Sciencemadness Discussion Board

amalgam?

jar-jar - 1-2-2015 at 01:37

First to say, I'm in a no way a chemist or something similar, I know only the very basic stuff from high school, and to be honest it never really grabbed me back then, though I was good at it, probably because we never did experiments or idk, It wasn't until soon I became interested in chemistry and started experimenting on my own with some basic stuff and searching for info on the web, and I found this forum one of the few of it's kind, and now, I have some question I want to ask, because I can't find any practical explanation anywhere, so I registered here, I just hope this is not very dummy question...
It's about mercury. I'm trying to reshape metal without heating it (mostly brass ,copper and cupro-nickel), and figured out the only way would be to use amalgam (mercury or gallium). So I got a drop of mercury, and put it on a brass coin, but the mercury won't eat through it. I also tried mixing the mercury with tiny copper wires I have burned to assure it is not insulated, but still no result at all, after 10 minutes or so, and I've been watching videos on youtube how amalgam is made for seconds, and how it will eat through solid aluminum, so how to properly prepare the amalgam, and then how to evaporate and collect the mercury? Also, any metal but iron will create amalgam, right? And is it the same with gallium?

[Edited on 1-2-2015 by jar-jar]

vmelkon - 5-2-2015 at 09:06

Reshape metal without heating it?
I guess you imagine that it will be a semi-solid.
I have limited experience with it. I dropped a piece of lead in mercury and a portion dissolves in it while the rest doesn't back in 1990. You get a solid chunk of lead in a lead-mercury (liquid) alloy.

Make sure that your copper wire is clean. Scrape it with a knife or razor. For the brass coin, sand paper it.

Tip : Heating it will probably increase the rate of dissolution.

Quote: Originally posted by jar-jar  
how to evaporate and collect the mercury?

This is best done with a distillation kit made of iron. Some have done with standard lab glass. The thermal shock will be very high. Don't put water in the condensor. Let it air cool.

Quote: Originally posted by jar-jar  
Also, any metal but iron will create amalgam, right? And is it the same with gallium?

Platinum, tungsten and tantalum. I don't know much about gallium.

Bert - 5-2-2015 at 19:01

No offense is meant by this, BUT:

If you evaporate Mercury from an amalgam, you will likely hurt yourself. I wouldn't distill Mercury, and I DID pay attention in HS chemistry.

There are other ways: Casting, sintering powdered metals-

If you own a microwave, you've got a heat source for a home made kiln/furnace that can smelt metals to cast Silver, Tin, Copper bronzes- Cupro Nickel, I don't know.

https://m.youtube.com/watch?v=ZJvCuGmRWL8

blogfast25 - 5-2-2015 at 19:42

Nice vid, Bert. My experience with a fireclay/perlite charcoal fired furnace is that that ad hoc refractory doesn't last for very long. Cheap and easy compared to 'real' refractories, though...

[Edited on 6-2-2015 by blogfast25]