Quicksilver

Just one point of interest is that Mercury is cleaned with Nitric acid, Swilled around and put through a Chamio leather to filter it. When sitting in the bowls under Barometer tubes it does get dirty.

Edited By Clive Hartland on 04/06/2019 21:20:32

Clive ~ we used to just squeeze the mercury through a new chamois leather to clean it. I would doubt it'd be cleaned with nitric acid, even if dilute it would form mercuric and mercurous nitrate salts.

The reason Mercury writes off aircraft is that the mercury is unchanged by the reaction it causes allowing corrosion to go on forever. Given enough time, a drop of mercury could convert all the Aluminium in an air-frame into white powder. Caustic Soda attacks Aluminium far more viciously but the damage is limited because the Hydroxide is consumed, just as an electric battery goes flat and dies.

Mercury is immortal because it breaks the thin oxide layer that normally protects Aluminium from atmospheric oxygen whilst also dissolving some of the Aluminium. The aluminium in the amalgam is unprotected from air and it burns slowly on the surface of the liquid. No flame or anything dramatic, just an accelerated process similar to severe rusting in steel. The new oxide formed falls off the mercury leaving it unchanged and ready to dissolve yet more of the aircraft. Being a liquid liable to break into droplets, Mercury can go almost anywhere. As an unreactive metal itself, it can't be chemically cleaned.

The worst case is a spillage in flight - it gets splashed into every nook, cranny, hole and crack.

Dave

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It also reacts very aggressively with silver halides [as in photographic film]

When I worked at Kodak, there was an absolute 'zero tolerance' ban on Mercury thermometers.

MichaelG.

You might want to check, but last I heard the way of dealing with small spillages of mercury is to scatter flowers of sulphur over the spill and mix it up well. (Flowers of sulphur is finely ground elemental sulphur) The sulphur and mercury react to form mercury sulphide, which is a stable non soluble solid. Not an organic compound so non toxic.

John

The usual Kiwi laid-back approach to life and 'She'll be right' approach to life failed on this occasion:

**LINK**

I suppose that with a few kg of salvaged Hg you could cause a whole town to be evacuated (for ever?). If I hadn't been exposed to the nasty neurotoxin in my childhood, I suppose I might have been more intelligent, and capable of something better than posting subversive stuff in fora like this...

John, that rings distant bells. I noticed bags of flowers of sulphur for sale in the animal care part of my local farm supply store. It seemed too good to ignore - a chance to procure something that seemed a bit 'naughty'. Apart from the obvious use (an ingredient necessary for historical attempts to blow up parliament buildings), I couldn't think of a sensible use for it, and what's it used for in/on animals? Anyway, thanks to your information, I can now deal with mercury spillages - a constant worry...

Fantastic story, Kiwi Bloke ...  [almost literally]

I suspect the toxic smell was evaporated residue from the carpet cleaning products.

MichaelG.

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Just confirmed that, in New York State at least ...  "Liquid mercury vaporizes (evaporates) at room temperature causing elevated levels of mercury in indoor air. Mercury vapor is not irritating and has no odor ..."

https://www.health.ny.gov/environmental/chemicals/mercury/docs/cleaning_up_a_small_mercury_spill.htm

Edited By Michael Gilligan on 04/06/2019 23:37:55

'I suspect the toxic smell was evaporated residue from the carpet cleaning products.' - or, perhaps, panic-induced soiled underwear...

Hi,

Clive is quite right about using nitric acid to clean mercury. I used to use it in a lab to determine the bulk density of porous fertiliser granules by measuring the force required to submerge them in a pool of mercury. The mercury required frequent cleaning and this was done in two stages.

The first one involved setting up a filter paper in a funnel and piercing a small hole in the bottom. The dirty mercury was put in the top and the mercury went through the hole while the foreign bits and some of the oxide was left on the filter.

The semi cleaned mercury was then put in the bottom of a Buchner flask and covered with dilute nitric acid. A bung fitted with a length of glass tubing was put in the top of the flask such that the end of the glass tubing was below the mercury. A vacuum was then applied to the side arm of the Buchner flask and air drawn through the mercury. Initially it just slopped from side to side but when the mercury was clean, it separated into a myriad of beads.

Most of the dilute nitric acid was decanted off (down the drain - this was 50 years ago) distilled water added and the process repeated 3 - 4 times to clear the rest of the acid from the mercury.

After decanting off as much of the water as possible the mercury was then dried by blotting it with filter paper. It came out bright and shiny.

We also used sulphur on mercury spills - the idea being to convert volatile elemental mercury to a non-volatile sulphide.

Regards,

Alan

My Nan used to buy weaner pigs and raise them for the Kitchen. She used to rub the back of the pigs with flowers of sulphur if they got skin issues.

My first practical chemistry experiment at school aged 11, was to heat a red powder (oxide of mercury ) in a test tube and test for oxygen with a glowing splint. Eventually, there was just mercury left in the tube. We also had a demonstration of the mercury barometer in the physics class. I remember chasing balls of the stuff over the bench top as we collected up the spillages.

Next time you are putting a handle on a file put some Flowers of Sulphur down the hole of the file handle first,then warm (not Cherry Red but hot) the file tang up THEN fit the handle. It will ensure a really good grip of the tang to the handle and you can repeat this almost indefinitely.

An observation on Flowers of Sulphur. It's made by subliming and the process leaves traces of Sulphuric Acid in the powder. Not a health hazard but Flowers of Sulphur are best avoided in situations where acid contamination is undesirable. I don't know if melting the Sulphur down removes the acid; I suspect not.

Before modern adhesives and fillers Sulphur and Lead were often used to plug gaps and form bonds. Araldite is stronger than both and it doesn't have to be poured molten! On the other hand Lead and Sulphur are very long lasting, particularly Lead.

Dave

I inserted a 3mm pure aluminium welding rod into a jar of mercury and the reaction made an audible creak, it seemed quite an aggressive reaction.

Mike

Back in the old days while serving in Aden I used to wash with a soap containing mercury, it seemed like a good idea, skin problems were common due to the high humidity and temperature. Found out years later that it was causing problems with behavior of people in east Africa. Could explain some mood shifts at the time.

" wash with a soap containing mercury, it seemed like a good idea "
Almost certainly it would have been PMN - phenyl mercuric nitrate. It was used extensively and effectively as an antiseptic.
Even today it's used in very low concentrations as a preservative in many eye drops.

Thanks for replies - all 58 of them! It seems that many have been interested by this remarkable substance. Having looked at the link to the gov website in Robert Atkinson's reply it does seem that possession is illegal because of the potential for making explosives. With 3% nitric acid? Good luck says Bob. Anyway he's disappeared now, taking the ghastly poison with him I hope, and good riddance.

When a child I broke a thermometer bulb and a bead of the dreadful metal fell into my dad's tooth powder jar. I went to get a spoon to extract it, but when I got back he was brushing his teeth. No trace left. It weighed on my conscience for some years. He made it to 94 though.

Fascinating vid of Hg/Al reaction from Neil, thanks for that.

Robin.

Edited By Robin Graham on 06/06/2019 00:20:09