little. A plant would typically operate 1000s of centrifuges with more than a 1000 in one train. Each centrifuge producing (yes I know they are chained..) an average of 4-8 grams of Highly enriched Uranium (U) per year. The operating costs would be huge. The time required would also take long. You would need a spacious factory for this. And ultimately, the price of both Palladium (Pd) and Platinum (Pt) does obviously not justify this. Oh well.

Joey