# Computer gold content and extraction **URL:** \ **Category:** Factual Questions\ **Created:** [September 26, 2006, 10:41pm UTC](https://boards.straightdope.com/t/computer-gold-content-and-extraction/374280 "2006-09-26T22:41:20Z")\ **Posts on this page:** 15\ **Page:** 1
**Author:** ![fifty-six](https://avatars.discourse-cdn.com/v4/letter/f/5daacb/32.png) [@fifty-six](https://boards.straightdope.com/u/fifty-six)\ **Post date:** [September 26, 2006, 10:41pm UTC](https://boards.straightdope.com/t/computer-gold-content-and-extraction/374280/1 "2006-09-26T22:41:20Z")
I have been collecting old CPUs and other computer equipment for a while now. I have maby 20+old CPUs and a stack of old cards. I have already taken apart most of my old hard drives and now have a nice collection of rare earth magnets. I want to do something with the CPU’s and other spare parts now. I know there is gold on them and that is what I think I want to do-Get the gold. My questions are What is the best way, and has anyone here done it before? I was thinking of just burning the lot and collecting the gold in the bottom of a steel tray. The other way is maby using Aqua Regia and pecipitate it out of that solution. I do not know much about using the acid but it may be worth the experiment. And for the final question How much gold is in a modern day computer namely the CPU and obvous gold plated cards? Thanks ---
**Author:** ![Chronos](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/chronos/32/134_2.png) [@Chronos](https://boards.straightdope.com/u/Chronos)\ **Post date:** [September 26, 2006, 11:02pm UTC](https://boards.straightdope.com/t/computer-gold-content-and-extraction/374280/2 "2006-09-26T23:02:01Z")
> [@](#): > > The other way is maby using Aqua Regia and pecipitate it out of that solution. I do not know much about using the acid but it may be worth the experiment. Uninformed opinion here, but I’d think that if you’re going the heavy-duty acid route, it’d be easier to do the reverse. Aqua regia will eat gold, but it’ll eat a lot of other stuff, too. On the other hand, almost any other acid you can think of will eat other stuff, but not gold. Use one of those, and you wouldn’t even need to precipitate out the metal. Either way, though, you’d probably want to do as much mechanical separation as you can, first. You wouldn’t want to saturate your acid on a bunch of useless junk. ---
**Author:** ![spingears](https://avatars.discourse-cdn.com/v4/letter/s/ebca7d/32.png) [@spingears](https://boards.straightdope.com/u/spingears)\ **Post date:** [September 26, 2006, 11:56pm UTC](https://boards.straightdope.com/t/computer-gold-content-and-extraction/374280/3 "2006-09-26T23:56:03Z")
[QUOTE=fifty-six] My questions are What is the best way, and has anyone here done it before? [/QUOTE] Carefully remove all of the little bits and pieces of contacts that are gold PLATED, not solid gold. Then acid will dissolve the brass base matal and ypu will have a little pile of gold dust. > [@](#): > > How much gold is in a modern day computer namely the CPU and obvous gold plated cards? Not much metalic gold. Gold plating on contacts. IMHO the game isn’t work the chase. Same applies to the CPU. Reclaiming gold from obsolete special items of national security applications is a viable enterprise. FYI these are not available as surplus. ---
**Author:** ![samclem](https://avatars.discourse-cdn.com/v4/letter/s/a9a28c/32.png) [@samclem](https://boards.straightdope.com/u/samclem)\ **Post date:** [September 27, 2006, 12:58am UTC](https://boards.straightdope.com/t/computer-gold-content-and-extraction/374280/4 "2006-09-27T00:58:38Z")
I work in a coin shop. We buy gold/silver/ect. from the public/dealers. We are the biggest in Northern Ohio. We know how to make money. If it can be done, we can do it or tell you how. As others have suggested, the gold plating from computer boards ain’t viable for recovery. Perhaps it is at $2000/ounce for gold. You can make more from working a shift at McDonald’s than recovering computer boards. ---
**Author:** ![Xema](https://avatars.discourse-cdn.com/v4/letter/x/9de053/32.png) [@Xema](https://boards.straightdope.com/u/Xema)\ **Post date:** [September 27, 2006, 1:18am UTC](https://boards.straightdope.com/t/computer-gold-content-and-extraction/374280/5 "2006-09-27T01:18:00Z")
I once knew a guy who used to recover gold from circuit boards. He indicated that boards form the 1960s and 70s were of interest, but by around 1980 manufacturers had figured out how to get by with amazingly little gold. Unless your boards are far out of the ordinary, I’d guess that your scheme is not likely to prove fruitful. ---
**Author:** ![Chronos](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/chronos/32/134_2.png) [@Chronos](https://boards.straightdope.com/u/Chronos)\ **Post date:** [September 27, 2006, 3:56am UTC](https://boards.straightdope.com/t/computer-gold-content-and-extraction/374280/6 "2006-09-27T03:56:11Z")
But then, I get the impression that the OP is mostly looking to do this for the fun of it, rather than for profit (how much profit is there in recycled rare earth magnets, for that matter?). In which case, it could certainly be worthwhile. ---
**Author:** ![groman](https://avatars.discourse-cdn.com/v4/letter/g/73ab20/32.png) [@groman](https://boards.straightdope.com/u/groman)\ **Post date:** [September 27, 2006, 4:15am UTC](https://boards.straightdope.com/t/computer-gold-content-and-extraction/374280/7 "2006-09-27T04:15:29Z")
I’ve heard there is a canadian mining corporation that extended into mining from PCBs as well as ore. The thing I heard is that PC motherboards contain as much if not more gold by weight than ore when it comes out of the ground, so if it’s worth mining as ore it’s worth mining from components. However, even if this is true, it is not worth mining gold ore as an individual unless you just look for chunks of gold and disregard the ore. ---
**Author:** ![fifty-six](https://avatars.discourse-cdn.com/v4/letter/f/5daacb/32.png) [@fifty-six](https://boards.straightdope.com/u/fifty-six)\ **Post date:** [September 27, 2006, 5:39pm UTC](https://boards.straightdope.com/t/computer-gold-content-and-extraction/374280/8 "2006-09-27T17:39:22Z")
[QUOTE= **Chronos**] But then, I get the impression that the OP is mostly looking to do this for the fun of it, rather than for profit (how much profit is there in recycled rare earth magnets, for that matter?). In which case, it could certainly be worthwhile. [/QUOTE] You are correct. I am not looking to get rich or even make a profit. I also do not wish to spend a fortune over it either. So what I am looking for is a fun way to do this that will most likley work. I love my magnets. I get them from microwaves and old computers. It is more fun to get them that way than buy from EBay. Same with the gold I would like to have a small piece of gold. I could gold pan or metal detect for half my life and get maby a piece, (I live in Alaska) buy from Ebay or do a fun experiment with cool acids or burn the stuff. Anyhow I do think that I may do this I was just hoping for a little help on how to best go about it and how much to expect. So I know what to look for. That will better determine my recovery rate. I am also using mostly CPUs. Is there more gold on them than the PCBs? I was gonna bust the pins off of all of the CPUs and test it out. Ok ways to recover the gold if any. Aqua Regia Other acids Scrape it off? boring Burn it [I could use a microwave](http://home.c2i.net/metaphor/mvpage.html) Any other suggestions or hints? Xema how did the guy you knew do it? Thanks all ---
**Author:** ![Dewey\_Finn](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/dewey_finn/32/4222_2.png) [@Dewey\_Finn](https://boards.straightdope.com/u/Dewey_Finn)\ **Post date:** [September 27, 2006, 7:30pm UTC](https://boards.straightdope.com/t/computer-gold-content-and-extraction/374280/9 "2006-09-27T19:30:57Z")
Another thing to consider is the cost of disposing of the toxic waste that’s going to result. My guess is that will cost as much or more than the gold you extract. ---
**Author:** ![fifty-six](https://avatars.discourse-cdn.com/v4/letter/f/5daacb/32.png) [@fifty-six](https://boards.straightdope.com/u/fifty-six)\ **Post date:** [September 27, 2006, 10:17pm UTC](https://boards.straightdope.com/t/computer-gold-content-and-extraction/374280/10 "2006-09-27T22:17:36Z")
[QUOTE=Dewey Finn] Another thing to consider is the cost of disposing of the toxic waste that’s going to result. My guess is that will cost as much or more than the gold you extract. [/QUOTE] Free at my dump ---
**Author:** ![OneCentStamp](https://avatars.discourse-cdn.com/v4/letter/o/13edae/32.png) [@OneCentStamp](https://boards.straightdope.com/u/OneCentStamp)\ **Post date:** [September 27, 2006, 10:47pm UTC](https://boards.straightdope.com/t/computer-gold-content-and-extraction/374280/11 "2006-09-27T22:47:08Z")
[QUOTE=fifty-six] Free at my dump [/QUOTE] Free \*and legal \* at your dump? :dubious: ---
**Author:** ![MrDantastic](https://avatars.discourse-cdn.com/v4/letter/m/b487fb/32.png) [@MrDantastic](https://boards.straightdope.com/u/MrDantastic)\ **Post date:** [September 27, 2006, 11:58pm UTC](https://boards.straightdope.com/t/computer-gold-content-and-extraction/374280/12 "2006-09-27T23:58:07Z")
As long as it takes more than 30 minutes to eat through a 2-liter bottle of cola, I’d say its fair game. Just kidding, don’t pollute. ---
**Author:** ![Xema](https://avatars.discourse-cdn.com/v4/letter/x/9de053/32.png) [@Xema](https://boards.straightdope.com/u/Xema)\ **Post date:** [September 28, 2006, 12:09am UTC](https://boards.straightdope.com/t/computer-gold-content-and-extraction/374280/13 "2006-09-28T00:09:23Z")
[QUOTE=fifty-six] how did the guy you knew do it? [/QUOTE] I’m not certain, but I think it was by smelting (IOW, heat). ---
**Author:** ![fifty-six](https://avatars.discourse-cdn.com/v4/letter/f/5daacb/32.png) [@fifty-six](https://boards.straightdope.com/u/fifty-six)\ **Post date:** [September 28, 2006, 2:13am UTC](https://boards.straightdope.com/t/computer-gold-content-and-extraction/374280/14 "2006-09-28T02:13:53Z")
[QUOTE= **OneCentStamp**] Free \*and legal \* at your dump? :dubious: [/QUOTE] Yea, we have hazardous waste collection days. Free and Legal ---
**Author:** ![spingears](https://avatars.discourse-cdn.com/v4/letter/s/ebca7d/32.png) [@spingears](https://boards.straightdope.com/u/spingears)\ **Post date:** [September 28, 2006, 2:30am UTC](https://boards.straightdope.com/t/computer-gold-content-and-extraction/374280/15 "2006-09-28T02:30:39Z")
[QUOTE=fifty-six] Any other suggestions or hints? [/QUOTE] I seem to recall after touring the Homestake gold mine processing facilities in Lead SD that one of the last operations after all the others for extracting gold that they leached the finely ground rock residue with a cyanide solution. Very poisonous stuff to be playing with unless you take the proper safety precautions. [**Cyanide Extraction of Gold From Ore**](http://www.mine-engineer.com/mining/minproc/cyanide_leach.htm) 4 Au + 8(NaCN) +O2 + 2 H2O = 4 NaAu(CN)2 + 4 NaOH Buying the cyanide in a small quantity will be a problem. Disposing of wast another.