Salvaging Gold From Old Electronics

If you’re hoarding old electronics like us, there’s a good probability you have a decent amount of gold sitting around in cardboard boxes and storage containers. Everything from old PCI cards, IC pins, and even printers have a non-negligible amount of precious metals in them, but how do you actually process those parts and recover that gold? [Josehf] has a great tutorial for gold recovery up on Instructables for the process that netted him an ounce of gold for three months’ work.

After cutting up a few circuit boards to remove the precious gold-bearing parts, [Josehf] threw these parts into a mixture of muriatic acid and hydrogen peroxide. After a week, the acid darkened and the gold slowly flaked off into dust. This gold dust was separated from the acid by passing it through a coffee filter and readied for melting into a single nugget.

Gold melts at 1064 ˚C, much hotter than what can be obtained by a simple propane torch. This melting point can be reduced by the addition of borax, allowing the simplest tools – a propane torch and a terra cotta crucible – to produce a small gold nugget.

For three months of collecting, stripping, and dissolving electronic parts, [Josehf] netted 576.5 grains of gold, or at current prices, about $1500 worth of the best conductor available. Not too bad, but not something we’d use as a retirement plan.

Thanks [Matthias] for sending this in.

79 thoughts on “Salvaging Gold From Old Electronics

          1. Anyone with a bit of chem knowledge can easily neutralize most of these toxic chemicals, the point of the cupellation is to oxidize any metals that aren’t gold. Then it goes into the muriatic acid bath where the non-gold metals form metal salts and water through a simple ion exchange. The gold is not oxidized so it does not form a metal salt and instead floats to the top as the other metals are dissolved. With some more chemical knowledge you could even figure out the remaining amount of acid (titration) and the amount of sodium hydroxide you would need to neutralize it, it neutralizes into table salt and water. See not so scary when you know just a little bit of chemistry.

          2. Besides some miscellaneous metal salts there is almost nothing else in there, and I am sure your local hazmat disposal center would be more than happy to take this waste off your hands instead of dumping it into a storm drain.

          3. Actually, be very little waste,of which even using nitric acid, sodium bicarbonate will nullify the acids ,he likely used less than 1 Litre or less in acid,minus the peroxide do recover the total of $1500

        1. Considering that a cell phone has 0.001 troy ounces ($1.27 on today’s rate), A LOT. The real question is how much would you have to spend in chemicals to treat the 1181 cell phones it would take to make $1500? Let alone, the time it takes to take apart that many phones.

          1. Yeah, I once worked it out as a buck per phone. Woohoo!

            I once for a ‘scrapper’ site, their line of thinking seemed to be “don’t extract the gold, sell the scrap to some sucker”, like those upthread…

          2. With current precious metals prices today that $1500 becomes 3000$ & each phone is worth $4-5$, plus you aren’t treating the entire phone,just very small components,lol,not that much chemical s,& some can be reused

        2. Oh Contrair Moomfrere I found out quite by Accident that Some Motherboards Contain ALOT of GOLD! I had attended a Private Business Auction in Milwaukee, Wi. in 2008 It was supposed to be Live and Online. Thank Gosh that the Online Feed Crashed 10 minutes before the Auction. Well I got the Entire Contents of the Main Office for $35.00! In the Closet there were Boxes with Old Primitive IBM Servers in them. I just glanced over them a bit Before Packing them up and bringing them back to my Scrap Metal Business in Manitowoc, Wi. Well Kids the Server Boards inside where very Heavy. (3 server Boards weighed 7.76 pounds. ) I ground the Bords Up and gave them a Nice Nitric Bath (To get rid of the Silver) Followed by an AR Bath. I recovered 2.6 OUNCES of Gold from them boards! 99.5% pure! God Bless Ross Perot!

          1. Sounds almost impossible, from three boards even old server boards ,even if they were from 1996 & had pentium pro processors, the gold standard of 1 gm each,being they don’t have more than 4-5 on any single Board,adding all the other components ,they would have had to have been solid gold plated, literally,I’ve processed computer s for 15 years and have never seen them before???,adding the $ gold price was maybe $1000 per oz in 2013, maybe 10-12 grams, doubtful 2.7 oz,lol, still good 👍 though.

    1. I believe there is about 30 time more gold in a ton of cell phones than there is in a ton of gold ore, the mines that process gold ore isn’t doing it for fun

      cellphones/electronics scrap will have other sellable metals and some more nasty stuff
      but the things they use to extract gold from ore isn’t exactly spring water either

      1. 72g/ton is the number thrown around on ewaste. Ive no interest but I sold one of my old rockcrushers to a guy whos running PCBs through it. He seems to think its a great business…Id rather work a lode than a load of garbage.

        My lode claim averages 42g/ton (1.5oz) in free milling gold. If I was processing sulphides I could increase that significantly, but my operation is pretty small scale, and we have sufficient reserves to highgrade. So for now, we actually are processing with spring water…and gasoline for the crusher.

        If the 72g/ton is accurate than sure, a scrap heap is richer than my hole in the ground. But I know where my hole is. I have a significant reserve thats right there waiting for me to work it. Ewaste would require acquisition, storage, processing, and waste disposal….and uncertainty of supply. Ill stick to finding new metals and leave recycling to someone else.

        My placer claim is on a great river (I get between .75-1.25g/yard) but since CA has a ban on dredging I am lucky to pull an oz or two in a month and its actually alot of work. With dredging on the same claim I used to pull about an oz every 2-3 days. At this point we use it more as a campground than a gold claim. End of last season we strategically placed a number of gold traps so hopefully we will get a decent capture by next summer.

        1. I never met a guy who had his own gold mine! Is it all about processing rock nowadays? Nobody bothers digging in to find seams, and nuggets as big as yer fist?

          Whatever processing you need to use on sulphide, whatever that is (not a lot of gold miners where I live), I hope you’re keeping the waste. Or maybe you could sell it to a factory who do that themselves? Or do they only want the raw ore so they can get at the easy stuff as well?

          Anyway, pretty interesting.

          1. Nuggets as big as your fist are the dream….I once found one the size of my thumb….but most of my gold ranges from grains of sand to breakfast cereal size. I get some decent size chunks of silver and copper though.

            I have an extensive tailings pile from the previous generations of miners. I do a pretty even mix of new digging and processing old tailings that werent worth it back in the day but are with more modern equipment.

            My own “tailings” are separate from the historical ones. Refineries would take either sort, if I had assays done to determine actual content….but as odd as it may sound. I am not in it to get rich. Its more of a semilucrative hobby. It becomes very expensive and very bureaucratic if I were to scale up much from where I am at. Maybe one day.

            The big guys are all about processing tonnage. My mine has just over 100years of history. So my operation is more about finding offshoots, and areas that werent considered rich enough to be pursued way back when, while pushing forward along several areas that just hadnt been finished at the last closure in the 40s.

            Im really just a recreational hobbyist….but I use powered tools I have to file a “plan of operation”. Since I work an unpatented historical claim as long as I keep my tonnage low and machinery light I avoid alot of the expense of “reclamation and remediation”. If one day I decided the ground was hot enough, and I was motivated enough, Id have to put up an expensive bond to scale up.

            as they say MO Money MO problems.

            I started out panning, moved into dredging….I had put on alot of weight, deskjob, and was having stress related health issues. When I was a kid I loved camping, but just lost the desire. I hadnt taken a vacation in 4 years when my doctor told me I was shortening my life with my lifestyle. My kid found a “gold panning vacation” thing online. We spent 2 weeks and left with less gold than the trip cost us….but I enjoyed myself….got more exercise than Id had in 10 years…and felt so much more relaxed having gotten away from it all….that I was hooked.

            In my teenage years I was a novice spelunker…when that came up in conversation with a dredger up river from us he invited me to visit an abandoned mine he had been doing metal detecting around. We roped off and I took him on a 150ft shaft decent, and we spent a few hours exploring. I was hooked and spent my entire seasons take from the dredge, and a chunk of my 401k, to buy my claim from a speculator who was filling claims over historical lodes with expired documentation.

            My first season I got most of my gold with a broom, a shovel, and a shopvac…just cleaning up and opening tunnels. Ive come along way since then but still have much to learn…its a very expensive hobby, good equipment isnt cheap at all. Ive recently started welding classes so I can try my hand at building some equipment….who knows maybe one day Ill put together something worth submitting here as a “gold hacker” lol.

            I know more guys whove gone bust then struck it rich….but I know alot of guys who feel richer for having the itch. I joke with my kid that in a few more years, when the rest of my hair goes gray, Ill grow out my beard and retreat to the hills….I really hope they lift the moratorium on mining patents before Im too old….Building a cabin at the mine to retire would be a dream.

        2. You’re a dying breed. We (as in family) owned claims for probably nearly 50 years. We finally let them go shortly after my father passed. Without getting into details, as much as I would have liked to keep them it was just the realities we faced. To this day environmentalists still irk me given the amount of damage they do. it was an environmentalist who burned down our structures resulting in a massive forest fire about thirty years ago. Made it easier on us to do our mining with all the trees gone since then.

          But I digress. Keep it and enjoy it for as long as you can.

        3. Awesome “lode” pun. He really got the mother lode of asshole from you. Anyway, Economically viable doesn’t always mean environmentally friendly. It’s as simple as here is a massive amount of resources and… oh yeah, it’s a mess. I think this article is focusing too much on the quantities of gold in a bunch of junk rather than what you can potentially make with that gold. That’s what I am interested in. I want to hack my head off thinking that I’m at the mercy of mass production.

          If you really want to hack life, hack the very fabric that makes up our lives. Like that chemistry guy who sounds like he’s good at chemistry, make something! And AussieTech, you sound like a pretty Intelligent guy. Get that gold and make something that’s way beyond our frame of intelligence. Build yourself something.
          fonz, if you could recycle all the gold that was needed in the world, why is shocked still mining?

    1. Thermal conductivity (4 highest elements listed):

      1. Silver (highest): 4.29 W /cm K
      2. Copper: 4.01 W /cm K
      3. Gold: 3.17 W /cm K
      4. Aluminum: 2.37 W /cm K

      Electrical conductivity (4 highest elements listed)

      1. Silver (highest): 630,000 /Ohm cm
      2. Copper 596,000 /Ohm cm
      3. Gold 452,000 /Ohm cm
      4. Aluminum 377,000 /Ohm cm

      1. Diamond is actually a much better heat conductor than silver, around 5 times better for an average diamond.

        Then we have superfluids. A particular state of liquid helium that forms under 2.2K degrees has been shown to conduct heat as much as 100 times better than the best diamonds.

        1. And here we can observe the Common Pedant in his natural environment. Stay quiet folks! It’s not because they’re easily spooked, but rather for our safety (getting lectured to death is a terrible way to go).


          1. I still don’t understand why being a pedant is bad. Somehow folks these days have an unnatural aversion to being corrected or elaborated upon. To me, this is just more welcome information. Grammar and punctuation is no different. It’s as if, somehow, it is now politically incorrect to be as accurate as possible. Being accurate, even on internet posts, helps to proliferate accuracy. Why this is bad, I have no idea…

          2. “Grammar and punctuation is no different.”
            Before I get attacked for being a hypocritical pendant myself, the former sentence was a quick, improper, shortening of the sentence “Correct usage of grammar and punctuation is no different.” I also could have just used “are” instead of “is”… :)

  1. So has the author verified that this is 99.99% or better gold? I’m assuming no, and I wouldnt be surprised if there were other impurities in it which would effect the price. I was always under the assumption that gold was refined with cyanide.

    And since when could a propane torch not reach 1060C? According to wikipedia it gets up to 1995C and 2820C with oxygen.

    Anyways I doubt any coin store is going to give you $1,500 for a home made nugget if you havent gotten it assayed.

      1. They dont know if it is gold platen tungsten. If they believe it is gold, they wont know the purity, so they likely wont give you anything, especially when you tell them you made it yourself.

        1. Pawn shops deal in scrap gold all the time, you can test for the relative purity of gold in several ways (acid test for one) and for such a small piece of gold they could cut it in half with tin snips to test for a tungsten core. If its gold, which it is, a pawn shop will buy it, and any one that didn’t wouldn’t be in business very long.

    1. “next, give the acid and mercury a thorough mix with your hand” – yeeeeah, sounds like a great idea. But heeey it’ll be fine once he rubs the burnt skin off on a wall…no…i don’t think so. AAhh and they boil away the mercury D: at least they do it outside.. oh and they get scammed. Not easy living as an underdog i guess.

  2. Just looking at his method there are some major steps he has missed and a lot of wrong information in there. He doesn’t explain some of the pit falls in the methods, such as putting mixed metals, plastics and components in the same batch. He doesn’t explain what to do with the base metals from the pins which IIRC is a beryllium alloy. Preparation of the crucible? Humm, missing. Safety? What?

    There are a lot of extra things you have to worry about with gold recovery from e-waste. Epoxy filled fibreglass boards, chemical disposal. You need a good metric Tonne of motherboards to get one ounce of gold. You know what the biggest money spinner in E-waste is?…….It’s the plastics and steel. Gold is just the cherry on top.

  3. “Gold melts at 1064 ˚C, much hotter than what can be obtained by a simple propane torch.”
    This may be the case for some setups, but there are still cheap torches that can reach these temperatures with a few well-placed bricks. This tiny forge doesn’t give room to weld or melt anything but tiny quantities, but that’s fine in this instance. Wiki says max flame temp for propane is 1,995 °C in air, or 2,820 °C with oxygen. That’s well above the melting point of Aluminum, brass, and even iron!
    I only happen to know this because I’ve been looking into casting metal using lost-wax or lost-PLA processes. I want to make it easy for us to RepRap metal parts by printing molds out of plaster of paris, using a Universal Paste Extruder. Imagine printing your own hot end, or casting a replacement engine part in an afternoon!

    1. Its Not just about the temp – either of the flame or a teensy piece of thermocouple it can heat – its
      about the amount of energy it can deliver eg a certain mass & raise it to that temperature – its not
      as simplistic as many imagine.

      The key issue is radiative heat transfer loss, ie the heat loss – once the gold gets hot – very quickly
      exceeds the heat delivery capacity of the torch for THAT target temperature. Of course there
      are also conductive and convective heat losses but radiative goes up rather quickly…

  4. Prices for circuit boards start around $2.50/lb if you strip them out and take them to a scrapper. Extension cards and denser circuit boards from e.g. hard drives are more valuable. By the time you’ve filled a box about the size that you’d use to store file folders you’ve got about $80. At that point there are several online sites that you can ship the scrap to.

    1. I receive 17 cents a pound for mother board.I took one to see if it was worth selling it should I scrap myself.I would have to take around a ton to pay the gas to drive the distance to nearest place that buys.had to go there on unrelated issue and tested the market with two each of the boards. One stripped one not. At best I was paid for mid grade board .not worth my time to mess with at those price’s. And the online recyclers won’t post price or want minimum of so many pounds

  5. What about recovering the silver, rhodium and other precious metals used in electronics? To make recovery easier and more thorough I’d get one of those blenders in the Will it blend? videos. Chunk the stuff up then pulverize it so the acid can get at all the fine particles.

    Once the insoluble gold is out, there’s all the other good stuff dissolved in the acid. If there’s a solution that only dissolves silver, that could be used first then the silver extracted, probably by electrolysis onto a piece of silver.

  6. A propane torch is in fact hot enough to melt pure gold. I have done it myself with 24k casting grain on top of a chunk of graphite (to maintain purity). I used to melt pure silver on top of fire brick but found it was adding contaminants and modified my process as a result (there is no way I would have tried that method with gold). I also agree that the nugget in the picture does not appear to be pure gold; though I didn’t spend any time analyzing his chemical process to determine what else might be in the mixture.

  7. Some of the other elements in phones as well as the expensive hard-to-buy parts such as LCDs can actually get higher prices from fellow hackers than the gold.
    I’ve seen 3310 screens go as high as £12 on *bay and the higher resolution ones for even more.
    Also there are often Bluetooth chips in these which can be harvested for reuse and the SIM slots, microSD/etc and all sorts of handy widgets like small speakers, mics, accelerometers… the list goes on.

  8. I’m pretty sure Josehf’s retirement statement had much of his tongue in his cheek. At any rate he should have ended up with more money in his pocket with very little physical effort.

  9. In the former USSR a lot of electronics was made with generous amounts of gold, and other precious metals. This is the primary reason why old soviet computers or their parts are rare and hard to find: gold diggers destroyed them all. Not cool.

  10. In addition to the gold, there’s some extra “fun” money to be hand scrapping old electronics, but you won’t likely get rich doing it. If you do get rich, you are really working for it. I’m saving all of the gold that I can easily remove from the e-waste that I recycle. It’s pretty easy to store it and I’ll save it all until I’m ready to retire. I sort most of the rest of the e-waste and sell it to a recycler. Aluminum heat sinks and hard drive cases usually net me the most. It’s enough to keep my tank full of gas and put some away for retirement besides. I also don’t need a membership to a gym. Sometimes, the e-waste that is given to me can be sold as is for parts on e-bay or the parts themselves sold. I treat it like a part time job. Keeping everything organized is the key.

    Here’s the kicker part of my recycling story though: my name got passed around as an e-waste recycler by a few people. I was called in to make an estimate on removing an old internal mail system from several floors of a large office building that was being remodeled. I won the bidding war (mostly due to my being a complete greenhorn), hired three friends of mine and we laid out a plan to remove the metal railings and air pressure equipment over a three week period. It turns out much of that internal mailing system was not just made of aluminum, but also a lot of brass and steel. The net haul was more than 10x the amount I thought I was going to make as profit. My friends were paid more accordingly and the four of us laughed all the way to the bank. One of them paid off the rest of his student loans, another paid off his car loan, and the third added it to a downpayment on his house. I added my part to my retirement fund. All because I started recycling e-waste from my home and my name was out there.

  11. Heh, found a “good” source which is scrap reed switches.
    A lot of the non-Hg ones contain close to 1g gold for 160 of them, although this is for the very large 2″ long ones which are
    rarer than hen’s teeth.
    If you happen to come across these let me know, I sent a box of misc. scrap including some laser diodes (dead) and random PCB shrapnel and memory card edge connectors to some nice guy on ze high woltage forumz.
    1 kilo of dead microSD cards is worth quite a bit thanks to the edge connectors and multilayer chips with 100+ gold wires.

  12. My father works in technology, but I totally forgot that electronics have gold in them. I really liked how you mentioned that hydrogen peroxide and muriatic acid were able to strip of the the gold dust. I’d definitely like to try this out with my dad. Thanks for the sharing this cool article!

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