# Help with sweeps



## Rickthenewb (Nov 29, 2010)

Hi all, I currently have over 140 oz of mercury laden jewelry scrap. I bought a retort and am looking forward to using it. I have a couple questions. Is the retort supposed to get hot enough to melt the melt or just vaporize the mercury. Also the sweeps are made up of less then 1 percent mercury, 7% gold, 1%Pt, 34%silver, 28% Cu and over 30% of an unknown metal. I am wondering the best way to attack this. Any help will be appreciated. Thank you



rick


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## aflacglobal (Nov 29, 2010)

http://www.goldrefiningforum.com/phpBB3/viewtopic.php?f=56&t=661

http://goldrefiningforum.com/~goldrefi/phpBB3/viewtopic.php?t=1253&start=0&postdays=0&postorder=asc&highlight=


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## Harold_V (Nov 30, 2010)

Sweeps that contain mercury are sure to be troublesome. When you attempt to retort, the included waxes and oils are going to be a problem, but I see no way around the process unless you digest the lot in sodium hydroxide (lye). 

I advise you do your retorting in a room with positive evacuation of atmosphere, to insure you do not breath any vapors. I'm even more inclined to suggest you refuse to process the material, especially if you have no experience with retorts. Dying from breathing mercury vapors to recover some values isn't my idea of a good deal. 

Avoid working with mercury unless you have no other options. How it came to be mixed with that kind of waste is a mystery to me----it has no place in refining precious metals. It is not advised for recovery of metals, either, although that hasn't stopped many from the pursuit. 

In my estimation, the only material that a refiner should face that contains mercury would be dental waste. It should be handled with due respect, for the reasons mentioned, above. 

Harold


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## Rickthenewb (Nov 30, 2010)

Thank you Harold I appreciate the concern and understand the danger, the reason for this endeavor is I have a supplier who has a lot of antique jewelery sweeps (pre 1930's), it is my understanding that jewelry this old tends to have small amounts of mercury that came from the ore itself. I have a very good fume hood that I just had built with a very strong fan. Plus I have mercury cartridges for my face mask as an extra precaution. The percentage that I am charging is very good and there is much more of this stuff available. I though it would be worth it to have a small niche that most refiners do not want to attempt. I appreciate the help, I am just going to buy a book on the subject and I'll let you guys know my results. Any pointers are still welcome 


rick


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## nickvc (Nov 30, 2010)

The only mercury I can think of that was used in jewellery manufacturing was in the fire gilding process where the operators had a very short life expectancy.
Mercury and fine gold powder was mixed painted onto the items and then heated to vaporise the mercury leaving that rich gold colour seen on antique jewellery, this was used in the Victoian era and before but I'm fairly sure it would have died out by the 1930,s.
Are you sure there's mercury there? If your going to treat the sweeps your going to have to incinerate them and that's going to give off mercury vapours....not good! 
The only other reason I can see for mercury been there is if someone misguidedly tried to use it to recover the gold.


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## Backroads (Nov 30, 2010)

Rickthenewb

Sounds like your prepared for the mercury, I did'nt know they made mercury specific cartridges . . .I'm not sure if this has been mentioned, but standard repirators with activated charcoal filters, can have they're life extended, by keeping the respirator in a sealed tupperware container when not in use. I'm not familiar with the mercury cartridges though.
Having seen end stage, Alzhiemers disease I'm more afraid of what mercury does to the nervous system. "Mad as a Hatter" came from hatmakers, working with mercury, eons ago . . .I'm not so much afraid to die, as afraid to die horribly . . .just my two cents

Good Luck, Tim


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## Harold_V (Dec 1, 2010)

Rickthenewb said:


> Thank you Harold I appreciate the concern and understand the danger, the reason for this endeavor is I have a supplier who has a lot of antique jewelery sweeps (pre 1930's), it is my understanding that jewelry this old tends to have small amounts of mercury that came from the ore itself.


That's insane. Mercury vaporizes at a temperature well below the melting point of gold. If there's mercury present, it must have come from a different source. 

I processed jeweler's wastes on a daily basis, and know how lucrative they can be. I hope I didn't sound like I was trying to discourage you, for that wasn't the case. 

It might be wise to determine if the material really does contain mercury. I can't imagine how it might be there through normal channels. Anyone that has worked with gold understands how destructive it is to include mercury unless they used it for extraction from ores. 

Harold


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## dtectr (Dec 1, 2010)

nickvc said:


> The only other reason I can see for mercury been there is if someone misguidedly tried to use it to recover the gold.


that's my guess as well - someone at some point got a hold of some mercury & thought they'd just bypass that 'old crook refiner' 
& probably recovered SOME values, but like stated earlier, is probably drooling somewhere with a cork on the end of his fork.

I shiver when i still read of someone using/reccomending the Irish potatoe retort used by the old-time prospectors :shock: :roll: :shock:


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## goldsilverpro (Dec 1, 2010)

I agree with nick that it could be from fire gilding. A lot of those old techniques were still practiced by a few after they went out of vogue. Also, in this article, it seems like it might still be used, albeit rarely, for antique repairs when trying to duplicate the original technique used and the appearance. In fact, the author seems to be promoting it as a possible part of the jeweler's arsenal.

http://www.ganoksin.com/borisat/nenam/fire_gilding-9-3.htm


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## Rickthenewb (Dec 1, 2010)

I bought these on ebay last week
http://cgi.ebay.com/MERCURY-RETORT-GOLD-RECOVERY-/260678473353?pt=LH_DefaultDomain_0&hash=item3cb1a5d689
More work is needed on the fume hood, i am adding FRP and a plastic fan next week, then I believe I am ready to go.
If you think I need more please let me know.


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## Oz (Dec 1, 2010)

The mercury content could also come from gold jewelry that was accidentally exposed to mercury while it was worn. Once brought to a jeweler for repair, parts or all of the piece were put on the scrap pile.


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## Backroads (Dec 1, 2010)

> This is my fume hood



square, level, and plumb . . .

nothin half-a$$ed there! 

(ahhhhh . .I need a thumbs up smiley . . .)

Nice Carpentry!!!


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## nickvc (Dec 2, 2010)

goldsilverpro said:


> I agree with nick that it could be from fire gilding. A lot of those old techniques were still practiced by a few after they went out of vogue. Also, in this article, it seems like it might still be used, albeit rarely, for antique repairs when trying to duplicate the original technique used and the appearance. In fact, the author seems to be promoting it as a possible part of the jeweler's arsenal.
> 
> http://www.ganoksin.com/borisat/nenam/fire_gilding-9-3.htm



GSP the only place that I ever heard of that still used this process was in Switzerland of all places, and very expensive, which really isnt too surprising given the risks..


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## Palladium (Dec 2, 2010)

I have no knowledge in that field what so ever. I read that article with great interest and thought. I do have to say that somewhere in all that i get this OMG !!! feeling. They just talk to much about mercury this, vapor that and if im not mistaken i think that dude used the word brain damage. I'm telling you, I just can't afford to lose any more brain cells. I think of the people who don't use the proper safety precautions. As much as i practiced what i thought was proper safety practices that were thought of in the day to be the quality industry standards when i applied specialty coatings back when is was in my early 20's. I followed all the guidelines. Even with the proper training and the minimal exposure i had to the chemicals 20 years ago that would be where my cancer can be traced to. Point is i shiver when i think of procedures like that and the people who practice that trade.

Makes you wonder, How safe is really safe ??????


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## Rickthenewb (Dec 3, 2010)

This may sound really amateur but couldn't I just wash the sweeps in some type of detergent to clean the grease and oil off?


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## Barren Realms 007 (Dec 3, 2010)

Rickthenewb said:


> This may sound really amateur but couldn't I just wash the sweeps in some type of detergent to clean the grease and oil off?



Nope, you will still have traces along with traces of the detergent or soap you use.


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## Rickthenewb (Dec 3, 2010)

So this is going to pose a problem, I have to retort the mercury out but I also have to burn off the grease. will Mercury retort at a temperature lower than the incineration of the grease?


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## Barren Realms 007 (Dec 3, 2010)

That is something I am not sure of because I have not looked into the process that much.


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## Harold_V (Dec 3, 2010)

Rickthenewb said:


> So this is going to pose a problem, I have to retort the mercury out but I also have to burn off the grease. will Mercury retort at a temperature lower than the incineration of the grease?


Let me be clear. When I read your first post, my head wrapped around the word sweep instead of scrap. 

No, I don't know how I did that (it was not a part of your post), but it's not something I haven't done before. Some folks may consider me a bit of a moron. Sorry for the confusion.

Ok, lets get back to the subject at hand. 

I expect you are talking about bits of gold, or even entire objects made of gold, commonly called jewelry. Lets go with that for the moment. 

You can place them in a container of ammonia for a brief soak, which will remove oils and waxes (still to be found, but in far lower volume than my original thoughts). Most people don't clean their jewelry, so it's rather funky. My wife is likely the only exception I know. I'll provide a second choice, below. 

When you heat to remove mercury (using a retort), my experience (processing dental amalgam only) was that there will always be a trace that does not get eliminated. You can minimize that problem by raising the temperature of the retort to the point where the condensing tube and all areas beneath it are beyond the evaporation point of mercury.

Now that I have my head out of that dark place, know that you can simply retort the material you have without cleaning. Expect it to stink a little---and maybe even to condense a little oil in the recovery---but it will work adequately. If you'd like to clean it so there is no odor, if you have access to some lye, that will do a perfect job. Rinse well after cleaning. You should now be residue free. 

The condition I speak of was so horrible when running dental amalgam that I ran it under my large melting furnace hood, and had a strong detergent in the container where mercury accumulated. The smell was akin to that of burning your neighbor's dog.

Do use extreme care when retorting. Insure that the retort has a perfect seal.

Harold


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## Barren Realms 007 (Dec 3, 2010)

I did the same thing you did Harold...


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## Rickthenewb (Dec 7, 2010)

These are the two types of sweeps I have, I have never worked with sweeps before. Is this what they usually look like?


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## Harold_V (Dec 8, 2010)

It might help to disclose the source of your "sweeps". 

The top picture looks as if it is most likely alloy used in creating karat gold. It is sold in shot of various sizes, just as your picture depicts. If it is, it won't contain any gold, but it likely has silver, assuming it's not white in color. If it is, it's most likely just nickel. 

Second picture appears to contain some of the alloy as well, but it also resembles silver amalgam. The picture is too fuzzy and off color to make any determinations. 

The term "sweeps" is often misused. Sweeps, to some, are the filings from the work bench. To others, they are exactly what it sounds like--sweeps from the floor. They contain hair, saw blades, gold filings, fine dirt, bits of one's sandwich, and the list goes on. 

If you can be more specific, you may receive some guidelines. 

Harold


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## Rickthenewb (Dec 27, 2010)

I am being told it came from a jeweler, also what is the best method to separate these metals.


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## Harold_V (Dec 28, 2010)

Rickthenewb said:


> I am being told it came from a jeweler, also what is the best method to separate these metals.


Before you worry about making any separation, you should determine what you have. You may be spinning your wheels. You will be if I'm right in the assumption that you have alloying metal. It contains no values. It goes by another name----brass. 
Have you read any part of Hoke? If you haven't, please get on with doing so. You're not going to get anywhere stumbling along in the dark, and you can believe me when I tell you that if you ask too many obviously stupid questions (a sure sign you haven't done your homework) you will be largely ignored here. We are willing to help, but you must do your part. There are no magic shortcuts---you must gain an understanding. 

Harold


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## butcher (Dec 31, 2010)

Rick, Harold will give you the best advise, harsh but true, stick with it and you will learn to get that gold pure. welcome to the forum the best place to learn, and any member is willing to help you, but few will refine your gold for nothing, or do your home work, look again at the price of these metals and how hard they are to come by that little bit of study is well worth learning.


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## Rickthenewb (Jan 17, 2011)

ok, so I retorted the mercury from the sweeps and then I dissolved in nitric, I am getting an intense purple solution with the undissolved grit, gold and other metals on the bottom. the mud on the bottom is very difficult to clean as it keeps making more purple solution. What is this purple solution?


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## qst42know (Jan 17, 2011)

Mercury?

Where did the mercury come from?

If you want quality answers you really should include all the facts.

Where did you buy the retort?


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## Harold_V (Jan 18, 2011)

Rickthenewb said:


> ok, so I retorted the mercury from the sweeps and then I dissolved in nitric,


Lets talk about that first. Did you, indeed, recover any mercury? If so, why is it you haven't commented on the board, seeking further advice? 



> What is this purple solution?


Where I come from, it's called one hell of a mess. Had you been forthcoming with information, I could have saved you considerable trouble with this material. Unless you're prepared to make a full disclosure, I'm afraid you're on your own. None of us can provide answers when you refuse to provide needed information.

Harold


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## Rickthenewb (Jan 18, 2011)

I am sorry if I it looks like I am keeping information out but I thought my first post was pretty explanatory, I posted that a metal dealer in my town had some sweeps containing gold, silver, copper, platinum and mercury. I then asked some questions about retorting which were answered and helped me a lot. I even posted pictures of my sweeps along with my retort and my fume hood and the face mask cartridges I was using, then Harold pointed out that should read more on Hokes (which I did several times, and was really helpful). 

So I retorted all of my sweeps and recovered a little over 7 ozs of mercury more than what was said it contained). All the sweeps were retorted for over 3 hours to ensure that the mercury was evacuated. 

I then started dissolving the sweeps in nitric as it says to do in Hokes and I am now left with this purple solution with solids on the bottom, the solution is cloudy though and after further reading I am under the impression that it might be colloidal gold, its a real mess but I have been able to recover the silver out of some of it so far. When if try and clean the powder on the bottom it just keeps making more purple solution, I just want to understand what this is.

I have only dissolved about 1/3 of the sweeps so far and before I continue I thought I would see if there is another way of going about this. 

Again I apologize if I have not given enough information and will gladly give you more if needed.


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## qst42know (Jan 18, 2011)

Sorry I didn't go back far enough in your post. Completly spaced on the first page.


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## Harold_V (Jan 19, 2011)

Ok, if I was out of line with my comments, you have my apology. Thing is, when you've never experienced these things, it's hard to know what to do and keep out of trouble. You would have been much better served to continue to seek at least some advice, as a matter of safety. You're dealing with something that can get you in deep trouble. 

It would have been wise to have contacted the board once you retorted the material, and made it clear that you have removed mercury. That confirms my hunch that the second picture was old dental amalgam. It is rarely without "contamination" by gold and platinum group metals, especially if any of the material came from traps. 

Once retorted, I'm sure you must have noticed that traces of mercury remained on the surface of the retorted material. My procedure was to then incinerate the material in a large stainless (frying) pan, driving it to melting. That may seem an unreal goal, but being alloyed with tin, it melts at a reduced temperature, well below a red heat. Once molten, it would be stirred and allowed to oxidize. Removing from heat and continued stirring yields a mass of broken bits of metal, ready for further processing. Use a small diameter steel rod for stirring. Something ¼" in diameter or slgihtly larger will work fine. Don't use anything with a plastic handle---it's likely to melt. Wear a glove to protect your hand. Do not breath any of the smoke and/or fumes. 

This operation is of prime importance, for it allows dissolution of the material in dilute nitric without filtration issue. The solution would come out a pale blue color, and would contain silver along with traces of copper, which are a part of dental amalgam. 

The purple you are experiencing is as you suspected--it's colloidal gold, which can be recovered. The big issue now is if you can filter the material to the point where it can be separated from the dissolved silver. Without the prolonged roast, I'm not convinced you can, so you may have to resort to rinsing and allowing gravity to do the separation. Nothing wrong with that---it just creates more solution that you must deal with. Ultimately, you must end up with the solids in a filter, then they would be incinerated and screened. After that, you'd give them a boil in HCl (yes--a boil---that keeps the solids in suspension, preventing them from forming a hard cake on the bottom of your beaker), Keep the beaker covered with a watch glass. Tap water is acceptable for this operation. This solution should be valueless, but it should be tested with stannous chloride before being discarded. When you have rinsed the material to the point of the rinse water coming off clear of color, you can then dissolve the included values with AR---but very little should be used. The screening process should have separated any pieces large enough to require inquartation. 

You are dealing with waste material that has great potential, and will require diligence on your part to avoid losing values. If you study Hoke, you most likely can deal with everything without assistance, but if you have any questions, post them. I processed a large amount of this type of material and had worked out the kinks that can be troublesome. 

When you incinerate the recovered material from the retort, it's VERY important that you not be where you can breath any of the fumes. There will be traces of mercury present. Do this work in a fume hood. If you have no fume hood, do it on a windy day, with the wind coming from one side or the other---not from your back. That has the potential to curl the vapors and smoke towards you. 

Luck!

Harold


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## Rickthenewb (Apr 6, 2011)

Its been a while on my last post, this sweeps job turned out to be way more then what I was originally told, it had almost 10 times more mercury than I was told as well as a ton of nickel. Very little gold and some silver. I decided to return it to my metals dealer and focus more on the non mercury scrap. Thank you guys for the help you offered, I am sure I will have more fun projects to discuss soon.


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