Sulaiman
International Hazard
Posts: 3734
Registered: 8-2-2015
Location: 3rd rock from the sun
Member Is Offline
|
|
? How to recover waste mercury compounds ?
Sometime later this year I intend to do a little chemistry with mercury and its compounds,
if I can confidently recover the mercury after experimenting,
as I want negligible mercury environmental pollution.
I intend to have a mercury waste container and a still for final stages of purification,
but I do not have the experience to know what are the general requirements for mercury recovery,
if there are any.
Anyone here have experience of mercury recovery from amalgams and compounds that can advise me in advance ?
CAUTION : Hobby Chemist, not Professional or even Amateur
|
|
|
j_sum1
Administrator
Posts: 6337
Registered: 4-10-2014
Location: At home
Member Is Offline
Mood: Most of the ducks are in a row
|
|
This offering from NileRed is probably useful.
https://www.youtube.com/watch?v=S4T57SFntIs
Cody's lab has lots on Hg including recovery of metallic. (Ignore the loo flush. It ain't worth it.) He also has an early one where he cleans up a
mercury spill. I don't think he is that cautious any more. But that video demonstrates good practice.
|
|
|
Sulaiman
International Hazard
Posts: 3734
Registered: 8-2-2015
Location: 3rd rock from the sun
Member Is Offline
|
|
I have already watched almost all of Nile Red's videos 
I will see how the final stages of mercury recovery turn out.
I like the 'general' approach of converting all mercury to a single compound (HgS in this case) then processing that.
What I am considering is very difficult ... near 100% yield
as anything else = toxic waste.
I am hoping for something simple and universal like
' all mercury compounds and/or amalgams yield elementary mercury when ...... '
or some such simple approach.
As mercury and its salts are now 'illegal' here in UK
I assume that there are probably no convenient mercury recycling/waste facilities available to me,
so 99.9...% recovery is the only option that will allow me to experiment.
CAUTION : Hobby Chemist, not Professional or even Amateur
|
|
|
Amos
International Hazard
Posts: 1406
Registered: 25-3-2014
Location: Yes
Member Is Offline
Mood: No
|
|
Mercury that is in solution can be converted back to metallic mercury with more reactive metals; placing these solutions over a considerable piece of
copper wire should be pretty selective for mercury as copper is only capable of displacing a few metal ions in single replacement reactions.
Aluminium, iron in the form of steel wool, or zinc can all work too. If the mercury thus precipitated is dirty (which is likely if a high-surface area
metal source like aluminium foil or steel wool was used), it can likely be cleaned pretty effectively by prolonged stirring with hydrochloric acid or
sodium hydroxide solution, as these are reactive toward many metals but not toward mercury itself.
|
|
|
MrHomeScientist
International Hazard
Posts: 1806
Registered: 24-10-2010
Location: Flerovium
Member Is Offline
Mood: No Mood
|
|
I believe mercury amalgamates with copper though, or at least sticks to it. My dad used to coat copper pennies with Hg back in his school days. I
would use iron instead since that's what Hg flasks are made of, so compatibility won't be an issue.
|
|
|
Lefaucheux10
Harmless
Posts: 30
Registered: 28-8-2016
Member Is Offline
Mood: No Mood
|
|
Iron is one of the only metal wich dont amalgamated with mercury :/
|
|
|
MeshPL
Hazard to Others
Posts: 329
Registered: 20-4-2015
Location: Universe
Member Is Offline
Mood: No Mood
|
|
There are bunch of others, by example platinum group metals don't alloy with mercury... there are more like this: tungsten is another example.
|
|
|
Metacelsus
International Hazard
Posts: 2542
Registered: 26-12-2012
Location: Boston, MA
Member Is Offline
Mood: Double, double, toil and trouble
|
|
I've heard sulfur is good for cleaning up mercury spills. It reacts with mercury to form the insoluble sulfide. However, it wouldn't be very useful if
you wanted to recover metallic mercury.
|
|
|
Melgar
Anti-Spam Agent
Posts: 2004
Registered: 23-2-2010
Location: Connecticut
Member Is Offline
Mood: Estrified
|
|
If mercury is illegal in Britain, then I suppose you could always say that you found some in the course of working on some antique machine, and felt
it was your civic duty to turn it in to the proper authorities. If they suspect that you're doing it too often, I suppose you could insist that every
time you find even a drop, you immediately stop what you're doing to turn it in, insisting that you wouldn't want to store it, because that's illegal.
|
|
|
![[*]](images/xpblue/default_icon.gif){kind=icon}
