# Question on extracting gold **URL:** \ **Category:** Factual Questions\ **Created:** [January 3, 2020, 2:17am UTC](https://boards.straightdope.com/t/question-on-extracting-gold/845814 "2020-01-03T02:17:56Z")\ **Posts on this page:** 10\ **Page:** 1
**Author:** ![Saint\_Cad](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/saint_cad/32/18907_2.png) [@Saint\_Cad](https://boards.straightdope.com/u/Saint_Cad)\ **Post date:** [January 3, 2020, 2:17am UTC](https://boards.straightdope.com/t/question-on-extracting-gold/845814/1 "2020-01-03T02:17:56Z")
Suppose I have some scrap gold. I saw a video that basically melted it into shot then socked it in nitric acid (to get rid of all other metals), rinse, aqua regia starting with muriatic acid then adding nitric acid, then throw in some Stump Out for the sodium metabisulphite to get the gold out of solution, rinse it then melt it and cast it. Voila, a gold bar. Assuming you do this, how pure would the gold be? ---
**Author:** ![mixdenny](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/mixdenny/32/2962_2.png) [@mixdenny](https://boards.straightdope.com/u/mixdenny)\ **Post date:** [January 3, 2020, 6:25am UTC](https://boards.straightdope.com/t/question-on-extracting-gold/845814/2 "2020-01-03T06:25:26Z")
Sounds like that process is for reclaiming gold from circuit boards. Although the gold is quite pure there is lots of tin and lead in the solder plus nickel plating under the gold contacts. The process may remove them, though. The one small scale operation I watched a video on cost more in supplies then the gold was worth. Dennis ---
**Author:** ![DorkVader](https://avatars.discourse-cdn.com/v4/letter/d/73ab20/32.png) [@DorkVader](https://boards.straightdope.com/u/DorkVader)\ **Post date:** [January 3, 2020, 2:49pm UTC](https://boards.straightdope.com/t/question-on-extracting-gold/845814/3 "2020-01-03T14:49:22Z")
That is something that always made me sort of wonder, the reclamation of metals from electronics. How reusable are the chemicals that are used in the process, how much gold can be held in suspension before you _have_ to take it out? The lead, tin, and what ever metals other than gold that are used, do they just get discarded? (That seems foolish to me for a variety of reasons, but I’m not well informed) ---
**Author:** ![Joey\_P](https://avatars.discourse-cdn.com/v4/letter/j/919ad9/32.png) [@Joey\_P](https://boards.straightdope.com/u/Joey_P)\ **Post date:** [January 3, 2020, 3:12pm UTC](https://boards.straightdope.com/t/question-on-extracting-gold/845814/4 "2020-01-03T15:12:22Z")
> [@Saint\_Cad](#): > > Suppose I have some scrap gold. I saw a video that basically melted it into shot then socked it in nitric acid (to get rid of all other metals), rinse, aqua regia starting with muriatic acid then adding nitric acid, then throw in some Stump Out for the sodium metabisulphite to get the gold out of solution, rinse it then melt it and cast it. Voila, a gold bar. Assuming you do this, how pure would the gold be? Are you asking how pure it would be or how to find out how pure it would be. I’d imagine you could figure out the purity by finding the density. If you have enough and/or have sensitive enough equipment, it’s pretty straightforward to get the volume and mass. Though I’d think that might be more difficult trying to do it in your kitchen with a piece the size of some birdshot. In any case, if you didn’t see that on Cody’s Lab, check out his channel. I don’t recall if he’s separated gold out from other things, but if he has, I’m sure he explained how he found the purity…or maybe not, he’s sorta all over the place. ---
**Author:** ![Saint\_Cad](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/saint_cad/32/18907_2.png) [@Saint\_Cad](https://boards.straightdope.com/u/Saint_Cad)\ **Post date:** [January 5, 2020, 8:05pm UTC](https://boards.straightdope.com/t/question-on-extracting-gold/845814/5 "2020-01-05T20:05:13Z")
> [@Joey\_P](#): > > Are you asking how pure it would be or how to find out how pure it would be. “how pure would the gold be?” ---
**Author:** ![Saint\_Cad](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/saint_cad/32/18907_2.png) [@Saint\_Cad](https://boards.straightdope.com/u/Saint_Cad)\ **Post date:** [January 5, 2020, 11:38pm UTC](https://boards.straightdope.com/t/question-on-extracting-gold/845814/6 "2020-01-05T23:38:12Z")
> [@mixdenny](#): > > The one small scale operation I watched a video on cost more in supplies then the gold was worth. At first I would think that this is wrong. The chemicals are less than $50. Are you counting the furnace too? ---
**Author:** ![slaphead](https://avatars.discourse-cdn.com/v4/letter/s/e9bcb4/32.png) [@slaphead](https://boards.straightdope.com/u/slaphead)\ **Post date:** [January 6, 2020, 8:36am UTC](https://boards.straightdope.com/t/question-on-extracting-gold/845814/7 "2020-01-06T08:36:03Z")
> [@Saint\_Cad](#): > > At first I would think that this is wrong. The chemicals are less than $50. Are you counting the furnace too? If your labour is free, the input scrap is free and you can dispose of all the leftover chemicals for free, then for $50 of materials you would need to recover more than a gram of pure gold to make any profit at todays prices. I would suspect that getting that much out of electronic scrap would be difficult, but it sounds doable if you start with some broken jewelry or similar. Of course, any meaningful amount of broken gold jewelry already has a meaningful scrap value, and I would imagine that actually selling any meaningful amount of home-refined gold might be a bit challenging since it is an obvious method for disposing of stolen goods. ---
**Author:** ![Mangetout](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/mangetout/32/19_2.png) [@Mangetout](https://boards.straightdope.com/u/Mangetout)\ **Post date:** [January 6, 2020, 4:37pm UTC](https://boards.straightdope.com/t/question-on-extracting-gold/845814/8 "2020-01-06T16:37:56Z")
You can theoretically get high purity with the process described (something like 99.9% or more). In a homebrew process, it’s probably going to be hard to achieve the theoretical maximum purity without losing some gold in the process - and some of it will depend on the purity of reagents used - if for example the metabisulphite has small amounts of copper or nickel salts in it, you could be reintroducing impurities in the precipitation stage. Cody’s Lab on YouTube is a mine of useful information on recovery of gold - he’s done it from Jewellery, gold decoration on china ware, etc. > **[Cody'sLab](https://www.youtube.com/channel/UCu6mSoMNzHQiBIOCkHUa2Aw)** > > Aright everyone CodyDon here! (usually shortened to just "Cody") > Welcome to my channel! I simply post videos of the (sometimes crazy) things that I do; this includes science, bees, and anything else that I am working on. Enjoy! > > If you need to get in... ---
**Author:** ![Saint\_Cad](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/saint_cad/32/18907_2.png) [@Saint\_Cad](https://boards.straightdope.com/u/Saint_Cad)\ **Post date:** [January 7, 2020, 2:43am UTC](https://boards.straightdope.com/t/question-on-extracting-gold/845814/9 "2020-01-07T02:43:54Z")
I’ve seen Cody’s Lab. I was referring more to Sreetips god extraction process ---
**Author:** ![Mangetout](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/mangetout/32/19_2.png) [@Mangetout](https://boards.straightdope.com/u/Mangetout)\ **Post date:** [January 7, 2020, 10:41am UTC](https://boards.straightdope.com/t/question-on-extracting-gold/845814/10 "2020-01-07T10:41:08Z")
The answer is the same; you can achieve purity in excess of 99.9% using that method, if you do it correctly, and if your reagents are uncontaminated.