peg@psuecl.bitnet (PAUL E. GANTER) (02/27/90)
In article <25E934B0.37FC@deimos.cis.ksu.edu>, mac@harris.cis.ksu.edu (Myron A. Calhoun) writes: > Well, on a "real" (i.e., silver) dime mercury makes an amalgam with > the silver and discolors the dime. For more information on amalgams, > ask your dentist the next time you see him/her. > > I don't know anything mercury would do anything to the current no-silver > dimes, but if I had some mercury, I'd sure try it (after I got tired > of pushing the little puddle around in my hand. Would I wear a rubber > glove? Maybe. But we didn't use to. As someone once said, "Fools rush > in where angels fear to tread".) > --Myron. Not sure about the new dimes, but GOLD reacts pretty much the same way, apparently. At a previous job, we used mercury probes to examine raw semiconductor wafers. A spot of liquid mercury makes contact with one side of the wafer (the bare one), and a metal contact touches the gold- coated side of the wafer. (The gold is deposited in a vacuum chamber-- forget how thick it is...). Anyway, if you get the mercury on the gold, it very quickly removes it! We tried this with various other materials in preparation to build our own probe. We went with aluminum as it appeared unaffected by mercury. Just thought I'd throw that in.... Paul
forbes@aries.scs.uiuc.edu (Jeff Forbes) (02/27/90)
In article <89936@psuecl.bitnet> peg@psuecl.bitnet (PAUL E. GANTER) writes: > >Not sure about the new dimes, but GOLD reacts pretty much the same way, >apparently. At a previous job, we used mercury probes to examine raw >semiconductor wafers. A spot of liquid mercury makes contact with one >side of the wafer (the bare one), and a metal contact touches the gold- >coated side of the wafer. (The gold is deposited in a vacuum chamber-- >forget how thick it is...). Anyway, if you get the mercury on the gold, >it very quickly removes it! > >We tried this with various other materials in preparation to build our >own probe. We went with aluminum as it appeared unaffected by mercury. > >Just thought I'd throw that in.... > >Paul > The mercury cannot amalgamate the aluminum though the oxide coat. Aluminium can be amalgamated with certain mercury salts which is useful if you want to react the aluminum with something that cannot break through the oxide layer. Jeff
ornitz@kodak.UUCP (Barry Ornitz) (02/28/90)
In article <1990Feb27.055111.18154@ux1.cso.uiuc.edu> forbes@aries.scs.uiuc.edu (Jeff Forbes) writes: >The mercury cannot amalgamate the aluminum though the oxide coat. Aluminium >can be amalgamated with certain mercury salts which is useful if you want to >react the aluminum with something that cannot break through the oxide layer. Aluminum is fairly easy to amalgamate once you get through the oxide coating found on any aluminum surface that has been exposed to air. One simple way is to place the mercury in the bottom of a small container and cover it with hydrochloric acid. Take the aluminum piece to be coated and immerse it in the acid long enough for the oxide layer to be etched away; then immerse it into the mercury below. When the aluminum piece is removed, it should be coated with a thin layer of mercury. An interesting effect may be seen with aluminum amalgam. The aluminum in the surface of the amalgam will oxidize when exposed to air and slough off, but most of the mercury will remain and form new amalgam. This will continue until either the mercury or the aluminum is consumed. The aluminum oxide formed will be a light, fluffy material. If a piece of aluminum amalgam is placed in a spot where air currents are negligible, the oxide can sometimes form long, delicate "feathers". It is dangerous to handle these, however, because of the mercury content. Remember that while metallic mercury not be very dangerous to handle, mercury vapor is quite toxic. The finer the droplets of mercury from a spill are, the more surface area is exposed for vaporization. The mercury left in the "feathers" described above is extremely finely divided and thus quite hazardous. If you spill mercury, dust the area with sulfur before trying to vacuum it up. BTW, we have EXTREME restrictions on mercury use at this plant. Some of our products go into film manufacturing and mercury is a silver halide poison. We even restrict some cosmetics on employees that contain mercury compounds. ----------------- | ___ ________ | Dr. Barry L. Ornitz WA4VZQ | | / / | | UUCP: ....rutgers!rochester!kodak!ornitz | | / / | | Eastman Kodak Company | |< < K O D A K| | Eastman Chemical Company Research Laboratories | | \ \ | | P. O. Box 1972, Building 167B | |__\ \________| | Kingsport, TN 37662 615/229-4904 | | INTERNET: ornitz@kodak.kodak.com -----------------
gene@cooper.cooper.EDU (Gene (the Spook) ) (02/28/90)
in article <89936@psuecl.bitnet>, peg@psuecl.bitnet (PAUL E. GANTER) says: > Anyway, if you get the mercury on the gold, > it very quickly removes it! > > We tried this with various other materials in preparation to build our > own probe. We went with aluminum as it appeared unaffected by mercury. > > Just thought I'd throw that in.... Also, if you want a rather expensive but heatless desolderer, try a bit of mercury as well. We previously used solder as a means of sopping up spilled mercury. This way, you could scoop up some mushy glop instead of chasing around teeny balls of pure mercury. Loads of fun. Gene