Where theworld gathers for metal finishing
Q&As since 1989
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Recovering gold from electronics, page 7
June 25, 2008
I've bought the Shor SubZero/Aqua Regia Gold Refining Starter Kit ($55) which included all the consumable supplies needed to refine circuit boards and other gold bearing material. It included Precipitant, Precious Metal detection liquid, ammonia
[on
eBay or
Amazon] detection liquid, urea and the SubZero powder (safer then liquid Nitric/HCL solution).
The acid used in this process is muriatic acid (also known as hydrochloric) acid. This acid is corrosive (see warning label on your bottle). For this reason, this kind of refining is best done outdoors, away from anything that may be damaged by exposure to these fumes.
It must be pointed out that, like most industrial processes, refining gold in acid is quite safe when performed under controlled conditions. In addition, the return of gold, when you refine the material yourself, is 10 times the return when sent in to a commercial refining company.
To refine gold with the SubZero Aqua Regia, you will need the following additional items:
=protective clothing--minimum requirement: goggles and rubber gloves.
=muriatic or hydrochloric acid.
= baking soda [on
eBay or
Amazon]
(sodium bicarbonate) to neutralize the acid when finished.
=tap water and distilled water.
=containers for the boards.
Before refining:
Cut off those portions of the board that have gold. Discard the rest. Chips, which have gold inside as well as outside, must be broken open. On a small scale, one tap with a hammer should suffice.
In a glass or plastic container (a 5 gallon, clean white bucket will work well), add 1 lb SubZero to 1 gallon of muriatic or hydrochloric acid. Do not use a metal container. Not all the SubZero will dissolve. This is normal. Do not discard the undissolved SubZero. The undissolved SubZero is required to be in the solution for the gold to complete its dissolution.
Dissolving the gold:
The acid should be at room temperature. Place your boards in a plastic mesh, or plastic wire basket or a plastic mesh bag. The acid has to pass through the basket or bag, so make sure it is either plastic mesh or plastic wire.
Add the basket or bag, with your boards, to the acid solution. The metal will begin to fizz and give off an invisible or slightly brown fume. You can cover the container, but do not seal it tightly because you don't want a built up of gas pressure. You can speed up the process by heating your solution, but this creates added hazard- hot acid fumes more rapidly and is more corrosive. At room temperature, dissolving time is usually between 1 hour and 2 hours. Check the boards to make sure all the gold has been removed and dissolved into the aqua regia acid.
Remove the basket from the acid, taking care not to drip acid anywhere. The aqua regia is not used up yet, so you can use the same acid to dissolve the gold off more boards. You can continue to use this acid, several times, to dissolve the metal off additional boards until it is no longer effective. The acidy boards should be rinsed (with water) in another bucket. Any brown particles are likely to be gold and should be recovered and put into a future refining bath. If you believe that some solid bits have fallen into the solution during dissolving, then (after the acid is no longer effective in dissolving any more metal), you should pour the solution into a different bucket, leaving the solids behind. Any solids left in the solution will contaminate the pure gold you are about to precipitate.
Adjusting the pH & Precipitating the pure gold:
When the aqua regia is no longer effective (no longer dissolves the gold on the boards), it is time to recover the pure gold from the solution.
The acid will be a dark, emerald green color and should be clear, like Coca Cola, not murky or muddy looking (nothing floating inside the dark waters). If the acid is murky, it may contain particles and should be decanted into another bucket or it should be filtered.
Now add a pinch of urea to the dark acid solution. If it fizzes, add additional urea until it no longer fizzes. When there is no longer any fizzing, add 11 tablespoons of Storm Precipitant for every ounce of dissolved metal (dissolved metal content, not just dissolved gold content). Measure out and add the precipitant all at the same time. Immediately, the acid will change to a muddy brown appearance as brown particles of gold form in the acid. This brown "mud" is, despite its appearance, pure gold. If you want to speed the precipitation process, you can add the precipitant to very hot water before adding to the acid. This technique will precipitate the gold in only about 5 minutes (30-120 minutes is normal when not using this technique), but be aware that hot precipitant has a very strong, pungent odor.
Once precipitation is complete, test the acid for the presence of dissolved gold with Precious Metal Detection Liquid.
Testing to make sure no dissolved gold is discarded:
Precious metal detection liquid will detect the presence of dissolved gold, down to 4 parts of gold per million parts of acid, detecting the presence of about 1/1,000th of 1 gram of dissolved gold. Testing for the presence of dissolved gold is absolutely necessary to insure that no dissolved gold is thrown away with the waste acid.
To test, first immerse the end of the stirring rod in the acid. Remove it and touch that end to a paper towel to make a wet spot. Put a drop of gold detection liquid on the wet spot on the paper towel. If any gold is still dissolved in the acid, the wet spot will turn a purple-black or a purple-brown. If you see this color change then give the precipitant more time to work and/or add more precipitant.
Rinsing the pure gold:
The acid should now be a clear, amber or a green color with a brown mud at the bottom. Pour off the acid into another container. If you have a filter, you can use it. Do not pour off any of the mud. The mud is pure gold.
When all the acid is poured off, add tap water to the mud. Stir and let the mud settle. Pour off the water into the container with the acid. If you have a filter, you can use it. Do not pour off any particles of brown. Repeat this rinsing 3-4 times or more.
Testing to insure purity:
Test with aqua ammonia to insure high purity of your gold. Place a drop of aqua ammonia test liquid on the wet gold mud. If you see any change in color to blue, even a very pale blue, rinse and test again.
Give the mud a last rinse, this time with distilled water.
Drying and melting:
Rinse the mud into a beaker [beakers on
eBay or
Amazon] that is made to be heated or into glass coffee pot. Put the beaker or pot on a hot plate to dry the mud. Do not preheat the hot plate or thermal shock may cause the beaker to break.
Melt the dried mud (now a powder). If using a torch, first wrap the powder in tissue paper and then soak that in alcohol. Also, use a Burno crucible. This will keep your gold from being blown away by the gas pressure from the torch. The gold will again take on the appearance of metal. If you've followed the instructions carefully, the gold will be 99.95% pure with virtually no losses.
- Bend, Oregon
June , 2008
Hi, Mark. I appreciate your highly detailed response and I'm sure many of the readers do as well. But nobody should get a pass :-)
The statement that you'll get ten times as much by refining the gold yourself as from a refinery sounds exaggerated. Yes, you could latch up with a questionable refinery, but many times a careful assay is done that says exactly how much gold is in the product and you can clearly see what they are offering to pay per ounce, and it's a lot more than ten percent.
You tell readers to cut the tabs off circuit boards, break open the chips with a hammer in search of gold, and 'discard' the rest. This affirms the claim of so many environmental organizations that amateur recycling is a wrecking ball that scatters toxic waste everywhere.
Finally, these instructions sound applicable only to your own electronics that you may happen to have on hand; because if you buy e-waste, refine it, and sell the metal you are engaging in a regulated business which requires a host of permits and close monitoring by the regulatory authorities.
Thanks again for the great detail!
Regards,
Ted Mooney, P.E.
Striving to live Aloha
finishing.com - Pine Beach, New Jersey
Can somebody tell me if the older computer monitors more gold and other metals than the CPU? I have been ripping apart computer monitors, (understand the lead aspect...doing it safe), and been noticing these circuit boards are huge with little black platinum chips..........I guess anything on the difference of monitors and CPU would be great.
Elroy Kauffman- Fort Carson, Colorado
July 12, 2008
Well after reading all of that mmmm! I've got about a Kg of fingers that I wanted to get the gold out of, but to get hold of all the chemicals is a mission. So can I sell it anyway and what about the actual boards with all the resistors do people buy that to? or is there any money to be made out of this stuff? And to all those out there DANGER. FROM READING THIS PAGE IT SHOULD BE CLEAR...
Jason davis- durban south Africa
August 21, 2008
Dear ted mooney,
If everyone listened to people like you we would never have successful entrepreneurs. Sounds like you don't want to let the secrets out. Give these people more credit than what you are. Everyone came on this site to get information not to be scolded about "chemicals", proper training, and a bunch of other crap.
sincerely
- Jennings, Louisiana
September 20, 2008
Hi, Scott. No, not everyone came to this site already knowing that recovery of metals from e-waste can be dangerous and an environmental problem. Some came here open-minded, having perhaps a loosely formed idea that it might be an interesting hobby or good business, and wanting to hear all sides before deciding whether to go further. They've heard my side and they've heard a lot of other sides. You can tell them your side in detail as long as you cease the slurs, flaming, and ad hominem attacks. BTW, I've been a self-employed entrepreneur for 40 years now.
Regards,
Ted Mooney, P.E.
Striving to live Aloha
finishing.com - Pine Beach, New Jersey
September 21, 2008
I will say this that I worked for years for a company that dealt in used computer and data equip, I would make a weekly trip to Con ED in NYC to pick up their old equip then haul it to Long Island to be dumped in a container for China to be reclaimed. Due to the hazardous nature of this stuff the only place was china to ship to. I have hauled tons of circuit boards to FL for gold extraction then hauled the remains to a shipper for transport to China. This gold salvage is dangerous why not do copper, aluminum etc.
James Ganley- Cushing, Wisconsin
September 21, 2008
hey gold miners guess what if you just burn all the parts you have down to ash then wala
you have ash and steel and copper and GOLD but the steel and other metals are lighter than gold so if you heated your melting pot to the temp it takes to melt gold then take everything out and pan out the gold you can make a simple furnace out of a coffee can some charcoal and 1-2 lbs of air pressure put a hole in the can at the bottom of the can so you can add steady air into the charcoal and add the charcoal around your crucible then put a lid on the crucible set two red bricks on top of the can to cover it, add dirt to cover the whole burning can and bricks let it burn and get hot with 1 lb of air blowing into the can
Let 'er burn for about and hour then shut her down everything is by the way very very hot be careful don't get burnt wear gloves now uncover her and look you have all the metal melted
you have ash,pins,silver,platinum,gold,now what you need to do is smash it all down real fine
then pan out the heavy metals in a gold pan this will separate the steel from the heavies
then you can put the whole thing under water to clean it then you need to fire her back up and melt the gold all together I got 3.3 grams the first time and I SOLD IT TO A JEWELRY STORE AND LOOK DUDES NO CHEMICALS WERE USED AND I GOT A CLEAN BURN.....
hobbyist - OIL CITY, Pennsylvania
October 14, 2008
I have dissolved some scrap/ raw material in aqua regia; now please guide me on how to get back gold and silver from aqua regia. please give me formula.
thanks to u.
scrap - Lahore, Pakistan
October 26, 2008
I recently learned of a fella in Colorado who has discovered a safe way of gold recovery and they have been working on refining the process since April 2008. Search "Amalgamite". Very interesting. I have yet to try it. Came by here in search of what electronic parts might be worthy of salvage. Thank you.
Charlie Little- Mansfield, Arkansas
November 10, 2008
November 18, 2008
Dear Mr Panjala Mukesh,
I would like to know more about gold plating system. What kind of chemical is used to remove gold from electronic part and how to mix this chemical For a liter of chemical to mix how many gram of NaOH,SMNBS and potassium cyanide powder is needed. Thank you in advance for your information.
Regards,
Kash
- GEORGE TOWN, PENANG
I have been dissolving gold plate in mercury from computer contacts and pins for 6 months in a soft sealed glass container...I now have a fair bit of amalgam that I have thought to gravity strain thru coffee filters in the same glass apparatus...any thoughts and any ideas who might save me the time of processing 40-50 lbs of sister boards, memory stix and processor chips?
Alan patruse- Edison, New Jersey
December 26, 2008
Amalgamite process is just bismuth; it will work to get PM's but they all will be together and require further processing. Remember if it sounds too good to be true it probably is. For plated items a sulfuric cell is probably best, for stuff on printed circuit boards side cutters and a band saw to get rid of most of the unwanted material,then an AP bath, a mix of HCl and 3% hydrogen peroxide 3%) [affil links] and a fish tank bubbler,but please do not try this stuff without the proper equipment. and if you use the amalgamate thing please don't do it on the kitchen stove like they say you can. PCB's contain resins and other things that when burned could kill you. unless you have tons of material to work with(computer stuff) karat gold is another matter. your best to dump it on eBay you will usually get more than it's worth anyway and save yourself a headache.
Fan Kemmit- Minot, North Dakota
January 5, 2009
Well people, you have been taken. There is a lot of information on this site, some is good but incomplete, some is just plain BS, and the rest is questionable. You are being blinded with too much information so that you can not sort out what is pertinent from what is not. What this amounts to is that no one wants you to try this, they want to buy your scrap for half of what it's worth and process it themselves. There are many different methods outlined here, some are simple, some are not. If you are going to try this read everything you can find, pick the simplest least toxic method and do only small batches. I have a degree in Chemistry, and can tell you that some of this will work, I was here because I have a small amount of E-trash that I wanted to mine for gold to use in a home smelting operation (your not supposed to do that either). From what I have read here I'll be sending my E-trash to the dump, it's just not worth it. If you decide to go ahead, be very very careful, in my opinion, of all the outlined methods the copper removal method is probably best for home refiners. copper sulphate [on eBay or Amazon] is available in drug stores and in farm supply stores, it is used as a fungicide in vineyards, and to limit algae growth in ponds. Sulfuric acid is available as battery acid [affil links] in automotive parts stores and as acid drain cleaner [on eBay or Amazon] in home improvement stores, be careful and remember never pore water into acid, always pore the acid into the water. The person posting this method left out some details, use a low voltage power supply to remove the copper. A battery charger might work but the power supply from one of the computers your trashing could work. Use a voltage meter to determine which leads are which. You will want the 6 volt leads. Again I haven't tried this, I am expounding on a method listed previously on this site, and adding missing details. This method is described as a copper refining method in the book, "Modern Welding, copyright 2000," and should produce little toxic waste since all components are reusable.
Vern McNew- Cleveland, Arkansas
February 3, 2009
I want to thank Mr. Alcorn for his response. It was exactly what I needed. I have no desire to get myself killed playing with chemicals and electricity, but was trying to figure out how much I could make per board. I have a good mix of low-grade and very high-grade (audio boards with gold-plated connectors) boards, but did not know what to expect money-wise. The only other thing I need to figure out is if there are buyers out there for less than a ton of scrap. I currently have about 2 large boxes to dispose of. Thanks again!
Ralph A.- Dayton, Ohio
February 8, 2009
Hello, Panjala Mukesh.
Are you aware of any companies in India, that will extract gold and other metals from scrapped computer chips, wafers and PCB boards?
Buyer - Navsari, Gujrat India (also US)
March 3, 2009
April 7, 2009
I came to this site for information. A curiosity.
There are people in other countries wanting information on how to reclaim gold. Some on here say it's not worth the risk and effort to make a .40 cent profit, but in some of these countries a .40 cent profit is a good days wage which means you may be able to feed your family one more day.
Others come here thinking they're going to get rich quick. That's highly unlikely. Myself, I'm Disabled and if I can make a few bucks that's great. Especially if it keeps all this stuff out of the dump and get's it recycled.
Some say take it to a recycling point and sell it. It's not worth the risk. The response is they are all crooks and only pay them half what it's worth. How about I bring you scrap electronics that I think has a $1,000 dollars of gold in it and I demand you pay me what it's worth. Then you have to salvage and process this mess with all the risk and now you have a $1,000 dollars worth of gold to sell. All the expense, risk, plus all the other costs including getting rid of the waste product witch you will have to pay for out of pocket. What, You don't want to be the buyer anymore. Also, if I'm the buyer and you come in with a small quantity of stuff, at $20.00 bucks an hour for wage and benefits I've already lost money on the deal, So sure someone with a semi trailer load is going to get the better deal. There's money in the volume. After reading these comments here and learning more about the process I would be glad to get 10% of it's value for what I have laying around knowing it's not being dumped. Unfortunately, in my area you're not allowed to send it to the dump and the alternative is to pay a fee to dispose of it. Like $5 to $10 dollars just for the computer monitor.
Having been to this site I'll be glad just to find a place that would take it off my hands. I also know Quite a few people who have 2 to 4 computers piled in corners that are perfectly good and functional who hate to get rid of them because they do work. Problem is the their way out of date and way to slow and no one wants them. Most can't even be used on the web because they can't be upgrade to function with most web sites. To Slow For The New Software & To Little Memory That Can't Be Upgraded.
What would be a better alternative would be to have a small surcharge to cover reclaim and processing of all the materials involved so none of this stuff has to go to the dump. Also maybe a small $5 deposit so when it's taken to a recycling center you get your deposit back and for those who don't want to bother taking it to the recycler then I'm sure someone else would for the $5 bucks. Unless your the person who thinks he's getting ripped off and wants the $5 dollars back from the person who took it there for you. I'm sure he'll be willing to help you out next time. LOL...
Dave
Hobby - Bushnell, Illinois
The amount of info here is awesome. I wanted to give some of you who just want to get rid of this stuff, but actually have to pay to recycle it an alternative. I work for a major electronics retailer, two word name, and we did not go bankrupt... We offer free electronics recycling, or if a fee is required, we give it back as a gift card. We also have kiosks in every store to recycle batteries, ink cartridges and cell phones. You can also trade in those phones for gift cards on our web site as well.
I have the gold bug... It is infectious. I also am the only child of a chemist. If you think you are doing this safely, you are fooling yourself. Heavy metal poisoning is a TERRIBLE way to die. And those brown fumes one posting describes... they dissipate, but don't disappear. None of this backyard reclamation stuff does. The laws aren't there to keep the small guy down. They are there to keep my kids from getting poisoned by a neighbor. No one wants a meth lab next door to them, and most of what's described here is only less hazardous because the chemist isn't armed. Sell the e-scrap if you have large amounts of boards, etc. to a reputable refiner. Everyone has the cost/benefit screwed up here. Take the money you get and buy Gold Eagles, or maple leafs, or Krugerrands or what ever. That's a safe way to turn this into real gold you can trade on.
clifford vorrier- Valparaiso, Indiana USA
April 16, 2009
May 29, 2009
Mr. Mooney, I agree with Scott from Jennings, Louisiana. And, I now see that you and your company are sponsoring this forum, which explains a lot. We have now all read your warnings about chemistry possibly being dangerous. It, like many other things in life, such as electricity, both deserve and demand "respect". Moreover, knowledgeable recyclers were not born as such. They somewhere along the way learned to ply a trade, which your readers are trying to do. Can you blame them ? So, one, can you now cease with the preaching about the dangers of chemistry since you have now more than over-stated your point(s) ? Two, people have come to this site hoping to find information to help them achieve their goals. However, I agree with Scott, you are either obviously withholding the answers; otherwise, it would appear you don't know them in the first place.
So, what are you fishing for by sponsoring this site ?
Now for my story. I have been trying for somewhat over a year to develop both a working chemical process AND the mechanical processing of both handling and filtering these leaching solutions. When I say "develop" in terms of the chemistry, that basically means trial-and-error experimentation with both the leaching and precipitation techniques that permeate the Internet as well as many books on the subject that do exist out there. One of the things I have learned is that apparently any given technique may or may not work depending on a slew of variables. For example, I have mechanically gleaned the computer PCB's from over 300 computers, disk drives, connectors, etc., etc, and have stripped many components from them such as aluminum heat sinks, fans, batteries, etc. (So, there is NO question that quite a bit of gold is involved.) Like many folks, I use a pre-bath of dilute nitric acid to get many of the base metals out of the picture (including silver and palladium, both of which are totally soluble in nitric acid). I do two other baths which will get rid of the tin paste (metastannic acid [on
eBay or
Amazon]) and as much iron
as possible. (I regard the first of these two baths, one of which I discovered in my own experiments, as my trade secret.) I then use a dilute formula of aqua regia. I then tried using urea to kill the nitric acid oxidation potential (ORP). Then, I used sodium bisulfite to attempt the precipitation. Two (one-gallon) attempts failed. What I now suspect is that either (1) urea does NOT do what many people claim it does, or (2) the involvement of at least 12 metals and other compounds in e-scrap has altered and complicated that issue. Plus, another interesting thing can be found in the book, "Recovery and Refining of Precious Metals" by C.W. Ammen. I have both editions of his book, one of which is quite recent. Actually, what IS interesting IS that NO reference to UREA even exists in either of his books ANYWHERE. Could it be that he knows of what he DOES NOT speak ? Now, I estimate that I have somewhere between 50 to 100 ounces of gold sitting in my 50 gallons of aqua regia. One thought that I have had is that maybe the a/r is still not loaded enough. (Something akin to "critical mass" when one discusses nuclear technology?). Also, full-strength aqua regia is reputed (by Walter Lashley of A.S.A.T. a well-respected organization in Silver City, NM) to hold about 12.5 ounces of gold per gallon. The next thing that I am going to try is Sulfur Dioxide (a very toxic gas) as the precipitator. Mr. Mooney, I will join you (in part) about cautioning your contributors to this forum and it's other readers about chemicals. Folks, please have the proper "R-E-S-P-E-C-T" for the chemicals you use and how you use them. Use the proper rubber gloves [on
eBay or
Amazon], respirators, eye protection goggles [on
eBay or
Amazon], and even chemical protective suits. But, I will also say that life is a gamble. But, with caution and good judgment, you can reduce it to a mere calculated risk. And, if you want to go for the gold, GO FOR IT
!
Mr. Mooney, please note that I am NOT asking you for guidance, advice, recommendations, or anything else. I, too, started reading this forum looking for some answers.
However, I now know I will not find them here. If it takes more experimentation, then so be it. One of my aunts used to say, "Face Facts Fairly". Mr. Mooney, you are not telling anyone anything. And, many of the responders are even loaded with hot air, BS, baloney, and misinformation. And, UNLIKE Mr. Ammen, they DO speak of what they DO NOT know. However, let me add that Scott from La. neither slurred nor attacked you. He spoke the truth. If your fat and fragile ego can't either take a little honest criticism or face facts fairly, then may I suggest that you grow up.
- Raleigh, North Carolina
As for me not knowing certain answers, well, Duhhh! -- I curate a 60,000-thread public forum and don't claim to know the answers to every possible topic. But we've printed every submittal we've received on this thread, so if you don't see certain info, it's because no reader has yet provided it, not because we're withholding it.
You didn't see Scott's actual posting, you see it with words left out -- not because of a fragile ego, but because this is a "G" rated site, visited by thousands of elementary school children every day, who don't need to see vulgarities. Ad hominem slurs lead only to an endless waste of time like your posting and this response. Ad hominems interrupt the discussion and spoil a site, and I don't know how you can possibly be reading this thread and not realize the time that everybody is forced to waste because of them. Please take your arguing to Facebook or anywhere else.
Regards,
Ted Mooney, P.E.
Striving to live Aloha
finishing.com - Pine Beach, New Jersey
May 29, 2009
Bruce, you wonder what I am "fishing for". You can't judge the forest from a single tree. This thread is but one of 60,000 on this site, and I've already said that this thread is only peripherally related to the theme of my site, i.e., metal finishing. This website is my only business, so the continuing allusions to the vested interests of my company are truly getting silly.
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