Sciencemadness Discussion Board
Not logged in [Login ]
Go To Bottom

Printable Version  
 Pages:  1  2
Author: Subject: Advice on Mercury Spill
leu
National Hazard
****




Posts: 368
Registered: 13-10-2005
Member Is Offline

Mood: No Mood

[*] posted on 11-10-2006 at 15:43


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
View user's profile View All Posts By User
Eclectic
International Hazard
*****




Posts: 899
Registered: 14-11-2004
Member Is Offline

Mood: Obsessive

[*] posted on 11-10-2006 at 15:50


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]
View user's profile View All Posts By User
leu
National Hazard
****




Posts: 368
Registered: 13-10-2005
Member Is Offline

Mood: No Mood

[*] posted on 11-10-2006 at 17:07


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 425 times





Chemistry is our Covalent Bond
View user's profile View All Posts By User
not_important
International Hazard
*****




Posts: 3873
Registered: 21-7-2006
Member Is Offline

Mood: No Mood

[*] posted on 11-10-2006 at 21:22


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.
View user's profile View All Posts By User
solo
International Hazard
*****




Posts: 3809
Registered: 9-12-2002
Location: Estados Unidos de La Republica Mexicana
Member Is Offline

Mood: ....getting old and drowning in a sea of knowledge

[*] posted on 13-10-2006 at 04:49


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 315 times





It's better to die on your feet, than live on your knees....Emiliano Zapata.
View user's profile View All Posts By User
 Pages:  1  2

  Go To Top