Romix
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Mercury
Can mercury steam in LCD lamps be condensed at low temperatures?
What about shaking them in a container, cheacked with butane before shaking, making shore there's no leaks.
With presence of hydrogen chloride inside, would mercury steam react with it? It' should, forming solid salt. How exothermic is it?
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Bert
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Thread Moved
5-8-2015 at 18:50 |
Sulaiman
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As far as I know there is no mercury 'steam' in a CCFL,
at room temperature mercury is a liquid, with a little vapour.
when power is applied the little mercury vapour conducts and the lamp heats up
and more of the mercury is vapourised and the lamp brightness increases.
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diddi
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my guess is that at very low pressures, the Hg is basically a vapour. I t would probably revert to tiny globules if the tube was broken.
Beginning construction of periodic table display
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Romix
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Quote: Originally posted by Sulaiman  | As far as I know there is no mercury 'steam' in a CCFL,
at room temperature mercury is a liquid, with a little vapour.
when power is applied the little mercury vapour conducts and the lamp heats up
and more of the mercury is vapourised and the lamp brightness increases. |
It's in a liquid state at room temp? You sure?
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Sulaiman
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I believe that c3.5 mg of mercury is allowed per ccfl (<500mm long) and the internal pressure is around 5 Torr
so I think that there is liquid mercury present in a new ccfl.
Most of the mercury will slowly be ab/adsorbed by the electrodes and phosphor over the life of the lamp, which is why 3.5mg is allowed.
So I'm not SURE, but from what I've read I believe so.
although 3.5 mg is not a lot.
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Praxichys
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At that rate you'd need to break open 286 lights to get 1g of mercury, or 3861 to get 1ml. That's with 100% recovery. That would be like $572/g if
you bought the lights new.
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MrHomeScientist
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Yes. I have several pounds of the liquid at home.
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Sulaiman
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I have just under 1kg of mercury, and it is of course a liquid,
I thought that we all knew that mercury is liquid at STP,
the 'confusion' may be to some thinking that ccfl are under hard vacuum
in which case I'd expect no liquid mercury, only vapour
but ccfl have some mix of neon/helium/xenon (Penning mixture)
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