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leu
Hazard to Others
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Maag and Hecker of the USDA published this in the Journal of Environmental Quality 1(2), 192 (1972):
Mercury in the metallic or ionic form is a poisonous pollutant when added to our sewage systems. Solutions containing
mercury salts are frequently used in laboratories and proper disposal of such waste is a problem. We have developed a simple method for removing
mercury from waste solutions by a chemical displacement reaction. The metallic mercury is recovered, purified and reused. Waste solutions are poured
into a glass container containing several strips of aluminum foil and allowed to stand a minimum of seven to eight hours. Aluminum foil was chosen
because of convenience and availability, but other metals such as iron or zinc could be used. A transfer of valence electrons from the aluminum
atoms to the mercury ions results in the formation of aluminum ions and the free element mercury. The mercury globules can be recovered, purified, and
reused while the remaining solution containing the aluminum ions can be poured down the drain with no bad effect. The ability of metals to form ions
in solution depends upon the ease with which metals lose their valence electrons. Metals which are more chemically active (valence electrons possess
more energy) lose their valence electrons in solution more readily than metals which are less chemically active (valence electrons have less energy).
Since aluminum is more chemically active then mercury, the replacement reaction occurs spontaneousy in solution. Aluminum will replace mercury ions in
an acid, neutral or basic solution. In this procedure a dilute hydrochloric acid solution is recommended since elemental mercury is recovered without
further manipulation. Nitric acid (dilute or concentrated) and concentrated sulfuric acid will oxidize mercury to form mercuric salts. The mercury can
be recovered from the aluminum-mercury alloy formed in basic solutions by treatment with hydrochloric acid. The recovered mercury can be further
purified by distillation. Mercury pollution of our environment is a serious problem, but there is a second reason that mercury ions should not go
through the waste system. The iron and lead in waste pipes and traps are more chernically active than mercury. A transfer of' valence electrons occurs
betweern these metals and the mercury ions, resulting in waste pipe deterioration and release of lead into the waste system.
[Edited on 11-10-2006 by leu]
Chemistry is our Covalent Bond
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Eclectic
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There again, the metals are dissolving in a solution of mercury salts and precipitation metallic mercury. Maybe then amalgamation with lead, copper,
and zinc, but not iron. An iron nail will cause a "tree" of silver to form if immersed in a silver nitrate solution, but it's not amalgamating. Zinc
works well as a scavenger for mercury because it does not have a tightly adherent inert oxide coating and "wets" easily. The resulting alloy/solid
solution has a vapor pressure MUCH lower then elemental mercury. See dental amalgam mercury vapor pressure.
Sulfur works well because HgS is very insoluble. I read somewhere that to dissolve 1 gram would take more water than is contained in San Francisco
Bay.
[Edited on 11-10-2006 by Eclectic]
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leu
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According to the Journal of Chemical Education 50(11) 739 (1973):
Spilled Hg can be easily recovered by adding a small amount of a dry ice/acetone mixture to the Hg. It freezes within
seconds and can be picked up. When the Hg has melted it can be reused or purified.
US 3704875 which describes using zinc, magnesium, aluminum or iron amalgams to process either elemental or ionic mercury:
[Edited on 12-10-2006 by leu]
Attachment: US3704875A1.pdf (327kB)
This file has been downloaded 651 times
Chemistry is our Covalent Bond
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not_important
International Hazard
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While the following are solubilities of metals in mercury, I'd be surprised if there was more than an order of magnitude difference for mercury in the
metal.
From Sidwick's The Chemical Elements & Their Compounds, weight percent solubilities of metals in mercury:
Li 0,09
K 0.80
Cu 0,0032
Ag 0,04
Au 0,12
Mg 0,24
Ca 0,3
Zn 2,15
Cd 4,92
Al 0,003
In 0,0073
Tl 42,8
Sn 0,62
Pb 1,3
Bi 1,4
Pt 0,02
Mn 2,5 x 10-4
Ni 5,9 x 10-4
Co 1,7 x 10-7
Fe 1,0 x 10-17
V, Mo, W listed as near zero. It states than "1 cubic mm of iron amalgam contains 15 individual atoms of iron.
Mercury is stored and shipped in iron and steel containers, and pumped with steel pumps throught steel pipe. Doesn't sound like the industry is very
worried about the pipes dissolving.
Determing solubilities of uranium, thorium, and various fission product metals in mercury, using a steel extraction pot.
http://www.ornl.gov/info/reports/1960/3445603614435.pdf
I just plain doubt those patents. Patents often try to cover all possible bases, in many cases including things they didn't try but "might work". I've
wsted a lot of time attempting to use a patented process on on of the 'additional' substrates.
The recovery of mercury doesn't require an amalgam, see http://www.udl.com/pdf/p83.pdf THE RECOVERY AND RECYCLE OF MERCURY FROM CHLOR-ALKALI PLANT WASTEWATER SLUDGE
When you electrolize a solution containing a metal ion using a mercury cathode, the result has often been called an amalgam even though what has been
made is a dispersion of the metal in the mercury, x-ray studies showed them metal was in the form of crystals of the pure metal.
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solo
International Hazard
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Mercury Spills: The Vacuum Cleaner Solution
Recently, several articles appeared in rhtc Journol, dealing with the recovery of mercury spills ' In our laboratory, WP have been working for some
yema with several different mercury manumeters and from time to time, with spilled The major prohlem is to collect it from the junctions between the
tiles of the floor or of the bench. An efficient method, compatible with the subsequent purification of this expensive element consists of sucking it
up by means of a filter pump. About 5 m of vacuum tubing is connected hetween the pump and a trap, itself attached to 1 m of flexible plastie tube
(polypropylene, for example/ ending in the suction devke. This part consists of a length of glass or metal tuhe (inner diameter = 5 mm) flattened to
ohtain a small aoerture of about 0.5 X 5 mm. this size deoendine deoendin-e on the power of the pump. Larger dimensions tend to decrease the
efficiency of the suction, smaller cause rapid clogging (unclogging
is easy with a steel pin).
The trap is held in one hand, the other sweeping the area to be cleaned with the suction device. For comers difficult to access, one can use a glass
tuhe tapered to about 2 mm in place of the former device. Before stopping the pump (slowly, to avoid hack-draught) it is advisable to raise the
plastic tube vertically over the trap to ensure that the mercury drops into it. The recovered mercury is filtered and p~rified.~
' Lk Nardis, R L., and Maalanka, R.J. CHEMEDUC., 60,336 (1972): Idoux, J. P., J. CHEM. EDUC.,50,739 (1972): Bowmaker, G. A,, J. CHEM. EDUC., 51,
126 (1973).
Wilkin~nM, . C.. Chem. Reu. 72,575 (1972).
Campus Valrase Jean Francais Gal
06034 Nice Cedex, France Marcel Azzaro
............source Journal of Chemical Education 51, 126, 1973
-----------------------------------------------------------------------------------
.............included also are,
A Cleanup Procedure for Handling Mercury Spills
D. H. Anderson P. J. Murphy W. W. White
Journal of chemical Education # 2, pg.A74, 1978
An Improved Mercury Retriever
Melvin S. Newman
Journal of chemical Education # 2, pg.A78, 1978
Attachment: a clean up procedure for handling mercury.pdf (1.8MB)
This file has been downloaded 568 times
It's better to die on your feet, than live on your knees....Emiliano Zapata.
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