Does anyone know how to isolate the light isotopes of mercury?

[Mosheh Thezion]

ok.. simple question... I am asking for help.

does anyone know how to isolate, EASILY.. CHEAPLY.. the isotopes of mercury???

I seek and desire Hg 196... which naturally.. is .15% of all naturally occuring mercury.

 

Any thoughts???

 

-Mosheh Thezion

[JohnStu]

ok.. simple question... I am asking for help.

does anyone know how to isolate, EASILY.. CHEAPLY.. the isotopes of mercury???

I seek and desire Hg 196... which naturally.. is .15% of all naturally occuring mercury.

 

Any thoughts???

 

-Mosheh Thezion

 

 

Oh, what do you need it for. How come Hg 196. Is it radioactive lol.

 

 

My input would be the process would cost millions, certainly not cheap and takes weeks, minimum.

 

[John Cuthber]

The usual methods should work for mercury.

http://en.wikipedia.org/wiki/Isotope_separation

but they will never be quick or cheap.

 

There's also a great opportunity to get mercury poisoning.

Why do you want monoisotopic mercury?

[Moontanman]

Oh, what do you need it for. How come Hg 196. Is it radioactive lol.

 

 

My input would be the process would cost millions, certainly not cheap and takes weeks, minimum.

 

 

 

Radioactive mercury, that sounds particularly nasty as elements go...

[John Cuthber]

Did you all read the bit where it says "I seek and desire Hg 196... which naturally.. is .15% of all naturally occuring mercury."

So, just how radioactive is it likely to be?

[Enthalpy]

¹⁹⁶Hg is stable, its natural occurrence is 0.15%

http://www.webelements.com/mercury/isotopes.html

Isotope separation is long and costly. Only hydrogen is easier.

[Enthalpy]

Surprisingly, a patent by CEA tells a method:

Mix some mercury into a flow of oxygen and butadiene, irradiate by a mercury lamp depleted of the isotope 196, this separates the isotope 196 in the flow.

 

Which might be a variant of the laser method proposed for uranium enrichment...

 

I just wonder how the hell the ultra-faint optical frequency shift by the neutrons shall change light absorption by mercury in th gas mixture. All gases - including in the lamp - must be at a damned low pressure, or line widening due to the short mean free path will let all lines overlap.

 

Edit :

Webster and Zare, "Photochemical Isotope Separation of ¹⁹⁶ Hg by Reaction with Hydrogen Halides" J. Phys. Chem. 85, 1302 (1981)

tells 10mm Hg, a mystery for me. Maybe a multi-step separation.

 

Next interrogation: how much energy does it take per isolated atom? In that patent, I believe to understand every mercury atom is excited by inefficient optical means just to extract the 0.15% isotope, which is nearly as inefficient as mass spectroscopy. Present methods seek to expend less than one ionization energy per isolated atom, which is an advantage of diffusion and centrifugation over mass spectroscopy.

 

Finally, Mosheh Thezion, could you explain us this interest in ¹⁹⁶Hg? CEA paid a patent for it, so it must have some use, beyond the mere availability of mercury lamps?

 

Did someone finally find a neutron multiplicator that is less polluting than lead? It would be nice, since lead spallation makes D-T fusion reactors as polluting as uranium fission.

 

Or do you want to build lamps? From http://www.patentgen...nt/5205913.html :

"U.S. Pat. No. 4,379,252, the advantages of utilizing higher than normal levels of .sup.196 Hg in the Hg added to fluorescent lamps are described and include unexpectedly high efficiency gains in light output."

"The drawback of using this isotope lies in its high cost. For example, using conventional enrichment techniques, mercury which has been enhanced to contain about 35% of the .sup.196 Hg isotope can cost about $500 per milligram."

Which deepens the mystery for me.

 

Well, if ¹⁹⁶Hg radiates light so much better, you can probably build a lamp and collect in it the Hg fraction that is already de-excited. Or the one that is less prone to non-radiative de-excitation.

 

Will you tell us? Thanks!

[John Cuthber]

There's a very simple reason for wanting 196Hg

http://en.wikipedia.org/wiki/Synthesis_of_precious_metals#Gold_synthesis_in_a_nuclear_reactor

but, unless you happen to have a nuclear reactor...