Sciencemadness Discussion Board

Hope I didn't waste my money

hodges - 28-12-2004 at 15:52

I saw a good price on a few ounces of mercury (2) sulfate which a company was discontinuing. I bought it, figuring I can extract the mercury electrolytically. But then I looked up the compound and found out it decomposes to two insoluable salts in water.

Is there a way I can transform this to something soluable, such as mercury nitrate? I have a good selection of acids, including nitric. Or a better way to extract the mercury? I would prefer not to have to heat anything due to mercury vapor dangers.

HNO3 - 28-12-2004 at 17:17

Just because I'm lazy and don't want to look it up, what are the salts it decomposes into?

S.C. Wack - 28-12-2004 at 18:39

Mercuric nitrate hydrolyzes in plain water as well. In general, adding acid to the water first will prevent hydrolysis of mercuric salts. I've no idea if this works on the sulfate, but you might be able to get HgO from it by dumping the dissolved salt-in-acid into excess NaOH soln. And from there to whatever.

The product with water is the basic salt 2HgO.HgSO4.

hodges - 30-12-2004 at 16:14

CRC handbooks says mercury (2) sulfate is soluable in acids. So hopefully I can just dissolve the Hg2SO4 in dilute H2SO4 instead of water and electrolyze. I will use carbon rods for both electrodes and of course do this outside. Hopefully by keeping the current down I won't get too much erosion of the carbon rods. If I need to run a slow electrolyis for many days its not a problem. Hg has molecular weight 201 and valance 2. Thus 27 ampere-hours will give 201 / 2 grams of Hg or 3.7g of Hg per ampere-hour.

Organikum - 30-12-2004 at 17:55

Adding a hot solution of sodium carbonate should transform the sulfate into the carbonate which can be transformed into the chloride(s) with HCl.
The chlorides are used to almagamate Al and this is reacted with water to produce high-quality hydrogen, aluminium hydroxide and elemental mercury. Adding HCl makes the hydroxide sludge to watersoluble aluminium chloride.

Just a raw suggestion taken from red. aminations with Al/Hg. It works but for sure there are more elegant ways.

/ORG

PS: Maybe the sulfate almagamates Al ? Solubility is not a problem as the almost water-insoluble Hg2Cl2 works fine too. Try the sulfate with denat. alc. for almagamation.

Marvin - 3-1-2005 at 11:09

hodges,

You do not want to play around with soluable mercury salts. Trust me on this if nothing else. They make the metal look harmless by comparison and anything your body absorbs is with you very long term. Seal up the sulphate and forget you own it.

evilgecko - 3-1-2005 at 12:00

I agree with marvin. They are 10 times worse than lead salts.

Organikum - 3-1-2005 at 14:43

Mercury itself is rather nontoxic when not spilled or vaporized.
Mercury sulfates are not regarded as poisonous.
HgCl2 is VERY toxic.
Hg2Cl2 is not very toxic because of its low solubility.

My suggested almagamation works with Hg2Cl2 too and this would avoid the toxic HgCl2. But maybe even the sulfate almagamates aluminium? Could be.

But for getting the pure metal a distillation step would be needed and thats a problem as it should not be done without good equipment, I agree.
A standard distillation apparatus with grounded joints suffices though.

/ORG

Marvin - 3-1-2005 at 15:50

As a technical problem this is a no brainer. He could even just digest with sodium sulphide to produce cinnibar leech out the sodium sulphate and roast to get mercury as with traditional methods. Or with a decent distillation setup the sulphate will decompose to mercury at a high enough temperature.

Point is though anything he does will result in some mercury if successful as well as vast amounts of waste contaminated with mercury metal droplets, soluable mercury compounds, insoluables ones.....

The whole thing is an accident waiting to happen as well as a deeply bad idea from the outset.

"Mercury sulfates are not regarded as poisonous. "

From the jtbaker MSDS,

Health Rating: 4 - Extreme (Poison)

Ingestion:
Highly Toxic! Average lethal dose for inorganic mercury salts is about 1 gram. May cause burning of the mouth and pharynx, abdominal pain, vomiting, corrosive ulceration, bloody diarrhea. May be followed by a rapid and weak pulse, shallow breathing, paleness, exhaustion, central nervous system problems, tremors and collapse. Delayed death may occur from renal failure.
Skin Contact:
Causes irritaton and burns to skin. Symptoms include redness and pain. May cause skin allergy and sensitization. Can be absorbed through the skin with symptoms to parallel ingestion.

Exactly what species do you suggest regard Mercury sulphate as not poisonous? Even if it were not toxic the decade long potential effects on the central nervous system from even low doses would keep me away.


[Edited on 3-1-2005 by Marvin]

Organikum - 3-1-2005 at 19:28

Sorry, 1 gram LD50 is not "extreme" poisonous IMHO.

I never said these compounds are healthy, and vaporisation and sublimation is to be avoided like hell. (ingestion anyways).

The MERCK names mercuric sulfate as poisonous and mercurous sulfate has no warning at all.

We play here with many compounds which are not healthy, and I say care has to be taken all time. I just see no reason to demonize mercury and its salts. They can be used safely.

I myself encountered much more health problems when working with chlorinated compounds like benzylchloride and chloroacetone (and others), here it is hard to avoid all contact with fumes. With mercury and its salts I had never problems as avoiding contact is comparable easy.

/ORG

guaguanco - 4-1-2005 at 09:59

Quote:
Originally posted by Organikum
Sorry, 1 gram LD50 is not "extreme" poisonous IMHO.
...
We play here with many compounds which are not healthy, and I say care has to be taken all time. I just see no reason to demonize mercury and its salts. They can be used safely.
/ORG

As long as you dispose of your 'playthings' properly and thoroughly (at a hazardous-waste facility) when you are done. Anything short of that is irresponsible. I personally think 'playing' with mercury salts is inappropriate, since the risk of leaving a mercury-contaminated garage or backyard is too high.

BromicAcid - 5-1-2005 at 03:05

Guaguanco, I agree with you totally that mercury and its salts should not be used unless totally necessary and should definately not be considered play things. I've been doing chemistry at home for about 9 years now and only once did I ever use a mercury salt, and even then I ended up trying very hard to not let one bit into the enviorment, I boiled down the solution that I was left with after the reaction to powder and I'm storing it probably forever. As for the disposal of mercury in solution I posted a topic that seems to cover a few of the disposal options for mercury, so hodges, you might find it informative to look it over if you haven't already.

[Edited on 1/5/2005 by BromicAcid]

hodges - 5-1-2005 at 16:26

I received the mercury sulfate today (2 ounces). It is a fine white powder that looks sort of like flower. I have not done anything with it besides put it in the cabinet with my other chemicals.

I know one has to be very careful with mercury salts due to the potential for long-term buildup in the body. Obviously mercury and its salts are nothing to be disposed of casually. But I guess what I'm having a hard time understanding - maybe someone can enlighten me - is why in the past mercury was not a big deal.

I remember when I was in junior high school the teachers had beakers full of mercury to demonstrate things. Kids would always want to stick their finger in the mercury because it felt like a glove around your finger - I remember doing it a couple of times, and with the teacher's blessing.

When I was in college I remember buying "serpents eggs" from a fireworks store. These are mercury thiocyanate. I remember there were a lot of cautions on the package about the poisonous nature of these. But preseumably, when they are burned, aren't they going to leave mercury salts in the environment, and probably put some mercury vapor into the air also? I've even heard of these being used as indoor fireworks at professional shows and don't recall ever hearing of anyone being harmed by them. And I can't believe that everyone that ignites these carefully scoops up the ashes and takes them to a hazardous waste dump.

Doesn't mercury occur naturally, both as an oxide and as free metal, in some parts of the world? Granted if you make a soluable salt out of it this is no longer something natural. But assuming one is careful to turn any leftover mercury compounds to oxides or sulfides is it really going to be that big of a deal to the environment? How much environment damage is done by, say, 5 grams of mercury, compared with say the damage done by driving 100 miles in a large vehicle?

neutrino - 5-1-2005 at 16:53

Just my two cents:

In the past, people knew that the vapor was posinous but used the stuff anyway. I’m not sure how far back this goes, but in Vogel’s 3rd (1956), he talks about how you shouldn’t boil the stuff because the vapor was posinous but went around talking about amalgams and mercury-sealed stirrers as if they were safe everyday items. In the 4th edition (1978), though, he talked about the many dangers of the stuff in all forms.

In truth, though, I doubt all forms are posinous. The metal itself has a very low vapor pressure and is not easily absorbed in the body (people have swallowed ounces of the stuff without much effect because of its high surface tension). The vapors are very dangerous; I have read about people trying to recover the silver from fillings by boiling the mercury off dying very horrible deaths as a result. The insoluble salts are safe (like HgS, which is used in paint). The soluble salts, however, are very dangerous, because the mercury is absorbed readily into the body and stays there. The organo-mercury chemicals are <b>extremely</b> dangerous, as they are volatile and absorbed very easily (a scientist died of mercury poisoning when she spilled several drops of dimethylmercury on her latex glove).

I’m guessing that the fireworks would have generated mainly mercury oxide, which is pretty much insoluble (both Hg (I) and (II) oxide).

S.C. Wack - 5-1-2005 at 17:48

Well I've been doing chemistry at home for over 25 years now and I have no fear of Hg. Even though I was poisoned by mercury vapor myself in my early teens. The container was not tightly sealed and I was unaware that it evaporates appreciably at STP.

There is no reason to fear working with mercuric salts. They are not going to jump out of the flask and bite you. Why would you throw away Hg when it can be recycled?

The culture of hysteria is nothing new but it used to be confined to communism and atheism. The mercury in the air, ground, and fish has always been there and will continue after we exterminate ourselves. CCl4 was the solvent of choice in school. Picric acid, a favored acid. Yes, things have changed - and this mindset of regulation and lack of common sense will only get worse.

The change in the view of mercury is not due to any new information on Hg, all of its toxic properties have been known for a very long time.

HNO3 - 5-1-2005 at 17:52

I have researched this extensively. Mercury has a low vapor pressure, but since it is acumulative in the body the PEL is low. So, exposure is strictly discouraged.
Quote:
At high concentrations, mercury vapor inhalation produces acute necrotizing bronchitis and pneumonitis, which can lead to death from respiratory failure. Fatalities have resulted from heating elemental mercury in inadequately ventilated areas. Long-term exposure to mercury vapor primarily affects the CNS. The "Mad Hatter **?**," a character in the book Alice in Wonderland, was based on the brain disease that commonly affected hat makers who used liquid mercury as a treatment for hat felt. Early nonspecific signs include insomnia, forgetfulness, loss of appetite, and mild tremor and may be misdiagnosed as psychiatric illness. Continued exposure leads to progressive tremor and erethism, a syndrome characterized by red palms, emotional lability, and memory impairment. Salivation, excessive sweating, and hemoconcentration are accompanying autonomic signs. Mercury also accumulates in kidney tissues, directly causing renal toxicity, including proteinuria or nephrotic syndrome. Isolated renal effects may also be immunologic in origin. ...
...The amount of mercury in a single thermometer is usually insufficient to produce clinically significant exposure when ingested. However, the vapor can be absorbed; children, therefore, should not play with metallic mercury. Sporadic cases of acrodynia have resulted from children playing on carpet contaminated by metallic mercury. Once a carpet is contaminated, cleanup can be very difficult, and contaminated carpeting usually must be discarded. In the event of an elemental mercury spill, it is advisable to use a mercury spill kit. If no spill kit is available, parents can use paper to clean the spill, disposing of the material in 2 plastic bags. Vacuuming, which only disperses and volatizes the metal droplets, should be avoided. A parent can call local or state environmental health agencies for assistance. If a significant spill occurs, for example, several cubic centimeters, then consultation with a certified environmental cleaning company is advised. ... ...
From here.

BromicAcid - 6-1-2005 at 05:48

A lot of what you hear about mercury is just media hysteria, when I was younger my grandmother would break open mercury switches so I'd have something to play with, I kept it in my wallet of all places (I had a little plastic nintendo wallet) and would take it to school. Too bad mercury most damages those people in their youth, but I seem to have come out on top. My main reason for worrying about the disposal of mercury is that I live in a suburban area and have many children in my neighborhood, and all my sewage leads to the river, fish tend to bioaccumulate and children are the most affected by things, sure, my small amount of mercury that I would generate would probably seem insignificant, but mercury can be fairly toxic and can be converted to more hazardous derivatives once consumed or taken into molds for bioactivation.

guaguanco - 6-1-2005 at 09:07

Quote:
Originally posted by S.C. Wack
There is no reason to fear working with mercuric salts. They are not going to jump out of the flask and bite you. Why would you throw away Hg when it can be recycled?

The culture of hysteria is nothing new but it used to be confined to communism and atheism.


I agree that there is a lot of hysteria over chemicals. I agree that mercury *can* be handled safely. My points would be:

1) Hg(+2) salts are *far* more toxic than mercury metal.

2) The only viable longterm disposal of mercury salts is taking them to a hazardous waste disposal center. Parking a jar of HgSO4 on the garage shelf is not disposal, it's just (potentially) handing the problem to something else.

3) In my opinion, anyone handling Hg(+2) salts in their garage or kitchen who isn't at least somewhat scared just isn't paying attention.

flame away...

S.C. Wack - 6-1-2005 at 09:12

And what about the 25000 kg Hg landfilled per year in the US is the form of fluorescent lights? I doubt that mercury thermometers even come close, or are as likely to break, yet there have been mass thermometer exchanges here for years. I don't see the EPA coming in after someone drops one.

EDIT - dropped fluorescent, that is. The overzealous response to other sources is well known, that was my point.

[Edited on 6-1-2005 by S.C. Wack]

BromicAcid - 6-1-2005 at 09:55

Quote:
And what about the 25000 kg Hg landfilled per year in the US is the form of fluorescent lights?

But the amount of mercury that would otherwise be released for the extra coal that would be necessary to produce the power were those regular tungsten filament lights rather then fluorescent is greater then the amount put into landfills for fluorescent.
Quote:
I don't see the EPA coming in after someone drops one.


About a year ago I did a massive paper on the Superfund program in America, there were several instances in which a thermometer and mercury switche was broken and the EPA came in and charged the owners of the house tens of thousands of dollars for cleanup, they don't come often though because they don't know about spills, but they can and will if you let them know.

[Edited on 1/6/2005 by BromicAcid]

hodges - 6-1-2005 at 15:26

Quote:
Originally posted by S.C. Wack
There is no reason to fear working with mercuric salts. They are not going to jump out of the flask and bite you.


Actually, they might. I do fear mercury salts; I was just questioning how harmful they are to the environment, compared to other everyday things people do.

I'm sure a lot of us have worked with silver nitrate before. Most of the times when I work with silver nitrate, I can see at least one spot on my fingers a couple days later. I doubt that anyone who works with this chemical has escaped this. That implies that some amount of AgNO3 or its solution was splashed on my fingers. For mercury salts, this would be a danger, because they could be absorbed through the skin.

Mr. Wizard - 7-1-2005 at 16:43

Working with colored or staining chemicals educates you to how things don't stay where they are supposed to. Has anyone ever refilled an ink cartridge and been amazed at the mess? I once poured a very small amount of a soluble Hg salt down the toilet ( Bad, I know :-( ) flushed it, and was amazed to see it stain the bowl the next day! I have some metallic Mercury stored in a bottle, inside another plastic container, with .25 cm layer of sulfur inside the second bottle, and it is red from the sulfide! Even capped bottles leak vapor. Keeping a bottle of HCl anywhere near clean steel is a great way to make it rust, even if the lid is tight. It gets out. Liquid Bromine likewise, it will rust stainless steel.

It is an interesting observation that burning the coal to power regular bulbs releases more Hg than the trashed fluorescent bulbs release. Has anyone ever read how much radioactive K40, and other radioactive isotopes are released when coal burns? I wonder if the total volume of radioactivity is higher than Atomic Energy plants release per KW?

A simple way to get the Hg metal from the soluble salts solution would be to add some precipitated copper or zinc dust. Keeping the Hg salt in excess should yield the pure metal or an amalgam if you use an excess of zinc or copper . I don't recommend distilling it. As a kid I used to play with the metal, and I hate to say, I know what it smells like hot. It smells sort of like stale tuna salad with onions, with a metallic taste. I used to melt solder, lead and Mercury together to make 'alloys'. What I didn't melt, I spilled in my bedroom/lab. :( Can you say 'dain bramage' ? I know now that spilled mercury can cause a hazardous level of the metal in the air. I was really lucky not to be harmed. Maybe I just don't know yet. Live and learn, pass on what you can.

Organikum - 7-1-2005 at 20:12

So mercury sulfates almagamate similar to mercury chlorides?

I always thought this being true but up to now I never tried it.

Would save quite some hassle when preparing mercury salts for almagamation of Al in the preparation of "activated aluminium".
And less steps says less dangerous handling necessary.

/ORG

rikkitikkitavi - 9-1-2005 at 00:00

to return to the originall question:

Mix the HgSO4 with iron fillings, the finer the better.

Since Hg is more a noble than iron you will get Hg metall and FeSO4(aq). It might take a while to the low solubility of HgSO4, though. Good agitation is necesary aswell. Fe doesnt form amalgames with Hg.

Even if solubility of HgSO4 is very low, the equilibrium constant of the electrochemical conversion is extremely large so the reaction is basically 100 % in yield. (do the math your self).

But like I wrote, just because the equilibrum constant is very large in favour, it is still kinetically limited due to solubilites.

This way it will not have to go over nasty soluble Hg2+ salts, and it is contained in a closed box, with water .

And thinkt twice about the mercury. It is cool, but also very nasty in most forms.

/rickard

hodges - 9-1-2005 at 14:02

Yeah I have not had the nerve to do anything with it yet. I'm still trying to decide if its worth the risks, and if I really want to have mercury around anyway.

One thing I might do before too long is make maybe 0.1g of mercury thiocyanate (these are the "Pharoh's Serpents" snakes that swell up when ignited). I have all the chemicals needed for that. and could use a very tiny amount. Whereas if I'm making mercury I will be dealing with many grams of the salts.

PainKilla - 9-1-2005 at 16:06

I don't think mercury or its salts are that bad.... i have no small amount of it and I love poking and prodding it every once in a while....of course I dont where gloves :o. Just be sure to keep the container closed securely, and preferably wrapped in an air tight baggie.

Also, it is important to remember that mercury is really a pain in the ass on anything solid.... If you drop a drop (:p) on a desk, it WILL fall off into w/e direction the desk is leaning towards. I managed to drop a few grams and cleanup was a bitch, but I made it like new. Be careful that it doesn't roll off and all that, but otherwise mercury is pretty!

It's salts I would be more wary of but in general, I don't feel too much risk with them. For me its gases that "scare" me. The tought of not being able to control them if they get loose is the big thing. For solids and liquids....just get good thick resistant gloves.

enima - 8-3-2005 at 10:33

Wear gloves. I have worked with HgCl2 many times in the past, never have I touched it, nor do I ever intend to. Wear gloves and make sure that the glassware you use post reaction is solid. No leaks..etc..etc..