Chemical Forums
Specialty Chemistry Forums => Citizen Chemist => Topic started by: Fe$phi on October 08, 2013, 11:59:15 AM
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Hi guys I would like to start extracting precious metals from old electronics or really anything i could find for free how would i go about extracting the metals with what acids and then getting the metals to precipitate, also does anyone have any good ideas where i could find this stuff i was just thinking id go to the dump or something.
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Do you have solid medical insurance?
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yes i do, and i understand I could be working with dangerous acids i have chemistry equipment, and if theres something i need and don't have i have a lab i can go to and use their equipment after hours.
(including a fume hood)
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Look into extracting PMs from dental filling waste. Can get decent amounts this way. Modern electronics do not really contain enough metals to make this worthwhile except in perhaps the industrial slums of asia.
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okay my friend is a dentist I just ask him for the waste and he'll give it to me? and then what method should I use to purify it?
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Getting the waste is up to your social engineering skills.
http://www.sciencemadness.org/talk/viewthread.php?tid=5328&page=2
http://www.sciencemadness.org/talk/viewthread.php?tid=5700&page=2
https://sciencemadness.org/talk/viewthread.php?tid=5700
"I have successfully recovered 34g of pure gold from dental alloys and also the platinum and palladium.
After dissolution in aqua regia, the solution is diluted to make all the AgCl precipitate. The AgCl is boiled with dilute HCl to extract some palladium which has coprecipitated.
The combined solutions are boiled down in a still and evaporated two times with concentrated HCl to ensure that no nitrate ions are left (important).
The gold is then quantitatively precipitated by heating the solution to 80°C and bubbling in sulfur dioxide until no more gold (yellow to brown, crystalline, very dense precipitate) settles out. Don't mess with other reducing agents like dithionite, disulfite, FeSO4 or similar, they intruduce sodium or Fe(III) ions into the solution which will be a nuisance later.
The gold is washed and redissolved in aqua regia, boiled down, evaporated two times with HCl and precipitated by adding oxalic acid in excess, boiling and then slowly neutralizing the solution with ammonia until the solution is colorless.
This purification produces almost 999 fine gold. If gold of certainly 999 fineness is desired, it is redissolved, evaporated with HCl as before and precipitated this time with FeSO4.
The solution from the precipitation of the gold is bubbled with chlorine at room temperature to reoxidise the platinum to IV.
The solution is then boiled for an hour to reduce the oxidised palladium.
Ammonium chloride solution is added, yellow ammonium hexachloroplatinate precipitates which is filtered.
To the solution from before is addedmore ammonium chloride, it is cooled to 10°C and chlorine is bubbled in. Brick-red ammonium hexachloropalladate precipitates. It is rapidly filtered and washed with chlorine- containing NH4Cl solution (not with water!).
If the filtrate is still brown, the treatment with NH4Cl and chlorine and filtering of red precipitate is repeated. "
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okay so i got 3 pellets of amalgam from my dentist, mixed, it sounds like its just a mixture of mercury and silver, so your saying i mix this with aqua regia which is 3 parts hydrochloric acid 1 part nitric acid, then i add water to dilute it? and then i somehow take out the agcl that appears at the bottom(with a wooden spoon??) and put that with water and HCL and palladium appears along with AgCl and i boil that with HCL twice to get rid of all moisture and i get silver and palladium?? it doesnt sound like what i have has any palladium in it, he said its just mercury and silver so could someone please give me a procedure strictly for silver and mercury amalgam to extract the silver and from there ill move on to other extractions?
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I will be working with mercury soon, in small amounts at most a handful at a time, how can i work with it safely and after i have finished with it how can i nullify its effect by making it a harmless compound or storing it in something and also i will be boiling a solution at one point that mercury is in how could i do that safely?
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A handful of Mercury is a lot! 10ml could fit in the palm of your hand, that's 76g.
There are not many "safe" ways to handle mercury, accidental release is a major hazard if you don't have a clean up kit.
What experiment are you planning and what are you hoping to achieve?
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If you want to separate mercury from silver, one method is to directly heat it. I have heard of someone doing this to extract mercury. Of course, the silver left behind won't be pure.
Don't use a wooden spoon. Use glass or polyethylene.
Be careful with Hg salts. They are much more dangerous than metallic Hg.
I think you ends up with mercury salt, dissolved in the water. Silver ions bind with chloride to form the non soluble AgCl. Then, dry the whole thing to get rid of any acids. Add water to redissolve the HgCl2/HgNO3 and then filter to remove the solid AgCl.
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A handful of Mercury is a lot! 10ml could fit in the palm of your hand, that's 76g.
135 g
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usually, mercury is to be stored in airtight sealed glassware
you'd prefer to work with mercury in a ventilated hood.
If not available, I personally would go outside and work there, if possible: just to prevent contamination inside (which usually is much more difficult to handle)
try to avoid any spill whatsoever
take precautions that this might happen anyway: work in a drip pan, if possible, to catch up spill
try to collect spill and put it back into storage (large balls of mercury , for example)
if available, make use of a mercury collector device to pick up spill:
(http://www.phywe.de/images/43600_00.jpg)
(from: link (http://www.phywe.de/51/pid/9856/Quecksilberzange-.htm))
(available at some 10 bucks or so )
if you'd have "unclean " material contaminated with mercury remaining (or surfaces that are difficult to clean thereof: "black" strains...) , use powdered sulfur, apply it in a thin layer ...and wait.
It might take like a week or so, but after that, mercury sulfide should have formed.
this still is toxic, yes, but it isn't that voilatile anymore.
you now can collect it, and forward this sulfur / mercurysulfide to an accredited disposal
regards
Ingo
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A handful of Mercury is a lot! 10ml could fit in the palm of your hand, that's 76g.
135 g
Oh dear, yes it's density is 13.5 g/cm3, my apologies.
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thats awesome thanks man that makes a lot of sense to me, the only thing im still confused about is where the NO3 comes from?
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I plan to extract Ag from amalgam and will be producing HgCl and HgNO3 in side reactions and so like are gloves enough? if so what kind of gloves if not what else do i need for my personal protection i dont plan to spill any of this and if i do i will be working in a lab so i can set up a drip pan and other precautions.
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so you won't be working with elementary mercury at all, but with one of it's alloys?
how exactly will you try to "extract" the silver from the alloy?
regards
Ingo
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i thought it would be elemental because right now i have amalgam tablets (3) which are silver and mercury mixed so i will be mixing that with HCl and producing AgCl and HgCl (and maybe HgNO3???) i will then dry this and get just those two salts then ill add water and the Hg ones will dissolve, ill filter this through a filter paper(thats good right?) and then ill dry both individually so ill have separated the mercury and silver salts
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I plan to extract Ag from amalgam and will be producing HgCl and HgNO3 in side reactions and so like are gloves enough? if so what kind of gloves if not what else do i need for my personal protection i dont plan to spill any of this and if i do i will be working in a lab so i can set up a drip pan and other precautions.
So compounds of mercury, some of which are very soluble in water? No. Gloves aren't enough. At least not how you describe it --"so like are gloves enough?" You'll need the proper gloves, rated specifically for these particular chemicals by the manufacturer. A prominent mercury chemist poisoned herself using gloves that she thought were OK, but in fact, weren't resistant enough to organomercury compounds. We have casually mentioned the need for other engineering controls -- like externally ventilated hoods.
Simply put, your proposed procedure, is a cute thought experiment, but isn't appropriate for a "Citizen Chemist" manipulation.
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i thought it would be elemental because right now i have amalgam tablets (3) which are silver and mercury mixed so i will be mixing that with HCl and producing AgCl and HgCl (and maybe HgNO3???) i will then dry this and get just those two salts then ill add water and the Hg ones will dissolve, ill filter this through a filter paper(thats good right?) and then ill dry both individually so ill have separated the mercury and silver salts
asides from what the colleagues already mentioned:
you won' t get nitrates if you don't use nitric acid additionally.
however, using conc. nitric acid / hydrochloric acid as a mix ( which, if memory serves, is required to "break" the Hg-Ag-and then some - alloy , else, with pure HCl, next to nothing will happen) you will have nitroxides as side products, which are voilatile from the solution, and deadly poisenous.
:rarrow: definitively not something you wish to do without proper precautions ! this might quickly become suicidal!
and, having noted your other thread: Ag goes at US-$ 22,62 / oz.tr. these days
calculate like 25% by weight, typical, of silver in this dental alloy
calculate your costs , incl. further mercury salt modification / disposal
is this really worth your time?
regards
Ingo
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if i do i will be working in a lab so i can set up a drip pan and other precautions.
@Fe$phi
are you doing this in a home lab or are you taking it to a regular lab with hood etc.
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@billnotgates i plan to use a fume hood and at my school lab
@Arkcon i apologize i put it in here because though i am a student this is what i do in my free time i have chemistry equipment and what i don't have(like a fumehood) i can use at my school
@magician4 okay that makes sense one person mentioned using aqua regia but then someone else said i only needed HCl and yes it is worth it because if i can make the mercury harmless then i can get paid to take the dental waste and also get the silver from the dental waste
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These 2 threads are combined since the process of making precious metals selected creates mercury which needs to be dealt with
An additional note
@Fe$phi
We at Chemical Forums only want to make sure you stay safe.
As a citizen scientist we are not always knowledgeable about all the different things that can go wrong when doing an experiment.
You seem to be taking the correct steps by doing your project at a school that has facilities.
I wish you good fortune and hope this works for you but
STAY SAFE
That being said you might enlist not only the help here but also staff and teachers at the school to make sure all is safe.
Regards bill
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Thinking about this, once someone has a lump of gold or silver what do you do with it.
Go to the your favorite jeweler and sell it to them?
And, can we also sell the mercury to some entity?
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the silver or gold yes theres a place by my house and i will compare it with online prices and see which is better and for the mercury i dont know about selling it but i know if i can make it harmless that process actually is what the dentists normally pay for so it can be disposed of correctly
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Mercury disposal is extremely expensive, also although this sounds obvious Mercury is Mercury all you can do is change it's oxidation state.
You may find the cost of disposing of aqueous (or solid) mercury waste far exceeds the profit from selling the silver and what the dentists are paying you.
I would look into the logistics and cost of waste disposal by an authorised company before you start or you may be out of pocket by a considerable sum.
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i know if i can make it harmless that process actually is what the dentists normally pay for so it can be disposed of correctly
That's a bit naïve. You know almost nothing about chemistry, yet you assume with a random advice from some chemistry forum visitors you can design a process that will be economically competitive on the existing market? Don't you think people with much more knowledge already did their best to refine their procedures to make them as cheap as possible? Have you checked what are the local regulations? Or is your plan to get arrested for running an illegal lab dealing with heavy metal waste and pay a hefty fine? (That won't make you more competitive price wise, you know).
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@Arkcon i apologize i put it in here because though i am a student this is what i do in my free time i have chemistry equipment and what i don't have(like a fumehood) i can use at my school
Awesome. By all means, consolidate your plans into a proposal, and submit it to your school. I guarantee you they will never allow you to:
-- do things you barely understand
-- make money for yourself with their facility
-- generate liters of toxic waste in their facility, that they are responsible for
You don't have a fume hood, and you're not going to just "get" one. So when we tell you to use a fume hood, and you say, "got it", and people in this thread give you more dangerous procedures, I'm going to assume you're just going to say "yeah, yeah", then do them outside, with dish washing gloves, and a handkerchief tied over your nose.
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There is a lot of talk about disposal but what does that mean? I don't get it. Isn't mercury a wanted element? There are billions of fluorescent tubes being made. A lot of amateur chemist want to have some.
Personally, I payed a lot of money to buy 250 g of mercury. I don't consider it an element to be disposed of.
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@ Arkcon: the school has a fumehood is why i said got it
@ Borek: im not doing something illegal i would be performing the procedures in a lab at my school with teachers very with very small amounts and if all went well and i could do it then i would look into regulations other places than my school i could perform it and things like that but your all thinking well if you cant make money then dont try it im thinking well cant do it than dont try and make money this was suggested to me by someone answering my question on how could i start using chemistry to make money aside from working for a company
@ vmelkon: pure mercury right? not a compound? so after u see if i can do this then maybe ill look into extracting mercury rather than disposing of it, whichever is cheaper
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There is a lot of talk about disposal but what does that mean? I don't get it. Isn't mercury a wanted element?
define "wanted"
to the best of my knowledge, trade in mercury is very very low, and this metal isn't even a commodity in stock exchange, just OTC business, if you know what I mean.
however, there are inofficial "observations" of those trades, and by that , we know that world market prices for this are in the ballpark of 100 US-$ / kg
the only "huge" legal demands I am aware of is light bulbs industries and gold mining, and both are in need for extremely clean Hg, for obvious reasons.
with your scrap, to become a supplier to those companies offering clean Hg to the market ( and hence are certified, trustworthy ... you name it), that's where your problems come from - if you had it.
...and I doubt that Fe$phi will gain anything even remotely like it
regards
Ingo
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the only "huge" legal demands I am aware of is light bulbs industries and gold mining, and both are in need for extremely clean Hg, for obvious reasons.
There's a small use in contacts for relays and such I think. Not sure if that's banned now.
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so basically this is too advanced for me and if i could i wouldn't make much profit so i guess i can accept that thanks everyone
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If you want to separate mercury from silver, one method is to directly heat it. I have heard of someone doing this to extract mercury...
Just make sure you hold your breath...
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Mercury is commonly purified by distillation. Or at least it was back in early nineties when I worked with electrochemists using mercury electrodes.
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Mercury is commonly purified by distillation. Or at least it was back in early nineties when I worked with electrochemists using mercury electrodes.
You'd have to be as mad as a hatter to distil mercury. ;)
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If you don't know how, and if you don't have equipment - no doubt about it. But we are talking about a university lab, with a trained technician working in a room that was not used for anything else.
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If you don't know how, and if you don't have equipment - no doubt about it. But we are talking about a university lab, with a trained technician working in a room that was not used for anything else.
@Borek
Apologies if you know already, otherwise googling the origins of the phrase "mad as a hatter" might be fun..
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Apologies if you know already, otherwise googling the origins of the phrase "mad as a hatter" might be fun..
Good one, didn't know :) Joke was wasted on me :(
I always thought "mad as a hatter" is after the hatter from Alice in Wonderland, but apparently in the book it already alludes to an earlier saying.
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Apologies if you know already, otherwise googling the origins of the phrase "mad as a hatter" might be fun..
Good one, didn't know :) Joke was wasted on me :(
I always thought "mad as a hatter" is after the hatter from Alice in Wonderland, but apparently in the book it already alludes to an earlier saying.
It may not even be to do with felting...