Quicksilver

[Michael GilliganParticipant @michaelgilligan61133]

[Alan CharlestonParticipant @alancharleston78882]

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

[Nick Clarke 3Participant @nickclarke3]

Posted by Kiwi Bloke 1 on 04/06/2019 23:21:27:

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…

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.

[Anthony KnightsParticipant @anthonyknights16741]

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.

[pa4c pa4cParticipant @pa4cpa4c85075]

Posted by Kiwi Bloke 1 on 04/06/2019 23:21:27:

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. <snip> I couldn't think of a sensible use for it.

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.

[Neil WyattModerator @neilwyatt]

[SillyOldDufferModerator @sillyoldduffer]

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

[Mike PooleParticipant @mikepoole82104]

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

[Dave Shield 1Participant @daveshield1]

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.

[Fowlers FuryParticipant @fowlersfury]

" 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.

[Robin GrahamParticipant @robingraham42208]

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

[Colin WhittakerParticipant @colinwhittaker20544]

Working out in the Western Desert of Egypt in the late 1980s I was assigned a bunch of downhole oilfield PVT sample tools of uncertain maintenance history. I eventually decided the best thing I could do was to strip them down and clean them ready for whoever came after me.

Significant amounts of mercury were discovered and disposed of (I can't remember how) while using minimal safety equipment (it was during a period of low oil prices and cost saving on everything non essential). I seem to remember my wedding ring turning silvery and turning to the mechanic to borrow his gas torch to drive off the mercury.

Back in the UK on a field break I decided it might be wise to check on how much mercury I'd absorbed (not wanting to end up as a mad hatter) so I went to my local GP.

"I'd like you to check my mercury level."

"What do you mean? Check your blood pressure?"

"No, no. How much mercury is in my body. I've been working with mercury."

"That's a strange request. I don't know the answer but I'm sure the local hospital does. Let's give them a call……. Hm. They don't know either but they'll find out for us and call me back. Come back tomorrow."

The following day.

"Well there's one lab in the UK that does this analysis just outside Birmingham. They need a urine sample. Doesn't that make you feel special to think of your urine travelling across the UK to a special lab?"

The sample was given, the analysis made and the results obtained. On a safe scale of 0 to 13.5 units of something I was already up to 13 units! I therefore vowed to be much more mercury averse in future. Which cause of action seems to have been effective.

Cheers, Colin

[LADmachiningParticipant @ladmachining]

Posted by Meunier on 04/06/2019 20:02:32:

It may be an apocryphal story but was informed that the low hrs E.E Lightning in RAF Hendon museum in '70s had been retired due to mercury spillage in cockpit.
DaveD

The aircraft in question was XM170, which was contaminated during build. Very low flying time on the airframe when it was scrapped..

Link

[pgk pgkParticipant @pgkpgk17461]

Colin,

Sometime around end '70s a colleague saw a cat behaving oddly. For reasons that escape me he added lead poisoning to his list of differential diagnostics and sent a sample to the (then) Min of Ag and Fish at Weybridge for analysis. He luckily wrote 'heavy metal poisoning' rather than specifying Lead on the request form so Min. duly ran checks for all heavy metals. They turned up high mercury results.

By further coincidence I happened to be on duty when the owner rang for results. It turned out that it was a works cat and my further questioning discovered that the company did have a high level of employee headaches and sick days and prior to the current company (which traded in paper) the site had been owned by an electronics firm making mercury switches.

A major decontamination had to be carried out.

pgk

[Kiwi BlokeParticipant @kiwibloke62605]

There's clearly a lot of fear, verging on hysteria, about the hazards that surround us. A lot of it is amplified by the bureaucrats who seem to want to think for us and/or instruct us how to think. Keep the public anxious, in ignorance and submissive. Create the illusion that the masters are lovingly looking after the people, wrapping them snugly in cotton-wool and keeping the nasty, scary things away. When you're lying on the floor, paralysed with fear about all this, it's worth finding out what the greatest dangers to life and limb are – and what the government isn't doing about them…

Elemental Hg (and Pb – also hysterically demonized) really aren't that risky: it is unusual to be in a situation where significant absorption is likely. Anyone should know that inhaling fumes of more-or-less anything (including tobacco and other combustion products, of course) is to be avoided. Some heavy metal compounds – some salts and, particularly, some organic compounds are, however, horribly toxic. That includes some compounds of gold. Some gold compounds were (still are?) used to treat inflammatory arthritides. IIRC, the safe dose range was very narrow. Gold is a toxic metal! OK, again, elemental gold is 'safe', although it's, surprisingly, a recognised allergen. Perhaps our 'protectors' should ban gold, just to be on the safe side…

On a less cynical note, one metal that really is an 'everyday' danger to model engineers is copper. If you ever suspect that you have a penetrating eye injury (and this can be surprisingly painless, at the time) due to copper, or copper-alloy swarf, for goodness' sake please panic: get to A&E pronto (and make sure they understand the possibility of Cu in your eye). Copper destroys eyes, very quickly!

[Martin King 2Participant @martinking2]

Hi All,

Did I once read somewhere that metallic mercury was used as a treatment for syphilis? Blue Pill?

I hasten to add that I have no personal experience of this….!!

Cheers, Martin

[Don CoxParticipant @doncox80133]

My father used to tell the story that his father was given a mercury filled Fortin type barometer from a house he was working on. Having carried it, tucked horizontally under his arm, whilst walking from one side of Bath to the other, he was disappointed to find that the mercury had all run out! This was sometime pre second world war, imagine the hazard suited clean up campaign that would provoke today.

Dad ran his own electrical business and a couple of his customers were dentists, actually brothers, and he reckoned they were both mad as hatters (hatters, another part of the mercury story) The NHS still uses mercury amalgam for its bog standard fillings, my wife pays privately to have fillings in colour matched polymer which seems to have quite a long life. I did ask our dentist why they persisted in using what is generally regarded as a dangerous substance, his answer was that the biggest concern related to emissions from cremations, I told him that when it came to my turn I would try to keep my mouth shut.

[KEITH BEAUMONTParticipant @keithbeaumont45476]

Is "Float Glass" still made by molten glass being floated on Mercury? I can remember reading an article some years ago from Pilkington the glass makers, describing how this technique was far cheaper than the traditional way of making Plate Glass.

Keith

[Michael GilliganParticipant @michaelgilligan61133]

Posted by KEITH BEAUMONT on 06/06/2019 09:41:52:

Is "Float Glass" still made by molten glass being floated on Mercury? I can remember reading an article some years ago from Pilkington the glass makers, describing how this technique was far cheaper than the traditional way of making Plate Glass.

Keith

.

I'm almost sure that it was Tin, not Mercury … but if no-one gives a definitive answer, I will check later.

MichaelG.

[John HaineParticipant @johnhaine32865]

Never mercury, they used originally tin but now lead – see the informative article on Wikipedia. The bath has to be at the glass temperature so it doesn't freeze, mercury would boil away!

[Fowlers FuryParticipant @fowlersfury]

" Did I once read somewhere that metallic mercury was used as a treatment for syphilis? Blue Pill? "

Indeed – it was the only treatment from the middle ages, until Salvarsan was discovered in the early 1900s.
This complex molecule contained 3 ARSENIC rings, diamidodioxyarsenobenzol.
Whether the syphilis suffer preferred the toxicity of Hg to disfigurement and early death isn't recorded.

Really getting off-topic now

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