Sciencemadness Discussion Board

Scrounging for mercury

sparta - 30-9-2007 at 20:44

Just wondering how much mercury was in a 400W mercury vapor lamp, and how easy is it to get out?

Twospoons - 30-9-2007 at 20:51

Bugger all.
Bloody hard.

You want mercury tilt switches, or mercury thermometers.

sparta - 30-9-2007 at 21:57

How much mercury in an average tilt switch?

evil_lurker - 30-9-2007 at 22:17

Coupla grams maybe. Never measured it out, but its heavy.

woelen - 30-9-2007 at 23:24

Quote:
Originally posted by sparta
How much mercury in an average tilt switch?

I have switches with 3 grams of the metal in it. Your mileage may vary though.

not_important - 30-9-2007 at 23:47

Indeed, the amount can vary widely

http://www.newmoa.org/prevention/mercury/imerc/FactSheets/sw...

Be aware that there are some non-mercury tilt switches around. Some use metal balls that roll, some uses electrolytic liquid sensors and solid state switches integrated in a single capsule that resemble the old glass mercury switches in size and shape, a few use gallium-indium-tin alloys (those alloys wet most materials, unlike mercury, and so are more difficult to make practical switches with).

hashashan - 1-10-2007 at 00:08

You can always buy thermometers

YT2095 - 1-10-2007 at 02:39

Quote:
Originally posted by not_important
a few use gallium-indium-tin alloys (those alloys wet most materials, unlike mercury, and so are more difficult to make practical switches with).


agreed, Galinstan`s great for some Physics experiments like a Faraday motor, sadly with Mercury there`s quite a surface area exposed to the air and it`s not a good idea, but Galinstan does the same job and just as well for this app. ;)

Phosphor-ing - 1-10-2007 at 03:52

Someone asked about extracting Mercury a while back on this board. If I remember correctly there is a industrial switch, or something like that, that has 100 grams of mercury in it! Easily found on ebay if you know what to call it. UTSE to find it's name.

12AX7 - 1-10-2007 at 05:35

Oh, mercury switch? Those things are nice... iron core and a pool of mercury. Coil wrapped around pulls the slugs down, displacing mercury and making contact. Fun stuff, and they are indeed heavy and sloshy. Still probably a minimum of Hg in them, but more than most items at least.

Tim

Slimz - 1-10-2007 at 07:56

i think a large barometer would probably be the best source.. i have one that has at least 15-20 ml in it. maybe something like this
http://www.phys.ufl.edu/demo/2_FluidMechanics/B_StaticsFluid...
check yard sales / junk stores / flee markets...

[Edited on 1-10-2007 by Slimz]

chemkid - 1-10-2007 at 11:57

oh yes, i got a very large mercury thermometer with a good amount of mercury for a dollar and another mercury thermometer thrown in free at a flee market. Always look for old homes being destroyed or demolition sales so you can rip out the mercury switches.

Chemkid

indigofuzzy - 1-10-2007 at 18:54

What about getting ahold of a mercury sphygmomanometer?

MagicJigPipe - 14-10-2007 at 13:55

I hate to keep referring back to this website but you can by it from unitednuclear.com

It's $25 (+ UPS hazardous materials charge, unfortunatley) for a "2 ounce vial". If this is volume then that would be 812g. If that's a measurement of weight then it would only be 4mL. So, I can only assume it's volume which is a pretty good amount. Just expensive....

UnintentionalChaos - 14-10-2007 at 16:06

It's probably the 4ml. Evevrything on that site is overpriced.

chemrox - 14-10-2007 at 21:00

25$/812 g is expensive?? I think 4 ml is more like it. I got 5 ml out of an old sphygomanometer .. I don't think these Hg switches are available in the US anymore. Al Gore shipped all our environmental hazards abroad along with our manufacturing industry.

Antwain - 14-10-2007 at 23:21

I should count myself lucky, I guess. I have several kilos of Hg that I inherited (ie 1.5*200mL bottles * 13.5g/mL ~ 4.05kg). Perhaps I should be selling it if its worth that much.

kilowatt - 15-10-2007 at 02:03

If you happened to live in the UK, Labpak (now LP Chemical) sells it for £15.77/500g to anyone no questions asked. Of course the good old United States is doing everything in its power to prevent you from obtaining mercury. If you have a legitimate company, you could buy it from Gallade or somewhere for like $400/lb (haha, right).

I have found the most fruitful source to be old ignitrons. Of course it would be a sin to scrap a good/useable ignitron with known specs, besides the fact that they are insanely expensive. However every now and then you can find some old ones for very cheap. I got about 30mL (about 1lb) from just a couple old ignitrons. Still ended up costing about $80 for all that.:( At least I could reuse the glass-to-metal sealed anodes from them to make a mercury arc rectifier or other cool thing if I wanted to.

If you happened to be lucky enough to come across a significant amount of cinnabar you could extract it from that by distillation with flowing air. Be darn sure you have a well sealed iron retort and good condensers for that though, otherwise it could obviously be a risky process indeed.

Mercury contactors and tilt switches would be the next best bet, as others have said, followed by thermometers, barometers, etc. Even these things are getting hard to find and mercury is becoming ever more a thing of taboo in the US.:mad:

[Edited on 15-10-2007 by kilowatt]

Fleaker - 15-10-2007 at 09:01

Buying from a lab supplier is very expensive, but it's usually triple distilled.

You'd be surprised what some colleges want to get rid of (i.e. flasks of mercury) and some wouldn't mind letting a few pounds go if you can explain what exactly you are going to do with it. Saves them money, but good luck finding someone like that these days (though Theodore Gray did).

Alternatively, you can talk to a furnace repairman, they replace thermostats all the time. When my air conditioner needed replaced, the repairman replaced the thermostat. It had about 1.2mL of Hg in it. The repairman said that most people want him to take the switch. Well, over the years he'd accumulated probably a few kilograms of it in a plastic bottle. He's just drop the glass switch in, and it'd usually break from the momentum of hitting a pool of mercury covered with glass shards and metal debris. I've mentioned this before in the previous thread. Call one of these fellows, act responsible, and offer to take it off their hands, perhaps for some money and/or case of beer. Seeing as that fellow is also one of my neighbors, I'm sure he'd let me have it for free, but I've got enough mercury for what I do (which is mainly just to have).