Mercury retort

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heavymetal

Active member
Joined
Jun 28, 2007
Messages
27
Location
Georgia
Anybody know how to make a mercury retort? Had a guy supposed to make me one but he seems to have stolen my money. Trying to get it back but never returns my calls or answers them. He's in cali i'm in georgia so can't just go over to his house.
 
I've built a retort------but I also have equipment at my disposal.

Do you have access to machining and welding equipment? A retort isn't something you should cobble together-----your health is in the balance.

Harold
 
I think i do, father-in-law works for a sign company, know they have welding, pretty sure they have machining equip to make the signs with.
 
A retort is nothing but a simple still. A chamber that is sealed, and can be heated, with an outlet tube that is cooled to condense the mercury. If you'd like, I may be able to provide a rather poor picture of the one I built many years ago. It's very simple in design, and worked well.

It was machined from stainless, which turns out to be not the best choice. Mercury in intimate contact with the bottom of the retort had a tendency to dissolve the stainless to some degree. I ended up using a layer of thin asbestos paper in the bottom for each charge, which is best avoided.

If all you're doing is distilling existing mercury, that may not be a problem. I was heating my retort to a dull red heat to extract mercury from dental amalgam, which required super heating in order to remove it totally. The higher temperature certainly played a role in the erosion.

If you're handy with wood, and can make a pattern, having one cast in ductile iron would be the best of all worlds. The lid would need to be machined, as well as the face of the body, then proper clamps made to hold it closed while in use. If I was to build another, that's exactly how I'd build it. The clamps and screws could be made of stainless, which would limit long term corrosion.

It's important that any retort you use have the ability to be sealed totally----to avoid any vapors that might escape. I used to use an asbestos gasket between the lid and body to insure there was no leakage. It lasted for a few repetitions, then had to be replaced.

Ductile iron withstands thermal and mechanical shock considerably better than gray iron, which is the reason I recommend its use.

You likely don't need me to tell you to be careful with mercury----as I'm sure you would. It can cause serious health problems, and even lead to death.

Harold
 
Here's the picture (sorry about the poor quality----it was cropped from a larger picture of not great quality) of the small retort I built years ago. It's real simple-----the body diameter is about 4", with a flanged top, maybe 5" diameter. A larger size isn't real important unless you have a lot of material to process on a repeat basis. You can process a serious amount of material with one that size.

I don't recall the capacity, but the pot holds a couple of cups, maybe three. So you get an idea of size, the condensing tube is ½" diameter stainless, and the cooling tube that you see on the condensing tube was made from 2" stainless tubing. There's a couple thin stainless plates on each end that are silver soldered to the tubes, plus two fittings for water inlet and egress. I used 3/8" vinyl hose for the water supply. and a small pump to re-circulate water from a bucket. You could use tap water and run it to waste, but you'd waste a lot of water. Water should be introduced to the bottom fitting and allowed to overflow from the top fitting, assuring that the cooling chamber is always filled with water. You'll notice a fabric boot on the end of the condensing tube. You use that, slightly submerged in water, so if under some strange circumstance the retort pulls a vacuum, it allows air to be pulled, plus by keeping it only slightly submerged in water, it runs out of water before enough enters the tube to fill the retort.

The retort is held together by a half dozen C type clamps, made from stainless, drilled and tapped ¼"-20, with stainless hex head cap screws. It's important that an anti-seize agent be used to prevent the screws from galling to the clamps.

Do not make a retort from steel-----it will oxidize rapidly and render itself useless in short order. Ductile or gray iron will hold up much better, with ductile being the better choice because it has greater ductility and can be welded easier. It's important to have a metal lathe and mill at your disposal if you intend to build one. I can also answer any questions you may have. I've held back on details so it won't bore you to tears.

Harold
 
Thank you for the info and pic. Still looking for several things to try. The mercury sn't going no where and i will come into more as i dredge the waters of n georgia.
 
Harold, Would a preasure cooker with the pop off valve removed and a coupling screwed in where it was with Stainless tubing for a condensor work.

Just a thought.
 
Considering the ramifications of one that works improperly (leaking mercury vapors), plus the fact that you must heat the mercury to temperatures that will compromise the integrity of the aluminum pressure cooker, coupled with the possibility of aluminum being soluble in mercury, I'd suggest it's not a good idea.

Harold
 
They make them in stainless to. I would think that with a good seal for canning, that they should not leak. I tried. lol
 
The problem would come with the overheating the cooker, even if it's stainless. The temperatures involved in the process would destroy the seal, which is my main concern. I heated my retort to redness, but even if you didn't run one that hot, you do run them above 500° F, and I'm not convinced there's a seal made that will withstand the temperature. Even Teflon won't tolerate constant 500°, and I don't think anyone is making Teflon seals.

There's too much at stake here to use questionable procedures----it would truly be playing Russian Roulette. A retort need not be expensive, but it should be purpose built (so the features that are important don't fail), not clooged from something similar.

Harold
 
Please Do Not use/store ??? Mercury in Aluminum anything!
In 1981, while dredging on the Middle Fork of the Yuba River in Calif., I had to be especialy carefull when I started to hit Mercury in the gravels as it would EAT/amalgamate holes in the AL slucebox. I believe this happened because the Al Oxide, that usually protects Al from harm, is scoured off by the sand and gravel. The river could have had a higher or lower ph than 7 and contributed to the problem, I don't know answer to this as my pressing problem was solved. I solved it by sucking up the Mg with my Sniffter Bottle ever time I saw Mg being sucked up the dredge nozzle. I didn't seem to have any problem under the main riffles and matting on the box.
Hope this helps with question about using Al to retort Mg in.
PS At this time in my life I was Living off Gold Dredging!
 
if you want information on how to build a still from stainless go to this website although it doesn't pertain to gold refining it does have alot of information about still making/makers in "Australia" (legal to distill down under)

http://www.homedistiller.org/

and don't forget to check the forum over their
 
Mercury "eats" through Aluminum.
Most aluminum will have a layer of aluminum oxide on it because it has been exposed to air, but mercury amalgamates with pure aluminum, so even if there's the tiniest of scratches on the aluminum, then the mercury will amalgamate with it and expel it when it becomes aluminum oxide, exposing more fresh aluminum to which it can amalgamate.
process repeats....
 
I can confirm Lost Adams' and OMG's warning about Aluminum.

I have an Aviation background (military and civilian).

Mercury is absolutely prohibited in all aircraft. Not "maybe, if..." or "unless..." but Absolutely, no exceptions
prohibited
.

The reason is that if even the smallest mercury spill were to occur, the loose mercury will eventually contact the Aluminum structure (or skin) and will amalgamate (thus weakening) that Aluminum -- with catostrophic results.[/u][/i]
 
JOE S (INDY) said:
I can confirm Lost Adams' and OMG's warning about Aluminum.

I have an Aviation background (military and civilian).

Mercury is absolutely prohibited in all aircraft. Not "maybe, if..." or "unless..." but Absolutely, no exceptions
prohibited
.

The reason is that if even the smallest mercury spill were to occur, the loose mercury will eventually contact the Aluminum structure (or skin) and will amalgamate (thus weakening) that Aluminum -- with catostrophic results.[/u][/i]

During WWII, British SOE issued a Mercury 'crayon' to their field agents. It was supposedly was to be used to sabotage German aircraft on the ground by weakening the area where the 'crayon' was applied.

A number of years ago, I tested the effect of Mercury on aluminum sheet, and it did indeed make it very brittle where the Mercury was applied.
 
Mercury and gallium metal and salts are both devastating to aluminum. They are also catalytic in their effect. I use mercuric nitrate solution for making aluminum oxide, quite frequently.


Here's a link to an interesting article:

http://theodoregray.com/PeriodicTable/PopularScience/2004/10/1/index.html
 
Hi Folks
I have read this thread

I have been to google to get more info on this subject

Here is idea 1

http://practicalaction.org/practicalanswers/product_info.php?products_id=281

Here is idea 2
Hoke book page 189 is a picture of a retort

more ideas
http://www.sepor.com/new/retfrn.pdf?sepor=7386e4e25cff0507e77955c7c4385a70
http://www.machineryandequipment.com/pdfs/S731832.pdf




Hoke talks about using potatoes
I really didn't understand that very much
Maybe if I read it another day it will make sense

Hoke suggests using a cast iron retort
coated with chalk or painted with thin paste of clay


Hi Harold I read about your retort you use stainless stell and you say it wasnt the best choice
Maybe we could post that picture of the diagram again because its not possible to see it now

How about ready made retorts

There was a company selling mining equpiment that Raplh posted once
I cant find it now
Maybe they will have something ready
Thanks
 
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